An electric vehicle air conditioning system, control method and vehicle

Abstract

The application discloses an electric vehicle air conditioning system, a control method and a vehicle, and relates to the field of electric vehicles. The first aspect of the application discloses the air conditioning system, which comprises a PTC heat circulation loop and a motor cooling loop. The PTC heat circulation loop is connected with an expansion water tank of the motor cooling loop through a communication pipeline. The communication pipeline is configured to connect the expansion water tank of the motor cooling loop to the PTC heat circulation loop in series when the PTC heat circulation loop is used to heat a cab and the water temperature of the PTC heat circulation loop is lower than a set temperature. The second aspect of the application discloses the control method, which is implemented by using the air conditioning system. The control method comprises the following steps: connecting the expansion water tank of the motor cooling loop to the PTC heat circulation loop in series through the communication pipeline when the PTC heat circulation loop is used to heat the cab and the water temperature of the PTC heat circulation loop is lower than the set temperature. The third aspect of the application discloses a vehicle comprising the air conditioning system. The PTC heat circulation loop and the motor cooling loop share one expansion water tank, thereby improving the space of the vehicle.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric vehicles, in particular to an electric vehicle air conditioning system, a control method and a vehicle. BACKGROUND

[0002] The refrigeration and heating functions of the air conditioning system of a commercial electric vehicle are currently arranged separately, mainly consisting of a refrigeration system including an electric compressor, a condenser, an evaporator and a fan, and a heating system including a water pump, a water PTC (Positive Temperature Coefficient), an expansion tank, a heater core and a fan. In addition, a separate pipe system for cooling the motor and battery pack system is also arranged, which has a large expansion tank for system exhaust.

[0003] When the PTC water heating method is used in the current air conditioning heating system, the heating in the passenger compartment is mainly achieved by transferring the heat of the cooling liquid to the heater core through the water pump for heat exchange. The air conditioning system of this kind of heating system has an exhaust chamber connected in series in the heating system, which is arranged with an expansion tank for exhaust. Therefore, the heating system, the refrigeration system and the pipe cooling system all need to be arranged with space and intermediate connecting pipes, and at least two expansion tanks need to be arranged on the vehicle to meet the cooling of the air conditioning heating system and the battery pack system. This not only causes great limitations in space arrangement, but also has high production cost. SUMMARY

[0004] In view of the defects in the prior art, the purpose of the present application is to provide an electric vehicle air conditioning system, a control method and a vehicle to solve the problem of great limitations in space arrangement and high cost of the heating system, the refrigeration system and the pipe cooling system in the prior art.

[0005] To achieve the above purpose, the technical solution adopted by the present application is:

[0006] On the one hand, the present application provides an electric vehicle air conditioning system, comprising: a PTC heat circulation loop and a motor cooling loop, the PTC heat circulation loop being connected with the expansion tank of the motor cooling loop through a communication pipe, the communication pipe being configured to connect the expansion tank of the motor cooling loop in series to the PTC heat circulation loop when heating the passenger compartment by using the PTC heat circulation loop and the water temperature of the PTC heat circulation loop is less than a set temperature.

[0007] In some optional embodiments, the communication pipeline includes a first communication branch and a second communication branch, the PTC heat circulation loop is provided with a first three-way valve and a second three-way valve, the A communication port and the B communication port of the first three-way valve and the second three-way valve are connected in series in the PTC heat circulation loop, the two ends of the first communication branch are connected with the C communication port of the first three-way valve and the water inlet of the expansion tank respectively, and the two ends of the second communication branch are connected with the C communication port of the second three-way valve and the water outlet of the expansion tank respectively.

[0008] In some optional embodiments, the air conditioner refrigeration circulation loop is further provided with a condenser and an electric compressor.

[0009] In some optional embodiments, the communication pipeline is arranged between the water PTC and the water pump.

[0010] In some optional embodiments, the air conditioner refrigeration circulation loop is further provided with a condenser and an electric compressor.

[0011] In some optional embodiments, the heat exchanger is a parallel flow heat exchanger.

