A heat exchanger suitable for electric vehicle heat pump system

Abstract

The present invention relates to the technical field of electric vehicle heat pump systems, and discloses a heat exchanger suitable for electric vehicle heat pump systems, including a first collecting pipe and a second collecting pipe, a heat exchange zone is arranged between the first collecting pipe and the second collecting pipe, and the interior of the heat exchange zone includes flat tubes and fins. In the present invention, the two processes of the heat exchanger are coordinated with the multiple inlets and outlets of the upper cavity and the resistance plate is arranged in the second collecting pipe to make the flow of the refrigerant in the heat exchanger more uniform, so that the flow uniformity is greatly improved, especially when the refrigerant evaporates in the heat exchanger in the heat pump mode, due to the increase in the heat exchange area, the flow resistance is also lower, which also helps to improve the heat exchange capacity of the system, so that its heat exchange efficiency is higher, and a larger heat exchange amount is obtained, which is beneficial to improve the performance of the heat exchanger, and the condensation performance of the refrigerant in the heat exchanger in the cooling mode is not affected.

Description

Technical Field

[0001] The invention relates to the technical field of electric vehicle heat pump systems, and in particular to a heat exchanger suitable for electric vehicle heat pump systems. Background Art

[0002] The heating schemes for the passenger compartment of electric vehicles are mainly divided into two types: high-pressure PTC and heat pump. PTC heating is divided into air heating and water heating. PTC is used to heat air and water to achieve heating in the car. The structure is relatively simple and the energy conversion efficiency is low, which affects the vehicle's driving range by up to 30-40%, or even more. The heat pump air-conditioning system, the current mainstream is a three-heat exchanger structure. When the system is running in defrost and dehumidification mode, the refrigerant will pass through three heat exchangers, and the air will be dehumidified through the internal evaporator. The air will be cooled to the temperature required for defrosting, and then heated by the internal condenser and sent to the car room, solving the problem of safe driving of the car. The air temperature at the air outlet can also be controlled during defrosting.

[0003] At present, the heat exchanger of the electric vehicle heat pump system is usually a traditional heat exchanger. The commonly used heat exchangers are two-pass and three-pass, but there are problems of excessive resistance or uneven flow, which makes the refrigerant flow unevenly inside the pipeline, resulting in low heat exchange efficiency and small heat exchange amount of the heat exchanger, which seriously affects the heat exchange effect and efficiency of the electric vehicle heat pump system. Summary of the invention

[0004] 1. Technical issues to be solved

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to solve the problem that the heat exchanger of the current electric vehicle heat pump system is usually a traditional heat exchanger. The commonly used heat exchangers are two-pass and three-pass, but there are problems of excessive resistance or uneven flow, which makes the refrigerant flow uneven inside the pipeline, resulting in low heat exchange efficiency and small heat exchange amount of the heat exchanger, which seriously affects the heat exchange effect and heat exchange efficiency of the electric vehicle heat pump system. A heat exchanger suitable for the electric vehicle heat pump system is proposed.

[0006] (II) Technical solution

[0007] To achieve the above object, the present invention provides the following technical solution: A heat exchanger suitable for an electric vehicle heat pump system, comprising a first header and a second header, a heat exchange zone is arranged between the first header and the second header, the interior of the heat exchange zone comprises flat tubes and fins, and the flat tubes are arranged between the first header and the second header, and fins are installed between adjacent flat tubes;

[0008] The inner wall of the first liquid collecting pipe is provided with a partition plate, and the partition plate divides the interior of the first liquid collecting pipe into two cavities;

[0009] The outer side of the lower cavity of the first collecting pipe is connected with a first refrigerant inlet and outlet;

[0010] A second refrigerant inlet and outlet is installed outside the upper cavity of the first header, and a third refrigerant inlet and outlet is connected below the second refrigerant inlet and outlet through a pipeline, and the third refrigerant inlet and outlet is connected to the upper cavity of the first header.

[0011] Preferably, the second refrigerant inlet and outlet are located 10% to 50% from the top of the upper cavity of the first header, and the third refrigerant inlet and outlet are located 50% to 90% from the top of the upper cavity of the first header.

[0012] Preferably, the first refrigerant inlet and outlet are located at 20% to 70% of the bottom end of the lower cavity of the first collecting pipe, and the partition plate is arranged at 20% to 50% of the first collecting pipe.

