Double outdoor heat exchanger heat pump system

Abstract

A heat pump system with dual outdoor heat exchangers comprises: a compressor with a liquid storage separator, an indoor condenser, a main outdoor heat exchanger, an auxiliary outdoor heat exchanger and an indoor evaporator. The present invention can realize defrosting and heating at the same time, can realize continuous heating, achieve the effect of small attenuation of heating amount or even no attenuation, maximize the use of the capacity of the outdoor heat exchanger, when the system is cooling, the outdoor heat exchanger has the best heat dissipation capacity and the pressure loss is small, when the system is heating, the inlet and outlet of the outdoor heat exchanger are reversed to realize the overflow flow of refrigerant, thereby achieving the best evaporation effect, and the pressure loss is relatively small.

Description

Technical Field

[0001] The present invention relates to a technology in the field of automobile air conditioning, in particular to a heat pump system with double outdoor heat exchangers. Background Art

[0002] At present, new energy vehicles in the market use traditional air-conditioning systems for cooling and electric heating PTC for heating, which to a certain extent meets the requirements of passenger compartment comfort. However, the efficiency of electric heating PTC is always less than 1. As the ambient temperature decreases, the efficiency will decrease, and the battery energy consumption will increase, resulting in a significant reduction in the vehicle's range. As national policies and users put forward more and more requirements on the key parameter of automobiles - range, various heat pump systems have emerged, and the concept of thermal management of vehicles equipped with heat pump systems has become more and more popular.

[0003] The heat pump system adopts the reverse Carnot cycle principle, which can continuously absorb heat from the outdoor environment medium (air, water, or other heat sources), and then release it to the indoor space that needs to be heated. After heating for a period of time, the heat exchanger that absorbs heat from the outdoor environment medium will generate condensed water on the surface of the heat exchanger due to the low surface temperature and the presence of moisture in the environment. When the temperature of the outdoor environment medium is too low, frost or ice will condense on the surface of the heat exchanger, which will block the heat exchange fins of the heat exchanger, and the heating effect of the heat pump system will deteriorate and the efficiency will decrease. At this time, the defrost mode needs to be operated, and the high-temperature and high-pressure gaseous refrigerant discharged by the compressor directly enters the outdoor heat exchanger, and the purpose of defrosting the heat exchanger is achieved by hot gas defrosting. However, this mode sacrifices the heating effect of the passenger compartment to a certain extent, because the outdoor heat exchanger cannot absorb heat from the outdoor ambient air, and the heat released by the passenger compartment depends entirely on the work of the compressor, and only a small part can be used for heating, otherwise the defrost time will be extended, and the user experience will deteriorate, which is contrary to the original intention of installing a heat pump system to achieve energy-saving effects. Summary of the invention

[0004] In view of the shortcomings of low comfort in the passenger compartment of current new energy vehicles and the need for intermittent defrosting during heating in winter, the present invention proposes a heat pump system with dual outdoor heat exchangers, which can realize defrosting and heating at the same time, and can realize continuous heating, so as to achieve the effect of small attenuation of heating amount or even no attenuation, and maximize the use of the capacity of the outdoor heat exchanger. When the system is cooling, the outdoor heat exchanger has the best heat dissipation capacity and the smallest pressure loss. When the system is heating, the inlet and outlet of the outdoor heat exchanger are reversed to realize overflow flow of refrigerant, thereby achieving the best evaporation effect and relatively small pressure loss.

[0005] The present invention is achieved through the following technical solutions:

[0006] The present invention comprises: a compressor with a liquid storage separator, a condensing device, a main outdoor heat exchanger, an auxiliary outdoor heat exchanger and an indoor evaporator, wherein: the output end of the compressor is connected to the condensing device, the auxiliary outdoor heat exchanger, the main outdoor heat exchanger and the indoor evaporator in sequence, the output end of the indoor evaporator is connected to the input end of the liquid storage separator and forms a refrigeration circuit; a second three-way solenoid valve connected to the input end of the liquid storage separator is provided on the input end of the main outdoor heat exchanger, a first bypass is formed between the first port of the second three-way solenoid valve and the main outdoor heat exchanger, and a fourth bypass is formed between the second port of the second three-way solenoid valve and the input end of the liquid storage separator; a second bypass is formed between the output end of the main outdoor heat exchanger and the output end of the condensing device, and a second main throttle valve is provided on the second bypass; a first three-way solenoid valve is provided between the input end of the auxiliary outdoor heat exchanger and the third port of the second three-way solenoid valve, and a third bypass is formed between the first three-way solenoid valve and the auxiliary outdoor heat exchanger; the third port of the first three-way solenoid valve is connected to the output end of the main outdoor heat exchanger.