[0012] In some optional embodiments, a temperature sensor is further included for detecting the water temperature of the PTC heat circulation loop.

[0013] In some optional embodiments, the air conditioner refrigeration circulation loop is further provided with a condenser and an electric compressor.

[0014] When the PTC heat circulation loop is used to heat the cab and the water temperature of the PTC heat circulation loop is less than the set temperature, the expansion tank of the motor cooling loop is connected in series to the PTC heat circulation loop through the communication pipeline.

[0015] In some optional embodiments, connecting the expansion tank of the motor cooling loop to the PTC heat circulation loop includes connecting the A communication port and the C communication port of the first three-way valve and connecting the C communication port and the B communication port of the second three-way valve, when the water temperature of the PTC heat circulation loop is greater than or equal to the set temperature, connecting the A communication port and the B communication port of the first three-way valve and connecting the A communication port and the B communication port of the second three-way valve.

[0016] In some optional embodiments, the air conditioner refrigeration circulation loop is further provided with a condenser and an electric compressor.

[0017] Compared with the prior art, the advantages of the present invention are as follows: by sharing an expansion tank with the PTC thermal circulation circuit and the motor cooling circuit, one expansion tank and a large number of pipes can be reduced, thereby improving the space utilization of the vehicle; by connecting the pipes, not only can the air in the liquid in the PTC thermal circulation circuit be quickly discharged in the initial stage, but also the liquid in the PTC thermal circulation circuit will no longer flow into the expansion tank after the liquid temperature reaches the set temperature, reducing the flow path and heat loss, and improving the heating efficiency. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a connection diagram of an electric vehicle air conditioning system according to the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of an electric vehicle air conditioning system according to the present invention.

[0021] In the diagram: 10. Blower; 11. Water PTC; 12. Water pump; 13. Heat exchanger; 14. Intermediate heat exchanger; 15. First three-way valve; 16. Second three-way valve; 21. Condenser; 22. Electric compressor; 3. Temperature sensor; 40. Exhaust port; 41. Expansion tank; 5. Integrated heat exchanger. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0024] Firstly, such as Figure 1 As shown, this application provides an electric vehicle air conditioning system, including a PTC thermal circulation loop and a motor cooling loop. The PTC thermal circulation loop is connected to the expansion tank 41 of the motor cooling loop through a connecting pipe. The expansion tank 41 of the motor cooling loop provides stable system pressure and removes air released by the water during the heating process when the PTC thermal circulation loop is working.

[0025] Specifically, the communication pipeline is configured to connect the expansion tank 41 of the motor cooling circuit to the PTC heat circulation circuit in series when the PTC heat circulation circuit is used to heat the cab, and the water temperature of the PTC heat circulation circuit is less than the set temperature.

[0026] It can be understood that when the PTC heat circulation circuit is working, the temperature of the liquid in the system increases, the volume of the liquid increases, and the gas in the liquid is discharged. At this time, the expansion tank 41 of the motor cooling circuit is connected to the PTC heat circulation circuit through the communication pipeline, thereby providing stable system pressure for the PTC heat circulation circuit when working and removing the air released during the heating process. When the PTC heat circulation circuit works until the temperature of the liquid in the system rises to greater than or equal to the set temperature, the liquid state of the PTC heat circulation circuit has become stable at this time, and therefore the expansion tank 41 of the motor cooling circuit is no longer connected to the PTC heat circulation circuit. The circulation path of the liquid in the PTC heat circulation circuit can be reduced, and the heating rate and thermal efficiency of the liquid can be greatly improved.

[0027] The set temperature described above can be specifically set by those skilled in the art according to the performance of the liquid in the PTC heat circulation, which is not specifically limited here.

[0028] In some optional embodiments, the communication pipeline includes a first communication branch and a second communication branch, the PTC heat circulation circuit is provided with a first three-way valve 15 and a second three-way valve 16, the A communication port and the B communication port of the first three-way valve 15 and the second three-way valve 16 are connected in series in the PTC heat circulation circuit, and the two ends of the first communication branch are connected with the C communication port of the first three-way valve 15 and the water inlet of the expansion tank 41 respectively, and the two ends of the second communication branch are connected with the C communication port of the second three-way valve 16 and the water outlet of the expansion tank 41 respectively.