[0013] Preferably, a resistance plate is provided inside the second liquid collecting pipe, and the resistance plate is a partition with through holes, and the opening area of ​​the through holes of the resistance plate accounts for 10% to 90% of the cross-sectional area of ​​the second liquid collecting pipe.

[0014] Preferably, a fourth refrigerant inlet and outlet is provided outside the lower cavity of the first collecting pipe, and the fourth refrigerant inlet and outlet is provided below the first refrigerant inlet and outlet, and the fourth refrigerant inlet and outlet are connected to the first refrigerant inlet and outlet through a pipeline.

[0015] Preferably, the first refrigerant inlet and outlet are located 50% to 90% from the bottom of the lower cavity of the first manifold, and the fourth refrigerant inlet and outlet are located 10% to 50% from the bottom of the lower cavity of the first manifold.

[0016] Preferably, a fifth refrigerant inlet and outlet is arranged outside the upper cavity of the first collecting pipe, and the fifth refrigerant inlet and outlet is arranged below the third refrigerant inlet and outlet, and the fifth refrigerant inlet and outlet are connected to the third refrigerant inlet and outlet and the second refrigerant inlet and outlet through pipelines.

[0017] Preferably, the second refrigerant inlet and outlet are located at 10% to 30% of the top of the upper cavity of the first collecting pipe, the third refrigerant inlet and outlet are located at 30% to 60% of the top of the upper cavity of the first collecting pipe, and the fifth refrigerant inlet and outlet are located at 60% to 90% of the top of the upper cavity of the first collecting pipe.

[0018] (III) Beneficial effects

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] In the present invention, the two processes of the heat exchanger are coordinated with the multiple inlets and outlets of the upper cavity and a resistance plate is set in the second collecting pipe to make the flow of refrigerant in the heat exchanger more uniform, so that the flow uniformity is greatly improved, especially when the refrigerant evaporates in the heat exchanger in the heat pump mode, the flow resistance is also lower due to the increase in the heat exchange area, which is also helpful to improve the heat exchange capacity of the system, thereby making its heat exchange efficiency higher and obtaining a larger amount of heat exchange, which is beneficial to improving the performance of the heat exchanger, and the condensation performance of the refrigerant in the heat exchanger in the cooling mode is not affected, and the more uniform flow of refrigerant inside it also helps to delay the frost on the part of its outer surface in contact with the air in the heat pump mode. The frost forms more slowly and the defrost is faster, which reduces the maintenance cost of the heat exchanger and helps to extend the service life of the heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall three-dimensional structure of a heat exchanger suitable for an electric vehicle heat pump system in the present invention;

[0022] Figure 2 It is a schematic diagram of the flow structure of the heat exchanger in the heat pump mode of the present invention;

[0023] Figure 3 It is a schematic diagram of the flow structure of the heat exchanger in the cooling mode of the present invention;

[0024] Figure 4 It is a schematic diagram of the size structure of the heat exchange zone in the present invention;

[0025] Figure 5 It is a schematic diagram of the installation structure of the resistance plate and the second liquid collecting pipe in the present invention;

[0026] Figure 6 It is a schematic diagram of the opening structure of the resistance plate in the present invention;

[0027] Figure 7 It is a schematic diagram of the installation structure of the fourth refrigerant inlet and outlet and the first liquid collecting pipe in the present invention;

[0028] Figure 8 It is a schematic diagram of the installation structure of the fifth refrigerant inlet and outlet and the first liquid collecting pipe in the present invention.

[0029] In the figure: 1. first collecting pipe; 2. second collecting pipe; 3. flat tube; 4. fin; 5. first refrigerant inlet and outlet; 6. second refrigerant inlet and outlet; 7. third refrigerant inlet and outlet; 8. partition plate; 9. resistance plate; 10. fourth refrigerant inlet and outlet; 11. fifth refrigerant inlet and outlet. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] Example 1

[0032] See also Figure 1-Figure 4 , a heat exchanger suitable for an electric vehicle heat pump system, comprising a first header 1, a second header 2, a flat tube 3, a fin 4, a first refrigerant inlet and outlet 5, a second refrigerant inlet and outlet 6, a third refrigerant inlet and outlet 7, a partition plate 8, a resistance plate 9, a fourth refrigerant inlet and outlet 10 and a fifth refrigerant inlet and outlet 11, a heat exchange zone is arranged between the first header 1 and the second header 2, the interior of the heat exchange zone includes a flat tube 3 and a fin 4, and the flat tube 3 is arranged between the first header 1 and the second header 2, and fins 4 are installed between adjacent flat tubes 3, the fins 4 are corrugated fins 4, and the installation method of the heat exchanger adopts welding ears and bolts for installation, when used for passenger cars, it is usually installed in the heat dissipation module at the front air inlet of the vehicle, when used for commercial vehicles, it can be installed in the heat dissipation module at the front air inlet, and can also be installed in the heat exchange modules at the side, top and rear;

