Heat pump systems and their control methods

Abstract

This application discloses a heat pump system and its control method, belonging to the field of electric vehicle thermal management technology. The method includes: controlling a solenoid valve; controlling an electronic expansion valve; controlling a five-way valve; and, based on the control status of the solenoid valve, electronic expansion valve, and five-way valve, causing the heat pump system to execute a corresponding refrigerant circulation mode. In the embodiments of this application, by utilizing same-side evaporation, the operating ambient temperature of the heat pump can be reduced to as low as -30°C, achieving a wide temperature range heat pump air conditioning, and eliminating the need for auxiliary PTC in the passenger compartment and battery water heater. Furthermore, through the recovery of waste heat from the battery and motor, the energy-saving effect is improved by 20% compared to ordinary heat pumps.

Description

Technical Field

[0001] This application relates to the field of thermal management technology for electric vehicles, and more specifically, to a heat pump system and its control method. Background Technology

[0002] With the development of thermal management technology for electric vehicles, heat pump air conditioning is an important thermal management measure for energy saving in winter. Ordinary air conditioners primarily use PTC heating in winter. Whether it's a fan-heated or water-heated PTC, it essentially converts electrical energy directly into heat energy through the PTC fins, with a theoretical efficiency of 100%. However, considering losses, the actual efficiency may only be 90%. Heat pump air conditioning, on the other hand, has an efficiency of 200%. According to industry big data, the average energy consumption of a PTC in winter is about 2kW, while that of a heat pump air conditioner is about 1kW, resulting in energy savings of about 50%. Currently, heat pump air conditioners using R134a refrigerant can only be used in ambient temperatures above -10℃. At lower temperatures, an auxiliary PTC is required. Electric vehicles are currently mostly used in areas south of Beijing, but even in Beijing, the lowest winter temperature can reach -20℃. Solving the energy-saving heating problem in ambient temperatures between -20℃ and -10℃ is a crucial issue.

[0003] like Figure 1 As shown, a certain existing pure electric heat pump air conditioning system uses a short-tube throttling heat exchanger and switches the refrigerant flow direction through two solenoid valves. The disadvantages of this existing technology are: the heat pump system can only operate above an ambient temperature of -10°C; the battery, motor, and air conditioner are independent and lack integrated thermal management, resulting in limited energy savings; battery heating relies entirely on a water heater, which is costly and has a slow heating rate. Summary of the Invention

[0004] One objective of this application is to provide a new technical solution for a heat pump system and its control method, in order to overcome the shortcomings of the prior art.

[0005] A first aspect of the embodiments of this application provides a heat pump system, comprising:

[0006] Indoor evaporator, indoor condenser, gas-liquid separator, compressor, outdoor heat exchanger, motor Lcc heat exchanger, motor, battery Chiller heat exchanger, radiator, five-way valve, battery;

[0007] One end of the indoor evaporator is connected to the gas-liquid separator, the motor Lcc heat exchanger, and the battery Chiller heat exchanger. A third solenoid valve is connected between the indoor evaporator and the motor Lcc heat exchanger, and a fifth solenoid valve is connected between the indoor evaporator and the battery Chiller heat exchanger.

[0008] The other end of the indoor evaporator is connected to the indoor condenser, outdoor heat exchanger, motor Lcc heat exchanger, and battery Chiller heat exchanger via a fourth electronic expansion valve. A second check valve is connected between the fourth electronic expansion valve and the indoor condenser. A first check valve is connected between the fourth electronic expansion valve and the outdoor heat exchanger. A second electronic expansion valve is connected between the fourth electronic expansion valve and the motor Lcc heat exchanger. A third electronic expansion valve is connected between the electronic expansion valve and the battery Chiller heat exchanger. One end of the first electronic expansion valve is connected to the fourth electronic expansion valve, and the other end is connected between the outdoor heat exchanger and the first check valve.

[0009] The indoor condenser is connected to the outdoor heat exchanger via a first solenoid valve and a second solenoid valve. The indoor condenser is connected to the compressor via a first solenoid valve. One end of the first connecting device is connected between the second solenoid valve and the outdoor heat exchanger, and the other end is connected between the third solenoid valve and the motor Lcc heat exchanger. The indoor condenser is connected to the battery Chiller heat exchanger via a first solenoid valve and a fourth solenoid valve.

