Low-temperature heat pump heat management system and new energy vehicle

Abstract

The utility model discloses a low-temperature heat pump heat management system and a new energy vehicle, and the system comprises a first air conditioner heating loop, a second air conditioner heating loop and a third air conditioner heating loop, an exhaust port of a low-temperature heat pump compressor, a four-way valve, an indoor heat exchanger, an intermediate compensator, an air supply enthalpy increasing branch and an air supply port of the low-temperature heat pump compressor are sequentially connected to form a first air conditioner heating loop, and the first air conditioner heating loop is used for realizing air supply of a medium-pressure cavity of the compressor; an exhaust port of the low-temperature heat pump compressor, the four-way valve, the indoor heat exchanger, the intermediate compensator, the main electronic expansion valve, the outdoor heat exchanger, the four-way valve and an air suction port of the low-temperature heat pump compressor are sequentially connected to form a second air conditioner heating loop, and the second air conditioner heating loop is used for heating a compartment; an exhaust port of the low-temperature heat pump compressor, the four-way valve, the indoor heat exchanger, the intermediate compensator, a second one-way valve, a battery cooling branch and an air suction port of the low-temperature heat pump compressor are sequentially connected to form the third air conditioner heating loop, and the third air conditioner heating loop is used for achieving battery refrigeration and cooling during air conditioner heating.

Description

Technical Field

[0001] The utility model relates to the technical field of air-conditioning thermal management, and in particular to a low-temperature heat pump thermal management system and a new energy vehicle. Background Art

[0002] In low temperature environments, the battery capacity of new energy vehicles decays significantly, resulting in a significant decrease in the driving range and power performance of new energy vehicles. Secondly, the vehicle startup time is extended. At -30℃, the vehicle cannot start normally without external heating. Finally, it is difficult to charge the battery in low temperature environments. The traditional method of preheating before charging has the disadvantages of high energy consumption, long charging time, high cost, and complex structure, which also affects the service life of the power battery. The market needs a low-temperature thermal management solution to give full play to the effect of the battery.

[0003] At present, the thermal management technology of new energy vehicles is also facing the challenge of growing and diversifying demand. In order to achieve efficient, reliable and intelligent thermal management, it is necessary to strengthen the development of system integration and intelligent control technology.

[0004] At present, air conditioning thermal management products mainly rely on PTC heaters to provide heat source for cabin heating when the temperature is below -3℃. PTC liquid heaters provide heat source for battery heating. The thermal efficiency of PTC heat source is not higher than 1. Taking an 8-meter car as an example, cabin heating consumes about 6kw of electricity, which seriously affects the vehicle's range. Utility Model Content

[0005] In view of the above technical problems, the technical solution of the utility model provides a low-temperature heat pump thermal management system, which includes: a first air-conditioning heating circuit, a second air-conditioning heating circuit and a third air-conditioning heating circuit, wherein the exhaust port of the low-temperature heat pump compressor, the 4-way valve, the indoor heat exchanger, the intermediate compensator, the air-injection enthalpy-increasing branch and the air-injection port of the low-temperature heat pump compressor are connected in sequence to form the first air-conditioning heating circuit, and the first air-conditioning heating circuit is used to realize air replenishment in the compressor medium-pressure chamber; the exhaust port of the low-temperature heat pump compressor, the 4-way valve, the indoor heat exchanger, the intermediate compensator, the main electronic expansion valve, the outdoor heat exchanger, the 4-way valve and the air intake port of the low-temperature heat pump compressor are connected in sequence to form the second air-conditioning heating circuit, and the second air-conditioning heating circuit is used to realize cabin heating; the exhaust port of the low-temperature heat pump compressor, the 4-way valve, the indoor heat exchanger, the intermediate compensator, the second one-way valve, the battery cooling branch and the air intake port of the low-temperature heat pump compressor are connected in sequence to form the third air-conditioning heating circuit, and the third air-conditioning heating circuit is used to realize battery cooling and cooling during air-conditioning heating.