[0033] The inner wall of the first collecting pipe 1 is provided with a partition plate 8, and the partition plate 8 divides the interior of the first collecting pipe 1 into two cavities. By setting the partition plate 8, the flow of the refrigerant in the heat exchanger is divided into two processes when the heat exchanger is working;

[0034] The first refrigerant inlet and outlet 5 is connected to the outside of the lower cavity of the first collecting pipe 1. The first refrigerant inlet and outlet 5, the second refrigerant inlet and outlet 6 and the third refrigerant inlet and outlet 7 are provided with refrigerant, and the refrigerant is common R134a, R1234yf or CO2;

[0035] A second refrigerant inlet and outlet 6 is installed on the outside of the upper cavity of the first collecting pipe 1, and a third refrigerant inlet and outlet 7 is connected to the bottom of the second refrigerant inlet and outlet 6 through a pipeline, and the third refrigerant inlet and outlet 7 is connected to the upper cavity of the first collecting pipe 1. For the pipeline connecting the second refrigerant inlet and outlet 6 and the third refrigerant inlet and outlet 7, the length from the pipeline junction to the second refrigerant inlet and outlet 6 should be less than the length from the pipeline junction to the third refrigerant inlet and outlet 7; the number of bending times from the pipeline junction to the second refrigerant inlet and outlet 6 should also be less than the number of bending times from the pipeline junction to the third refrigerant inlet and outlet 7, so as to ensure that the resistance from the pipeline junction to the second refrigerant inlet and outlet 6 is less than the resistance from the pipeline junction to the third refrigerant inlet and outlet 7.

[0036] Furthermore, the position of the second refrigerant inlet and outlet 6 is 10% of the distance from the top of the upper cavity of the first collecting pipe 1, and the position of the third refrigerant inlet and outlet 7 is 50% of the distance from the top of the upper cavity of the first collecting pipe 1. The pipelines connecting the third refrigerant inlet and outlet 7 and the second refrigerant inlet and outlet 6 are connected to the external compressor after merging.

[0037] Furthermore, the first refrigerant inlet and outlet 5 is located 20% from the bottom end of the lower cavity of the first collecting pipe 1, and the partition plate 8 is arranged at 30% of the first collecting pipe 1. The first refrigerant inlet and outlet 5 is installed and connected with an external expansion valve or stop valve through a pipeline.

[0038] Furthermore, the dimensions of the heat exchange zone are length: 640 mm, height: 490 mm, and the distance from the center line of the partition plate 8 to the bottom flat tube 3 is 147 mm, and the distance from the center line of the partition plate 8 to the top flat tube 3 is 343 mm. The heat exchange area of ​​the lower process accounts for 147 / 490=30%, so the proportion of the heat exchange area of ​​the lower process to the total heat exchange area reaches 30%, which is conducive to achieving excellent heat exchange performance.

[0039] Furthermore, the number of flat tubes 3 connected to one side of the upper cavity of the first collecting tube 1 is 34, and the number of flat tubes 3 connected to one side of the lower cavity of the first collecting tube 1 is 14. The first collecting tube 1 and the second collecting tube 2 are cylindrical, and a part of the two sides of the flat tubes 3 will be inserted into them for brazing, thereby ensuring the working quality of the heat exchanger.

[0040] Working principle: When the heat exchanger is in heat pump mode, the function of the heat exchanger is an evaporator. The low-temperature and low-pressure refrigerant after throttling flows in from the first refrigerant inlet and outlet 5, passes through the lower first flow and the upper second flow, and flows out from the second refrigerant inlet and outlet 6 and the third refrigerant inlet and outlet 7. After merging at the pipeline confluence point, it flows to the compressor inlet. The working flow is as follows: Figure 2 As shown;

[0041] When the heat exchanger is in cooling mode, the function of the heat exchanger is a condenser. The high-temperature and high-pressure refrigerant flows through the pipeline junction and flows in from the second refrigerant inlet and outlet 6 and the third refrigerant inlet and outlet 7 respectively. After passing through the upper first flow and the lower second flow, it flows out from the first refrigerant inlet and outlet 5 and flows to the throttling element connected to the outside of the heat exchanger. The throttling element is an expansion valve.

