Indirect CO2 heat pump air conditioning system

Abstract

The invention relates to an indirect CO2 heat pump air conditioning system which adopts CO2 as a refrigerant, and a refrigerant loop comprises a compressor, a heat exchanger, a heat regenerator, an expansion valve, a plate heat exchanger and a gas-liquid separator which are connected through pipelines; the high-temperature cooling liquid loop comprises a heat exchanger, a first water pump and a warm air core body which are connected through pipelines. The low-temperature cooling liquid loop comprises a plate heat exchanger, a second water pump and a water-cooled evaporator which are connected through pipelines. CO2 is adopted as a refrigerant, the refrigerant does not directly enter the cabin, and heat exchange is conducted between the refrigerant and cooling liquid; and the high-temperature cooling liquid and the low-temperature cooling liquid after heat exchange with the refrigerant enter the cabin to exchange heat with cabin air, so that the functions of cabin refrigeration, heat pump heating, water heating PTC heating and defrosting and demisting are realized.

Description

Technical Field

[0001] This invention relates to the field of pure electric commercial vehicle technology, and in particular to an indirect CO2 heat pump air conditioning system. Background Technology

[0002] Existing air conditioning systems mostly use R134a refrigerant, achieving cooling through refrigerant circulation. New energy thermal management systems achieve heat pump heating by changing the flow direction of R134a, allowing the refrigerant to directly enter the cabin; however, R134a is not an environmentally friendly refrigerant, and the system is limited by the physical properties of R134a, resulting in poor heat pump heating performance at low temperatures (-10℃).

[0003] Existing CO2 heat pump air conditioning systems mostly adopt a direct type, with the compressor and condenser located in different positions on the chassis, and the evaporator located in the cabin; however, the components related to the refrigerant circuit are scattered, resulting in long refrigerant pipes and many joints; due to the high pressure of the CO2 system, sealing is difficult, and refrigerant leakage is a serious problem. Summary of the Invention

[0004] The purpose of this invention is to provide an indirect CO2 heat pump air conditioning system that addresses the shortcomings of existing technologies.

[0005] This invention is achieved using the following technical solution:

[0006] An indirect CO2 heat pump air conditioning system, using CO2 as a refrigerant, includes:

[0007] A refrigerant circuit, comprising a compressor, heat exchanger, regenerator, expansion valve, plate heat exchanger, and gas-liquid separator connected by pipelines;

[0008] A high-temperature coolant circuit, comprising a heat exchanger, a water pump, and a heater core connected by pipes;

[0009] The cryogenic coolant circuit includes a plate heat exchanger, a water pump, and a water-cooled evaporator connected by pipes.

[0010] As a further explanation of the invention, the refrigerant circuit is centrally located within the heat pump unit.

[0011] As a further explanation of the invention, it also includes a blower and a damper mechanism; the warm air core, the water-cooled evaporator, the blower and the damper mechanism together constitute an air conditioning unit assembly.

[0012] As a further explanation of the invention, the high-temperature coolant circuit also includes a water-heated PTC; the water-heated PTC is connected to the water pump.

[0013] As a further illustration of the invention, the high-temperature coolant circuit also includes an outdoor heat exchanger; the outdoor heat exchanger is disposed between the water-cooled PTC and the heat exchanger.

[0014] As a further illustration of the invention, the cryogenic coolant circuit also includes a motor; the motor is disposed between the second water pump and the plate heat exchanger.

[0015] As a further explanation of the invention, the water-cooled PTC, the heating core, and the outdoor heat exchanger are connected by a three-way valve.

[0016] As a further explanation of the invention, the second water pump, the motor, and the water-cooled evaporator are connected by a third-way valve.

[0017] Compared with the prior art, the present invention has the following beneficial technical effects:

[0018] The indirect CO2 heat pump air conditioning system provided by this invention uses CO2 as the refrigerant, solving the environmental problem of R134a refrigerant. It can operate in an environment of -30℃ to 45℃, solving the problem of poor heating performance of R134a refrigerant at low temperatures, and effectively improving the competitiveness of new energy vehicles in low-temperature conditions. At the same time, under low-temperature (-20℃) heat pump conditions, the COP is greater than 2, which is higher than the COP of PTC heating and R134a heat pump heating, which can reduce the energy consumption of the whole vehicle and increase the driving range of the whole vehicle. In addition, the refrigerant circuit components are concentrated in the unit, and the pipeline and key components are connected by welding, which can effectively solve the refrigerant leakage problem and ensure the reliability of the system. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the CO2 heat pump air conditioning system of the present invention;

[0020] Figure 2 This is a schematic diagram of the air conditioning refrigeration principle of the present invention;

[0021] Figure 3 This is a schematic diagram of the heating principle of the air conditioner heat pump of the present invention;

[0022] Figure 4 This is a schematic diagram of the PTC heating principle of the air conditioning water heating system of the present invention;

[0023] Figure 5 This is a schematic diagram illustrating the air conditioner defrosting and defogging principle of the present invention.

