A heat pump air conditioning system and a control method of a heat pump air conditioning system

Abstract

This application discloses a heat pump air conditioning system and a control method for the heat pump air conditioning system. The system includes a refrigerant circuit, a coolant circuit, a fan, and a first heat exchanger connected to the refrigerant circuit and the coolant circuit respectively. The refrigerant circuit includes a compressor, a second heat exchanger, a first throttling valve, an evaporator, a second throttling valve, and a condenser connected in sequence. The first heat exchanger has a first side and a second side opposite to each other. The first side is provided with a heat source inlet and a cold source outlet, and the second side is provided with a heat source outlet and a cold source inlet. The heat source inlet is connected to the outlet of the compressor, and the heat source outlet is connected to the inlet of the second heat exchanger. The coolant circuit includes a water-cooled core. The inlet of the water-cooled core is connected to the cold source outlet, and the outlet of the water-cooled core is connected to the cold source inlet. The fan blows air to the evaporator, the second heat exchanger, and the water-cooled core arranged in sequence at intervals. The refrigerant exchanges heat with the coolant in the first heat exchanger, and the water-cooled core acts as a heat source, so as to equalize the outlet air temperature and reduce costs.

Description

Technical Field

[0001] This application relates to the field of heat pump air conditioning technology, specifically to a heat pump air conditioning system and a control method for the heat pump air conditioning system. Background Technology

[0002] With the further advancement of environmentally friendly refrigerant policies for automotive heat pump air conditioning, heat pump systems using natural CO2 as the refrigerant are expected to become the mainstream technology in the automotive field for a considerable period of time. On the one hand, existing CO2 heat pump systems are limited by their limited system selection capabilities. Using an internal air cooler directly as a heat exchanger before the air outlet results in a large temperature difference between the two sides of the internal air cooler, leading to uneven air temperature reaching the passenger compartment and poor passenger comfort.

[0003] On the other hand, in response to the above problems, existing technologies have added water PTC (thermistor) or air PTC to the heat pump system for post-heating. Although both can achieve the effect of almost leveling the outlet air temperature, the cost of electric heaters is high. If the heat pump system body is made smaller to reduce the overall cost, the COP (coefficient of performance) of the heat pump system will decrease, resulting in a decrease in the overall energy efficiency during the heating process, which creates a negative effect of robbing Peter to pay Paul. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a heat pump air conditioning system and a control method for the heat pump air conditioning system. It eliminates the need for an additional electric heater by adding a first heat exchanger at the compressor outlet of the heat pump system. This provides a heat source for a water-cooled core with a small surface temperature difference added to the rear end of the second heat exchanger, thereby reducing the temperature difference of the hot air outlet and achieving uniform heat distribution in the outlet air. This method is cost-effective.

[0005] To achieve the above objectives, the present invention provides a heat pump air conditioning system, the system comprising a refrigerant circuit, a coolant circuit, a fan, and a first heat exchanger connected to the refrigerant circuit and the coolant circuit respectively; The refrigerant circuit includes a compressor, a second heat exchanger, a first expansion valve, an evaporator, a second expansion valve, and a condenser connected in sequence. The first heat exchanger has a first side and a second side arranged opposite to each other. The first side is provided with a heat source inlet and a cold source outlet, and the second side is provided with a heat source outlet and a cold source inlet. The heat source inlet is connected to the outlet of the compressor, and the heat source outlet is connected to the inlet of the second heat exchanger. The coolant circuit includes a water-cooled core. The inlet of the water-cooled core is connected to the cold source outlet, and the outlet of the water-cooled core is connected to the cold source inlet. The fan is used to blow air onto the evaporator, the second heat exchanger, and the water-cooled core arranged at intervals in sequence, so that the air passes through the water-cooled core and is then sent into the interior of the vehicle compartment. Optionally, the refrigerant circuit further includes a regenerator having a first port and a second port, a third port and a fourth port that are interconnected. The first port is connected to the outlet of the evaporator, the second port is connected to the inlet of the second throttle valve, the third port is connected to the outlet of the condenser, and the fourth port is connected to the inlet of the compressor.

