Control methods for heat pump systems, on-board controllers, heat pump control systems, and automobiles

Abstract

This invention discloses a control method for a heat pump system, an on-board controller, a heat pump control system, and a vehicle. The method includes: acquiring first measured data; determining the current mode of the heat pump system based on the first measured data; if the current mode of the heat pump system is an air-source heat pump mode, controlling the refrigerant circuit to preheat the air in the duct, and then controlling the coolant circuit to heat the preheated air in the duct. This method, when the heat pump system is in air-source heat pump mode, controls the refrigerant and coolant circuits to perform two consecutive heat exchanges on the air in the duct of the air conditioning unit, improving heating efficiency and achieving energy savings and improved heating efficiency in the passenger compartment.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to a control method for a heat pump system, an on-board controller, a heat pump control system, and an automobile. Background Technology

[0002] With the continuous development of vehicle technology, users' demands for automotive comfort are gradually increasing, especially in low ambient temperatures, where it is necessary to raise the temperature of the passenger compartment to improve user comfort. Current technologies typically employ methods such as direct heating with heaters, direct heat pump air conditioning, and indirect heat pump air conditioning to raise the passenger compartment temperature. However, these methods consume a lot of energy, resulting in low heating efficiency. Therefore, how to reduce heating energy consumption and improve passenger compartment heating efficiency is a technical problem that needs to be solved. Summary of the Invention

[0003] This invention provides a control method for a heat pump system, an on-board controller, a heat pump control system, and a vehicle, to address the problem of how to reduce heating energy consumption and improve the heating efficiency of the passenger compartment.

[0004] A control method for a heat pump system, the heat pump system comprising an air conditioning unit, an air duct passing through the air conditioning unit, and a refrigerant circuit and a coolant circuit connected to the air conditioning unit, comprising:

[0005] Obtain the first measured data;

[0006] Based on the first measured data, the current mode of the heat pump system is determined;

[0007] If the current mode of the heat pump system is air source heat pump mode, then control the refrigerant circuit to preheat the air in the air duct, and then control the coolant circuit to heat the preheated air in the air duct.

[0008] Preferably, the refrigerant circuit includes a battery heat exchanger;

[0009] The first measured data includes the first ambient temperature and the inlet water temperature of the heat exchanger corresponding to the battery heat exchanger;

[0010] Determining the current mode of the heat pump system based on the first measured data includes:

[0011] If the first ambient temperature is within the first ambient temperature range and the heat exchanger inlet water temperature is within the first water temperature range, then the current mode of the heat pump system is determined to be the air source heat pump mode.

[0012] Preferably, the air conditioning unit includes an evaporator and a heater core; the refrigerant circuit includes a preheating circuit, which includes a compressor, a condenser, an electronic expansion valve, and the evaporator connected in sequence; the coolant circuit includes a condenser, a heater, and the heater core connected in sequence; the preheating circuit and the coolant circuit exchange heat through the condenser.

[0013] The control of the refrigerant circuit to preheat the air in the duct includes:

[0014] The preheating circuit is controlled to be turned on, the compressor is controlled to operate based on the target speed, and the electronic expansion valve is controlled to operate based on the target opening degree, so that the refrigerant in the preheating circuit preheats the air in the air duct.

[0015] Preferably, controlling the compressor to operate based on a target speed includes:

[0016] Obtain the second measured data;

[0017] Based on the second measured data, the speed of the first compressor corresponding to the compressor is determined;

[0018] Based on the first compressor speed and the preset maximum speed, the target speed of the compressor is determined, and the compressor is controlled to operate based on the target speed.

[0019] Preferably, after controlling the compressor to operate based on the target speed, the control method of the heat pump system further includes:

[0020] Obtain the compressor's discharge temperature, discharge pressure, measured pressure ratio, and measured speed;

[0021] If the exhaust temperature is greater than the preset temperature, the exhaust pressure is greater than the preset pressure, the measured pressure ratio is greater than the preset pressure ratio, or the measured speed is equal to the preset maximum speed, then the process of obtaining the second measured data is repeated.

[0022] Preferably, controlling the electronic expansion valve to operate based on a target opening degree includes:

[0023] Obtain the third set of measured data;

[0024] Based on the third measured data, the target opening degree of the electronic expansion valve is determined, and the electronic expansion valve is controlled to operate based on the target opening degree.

[0025] Preferably, the electronic expansion valve includes a first electronic expansion valve disposed at the input end of the evaporator;

[0026] The third measured data includes the actual superheat of the compressor;

[0027] The determination of the target opening degree of the electronic expansion valve based on the third measured data includes:

[0028] Based on the actual superheat and the target superheat of the compressor, the theoretical pressure corresponding to the compressor is determined;

[0029] Based on the theoretical pressure and the target pressure corresponding to the compressor, the target opening degree of the first electronic expansion valve is determined.

[0030] Preferably, the electronic expansion valve includes a second electronic expansion valve disposed at the output end of the evaporator;

[0031] The third measured data includes the measured temperature, the air intake volume of the air conditioning unit, and the measured pressure corresponding to the output end of the evaporator.

[0032] The determination of the target opening degree of the electronic expansion valve based on the third measured data includes:

[0033] The saturated refrigerant temperature is determined based on the measured temperature and the air intake volume of the air conditioning unit.

[0034] Determine the saturated refrigerant pressure based on the saturated refrigerant temperature;

[0035] Based on the saturated refrigerant pressure and the measured pressure, the target opening degree of the second electronic expansion valve is determined.

[0036] Preferably, the measured temperature includes the second ambient temperature and the vehicle interior temperature;

[0037] Determining the saturated refrigerant temperature based on the measured temperature and the air intake volume of the air conditioning unit includes:

[0038] If the air conditioning unit is a single-layer flow air conditioning unit, the saturated refrigerant temperature is determined based on the second ambient temperature and the air intake volume of the air conditioning unit.

[0039] If the air conditioning unit is a dual-flow air conditioning unit, the saturated refrigerant temperature is determined based on the vehicle interior temperature and the air intake volume of the air conditioning unit.

[0040] Preferably, the operation of the control coolant circuit to heat the preheated air in the air duct includes:

[0041] Obtain the actual inlet liquid temperature of the heating element in the air conditioning unit;

[0042] If the actual inlet temperature is lower than the target inlet temperature, the heater in the coolant circuit is controlled to heat the coolant until the actual inlet temperature is not lower than the target inlet temperature. Then, the coolant corresponding to the target inlet temperature is controlled to enter the heater core to heat the preheated air in the air duct.

[0043] Preferably, after the control coolant circuit operates to heat the preheated air in the air duct, the control method of the heat pump system further includes:

[0044] Obtain the compressor's discharge temperature, discharge pressure, and measured pressure ratio;

[0045] If the exhaust temperature is greater than the preset temperature, the exhaust pressure is greater than the preset pressure, or the measured pressure ratio is greater than the preset pressure ratio, then the compressor is controlled to reduce its speed.

[0046] An on-board controller includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the control method of the heat pump system described above.

[0047] A heat pump control system includes a heat pump system and the aforementioned vehicle controller, wherein the vehicle controller is connected to the heat pump system.

[0048] An automobile includes the aforementioned heat pump control system.