[0007] The main outdoor heat exchanger and the auxiliary outdoor heat exchanger form a double outdoor heat exchanger module, and a main throttle valve with a two-way throttling function is arranged therebetween.

[0008] The present invention relates to a control method for the above-mentioned system, including a cooling mode, three heating modes, a low-temperature dehumidification mode and a high-temperature dehumidification mode, wherein: when the cooling mode, the third heating mode and the high-temperature dehumidification mode are used to assist the outdoor heat exchanger in defrosting, the system refrigerant enters from the inlet and flows out from the outlet of the outdoor heat exchanger; in the first heating mode, the second heating mode and the low-temperature dehumidification mode, the system refrigerant enters from the outlet and flows out from the inlet of the outdoor heat exchanger; when the main outdoor heat exchanger is defrosted in the second heating mode, the main outdoor heat exchanger realizes the condenser function, and the auxiliary outdoor heat exchanger realizes the evaporator function; when the auxiliary outdoor heat exchanger is defrosted in the third heating mode, the main outdoor heat exchanger realizes the evaporator function, and the auxiliary outdoor heat exchanger realizes the condenser function.

[0009] A sixth stop valve is arranged on the first bypass, a second stop valve is arranged on the third bypass, and a fifth stop valve is connected in parallel to the second main throttle valve.

[0010] The condensing device is further provided with an auxiliary plate heat exchanger, the input end and the output end of the plate heat exchanger are respectively connected to the input end of the compressor and the auxiliary outdoor heat exchanger.

[0011] Technical Effects

[0012] Compared with the prior art, the technical effects of the present invention include:

[0013] 1. When the heat pump system is cooling and heating, the refrigerant flow direction of the outdoor heat exchanger inlet and outlet is reversed, so that the heat exchange effect and pressure loss of the outdoor heat exchanger when acting as a condenser and evaporator can achieve the best balance, reducing system energy consumption, improving heat exchange effect, and thus improving system heat exchange efficiency;

[0014] 2. It fundamentally solves the problem that when the system is continuously heating, the outdoor heat exchanger will continue to frost, and the system's heat exchange capacity will be greatly reduced. The heating effect of the passenger cabin has to be sacrificed and the defrost mode has to be operated. The heat pump system can independently achieve continuous and uninterrupted heating without relying on other power-consuming equipment, while taking into account the operation of the defrost mode, which greatly improves the comfort of the passenger cabin;

[0015] 3. The heat pump system can achieve high temperature and high humidity, low temperature and high humidity dehumidification effects, thereby meeting the comfort requirements of the passenger cabin under multiple ambient temperatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the present invention;

[0017] Figure 2 Schematic diagram of the refrigerant flow path when the cooling mode is running in Example 1, wherein the solid line portion represents the medium refrigerant flow path, and the dotted line portion represents the refrigerant non-circulating state;

[0018] Figure 3 Schematic diagram of the refrigerant flow path when the first heating mode is operated in Example 1, wherein the solid line portion represents the medium refrigerant flow path, and the dotted line portion represents the refrigerant non-circulating state;

[0019] Figure 4 Schematic diagram of the refrigerant flow path when the second heating mode is operated in Example 1, wherein the solid line portion represents the medium refrigerant flow path, and the dotted line portion represents the refrigerant non-circulating state;

[0020] Figure 5 Schematic diagram of the refrigerant flow path when the third heating mode is operated in Example 1, wherein the solid line portion represents the medium refrigerant flow path, and the dotted line portion represents the refrigerant non-circulating state;

[0021] Figure 6 Schematic diagram of the refrigerant flow path when the low-temperature dehumidification mode is running in Example 1, wherein the solid line portion represents the medium refrigerant flow path, and the dotted line portion represents the refrigerant non-circulation state;

[0022] Figure 7 Schematic diagram of the refrigerant flow path when the high temperature mode is operated in Example 1, wherein the solid line portion represents the medium refrigerant flow path, and the dotted line portion represents the refrigerant non-circulation state;

[0023] Figure 8 This is variant embodiment 2 of the double outdoor heat exchanger heat pump system;

