How does an Air Source Heat Pump Heat and Cool?
An air source heat pump realizes heating and cooling functions through refrigerant circulation and reverse thermodynamic cycle. Its core principle is to absorb or release heat from the air and transfer energy efficiently. The following is the specific process of air source heat pump heating and cooling:
1. Heating process (winter heating)
* Heat absorption stage:
The evaporator absorbs heat energy from the environment to turn the low-temperature and low-pressure medium gas into gas.
* Compression stage:
The compressor compresses the low-temperature and low-pressure gaseous medium into high-temperature and high-pressure gas.
* Exothermic stage:
The high-temperature and high-pressure gas releases heat in the condenser, heats water or air, and then turns into low-temperature and low-pressure gas through the expansion valve.
* Circulation stage:
The low-temperature and low-pressure gas returns to the evaporator, continues to absorb heat, and starts the next cycle.
2. Refrigeration process (summer cooling)
* Heat absorption stage:
The evaporator absorbs heat from the indoor air to evaporate the liquid refrigerant into gas.
* Compression stage:
The compressor compresses the low-temperature and low-pressure gaseous refrigerant into high-temperature and high-pressure gas.
* Heat release stage:
high temperature and high pressure gas releases heat to the outdoor air in the condenser and condenses into liquid.
* Throttling stage:
liquid refrigerant is converted into low temperature and low pressure steam through the expansion valve and returns to the evaporator.
* Circulation stage:
The refrigerant absorbs heat in the evaporator and continues to circulate.
3. Comparison of core components and functions of heat pumps in two modes
* Four-way valve
Heating mode: maintain refrigerant flow direction (heat absorption outdoors → heat release indoors)
Cooling mode: switch flow direction (heat absorption indoors → heat release outdoors)
* Evaporator
Heating mode: heat absorption outdoors
Cooling mode: heat absorption indoors
* Condenser
Heating mode: heat release indoors
Cooling mode: heat release outdoors
* Compressor
Heating mode: increase refrigerant pressure and temperature
Cooling mode: increase refrigerant pressure and temperature
* Expansion valve
Heating mode: throttling and reducing pressure, regulating refrigerant flow
Cooling mode: throttling and reducing pressure, regulating refrigerant flow
Therefore, air source heat pumps transfer heat between indoors and outdoors through refrigerant phase change and direction switching. Its essence is a "heat carrier" rather than direct power generation or combustion heat generation, so it has high energy efficiency and strong environmental protection, and is an energy-saving solution to replace traditional boilers and air conditioners.
