An over-lap heat pump system for an electric vehicle

Abstract

The application discloses a kind of for electric vehicle's overlay heat pump system, which includes low pressure stage compression device, high pressure stage compression device and functional heat exchange device, low pressure stage compression device includes the low pressure stage compressor, low pressure stage evaporator, low pressure expansion valve and low pressure stage intercooler connected in sequence, high pressure stage compression device includes high pressure stage compressor, high pressure stage four-way valve, air side heat exchanger, water side heat exchanger, cabin heat exchanger and battery heat exchanger, the compressor outlet of high pressure stage compressor is selectively communicated with one of air side heat exchanger and water side heat exchanger, air side heat exchanger is communicated with cabin heat exchanger and battery heat exchanger respectively, and functional heat exchange device includes motor heat exchange component, heat exchange water tank, battery heat exchange piece and cabin heat exchange piece.The overlay heat pump system can better meet the scene that outdoor ambient temperature is too low, and meet the use demand of various scenes.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric vehicles, and particularly relates to an overlapped heat pump system for an electric vehicle. BACKGROUND

[0002] The heat management system of an electric vehicle is usually composed of a compressor module, a battery heat exchange module, a motor heat exchange module and a cabin heat exchange module, and in summer, the battery, the motor and the cabin are cooled by a heat exchange circuit formed between the compressor module and the battery heat exchange module, the motor heat exchange module and the cabin heat exchange module, and in winter, the battery, the motor and the cabin are heated by a heat exchange circuit formed between the compressor module and the battery heat exchange module and the cabin heat exchange module. However, in the scenario of low outdoor ambient temperature, the existing vehicle heat management system cannot meet the use demand well. SUMMARY

[0003] The present application aims to provide an overlapped heat pump system for an electric vehicle, which can better meet the scenario of low outdoor ambient temperature and can switch the working state according to the outdoor ambient temperature and the running state of the electric vehicle, so as to meet the use demand in various scenarios.

[0004] To achieve the above technical effects, the technical scheme of the present application is as follows:

[0005] The application discloses an overlapped heat pump system for an electric vehicle, comprising: a low-pressure stage compression device, the low-pressure stage compression device comprising a low-pressure stage compressor, a low-pressure stage evaporator, a low-pressure expansion valve and a low-pressure stage intercooler connected in sequence, and a first working medium flowing through the low-pressure stage compression device; a high-pressure stage compression device, the high-pressure stage compression device comprising a high-pressure stage compressor, a high-pressure stage four-way valve, an air-side heat exchanger, a water-side heat exchanger, a cabin heat exchanger and a battery heat exchanger, a compressor outlet of the high-pressure stage compressor being selectively communicated with one of the air-side heat exchanger and the water-side heat exchanger, and the air-side heat exchanger being communicated with the cabin heat exchanger and the battery heat exchanger respectively; a second working medium flowing through the high-pressure stage compression device, the second working medium being capable of exchanging heat with the first working medium in the low-pressure stage intercooler; a functional heat exchange device, the functional heat exchange device comprising a motor heat exchange assembly, a heat exchange water tank and a battery heat exchange element and a cabin heat exchange element; wherein: a heat exchange inlet of the motor heat exchange assembly is selectively communicated with one of a heat exchange outlet of the heat exchange water tank and a heat exchange outlet of the battery heat exchange element, and a heat exchange outlet of the motor heat exchange assembly is communicated with one of a heat exchange inlet of the heat exchange water tank and a heat exchange inlet of the cabin heat exchange element; a heat exchange inlet of the battery heat exchange element is communicated with a heat exchange outlet of the battery heat exchanger, and a heat exchange outlet of the battery heat exchange element is selectively communicated with one of a heat exchange inlet of the battery heat exchanger and a heat exchange inlet of the motor heat exchange assembly; a heat exchange inlet of the cabin heat exchange element is selectively communicated with one of the heat exchange outlet of the motor heat exchange assembly and a heat exchange outlet of the cabin heat exchanger, and a heat exchange outlet of the cabin heat exchange element is selectively communicated with one of the heat exchange inlet of the cabin heat exchanger and the heat exchange inlet of the battery heat exchanger.

[0006] In some embodiments, the overlapped heat pump system for the electric vehicle further comprises a motor expansion water tank and a motor water pump connected in series, an inlet of the motor water pump being communicated with the motor expansion water tank and the motor heat exchange assembly, and an outlet of the motor water pump being selectively communicated with one of the heat exchange water tank, the water-side heat exchanger and the cabin heat exchange element.

[0007] In some embodiments, the heat pump system for an electric vehicle further comprises a first three-way valve and a second three-way valve, a first valve port of the first three-way valve is in communication with an outlet of the motor water pump, a second valve port of the first three-way valve is in communication with a heat exchange inlet of the heat exchange water tank, a third valve port of the first three-way valve is in communication with a first valve port of the second three-way valve, the first valve port of the first three-way valve is switchably in communication with the second valve port of the first three-way valve and the third valve port of the first three-way valve; a second valve port of the second three-way valve is in communication with a heat exchange inlet of the cabin heat exchange component, a third valve port of the second three-way valve is in communication with a heat exchange inlet of the water-side heat exchanger, the first valve port of the second three-way valve is switchably in communication with the second valve port of the second three-way valve and the third valve port of the second three-way valve.

[0008] In some embodiments, the heat pump system for an electric vehicle further comprises a battery expansion water tank and a battery water pump, an inlet of the battery water pump is in communication with the battery expansion water tank and a battery heat exchanger; an outlet of the battery water pump is in communication with the battery heat exchange component.

[0009] In some embodiments, the heat pump system for an electric vehicle further comprises a third three-way valve and a four-way control valve, a first valve port of the third three-way valve is in communication with a heat exchange outlet of the heat exchange water tank, a second valve port of the third three-way valve is in communication with an evaporation inlet of the low-pressure stage evaporator, a third valve port of the third three-way valve is in communication with a first valve port of the four-way control valve, the first valve port of the third three-way valve is switchably in communication with the second valve port of the third three-way valve and the third valve port of the third three-way valve; the first valve port of the four-way control valve is in communication with a heat exchange outlet of the cabin heat exchange component through a cabin control valve, a second valve port of the four-way control valve is in communication with a heat exchange inlet of the battery heat exchanger, a third valve port of the four-way control valve is in communication with a heat exchange outlet of the battery heat exchange component, a fourth valve port of the four-way control valve is in communication with a heat exchange inlet of the motor heat exchange assembly, the first valve port of the four-way control valve is switchably in communication with the second valve port of the four-way control valve and the fourth valve port of the four-way control valve, the fourth valve port of the four-way control valve is switchably in communication with the second valve port of the four-way control valve and the fourth valve port of the four-way control valve.

