Variable heat return quantity heat management system based on new energy automobile R290 refrigerant

Abstract

The invention relates to the technical field of new energy automobile heat management, and belongs to a variable heat return quantity heat management system based on a new energy automobile R290 refrigerant, which can realize the functions of a refrigeration mode, a heat pump heating mode, a hot gas bypass mode and the like. The intermediate heat exchanger is used as a forced supercooling section and a heat regenerator of a water-cooling condenser in a refrigeration mode, and is used as an economizer in a heating mode; through the bypass ERV + EXV throttling mode, the refrigerant flow passing through the intermediate heat exchanger can be dynamically adjusted according to different compressor rotating speeds and suction superheat degrees, and the problem that the suction superheat degree is large when the intermediate heat exchanger is matched with different refrigerant flows is solved. The air suction superheat degree can be accurately adjusted, the COP is improved compared with a traditional system, and meanwhile the reliability of the compressor is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal management of new energy vehicles, and pertains to a variable heat recovery thermal management system based on R290 refrigerant of new energy vehicles. Background Art

[0002] As a natural, environmentally friendly refrigerant, R290 (propane) enjoys broad demand and application prospects in the new energy vehicle market. With tightening global environmental regulations and the gradual phase-out of the traditional high-GWP refrigerant R134a, R290, with its low GWP of 3.3 and zero ODP, has become a mainstream alternative in line with the low-carbon transition. Compared to synthetic refrigerants like R1234yf, R290 offers a higher latent heat of vaporization and lower cost, reducing system refrigerant charge and improving energy efficiency and economy. It is particularly well-suited for new energy vehicles that require both cooling and heating. To maintain a certain suction superheat, secondary circuit thermal management systems based on R290 refrigerant typically utilize a regenerator to increase high-pressure side subcooling and low-pressure side superheat. However, under varying operating modes and compressor speeds, the inability of the regenerator to adjust can often lead to abnormal suction superheat, significantly limiting compressor performance.

[0003] In view of the above problems, the present invention proposes a thermal management system with variable heat recovery based on R290 refrigerant. Summary of the Invention

[0004] In response to the above technical problems, the present invention provides a variable heat recovery thermal management system based on R290 refrigerant for new energy vehicles.

[0005] To achieve the above object, the present invention provides the following technical solutions: The present invention provides a variable heat recovery heat management system based on R290 refrigerant for new energy vehicles, comprising a refrigerant circuit, a heating / cooling water circuit, and a cooling / heating water absorption circuit, wherein the refrigerant circuit is respectively connected to the heating / cooling water circuit and the cooling / heating water absorption circuit; The refrigerant circuit includes a first circuit and a second circuit, wherein the first circuit and the second circuit flow along the refrigerant to the common compressor, the agent-side channel of the water-cooled condenser, the high-pressure side channel of the intermediate heat exchanger, the liquid storage tank, the electronic expansion valve and the agent-side channel of the battery cooler; The first loop flows from the compressor through the agent side channel of the water-cooled condenser, the high-pressure side channel of the intermediate heat exchanger, the liquid storage tank, the electronic expansion valve, the agent side channel of the battery cooler, and then returns to the compressor through the low-pressure side channel of the intermediate heat exchanger; The second circuit flows from the compressor through the agent side channel of the water-cooled condenser, the high-pressure side channel of the intermediate heat exchanger, the liquid storage tank, the electronic expansion valve, the agent side channel of the battery cooler, and then returns to the compressor through the large-diameter electronic expansion valve 2.

[0006] Preferably, the circuit inlet of the heating / cooling water circuit is connected to the liquid side channel outlet of the water-cooled condenser, and the circuit outlet of the heating / cooling water circuit is connected to the liquid side channel inlet of the water-cooled condenser.

[0007] Preferably, the circuit inlet of the refrigeration / hot water absorption circuit is connected to the liquid side channel outlet of the battery cooler, and the circuit outlet of the refrigeration / hot water absorption circuit is connected to the liquid side channel inlet of the battery cooler.

[0008] Preferably, a large-diameter electronic expansion valve is connected in parallel at both ends of the compressor, the outlet of the large-diameter electronic expansion valve is connected to the outlet of the agent side channel of the battery cooler, and the inlet of the large-diameter electronic expansion valve is connected between the compressor outlet and the inlet of the agent side channel of the water-cooled condenser.

[0009] Preferably, a low-pressure temperature sensor is provided at the compressor inlet, and a high-pressure temperature sensor is provided at the liquid storage tank outlet.