[0029] It can be understood that the first three-way valve 15 and the second three-way valve 16 are used to connect or disconnect the expansion tank 41 and the PTC heat circulation circuit. The expansion tank 41 is used for the cooling liquid of the motor and the battery system in the motor cooling circuit to be deaerated, pressure-stabilized and water-supplied. The PTC heat circulation circuit and the motor cooling circuit share one expansion tank 41, thereby reducing one expansion tank and a large number of pipelines and improving the space arrangement rate of the vehicle.

[0030] For example, when the PTC heat circulation loop is used to heat the passenger compartment and the water temperature of the PTC heat circulation loop is less than the set temperature, the A communication port of the first three-way valve 15 is connected with the C communication port, the C communication port and the B communication port of the second three-way valve 16 are connected, and the expansion water tank 41 is connected in series with the PTC heat circulation loop; when the water temperature of the PTC heat circulation loop is greater than or equal to the set temperature, the A communication port of the first three-way valve 15 is connected with the B communication port, the A communication port and the B communication port of the second three-way valve 16 are connected, and the expansion water tank 41 is disconnected with the PTC heat circulation loop.

[0031] In some optional embodiments, the PTC heat circulation loop comprises a water PTC 11, a water pump 12, a heat exchanger 13 and an intermediate exchanger 14 connected in sequence, and the air conditioning refrigeration circulation loop is connected with the PTC heat circulation loop through the intermediate exchanger 14.

[0032] It can be understood that the water pump 12 is a power unit of the entire PTC heat circulation loop, which drives the liquid in the loop to flow; the water PTC heats the liquid in the loop, so that the temperature of the liquid rapidly rises; the liquid after being heated flows into the heat exchanger 13, where heat exchange occurs, and the air flow with lower temperature is driven by the electric blower 10 to flow through the heat exchanger 13, so as to absorb the heat of the system liquid inside the heat exchanger 13, and the temperature of the system liquid is reduced, and the temperature of the air flow outside the heat exchanger 13 is increased, and the air flow after being heated flows into the passenger compartment to meet the heating demand. The system liquid after being cooled flows out of the heat exchanger 13, and then flows through the water pump 12, so as to form a PTC heat circulation loop.

[0033] In this example, the heat exchanger 13 is a flat heat exchanger, which integrates the existing heater core and evaporator. Compared with the air flow driven by the electric blower 10 to flow through the heater core and the evaporator, the air resistance is smaller, and the required power of the blower is also smaller. The intermediate exchanger 14 is a Chiller (water and refrigerant exchanger), which is used to realize heat exchange between the refrigerant and the water, so as to cool the liquid in the circulation loop.

[0034] Since the air conditioning refrigeration circulation loop is connected with the PTC heat circulation loop through the intermediate exchanger 14, the air conditioning refrigeration circulation loop and the PTC heat circulation loop share the water pump 12 and the heat exchanger 13.

[0035] Optionally, the air conditioning refrigeration circulation loop comprises a condenser 21 and an electric compressor 22.

[0036] Specifically, when the ambient temperature is high in summer, the air conditioning refrigeration cycle is opened, the water PTC 11 is not working, the A communication port of the first three-way valve 15 is connected with the B communication port, the A communication port of the second three-way valve 16 is connected with the B communication port, the electric compressor 22 pressurizes the refrigerant and then enters the condenser 21, so that the refrigerant is extracted from the low-pressure area, compressed, cooled and condensed in the high-pressure area, and the heat is dissipated to the air through the heat dissipation fins, the refrigerant also changes from gas to liquid, the pressure increases and the temperature decreases, and then the liquid in the PTC heat cycle is heat-exchanged with the liquid in the PTC heat cycle, the temperature of the liquid in the PTC heat cycle is lowered, the cooled liquid is driven by the water pump 12 and then flows into the heat exchanger 13, heat exchange occurs here, the electric blower 10 is driven to flow the air with a higher temperature into the heat exchanger 13, the system liquid absorbs heat and the temperature rises, the temperature of the air outside the heat exchanger 13 decreases, and the cooled air flows into the passenger cabin to meet the cooling demand.

