How heat pump air conditioning systems work
The pure electric vehicle heat pump air conditioning system consists of an electric compressor, an internal and external heat exchanger, a four-way directional valve, a throttle mechanism, a cooling fan and a liquid storage tank, etc. The compressor is usually driven by an electric motor and works by compressing the working gas through a piston or spiral structure; the liquid storage tank contains a desiccant, which stores the excess refrigerant and absorbs the water mixed with it; the throttle mechanism consists of a capillary tube and an expansion valve, which controls the flow of refrigerant from the condenser to the evaporator by The internal heat exchanger is used as an evaporator in the refrigeration mode and as a condenser in the heating mode; the external heat exchanger is used as a condenser in the refrigeration mode and as an evaporator in the heating mode.
When the heat pump air conditioner is heating, the low-temperature and low-pressure gaseous refrigerant enters the compressor, which compresses it into a high-temperature and high-pressure refrigerant; subsequently, the high-temperature and high-pressure refrigerant flows into the internal heat exchanger through the four-way reversing valve, at which time the refrigerant dissipates heat into the interior of the vehicle and becomes a medium-temperature and high-pressure liquid after isobaric condensation; the pressure drops sharply after the throttling mechanism, and the refrigerant transforms from a liquid to a gas-liquid mixture and flows to the external heat exchanger, where it absorbs heat from the external environment and evaporates into a low-temperature and low-pressure gas. The four-way reversing valve is used to change the flow direction of the working mass to complete the switch from heating mode to cooling mode.
