A secondary loop heat pump air conditioning system

Abstract

A secondary loop heat pump air conditioning system includes a refrigerant loop, a chilled water loop, a hot water loop, and a battery loop. The compressor exhaust port is sequentially connected to a third electronic expansion valve, a water-cooled condenser, a first electronic expansion valve, a plate heat exchanger, a gas-liquid separator, and the compressor inlet to form the refrigerant loop. The chilled water loop, hot water loop, and battery loop are connected via a six-way valve. The chilled water loop is formed by connecting the fifth working port of the six-way valve to a first three-way valve, then to the plate heat exchanger and the cold air core, respectively. The plate heat exchanger is connected to a second water pump and then to the sixth working port of the six-way valve connected to the cold air core. The hot water loop is formed by connecting the fourth working port of the six-way valve to the water-cooled condenser via the first water pump, then to a second three-way valve. The second three-way valve is connected to the fourth working port of the six-way valve and the warm air core, respectively. The warm air core is connected to the first water pump. The battery loop is formed by connecting the first working port of the six-way valve to the battery cooling plate via the battery water pump, then to the inlet of a one-way valve and the second working port of the six-way valve, and the outlet of the one-way valve is connected to the battery water pump.

Description

Technical Field

[0001] This invention relates to the field of automotive air conditioning, and more specifically to a secondary loop heat pump air conditioning system. Background Technology

[0002] Currently, most new energy vehicles in China use R134a as a refrigerant. However, R134a is a strong greenhouse gas, and its emissions will contribute to global warming. According to relevant laws and regulations, R134a will be replaced by other more environmentally friendly refrigerants, such as R290. However, R290 is a flammable and explosive refrigerant, posing certain safety hazards. Therefore, a secondary circuit is required to prevent R290 from entering the passenger compartment and ensure its safety.

[0003] In existing heat pump system technologies, both the battery and the passenger compartment in the secondary loop are cooled by plate heat exchangers, while both are heated by water-cooled condensers. Because the battery and passenger compartment share the same cold source plate heat exchanger and heat source water-cooled condenser, and their cooling / heating performance requirements differ significantly, it is difficult to simultaneously meet the different cooling or heating performance needs of the battery and passenger compartment. That is, while meeting the battery's cooling needs, it is impossible to simultaneously meet the different cooling performance needs of the passenger compartment, or vice versa. The same applies to heating. Therefore, there is an urgent need for a heat pump air conditioning system that can simultaneously meet the cooling or heating needs of both the battery and the passenger compartment. Summary of the Invention

[0004] To address the problems existing in the aforementioned heat pump system technologies, this invention proposes a secondary loop air conditioning system. This system uses a secondary loop to cool and heat the passenger compartment and the battery, preventing refrigerant from entering the passenger compartment and improving safety. At the same time, while meeting the cooling and heating needs of the passenger compartment, the system ensures that the different cooling and heating performance requirements of the battery are met through water mixing via a single-way valve loop.

[0005] The technical solution of this invention is a secondary loop heat pump air conditioning system, including a refrigerant loop, a chilled water loop, a hot water loop, and a battery loop. The refrigerant loop includes a compressor, an electronic expansion valve, a water-cooled condenser, a plate heat exchanger, and a gas-liquid separator. The compressor's exhaust port is sequentially connected to a third electronic expansion valve, the refrigerant passage of the water-cooled condenser, a first electronic expansion valve, the refrigerant passage of the plate heat exchanger, the gas-liquid separator, and the compressor's inlet to form the refrigerant loop. The chilled water loop, the hot water loop, and the battery loop are connected through a six-way valve. The chilled water loop has its fifth working port connected to a first three-way valve. The first three-way valve is respectively connected to the chilled water passage of the plate heat exchanger and the air inlet of the compressor. The cold air core of the air conditioning unit is connected to a plate heat exchanger via a second water pump. Both the second water pump and the cold air core are connected to the sixth working port of a six-way valve. The hot water circuit is connected to the hot water channel of a water-cooled condenser via the fourth working port of the six-way valve and a first water pump. The water-cooled condenser is connected to a second three-way valve, which is connected to the fourth working port of the six-way valve and the warm air core of the air conditioning unit. The warm air core is connected to the first water pump, which is bypassed to a bypass kettle. The battery circuit is connected to a battery cooling plate via a battery water pump via the first working port of the six-way valve. The battery cooling plate is connected to the inlet of a one-way valve and the second working port of the six-way valve, and the outlet of the one-way valve is connected to the battery water pump.