[0037] When the ambient temperature is low in winter, the air conditioning refrigeration cycle is closed, the Chiller is not working, the water PTC 11 of the PTC heat cycle is opened, the liquid in the cycle is heated, and the temperature of the liquid rapidly rises; when the water temperature of the PTC heat cycle is less than the set temperature, the A communication port of the first three-way valve 15 is connected with the C communication port, the C communication port of the second three-way valve 16 is connected with the B communication port, the expansion tank 41 is connected in series with the PTC heat cycle at this time, the liquid in the system is vented and controlled in pressure, and then the gas is discharged from the vent hole 40, the liquid treated by the expansion tank is driven by the water pump 12 and circulated in the PTC heat cycle, until the water temperature of the PTC heat cycle is greater than or equal to the set temperature, the A communication port of the first three-way valve 15 is connected with the B communication port, the A communication port of the second three-way valve 16 is connected with the B communication port, the expansion tank 41 is disconnected from the PTC heat cycle at this time, so as to reduce the circulation path of the liquid in the system. During the working of the water PTC 11, the heated liquid flows into the heat exchanger 13, heat exchange occurs here, the electric blower 10 is driven to flow the air with a lower temperature into the heat exchanger 13, the heat of the system liquid inside the heat exchanger 13 is absorbed, the temperature of the system liquid decreases and the temperature of the air outside the heat exchanger 13 rises, the heated air flows into the passenger cabin to meet the heating demand.

[0038] Preferably, the communication pipeline is arranged between the water PTC 11 and the water pump 12.

[0039] It can be understood that the liquid directly flows out from the water PTC 11 after being heated into the expansion water tank 41, which can improve the exhaust and pressure control effect of the liquid in the system, and avoid the displacement path of the gas generated after the liquid is heated in the system pipeline increasing to cause abnormal sound. At the same time, the expansion water tank 41 is located at the highest position of the entire system structure, and the exhaust hole 40 is located at the top of the expansion water tank 41 to improve the exhaust efficiency.

[0040] In some optional embodiments, the above-mentioned electric vehicle air conditioning system further comprises a temperature sensor 3 for detecting the water temperature of the PTC heat circulation loop.

[0041] It can be understood that the temperature sensor 3 detects the water temperature of the PTC heat circulation loop, and then sends the detected information to the control system. The control system controls the first three-way valve 15 and the second three-way valve 16 according to the detected water temperature of the PTC heat circulation loop, so as to realize that when the water temperature of the PTC heat circulation loop is less than the set temperature, the expansion water tank 41 of the motor cooling loop is connected in series to the PTC heat circulation loop; when the PTC heat circulation loop works until the temperature of the liquid in the system rises to greater than or equal to the set temperature, the expansion water tank 41 is disconnected from the PTC heat circulation loop.

[0042] In some optional embodiments, as shown in Figure 2 The Chiller can also be integrated with the heat exchanger 13 and the electric blower 10 to form an integrated heat exchanger 5 in communication with the passenger cabin air outlet, so as to further reduce the arrangement size, reduce the length of the pipeline, reduce the cost, and also reduce the risk of leakage.

[0043] In a second aspect, the application also provides a control method of an electric vehicle air conditioning system, which is implemented by using the above-mentioned electric vehicle air conditioning system, and comprises the following steps:

[0044] When the PTC heat circulation loop is used to heat the cab, and the water temperature of the PTC heat circulation loop is less than the set temperature, the expansion water tank 41 of the motor cooling loop is connected in series to the PTC heat circulation loop through the communication pipeline.

[0045] Specifically, the electric vehicle air conditioning system comprises a PTC heat circulation loop and a motor cooling loop, and the PTC heat circulation loop is connected with the expansion water tank 41 of the motor cooling loop through a communication pipeline.

