U.S. patent application number 12/310531 was filed with the patent office on 2010-07-29 for heat accumulator, method for manufacturing heat accumulator, and vehicle-mounted thermal system including accumulator.
Invention is credited to Jinichi Hiyama.
Application Number | 20100186924 12/310531 |
Document ID | / |
Family ID | 39135815 |
Filed Date | 2010-07-29 |
United States Patent
Application |
20100186924 |
Kind Code |
A1 |
Hiyama; Jinichi |
July 29, 2010 |
Heat accumulator, method for manufacturing heat accumulator, and
vehicle-mounted thermal system including accumulator
Abstract
In an accumulator including a vacuum heat-insulating layer 2 at
the outer periphery of a liquid reserving portion 1, the liquid
reserving portion 1 and the vacuum heat-insulating layer 2 are
formed by stacking a plurality of tank constituting elements 10
composed of plate members of an identical cross-sectional shape.
The liquid reserving portion 1 is composed of liquid reserving
portion spaces 10f made to communicate by stacking the tank
constituting element 10. The vacuum heat-insulating layer 2 is
composed of heat insulating layer space 10e which are made to
communicate by stacking the tank constituting elements 10 and are
evacuated. The openings of the stacked tank constituting elements
10 at the both ends are closed with inlet and outlet cover plates 8
and 9.
Inventors: |
Hiyama; Jinichi; (Saitama,
JP) |
Correspondence
Address: |
WENDEROTH, LIND & PONACK, L.L.P.
1030 15th Street, N.W.,, Suite 400 East
Washington
DC
20005-1503
US
|
Family ID: |
39135815 |
Appl. No.: |
12/310531 |
Filed: |
August 27, 2007 |
PCT Filed: |
August 27, 2007 |
PCT NO: |
PCT/JP2007/066527 |
371 Date: |
February 27, 2009 |
Current U.S.
Class: |
165/10 ;
165/104.31; 165/166; 165/42; 29/890.06 |
Current CPC
Class: |
F01P 2037/02 20130101;
F01P 2005/105 20130101; F01P 2011/205 20130101; Y02E 60/14
20130101; F01P 2060/08 20130101; F01P 7/165 20130101; F28D 20/021
20130101; Y10T 29/49394 20150115; F28D 9/0012 20130101; Y02E 60/145
20130101 |
Class at
Publication: |
165/10 ; 165/166;
29/890.06; 165/42; 165/104.31 |
International
Class: |
F28D 17/02 20060101
F28D017/02; F28F 3/08 20060101 F28F003/08; B21D 51/16 20060101
B21D051/16; B61D 27/00 20060101 B61D027/00; F28D 15/00 20060101
F28D015/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 28, 2006 |
JP |
2006-230055 |
Aug 28, 2006 |
JP |
2006-230056 |
Aug 28, 2006 |
JP |
2006-230057 |
Claims
1-22. (canceled)
23. A heat accumulator, comprising: a liquid reserving portion; a
heat-insulating layer provided on an outer periphery of the liquid
reserving portion; a plurality of stacked tank constituting
elements configured to form the liquid reserving portion and the
heat-insulating layer, the tank constituting elements being formed
by plate members of an identical cross-sectional shape; an inlet
cover plate provided at an inlet of the stacked tank constituting
elements and to which an inlet pipe is connected; and an outlet
cover plate provided at an outlet of the stacked tank constituting
elements and to which an outlet pipe is connected, each of the tank
constituting elements including first and second partition walls
which are coaxially arranged and a heat-insulating layer space
formed between the first and second partition walls, the liquid
reserving portion being formed by a liquid reserving portion space
surrounded by the second partition wall of each of the plurality of
tank constituting elements stacked, the heat-insulating layer being
formed by the heat-insulating layer spaces which are made to
communicate by stacking the tank constituting elements and are
evacuated. a brazing fill material which is warmed under evacuation
being provided between at least adjacent tank constituting
elements.
24. The heat accumulator according to claim 23, further comprising:
a heat storage layer between the liquid reserving portion and the
heat-insulating layer, the heat storage layer being filled with a
heat storage material absorbing and releasing heat along with its
phase transition between liquid and solid phases.
25. The heat accumulator according to claim 24, wherein the heat
storage material includes, as a latent heat storage material, a
paraffin material storing heat of fusion during its phase
transition from the solid to liquid phase in a temperature range
not lower than a melting point and releasing heat of solidification
during its phase transition from the liquid to solid phase in a
temperature range not higher than a freezing point.
26. The heat accumulator according to claim 25, wherein the heat
storage material is paraffin capsules including the paraffin
material encapsulated in spherical coatings as microcapsules, and
the heat storage layer is filed with aggregates of the paraffin
capsules taking an account of a change in volume during the phase
transition between the liquid and solid phases.
27. The heat accumulator according to claim 24, further comprising
as constituent parts: an inlet end plate, an inlet cover plate, an
outlet end plate, an outlet cover plate, and the tank constituting
elements, the heat accumulator characterized in that an inlet pipe
is fixed to at least any one of the inlet cover and end plates, an
outlet pipe is fixed to at least any one of the outlet cover and
end plates, and an inner rib protruding in a direction orthogonal
to a flow of a heat medium from an inlet to an outlet is formed on
a partition wall separating the liquid reserving portion space of
each of the tank constituting elements.
28. The heat accumulator according to claim 24, wherein each of the
tank constituting elements includes first, second, and third
partition walls coaxially arranged; a heat-insulating layer space
is formed between the first and second partition walls; a heat
storage layer space is formed between the second and third
partition walls; and a liquid reserving portion space is surrounded
by the third partition wall, the plurality of tank constituting
elements are stacked with openings of the stacked tank constituting
elements at both ends closed with the inlet and outlet cover plates
to constitute a container, the liquid reserving portion is composed
of the liquid reserving portion spaces made to communicate by
stacking the tank constituting elements, the heat-insulating layer
is composed of the heat-insulating layer spaces which are made to
communicate by stacking the tank constituting elements and are
evacuated, and the heat storage layer composed of the heat storage
layer spaces made to communicate by stacking the tank constituting
elements.
29. The heat accumulator according to claim 24, wherein the heat
accumulator is manufactured by: stacking the plurality of tank
constituting elements with brazing filler metal applied thereto;
closing the openings of the stacked tank constituting elements at
the both ends with the inlet and outlet cover plates to temporarily
assemble a container; evacuating the temporarily assembled
container in a furnace and increasing the temperature of the
furnace for vacuum brazing to evacuate both the heat-insulating
layer and heat storage layer; and then filling the evacuated heat
storage layer with the heat storage material by vacuum suction.
30. A method of manufacturing a heat accumulator including a vacuum
heat-insulating layer at the outer periphery of a liquid reserving
portion, comprising: a part processing step of processing
constituent parts constituting the heat accumulator; a temporary
assembly step of assembling the processed constituent parts into a
container; and a brazing step of evacuating the temporarily
assembled container in a furnace and increasing temperature of the
furnace to braze the constituent parts into a unit in vacuum
atmosphere.
31. The method of manufacturing a heat accumulator according to
claim 30, wherein the heat accumulator includes the vacuum
heat-insulating layer at the outer periphery of the liquid
reserving portion, in the part processing step, an inlet cover
plate, an outlet cover plate, and a plurality of tank constituting
elements which are composed of plate members of an identical
cross-sectional shape and which each have a liquid reserving
portion space and a vacuum heat-insulating layer space are
processed, and in the temporary assembly step, the plurality of
tank constituting elements are stacked, and then, openings of the
stacked tank constituting elements are closed with the inlet and
outlet cover plates to form the liquid reserving portion and vacuum
heat-insulating layer.
32. The method of manufacturing a heat accumulator according to
claim 31, wherein the temporary assembly step includes: a brazing
filler metal applying step of applying brazing filer metal to the
tank constituting elements; a sub-assembly step of stacking the
tank constituting elements with the brazing filler metal applied
thereto; and an assembly step of closing the openings of the
stacked tank constituting elements with the inlet and outlet cover
plates to constitute a container.
33. The method of manufacturing a heat accumulator according to
claim 30, wherein the heat accumulator includes a heat storage
layer and a vacuum heat-insulating layer at the outer periphery of
the liquid reserving portion, and the heat storage layer is filled
with a heat storage material absorbing and releasing heat along
with its phase transition between liquid and solid phases, in the
part processing step, an inlet cover plate, an outlet cover plate,
and a plurality of tank constituting elements which are composed of
plate members of an identical cross-sectional shape and which each
have a liquid reserving portion space, a heat storage layer space,
and a vacuum heat-insulating layer space are processed, and in the
temporary assembly step, the plurality of tank constituting
elements are stacked, and then, openings of the stacked tank
constituting elements are closed with the inlet and outlet cover
plates to form the liquid reserving portion, heat storage layer,
and vacuum heat-insulating layer.
34. The method of manufacturing a heat accumulator according to
claim 33, wherein air grooves are provided at joint portions in
joint surfaces of the stacked tank constituting elements, each
joint portion connecting the liquid reserving portion space and the
vacuum heat-insulating space with the heat storage layer space
interposed therebetween, and in the brazing step, at evacuation in
the furnace, the liquid reserving portion spaces and the respective
vacuum heat insulating layer spaces are allowed to communicate with
each other through the air grooves and, at brazing by increasing
the temperature of the furnace, the air grooves are filled with the
brazing filler metal by capillary to close the air grooves.
35. The method of manufacturing a heat accumulator according to
claim 33, wherein in the brazing step, the heat storage layer is
evacuated together with the vacuum heat-insulating layer to lower
than atmospheric pressure at the end of the process, and the method
further comprises, after the brazing step, a heat storage material
encapsulation step of filling the evacuated heat storage layer with
the heat storage material by vacuum suction and then sealing a
portion through which the heat storage material is filled in.
36. The method of manufacturing a heat accumulator according to
claim 35, wherein a thin-wall portion made thinner than a standard
thickness is formed in a heat storage material encapsulation port
formed in any one of the inlet and outlet members, and in the heat
storage material encapsulation step, a tip of an injector charged
with the heat storage material is inserted into the heat storage
material encapsulation port to break through the thin-wall portion
to suck the heat storage material into the heat storage layer by
vacuum suction force, and then, a cap is inserted into and engaged
with the broken heat storage material encapsulation port to close
the broken heat storage material encapsulation port.
37. The method of manufacturing a heat accumulator according to
claim 30, wherein the heat accumulator includes a heat storage
layer and a vacuum heat-insulating layer at the outer periphery of
a liquid reserving portion, the heat storage layer being filled
with a heat storage material absorbing and releasing heat along
with its phase transition between liquid and solid phases, in the
part processing step, an inlet plate member, an outlet plate
member, and three cylindrical members forming the liquid reserving
portion, heat storage layer, and vacuum heat-insulating layer are
processed, and in the temporary assembly step, the three
cylindrical members are assembled in a coaxial fashion, and then,
openings thereof are closed with the inlet and outlet plate members
to form the liquid reserving portion, heat storage layer, and
vacuum heat-insulating layer.
38. A vehicle-mounted thermal system including a heat accumulator,
the vehicle-mounted thermal system comprising: a vehicle-mounted
heat source heating a heat medium while a power unit is being
driven; a vehicle-mounted heat demand source requiring a hot heat
medium when the power unit starts from a stopped state where
temperature of the heat medium decreases; and a heat medium circuit
connecting the vehicle-mounted heat source and the vehicle-mounted
heat demand source, characterized in that the heat medium circuit
is provided with the heat accumulator whose inlet is connected to
the vehicle-mounted heat source and whose outlet is connected to
the vehicle-mounted heat demand source, the heat accumulator
includes a heat storage layer between a liquid reserving portion
and a heat-insulating layer, the heat storage layer being filled
with a heat storage material absorbing and releasing heat along
with its phase transition between liquid and solid phases, a
circuit connecting the vehicle-mounted heat source and the inlet of
the heat accumulator is provided with a first valve, a circuit
connecting the vehicle-mounted heat demand source and the outlet of
the heat accumulator is provided with a second valve, and the heat
accumulator includes heat medium circulation control means which
opens the first and second valves while the power unit is being
driven; closes the first and second valves when the power unit
stops; and opens the first and second valves when the power unit
starts.
39. The vehicle-mounted heat system including the heat accumulator
according to claim 38, wherein the vehicle-mounted heat source is
an engine heating coolant while being driven, the heat-mounted heat
demand source is the engine allowing temperature of coolant to
decrease while being stopped and a heater core of an air
conditioner using the engine coolant as a heating medium, the heat
medium circulation control means opens the second valve to the
engine at the start of the engine when engine warm-up has priority
and opens the second valve to the heater core at the start of the
engine when passenger compartment heating has priority.
40. The vehicle-mounted heat system including the heat accumulator
according to claim 38, characterized in that the vehicle-mounted
heat source is an engine heating coolant while being driven, the
heat-mounted heat demand source is the engine allowing temperature
of coolant to decrease while being stopped and a heater core of an
air conditioner using the engine coolant as a heating medium, a
circuit connecting the second valve and the heater core is provided
with a pump, the heat medium circulation control means opens the
second valve to the engine at the start of the engine when engine
warm-up has priority, and the heat medium circulation control means
opens the second valve to the heater core and activate the pump to
regulate a rate of flow from the heat accumulator to the heater
core at the start of the engine when passenger compartment heating
has priority.
41. The vehicle-mounted heat system including the heat accumulator
according to claim 38, wherein the vehicle-mounted heat source is
an inverter cooler heating inverter coolant while being driven and
a battery cooler heating battery coolant while being driven, the
heat-mounted heat demand source is a heater core of an air
conditioner using the inverter and battery coolant as a heating
medium, and the heat medium circulation control means opens the
first and second valves at the start of an engine.
42. The vehicle-mounted heat system including the heat accumulator
according to claim 38, wherein the vehicle-mounted heat source is
an inverter cooler heating inverter coolant while being driven and
a battery cooler heating battery coolant while being driven, the
heat-mounted heat demand source is a heater core of an air
conditioner using the inverter and battery coolant as a heating
medium, a circuit connecting the second valve and the heater core
is provided with a pump, and the heat medium circulation control
means opens the first and second valves and activates the pump to
regulate a rate of flow from the heat accumulator to the heater
core at the start of an engine.
Description
TECHNICAL FIELD
[0001] The present invention relates to a heat accumulator employed
in an engine coolant circulation circuit or the like in order to
accelerate engine warm up or to increase the heating performance,
and relates to a method for manufacturing the heat accumulator and
a vehicle-mounted thermal system including the same.
BACKGROUND ART
[0002] A known conventional heat accumulator which stores engine
coolant and keeps the heat thereof is a heat accumulator having a
double structure of metallic inner and outer containers in which
the gap between the containers is evacuated for thermal insulation
(for reference, see Patent Document 1).
[0003] In a vehicle-mounted thermal system including the
conventional heat accumulator, engine coolant which becomes hot
while the vehicle is running is taken into the heat accumulator,
and the hot engine coolant is stored in the heat accumulator and is
kept warm while the vehicle is stopped. At the next start of the
engine, the hot engine coolant in the heat accumulator is fed to
the engine and a heater core for a passenger compartment heater and
used in quick engine warm up and quick heating.