[0049] The aforementioned heat pump system control method, vehicle controller, heat pump control system, and vehicle, based on the first measured data, enable the determined current mode of the heat pump system to better match the current conditions of the passenger compartment, thereby improving user comfort. When the heat pump system is in air-source heat pump mode, controlling the refrigerant and coolant circuits allows for two consecutive heat exchanges with the air in the air duct of the air conditioning unit, improving heating efficiency and achieving energy savings while increasing the heating efficiency of the passenger compartment. Attached Figure Description

[0050] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0051] Figure 1 This is a flowchart of a control method for a heat pump system according to an embodiment of the present invention;

[0052] Figure 2 This is another flowchart of a control method for a heat pump system according to one embodiment of the present invention;

[0053] Figure 3 This is another flowchart of a control method for a heat pump system according to one embodiment of the present invention;

[0054] Figure 4This is another flowchart of a control method for a heat pump system according to one embodiment of the present invention;

[0055] Figure 5 This is another flowchart of a control method for a heat pump system according to one embodiment of the present invention;

[0056] Figure 6 This is another flowchart of a control method for a heat pump system according to one embodiment of the present invention;

[0057] Figure 7 This is another flowchart of a control method for a heat pump system according to one embodiment of the present invention;

[0058] Figure 8 This is another flowchart of a control method for a heat pump system according to one embodiment of the present invention;

[0059] Figure 9 This is another flowchart of a control method for a heat pump system according to one embodiment of the present invention;

[0060] Figure 10 This is a schematic diagram of an on-board controller according to one embodiment of the present invention;

[0061] Figure 11 This is a schematic diagram of a refrigerant circuit in one embodiment of the present invention;

[0062] Figure 12 This is a schematic diagram of a coolant circuit in one embodiment of the present invention;

[0063] In the diagram: 1. Compressor; 2. Condenser; 201. Coolant side; 202. Refrigerant side; 3. First check valve; 4. First solenoid valve; 5. Third solenoid valve; 6. Outdoor heat exchanger; 7. Second solenoid valve; 8. Second check valve; 9. Receiver tank; 10. Regenerator; 11. Third electronic expansion valve; 12. Battery heat exchanger; 13. First electronic expansion valve; 14. Air conditioning unit; 141. Evaporator; 142. Heater core; 143. Air duct; 15. Fourth solenoid valve; 16. Second electronic expansion valve; 17. Third check valve; 18. Heater; 19. Water pump; 20. Three-way valve. Detailed Implementation

[0064] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0065] The control method for a heat pump system provided in this embodiment of the invention can be applied to, for example... Figure 10The vehicle controller shown aims to reduce heating energy consumption and improve the heating efficiency of the passenger compartment.

[0066] In one embodiment, such as Figure 1 As shown, a control method for a heat pump system is provided. The heat pump system includes an air conditioning unit, an air duct passing through the air conditioning unit, and a refrigerant circuit and a coolant circuit connected to the air conditioning unit, comprising:

[0067] Obtain the first measured data;

[0068] Based on the first measured data, the current mode of the heat pump system is determined;

[0069] If the current mode of the heat pump system is air source heat pump mode, then the refrigerant circuit is controlled to preheat the air in the duct, and the coolant circuit is controlled to heat the preheated air in the duct.

[0070] In one embodiment, a heat pump system is provided, including an air conditioning unit 14, an air duct 143 passing through the air conditioning unit 14, and a refrigerant circuit and a coolant circuit connected to the air conditioning unit 14. The refrigerant circuit is used to preheat the air in the air duct 143 of the air conditioning unit 14; the coolant circuit is used to heat the preheated air in the air duct 143 of the air conditioning unit 14.

[0071] like Figure 11 and Figure 12 As shown, the heat pump system includes an air conditioning unit 14 and a refrigerant circuit and a coolant circuit connected to the air conditioning unit 14. The refrigerant circuit includes a condenser 2, which includes a refrigerant side 202 and a coolant side 201. The air conditioning unit 14 includes an evaporator 141, a heater core 142, and an air duct 143 that passes through the interior of the air conditioning unit 14.

[0072] Depend on Figure 11 It is known that the compressor 1 in the refrigerant circuit outputs a gaseous refrigerant with a higher temperature. The gaseous refrigerant flows to the refrigerant side 202 of the compressor 1. On the refrigerant side 202 of the compressor 1, heat is exchanged with the coolant (e.g., water) on the coolant side 201 of the compressor 1, heating the coolant on the coolant side 201 of the compressor 1. The refrigerant then becomes liquid refrigerant with a lower temperature on the refrigerant side 202. When the external environment is cold, the temperature of the refrigerant after the temperature drop is still higher than the external environment temperature. The refrigerant after the temperature drop flows to the evaporator 141 of the air conditioning unit 14 in the refrigerant circuit to preheat the cold air entering the air duct 143 of the air conditioning unit 14 from outside the vehicle, i.e., to perform the first heating, and obtain preheated air. The waste heat of the refrigerant after the temperature drop is fully utilized to preheat the cold air, achieving the purpose of secondary utilization of the waste heat after the refrigerant condenses.

[0073] Depend on Figure 12 As can be seen, in the coolant circuit, the coolant in the condenser 2 is heated by the refrigerant on the refrigerant side 202, generating hot coolant. This hot coolant flows into the heater core 142 of the air conditioning unit 14, further heating the air preheated by the refrigerant circuit, thus heating the cold air. The secondarily heated air is then delivered to the passenger compartment to achieve the purpose of heating the passenger compartment. Understandably, the refrigerant circuit preheats the cold air passing through the evaporator 141, and the coolant circuit further heats the preheated air passing through the heater core 142. The secondarily heated air enters the passenger compartment, completing the heating process. This process fully utilizes the heat from the refrigerant output by the compressor 1, heating the outside cold air entering the air duct 143 of the air conditioning unit 14 twice through the refrigerant and coolant circuits, thus completing the passenger compartment heating. This achieves secondary utilization of the waste heat after refrigerant condensation, reducing energy consumption and improving the heating efficiency of the passenger compartment.

[0074] The first measured data refers to the data collected in real time. This first measured data is used to determine the current mode of the heat pump system. The current mode refers to the operating mode of the heat pump system at present.

[0075] As an example, in step S101, the vehicle controller acquires the first measured data collected in real time by the data acquisition device. In this example, the data acquisition device includes, but is not limited to, sensors. For example, the first measured data includes, but is not limited to, the passenger compartment temperature and the ambient temperature.

[0076] As an example, in step S102, the vehicle controller determines the current mode of the heat pump system based on the first measured data. The heat pump system is used to regulate the passenger compartment temperature. The current mode of the heat pump system needs to be determined based on the collected first measured data to ensure timely adjustment of the passenger compartment temperature and improve user comfort. In this example, the first measured data may include the passenger compartment temperature and the ambient temperature. The vehicle controller compares the passenger compartment temperature and the ambient temperature and determines the current mode of the heat pump system based on the comparison result. For example, if the passenger compartment temperature is higher than the ambient temperature, and the temperature difference between the passenger compartment temperature and the ambient temperature is greater than a certain threshold, the current mode of the heat pump system is determined to be cooling mode; if the passenger compartment temperature is lower than the ambient temperature, and the temperature difference between the ambient temperature and the passenger compartment temperature is greater than a certain threshold, the current mode of the heat pump system is determined to be heating mode. In this example, based on the first measured data, the determined current mode of the heat pump system is more consistent with the current conditions of the passenger compartment, improving user comfort.

[0077] Among them, the air source heat pump mode refers to the heating mode in which the cold air entering the air conditioning unit 14 is preheated by the evaporator 141 of the air conditioning unit 14.

[0078] As an example, in step S103, when the vehicle controller determines that the current mode of the heat pump system is the air source heat pump mode, it controls the operation of the refrigerant circuit to exchange heat with the cold air in the air duct 143 of the air conditioning unit 14, thereby preheating the cold air and obtaining preheated air; then it controls the operation of the coolant circuit to exchange heat with the preheated air in the air duct 143 of the air conditioning unit 14, thereby reheating the preheated air and obtaining heated air. The heated air is then input into the passenger compartment along the air duct 143 of the air conditioning unit 14 to achieve heating of the passenger compartment.

