CN117382383A - Heat pump system, refrigerant backflow control method and device thereof and vehicle - Google Patents

Abstract

The invention discloses a heat pump system, a refrigerant backflow control method, a device and a vehicle thereof, wherein the heat pump system comprises a first refrigerant loop, a second refrigerant loop and an on-off valve, and the method comprises the following steps: controlling an on-off valve to heat a target area by the first refrigerant loop in response to a heating mode instruction; acquiring the high-pressure of the first refrigerant circuit; and when the high-pressure is greater than the first preset pressure threshold, controlling the on-off valve to enable the second refrigerant loop to be connected with the first refrigerant loop in series so as to heat the target area through the second refrigerant loop and the first refrigerant loop. The method can realize the double heating of the target area by controlling the on-off valve, thereby improving the heat exchange efficiency of the heat pump system, reducing the energy consumption of the system and avoiding the backflow of the refrigerant.

Description

Heat pump system, refrigerant backflow control method and device thereof and vehicle

Technical Field

The present invention relates to the field of vehicle technologies, and in particular, to a method for controlling refrigerant reflux of a heat pump system, a device for controlling refrigerant reflux of a heat pump system, and a vehicle.

Background

At present, the market occupation rate of new energy electric vehicles is gradually increased, and more electric vehicles are marked with heat pump systems for improving the energy utilization rate of the electric vehicles and reducing the power consumption of the whole electric vehicles.

In the related art, a heat pump system is provided with a compressor hot gas bypass valve, when the heat pump system is started in a low-temperature environment (such as below-15 ℃), the compressor is started in a cold mode, when the compressor heat pump bypass valve is opened, the heat quantity is gradually increased along with the rising of the rotating speed of the compressor, the low-pressure can be higher than 1.6bar, the air inlet temperature of an evaporator is low, the pressure at the evaporator is low, and the refrigerant flows back to the evaporator, so that the main-path refrigerant is insufficient, the operation of the system is influenced, and the heat exchange efficiency of the system is reduced.

Disclosure of Invention

The present invention aims to solve at least one of the technical problems in the related art to some extent. Therefore, a first object of the present invention is to provide a method for controlling the refrigerant reflux of a heat pump system, which can control an on-off valve to heat a target area twice, thereby improving the heat exchange efficiency of the heat pump system, reducing the energy consumption of the system, and avoiding the refrigerant reflux.

A second object of the present invention is to propose a heat pump system.

A third object of the present invention is to provide a refrigerant return flow control device for a heat pump system.

A fourth object of the present invention is to propose a vehicle.

To achieve the above object, an embodiment of a first aspect of the present invention provides a method for controlling refrigerant reflux of a heat pump system, the heat pump system including a first refrigerant circuit, a second refrigerant circuit, and an on-off valve, the method including: controlling the on-off valve to heat the target area by the first refrigerant loop in response to a heating mode instruction; acquiring a high pressure of the first refrigerant circuit; and when the high-pressure is greater than a first preset pressure threshold, controlling the on-off valve to enable the second refrigerant loop to be connected with the first refrigerant loop in series so as to heat the target area through the second refrigerant loop and the first refrigerant loop.

According to the refrigerant reflux control method of the heat pump system, firstly, the on-off valve is controlled to heat the target area through the first refrigerant loop in response to the heating mode instruction, then the high-pressure of the first refrigerant loop is obtained, and when the high-pressure is larger than the first preset pressure threshold value, the on-off valve is controlled to connect the second refrigerant loop and the first refrigerant loop in series so as to heat the target area through the second refrigerant loop and the first refrigerant loop. Therefore, the method can control the on-off valve to heat the target area twice, so that the heat exchange efficiency of the heat pump system can be improved, the energy consumption of the system can be reduced, and the back flow of the refrigerant can be avoided.

In addition, the refrigerant return flow control method of the heat pump system according to the above embodiment of the present invention may further have the following additional technical features:

according to one embodiment of the present invention, the on-off valve comprises a first on-off valve, a second on-off valve and a third on-off valve, the first refrigerant circuit comprises a compressor, a first heat exchanger, a first throttling element and a second heat exchanger, the second refrigerant circuit comprises a second throttling element and a third heat exchanger, an exhaust port of the compressor is connected with the first end of the first heat exchanger, the second end of the first heat exchanger is respectively connected with one end of the first on-off valve and one end of the second on-off valve, the other end of the first on-off valve is respectively connected with one end of the first throttling element and one end of the second throttling element, the other end of the first throttling element is connected with the first end of the second heat exchanger, the other end of the second throttling element is respectively connected with the other end of the second on-off valve and one end of the third on-off valve through the third heat exchanger, and the second end of the second heat exchanger and the other end of the third on-off valve are respectively connected with the air suction port of the compressor; wherein the controlling the on-off valve to connect the second refrigerant circuit in series with the first refrigerant circuit to heat the target area through the second refrigerant circuit and the first refrigerant circuit includes: controlling the second on-off valve to be in an open state, and controlling the first on-off valve and the third on-off valve to be in a closed state so as to connect the second refrigerant loop and the first refrigerant loop in series; the second throttling element, the first throttling element and the compressor are controlled to be in an open state so as to heat the target area through the second refrigerant loop and the first refrigerant loop.

