Vehicle Interior Heat Exchanger
The thermal efficiency of a heat exchanger which is disposed on a blowing path in a vehicle interior and operates as a condenser is enhanced. In a vehicle interior heat exchanger 1 which functions as a condenser, a pair of tube groups 13A and 13B have a plurality of stacked cooling medium circulation tubes 11 and are arranged side by side in a blowing direction so as to face each other, on one end side in an axial direction of the cooling medium circulation tubes 11, an inlet side header tank 14A which has a cooling medium inlet tube 14a and to which each of the cooling medium circulation tubes 11 of the tube group 13A on one side is connected for communication and an outlet side header tank 14B which has a cooling medium outlet tube 14b and to which each of the cooling medium circulation tubes 11 of the tube group 13B on the other side is connected for communication are arranged separately and with a space therebetween, and on the other end side in the axial direction of the cooling medium circulation tubes 11, a single intermediate header tank 15 to which each of the cooling medium circulation tubes 11 of the pair of tube groups 13A and 13B is connected for communication is disposed.
The present invention relates to a vehicle interior heat exchanger in a vehicle heat pump apparatus.
BACKGROUND ARTIn Patent Document 1, a heat pump apparatus (air-conditioning apparatus) of a vehicle with an engine is of a counterflow type in which a cooling medium in a mixed gas-liquid state is circulated from the inlet side of an evaporator in one direction that intersects a blowing direction and is thereafter reversed to be circulated in the reverse direction so as to flow out from the outlet side on the same side as the inlet side as a gaseous cooling medium, and suppresses temperature distribution unevenness of cooling air that is blown into the vehicle interior.
CITATION LIST Patent Document
- [Patent Document 1] Japanese Patent No. 3214318
Meanwhile, in an electric vehicle or a hybrid vehicle with a small engine, heating by a heater core using exhaust heat from the engine is difficult. Therefore, performing heating by operating a vehicle interior heat exchanger of a heat pump cycle as a condenser is considered.
Even in such a case in which a vehicle interior heat exchanger is used as a condenser, employing a counterflow type cooling medium flow path used in an evaporator is effective in suppressing temperature distribution unevenness of heating air.
However, in a heat exchanger that operates as a condenser, the temperature difference between the cooling medium inlet side through which a gaseous cooling medium at high temperature and high pressure flows in and the cooling medium outlet side through which a condensed liquid cooling medium at low temperature flows out is increased to about 30° C. (about 10° C. in the evaporator).
Therefore, due to heat exchange between the cooling medium inlet side at high temperature and the cooling medium outlet side at low temperature, there is a concern that the efficiency of the heat exchanger, and furthermore, the thermal efficiency of the heat pump cycle, may be reduced.
The present invention has been made focusing on the problems of the related art, and an object thereof is to suppress heat exchange between the inlet side and the outlet side of a heat exchanger while making the temperature distribution of a heating air from a vehicle interior heat exchanger that is operated as a condenser uniform, thereby maintaining favorable thermal efficiency.
Means for Solving the ProblemsThe present invention has first to third aspects, and a heat exchanger of a vehicle heat pump apparatus, which is disposed on a blowing path in a vehicle interior and functions at least as a condenser, has the following configuration which is common in the first to third aspects.
A pair of tube groups which have a plurality of stacked cooling medium circulation tubes are arranged side by side in a blowing direction of the blowing path so as to face each other.
On one end side in an axial direction of the cooling medium circulation tubes, there are arranged an inlet side header tank which has a cooling medium inlet and to which each of the cooling medium circulation tubes of the tube group on one side is connected for communication, and an outlet side header tank which has a cooling medium outlet and to which each of the cooling medium circulation tubes of the tube group on the other side is connected for communication.
On the other end side in the axial direction of the cooling medium circulation tubes, there is disposed a single intermediate header tank to which each of the cooling medium circulation tubes of the pair of tube groups is connected for communication.
In addition, in the first aspect, the inlet side header tank and the outlet side header tank are arranged separately with a space therebetween.
In addition, in the second aspect, the inlet side header tank and the outlet side header tank of the inlet and outlet side header tank are arranged in one body via a heat insulation layer.
