U.S. patent application number 13/498974 was filed with the patent office on 2012-10-11 for heat exchanger and air conditioner incorporating same.
This patent application is currently assigned to SHARP KABUSHIKI KAISHA. Invention is credited to Kazuhisa Mishiro, Masakazu Suzuki.
Application Number | 20120255703 13/498974 |
Document ID | / |
Family ID | 43900131 |
Filed Date | 2012-10-11 |
United States Patent
Application |
20120255703 |
Kind Code |
A1 |
Mishiro; Kazuhisa ; et
al. |
October 11, 2012 |
HEAT EXCHANGER AND AIR CONDITIONER INCORPORATING SAME
Abstract
A heat exchanger (1) includes: two vertical header pipes (2, 3)
which are arranged apart in parallel; a plurality of flat tubes (4)
which are arranged between the header pipes and in which
refrigerant passages (5) provided therewithin communicate with an
interior of the header pipes; and corrugated fins (6) which are
arranged between the flat tubes. The flat tubes are configured to
form one or more turns. In the header pipe on the refrigerant
piping connection side, a temperature sensor (11) for sensing the
temperature of a refrigerant is arranged at a location through
which the refrigerant in a gas-liquid two-phase state flows. The
temperature sensor is attached to the header pipe with a metal
fitting (12).
Inventors: |
Mishiro; Kazuhisa;
(Osaka-shi, JP) ; Suzuki; Masakazu; (Osaka-shi,
JP) |
Assignee: |
SHARP KABUSHIKI KAISHA
Osaka-Shi
JP
|
Family ID: |
43900131 |
Appl. No.: |
13/498974 |
Filed: |
September 15, 2010 |
PCT Filed: |
September 15, 2010 |
PCT NO: |
PCT/JP2010/065922 |
371 Date: |
June 13, 2012 |
Current U.S.
Class: |
165/11.1 |
Current CPC
Class: |
F25B 39/00 20130101;
F28F 27/00 20130101; F28D 1/05375 20130101; F25B 2700/2117
20130101; F28F 9/007 20130101; F28F 2275/08 20130101 |
Class at
Publication: |
165/11.1 |
International
Class: |
F28F 27/00 20060101
F28F027/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 19, 2009 |
JP |
2009-240332 |
Claims
1. A side-flow-type parallel flow heat exchanger that includes: two
header pipes which are arranged apart in parallel; and a plurality
of flat tubes which are arranged between the two header pipes and
in which refrigerant passages provided therewithin communicate with
an interior of the header pipes, wherein the flat tubes are
configured to form one or more turns, and, in one of the two header
pipes, a temperature sensor for sensing a temperature of a
refrigerant is arranged at a location through which the refrigerant
in a gas-liquid two-phase state flows.
2. The heat exchanger of claim 1, wherein the header pipe at which
the temperature sensor is arranged is the header pipe on a
refrigerant piping connection side.
3. The heat exchanger of claim 2, wherein a number of turns is set
at an odd number of three or more.
4. The heat exchanger of claim 1, wherein the temperature sensor is
attached to the header pipe with a metal fitting including a
temperature sensor insertion portion and a header pipe holding
portion.
5. An air conditioner wherein the heat exchanger of claim 1 is
incorporated in an indoor unit.
6. An air conditioner wherein the heat exchanger of claim 1 is
incorporated in an outdoor unit.
7. The heat exchanger of claim 2, wherein the temperature sensor is
attached to the header pipe with a metal fitting including a
temperature sensor insertion portion and a header pipe holding
portion.
8. The heat exchanger of claim 3, wherein the temperature sensor is
attached to the header pipe with a metal fitting including a
temperature sensor insertion portion and a header pipe holding
portion.
Description
TECHNICAL FIELD
[0001] The present invention relates to a side-flow-type parallel
flow heat exchanger and an air conditioner incorporating such a
side-flow-type parallel flow heat exchanger.
BACKGROUND ART
[0002] A parallel flow heat exchanger in which a plurality of flat
tubes are arranged between two header pipes, a plurality of
refrigerant passages within the flat tube communicate with the
interior of the header pipes and a fin such as a corrugated fin is
arranged between the flat tubes is widely used in automobile air
conditioners and building air conditioners. Examples of this type
of heat exchanger are disclosed in patent documents 1 and 2.