According to an embodiment of the present invention, the controlling the on-off valve to heat the first refrigerant circuit to the target area includes: the second on-off valve is controlled to be in a closed state, the first on-off valve is controlled to be in an open state, the third on-off valve is controlled to be in an open or closed state, and the first throttling element and the compressor are controlled to be in an open state so as to heat the target area through the first refrigerant loop.

According to one embodiment of the invention, the first refrigerant circuit further comprises a third throttling element, and two ends of the third throttling element are correspondingly connected with the exhaust port and the air suction port of the compressor; wherein upon a cold start of the compressor, the method further comprises: and controlling the opening degree of the third throttling element to enable the suction superheat degree of the compressor to be larger than a preset suction superheat degree, and controlling the first throttling element to be in an opening state when the suction superheat degree is larger than the preset suction superheat degree.

According to one embodiment of the invention, the method further comprises: and responding to a refrigerating mode instruction, controlling the second on-off valve to be in a closed state, controlling the first on-off valve and the third on-off valve to be in an open state, and controlling the second throttling element and the compressor to be in an open state so as to refrigerate the target area.

According to one embodiment of the invention, the heat pump system further comprises a battery heat exchange circuit for exchanging heat to a battery, the battery heat exchange circuit being connected to the first refrigerant circuit, the method further comprising, while cooling the target area: acquiring the refrigeration requirement of the battery; the first refrigerant circuit is controlled based on the cooling requirement of the battery so that the first refrigerant circuit cools the battery through the battery heat exchange circuit.

According to one embodiment of the present invention, the controlling the first refrigerant circuit based on the cooling requirement of the battery to cool the battery through the battery heat exchange circuit includes: and controlling the opening degree of the first throttling element based on the refrigeration requirement of the battery so as to enable the second heat exchanger to exchange heat with the battery heat exchange loop, so that the battery is refrigerated through the battery heat exchange loop.

To achieve the above object, a second aspect of the present invention provides a heat pump system, comprising: the heat pump system comprises a memory, a processor and a program stored in the memory and capable of running on the processor, wherein the processor realizes the refrigerant reflux control method of the heat pump system when executing the program.

According to the heat pump system provided by the embodiment of the invention, through the refrigerant reflux control method of the heat pump system, the on-off valve can be controlled to heat the target area twice, so that the heat exchange efficiency of the heat pump system can be improved, the energy consumption of the system can be reduced, and the refrigerant reflux can be avoided.

To achieve the above object, an embodiment of a third aspect of the present invention provides a refrigerant return flow control device of a heat pump system including a first refrigerant circuit, a second refrigerant circuit, and an on-off valve, the device including: the control module is used for responding to a heating mode instruction and controlling the on-off valve to heat the first refrigerant loop to the target area; an acquisition module for acquiring a high pressure of the first refrigerant circuit; and the control module is further used for controlling the on-off valve to enable the second refrigerant loop to be connected with the first refrigerant loop in series when the high-pressure is larger than a first preset pressure threshold value so as to heat the target area through the second refrigerant loop and the first refrigerant loop.

According to the refrigerant reflux control device of the heat pump system, the control module responds to a heating mode instruction, controls the on-off valve to enable the first refrigerant loop to heat the target area, the acquisition module acquires the high-pressure of the first refrigerant loop, and the control module is further used for controlling the on-off valve to enable the second refrigerant loop to be connected in series with the first refrigerant loop when the high-pressure is larger than a first preset pressure threshold value so as to heat the target area through the second refrigerant loop and the first refrigerant loop. Therefore, the device can heat the target area twice by controlling the on-off valve, so that the heat exchange efficiency of the heat pump system can be improved, the energy consumption of the system can be reduced, and the back flow of the refrigerant can be avoided.

In order to achieve the above object, a fourth aspect of the present invention provides a vehicle including the refrigerant return control device of the heat pump system.

According to the vehicle provided by the embodiment of the invention, through the refrigerant reflux control device of the heat pump system, the on-off valve can be controlled to heat the target area twice, so that the heat exchange efficiency of the heat pump system can be improved, the energy consumption of the system can be reduced, and the refrigerant reflux can be avoided.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

Fig. 1 is a flowchart of a refrigerant return flow control method of a heat pump system according to an embodiment of the present invention;

fig. 2 is a schematic structural view of a heat pump system according to an embodiment of the present invention;

fig. 3 is a schematic structural view of a heat pump system in the related art;

FIG. 4 is a block schematic diagram of a heat pump system according to an embodiment of the invention;

fig. 5 is a block schematic diagram of a refrigerant return control device of a heat pump system according to an embodiment of the invention;

fig. 6 is a block schematic diagram of a vehicle according to an embodiment of the invention.

Reference numerals:

a first refrigerant circuit 10; a compressor 11; a first heat exchanger 12; a first throttling element 13; a second heat exchanger 14; a third throttling element 15;

a second refrigerant circuit 20; a second throttling element 21; a third heat exchanger 22;

a warm air circuit 30; a nine-way valve 40; a three-way valve 50; a battery heat exchange circuit 60; an electrically driven heat exchange circuit 70; an ambient heat exchange circuit 80;

an on-off valve 90; a first on-off valve SOV1; a second on-off valve SOV2; a third on-off valve SOV3;

a heat pump system 200; a memory 210; a processor 220;

a low temperature control device 100 of the heat pump system; a first control module 110; a second control module 120;

a vehicle 300.

