Low-pressure side air supply enthalpy increasing heat pump system

Abstract

The utility model discloses a low-pressure side air supply enthalpy increasing heat pump system which comprises a refrigerant circulation loop, a cooling water circulation loop and a warm air circulation loop. Fuel oil amp of the cooling water circulation loop and the refrigerant circulation loop; the hot water heat exchanger is communicated through lines; and the warm air circulation loop is communicated with the condenser branch of the refrigerant circulation loop. According to the multi-heat-source dynamic cooperative heating system, multi-heat-source dynamic cooperative heating for the power battery is achieved, and the condenser branch / condenser bypass is dynamically switched through the refrigerant three-way valve so as to be matched with different working conditions; a power battery branch and an evaporator branch are designed in parallel; an independent electronic expansion valve independently controls the refrigerant flow of refrigeration of a power battery / a passenger compartment; and the four-way valve is linked with a condenser bypass so as to preferentially guarantee the heating requirement of the battery.

Description

Technical Field

[0001] This utility model relates to the technical field of heat pump systems for new energy vehicles, specifically, a low-pressure side gas injection enthalpy-increasing heat pump system. Background Technology

[0002] In the thermal management process of new energy vehicles, traditional single-stage compression heat pumps have low compressor exhaust temperature under low temperature (-15℃) and high pressure ratio conditions, making it difficult to meet the heating needs of the vehicle interior and power battery. Single-stage compression also leads to high compressor power consumption and a significant decrease in the coefficient of performance (COP) under low temperature conditions, increasing vehicle energy consumption and shortening the driving range.

[0003] Existing systems cannot effectively utilize low-pressure side energy, lack targeted optimization for low-temperature operating conditions, and are unable to meet the thermal management needs of different scenarios. Utility Model Content

[0004] The purpose of this utility model is to provide a low-pressure side gas injection enthalpy-increasing heat pump system, which improves the heating capacity in a -35℃ environment by injecting refrigerant at the front end of the compressor through low-pressure side gas injection enthalpy-increasing, thereby avoiding the need for compressor structural modification; it realizes dynamic coordination of multiple heat sources to heat the power battery, and dynamically switches the condenser branch / condenser bypass through a refrigerant three-way valve to match different operating conditions.

[0005] The present invention solves the above problems through the following technical solution:

[0006] A low-pressure side gas injection enthalpy-increasing heat pump system includes: a refrigerant circulation loop, a cooling water circulation loop, and a heating air circulation loop;

[0007] The refrigerant circulation loop includes a loop formed by connecting the compressor circuit and the condenser branch, and then connecting them in parallel to the power battery branch and the evaporator branch. The compressor circuit is connected in parallel to a fuel oil and hot water heat exchanger circuit to heat the power battery and / or the evaporator. The condenser branch is connected in parallel to a condenser bypass, and the connection between the fuel oil and hot water heat exchanger circuit and the switching between the condenser branch and the condenser bypass are realized through a refrigerant three-way valve. The condenser bypass and the condenser branch are also connected through a four-way valve.

[0008] The cooling water circulation loop is connected to the fuel oil & hot water heat exchanger circuit of the refrigerant circulation loop;

[0009] The condenser branch of the warm air circulation loop is connected to the refrigerant circulation loop.

[0010] As a further improvement of this utility model, the compressor circuit is formed by sequentially connecting the refrigerant three-way valve II, the gas-liquid separator, the compressor, and the refrigerant three-way valve I.

[0011] As a further improvement of this utility model, the condenser branch is formed by sequentially connecting a water-cooled condenser, a first electronic expansion valve, a condenser, and a first one-way valve; the condenser bypass is formed by a shut-off valve in conjunction with a refrigerant three-way valve I through a pipeline.

[0012] As a further improvement of this utility model, the condenser branch at the rear end of the first electronic expansion valve and the pipeline at the front end of the shut-off valve are connected through a four-way valve, and the condenser branch at the front end of the first electronic expansion valve is connected to the condenser bypass through the four-way valve.

[0013] As a further improvement of this utility model, a third electronic expansion valve is provided at the front end of the power battery in the power battery branch, and a second electronic expansion valve is provided at the front end of the evaporator in the evaporator branch, so as to connect the power battery and / or evaporator in the refrigerant circulation loop through the third electronic expansion valve and the second electronic expansion valve.