[0003] In an air conditioner, an operation is controlled based on
the temperature of a heat exchanger where a refrigerant flows, and
this technical means is commonly used. An example of such an air
conditioner is disclosed in patent document 3.
[0004] In general, in the heat exchanger of an indoor unit in an
air conditioner, as disclosed in patent document 4, auxiliary
piping connected to an outdoor unit is provided. It is necessary to
connect not only refrigerant piping but also a power supply line
and a signal line to the outdoor unit. In general, an electrical
component box holding a control board to which the power supply
line and the signal line are connected and the like is arranged
next to the auxiliary piping so that the power supply line and the
signal line are easily put together with the refrigerant
piping.
[0005] In a parallel flow heat exchanger, a plurality of flat tubes
are divided into a few groups, a refrigerant is passed through a
first group of flat tubes from a first header pipe to a second
header pipe, then the refrigerant is returned through a second
group of flat tubes from the second header pipe to the first header
pipe and the refrigerant is passed again through a third group of
flat tubes from the first header pipe to the second header pipe. As
described above, the refrigerant is often passed along a zigzag
route. As disclosed in patent document 2, the number of times the
direction of flow of the refrigerant is changed between the first
header pipe and the second header pipe is referred to as the
"number of turns."
RELATED ART DOCUMENT
Patent Document
[0006] Patent document 1: JP-A-S63-34466
[0007] Patent document 2: JP-A-H6-213534
[0008] Patent document 3: JP-A-2009-41829
[0009] Patent document 4: JP-A-2000-297948
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
[0010] In an air conditioner, in order to ensure safety at the time
of operation, it is necessary to find the pressure within a heat
exchanger and perform control based on the resulting information.
Practically, instead of directly measuring the pressure, the
pressure is estimated by measuring the temperature of a
refrigerant.
[0011] When a heat exchanger is used as a condenser, a refrigerant
in an overheated gaseous state flows in, is then changed into a
gas-liquid two-phase state as heat exchange proceeds and is changed
into a supercooled state and then a liquid state as condensation
further proceeds. The temperature of the refrigerant differs
depending on its state, that is, the gaseous sate, the gas-liquid
two-phase state and the liquid state. In order to estimate the
pressure, it is necessary to measure the temperature of the
refrigerant in the gas-liquid two-phase state in which the
temperature is stable.
[0012] An object of the present invention into make the temperature
of a refrigerant to measured useful for control in a so-called
side-flow-type parallel flow heat exchanger where the refrigerant
flows through horizontal flat tubes.
Means for Solving the Problem
[0013] To achieve the above object, according to the present
invention, there is provided a side-flow-type parallel flow heat
exchanger that includes: two header pipes which are arranged apart
in parallel; and a plurality of flat tubes which are arranged
between the two header pipes and in which refrigerant passages
provided therewithin communicate with an interior of the header
pipes, in which the flat tubes are configured to form one or more
turns, and, in one of the two header pipes, a temperature sensor
for sensing the temperature of a refrigerant is arranged at a
location through which the refrigerant in a gas-liquid two-phase
state flows.
[0014] In this configuration, the temperature of the refrigerant in
the gas-liquid two-phase state which can be regarded as a
refrigerant condensation temperature or a refrigerant vaporization
temperature is measured, and thus it is possible to accurately
estimate the pressure of the refrigerant.
[0015] In the heat exchanger configured as described above, the
header pipe at which the temperature sensor is arranged is
preferably the header pipe on the refrigerant piping connection
side.
[0016] When an air conditioner is composed of an outdoor unit and
an indoor unit, in general, refrigerant piping and power supply
wiring or signal wires are put together and piping and wiring are
performed thereon. When the temperature sensor is arranged at the
header pipe on the side of the refrigerant wiring, it is possible
to easily wire the temperature sensor and reduce the length of the
wiring and the cost of materials.
[0017] In the heat exchanger configured as described above, the
number of turns is preferably set at an odd number of three or
more.
[0018] When the number of turns is set as described above, the
entrance and the exit of the refrigerant are arranged in the same
header pipe, and thus it is possible to acquire a portion of the
header pipe through which the refrigerant in the gas-liquid
two-phase state flows.