[0024] Fig. 9 This is variant embodiment 3 of the double outdoor heat exchanger heat pump system;

[0025] In the figure: 1 compressor, 2 indoor condenser, 3 first stop valve, 4 auxiliary outdoor heat exchanger, 5 first main throttle valve, 6 main outdoor heat exchanger, 7 second main throttle valve, 8 first three-way solenoid valve, 9 second three-way solenoid valve, 10 first auxiliary throttle valve, 11 indoor evaporator, 12 liquid storage separator, 13 second stop valve, 14 third stop valve, 15 second auxiliary throttle valve, 16 fifth stop valve, 17 sixth stop valve, 18 seventh stop valve, 19 kettle, 20 pump, 21 plate heat exchanger, 22 warm air core, first bypass a, second bypass b, third bypass c, fourth bypass d. DETAILED DESCRIPTION

[0026] Example 1

[0027] like Figure 1 As shown, this embodiment includes: a compressor 1 with a liquid storage separator 12, an indoor condenser 2, a main outdoor heat exchanger 6, an auxiliary outdoor heat exchanger 4 and an indoor evaporator 11, wherein:

[0028] The output end of the compressor 1 is connected to the indoor condenser 2, the auxiliary outdoor heat exchanger 4, the main outdoor heat exchanger 6 and the indoor evaporator 11 in sequence, and the output end of the indoor evaporator 11 is connected to the input end of the liquid storage separator 12 to form a refrigeration circuit;

[0029] A second three-way solenoid valve 9 connected to the input end of the liquid storage separator 12 is provided at the input end of the main outdoor heat exchanger 6, a first bypass is formed between the first port of the second three-way solenoid valve 9 and the main outdoor heat exchanger 6, and a fourth bypass is formed between the second port of the second three-way solenoid valve 9 and the input end of the liquid storage separator 12;

[0030] A second bypass is provided between the output end of the main outdoor heat exchanger 6 and the output end of the indoor condenser 2, and a second main throttle valve 7 is provided on the second bypass;

[0031] A first three-way solenoid valve 8 is provided between the input end of the auxiliary outdoor heat exchanger 4 and the third port of the second three-way solenoid valve 9, and a third bypass is provided between the first three-way solenoid valve 8 and the auxiliary outdoor heat exchanger 4; the third port of the first three-way solenoid valve 8 is connected to the output end of the main outdoor heat exchanger 6.

[0032] A first stop valve 3 is provided between the output end of the indoor condenser 2 and the auxiliary outdoor heat exchanger 4 .

[0033] The output end of the auxiliary outdoor heat exchanger 4 is provided with a first main throttle valve 5 .

[0034] The input end of the indoor evaporator 11 is provided with a first auxiliary throttle valve 10 with a cut-off function.

[0035] This system performs specific temperature control in the following ways:

[0036] ① Cooling mode

[0037] like Figure 2 As shown, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 1 flows through the indoor condenser 2, passes through the first stop valve 3, enters the auxiliary outdoor heat exchanger 4, releases heat to the environment to achieve a pre-cooling effect, then flows through the first main throttle valve 5 and enters the main outdoor heat exchanger 6, continues to release heat to the outdoor environment to achieve a supercooling state, then flows through the first three-way solenoid valve 8, enters the first auxiliary throttle valve 10 for throttling, becomes a low-temperature and low-pressure two-phase refrigerant, enters the indoor evaporator 11, absorbs the heat of the wind blown into the passenger compartment by the blower and becomes a low-pressure and low-temperature gaseous refrigerant, achieving the effect of cooling the passenger compartment, and finally flows through the gas-liquid separator and enters the compressor to complete a cycle;

[0038] In this mode, the temperature damper in the air-conditioning box is closed, the first stop valve 3 and the first main throttle valve 5 are opened, the right part of the first three-way solenoid valve 8 is connected, the second three-way solenoid valve 9 is completely closed, and the first auxiliary throttle valve 10 has a throttling function.