[0079] like Figure 11 and Figure 12 As shown, when the current mode of the heat pump system is air source heat pump mode, the vehicle controller controls the refrigerant flowing into the evaporator 141 of the air conditioning unit 14, whose temperature is higher than the air temperature, to preheat the air (i.e., primary heating), resulting in preheated air. This achieves secondary utilization of the refrigerant's waste heat, improves the heat utilization rate of the refrigerant, and reduces energy consumption. The vehicle controller controls the high-temperature coolant (e.g., water) in the heating core 142 of the air conditioning unit 14 to perform secondary heating on the preheated air. This secondary heating on the basis of preheated air not only saves energy but also improves heating efficiency. In this example, in air source heat pump mode, the refrigerant circuit and coolant circuit are controlled to operate, performing two consecutive heat exchanges on the air in the air duct 143 of the air conditioning unit 14. Compared to a heat pump system that only performs one heat exchange, this method improves energy efficiency by 10%, effectively improving heating efficiency, thereby achieving the goal of saving energy and improving the heating efficiency of the passenger compartment.

[0080] In this embodiment, based on the first measured data, the current mode of the determined heat pump system can be made more consistent with the current situation of the passenger cabin, thereby improving the user's comfort experience. When the heat pump system is in air source heat pump mode, the refrigerant circuit and coolant circuit are controlled to operate, and the air in the air duct 143 of the air conditioning unit 14 undergoes two consecutive heat exchanges, improving heating efficiency, thereby achieving the purpose of saving energy consumption and improving the heating efficiency of the passenger cabin.

[0081] In one embodiment, such as Figure 11 As shown, the refrigerant circuit includes a battery heat exchanger 12;

[0082] The first measured data includes the first ambient temperature and the inlet water temperature of the heat exchanger corresponding to the battery heat exchanger.

[0083] Step S102, which is to determine the current mode of the heat pump system based on the first measured data, includes:

[0084] If the first ambient temperature is within the first ambient temperature range and the heat exchanger inlet water temperature is within the first water temperature range, then the current mode of the heat pump system is determined to be the air source heat pump mode.

[0085] The refrigerant circuit includes a battery heat exchanger 12, which is connected to the battery / electric hot water system for heat exchange with the refrigerant. The battery heat exchanger 12 exchanges heat with the refrigerant through the battery / electric hot water system. If the inlet water temperature of the battery heat exchanger 12 is low, it indicates that the current temperature of the battery / electric hot water system is low, and the overall vehicle temperature is also low. Therefore, the inlet water temperature of the battery heat exchanger 12 can reflect the current temperature of the vehicle to a certain extent and can be used to determine the current mode of the heat pump system. The heat exchanger inlet water temperature refers to the water temperature entering the battery heat exchanger 12 in the refrigerant circuit. The first ambient temperature refers to the ambient temperature collected to determine the current mode of the heat pump system.

[0086] The first ambient temperature range is a pre-set temperature range used for comparison and judgment of the first ambient temperature. The first water temperature range is a pre-set temperature range used for comparison and judgment of the heat exchanger inlet water temperature.

[0087] As an example, when the vehicle controller determines that the first ambient temperature is within a first ambient temperature range and the heat exchanger inlet water temperature is within a first water temperature range, it determines that the current mode of the heat pump system is air source heat pump mode. In this example, the first ambient temperature range is [-15℃, 0℃), and the first water temperature range is [-15℃, 5℃). Understandably, [-15℃, 0℃) and [-15℃, 5℃) represent lower temperature states. When the first ambient temperature and the heat exchanger inlet water temperature are within the above ranges, the current mode of the heat pump system is determined to be air source heat pump mode to improve heating efficiency, thereby reducing heating energy consumption, improving the heating efficiency of the passenger compartment, and enhancing the user's comfort experience.

[0088] In this embodiment, the current mode of the heat pump system can be determined more accurately based on the first ambient temperature and the heat exchanger inlet water temperature, thereby improving the user's comfort experience.

[0089] In another embodiment, step S102, namely determining the current mode of the heat pump system based on the first measured data, further includes:

[0090] If the first ambient temperature is within the second ambient temperature range and the heat exchanger inlet water temperature is within the second water temperature range, then the current mode of the heat pump system is determined to be heater heating mode.

[0091] If the first ambient temperature is within the third ambient temperature range and the heat exchanger inlet water temperature is within the third water temperature range, then the current mode of the heat pump system is determined to be the water source heat pump mode.

[0092] If the first ambient temperature is within the fourth ambient temperature range, then the current mode of the heat pump system is determined to be heat pump dehumidification mode.

[0093] If the first ambient temperature is within the fifth temperature range, then the current mode of the heat pump system is determined to be cooling and dehumidifying mode.

[0094] The second to fifth ambient temperature ranges are pre-set temperature ranges used to compare and determine the first ambient temperature. The second and third water temperature ranges are pre-set temperature ranges used to compare and determine the heat exchanger inlet water temperature. The heater heating mode refers to directly heating the coolant through the heater 18 in the coolant circuit, and then exchanging heat between the heated coolant and the cold air to increase the cabin temperature.

[0095] In this embodiment, the maximum value of the second ambient temperature range is less than the minimum value of the third ambient temperature range, the maximum value of the third ambient temperature range is less than the minimum value of the first ambient temperature range, the maximum value of the first ambient temperature range is less than the minimum value of the fourth ambient temperature range, and the maximum value of the fourth ambient temperature range is less than the minimum value of the fifth ambient temperature range.

[0096] The maximum value of the second water temperature range is less than the minimum value of the first water temperature range, and the maximum value of the first water temperature range is less than the minimum value of the third water temperature range.

[0097] As an example, when the vehicle controller determines that the first ambient temperature is within the second ambient temperature range and the heat exchanger inlet water temperature is within the second water temperature range, it determines that the current mode of the heat pump system is heater heating mode. For example, if the second ambient temperature range is less than -15°C and the second water temperature range is less than -15°C, and the first ambient temperature is within the second ambient temperature range while the heat exchanger inlet water temperature is within the second water temperature range, the current mode of the heat pump system is determined to be heater heating mode. The coolant is directly heated by the heater 18 in the coolant circuit, and then the heated coolant exchanges heat with the cold air to directly heat the cold air, thus directly heating the passenger compartment.

[0098] Among them, the water source heat pump mode refers to the mode of achieving heating through the battery heat exchanger 12.

[0099] As an example, when the vehicle controller determines that the first ambient temperature is within the third ambient temperature range and the heat exchanger inlet water temperature is within the third water temperature range, it determines that the current mode of the heat pump system is water source heat pump mode. For example, if the third ambient temperature range is [-15℃, -10℃) and the third water temperature range is greater than 5℃, and the first ambient temperature is within the third ambient temperature range and the heat exchanger inlet water temperature is within the third water temperature range, it determines that the temperature of the battery heat exchanger 12 is higher than the first ambient temperature. In this case, the current mode of the heat pump system is determined to be water source heat pump mode, and heat is exchanged with the battery / electrically driven hot water system through the battery heat exchanger 12 to achieve heating by the heat pump system.

[0100] Among them, the heat pump dehumidification mode refers to the mode of dehumidifying the air in the passenger cabin.

[0101] As an example, when the vehicle controller determines that the first ambient temperature is within the fourth ambient temperature range, it determines that the current mode of the heat pump system is heat pump dehumidification mode. For example, if the fourth ambient temperature range is [0℃, 25℃], when the first ambient temperature is within the fourth ambient temperature range, the current mode of the heat pump system is determined to be heat pump dehumidification mode. The heat pump system is then controlled to dehumidify the air in the air duct 143 inside the air conditioning unit 14, and the dehumidified air is delivered to the passenger compartment to achieve dehumidification of the passenger compartment.

[0102] The cooling and dehumidification mode refers to the mode that lowers the temperature of the passenger cabin by cooling and dehumidifying the air in the passenger cabin.

[0103] As an example, when the vehicle controller determines that the first ambient temperature is within the fifth temperature range, it determines that the current mode of the heat pump system is cooling and dehumidifying mode. For example, if the fifth temperature range is greater than 25°C, and the first ambient temperature is within the fifth ambient temperature range, the controller determines that the current mode of the heat pump system is cooling and dehumidifying mode, controls the heat pump system to cool and dehumidify the air in the air duct 143 inside the air conditioning unit 14, and delivers the cooled and dehumidified air to the passenger compartment to achieve cooling and dehumidification of the passenger compartment.

