U.S. patent application number 11/784442 was filed with the patent office on 2007-10-11 for exhaust heat recovery apparatus.
This patent application is currently assigned to DENSO Corporation. Invention is credited to Yukinori Hatano, Masashi Miyagawa, Fumiaki Nakamura.
Application Number | 20070235164 11/784442 |
Document ID | / |
Family ID | 38513657 |
Filed Date | 2007-10-11 |
United States Patent
Application |
20070235164 |
Kind Code |
A1 |
Miyagawa; Masashi ; et
al. |
October 11, 2007 |
Exhaust heat recovery apparatus
Abstract
An evaporator has tubes, and evaporates working fluid therein by
heat of exhaust gas. A condenser emits heat of the working fluid
toward coolant so as to condense the working fluid, and returns the
condensed working fluid to the evaporator. A fin for increasing an
area for transmitting heat is disposed between the tubes, and is
connected to the tubes. The fin has an operation force reducing
part for reducing an operation force applied to the fin in
accordance with a thermal expansion difference between the tubes.
The operation force reducing part is disposed at a midpoint of the
fin between the tubes.
Inventors: |
Miyagawa; Masashi;
(Ichinomiya-city, JP) ; Nakamura; Fumiaki;
(Kariya-city, JP) ; Hatano; Yukinori;
(Okazaki-city, JP) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O. BOX 828
BLOOMFIELD HILLS
MI
48303
US
|
Assignee: |
DENSO Corporation
Kariya-city
JP
|
Family ID: |
38513657 |
Appl. No.: |
11/784442 |
Filed: |
April 6, 2007 |
Current U.S.
Class: |
165/104.14 |
Current CPC
Class: |
F01N 5/02 20130101; F28D
15/0275 20130101; F02G 5/02 20130101; F28F 2270/00 20130101; Y02T
10/16 20130101; Y02T 10/12 20130101; F28D 15/0266 20130101; F01N
3/10 20130101; F28F 2265/26 20130101; Y02T 10/166 20130101; F28F
1/126 20130101; F28D 1/05366 20130101; F28D 21/0003 20130101 |
Class at
Publication: |
165/104.14 |
International
Class: |
F28D 15/00 20060101
F28D015/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 7, 2006 |
JP |
2006-106786 |
Claims
1. An exhaust heat recovery apparatus comprising: an evaporator
having a plurality of tubes arranged in an arrangement direction,
and a fin for increasing an area for transmitting heat, the
evaporator evaporating working fluid therein by heat of exhaust gas
discharged from an internal combustion engine; and a condenser for
emitting heat of the working fluid flowing from the evaporator
toward coolant of the internal combustion engine so as to condense
the working fluid, and returning the condensed working fluid to the
evaporator, wherein the fin is disposed between the tubes in the
arrangement direction, and connected to a face of the tube, the fin
has an operation force reducing part for reducing an operation
force applied to the fin in accordance with a thermal expansion
difference between the tubes in a tube longitudinal direction, and
the operation force reducing part is disposed at a midpoint of the
fin in the arrangement direction.
2. The exhaust heat recovery apparatus according to claim 1,
wherein the fin is a corrugated fin having a wave shape, and
separated into a plurality of fin layers in the arrangement
direction, and the operation force reducing part is a
non-connection part such that opposing fin layers are not connected
to each other.
3. The exhaust heat recovery apparatus according to claim 2,
further comprising a separation plate for separating the opposing
fin layers, wherein the separation plate is connected to only one
of the opposing fin layers.
4. The exhaust heat recovery apparatus according to claim 1,
wherein the fin is a corrugated fin having a wave shape, and
separated into a plurality of fin layers in the arrangement
direction, and opposing fin layers are displaceable between the
tubes, when at least one of the opposing fin layers has the
operation force reducing part.
5. The exhaust heat recovery apparatus according to claim 4,
further comprising a separation plate for separating the opposing
fin layers, wherein the separation plate is connected to only one
of the opposing fin layers.
6. The exhaust heat recovery apparatus according to claim 1,
wherein the operation force reducing part is a bent part, at which
the midpoint of the fin is bent.
7. The exhaust heat recovery apparatus according to claim 6,
wherein the bent part is disposed at an approximately center
position of the fin between the tubes in the arrangement direction,
and the bent part has an obtuse angle.