In addition, in the third aspect, the inlet side header tank and the outlet side header tank of the inlet and outlet side header tank are arranged in one body. In addition, the cooling medium inlet and the cooling medium outlet are formed at end portions on the sides opposite to each other in a stacking direction of the cooling medium circulation tubes of the corresponding tanks.
Advantageous Effects of the InventionIn the configuration which is common to the first to third aspects, there are formed counterflow type cooling medium flow paths in which the cooling medium introduced to the inlet side header tank from the cooling medium inlet reaches the inside of the intermediate header tank through the cooling medium circulation tubes of the tube group on the inlet side, reaches the inside of the outlet side header tank through the cooling medium circulation tubes of the tube group on the outlet side from the intermediate header tank, and flows out from the cooling medium outlet.
In this type of cooling medium flow path, the average temperature of the temperature of the inlet side tube group and the temperature of the outlet side tube group is made uniform in the entire region of the cross-section of the blowing path of the heat exchanger, and thus the temperature distribution of the heating air after passing through the heat exchanger is made uniform.
In addition, in the first aspect, since the inlet side header tank and the outlet side header tank are separately formed and are arranged with a space therebetween, heat exchange between the high-temperature cooling medium in the vicinity of the inlet side header tank and the low-temperature cooling medium in the vicinity of the outlet side header tank is suppressed, thereby maintaining favorable thermal efficiency.
In addition, in the second aspect, heat exchange between the high-temperature cooling medium in the vicinity of the inlet side header tank and the low-temperature cooling medium in the vicinity of the outlet side header tank is suppressed due to the interposition of the heat insulation layer and thus favorable thermal efficiency is able to be maintained. In addition, by forming these tanks in one body, the strength is enhanced and the assembly characteristics of the heat exchanger are also enhanced.
In addition, in the third aspect, the cooling medium inlet which has the highest temperature and the cooling medium outlet which has the lowest temperature are formed at positions farthest from each other between the two tanks. Therefore, heat exchange between regions having a high temperature difference is suppressed and thus favorable thermal efficiency is able to be maintained. In addition, by forming these tanks in one body, the strength is enhanced and the assembly characteristics of the heat exchanger are also enhanced.
Hereinafter, embodiments of the present invention will be described.
The air-conditioning apparatus is configured by connecting a vehicle interior heat exchanger 1 disposed on a blowing path 51 in the vehicle interior, a vehicle exterior heat exchanger 2 disposed on the vehicle exterior, a four-way switching valve 3, a compressor 4, and expansion valves 5A and 5B and check valves 6A and 6B which are respectively connected in parallel so as to form a circulation passage via a cooling medium pipe 7.
A fan 52 is disposed on the blowing path 51 in the vehicle interior, and vehicle interior air is blown by the fan 52 so as to be circulated via the vehicle interior heat exchanger 1, thereby performing cooling or heating.
During heating, the four-way valve 3 is switched to a state indicated by a solid line as illustrated, and a cooling medium pressurized by the compressor 4 flows into the vehicle interior heat exchanger 1 via the four-way valve 3 and is condensed and liquefied through heat exchange (heat dissipation) with the vehicle interior air. Due to the heat exchange, the vehicle interior air is heated. The heated vehicle interior air is blown by the fan 52 into the vehicle interior so as to heat the vehicle interior.
In addition, the liquid cooling medium reaches the expansion valve 5B through the check valve 6A, is depressurized into a mist state, flows into the vehicle exterior heat exchange 2, is vaporized (gasified) through heat exchange (heat absorption) with outside air, and is thereafter returned to the intake port of the compressor 4 and is pressurized again. This cycle is repeated.
During cooling, the cooling medium which is pressurized by driving the compressor 4 flows into the vehicle exterior heat exchanger 2 via the four-way valve 3 in a state indicated by a dotted line as illustrated, and the gas cooling medium is condensed and liquefied through heat exchange (heat dissipation) with outside air. The liquid cooling medium reaches the expansion valve 5A through the check valve 6B, is depressurized into a mist state, and flows into the vehicle interior heat exchanger 1.