[0006] Optionally, the refrigerant circuit further includes a regenerator, a first shut-off valve, a second shut-off valve, a third shut-off valve, and a fourth shut-off valve. The regenerator has a first port connected to the second port, and a third port connected to the fourth port. The first port is connected to the second throttle valve, the second port is connected to the inlet of the condenser, the third port is connected to the outlet of the condenser, and the fourth port is connected to the inlet of the compressor. The first shut-off valve is connected between the heat source outlet and the second heat exchanger, the second shut-off valve is connected between the heat source outlet and the condenser, the third shut-off valve is connected between the evaporator and the third port, and the fourth shut-off valve is connected between the condenser and the third port.

[0007] Optionally, the system further includes a display unit, and the refrigerant circuit further includes pressure and temperature sensors. The display unit is electrically connected to the pressure and temperature sensors and is used to display the pressure and temperature status fed back by the pressure and temperature sensors.

[0008] Optionally, the system further includes a controller, the coolant circuit further includes a water pump, the controller is electrically connected to the water pump, the outlet of the water heating core is connected to the inlet of the water pump, the outlet of the water pump is connected to the cold source inlet of the first heat exchanger, and the controller is used to control the opening degree of the water pump.

[0009] The present invention also provides a control method for a heat pump air conditioning system, the method comprising: The compressor is controlled to drive the refrigerant in the first state in the refrigerant circuit to flow into the first heat exchanger in the first direction and exchange heat with the coolant in the coolant circuit, thereby reducing the temperature of the refrigerant in the first state; after cooling, the refrigerant in the first state flows sequentially to the second heat exchanger, the first throttle valve, and the evaporator. The coolant is controlled to flow towards the first heat exchanger in a second direction opposite to the first direction, and to exchange heat with the refrigerant in the first state, thereby raising the temperature of the coolant; the heated coolant is then controlled to flow into the water heating core. The fan is controlled to blow air onto the evaporator, the second heat exchanger, and the water heating core.

[0010] Optionally, the refrigerant, after being cooled and in the first state, flows sequentially to the second heat exchanger, the first expansion valve, and the evaporator, including: The refrigerant in the first state flowing out of the second heat exchanger is controlled to flow sequentially to the first throttling valve and the evaporator, so that the state of the refrigerant changes from the first state to the second state. The refrigerant in the second state flowing out of the evaporator is controlled to flow sequentially to the second throttle valve and the condenser before flowing to the compressor, so that the compressor changes the state of the refrigerant from the second state back to the first state. The compressor is controlled to drive the refrigerant in the first state in the refrigerant circuit to flow into the first heat exchanger in the first direction.

[0011] Optionally, the method further includes: In the preset heating mode of the heat pump air conditioning system, the second shut-off valve and the third shut-off valve are controlled to close, and the first shut-off valve, the fourth shut-off valve and the first throttle valve are controlled to open. In the preset cooling mode of the heat pump air conditioning system, the first shut-off valve, the fourth shut-off valve, and the first throttle valve are controlled to close, while the second shut-off valve and the third shut-off valve are controlled to open.

[0012] Optionally, the method further includes: The pressure and temperature sensors are controlled to monitor the pressure and temperature of the refrigerant circuit; When the pressure of the refrigerant circuit deviates from the preset safe pressure threshold range, or when the temperature of the refrigerant circuit deviates from the preset safe temperature threshold range, the pressure status and the temperature status are displayed on the display unit.

[0013] Optionally, the method further includes: In response to the operation of the controller, the opening of the water pump is increased to increase the flow rate of the coolant in the coolant circuit, thereby raising the temperature of the coolant flowing into the water heater core.

[0014] This invention involves installing a first heat exchanger at the compressor outlet of a heat pump system. The refrigerant in the refrigerant circuit exchanges heat with the coolant in the coolant circuit within this first heat exchanger. After heat exchange, the refrigerant flows through a second heat exchanger, while the coolant flows through a water-heating core, with their flow directions opposite. This regulates the temperature of the air blown from the fan to the second heat exchanger before it reaches the water-heating core, resulting in a more uniform outlet air temperature. This ultimately achieves the goal of uniformly heating the air arriving inside the passenger compartment, improving passenger comfort. Compared to adding an electric heater to the heat pump system, this method is lower in cost and more universally applicable. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of a heat pump air conditioning system according to an embodiment of this application. Figure 1 ; Figure 2 This is a schematic diagram of the structure of a heat pump air conditioning system according to an embodiment of this application. Figure 2 ; Figure 3 This is a schematic diagram of the heating mode of a heat pump air conditioning system according to an embodiment of this application. Figure 4 This is a schematic diagram of the cooling mode of a heat pump air conditioning system according to an embodiment of this application; Figure 5 This is a schematic flowchart illustrating a control method for a heat pump air conditioning system according to an embodiment of this application. Detailed Implementation

[0017] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. Based on the description of the present invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present invention.