[0010] In some embodiments, the heat pump system for an electric vehicle further comprises a cabin expansion water tank and a cabin water pump, an inlet of the cabin water pump is in communication with the cabin expansion water tank and the cabin heat exchange component, an outlet of the cabin water pump is in communication with the cabin heat exchanger.

[0011] In some embodiments, the superimposed heat pump system for the electric vehicle further comprises a fourth three-way valve and a fifth three-way valve, a first valve port of the fourth three-way valve is in communication with the high-pressure four-way valve, a second valve port of the fourth three-way valve is in communication with the heat exchange outlet of the low-pressure intercooler, a third valve port of the fourth three-way valve is in communication with the air-side heat exchanger and the water-side heat exchanger, the first valve port of the fourth three-way valve is switchably in communication with the second valve port and the third valve port of the fourth three-way valve; a first valve port of the fifth three-way valve is in communication with the cabin heat exchanger and the battery heat exchanger, a second valve port of the fifth three-way valve is in communication with the air-side heat exchanger, a third valve port of the fifth three-way valve is in communication with the water-side heat exchanger, the first valve port of the fifth three-way valve is switchably in communication with the second valve port and the third valve port of the fifth three-way valve.

[0012] In some embodiments, the superimposed heat pump system for the electric vehicle further comprises an economizer, a first interface of the economizer is in communication with one of the air-side heat exchanger and the water-side heat exchanger, a second interface of the economizer is in communication with the cabin heat exchanger and the battery heat exchanger, a third interface of the economizer is in communication with the high-pressure compressor through a one-way valve, and a fourth interface of the economizer is in communication with one of the air-side heat exchanger and the water-side heat exchanger through a two-way control valve.

[0013] In some embodiments, the superimposed heat pump system for the electric vehicle further comprises a cabin heater arranged on the cabin heat exchanger.

[0014] In some embodiments, the superimposed heat pump system for the electric vehicle further comprises a battery heater connected between the battery heat exchanger and the battery heat exchanger.

[0015] The superimposed heat pump system for the electric vehicle has the following advantages: the low-pressure compressor and the high-pressure compressor are arranged, the high-pressure compressor comprises the air-side heat exchanger capable of exchanging heat with air and the water-side heat exchanger capable of exchanging heat with cooling liquid, and the second working medium can exchange heat with the first working medium in the low-pressure intercooler, so that the second working medium takes the first working medium and air as heat sources in the case of extremely low temperature, and the second working medium takes cooling water as a heat source, which improves the heat source quality and ensures the heating efficiency. At the same time, the superimposed heat pump system for the electric vehicle can take the waste heat of the battery, the motor or the electric control circuit board as a heat source for cabin heating according to the working state of the electric vehicle and the ambient temperature, which improves the waste heat utilization rate of the electric vehicle and is beneficial to improving the mileage of the electric vehicle.

[0016] Additional aspects and advantages of the application will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or can be learned by practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a structural schematic diagram of an overlapping heat pump system for an electric vehicle in a refrigeration working condition according to an embodiment of the application;

[0018] Figure 2 is a structural schematic diagram of an overlapping heat pump system for an electric vehicle in a natural cooling working condition according to an embodiment of the application;

[0019] Figure 3 is a structural schematic diagram of an overlapping heat pump system for an electric vehicle in an air source heat pump two-stage compression working condition according to an embodiment of the application;

[0020] Figure 4 is a structural schematic diagram of an overlapping heat pump system for an electric vehicle in an electric machine electric control source heat pump working condition according to an embodiment of the application;

[0021] Figure 5 is a structural schematic diagram of an overlapping heat pump system for an electric vehicle in a battery source heat pump working condition according to an embodiment of the application;

[0022] Figure 6 is a structural schematic diagram of an overlapping heat pump system for an electric vehicle in a natural heating working condition according to an embodiment of the application.

[0023] REFERENCE NUMERALS:

[0024] 1, high-pressure stage compressor; 2, high-pressure stage four-way valve; 3, water side heat exchanger; 4, air side heat exchanger; 5, cabin heat exchanger; 6, cabin heat exchange element; 7, battery heat exchanger; 8, fourth three-way valve; 9, fifth three-way valve; 10, heating electronic expansion valve; 11, refrigeration two-way valve; 12, battery refrigeration electronic expansion valve; 13, battery heating two-way valve; 14, cabin heating two-way valve; 15, cabin refrigeration electronic expansion valve; 16, economizer; 17, two-way control valve; 18, battery expansion water tank; 19, battery water pump; 20, battery heat exchange element; 21, four-way control valve; 22, battery heater; 23, electric control heat exchange element; 24, electric machine heat exchange element; 25, electric machine expansion water tank; 26, electric machine water pump; 27, heat exchange water tank; 28, first three-way valve; 29, third three-way valve; 30, second three-way valve; 31, cabin control valve; 32, cabin expansion water tank; 33, cabin water pump; 34, cabin heater; 35, one-way valve; 101, low-pressure stage compressor; 102, low-pressure stage evaporator; 103, low-pressure stage intercooler; 104, low-pressure expansion valve. DETAILED DESCRIPTION

[0025] In order to make the technical problems solved by the present application, the technical solutions adopted and the technical effects achieved more clear, the technical solutions of the present application are further illustrated below in conjunction with the accompanying drawings and specific embodiments.

[0026] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0027] In addition, the features defined as "first" and "second" can explicitly or implicitly include one or more of the features, which are used to distinguish the described features, and there is no order or difference. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0028] In the description of the present application, it should be noted that unless otherwise specified and limited, the terms "mounting", "communication", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly communicated, or it can be indirectly communicated through an intermediate medium, or it can be the communication between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0029] The specific structure of the heat pump system for the electric vehicle is described below with reference to the accompanying drawings. Figures 1-6 The specific structure of the heat pump system for the electric vehicle is described below with reference to the accompanying drawings.