Patent Document 1: Japanese Patent Application Publication No.
2004-20027
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
[0004] However, the conventional heat accumulator is composed of
the inner and outer containers formed by drawing metallic plates.
Accordingly, when there is a need to change necessary capacity of
the heat accumulator for the purpose of application to different
types of vehicles or the like, the conventional heat accumulator
cannot respond to the change in necessary capacity. It is therefore
necessary to change the processing die or make a new processing
die, thus causing an increase in cost, a loss for setup at
manufacturing, and the like.
[0005] Moreover, in manufacturing the conventional heat
accumulator, metallic plates are drawn and welded into main
components of the inner and outer containers. The inner and outer
containers are joined to other components with a space between the
containers, and then the components are fixed by welding or the
like, so that a container is manufactured. After the container is
manufactured, evacuation is performed for the container to form a
vacuum heat-insulating layer at an entirely different process, thus
manufacturing the heat accumulator. When the evacuation is
performed in the air atmosphere using a vacuum pump at the
evacuation step, the degree of vacuum of the vacuum heat-insulating
layer varies for each product. In addition, the fixing step of
fixing the components and the evacuation step of forming the vacuum
heat-insulating layer are performed at the steps entirely different
from each other, and it takes a great deal of labor hours and
efforts to manufacture the heat accumulator.
[0006] Furthermore, in the vehicle-mounted thermal system including
the conventional heat accumulator, at the start of the engine,
during the first cycle of circulation cycles of the engine coolant,
hot engine coolant is fed to the engine or the heater core of the
passenger compartment heater, but during and after the second
cycle, the hot engine coolant is affected by temperature of a
system environment including the engine, air, and the like and
moreover is mixed with cold engine coolant. Accordingly, the hot
coolant has heat instantly removed, and the cold engine coolant
starts to circulate. Accordingly, the quick warm-up performance of
the engine and quick heating performance in the passenger
compartment cannot meet the expectations.
[0007] The present invention has been made in the light of the
aforementioned problems, and a first object of the present
invention is to provide a heat accumulator capable of easily
responding a request for changing the necessary capacity without an
increase in cost by just increasing or decreasing the number of
stacked tank constituting elements.
[0008] A second object of the present invention is to provide a
method of manufacturing a heat accumulator which is capable of
forming a vacuum heat-insulating layer having an unvarying and
stable vacuum quality and is capable of simplifying the process to
reduce the manufacturing efforts and shorten the manufacturing
time.
[0009] Another object is to provide a compact heat accumulator
having high heat storage performance. Moreover, a third object of
the present invention is to provide a vehicle-mounted thermal
system including a heat accumulator which is capable of achieving
acceleration of engine warm-up and an increase in heating
performance in the passenger compartment meeting expectations at
the start of the power unit with a simple heat medium circulation
control.
Means for Solving the Problems
[0010] To accomplish the aforementioned first object, according to
the present invention, a heat accumulator includes: a
heat-insulating layer at the outer periphery of a liquid reserving
portion, in which the liquid reserving portion and heat insulating
layer are formed by stacking a plurality of tank constituting
elements composed of plate members of an identical cross-sectional
shape.
[0011] To accomplish the aforementioned second object, according to
the present invention, a method of manufacturing a heat accumulator
including a vacuum heat-insulating layer at the outer periphery of
a liquid reserving portion includes: a part processing step of
processing constituent parts constituting the heat accumulator; a
temporary assembly step of assembling the processed constituent
parts into a container; and a brazing step of evacuating the
temporarily assembled container in a furnace and increasing
temperature of the furnace to braze the constituent parts into a
unit in vacuum atmosphere.
[0012] To achieve the aforementioned third object, according to the
present invention, in a vehicle-mounted thermal system including a
heat accumulator, the vehicle-mounted thermal system including: a
vehicle-mounted heat source heating a heat medium while a power
unit is being driven; a vehicle-mounted heat demand source
requiring a hot heat medium when the power unit starts from a
stopped state where temperature of the heat medium decreases; and a
heat medium circuit connecting the vehicle-mounted heat source and
the vehicle-mounted heat demand source, in which the heat medium
circuit is provided with the heat accumulator whose inlet is
connected to the vehicle-mounted heat source and whose outlet is
connected to the vehicle-mounted heat demand source; the heat
accumulator includes a heat storage layer between a liquid
reserving portion and a heat-insulating layer; the heat storage
layer being filled with a heat storage material absorbing and
releasing heat along with its phase transition between liquid and
solid phases; a circuit connecting the vehicle-mounted heat source
and the inlet of the heat accumulator is provided with a first
valve; a circuit connecting the vehicle-mounted heat demand source
and the outlet of the heat accumulator is provided with a second
valve; and the heat accumulator includes heat medium circulation
control means which opens the first and second valves while the
power unit is being driven, closes the first and second valves when
the power unit stops, and opens the first and second valves when
the power unit starts.
EFFECTS OF THE INVENTION
[0013] According to the heat accumulator of the present invention,
it is possible to satisfy the request to change the necessary
capacity by only increasing or decreasing the number of the stacked
tanks constituting elements composed of the plate members of an
identical cross-sectional shape. Specifically, in the case of a
heat accumulator having a structure composed of an inner and outer
containers manufactured by drawing and the like, changing the
necessary capacity of the heat accumulator requires replacing a
drawing die or producing a new drawing die, thus leading to an
increase in cost, a loss at manufacturing setup, or the like.
[0014] On the other hand, in the present invention, the heat
accumulator has a stacking structure including the plurality of
tank constituting elements stacked on each other. Accordingly, it
is possible to immediately change the capacity from a certain
capacity to a different capacity in the minimum unit equivalent to
the capacity of the single tank constituting element if a plurality
of tank constituting elements are prepared in advance. Accordingly,
the request to change the necessary capacity is satisfied by
increasing or decreasing the number of stacked tank constituting
elements. Consequently, the request to change the necessary
capacity is easily satisfied by only increasing or decreasing the
number of stacked tank constituting elements without increasing the
cost.
[0015] According to the method of manufacturing a heat capacity, in
the part processing step, the constituent parts constituting the
heat accumulator are processed, and in the temporary assembly step,
the processed constituent parts are assembled into a container. In
the brazing step, the temporarily assembled container is evacuated
in a furnace and increase in temperature to braze the constituent
parts into a unit in the vacuum atmosphere. The heat accumulator
having a vacuum heat-insulating layer at the outer periphery of the
liquid reserving portion is thus manufactured.
[0016] In this manner, in the brazing step, by controlling the
vacuum atmosphere in the furnace into a stable vacuum atmosphere,
compared to the case of evacuation in the air atmosphere under
individual control, the vacuum heat-insulating layer having stable
and unvarying vacuum quality can be formed.
[0017] Moreover, in the brazing process, fixation of the parts and
evacuation can be both achieved. Accordingly, compared to the case
of evacuating the vacuum heat-insulating layer in another process
after fixing the parts by welding or the like, the processes can be
simplified, and the manufacturing efforts and time can be
reduced.
[0018] It is therefore possible to form the vacuum heat-insulating
layer with unvarying and stable vacuum quality and reduce the
manufacturing efforts and time by the simplification of the
process.
[0019] Furthermore, according to the vehicle-mounted heat system
including the heat accumulator of the present invention, while the
power unit is driven, the first and second valves are opened by the
heat medium circulation control means. Accordingly, when the heat
storage material receives heat from the hot heat medium passing the
heat accumulator from the inlet to the outlet and the temperature
of the heat storage material reaches the melting point, the heat
storage material changes the phase thereof from the solid to liquid
phase and absorbs heat energy during the phase transition.
[0020] When the power unit stops, the first and second valves are
closed by the heat medium circulation control means. The hot heat
medium is then enclosed by the liquid reserving portion surrounded
by the two layers of the heat-insulating layer and heat storage
layer.
[0021] Furthermore, when the power unit starts, the first and
second valves are opened by the heat medium circulation control
means. The hot heat medium stored is fed to the vehicle-mounted
heat demand source during the first cycle of the circulation cycles
of the heat medium. Thereafter, the hot heat medium is affected by
the temperature of the system environment and is mixed with cold
heat medium. The temperature of the engine coolant within the heat
accumulator therefore decreases. However, during and after the
second cycle where the temperature of the heat storage material
decreases to the freezing point because of the decrease in
temperature of the heat medium, the heat storage material changes
the phase thereof from the liquid to the solid phase. The heat
stored in the heat storage material is released along with this
phase transition. The decrease in temperature of the heat medium is
prevented by the heat released from the heat storage material, and
the heat medium kept hot is fed to the vehicle-mounted heat demand
source.
[0022] Consequently, with such a simple heat medium circulation
control, at the start of the power unit, it is possible to, for
example, when the vehicle-mounted heat demand source is an engine,
achieve expected warm-up promotion of the engine and, when the
vehicle-mounted heat demand source is a heater core, achieve an
expected increase in passenger compartment heating performance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a vertical-sectional front view showing a heat
accumulator of Embodiment 1 of the present invention.
[0024] FIG. 2 is an enlarged view of part A of FIG. 1 showing the
heat accumulator of Embodiment 1.
[0025] FIG. 3 is an external perspective view showing the heat
accumulator of Embodiment 1.
[0026] FIG. 4 is a sectional perspective view showing the heat
accumulator of Embodiment 1.
[0027] FIG. 5 is an exploded perspective view showing the heat
accumulator of Embodiment 1.
[0028] FIG. 6 is a process diagram showing vacuum brazing of a heat
accumulator S1 of Embodiment 1.
[0029] FIG. 7 is a vertical-sectional front view showing a heat
accumulator of Embodiment 2.
[0030] FIG. 8 is an enlarged view of part B of FIG. 7 showing the
heat accumulator of Embodiment 2 of the present invention.
[0031] FIG. 9 is an external perspective view showing the heat
accumulator of Embodiment 2.
[0032] FIG. 10 is a sectional perspective view showing the heat
accumulator of Embodiment 2.
[0033] FIG. 11 is an exploded perspective view showing the heat
accumulator of Embodiment 2.
[0034] FIG. 12 is a process diagram showing vacuum brazing of a
heat accumulator S2 of Embodiment 2.
[0035] FIG. 13 is a view showing an air groove of the heat
accumulator S2 of Embodiment 2, which is provided for increasing
the degree of vacuum at a brazing step in a furnace.
[0036] FIG. 14 is an explanatory view showing a heat storage
material encapsulation process in the vacuum brazing of the heat
accumulator S2 of Embodiment 2.
[0037] FIG. 15 is an engine coolant circulation circuit diagram
showing a first example of the engine coolant circulation system
including the heat accumulator S2 of Embodiment 2.
[0038] FIG. 16 is an engine coolant circulation circuit diagram
showing a second example of the engine coolant circulation system
including the heat accumulator S2 of Embodiment 2.
[0039] FIG. 17 is a coolant circulation circuit diagram showing a
first example of an electrical equipment coolant circulation system
for a driving motor including the heat accumulator S2 of Embodiment
2.
[0040] FIG. 18 is a coolant circulation circuit diagram showing a
second example of an electrical equipment coolant circulation
system for a driving motor including the heat accumulator S2 of
Embodiment 2.
[0041] FIG. 19 is a vertical-sectional front view showing a heat
accumulator manufactured by a manufacturing method of Embodiment 3
of the present invention.
[0042] FIG. 20 is an enlarged view of part C of FIG. 19 showing the
heat accumulator manufactured by the manufacturing method of
Embodiment 3.
[0043] FIG. 21 is an external perspective view showing the heat
accumulator manufactured by the manufacturing method of Embodiment
3.
[0044] FIG. 22 is a sectional perspective view showing the heat
accumulator manufactured by the manufacturing method of Embodiment
3.
[0045] FIG. 23 is an exploded perspective view showing the heat
accumulator manufactured by the manufacturing method of Embodiment
3.
[0046] FIG. 24 is an operation explanatory view explaining a heat
storing operation and a heat releasing operation in the heat
accumulator of Embodiment 3.
[0047] FIG. 25 is an engine coolant temperature comparative
characteristic diagram at the start of the engine for cases without
a heat accumulator, with a conventional heat accumulator, and with
the heat accumulator of Embodiment 3.
[0048] FIG. 26 is an engine coolant circulation circuit diagram
showing an engine coolant circulation system (an example of a
vehicle-mounted thermal system) including the heat accumulator S of
Embodiment 4 of the present invention.
[0049] FIG. 27 is an explanatory view of an engine coolant
circulation operation in the engine coolant circulation system of
Embodiment 4.
[0050] FIG. 28 is an engine coolant circulation circuit diagram
showing an engine coolant circulation system (an example of the
vehicle-mounted thermal system) including the heat accumulator S of
Embodiment 5 of the present invention.
[0051] FIG. 29 is an explanatory view of an engine coolant
circulation operation in the engine coolant circulation system of
Embodiment 5.
[0052] FIG. 30 is a coolant circulation circuit diagram showing an
electrical equipment coolant circulation system for a driving motor
(an example of the vehicle-mounted thermal system) including the
heat accumulator S of Embodiment 6 of the present invention.
[0053] FIG. 31 is an explanatory view of a coolant circulation
operation in the electrical equipment coolant circulation system
for a driving motor of Embodiment 6.
[0054] FIG. 32 is a coolant circulation circuit diagram showing an
electrical equipment coolant circulation system for a driving motor
(an example of the vehicle-mounted thermal system) including the
heat accumulator S of Embodiment 7 of the present invention.
[0055] FIG. 33 is an explanatory view of a coolant circulation
operation at the electrical equipment coolant circulation system
for a driving motor of Embodiment 7.