[0014] As a further improvement of this utility model, the front end of the fuel oil & hot water heat exchanger circuit is connected to a refrigerant three-way valve II, and a fourth electronic expansion valve is provided at the front end of the fuel oil & hot water heat exchanger to connect and control the fuel oil & hot water heat exchanger circuit through the fourth electronic expansion valve.

[0015] As a further improvement of this utility model, temperature sensors are provided at both the front of the water-cooled condenser and the rear of the evaporator in the condenser branch.

[0016] As a further improvement of this utility model, pressure sensors are provided after the water-cooled condenser and after the condenser in the condenser branch, as well as after the power battery in the power battery branch.

[0017] As a further improvement of this utility model, a one-way valve is provided at the rear end of both the power battery branch and the evaporator branch to prevent backflow.

[0018] A condensation temperature sensor and an indoor temperature sensor are also installed next to the power battery branch and the evaporator branch.

[0019] As a further improvement of this utility model, the cooling water circulation loop is formed by sequentially connecting the fuel oil & hot water heat exchanger, the drive motor system, the radiator, the expansion tank I and the motor water pump, wherein a first water temperature sensor is also provided after the motor water pump.

[0020] And / or the aforementioned warm air circulation loop is formed by sequentially connecting a water-cooled condenser, a warm air core, a warm air water pump, and an expansion tank II, wherein a second water temperature sensor is also installed after the warm air core.

[0021] Compared with the prior art, this utility model has the following advantages and beneficial effects:

[0022] (1) This utility model overcomes the industry problem of low heating efficiency of new energy vehicles in extremely cold environments of -35℃ and difficulty in balancing power battery temperature control and passenger cabin comfort by using low-pressure side gas replenishment enthalpy enhancement and fuel-heat pump dual-source coupling design. At the same time, it uses a four-way valve and multiple electronic expansion valves to achieve optimal dynamic thermal management.

[0023] (2) The present invention designs the power battery branch and the evaporator branch in parallel: a separate electronic expansion valve independently controls the refrigerant flow of the power battery / passenger compartment; a four-way valve is linked to the condenser bypass to prioritize the battery heating needs.

[0024] (3) The key nodes of this utility model are equipped with temperature / pressure sensor groups such as battery branch and condenser outlet to monitor the refrigerant status in real time, prevent overcooling / overheating, and ensure safety and reliability. Attached Figure Description

[0025] Figure 1 This is a circuit diagram of a low-pressure side gas injection enthalpy-increasing heat pump system according to the present invention;

[0026] Figure 2 This is a circuit diagram of the system in the low-temperature battery heating mode of this utility model;

[0027] Figure 3 This is a circuit diagram of the system in the low-temperature battery heating and crew cabin heating mode of this utility model.

[0028] Figure 4 This is a circuit diagram of the system in the power battery cooling mode of this utility model.

[0029] Figure 5 This is a circuit diagram of the system in the simultaneous cooling mode of the power battery and the passenger compartment of this utility model.

[0030] Figure reference numerals: 100, Gas-liquid separator; 101, Compressor; 102, Water-cooled condenser; 103, Condenser; 104, Power battery; 105, Evaporator; 106, Fuel oil & hot water heat exchanger; 107, Refrigerant three-way valve I; 108, Refrigerant three-way valve II; 109, Temperature sensor I; 110, Temperature sensor II; 111, Pressure sensor I; 112, Pressure sensor II; 113, Pressure sensor III; 21, Motor water pump; 22, Expansion tank I; 23 1. Radiator; 24. Water temperature sensor I; 25. Drive motor system; 26. Heater water pump; 27. Water temperature sensor II; 28. Heater core; 29. ​​Expansion tank II; EXV1. First electronic expansion valve; EXV2. Second electronic expansion valve; EXV3. Third electronic expansion valve; EXV4. Fourth electronic expansion valve; CV1. First check valve; SOV1. Shut-off valve; AT1. Condensate temperature sensor; AT2. Indoor temperature sensor; AT3. Outdoor temperature sensor. Detailed Implementation

[0031] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0032] Example:

[0033] Combined with appendix Figure 1-5 As shown, a low-pressure side gas-fuel-injection enthalpy-increasing heat pump system includes: a refrigerant circulation loop, a cooling water circulation loop, and a heating air circulation loop.

[0034] The refrigerant circulation loop is formed by connecting the compressor line and the condenser branch, and then connecting them in parallel to the power battery branch 104 and the evaporator branch 105. The compressor line is connected in parallel to the fuel oil and hot water heat exchanger line, and the condenser branch is connected in parallel to the condenser 103 bypass. The connection of the fuel oil and hot water heat exchanger line and the switching of the condenser branch and the condenser 103 bypass are realized through the refrigerant three-way valve.