[0030] The present application discloses a kind of for electric vehicle's heat pump system, as Figures 1-6As shown, the heat pump system for the electric vehicle of the embodiment comprises a low-pressure stage compression device, a high-pressure stage compression device, and a functional heat exchange device. The low-pressure stage compression device comprises a low-pressure stage compressor 101, a low-pressure stage evaporator 102, a low-pressure stage expansion valve 104, and a low-pressure stage intercooler 103 connected in sequence, and a first working medium flows through the low-pressure stage compression device. The high-pressure stage compression device comprises a high-pressure stage compressor 1, a high-pressure stage four-way valve 2, an air-side heat exchanger 4, a water-side heat exchanger 3, a cabin heat exchanger 5, and a battery heat exchanger 7. The compressor outlet of the high-pressure stage compressor 1 is selectively communicated with one of the air-side heat exchanger 4 and the water-side heat exchanger 3, and the air-side heat exchanger 4 is respectively communicated with the cabin heat exchanger 5 and the battery heat exchanger 7. A second working medium flows through the high-pressure stage compression device, and the second working medium can exchange heat with the first working medium in the low-pressure stage intercooler 103. The functional heat exchange device comprises a motor heat exchange assembly, a heat exchange water tank 27, and a battery heat exchange piece 20 and a cabin heat exchange piece 6. In the embodiment, the motor heat exchange assembly comprises a motor heat exchange piece 24 and an electric control heat exchange piece 23 connected in series. The motor heat exchange piece 24 can cool the motor of the electric vehicle, and the electric control heat exchange piece 23 can exchange heat with the electric control circuit board of the electric vehicle for controlling the motor.

[0031] The heat exchange inlet of the motor heat exchange assembly is selectively communicated with one of the heat exchange outlet of the heat exchange water tank 27 and the heat exchange outlet of the battery heat exchange piece 20, and the heat exchange outlet of the motor heat exchange assembly is communicated with one of the heat exchange inlet of the heat exchange water tank 27 and the heat exchange inlet of the cabin heat exchange piece 6. The heat exchange inlet of the battery heat exchange piece 20 is communicated with the heat exchange outlet of the battery heat exchanger 7, and the heat exchange outlet of the battery heat exchange piece 20 is selectively communicated with one of the heat exchange inlet of the battery heat exchanger 7 and the heat exchange inlet of the motor heat exchange assembly. The heat exchange inlet of the cabin heat exchange piece 6 is selectively communicated with one of the heat exchange outlet of the motor heat exchange assembly and the heat exchange outlet of the cabin heat exchanger 5, and the heat exchange outlet of the cabin heat exchange piece 6 is selectively communicated with one of the heat exchange inlet of the cabin heat exchanger 5 and the heat exchange inlet of the battery heat exchanger 7.

[0032] First of all, it should be pointed out that the compressor module of the existing heat management system of the electric vehicle is usually a single-stage compressor device. In the case of extremely low ambient temperature, the evaporation temperature and the condensation temperature of the compressor device will be too large, thereby causing the heating to be unstable. Moreover, in the process of heating in winter, the heat source of the existing heat management system of the electric vehicle is air heat source, and the waste heat of the motor or the battery cannot be utilized, thereby leading to low utilization efficiency of the waste heat of the electric vehicle, and thereby shortening the driving distance of the electric vehicle.

[0033] The heat pump system for the electric vehicle disclosed in the embodiment can have six working conditions according to the switchable connection states of various components, which are as follows:

[0034] Refrigeration working condition:

[0035] As Figure 1 shown, when the external environment temperature is high and the electric vehicle is in driving state, the cabin, battery, motor and electric control circuit board all need to be cooled down. In this working condition, the high-pressure stage compression device is started, the low-pressure stage compression device is closed, and the second working medium flows from the outlet of the high-pressure stage compressor 1, passes through the air side heat exchanger 4, and is then divided into two streams, one of which flows to the cabin heat exchanger 5, and the other of which flows to the battery heat exchanger 7, and finally returns to the high-pressure stage compressor 1 through the high-pressure stage four-way valve 2. Thus, the cabin heat exchanger 5 and the cabin heat exchange element 6 form a cabin refrigeration circuit, and the second working medium in the cabin heat exchanger 5 can exchange heat with the cooling liquid flowing out of the cabin heat exchange element 6, so that the cooling liquid is cooled down to achieve cabin cooling. The battery heat exchanger 7 and the battery heat exchange element 20 form a cabin refrigeration circuit, and the second working medium in the battery heat exchanger 7 can exchange heat with the cooling liquid flowing out of the battery heat exchange element 20, so that the cooling liquid is cooled down to achieve battery cooling. The cooling liquid in the heat exchange water tank 27 can achieve cooling of the motor and the electric control circuit board after flowing to the electric control heat exchange element 23 and the motor heat exchange element 24. In this working condition, the overlapped heat pump system uses ambient air as a heat source to achieve cooling of the battery, motor, electric control circuit board and cabin.

[0036] Natural cooling condition:

[0037] As Figure 2 shown, when the external environment temperature is moderate, the cabin does not need to be cooled down, and the motor, battery and electric control circuit board all need to be cooled down, at this time the electric vehicle is generally in parking or normal driving state. In this working condition, the high-pressure stage compression device and the low-pressure stage compression device are both closed, and the cooling liquid in the heat exchange water tank 27 passes through the battery heat exchanger 7, the battery heat exchange element 20, the electric control heat exchange element 23 and the motor heat exchange element 24 in turn and then returns to the heat exchange water tank 27. In this working condition, the overlapped heat pump system uses ambient air as a heat source to achieve cooling of the battery, motor and electric control circuit board.