[0046] It can be understood that when the PTC heat circulation loop works, the volume of the liquid in the system increases due to the temperature rise, and the gas in the liquid is discharged. At this time, the expansion tank 41 of the motor cooling loop is connected in series to the PTC heat circulation loop through the communication pipeline, thereby providing stable system pressure and discharging the air released by the water during heating when the PTC heat circulation loop works. When the PTC heat circulation loop works until the temperature of the liquid in the system rises to greater than or equal to the set temperature, the liquid state of the PTC heat circulation loop has become stable at this time, and therefore the expansion tank 41 of the motor cooling loop is no longer connected in series to the PTC heat circulation loop, which can reduce the circulation path of the liquid in the PTC heat circulation loop, and the heating rate and thermal efficiency of the liquid can be greatly improved.

[0047] By sharing one expansion tank 41 for the PTC heat circulation loop and the motor cooling loop, one expansion tank and a large number of pipelines can be reduced, the space arrangement rate is improved, and the air in the liquid in the system can be gradually discharged clean at the beginning of the heating stage, reducing the abnormal noise caused by the gas in the pipeline during heating.

[0048] The set temperature described above can be specifically set by a person skilled in the art according to the performance of the liquid in the PTC heat circulation loop, which is not specifically limited here.

[0049] In some optional embodiments, the communication pipeline includes a first communication branch and a second communication branch, the PTC heat circulation loop is provided with a first three-way valve 15 and a second three-way valve 16, the A communication port and the B communication port of the first three-way valve 15 and the second three-way valve 16 are connected in series in the PTC heat circulation loop, the two ends of the first communication branch are connected with the C communication port of the first three-way valve 15 and the water inlet of the expansion tank 41 respectively, and the two ends of the second communication branch are connected with the C communication port of the second three-way valve 16 and the water outlet of the expansion tank 41 respectively.

[0050] It can be understood that the first three-way valve 15 and the second three-way valve 16 are used to connect or disconnect the expansion tank 41 and the PTC heat circulation loop. The expansion tank 41 discharges the cooling liquid of the motor and the battery pack system in the motor cooling loop, stabilizes the pressure, and replenishes water.

[0051] In some alternative embodiments, when the cab is heated by the PTC heat circulation loop, and the water temperature of the PTC heat circulation loop is less than the set temperature, the A communication port of the first three-way valve 15 is connected with the C communication port, the C communication port and the B communication port of the second three-way valve 16 are connected, and the expansion water tank 41 is connected in series with the PTC heat circulation loop; when the water temperature of the PTC heat circulation loop is greater than or equal to the set temperature, the A communication port of the first three-way valve 15 is connected with the B communication port, and the A communication port and the B communication port of the second three-way valve 16 are connected, and the expansion water tank 41 is disconnected with the PTC heat circulation loop.

[0052] In some alternative embodiments, the PTC heat circulation loop comprises a water PTC 11, a water pump 12, a heat exchanger 13 and an intermediate exchanger 14 connected in sequence, and the air conditioner refrigeration circulation loop is connected with the PTC heat circulation loop through the intermediate exchanger 14.

[0053] Since the air conditioner refrigeration circulation loop is connected with the PTC heat circulation loop through the intermediate exchanger 14, the air conditioner refrigeration circulation loop and the PTC heat circulation loop share the water pump 12 and the heat exchanger 13.

[0054] Optionally, the air conditioner refrigeration circulation loop comprises a condenser 21 and an electric compressor 22 connected in sequence with the intermediate exchanger 14.

[0055] Specifically, when the ambient temperature is high in summer, the air conditioner refrigeration circulation loop is turned on, the water PTC 11 does not work, the A communication port of the first three-way valve 15 is connected with the B communication port, the A communication port and the B communication port of the second three-way valve 16 are connected, the electric compressor 22 pressurizes the refrigerant and then enters the condenser 21, so that the refrigerant is extracted from the low-pressure area, compressed and sent to the high-pressure area to be cooled and condensed, and the heat is dissipated to the air through the heat dissipation fins, and the refrigerant also changes from gas to liquid, the pressure increases, and the temperature decreases, and then the refrigerant exchanges heat with the liquid in the PTC heat circulation loop through the Chiller, so as to reduce the temperature of the liquid in the PTC heat circulation loop, and the cooled liquid is driven by the water pump 12 and then flows into the heat exchanger 13, where heat exchange occurs, and the electric blower 10 drives the air flow with a higher temperature to flow through the heat exchanger 13, the system liquid absorbs heat and the temperature rises, the temperature of the air flow outside the heat exchanger 13 decreases, and the cooled air flow flows into the passenger compartment to meet the refrigeration demand.