8. The exhaust heat recovery apparatus according to claim 6,
wherein the bent part has a S-letter shape.
9. The exhaust heat recovery apparatus according to claim 6,
wherein the fin is a corrugated fin having a wave shape.
10. The exhaust heat recovery apparatus according to claim 1,
further comprising a valve mechanism for opening and closing a
passage, through which the working fluid returns from the condenser
to the evaporator, in accordance with at least one of a pressure of
the working fluid, a temperature of the coolant and a temperature
of the working fluid.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is based on Japanese Patent Application No.
2006-106786 filed on Apr. 7, 2006, the disclosure of which is
incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an exhaust heat recovery
apparatus. For example, the recovery apparatus is typically used in
a vehicle having an internal combustion engine, and recovers
exhaust heat from the engine.
[0004] 2. Description of Related Art
[0005] JP-A-7-120178 discloses an exhaust heat recovery apparatus
including a heat siphon, in which an evaporator and a condenser are
connected in a loop. The evaporator includes plural tubes, and is
disposed in an exhaust pipe of an engine. The condenser is disposed
at a coolant side of the engine, and recovers exhaust heat from the
engine into coolant.
[0006] In order to promote heat-exchange between thermal media and
exhaust gas in the evaporator, a fin is brazed to an outer surface
of the tube so as to increase a thermal transmission area.
[0007] However, when a temperature distribution is generated in a
flow of exhaust gas having high temperature, a temperature
difference may be generated between the tubes in accordance with
the temperature distribution. Therefore, a thermal expansion
difference may be generated between the tubes, and a tensile load
may be applied to the fin. For example, a rupture may be generated
in a fillet between the tube and the fin.
SUMMARY OF THE INVENTION
[0008] In view of the foregoing and other problems, it is an object
of the present invention to provide an exhaust heat recovery
apparatus.
[0009] According to an example of the present invention, an exhaust
heat recovery apparatus includes an evaporator and a condenser. The
evaporator has a plurality of tubes arranged in an arrangement
direction, and a fin for increasing an area for transmitting heat.
The evaporator evaporates working fluid therein by heat of exhaust
gas discharged from an internal combustion engine. The condenser
emits heat of the working fluid flowing from the evaporator toward
coolant of the internal combustion engine so as to condense the
working fluid, and returns the condensed working fluid to the
evaporator. The fin is disposed between the tubes in the
arrangement direction, and is connected to a face of the tube. The
fin has an operation force reducing part for reducing an operation
force applied to the fin in accordance with a thermal expansion
difference between the tubes in a tube longitudinal direction. The
operation force reducing part is disposed at a midpoint of the fin
in the arrangement direction.
[0010] Accordingly, the fin can be restricted from being damaged by
the thermal expansion difference between the tubes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The above and other objects, features and advantages of the
present invention will become more apparent from the following
detailed description made with reference to the accompanying
drawings. In the drawings:
[0012] FIG. 1 is a schematic diagram showing an exhaust heat
recover apparatus, according to a first embodiment of the present
invention, mounted in a vehicle;
[0013] FIG. 2 is a schematic cross-sectional view showing the
exhaust heat recover apparatus;
[0014] FIG. 3 is an enlarged cross-sectional view of tubes and fin
layers of the exhaust heat recover apparatus;
[0015] FIG. 4 is an enlarged cross-sectional view of tubes and fin
layers of the exhaust heat recover apparatus;
[0016] FIG. 5 is an enlarged cross-sectional view of tubes and a
fin of an exhaust heat recover apparatus according to a second
embodiment;
[0017] FIG. 6 is an enlarged cross-sectional view of tubes and a
fin of the exhaust heat recover apparatus according to the second
embodiment; and
[0018] FIG. 7 is a schematic cross-sectional view showing an
exhaust heat recovery apparatus according to a third
embodiment.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
First Embodiment
[0019] An exhaust heat recovery apparatus 100 in a first embodiment
will be described with reference to FIGS. 1-3. The apparatus 100 is
used in a vehicle having an engine 10 as a driving source, and
disposed between an exhaust pipe 11 and an exhaust heat recovery
circuit 30 of the engine 10, as shown in FIG. 1.
