Heat pump air-conditioning system of electric vehicle

Abstract

The invention relates to a heat pump air-conditioning system of an electric vehicle. The heat pump air-conditioning system comprises a compressor, a condenser inside the vehicle, a condenser outside the vehicle, expansion valves, a first stop valve, a second stop valve, an evaporator inside the vehicle and a liquid and gas separator. The heat pump air-conditioning system is characterized by further comprising an evaporator outside the vehicle. A first stroke section is formed between an outlet of the compressor and an inlet of the condenser outside the vehicle, and the condenser inside the vehicle is serially connected onto the stroke section; a second stroke section is formed between an inlet and an outlet of the condenser outside the vehicle; a third stroke section is formed between an outlet of the condenser outside the vehicle and an inlet of the liquid and gas separator and comprises a first branch and a second branch, the first stop valve and the evaporator inside the vehicle are serially connected to form the first branch, the second stop valve and the evaporator outside the vehicle are serially connected to form the second branch, and the expansion valves are arranged at front ends of the two evaporators; and a fourth stroke section is formed between the inlet and an outlet of the liquid and gas separator. The evaporator outside the vehicle is arranged behind the condenser outside the vehicle, heat discharged from the condenser outside the vehicle is transferred to the evaporator outside the vehicle, so that the temperature of the periphery of the evaporator outside the vehicle is increased, and working conditions at the temperature below minus 5 DEG C are met.

Description

technical field [0001] The invention relates to an automobile air-conditioning system, in particular to an electric automobile heat pump air-conditioning system. Background technique [0002] Electric vehicles do not have the engine waste heat that traditional vehicles use for heating, so they cannot provide a heating source. Therefore, the air-conditioning system of electric vehicles must have its own heating function, that is, heat pump air-conditioning system and / or electric heating are used for heating. At present, there are two common heat pump systems as follows, see Figure 5 and Figure 6 : [0003] Figure 5 It is the simplest and common heat pump system for automobile air conditioners. The heat pump system is composed of a compressor 1, a four-way reversing valve 14, an external heat exchanger 15, an internal heat exchanger 16, a liquid-gas separator 8 and an expansion valve 4. . The heat pump system uses few parts and low cost, and the flow direction of the re...

AI Technical Summary

Problems solved by technology

This system is in Figure 5 Improvements are made on the basis of the system shown, adding an in-car condenser 2, an expansion valve 17, two check valves (18, 19), and two shut-off valves (5, 6). It can realize the function of heating and dehumidification, but because in the heating cycle, the external heat exchanger is used as an evaporator and needs to absorb the heat of the external environment, so when the external temperature is low, the temperature of the external heat exchanger is close to the external ambient temperature , the external heat exchanger cannot effectively absorb heat from the external environment, causing the system to fail to continue to operate

In addition, when the temperature outside the vehicle is low, if the air contains more moisture, the moisture in the air will frost on the surface of the external heat exchanger, and the frosted external heat exchanger can no longer effectively absorb heat from the external environment. Absorbs heat, causing the system to no longer provide heating

Therefore, the system generally cannot work normally below -5°C

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