[0038] Air source heat pump two-stage compression condition:

[0039] As Figure 3As shown, when the external environment is extremely cold, the cabin and battery need to be heated. At this time, the electric vehicle is generally in a parked or short-term driving state. Under this condition, both the high-pressure stage compressor and the low-pressure stage compressor are turned on. The coolant in the hot water tank 27 flows through the low-pressure stage evaporator 102, the electronically controlled heat exchanger 23, and the motor heat exchanger 24 back to the hot water tank 27 to form a motor cooling circuit. The first working medium flows out of the low-pressure stage compressor 101 and passes through the low-pressure stage intercooler 103, the low-pressure expansion valve 104, and the low-pressure stage evaporator 102 in sequence before returning to the low-pressure stage compressor 101. The first working medium and the coolant flowing out of the hot water tank 27 can exchange heat in the low-pressure stage evaporator 102, which increases the temperature of the first working medium and decreases the temperature of the coolant. The second working medium, after flowing out of the high-pressure stage compressor 1, splits into two streams. One stream flows to the cabin heat exchanger 5, and the other flows to the battery heat exchanger 7. After flowing through the cabin heat exchanger 5 and the battery heat exchanger 7 respectively, the two streams of the second working medium merge and flow to the air-side heat exchanger 4, and then return to the high-pressure stage compressor 1 via the low-pressure stage intercooler 103. Thus, the cabin heat exchanger 5 and the cabin heat exchange component 6 constitute a cabin heating circuit. In the cabin heat exchanger 5, the second working medium can exchange heat with the coolant flowing out of the cabin heat exchange component 6, causing the coolant to heat up and thus achieving cabin heating. The battery heat exchanger 7 and the battery heat exchange component 20 constitute a cabin heating circuit. In the battery heat exchanger 7, the second working medium can exchange heat with the coolant flowing out of the battery heat exchange component 20, causing the coolant to heat up and thus achieving battery heating. The second working medium can exchange heat with the first working medium within the low-pressure stage intercooler 103, causing the second working medium to heat up and the first working medium to cool down. In other words, in this state, the low-pressure stage evaporator 102 uses the heat exchange tank 27 as a heat source for evaporating the first working medium, while the high-pressure stage evaporator uses both the first working medium and ambient air as heat sources. In existing technologies, when the ambient temperature is too low, the working medium of the compressor module has difficulty obtaining heat from the air, which reduces the heating efficiency for the cabin and battery. However, in this embodiment, a low-pressure stage compressor and a high-pressure stage compressor are provided. Even at extremely low ambient temperatures, the first working medium can obtain heat from the coolant in the heat exchange tank 27, and the second working medium can obtain heat from the first working medium within the low-pressure stage intercooler 103, ensuring efficient heating for the cabin and battery.

[0040] Motor-controlled heat pump operating conditions:

[0041] like Figure 4As shown, when the external environment is extremely low, the cabin and the battery need to be heated, but the electric vehicle has been driven for a period of time, and the motor and the electric control circuit board can generate a lot of heat. In this working condition, the high-pressure stage compression device is opened, and the low-pressure stage compression device is closed. The electric control heat exchange element 23, the motor heat exchange element 24, and the water side heat exchanger 3 constitute a motor and electric control cooling circuit. The second working medium flows out from the high-pressure stage compressor 1 and is divided into two streams, one of which flows to the cabin heat exchanger 5, and the other of which flows to the battery heat exchanger 7. After the two streams of the second working medium flow through the cabin heat exchanger 5 and the battery heat exchanger 7 respectively, they are combined and flow to the water side heat exchanger 3, and then return to the high-pressure stage compressor 1 through the water side heat exchanger 3. Thus, the cabin heat exchanger 5 and the cabin heat exchange element 6 constitute a cabin heating circuit, and the second working medium in the cabin heat exchanger 5 can exchange heat with the cooling liquid flowing out of the cabin heat exchange element 6, so that the cooling liquid is heated to heat the cabin. The battery heat exchanger 7 and the battery heat exchange element 20 constitute a cabin heating circuit, and the second working medium in the battery heat exchanger 7 can exchange heat with the cooling liquid flowing out of the battery heat exchange element 20, so that the cooling liquid is heated to heat the battery. In this state, the high-pressure stage evaporator uses the first working medium to absorb the heat of the cooling liquid of the motor and the electric control circuit board in the water side heat exchanger 3 to realize evaporation, that is, in this working condition, the high-pressure stage compression device uses the heat of the cooling liquid of the motor and the electric control circuit board as a heat source to complete the circulation of the second working medium. Compared with the air heat source, using the cooling liquid of the motor and the electric control circuit board as a heat source can improve the quality of the heat source and improve the heating efficiency of the high-pressure stage compression device, thereby achieving the effect of energy saving.

[0042] Battery source heat pump working condition:

[0043] As Figure 5As shown, when the external environment is extremely cold, the electric vehicle is generally in a parked state. At this time, the cabin needs to be heated, and the motor and electronic control circuit board are in a stopped state with relatively low temperatures, unable to serve as a heat source. However, the battery is still working and can generate a lot of heat. Under this condition, the high-pressure stage compressor is turned on, and the low-pressure stage compressor is turned off. The electronic control heat exchanger 23, the motor heat exchanger 24, the water-side heat exchanger 3, the battery heat exchanger 7, and the battery heat exchanger 20 constitute the battery cooling circuit. The second working medium flows out of the high-pressure stage compressor 1 and splits into two streams. One stream flows to the cabin heat exchanger 5, and the other flows to the battery heat exchanger 7. After flowing through the cabin heat exchanger 5 and the battery heat exchanger 7 respectively, the two streams of the second working medium merge and flow to the water-side heat exchanger 3, and then return to the high-pressure stage compressor 1. Therefore, the cabin heat exchanger 5 and the cabin heat exchange component 6 constitute the cabin heating circuit. Within the cabin heat exchanger 5, the second working medium exchanges heat with the coolant flowing out of the cabin heat exchange component 6, causing the coolant to heat up and thus heating the cabin. In this state, the high-pressure stage evaporator uses the first working medium to absorb heat from the coolant in the water-side heat exchanger 3 to achieve evaporation. In other words, under this operating condition, the high-pressure stage compressor uses the heat from the battery coolant as a heat source to complete the circulation of the second working medium. Compared to air as a heat source, using the battery coolant as a heat source improves the quality of the heat source and increases the heating efficiency of the high-pressure stage compressor, thereby achieving energy savings.