[0020] The engine 10 is a water-cooled internal combustion engine,
and includes the exhaust pipe 11, through which exhaust gas
generated by a fuel combustion in the engine 10 flows. The exhaust
pipe 11 includes a catalytic converter 12 for cleaning exhaust gas.
Further, the engine 10 includes a radiator circuit 20, the exhaust
gas recovery circuit 30 and a heater circuit 40. Coolant for
cooling the engine 10 circulates in each of the radiator circuit 20
and the exhaust gas recovery circuit 30. The heater circuit 40
heats air-conditioning air by using the coolant (warm-water).
[0021] The radiator circuit 20 includes a radiator 21, a water pump
22 for making coolant to circulate, a passage 23 for bypassing the
radiator 21 and a thermostat 24. The radiator 21 cools coolant by
exchanging heat with outside air. The thermostat 24 controls an
amount of coolant flowing through the radiator 21 and an amount of
coolant flowing through the passage 23. Especially, when warm-up of
the engine 10 is performed, the amount of coolant flowing through
the passage 23 is increased so as to promote the warm-up of the
engine 10. That is, supercooling of coolant by the radiator 21 can
be reduced.
[0022] The exhaust heat recovery circuit 30 is branched from the
radiator circuit 20 at an outlet of the engine 10, and connected to
the water pump 22. Due to the water pump 22, coolant can circulate.
A water tank 140 (condenser 130) of the recovery apparatus 100 is
connected to the recovery circuit 30. The water tank 140 (condenser
130) will be described below.
[0023] Coolant (warm-water) is discharged into the heater circuit
40 from the engine 10 at a position different from the outlet for
the radiator circuit 20, and the heater circuit 40 joins to a
downstream side of the exhaust heat recovery circuit 30. A heater
core 41 is arranged in the heater circuit 40, and operates as a
heat exchanger for heating. The coolant (warm-water) circulates in
the heater circuit 40 due to the water pump 22. The heater core 41
is arranged in an air-conditioning case of an air-conditioning unit
(not shown). Air-conditioning air is sent by a fan (not shown), and
the heater core 41 heats the air-conditioning air by exchanging
heat with the warm-water.
[0024] As shown in FIG. 2, the recovery apparatus 100 includes a
loop-type heat pipe 101, in which an evaporator 110 and the
condenser 130 are connected to each other by a connection passage
115 and a reflux passage 135. The evaporator 110 is disposed in a
duct 120, and the condenser 130 is disposed in the water tank
140.
[0025] The heat pipe 101 has a filling part (not shown), and is
evacuated (depressurized) through the filling part. Then, working
fluid (water) is filled in the heat pipe 101 through the filling
part. Thereafter, the filling part of the heat pipe 101 is sealed.
Water has a boiling point of 100.degree. C. at one atmosphere.
However, water in the heat pipe 101 has the boiling point of
5-10.degree. C., because the heat pipe 101 is depressurized to 0.01
atmosphere, for example. In addition, alcohol, fluorocarbon or
chlorofluorocarbon may be used as the working fluid other than
water.
[0026] Parts (to be described below) of the recovery apparatus 100
are made of a stainless material having a high performance for
enduring corrosion. The parts are integrally brazed using a brazing
material at a joint or fitting part, after the parts are
assembled.
[0027] The evaporator 110 includes tubes 111, fins 112, a bottom
tank 113 and a top tank 114. The tube 111 is a long and thin pipe
having a flat shape, and a longitudinal direction of the tube 111
corresponds to an up-and-down direction in FIG. 2. The tubes 111
are arranged in a width direction corresponding to a left-and-right
direction in FIG. 2, and a predetermined tube pitch (interval) is
provided between the tubes 111. Further, the tubes 111 are arranged
in a thickness direction perpendicular to the tube longitudinal
direction and the width direction.
[0028] The fin 112 made of a thin wall material is disposed between
the tubes 111 in the width direction, and is connected to each
outer wall (face) of the tubes 111. The fin 112 will be described
below.
[0029] The bottom tank 113 is a flat container, and disposed at a
bottom end of the tube 111 in the longitudinal direction. The top
tank 114 is a flat container, and disposed at a top end of the tube
111 in the longitudinal direction. Each of the bottom tank 113 and
the top tank 114 has a hole (not shown), and the tube 111 is
inserted into the hole to be connected to the tank 113, 114. Thus,
the tube 111 can communicate with the tank 113, 114.