Detailed Description

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention.

A refrigerant return flow control method of a heat pump system, a refrigerant return flow control device of a heat pump system, and a vehicle according to embodiments of the present invention are described below with reference to the accompanying drawings.

Fig. 1 is a flowchart of a refrigerant return flow control method of a heat pump system according to an embodiment of the present invention.

As shown in fig. 2, the heat pump system includes a first refrigerant circuit 10, a second refrigerant circuit 20, and an on-off valve 90, wherein the flow direction of the refrigerant in the first refrigerant circuit 10, the second refrigerant circuit 20 can be adjusted by controlling the opening or closing of the on-off valve 90.

As shown in fig. 1, the method for controlling the refrigerant return of the heat pump system according to the embodiment of the invention may include the following steps:

s1, responding to a heating mode instruction, controlling the on-off valve to heat the target area by the first refrigerant loop.

Wherein the target area is a passenger compartment when the heat pump system is disposed in a vehicle.

S2, acquiring the high-pressure of the first refrigerant circuit.

Wherein the high pressure of the first refrigerant circuit may be obtained by a pressure sensor provided at the high pressure side of the first refrigerant circuit.

And S3, when the high-pressure is greater than a first preset pressure threshold, controlling the on-off valve to enable the second refrigerant loop to be connected with the first refrigerant loop in series so as to heat the target area through the second refrigerant loop and the first refrigerant loop. The first preset pressure threshold value can be calibrated according to actual conditions.

Specifically, in a colder environment, such as winter in north, a user can issue a heating command when using a vehicle, when receiving the heating command, a controller of the heat pump system controls the on-off valve to enable the first refrigerant loop to heat the passenger cabin, the controller acquires the high-pressure of the first refrigerant loop in real time through a pressure sensor arranged on the high-pressure side of the first refrigerant loop, compares the high-pressure with a first preset pressure threshold value, and controls the on-off valve to enable the second refrigerant loop to be connected with the first refrigerant loop in series when the high-pressure is larger than the first preset pressure threshold value, so that the refrigerant with higher temperature in the first refrigerant loop heats the target area secondarily through the second refrigerant loop, and the refrigerant after heat release flows into the first refrigerant loop. Therefore, the on-off valve can be controlled to heat the target area twice, so that the heat exchange efficiency of the heat pump system can be improved, the energy consumption of the system can be reduced, and the refrigerant backflow can be avoided.

In one embodiment of the present invention, as shown in fig. 2, the heat pump system includes a first refrigerant circuit 10, a second refrigerant circuit 20, and an on-off valve 90, wherein the on-off valve 90 includes a first on-off valve SOV1, a second on-off valve SOV2, and a third on-off valve SOV3, the first refrigerant circuit 10 includes a compressor 11, a first heat exchanger 12, a first throttling element 13, and a second heat exchanger 14, the second refrigerant circuit 20 includes a second throttling element 21 and a third heat exchanger 22, an exhaust port of the compressor 11 is connected to a first end of the first heat exchanger 12, a second end of the first heat exchanger 12 is connected to one end of the first on-off valve SOV1 and one end of the second on-off valve SOV2, respectively, the other end of the first on-off valve SOV1 is connected to one end of the first throttling element 13 and one end of the second throttling element 21, the other end of the first throttling element 13 is connected to a first end of the second heat exchanger 14, the other end of the second throttling element 21 is connected to a second end of the second on-off valve SOV2 and the other end of the third on-off valve SOV3, respectively, and the other end of the second throttling element 21 is connected to the second end of the second on-off valve SOV3 and the second on-off valve 14 through the third heat exchanger 22. The first heat exchanger 12 may be a water-cooled condenser, the first throttling element 13 and the second throttling element 21 may be expansion valves, and the third heat exchanger 22 may be an evaporator. The heat pump system further comprises a warm air circuit 30, a battery heat exchange circuit 60, an electric drive heat exchange circuit 70 and an environmental heat exchange circuit 80, wherein when the heat supplementing capability is sufficient, it is indicated that the current heat pump circuit 10 has enough heat to provide heat for the warm air circuit 30, so that the rest of the heat can release heat to one or more of the battery heat exchange circuit 60, the electric drive heat exchange circuit 70 and the environmental heat exchange circuit 80; when the heat supplementing capability is insufficient, the warm air circuit 30 or the heat pump circuit 10 can be controlled to absorb heat from at least one of the battery heat exchange circuit 60, the electric drive heat exchange circuit 70 and the environment heat exchange circuit 80 so as to supplement heat to the passenger compartment. That is, when the heat supplementing capability is insufficient, it is indicated that the current heat pump circuit 10 does not have enough heat to provide heat to the warm air circuit 30, and therefore, heat can be released to the warm air circuit 30 through one or more of the battery heat exchange circuit 60, the electric drive heat exchange circuit 70 and the environment heat exchange circuit 80, so that the heat of the refrigerant in the warm air circuit 30 is increased to supplement heat to the passenger compartment. Heat may also be released to the heat pump circuit 10 through one or more of the battery heat exchange circuit 60, the electrically driven heat exchange circuit 70, and the ambient heat exchange circuit 80, and heat may be provided to the warm air circuit through the heat pump circuit to supplement the passenger compartment. The heat pump system further comprises a nine-way valve 40 and a three-way valve 50, and is connected with the battery heat exchange loop 60, the electric drive heat exchange loop 70 and the environment heat exchange loop 80 through the nine-way valve 40 and the three-way valve 50; by controlling the nine-way valve 40 and the three-way valve 50, it is possible to control the heat pump circuit 10 to supply heat to the warm air circuit 30 to supplement heat to the passenger compartment, and to control the warm air circuit 30 to absorb heat from the battery heat exchange circuit 60 or the electric drive heat exchange circuit 70, or to release heat to at least one of the battery heat exchange circuit 60, the electric drive heat exchange circuit 70, and the ambient heat exchange circuit 80.