EXPLANATION OF REFERENCE SYMBOLS AND NUMERALS
[0056] S1: HEAT ACCUMULATOR [0057] 1: LIQUID RESERVING PORTION
[0058] 2: VACUUM HEAT-INSULATING LAYER (HEAT-INSULATING LAYER)
[0059] 6: INLET PIPE [0060] 7: OUTLET PIPE [0061] 8: INLET COVER
PLATE [0062] 9: OUTLET COVER PLATE [0063] 10a: FIRST PARTITION WALL
[0064] 10b: SECOND PARTITION WALL [0065] 10c: INNER RIB [0066] 10d:
OUTER RIB [0067] 10e: HEAT-INSULATING LAYER SPACE [0068] 10f LIQUID
RESERVING PORTION SPACE [0069] 10g: POSITIONING PROTRUSION [0070]
S2: HEAT ACCUMULATOR [0071] 2: SIDE VACUUM HEAT-INSULATING LAYER
(HEAT-INSULATING LAYER) [0072] 3: INLET END VACUUM HEAT-INSULATING
LAYER (HEAT-INSULATING LAYER) [0073] 4: OUTLET END VACUUM
HEAT-INSULATING LAYER (HEAT-INSULATING LAYER) [0074] 15: INLET END
PLATE [0075] 16: INLET COVER PLATE [0076] 17: OUTLET END PLATE
[0077] 18: OUTLET COVER PLATE [0078] 19: TANK CONSTITUTING ELEMENT
[0079] 19a: FIRST PARTITION WALL [0080] 19b: SECOND PARTITION WALL
[0081] 19c: THIRD PARTITION PORTION [0082] 19d: INNER RIB [0083]
19e: OUTER RIB [0084] 19f HEAT-INSULATING LAYER SPACE [0085] 19g:
HEAT STORAGE LAYER SPACE [0086] 19h: LIQUID RESERVING PORTION SPACE
[0087] 19i: POSITIONING PROTRUSION [0088] 19j: AIR GROOVE [0089]
20: CAP [0090] 21: ENGINE [0091] 22: HEATER CORE [0092] 23: FIRST
VALVE [0093] 24: SECOND VALVE [0094] 25: RADIATOR [0095] 26: THERMO
VALVE [0096] 27: CIRCULATION PUMP [0097] 28: CONTROLLER [0098] 29:
PUMP [0099] 30: INVERTER COOLER [0100] 31: BATTERY COOLER [0101]
S3: HEAT ACCUMULATOR [0102] 38: FIRST CYLINDRICAL SIDE PLATE
(CYLINDRICAL MEMBER) [0103] 39: FIRST INLET END PLATE (INLET PLATE
MEMBER) [0104] 40: FIRST OUTLET END PLATE (OUTLET PLATE MEMBER)
[0105] 41: SECOND CYLINDRICAL SIDE PLATE (CYLINDRICAL MEMBER)
[0106] 42: SECOND INLET END PLATE (INLET PLATE MEMBER) [0107] 43:
SECOND OUTLET END PLATE (OUTLET PLATE MEMBER) [0108] 44: ACCORDION
CYLINDRICAL PLATE (CYLINDRICAL PLATE)
BEST MODES FOR CARRYING OUT THE INVENTION
[0109] Hereinafter, a description is given of best modes for
implementing a heat accumulator of the present invention based on
Embodiments 1 to 7 shown in the drawings.
Embodiment 1
[0110] First, the constitution is described.
[0111] FIG. 1 is a vertical-sectional front view showing a heat
accumulator of Embodiment 1; FIG. 2 is an enlarged view of part A
of FIG. 1 showing the heat accumulator of Embodiment 1; FIG. 3 is
an external perspective view showing the heat accumulator of
Embodiment 1; FIG. 4 is a sectional perspective view showing the
heat accumulator of Embodiment 1; and FIG. 5 is an exploded
perspective view showing the heat accumulator of Embodiment 1.
[0112] As shown in FIGS. 1 to 5, a heat accumulator S1 of
Embodiment 1 includes a liquid reserving portion 1, a vacuum
heat-insulating layer (heat-insulating layer) 2, an inlet pipe 6,
an outlet pipe 7, an inlet cover plate 8, an outlet cover plate 9,
and tank constituting elements 10.
[0113] The heat accumulator S1 of Embodiment 1 includes the vacuum
heat-insulating layer 2 at the outer periphery of the liquid
reserving portion 1. The liquid reserving portion 1 and the vacuum
heat-insulating layer 2 are formed by stacking the plurality of
tank constituting elements 10 which are composed of plate members
of an identical sectional shape.
[0114] The heat accumulator S1 of Embodiment 1 includes the inlet
and the outlet cover plate 8 and 9 and the tank constituting
elements 10 as constituent parts. The inlet pipe 6 is fixed to the
inlet cover plate 8, and the outlet pipe 7 is fixed to the outlet
cover plate 9.
[0115] As shown in FIG. 5, each of the tank constituting elements
10 of the heat accumulator S1 of Embodiment 1 includes a first
partition wall 10a, a second partition wall 10b, an inner rib 10c,
and an outer rib 10d coaxially arranged. The first and second
partition walls 10a and 10b are radially joined at about four
places of an entire circumference to form heat-insulating layer
spaces 10e between the joint places. The space surrounded by the
second partition wall 10b serves as a liquid reserving portion
space 10f. The inner rib 10c protrudes from the second partition
wall 10b towards the liquid reserving portion 1. The outer rib 10d
protrudes outward from the first partition wall 10a and includes an
axially bent portion at a part of the circumference for exterior
shape alignment at the stacking. At the joint places between the
first and second partition walls 10a and 10b, positioning
protrusions 10g protruding in a tank axis direction are formed (see
FIG. 2).
[0116] In the heat accumulator S1 of Embodiment 1, a plurality of
the tank constituting elements 10 are stacked on each other, facing
alternate directions, and the openings of the stacked tank
constituting elements 10 at the both ends are closed by the inlet
and outlet cover plates 8 and 9, thus constituting a container.
[0117] The liquid reserving portion 1 is composed of the liquid
reserving portion spaces 10f made to communicate with each other by
stacking the tank constituting elements 10.
[0118] The vacuum heat-insulating layer 2 is formed by evacuating
the heat-insulating layer spaces 10 made to communicate with each
other by stacking the tank constituting elements 10.
[0119] The method of manufacturing the heat insulator S1 of
Embodiment 1 is a vacuum brazing as follows: Brazing filler metal
is applied to the plurality of tank constituting elements 10, and
the plurality of tank constituting elements 10 are stacked on each
other. The openings of the stacked tank constituting elements 10 at
both ends are closed by the inlet and outlet cover plates 8 and 9,
temporarily assembling a container. The temporarily assembled
container is evacuated in a furnace and then the temperature is
increased.
[0120] Next, the operations thereof are described.
[Manufacturing Method of Heat Accumulator]
[0121] FIG. 6 is a process diagram showing vacuum brazing for the
heat accumulator S1 of Embodiment 1. Hereinafter, the vacuum
brazing for the heat accumulator S1 of Embodiment 1 is described
using FIG. 6.
[0122] Tart Processing Process
[0123] In a first part processing process of step S1, the tank
constituting elements 10 are processed by pressing or punching
plate materials.
[0124] In a second part processing process of step S2, the inlet
and outlet cover plates 8 and 9 are processed by pressing or
punching plate materials.
[0125] In a third part processing process of step S3, the inlet and
outlet pipes 6 and 7 are processed by pipe forming from plate
materials, drawing, or the like.
[0126] Brazing Filler Metal Applying Process
[0127] In a brazing filler metal applying process of step S4,
brazing filler metal is applied to the plurality of tank
constituting elements 10 (for example, stainless steel) processed
at the first part processing process of the step S1.
[0128] Tart Sub-Assembly Process (Stacking Process)
[0129] In a part sub-assembly process of step S5, a desired number
of the tank constituting elements 10 with the brazing filler metal
applied thereto in the brazing filler metal applying process of the
step S4 are stacked according to the designed value of the liquid
reserving capacity. In the case of Embodiment 1, the plurality of
tank constituting elements 10 are stacked on each other facing
alternate directions so as to provide a stack shown in FIGS. 1 to
5.
[0130] Assembly Process
[0131] In an assembly process of step 6, the stacked tank
constituting elements 10 assembled in the part sub-assembly process
of the step S5 are joined with the parts including the inlet and
outlet cover plates 8 and 9 and inlet and outlet pipes 6 and 7,
which are processed at the second and third part processing
processes of the steps S2 and S3, as shown in FIG. 5, to be
temporarily built into a container shape as a whole. At this time,
the brazing filler metal is applied to the portions necessary to be
brazed other than the stacked constituting elements 10.
[0132] Jig Setting Process
[0133] In a jig setting process of step S7, the temporarily
fabricated container is set to a brazing jig so that the individual
parts temporarily fabricated into the container shape in the
assembly process of the step S6 are not displaced and secure the
unity thereof.
[0134] Brazing Process
[0135] In a brazing process of the step S8, the individual parts
are fixed by vacuum brazing at the following in-furnace
process.
[0136] The in-furnace process includes: an evacuation process to
evacuate the inside of the furnace (step S8a); a warming process to
increase temperature within the furnace (step S8b); a brazing
process to fix the parts with melted brazing filler metal (step
S8c); and a cooling process to cool the container fixed by brazing
(step S8d).
[0137] Air Sealing Process
[0138] In an air sealing process of step S9, the air tightness
keeping the vacuum of the vacuum heat-insulating layer 2 of the
brazed container taken out of the furnace is secured.
[0139] Shipping Inspection Process
[0140] In a shipping inspection process of step S10, shipping
inspection is made in terms of check items including whether the
vacuum of the vacuum heat-insulating layer 2 is maintained with no
brazing defects.
[0141] Tacking Process
[0142] In a packing process of step S11, products which pass the
shipping inspection are packed.
[0143] Shipping Process
[0144] In a shipping process of step S12, the packed products are
shipped from a factory.
[Heat Storing and Releasing Operation]
[0145] In the heat accumulator S1 of Embodiment 1, when a hot heat
medium passing the liquid reserving portion 1 stops circulating,
part of the hot heat medium is enclosed in the liquid reserving
portion 1 surrounded by the vacuum heat-insulating layer 2. The
heat medium stored in the liquid reserving portion 1 within the
heat accumulator S1 is therefore prevented from cooling and is kept
hot.
[0146] For using the hot heat medium within the liquid reserving
portion 1 of the heat accumulator S1, the hot heat medium in the
liquid reserving portion 1 is released through the outlet pipe 7.
When the hot heat medium is configured to be released to the engine
as hot engine coolant at the start of the engine, the engine
warm-up can be accelerated. When the hot heat medium is configured
to be released to the heater core at the start of the engine, the
heating performance in the passenger compartment can be
increased.
[Operation of Responding to Change in Necessary Capacity]
[0147] In the heat accumulator S1 of Embodiment 1, the liquid
reserving portion 1 and vacuum heat-insulating layer 2 are formed
by stacking the plurality of tank constituting elements 10 composed
of the plate members of an identical cross-sectional shape.
[0148] Accordingly, the request to change the necessary capacity
can be satisfied by increasing or decreasing the number of the
stacked tank constituting elements 10 composed of the plate members
of an identical cross-sectional shape.
[0149] Specifically, in the case of a heat accumulator having a
structure composed of an inner and outer containers manufactured by
drawing and the like as the conventional art, changing the
necessary capacity of the heat accumulator requires replacing the
drawing die or producing a new drawing die, thus leading to an
increase in cost, a loss at manufacturing setup, or the like.
[0150] On the other hand, in Embodiment 1, the heat accumulator S1
has a stacking structure including the plurality of tank
constituting elements 10 stacked on each other. Accordingly, the
request to change the necessary capacity is satisfied by increasing
or decreasing the number of stacked tank constituting elements 10,
and the change of the drawing die, which increases the cost, is not
necessary.
[0151] In other words, in the case of Embodiment 1, it is possible
to immediately produce a heat accumulator with a different capacity
if a plurality of the tank constituting elements 10 are prepared in
advance. When there is a request to increase the necessary capacity
with respect to a heat accumulator with a certain capacity, the
number of tank constituting elements 10 stacked is increased. When
there is a request to reduce the necessary capacity, the number of
tank constituting elements 10 stacked is reduced. Herein, the
capacity can be changed in units equivalent to the capacity of the
single tank constituting element 10.
[0152] Next, the effects thereof are described.
[0153] According to the heat accumulator S1 of Embodiment 1, the
effects enumerated in the following can be obtained.
(1) In the heat accumulator including the vacuum heat-insulating
layer 2 in the outer periphery of the liquid reserving portion 1,
the liquid reserving portion 1 and vacuum heat-insulating layer 2
are formed by stacking the plurality of tank constituting elements
10 composed of the plate members of an identical cross-sectional
shape. It is therefore possible to easily satisfy the request to
change the necessary capacity without increasing the cost by just
increasing or decreasing the number of stacked tank constituting
elements. (2) The heat accumulator S1 includes the inlet and outlet
cover plates 8 and 9 and tank constituting elements 10 as the
constituent parts. The inlet pipe 6 is fixed to the inlet cover
plate 8, and the outlet pipe 7 is fixed to the outlet cover plate
9. Each of the tank constituting elements 10 includes the first and
second partition walls 10a and 10b coaxially arranged. Between the
first and second partition walls 10a and 10b, the heat-insulating
layer space 10e is formed. The liquid reserving portion space 10f
is surrounded by the second partition wall 10b. The plurality of
tank constituting elements 10 are stacked, and the openings of the
stacked tank constituting elements 10 at the both ends are closed
by the inlet and outlet cover plates 8 and 9, thus constituting the
container. The liquid reserving portion 1 is composed of the liquid
reserving portion spaces 10f, which are made to communicate with
each other by stacking the tank constituting elements 10, and the
vacuum heat-insulating layer 2 is composed of evacuating the
heat-insulating layer spaces 10e, which are made to communicate
with each other by stacking the tank constituting elements 10. It
is therefore possible to provide the stacking-type heat accumulator
S1 which includes the vacuum heat-insulating layer 2 at the outer
periphery of the liquid reserving portion 1 and has high
responsiveness to the request to change the necessary capacity. (3)
The heat accumulator S1 is manufactured as follows: The plurality
of tank constituting elements 10 are stacked on each other with the
brazing filler metal applied thereto, and the openings of the
stacked tank constituting elements 10 at the both ends are closed
with the inlet and outlet cover plates 8 and 9 to be temporarily
assembled. The temporarily assembled container is subjected to
vacuum brazing, which evacuates the temporarily assembled container
within the furnace and then increases the temperature thereof. In
other words, fixation of the parts and evacuation are both
performed at the vacuum brazing process. Accordingly, compared to
the case where the parts are fixed by welding, brazing, or the like
and then the vacuum heat-insulating layer is evacuated at a
different process, it is possible to reduce the variations in
degree of vacuum of the vacuum heat-insulating layer 2 and to
shorten the manufacturing time by the simplified process.
[0154] According to the method of manufacturing the heat
accumulator S1 of Embodiment 1, the effects enumerated below can be
obtained.
(1) The method of manufacturing the heat accumulator S1 including
the vacuum heat-insulating layer 2 at the outer periphery of the
liquid reserving portion 1 includes: the part processing processes
to process the constituent parts constituting the heat accumulator
S1 (steps S1 to S3); the temporary assembly process to assemble the
processed constituent parts into a container form (step S4 to S6);
and the brazing process to evacuate the temporarily assembled
container within the furnace and then increase the temperature
thereof for brazing the constituent parts into a unit in the vacuum
atmosphere. Accordingly, it is possible to form the vacuum
heat-insulating layer 2 with unvarying and stable vacuum quality
and to reduce the manufacturing efforts and time by the simplified
process. (2) The heat accumulator S1 includes the vacuum
heat-insulating layer 2 at the outer periphery of the liquid
reserving portion 1: In the part processing processes (steps S1 to
S3), the tank constituting elements 10, which are composed of plate
members having a same cross-sectional shape and each of which
includes the liquid reserving portion space 10f and vacuum
heat-insulating space 10e, and the inlet and outlet cover plates 8
and 9 are processed. In the temporary assembly process (steps S4 to
S6), the plurality of tank constituting elements 10 are stacked,
and the openings of the stacked tank constituting elements 10 are
closed with the inlet and outlet cover plates 8 and 9, thus forming
the liquid reserving portion 1 and vacuum heat-insulating layer 2.