[0030] The evaporator 110 is disposed in the duct 120. The duct 120
is a cylinder having a cross-section of rectangle, and exhaust gas
flows inside of the duct 120 as described below. The evaporator 110
is disposed in the duct 120 such that the thickness direction
corresponds to a flowing direction of the exhaust gas.
[0031] The condenser 130 includes a tube 131, a fin 132, a bottom
tank 133 and a top tank 134. A longitudinal direction of the tube
131 corresponds to the up-and-down direction in FIG. 2. The fin 132
is formed into a crank shape, and disposed between the tubes 131 so
as to be connected to the tubes 131. The tube 131 is connected to
the tank 133, 134 so as to communicate with the tank 133, 134.
[0032] The condenser 130 is disposed in the water tank 140. The
water tank 140 is a container elongated to correspond to the
longitudinal direction of the tube 131. An introducing pipe 141 for
introducing coolant into the water tank 140 is disposed at an end
of the water tank 140, and a discharging pipe 142 for discharging
coolant outward is disposed at the other end of the water tank
140.
[0033] The condenser 130 is disposed at a side of the evaporator
110. The top tank 114 of the evaporator 110 and the top tank 134 of
the condenser 130 are connected by the connection passage 115
passing through the duct 120 and the water tank 140. Further, the
bottom tank 113 of the evaporator 110 and the bottom tank 133 of
the condenser 130 are connected by the reflux passage 135 passing
through the duct 120 and the water tank 140. Therefore, the heat
pipe 101 is formed by connecting the bottom tank 113, the tube 111,
the top tank 114, the connection passage 115, the top tank 134, the
tube 131, the bottom tank 133 and the reflux passage 135 in a loop
in this order.
[0034] A clearance is provided between the duct 120 and the water
tank 140. Positions of the connection passage 115 and the reflux
passage 135 correspond to a position of the clearance, so that the
passages 115, 135 operate as a thermal insulation part 121 between
the evaporator 110 and the condenser 130.
[0035] A thin-wall band plate is formed into a wave shape by a
roller process so as to make the fin 112 to be corrugated. As shown
in FIG.3, the fin 112 is separated into plural fin layers in the
width direction between the tubes 111. Here, in the first
embodiment, the fin 112 is separated into two fin layers 1121,
1122. Each of the fin layers 1121, 1122 is connected to a wall
(face) of the tube 111 by forming a fillet of brazing.
[0036] Further, a separation plate 116 made of a thin-wall board
material is provided between the fin layers 1121, 1122. The plate
116 is connected to one of the fin layers, and is not connected to
the other fin layer. In this embodiment, the plate 116 is connected
to the fin layer 1122, and is not connected to the fin layer 1121
so as to form an operation force reducing part 112a (non-connection
part), which is displaceable relative to the plate 116 and the fin
layer 1122. Alternatively, the plate 116 may be connected to the
fin layer 1121, and is not connected to the fin layer 1122 so as to
form the non-connection part 112a
[0037] As described above, the evaporator 110 (duct 120) of the
recovery apparatus 100 is disposed in the exhaust pipe 11 at
downstream side of the catalytic converter 12, and the introducing
pipe 141 and the discharging pipe 142 of the recovery apparatus 100
are connected to the exhaust heat recovery circuit 30.
[0038] Next, operation and advantage of the recovery apparatus 100
will be described. When the engine 10 is actuated, the water pump
22 is also actuated so that coolant circulates in the radiator
circuit 20, the exhaust heat recovery circuit 30 and the heater
circuit 40. Exhaust gas generated in the engine 10 flows in the
exhaust pipe 11 through the catalytic converter 12, and is
discharged outside through the evaporator 110 of the recovery
apparatus 100. Further, coolant circulating in the exhaust heat
recovery circuit 30 passes through the water tank 140 (condenser
130) of the recover apparatus 100.
[0039] After the engine 10 is actuated, water in the evaporator 110
of the heat pipe 101 receives heat from exhaust gas flowing in the
duct 120 so as to be vaporized. The vapor rises through the tube
111, and flows into the condenser 130 (the top tank 134 and the
tube 131) through the top tank 114 and the connection passage 115.