[0010] The compressor is connected between the gas-liquid separator and the outdoor heat exchanger, and a second solenoid valve is connected between the compressor and the outdoor heat exchanger; one end of the second connecting device is connected between the first one-way valve and the third electronic expansion valve, and the other end is connected between the third electronic expansion valve and the battery Chiller heat exchanger, and a third one-way valve is provided on the second connecting device.

[0011] The motor Lcc heat exchanger is also connected between the motor and the cooling water tank. The motor is connected to the fifth valve of the five-way valve, wherein the five-way valve includes a first valve, a second valve, a third valve, a fourth valve, and a fifth valve. The battery Chiller heat exchanger is connected between the fourth valve and the battery. The battery is connected to the third valve, and the cooling water tank is connected to the second valve. One end of the third connecting device is connected between the motor Lcc heat exchanger and the cooling water tank, and the other end is connected to the first valve.

[0012] Optionally, the method includes:

[0013] Control the solenoid valve;

[0014] Control the electronic expansion valve;

[0015] Control the five-way valve;

[0016] Based on the control status of the solenoid valve, electronic expansion valve, and five-way valve, the heat pump system is prompted to execute the corresponding refrigerant circulation mode. The refrigerant circulation modes include a cooling mode, a passenger compartment ambient temperature heat pump heating mode, a passenger compartment low temperature heat pump heating mode without waste heat recovery, a passenger compartment low temperature heat pump heating mode with waste heat recovery, a high energy efficiency ratio battery heating-ambient temperature heat pump heating mode, and a high performance battery heating-low temperature heat pump heating mode.

[0017] Optionally, based on the control status of the solenoid valve and the electronic expansion valve, the heat pump system is prompted to execute a corresponding refrigerant circulation mode, including:

[0018] The first, third, and fourth solenoid valves are closed, while the second and fifth solenoid valves are opened.

[0019] The first and second electronic expansion valves are closed, and the third and fourth electronic expansion valves are opened.

[0020] The indoor evaporator absorbs heat, and the outdoor heat exchanger dissipates heat, so the heat pump system operates in cooling mode.

[0021] Optionally, based on the control status of the solenoid valve and the electronic expansion valve, the heat pump system is prompted to execute a corresponding refrigerant circulation mode, including:

[0022] Open the first and third solenoid valves, and close the second, fourth, and fifth solenoid valves;

[0023] The first electronic expansion valve is opened, and the second, third, and fourth electronic expansion valves are closed.

[0024] The indoor condenser dissipates heat, while the outdoor heat exchanger absorbs heat. The heat pump system operates in a normal temperature heat pump heating mode for the passenger cabin.

[0025] Optionally, based on the control status of the solenoid valve and the electronic expansion valve, the heat pump system is prompted to execute a corresponding refrigerant circulation mode, including:

[0026] Open the first solenoid valve and close the second, third, fourth, and fifth solenoid valves;

[0027] Open the fourth electronic expansion valve and close the first, second, and third electronic expansion valves;

[0028] The indoor evaporator absorbs heat and the indoor condenser dissipates heat, with the heat pump system operating in a low-temperature heat pump heating mode for the passenger compartment without waste heat recovery.

[0029] Optionally, based on the control status of the solenoid valve, electronic expansion valve, and five-way valve, the heat pump system is prompted to execute a corresponding refrigerant circulation mode, including:

[0030] Open the first and third solenoid valves, and close the second, fourth, and fifth solenoid valves;

[0031] Open the second electronic expansion valve and close the first, third, and fourth electronic expansion valves;

[0032] Connect the first and fifth valves, and also connect the first and second valves, while closing the fourth valve;

[0033] The Lcc heat exchanger of the motor absorbs heat, and the heat pump system executes a low-temperature heat pump heating mode for the crew cabin with waste heat recovery.

[0034] Optionally, based on the control status of the solenoid valve, electronic expansion valve, and five-way valve, the heat pump system is prompted to execute a corresponding refrigerant circulation mode, including:

[0035] Open the first and third solenoid valves, and close the second, fourth, and fifth solenoid valves;

[0036] Open the second electronic expansion valve and close the first, third, and fourth electronic expansion valves;

[0037] Connect the first and fourth valves, and also connect the third and fifth valves, while closing the second valve;

[0038] The Lcc heat exchanger of the motor absorbs heat, and the heat pump system executes a low-temperature heat pump heating mode for the crew cabin with waste heat recovery.