The cooling medium in the mist state is vaporized through heat exchange (heat absorption) with the vehicle interior air into a gaseous state and thus cools the vehicle interior air. The cooled vehicle interior air is blown by the fan 52 into the vehicle interior and cools the vehicle interior. The gaseous cooling medium is returned to the intake port of the compressor 4 and is pressurized again. This cycle is repeated.
As described above, the vehicle interior heat exchanger 1 that operates as a condenser during heating is configured as described below. In addition, the cooling medium circulation direction is reversed between when the heat exchanger 1 operates as a condenser during heating and when the heat exchanger 1 operates as an evaporator during cooling. Hereinafter, the cooling medium circulation direction at the time of operation as a condenser will be described.
A pair of tube groups 13A and 13B is formed by stacking a plurality of cooling medium circulation tubes 11 having flat passage cross-sections in the vertical direction via corrugated fins, and the pair of tube groups 13A and 13B face each other and are arranged in two rows so as to be spaced apart in the blowing direction of the blowing path 51. Each of the cooling medium circulation tubes 11 and the corrugated fins are fixed by brazing or the like.
On both sides in the tube axis direction of the two rows of the tube groups 13A and 13B, header tanks that extend in the stacking direction of the cooling medium circulation tubes 11 are respectively arranged.
In the header tanks arranged on one side (on the left in the figure) in the axial direction of the tubes, inlet side header tank 14A and outlet side header tank 14B are separately formed and are arranged with a space therebetween. The inlet side header tank 14A and the outlet side header tank 14B have a shape in which, for example, the upper and lower end surfaces of circular pipe members are blocked by lid members and as described later, a plurality of holes through which the end portions of the cooling medium circulation tubes 11 are inserted are open.
In the inlet side header tank 14A, one end portion of each of the cooling medium circulation tubes 11 of the tube group 13A on the downstream side in the blowing direction is inserted into the corresponding hole so as to communicate with the inside of the tank and is fixed by brazing or the like.
At the upper portion of the inlet side header tank 14A, a cooling medium inlet tube 14a which is connected to the external upstream side cooling medium pipe 7 communicates with the inside of the tank and is connected thereto by brazing.
In the outlet side header tank 14B, one end portion of each of the cooling medium circulation tubes 11 of the tube group 13B on the upstream side in the blowing direction is inserted into the corresponding hole so as to communicate with the inside of the tank and is fixed by brazing or the like.
At the lower end portion of the outlet side header tank 14B, a cooling medium outlet tube 14b which is connected to the external downstream side cooling medium pipe 7 communicates with the inside of the tank and is connected thereto by brazing.
The cooling medium inlet tube 14a and the cooling medium outlet tube 14b are formed so that the front end portions thereof airtightly penetrate through the passage wall of the blowing path 51 in the vehicle interior and are connected to the external upstream side cooling medium pipe 7 and downstream side cooling medium pipe 7 on the vehicle exterior, respectively.
In addition, an intermediate header tank 15 arranged on the other side (on the right in the figure) in the axial direction of the tubes is formed of a single tank so that the end portions of all the cooling medium circulation tubes 11 of both the tube groups 13A and 13B are inserted into corresponding holes for communication and are fixed by brazing or the like.
In the vehicle interior heat exchanger 1 configured as described above, the flow of the cooling medium when the vehicle interior heat exchanger 1 operates as a condenser during heating is described with reference to
The gaseous cooling medium at high pressure and high temperature which flows into the inlet side header tank 14A from the upstream side cooling medium pipe 7 via the cooling medium inlet tube 14a is diffused in the inlet side header tank 14A and at the same time reaches the inside of the intermediate header tank 15 on the opposite side through each of the cooling medium circulation tubes 11 of the tube group 13A.
After joining together in the inside of the intermediate header tank 15, the cooling medium is turned in the reverse direction, reaches the inside of the outlet tank 14B through each of the cooling medium circulation tubes 11 of the tube group 13B on the upstream side in the blowing direction, and flows out to the downstream side cooling medium pipe 7 from the cooling medium outlet tube 14b.
