Passenger car air conditioning system using carbon dioxide refrigerant

Abstract

The utility model provides a passenger car air-conditioning system using a carbon dioxide refrigerant, which belongs to the technical field of pure electric passenger car air conditioners and comprises a compressor, an outlet hole of the compressor is connected with an inlet of an electromagnetic three-way reversing valve, and a second outlet of the electromagnetic three-way reversing valve is connected with a high-pressure side of an evaporator core. The low-pressure side of the evaporator core is connected with an inlet of the second electromagnetic valve and an inlet of the high-pressure control valve, an outlet of the high-pressure control valve is connected with an inlet of the flash valve and a first inlet of the plate heat exchanger, and an outlet of the flash valve, an outlet of the second electromagnetic valve and an outlet of the third electromagnetic valve are all connected with an inlet of the gas-liquid separator. An outlet of the gas-liquid separator is connected with a second inlet of the plate heat exchanger. A second outlet of the plate heat exchanger is connected with an inlet of the compressor. The utility model can reduce the outlet pressure and temperature of the compressor and improve the heating efficiency of the air-conditioning system.

Description

Technical Field

[0001] The utility model belongs to the technical field of pure electric bus air conditioners, and in particular relates to a bus air conditioner system using carbon dioxide refrigerant. Background Art

[0002] Since pure electric buses have no engine waste heat to utilize, the current air conditioning heating method of pure electric buses mainly relies on PTC heaters or air conditioning heat pumps. When heating the buses in winter, the efficiency of PTC heaters cannot be greater than 1, resulting in a reduction in the vehicle's winter mileage. The air conditioning heat pump uses R410A or R407C refrigerants, which cannot meet the heating needs in ultra-low temperature environments and have an impact on the environment.

[0003] Carbon dioxide (CO2) does not damage the ozone layer (ODP = 0), has an extremely low greenhouse gas effect (GWP = 1), is non-toxic and non-flammable, and has the advantages of good heat transfer performance, low flow resistance and large unit cooling capacity. Currently, pure electric bus air-conditioning systems using carbon dioxide as a refrigerant have emerged.

[0004] However, air-conditioning systems using carbon dioxide refrigerant need to adopt a transcritical cycle. The outlet pressure and temperature of the compressor are high. If the heat exchange capacity of the cooler (condenser) is insufficient, the heating efficiency of the carbon dioxide air-conditioning system will be affected. Utility Model Content

[0005] In view of the defects or shortcomings in the existing technology, the utility model provides a bus air-conditioning system using carbon dioxide refrigerant, which can reduce the compressor outlet pressure and temperature and improve the heating efficiency of the air-conditioning system.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0007] An embodiment of the present utility model provides a passenger car air conditioning system using carbon dioxide refrigerant, comprising a compressor, wherein an outlet hole of the compressor is connected to an inlet of an electromagnetic three-way reversing valve, and a second outlet of the electromagnetic three-way reversing valve is connected to a high-pressure side of an evaporator core;

[0008] The low-pressure side of the evaporator core is respectively connected to the inlet of the second solenoid valve and the inlet of the high-pressure control valve, and the outlet of the high-pressure control valve is respectively connected to the inlet of the flash valve and the first inlet of the plate heat exchanger, wherein the outlet of the flash valve, the outlet of the second solenoid valve and the outlet of the third solenoid valve are all connected to the inlet of the gas-liquid separator, the outlet of the gas-liquid separator is connected to the second inlet of the plate heat exchanger, and the second outlet of the plate heat exchanger is connected to the inlet of the compressor.

[0009] Furthermore, the first outlet of the electromagnetic three-way reversing valve is connected to the high-pressure side of the condenser core, and the low-pressure side of the condenser core is respectively connected to the inlet of the first solenoid valve and the inlet of the third solenoid valve, the outlet of the third solenoid valve is connected to the inlet of the gas-liquid separator, the outlet of the first solenoid valve is connected to the first drying filter and the first expansion valve in sequence, and the outlet of the first expansion valve and the second outlet of the electromagnetic three-way reversing valve are both connected to the high-pressure side of the evaporator core.