It is therefore possible to provide the method of manufacturing the
stacking-type heat accumulator S1 which includes the vacuum
heat-insulating layer 2 at the outer periphery of the liquid
reserving portion 1 and has responsiveness to the request to change
the necessary capacity. (3) The temporary assembly process includes
the brazing material application process to apply the brazing
filler metal to the tank constituting elements 10 (step S4); the
sub-assembly process to stack the tank constituting elements 10
with the brazing filler metal applied thereto (step S5); and the
assembly process to close the openings of the stacked tank
constituting elements 10 with the inlet and outlet cover plates 8
and 9 for fabrication into a container form (step S6). Accordingly,
employment of the sub-assembly process to stack the tank
constituting elements 10 with the brazing filler material applied
thereto allows the plurality of stacked tank constituting elements
10 to be reliably brazed and fixed in the brazing process (step
S8).
Embodiment 2
[0155] Embodiment 2 is a heat accumulator including a liquid
reserving portion, a vacuum heat-insulating layer, and a heat
storage layer while Embodiment 1 is the heat accumulator including
the liquid reserving portion and the vacuum heat-insulating
layer.
[0156] First, the constitution thereof is described.
[0157] FIG. 7 is a vertical-sectional front view showing a heat
accumulator of Embodiment 2; FIG. 8, an enlarged view of part B of
FIG. 7 showing the heat accumulator of Embodiment 2; FIG. 9, an
external perspective view showing the heat accumulator of
Embodiment 2; FIG. 10, a sectional perspective view showing the
heat accumulator of Embodiment 2; and FIG. 11, an exploded
perspective view showing the heat accumulator of Embodiment 2.
[0158] As shown in FIGS. 7 to 11, a heat accumulator S2 of
Embodiment 2 includes a liquid reserving portion 1, a side vacuum
heat-insulating layer (heat-insulating layer) 2, an inlet end
vacuum heat-insulating layer 3 (heat-insulating layer), an outlet
end vacuum heat-insulating layer 4 (heat-insulating layer), a heat
storage layer 5, an inlet pipe 6, an outlet pipe 7, an inlet end
plate 15, an inlet cover plate 16, an outlet end plate 17, an
outlet cover plate 18, and tank constituting elements 19.
[0159] The heat accumulator S2 of Embodiment 2 includes the vacuum
heat-insulating layers 2, 3, and 4 at the outer periphery of the
liquid reserving portion 1. Between the liquid reserving portion 1
and side vacuum heat-insulating layer 2, the heat storage layer 5
is provided, which is filled with a heat storage material absorbing
or releasing heat during phase transition between liquid and solid
phases.
[0160] The heat accumulator S2 of Embodiment 2 includes the inlet
and outlet end plates 15 and 17, the inlet and outlet cover plates
16 and 18, and the tank constituting elements 19 as constituent
parts. The inlet pipe 6 is fixed to the inlet end plate 15, and the
outlet pipe 7 is fixed to the outlet end plate 17.
[0161] Furthermore, as shown in FIG. 8, on a third partition wall
19c separating a liquid reserving portion space 19h of each tank
constituting element 19, an inner rib 19d protruding in a direction
orthogonal to the flow of the heat medium from the inlet to the
outlet is formed. As shown in FIG. 8, the adjacent third partition
walls 19c and 19c and the adjacent inner ribs 19d and 19d abut on
each other to form protrusions orthogonal to the flow.
[0162] The heat storage material encapsulated in the heat storage
layer 5 is a paraffin material as a latent heat storage material.
The paraffin raw material stores heat of fusion during phase
transition from the solid to the liquid phase in a temperature
range not lower than the melting point and releases heat of
solidification during phase transition from the solid to the liquid
phase in a temperature range not higher than the freezing point.
The heat storage material is paraffin capsules, which include the
paraffin material encapsulated in spherical coatings as
microcapsules. The heat storage layer 5 is filled with aggregates
of the paraffin capsules taking an account of a change in volume
(about 10%) accompanied with the phase transition between the
liquid and solid phases.
[0163] Herein, the reason for using the paraffin material as the
heat storage material is that the phase transition temperature
including the melting point (melting temperature) and freezing
point (freezing temperature) can be set in a wide range of
temperature (-50 to 80.degree. C.) depending on the number of
carbon chains and moreover that the amount of stored heat (latent
heat of fusion) thereof is about 130 to 250 kJ/kg, which is higher
than those of the other materials.
[0164] For example, in the case of using the heat accumulator in a
vehicle-mounted thermal system circulating engine coolant to the
heater core, the phase transition temperature is preferably about
50 to 60.degree. C. or more. The reason therefor is that the
temperature of the engine coolant does not always reach 80.degree.
C. in winter or some cases. Moreover, the air outlet temperature
feeling warm is 30.degree. C., and the phase transition temperature
required to provide an air outlet temperature of not lower than
30.degree. C. is about 50 to 60.degree. C. or more as described
above.
[0165] In the case of manufacturing the heat accumulator S2 of
Embodiment 2 by vacuum brazing, as shown in FIG. 11, the outlet end
plate 17 of the heat accumulator S2 is provided with a heat storage
material encapsulation port 17a for encapsulating the heat storage
material, which is protruded towards the outlet cover plate 18. In
the outlet cover plate 18, an encapsulation port hole 18a
penetrating the heat storage material encapsulation port 17a is
formed. The heat storage material encapsulation port 17a is closed
by a cap 20 made of resin, rubber, or the like after the heat
storage material is encapsulated.
[0166] Each tank constituting element 19 includes first and second
partition walls 19a and 19b, the third partition wall 19c, the
inner rib 19d, and an outer rib 19e arranged coaxially. The first
and second partition walls 19a and 19b are radially joined at about
four places of the entire circumference to form heat-insulating
layer spaces 19f between the joint places. The second and third
partition walls 19b and 19c are radially joined at about four
places of the entire circumference to form heat storage layer
spaces 19g between the joint places. The space surrounded by the
third partition wall 19c serves as a liquid reserving portion space
19h. The inner rib 19d protrudes from the third partition wall 19c
towards the liquid reserving portion 1. The outer rib 19e protrudes
outward from the first partition wall 19a and includes an axially
bent portion at a part of the circumference for exterior shape
alignment for stacking. At the joint places between the first and
second partition walls 19a and 19b, positioning protrusions 19i
protruding in a tank axis direction are formed (see FIG. 8).
[0167] In the heat accumulator S2 of Embodiment 2, a plurality of
the tank constituting elements 19 are stacked facing in alternate
directions, and the openings of the stacked tank constituting
elements 19 at the both ends are closed by the inlet end and cover
plates 15 and 16 and the outlet end and cover plates 17 and 18 to
constitute a container.
[0168] The liquid reserving portion 1 is composed of the liquid
reserving portion spaces 19h made to communicate with each other by
stacking the tank constituting elements 19.
[0169] The vacuum heat-insulating layer 2 is formed by evacuating
the heat-insulating layer spaces 19f made to communicate with each
other by stacking the tank constituting elements 19. The inlet end
vacuum heat-insulating layer 3 is formed by evacuating the space
formed by the inlet end and cover plates 15 and 16. The outlet end
vacuum heat-insulating layer 4 is formed by evacuating the space
formed by the inlet end and cover plates 17 and 18.
[0170] The heat storage layer 5 is composed of the heat storage
layer spaces 19g made to communicate by stacking the tank
constituting elements 19.
[0171] The heat insulator S2 of Embodiment 2 is manufactured by a
manufacturing method as follows: Brazing filler metal is applied to
the plurality of tank constituting elements 19, and the plurality
of tank constituting elements 19 are stacked. The openings of the
stacked tank constituting elements 19 at both ends are closed by
the inlet and outlet cover plates 16 and 18, temporarily assembling
a container. The temporarily assembled container is evacuated in a
furnace and then the temperature is increased for vacuum brazing,
thus evacuating the vacuum heat-insulating layers 2, 3, and 4 and
heat storage layer 5 together. Thereafter, the evacuated heat
storage layer 5 is filled with the heat storage material by vacuum
suction.
[0172] Next, operations thereof are described.
[Manufacturing Method of Heat Accumulator]
[0173] FIG. 12 is a process diagram showing vacuum brazing of the
heat accumulator S2 of Embodiment 2; FIG. 13 is a view showing an
air groove of the heat accumulator S2 of Embodiment 2, which is
provided for increasing the degree of vacuum at a brazing process
in the furnace; and FIG. 14 is an explanatory view showing a heat
storage material encapsulation process at the vacuum brazing of the
heat accumulator S2 of Embodiment 2. Hereinafter, the vacuum
brazing for the heat accumulator S2 of Embodiment 2 is described
using FIGS. 12 to 14.
[0174] Tart Processing Process
[0175] In a first part processing process of step S1, the tank
constituting elements 19 are processed by pressing or punching
plate materials.
[0176] In a second part processing process of step S2, the inlet
and outlet cover plates 16 and 18 are processed by pressing or
punching plate materials.
[0177] In a third part processing process of step S3, the inlet and
outlet end plates 15 and 17 are processed by pressing or punching
plate materials.
[0178] In a fourth part processing process of step S4, the inlet
and outlet pipes 6 and 7 are processed by pipe forming of plate
materials.
[0179] In a fifth part processing process of step S5, the cap 20 is
formed by pressing or punching a plate material, drawing, or the
like.
[0180] Brazing Filler Metal Applying Process
[0181] In a brazing filler metal applying process of step S6,
brazing filler metal is applied to the plurality of tank
constituting elements 19 (for example, stainless steel) processed
at the first part processing process of the step S1.
[0182] Part Sub-Assembly Process (Stacking Process)
[0183] In a part sub-assembly process of step S7, a desired number
of the tank constituting elements 19 with the brazing filler metal
applied thereto at the brazing filler metal applying process of the
step S6 are stacked according to the designed value of the liquid
storage capacity. In the case of Embodiment 2, the plurality of
tank constituting elements 19 are stacked facing in alternate
directions so as to provide a stack shown in FIGS. 7 to 11.
[0184] Assembly Process
[0185] In an assembly process of step 8, the stacked tank
constituting elements 19 assembled in the part sub-assembly process
of the step S7 are joined with the parts processed at the second to
fifth part processing processes, including the inlet and outlet
cover plates 16 and 18, the inlet and outlet end plates 15 and 17,
the inlet and outlet pipes 6 and 7, and the cap 20, to be
temporarily built into a container shape as a whole. At this time,
the brazing filler metal is applied to the portions necessary to be
brazed other than the stacked constituting elements 19.
[0186] Jig Setting Process
[0187] In a jig setting process of step S9, the temporarily
built-up container is set to a brazing jig so that the individual
parts temporarily built into the container shape in the assembly
process of the step S8 are not displaced and secure the unity
thereof.
[0188] Brazing Process
[0189] In a brazing process of the step S10, the individual parts
are fixed by vacuum brazing at the following in-furnace
process.
[0190] The in-furnace process includes: an evacuation process to
evacuate the inside of the furnace (step S10a); a warming process
to increase temperature within the furnace (step Slob); a brazing
process to fix the parts with melted brazing filler metal (step
S10c); and a cooling process to cool the container fixed by brazing
(step S10d).
[0191] In the evacuation process of the step S10a, in order to
further increase the degree of vacuum, as shown in FIG. 13(a), air
grooves 19j are formed at the joint places radially connecting the
second and third partition walls 19b and 19c. Accordingly, in the
stacked tank constituting elements 19, as shown in FIG. 13(b), the
liquid reserving portion 1 and side vacuum heat-insulating layer 2
communicate with each other through the pairs of air grooves 19j
and 19j facing each other.
[0192] Air Sealing Process
[0193] In an air sealing process of step S11, the air tightness
keeping the vacuum of the vacuum heat-insulating layers 2 to 4 and
heat storage layer 5 of the brazed container taken out of the
furnace is secured.
[0194] Heat Storage Material Encapsulation Process
[0195] In a heat storage material encapsulation process of step
S12, the heat storage material is encapsulated using evacuation by
the evacuated heat storage layer 5.
[0196] Specifically, as shown in FIG. 14(a), in the case of vacuum
brazing, the heat storage layer 5 is also evacuated. Moreover, in
the heat storage encapsulation port 17a formed at the outlet end
plate 17, a thin wall portion 17a' made thinner than a standard
plate thickness is formed.
[0197] As shown in FIG. 14(b), when the tip end of a filler charged
with a heat storage material P (paraffin) is inserted into the heat
storage material encapsulation port 17a to break through the thin
wall portion 17a', the heat storage material P is sucked at once
into the heat storage layer 5 by vacuum suction force of the heat
storage layer 5. Since the heat storage layer 5 is evacuated, the
heat storage material is uniformly encapsulated within a short
time. After the heat storage layer 5 is filled with the heat
storage material P, the cap 20 is inserted and engaged as shown in
FIG. 14(c) to close the broken heat storage material encapsulation
port 17a.
[0198] Shipping Inspection Process
[0199] In a shipping inspection process of step S13, shipping
inspection is performed in terms of check items including whether
the vacuum of the vacuum heat-insulating layer 2 is maintained with
no brazing defects and whether the heat storage layer 5 is filled
with the heat storage material P.
[0200] Packing Process
[0201] In a packing process of step S14, products which pass the
shipping inspection are packed.
[0202] Shipping Process
[0203] In a shipping process of step S15, the packed products are
shipped from a factory.
[Heat Storing and Releasing Operation]
[0204] A description is given of heat storing and releasing
operations by the heat accumulator 2 of Embodiment 2.
[0205] With regard to the heat absorbing operation of the heat
storage material, while hot heat medium circulates through the
liquid reserving portion 1 within the heat accumulator 2 by a flow
from the inlet pipe 6 to the outlet pipe 7, the heat storage
material within the heat storage layer 5 receives heat from the hot
heat medium through the third partition walls 19c including the
inner ribs 19d. Upon receiving the heat, the heat storage material
increases in temperature. When the temperature of the heat storage
material reaches the melting point thereof, the heat storage
material changes the phase thereof from the solid to the liquid
phase and absorbs heat energy along with this phase transition.
[0206] In Embodiment 2, the heat storage material is paraffin
capsules. Accordingly, when the temperature of the heat storage
material is low as less than the melting point, the encapsulated
paraffin is solid like wax. On the other hand, when the temperature
of the heat storage material reaches the melting point or more,
solid paraffin gradually liquefies and becomes completely liquid
within the capsules when the heat storage material absorbs heat at
maximum.
[0207] With regard to the operation of storing heat in the heat
medium within the liquid reserving portion 1, when a hot heat
medium passing the liquid reserving portion 1 stops circulating,
part of the hot heat medium is enclosed in the liquid reserving
portion 1 surrounded by two layers of each of the vacuum
heat-insulating layers 2 to 4 and heat storage layer 5 and is
prevented from decreasing in temperature. The heat medium stored in
the liquid reserving portion 1 within the heat accumulator S2 is
kept hot.