[0044] Natural heating mode:

[0045] like Figure 6 As shown, when the ambient temperature is relatively low and the cabin needs heating, the motor, electronic control circuit board, and battery are all in normal working condition and can all serve as heat sources. Under this condition, both the high-pressure and low-pressure compression devices are shut down. The electronic control heat exchanger 23, motor heat exchanger 24, cabin heat exchanger 6, battery heat exchanger 7, and battery heat exchanger 20 constitute the motor-electronic control-battery cooling circuit. In this state, the heat generated by the battery, electronic control circuit board, and battery is directly used as the heat source for heating the cabin, improving energy efficiency while achieving stable cabin heating.

[0046] In summary, the heat pump system for the electric vehicle according to the present embodiment, due to the low-pressure stage compression device and the high-pressure stage compression device, the high-pressure stage compression device includes the air-side heat exchanger 4 capable of exchanging heat with air and the water-side heat exchanger 3 capable of exchanging heat with cooling liquid, and the second working medium can exchange heat with the first working medium in the low-pressure stage intercooler 103, so that in the case of extremely low temperature, the second working medium takes the first working medium and air as heat source, and the second working medium takes cooling water as heat source, which improves the heat source quality and ensures the heating efficiency. At the same time, the heat pump system for the electric vehicle according to the present embodiment can also take the waste heat of the battery, motor or electric control circuit board as heat source for cabin heating according to the working state of the electric vehicle and the ambient temperature, which improves the waste heat utilization rate of the electric vehicle and is beneficial to improve the mileage of the electric vehicle.

[0047] Optionally, in the present embodiment, the first working medium is carbon dioxide and the second working medium is R1234yf refrigerant. Of course, in other embodiments of the present application, the first working medium and the second working medium can also be selected as other refrigerants according to actual needs.

[0048] As shown in Figure 1 , the heat pump system for the electric vehicle according to the present embodiment further includes a motor expansion water tank 25 and a motor water pump 26 connected in series, the inlet of the motor water pump 26 is in communication with the motor expansion water tank 25 and the motor heat exchange assembly, and the outlet of the motor water pump 26 is selectively in communication with one of the heat exchange water tank 27, the water-side heat exchanger 3 and the cabin heat exchange member 6. It can be understood that the motor water pump 26 can ensure the stable circulation of the cooling liquid in the motor cooling circuit, so as to ensure that the heat exchange of the cooling liquid can be stably carried out. And the motor expansion water tank 25 can play the role of cooling liquid buffer, avoiding the phenomenon that too much or too little cooling liquid in the whole circuit affects the heat exchange effect.

[0049] Further, as shown in Figure 1 , the heat pump system for the electric vehicle further includes a first three-way valve 28 and a second three-way valve 30, the first valve port of the first three-way valve 28 is in communication with the outlet of the motor water pump 26, the second valve port of the first three-way valve 28 is in communication with the heat exchange inlet of the heat exchange water tank 27, the third valve port of the first three-way valve 28 is in communication with the first valve port of the second three-way valve 30, and the first valve port of the first three-way valve 28 is switchably in communication with the second valve port of the first three-way valve 28 and the third valve port of the first three-way valve 28. The second valve port of the second three-way valve 30 is in communication with the heat exchange inlet of the cabin heat exchange member 6, the third valve port of the second three-way valve 30 is in communication with the heat exchange inlet of the water-side heat exchanger 3, and the first valve port of the second three-way valve 30 is switchably in communication with the second valve port of the second three-way valve 30 and the third valve port of the second three-way valve 30.

[0050] It can be understood that in the refrigeration working condition, the natural cooling working condition and the air source heat pump two-stage compression working condition, the first valve port of the first three-way valve 28 is in communication with the second valve port, so that the cooling liquid can enter the heat exchange water tank 27 under the driving of the motor water pump 26. In the motor electric control source heat pump working condition and the battery source heat pump working condition, the first valve port of the first three-way valve 28 is in communication with the third valve port, and the first valve port of the second three-way valve 30 is in communication with the third valve port, so that the cooling liquid can enter the water side heat exchanger 3 under the driving of the motor water pump 26. In the natural heating working condition, the first valve port of the first three-way valve 28 is in communication with the second valve port, and the first valve port of the second three-way valve 30 is in communication with the second valve port, so that the cooling liquid can enter the cabin heat exchanger 5 under the driving of the motor water pump 26. Therefore, the first three-way valve 28 and the second three-way valve 30 can realize the switching of multiple working conditions, simplify the structure of the entire overlapped heat pump system for the electric vehicle, and reduce the manufacturing cost. Of course, in other embodiments of the present application, a plurality of two-way valves can be used to replace the functions of the first three-way valve 28 and the second three-way valve 30.

[0051] As shown in Figure 1 The overlapped heat pump system for the electric vehicle of the present embodiment further comprises a battery expansion water tank 18 and a battery water pump 19. The inlet of the battery water pump 19 is in communication with the battery expansion water tank 18 and the battery heat exchanger 7. The outlet of the battery water pump 19 is in communication with the battery heat exchange 20. It can be understood that the battery water pump 19 can ensure the stable circulation of the cooling liquid in the battery cooling circuit, so as to ensure that the heat exchange of the cooling liquid can be stably carried out. The battery expansion water tank 18 can play the role of cooling liquid buffer, avoiding the phenomenon that the cooling liquid in the entire circuit is too much or too little, thereby affecting the heat exchange effect.

[0052] Further, as shown in Figure 1As shown, the cascaded heat pump system for electric vehicles also includes a third three-way valve 29 and a four-way control valve 21. The first valve port of the third three-way valve 29 is connected to the heat exchange outlet of the hot water tank 27, the second valve port of the third three-way valve 29 is connected to the evaporation inlet of the low-pressure stage evaporator 102, the third valve port of the third three-way valve 29 is connected to the first valve port of the four-way control valve 21, and the first valve port of the third three-way valve 29 can be switched to be connected to the second valve port and the third valve port of the third three-way valve 29. The first port of the four-way control valve 21 is connected to the heat exchange outlet of the cabin heat exchanger 6 via the cabin control valve 31. The second port of the four-way control valve 21 is connected to the heat exchange inlet of the battery heat exchanger 7. The third port of the four-way control valve 21 is connected to the heat exchange outlet of the battery heat exchanger 20. The fourth port of the four-way control valve 21 is connected to the heat exchange inlet of the motor heat exchange assembly. The first port of the four-way control valve 21 can be switched to be connected to the second port and the fourth port of the four-way control valve 21. The fourth port of the four-way control valve 21 can be switched to be connected to the second port and the fourth port of the four-way control valve 21.