[0019] In the heat exchanger configured as described above, the
temperature sensor is preferably attached to the header pipe with a
metal fitting including a temperature sensor insertion portion and
a header pipe holding portion.
[0020] With this configuration, it is possible to easily attach the
temperature sensor without the need to process the header pipe.
[0021] According to the present invention, there is provided an air
conditioner in which the heat exchanger configured as described
above is incorporated in an indoor unit.
[0022] With this configuration, it is possible to provide an air
conditioner that can appropriately perform control to accurately
estimate the pressure of the refrigerant in the heat exchanger of
the indoor unit.
[0023] According to the present invention, there is provided an air
conditioner in which the heat exchanger configured as described
above is incorporated in an outdoor unit.
[0024] With this configuration, it is possible to provide an air
conditioner that can appropriately perform control to accurately
estimate the pressure of the refrigerant in the heat exchanger of
the outdoor unit.
Advantages of the Invention
[0025] According to the present invention, it is possible to
accurately estimate the pressure of a refrigerant flowing through a
heat exchanger, with the result that various types of control can
be reliably performed. The detection of abnormality when the air
conditioner is operated is easily performed.
BRIEF DESCRIPTION OF DRAWINGS
[0026] [FIG. 1] A schematic vertical cross-sectional view of a heat
exchanger illustrating an embodiment of the present invention;
[0027] [FIG. 2] A vertical cross-sectional view of the heat
exchanger taken along line A-A of FIG. 1;
[0028] [FIG. 3] A partial front view of the heat exchange
illustrating a method of attaching a temperature sensor;
[0029] [FIG. 4] A front view of a metal fitting for attaching the
temperature sensor;
[0030] [FIG. 5] A top view of the metal fitting for attaching the
temperature sensor;
[0031] [FIG. 6] A schematic diagram showing the configuration of an
air conditioner incorporating the heat exchanger according to the
present invention, and showing a state where a heating operation is
performed; and
[0032] [FIG. 7] A schematic diagram showing the configuration of
the air conditioner incorporating the heat exchanger according to
the present invention, and showing a state where a cooling
operation is performed.
MODE FOR CARRYING OUT THE INVENTION
[0033] The structure of a side-flow-type parallel flow heat
exchanger according to an embodiment of the present invention will
be described with reference to FIG. 1. In FIG. 1, the upper side of
the plane of the figure is the upper side of the actual heat
exchanger, and the lower side of the plane of the figure is the
lower side of the actual heat exchanger. In the heat exchanger 1,
two vertical header pipes 2 and 3 are arranged apart in a
horizontal direction in parallel, and a plurality of horizontal
flat tubes 4 are arranged between the header pipes 2 and 3 in a
vertical direction with a predetermined pitch. The flat tube 4 is a
long slender component that is formed by extruding metal, and
refrigerant passages 5 for circulating a refrigerant are formed
within the flat tube 4. Since the flat tubes 4 are arranged such
that the direction of extrusion, which is the longitudinal
direction of the flat tubes 4, is horizontal, the direction of
circulation of the refrigerant in the refrigerant passage 5 is also
horizontal. A plurality of refrigerant passages 5 that have the
same cross-sectional shape and the same cross-sectional area are
arranged in the depth direction of FIG. 1, and thus the cross
section of the flat tube 4 is in the shape of a harmonica, as shown
in FIG. 2. Each of the refrigerant passages 5 communicates with the
interior of the header pipes 2 and 3. A corrugated fin 6 is
arranged between the adjacent flat tubes 4. Among the vertically
arranged corrugated fins 6, a side plate 10 is arranged on the
outside of each of the uppermost corrugated fin 6 and the lowermost
corrugated fin 6.
[0034] Each of the header pipes 2 and 3, the flat tube 4, the
corrugated fin 6 and the side plate 10 is formed of a meal, such as
aluminum, having a good thermal conductivity. The flat tubes 4, the
corrugated fins 6 and the side plates 10 are fixed, by brazing or
welding, to the header pipes 2 and 3, the flat tubes 4 and the
corrugated fins 6, respectively.
[0035] The heat exchanger 1 is a side flow type, and refrigerant
ports 7 and 8 are provided only on the side of the header pipe 3.