[0018] The following specific embodiments illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification.

[0019] In the description of this invention, unless otherwise expressly specified and limited, the terms "first," "second," "third," etc., are used merely to distinguish elements with similar properties, and not to indicate or imply relative importance or a specific order.

[0020] Furthermore, the terms “including,” “comprising,” or any other variations thereof are intended to cover non-exclusive inclusion, which includes not only the elements listed but also other elements not expressly listed.

[0021] Please refer to Figure 1 , Figure 1A schematic diagram of a heat pump air conditioning system is shown. The system includes a refrigerant circuit 10, a coolant circuit 20, a fan 30, and a first heat exchanger 40 connected to both the refrigerant circuit 10 and the coolant circuit 20. The coolant circuit 20 contains only coolant, primarily used to exchange heat with the refrigerant to raise its temperature before flowing to the water-heating core 201, making the water-heating core 201 a heat source that dissipates constant heat. The refrigerant circuit 10 contains only coolant and is mainly used for cooling, heating, and dehumidifying the vehicle compartment. Preferably, the first heat exchanger 40 is a water-cooled air-cooled unit. The refrigerant circuit 10 includes a compressor 101, a second heat exchanger 102, a first throttle valve 103, an evaporator 104, a second throttle valve 105, and a condenser 106 connected in sequence. The first heat exchanger 100 has a first side and a second side arranged opposite to each other. The first side has a heat source inlet and a cold source outlet, and the second side has a heat source outlet and a cold source inlet. The heat source inlet is connected to the outlet of the compressor 101, and the heat source outlet is connected to the inlet of the second heat exchanger 102. The coolant circuit 20 includes a water-heated core 201. The inlet of the water-heated core 201 is connected to the cold source outlet, and the outlet of the water-heated core 201 is connected to the cold source inlet. A fan 30 is used to blow air onto the evaporator 104, the second heat exchanger 102, and the water-heated core 201 arranged at intervals in sequence, so that the air is delivered into the interior of the vehicle compartment after passing through the water-heated core 201. Understandably, if only the first heat exchanger 40 is used for vehicle interior heating, the coolant temperature drops significantly after heat exchange with the internal heat exchanger, resulting in low outlet air temperature and poor comfort. If only the internal second heat exchanger 102 is used for vehicle interior heating, although the average outlet air temperature can be increased, the large temperature difference between the inlet and outlet sides of the second heat exchanger 102 leads to a large temperature difference in the outlet air reaching the passenger compartment after the airflow (uneven outlet air temperature on the left and right sides of the passenger compartment). This application addresses this by reversing the inlet and outlet of the heat source and the inlet and outlet of the cold source on opposite sides of the first heat exchanger 40, creating a counter-flow effect between the refrigerant and coolant inside the first heat exchanger 40, thereby achieving the goal of the refrigerant flowing to the second heat exchanger 102 and the coolant flowing to the water heating core 201 flowing in opposite directions. In this embodiment, the second heat exchanger 102 is an air-cooled unit.