[0006] Furthermore, the intermediate compensator includes a first inlet, a first outlet, a second inlet and a second outlet, the first outlet is connected to the first inlet, and the second outlet is connected to the second inlet, wherein the first inlet is connected to the indoor heat exchanger, the first outlet is connected to the main electronic expansion valve, the first outlet is also connected to the second one-way valve, and the second outlet is connected to the air supply port of the low-temperature heat pump compressor; and the second inlet is connected to the first outlet through the air supply branch electronic expansion valve, thereby forming the air supply and enthalpy increase branch.

[0007] Furthermore, the system also includes a first air-conditioning refrigeration circuit and a second air-conditioning refrigeration circuit, wherein the low-temperature heat pump compressor exhaust port, the 4-way valve, the outdoor heat exchanger, the main electronic expansion valve, the intermediate compensator, the indoor heat exchanger, the 4-way valve and the low-temperature heat pump compressor intake port are connected in sequence to form the first air-conditioning refrigeration circuit, and the first air-conditioning refrigeration circuit is used to cool the vehicle compartment; the low-temperature heat pump compressor exhaust port, the 4-way valve, the outdoor heat exchanger, the first one-way valve, the battery cooling branch and the low-temperature heat pump compressor intake port are connected in sequence to form the second air-conditioning refrigeration circuit, and the second air-conditioning refrigeration circuit is used to cool the battery during air-conditioning refrigeration.

[0008] Furthermore, the battery cooling branch includes a battery cooling electronic expansion valve and a battery plate heat exchanger connected in sequence, and the battery plate heat exchanger is used to cool down the antifreeze fluid flowing through it.

[0009] Furthermore, a sight glass is provided between the outdoor heat exchanger and the main electronic expansion valve.

[0010] Furthermore, a bidirectional drying filter is provided between the indoor heat exchanger and the intermediate compensator.

[0011] Furthermore, a high-pressure pressure sensor is provided near one end of the exhaust port of the low-temperature heat pump compressor, and a low-pressure pressure sensor is provided near one end of the suction port of the low-temperature heat pump compressor.

[0012] Furthermore, an ambient temperature probe is provided between the outdoor heat exchanger and the sight glass, a return air temperature probe is provided near the air outlet of the battery plate heat exchanger, and a return air temperature sensor is provided near one end of the air intake of the low-temperature heat pump compressor.

[0013] Furthermore, the compressor refrigerant adopts R410A.

[0014] The technical solution of the utility model also provides a new energy vehicle, which includes the low-temperature heat pump thermal management system as described above.

[0015] The low-temperature heat pump management technology provided by the technical solution of the utility model has the following beneficial technical effects:

[0016] (1) The operating range of the air conditioning heat pump extends from -3°C to -25°C. Even at -25°C, the energy efficiency can be greater than 1, providing an efficient heat source for heating the vehicle and the battery.

[0017] (2) By optimizing the refrigeration system circulation loop, the battery thermal management branch can also be cooled in the heat pump state to meet the need for battery cooling under low temperature conditions (even below 0°C), when the battery is charging or even discharging;

[0018] (3) By optimizing the refrigeration cycle, adding intermediate heat exchangers, and increasing medium-pressure return air, the energy efficiency of the air-conditioning system can be improved through this air replenishment and enthalpy increase technology, especially extending the working range and energy efficiency of the low-temperature heat pump, greatly reducing the energy required to heat up low-temperature vehicles and increasing the vehicle's cruising range. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 It is a cycle diagram of the thermal management system of the air-conditioning unit of the utility model in the heating working state;

[0021] Figure 2 It is a partial structural diagram of the first heating circuit of the air conditioner of the utility model;

[0022] Figure 3 It is a partial structural diagram of the third circuit of the air conditioner heating system of the utility model;

[0023] Figure 4 It is a cycle diagram of the thermal management system of the air-conditioning unit of the utility model in the refrigeration working state;

[0024] Figure 5 It is a partial structural diagram of the first refrigeration circuit of the air conditioner of the utility model;

[0025] Figure 6 It is a partial structural diagram of the air-conditioning refrigeration second circuit of the utility model;

[0026] Figure 7 It is a schematic diagram of the air-supplying and enthalpy-increasing branch of the air-conditioning unit of the utility model in the refrigeration working state.