[0010] Furthermore, the first outlet of the plate heat exchanger is connected to the inlet of the second drying filter, the outlet of the second drying filter is connected to the inlet of the second expansion valve, and the outlet of the second expansion valve is connected to the inlet of the condenser core.

[0011] Furthermore, a high-pressure relief valve is provided on the pipeline between the outlet of the compressor and the electromagnetic three-way reversing valve.

[0012] Furthermore, a low-pressure relief valve is provided on the pipeline between the inlet of the compressor and the second outlet of the plate heat exchanger.

[0013] Furthermore, a condensing fan is provided on one side of the condenser core, and the condenser core and the condensing fan are both located outside the vehicle compartment.

[0014] Furthermore, an evaporation fan is provided on the outside of the evaporator core, and the evaporator core and the evaporation fan are both located inside the vehicle compartment.

[0015] Furthermore, a plurality of evaporator cores are provided, and the plurality of evaporator cores are evenly distributed inside the passenger car compartment.

[0016] Furthermore, the compressor is an electrically driven variable frequency compressor.

[0017] Furthermore, the refrigerant circulating in the system is carbon dioxide.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] The utility model connects the outlet of the evaporator core to the flash valve through a high-pressure control valve. When the refrigerant passes through the flash valve, it is converted from medium temperature and high pressure to low temperature and low pressure, which can effectively reduce the pressure and temperature of the compressor discharge outlet, thereby improving the heating efficiency of the air-conditioning system and achieving system efficiency improvement of carbon dioxide transcriticality. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of a passenger car air conditioning system in an embodiment of the present utility model;

[0021] Among them, 1. Compressor; 2. Solenoid three-way reversing valve; 3. Condenser core; 4. Condensing fan; 5. First solenoid valve; 6. Third solenoid valve; 7. First drying filter; 8. First expansion valve; 9. Evaporator core; 10. Evaporating fan; 11. Second solenoid valve; 12. High-pressure control valve; 13. Flash valve; 14. Plate heat exchanger; 15. Gas-liquid separator; 16. Second drying filter; 17. Second expansion valve. DETAILED DESCRIPTION

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] A typical implementation of the present invention is as follows: Figure 1 As shown, a bus air-conditioning system using carbon dioxide refrigerant includes a compressor 1, the outlet hole of the compressor 1 is connected to the inlet of an electromagnetic three-way reversing valve 2, the first outlet of the electromagnetic three-way reversing valve 2 is connected to the high-pressure side of a condenser core 3, a condensing fan 4 is provided on one side of the condenser core 3 to dissipate heat from the condenser core 3, the condenser core 3 and the condensing fan 4 are both located outside the vehicle compartment, the low-pressure side of the condenser core 3 is respectively connected to the inlet of a first electromagnetic valve 5 and the inlet of a third electromagnetic valve 6, wherein the outlet of the first electromagnetic valve 5 is connected to the inlet of a first drying filter 7, the outlet of the first drying filter 7 is connected to the inlet of a first expansion valve 8, the outlet of the first expansion valve 8 and the second outlet of the electromagnetic three-way reversing valve 2 are both connected to the high-pressure side of an evaporator core 9, an evaporating fan 10 is provided outside the evaporator core 9, and the evaporating fan 10 is used to send the temperature of the evaporator core 9 into the vehicle compartment, thereby cooling or heating the vehicle compartment interior, and the evaporator core 9 and the evaporating fan 10 are both located inside the vehicle compartment.

[0024] The low-pressure side of the evaporator core 9 is respectively connected to the inlet of the second solenoid valve 11 and the inlet of the high-pressure control valve 12, and the outlet of the high-pressure control valve 12 is respectively connected to the inlet of the flash valve 13 and the first inlet of the plate heat exchanger 14. The medium-temperature and high-pressure refrigerant flows into the first inlet of the plate heat exchanger 14 and the flash valve 13 respectively, wherein the outlet of the flash valve 13 and the outlet of the second solenoid valve 11 and the outlet of the third solenoid valve 6 are all connected to the inlet of the gas-liquid separator 15, and the outlet of the gas-liquid separator 15 is connected to the second inlet of the plate heat exchanger 14, and the second outlet of the plate heat exchanger 14 is connected to the inlet of the compressor 1. By setting the gas-liquid separator 15, the compressor 1 can be prevented from inhaling liquid refrigerant in a low-temperature environment, causing liquid hammer in the compressor 1 and causing damage to the compressor 1.