It should be noted that, as shown in fig. 3, comparing the heat pump system shown in fig. 3 with the heat pump system shown in fig. 2, it can be found that, in the heat pump system shown in fig. 2, there are no first on-off valve SOV1, second on-off valve SOV2 and third on-off valve SOV3, and if the pressure of the suction port of the compressor 11 is greater than the saturation pressure of the refrigerant in the third heat exchanger 22 during heating, the refrigerant will flow back to the third heat exchanger 22, resulting in insufficient refrigerant in the first refrigerant circuit 10 and affecting the system operation. In the heat pump system shown in fig. 3, the second refrigerant circuit 20 is connected in series with the first refrigerant circuit 10 by controlling the on-off valve, so that the target area is heated by the second refrigerant circuit 20 and the first refrigerant circuit 10, and the refrigerant can be prevented from flowing back to the third heat exchanger. In connection with the specific embodiment, how the on-off valve 90 is controlled to connect the second refrigerant circuit 20 in series with the first refrigerant circuit 10 will be described below.

According to one embodiment of the present invention, controlling an on-off valve to connect a second refrigerant circuit in series with a first refrigerant circuit to heat a target area through the second refrigerant circuit and the first refrigerant circuit includes: controlling the second on-off valve to be in an open state, and controlling the first on-off valve and the third on-off valve to be in a closed state so as to connect the second refrigerant loop and the first refrigerant loop in series; the second throttling element, the first throttling element and the compressor are controlled to be in an open state so as to heat the target area through the second refrigerant loop and the first refrigerant loop.

Specifically, when the controller of the heat pump system receives a heating instruction, the controller controls the compressor to start to operate, the first throttling element is started, so that liquid refrigerant in a low-temperature low-pressure state is converted into gaseous refrigerant in a high-temperature high-pressure state through work done by the compressor, the gaseous refrigerant in the high-temperature high-pressure state is conveyed to the first heat exchanger through the exhaust port of the compressor, water in the first heat exchanger is discharged by the gaseous refrigerant in the high-temperature high-pressure state to heat water in the first heat exchanger, heat can be transferred to the passenger cabin by the warm air loop, and the passenger cabin is heated. The controller acquires high pressure in real time through a pressure sensor arranged at an exhaust port of the compressor, compares the high pressure with a first preset pressure threshold, controls the second throttling element to be opened and controls the second on-off valve to be opened when the high pressure is larger than the first preset pressure threshold, the first on-off valve and the third on-off valve are closed, the second refrigerant loop is connected with the first refrigerant loop in series, and the refrigerant which flows out of the first heat exchanger and still carries heat flows into the third heat exchanger through the second on-off valve to exchange heat so as to heat air around the third heat exchanger, and blows the air into the passenger cabin through the fan so as to secondarily heat the passenger cabin. The refrigerant flowing out of the third heat exchanger flows into the second heat exchanger through the second throttling element and the second throttling element in sequence to absorb heat of one or more of the battery heat exchange loop, the electric drive heat exchange loop and the environment heat exchange loop, and then flows into the compressor, so that the simultaneous heating of the target area through the second refrigerant loop and the first refrigerant loop is completed. Therefore, the target area can be heated twice, so that the heat exchange efficiency of the whole system can be improved, the energy consumption of the system is reduced, and the third heat exchanger is used as a secondary heat exchange device, so that the refrigerant flows and heats the target area when the target area is heated, and the phenomenon that the refrigerant returns to the third heat exchanger is avoided.

According to one embodiment of the present invention, controlling an on-off valve to cause a first refrigerant circuit to heat a target area includes: the second on-off valve is controlled to be in a closed state, the first on-off valve is controlled to be in an open state, the third on-off valve is controlled to be in an open or closed state, and the first throttling element and the compressor are controlled to be in an open state so as to heat the target area through the first refrigerant loop.