[0022] In the illustrated structure, the coolant flowing into the water-heating core 201 flows from right to left, while the refrigerant flowing into the second heat exchanger 102 flows from left to right. The fan 30 blows air onto the evaporator 104, the second heat exchanger 102, and the water-heating core 201, which are arranged at intervals, so that the air blown by the fan 30 passes through the water-heating core 201 and is then delivered into the passenger compartment. By setting up a first heat exchanger 40 for heat exchange between the coolant and refrigerant, the inlet water temperature of the water-heating core 201 reaches approximately the average surface temperature of the second heat exchanger 102 (or the average outlet air temperature of the second heat exchanger 102). This allows for secondary adjustment of the outlet air temperature of the second heat exchanger 102. Air with an initial temperature lower than the inlet water temperature is heated by the water-heating core 201, while air with an initial temperature higher than the inlet water temperature is cooled by the water-heating core 201. After this secondary adjustment, the outlet air temperature in each area tends to approach the inlet water temperature, resulting in a more uniform final outlet air temperature. For example, the high-temperature, high-pressure refrigerant flowing from compressor 101 to the first heat exchanger 40 exchanges heat with the coolant, causing its temperature to drop from 120°C to 100°C. Conversely, the coolant temperature rises to 90°C. Afterward, the 100°C refrigerant flows to the second heat exchanger 102 for secondary heat exchange, and its temperature drops to 60°C after exiting the second heat exchanger 102. The 90°C coolant flows to the water-heating core 201 for secondary heat exchange, and its temperature drops to 80°C after exiting the water-heating core 201. This creates an effect where the left side of the second heat exchanger 102 has a higher temperature than the right side, and the left side of the water-heating core 201 has a lower temperature than the right side. Calculations show that the average surface temperatures of the second heat exchanger 102 and the water-heating core 201 are close to or equal. The average surface temperature of the former is (100+60) / 2=80℃, and the average surface temperature of the latter is (90+80) / 2=85℃. This ensures that when the fan 30 blows air onto the evaporator 104, the second heat exchanger 102, and the water-heating core 201, which are arranged at intervals, the outlet air temperature is balanced internally. This results in uniformly heated air being delivered into the passenger compartment after passing through the water-heating core 201. Since the refrigerant is in a low-temperature two-phase state within the evaporator 104, the temperature difference between the two sides of the evaporator 104 is small and can be ignored.

[0023] Please refer to Figure 2The refrigerant circuit 10 also includes a regenerator 107, which has a first port and a second port, a third port and a fourth port that are interconnected. The first port is connected to the outlet of the evaporator 104, the second port is connected to the inlet of the second throttling valve 105, the third port is connected to the outlet of the condenser 106, and the fourth port is connected to the inlet of the compressor 101. Specifically, in this embodiment, a regenerator 107 is added to the system to reduce heat flow loss. On the low-pressure side, the regenerator 107 increases the temperature of the refrigerant vapor entering the compressor 101 and reduces the refrigerant inlet pressure due to the pressure drop, both of which increase the specific capacity of the refrigerant and thus reduce the mass flow rate. On the high-pressure side, the refrigerant before the valve is cooled by the refrigerant before the suction port of the compressor 101 on the low-pressure side, ensuring sufficient subcooling of the refrigerant before the valve during the throttling process and ensuring the suction superheat of the compressor 101. In the illustrated structure, the first port of the regenerator 107 is the upper left port, which is connected to the outlet of the evaporator 104; the second port is the lower left port, which is connected to the inlet of the second throttle valve 105; the third port is the upper right port, which is connected to the outlet of the condenser 106; and the fourth port is the lower right port, which is connected to the inlet of the compressor 101.

[0024] Please refer to Figure 3 or Figure 4 The refrigerant circuit 10 also includes a regenerator 107, a first shut-off valve 108, a second shut-off valve 109, a third shut-off valve 110, and a fourth shut-off valve 111. The regenerator 107 has a first port connected to the second port, and a third port connected to the fourth port. The first port is connected to the second throttle valve 105, the second port is connected to the inlet of the condenser 106, the third port is connected to the outlet of the condenser 106, and the fourth port is connected to the inlet of the compressor 101. The first shut-off valve 108 is connected between the heat source outlet and the second heat exchanger 102, the second shut-off valve 109 is connected between the heat source outlet and the condenser 106, the third shut-off valve 110 is connected between the evaporator 104 and the third port, and the fourth shut-off valve 111 is connected between the condenser 106 and the third port. Specifically, by setting the first shut-off valve 108, the second shut-off valve 109, the third shut-off valve 110, and the fourth shut-off valve 111, the heat pump air conditioning system has a heating mode and a cooling mode. In the illustrated structure, the first shut-off valve 108 is connected between the heat source outlet of the first heat exchanger 40 and the inlet of the second heat exchanger 102; the second shut-off valve 109 is connected between the heat source outlet of the first heat exchanger 40 and the condenser 106; the third shut-off valve 110 is connected between the evaporator 104 and the third port of the regenerator 107; and the fourth shut-off valve 111 is connected between the condenser 106 and the third port of the regenerator 107. In this embodiment, the function of the regenerator 107 is similar to that described above and will not be repeated here.