[0039] ②First heating mode

[0040] like Figure 3 As shown, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 1 flows into the indoor condenser 2, and the wind blown into the blower releases heat to become a high-pressure medium-temperature supercooled refrigerant, and is throttled in the second main throttle valve 7 on the second bypass b to become a low-temperature and low-pressure two-phase refrigerant, and flows into the main outdoor heat exchanger 6, absorbs heat in the environment to become a low-temperature and low-pressure gaseous / two-phase refrigerant, and then flows into the first bypass a, passes through the second three-way solenoid valve 9, and flows into the liquid storage separator 12 to complete the separation of gas and liquid, and the saturated gaseous refrigerant enters the compressor 1 to complete a cycle;

[0041] In this mode, the temperature damper in the air conditioner is opened, the first stop valve 3, the first main throttle valve 5, the first three-way solenoid valve 8, and the first auxiliary throttle valve 10 are completely closed, and the upper part of the second three-way solenoid valve 9 is connected.

[0042] ③ Second heating mode

[0043] like Figure 4As shown, when frost is detected on the surface of the main outdoor heat exchanger 6, which affects the heat exchange effect, the heat pump system will start the second heating mode. The high-temperature and high-pressure gaseous refrigerant discharged from the compressor 1 flows into the indoor condenser 2, and the wind blown into the blower releases heat to become a high-pressure medium-temperature supercooled refrigerant, enters the second bypass b, flows through the second main throttle valve 7, flows into the main outdoor heat exchanger 6, releases heat, melts the frost on the surface of the main outdoor heat exchanger 6 to become a high-pressure low-temperature supercooled refrigerant, and then after throttling by the first main throttle valve 5, becomes a low-temperature and low-pressure two-phase refrigerant, flows into the auxiliary outdoor heat exchanger 4, absorbs heat from the environment to become a low-temperature and low-pressure gaseous / two-phase refrigerant, enters the third bypass c, and then flows through the first three-way solenoid valve 8 and the second three-way solenoid valve 9, enters the liquid storage separator 12 through the fourth bypass d to complete gas-liquid separation, and the saturated gaseous refrigerant enters the compressor 1 to complete a cycle;

[0044] In this mode, the temperature damper in the air-conditioning box is opened, the first stop valve 3 and the first auxiliary throttle valve 10 are completely closed, the second main throttle valve 7 is opened, the lower part of the first three-way solenoid valve 8 is connected, the right part of the second three-way solenoid valve 9 is connected, and the first main throttle valve 6 has a throttling function.

[0045] ④Third heating mode

[0046] like Figure 5 As shown, when the system determines through the sensor that the surface of the auxiliary outdoor heat exchanger 4 is frosted, causing the heating effect to deteriorate, the third heating mode will be activated. The high-temperature and high-pressure gaseous refrigerant discharged from the compressor 1 flows through the indoor condenser 2, and the wind blown into the blower releases heat to become a high-pressure medium-temperature supercooled refrigerant, passes through the first stop valve 3, enters the auxiliary outdoor heat exchanger 4, melts the frost on the surface of the auxiliary outdoor heat exchanger 4 to become a high-pressure and low-temperature supercooled refrigerant, flows into the first main throttle valve 5 for throttling, and then enters the main outdoor heat exchanger 6, absorbs heat from the environment to become a low-temperature and low-pressure gaseous / two-phase refrigerant, and then flows through the first three-way solenoid valve 8 and the second three-way solenoid valve 9 in sequence, enters the liquid storage separator 12 through the fourth bypass d to complete gas-liquid separation, and the saturated gaseous refrigerant enters the compressor 1 to complete a cycle;

[0047] In this mode, the temperature damper in the air-conditioning box is opened, the first stop valve 3 is opened, the second main throttle valve 7 and the first auxiliary throttle valve 10 are completely closed, the right parts of the first three-way solenoid valve 8 and the second three-way solenoid valve 9 are connected, and the first main throttle valve 6 has a throttling function.

[0048] ⑤Low temperature dehumidification mode

[0049] like Figure 6As shown, when the car is in a low temperature and high humidity environment, the dehumidification mode needs to be started for the comfort of the passenger compartment. The high temperature and high pressure gaseous refrigerant discharged from the compressor 1 flows into the indoor condenser 2, releases heat to the dry cold air flowing through the indoor evaporator 11, becomes a high pressure medium temperature supercooled refrigerant, enters the second bypass b, flows into the second main throttle valve 7 for throttling, and then enters the main outdoor heat exchanger 6, absorbs heat in the environment to become a low temperature and low pressure gaseous / two-phase refrigerant, then passes through the first main throttle valve 5, enters the auxiliary outdoor heat exchanger 4, absorbs heat in the environment to become a low temperature and low pressure gaseous / two-phase refrigerant, enters the third bypass c, then flows through the first three-way solenoid valve 8, enters the first auxiliary throttle valve 10 for secondary throttling, becomes a low temperature and low pressure two-phase refrigerant, absorbs the heat of the air blown by the blower to become a low pressure and low temperature gaseous refrigerant, analyzes the water in the air, and achieves the effect of dehumidifying the passenger compartment, passes through the liquid storage separator 12, and enters the compressor 1 to complete a cycle;