Specifically, when the controller of the heat pump system receives a heating instruction, the controller controls the compressor to start, the first throttling element to start and the second throttling element to close, and controls the first on-off valve to start and the second on-off valve to close, so that liquid refrigerant in a low-temperature and low-pressure state is converted into gaseous refrigerant in a high-temperature and high-pressure state through work of the compressor, the gaseous refrigerant in the high-temperature and high-pressure state is conveyed into the first heat exchanger through an exhaust port of the compressor, the gaseous refrigerant in the high-temperature and high-pressure state heats water in the first heat exchanger to heat water in the first heat exchanger, the warm air loop can transfer heat of the first heat exchanger to the passenger cabin to heat the passenger cabin, and the refrigerant flowing out of the first heat exchanger flows into the second heat exchanger through the first on-off valve and the first throttling element and then flows into the compressor, so that heating of a target area through the first refrigerant loop is completed. In the process of heating the target area by the first refrigerant circuit, when the pressure of the suction port of the compressor is higher than the saturation pressure of the refrigerant in the third heat exchanger in the state where the third on-off valve is opened, there may be a case where a small amount of refrigerant flows back to the third heat exchanger from the suction port of the compressor, but when the third on-off valve is in the closed state, there may not be such a case.

Further, as the compressor operates, the high pressure at the exhaust port of the compressor is gradually increased, the controller acquires the high pressure in real time through a pressure sensor arranged at the exhaust port of the compressor, when the high pressure is greater than a first preset pressure threshold value, the controller controls the second on-off valve to be opened, the first on-off valve and the third on-off valve to be closed, and controls the second throttling element to be opened, at the moment, the second refrigerant loop is connected in series with the first refrigerant loop, and the refrigerant which flows out of the first heat exchanger and still carries heat flows into the third heat exchanger through the second on-off valve to exchange heat so as to heat air around the third heat exchanger, and the air is blown into the passenger cabin through the fan so as to secondarily heat the passenger cabin. The refrigerant flowing out of the third heat exchanger flows into the second heat exchanger through the second throttling element and the second throttling element in sequence so as to absorb heat of one or more of the battery heat exchange loop, the electric drive heat exchange loop and the environment heat exchange loop, and then flows into the compressor. With the progress of the secondary heat exchange, the heating power of the compressor is reduced, the high pressure is reduced, when the high pressure is smaller than a second preset pressure threshold (which can be 12 bar), the controller controls the second throttling element to be closed, controls the first on-off valve to be opened, the second on-off valve to be closed and the third on-off valve to be opened or closed, and switches the state of heating the target area through the second refrigerant loop and the first refrigerant loop to the state of heating the target area through the first refrigerant loop, so that the condition that the heating power of the compressor is too low can be avoided.

According to an embodiment of the present invention, as shown in fig. 2, the first refrigerant circuit 10 further includes a third throttling element 15, both ends of the third throttling element 15 being correspondingly connected to the discharge port and the suction port of the compressor 11; wherein, at the time of cold start of the compressor, the method further comprises: and controlling the opening of the third throttling element to enable the suction superheat degree of the compressor to be larger than the preset suction superheat degree, and controlling the first throttling element to be in an opening state when the suction superheat degree is larger than the preset suction superheat degree. The preset suction superheat degree can be calibrated according to actual conditions.

Specifically, when the low-temperature environment requires heating, the body temperature of the compressor is low, the pressure of the air inlet of the compressor is low, and the air inlet of the compressor has no superheat degree, so that the compressor needs to be cold started to avoid triggering the low-pressure protection of the compressor. When the compressor is cold started, the controller controls the opening of the third throttling element to be adjusted to the maximum, the first throttling element and the second throttling element are closed, the compressor is controlled to operate at a lower rotating speed, the refrigerant in the compressor flows out of the exhaust port and enters the air suction port through the third throttling element, the refrigerant is heated by the heat of the compressor, the air suction pressure is gradually increased, when the air suction pressure is larger, the opening of the third throttling element is properly reduced to reduce the air suction pressure, the temperature of the air suction port of the compressor is also increased along with the operation of the compressor, the controller detects the temperature of the air suction port of the compressor in real time through a temperature sensor arranged at the air inlet of the compressor, acquires the pressure of the refrigerant of the air suction port of the current compressor in real time through the pressure sensor, and acquires the saturation temperature corresponding to the current pressure in a table look-up mode. The controller calculates the suction superheat degree according to the temperature and the saturation temperature of the suction port of the compressor, compares the suction superheat degree with a preset suction superheat degree, and controls the first throttling element to be opened when the suction superheat degree is larger than the preset suction superheat degree.

According to one embodiment of the invention, the method further comprises: and responding to the refrigerating mode instruction, controlling the second on-off valve to be in a closed state, controlling the first on-off valve and the third on-off valve to be in an open state, and controlling the second throttling element and the compressor to be in an open state so as to refrigerate the target area.