[0027] Among them, 1- compressor, 2- 4-way valve, 3- outdoor heat exchanger, 4- main electronic expansion valve, 5- intermediate compensator, 6- indoor heat exchanger, 7- first one-way valve, 8- second one-way valve, 9- air supply branch electronic expansion valve, 10- battery cooling electronic expansion valve, 11- battery plate heat exchanger, 12- sight glass, 13- two-way drying filter, 14- high pressure sensor, 15- low pressure sensor, 16- ambient temperature probe, 17- return air temperature probe, 18- return air temperature sensor, 19- valve core, 20- safety valve, 21- gas-liquid separator, 22- water outlet temperature sensor, 23- expansion water tank, 24- battery pack, 25- water pump. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0029] The low-temperature heat pump thermal management system of the utility model is mainly composed of a compressor, a condenser, a drying filter, an expansion valve, a compensator, an evaporator, a battery cooling branch check valve, a battery cooling branch expansion valve, a battery branch plate heat exchanger, a fan for enhancing heat exchange, etc.

[0030] like Figure 1 As shown, when the air-conditioning unit heat pump is in working state, the unit operates according to the heating function. The high-pressure refrigerant first enters the indoor heat exchanger 6. Heat exchange is carried out in the indoor heat exchanger 6, and the high-temperature and high-pressure refrigerant undergoes a phase change after condensation, and the gaseous state condenses into a high-temperature and high-pressure liquid state. The indoor air absorbs heat and heats up through heat exchange in the heat exchanger, and the temperature of the car compartment is increased, achieving the purpose of heating the car compartment. After condensation, the high-temperature and high-pressure liquid refrigerant passes through the two-way drying filter 13 and enters the intermediate compensator 5, and then is divided into three branches, which respectively realize the functions of medium-pressure chamber air replenishment, main circuit car heating, and battery thermal management cooling antifreeze.

[0031] like Figure 2 As shown, in the first branch, a part of the refrigerant passes through the intermediate compensator (also a heat exchanger) 5 to form an air replenishment and enthalpy increase branch. The throttled gaseous refrigerant returns to the medium-pressure chamber of the compressor 1 through the compensator 5, increasing the mass flow of the return air, providing the total mass flow of the system, and improving the heating capacity of the entire system; at this time, the electronic expansion valve 9 of this branch is opened and the opening is automatically adjusted according to demand. The refrigerant vaporized in the compensator returns to the low-pressure pipeline of the compressor 1. For details, see Figure 2The high-temperature and high-pressure liquid refrigerant enters the compensator 5 from the first inlet A, and after being cooled, it has a certain degree of subcooling; it passes through the first outlet B to the throttling expansion valve 9. Through the throttling expansion valve 9, the liquid refrigerant is throttled and reduced in pressure from a relatively high-temperature and high-pressure liquid to a low-temperature and low-pressure liquid (a small amount of gas), and then passes through the second inlet C to the compensator 5 for heat exchange and phase change to a gaseous refrigerant, and then returns to the compressor from the second outlet D.

[0032] like Figure 1 As shown, in the second branch, the high-temperature and high-pressure liquid refrigerant flows through the main electronic expansion valve 4, and after throttling and reducing the pressure, it passes through the two-way drying filter 13, flows through the outdoor heat exchanger 3, absorbs external energy, and the liquid refrigerant evaporates into gaseous refrigerant and returns to the compressor 1.