While the cooling medium passes through each of the cooling medium circulation tubes 11 of the two tube groups 13A and 13B as described above, the cooling medium dissipates heat through heat exchange with the blown air that is circulated while coming into contact with the outer surface of each of the tubes 11 and dissipates heat through heat exchange with the corrugated fins cooled by the blown air that comes into contact with the outer surface thereof, thereby being efficiently cooled, condensed, and liquefied.
In addition, due to the counterflow type cooling medium flow paths, a region close to the cooling medium inlet, through which the gaseous cooling medium at high temperature is circulated at high density in the tube group 13A on the downstream side in the blowing direction, overlaps a region close to the cooling medium outlet, through which the liquid cooling medium at low temperature condensed in the tube group 13B on the upstream side in the blowing direction is circulated, in the blowing direction.
On the other hand, the difference between the temperatures of the cooling medium (or gas-to-liquid ratio) that is circulated through the tube groups 13A and 13B on the downstream side and on the upstream side in the blowing direction is reduced as the cooling medium is close to the intermediate header tank 15 on the opposite side.
That is, in the entire region of the cross-section of the blowing path, the average value (average temperature or average gas-to-liquid ratio) of the cooling medium temperature (gas-to-liquid ratio) of the tube group 13A on the downstream side in the blowing direction and the cooling medium temperature (gas-to-liquid ratio) of the tube group 13B on the upstream side is made uniform. Accordingly, the temperature of the heating air that is blown into the vehicle interior while passing through the vehicle interior heat exchanger 1 for heat exchange is made uniform, and thus comfortable heating is able to be achieved.
Meanwhile, in the vehicle interior heat exchanger 1 which operates as a condenser, as described above, the temperature difference between the vicinity of the cooling medium inlet and the vicinity of the cooling medium outlet is particularly large.
For example, in a case of vehicle interior heating by a heater core using engine cooling water, the temperature difference between the outlet and the inlet due to heat exchange with air is about 10° C. (sensible heat change). Even in a case in which the vehicle interior heat exchanger 1 is used as the evaporator (evaporator) during cooling, the temperature difference between the outlet and the inlet is about 10° C. (latent heat change).
In contrast, in a case in which the vehicle interior heat exchanger 1 is operated as a condenser, the cooling medium flows into the inlet side in a completely gasified state at high temperature and flows out from the outlet side in a low-temperature liquid state of being condensed by heat dissipation. Therefore, the temperature difference between the outlet and the inlet is as large as about 30° C. (latent heat change).
When heat exchange between the inlet side and the outlet side with a large temperature difference is performed as such, the liquefied low-temperature cooling medium on the outlet side is re-heated by the gaseous cooling medium at high temperature on the inlet side, resulting in a reduction in heat exchange efficiency.
Therefore, in the first embodiment, the inlet and outlet side header tank is separately formed into the inlet side header tank 14A and the outlet side header tank 14B and are arranged with a space therebetween.
Accordingly, heat exchange between the high-temperature gaseous cooling medium in the inlet side header tank 14A and the low-temperature liquid cooling medium cooled in the outlet side header tank 14B is able to be effectively suppressed, thereby sufficiently suppressing a reduction in thermal efficiency.
In addition, due to the configuration in which the cooling medium inlet tube 14a and the cooling medium outlet tube 14b are connected to the cooling medium pipe 7 on the vehicle exterior, even in a case in which problems such as looseness or shift of the connection occur, a situation in which the cooling medium leaks into the vehicle interior and affects occupants is avoided.
In addition, since the cooling medium outlet tube 14b is arranged at the lower end portion of the outlet tank 14B, the liquid cooling medium and an oil contained in the cooling medium smoothly flow out from the cooling medium outlet tube 14b and is prevented from staying at the lower portion of the outlet tank 14B, thereby maintaining favorable thermal efficiency.
As in the first embodiment, an inlet side header tank member 21A and an outlet side header tank member 21B, each of which is formed as a circular pipe member (may also be formed by extrusion), are connected by a pair of plates 21C and 21D that circumscribe the circular cross-sections thereof and are integrated into a shape in which the entire outer cross-sections of the upper and lower ends are blocked by lid members. Other configurations are the same as those of the first embodiment, and a cooling medium inlet tube 21a and a cooling medium outlet tube 21b are connected to corresponding positions of the integrated inlet and outlet side header tank 21.