[0039] Optionally, based on the control status of the solenoid valve, electronic expansion valve, and five-way valve, the heat pump system is prompted to execute a corresponding refrigerant circulation mode, including:

[0040] Open the third and fourth solenoid valves, and close the first, second, and fifth solenoid valves;

[0041] The first electronic expansion valve is opened, and the second, third, and fourth electronic expansion valves are closed.

[0042] Connect the first and fourth valves, and connect the third and fifth valves, while closing the second valve;

[0043] The outdoor heat exchanger absorbs heat, and the battery chiller heats up the heat, with the heat pump system operating in a high-efficiency battery heating-normal temperature heat pump heating mode.

[0044] Optionally, based on the control status of the solenoid valve, electronic expansion valve, and five-way valve, the heat pump system is prompted to execute a corresponding refrigerant circulation mode, including:

[0045] Open the third and fourth solenoid valves, and close the first, second, and fifth solenoid valves;

[0046] The second electronic expansion valve is opened, and the first, third, and fourth electronic expansion valves are closed.

[0047] Connect the first and fourth valves, and also connect the third and fifth valves, while closing the second valve;

[0048] The motor Lcc heat exchanger absorbs heat, and the battery chiller dissipates heat, enabling the heat pump system to perform high-performance battery heating - low-temperature heat pump heating mode.

[0049] Advantages of this application embodiment: It widens the operating temperature range of the heat pump air conditioner; based on the heat pump air conditioner, it utilizes the energy of the environment, passenger compartment, drive system, and battery through components such as solenoid valves, electronic expansion valves, and electronic five-way water valves for efficient and intelligent management; it eliminates the need for water heaters and high-pressure PTC in the passenger compartment, utilizing same-side evaporation and condensation of the compressor for heating; through the water circulation of the five-way valve in conjunction with the heat pump air conditioner, the heating performance reaches over 8kW, and the battery low-temperature heating rate is ≥0.8℃ / min; this application embodiment integrates the refrigerant side of the air conditioner and the water side of the battery and motor into a single large module, completely connecting the refrigerant-side energy and water-side energy; utilizing same-side evaporation, the operating temperature of the heat pump can be as low as -30℃, achieving a wide temperature range heat pump air conditioner, and eliminating the need for auxiliary PTC in the passenger compartment and battery water heater; through waste heat recovery from the battery and motor, the energy-saving effect is improved by 20% compared to ordinary heat pumps; it supports heat dissipation for 4C super-fast charging.

[0050] Other features and advantages of this application will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0051] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the present application and, together with their description, serve to explain the principles of the present application.

[0052] Figure 1 This is a diagram of the architecture of a heat pump (air conditioning) system in the existing technology;

[0053] Figure 2 This is a diagram of the heat pump (air conditioning) system architecture according to an embodiment of this application;

[0054] Figure 3This is a schematic diagram of Mode 1 for the definition of a five-way valve in an embodiment of this application;

[0055] Figure 4 This is a schematic diagram of Mode 2 for the definition of a five-way valve in the embodiments of this application;

[0056] Figure 5 This is a schematic diagram of Mode 3 for the definition of a five-way valve in the embodiments of this application;

[0057] Figure 6 This is a schematic diagram of Mode 4 for the definition of a five-way valve in the embodiments of this application;

[0058] Figure 7 This is a schematic diagram of the heat pump system executing the cooling mode in an embodiment of this application;

[0059] Figure 8 This is a schematic diagram of the heat pump system in the embodiment of this application executing the ambient temperature heat pump heating mode of the passenger compartment;

[0060] Figure 9 This is a schematic diagram of the low-temperature heat pump heating mode of the crew cabin in the embodiment of the application, in which the heat pump system performs no waste heat recovery.

[0061] Figure 10 This is a schematic diagram of one of the low-temperature heat pump heating modes for the crew cabin with waste heat recovery, as implemented by the heat pump system in this application embodiment.

[0062] Figure 11 This is a schematic diagram of the second low-temperature heat pump heating mode for the crew cabin with waste heat recovery, as implemented by the heat pump system in this application embodiment.