[0050] In this mode, the temperature damper in the air-conditioning box is opened, the first stop valve 3 and the second three-way solenoid valve 9 are completely closed, the first main throttle valve 5 is opened, the lower part of the first three-way solenoid valve 8 is connected, and the second main throttle valve 7 and the first auxiliary throttle valve 10 have throttling function.

[0051] ⑥High temperature dehumidification mode

[0052] like Figure 7 As shown, when the car is in a high temperature and high humidity environment, the dehumidification mode also needs to be started for the comfort of the passenger compartment. The high temperature and high pressure gaseous refrigerant discharged from the compressor 1 flows through the indoor condenser 2, passes through the first stop valve 3, enters the auxiliary outdoor heat exchanger 4, releases heat to the air in the outdoor environment to achieve a pre-cooling effect, and becomes a high pressure and high temperature gaseous refrigerant, and then passes through the first main throttle valve 5, enters the main outdoor heat exchanger 6, releases heat to the air in the environment to achieve a supercooling effect, and becomes a high pressure medium temperature supercooled refrigerant, then flows through the first three-way solenoid valve 8, enters the first auxiliary throttle valve 10 for throttling, and becomes a low temperature and low pressure two-phase refrigerant, absorbs the heat of the air blown in by the blower to become a low pressure and low temperature gaseous refrigerant, analyzes the water in the air, and achieves the effect of dehumidifying the passenger compartment, passes through the liquid storage separator 12, and enters the compressor 1 to complete a cycle;

[0053] In this mode, the temperature damper in the air-conditioning box is closed, the first stop valve 3 and the first main throttle valve 5 are opened, the right part of the first three-way solenoid valve 8 is connected, the second three-way solenoid valve 9 and the second main throttle valve 7 are completely closed, and the first auxiliary throttle valve 10 has a throttling function.

[0054] Example 2

[0055] like Figure 8As shown, compared with Example 1, in this embodiment, a sixth stop valve 17 is arranged on the first bypass a, a second stop valve 13 is arranged on the third bypass c, and a fifth stop valve 16 is connected in parallel to the second main throttle valve 7, so as to realize the basic functions of cooling, heating and dehumidification of the above-mentioned heat pump system, and to switch the mode to avoid frosting conditions in advance or to heat and defrost at the same time, thereby truly solving the problem that frosting of the heat pump requires sacrificing the heating effect.

[0056] Example 3

[0057] like Fig. 9 As shown, compared with Example 1, this embodiment adopts a heater core 22 to replace the indoor condenser 2, and an auxiliary plate heat exchanger 21 is further arranged between the heater core 2, the first stop valve 3 and the compressor 1, and the first input end and the first output end of the plate heat exchanger 21 are respectively connected to the compressor 1 and the first stop valve 3, and the second input end and the second output end are respectively connected to the auxiliary pump body 20 with a water source 19 and the heater core 22.

[0058] This embodiment can also realize the above-mentioned modes, but due to the addition of heat exchange equipment, compared with the heat pump system of Example 1, under the same conditions, the heat loss increases. However, it also makes up for the disadvantage of the attenuation of air volume under refrigeration and high-temperature dehumidification in Example 1 to a certain extent. The air conditioner box can cancel the temperature damper, which reduces the control difficulty and increases the air output of the air conditioner box under refrigeration and high-temperature dehumidification.

[0059] In this embodiment, there are two main and auxiliary outdoor heat exchangers in the front cabin of the vehicle, and a bypass passage a and a two-way throttling device 5 are connected in sequence between the main outdoor heat exchanger 6 and the auxiliary outdoor heat exchanger 4. The existence of this key combination enables the dual outdoor heat exchangers to work uninterruptedly, making it possible to provide a steady supply of heat for the heat pump system.