When the inlet and outlet side header tank 21 are integrated as described above, a space enclosed by the adjacent wall portions of the inlet side header tank member 21A and the outlet side header tank member 21B, the pair of the plates 21C and 21D, and the lid members at the upper and lower ends is interposed as an air heat insulation layer 22. Therefore, even in the integrated tank, heat exchange between the high-temperature gaseous cooling medium in the inlet side header tank 21A and the low-temperature liquid cooling medium in the outlet side header tank 21B is able to be suppressed as much as possible by the interposition of the air heat insulation layer 22, thereby maintaining favorable thermal efficiency.
In addition, since the inlet side header tank and the outlet side header tank are integrated into the inlet and outlet side header tank 21, the strength of the tank is increased. In addition, both the tube groups 13A and 13B are connected to and supported by the integrated tanks on both sides in the tube axis direction, and thus the strength of the entire heat exchanger 1 is increased.
In addition, the integrated tank enables the cooling medium circulation tubes 11 of both the tube groups 13A and 13B to be simultaneously assembled to the inlet side header tank 21A and the outlet side header tank 21B, and thus the manufacturing efficiency of the heat exchanger is increased.
An inlet and outlet side header tank 31 is integrally formed in a box shape having the same outer shape as the intermediate header tank 15, and the tank internal space is partitioned into an inlet side header tank 31A to which the inlet side tube group 13A is connected for communication and an outlet side header tank 31B to which the outlet side tube group 13B is connected for communication by a partition wall 32.
Here, a cooling medium inlet tube 31a is connected to the upper end portion of the inlet side header tank 31A, and a cooling medium outlet tube 31b is connected to the lower end portion of the outlet side header tank 31B.
Here, the region in the vicinity of the cooling medium inlet tube 31a is a part where the high-temperature gaseous cooling medium directly flows in and thus has the highest temperature. On the other hand, the region in the vicinity of the cooling medium outlet tube 31b is a part where the cooled liquid cooling media flowing out from the cooling medium circulation tubes 11 of the tube group 13B join together and thus has the lowest temperature.
In addition, the cooling medium inlet tube 31a and the cooling medium outlet tube 31b are disposed at diagonal positions which are farthest from each other in the inlet and outlet side header tank 31, and thus the region which has the highest temperature is able to be located away from the region which has the lowest temperature in the heat exchanger as far as possible. Therefore, heat exchange between the high-temperature region and the low-temperature region is suppressed, thereby maintaining favorable thermal efficiency.
In addition, an increase in the strength of the tank as a result of the integration as the inlet and outlet side header tank 31, an increase in the strength of the entire heat exchanger 1 as a result of connecting and supporting both of the tube groups 13A and 13B to the integrated tanks on both sides in the tube axis direction, and an increase in the manufacturing efficiency of the heat exchanger as a result of enabling the cooling medium circulation tubes 11 of the tube groups 13A and 13B to be simultaneously assembled to the integrated tanks are the same as those in the second embodiment.
Moreover, for example, the inlet and outlet side header tank 31 and the intermediate header tank 15 are generalized by using members having the same outer shape, and the partition wall 32 is formed by connecting a partition plate as a separate member, thereby achieving a reduction in cost.
The embodiments described above have a configuration in which the vehicle interior heat exchanger 1 is switched between the operations of a condenser and an evaporator. However, the configuration according to the present invention may be applied to a condenser of a system having a configuration in which a condenser and an evaporator are provided separately on the blowing path in the vehicle interior so as to be switched depending on heating and cooling.
In addition, a configuration in which a number of flat plate-like fins through which the cooling medium circulation tubes penetrate are arranged in the vertical direction instead of the corrugated fins may also be employed.