[0063] Figure 12 This is a schematic diagram of the heat pump system in the embodiment of this application performing a high-efficiency battery heating-room temperature heat pump heating mode;

[0064] Figure 13 This is a schematic diagram illustrating the high-performance battery heating-low-temperature heat pump heating mode performed by the heat pump system in this embodiment of the application. Detailed Implementation

[0065] Various exemplary embodiments of this application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of this application.

[0066] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0067] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0068] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0069] This application provides a heat pump system and its control method.

[0070] A heat pump system includes: an indoor evaporator, an indoor condenser, a gas-liquid separator, a compressor, an outdoor heat exchanger, a motor Lcc heat exchanger, a motor, a battery Chiller heat exchanger, a water tank, a five-way valve, and a battery. One end of the indoor evaporator is connected to the gas-liquid separator, the motor Lcc heat exchanger, and the battery Chiller heat exchanger. A third solenoid valve connects the indoor evaporator to the motor Lcc heat exchanger, and a fifth solenoid valve connects the indoor evaporator to the battery Chiller heat exchanger. The other end of the indoor evaporator is connected to the indoor condenser, the outdoor heat exchanger, and the battery Chiller heat exchanger via a fourth electronic expansion valve. The system connects to the motor Lcc heat exchanger and the battery Chiller heat exchanger. A second check valve connects the fourth electronic expansion valve to the indoor condenser. A first check valve connects the fourth electronic expansion valve to the outdoor heat exchanger. A second electronic expansion valve connects the fourth electronic expansion valve to the motor Lcc heat exchanger. A third electronic expansion valve connects the electronic expansion valve to the battery Chiller heat exchanger. One end of the first electronic expansion valve is connected to the fourth electronic expansion valve, and the other end is connected between the outdoor heat exchanger and the first check valve. The indoor condenser is connected to the outdoor heat exchanger via a first solenoid valve and a second solenoid valve. The heat exchanger is connected as follows: a first solenoid valve connects the indoor condenser to the compressor; one end of a first connecting device connects the second solenoid valve to the outdoor heat exchanger, and the other end connects the third solenoid valve to the motor Lcc heat exchanger; the indoor condenser is connected to the battery Chiller heat exchanger via the first and fourth solenoid valves; the compressor is connected between the gas-liquid separator and the outdoor heat exchanger, and a second solenoid valve connects the compressor to the outdoor heat exchanger; one end of a second connecting device connects the first one-way valve to the third electronic expansion valve, and the other end connects the third electronic expansion valve to the electric motor Lcc heat exchanger. Between the pool and the Chiller heat exchanger, a third one-way valve is provided on the second connecting device; the motor Lcc heat exchanger is also connected between the motor and the cooling water tank, and the motor is connected to the fifth valve of the five-way valve, wherein the five-way valve includes a first valve, a second valve, a third valve, a fourth valve, and a fifth valve; the battery Chiller heat exchanger is connected between the fourth valve and the battery, the battery is connected to the third valve, and the cooling water tank is connected to the second valve; one end of the third connecting device is connected between the motor Lcc heat exchanger and the cooling water tank, and the other end is connected to the first valve.

[0071] A heat pump system control method is provided for controlling the heat pump system of claim 1. The method includes: controlling a solenoid valve; controlling an electronic expansion valve; controlling a five-way valve; and, based on the control status of the solenoid valve, the electronic expansion valve, and the five-way valve, causing the heat pump system to execute a corresponding refrigerant circulation mode. The refrigerant circulation mode includes a cooling mode, a passenger compartment ambient temperature heat pump heating mode, a passenger compartment low-temperature heat pump heating mode without waste heat recovery, a passenger compartment low-temperature heat pump heating mode with waste heat recovery, a high-efficiency battery heating-ambient temperature heat pump heating mode, and a high-performance battery heating-low-temperature heat pump heating mode.

[0072] Based on the control status of the solenoid valves and electronic expansion valves, the heat pump system is prompted to execute the corresponding refrigerant circulation mode, including: closing the first, third, and fourth solenoid valves and opening the second and fifth solenoid valves; closing the first and second electronic expansion valves and opening the third and fourth electronic expansion valves; the indoor evaporator absorbs heat and the outdoor heat exchanger dissipates heat, and the heat pump system executes the cooling mode.