Specifically, when a user needs to refrigerate the passenger cabin, a refrigeration mode instruction can be issued, when the controller receives the refrigeration mode instruction, the second on-off valve is controlled to be closed, the first on-off valve and the third on-off valve are controlled to be opened, the second throttling element is controlled to be opened, the compressor is controlled to start to operate, high-temperature and high-pressure gaseous refrigerant output by the compressor is subjected to heat exchange through the first heat exchanger and is changed into low-temperature and low-pressure liquid refrigerant, the low-temperature and low-pressure liquid refrigerant flows into the third heat exchanger through the first on-off valve and the second throttling element, the refrigerant exchanges heat with ambient air in the third heat exchanger, heat is absorbed to reduce the temperature of the ambient air, and the air is blown into the passenger cabin through the fan, so that the refrigeration of the passenger cabin is completed. It should be understood that, in the related art, in order to avoid occurrence of the backflow of the refrigerant, a check valve is generally installed at the outlet of the third heat exchanger (evaporator), but the pressure drop of the check valve is large, which results in high pressure of the evaporator during refrigeration and poor cooling effect of the passenger compartment. Therefore, by the method of the embodiment, the refrigerating effect of the passenger cabin can be ensured, a one-way valve does not need to be added at the outlet of the evaporator, and the cost is saved.

According to one embodiment of the invention, the heat pump system further comprises a battery heat exchange circuit for exchanging heat to the battery, the battery heat exchange circuit being connected to the first refrigerant circuit, the method further comprising, when cooling the target area: acquiring the refrigeration requirement of a battery; the first refrigerant circuit is controlled based on the cooling demand of the battery to cool the battery through the battery heat exchange circuit.

Further, according to an embodiment of the present invention, controlling the first refrigerant circuit based on a cooling requirement of the battery to cause the first refrigerant circuit to cool the battery through the battery heat exchange circuit includes: and controlling the opening degree of the first throttling element based on the refrigeration requirement of the battery so as to enable the second heat exchanger to exchange heat with the battery heat exchange loop, so that the battery is refrigerated through the battery heat exchange loop.

Specifically, in the vehicle refrigeration operation process, the controller can acquire the temperature of the battery in real time through the temperature sensor arranged at the battery, and when the temperature of the battery is higher than a certain value (such as 38 ℃), the battery is determined to be required to be refrigerated and cooled, the controller controls the first throttling element to be opened, the third heat exchanger is connected with the second heat exchanger in parallel, the low-temperature low-pressure liquid refrigerant flows into the third heat exchanger through the first on-off valve and the second throttling element to refrigerate the passenger cabin, and simultaneously flows into the second heat exchanger through the first throttling element, so that the second heat exchanger exchanges heat with the battery heat exchange loop through the nine-way valve, the temperature of the battery heat exchange loop cooling liquid is reduced, and the low-temperature cooling liquid of the battery heat exchange loop can refrigerate and cool the battery through the battery. It should be understood that the opening degree of the first throttling element can be adjusted according to the temperature of the battery, for example, when the temperature of the battery is relatively high (such as 50 ℃), the opening degree of the first throttling element can be adjusted to the maximum opening degree, and the heat exchange amount with the heat exchange loop of the battery is increased, so that the battery is quickly cooled, and safety accidents caused by overheat of the battery can be avoided; when the temperature of the battery is not particularly high (e.g., 42 ℃), the opening degree of the first throttling element may be adjusted to one third of the maximum opening degree to cool the battery. Therefore, the passenger cabin can be refrigerated and cooled in time, and the safety coefficient of the vehicle is improved.

In one embodiment of the present invention, as shown in fig. 2, a liquid storage tank is provided between the first heat exchanger 12 and the on-off valve 90.

In summary, according to the method for controlling the refrigerant backflow of the heat pump system according to the embodiment of the invention, firstly, the on-off valve is controlled to heat the target area by the first refrigerant loop in response to the heating mode command, then the high-pressure of the first refrigerant loop is obtained, and when the high-pressure is greater than the first preset pressure threshold, the on-off valve is controlled to connect the second refrigerant loop and the first refrigerant loop in series so as to heat the target area by the second refrigerant loop and the first refrigerant loop. Therefore, the method can control the on-off valve to heat the target area twice, so that the heat exchange efficiency of the heat pump system can be improved, the energy consumption of the system can be reduced, and the back flow of the refrigerant can be avoided.

Corresponding to the embodiment, the invention also provides a heat pump system.

Fig. 4 is a block schematic diagram of a heat pump system according to an embodiment of the invention.

As shown in fig. 4, a heat pump system 200 according to an embodiment of the present invention includes: the above-described method for controlling the refrigerant return flow of the heat pump system is implemented by the memory 210, the processor 220, and a program stored in the memory 210 and executable on the processor 220, when the processor 210 executes the program.

According to the heat pump system provided by the embodiment of the invention, through the refrigerant reflux control method of the heat pump system, the on-off valve can be controlled to heat the target area twice, so that the heat exchange efficiency of the heat pump system can be improved, the energy consumption of the system can be reduced, and the refrigerant reflux can be avoided.

Corresponding to the embodiment, the invention also provides a refrigerant reflux control device of the heat pump system.

Fig. 5 is a block schematic diagram of a refrigerant return control device of a heat pump system according to an embodiment of the invention.

As shown in fig. 5, in the refrigerant return flow control device of the heat pump system according to the embodiment of the present invention, the heat pump system includes a first refrigerant circuit, a second refrigerant circuit, and an on-off valve, and the device 100 may include: a control module 110 and an acquisition module 120.

Wherein, the control module 110 is used for responding to the heating mode instruction and controlling the on-off valve to heat the target area by the first refrigerant loop. The acquisition module 120 is used for acquiring the high-pressure of the first refrigerant circuit. The control module 110 is further configured to control the on-off valve to connect the second refrigerant circuit in series with the first refrigerant circuit to heat the target area through the second refrigerant circuit and the first refrigerant circuit when the high pressure is greater than the first preset pressure threshold.

