The cooling of a heat pump air conditioner can be summarized as a heat transfer process of 'absorbing heat indoors and releasing heat outdoors.' The specific process is as follows:
1. Absorbing heat and lowering temperature indoors
In the indoor unit evaporator, low-temperature, low-pressure liquid refrigerant comes into contact with indoor air, absorbs the heat from the air, and evaporates into gas. As the heat is taken away, the indoor air cools down. The indoor unit fan continues to operate, accelerating air circulation to ensure a uniform decrease in indoor temperature.
2. Compression and pressure increase by the compressor
The low-temperature, low-pressure gaseous refrigerant is drawn into the compressor, which consumes electrical energy to perform mechanical work, compressing it into high-temperature, high-pressure gaseous refrigerant. This step is the core of energy conversion. In variable-frequency models, adjusting the compressor speed can precisely match the cooling demand and thus reduce energy waste.
3. Outdoor Side Heat Dissipation
High-temperature, high-pressure gaseous refrigerant flows into the outdoor unit condenser, exchanges heat with the outdoor air, and condenses into liquid after releasing the absorbed heat. The outdoor unit fan expels the heat outside, completing the transfer of indoor heat to the outdoors.
4. Throttling and Pressure Reduction Cycle
High-temperature, high-pressure liquid refrigerant flows through a capillary tube (or electronic expansion valve), causing a sudden drop in pressure and temperature, turning back into low-temperature, low-pressure misty refrigerant (gas-liquid mixture), which then flows back into the indoor unit evaporator to start the next cycle.