[0208] In other words, even if the circulation of the hot medium is
stopped for a long time and the outside temperature around the heat
accumulator S2 becomes low, the double heat-insulating structure by
the vacuum heat-insulating layers 2 to 4 and heat storage layer 5
minimizes the heat energy escaping from the heat medium stored in
the liquid reserving portion 1. It is therefore possible to achieve
so high heat retention of the heat accumulator S2 that the heat
medium of the liquid reserving portion 1 is kept hot even after a
long period of time.
[0209] With regard to the operation of releasing the hot heat
medium, in the case of using the hot heat medium within the liquid
reserving portion 1 of the heat accumulator S2, first the hot heat
medium of the liquid reserving portion 1 is released through the
outlet pipe 7. Along with the release of the hot heat medium, a
cold heat medium is introduced into the liquid reserving portion 1
of the heat accumulator 2 through the inlet pipe 6 and is mixed
with the hot heat medium. Accordingly, the temperature of the heat
medium within the reservoir 1 of the heat accumulator S2 is
lowered.
[0210] With regard to the operation of releasing heat from the heat
storage material, when the heat medium within the liquid reserving
portion 1 of the heat accumulator S2 decreases in temperature and
draws heat from the heat storage material within the heat storage
layer 5 through the third partition walls 19c including the inner
ribs 19d, the temperature of the heat storage material is lowered.
When the temperature of the heat storage material then reaches the
freezing point, the phase of the heat storage material changes from
the liquid to the solid phase. Along with this phase transition,
the heat storage material releases the absorbed heat and continues
to supply the heat energy due to the latent heat to the heat medium
through the third partition walls 19c including the inner ribs 19d,
thus preventing the temperature of the heat medium from being
lowered.
[0211] In Embodiment 2, the heat storage material is paraffin
capsules. Accordingly, when the temperature of the heat storage
material is higher than the freezing point, the encapsulated
paraffin is liquid. On the other hand, when the temperature of the
heat storage material is reduced to the freezing point or less,
liquid paraffin gradually solidifies to release heat and becomes
solid within the capsules when the heat storage material releases
heat at maximum.
[0212] As described above, the heat accumulator 2 of Embodiment 2
effectively utilizes "sensible heat" stored in the heat medium with
the heat retention maintained and "latent heat" released from the
heat storage material of the heat storage layer 5.
[0213] Accordingly, in an application of the heat accumulator 2 to
the engine coolant circulation circuit, introducing hot engine
coolant to the engine side at the start of the engine can
considerably reduces time taken for the engine to reach the engine
warm-up temperature. Moreover, in another application thereof to
the engine coolant circulation circuit, introducing the hot engine
coolant to the heater core side at the start of the engine can
increased the passenger compartment heating performance.
[0214] The "sensible heat" is heat energy stored without phase
transition, and "latent heat" is heat energy absorbed or released
during phase transitions between the solid and liquid phases. The
amount of heat stored in the form of "latent heat" is several
orders of magnitude higher than that of "sensible heat."
[Heat Exchange Promotion Operation]
[0215] The heat accumulator S2 of Embodiment 2 includes the inlet
end and cover plates 15 and 16, the outlet end and cover plates 17
and 18, and the tank constituting elements 19, and the inlet and
outlet pipes 6 and 7 are fixed to the inlet and outlet end plates
15 and 17, respectively. On the third partition walls 19c
separating the liquid reserving portion spaces 19h of the tank
constituting elements 19, the inner ribs 19d protruding in the
direction orthogonal to the flow of the heat medium from the inlet
to the outlet are formed.
[0216] Accordingly, the flow of the heat medium from the inlet pipe
6 to the outlet pipe 7 meanders along the protrusions and recesses
composed of the third partition walls 19c and inner ribs 19d. When
the heat storage material encapsulated in the heat storage layer 5
absorbs heat from the heat medium, the effective area for heat
absorption is larger than that in the case of a straight
cylindrical pipe, providing high heat absorption efficiency. In a
similar way, when the heat storage material encapsulated in the
heat storage layer 5 releases heat to the heat medium, the
effective area for heat release is larger than that in the case of
the straight cylindrical pipe, thus resulting in high heat release
efficiency. The protrusions and recesses composed of the third
partition walls 19c and inner ribs 19d can thus promote the heat
exchange efficiency.
[Application Example of Heat Accumulator S2 to Engine Coolant
Circulation System]
[0217] FIG. 15 is an engine coolant circulation circuit diagram
showing a first example of an engine coolant circulation system
including the heat accumulator S2 of Embodiment 2.
[0218] An engine 21 heating engine coolant while being driven and
the engine 21 and a heater core 22 which require the heated engine
coolant when the engine is started from the engine stop state,
where the temperature of the engine coolant decreases, are
connected through an engine coolant circulation circuit.
[0219] The engine coolant circulation circuit is provided with the
heat accumulator S2 whose inlet side is connected to the engine 21
and whose outlet side is connected to the engine 21 and heater core
22.
[0220] The circuit connecting the engine 21 and the inlet side of
the heat accumulator S2 is provided with a first valve 23, and the
circuit connecting the outlet side of the heat accumulator S2 and
the engine 21 and heater core 22 is provided with a second valve
24. The engine coolant circulation circuit connecting the engine 21
and a radiator 25 is provided with a thermo valve 26 and a
circulation pump 27.
[0221] Operations of the first and second valves 23 and 24 and the
circulation pump 27 are controlled by a controller 28.
[0222] The controller 28 makes control as follows: the controller
28 opens the first and second valves 23 and 24 while the engine 21
is being driven and closes the first and second valves 23 and 24
when the engine 21 is stopped. At the start of the engine 21, the
controller 28 opens the second valve 24 to the engine 21 side when
the engine warm-up has priority, and opens the second valve 24 to
the heater core 22 side when the passenger compartment heating has
priority.
[0223] Accordingly, at the start of the engine, by continuing to
feed hot engine coolant from the heat accumulator S2 utilizing
"sensible heat" and "latent heat," expected promotion of warm-up of
the engine 2 can be achieved when the engine warm-up has priority
while an expected increase in heating performance in the passenger
compartment can be achieved when the passenger compartment heating
has priority.
[0224] FIG. 16 is an engine coolant circulation circuit diagram
showing a second example of the engine coolant circulation system
including the heat accumulator S2 of Embodiment 2.
[0225] This second example is an example of further providing a
pump 29 for the circuit connecting the second valve 24 and the
heater core 22 in the engine coolant circulation system shown in
FIG. 15.
[0226] Accordingly, in addition to the effects of the first
example, the second example further provides an effect on
controlling the heating performance by regulating the flow rate
when the passenger compartment heating has priority.
[Application Example of Heat Accumulator S2 to Electrical Part
Coolant Circulation System for Driving Motor]
[0227] FIG. 17 is a coolant circulation circuit diagram showing a
first example of an electrical equipment coolant circulation system
for a driving motor including the heat accumulator S2 of Embodiment
2.
[0228] In this first example, a vehicle-mounted heat source
includes an inverter cooler 30 which heats inverter coolant while
being driven and a battery cooler 31 which heats battery coolant
while being driven. A vehicle-mounted heat demand source includes a
heater core 22 of an air conditioner using the inverter coolant and
battery coolant as heating medium.
[0229] The controller 28 makes control at the start of the engine
to open the first valve 23 provided on the inlet side of the heat
accumulator S1 and the second valve 24 provided on the outlet side
of the heat accumulator S2. Accordingly, it is possible to achieve
an expected increase in passenger compartment heating performance
at the start of the engine in a hybrid vehicle.
[0230] FIG. 18 is a coolant circulation circuit diagram showing a
second example of the electrical equipment coolant circulation
system for a driving motor including the heat accumulator S2 of
Embodiment 2.
[0231] This second example is an example further providing the pump
29 for the circuit connecting the second valve 24 and the heater
core 22 in the electrical equipment coolant circulation system for
a driving motor shown FIG. 17.
[0232] Accordingly, in addition to the effects of the first
example, the second example further provides an effect on
controlling the heating performance by regulating the flow rate at
the start of the engine.
[0233] Next, effects thereof are described.
[0234] In addition to the effect (1) in the heat accumulator S1 of
Embodiment 1, the heat accumulator S2 of Embodiment 2 can provide
the effects enumerated below.
(4) The heat storage layer 5 filled with the heat storage material
absorbing and releasing heat during phase transition between liquid
and solid phases is provided between the liquid reserving portion 1
and each of the vacuum heat-insulating layers 2, 3, and 4.
Accordingly, it is possible to provide the heat accumulator S2
having so high heat storage performance that can increase the
warm-up performance or passenger compartment heating performance at
the start of the engine because of "latent heat" released from the
heat storage material in the heat storage layer 5. (5) The heat
storage material is a paraffin material, as a latent heat storage
material, which stores the heat of fusion during phase transition
from the solid to the liquid phase in the temperature range not
lower than the melting point and which releases the heat of
solidification during phase transition from the liquid to the solid
phase in the temperature range not higher than the freezing point.
Accordingly, it is possible to obtain a high storage of heat even
with a little amount of the heat storage material. Moreover, the
paraffin material has high flexibility in setting the phase
transition temperature, and accordingly, the phase transition
temperature can be properly set depending on the intended use. (6)
The heat storage material includes paraffin capsules, which include
the paraffin material encapsulated in spherical coatings as
microcapsules. The heat storage layer 5 is filled with aggregates
of the paraffin capsules taking an account of a change in volume
due to phase transition between liquid and solid phases.
Accordingly, the volatile characteristic, which is a fault of the
paraffin material, can be prevented by the spherical coatings, and
the operation of deformation force due to the change in volume can
be reduced, thus securing the endurance reliability for long-term
use. (7) The heat accumulator S2 includes the inlet end and cover
plates 15 and 16, the outlet end and cover plates 17 and 18, and
the tank constituting elements 19 as the constituent parts.
Moreover, the inlet pipe 6 is fixed to the inlet end plate 15, and
the outlet pipe 7 is fixed to the outlet end plate 17. Furthermore,
on the third partition walls 19c separating the liquid reserving
portion spaces 19h of the tank constituting elements 19, the inner
ribs 19d protruding in the direction orthogonal to the flow of the
heat medium from the inlet to outlet is formed. Accordingly, the
heat storage material encapsulated in the heat storage layer 5 has
high heat absorption and release efficiencies, thus accelerating
the heat exchange. It is therefore possible to provide a high
latent heat effect by the heat storage material. (8) Each of the
tank constituting elements 19 includes the first to third partition
walls 19a to 19c coaxially arranged. The heat-insulating layer
space 19f is formed between the first and second partition walls
19a and 19b, and the heat storage layer space 19g is formed between
the second and third partition walls 19b and 19c. The liquid
reserving portion space 19h is surrounded by the third partition
wall 19c. The plurality of tank constituting elements 19 are
stacked, and the openings of the stacked tank constituting elements
19 at the both ends are closed by the inlet and outlet cover plates
16 and 18, thus constituting a container. The liquid reserving
portion 1 is composed of the liquid reserving portion spaces 19h
made to communicate with each other by stacking the tank
constituting elements 19, and the vacuum heat-insulating layer 2 is
composed of the heat-insulating layer spaces 19f which are made to
communicate by stacking the tank constituting elements 19 and then
evacuated. The heat storage layer 5 is composed of the heat storage
layer spaces 19g made to communicate by stacking the tank
constituting elements 19. Accordingly, it is possible to provide
the stacking-type heat accumulator S2 which includes the heat
storage layer 5 and vacuum heat-insulating layer 2 at the outer
periphery of the liquid reserving portion 1 and has a high heat
storage performance and high responsiveness to the request to
change the necessary capacity. (9) The heat accumulator S2 is
manufactured as follows: The plurality of tank constituting
elements 19 are stacked on each other with the brazing filler metal
applied thereto, and the openings of the stacked tank constituting
elements 19 at the both ends are closed with the inlet and outlet
cover plates 16 and 18, thus temporarily assembling a container.
Vacuum brazing is then performed to evacuate the temporarily
assembled container within the furnace and then to increase the
temperature thereof to evacuate both the heat-insulating layer 2
and heat storage layer 5. The evacuated heat storage layer 5 is
filled with the heat storage material P by vacuum suction. In other
words, fixing of the parts and evacuation are both performed at the
vacuum brazing process. Accordingly, compared to the case where the
parts are fixed by welding, brazing, or the like and then the
vacuum heat-insulating layer is evacuated by a different process,
it is possible to reduce variations in the degree of vacuum of the
vacuum heat-insulating layer 2 and shorten the manufacturing time
because of the simplified process. Moreover, by using the vacuum of
the heat storage layer 5, the heat storage material P can be
encapsulated by vacuum suction. Accordingly, the heat storage layer
5 can be uniformly filled with the heat storage material P within a
short encapsulation time.
[0235] The method of manufacturing the heat accumulator 2 of
Embodiment 2 can provide the effects enumerated below in addition
to the effect (1) of the method of manufacturing the heat
accumulator S1 of Embodiment 1.
(4) The heat accumulator S2 includes the heat storage layer 5 and
vacuum heat-insulating layer 2 at the outer periphery of the liquid
reserving portion 1, and the heat storage layer 5 is filled with
the heat storage material P which absorbs and releases heat along
with its phase transition between liquid and solid phases. The part
processing processes (steps S1 to S5) processes the inlet and
outlet cover plates 16 and 18 and the tank constituting elements 19
each of which includes the liquid reserving portion space 19h, heat
storage layer space 19g, and heat-insulating layer space 19f and
which is a plate material with a same cross-sectional shape, and
the temporary assembly process (steps S6 to S8) stacks the
plurality of tank constituting elements 19 and closes the openings
thereof with the inlet and outlet cover plates 16 and 18, thus
forming the liquid reserving portion 1, heat storage layer 5, and
vacuum heat-insulating layer 2. Accordingly, it is possible to
provide the method of manufacturing the stacking-type heat
accumulator S2 which including the heat storage layer 5 and vacuum
heat-insulating layer 2 at the outer periphery of the liquid
reserving portion 1 and has a high heat storage performance and
high responsiveness to the request to change the necessary
capacity. (5) In the joint surfaces of the stacked tank
constituting elements 19, the air grooves 19j are provided at the
joint places connecting the liquid reserving portion space 19h and
heat-insulating layer space 19f with the heat storage space 19g
interposed therebetween. In the brazing process (step 10), the
liquid reserving portion spaces 19h and the heat-insulating layer
spaces 19f communicate with each other through the air grooves 19j
at evacuation within the furnace, and the air grooves 19j are
filled and closed with the brazing filler metal by capillary at
brazing by increasing the temperature within the furnace.