According to one embodiment of the present invention, the on-off valve includes a first on-off valve, a second on-off valve, and a third on-off valve, the first refrigerant circuit includes a compressor, a first heat exchanger, a first throttling element, and a second heat exchanger, the second refrigerant circuit includes a second throttling element, and a third heat exchanger, an exhaust port of the compressor is connected to a first end of the first heat exchanger, a second end of the first heat exchanger is connected to one end of the first on-off valve and one end of the second on-off valve, another end of the first on-off valve is connected to one end of the first throttling element and one end of the second throttling element, another end of the second throttling element is connected to one end of the second heat exchanger, another end of the second throttling element is connected to another end of the second on-off valve and one end of the third on-off valve, and another end of the second heat exchanger is connected to an intake port of the compressor; the control module 110 controls the on-off valve to connect the second refrigerant loop and the first refrigerant loop in series, so as to heat the target area through the second refrigerant loop and the first refrigerant loop, and is specifically used for controlling the second on-off valve to be in an open state, and the first on-off valve and the third on-off valve to be in a closed state, so that the second refrigerant loop and the first refrigerant loop are connected in series; the second throttling element, the first throttling element and the compressor are controlled to be in an open state so as to heat the target area through the second refrigerant loop and the first refrigerant loop.

According to one embodiment of the present invention, the control module 110 controls the on-off valve to heat the first refrigerant circuit to the target area, specifically, controls the second on-off valve to be in the closed state, the first on-off valve to be in the open state, the third on-off valve to be in the open or closed state, and controls the first throttling element and the compressor to be in the open state to heat the target area through the first refrigerant circuit.

According to one embodiment of the invention, the first refrigerant circuit further comprises a third throttling element, and two ends of the third throttling element are correspondingly connected with the exhaust port and the air suction port of the compressor; the control module 110 is further configured to control the opening of the third throttling element to make the suction superheat degree of the compressor greater than a preset suction superheat degree when the compressor is cold started, and control the first throttling element to be in an open state when the suction superheat degree is greater than the preset suction superheat degree.

According to one embodiment of the present invention, the control module 110 is further configured to control the second on-off valve to be in the closed state, the first on-off valve and the third on-off valve to be in the open state, and the second throttling element and the compressor to be in the open state in response to the cooling mode command, so as to cool the target area.

According to one embodiment of the present invention, the heat pump system further includes a battery heat exchange circuit for exchanging heat with the battery, the battery heat exchange circuit is connected to the first refrigerant circuit, and the control module 110 is further configured to obtain a cooling requirement of the battery when cooling the target area; the first refrigerant circuit is controlled based on the cooling demand of the battery to cool the battery through the battery heat exchange circuit.

According to one embodiment of the invention, the control module 110 controls the first refrigerant circuit based on the cooling requirement of the battery, so that the first refrigerant circuit cools the battery through the battery heat exchange circuit, and is specifically used for controlling the opening degree of the first throttling element based on the cooling requirement of the battery, so that the second heat exchanger exchanges heat with the battery heat exchange circuit, so that the battery is cooled through the battery heat exchange circuit.

It should be noted that, for details not disclosed in the refrigerant return flow control device of the heat pump system in the embodiment of the present invention, please refer to details disclosed in the refrigerant return flow control method of the heat pump system in the embodiment of the present invention, and details are not described here again.

According to the refrigerant reflux control device of the heat pump system, the control module responds to a heating mode instruction, controls the on-off valve to enable the first refrigerant loop to heat the target area, the acquisition module acquires the high-pressure of the first refrigerant loop, and the control module is further used for controlling the on-off valve to enable the second refrigerant loop to be connected in series with the first refrigerant loop when the high-pressure is larger than a first preset pressure threshold value so as to heat the target area through the second refrigerant loop and the first refrigerant loop. Therefore, the device can heat the target area twice by controlling the on-off valve, so that the heat exchange efficiency of the heat pump system can be improved, the energy consumption of the system can be reduced, and the back flow of the refrigerant can be avoided.

Corresponding to the embodiment, the invention also provides a vehicle.

Fig. 6 is a block schematic diagram of a vehicle according to one embodiment of the invention.

As shown in fig. 6, a vehicle 300 of an embodiment of the invention may include the refrigerant return control device 100 of the heat pump system described above.

According to the vehicle provided by the embodiment of the invention, through the refrigerant reflux control device of the heat pump system, the on-off valve can be controlled to heat the target area twice, so that the heat exchange efficiency of the heat pump system can be improved, the energy consumption of the system can be reduced, and the refrigerant reflux can be avoided.

It should be noted that the logic and/or steps represented in the flowcharts or otherwise described herein, for example, may be considered as a ordered listing of executable instructions for implementing logical functions, and may be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. For the purposes of this description, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic device) having one or more wires, a portable computer diskette (magnetic device), a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). In addition, the computer readable medium may even be paper or other suitable medium on which the program is printed, as the program may be electronically captured, via, for instance, optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner, if necessary, and then stored in a computer memory.