[0010] In view of the above system, the present invention also provides a control method for a variable heat recovery thermal management system based on R290 refrigerant for new energy vehicles: The variable regenerative heat management system has operating modes including cooling mode, heat pump heating mode, and hot gas bypass heating mode. In all three modes, the high-temperature and high-pressure superheated refrigerant flows through at least the first circuit and / or the second circuit from the compressor back to the compressor. In the cooling mode, the high-temperature, high-pressure, superheated refrigerant flows through the first circuit and / or the second circuit from the compressor back to the compressor; the high-temperature, high-pressure, superheated refrigerant exchanges heat in the water-cooled condenser, condenses the high-temperature, high-pressure, superheated refrigerant, and dissipates the heat via the heating / cooling water circuit. The condensed refrigerant exchanges heat in the battery cooler; the antifreeze on the liquid side of the battery cooler is cooled and enters the cooling / heating water circuit to cool the passenger compartment; In the heat pump heating mode, the high-temperature, high-pressure superheated refrigerant flows through the first circuit and / or the second circuit from the compressor back to the compressor; the high-temperature, high-pressure superheated refrigerant exchanges heat in the water-cooled condenser, condenses, and the heat enters the heating / cooling water circuit to heat the passenger compartment or the battery; the condensed refrigerant exchanges heat in the battery cooler, and the antifreeze on the liquid side of the battery cooler is cooled and then enters the cooling / heating water circuit to absorb heat from the air or the electric drive; In the hot gas bypass heating mode, a part of the high-temperature and high-pressure superheated refrigerant flows through the first circuit and / or the second circuit from the compressor back to the compressor. This part of the high-temperature and high-pressure superheated refrigerant exchanges heat in the water-cooled condenser, and the high-temperature and high-pressure superheated refrigerant is condensed. The heat enters the heating / cooling water circuit to heat the passenger compartment or heat the battery. At this time, the refrigeration / heating water circuit does not work; the other part of the high-temperature and high-pressure superheated refrigerant is pumped out from the compressor, passes through the large-diameter electronic expansion valve, and merges with the refrigerant at the outlet of the battery cooler on the agent side to supplement enthalpy on the low-pressure side of the system, thereby increasing the pressure of the low-pressure side of the refrigerant and returning to the compressor.

[0011] Preferably, during the operation of the refrigerant system in the upper cooling mode, heat pump heating mode and hot gas bypass heating mode: By adjusting the opening of the electronic expansion valve and the opening of the large-diameter electronic expansion valve 2, the refrigerant flow through the intermediate heat exchanger and the system suction superheat are dynamically adjusted to ensure that the system is in the optimal suction superheat range, as follows: The electronic expansion valve is used for throttling. If the system suction superheat is too high, by increasing the opening of the large-diameter electronic expansion valve 2, part of the refrigerant does not pass through the intermediate heat exchanger for heat exchange and directly returns to the compressor, thereby reducing the refrigerant flow through the intermediate heat exchanger and reducing the system suction superheat; if the system suction superheat is too low, by reducing the opening of the large-diameter electronic expansion valve 2, the refrigerant flow through the intermediate heat exchanger is increased, thereby increasing the system superheat.

[0012] In the system's working mode, the intermediate heat exchanger acts as both an economizer and a forced subcooling circuit breaker for the water-cooled condenser, using high-temperature refrigerant to heat and evaporate the low-pressure side refrigerant again, thereby improving the quality of the low-temperature refrigerant and ensuring the suction superheat.

[0013] Compared with the prior art, the present invention provides a variable heat recovery thermal management system based on R290 refrigerant for new energy vehicles, which has the following beneficial effects: The present invention can achieve functions such as cooling mode, heat pump heating mode, and hot gas bypass mode. By using the intermediate heat exchanger as the forced subcooling section and regenerator of the water-cooled condenser in cooling mode, the present invention serves as an economizer in heating mode. By bypassing the ERV+EXV throttling method, the refrigerant flow through the intermediate heat exchanger can be dynamically adjusted according to different compressor speeds and suction superheat, solving the problem of high suction superheat caused by the intermediate heat exchanger adapting to different refrigerant flow rates. This invention can achieve precise adjustment of suction superheat, improves the COP compared to traditional systems, and also ensures the reliability of the compressor.

[0014] The features and advantages of the present invention will be described in detail through embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1This is a system architecture diagram of a variable heat recovery thermal management system based on R290 refrigerant for new energy vehicles according to the present invention; Figure 2 The operating diagrams of the cooling mode and the heat pump heating mode of the present invention; Figure 3 The operating diagram of the hot gas bypass heating mode of the present invention. DETAILED DESCRIPTION

[0016] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and examples. However, it should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the present invention.