[0053] Understandably, in cooling mode, the first and third ports of the third three-way valve 29 are connected, and the first and fourth ports of the four-way control valve 21 are connected, while the third and second ports are connected, allowing the coolant to enter the battery heat exchanger 7 under the drive of the battery pump. In natural cooling mode, the first and third ports of the third three-way valve 29 are connected, and the first and second ports of the four-way control valve 21 are connected, while the third and fourth ports are connected, allowing the coolant to enter the electrically controlled heat exchanger 23 under the drive of the battery water pump 19. In two-stage compression mode of the air source heat pump, the first and second ports of the third three-way valve 29 are connected, and the first and fourth ports of the four-way control valve 21 are connected, while the third and second ports are connected, allowing the coolant to enter the battery heat exchanger 7 under the drive of the battery pump. In the motor-controlled heat pump mode, the coolant bypasses the third three-way valve 29. The first and fourth ports of the four-way control valve 21 are connected, and the third port is connected to the second port. The coolant can then enter the battery heat exchanger 7 under the drive of the battery pump. In both battery-driven heat pump and natural cooling modes, the coolant bypasses the third three-way valve 29. The first and second ports of the four-way control valve 21 are connected, and the third and fourth ports are connected. The coolant can then enter the electrically controlled heat exchanger 23 under the drive of the battery pump. Therefore, by using the third three-way valve 29 and the four-way control valve 21, switching between multiple operating conditions can be achieved, simplifying the entire cascaded heat pump system structure for electric vehicles and reducing manufacturing costs. Of course, in other embodiments of the invention, multiple two-way valves can be used to replace the functions of the third three-way valve 29 and the four-way control valve 21.

[0054] like Figure 1As shown, the heat pump system for electric vehicle of the embodiment further comprises a cabin expansion tank 32 and a cabin water pump 33, the inlet of the cabin water pump 33 is communicated with the cabin expansion tank 32 and the cabin heat exchange element 6, and the outlet of the cabin water pump 33 is communicated with the cabin heat exchanger 5. It can be understood that the cabin water pump 33 can ensure the stable circulation of the cooling liquid in the cabin cooling loop, thereby ensuring that the heat exchange of the cooling liquid can be stably carried out. And the cabin expansion tank 32 can play the role of cooling liquid buffer, avoiding the phenomenon that the cooling liquid in the whole loop is too much or too little, thereby affecting the heat exchange effect.

[0055] Further, as shown in the figure, Figure 1 As shown, the heat pump system for electric vehicle of the embodiment further comprises a fourth three-way valve 8 and a fifth three-way valve 9, the first valve port of the fourth three-way valve 8 is communicated with the high-pressure four-way valve 2, the second valve port of the fourth three-way valve 8 is communicated with the heat exchange outlet of the low-pressure intercooler 103, the third valve port of the fourth three-way valve 8 is communicated with the air-side heat exchanger 4 and the water-side heat exchanger 3, and the first valve port of the fourth three-way valve 8 is switchably communicated with the second valve port and the third valve port of the fourth three-way valve 8. The first valve port of the fifth three-way valve 9 is communicated with the cabin heat exchanger 5 and the battery heat exchanger 7, the second valve port of the fifth three-way valve 9 is communicated with the air-side heat exchanger 4, and the third valve port of the fifth three-way valve 9 is communicated with the water-side heat exchanger 3. The first valve port of the fifth three-way valve 9 is switchably communicated with the second valve port and the third valve port of the fifth three-way valve 9.

[0056] It can be understood that in the refrigeration working condition, the first valve port of the fourth three-way valve 8 is communicated with the third valve port, and the first valve port of the fifth three-way valve 9 is communicated with the second valve port. In the natural cooling working condition and the natural heating working condition, the cooling liquid does not pass through the fourth three-way valve 8 and the fifth three-way valve 9. In the air source heat pump two-stage compression working condition, the first valve port of the fourth three-way valve 8 is communicated with the second valve port, and the first valve port of the fifth three-way valve 9 is communicated with the second valve port, so that the first cooling medium and the second cooling medium can exchange heat in the low-pressure intercooler 103. In the motor electric control source heat pump working condition, the first valve port of the fourth three-way valve 8 is communicated with the third valve port, and the first valve port of the fifth three-way valve 9 is communicated with the third valve port, so that the second cooling medium and the cooling liquid can exchange heat in the water-side heat exchanger 3. Therefore, the fourth three-way valve 8 and the fifth three-way valve 9 can realize the switching of multiple working conditions, simplify the structure of the whole heat pump system for electric vehicle, and reduce the manufacturing cost. Of course, in other embodiments of the present application, a plurality of two-way valves can be used to replace the functions of the fourth three-way valve 8 and the fifth three-way valve 9.

[0057] Further, as shown in the figure, Figure 1As shown, the first valve port of the fifth three-way valve 9 is connected in parallel with the cabin heat exchanger 5 and the battery heat exchanger 7, and is equipped with a heating electronic expansion valve 10 and a cooling two-way valve 11. It can be understood that under the air source heat pump two-stage compression operation, the motor-controlled heat pump operation, and the battery source heat pump operation, the second working medium flowing to the air-side heat exchanger 4 or the water-side heat exchanger 3 needs to have a low liquid component and a high gaseous component to facilitate heat absorption within the air-side heat exchanger 4 or the water-side heat exchanger 3. However, under the cooling operation, the second working medium flowing out of the air-side heat exchanger 4 or the water-side heat exchanger 3 does not require throttling and cooling. In this embodiment, a heating electronic expansion valve 10 and a cooling two-way valve 11 are added. Under the conditions of air-source heat pump two-stage compression, motor-controlled heat pump, and battery-source heat pump, the second working medium flows from the heating electronic expansion valve 10 to the air-side heat exchanger 4 or the water-side heat exchanger 3. Under the cooling condition, the second working medium flows through the cooling two-way valve 11 to the cabin heat exchanger 5 and the battery heat exchanger 7. This improves the energy efficiency of the high-pressure stage compression device, thereby achieving energy-saving functionality and extending the electric vehicle's mileage.