It is to be understood that portions of the present invention may be implemented in hardware, software, firmware, or a combination thereof. In the above-described embodiments, the various steps or methods may be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, may be implemented using any one or combination of the following techniques, as is well known in the art: discrete logic circuits having logic gates for implementing logic functions on data signals, application specific integrated circuits having suitable combinational logic gates, programmable Gate Arrays (PGAs), field Programmable Gate Arrays (FPGAs), and the like.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

While embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the invention.

Claims (10)

1. A refrigerant return flow control method of a heat pump system, the heat pump system including a first refrigerant circuit, a second refrigerant circuit, and an on-off valve, the method comprising:

controlling the on-off valve to heat the target area by the first refrigerant loop in response to a heating mode instruction;

acquiring a high pressure of the first refrigerant circuit;

and when the high-pressure is greater than a first preset pressure threshold, controlling the on-off valve to enable the second refrigerant loop to be connected with the first refrigerant loop in series so as to heat the target area through the second refrigerant loop and the first refrigerant loop.

2. The method of claim 1, wherein the on-off valve comprises a first on-off valve, a second on-off valve, and a third on-off valve, the first refrigerant circuit comprises a compressor, a first heat exchanger, a first throttling element, and a second heat exchanger, the second refrigerant circuit comprises a second throttling element, and a third heat exchanger, a discharge port of the compressor is connected to a first end of the first heat exchanger, a second end of the first heat exchanger is connected to one end of the first on-off valve and one end of the second on-off valve, respectively, the other end of the first on-off valve is connected to one end of the first throttling element and one end of the second throttling element, respectively, the other end of the first throttling element is connected to a first end of the second heat exchanger, the other end of the second throttling element is connected to the other end of the second on-off valve and one end of the third on-off valve, respectively, and the other end of the second heat exchanger and the other end of the third on-off valve are connected to the compressor, respectively; wherein,

The controlling the on-off valve to connect the second refrigerant circuit in series with the first refrigerant circuit to heat the target area through the second refrigerant circuit and the first refrigerant circuit includes:

controlling the second on-off valve to be in an open state, and controlling the first on-off valve and the third on-off valve to be in a closed state so as to connect the second refrigerant loop and the first refrigerant loop in series;

the second throttling element, the first throttling element and the compressor are controlled to be in an open state so as to heat the target area through the second refrigerant loop and the first refrigerant loop.

3. The method of claim 2, wherein said controlling the on-off valve to cause the first refrigerant circuit to heat a target area comprises:

the second on-off valve is controlled to be in a closed state, the first on-off valve is controlled to be in an open state, the third on-off valve is controlled to be in an open or closed state, and the first throttling element and the compressor are controlled to be in an open state so as to heat the target area through the first refrigerant loop.

4. A method according to claim 3, wherein the first refrigerant circuit further comprises a third throttling element, both ends of which are connected to the discharge port and the suction port of the compressor, respectively; wherein upon a cold start of the compressor, the method further comprises:

And controlling the opening degree of the third throttling element to enable the suction superheat degree of the compressor to be larger than a preset suction superheat degree, and controlling the first throttling element to be in an opening state when the suction superheat degree is larger than the preset suction superheat degree.

5. The method according to claim 2, wherein the method further comprises:

and responding to a refrigerating mode instruction, controlling the second on-off valve to be in a closed state, controlling the first on-off valve and the third on-off valve to be in an open state, and controlling the second throttling element and the compressor to be in an open state so as to refrigerate the target area.

6. The method of claim 5, wherein the heat pump system further comprises a battery heat exchange circuit for exchanging heat to a battery, the battery heat exchange circuit being connected to the first refrigerant circuit, the method further comprising, while cooling the target area:

acquiring the refrigeration requirement of the battery;

the first refrigerant circuit is controlled based on the cooling requirement of the battery so that the first refrigerant circuit cools the battery through the battery heat exchange circuit.

7. The method of claim 6, wherein controlling the first refrigerant circuit based on the cooling demand of the battery to cause the first refrigerant circuit to cool the battery through the battery heat exchange circuit comprises:

And controlling the opening degree of the first throttling element based on the refrigeration requirement of the battery so as to enable the second heat exchanger to exchange heat with the battery heat exchange loop, so that the battery is refrigerated through the battery heat exchange loop.

8. A heat pump system, comprising: a memory, a processor, and a program stored on the memory and executable on the processor, which when executed, implements the refrigerant return control method of the heat pump system according to any one of claims 1 to 7.

9. A refrigerant return flow control device of a heat pump system, the heat pump system including a first refrigerant circuit, a second refrigerant circuit, and an on-off valve, the device comprising:

the control module is used for responding to a heating mode instruction and controlling the on-off valve to heat the first refrigerant loop to the target area;

an acquisition module for acquiring a high pressure of the first refrigerant circuit;

and the control module is further used for controlling the on-off valve to enable the second refrigerant loop to be connected with the first refrigerant loop in series when the high-pressure is larger than a first preset pressure threshold value so as to heat the target area through the second refrigerant loop and the first refrigerant loop.

10. A vehicle characterized by comprising the refrigerant return control device of the heat pump system according to claim 9.