Accordingly, air is smoothly evacuated from the heat-insulating
layer spaces 19f by evacuation at the brazing process, thus further
increasing the degree of vacuum of the vacuum heat-insulating layer
2. (6) The brazing process (step S10) evacuates the heat storage
layer 5 together with the vacuum heat-insulating layer 2 to less
than the atmospheric pressure at the end of the process. After the
brazing process, the heat storage material encapsulation process
(step S12) is added, which fills the evacuated heat storage layer 5
with the heat storage material P by vacuum suction and then seals
the encapsulation port. Accordingly, at encapsulating the heat
storage material P in the heat storage layer 5 using the evacuated
heat storage layer 5, the heat storage material P can be
encapsulated uniformly and within a shorter time compared to the
case of encapsulating the heat storage material P by pouring in the
air atmosphere. (7) The heat storage material encapsulation port
17a formed in the outlet end plate 17 includes the thin wall
portion 17a' made thinner than the standard plate thickness. In the
heat storage material encapsulation process (step S12), the tip of
the injector charged with the heat storage material P is inserted
into the heat storage material encapsulation port 17a to break
through the thin wall portion 17a, thus the heat storage layer 5 is
caused to suck the heat storage material P thereinto by vacuum
suction. After the heat storage layer 5 is filled with the heat
storage material P, the cap 20 is inserted into and engaged with
the broken heat storage material encapsulation port 17a to close
the port 17a. Accordingly, in encapsulating the heat storage
material P in the heat storage layer 5 using the evacuated heat
storage layer 5, by using the heat storage material encapsulation
port 17a including the previously formed thin wall portion 17a',
the heat storage material P can be encapsulated in the heat storage
layer 5 with an easy insert operation. Moreover, the encapsulation
port can be sealed with the easy operation of inserting the cap
20.
Embodiment 3
[0236] Embodiment 3 is an example of a method of manufacturing a
multi-container type heat accumulator including a liquid reserving
portion, a heat-insulting layer, and a heat storage layer while
Embodiment 2 shows the method of manufacturing the stacking-type
heat accumulator.
[0237] First, the constitution thereof is described.
[0238] FIG. 19 is a vertical-sectional front view showing a heat
accumulator manufactured by a manufacturing method of Embodiment 3.
FIG. 20 is an enlarged view of part C of FIG. 19 showing the heat
accumulator manufactured by the manufacturing method of Embodiment
3. FIG. 21 is an external perspective view showing the heat
accumulator manufactured by the manufacturing method of Embodiment
3. FIG. 22 is a sectional perspective view showing the heat
accumulator manufactured by the manufacturing method of Embodiment
3. FIG. 23 is an exploded perspective view showing the heat
accumulator manufactured by the manufacturing method of Embodiment
3.
[0239] As shown in FIGS. 19 to 23, the heat accumulator S3 of
Embodiment 3 includes a liquid reserving portion 1, a side vacuum
heat-insulating layer (vacuum heat-insulating layer) 2, an inlet
end vacuum heat-insulating layer 3 (vacuum heat-insulating layer),
an outlet end vacuum heat-insulating layer 4 (heat-insulating
layer), a heat storage layer 5, an inlet pipe 6, an outlet pipe 7,
a first cylinder side plate 38 (a cylindrical member), a first
inlet end plate 39 (an inlet plate member), a first outlet end
plate 40 (an outlet plate member), a second cylinder side plate 41
(a cylindrical member), a second inlet end plate 42 (an inlet plate
member), a second outlet end plate 43 (an outlet plate member), and
an accordion cylinder plate 44 (a cylindrical member).
[0240] The heat accumulator S3 of Embodiment 3 includes the vacuum
heat-insulating layers 2, 3, and 4 at the outer periphery of the
liquid reserving portion 1 and a heat storage layer 5 between the
liquid reserving portion 1 and the side vacuum heat-insulating
layer 2, the heat storage layer 5 being filled with a heat storage
material which absorbs and releases heat along with its phase
transition between liquid and solid phases.
[0241] The liquid reserving portion 1 is provided with the inlet
pipe 6 through which a heat medium flows into the liquid reserving
portion 1 and the outlet pipe 7 through which the heat medium flows
out. The wall member separating the liquid reserving portion 1 and
the heat storage layer 5 is the accordion cylinder plate 44 having
roughness of a waveform sectional shape in a direction orthogonal
to the flow of the heat medium from the inlet to the outlet.
[0242] The inlet pipe 6 penetrates the second and first inlet end
plates 42 and 39 to be fixed, and the outlet pipe 7 penetrates the
second and first outlet end plates 43 and 40 to be fixed.
[0243] The heat storage material filled in the heat storage layer 5
is a paraffin material as a latent heat storage material. The
paraffin material stores heat of fusion during phase transition
from the solid to the liquid phase in a temperature range not lower
than the melting temperature and releases heat of solidification
during phase transition from the solid phase to the liquid phase in
a temperature range not higher than the freezing temperature. The
heat storage material includes paraffin capsules, which include the
paraffin material encapsulated in spherical coatings as
microcapsules. The heat storage layer 5 is filled with aggregates
of the paraffin capsules taking an account of a change in volume
(about 10%) along with its phase transition between the liquid and
solid phases.
[0244] The inner container includes the first cylinder side plate
38, first inlet end plate 39, and first outlet end plat 40. Within
the first cylinder side plate 38, the accordion cylinder plate 44
is provided coaxially with the first cylinder side plate 38.
[0245] The outer container is provided outside of the inner
container and includes the second cylinder side plate 41, second
inlet end plate 42, and second outlet end plate 43.
[0246] The liquid reserving portion 1 is composed of a cylindrical
space surrounded by the accordion cylinder plate 44, first inlet
end plate 39, and first outlet end plate 40. Positioning of the
accordion cylinder plate 44 relative to the both end plates 39 and
40 is performed by a step 39a formed in the first inlet end plate
39 and a step 40a formed in the first outlet end plate 40.
[0247] The heat-insulating layer includes the side vacuum
heat-insulating layer 2, inlet end vacuum heat-insulating layer 3,
and outlet end vacuum heat-insulating layer 4 and is composed of
evacuated gap formed between the inner and outer containers.
[0248] The side vacuum heat-insulating layer 2 is formed as a
cylindrical layer between the first and second cylinder side plates
38 and 41. The inlet end vacuum heat-insulating layer 3 is formed
between the first and second inlet end plates 39 and 42. The outlet
end vacuum heat-insulating layer 4 is formed between the first and
second outlet end plates 40 and 43. The radial gap of the side
vacuum heat-insulating layer 2 is positioned by an annular
protrusion 42a formed in the second inlet side plate 42 and an
annular protrusion 43a formed in the second outlet end plate 43 and
can be maintained at constant without changing the relative
position even if external force is applied thereto.
[0249] The heat storage layer 5 is composed of a cylindrical space
formed between the first cylinder side plate 38 and accordion
cylinder plate 44. The radial gap of the heat storage layer 5 can
be maintained at constant by the first cylinder plate 38 positioned
by the annular protrusions 42a and 43a and the accordion cylinder
plate 44 positioned by the steps 39a and 40a.
[0250] Next, the operations thereof are described.
[Heat Storage Operation]
[0251] With regard to the heat absorbing operation of the heat
storage material, while a hot heat medium circulates through the
liquid reserving portion 1 within the heat accumulator S3 through a
flow from the inlet pipe 6 to the outlet pipe, the heat storage
material within the heat storage layer 5 receives heat from the hot
heat medium through the accordion cylinder plate 44. Upon receiving
the heat, the heat storage layer increases in temperature. When the
temperature of the heat storage material reaches the melting point
of the heat storage material, the heat storage material changes the
phase thereof from the solid to the liquid phase and absorbs heat
energy during this phase transition.
[0252] In Embodiment 3, the heat storage material includes paraffin
capsules. Accordingly, when the temperature of the heat storage
material is as low as less than the melting point, the encapsulated
paraffin is solid like wax. On the other hand, when the temperature
of the heat storage material reaches the melting point or more,
solid paraffin gradually liquefies and becomes completely liquid
within the capsules when the heat storage material absorbs heat at
maximum.
[0253] With regard to the operation of storing heat in the heat
medium within the liquid reserving portion 1, when the hot heat
medium passing the liquid reserving portion 1 stops circulating, as
shown in FIG. 24(a), part of the hot heat medium is enclosed in the
liquid reserving portion 1 surrounded by two layers of each of the
vacuum heat-insulating layers 2 to 4 and the heat storage layer 5
and is prevented from cooling. The heat medium stored in the liquid
reserving portion 1 is kept hot.
[0254] In other words, even if the circulation of the hot medium is
stopped for a long time and the outside temperature around the heat
accumulator S3 becomes low, the double heat-insulating structure of
each of the vacuum heat-insulating layers 2 to 4 and the heat
storage layer 5 minimizes the heat energy escaping from the heat
medium stored in the liquid reserving portion 1. It is therefore
possible to achieve so high heat retention that the heat medium of
the liquid reserving portion 1 is kept hot even after a long period
of time.
[Heat Releasing Operation]
[0255] With regard to the operation of releasing the hot heat
medium, in the case of using the hot heat medium within the liquid
reserving portion 1 of the heat accumulator S3, first the hot heat
medium of the liquid reserving portion 1 is released through the
outlet pipe 7. Along with the release of the hot heat medium, as
shown in FIG. 24(b), cold heat medium is introduced into the liquid
reserving portion 1 of the heat accumulator S3 through the inlet
pipe 6 and mixed with the hot heat media, lowering the temperature
of the heat medium within the reservoir 1 of the heat accumulator
S3.
[0256] With regard to the operation of releasing heat from the heat
storage material, when the heat medium within the liquid reserving
portion 1 of the heat accumulator S3 becomes cold and draws heat
from the heat storage material within the heat storage layer 5
through the accordion cylinder plate 44, the temperature of the
heat storage material is lowered. When the temperature of the heat
storage material then reaches the freezing point, the phase of the
heat storage material changes from the liquid to the solid phase as
shown in FIG. 24(c). During the phase transition, the heat absorbed
by the heat storage material is released, and the heat energy by
the latent heat continues to be supplied to the heat medium through
the accordion cylinder plate 44, thus preventing the temperature of
the heat medium from being lowered.
[0257] In Embodiment 3, the heat storage material includes the
paraffin capsules. Accordingly, when the temperature of the heat
storage material is higher than the freezing point, the
encapsulated paraffin is liquid. On the other hand, when the
temperature of the heat storage material is reduced to the freezing
point or less, liquid paraffin gradually solidifies to release heat
and becomes solid within the capsules when the heat storage
material releases heat at maximum.
[Heat Storage Performance Comparison]
[0258] Comparison is made for the heat storage performance based on
the comparative characteristics of the engine coolant temperature
at the start of the engine shown in FIG. 25.
[0259] In FIG. 25, the characteristic indicated by a dotted line
shows an engine coolant temperature characteristic in the case
where there is no heat accumulator in the circulation circuit of
engine coolant; the characteristic indicated by a dashed-dotted
line shows an engine coolant temperature characteristic in the case
where a conventional heat accumulator is provided in the
circulation circuit of engine coolant; and the characteristic
indicated by a solid line shows an engine coolant temperature
characteristic in the case where the heat accumulator S3 is
provided in the circulation circuit of engine coolant.
[0260] When the engine starts in the case where there is no heat
accumulator in the circulation circuit of engine coolant, as
indicated by the dotted line of FIG. 25, the engine coolant
temperature which is equal to the outside temperature level at the
start of the engine increases by the heat energy due to the engine
being driven. In FIG. 25, it is assumed that the engine coolant
temperature increases at a constant gradient.
[0261] When the engine starts in the case where the conventional
heat accumulator (including only the vacuum heat-insulating layer)
is provided in the circulation circuit of engine coolant, as
indicated by the dashed-dotted line of FIG. 25, hot engine coolant
is fed from the heat accumulator at the start of the engine, and
accordingly the engine coolant temperature rises just after the
start. However, the hot engine coolant is immediately mixed with
cold engine coolant to drop in temperature. The engine coolant
temperature then increases along the dotted line.
[0262] When the engine starts in the case where the heat
accumulator S3 of Embodiment 3 is provided in the circulation
circuit of engine coolant, as indicated by the solid line of FIG.
25, hot engine coolant is fed from the heat accumulator at the
start of the engine, and the engine coolant temperature rises just
after the start. Subsequently, the hot engine coolant is mixed with
cold engine coolant to once drop in temperature. However, release
of the heat stored in the heat storage material prevents the drop
in temperature of the engine coolant, and the engine coolant
temperature increases during and after the second cycle.
[0263] The comparison in performances of the heat accumulators by
the coolant temperature characteristics relates to "sensible heat"
and "latent heat." The "sensible heat" is heat energy stored
without phase transition. The "latent heat" is heat energy absorbed
or released along with its phase transitions between solid and
liquid phases. The amount of heat stored in the form of "latent
heat" is several orders of magnitude higher than that of "sensible
heat."
[0264] On the other hand, a conventional heat accumulator (for
example, see Japanese Patent Application publication No.
2004-20027) stores hot engine coolant, or utilizes only the
"sensible heat." As shown in FIG. 25, therefore, once the stored
hot engine coolant is used out, there is no addition of heat
energy. In other words, the sensible heat effect is low.
Accordingly, compared to time T3 for the engine coolant to reach
warm-up temperature in the case where there is no heat accumulator
in the engine coolant circulation circuit, time T2 for the engine
coolant to reach the warm-up temperature is just slightly
shortened.
[0265] On the other hand, the heat accumulator S3 of Embodiment 3
holds temperature retention while utilizing both the sensible heat
stored in the heat medium and the latent heat released from the
heat storage material of the heat storage layer 5. As shown in FIG.
25, therefore, to the sensible heat effect, the latent heat effect
providing additional heat energy is added. Accordingly, compared to
the time T3 for the engine coolant to reach the warm-up temperature
in the case where there is no heat accumulator in the engine
coolant circulation circuit, time T1 for the engine coolant to
reach the warm-up temperature is considerably shortened.
[Heat Accumulator Manufacturing Method]
[0266] The heat accumulator S3 of Embodiment 3 is manufactured by
vacuum brazing including a part processing process, a temporary
assembly process, and a brazing process.
[0267] Part Processing Process
[0268] In the part processing process, the constituent parts
constituting the heat accumulator S3 are processed. Specifically,
the three cylindrical members 38, 41, and 44 forming the liquid
reserving portion 1, heat storage layer 5, and vacuum
heat-insulating layer 2, the inlet plate members 39 and 42, the
outlet plate members 40 and 43, and the inlet and outlet pipes 6
and 7 are processed by pressing, punching, or the like.
[0269] Temporary Assembly Process
[0270] In the temporary assembly process, the processed constituent
parts are assembled into a container. Specifically, the three
cylindrical members 38, 41, and 44 are assembled in a coaxial form,
and the openings thereof are covered with the inlet plate members
39 and 42 and the outlet plate members 40 and 43, thus forming the
liquid reserving portion 1, heat storage layer 5, and vacuum
heat-insulating layer 2.