[0104] In this embodiment, the current mode of the heat pump system is determined based on the first ambient temperature and / or the heat exchanger inlet water temperature, which is more consistent with the actual temperature conditions of the passenger compartment and can improve the comfort experience of users driving the vehicle.

[0105] In one embodiment, the air conditioning unit includes an evaporator and a heater core; the refrigerant circuit includes a preheating circuit, which includes a compressor, a condenser, an electronic expansion valve, and an evaporator connected in sequence; the coolant circuit includes a condenser, a heater, and a heater core connected in sequence; the preheating circuit and the coolant circuit exchange heat through the condenser.

[0106] Step S103, which controls the operation of the refrigerant circuit to preheat the air in the duct, includes: controlling the preheating circuit to be turned on, controlling the compressor to operate based on the target speed, and controlling the electronic expansion valve to operate based on the target opening, so that the refrigerant in the preheating circuit preheats the air in the duct.

[0107] In one embodiment, such as Figure 11 As shown, the refrigerant circuit includes a battery heat exchanger 12, which is used to exchange heat with the battery / electric drive hot water system. The battery / electric drive hot water system is the system in the vehicle that exchanges heat between the battery and the electric drive.

[0108] In one embodiment, such as Figure 11 and Figure 12As shown, the air conditioning unit 14 includes an evaporator 141 and a heater core 142; the refrigerant circuit includes a preheating circuit, which includes a compressor 1, a condenser 2, an electronic expansion valve and an evaporator 141 connected in sequence; the coolant circuit includes a condenser 2, a heater 18 and a heater core 142 connected in sequence; the preheating circuit and the coolant circuit exchange heat through the condenser 2.

[0109] As an example, such as Figure 11 As shown, the refrigerant circuit includes a compressor 1, a condenser 2, a first solenoid valve 4, a first electronic expansion valve 13, an evaporator 141 of the air conditioning unit 14, a second electronic expansion valve 16, and a second solenoid valve 7. The discharge port of the compressor 1 is connected to the input terminal of the refrigerant side 202 of the condenser 2. The output terminal of the refrigerant side 202 of the condenser 2 is connected to one end of the second solenoid valve 7. The other end of the second solenoid valve 7 is connected to one end of the first electronic expansion valve 13. The other end of the first electronic expansion valve 13 is connected to the input terminal of the evaporator 141. The output terminal of the evaporator 141 is connected to one end of the second electronic expansion valve 16. The other end of the second electronic expansion valve 16 is connected to one end of the first solenoid valve 4. The other end of the first solenoid valve 4 is connected to the suction port of the compressor 1, forming a preheating circuit. In air source heat pump mode, the vehicle controller opens the first solenoid valve 4 and the second solenoid valve 7, and closes the remaining solenoid valves (the third solenoid valve 5 and the fourth solenoid valve 15 in the refrigerant circuit). It also opens the first electronic expansion valve 13 and the second electronic expansion valve 16, and closes the remaining electronic expansion valve (the third electronic expansion valve 11 in the refrigerant circuit), forming a conductive preheating circuit. This preheating circuit is connected to the evaporator 141 in the air conditioning unit 14. It utilizes the principle that the temperature of the refrigerant in the refrigerant side 202 of the condenser 2, after cooling, is still higher than the temperature of the cold air. This preheating preheats the cold air entering the evaporator 141 through the air duct 143 within the air conditioning unit 14, achieving full utilization of the refrigerant's waste heat, reducing the heating energy consumption of the heat pump system, and improving heating efficiency. The condenser 2 includes, but is not limited to, a water-cooled condenser. In this example, in the conducting preheating circuit, the compressor 1 outputs high-temperature gaseous refrigerant to the refrigerant side 202 of the condenser 2 to heat the coolant (e.g., water) in the coolant side 201 of the condenser 2. The refrigerant carrying the residual heat flows into the evaporator 141 of the air conditioning unit 14 through the conducting second solenoid valve 7 and the first electronic expansion valve 13 in sequence, preheating the cold air that passes through the evaporator 141 and whose temperature is lower than that of the refrigerant, so as to make full use of the residual heat of the refrigerant and improve the efficiency of subsequent heating.

[0110] As an example, such as Figure 12As shown, the coolant circuit includes the heater core 142 of the air conditioning unit 14, a three-way valve 20, a water pump 19, a condenser 2, and a heater 18. The three-way valve 20 includes, but is not limited to, a proportional three-way valve 20, and the water pump 19 includes, but is not limited to, a heater water pump 19. In this example, as... Figure 12 As shown, the three-way valve 20 includes terminals A, B, and C. Terminal A is connected to the coolant output terminal of the air conditioning unit 14, and terminal C is connected to the input terminal of the water pump 19. In air source heat pump mode, the vehicle controller controls the A and C terminals of the three-way valve 20 to be open, while the remaining terminals (A to B and C to B) are closed, thus achieving the conduction of the coolant circuit. In this example, the output terminal of the heater core 142 is connected to terminal A of the three-way valve 20, the C terminal of the three-way valve 20 is connected to the input terminal of the water pump 19, the output terminal of the water pump 19 is connected to the input terminal of the coolant side 201 of the condenser 2, the output terminal of the coolant side 201 of the condenser 2 is connected to the input terminal of the heater 18, and the output terminal of the heater 18 is connected to the input terminal of the heater core 142, forming a coolant circuit. Since the coolant circuit includes the coolant side 201 of the condenser 2, and in the refrigerant circuit, the high-temperature gaseous refrigerant exchanges heat with the coolant (e.g., water) on the refrigerant side 202 of the condenser 2 and the coolant side 201, resulting in a higher-temperature coolant, heat exchange between the refrigerant circuit and the coolant circuit is achieved. The vehicle controller controls the water pump 19 in the coolant circuit to input the higher-temperature coolant from the coolant side 201 of the condenser 2 to the heater core 142 of the air conditioning unit 14, which performs secondary heating on the preheated air, improving heating efficiency. In this case, compared to directly heating the cold air, energy consumption can be saved.

[0111] The preheating circuit refers to the refrigerant circuit used for preheating in air-source heat pump mode. The target speed refers to the normal operating speed of compressor 1 when preheating the air inside the air conditioning unit 14. The target opening degree refers to the opening degree of the electronic expansion valve when it is operating normally.

[0112] As an example, when the vehicle controller determines that the current mode of the heat pump system is air source heat pump mode, it controls the preheating circuit corresponding to the air source heat pump mode in the refrigerant circuit to be turned on, so as to realize a heat exchange (preheating) of the cold air entering the air duct 143 of the air conditioning unit 14. In this example, as Figure 11As shown, the first solenoid valve 4, the second solenoid valve 7, the first electronic expansion valve 13, and the second electronic expansion valve 16 in the preheating circuit are activated to enable the preheating circuit to perform a primary heat exchange (preheating) on ​​the cold air entering the air duct 143 of the air conditioning unit 14. This method allows for the secondary utilization of the waste heat of the refrigerant after cooling in the preheating circuit, saving energy and improving the heating efficiency of the passenger compartment. In air source heat pump mode, the vehicle controller controls the compressor 1 in the activated preheating circuit to operate at a target speed and controls the electronic expansion valve in the preheating circuit to operate at a target opening, so that the cooled refrigerant in the preheating circuit preheats the air in the air duct 143 of the air conditioning unit 14. This method utilizes the fact that the temperature of the cooled refrigerant is higher than the temperature of the cold air in the air duct 143, using the cooled refrigerant to preheat the cold air in the air duct 143 (i.e., primary heating), and reuses the waste heat of the cooled refrigerant in the preheating circuit, saving energy and achieving a more efficient heating effect.

[0113] In this embodiment, in the air source heat pump mode, the preheating circuit corresponding to the air source heat pump mode is turned on in the refrigerant circuit. The compressor 1 in the preheating circuit is controlled to work based on the target speed, and the electronic expansion valve in the preheating circuit is controlled to work based on the target speed, so that the refrigerant in the preheating circuit preheats the air in the air duct 143, and the waste heat of the refrigerant after cooling in the preheating circuit is reused to save energy and enable the passenger cabin to be heated more efficiently.