[0025] Optionally, the system also includes a display unit (not shown in the figure), and the refrigerant circuit 10 also includes pressure and temperature sensors 50. The display unit (not shown in the figure) is electrically connected to the pressure and temperature sensors 50 to display the pressure and temperature status fed back by the pressure and temperature sensors 50. Specifically, in the illustrated structure, multiple pressure and temperature sensors 50 are provided, for example, two pressure and temperature sensors 50 are respectively set at both ends of the compressor 101, to monitor the pressure and temperature of the refrigerant at both ends of the compressor 101, and display the pressure and temperature values ​​in real time on the display unit (not shown in the figure) to inform the driver whether the vehicle's heat pump system has malfunctioned, and also to provide feedback on the specific location of the malfunction. For example, the display unit (not shown in the figure) can be a central control display screen, instrument panel, HUD, etc. in the vehicle, or a mobile portable terminal such as a mobile phone or tablet computer. The display unit (not shown in the figure) and the pressure and temperature sensors 50 can be connected by electrical signals, communication, or wires, which is not limited here.

[0026] Optionally, the system also includes a controller (not shown in the figure), and the coolant circuit 20 also includes a water pump 202. The controller (not shown in the figure) is electrically connected to the water pump 202. The outlet of the water heating core 201 is connected to the inlet of the water pump 202, and the outlet of the water pump 202 is connected to the cold source inlet of the first heat exchanger 40. The controller (not shown in the figure) is used to control the opening degree of the water pump 202. Specifically, the two ends of the water pump 202 are respectively connected to the outlet of the water heating core 201 and the cold source inlet of the first heat exchanger 40, and the controller (not shown in the figure) is used to control the opening degree of the water pump 202. At this time, the maximum heating capacity of the system depends not only on the opening degree adjustment of the first throttle valve 103, but also strongly coupled to the water flow rate through the water pump 202. Unlike the existing heating systems using water PTC, the water PTC system is completely decoupled from the heat pump system and exists independently, without the aforementioned associated control operation. Furthermore, the optimal water flow rate under various operating conditions can be initially confirmed through one-dimensional simulation calculations. Then, typical operating conditions are selected for real-vehicle calibration. Based on the real-vehicle data, the target water flow rate under all operating conditions is corrected, ultimately achieving the calibration of the optimal water flow rate under each operating condition. For example, the controller (not shown in the figure) can be an in-vehicle infotainment system, a multi-function steering wheel, central control buttons, etc., or a mobile portable terminal such as a mobile phone or tablet. The controller (not shown in the figure) and the water pump 202 can be connected via electrical signals, communication, or wires; no limitation is made here.

[0027] Please refer to Figure 5 , Figure 5 A flowchart illustrating a control method for a heat pump air conditioning system is shown. The method includes: S1. The compressor 101 is controlled to drive the refrigerant in the first state in the refrigerant circuit 10 to flow into the first heat exchanger 40 along the first direction, and exchange heat with the coolant in the coolant circuit 20, thereby reducing the temperature of the refrigerant in the first state; the refrigerant in the first state after cooling is then controlled to flow sequentially to the second heat exchanger 102, the first throttle valve 103, and the evaporator 104. Specifically, in this embodiment, the compressor 101 drives the refrigerant in the first state in the refrigerant circuit 10 to flow into the first heat exchanger 40 along the first direction, and exchange heat with the coolant in the coolant circuit 20 in the first heat exchanger 40, thereby reducing the temperature of the refrigerant in the first state, and then the refrigerant in the first state after cooling is controlled to flow sequentially to the second heat exchanger 102, the first throttle valve 103, and the evaporator 104 for heat exchange.

[0028] S2. Control the coolant to flow towards the first heat exchanger 40 in a second direction opposite to the first direction, and exchange heat with the refrigerant in the first state to raise the temperature of the coolant; control the heated coolant to flow into the water heating core 201. Specifically, in this embodiment, synchronous with step S1, the coolant is driven to flow towards the first heat exchanger 40 in a second direction opposite to the first direction, and exchanges heat with the refrigerant in the refrigerant circuit 10 in the first heat exchanger 40 to raise the temperature of the coolant. Then, the heated coolant flows into the water heating core 201 for heat exchange, so that the nearly uniformly heated water heating core 201 serves as the last heat exchanger flowing into the interior of the vehicle to ensure the uniformity of the outlet air temperature.