In other words, the header pipe 3 is a header pipe on the
refrigerant piping connection side. Within the header pipe 3, two
partitions 9a and 9c are arranged apart in the vertical direction;
within the header pipe 2, a partition 9b is provided at the
midpoint between the partitions 9a and 9c in height.
[0036] When the heat exchanger 1 is used as a condenser, as
indicated by a solid arrow line, the refrigerant flows in through
the refrigerant port 7 on the upper side. The refrigerant that has
flowed in through the refrigerant port 7 is blocked by the
partition 9a, and flows toward the header pipe 2 through the flat
tubes 4. The flow of the refrigerant is represented by a leftward
pointing block arrow. The refrigerant that has flowed into the
header pipe 2 is blocked by the partition 9b, and flows toward the
header pipe 3 through other flat tubes 4. This is the first turn,
and the flow of the refrigerant after the turn is represented by a
rightward pointing block arrow. The refrigerant that has flowed
into the header pipe 3 is blocked by the partition 9c, and flows
again toward the header pipe 2 through yet other flat tubes 4. This
is the second turn, and the flow of the refrigerant after the turn
is represented by a leftward pointing block arrow. The refrigerant
that has flowed into the header pipe 2 is returned, and flows again
toward the header pipe 3 through yet another flat tube 4. This is
the third turn, and the flow of the refrigerant after the turn is
represented by a rightward pointing block arrow. The refrigerant
finally flows out through the refrigerant port 8.
[0037] As described above, the refrigerant flows from top to bottom
along a zigzag route while making turns repeatedly. The case where
the number of partitions is three has been described above; this is
an example. The number of partitions and the resulting number of
turns can be set at arbitrary numbers as necessary.
[0038] In the configuration of FIG. 1, a plurality of flat tubes 4
arranged in a region of height between the refrigerant port 7 and
the partition 9a constitute a flow passage, a plurality of flat
tubes 4 arranged in a region of height between the partition 9a and
the partition 9b constitute another flow passage, a plurality of
flat tubes 4 arranged in a region of height between the partition
9b and the partition 9c constitute yet another flow passage and a
plurality of flat tubes 4 arranged in a region of height between
the partition 9c and the refrigerant port 8 constitute yet another
flow passage. These flow passages are referred, in the order in
which they have been described, to as a "first flow passage," a
"second flow passage," a "third flow passage" and a "fourth flow
passage."
[0039] When the heat exchanger 1 is used as an evaporator, the flow
of the refrigerant is reversed. Specifically, the refrigerant flows
into the header pipe 3 through the refrigerant port 8 as indicated
by a dotted arrow of FIG. 1, is blocked by the partition 9c and
flows toward the header pipe 2 through the fourth flow passage, is
blocked by the partition 9b in the header pipe 2 and flows toward
the header pipe 3 through the third flow passage, is blocked by the
partition 9a in the header pipe 3 and flows again toward the header
pipe 2 through the second flow passage, is returned in the header
pipe 2 and flows again toward the header pipe 3 through the first
flow passage and flows out through the refrigerant port 7.
[0040] A temperature sensor 11 obtained by sealing a thermistor in
a metallic case is attached so as to measure the temperature of the
refrigerant flowing within the heat exchanger 1. The temperature
sensor 11 is arranged at a location corresponding to the second
flow passage and the third flow passage within the header pipe 3.
This location is selected for the following reason.
[0041] When the heat exchanger 1 is used as a condenser, the
refrigerant in an overheated state flows in through the refrigerant
port 7 on the upper side, and the refrigerant here is in a gaseous
state. Thereafter, as thermal exchange proceeds through the first
flow passage, the refrigerant is changed into a gas-liquid
two-phase state, and gradually condenses. In the vicinity of the
exit of the fourth flow passage through which the refrigerant flows
out, the refrigerant is in a supercooled state, and is liquid.
Since the temperature (two-phase temperature) of the refrigerant in
the gas-liquid two-phase state can be regarded as a refrigerant
condensation temperature or a refrigerant vaporization temperature,
and is suitable as a reference temperature for control, the
temperature sensor 11 is arranged at a location where the two-phase
temperature can be measured.