[0073] Based on the control status of the solenoid valves and electronic expansion valves, the heat pump system is prompted to execute the corresponding refrigerant circulation mode, including: opening the first and third solenoid valves and closing the second, fourth, and fifth solenoid valves; opening the first electronic expansion valve and closing the second, third, and fourth electronic expansion valves; the indoor condenser dissipates heat, the outdoor heat exchanger absorbs heat, and the heat pump system executes the passenger cabin ambient temperature heat pump heating mode.

[0074] Based on the control status of the solenoid valves and electronic expansion valves, the heat pump system is prompted to execute the corresponding refrigerant circulation mode, including: opening the first solenoid valve and closing the second, third, fourth, and fifth solenoid valves; opening the fourth electronic expansion valve and closing the first, second, and third electronic expansion valves; the indoor evaporator absorbs heat and the indoor condenser dissipates heat, and the heat pump system executes a low-temperature heat pump heating mode for the passenger compartment without waste heat recovery.

[0075] Based on the control status of the solenoid valves, electronic expansion valves, and five-way valves, the heat pump system is prompted to execute the corresponding refrigerant circulation mode, including: opening the first and third solenoid valves and closing the second, fourth, and fifth solenoid valves; opening the second electronic expansion valve and closing the first, third, and fourth electronic expansion valves; connecting the first and fifth-way valves, and connecting the first and second-way valves, and closing the fourth-way valve; the motor Lcc heat exchanger absorbs heat, and the heat pump system executes a low-temperature heat pump heating mode for the passenger cabin with waste heat recovery.

[0076] Based on the control status of the solenoid valves, electronic expansion valves, and five-way valves, the heat pump system is prompted to execute the corresponding refrigerant circulation mode, including: opening the first and third solenoid valves and closing the second, fourth, and fifth solenoid valves; opening the second electronic expansion valve and closing the first, third, and fourth electronic expansion valves; connecting the first and fourth-way valves, as well as the third and fifth-way valves, and closing the second-way valve; the motor Lcc heat exchanger absorbs heat, and the heat pump system executes a low-temperature heat pump heating mode for the passenger cabin with waste heat recovery.

[0077] Based on the control status of the solenoid valve, electronic expansion valve, and five-way valve, the heat pump system is prompted to execute the corresponding refrigerant circulation mode, including: opening the third and fourth solenoid valves and closing the first, second, and fifth solenoid valves; opening the first electronic expansion valve and closing the second, third, and fourth electronic expansion valves; connecting the first and fourth valves, and connecting the third and fifth valves, and closing the second valve; the outdoor heat exchanger absorbs heat, the battery Chiller heat exchanger dissipates heat, and the heat pump system executes a high-efficiency battery heating-room temperature heat pump heating mode.

[0078] Based on the control status of the solenoid valve, electronic expansion valve, and five-way valve, the heat pump system is prompted to execute the corresponding refrigerant circulation mode, including: opening the third and fourth solenoid valves and closing the first, second, and fifth solenoid valves; opening the second electronic expansion valve and closing the first, third, and fourth electronic expansion valves; connecting the first and fourth-way valves, as well as the third and fifth-way valves, and closing the second-way valve; the motor Lcc heat exchanger absorbs heat, the battery chiller dissipates heat, and the heat pump system executes a high-performance battery heating-low-temperature heat pump heating mode.

[0079] like Figure 2 As shown, in this embodiment of the application, the refrigerant side of the air conditioner and the water side of the battery and motor are all integrated into one large module, which completely connects the energy on the refrigerant side and the energy on the water side.

[0080] Refrigerant-side loop definition: The system is equipped with a high-pressure P&T sensor at the compressor discharge port and a low-pressure P&T sensor at the gas-liquid separator inlet; the first, second, and fourth solenoid valves select which heat exchanger the high-temperature gas from the compressor flows into, thus determining the mode selection: cooling, passenger compartment heating, or battery heating. The fourth electronic expansion valve at the evaporator inlet and the third electronic expansion valve at the chiller inlet achieve passenger compartment cooling and battery chiller cooling. Three one-way valves ensure that the refrigerant does not flow backwards; the LCC waste heat recovery unit, through a five-way valve, enables waste heat recovery from the motor and battery.