[0042] Example 2

[0043] See also Figure 5-Figure 6 The difference between this embodiment and embodiment 1 is that a resistance plate 9 is provided inside the second liquid collecting pipe 2, and the resistance plate 9 is a partition with a through hole, and the opening area of ​​the through hole of the resistance plate 9 accounts for 10% of the cross-sectional area of ​​the second liquid collecting pipe 2;

[0044] For the lower cavity, when the number of flat tubes 3 inside the lower process of the heat exchange zone is greater than 8, a resistance plate 9 is arranged inside the second collecting pipe 2, and the height of the resistance plate 9 inside the collecting pipe 2 can be adjusted according to performance requirements. The height adjustment of the resistance plate 9 needs to be adjusted according to the flow uniformity of the lower process and the upper process. The height of the resistance plate 9 should be set at a position where the flow uniformity difference is large, so as to better balance the flow resistance in different areas, make the flow of the refrigerant more uniform, thereby significantly improving the efficiency and performance of the heat exchanger. Through the setting of the resistance plate 9, the flow uniformity of the lower process of the heat exchanger is improved, thereby further increasing the performance of the heat exchanger.

[0045] Example 3

[0046] See also Figure 7 The difference between this embodiment and embodiment 1 is that: a fourth refrigerant inlet and outlet 10 is provided outside the lower cavity of the first header 1, and the fourth refrigerant inlet and outlet 10 is provided below the first refrigerant inlet and outlet 5, and the fourth refrigerant inlet and outlet 10 is connected to the first refrigerant inlet and outlet 5 through a pipeline;

[0047] For the lower cavity, when the number of flat tubes 3 inside the lower process of the heat exchange zone is greater than 8 or the height of the lower cavity is too large, a fourth refrigerant inlet and outlet 10 is provided, and the position of the first refrigerant inlet and outlet 5 is 70% from the bottom end of the lower cavity of the first collecting pipe 1, and the position of the fourth refrigerant inlet and outlet 10 is 30% from the bottom end of the lower cavity of the first collecting pipe 1.

[0048] The heat exchanger performance can be improved by adding the fourth refrigerant inlet and outlet 10 in the lower cavity of the first header 1 .

[0049] Example 4

[0050] See also Figure 8 The difference between this embodiment and embodiment 1 is that a fifth refrigerant inlet and outlet 11 is provided on the outside of the upper cavity of the first collecting pipe 1, and the fifth refrigerant inlet and outlet 11 is provided below the third refrigerant inlet and outlet 7, and the fifth refrigerant inlet and outlet 11 is connected with the third refrigerant inlet and outlet 7 and the second refrigerant inlet and outlet 6 through a pipeline. The fifth refrigerant inlet and outlet 11 is provided when the height of the upper cavity of the heat exchange zone is too large or the number of flat tubes is large, so as to improve the performance.

[0051] Further, the position of the second refrigerant inlet and outlet 6 is 10% of the distance from the top of the upper cavity of the first collecting pipe 1, the position of the third refrigerant inlet and outlet 7 is 30% of the distance from the top of the upper cavity of the first collecting pipe 1, and the position of the fifth refrigerant inlet and outlet 11 is 60% of the distance from the top of the upper cavity of the first collecting pipe 1, and for the pipelines connecting the second refrigerant inlet and outlet 6, the third refrigerant inlet and outlet 7 and the fifth refrigerant inlet and outlet 11, the length from the confluence point of the pipelines to the second refrigerant inlet and outlet 6 should be less than the length from the confluence point of the pipelines to the third refrigerant inlet and outlet 7, and the length from the confluence point of the pipelines to the third refrigerant inlet and outlet 7 should be less than the length from the confluence point of the pipelines to the third refrigerant inlet and outlet 7. The length of the pipeline should be less than the length from the pipeline confluence point to the fifth refrigerant inlet and outlet 11; the number of bends from the pipeline confluence point to the second refrigerant inlet and outlet 6 should also be less than the number of bends from the pipeline confluence point to the third refrigerant inlet and outlet 7, and the number of bends from the pipeline confluence point to the third refrigerant inlet and outlet 7 should also be less than the number of bends from the pipeline confluence point to the fifth refrigerant inlet and outlet 11, so as to ensure that the resistance from the pipeline confluence point to the second refrigerant inlet and outlet 6 is less than the resistance from the pipeline confluence point to the third refrigerant inlet and outlet 7, and the resistance from the pipeline confluence point to the third refrigerant inlet and outlet 7 is less than the resistance from the pipeline confluence point to the fifth refrigerant inlet and outlet 11

[0052] The upper performance of the heat exchanger can be improved by adding the fifth refrigerant inlet and outlet 11 in the upper cavity of the first header 1.