[0060] This embodiment is aimed at the existing automobile air conditioning system, which uses a single outdoor heat exchanger and does not have the ability of zone control. In addition, in a specific system operation mode, it can only achieve one function: heat absorption or heat dissipation. In the ambient temperature range of -7 to 10°C, the heat pump system operates in the heating mode for a long time, and the surface of the outdoor heat exchanger is prone to frost or even blockage of the channel, resulting in a significant reduction in the heat exchange capacity of the outdoor heat exchanger. At this time, it is hoped that the outdoor heat exchanger can dissipate heat and defrost to improve the heat exchange capacity of the outdoor heat exchanger, and it is also hoped that the outdoor heat exchanger will not absorb much heat from the ambient air without causing a large attenuation.

[0061] By using the main and auxiliary outdoor heat exchanger modules, the state of the refrigerant entering the two outdoor heat exchangers can be controlled by a two-way throttle valve, thereby realizing refrigerant zoning control and coordinated control of the two outdoor heat exchangers, thereby realizing different functions in different modes and enabling the system to operate continuously and uninterruptedly.

[0062] Compared with the prior art, this device improves the heat dissipation capacity of the outdoor heat exchanger in the cooling mode. The dual outdoor heat exchangers can be partially stacked, which is equivalent to making full use of the front cabin space of the vehicle. The total area of ​​the unfolded fins of the dual outdoor heat exchangers is greater than that of the single outdoor heat exchanger, which enhances the heat dissipation performance. Whether in cooling or heating mode, two-stage throttling can be turned on. When the compressor suction superheat remains unchanged, the subcooling degree of the high-pressure section increases, and the enthalpy difference between the evaporation inlet and outlet of the low-pressure section increases, and the cooling and heating effects are enhanced. Due to the presence of the above-mentioned main and auxiliary outdoor heat exchanger modules, in the heating mode, if any outdoor heat exchanger is frosted, the other can work normally. The medium-temperature refrigerant will first flow through the frosted outdoor heat exchanger to melt the frost layer on the surface of the fins. The reduction in the refrigerant temperature also increases the subcooling degree of the high-pressure section, and then passes through the two-way throttle valve. After throttling, it enters another outdoor heat exchanger to absorb heat from the ambient air, providing a steady stream of heat for the heat pump system.

[0063] The above-mentioned specific implementation can be partially adjusted in different ways by those skilled in the art without departing from the principle and purpose of the present invention. The protection scope of the present invention shall be based on the claims and shall not be limited by the above-mentioned specific implementation. Each implementation scheme within its scope shall be subject to the constraints of the present invention.