[0033] like Figure 3 As shown, in the third branch, it is used for battery thermal management and battery cooling. In this branch, when the heat pump is in operation, the high-temperature and high-pressure liquid refrigerant passes through the second one-way valve 8, is heat-exchanged and vaporized into gas by the battery plate heat exchanger 11, and then returns to the compressor 1. The antifreeze with a higher temperature flows through the plate heat exchanger 11, and the antifreeze cools down after heat exchange.

[0034] When the heat pump is running, after the three return air lines are combined, the gaseous refrigerant returns to the compressor, and after passing through the compressor, it becomes a high-temperature and high-pressure gas and enters the next cycle. This cycle repeats itself.

[0035] The difference between the above scheme of the utility model and the common thermal management system is that the currently commonly used heat pump technology does not have an air replenishment and enthalpy increase circuit; there is no low-temperature heat pump state, and the battery heat pipe can also be a cooling circuit. The thermal management system can realize the dual functions of main circuit heating and auxiliary circuit cooling.

[0036] like Figure 4 As shown, the 4-way valve is switched to the refrigeration working state of the air conditioning unit. After being discharged from the compressor 1, the high-temperature and high-pressure refrigerant gas passes through the 4-way valve 2, flows through the outdoor heat exchanger 3, and the sight glass 12 to be divided into two branches.

[0037] like Figure 5 As shown, in the first branch, the high-temperature and high-pressure liquid refrigerant passes through the main electronic expansion valve 4, throttling and reducing the pressure, and becomes a low-temperature and low-pressure liquid refrigerant, passes through the compensator 5, and then reaches the indoor heat exchanger 6. The refrigerant in this loop flows through the indoor heat exchanger 6 (evaporator), exchanges heat with the indoor air, and the liquid refrigerant evaporates and absorbs heat to undergo a phase change, gasifying into a gaseous state, and the gaseous refrigerant returns to the compressor 1. At the same time, the indoor hot air is cooled after heat exchange.

[0038] like Figure 6As shown, in the second branch, the liquid refrigerant passes through the first one-way valve 7 and reaches the battery cooling branch electronic expansion valve 10. The high-temperature and high-pressure liquid refrigerant becomes low-temperature and low-pressure liquid refrigerant after throttling and pressure reduction, and then flows through the battery plate heat exchanger 11. In the plate heat exchanger 11, the low-temperature and low-pressure refrigerant absorbs heat and vaporizes into gas, and then returns to the compressor. The antifreeze with a higher temperature flows through the plate heat exchanger, and the antifreeze cools down after heat exchange;

[0039] like Figure 7 As shown, in the cooling working mode, the electronic expansion valve 9 of the compensator branch is closed. No refrigerant passes through this branch.

[0040] In an embodiment of the utility model, a low-temperature heat pump thermal management system is provided, which includes: a first air-conditioning heating circuit, a second air-conditioning heating circuit and a third air-conditioning heating circuit, wherein the exhaust port of the low-temperature heat pump compressor, the 4-way valve, the indoor heat exchanger, the intermediate compensator, the air-injection enthalpy-increasing branch and the air-injection port of the low-temperature heat pump compressor are connected in sequence to form the first air-conditioning heating circuit, and the first air-conditioning heating circuit is used to realize air replenishment in the compressor medium-pressure chamber; the exhaust port of the low-temperature heat pump compressor, the 4-way valve, the indoor heat exchanger, the intermediate compensator, the main electronic expansion valve, the outdoor heat exchanger, the 4-way valve and the air intake port of the low-temperature heat pump compressor are connected in sequence to form the second air-conditioning heating circuit, and the second air-conditioning heating circuit is used to realize cabin temperature increase; the exhaust port of the low-temperature heat pump compressor, the 4-way valve, the indoor heat exchanger, the intermediate compensator, the second one-way valve, the battery cooling branch and the air intake port of the low-temperature heat pump compressor are connected in sequence to form the third air-conditioning heating circuit, and the third air-conditioning heating circuit is used to realize battery cooling and cooling during air-conditioning heating.