[0081] Water-side circuit definition: The integrated kettle is defined as follows: ①-LCC outlet; ②-Radiator outlet; ③-Battery outlet; ④-Battery chiller inlet; ⑤-Motor inlet;

[0082] Four modes are defined for the five-way valve:

[0083] like Figure 3 As shown, Mode 1: Motor and battery water circulation are independent. 2-5 are on, 3-4 are on, and 1 is off.

[0084] like Figure 4 As shown, Mode 2: The motor and battery are connected in series with the water circulation system. Five-way valves 1-4 are connected, 3-5 are connected, and 2 is closed. The coolant circulation loop is a large loop, with the motor and battery connected in series, bypassing the radiator. The battery can be heated separately using the motor's waste heat; the heat pump air conditioner can simultaneously absorb waste heat from both the battery and motor.

[0085] like Figure 5 As shown, the five-way valve has 2-4 connected, 3-5 connected, and 4 closed. This means the coolant circulation loop is a large loop passing through the radiator, while the battery and motor are cooled by the vehicle's radiator.

[0086] like Figure 6 As shown, the five-way valve has 3-5 connected, 1 to -2 connected (battery water pump not working), and 4 closed. The heat pump air conditioner recovers waste heat from the motor through the LCC.

[0087] Air conditioning operating modes: A detailed description of the control logic for six typical operating conditions of the heat pump system, including occupant cooling, occupant cabin heat pump heating, and battery heat pump heating.

[0088] like Figure 7 As shown, refrigeration includes individual cabin cooling, individual battery cooling, and simultaneous cabin and battery cooling; this description focuses on simultaneous cabin and battery cooling. The first solenoid valve is closed, the second solenoid valve is open, the third solenoid valve is closed, the fourth solenoid valve is closed, and the fifth solenoid valve is open. The first electronic expansion valve is closed, and the second electronic expansion valve is closed. The third and fourth electronic expansion valves are open and function as throttling valves.

[0089] like Figure 8 As shown, the passenger compartment is heated by a heat pump at ambient temperature: when the ambient temperature is ≥-10℃, the outdoor heat exchanger has sufficient evaporation capacity and can directly absorb heat from the air, eliminating the need for the LCC to absorb waste heat from the motor. Under this condition, the first and third solenoid valves are open, the second, fourth, and fifth solenoid valves are closed, and the cooling fan is on.

[0090] like Figure 9As shown, the passenger compartment low-temperature heat pump - without waste heat recovery: The ambient temperature is < -10℃, and the outdoor heat exchanger cannot absorb heat from the environment; this temperature range is defined as a low-temperature heat pump. At low temperatures, if the vehicle is parked, neither the battery nor the motor generates heat; instead, evaporation and condensation occur on the same side of the vehicle interior. Effective heat equals the work done by the compressor itself.

[0091] like Figure 10 As shown, the crew compartment cryogenic heat pump has waste heat recovery: motor waste heat recovery: when the LCC inlet water temperature is ≥-15℃ and the battery temperature is ≤10℃, the LCC is used to recover the motor's waste heat. In this condition, the first and third solenoid valves are open, and the second, fourth, and fifth solenoid valves are closed. The five-way valve operates in mode 4, and the LCC and motor water circuit are connected in series.

[0092] like Figure 11 As shown, the motor waste heat and battery waste heat recovery are implemented as follows: In operating mode 1, the first and third solenoid valves are open; the second, fourth, and fifth solenoid valves are closed. The five-way valve operates in mode 4, with the LCC connected in series with the motor water circuit. In mode 2, the five-way valve operates in series with the LCC and the motor water circuit.

[0093] like Figure 12 As shown, battery heating - ambient temperature heat pump heating (high energy efficiency ratio): when the ambient temperature is ≥-5℃, the efficiency of absorbing heat from the environment is relatively high. It can absorb heat from the environment through the outdoor heat exchanger alone, and the heat pump system heats the battery chiller, and then heats the battery through the cooling circuit.

[0094] like Figure 13 As shown, battery heating - low-temperature heat pump heating (high performance): When the ambient temperature is < -5℃, the environment's heat absorption capacity decreases. Heating is achieved through a locked-rotor motor, using a five-way valve in mode two. The hot water from the locked-rotor motor circulates and evaporates within the LCC waste heat recovery unit, meaning evaporation occurs on the same side of the water. At this point, the heating capacity equals the compressor's maximum power plus the motor's locked-rotor heating power. This same-side evaporation allows the compressor to operate at a higher power output (approximately 5.5kW), and the motor's locked-rotor heating power is approximately 5kW, resulting in a total heating capacity of approximately 10kW. At low temperatures, the battery's temperature rise rate will exceed 1℃ / min, significantly shortening the low-temperature charging time.