[0029] S3. Control the fan 30 to blow air onto the evaporator 104, the second heat exchanger 102, and the water-heating core 201. Specifically, by adding a first heat exchanger 40 at the outlet of the compressor 101 in the heat pump system, not only is a heat source provided for the water-heating core 201, but a water-heating core 201 with a smaller surface temperature difference is also added at the rear end of the direct second heat exchanger 102, which has a high surface temperature difference, thereby reducing the temperature difference of the outlet air and achieving the purpose of uniform heat distribution. Moreover, the heat dissipation area of ​​the refrigerant has increased from one or two in the prior art to three, which greatly improves the heat dissipation efficiency of the low-pressure side of the heat pump system and improves the system energy efficiency.

[0030] Furthermore, the maximum capacity and optimal energy efficiency of a CO2 heat pump system are more dependent on the temperature before the throttling valve compared to conventional refrigerant systems. The lower the temperature before the valve, the greater the enthalpy difference in the heat exchange process on both the high and low pressure sides, and the less likely it is to cause high compressor discharge temperature due to increasing the pressure difference between high and low pressure to improve heat exchange efficiency. This application provides a heat source for the water-cooled core 201 by executing steps S1-S3 without changing the air conditioning unit structure, ensuring the uniformity of the hot air outlet temperature. On the high-pressure side of the system, a first heat exchanger 40 (water-cooled air-cooled) is added to the existing second heat exchanger 102 (air-cooled), resulting in a larger heat dissipation area. This allows for a lower temperature before the valve even at low to medium airflow rates during heating, enabling the heat pump system to operate in a more efficient range. Moreover, since no additional water-based PTC is required, the system cost is lower.

[0031] Optionally, after the refrigerant in the first state after being cooled down as described in step S2 flows sequentially to the second heat exchanger 102, the first throttle valve 103, and the evaporator 104, the process includes: controlling the refrigerant in the first state flowing out of the second heat exchanger 102 to flow sequentially to the first throttle valve 103 and the evaporator 104, so that the state of the refrigerant changes from the first state to the second state; controlling the refrigerant in the second state flowing out of the evaporator 104 to flow sequentially to the second throttle valve 105 and the condenser 106, and then to the compressor 101, so that the compressor 101 changes the state of the refrigerant back from the second state to the first state; and controlling the compressor 101 to drive the refrigerant in the first state in the refrigerant circuit to flow into the first heat exchanger 40 along a first direction. Specifically, in this embodiment, the refrigerant is compressed by the compressor 101 into a high-temperature, high-pressure gaseous state. After liquefying and releasing heat through the second heat exchanger 102, the first throttle valve 103, and the evaporator 104, it becomes a room-temperature, high-pressure liquid. Then, it is depressurized by the second throttle valve 105 and vaporized and absorbed heat through the condenser 106, becoming a low-temperature, low-pressure liquid. The liquid refrigerant returns to the compressor 101 to be pressurized and vaporized into a high-temperature, high-pressure gaseous state, and then circulates in the heat pump system.

[0032] Optionally, the method further includes: in the preset heating mode of the heat pump air conditioning system, controlling the second shut-off valve 109 and the third shut-off valve 110 to close, and controlling the first shut-off valve 108, the fourth shut-off valve 111, and the first throttling valve 103 to open; in the preset cooling mode of the heat pump air conditioning system, controlling the first shut-off valve 108, the fourth shut-off valve 111, and the first throttling valve 103 to close, and controlling the second shut-off valve 109 and the third shut-off valve 110 to open. Specifically, in this embodiment, the heat pump air conditioning system has a heating mode and a cooling mode. In the heating mode, the second shut-off valve 109 and the third shut-off valve 110 are closed, and the first shut-off valve 108, the fourth shut-off valve 111, and the first throttling valve 103 are open, and the refrigerant flows as follows: Figure 3 As shown. In cooling mode, the first shut-off valve 108, the fourth shut-off valve 111, and the first throttle valve 103 are closed, while the second shut-off valve 109 and the third shut-off valve 110 are open, and the refrigerant flows as follows. Figure 4 As shown.