[0041] Furthermore, the intermediate compensator includes a first inlet, a first outlet, a second inlet and a second outlet, the first outlet is connected to the first inlet, and the second outlet is connected to the second inlet, wherein the first inlet is connected to the indoor heat exchanger, the first outlet is connected to the main electronic expansion valve, the first outlet is also connected to the second one-way valve, and the second outlet is connected to the air supply port of the low-temperature heat pump compressor; and the second inlet is connected to the first outlet through the air supply branch electronic expansion valve, thereby forming the air supply and enthalpy increase branch.

[0042] Furthermore, the system also includes a first air-conditioning refrigeration circuit and a second air-conditioning refrigeration circuit, wherein the low-temperature heat pump compressor exhaust port, the 4-way valve, the outdoor heat exchanger, the main electronic expansion valve, the intermediate compensator, the indoor heat exchanger, the 4-way valve and the low-temperature heat pump compressor intake port are connected in sequence to form the first air-conditioning refrigeration circuit, and the first air-conditioning refrigeration circuit is used to cool the vehicle compartment; the low-temperature heat pump compressor exhaust port, the 4-way valve, the outdoor heat exchanger, the first one-way valve, the battery cooling branch and the low-temperature heat pump compressor intake port are connected in sequence to form the second air-conditioning refrigeration circuit, and the second air-conditioning refrigeration circuit is used to cool the battery during air-conditioning refrigeration.

[0043] Furthermore, the battery cooling branch includes a battery cooling electronic expansion valve and a battery plate heat exchanger connected in sequence, and the battery plate heat exchanger is used to cool down the antifreeze fluid flowing through it.

[0044] Furthermore, a sight glass is provided between the outdoor heat exchanger and the main electronic expansion valve.

[0045] Furthermore, a bidirectional drying filter is provided between the indoor heat exchanger and the intermediate compensator.

[0046] Furthermore, a high-pressure pressure sensor is provided near one end of the exhaust port of the low-temperature heat pump compressor, and a low-pressure pressure sensor is provided near one end of the suction port of the low-temperature heat pump compressor.

[0047] Furthermore, an ambient temperature probe is provided between the outdoor heat exchanger and the sight glass, a return air temperature probe is provided near the air outlet of the battery plate heat exchanger, and a return air temperature sensor is provided near one end of the air intake of the low-temperature heat pump compressor.

[0048] Furthermore, the compressor refrigerant adopts R410A.

[0049] In another embodiment of the present invention, a new energy vehicle is provided, which includes the low-temperature heat pump thermal management system as described above.

[0050] Beneficial technical effects of the technical solution of the utility model:

[0051] (1) Add an air replenishment and enthalpy increase branch to the medium-pressure chamber of the ultra-low temperature compressor to improve the energy efficiency of heating in a low-temperature environment and extend the ambient operating temperature from -3°C to -25°C.

[0052] Usually, the operating temperature of heat pump air conditioner is -3℃. At this time, the comprehensive energy efficiency ratio of heat pump is greater than 1, which is higher than that of PTC electric heating.

[0053] If R410A refrigerant is used, the operating temperature range of the heat pump air conditioner will extend to -15°C. However, this technology uses R410A refrigerant and adds an air supply and enthalpy increase branch, and the operating temperature range will extend to -25°C.

[0054] (2) Add a double one-way valve (first one-way valve 7 and second one-way valve 8) circuit. This special circuit forms a thermal management system that can realize cooling and cooling functions when the cabin is running in summer and heating in winter.

[0055] The above embodiments are only for illustrating the technical concept and features of the utility model, and their purpose is to enable ordinary technicians in the field to understand the content of the utility model and implement it. They cannot be used to limit the protection scope of the utility model. All equivalent changes or modifications made according to the spirit of the utility model should be included in the protection scope of the utility model.