Claims

1. A new energy vehicle dual outdoor heat exchanger heat pump system with three heating modes, characterized in that: include: A compressor with a liquid storage separator, an indoor condenser, a main outdoor heat exchanger, an auxiliary outdoor heat exchanger and an indoor evaporator, wherein: the output end of the compressor is connected to the indoor condenser, the auxiliary outdoor heat exchanger, the main outdoor heat exchanger and the indoor evaporator in sequence, the output end of the indoor evaporator is connected to the input end of the liquid storage separator to form a refrigeration circuit; a second three-way solenoid valve connected to the input end of the liquid storage separator is provided on the input end of the main outdoor heat exchanger, a first bypass is formed between the first port of the second three-way solenoid valve and the main outdoor heat exchanger, and a second three-way solenoid valve is connected to the input end of the liquid storage separator. A fourth bypass is provided between the second port and the input end of the liquid storage separator; a second bypass is provided between the output end of the main outdoor heat exchanger and the output end of the indoor condenser, and a second main throttle valve is provided on the second bypass; a first three-way solenoid valve is provided between the input end of the auxiliary outdoor heat exchanger and the third port of the second three-way solenoid valve, a third bypass is provided between the first port of the first three-way solenoid valve and the auxiliary outdoor heat exchanger, and the second port of the first three-way solenoid valve is connected to the third port of the second three-way solenoid valve; the third port of the first three-way solenoid valve is connected to the output end of the main outdoor heat exchanger; The first heating mode of the three heating modes is as follows: the high-temperature and high-pressure gaseous refrigerant discharged from the compressor flows into the indoor condenser, and the wind blown into the blower releases heat to become a high-pressure medium-temperature supercooled refrigerant, and is throttled in the second main throttle valve on the second bypass to become a low-temperature and low-pressure two-phase refrigerant, and flows into the main outdoor heat exchanger, absorbs heat in the environment to become a low-temperature and low-pressure gaseous / two-phase refrigerant, and then flows into the first bypass, passes through the second three-way solenoid valve, flows into the liquid storage separator to complete the separation of gas and liquid, and the saturated gaseous refrigerant enters the compressor to complete a cycle; A first stop valve is provided between the output end of the indoor condenser and the auxiliary outdoor heat exchanger; a first main throttle valve is provided at the output end of the auxiliary outdoor heat exchanger; a first auxiliary throttle valve with a stop function is provided at the input end of the indoor evaporator; In the first heating mode, the temperature damper in the air conditioner is opened, the first stop valve, the first main throttle valve, the first three-way solenoid valve, and the first auxiliary throttle valve are completely closed, and the first port and the second port of the second three-way solenoid valve are connected; The second heating mode among the three heating modes means that when frost is detected on the surface of the main outdoor heat exchanger, which affects the heat exchange effect, the heat pump system will start the second heating mode; the high-temperature and high-pressure gaseous refrigerant discharged from the compressor flows into the indoor condenser, and the wind blown into the blower releases heat to become a high-pressure medium-temperature supercooled refrigerant, enters the second bypass, flows through the second main throttle valve, flows into the main outdoor heat exchanger, releases heat, melts the frost on the surface of the main outdoor heat exchanger to become a high-pressure low-temperature supercooled refrigerant, and then after throttling by the first main throttle valve, becomes a low-temperature and low-pressure two-phase refrigerant, flows into the auxiliary outdoor heat exchanger, absorbs heat in the environment to become a low-temperature and low-pressure gaseous / two-phase refrigerant, enters the third bypass, and then flows through the first three-way solenoid valve and the second three-way solenoid valve, enters the liquid storage separator through the fourth bypass to complete gas-liquid separation, and the saturated gaseous refrigerant enters the compressor to complete a cycle; In the second heating mode, the temperature damper in the air conditioner is opened, the first stop valve and the first auxiliary throttle valve are completely closed, the second main throttle valve is opened, the first port and the second port of the first three-way solenoid valve are connected, the third port and the second port of the second three-way solenoid valve are connected, and the first main throttle valve has a throttling function; The third heating mode among the three heating modes means: when the system determines through the sensor that the frost on the surface of the auxiliary outdoor heat exchanger causes the heating effect to deteriorate, the third heating mode will be activated; the high-temperature and high-pressure gaseous refrigerant discharged from the compressor flows through the indoor condenser, and the wind blown into the blower releases heat to become a high-pressure medium-temperature supercooled refrigerant, passes through the first stop valve, enters the auxiliary outdoor heat exchanger, melts the frost on the surface of the auxiliary outdoor heat exchanger to become a high-pressure and low-temperature supercooled refrigerant, flows into the first main throttle valve for throttling, and then enters the main outdoor heat exchanger, absorbs heat from the environment to become a low-temperature and low-pressure gaseous / two-phase refrigerant, and then flows through the first three-way solenoid valve and the second three-way solenoid valve in sequence, enters the liquid storage separator through the fourth bypass to complete gas-liquid separation, and the saturated gaseous refrigerant enters the compressor to complete a cycle; In the third heating mode, the temperature damper in the air-conditioning box is opened, the first stop valve is opened, the second main throttle valve and the first auxiliary throttle valve are completely closed, the third port and the second port of the first three-way solenoid valve are connected, the third port and the second port of the second three-way solenoid valve are connected, and the first main throttle valve has a throttling function.

2. A control method for the double outdoor heat exchanger heat pump system of a new energy vehicle according to claim 1, characterized in that: include: Cooling mode, three heating modes, low-temperature dehumidification mode and high-temperature dehumidification mode, among which: when the cooling mode, the third heating mode and the high-temperature dehumidification mode are used to assist the outdoor heat exchanger in defrosting, the system refrigerant enters from the inlet and flows out from the outlet of the outdoor heat exchanger; in the first heating mode, the second heating mode and the low-temperature dehumidification mode, the system refrigerant enters from the outlet and flows out from the inlet of the outdoor heat exchanger; when the main outdoor heat exchanger is defrosted in the second heating mode, the main outdoor heat exchanger realizes the condenser function, and the auxiliary outdoor heat exchanger realizes the evaporator function; when the auxiliary outdoor heat exchanger is defrosted in the third heating mode, the main outdoor heat exchanger realizes the evaporator function, and the auxiliary outdoor heat exchanger realizes the condenser function.