[0035] Specifically, the compressor circuit is formed by sequentially connecting the refrigerant three-way valve II 108, the gas-liquid separator 100, the compressor 101, and the refrigerant three-way valve I 107; the condenser branch is formed by sequentially connecting the water-cooled condenser 102, the first electronic expansion valve EXV1, the condenser 103, and the first one-way valve CV1; the condenser 103 bypass is formed by the shut-off valve SOV1 through a pipeline and in cooperation with the refrigerant three-way valve I 107; and the power battery 104 branch has a third electronic expansion valve EXV3 installed at the front end of the power battery 104. The evaporator 105 branch is equipped with a second electronic expansion valve EXV2 at the front end of the evaporator 105, so as to connect the power battery 104 and / or the evaporator 105 in the refrigerant circulation loop through the third electronic expansion valve EXV3 and the second electronic expansion valve EXV2; the fuel oil & hot water heat exchanger line is connected to the refrigerant three-way valve II 108 at the front end, and the fuel oil & hot water heat exchanger 106 is equipped with a fourth electronic expansion valve EXV4 at the front end, so as to connect and control the fuel oil & hot water heat exchanger line through the fourth electronic expansion valve EXV4.

[0036] Preferably, temperature sensors are installed before the water-cooled condenser 102 and after the evaporator 105. Temperature sensor I 109 is installed before the water-cooled condenser 102, and temperature sensor II 110 is installed after the evaporator 105. Pressure sensors are installed after the water-cooled condenser 102, after the condenser 103, and after the power battery 104. These are pressure sensor I 111, pressure sensor II 112, and pressure sensor III 113, respectively. Furthermore, one-way valves are installed at the rear ends of the power battery 104 branch and the evaporator 105 branch to prevent backflow.

[0037] In a further preferred embodiment, a condensing temperature sensor AT1 and an indoor temperature sensor AT2 are also installed next to the power battery branch 104 and the evaporator branch 105; an outdoor temperature sensor AT3 is also installed next to the condenser.

[0038] The cooling water circulation loop is connected to the fuel oil and hot water heat exchanger circuit of the refrigerant circulation loop; the heating air circulation loop is connected to the condenser branch of the refrigerant circulation loop.

[0039] The cooling water circulation loop is formed by sequentially connecting the fuel oil and hot water heat exchanger 106, the drive motor system 25, the radiator 23, the expansion tank I 22, and the motor water pump 21. A water temperature sensor I 24 is also installed after the motor water pump 21.

[0040] The warm air circulation loop is formed by sequentially connecting the water-cooled condenser 102, the warm air core 28, the warm air water pump 26, and the expansion tank II 29. A water temperature sensor II 27 is also installed after the warm air core 28.

[0041] Optionally, a gas replenishment branch is added to the low-pressure side of a low-pressure side gas replenishment enthalpy-increasing heat pump system, connecting the gas-liquid separator 100, the refrigerant three-way valve, and the intermediate chamber of the compressor 101. The gas replenishment branch is equipped with a throttling device such as a capillary tube or a small expansion valve to control the gas replenishment flow rate. The compressor 101, condenser 103, evaporator 105, water-cooled condenser 102, expansion valve, and coolant circulation module including the heater core 28, power battery 104, and water pump are retained, forming a dual-circulation system of refrigerant and coolant. Temperature and pressure sensors are integrated, and the system parameters are monitored in real time by the electronic control unit to regulate the opening degree of the refrigerant three-way valve and expansion valve, as well as the gas replenishment flow rate.

[0042] The specific working principle is as follows:

[0043] ① Low-temperature battery heating mode (-35℃~-10℃) – Fuel PTC supplementary heating:

[0044] Actuator state Actuator state Actuator state fuel heat exchanger Ignition work EXV3 Full open electric motor water pump Adjust according to the water temperature of the drive system Compressor EACP Work, PID regulation EXV2 closure Cooling fan Not working EXV1 closure EXV4 Proportional adjustment and control of subcooling. Condenser fan Not working Refrigerant three-way valve I AC Refrigerant three-way valve II AC SOV1 Open warm air pump If not working, prioritize battery heating.

[0045] At this time, the refrigerant circulation loop circulates counterclockwise as shown in the diagram, the cooling water circulation loop circulates clockwise as shown in the diagram, and the heating air circulation loop circulates counterclockwise as shown in the diagram.