[0056] When the winter temperature environment is low, the air conditioning refrigeration cycle is closed, the Chiller does not work, the water PTC 11 of the PTC heat cycle is opened, and the liquid in the cycle is heated to rapidly increase the temperature of the liquid. When the water temperature of the PTC heat cycle is less than the set temperature, the A communication port of the first three-way valve 15 is connected with the C communication port, the C communication port and the B communication port of the second three-way valve 16 are connected, the expansion tank 41 is connected in series with the PTC heat cycle at this time, the liquid in the system is vented and controlled, and then the gas is discharged from the exhaust hole 40. The liquid treated by the expansion tank is driven by the water pump 12 and circulates in the PTC heat cycle. When the water temperature of the PTC heat cycle is greater than or equal to the set temperature, the A communication port of the first three-way valve 15 is connected with the B communication port, the A communication port and the B communication port of the second three-way valve 16 are connected, and the expansion tank 41 is disconnected with the PTC heat cycle at this time, so as to reduce the circulation path of the liquid in the system. In the process of working of the water PTC 11, the heated liquid flows into the heat exchanger 13, heat exchange occurs in the heat exchanger 13, the air flow with low temperature is driven by the electric blower 10 to flow into the heat exchanger 13, absorbs the heat of the system liquid inside the heat exchanger 13, the temperature of the system liquid is reduced, and the temperature of the air flow outside the heat exchanger 13 is increased. The heated air flow flows into the passenger cabin to meet the heating demand.

[0057] In a third aspect, the application further provides a vehicle comprising the electric vehicle air conditioning system.

[0058] Specifically, the electric vehicle air conditioning system comprises a PTC heat cycle and a motor cooling cycle, the PTC heat cycle is connected with the expansion tank 41 of the motor cooling cycle through a communication pipeline, and the expansion tank 41 of the motor cooling cycle is used to provide stable system pressure and remove air released in the heating process when the PTC heat cycle works. The communication pipeline is configured to connect the expansion tank 41 of the motor cooling cycle to the PTC heat cycle when the PTC heat cycle is used to heat the cab and the water temperature of the PTC heat cycle is less than the set temperature.

[0059] The PTC heat cycle and the motor cooling cycle share one expansion tank 41, so that one expansion tank and a large number of pipelines can be reduced, and the space arrangement rate of the vehicle can be improved.

[0060] In some alternative embodiments, the above-mentioned communication pipeline includes a first communication branch and a second communication branch, the PTC heat circulation loop is provided with a first three-way valve 15 and a second three-way valve 16, the A communication port and the B communication port of the first three-way valve 15 and the second three-way valve 16 are connected in series in the PTC heat circulation loop, and the two ends of the first communication branch are connected with the C communication port of the first three-way valve 15 and the water inlet of the expansion tank 41 respectively, and the two ends of the second communication branch are connected with the C communication port of the second three-way valve 16 and the water outlet of the expansion tank 41 respectively.

[0061] In some alternative embodiments, the PTC heat circulation loop includes a water PTC 11, a water pump 12, a heat exchanger 13 and an intermediate exchanger 14 connected in sequence, and the air conditioning refrigeration circulation loop is connected with the PTC heat circulation loop through the intermediate exchanger 14. The air conditioning refrigeration circulation loop includes a condenser 21 and an electric compressor 22.

[0062] It can be understood that the heat exchanger 13 is also provided with an electric blower 10, which exchanges heat between air and the heat exchanger 13 system through the electric blower 10, so as to raise or lower the temperature of the airflow, and send the airflow with raised or lowered temperature into the passenger cabin, so as to meet the cooling or heating demand of the vehicle passengers.