[0006] Preferably, the six-way valve includes two control modes: cooling and heating. In the cooling mode, the first working port of the six-way valve is connected to the fifth working port, the second working port is connected to the sixth working port, and the third working port is connected to the fourth working port. In the heating mode, the first working port of the six-way valve is connected to the third working port, the second working port is connected to the fourth working port, and the fifth working port is connected to the sixth working port.

[0007] Preferably, a first temperature sensor and a second temperature sensor are respectively provided at both ends of the battery cold plate.

[0008] Preferably, a third temperature sensor is provided between the first three-way valve and the cold air core, and a fourth temperature sensor is provided between the second three-way valve and the warm air core.

[0009] Preferably, the compressor's exhaust port is bypassed by a second electronic expansion valve to the compressor's intake port.

[0010] Preferably, the refrigerant circuit uses R290 as the refrigerant.

[0011] The advantage of this invention lies in its ability to meet the different performance requirements of simultaneously cooling or heating the passenger compartment and the battery. When simultaneously cooling or heating the passenger compartment and the battery, this invention controls the water flow distribution to and from the passenger compartment and the battery by adjusting a first three-way valve or a second three-way valve to meet the passenger compartment's flow requirements, and uses system control to meet the passenger compartment's temperature requirements. If the battery temperature and flow cannot be met, the battery water pump can be activated to increase the water flow rate in the battery circuit to meet the battery's flow requirements. Simultaneously, the one-way valve circuit operates, and the water circulating into the battery circuit also plays a role in mixing the water. This mixing can raise or lower the battery's inlet water temperature, ensuring the battery's temperature requirements are met. Attached Figure Description

[0012] Figure 1 This is a system structure diagram of the present invention;

[0013] Figure 2 The diagram shows two control modes of the six-way valve of this invention. Implementation

[0014] See Figures 1 to 2A secondary loop heat pump air conditioning system includes a refrigerant loop, a chilled water loop, a hot water loop, and a battery loop. The refrigerant loop uses R290 as the refrigerant and includes a compressor 8, an electronic expansion valve, a water-cooled condenser 10, a plate heat exchanger 12, and a gas-liquid separator 13. The exhaust port of the compressor 8 is sequentially connected to a third electronic expansion valve 9, the refrigerant passage of the water-cooled condenser 10, a first electronic expansion valve 11, the refrigerant passage of the plate heat exchanger 12, the gas-liquid separator 13, and the intake port of the compressor 9 to form a refrigerant loop. The exhaust port of the compressor 8 is bypassed by a second electronic expansion valve 14 to the intake port of the compressor. The function of bypassing the second electronic expansion valve 14 is to increase the suction pressure of the compressor 9. The cold water circuit, hot water circuit, and battery circuit are connected by a six-way valve 7. The cold water circuit is connected to the first three-way valve 20 via the fifth working port 5 of the six-way valve 7. The first three-way valve 20 is connected to the cold water channel of the plate heat exchanger 12 and the cold air core 22 of the air conditioning unit. A third temperature sensor 21 is provided between the first three-way valve 20 and the cold air core 22. The third temperature sensor 21 is used to detect the water temperature flowing through the cold air core 22. The plate heat exchanger 12 is connected to a second water pump 19. The second water pump 19 and the cold air core 22 are both connected to the sixth working port 6 of a six-way valve 7. The hot water circuit is connected to the hot water channel of the water-cooled condenser 10 via the fourth working port 4 of the six-way valve 7 and the first water pump 15. The water-cooled condenser 10 is connected to a second three-way valve 16. The second three-way valve 16 is connected to the fourth working port 4 of the six-way valve 7 and the warm air core 18 of the air conditioning unit. A fourth temperature sensor 17 is provided between the second three-way valve 16 and the warm air core 18 to detect the water temperature flowing through the warm air core 18. The warm air core 18 is connected to the first water pump 15, which is bypassed to a bypass kettle 28. The bypass kettle 28 is used to replenish water to the circuit. The battery circuit consists of a six-way valve 7 whose first working port 1 is connected to a battery cooling plate 25 via a battery water pump 23. A first temperature sensor 24 and a second temperature sensor 26 are respectively installed at both ends of the battery cooling plate 25. The temperature of the water flowing into and out of the battery cooling plate is determined by the first temperature sensor 24 and the second temperature sensor 26, thereby confirming whether the battery temperature requirement is met. The battery cooling plate 25 is connected to the inlet of a one-way valve 27 and the second working port 2 of the six-way valve 7. The outlet of the one-way valve 27 is connected to the battery water pump 23.