[0095] As mentioned above, the refrigerant circulation modes are categorized as follows: First, cooling: indoor evaporator absorbs heat, outdoor heat exchanger dissipates heat; Second, passenger compartment ambient temperature heat pump heating: indoor condenser dissipates heat, outdoor heat exchanger absorbs heat; Third, passenger compartment low temperature heat pump heating (no waste heat recovery): indoor evaporator absorbs heat, indoor condenser dissipates heat; Fourth, passenger compartment low temperature heat pump heating (with waste heat recovery): motor Lcc heat exchanger absorbs heat; Fifth, battery heating - ambient temperature heat pump heating (high energy efficiency ratio): battery Chiller heat exchanger dissipates heat, outdoor heat exchanger absorbs heat; Sixth, battery heating - low temperature heat pump heating (high performance): motor Lcc heat exchanger absorbs heat, battery Chiller heat exchanger dissipates heat.

[0096] This application can also be applied to household air conditioning systems.

[0097] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. A heat pump system, characterized in that, include: Indoor evaporator, indoor condenser, gas-liquid separator, compressor, outdoor heat exchanger, motor Lcc heat exchanger, motor, battery Chiller heat exchanger, radiator, five-way valve, battery; One end of the indoor evaporator is connected to the gas-liquid separator, the motor Lcc heat exchanger, and the battery Chiller heat exchanger. A third solenoid valve is connected between the indoor evaporator and the motor Lcc heat exchanger, and a fifth solenoid valve is connected between the indoor evaporator and the battery Chiller heat exchanger. The other end of the indoor evaporator is connected to the indoor condenser, outdoor heat exchanger, motor Lcc heat exchanger, and battery Chiller heat exchanger via a fourth electronic expansion valve. A second check valve is connected between the fourth electronic expansion valve and the indoor condenser. A first check valve is connected between the fourth electronic expansion valve and the outdoor heat exchanger. A second electronic expansion valve is connected between the fourth electronic expansion valve and the motor Lcc heat exchanger. A third electronic expansion valve is connected between the fourth electronic expansion valve and the battery Chiller heat exchanger. One end of the first electronic expansion valve is connected to the fourth electronic expansion valve, and the other end is connected between the outdoor heat exchanger and the first check valve. The indoor condenser is connected to the outdoor heat exchanger via a first solenoid valve and a second solenoid valve. The indoor condenser is connected to the compressor via a first solenoid valve. One end of the first connecting device is connected between the second solenoid valve and the outdoor heat exchanger, and the other end is connected between the third solenoid valve and the motor Lcc heat exchanger. The indoor condenser is connected to the battery Chiller heat exchanger via a first solenoid valve and a fourth solenoid valve. The compressor is connected between the gas-liquid separator and the outdoor heat exchanger, and a second solenoid valve is connected between the compressor and the outdoor heat exchanger; one end of the second connecting device is connected between the first one-way valve and the third electronic expansion valve, and the other end is connected between the third electronic expansion valve and the battery Chiller heat exchanger, and a third one-way valve is provided on the second connecting device. The motor Lcc heat exchanger is also connected between the motor and the cooling water tank. The motor is connected to the fifth valve of the five-way valve, wherein the five-way valve includes a first valve, a second valve, a third valve, a fourth valve, and a fifth valve. The battery Chiller heat exchanger is connected between the fourth valve and the battery. The battery is connected to the third valve, and the cooling water tank is connected to the second valve. One end of the third connecting device is connected between the motor Lcc heat exchanger and the cooling water tank, and the other end is connected to the first valve.

2. A heat pump system control method for controlling the heat pump system of claim 1, characterized in that, The method includes: Control the solenoid valve; Control the electronic expansion valve; Control the five-way valve; Based on the control status of the solenoid valve, electronic expansion valve, and five-way valve, the heat pump system is prompted to execute the corresponding refrigerant circulation mode. The refrigerant circulation modes include a cooling mode, a passenger compartment ambient temperature heat pump heating mode, a passenger compartment low temperature heat pump heating mode without waste heat recovery, a passenger compartment low temperature heat pump heating mode with waste heat recovery, a high energy efficiency ratio battery heating-ambient temperature heat pump heating mode, and a high performance battery heating-low temperature heat pump heating mode.