[0058] like Figure 1 As shown, a cabin heating two-way valve 14 and a cabin cooling electronic expansion valve 15 are connected in parallel between the cabin heat exchanger 5 and the air-side heat exchanger 4. It is understood that in cooling mode, the second working medium of the cabin heat exchanger 5 requires a low liquid component and a high gaseous component to facilitate heat absorption within the cabin heat exchanger 5 and reduce the temperature of the coolant. However, in the air source heat pump two-stage compression mode, the motor-controlled heat pump mode, and the battery source heat pump mode, the second working medium flowing out of the cabin heat exchanger 5 does not require throttling for cooling. In this embodiment, a cabin heating two-way valve 14 and a cabin cooling electronic expansion valve 15 are added. In the air source heat pump two-stage compression mode, the motor-controlled heat pump mode, and the battery source heat pump mode, the second working medium flows from the cabin heating two-way valve 14 to the air-side heat exchanger 4 or the water-side heat exchanger 3. In cooling mode, the second working medium flows through the cabin cooling electronic expansion valve 15 to the cabin heat exchanger 5. This can improve the energy efficiency of the high-pressure stage compressor, thereby achieving energy-saving functions and helping to extend the range of electric vehicles.

[0059] like Figure 1As shown, the battery heat exchanger 7 and the air side heat exchanger 4 are connected in parallel by a battery heating two-way valve 13 and a battery cooling electronic expansion valve 12. It can be understood that in the cooling state, the second working medium of the battery heat exchanger 7 needs to have a small liquid component and a large gaseous component, so that heat can be absorbed in the battery heat exchanger 7 to reduce the temperature of the cooling liquid. In the air source heat pump two-stage compression working condition, the motor and electric control source heat pump working condition, and the battery source heat pump working condition, the second working medium flowing out of the battery heat exchanger 7 does not need to be throttled and cooled. In this embodiment, the battery heating two-way valve 13 and the battery cooling electronic expansion valve 12 are additionally provided. In the air source heat pump two-stage compression working condition, the motor and electric control source heat pump working condition, and the battery source heat pump working condition, the second working medium flows from the battery heating two-way valve 13 to the air side heat exchanger 4 or the water side heat exchanger 3, and in the cooling working condition, the second working medium flows to the battery heat exchanger 7 through the battery cooling electronic expansion valve 12. In this way, the energy efficiency of the high-pressure stage compression device can be improved, thereby achieving the energy saving function and prolonging the mileage of the electric vehicle.

[0060] As shown in the figure, Figure 1 The overlapped heat pump system for the electric vehicle of the present embodiment further comprises an economizer 16, the first interface of the economizer 16 being in communication with one of the air side heat exchanger 4 and the water side heat exchanger 3, the second interface of the economizer 16 being in communication with the cabin heat exchanger 5 and the battery heat exchanger 7, the third interface of the economizer 16 being in communication with the high-pressure stage compressor 1 through a one-way valve 35, and the fourth interface of the economizer 16 being in communication with one of the air side heat exchanger 4 and the water side heat exchanger 3 through a two-way control valve 17. It can be understood that the economizer 16 can divide the second working medium entering the economizer 16 into two parts, one part is throttled to further cool in the form of heat expansion, and the other part is cooled to supercooling, and the stable supercooled liquid directly enters the air side heat exchanger 4 or the water side heat exchanger 3 to evaporate. The other part of the uncooled gaseous refrigerant reenters the high-pressure stage compressor 1 through the communication pipeline of the economizer 16 and the high-pressure stage compressor 1 to continue compression and enter the cycle. It stabilizes the liquid second working medium by expansion refrigeration to improve the system capacity and efficiency.

[0061] As shown in the figure, Figure 1 The overlapped heat pump system for the electric vehicle of the present embodiment further comprises a cabin heater 34 arranged on the cabin heat exchanger 6. It can be understood that the cabin heater 34 can supplement heating when the entire overlapped heat pump system for the electric vehicle is insufficient in heating capacity, so as to ensure stable heating when the cabin needs to be heated, and ensure that the cabin is at a relatively comfortable temperature, thereby improving user satisfaction.

[0062] As shown in the figure, Figure 1As shown, the overlapped heat pump system for electric vehicle of the embodiment further comprises a battery heater 22 connected between the battery heat exchanger 7 and the battery heat exchange member 20. It can be understood that the battery heater 22 can supplement heating when the heating capacity of the entire overlapped heat pump system for electric vehicle is insufficient, and ensure that the battery can be stably heated when the battery needs to be heated, so that the battery can work stably and the service life of the battery is prolonged.

[0063] In the description of the present specification, the description referring to the terms "some embodiments", "other embodiments", and the like means that the specific features, structures, materials or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0064] The above is only the preferred embodiment of the present application, and for those skilled in the art, according to the idea of the present application, the specific implementation and application range can be changed, and the content of the specification should not be understood as the limitation of the present application.