[0017] See Figure 1-Figure 3 A variable heat recovery heat management system based on R290 refrigerant for new energy vehicles includes a refrigerant circuit, a heating / cooling water circuit 9, and a cooling / heating water absorption circuit 10. The refrigerant circuit is connected to the heating / cooling water circuit 9 and the cooling / heating water absorption circuit 10 respectively; The refrigerant circuit includes a first circuit and a second circuit, and the first circuit and the second circuit flow along the refrigerant to the common compressor 1, the agent side channel of the water-cooled condenser 2, the high-pressure side channel of the intermediate heat exchanger 3, the liquid storage tank 4, the electronic expansion valve 6 and the agent side channel of the battery cooler 7; The first circuit flows from the compressor 1 through the agent side channel of the water-cooled condenser 2, the high-pressure side channel of the intermediate heat exchanger 3, the liquid storage tank 4, the electronic expansion valve 6, the agent side channel of the battery cooler 7, and then through the low-pressure side channel of the intermediate heat exchanger 3 back to the compressor 1; The second circuit flows from the compressor 1 through the agent side channel of the water-cooled condenser 2, the high-pressure side channel of the intermediate heat exchanger 3, the liquid storage tank 4, the electronic expansion valve 6, the agent side channel of the battery cooler 7, and then returns to the compressor 1 through the large-diameter electronic expansion valve 2 12.

[0018] Preferably, the circuit inlet of the heating / cooling water circuit 9 is connected to the liquid side channel outlet of the water-cooled condenser 2 , and the circuit outlet of the heating / cooling water circuit 9 is connected to the liquid side channel inlet of the water-cooled condenser 2 .

[0019] Preferably, the circuit inlet of the refrigeration / hot water absorption circuit 10 is connected to the liquid side channel outlet of the battery cooler 7, and the circuit outlet of the refrigeration / hot water absorption circuit 10 is connected to the liquid side channel inlet of the battery cooler 7.

[0020] Preferably, a large-diameter electronic expansion valve 8 is connected in parallel at both ends of the compressor 1, the outlet of the large-diameter electronic expansion valve 8 is connected to the outlet of the agent side channel of the battery cooler 7, and the inlet of the large-diameter electronic expansion valve 8 is connected between the outlet of the compressor 1 and the inlet of the agent side channel of the water-cooled condenser 2.

[0021] Preferably, a low-pressure temperature sensor 11 is provided at the inlet of the compressor 1 , and a high-pressure temperature sensor 5 is provided at the outlet of the liquid storage tank 4 .

[0022] In view of the above system, the present invention also provides a control method for a variable heat recovery thermal management system based on R290 refrigerant for new energy vehicles: The operating modes of the variable regenerative heat management system include cooling mode, heat pump heating mode, and hot gas bypass heating mode. In all three modes, the high-temperature and high-pressure superheated refrigerant flows through at least the first circuit and / or the second circuit from compressor 1 back to compressor 1; In the cooling mode, the high-temperature, high-pressure, superheated refrigerant flows through the first circuit and / or the second circuit from compressor 1 back to compressor 1; the high-temperature, high-pressure, superheated refrigerant exchanges heat in the water-cooled condenser 2, condenses the high-temperature, high-pressure, superheated refrigerant, and the heat is dissipated by the heating / cooling water circuit 9. The condensed refrigerant exchanges heat in the battery cooler 7; the antifreeze on the liquid side of the battery cooler 7 is cooled and enters the cooling / heating water circuit 10 to cool the passenger compartment; In the heat pump heating mode, the high-temperature, high-pressure superheated refrigerant flows through the first circuit and / or the second circuit from the compressor 1 back to the compressor 1; the high-temperature, high-pressure superheated refrigerant exchanges heat in the water-cooled condenser 2, is condensed, and the heat enters the heating / cooling water circuit 9 to heat the passenger compartment or the battery; the condensed refrigerant exchanges heat in the battery cooler 7, and the antifreeze on the liquid side of the battery cooler 7 is cooled and enters the cooling / heating water circuit 10 to absorb heat from the air or the electric drive; In the hot gas bypass heating mode, a part of the high-temperature and high-pressure superheated refrigerant flows through the first circuit and / or the second circuit from the compressor 1 back to the compressor 1, and this part of the high-temperature and high-pressure superheated refrigerant exchanges heat in the water-cooled condenser 2, and the high-temperature and high-pressure superheated refrigerant is condensed, and the heat enters the heating / cooling water circuit 9 to heat the passenger compartment or heat the battery. At this time, the refrigeration / heating water circuit 10 is not working; the other part of the high-temperature and high-pressure superheated refrigerant is pumped out from the compressor 1, passes through the large-diameter electronic expansion valve 8, and merges with the refrigerant at the outlet of the battery cooler 7, replenishes enthalpy on the low-pressure side of the system, increases the pressure of the low-pressure side of the refrigerant, and returns to the compressor 1.