[0271] Brazing Process
[0272] In the brazing process, after brazing filer metal is applied
to the assembled parts and the assembled parts are shaped into a
container by a jig, the assembled container is put into a furnace
and subjected to: a evacuation process of evacuating the inside of
the furnace; a warming process of increasing the temperature within
the furnace; a brazing process of fixing the parts with the melted
brazing filler metal; and a cooling process of cooling the
container fixed by brazing, thus completing fixation by
brazing.
[0273] As for the encapsulation of the heat storage material in the
heat storage layer 5, similar to the case of Embodiment 2, the heat
storage layer 5 may be filled by evacuation, or the heat storage
material may be poured into the heat storage layer 5 in the air
atmosphere.
[0274] Through the aforementioned processes, the heat accumulator
S3 is manufactured.
[0275] In the brazing process, therefore, by controlling the vacuum
atmosphere in the furnace into a stable vacuum atmosphere, compared
to the case of evacuation in the air atmosphere under individual
control, the vacuum heat-insulating layers 2, 3, and 4 having
stable and unvarying vacuum quality can be formed.
[0276] Moreover, in the brazing process, fixation of the parts and
evacuation can be both achieved. Accordingly, compared to the case
of evacuating the vacuum heat-insulating layers in another process
after fixing the parts by welding or the like, the processes can be
simplified, and the manufacturing efforts and time can be
reduced.
[0277] Next, the effects thereof are described.
[0278] The method of manufacturing the heat accumulator S3 of
Embodiment 3 can provide the following effects in addition to the
effect of (1) of the method of manufacturing the heat accumulator
S1 of Embodiment 1:
(8) The heat accumulator S2 includes the heat storage layer 5 and
vacuum heat-insulating layer 2 at the outer periphery of the liquid
reserving portion 1, and the heat storage layer 5 is filled with
the heat storage material P which absorbs and releases heat along
with its phase transition between liquid and solid phases. In the
part processing process, the three cylindrical members 38, 41, and
44 forming the liquid reserving portion 1, heat storage layer 5,
and vacuum heat-insulating layer 2, the inlet plate members 39 and
42, and the outlet end plate members 40 and 43 are processed. In
the temporary assembly process, the three cylindrical members 38,
41, and 44 are assembled in a coaxial fashion, and the openings
thereof are covered with the inlet plate members 39 and 42 and the
outlet plate members 40 and 43, thus forming the liquid reserving
portion 1, heat storage layer 5, and vacuum heat-insulating layer
2. It is therefore possible to provide the method of manufacturing
the multi-container type heat accumulator S3 which includes the
heat storage layer 5 and vacuum heat-insulating layer 2 at the
outer periphery of the liquid reserving portion 1 and having a high
heat storage performance.
Embodiment 4
[0279] Embodiment 4 is an example of an application of the heat
accumulator S2 of Embodiment 2 or the heat accumulator S3 of
Embodiment 3 (hereinafter, referred to as a heat accumulator 5) to
a vehicle-mounted thermal system in which a vehicle-mounted heat
source and a vehicle-mounted heat demand source are connected
through a heat medium circuit.
[0280] First, the constitution thereof is described.
[0281] FIG. 26 is an engine coolant circulation circuit diagram
showing an engine coolant circulation system (an example of a
vehicle-mounted thermal system) including the heat accumulator S of
Embodiment 4.
[0282] The engine 21 (the vehicle-mounted heat source) which heats
engine coolant (heat medium) while being driven and the engine 21
and heater core 22 (the vehicle-mounted heat demand source) which
demands heated engine coolant at the start of the engine from the
engine stopped state where the temperature of the engine coolant
decreases are connected through the engine coolant circulation
circuit.
[0283] The engine 21 serves as the vehicle-mounted heat source
because the engine 21 heats the coolant while being driven and also
serves as the vehicle-mounted heat demand source because the
temperature of the coolant drops while the engine 21 is
stopped.
[0284] The heater core 22, which is arranged in a unit of an air
conditioner controlling temperature in the passenger compartment,
uses the engine coolant as the heating medium and therefore serves
as the vehicle-mounted heat demand source.
[0285] In the engine coolant circulation circuit, the heat
accumulator S whose inlet is connected to the engine 21 and whose
outlet is connected to the engine 21 and heater core 22 is
provided.
[0286] In the heat accumulator S, the heat storage layer 5 filled
with the heat storage material which absorbs or releases heat
during the phase transition between liquid and solid phases is
provided between the liquid reserving portion 1 and each of the
heat-insulating layers 2, 3, and 4 (see Embodiments 2 and 3).
[0287] The circuit connecting the engine 21 and the inlet of the
heat accumulator S is provided with a first valve 23, and the
circuit connecting the outlet of the heat accumulator S and the
engine 21 and heater core 22 is provided with a second valve 24.
The engine coolant circulation circuit connecting the engine 21 and
radiator 25 is provided with a thermo-valve 26 and a circulation
pump 27.
[0288] The operations of the first and second valves 23 and 24 and
circulation pump 27 are controlled by a controller 28 (a heat
medium circulation controlling unit).
[0289] The controller 28, basically, makes control to open the
first and second valve 23 and 24 while the engine is being driven;
closes the first and second valves 23 and 24 when the engine 21
stops; and open the first and second valves 23 and 24 when the
engine 21 starts.
[0290] On the other hand, in the case of Embodiment 4, there are
two vehicle-mounted demand sources. The controller 28 therefore
makes control to open the second valve 24 to the engine 21 at the
start of the engine when the engine warm-up has priority and open
the second valve 24 to the heater core 22 at the start of the
engine while the passenger compartment heating has priority.
[0291] Next, the operations thereof are described.
[Heat Storing Operation]
[0292] During normal running state by engine drive, by the
controller 28, the first valve 23 is opened; and during use of a
heater, the second valve 24 is opened to the heater core 22; and
the circulation pump 27 is driven.
[0293] Accordingly, as shown in FIG. 27(a), hot engine coolant from
the engine 21 passes the heat accumulator S from the inlet to the
outlet and is further fed to the engine 21 through the heater core
22 during use of the heater. When the temperature of the engine
coolant increases and reaches the melting point of the heat storage
material, the heat storage material changes the phase thereof from
the solid to the liquid phase and absorbs heat energy during this
phase transition.
[0294] When the engine 21 stops, by the controller 28, the first
and second valves 23 and 24 are closed, and the circulation pump 27
is stopped.
[0295] Accordingly, as shown in FIG. 27(b), the engine coolant is
enclosed in the liquid reserving portion 1 surrounded by the two
layers of each of the heat-insulating layers 2, 3, and 4 and the
heat storage layer 5. The engine coolant stored in the heat
accumulator S is therefore prevented from decreasing in temperature
and is kept hot.
[Engine Warm-Up Priority]
[0296] Thereafter, when the engine warm-up has priority, at the
start of the engine 21, by the controller 28, the first valve 23 is
opened; the second valve 24 is opened to the engine 21; and the
circulation pump is driven.
[0297] Accordingly, as shown in FIG. 27(c), the hot engine coolant
stored in the heat accumulator S is fed to the engine 21 during the
first cycle of the circulation cycles of the engine coolant. The
hot engine coolant is affected by the temperature of the system
environment and is mixed with cold engine coolant. The temperature
of the engine coolant within the heat accumulator S therefore
decreases.
[0298] However, during and after the second cycle where the
temperature of the heat storage material decreases to the freezing
point because of the decrease in temperature of the engine coolant
within the heat accumulator S, the heat storage material changes
the phase thereof from the liquid to the solid phase. The heat
stored in the heat storage material is released during this phase
transition, and the heat energy due, to the latent heat continues
to be supplied to the engine coolant. During and after the second
cycle, the decrease in temperature of the engine coolant is
prevented by the heat released from the heat storage material, and
the engine coolant kept hot is fed to the engine 21.
[Passenger Compartment Heating Priority]
[0299] On the other hand, when the passenger compartment heating
has priority, at the start of the engine 21, by the controller 28,
the first valve 23 is opened; the second valve 24 is opened to the
heater core 22; and the circulation pump 27 is driven.
[0300] Accordingly, as shown in FIG. 27(d), the hot engine coolant
stored in the heat accumulator S is fed to the heater core 22
during the first cycle of the circulation cycles of the engine
coolant. The hot engine coolant is affected by the temperature of
the system environment and is mixed with cold engine coolant. The
temperature of the engine coolant within the heat accumulator S
therefore decreases.
[0301] However, during and after the second cycle where the
temperature of the heat storage material decreases to the freezing
point because of the decrease in temperature of the engine coolant
within the heat accumulator S, the heat storage material changes
the phase thereof from the liquid to the solid phase. The heat
stored in the heat storage material is released during this phase
transition, and the heat energy due to the latent heat continues to
be supplied to the engine coolant. During and after the second
cycle, the decrease in temperature of the engine coolant is
prevented by the heat released from the heat storage material, and
the engine coolant kept hot is fed to the heater core 22.
[0302] Next, the effects thereof are described.
[0303] The engine coolant circulation system including the heat
accumulator S of Embodiment 4 can provide the effects enumerated
below:
(1) In the vehicle-mounted thermal system in which the
vehicle-mounted heat source which heats the heat medium while the
power unit is being driven is connected, through the heat medium
circuit, to the vehicle-mounted heat demand source which requires
the hot heat medium when the power unit starts from the power unit
stopped state where the temperature of the heat medium decreases,
the heat medium circuit is provided with the heat accumulator S
whose inlet is connected to the vehicle-mounted heat source and
whose outlet is connected to the vehicle-mounted heat demand
source. The heat accumulator S includes the heat storage layer 5
between the liquid reserving portion 1 and each of the
heat-insulating layer 2, 3, and 4, the heat storage layer 5 being
filled with the heat storage material absorbing or releasing heat
along with its phase transition between liquid and solid phases.
The circuit connecting the vehicle-mounted heat source and the
inlet of the heat accumulator S is provided with the first valve
23, and the circuit connecting the outlet of the heat accumulator S
and the vehicle-mounted heat demand source is provided with the
second valve 24. Furthermore, the vehicle-mounted thermal system
includes the controller 28 which opens the first and second valves
23 and 24 while a power unit is being driven; closes the same when
the power unit stops; and opens the same when the power unit
starts. Accordingly, with such a simple heat medium circulation
control, the hot heat medium continues to be fed to the
vehicle-mounted heat demand source from the heat accumulator S
utilizing "sensible heat" and "latent heat" at the start of the
power unit. It is therefore possible to achieve expected engine
warm-up promotion and an expected increase in passenger compartment
heating performance. (2) The vehicle-mounted heat source includes
the engine 21 heating the coolant while being driven, and the
vehicle-mounted heat demand source includes the engine 21 which
decreases the temperature of the coolant while being stopped and
the heater core 22 of the air conditioner using the engine coolant
as the heating medium. The controller 28 opens the second valve 24
to the engine 21 at the start of the engine when the engine warm-up
has priority and opens the second valve 24 to the heater core 22 at
the start of the engine when the passenger compartment heating has
priority. Accordingly, with such a simple heat medium circulation
control, it is possible to achieve expected warm-up promotion of
the engine 21 when the engine warm-up has priority and to achieve
an expected increase in passenger compartment heating performance
when the passenger compartment heating has priority.
Embodiment 5
[0304] Embodiment 5 is an example of, in the engine coolant
circulation system including the heat accumulator S of Embodiment
4, further including a pump 29 in the circuit connecting the second
valve 24 and heater core 22.
[0305] First, the constitution thereof is described.
[0306] FIG. 28 is an engine coolant circulation circuit diagram
showing an engine coolant circulation system (an example of the
vehicle-mounted thermal system) including the heat accumulator S of
Embodiment 5.
[0307] In Embodiment 5, the vehicle-mounted heat source includes
the engine 21 which heats the coolant while being driven, and the
vehicle-mounted heat demand source includes the engine 21 which
decreases the temperature of the coolant while being stopped and
the heater core 22 of an air conditioner using the engine coolant
as the heating medium.
[0308] The circuit connecting the second valve 24 and heater core
22 is provided with the pump 29. The controller 28 opens the valve
24 to the engine 21 at the start of the engine 21 when the engine
warm-up has priority. When the passenger compartment heating has
priority, at the start of the engine 21, the controller 28 opens
the second valve 24 to the heater core 22 and activates the pump 29
to regulate the rate of flow from the heat accumulator S to the
heater core 22. For the other constitution is the same as that of
Embodiment 4, corresponding components are given the same reference
numerals and symbols, and the description thereof is omitted.
[0309] Next, the operations thereof are described.
[Heat Storing Operation].
[0310] During normal running state by engine drive, by the
controller 28, the first valve 23 is opened, and during use of a
heater, the second valve 24 is opened to the heater core 22, and
the pump 29 and circulation pump 27 are driven.
[0311] Accordingly, as shown in FIG. 29(a), hot engine coolant from
the engine 21 passes the heat accumulator S from the inlet to the
outlet and, during use of the heater, is further fed to the engine
21 through the heater core 22. When the temperature of the engine
coolant increases and reaches the melting point of the heat storage
material, the heat storage material changes the phase thereof from
the solid to the liquid phase and absorbs heat energy during this
phase transition.
[0312] When the engine 21 then stops, by the controller 28, the
first and second valves 23 and 24 are closed, and the pump 29 and
circulation pump 27 are stopped.
[0313] Accordingly, as shown in FIG. 29(b), the engine coolant is
enclosed in the liquid reserving portion 1 surrounded by the two
layers of each of the heat-insulating layers 2, 3, and 4 and the
heat storage layer 5. The decrease in temperature of the engine
coolant stored in the heat accumulator S is therefore prevented,
and the engine coolant is kept hot.
[Engine Warm-up Priority]
[0314] Thereafter, when the engine warm-up has priority, at the
start of the engine 21, by the controller 28, the first valve 23 is
opened; the second valve 24 is opened to the engine 21; and the
circulation pump 27 is driven.
[0315] Accordingly, as shown in FIG. 29(c), the hot engine coolant
stored in the heat accumulator S is fed to the engine 21 during the
first cycle of the circulation cycles of the engine coolant. The
hot engine coolant is affected by the temperature of the system
environment and is mixed with cold engine coolant. The temperature
of the engine coolant within the heat accumulator S therefore
decreases.
[0316] However, during and after the second cycle where the
temperature of the heat storage material decreases to the freezing
point because of the decrease in temperature of the engine coolant
within the heat accumulator S, the heat storage material changes
the phase thereof from the liquid to the solid phase. The heat
stored in the heat storage material is released during this phase
transition, and the heat energy due to the latent heat continues to
be supplied to the engine coolant. During and after the second
cycle, the decrease in temperature of the engine coolant is
prevented by the heat released from the heat storage material, and
the engine coolant kept hot is fed to the engine 21.
[Passenger Compartment Heating Priority]
[0317] On the other hand, when the passenger compartment heating
has priority, at the start of the engine 21, by the controller 28,
the first valve 23 is opened; the second valve 24 is opened to the
heater core 22 while the pump 29 is driven and controlled; and the
circulation pump 27 is driven.