[0042] When the heat exchanger 1 is used as an evaporator, the
refrigerant in the gas-liquid two-phase state flows in through the
refrigerant port 8 on the lower side. Thereafter, thermal exchange
proceeds with the refrigerant in the gas-liquid two-phase state,
and the refrigerant gradually vaporizes. In the vicinity of the
exit of the first flow passage through which the refrigerant flows
out, the refrigerant is either in the gas-liquid two-phase state or
in the gaseous state. Since the temperature (the two-phase
temperature) of the refrigerant in the gas-liquid two-phase state
can be regarded as the refrigerant vaporization temperature, and is
suitable as the reference temperature for control, the temperature
sensor 11 is arranged at a location where the two-phase temperature
can be measured.
[0043] As described previously, in the heat exchanger of an indoor
unit in an air conditioner, auxiliary piping connected to an
outdoor unit is provided. It is necessary to connect not only
refrigerant piping but also a power supply line and a signal line
to the outdoor unit. In general, an electrical component box
holding a control board to which the power supply line and the
signal line are connected and the like is arranged next to the
auxiliary piping so that the power supply line and the signal line
are easily put together with the refrigerant piping. Since the
temperature sensor 11 is wired from the electrical component box
described above, with consideration given to the length of the
wiring, it is preferable to attach the temperature sensor 11 to the
side of the auxiliary piping of the heat exchanger 1.
[0044] In the heat exchanger 1 that is the side-flow-type parallel
flow heat exchanger, the header pipe 3 is a header pipe on the
refrigerant piping connection side, and not only the refrigerant
piping but also the power supply wiring and the signal line are
nearby. Hence, the temperature sensor 11 is attached to the header
pipe 3, and the temperature sensor 11 is arranged at the location
(preferably the midpoint between the partition 9a and the partition
9c) corresponding to the second turn.
[0045] Consider now the number of turns. If there is only one turn,
when the heat exchanger 1 is used as a condenser, refrigerant
entrance piping and refrigerant exit piping are connected to one of
the header pipes, and, on the refrigerant entrance side, the header
pipe is filled with the refrigerant in the overheated state, and,
on the refrigerant exit side, the header pipe is filled with the
refrigerant in the supercooled state, with the result that the
refrigerant in the gas-liquid two-phase state cannot be present in
the header pipe. When the heat exchanger 1 is used as a condenser,
the number of turns is preferably an odd number of three or more
such that conditions under which the refrigerant in the gas-liquid
two-phase state can be present and the refrigerant flowing from the
header pipe on the refrigerant piping connection side is finally
returned to the header pipe on the refrigerant piping connection
side are satisfied. In the embodiment, three, that is the number of
turns, is a number that satisfies the minimum requirement.
[0046] The temperature sensor 11 is attached to the header pipe 3
with a metal fitting 12 shown in FIGS. 3 to 5. The metal fitting 12
is formed of a steel plate having a good spring characteristic, and
includes: a temperature sensor insertion portion 13 to which the
temperature sensor 11 is press-fitted; and a header pipe holding
portion 14 which holds the header pipe 3. In the entrance portion
of the header pipe holding portion 14, a pair of guide parts 15 is
formed that extends and tapers to guide the header pipe 3.
[0047] In a portion of the temperature sensor insertion portion 13
that is farthest from the header pipe holding portion 14, a bending
portion 16 having a small radius is formed. The bending portion 16
helps to maintain the holding force of the metal fitting 12.
[0048] In the boundary between the temperature sensor insertion
portion 13 and the header pipe holding portion 14, a holding part
17 is formed that is curved along the outer surface of the
temperature sensor 11. The holding part 17 functions to hold the
temperature sensor 11, and also functions to prevent the
temperature sensor 11 from making contact with the header pipe 3.
As the material of the metallic case of the temperature sensor 11,
copper is often used because copper has excellent thermal
conductivity and is easily processed; when copper makes contact
with the header pipe 3 made of aluminum, there is a danger that the
aluminum corrodes by electrical corrosion and thus a hole is formed
in the header pipe 3. When the holding part 17 is present, it
intervenes between the header pipe 3 and the temperature sensor 11,
and thus it is possible to prevent the aluminum from making contact
with the copper, with the result that the electrical corrosion can
be avoided.