[0023] During the operation of the refrigerant system in the upper cooling mode, heat pump heating mode and hot gas bypass heating mode: By adjusting the opening of the electronic expansion valve 6 and the opening of the large-diameter electronic expansion valve 2 12, the refrigerant flow through the intermediate heat exchanger 3 and the system suction superheat are dynamically adjusted to ensure that the system is in the optimal suction superheat range, as follows: The electronic expansion valve 6 is used for throttling. If the system suction superheat is too high, by increasing the opening of the large-diameter electronic expansion valve 2 12, part of the refrigerant does not pass through the intermediate heat exchanger 3 for heat exchange, and directly returns to the compressor 1, thereby reducing the refrigerant flow through the intermediate heat exchanger 3 and reducing the system suction superheat; if the system suction superheat is too low, by reducing the opening of the large-diameter electronic expansion valve 2 12, the refrigerant flow through the intermediate heat exchanger 3 is increased, thereby increasing the system superheat.

[0024] It is further explained that the intermediate heat exchanger 3 has a microchannel inside, and the high-pressure side refrigerant and the low-pressure side refrigerant exchange heat inside it. In the working mode of the system, the intermediate heat exchanger 3 acts as both an economizer and a forced subcooling circuit breaker for the water-cooled condenser 2. The high-temperature refrigerant is used to heat and evaporate the low-pressure side refrigerant again, thereby improving the quality of the low-temperature refrigerant and ensuring the suction superheat.

[0025] This invention cleverly utilizes the ERV+EXV (electronic expansion valve + large-diameter electronic expansion valve) throttling method to achieve functions such as cooling, heat pump heating, and hot gas bypass heating. Compared with traditional systems, it improves the COP and effectively reduces energy consumption. This thermal management system solution can replace the traditional R134a refrigerant system and can achieve effective heating under low ambient temperatures.

[0026] Through the present invention, the intermediate heat exchanger is fully utilized as a regenerator, economizer, and forced subcooling section of the LCC, thereby solving the problems of high pressure, insufficient subcooling, and low suction superheat of R290 in different operating modes.

[0027] This invention dynamically adjusts the refrigerant flow through the intermediate heat exchanger based on the compressor speed and intake superheat, resolving the problem of high intake superheat caused by the intermediate heat exchanger adapting to different refrigerant flow rates. This invention enables precise adjustment of intake superheat, improving the cost-effectiveness (COP) compared to traditional systems while also ensuring compressor reliability.

[0028] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A variable heat recovery thermal management system based on R290 refrigerant for new energy vehicles, characterized by: It comprises a refrigerant circuit, a heating / cooling water circuit (9) and a cooling / heating water absorption circuit (10), wherein the refrigerant circuit is respectively connected to the heating / cooling water circuit (9) and the cooling / heating water absorption circuit (10); The refrigerant circuit includes a first circuit and a second circuit, wherein the first circuit and the second circuit flow along the refrigerant to the common compressor (1), the agent side channel of the water-cooled condenser (2), the high-pressure side channel of the intermediate heat exchanger (3), the liquid storage tank (4), the electronic expansion valve (6) and the agent side channel of the battery cooler (7); The first circuit flows from the compressor (1) through the agent side channel of the water-cooled condenser (2), the high-pressure side channel of the intermediate heat exchanger (3), the liquid storage tank (4), the electronic expansion valve (6), the agent side channel of the battery cooler (7), and then through the low-pressure side channel of the intermediate heat exchanger (3) back to the compressor (1); The second circuit flows from the compressor (1) through the agent side channel of the water-cooled condenser (2), the high-pressure side channel of the intermediate heat exchanger (3), the liquid storage tank (4), the electronic expansion valve (6), the agent side channel of the battery cooler (7), and then returns to the compressor (1) through the large-diameter electronic expansion valve 2 (12).

2. A variable heat recovery thermal management system based on R290 refrigerant for new energy vehicles according to claim 1, characterized in that: The circuit inlet of the heating / cooling water circuit (9) is connected to the liquid side channel outlet of the water-cooled condenser (2), and the circuit outlet of the heating / cooling water circuit (9) is connected to the liquid side channel inlet of the water-cooled condenser (2).