[0063] When the ambient temperature is high in summer, the air conditioning refrigeration circulation loop is opened, at this time the water PTC 11 does not work, the A communication port and the B communication port of the first three-way valve 15 are connected, the A communication port and the B communication port of the second three-way valve 16 are connected, and the electric compressor 22 pressurizes the refrigerant and then enters the condenser 21, so that the refrigerant is extracted from the low-pressure area, compressed and sent to the high-pressure area to be cooled and condensed, and heat is dissipated to the air through the heat dissipation fins, and the refrigerant also changes from gas to liquid, the pressure increases and the temperature decreases, and then the liquid is heat-exchanged with the liquid in the PTC heat circulation loop through the Chiller, so as to reduce the temperature of the liquid in the PTC heat circulation loop. The cooled liquid is driven by the water pump 12 and then flows into the heat exchanger 13, where heat exchange occurs, and the electric blower 10 is used to drive the airflow with higher temperature in the heat exchanger 13, so that the system liquid absorbs heat and the temperature rises, and the temperature of the airflow outside the system decreases, and the cooled airflow flows into the passenger cabin to meet the cooling demand.

[0064] When the winter temperature environment is low, the air conditioning refrigeration cycle circuit is closed, the Chiller does not work, the water PTC 11 of the PTC heat cycle circuit is opened, and the liquid in the circuit is heated to rapidly increase the temperature of the liquid; when the water temperature of the PTC heat cycle circuit is less than the set temperature, the A communication port of the first three-way valve 15 is connected with the C communication port, the C communication port and the B communication port of the second three-way valve 16 are connected, at this time, the expansion tank 41 is connected with the PTC heat cycle circuit in series, the liquid in the system is exhausted and pressure controlled, then the gas is discharged from the exhaust hole 40, the liquid treated by the expansion tank is driven by the water pump 12 and circulates in the PTC heat cycle circuit, until the water temperature of the PTC heat cycle circuit is greater than or equal to the set temperature, the A communication port of the first three-way valve 15 is connected with the B communication port, the A communication port and the B communication port of the second three-way valve 16 are connected, at this time, the expansion tank 41 is disconnected with the PTC heat cycle circuit to reduce the circulation path of the liquid in the system. In the process of working of the water PTC 11, the heated liquid flows into the heat exchanger 13, heat exchange occurs here, the air flow with lower temperature is driven by the electric blower 10 to flow into the heat exchanger 13, absorbs the heat of the system liquid inside the heat exchanger 13, the temperature of the system liquid is reduced, the temperature of the air flow outside the heat exchanger 13 is increased, the heated air flow flows into the passenger cabin to meet the heating demand.

[0065] The electric vehicle air conditioning system, control method and vehicle can reduce one expansion tank and a large number of pipelines by sharing one expansion tank 41 for the PTC heat cycle circuit and the motor cooling circuit, improve the space arrangement rate of the vehicle; the first communication branch and the second communication branch, and the first three-way valve 15 and the second three-way valve 16 are arranged, so that the expansion tank 41 of the PTC heat cycle circuit and the motor cooling circuit can be connected or disconnected according to the temperature of the liquid in the PTC heat cycle circuit, not only the air in the liquid in the PTC heat cycle circuit can be rapidly discharged in the initial stage, but also the liquid in the PTC heat cycle circuit does not flow into the expansion tank 41 when the temperature of the liquid in the PTC heat cycle circuit reaches the set temperature, the flow path and heat loss are reduced, and the heating efficiency is improved; the PTC heat cycle circuit and the air conditioning refrigeration cycle circuit are connected in one circuit through the intermediate exchanger 14, the terminal of the air conditioning system is unified, and the arrangement space and system wind resistance of the air conditioning in the cab are greatly reduced; the communication pipeline is arranged between the water PTC 11 and the water pump 12, the exhaust and pressure control effect of the liquid in the system can be improved, the displacement path of the liquid after the liquid is heated to generate gas in the system pipeline is increased to avoid abnormal sound, at the same time, the expansion tank 41 is located at the highest position of the entire system structure, and the exhaust hole 40 is located at the top of the expansion tank 41 to improve the exhaust efficiency; the temperature sensor 3 is arranged to control the first three-way valve 15 and the second three-way valve 16 according to the detected water temperature of the PTC heat cycle circuit, and the connection or disconnection of the expansion tank 41 and the PTC heat cycle circuit is realized.