[0114] In one embodiment, such as Figure 2 As shown, controlling the compressor to operate based on the target speed includes:

[0115] S201: Obtain the second measured data;

[0116] S202: Based on the second measured data, determine the first compressor speed corresponding to the compressor;

[0117] S203: Based on the first compressor speed and the preset maximum speed, determine the target speed of the compressor and control the compressor to work based on the target speed.

[0118] The second measured data refers to the data collected in real time from the refrigerant circuit, used to determine the speed of the first compressor corresponding to compressor 1. The speed of the first compressor refers to the theoretical speed of compressor 1 determined based on the second measured data.

[0119] As an example, in step S201, the vehicle controller acquires second measured data for determining the speed of the first compressor corresponding to compressor 1. In this example, the second measured data includes, but is not limited to, the actual inlet temperature and target inlet temperature of the coolant entering the heater core 142 of the air conditioning unit 14 in the coolant circuit. The target inlet temperature refers to the temperature of the coolant entering the heater core 142 required to heat the preheated air to the required temperature of the passenger compartment. This target inlet temperature can be obtained based on the required temperature of the passenger compartment, the temperature of the preheated air, and the specific heat capacity of the coolant. Alternatively, the target inlet temperature can be preset. The actual inlet temperature refers to the actual temperature of the coolant entering the heater core 142. Understandably, in air source heat pump mode, the temperature of the passenger compartment needs to be raised to a certain temperature to achieve heating. At this time, a coolant with a higher temperature needs to be introduced into the warm air core 142 of the air conditioning unit 14. The air in the air duct 143 is heated by the warm air core 142 of the air conditioning unit, so that the air in the air duct 143 is raised to the temperature required by the passenger compartment. Therefore, the temperature required by the passenger compartment corresponds to a specific target inlet liquid temperature to complete the heating of the passenger compartment. Figure 11 In the refrigerant circuit, compressor 1 outputs a high-temperature refrigerant to the refrigerant side 202 of condenser 2, where it exchanges heat with the coolant in the coolant side 201 of the condenser, thus heating the coolant. In air source heat pump mode, the heated coolant in the coolant circuit is delivered to the heater core 142 of the air conditioning unit 14, heating the air passing through the heater core 142 in the air inlet and outlet ducts of the air conditioning unit 14. The temperature of the heated coolant delivered to the heater core 142 of the air conditioning unit 14 is the actual inlet temperature. Generally, water is selected as the coolant.

[0120] As an example, in step S202, the vehicle controller uses a preset control algorithm to process the second measured data to determine the first compressor speed corresponding to compressor 1. The preset control algorithm includes, but is not limited to, the PI (Proportional-Integral) control algorithm. In this example, the vehicle controller uses the preset control algorithm to process the target inlet temperature and the actual inlet temperature of the heater core 142 in the air conditioning unit 14 to determine the first compressor speed corresponding to compressor 1, thereby determining the target speed of compressor 1.

[0121] The preset maximum speed refers to the maximum safe speed that compressor 1 can achieve. Generally, if the speed of compressor 1 exceeds the preset maximum speed, compressor 1 is in an unsafe state. Therefore, a preset maximum speed needs to be set to determine whether the speed of compressor 1 is normal, in order to ensure the safety performance of compressor 1. The target speed refers to the operating speed of compressor 1 determined based on the first compressor speed and the preset maximum speed.

[0122] As an example, in step S203, the vehicle controller uses a preset control algorithm to process the first compressor speed and a preset maximum speed to determine the target speed of compressor 1, and controls compressor 1 to operate based on the target speed, so that the temperature of the coolant entering the heater core 142 rises to the target inlet temperature. In this example, when compressor 1 is working, it outputs a high-temperature gaseous refrigerant through the exhaust port of compressor 1 to the refrigerant side 202 of condenser 2, where it exchanges heat with the coolant (e.g., water) on the coolant side 201 of condenser 2 to obtain a high-temperature coolant. The high-temperature coolant flows into the heater core 142 of the air conditioning unit 14 through the coolant circuit. Therefore, controlling compressor 1 to operate based on the target speed can raise the temperature of the coolant entering the heater core 142 to the target inlet temperature, so that the heater core 142 of the air conditioning unit 14 can heat the air in the air duct 143 to achieve heating of the passenger compartment. The preset control algorithm includes, but is not limited to, the PI (Proportional-Integral) control algorithm.

[0123] In this embodiment, the target speed of compressor 1 is determined more accurately based on the first compressor speed and the preset maximum speed, so that the temperature of the coolant entering the heater core 142 is raised to the target inlet temperature, so that the heater core 142 of the air conditioning unit 14 can heat the air in the air duct 143 and realize the heating of the passenger compartment.

[0124] In another embodiment, such as Figure 3 As shown, after step S203, that is, after controlling the compressor to operate based on the target speed, the control method of the heat pump system further includes:

[0125] S301: Obtain the compressor's discharge temperature, discharge pressure, measured pressure ratio, and measured speed;

[0126] S302: If the exhaust temperature is greater than the preset temperature, the exhaust pressure is greater than the preset pressure, the measured pressure ratio is greater than the preset pressure ratio, or the measured speed is equal to the preset maximum speed, then repeat the process to obtain the second measured data.

[0127] Here, the discharge temperature of compressor 1 refers to the temperature of the discharge port of compressor 1. The discharge pressure refers to the pressure of the discharge port of compressor 1. The discharge port refers to the port through which compressor 1 discharges gaseous refrigerant at a relatively high temperature. For example... Figure 11 As shown, a temperature sensor is installed at the discharge port of compressor 1 to collect the discharge temperature T4 of compressor 1. The measured pressure ratio refers to the ratio of the discharge pressure of compressor 1 to the suction pressure of compressor 1. The suction pressure refers to the pressure at the suction port of compressor 1. The suction port is the port through which compressor 1 draws in liquid refrigerant at a lower temperature. Figure 11As shown, the temperature and pressure sensor can collect the suction port pressure P3 of compressor 1. The temperature sensor can collect the discharge port pressure P1 of compressor 1, and the measured pressure ratio is P1 / P3. A low-pressure refrigerant temperature and pressure sensor is selected. The measured speed refers to the real-time speed of compressor 1.

[0128] As an example, in step S301, after controlling the compressor 1 to operate at the target speed, the on-board controller continues to monitor the discharge temperature, discharge pressure, measured pressure ratio, and measured speed of the compressor 1 in real time to achieve safe control of the compressor 1. Understandably, if at least one of the discharge temperature, discharge pressure, measured pressure ratio, or measured speed of the compressor 1 is too high, it will reduce the safety performance of the compressor 1. Therefore, after controlling the compressor 1 to operate at the target speed, it is necessary to monitor the discharge temperature, discharge pressure, measured pressure ratio, and measured speed of the compressor 1 in real time to ensure the safety performance of the compressor 1, and thus ensure the safe heating performance of the refrigerant circuit and coolant circuit.

[0129] Among these, preset temperature refers to the preset temperature used to determine the magnitude of exhaust temperature. Preset pressure ratio refers to the preset pressure ratio used to determine the magnitude of measured pressure ratio. Preset pressure refers to the preset pressure used to determine the magnitude of exhaust pressure.

[0130] As an example, in step S302, when the vehicle controller determines that the exhaust temperature is greater than the preset temperature, the exhaust pressure is greater than the preset pressure, the measured pressure ratio is greater than the preset pressure ratio, or the measured speed is equal to the preset maximum speed, it repeats steps S201 to S203 until the exhaust temperature is no greater than the preset temperature, the exhaust pressure is no greater than the preset pressure, the measured pressure ratio is no greater than the preset pressure ratio, and the measured speed is less than the preset maximum speed. It then obtains the adjusted target speed of the compressor and controls the compressor to operate based on the target speed. Understandably, when any of the exhaust temperature, exhaust pressure, measured pressure ratio, or measured speed of compressor 1 is too high, the target speed of compressor 1 needs to be adjusted in real time to ensure the safety performance of compressor 1, and thus ensure the safe heating performance of the refrigerant circuit and coolant circuit.