[0318] Accordingly, as shown in FIG. 29(d), the hot engine coolant
stored in the heat accumulator S is fed to the heater core 22
during the first cycle of the circulation cycles of the engine
coolant. The hot engine coolant is affected by the temperature of
the system environment and is mixed with cold engine coolant. The
temperature of the engine coolant within the heat accumulator S
therefore decreases.
[0319] However, during and after the second cycle where the
temperature of the heat storage material decreases to the freezing
point because of the decrease in temperature of the engine coolant
within the heat accumulator S, the heat storage material changes
the phase thereof from the liquid to the solid phase. The heat
stored in the heat storage material is released during this phase
transition, and the heat energy due to the latent heat continues to
be supplied to the engine coolant. During and after the second
cycle, the decrease in temperature of the engine coolant is
prevented by the heat released from the heat storage material, and
the engine coolant kept hot is fed to the heater core 22 through
the pump 29 regulating the flow rate.
[0320] Next, the effects thereof are described.
[0321] The engine coolant circulation system including the heat
accumulator S of Embodiment 5 can provide the effects enumerated
below in addition to the effect (1) of Embodiment 4:
(3) The vehicle-mounted heat source includes the engine 21 which
heats the coolant while being driven, and the vehicle-mounted heat
demand source includes the engine 21 which decreases the
temperature of the coolant while being stopped and the heater core
22 of an air conditioner using the engine coolant as the heating
medium. The circuit connecting the second valve 24 and the heater
core 22 is provided with the pump 29. Furthermore, the controller
28 opens the second valve 24 to the engine 21 at the start of the
engine 21 when the engine warm-up has priority and opens the second
valve 24 to the heater core 22 and activates the pump 29 to
regulate the rate of flow from the heat accumulate S to the heater
core 22 at the start of the engine 21 when the passenger
compartment heating has priority. Accordingly, with such a simple
heat medium circulation control, when the engine warm-up has
priority, it is possible to achieve expected engine warm-up
promotion. Furthermore, when the passenger compartment heating has
priority, it is possible to achieve an expected increase in
passenger compartment heating performance and control the heating
performance by regulating the flow rate.
Embodiment 6
[0322] Embodiment 6 is an example of an application of an
electrical equipment coolant circulation system for a drive motor
of a hybrid vehicle while Embodiments 4 and 5 are application
examples of the engine coolant circulation system of an engine
vehicle.
[0323] First, the constitution thereof is described.
[0324] FIG. 30 is a coolant circulation circuit diagram showing an
electrical equipment coolant circulation system for a drive motor
(an example of the vehicle-mounted thermal system) including the
heat accumulator S of Embodiment 6.
[0325] In Embodiment 6, the vehicle-mounted source includes an
inverter cooler 30 which heats inverter coolant while being driven
and a battery cooler 31 which heats battery coolant while being
driven. The vehicle-mounted heat demand source includes the heater
core 22 of an air conditioner using the inverter and battery
coolant as the heating medium.
[0326] Herein, the drive motor of the hybrid vehicle is a high
output three-phase AC motor or the like. Accordingly, the inverter
which converts alternating current (motor side) to direct current
(battery side) and vice versa is large-size and requires water
cooling because the switching circuit, capacitors, and the like
generate heat. As for the driving battery, a large-size battery for
a driving motor is mounted separately from the battery for
vehicle-mounted electrical equipment and requires water
cooling.
[0327] The controller 28 makes control to open the first and second
valves 23 and 24 at the start of the engine. For the other
constitution is the same as that of Embodiments 4 and 5, the
corresponding components are given the same reference numerals and
symbols, and the description thereof is omitted.
[0328] Next, the operations thereof are described.
[Heat Storing Operation]
[0329] During normal running state by engine drive, by the
controller 28, the first and second valves 23 and 24 are opened,
and the circulation pump 27 is driven.
[0330] Accordingly, as shown in FIG. 31(a), hot coolant from the
inverter cooler 30 and battery cooler 31 passes the heat
accumulator S from the inlet to the outlet and is further fed to
the radiator 25 and heater core 22. When the temperature of the
coolant increases and reaches the melting point of the heat storage
material, the heat storage material changes the phase thereof from
the solid to the liquid phase and absorbs heat energy during this
phase transition.
[0331] When the engine is stopped, by the controller 28, the first
and second valves 23 and 24 are closed, and the circulation pump 27
is stopped.
[0332] Accordingly, as shown in FIG. 31(b), the coolant is enclosed
in the liquid reserving portion 1 surrounded by the two layers of
each of the heat-insulating layers 2, 3, and 4 and the heat storage
layer 5, so that the temperature of the coolant stored in the heat
accumulator S2 is prevented from decreasing. The coolant is
therefore kept hot.
[Engine Start]
[0333] At the start of the engine (at the start of passenger
compartment heating), by the controller 28, the first and second
valves 23 and 24 are opened, and the circulation pump 27 is
driven.
[0334] Accordingly, as shown in FIG. 31 (c), the hot engine coolant
stored in the heat accumulator S is fed to the heater core 22
during the first cycle of the circulation cycles of the coolant.
The hot coolant is affected by the temperature of the system
environment and is mixed with cold coolant. The temperature of the
coolant within the heat accumulator S therefore decreases.
[0335] However, during and after the second cycle where the
temperature of the heat storage material decreases to the freezing
point because of the decrease in temperature of the coolant within
the heat accumulator S, the heat storage material changes the phase
thereof from the liquid to the solid phase. The heat stored in the
heat storage material is released during this phase transition, and
the heat energy due to the latent heat continues to be supplied to
the coolant. During and after the second cycle, the decrease in
temperature of the engine coolant is prevented by the heat released
from the heat storage material, and the coolant kept hot is fed to
the heater core 22.
[0336] Next, the effects thereof are described.
[0337] The electrical equipment coolant circulation system for a
drive motor including the heat accumulator S of Embodiment 6 can
provide the effect below in addition to the effect (1) of
Embodiment 4:
(4) The vehicle-mounted heat source includes the inverter cooler 30
which heats the inverter coolant while being driven and the battery
cooler 31 which heats the battery coolant while being driven. The
vehicle-mounted heat demand source includes the heater core 22 of
an air conditioner using the inverter and battery coolant as the
heating medium. The controller 28 makes control to open the first
and second valves 23 and 24 at the start of the engine.
Accordingly, it is possible to achieve an expected increase in
passenger compartment heating performance at the start of the
engine.
Embodiment 7
[0338] Embodiment 7 is an example of, in the electrical equipment
coolant circulation system for a drive motor including the heat
accumulator S of Embodiment 6, further including a pump 29 for the
circuit connecting the second valve 24 and heater core 22.
[0339] First, the constitution thereof is described.
[0340] FIG. 32 is a coolant circulation circuit diagram showing an
electrical equipment coolant circulation system for a drive motor
(an example of the vehicle-mounted thermal system) including the
heat accumulator S of Embodiment 7.
[0341] In Embodiment 7, the vehicle-mounted heat source includes
the inverter cooler 30 which heats the inverter coolant while being
driven and the battery cooler 31 which heats the battery coolant
while being driven. The vehicle-mounted heat demand source includes
the heater core 22 of an air conditioner using the inverter and
battery coolant as the heating medium.
[0342] The circuit connecting the second valve 24 and heater core
22 is provided with the pump 29. The controller 28 makes control at
the start of the engine 21 to open the first and second valves 23
and 24 at the start of the engine and activate the pump 29 to
regulate the rate of flow from the heat accumulator S to the heater
core 22. Since the other constitution is the same as that of
Embodiment 4, corresponding components are given the same reference
numerals and symbols, and the description thereof is omitted.
[0343] Next, the operations thereof are described.
[Heat Storing Operation]
[0344] During normal running state where one of the engine and
motor is being driven, by the controller 28, the first and second
valves 23 and 24 are opened; and circulation pump 27 are driven.
Moreover, during use of the heater, the pump is driven.
[0345] Accordingly, as shown in FIG. 33(a), hot coolant from the
inverter and battery coolers 30 and 31 passes the heat accumulator
S from the inlet to the outlet and is further fed to the radiator
25 and to the heater core 22 during use of the heater. When the
temperature of the engine coolant increases and reaches the melting
point of the heat storage material, the heat storage material
changes the phase thereof from the solid to the liquid phase and
absorbs heat energy during this phase transition.
[0346] When the engine then stops, by the controller 28, the first
and second valves 23 and 24 are closed, and the pump 29 and
circulation pump 27 are stopped.
[0347] Accordingly, as shown in FIG. 33 (b), the coolant is
enclosed in the liquid reserving portion 1 surrounded by the two
layers of each of the heat-insulating layers 2, 3, and 4 and the
heat storage layer 5. The temperature of the engine coolant stored
in the heat accumulator S is therefore prevented from decreasing,
and the engine coolant is kept hot.
[Engine Start]
[0348] At the start of the engine (at the start of passenger
compartment heating), by the controller 28, the first and second
valves 23 and 24 are opened; the circulation pump 27 is driven; and
the pump 29 is driven for regulating the flow rate.
[0349] Accordingly, as shown in FIG. 33 (c), the hot coolant stored
in the heat accumulator S is fed to the heater core 22 through the
pump 29 during the first cycle of the circulation cycles of the
coolant. The hot coolant is affected by the temperature of the
system environment and is mixed with cold coolant. The temperature
of the coolant within the heat accumulator S therefore
decreases.
[0350] However, during and after the second cycle where the
temperature of the heat storage material decreases to the freezing
point because of the decrease in temperature of the coolant within
the heat accumulator S, the heat storage material changes the phase
thereof from the liquid to the solid phase. The heat stored in the
heat storage material is released during this phase transition, and
the heat energy due to the latent heat continues to be supplied to
the coolant. During and after the second cycle, the decrease in
temperature of the engine coolant is prevented by the heat released
from the heat storage material, and the coolant kept hot is fed to
the heater core 22 through the pump 29 regulating the flow
rate.
[0351] Next, the effects thereof are described.
[0352] The electrical equipment coolant circulation system for a
drive motor including the heat accumulator S of Embodiment 7 can
provide the effect below in addition to the effect (1) of
Embodiment 4:
(5) The vehicle-mounted heat source includes the inverter cooler 30
which heats the inverter coolant while being driven and the battery
cooler 31 which heats the battery coolant while being driven. The
vehicle-mounted heat demand source includes the heater core 22 of
an air conditioner using the inverter and battery coolant as the
heating medium. The circuit connecting the second valve 24 and the
heater core 22 is provided with the pump 29. Furthermore, at the
start of the engine, the controller 28 opens the first and second
valves 23 and 24 and activates the pump 29 to regulate the rate of
flow from the heat accumulate S to the heater core 22. Accordingly,
it is possible to achieve an expected increase in passenger
compartment heating performance at the start of the engine of the
hybrid vehicle and control the heating performance by regulating
the flow rate.
[0353] Hereinabove, the heat accumulator of the present invention,
the method of manufacturing the heat accumulator, and the
vehicle-mounted thermal system including the same are described
based on Embodiments 1 to 7. However, the specific constitution is
not limited to these embodiments, and various changes, additions,
and the like can be made for the design without departing from the
scope of the present invention according to claims.
[0354] Embodiments 1 and 2 show the examples where the plurality of
tank constituting elements are stacked facing alternate directions,
but the plurality of tank constituting elements are stacked facing
a same direction. Moreover, in Embodiments 1 and 2, the inlet and
outlet cover members and tank constituting elements are the
constituent parts. However, the cover members may be omitted if the
tank constituting elements are configured to have such a
cross-sectional shape that allows the tank constituting elements to
serve as the cover members. In other words, such a heat accumulator
that includes the liquid reserving portion and heat-insulating
layer formed by stacking the plurality of tank constituting
elements composed of plate members of an identical cross-sectional
shape is included in the present invention.
[0355] In Embodiment 2, the heat storage material is the paraffin
material but may be another heat storage material such as
polyethylene glycol whose phase transition temperature can be set
according to the degree of polymerization or inorganic salt
hydrate/aqueous solution with a wide range of phase transition
temperature (for example, sodium acetate, sodium acetate mixture,
calcium chloride hexahydrate, or the like).
[0356] In Embodiment 2, the heat storage material includes the
paraffin capsules including the paraffin material encapsulated in
spherical coatings as microcapsules. However, the heat storage
material may be one subjected to another treatment/processing as
follows: the heat storage material may be encapsulated in a resin
container to be packaged or the heat storage material may be
kneaded with resin to be shaped and laminate coated.
[0357] In the method of manufacturing the heat accumulator, the
shapes of the constituent parts constituting the heat accumulator
are not limited to the shapes shown in Embodiments 1 to 3 and may
be varied according to the structure type of the heat accumulator.
Moreover, in the temporary assembly process, the processed
constituent parts may be assembled one after another into a
container form without the sub-assembly process. In other words,
the manufacturing method including at least: the part processing
process to process the constituent parts constituting the heat
accumulator; the temporary assembly process to assemble the
processed constituent parts into a container; and the brazing
process to evacuate the temporarily assembled container in a
furnace and increase the temperature thereof to braze the
constituent parts into a unit in the vacuum atmosphere is included
in the present invention.
INDUSTRIAL AVAILABILITY
[0358] Embodiments 1 and 2 show the examples of the application of
the heat accumulator using water as the heat medium, but the heat
medium may be liquid other than water. Moreover, the above
embodiments show the examples of the application of the engine
coolant circulation system of an engine vehicle and the electrical
equipment coolant circulation system for a drive motor of a hybrid
vehicle. The present invention can be also applied to heat
accumulators for various purposes other than vehicles.
[0359] Embodiment 1 shows the example of the method of
manufacturing the stacking-type heat accumulator including the
liquid reserving portion and vacuum heat-insulating layer, and
Embodiment 2 shows the example of the method of manufacturing the
stacking-type heat accumulator including the liquid reserving
portion, heat storage layer, and vacuum heat-insulating layer.
Embodiment 3 shows the example of the method of manufacturing the
multi-container heat accumulator including the liquid reserving
portion, heat storage layer, and vacuum heat-insulating layer.
However, the present invention can be applied to a method of
manufacturing a multi-container heat accumulator including a liquid
reserving portion and a vacuum heat-insulating layer. In other
words, the present invention can be applied to a method of
manufacturing a heat accumulator including at least a liquid
reserving portion and a vacuum heat-insulating layer.
[0360] Embodiments 4 and 5 show the examples of the engine coolant
circulation system of an engine vehicle as the vehicle-mounted heat
system; and Embodiments 6 and 7 show the examples of the electrical
equipment coolant circulation system for a drive motor of a hybrid
vehicle as the vehicle-mounted heat system. The present invention
can be also applied to an electrical equipment coolant circulation
system for a drive motor of an electrical vehicle and the like. In
other words, the present invention can be applied to a
vehicle-mounted thermal system in which the vehicle-mounted heat
source which heats the heat medium while a power unit is being
driven and the vehicle-mounted demand source which requires hot
heat medium when the power unit starts from the power unit stopped
state where the temperature of the heat medium decreases are
connected through the heat medium circuit.
* * * * *