[0015] The six-way valve 7 of the present invention includes two control modes: cooling and heating. In the cooling mode, the first working port 1 of the six-way valve 7 is connected to the fifth working port 5, the second working port 2 is connected to the sixth working port 6, and the third working port 3 is connected to the fourth working port 4. In the heating mode, the first working port 1 of the six-way valve is connected to the third working port 3, the second working port 2 is connected to the fourth working port 4, and the fifth working port 5 is connected to the sixth working port 6.

[0016] The cooling mode is used to cool the crew compartment and battery. Its working principle is as follows: In the cooling mode with the six-way valve 7, the compressor 8 provides the power for the circulation of R290 in the refrigerant circuit. The compressor 8 compresses the R290 refrigerant into high-temperature, high-pressure R290. The R290 flows from the compressor 8's exhaust port through the third electronic expansion valve 9, the water-cooled condenser 10, and the first electronic expansion valve 11, where it absorbs heat from the water in the cold water circuit at the plate heat exchanger 12, lowering the water temperature. Finally, it returns to the compressor 8's suction port via the gas-liquid separator 13. At this time, the water temperature in the cold water circuit is cooled at the plate heat exchanger 12, and the second water pump 19 provides power for the water flow. When the water flows to the first three-way valve 20, the flow is controlled according to the cooling needs of the crew compartment and battery. The first three-way valve 20 regulates the water flow to the cold air core 22 and the battery circuit. Part of the cold water flows to the cold air core 22 of the air conditioning unit, and the blower distributes the cold energy to the passenger compartment to complete the passenger compartment cooling. The other part of the cold water flows from the cold water circuit to the battery circuit through the six-way valve 7 to cool the battery cold plate 25, thus completing the simultaneous cooling of the passenger compartment and the battery. However, if the first three-way valve 20 cannot meet the cooling needs of the passenger compartment and the battery at the same time, the needs of the passenger compartment will be prioritized. At the same time, the battery water pump 23 and the one-way valve 27 are opened in the battery circuit. The battery water pump 23 accelerates the water flow in the battery circuit, and the one-way valve 27 operates in the circuit and the water flowing into the battery circuit also plays a role in mixing water. Mixing water can increase the battery inlet water temperature and ensure the battery temperature requirements.