[0053] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A heat exchanger suitable for an electric vehicle heat pump system, comprising a first header (1) and a second header (2), characterized in that: A heat exchange zone is provided between the first liquid collecting tube (1) and the second liquid collecting tube (2), the interior of the heat exchange zone comprises flat tubes (3) and fins (4), the flat tubes (3) are provided between the first liquid collecting tube (1) and the second liquid collecting tube (2), and fins (4) are installed between adjacent flat tubes (3); The inner wall of the first liquid collecting pipe (1) is provided with a partition plate (8), and the partition plate (8) divides the interior of the first liquid collecting pipe (1) into two cavities; The outer side of the lower cavity of the first collecting pipe (1) is connected to a first refrigerant inlet and outlet (5); A second refrigerant inlet and outlet (6) is installed outside the upper cavity of the first collecting pipe (1), and a third refrigerant inlet and outlet (7) is connected to the lower part of the second refrigerant inlet and outlet (6) through a pipeline, and the third refrigerant inlet and outlet (7) is connected to the upper cavity of the first collecting pipe (1); A fourth refrigerant inlet and outlet (10) is arranged outside the lower cavity of the first collecting pipe (1), and the fourth refrigerant inlet and outlet (10) is arranged below the first refrigerant inlet and outlet (5), and the fourth refrigerant inlet and outlet (10) is connected to the first refrigerant inlet and outlet (5) through a pipeline; For the pipeline connecting the second refrigerant inlet and outlet (6) and the third refrigerant inlet and outlet (7), the length from the pipeline junction to the second refrigerant inlet and outlet (6) should be shorter than the length from the pipeline junction to the third refrigerant inlet and outlet (7); the number of bends from the pipeline junction to the second refrigerant inlet and outlet (6) should also be shorter than the number of bends from the pipeline junction to the third refrigerant inlet and outlet (7).

2. A heat exchanger suitable for an electric vehicle heat pump system according to claim 1, characterized in that: The position of the second refrigerant inlet and outlet (6) is 10% to 50% of the top of the upper cavity of the first collecting pipe (1), and the position of the third refrigerant inlet and outlet (7) is 50% to 90% of the top of the upper cavity of the first collecting pipe (1).

3. A heat exchanger suitable for an electric vehicle heat pump system according to claim 1, characterized in that: The first refrigerant inlet and outlet (5) is located at 20% to 70% of the bottom end of the lower cavity of the first collecting pipe (1), and the partition plate (8) is arranged at 20% to 50% of the first collecting pipe (1).

4. A heat exchanger suitable for an electric vehicle heat pump system according to claim 1, characterized in that: A resistance plate (9) is arranged inside the second liquid collecting pipe (2), and the resistance plate (9) is a partition with a through hole, and the opening area of ​​the through hole of the resistance plate (9) accounts for 10% to 90% of the cross-sectional area of ​​the second liquid collecting pipe (2).

5. The heat exchanger suitable for an electric vehicle heat pump system according to claim 1, characterized in that: The first refrigerant inlet and outlet (5) is located at 50% to 90% of the bottom end of the lower cavity of the first collecting pipe (1), and the fourth refrigerant inlet and outlet (10) is located at 10% to 50% of the bottom end of the lower cavity of the first collecting pipe (1).

6. A heat exchanger suitable for an electric vehicle heat pump system according to claim 1, characterized in that: A fifth refrigerant inlet and outlet (11) is arranged outside the upper cavity of the first collecting pipe (1), and the fifth refrigerant inlet and outlet (11) is arranged below the third refrigerant inlet and outlet (7), and the fifth refrigerant inlet and outlet (11) is connected to the third refrigerant inlet and outlet (7) and the second refrigerant inlet and outlet (6) through a pipeline.

7. A heat exchanger suitable for an electric vehicle heat pump system according to claim 6, characterized in that: The position of the second refrigerant inlet and outlet (6) is 10% to 30% from the top of the upper cavity of the first collecting pipe (1), the position of the third refrigerant inlet and outlet (7) is 30% to 60% from the top of the upper cavity of the first collecting pipe (1), and the position of the fifth refrigerant inlet and outlet (11) is 60% to 90% from the top of the upper cavity of the first collecting pipe (1).

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