Vapor flowing into the condenser 130 is cooled by coolant flowing
from the exhaust heat recovery circuit 30 into the water tank 140,
and condensed into condensed water. The condensed water returns to
the bottom tank 113 of the evaporator 110 through the reflux
passage 135.
[0040] Heat is transmitted from exhaust gas to water, that is, heat
is transported from the evaporator 110 to the condenser 130. Then,
the transmitted heat is emitted as condensed latent heat, when
vapor is condensed in the condenser 130. Thus, coolant flowing
through the exhaust heat recovery circuit 30 is heated in a
positive manner. That is, the engine 10 can be more effectively
warmed up. Therefore, friction loss of the engine 10 can be
reduced, and fuel for improving cold startability can be reduced.
Thus, gas mileage (fuel-efficiency) can be improved. Further,
warming performance of the heater circuit 40 (heater core 41) using
coolant as a heat source can be improved. In addition, a part of
heat of exhaust gas is conducted (transmitted) from the evaporator
110 to the condenser 130 through the outer wall of the heat pipe
101.
[0041] Further, because the plural tubes 111 and the plural fins
112 are provided in the evaporator 110, area for receiving heat
from exhaust gas can be increased. Therefore, evaporation of the
working fluid can be accelerated in the evaporator 110, and heat
transportation amount from the evaporator 110 to the condenser 130
can be increased.
[0042] Further, because the thermal insulation part 121 is provided
between the evaporator 110 and the condenser 130, the evaporator
110 is restricted from being cooled by coolant in the condenser
130. Thus, condensing operation in the evaporator 110 can be
reduced.
[0043] In the first embodiment, the fin 112 of the evaporator 110
is separated into the fin layers 1121, 1122, and the non-connection
part 112a (operation force reducing part) is provided between the
fin layers 1121, 1122. The fin layers 1121, 1122 are not connected
to each other, due to the non-connection part 112a. For example, if
a flow of exhaust gas has temperature distribution in the duct 120,
temperature difference is generated between the tubes 111, so that
a thermal expansion difference is generated between the tubes 111.
However, in this embodiment, due to the non-connection part 112a,
tensile force (operation force) applied to the fin layer 1121, 1122
can be reduced. That is, the fin layers 1121, 1122 are displaceable
between the tubes 111 in accordance with the thermal expansion of
the tubes 111. Therefore, the fin layers 1121, 1122 are restricted
from being damaged, because the operation force applied to the fin
layers 1121, 1122 can be reduced.
[0044] Further, because the plate 116 is arranged between the fin
layers 1121, 1122, a peak (valley) of the fin layer 1121 and a peak
(valley) of the fin layer 1122 do not overlap (contact) with each
other, when the fin layers 1121, 1122 are assembled between the
tubes 111. Thus, the fin layers 1121, 1122 can be easily
assembled.
[0045] The fin 112 is separated into the two fin layers 1121, 1122.
However, the fin 112 may be separated into three layers 1121, 1122,
1123, as shown in FIG. 4. In this case, the plate 116 is arranged
between opposing fin layers 1121, 1122, (1122, 1123). Further, the
fin 112 may be separated into four or more fin layers, and the
plate 116 may be arranged between opposing fin layers.
Second Embodiment
[0046] A second embodiment will be described with reference to
FIGS. 5 and 6. Only one corrugated fin 112 is disposed between the
tubes 111 in the width direction in the second embodiment. The fin
112 has a bent part 112b (operation force reducing part) at the
midpoint of the fin 112 between the tubes 111. The other parts in
the second embodiment will be made similar to the first
embodiment.
[0047] As shown in FIG. 5, the bent part 112b is formed by bending
the fin 112 at an approximately center position between the tubes
111, and has an obtuse angle. However, the bent part 112b may have
an acute angle. Alternatively, as shown in FIG. 6, the bent part
112b is formed by bending the whole fin 112 between the tubes 111
like a S-letter shape.
[0048] Thereby, when the thermal expansion difference is generated
between the tubes 111 in the tube longitudinal direction, operation
force is not directly applied to the fin 112 until when the bent
part 112b becomes a linear shape. Thus, the fin 112 can be
restricted from being damaged.
[0049] The bent part 112b may be formed into other shape such as a
wave other than the shapes shown in FIGS. 5 and 6. Further, the fin
112 may be a plate fin other than the corrugated fin.