[0024] In the diagram, 1. Compressor; 2. Heat exchanger; 3. Regenerator; 4. Expansion valve; 5. Plate heat exchanger; 6. Gas-liquid separator; 7. Blower; 8. Water-cooled evaporator; 9. Damper mechanism; 10. Heater core; 11. Water pump one; 12. PTC water heater; 13. Three-way valve one; 14. Outdoor heat exchanger; 15. Water pump two; 16. Three-way valve two; 17. Motor. Detailed Implementation

[0025] like Figure 1 As shown, an indirect CO2 heat pump air conditioning system, using CO2 as a refrigerant, includes:

[0026] The refrigerant circuit includes a compressor 1, a heat exchanger 2, a regenerator 3, an expansion valve 4, a plate heat exchanger 5, and a gas-liquid separator 6 connected by pipelines.

[0027] High-temperature coolant circuit, which includes heat exchanger 2, water pump 11, and heater core 10 connected by pipes;

[0028] The cryogenic coolant circuit includes a plate heat exchanger 5 with pipe connections, a water pump 15, and a water-cooled evaporator 8.

[0029] The refrigerant circuit is centrally located within the heat pump unit. With all refrigerant circuit components concentrated within the unit, and welding processes used between piping and key components, refrigerant leakage is effectively prevented, ensuring system reliability.

[0030] It also includes a blower 7 and a damper mechanism 9; the heater core 10, water-cooled evaporator 8, blower 7 and damper mechanism 9 together constitute the air conditioning unit assembly. The fluid medium flowing in the water-cooled evaporator 8 is coolant, and heat is exchanged with the air in the cabin through the low-temperature coolant.

[0031] The high-temperature coolant circuit also includes a water-heating PTC12; the water-heating PTC12 is connected to water pump 11.

[0032] The high-temperature coolant circuit also includes an outdoor heat exchanger 14; the outdoor heat exchanger 14 is located between the water heating PTC 12 and the heat exchanger 2.

[0033] The cryogenic coolant circuit also includes a motor 17; the motor 17 is located between the water pump 15 and the plate heat exchanger 5.

[0034] The water-cooled PTC, the heating core 10, and the outdoor heat exchanger are connected by a three-way valve 13.

[0035] The water pump 215, the motor, and the water-cooled evaporator 8 are connected via a three-way valve 216.

[0036] The indirect CO2 heat pump air conditioning system provided by this invention uses CO2 as the refrigerant, solving the environmental problem of R134a refrigerant. It can operate in environments ranging from -30℃ to 45℃, addressing the poor heating performance of R134a refrigerant at low temperatures, effectively improving the competitiveness of new energy vehicles in low-temperature conditions. Simultaneously, under low-temperature (-20℃) heat pump conditions, its COP > 2, higher than that of PTC heating and R134a heat pump heating, reducing overall vehicle energy consumption and increasing driving range. Furthermore, the refrigerant circuit components are concentrated within the unit, and welding is used between pipes and key components, effectively solving refrigerant leakage problems and ensuring system reliability. The refrigerant does not directly enter the cabin; instead, it exchanges heat with the coolant. The high-temperature and low-temperature coolants, after heat exchange with the refrigerant, enter the cabin and exchange heat with the cabin air, thereby achieving cabin cooling, heat pump heating, PTC water heating, and defrosting / defogging functions. Specific embodiments are as follows:

[0037] Example 1

[0038] like Figure 2 As shown, in air conditioning cooling mode, the three loops cycle as follows:

[0039] Refrigerant circuit flow: Compressor 1 → Heat exchanger 2 → Regenerator 3 → Expansion valve 4 → Plate heat exchanger 5 → Gas-liquid separator 6 → Regenerator 3 → Compressor 1.

[0040] High-temperature coolant circuit flow direction: heat exchanger 2 → water pump 11 → three-way valve 13 → outdoor heat exchanger 14 → heat exchanger 2;

[0041] Low-temperature coolant circuit flow direction: Plate heat exchanger 5 → Water pump 2 15 → Three-way valve 2 16 → Water-cooled evaporator 8 → Plate heat exchanger 5.

[0042] Compressor 1 operates, and CO2 refrigerant circulates within the heat pump unit. The fan operates, cooling the high-temperature coolant through outdoor heat exchanger 14. The high-temperature coolant cools the refrigerant within heat exchanger 2. After being throttled by expansion valve 4, the CO2 refrigerant absorbs heat from the coolant in plate heat exchanger 5. The low-temperature coolant is then transported to water-cooled evaporator 8 by water pump 15, where it is cooled. Air in the cabin flows through water-cooled evaporator 8 under the action of blower 7 and enters the cabin, further cooling it.

[0043] Example 2

[0044] like Figure 3 As shown, in the air conditioner heat pump heating mode, the three loops cycle as follows:

[0045] Refrigerant circuit flow: Compressor 1 → Heat exchanger 2 → Regenerator 3 → Expansion valve 4 → Plate heat exchanger 5 → Gas-liquid separator 6 → Regenerator 3 → Compressor 1.