REFERENCE SIGNS LIST
-
- 1 Vehicle interior heat exchanger
- 2 Vehicle exterior heat exchanger
- 7 Cooling medium pipe
- 11 Cooling medium circulation tube
- 13A, 13B Tube group
- 14A Inlet side header tank
- 14B Outlet side header tank
- 14a Cooling medium inlet tube
- 14b Cooling medium outlet tube
- 15 Intermediate header tank
- 21A Inlet side header tank member
- 21B Outlet side header tank member
- 21C, 21D Plate
- 21a Cooling medium inlet tube
- 21b Cooling medium outlet tube
- 31 Inlet and outlet side header tank
- 31A Inlet side header tank
- 31B Outlet side header tank
- 31a Cooling medium inlet tube
- 31b Cooling medium outlet tube
- 32 Partition wall
- 51 Blowing path
- 52 Fan
Claims
1. A vehicle interior heat exchanger of a vehicle heat pump apparatus, which is disposed on a blowing path in a vehicle interior and functions at least as a condenser,
- wherein a pair of tube groups which have a plurality of stacked cooling medium circulation tubes are arranged side by side in a blowing direction of the blowing path so as to face each other,
- wherein, on one end side in an axial direction of the cooling medium circulation tubes, an inlet side header tank, which has a cooling medium inlet and to which each of the cooling medium circulation tubes of the tube group on one side is connected for communication, and an outlet side header tank, which has a cooling medium outlet and to which each of the cooling medium circulation tubes of the tube group on the other side is connected for communication, are arranged separately and with a space therebetween, and
- wherein, on the other end side in the axial direction of the cooling medium circulation tubes, a single intermediate header tank to which each of the cooling medium circulation tubes of the pair of tube groups is connected for communication is disposed.
2. A vehicle interior heat exchanger of a vehicle heat pump apparatus, which is disposed on a blowing path in a vehicle interior and functions at least as a condenser,
- wherein a pair of tube groups which have a plurality of stacked cooling medium circulation tubes are arranged side by side in a blowing direction of the blowing path so as to face each other,
- wherein, on one end side in an axial direction of the cooling medium circulation tubes, an inlet side header tank, which has a cooling medium inlet and to which each of the cooling medium circulation tubes of the tube group on one side is connected for communication, and an outlet side header tank, which has a cooling medium outlet and to which each of the cooling medium circulation tubes of the tube group on the other side is connected for communication, are arranged in one body via a heat insulation layer, and
- wherein, on the other end side in the axial direction of the cooling medium circulation tubes, a single intermediate header tank to which each of the cooling medium circulation tubes of the pair of tube groups is connected for communication is disposed.
3. A vehicle interior heat exchanger of a vehicle heat pump apparatus, which is disposed on a blowing path in a vehicle interior and functions at least as a condenser,
- wherein a pair of tube groups which have a plurality of stacked cooling medium circulation tubes are arranged side by side in a blowing direction of the blowing path so as to face each other,
- wherein, on one end side in an axial direction of the cooling medium circulation tubes, an inlet side header tank, which has a cooling medium inlet and to which each of the cooling medium circulation tubes of the tube group on one side is connected for communication, and an outlet side header tank, which has a cooling medium outlet and to which each of the cooling medium circulation tubes of the tube group on the other side is connected for communication, are arranged in one body,
- wherein the cooling medium inlet and the cooling medium outlet are formed at end portions on sides opposite to each other in a stacking direction of the cooling medium circulation tubes of the tanks, and
- wherein, on the other end side in the axial direction of the cooling medium circulation tubes, a single intermediate header tank to which each of the cooling medium circulation tubes of the pair of tube groups is connected for communication is disposed.
4. The vehicle interior heat exchanger according to claim 1,
- wherein the plurality of cooling medium circulation tubes are arranged in a vertical direction and the cooling medium outlet is disposed at a lower end portion of the outlet side header tank.
5. The vehicle interior heat exchanger according to claim 1,
- wherein the cooling medium inlet and the cooling medium outlet are connected to an external cooling medium pipe on a vehicle exterior.
Type: Application
Filed: Apr 15, 2011
Publication Date: Feb 28, 2013
Inventors: Yuuichi Matsumoto (Isesaki-shi), Yusuke Iino (Isesaki-shi)
Application Number: 13/695,612
International Classification: F28F 9/02 (20060101);