3. The method according to claim 2, characterized in that: The refrigeration mode refers to: the high-temperature and high-pressure gaseous refrigerant discharged from the compressor flows through the indoor condenser, passes through the first stop valve, enters the auxiliary outdoor heat exchanger, releases heat to the environment to achieve a pre-cooling effect, then flows through the first main throttle valve to enter the main outdoor heat exchanger, continues to release heat to the outdoor environment to achieve a supercooling state, then flows through the first three-way solenoid valve, enters the first auxiliary throttle valve for throttling, becomes a low-temperature and low-pressure two-phase refrigerant, enters the indoor evaporator, absorbs the heat of the wind blown into the passenger compartment by the blower, becomes a low-pressure and low-temperature gaseous refrigerant, achieves the effect of cooling the passenger compartment, and finally flows through the gas-liquid separator and enters the compressor to complete a cycle; In cooling mode, the temperature damper in the air-conditioning box is closed, the first stop valve and the first main throttle valve are opened, the main outdoor heat exchanger is connected to the first auxiliary throttle valve through the second port of the first three-way solenoid valve, the second three-way solenoid valve is completely closed, and the first auxiliary throttle valve has a throttling function.

4. The method according to claim 3, characterized in that: The low-temperature dehumidification mode means that when the car is in a low-temperature and high-humidity environment, the dehumidification mode needs to be started for the comfort of the passenger compartment; the high-temperature and high-pressure gaseous refrigerant discharged from the compressor flows into the indoor condenser, releases heat to the dry cold air flowing through the indoor evaporator, becomes a high-pressure medium-temperature supercooled refrigerant, enters the second bypass, flows into the second main throttle valve for throttling, and then enters the main outdoor heat exchanger, absorbs heat in the environment and becomes a low-temperature and low-pressure gaseous / two-phase refrigerant, then passes through the first main throttle valve, enters the auxiliary outdoor heat exchanger, absorbs heat in the environment and becomes a low-temperature and low-pressure gaseous / two-phase refrigerant, enters the third bypass, then flows through the first three-way solenoid valve, enters the first auxiliary throttle valve for secondary throttling, becomes a low-temperature and low-pressure two-phase refrigerant, absorbs the heat of the air blown in by the blower and becomes a low-pressure and low-temperature gaseous refrigerant, analyzes the water in the air, and achieves the effect of dehumidifying the passenger compartment, passes through the liquid storage separator, and enters the compressor to complete a cycle; In the low-temperature dehumidification mode, the temperature damper in the air-conditioning box is opened, the first stop valve and the second three-way solenoid valve are completely closed, the first main throttle valve is opened, and the auxiliary outdoor heat exchanger is connected to the first auxiliary throttle valve through the first and second ports of the first three-way solenoid valve, and the second main throttle valve and the first auxiliary throttle valve have throttling functions.

5. The method according to claim 3, characterized in that: The high-temperature dehumidification mode means that when the car is in a high-temperature and high-humidity environment, the dehumidification mode needs to be started for the comfort of the passenger compartment; the high-temperature and high-pressure gaseous refrigerant discharged from the compressor flows through the indoor condenser, passes through the first stop valve, enters the auxiliary outdoor heat exchanger, releases heat to the air in the outdoor environment to achieve a pre-cooling effect, and becomes a high-pressure and high-temperature gaseous refrigerant, and then passes through the first main throttle valve, enters the main outdoor heat exchanger, releases heat to the air in the environment to achieve a supercooling effect, and becomes a high-pressure medium-temperature supercooled refrigerant, then flows through the first three-way solenoid valve, enters the first auxiliary throttle valve for throttling, and becomes a low-temperature and low-pressure two-phase refrigerant, absorbs the heat of the air blown in by the blower to become a low-pressure and low-temperature gaseous refrigerant, analyzes the water in the air, and achieves the effect of dehumidifying the passenger compartment, passes through the liquid storage separator, and enters the compressor to complete a cycle; In the high-temperature dehumidification mode, the temperature damper in the air-conditioning box is closed, the first stop valve and the first main throttle valve are opened, the main outdoor heat exchanger is connected to the first auxiliary throttle valve through the third and second ports of the first three-way solenoid valve, the second three-way solenoid valve and the second main throttle valve are completely closed, and the first auxiliary throttle valve has a throttling function.

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