[0033] Optionally, the method further includes: controlling the pressure and temperature sensors 50 to monitor the pressure and temperature of the refrigerant circuit 10; when the pressure of the refrigerant circuit 10 deviates from a preset safe pressure threshold range, or when the temperature of the refrigerant circuit 10 deviates from a preset safe temperature threshold range, displaying the pressure and temperature status on the display unit. Specifically, multiple pressure and temperature sensors 50 are distributed throughout the system, for example, two pressure and temperature sensors 50 are respectively installed at both ends of the compressor 101 to monitor the pressure and temperature of the refrigerant at both ends of the compressor 101, and display the pressure and temperature values ​​on the display unit in real time. In this embodiment, when the pressure of the refrigerant circuit 10 deviates from the preset safe pressure threshold range, or when the temperature of the refrigerant circuit 10 deviates from the preset safe temperature threshold range, it means that the pressure or temperature of the refrigerant is too high or too low, and immediate cooling and heating are required respectively. At this time, the display unit will display the pressure and temperature status fed back by the pressure and temperature sensors 50 to prompt the driver or passengers to take appropriate measures.

[0034] Optionally, the method further includes: in response to the operation of the controller, increasing the opening of the water pump 202 to increase the flow rate of the coolant in the coolant circuit 20, thereby raising the temperature of the coolant flowing into the water heater core 201. Specifically, in this embodiment, the driver or passenger can adjust the opening of the water pump 202 through the controller. When the opening of the water pump 202 is increased, the flow rate of the coolant flowing into the first heat exchanger 40 increases, thereby removing more heat from the refrigerant during the heat exchange process with the refrigerant. The temperature of the coolant flowing into the water heater core 201 increases, and the temperature difference between the temperature of the coolant flowing into the water heater core 201 and its average intake air temperature increases, thereby increasing the outlet air temperature entering the vehicle compartment.

[0035] This invention provides a first heat exchanger 40 at the outlet of the compressor 101 in a heat pump system. This allows the refrigerant in the refrigerant circuit 10 to exchange heat with the coolant in the coolant circuit 20 within the first heat exchanger 40. After the heat exchange, the refrigerant flows through a second heat exchanger 102, and the coolant flows through a water-heating core 201, with the two flowing in opposite directions. This regulates the temperature of the air blown from the fan 30 to the second heat exchanger 102 and then reaches the water-heating core 201, thus homogenizing the air temperature and achieving uniform heating of the hot air that finally reaches the interior of the vehicle, thereby improving passenger comfort.

[0036] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this invention should be included within the scope of protection of this invention. Therefore, the scope of protection of this invention should be determined by the appended claims.

Claims

1. A heat pump air conditioning system, characterized in that, The system includes a refrigerant circuit, a coolant circuit, a fan, and a first heat exchanger that is connected to the refrigerant circuit and the coolant circuit respectively. The refrigerant circuit includes a compressor, a second heat exchanger, a first throttle valve, an evaporator, a second throttle valve, and a condenser connected in sequence. The first heat exchanger has a first side and a second side arranged opposite to each other. The first side is provided with a heat source inlet and a cold source outlet, and the second side is provided with a heat source outlet and a cold source inlet. The heat source inlet is connected to the outlet of the compressor, and the heat source outlet is connected to the inlet of the second heat exchanger. The coolant circuit includes a water-cooled core. The inlet of the water-cooled core is connected to the cold source outlet, and the outlet of the water-cooled core is connected to the cold source inlet. The fan is used to blow air onto the evaporator, the second heat exchanger, and the water-cooled core arranged at intervals in sequence, so that the air is delivered into the interior of the vehicle after passing through the water-cooled core. In this process, the refrigerant flowing to the second heat exchanger and the coolant flowing to the water heating core are in opposite directions.

2. The system according to claim 1, characterized in that, The refrigerant circuit also includes a regenerator, which has a first port and a second port, a third port and a fourth port that are interconnected. The first port is connected to the outlet of the evaporator, the second port is connected to the inlet of the second throttle valve, the third port is connected to the outlet of the condenser, and the fourth port is connected to the inlet of the compressor.

3. The system according to claim 1, characterized in that, The refrigerant circuit further includes a regenerator, a first shut-off valve, a second shut-off valve, a third shut-off valve, and a fourth shut-off valve. The regenerator has a first port and a second port, and a third port and a fourth port that are interconnected. The first port is connected to the second throttle valve, the second port is connected to the inlet of the condenser, the third port is connected to the outlet of the condenser, and the fourth port is connected to the inlet of the compressor. The first shut-off valve is connected between the heat source outlet and the second heat exchanger, the second shut-off valve is connected between the heat source outlet and the condenser, the third shut-off valve is connected between the evaporator and the third port, and the fourth shut-off valve is connected between the condenser and the third port.