[0046] Connect ports A-C of the second refrigerant three-way valve, adjust the fourth electronic expansion valve EXV4 to connect the fuel oil & hot water heat exchanger circuit and the compressor circuit, igniting the fuel oil heat exchanger 106 and operating the compressor 101; connect ports A-C of the refrigerant three-way valve I 107 to connect the compressor circuit and the condenser bypass; fully open the third electronic expansion valve, and close the first and second electronic expansion valves to connect the power battery branch circuit and the compressor circuit. The cooling fan and condenser 103 fan only operate when the temperature is above 45°C.

[0047] ② Low-temperature battery heating and passenger compartment heating mode (-35℃~-10℃) – fuel PTC supplemental heating:

[0048] Actuator state Actuator state Actuator state fuel heat exchanger Ignition work EXV3 Full open electric motor water pump Adjust according to the water temperature of the drive system compressor Work, PID regulation EXV2 closure Cooling fan Not working EXV1 Full open EXV4 Proportional adjustment of subcooling Condenser fan Not working Refrigerant three-way valve I AC, AB ratio adjustment Refrigerant three-way valve II AC SOV1 Open warm air heat pump Work

[0049] At this time, the refrigerant circulation loop, the cooling water circulation loop, and the heating air circulation loop all circulate counterclockwise as shown in the diagram.

[0050] Connect ports A-C of the second refrigerant three-way valve, adjust the fourth electronic expansion valve EXV4 to connect the fuel oil & hot water heat exchanger circuit and the compressor circuit, ignite the fuel oil heat exchanger 106, and operate the compressor 101; connect ports A-C and A-B of the refrigerant three-way valve I 107 to connect the compressor circuit and the condenser 103 bypass, and connect the condenser branch at the rear of the first electronic expansion valve to the pipeline at the front of the shut-off valve SOV1 through a four-way valve, and connect the condenser branch at the front of the first electronic expansion valve to the condenser bypass through the four-way valve; fully open the third electronic expansion valve, fully open the first electronic expansion valve, and close the second electronic expansion valve to connect the power battery branch and the compressor circuit; achieve heating for the power battery 104 and the passenger compartment.

[0051] ③ Low-temperature battery heating and passenger cabin heating mode – water source heat pump:

[0052] Actuator state Actuator state Actuator state fuel heat exchanger When powered off, the Chiller electric drive system absorbs heat from the water source. EXV3 Full open electric motor water pump Adjust according to the water temperature of the drive system compressor Work, PID regulation EXV2 closure Cooling fan Not working EXV1 Full open EXV4 Proportional adjustment of subcooling Condenser fan Not working Refrigerant three-way valve I AC, AB ratio adjustment Refrigerant three-way valve II AC SOV1 Open warm air pump Work

[0053] The difference between this mode and fuel-fired heat exchanger supplemental heating is that the fuel-fired heat exchanger is shut down, and heat is absorbed from the water source through the chiiller electric drive system.

[0054] ④ Power battery cooling mode:

[0055] Actuator state Actuator state Actuator state fuel heat exchanger Power off EXV3 Proportional Adjustment electric motor water pump Adjust according to the water temperature of the drive system compressor Work, PID regulation EXV2 closure Cooling fan The speed is adjusted according to the heat exchange rate. EXV1 Full open EXV4 closure Condenser fan During operation, the speed is adjusted according to the pressure. Refrigerant three-way valve I AC Refrigerant three-way valve II AB SOV1 closure warm air pump closure

[0056] At this time, the heating air circulation loop is not working, the cooling water circulation loop is working, and the power battery branch 104 is directly connected to the compressor circuit through the second refrigerant three-way valve. Furthermore, the refrigerant three-way valve I107 is connected to the condenser branch located behind the first electronic expansion valve through the pipe at the front end of the shut-off valve SOV1 of the condenser 103 bypass. In cooling mode, the heating air circulation loop is not operating.

[0057] ⑤ Simultaneous cooling mode for both the power battery and the passenger compartment:

[0058] Actuator state Actuator state Actuator state fuel heat exchanger Power off EXV3 Proportional Adjustment electric motor water pump Adjust according to the water temperature of the drive system compressor Work, PID regulation EXV2 Proportional Adjustment Cooling fan The speed is adjusted according to the heat exchange rate. EXV1 Full open EXV4 closure Condenser fan During operation, the speed is adjusted according to the pressure. Refrigerant three-way valve I AC Refrigerant three-way valve II AB SOV1 closure warm air pump closure

[0059] At this point, the difference from the power battery cooling mode is that the condenser branch is also connected to the evaporator branch at the rear end.