[0017] The heating mode is used to heat the crew compartment and battery. Its working principle is as follows: In the heating mode of the six-way valve 7, the compressor 8 provides the power for the circulation of R290 in the refrigerant circuit. The compressor 8 compresses the R290 refrigerant into high-temperature, high-pressure R290. The R290 exits the compressor 8's exhaust port, passes through the third electronic expansion valve 9, and releases heat in the water-cooled condenser 10, raising the water temperature in the hot water circuit. The R290 then passes through the first electronic expansion valve 11, plate heat exchanger 12, and gas-liquid separator 13 before returning to the compressor 8's suction port. At this time, the water temperature in the hot water circuit rises at the water-cooled condenser 10, providing power for water flow via the first water pump 15. When the water flows to the second three-way valve 16, the flow is adjusted according to the heating needs of the crew compartment and battery by controlling the second and third... The valve 16 regulates the water flow to the heater core 18 and the battery circuit. Part of the hot water flows to the heater core 18 of the air conditioning unit, and the heat is dissipated to the passenger compartment by the blower to complete the heating of the passenger compartment. The other part of the hot water flows from the hot water circuit to the battery circuit through the six-way valve 7 to heat the battery cold plate 25 and complete the simultaneous heating of the passenger compartment and the battery. However, if the second and third-way valves 16 cannot meet the heating needs of the passenger compartment and the battery at the same time, the needs of the passenger compartment are given priority. At the same time, the battery water pump 23 and the one-way valve 27 are opened in the battery circuit. The battery water pump 23 accelerates the water flow in the battery circuit. The one-way valve 27 operates in the circuit and the water flowing into the battery circuit also plays a role in mixing water. Mixing water can reduce the battery inlet water temperature and ensure the battery temperature requirements.

Claims

1. A secondary loop heat pump air conditioning system, comprising a refrigerant loop, a chilled water loop, a hot water loop, and a battery loop, wherein the refrigerant loop comprises a compressor (8), an electronic expansion valve, a water-cooled condenser (10), a plate heat exchanger (12), and a gas-liquid separator (13), wherein the exhaust port of the compressor (8) is sequentially connected to a third electronic expansion valve (9), the refrigerant passage of the water-cooled condenser (10), a first electronic expansion valve (11), the refrigerant passage of the plate heat exchanger (12), the gas-liquid separator (13), and the air inlet of the compressor (8) to form a refrigerant loop, characterized in that: The cold water circuit, hot water circuit, and battery circuit are connected by a six-way valve (7). The cold water circuit is connected to the first three-way valve (20) via the fifth working port (5) of the six-way valve (7). The first three-way valve (20) is connected to the cold water channel of the plate heat exchanger (12) and the cold air core (22) of the air conditioning unit. The plate heat exchanger (12) is connected to the second water pump (19). The second water pump (19) and the cold air core (22) are both connected to the sixth working port (6) of the six-way valve (7). The hot water circuit is connected to the hot water channel of the water-cooled condenser (10) via the fourth working port (4) of the six-way valve (7) through the first water pump (15). The condenser (10) is connected to the second three-way valve (16), which is connected to the fourth working port (4) of the six-way valve (7) and the heating core (18) of the air conditioning unit. The heating core (18) is connected to the first water pump (15), which is connected to a bypass kettle (28) via a bypass. The battery circuit is connected to the first working port (1) of the six-way valve (7) via the battery water pump (23) and the battery cold plate (25). The battery cold plate (25) is connected to the inlet of a one-way valve (27) and the second working port (2) of the six-way valve (7). The outlet of the one-way valve (27) is connected to the battery water pump (23).

2. The secondary loop heat pump air conditioning system according to claim 1, characterized in that: The six-way valve (7) includes two control modes: cooling and heating. In the cooling mode, the first working port (1) of the six-way valve (7) is connected to the fifth working port (5), the second working port (2) is connected to the sixth working port (6), and the third working port (3) is connected to the fourth working port (4). In the heating mode, the first working port (1) of the six-way valve is connected to the third working port (3), the second working port (2) is connected to the fourth working port (4), and the fifth working port (5) is connected to the sixth working port (6).

3. The secondary loop heat pump air conditioning system according to claim 1, characterized in that: The battery cold plate (25) is provided with a first temperature sensor (24) and a second temperature sensor (26) at both ends.

4. A secondary loop heat pump air conditioning system according to claim 1, characterized in that: A third temperature sensor (21) is provided between the first three-way valve (20) and the cold air core (22), and a fourth temperature sensor (17) is provided between the second three-way valve (16) and the warm air core (18).

5. A secondary loop heat pump air conditioning system according to claim 1, characterized in that: The exhaust port of the compressor (8) is bypassed by a second electronic expansion valve (14) to the intake port of the compressor.

6. A secondary loop heat pump air conditioning system according to claim 1, characterized in that: The refrigerant circuit uses R290 as the refrigerant.

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