[0131] In this embodiment, the discharge temperature, discharge pressure, measured pressure ratio, and measured speed of compressor 1 are monitored in real time. When the discharge temperature, discharge pressure, measured pressure ratio, and measured speed of compressor 1 are too high, the target speed of compressor 1 is adjusted in real time to ensure the safety performance of compressor 1, and thus ensure the safety performance of the refrigerant circuit and coolant circuit in heating.

[0132] In one embodiment, such as Figure 4 As shown, controlling the electronic expansion valve to operate based on the target opening degree includes:

[0133] S401: Obtain the third measured data;

[0134] S402: Based on the third measured data, determine the target opening degree of the electronic expansion valve and control the electronic expansion valve to operate based on the target opening degree.

[0135] The third measured data refers to the measured opening of the electronic expansion valve used to control the preheating circuit.

[0136] As an example, in step S401, the vehicle controller acquires third measured data for controlling the opening degree of the electronic expansion valve. Understandably, as... Figure 11 As shown, the preheating circuit includes a first electronic expansion valve 13 and a second electronic expansion valve 16. The opening degree of the first electronic expansion valve 13 is related to the superheat of the compressor 1's suction port. Therefore, it is necessary to control the opening degree of the first electronic expansion valve 13 to control the superheat of the compressor 1's suction port and ensure the safety performance of the compressor 1. The opening degree of the second electronic expansion valve 16 is related to the temperature of the evaporator 141 in the air conditioning unit 14. The larger the opening degree of the second electronic expansion valve 16, the lower the temperature of the evaporator 141. Therefore, it is necessary to control the opening degree of the second electronic expansion valve 16 to control the temperature of the evaporator 141, thereby fully utilizing the waste heat of the refrigerant to preheat the cold air.

[0137] As an example, in step S402, the vehicle controller uses a preset control algorithm to process the third measured data, determines the target opening degree of the electronic expansion valve in the preheating circuit, and controls the electronic expansion valve to operate based on the target opening degree. The preset control algorithm includes, but is not limited to, the PI (Proportional-Integral) control algorithm.

[0138] In this embodiment, the target opening degree of the electronic expansion valve can be determined more accurately based on the third measured data, so as to ensure the normal preheating function of the preheating circuit based on the target opening degree.

[0139] In one embodiment, the electronic expansion valve includes a first electronic expansion valve disposed at the input end of the evaporator, and the third measured data includes the actual superheat of the compressor.

[0140] like Figure 5 As shown, step S402, which is to determine the target opening degree of the electronic expansion valve based on the third measured data, includes:

[0141] S501: Based on the actual superheat and the target superheat of the compressor, determine the theoretical pressure corresponding to the compressor;

[0142] S502: Determine the target opening degree of the first electronic expansion valve based on the theoretical pressure and the target pressure corresponding to the compressor.

[0143] like Figure 11 As shown, the first electronic expansion valve 13 is disposed between the exhaust port of the compressor 1 and the input end of the evaporator 141, and is used to control the superheat of the suction port of the compressor 1 based on the target opening degree of the first electronic expansion valve 13.

[0144] The actual superheat of compressor 1 refers to the superheat actually measured at the suction port of compressor 1. Figure 11 It is known that the expansion valve in the preheating circuit includes a first electronic expansion valve 13. The opening degree of this first electronic expansion valve 13 is used to control the superheat of the suction port of the compressor 1. Therefore, it is necessary to determine the target opening degree of the first electronic expansion valve 13 to control the superheat of the compressor 1, ensure that the refrigerant at the suction port of the compressor 1 carries a suitable superheat, protect the compressor 1 from liquid slugging and damage, and thus ensure the safe operation of the compressor 1. In this example, the target pressure corresponding to the first electronic expansion valve 13 in the preheating circuit is determined to more accurately determine the target opening degree corresponding to the first electronic expansion valve 13.

[0145] The target superheat refers to the preset superheat. The theoretical pressure refers to the pressure at the suction port of compressor 1, determined based on the actual superheat and the target superheat.

[0146] As an example, in step S501, the vehicle controller uses a preset control algorithm to process the actual superheat corresponding to the intake port of compressor 1 and the target superheat corresponding to the intake port of compressor 1, thereby determining the theoretical pressure of the intake port of compressor 1 more accurately. The preset control algorithm includes, but is not limited to, the PI (Proportional-Integral) control algorithm.

[0147] The target pressure refers to the preset pressure at the intake port of compressor 1.

[0148] As an example, in step S502, the vehicle controller uses a preset control algorithm to process the theoretical pressure of the compressor 1's intake port and the target pressure of the compressor 1's intake port, and determines the target opening degree corresponding to the first electronic expansion valve 13 more accurately.

[0149] In this embodiment, the target opening degree of the first electronic expansion valve 13 is determined so that the refrigerant at the suction port of the compressor 1 carries a suitable superheat degree according to the target opening degree of the first electronic expansion valve 13, so as to protect the compressor 1 from liquid slugging and damage, and thus ensure the safe operation of the compressor 1.

[0150] In another embodiment, the electronic expansion valve includes a second electronic expansion valve disposed at the output end of the evaporator, and the third measured data includes the measured temperature, the air intake volume of the air conditioning unit, and the measured pressure corresponding to the output end of the evaporator.

[0151] like Figure 6 As shown, step S402, which is to determine the target opening degree of the electronic expansion valve based on the third measured data, includes:

[0152] S601: Determine the saturated refrigerant temperature based on the measured temperature and the air intake volume of the air conditioning unit;

[0153] S602: Determine the saturated refrigerant pressure based on the saturated refrigerant temperature;

[0154] S603: Determine the target opening degree of the second electronic expansion valve based on the saturated refrigerant pressure and the measured pressure.

[0155] like Figure 11 As shown, the second electronic expansion valve 16 is disposed between the output end of the evaporator 141 and the suction port of the compressor 1, and is used to control the evaporator 141 to preheat the air in the air duct 143 based on the target opening degree of the second electronic expansion valve 16. Understandably, controlling the second electronic expansion valve 16 to operate based on the target opening degree can effectively increase the preheating temperature of the air in the air duct 143 by the evaporator 141, saving energy and improving heating efficiency.

[0156] Among them, the measured temperature refers to the temperature measured in real time related to the opening degree of the electronic expansion valve. The air intake volume of the air conditioning unit refers to the volume of air (i.e., air volume) entering the air conditioning unit 14. The measured pressure refers to the pressure actually collected at the output end of the evaporator 141 of the air conditioning unit 14. Understandably, as... Figure 11 As shown, a pressure sensor can be installed at the output end of the evaporator 141 of the air conditioning unit 14 to collect the pressure at the output end of the evaporator 141 in real time and obtain the measured pressure P3, which is the measured pressure at the output end of the evaporator 141.

[0157] Saturated refrigerant temperature refers to the temperature of the refrigerant in the refrigerant circuit.

[0158] As an example, in step S601, the vehicle controller processes the measured temperature and the air intake volume of the air conditioning unit to obtain the saturated refrigerant temperature in the refrigerant circuit. In this example, the vehicle controller uses a PI (Proportional-Integral) control algorithm to process the measured temperature and the air intake volume of the air conditioning unit to obtain the saturated refrigerant temperature in the refrigerant circuit. Understandably, the saturated refrigerant temperature can be determined by the measured temperature and the air intake volume of the air conditioning unit.

[0159] Among them, the saturated refrigerant pressure refers to the pressure value at the output end of the evaporator 141 of the air conditioning unit 14 corresponding to the saturated refrigerant temperature.