Third Embodiment
[0050] A third embodiment will be described with reference to FIG.
7. The reflux passage 135 connecting the condenser 130 and the
evaporator 110 includes a valve mechanism 150 in the third
embodiment. The other parts in the third embodiment will be made
similar to the first and second embodiments.
[0051] The valve mechanism 150 is made of a diaphragm, and opens
and closes the reflux passage 135 in accordance with an inner
pressure of the heat pipe 101, for example. The inner pressure of
the heat pipe 101 corresponds to a pressure of the working fluid.
When the inner pressure of the heat pipe 101 is larger than a
predetermined value, the valve mechanism 150 closes the reflux
passage 135. When the inner pressure of the heat pipe 101 is equal
to or smaller than the predetermined value, the valve mechanism 150
opens the reflux passage 135.
[0052] After the engine 10 is actuated, coolant temperature is
increased, and the inner pressure of the heat pipe 101 is gradually
increased. In addition, the inner pressure of the heat pipe 101 is
varied in accordance with an operation state, e.g., acceleration,
deceleration, or stop, of the vehicle, because an amount of exhaust
heat is varied by a load for the engine 10.
[0053] When the inner pressure of the heat pipe 101 is equal to or
smaller than the predetermined value, the valve mechanism 150 opens
the reflux passage 135. Then, heat is transported from exhaust gas
to coolant. That is, exhaust gas recovery is performed.
[0054] Thereafter, when the coolant temperature becomes larger than
a predetermined value (70.degree. C.), and when the inner pressure
of the heat pipe 101 is larger than the predetermined value, the
valve mechanism 150 closes the reflux passage 135. Thus, reflux of
condensed water in the heat pipe 101 is stopped. Then, water in the
evaporator 110 is completely evaporated (the evaporator 110 is
dried out), and the vapor flows into the condenser 130. Further,
the vapor is condensed into water, and the condensed water is
stored in the condenser 130.
[0055] That is, thermal transportation (exhaust heat recovery) due
to the vaporizing and the condensing is stopped. Thus, only the
thermal conduction (transmission) through the outer wall of the
heat pipe 101 is performed so as to transmit heat to the coolant
side. If the exhaust heat recovery is continued while exhaust gas
temperature is increased due to an increased load of the engine 10,
the coolant temperature may be too much increased. In this case,
the radiator 21 may be overheated, because a load applied to the
radiator 21 exceeds its capacity. However, in this embodiment, the
radiator 21 can be prevented from being overheated, because the
exhaust heat recovery can be stopped.
[0056] If the inner pressure of the heat pipe 101 becomes equal to
or smaller than the predetermined value, the valve mechanism 150
opens the reflux passage 135 again, and the thermal transportation
(exhaust heat recovery) can be restarted.
[0057] Here, when the exhaust heat recovery is restarted, the valve
mechanism 150 opens the reflux passage 135 so that working fluid is
returned to the tube 111 of the evaporator 110 from the condenser
130. At this time, flowing amount of the working fluid becomes
different among the tubes 111, due to a difference in a distance
between the valve mechanism 150 and each tube 111. Therefore, the
thermal expansion difference is easily generated by the difference
in the flowing amount of the working fluid, in addition to the
temperature distribution in the flow of exhaust gas. Then, the
thermal expansion difference generates operation force, and the
operation force may damage the fin 112. However, in this
embodiment, due to the operation force reducing part (the
non-connection part 112a and the bent part 112b) of the fin 112,
the fin 112 can be restricted from being damaged. Thus, when the
recovery apparatus 100 includes the valve mechanism 150, the
operation force reducing part 112a, 112b can be effective.
[0058] The valve mechanism 150 is the diaphragm for opening and
closing the reflux passage 135 in accordance with the pressure of
working fluid. However, the valve mechanism 150 may be a
thermostatic valve using wax for opening and closing the reflux
passage 135 in accordance with a temperature of coolant or working
fluid.
Other Embodiments
[0059] In the above embodiments, the condenser 130 is arranged at
the side of the evaporator 110. However, the condenser 130 may be
arranged above the evaporator 110. In this case, the tube 131 of
the condenser 130 is horizontally arranged.
[0060] Such changes and modifications are to be understood as being
within the scope of the present invention as defined by the
appended claims.
* * * * *