3. The heat pump system control method according to claim 2, characterized in that, Based on the control status of the solenoid valve and electronic expansion valve, the heat pump system is prompted to execute the corresponding refrigerant circulation mode, including: The first, third, and fourth solenoid valves are closed, while the second and fifth solenoid valves are opened. The first and second electronic expansion valves are closed, and the third and fourth electronic expansion valves are opened. The indoor evaporator absorbs heat, and the outdoor heat exchanger dissipates heat, so the heat pump system operates in cooling mode.

4. The heat pump system control method according to claim 2, characterized in that, Based on the control status of the solenoid valve and electronic expansion valve, the heat pump system is prompted to execute the corresponding refrigerant circulation mode, including: Open the first and third solenoid valves, and close the second, fourth, and fifth solenoid valves; The first electronic expansion valve is opened, and the second, third, and fourth electronic expansion valves are closed. The indoor condenser dissipates heat, while the outdoor heat exchanger absorbs heat. The heat pump system operates in a normal temperature heat pump heating mode for the passenger cabin.

5. The heat pump system control method according to claim 2, characterized in that, Based on the control status of the solenoid valve and electronic expansion valve, the heat pump system is prompted to execute the corresponding refrigerant circulation mode, including: Open the first solenoid valve and close the second, third, fourth, and fifth solenoid valves; Open the fourth electronic expansion valve and close the first, second, and third electronic expansion valves; The indoor evaporator absorbs heat and the indoor condenser dissipates heat, with the heat pump system operating in a low-temperature heat pump heating mode for the passenger compartment without waste heat recovery.

6. The heat pump system control method according to claim 2, characterized in that, Based on the control status of the solenoid valve, electronic expansion valve, and five-way valve, the heat pump system is prompted to execute the corresponding refrigerant circulation mode, including: Open the first and third solenoid valves, and close the second, fourth, and fifth solenoid valves; Open the second electronic expansion valve and close the first, third, and fourth electronic expansion valves; Connect the first and fifth valves, and also connect the first and second valves, while closing the fourth valve; The Lcc heat exchanger of the motor absorbs heat, and the heat pump system executes a low-temperature heat pump heating mode for the crew cabin with waste heat recovery.

7. The heat pump system control method according to claim 2, characterized in that, Based on the control status of the solenoid valve, electronic expansion valve, and five-way valve, the heat pump system is prompted to execute the corresponding refrigerant circulation mode, including: Open the first and third solenoid valves, and close the second, fourth, and fifth solenoid valves; Open the second electronic expansion valve and close the first, third, and fourth electronic expansion valves; Connect the first and fourth valves, and also connect the third and fifth valves, while closing the second valve; The Lcc heat exchanger of the motor absorbs heat, and the heat pump system executes a low-temperature heat pump heating mode for the crew cabin with waste heat recovery.

8. The heat pump system control method according to claim 2, characterized in that, Based on the control status of the solenoid valve, electronic expansion valve, and five-way valve, the heat pump system is prompted to execute the corresponding refrigerant circulation mode, including: Open the third and fourth solenoid valves, and close the first, second, and fifth solenoid valves; The first electronic expansion valve is opened, and the second, third, and fourth electronic expansion valves are closed. Connect the first and fourth valves, and connect the third and fifth valves, while closing the second valve; The outdoor heat exchanger absorbs heat, and the battery chiller heats up the heat, with the heat pump system operating in a high-efficiency battery heating-normal temperature heat pump heating mode.

9. The heat pump system control method according to claim 2, characterized in that, Based on the control status of the solenoid valve, electronic expansion valve, and five-way valve, the heat pump system is prompted to execute the corresponding refrigerant circulation mode, including: Open the third and fourth solenoid valves, and close the first, second, and fifth solenoid valves; The second electronic expansion valve is opened, and the first, third, and fourth electronic expansion valves are closed. Connect the first and fourth valves, and also connect the third and fifth valves, while closing the second valve; The motor Lcc heat exchanger absorbs heat, and the battery chiller dissipates heat, enabling the heat pump system to perform high-performance battery heating - low-temperature heat pump heating mode.

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