[0160] As an example, in step S602, the vehicle controller processes the saturated refrigerant temperature to determine the saturated refrigerant pressure. In this example, the vehicle controller can query a pre-stored refrigerant characteristic table in the system database to determine the saturated refrigerant pressure corresponding to the saturated refrigerant temperature.

[0161] As an example, in step S603, the vehicle controller uses a preset algorithm to process the saturated refrigerant pressure and the measured pressure to determine the target opening degree of the second electronic expansion valve 16. The preset algorithm includes, but is not limited to, a PI (Proportional-Integral) control algorithm. The target opening degree of the second electronic expansion valve 16 is used to control the preheating temperature of the air in the air duct 143 by the evaporator 141 of the air conditioning unit 14. Figure 11 As shown, the target opening degree of the second electronic expansion valve 16 determines the preheating time of the refrigerant in the evaporator 141 of the preheating circuit on the cold air in the air duct 143. Therefore, the opening degree of the second electronic expansion valve 16 is controlled in order to control the temperature of the preheated air.

[0162] In this embodiment, by processing the saturated refrigerant pressure and the measured pressure, the target opening degree of the second electronic expansion valve 16 can be determined more accurately, so as to control the opening degree of the second electronic expansion valve 16 and thus control the temperature of the preheated air.

[0163] In one embodiment, the measured temperature includes the second ambient temperature and the vehicle interior temperature.

[0164] like Figure 7 As shown, step S601, which is to determine the saturated refrigerant temperature based on the measured temperature and the air intake volume of the air conditioning unit, includes:

[0165] S701: If the air conditioning unit is a single-layer flow air conditioning unit, the saturated refrigerant temperature shall be determined based on the second ambient temperature and the air intake volume of the air conditioning unit.

[0166] S702: If the air conditioning unit is a dual-flow air conditioning unit, the saturated refrigerant temperature is determined based on the vehicle interior temperature and the air intake volume of the air conditioning unit.

[0167] The second ambient temperature refers to the ambient temperature in air source heat pump mode. Single-layer flow air conditioning units and dual-layer flow air conditioning units are different types of air conditioning units.14 The difference between single-layer flow and dual-layer flow air conditioning units is that the air entering a single-layer flow air conditioning unit comes entirely from the outside environment; the air entering a dual-layer flow air conditioning unit comes partly from the outside environment and partly from the passenger compartment. Understandably, in air source heat pump mode, when a single-layer flow air conditioning unit heats air, it only heats the air from the outside environment, while a dual-layer flow air conditioning unit needs to heat both the air from the outside environment and the air from the passenger compartment.

[0168] As an example, in step S701, when the vehicle controller determines that the air conditioning unit 14 is a single-layer flow air conditioning unit, it processes the second ambient temperature and the air conditioning unit's air intake volume from the third measured data to obtain the saturated refrigerant temperature. In this example, the vehicle controller uses a preset control algorithm to process the second ambient temperature and the air conditioning unit's air intake volume to obtain the saturated refrigerant temperature. The preset control algorithm includes, but is not limited to, the PI (Proportional-Integral) control algorithm.

[0169] As an example, in step S702, when the vehicle controller determines that the air conditioning unit 14 is a dual-flow air conditioning unit, it processes the in-vehicle temperature and the air intake volume of the air conditioning unit in the second measured data to obtain the saturated refrigerant temperature. In this example, the vehicle controller uses a preset control algorithm to process the in-vehicle temperature and the air intake volume of the air conditioning unit to obtain the saturated refrigerant temperature. The preset control algorithm includes, but is not limited to, the PI (Proportional-Integral) control algorithm.

[0170] Understandably, the refrigerant circuit is used to preheat the cold air entering the air conditioner, and the ambient temperature is generally lower than the vehicle interior temperature. Therefore, for a single-layer flow air conditioning unit, since its air source is the outside environment, the saturated refrigerant temperature is directly determined based on the ambient temperature. For a dual-layer flow air conditioning unit, since its air source is both the outside environment and the vehicle interior, the saturated refrigerant temperature needs to be determined based on the higher vehicle interior temperature. This allows for the determination of the saturated refrigerant pressure, and subsequently the target opening of the second electronic expansion valve 16, to complete the heating function of the passenger compartment in air source heat pump mode.

[0171] In this embodiment, the saturated refrigerant temperature can be determined more accurately according to the type of air conditioning unit 14, so as to realize the heating function of the passenger cabin in air source heat pump mode based on the saturated refrigerant temperature.

[0172] In one embodiment, such as Figure 8 As shown, step S103, which controls the coolant circuit to heat the preheated air in the air duct, includes:

[0173] S801: Obtain the actual liquid inlet temperature of the heater core in the air conditioning unit;

[0174] S802: If the actual inlet temperature is lower than the target inlet temperature, the heater in the coolant circuit is controlled to heat the coolant until the actual inlet temperature is not lower than the target inlet temperature. The coolant corresponding to the target inlet temperature is then controlled to enter the heater core to heat the preheated air in the air duct.

[0175] As an example, in step S801, the vehicle controller obtains the actual inlet temperature of the heating core 142 of the air conditioning unit 14 in the coolant circuit, in order to determine whether the actual inlet temperature reaches the target inlet temperature required for heating the passenger compartment, so as to determine whether the temperature of the air in the air duct 143 after heating can meet the heating requirements of the passenger compartment under the current conditions.

[0176] As an example, in step S802, when the vehicle controller determines that the actual inlet temperature is lower than the target inlet temperature, it controls the heater 18 in the coolant circuit to heat the coolant until the actual inlet temperature is not lower than the target inlet temperature. Then, the heater 18 stops heating, allowing coolant at the target inlet temperature to enter the heater core 142 of the air conditioning unit 14. This ensures that the air temperature after the heater core 142 reheats the air preheated by the evaporator 141 meets the heating requirements of the passenger compartment, achieving the purpose of reheating the air preheated by the evaporator 141, improving the heating efficiency of the air, and thus improving the heating efficiency of the passenger compartment. Understandably, if the actual inlet temperature of the coolant entering the heater core 142 of the air conditioning unit 14 cannot reach the target inlet temperature required for the air conditioning unit 14 to perform reheating, then the heater 18 connected to the output end of the condenser 2 in the coolant circuit needs to be turned on to heat the coolant until the actual inlet temperature reaches the target inlet temperature, in order to meet the heating requirements of the passenger compartment.

[0177] In this embodiment, when the actual inlet temperature is lower than the target inlet temperature, the heater 18 in the coolant circuit is controlled to heat the coolant until the actual inlet temperature is not lower than the target inlet temperature, so as to meet the heating needs of the passenger compartment, ensure the heating of the passenger compartment in the air source heat pump mode, and improve the heating efficiency.

[0178] In another embodiment, such as Figure 9 As shown, after step S103, that is, after controlling the coolant circuit to heat the preheated air in the air duct, the control method of the heat pump system further includes:

[0179] S901: Obtain the compressor's discharge temperature, discharge pressure, and measured pressure ratio;

[0180] S902: If the exhaust temperature is greater than the preset temperature, the exhaust pressure is greater than the preset pressure, or the measured pressure ratio is greater than the preset pressure ratio, the compressor will be controlled to reduce its speed.

[0181] As an example, in step S901, the vehicle controller controls the operation of the coolant circuit to heat the preheated air in the air duct 143 until the actual inlet temperature is not less than the target inlet temperature. Then, it continues to monitor the exhaust temperature, exhaust pressure and measured pressure ratio of the compressor 1 in real time to ensure the safety performance of the compressor 1.

[0182] As an example, in step S902, when the vehicle controller determines that the exhaust temperature is greater than a preset temperature, the exhaust pressure is greater than a preset pressure, or the measured pressure ratio is greater than a preset pressure ratio, it controls the compressor 1 to reduce its target speed according to a preset speed reduction standard, in order to further ensure the safety performance of the compressor 1. In this example, the preset speed reduction standard can be reducing the target speed of the compressor 1 by a preset speed. For example, when the exhaust temperature is greater than a preset temperature, the exhaust pressure is greater than a preset pressure, or the measured pressure ratio is greater than a preset pressure ratio, the target speed of the compressor 1 is reduced by n rpm. That is, if the target speed is N rpm, then the target speed after deceleration is (Nn) rpm.