[0025] By setting up a high-pressure control valve 12, the medium-temperature and high-pressure liquid can be converted into a medium-temperature and medium-pressure gas-liquid mixture, and after passing through the flash valve 13, it is converted into pure gas to replenish the compressor 1, effectively preventing the liquid from entering the compressor 1 and causing damage, and realizing the improvement of the efficiency of the carbon dioxide transcritical system.

[0026] The first outlet of the plate heat exchanger 14 is connected to the inlet of the second filter drier 16 , the outlet of the second filter drier 16 is connected to the inlet of the second expansion valve 17 , and the outlet of the second expansion valve 17 is connected to the inlet of the condenser core 3 .

[0027] There are multiple evaporator cores 9, and the multiple evaporator cores 9 are evenly distributed inside the bus compartment, thereby ensuring the air conditioning cooling and heating effects in the bus compartment.

[0028] A high-pressure relief valve (not shown in the figure) is provided on the pipeline between the outlet of the compressor 1 and the electromagnetic three-way reversing valve 2, and a low-pressure relief valve (not shown in the figure) is provided on the pipeline between the inlet of the compressor 1 and the second outlet of the plate heat exchanger 14. By providing the high-pressure relief valve and the low-pressure relief valve, extreme phenomena such as explosion caused by excessive pressure in the system are prevented.

[0029] Compressor 1 is an electrically driven variable frequency compressor. The refrigerant circulating in the system is carbon dioxide. The use of natural and environmentally friendly carbon dioxide refrigerant can overcome the problem of low heating efficiency of pure electric buses in winter.

[0030] During the refrigeration cycle, the high-temperature and high-pressure gas coming out of the compressor 1 passes through the electromagnetic three-way reversing valve 2 and flows into the condenser core 3 for cooling. After the condensing fan 4 dissipates heat to the environment, the first solenoid valve 5 opens, the third solenoid valve 6 closes, and enters the first expansion valve 8 after passing through the first drying filter 7. After throttling and cooling, it enters the evaporator core 9 for evaporation. The cooled air-conditioning is sent into the interior of the vehicle for cooling under the action of the evaporating fan 10, realizing the refrigeration function of the air-conditioning system; the second solenoid valve 11 opens, the high-pressure control valve 12 closes, and the second expansion valve 17 closes. The low-temperature and low-pressure refrigerant coming out of the evaporator core 9 enters the gas-liquid separator 15, and then returns to the compressor 1 through the second inlet and second outlet of the plate heat exchanger 14, completing the refrigeration cycle of the air-conditioning. At this time, the plate heat exchanger 14 is only for refrigerant to pass through and is used as an air-conditioning pipeline.

[0031] During the heating cycle, the high-temperature and high-pressure gas from the compressor 1 flows into the evaporator core 9 through the electromagnetic three-way reversing valve 2 for cooling. Under the action of the evaporating fan 10, the temperature in the vehicle cabin rises, thereby meeting the heating demand of the air-conditioning system; the second solenoid valve 11 is closed, the high-pressure control valve 12 is opened, and the medium-temperature and high-pressure refrigerant flows into the first inlet and flash valve 13 of the plate heat exchanger 14 respectively. One path of refrigerant flows out from the first outlet of the plate heat exchanger 14, passes through the second drying filter 16 and the second expansion valve 17 respectively, and flows into the condenser core 3. After being supercooled by the condenser core 3, the condensing fan 4 condenses it. The first solenoid valve 5 is closed, and the third solenoid valve 6 is opened. The refrigerant flows into the third solenoid valve 6 and then merges with the refrigerant flowing out of the flash valve 13, and flows into the gas-liquid separator 15 together. After passing through the second inlet and second outlet of the plate heat exchanger 14, the refrigerant is heated in the plate heat exchanger 14 and then returns to the compressor 1 to absorb air, completing the heating cycle.