[0066] In the description of the present application, it should be noted that the terms "upper", "lower", and the like are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. Unless otherwise expressly specified and limited, the terms "mounting", "connecting", "connecting" should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0067] It should be noted that in the present application, relational terms such as "first" and "second" and the like are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the sentence "including a" does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0068] The above is only a specific embodiment of the present application, which enables those skilled in the art to understand or implement the present application. Various modifications of these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features applied herein.

Claims

1. An air conditioning system for an electric vehicle, characterized by, The system comprises: a PTC heat circulation loop and a motor cooling loop, the PTC heat circulation loop is connected with an expansion water tank (41) of the motor cooling loop through a communication pipeline, the communication pipeline is configured to connect the expansion water tank (41) of the motor cooling loop in series to the PTC heat circulation loop when the PTC heat circulation loop is used to heat the cab and the water temperature of the PTC heat circulation loop is less than a set temperature; the PTC heat circulation loop comprises a water PTC (11), a water pump (12), a heat exchanger (13) and an intermediate exchanger (14) connected in sequence, and the air conditioning refrigeration circulation loop is connected with the PTC heat circulation loop through the intermediate exchanger (14), and the communication pipeline is arranged between the water PTC (11) and the water pump (12); a temperature sensor (3) is arranged to detect the water temperature of the PTC heat circulation loop; the communication pipeline comprises a first communication branch and a second communication branch, a first three-way valve (15) and a second three-way valve (16) are arranged on the PTC heat circulation loop, the A communication port and the B communication port of the first three-way valve (15) and the second three-way valve (16) are connected in series in the PTC heat circulation loop, the two ends of the first communication branch are connected with the C communication port of the first three-way valve (15) and the water inlet of the expansion water tank (41) respectively, and the two ends of the second communication branch are connected with the C communication port of the second three-way valve (16) and the water outlet of the expansion water tank (41) respectively; the expansion water tank (41) of the motor cooling loop is connected in series to the PTC heat circulation loop, which comprises that the A communication port of the first three-way valve (15) is connected with the C communication port, and the C communication port and the B communication port of the second three-way valve (16) are connected; when the water temperature of the PTC heat circulation loop is greater than or equal to the set temperature, the A communication port of the first three-way valve (15) is connected with the B communication port, and the A communication port and the B communication port of the second three-way valve (16) are connected.

2. The electric vehicle air conditioning system of claim 1, wherein, The air conditioning refrigeration circulation loop is further provided with a condenser (21) and an electric compressor (22).

3. The electric vehicle air conditioning system of claim 1, wherein, The heat exchanger (13) is a parallel flow heat exchanger.

4. A control method of an air conditioning system for an electric vehicle, characterized by, The electric vehicle air conditioning system is implemented by using the system according to any one of claims 1-3, comprising the following steps: when the PTC heat circulation loop is used to heat the cab and the water temperature of the PTC heat circulation loop is less than a set temperature, the expansion water tank (41) of the motor cooling loop is connected in series to the PTC heat circulation loop through a communication pipeline.

5. The control method according to claim 4, characterized by, the expansion water tank (41) of the motor cooling loop is connected in series to the PTC heat circulation loop, which comprises that the A communication port of the first three-way valve (15) is connected with the C communication port, and the C communication port and the B communication port of the second three-way valve (16) are connected; when the water temperature of the PTC heat circulation loop is greater than or equal to the set temperature, the A communication port of the first three-way valve (15) is connected with the B communication port, and the A communication port and the B communication port of the second three-way valve (16) are connected.

6. A vehicle characterized by comprising: The electric vehicle air conditioning system comprises the system according to any one of claims 1-3.

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