[0183] In this embodiment, after determining that the actual inlet liquid temperature is not less than the target inlet liquid temperature, the discharge temperature, discharge pressure and measured pressure ratio of compressor 1 are monitored in real time. If the discharge temperature is greater than the preset temperature, the discharge pressure is greater than the preset pressure, or the measured pressure ratio is greater than the preset pressure ratio, the compressor 1 is controlled to reduce its speed, which can further improve the safety performance of compressor 1.

[0184] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0185] In one embodiment, such as Figure 10 As shown, an in-vehicle controller is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the control method of the heat pump system described in the above embodiments, for example... Figure 1 As shown in S101-S103, or Figures 2 to 9 As shown in the figure, to avoid repetition, it will not be repeated here.

[0186] In one embodiment, a heat pump control system is provided, including a heat pump system and an on-board controller as described in the above embodiment, wherein the on-board controller is connected to the heat pump system.

[0187] In one embodiment, a vehicle is provided, including the heat pump control system described in the above embodiment. In this embodiment, the heat pump control system executes the control method of the heat pump system, which can effectively reduce energy consumption and improve the heating efficiency of the passenger compartment. The vehicle including the heat pump control system can still have a high driving range even in low ambient temperatures, and has broad application prospects.

[0188] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM), etc.

[0189] 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, and should all be included within the protection scope of the present invention.

Claims

1. A control method for a heat pump system, the heat pump system comprising an air conditioning unit, an air duct passing through the air conditioning unit, and a refrigerant circuit and a coolant circuit connected to the air conditioning unit, the refrigerant circuit comprising a battery heat exchanger and a preheating circuit, the coolant circuit comprising a heater, the preheating circuit comprising an electronic expansion valve and an evaporator connected in sequence, the electronic expansion valve comprising a second electronic expansion valve disposed at the output end of the evaporator, characterized in that, include: Obtain the first measured data; The first measured data includes the first ambient temperature and the inlet water temperature of the heat exchanger corresponding to the battery heat exchanger; Based on the first measured data, the current mode of the heat pump system is determined, including: If the first ambient temperature is within the second ambient temperature range and the heat exchanger inlet water temperature is within the second water temperature range, then the current mode of the heat pump system is determined to be heater heating mode; if the first ambient temperature is within the third ambient temperature range and the heat exchanger inlet water temperature is within the third water temperature range, then the current mode of the heat pump system is determined to be water source heat pump mode; the heater heating mode refers to the mode in which the coolant is heated by a heater in the coolant circuit, and the heated coolant exchanges heat with the cold air to increase the temperature of the passenger compartment; the water source heat pump mode refers to the mode in which heating is achieved through a battery heat exchanger. If the current mode of the heat pump system is air source heat pump mode, then control the refrigerant circuit to preheat the air in the air duct, and then control the coolant circuit to heat the preheated air in the air duct. The step of controlling the operation of the refrigerant circuit to preheat the air in the duct includes: Acquire third measured data; the third measured data includes measured temperature, air intake volume of the air conditioning unit, and measured pressure corresponding to the output end of the evaporator; The saturated refrigerant temperature is determined based on the measured temperature and the air intake volume of the air conditioning unit. Determine the saturated refrigerant pressure based on the saturated refrigerant temperature; Based on the saturated refrigerant pressure and the measured pressure, the target opening degree of the second electronic expansion valve is determined, and the electronic expansion valve is controlled to operate based on the target opening degree.

2. The control method for a heat pump system as described in claim 1, characterized in that, Determining the current mode of the heat pump system based on the first measured data includes: If the first ambient temperature is within the first ambient temperature range and the heat exchanger inlet water temperature is within the first water temperature range, then the current mode of the heat pump system is determined to be the air source heat pump mode.

3. The control method for a heat pump system as described in claim 1, characterized in that, The air conditioning unit includes an evaporator and a heater core; the refrigerant circuit includes a preheating circuit, which includes a compressor and a condenser connected in sequence; the coolant circuit includes a condenser, a heater, and the heater core connected in sequence; the preheating circuit and the coolant circuit exchange heat through the condenser. The control of the refrigerant circuit to preheat the air in the duct includes: The preheating circuit is controlled to be turned on, and the compressor is controlled to operate based on the target speed, so that the refrigerant in the preheating circuit preheats the air in the air duct.

4. The control method for a heat pump system as described in claim 3, characterized in that, The control of the compressor to operate based on a target speed includes: Obtain the second measured data; Based on the second measured data, the speed of the first compressor corresponding to the compressor is determined; Based on the first compressor speed and the preset maximum speed, the target speed of the compressor is determined, and the compressor is controlled to operate based on the target speed.

5. The control method for a heat pump system as described in claim 4, characterized in that, After controlling the compressor to operate based on the target speed, the control method for the heat pump system further includes: Obtain the compressor's discharge temperature, discharge pressure, measured pressure ratio, and measured speed; If the exhaust temperature is greater than the preset temperature, the exhaust pressure is greater than the preset pressure, the measured pressure ratio is greater than the preset pressure ratio, or the measured speed is equal to the preset maximum speed, then the process of obtaining the second measured data is repeated.

6. The control method for a heat pump system as described in claim 3, characterized in that, The control of the electronic expansion valve to operate based on a target opening degree includes: Based on the third measured data, the target opening degree of the electronic expansion valve is determined, and the electronic expansion valve is controlled to operate based on the target opening degree.

7. The control method for a heat pump system as described in claim 6, characterized in that, The electronic expansion valve includes a first electronic expansion valve disposed at the input end of the evaporator; The third measured data includes the actual superheat of the compressor; The determination of the target opening degree of the electronic expansion valve based on the third measured data includes: Based on the actual superheat and the target superheat of the compressor, the theoretical pressure corresponding to the compressor is determined; Based on the theoretical pressure and the target pressure corresponding to the compressor, the target opening degree of the first electronic expansion valve is determined.

8. The control method for a heat pump system as described in claim 1, characterized in that, The measured temperatures include the second ambient temperature and the vehicle interior temperature; Determining the saturated refrigerant temperature based on the measured temperature and the air intake volume of the air conditioning unit includes: If the air conditioning unit is a single-layer flow air conditioning unit, the saturated refrigerant temperature is determined based on the second ambient temperature and the air intake volume of the air conditioning unit. If the air conditioning unit is a dual-flow air conditioning unit, the saturated refrigerant temperature is determined based on the vehicle interior temperature and the air intake volume of the air conditioning unit.

9. The control method for a heat pump system as described in claim 3, characterized in that, The control of the coolant circuit to heat the preheated air in the air duct includes: Obtain the actual inlet liquid temperature of the heating element in the air conditioning unit; If the actual inlet temperature is lower than the target inlet temperature, the heater in the coolant circuit is controlled to heat the coolant until the actual inlet temperature is not lower than the target inlet temperature. Then, the coolant corresponding to the target inlet temperature is controlled to enter the heater core to heat the preheated air in the air duct.

10. The control method for a heat pump system as described in claim 9, characterized in that, After the control coolant circuit operates to heat the preheated air in the air duct, the control method of the heat pump system further includes: Obtain the compressor's discharge temperature, discharge pressure, and measured pressure ratio; If the exhaust temperature is greater than the preset temperature, the exhaust pressure is greater than the preset pressure, or the measured pressure ratio is greater than the preset pressure ratio, then the compressor is controlled to reduce its speed.

11. An on-board controller, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the control method of the heat pump system as described in any one of claims 1 to 10.

12. A heat pump control system, characterized in that, It includes a heat pump system and the vehicle controller of claim 11, wherein the vehicle controller is connected to the heat pump system.

13. A car, characterized in that, Includes the heat pump control system as described in claim 12.

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