4. The system according to claim 1, characterized in that, The system also includes a display unit, and the refrigerant circuit also includes pressure and temperature sensors. The display unit is electrically connected to the pressure and temperature sensors and is used to display the pressure and temperature status fed back by the pressure and temperature sensors.

5. The system according to claim 1, characterized in that, The system also includes a controller, and the coolant circuit also includes a water pump. The controller is electrically connected to the water pump, the outlet of the water heating core is connected to the inlet of the water pump, and the outlet of the water pump is connected to the cold source inlet of the first heat exchanger. The controller is used to control the opening degree of the water pump.

6. A control method for a heat pump air conditioning system, applied to the heat pump air conditioning system as described in any one of claims 1-5, characterized in that, The method includes: The compressor is controlled to drive the refrigerant in the first state in the refrigerant circuit to flow into the first heat exchanger in the first direction and exchange heat with the coolant in the coolant circuit, thereby reducing the temperature of the refrigerant in the first state; after cooling, the refrigerant in the first state flows sequentially to the second heat exchanger, the first throttle valve, and the evaporator. The coolant is controlled to flow towards the first heat exchanger in a second direction opposite to the first direction, and to exchange heat with the refrigerant in the first state, thereby raising the temperature of the coolant; the heated coolant is then controlled to flow into the water heating core. The fan is controlled to blow air onto the evaporator, the second heat exchanger, and the water heating core.

7. The method according to claim 6, characterized in that, The refrigerant, after being cooled and placed in the first state, flows sequentially to the second heat exchanger, the first expansion valve, and the evaporator, including: The refrigerant in the first state flowing out of the second heat exchanger is controlled to flow sequentially to the first throttling valve and the evaporator, so that the state of the refrigerant changes from the first state to the second state. The refrigerant in the second state flowing out of the evaporator is controlled to flow sequentially to the second throttle valve and the condenser before flowing to the compressor, so that the compressor changes the state of the refrigerant from the second state back to the first state. The compressor is controlled to drive the refrigerant in the first state in the refrigerant circuit to flow into the first heat exchanger in the first direction.

8. The method according to claim 6, characterized in that, The refrigerant circuit further includes a regenerator, a first shut-off valve, a second shut-off valve, a third shut-off valve, and a fourth shut-off valve. The regenerator has a first port and a second port, and a third port and a fourth port that are interconnected. The first port is connected to the second throttle valve, the second port is connected to the inlet of the condenser, the third port is connected to the outlet of the condenser, and the fourth port is connected to the inlet of the compressor. The first shut-off valve is connected between the heat source outlet and the second heat exchanger, the second shut-off valve is connected between the heat source outlet and the condenser, the third shut-off valve is connected between the evaporator and the third port, and the fourth shut-off valve is connected between the condenser and the third port. The method further includes: in the preset heating mode of the heat pump air conditioning system, controlling the second shut-off valve and the third shut-off valve to close, and controlling the first shut-off valve, the fourth shut-off valve and the first throttle valve to open; In the preset cooling mode of the heat pump air conditioning system, the first shut-off valve, the fourth shut-off valve, and the first throttle valve are controlled to close, while the second shut-off valve and the third shut-off valve are controlled to open.

9. The method according to claim 6, characterized in that, The system also includes a display unit, and the refrigerant circuit also includes pressure and temperature sensors. The display unit is electrically connected to the pressure and temperature sensors and is used to display the pressure and temperature status fed back by the pressure and temperature sensors. The method further includes: controlling the pressure and temperature sensors to monitor the pressure and temperature of the refrigerant circuit; When the pressure of the refrigerant circuit deviates from the preset safe pressure threshold range, or when the temperature of the refrigerant circuit deviates from the preset safe temperature threshold range, the pressure status and the temperature status are displayed on the display unit.

10. The method according to claim 6, characterized in that, The system also includes a controller, and the coolant circuit also includes a water pump. The controller is electrically connected to the water pump, the outlet of the water heating core is connected to the inlet of the water pump, the outlet of the water pump is connected to the cold source inlet of the first heat exchanger, and the controller is used to control the opening degree of the water pump. The method further includes: in response to the operation of the controller, increasing the opening of the water pump to increase the flow rate of the coolant in the coolant circuit, thereby increasing the temperature of the coolant flowing into the water heater core.

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