Claims

1. A low temperature heat pump thermal management system, characterized in that: include: The first air conditioning heating circuit, the second air conditioning heating circuit and the third air conditioning heating circuit, wherein: The low-temperature heat pump compressor exhaust port, the 4-way valve, the indoor heat exchanger, the intermediate compensator, the air replenishment enthalpy increase branch and the low-temperature heat pump compressor air replenishment port are sequentially connected to form a first air conditioning heating circuit, and the first air conditioning heating circuit is used to realize air replenishment in the compressor medium-pressure chamber; The low-temperature heat pump compressor exhaust port, the 4-way valve, the indoor heat exchanger, the intermediate compensator, the main electronic expansion valve, the outdoor heat exchanger, the 4-way valve and the low-temperature heat pump compressor intake port are sequentially connected to form a second air conditioning heating circuit, and the second air conditioning heating circuit is used to achieve cabin temperature increase; The exhaust port of the low-temperature heat pump compressor, the 4-way valve, the indoor heat exchanger, the intermediate compensator, the second one-way valve, the battery cooling branch and the intake port of the low-temperature heat pump compressor are connected in sequence to form the third air-conditioning heating circuit, and the third air-conditioning heating circuit is used to realize battery cooling and cooling during air-conditioning heating.

2. The system according to claim 1, characterized in that The intermediate compensator comprises a first inlet, a first outlet, a second inlet and a second outlet, the first outlet is connected to the first inlet, and the second outlet is connected to the second inlet, wherein: The first inlet is connected to the indoor heat exchanger, the first outlet is connected to the main electronic expansion valve, the first outlet is also connected to the second one-way valve, and the second outlet is connected to the low-temperature heat pump compressor air supply port; and The second inlet is connected to the first outlet through the air-compensating branch electronic expansion valve, thereby forming the air-compensating enthalpy-increasing branch.

3. The system according to claim 2, characterized in that The system also includes an air conditioning refrigeration first circuit and an air conditioning refrigeration second circuit, wherein: The low-temperature heat pump compressor exhaust port, the 4-way valve, the outdoor heat exchanger, the main electronic expansion valve, the intermediate compensator, the indoor heat exchanger, the 4-way valve and the low-temperature heat pump compressor intake port are sequentially connected to form the air conditioning and refrigeration first circuit, and the air conditioning and refrigeration first circuit is used to achieve cabin cooling; The low-temperature heat pump compressor exhaust port, the 4-way valve, the outdoor heat exchanger, the first one-way valve, the battery cooling branch and the low-temperature heat pump compressor intake port are connected in sequence to form the air conditioning refrigeration second circuit, and the air conditioning refrigeration second circuit is used to realize battery cooling and cooling during air conditioning refrigeration.

4. The system according to claim 3, characterized in that The battery cooling branch includes a battery cooling electronic expansion valve and a battery plate heat exchanger connected in sequence, and the battery plate heat exchanger is used to cool down the antifreeze fluid flowing through it.

5. The system according to claim 4, characterized in that A sight glass is also provided between the outdoor heat exchanger and the main electronic expansion valve.

6. The system according to claim 5, characterized in that A bidirectional drying filter is also arranged between the indoor heat exchanger and the intermediate compensator.

7. The system according to claim 6, characterized in that A high-pressure pressure sensor is arranged near one end of the exhaust port of the low-temperature heat pump compressor, and a low-pressure pressure sensor is arranged near one end of the suction port of the low-temperature heat pump compressor.

8. The system according to claim 7, characterized in that An ambient temperature probe is arranged between the outdoor heat exchanger and the sight glass, a return air temperature probe is arranged near the air outlet end of the battery plate heat exchanger, and a return air temperature sensor is arranged near one end of the air intake port of the low-temperature heat pump compressor.

9. The system according to any one of claims 1 to 8, characterized in that: The compressor refrigerant uses R410A.

10. A new energy vehicle, characterized in that: The invention comprises a low-temperature heat pump thermal management system as claimed in any one of claims 1 to 9.

Images