3. A variable heat recovery thermal management system based on R290 refrigerant for new energy vehicles according to claim 1, characterized in that: The circuit inlet of the refrigeration / heat water absorption circuit (10) is connected to the liquid side channel outlet of the battery cooler (7), and the circuit outlet of the refrigeration / heat water absorption circuit (10) is connected to the liquid side channel inlet of the battery cooler (7).

4. A variable heat recovery thermal management system based on R290 refrigerant for new energy vehicles according to claim 1, characterized in that: A large-diameter electronic expansion valve (8) is also connected in parallel at both ends of the compressor (1), the outlet of the large-diameter electronic expansion valve (8) is connected to the outlet of the agent side channel of the battery cooler (7), and the inlet of the large-diameter electronic expansion valve (8) is connected between the outlet of the compressor (1) and the inlet of the agent side channel of the water-cooled condenser (2).

5. The variable heat recovery thermal management system based on R290 refrigerant for new energy vehicles according to claim 1, characterized in that: A low-pressure temperature sensor (11) is provided at the inlet of the compressor (1), and a high-pressure temperature sensor (5) is provided at the outlet of the liquid storage tank (4).

6. A control method for a variable heat recovery thermal management system based on R290 refrigerant for new energy vehicles according to any one of claims 1 to 5, characterized in that: The operating modes of the variable regenerative heat management system include a cooling mode, a heat pump heating mode, and a hot gas bypass heating mode. In the three modes, the high-temperature and high-pressure superheated refrigerant flows through at least the first circuit and / or the second circuit from the compressor (1) back to the compressor (1); In the cooling mode, the high-temperature and high-pressure superheated refrigerant flows through the first circuit and / or the second circuit from the compressor (1) back to the compressor (1); the high-temperature and high-pressure superheated refrigerant exchanges heat in the water-cooled condenser (2), the high-temperature and high-pressure superheated refrigerant is condensed, and the heat is dissipated by means of the heating / cooling water circuit (9), and the condensed refrigerant exchanges heat in the battery cooler (7); the antifreeze on the liquid side of the battery cooler (7) is cooled and enters the cooling / heating water circuit (10) to cool the passenger compartment; In the heat pump heating mode, the high-temperature and high-pressure superheated refrigerant flows through the first circuit and / or the second circuit from the compressor (1) back to the compressor (1); the high-temperature and high-pressure superheated refrigerant exchanges heat in the water-cooled condenser (2), the high-temperature and high-pressure superheated refrigerant is condensed, and the heat enters the heating / cooling water circuit (9) to heat the passenger cabin or the battery; the condensed refrigerant exchanges heat in the battery cooler (7), and the antifreeze on the liquid side of the battery cooler (7) is cooled and enters the refrigeration / heating water circuit (10) to absorb heat from the air or the electric drive; In the hot gas bypass heating mode, a portion of the high-temperature and high-pressure superheated refrigerant flows through the first circuit and / or the second circuit from the compressor (1) back to the compressor (1), and the portion of the high-temperature and high-pressure superheated refrigerant exchanges heat in the water-cooled condenser (2). The high-temperature and high-pressure superheated refrigerant is condensed, and the heat enters the heating / cooling water circuit (9) to heat the passenger cabin or the battery. At this time, the cooling / heating water circuit (10) does not work; the other portion of the high-temperature and high-pressure superheated refrigerant is pumped out from the compressor (1), passes through the large-diameter electronic expansion valve (8), and merges with the refrigerant at the outlet of the battery cooler (7) on the agent side, replenishes enthalpy on the low-pressure side of the system, increases the pressure of the low-pressure side of the refrigerant, and returns to the compressor (1).

7. The control method of a variable heat recovery thermal management system based on R290 refrigerant for new energy vehicles according to claim 6, characterized in that: During the operation of the refrigerant system in the upper cooling mode, heat pump heating mode and hot gas bypass heating mode: By adjusting the opening of the electronic expansion valve (6) and the opening of the large-diameter electronic expansion valve 2 (12), the refrigerant flow through the intermediate heat exchanger (3) and the system suction superheat are dynamically adjusted to ensure that the system is in the optimal suction superheat range, as follows: The electronic expansion valve (6) is used for throttling. If the system suction superheat is too high, the opening of the large-diameter electronic expansion valve 2 (12) is increased so that part of the refrigerant does not pass through the intermediate heat exchanger (3) for heat exchange and directly returns to the compressor (1), thereby reducing the refrigerant flow through the intermediate heat exchanger (3) and reducing the system suction superheat. If the system suction superheat is too low, the opening of the large-diameter electronic expansion valve 2 (12) is reduced to increase the refrigerant flow through the intermediate heat exchanger (3) and increase the system superheat.

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