Claims

1. A cascaded heat pump system for electric vehicles, characterized in that, include: A low-pressure stage compression device, comprising a low-pressure stage compressor (101), a low-pressure stage evaporator (102), a low-pressure expansion valve (104), and a low-pressure stage intercooler (103) connected in sequence, wherein a first working medium flows through the low-pressure stage compression device; A high-pressure stage compression device includes a high-pressure stage compressor (1), a high-pressure stage four-way valve (2), an air-side heat exchanger (4), a water-side heat exchanger (3), a cabin heat exchanger (5), and a battery heat exchanger (7). The compressor outlet of the high-pressure stage compressor (1) can be selectively connected to one of the air-side heat exchanger (4) and the water-side heat exchanger (3). The air-side heat exchanger (4) is connected to the cabin heat exchanger (5) and the battery heat exchanger (7), respectively. A second working medium flows through the high-pressure stage compression device, and the second working medium can exchange heat with the first working medium in the low-pressure stage intercooler (103). A functional heat exchange device, comprising a motor heat exchange assembly, a hot water tank (27), a battery heat exchange component (20), and a cabin heat exchange component (6); wherein: The heat exchange inlet of the motor heat exchange assembly can be selectively connected to one of the heat exchange outlet of the hot water tank (27) and the heat exchange outlet of the battery heat exchange component (20), and the heat exchange outlet of the motor heat exchange assembly is connected to one of the heat exchange inlet of the hot water tank (27) and the heat exchange inlet of the cabin heat exchange component (6). The heat exchange inlet of the battery heat exchanger (20) is connected to the heat exchange outlet of the battery heat exchanger (7), and the heat exchange outlet of the battery heat exchanger (20) may be selectively connected to one of the heat exchange inlet of the battery heat exchanger (7) and the heat exchange inlet of the motor heat exchange assembly. The heat exchange inlet of the cabin heat exchanger (6) may be selectively connected to one of the heat exchange outlet of the motor heat exchange assembly and the heat exchange outlet of the cabin heat exchanger (5), and the heat exchange outlet of the cabin heat exchanger (6) may be selectively connected to one of the heat exchange inlet of the cabin heat exchanger (5) and the heat exchange inlet of the battery heat exchanger (7). The cascaded heat pump system for electric vehicles further includes a fourth three-way valve (8) and a fifth three-way valve (9). The first port of the fourth three-way valve (8) is connected to the high-pressure stage four-way valve (2), the second port of the fourth three-way valve (8) is connected to the heat exchange outlet of the low-pressure stage intercooler (103), and the third port of the fourth three-way valve (8) is connected to the air-side heat exchanger (4) and the water-side heat exchanger (3). The first port of the fourth three-way valve (8) is switchably connected to the second port of the fourth three-way valve (9). The valve port is connected to the third valve port of the fourth three-way valve (8); the first valve port of the fifth three-way valve (9) is connected to the cabin heat exchanger (5) and the battery heat exchanger (7); the second valve port of the fifth three-way valve (9) is connected to the air-side heat exchanger (4); the third valve port of the fifth three-way valve (9) is connected to the water-side heat exchanger (3); the first valve port of the fifth three-way valve (9) can be switched to be connected to the second valve port and the third valve port of the fifth three-way valve (9).

2. The cascaded heat pump system for electric vehicles according to claim 1, characterized in that, The cascaded heat pump system for electric vehicles also includes a motor expansion tank (25) and a motor water pump (26) connected in series. The inlet of the motor water pump (26) is connected to the motor expansion tank (25) and the motor heat exchange assembly, and the outlet of the motor water pump (26) is optionally connected to one of the heat exchange tank (27), the water-side heat exchanger (3), and the cabin heat exchanger (6).

3. The cascaded heat pump system for electric vehicles according to claim 2, characterized in that, The cascaded heat pump system for electric vehicles further includes a first three-way valve (28) and a second three-way valve (30). The first valve port of the first three-way valve (28) is connected to the outlet of the motor water pump (26), the second valve port of the first three-way valve (28) is connected to the heat exchange inlet of the hot water tank (27), and the third valve port of the first three-way valve (28) is connected to the first valve port of the second three-way valve (30). The first valve port of the first three-way valve (28) can be switched to be connected to the second valve port and the third valve port of the first three-way valve (28). The second valve port of the second three-way valve (30) is connected to the heat exchange inlet of the cabin heat exchanger (6), and the third valve port of the second three-way valve (30) is connected to the heat exchange inlet of the water-side heat exchanger (3). The first valve port of the second three-way valve (30) can be switched to be connected to the second valve port and the third valve port of the second three-way valve (30).

4. The cascaded heat pump system for electric vehicles according to any one of claims 1-3, characterized in that, The cascaded heat pump system for electric vehicles also includes a battery expansion tank (18) and a battery water pump (19). The inlet of the battery water pump (19) is connected to the battery expansion tank (18) and the battery heat exchanger (7); the outlet of the battery water pump (19) is connected to the battery heat exchanger (20).

5. The cascaded heat pump system for electric vehicles according to any one of claims 1-3, characterized in that, The cascaded heat pump system for electric vehicles further includes a third three-way valve (29) and a four-way control valve (21). The first port of the third three-way valve (29) is connected to the heat exchange outlet of the hot water tank (27), the second port of the third three-way valve (29) is connected to the evaporation inlet of the low-pressure stage evaporator (102), and the third port of the third three-way valve (29) is connected to the first port of the four-way control valve (21). The first port of the third three-way valve (29) is switchably connected to both the second port and the third port of the third three-way valve (29). The first port of the four-way control valve (21) is connected to the seat via a cabin control valve (31). The heat exchange outlet of the chamber heat exchanger (6) is connected, the second valve port of the four-way control valve (21) is connected to the heat exchange inlet of the battery heat exchanger (7), the third valve port of the four-way control valve (21) is connected to the heat exchange outlet of the battery heat exchanger (20), the fourth valve port of the four-way control valve (21) is connected to the heat exchange inlet of the motor heat exchange assembly, the first valve port of the four-way control valve (21) can be switched to be connected to the second valve port and the fourth valve port of the four-way control valve (21), and the fourth valve port of the four-way control valve (21) can be switched to be connected to the second valve port and the fourth valve port of the four-way control valve (21).

6. The cascaded heat pump system for electric vehicles according to any one of claims 1-3, characterized in that, The cascaded heat pump system for electric vehicles also includes a cabin expansion tank (32) and a cabin water pump (33). The inlet of the cabin water pump (33) is connected to the cabin expansion tank (32) and the cabin heat exchanger (6), and the outlet of the cabin water pump (33) is connected to the cabin heat exchanger (5).

7. The cascaded heat pump system for electric vehicles according to any one of claims 1-3, characterized in that, The cascaded heat pump system for electric vehicles also includes an economizer (16), the first interface of which is connected to one of the air-side heat exchanger (4) and the water-side heat exchanger (3), the second interface of which is connected to the cabin heat exchanger (5) and the battery heat exchanger (7), the third interface of which is connected to the high-pressure stage compressor (1) through a one-way valve (35), and the fourth interface of which is connected to one of the air-side heat exchanger (4) and the water-side heat exchanger (3) through a two-way control valve (17).

8. The cascaded heat pump system for electric vehicles according to any one of claims 1-3, characterized in that, The cascaded heat pump system for electric vehicles also includes a cabin heater (34), which is disposed on the cabin heat exchanger (6).

9. The cascaded heat pump system for electric vehicles according to any one of claims 1-3, characterized in that, The cascaded heat pump system for electric vehicles also includes a battery heater (22) connected between the battery heat exchanger (7) and the battery heat exchanger (20).

Images