[0060] In cooling mode, the heating air circulation loop does not operate.

[0061] Although the present invention has been described herein with reference to illustrative embodiments, the above embodiments are merely preferred embodiments of the present invention, and the implementation of the present invention is not limited to the above embodiments. It should be understood that those skilled in the art can design many other modifications and implementations, which will fall within the scope and spirit of the principles disclosed in this application.

Claims

1. A low-pressure side gas-fuel-injection enthalpy-enhancing heat pump system, characterized in that, include: Refrigerant circulation loop, cooling water circulation loop, and heating air circulation loop; The refrigerant circulation loop includes a loop formed by connecting the compressor circuit and the condenser branch, and then connecting them in parallel to the power battery branch and the evaporator branch. The compressor circuit is connected in parallel to a fuel oil and hot water heat exchanger circuit to heat the power battery and / or the evaporator. The condenser branch is connected in parallel to a condenser bypass, and the connection between the fuel oil and hot water heat exchanger circuit and the switching between the condenser branch and the condenser bypass are realized through a refrigerant three-way valve. The condenser bypass and the condenser branch are also connected through a four-way valve. The cooling water circulation loop is connected to the fuel oil & hot water heat exchanger circuit of the refrigerant circulation loop; The condenser branch of the warm air circulation loop is connected to the refrigerant circulation loop.

2. The low-pressure side gas replenishment enthalpy-increasing heat pump system according to claim 1, characterized in that, The compressor circuit is formed by connecting the refrigerant three-way valve II, the gas-liquid separator, the compressor, and the refrigerant three-way valve I in sequence.

3. The low-pressure side gas replenishment enthalpy-increasing heat pump system according to claim 2, characterized in that, The condenser branch is formed by sequentially connecting a water-cooled condenser, a first electronic expansion valve, a condenser, and a first one-way valve; the condenser bypass is formed by a shut-off valve in conjunction with a refrigerant three-way valve I through a pipeline.

4. The low-pressure side gas replenishment enthalpy-increasing heat pump system according to claim 3, characterized in that, The condenser branch at the rear end of the first electronic expansion valve is connected to the pipeline at the front end of the shut-off valve through a four-way valve, and the condenser branch at the front end of the first electronic expansion valve is connected to the condenser bypass through the four-way valve.

5. The low-pressure side gas replenishment enthalpy-increasing heat pump system according to claim 1, characterized in that, The power battery branch is equipped with a third electronic expansion valve at the front end of the power battery, and the evaporator branch is equipped with a second electronic expansion valve at the front end of the evaporator, so as to connect the power battery and / or evaporator in the refrigerant circulation loop through the third electronic expansion valve and the second electronic expansion valve.

6. The low-pressure side gas replenishment enthalpy-increasing heat pump system according to claim 1, characterized in that, The fuel oil and hot water heat exchanger circuit is connected to a refrigerant three-way valve II at the front end, and a fourth electronic expansion valve is installed at the front end of the fuel oil and hot water heat exchanger to connect and control the fuel oil and hot water heat exchanger circuit.

7. The low-pressure side gas replenishment enthalpy-increasing heat pump system according to claim 1, characterized in that, Temperature sensors are installed before the water-cooled condenser and at the rear of the evaporator in the condenser branch.

8. The low-pressure side gas replenishment enthalpy-increasing heat pump system according to claim 1, characterized in that, Pressure sensors are installed after the water-cooled condenser and after the condenser in the condenser branch, as well as after the power battery in the power battery branch.

9. The low-pressure side gas replenishment enthalpy-increasing heat pump system according to claim 1, characterized in that, Both the power battery branch and the evaporator branch are equipped with one-way valves at their rear ends to prevent backflow. A condensation temperature sensor and an indoor temperature sensor are also installed next to the power battery branch and the evaporator branch.

10. A low-pressure side gas injection enthalpy-increasing heat pump system according to any one of claims 1-9, characterized in that, The cooling water circulation loop is formed by sequentially connecting the fuel oil & hot water heat exchanger, the drive motor system, the radiator, the expansion tank I and the motor water pump. A first water temperature sensor is also installed after the motor water pump. And / or the aforementioned warm air circulation loop is formed by sequentially connecting a water-cooled condenser, a warm air core, a warm air water pump, and an expansion tank II, wherein a second water temperature sensor is also installed after the warm air core.

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