[0049] The heat exchanger 1 can be incorporated in a separate-type
air conditioner. The separate-type air conditioner is composed of
an outdoor unit and an indoor unit; the outdoor unit includes a
compressor, a four-way valve, an expansion valve, an outdoor heat
exchanger and an outdoor blower; the indoor unit includes an indoor
heat exchanger and an indoor blower. The outdoor heat exchanger
functions as an evaporator when a heating operation is performed,
and also functions as a condenser when a cooling operation is
performed. The indoor heat exchanger functions as a condenser when
a heating operation is performed, and also functions as an
evaporator when a cooling operation is performed.
[0050] The basic configuration of a separate-type air conditioner
using a heat pump cycle as a refrigeration cycle is shown in FIG.
6. The heat pump cycle 101 is formed by connecting, in a loop, a
compressor 102, a four-way valve 103, an outdoor heat exchanger
104, a decompression expansion device 105 and an indoor heat
exchanger 106. The compressor 102, the four-way valve 103, the heat
exchanger 104 and the decompression expansion device 105 are housed
in the enclosure of an outdoor unit; the heat exchanger 106 is
housed in the enclosure of an indoor unit. The heat exchanger 104
is combined with an outdoor blower 107; the heat exchanger 106 is
combined with an indoor blower 108. The blower 107 includes a
propeller fan; the blower 108 includes a cross-flow fan.
[0051] The side-flow-type parallel flow heat exchanger of the
present invention can be used as the indoor heat exchanger 106. In
the heat exchanger 106, the two heat exchangers 1 are combined so
as to be dogleg-shaped.
[0052] FIG. 6 shows a state when a heating operation is performed.
Here, the refrigerant of high temperature and high pressure
discharged from the compressor 102 enters the heat exchanger 106,
where the refrigerant emits heat and condenses. The refrigerant
that has flowed out of the heat exchanger 106 enters, through the
decompression expansion device 105, the outdoor heat exchanger 104,
where the refrigerant expands. Then, the refrigerant takes in heat
from outdoor air, and thereafter returns to the compressor 102. An
air current generated by the indoor blower 108 facilitates the
discharge of the heat from the heat exchanger 106; an air current
generated by the outdoor blower 107 facilitates the absorption of
the heat by the heat exchanger 104.
[0053] FIG. 7 shows a state when a cooling operation or a
defrosting operation is performed. Here, the four-way valve 103 is
switched, and the flow of the refrigerant is reversed as compared
with the case where a heating operation is performed. Specifically,
the refrigerant of high temperature and high pressure discharged
from the compressor 102 enters the heat exchanger 104, where the
refrigerant emits heat and condenses. The refrigerant that has
flowed out of the heat exchanger 104 enters, through the
decompression expansion device 105, the indoor heat exchanger 106,
where the refrigerant expands. Then, the refrigerant takes in heat
from indoor air, and thereafter returns to the compressor 102. The
air current generated by the outdoor blower 107 facilitates the
discharge of the heat from the heat exchanger 104; the air current
generated by the indoor blower 108 facilitates the absorption of
the heat by the heat exchanger 106.
[0054] As described above, the heat exchanger 1 is used as the
indoor heat exchanger 106, and thus it is possible to accurately
estimate the pressure of the refrigerant flowing through the heat
exchanger 106, with the result that various types of control can be
reliably performed. The detection of abnormality when the air
conditioner is operated is easily performed.
[0055] The heat exchanger 1 can also be used as the outdoor heat
exchanger 104. In this way, it is also possible to accurately
estimate the pressure of the refrigerant flowing through the heat
exchanger 104, with the result that various types of control can be
reliably performed. The detection of abnormality when the air
conditioner is operated is easily performed.
[0056] Although the embodiment of the present invention has been
described above, the scope of the present invention is not limited
to the embodiment. Many modifications are possible without
departing from the spirit of the present invention.
INDUSTRIAL APPLICABILITY
[0057] The present invention is widely utilized as a side-flow-type
parallel flow heat exchanger.
LIST OF REFERENCE SYMBOLS
[0058] 1 heat exchanger
[0059] 2, 3 header pipe
[0060] 4 flat tube
[0061] 5 refrigerant passage
[0062] 6 corrugated fin
[0063] 9a, 9b, 9c partition
[0064] 11 temperature sensor
[0065] 12 metal fitting
* * * * *