[0046] High-temperature coolant circuit flow direction: heat exchanger 2 → water pump 11 → three-way valve 13 → heater core 10 → heat exchanger 2;

[0047] Low-temperature coolant circuit flow direction: Plate heat exchanger 5 → Water pump 2 15 → Three-way valve 2 16 → Motor 17 → Plate heat exchanger 5.

[0048] Compressor 1 operates, and CO2 refrigerant circulates within the heat pump unit. The high-temperature refrigerant circulates within the heat pump unit and exchanges heat with the coolant in heat exchanger 2, heating the coolant and cooling the refrigerant. After being heated, the high-temperature coolant enters the heater core 10 under the action of water pump 11. The air conditioning unit's damper mechanism 9 opens, and cabin air flows through the heater core 10 under the action of blower 7 before entering the cabin to heat it. Water pump 15 operates, and the low-temperature coolant, heated by motor 17, enters the plate heat exchanger 5 to exchange heat with the refrigerant. After absorbing heat through evaporation, the refrigerant passes through gas-liquid separator 6 and regenerator 3 before entering compressor 1.

[0049] Example 3

[0050] like Figure 4 As shown, in the PTC heating mode of the air conditioning water heating system, only the high-temperature coolant circuit circulates.

[0051] When the PTC12 water heater is turned on, the coolant is heated after flowing through the PTC12 under the action of the water pump 11, and the high-temperature coolant enters the heater core 10; when the air conditioning unit assembly damper mechanism 9 is turned on, the air in the cabin flows through the heater core 10 under the action of the blower 7 and enters the cabin to heat the cabin.

[0052] Example 4

[0053] like Figure 5 As shown, the air conditioner's defrost and defog mode operates in three loops as follows:

[0054] Refrigerant circuit flow: Compressor 1 → Heat exchanger 2 → Regenerator 3 → Expansion valve 4 → Plate heat exchanger 5 → Gas-liquid separator 6 → Regenerator 3 → Compressor 1.

[0055] High-temperature coolant circuit flow direction: heat exchanger 2 → water pump 11 → three-way valve 13 → heater core 10 → heat exchanger 2;

[0056] Low-temperature coolant circuit flow direction: Plate heat exchanger 5 → Water pump 2 15 → Three-way valve 2 16 → Water-cooled evaporator 8 → Plate heat exchanger 5.

[0057] Compressor 1 operates, and CO2 refrigerant circulates within the heat pump unit. High-temperature refrigerant exchanges heat with the coolant in heat exchanger 2, heating the coolant and cooling the refrigerant. The heated coolant then enters the heater core 10 under the action of water pump 11. After being throttled by expansion valve 4, the refrigerant absorbs heat from the coolant in plate heat exchanger 5. The low-temperature coolant is then transported to the water-cooled evaporator 8 under the action of water pump 15, where it is cooled. The air conditioning unit's damper mechanism 9 opens, and cabin air flows through the water-cooled evaporator 8 under the action of blower 7. Condensation forms on the humid air at the water-cooled evaporator 8, drying the air. The dried air then flows through the heater core 10 and is heated. The hot, dry air enters the cabin to defrost and defog it.

[0058] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An indirect CO2 heat pump air conditioning system, characterized in that, Using CO2 as a refrigerant includes: A refrigerant circuit, comprising a compressor, heat exchanger, regenerator, expansion valve, plate heat exchanger, and gas-liquid separator connected by pipelines; A high-temperature coolant circuit, comprising a heat exchanger, a water pump, and a heater core connected by pipes; The cryogenic coolant circuit includes a plate heat exchanger, a water pump, and a water-cooled evaporator connected by pipes.

2. The indirect CO2 heat pump air conditioning system as described in claim 1, characterized in that, The refrigerant circuit is centrally located within the heat pump unit.

3. The indirect CO2 heat pump air conditioning system as described in claim 2, characterized in that, It also includes a blower and a damper mechanism; the heating core, the water-cooled evaporator, the blower and the damper mechanism together constitute the air conditioning unit assembly.

4. The indirect CO2 heat pump air conditioning system as described in claim 3, characterized in that, The high-temperature coolant circuit also includes a water-heated PTC; the water-heated PTC is connected to the water pump.

5. The indirect CO2 heat pump air conditioning system as described in claim 4, characterized in that, The high-temperature coolant circuit also includes an outdoor heat exchanger; the outdoor heat exchanger is located between the water-cooled PTC and the heat exchanger.

6. The indirect CO2 heat pump air conditioning system as described in claim 5, characterized in that, The cryogenic coolant circuit also includes a motor; the motor is located between the second water pump and the plate heat exchanger.

7. The indirect CO2 heat pump air conditioning system as described in claim 6, characterized in that, The water-cooled PTC, the heating core, and the outdoor heat exchanger are connected by a three-way valve.

8. The indirect CO2 heat pump air conditioning system as described in claim 7, characterized in that, The second water pump, the motor, and the water-cooled evaporator are connected via a three-way valve.

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