[0032] A portion of the refrigerant is converted from medium temperature and high pressure to low temperature and low pressure when passing through the flash valve 13, which can effectively reduce the pressure and temperature of the compressor 1 discharge port, thereby improving the heating efficiency of the air-conditioning system and achieving carbon dioxide transcritical system efficiency improvement.

[0033] The setting of the high-pressure control valve 12 and the flash valve 13 can improve the heating efficiency of the air-conditioning system. The high-pressure control valve 12 can convert the medium-temperature and high-pressure liquid into a medium-temperature and medium-pressure gas-liquid mixture, and after passing through the flash valve 13, it is converted into pure gas to replenish the compressor 1, effectively preventing the liquid from entering the compressor 1 and causing damage, and realizing the improvement of the efficiency of the carbon dioxide transcritical system.

[0034] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A passenger car air conditioning system using carbon dioxide refrigerant, characterized in that: It includes a compressor, wherein the outlet hole of the compressor is connected to the inlet of the electromagnetic three-way reversing valve, and the second outlet of the electromagnetic three-way reversing valve is connected to the high-pressure side of the evaporator core; The low-pressure side of the evaporator core is respectively connected to the inlet of the second solenoid valve and the inlet of the high-pressure control valve, and the outlet of the high-pressure control valve is respectively connected to the inlet of the flash valve and the first inlet of the plate heat exchanger, wherein the outlet of the flash valve, the outlet of the second solenoid valve and the outlet of the third solenoid valve are all connected to the inlet of the gas-liquid separator, the outlet of the gas-liquid separator is connected to the second inlet of the plate heat exchanger, and the second outlet of the plate heat exchanger is connected to the inlet of the compressor.

2. A passenger car air conditioning system using carbon dioxide refrigerant as claimed in claim 1, characterized in that: The first outlet of the electromagnetic three-way reversing valve is connected to the high-pressure side of the condenser core, and the low-pressure side of the condenser core is respectively connected to the inlet of the first solenoid valve and the inlet of the third solenoid valve. The outlet of the third solenoid valve is connected to the inlet of the gas-liquid separator. The outlet of the first solenoid valve is connected to the first drying filter and the first expansion valve in sequence. The outlet of the first expansion valve and the second outlet of the electromagnetic three-way reversing valve are both connected to the high-pressure side of the evaporator core.

3. A passenger car air conditioning system using carbon dioxide refrigerant as claimed in claim 2, characterized in that: The first outlet of the plate heat exchanger is connected to the inlet of the second drying filter, the outlet of the second drying filter is connected to the inlet of the second expansion valve, and the outlet of the second expansion valve is connected to the inlet of the condenser core.

4. A passenger car air conditioning system using carbon dioxide refrigerant as claimed in claim 1, characterized in that: A high-pressure relief valve is provided on the pipeline between the outlet of the compressor and the electromagnetic three-way reversing valve.

5. The passenger car air conditioning system using carbon dioxide refrigerant as claimed in claim 1, characterized in that: A low-pressure relief valve is provided on the pipeline between the inlet of the compressor and the second outlet of the plate heat exchanger.

6. A passenger car air conditioning system using carbon dioxide refrigerant as claimed in claim 2, characterized in that: A condensing fan is provided on one side of the condenser core, and both the condenser core and the condensing fan are located outside the vehicle compartment.

7. A passenger car air conditioning system using carbon dioxide refrigerant as claimed in claim 1, characterized in that: An evaporation fan is arranged outside the evaporator core, and both the evaporator core and the evaporation fan are located inside the vehicle compartment.

8. The passenger car air conditioning system using carbon dioxide refrigerant as claimed in claim 1, characterized in that: There are multiple evaporator cores, and the multiple evaporator cores are evenly distributed inside the passenger car.

9. The passenger car air conditioning system using carbon dioxide refrigerant as claimed in claim 1, characterized in that: The compressor is an electrically driven variable frequency compressor.

10. The passenger car air conditioning system using carbon dioxide refrigerant as claimed in claim 1, characterized in that: The refrigerant circulating in the system is carbon dioxide.

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