A Heat Pump is a device that transfers thermal energy from a low temperature heat source to a high temperature heat source. The low-temperature heat source commonly used in heat pump installations is the medium around us - air, river water, sea water, urban sewage, surface water, ground water, water, fire water tanks, or working fluids discharged from industrial production equipment. Often there is a temperature close to the surrounding medium. The heat pump unit works in the same way as a compression chiller. In small air conditioners, in order to fully utilize their performance, summer air conditioning cooling or winter heating is done using the same equipment, as is the heat pump. When heating in winter, the evaporator and condenser in the air conditioner are exchanged through a reversing valve.
The working cycle of the heat pump is exactly the opposite of the working cycle of the heat engine. The heat engine uses the energy of the high temperature heat source to generate mechanical work, and the heat pump transfers the heat of the low temperature heat source to the high temperature object by consuming mechanical work.
The basic principle of heat pump water heater: it is mainly composed of compressor, heat exchanger, axial flow fan, heat preservation water tank, water pump, liquid storage tank, filter, electronic expansion valve and electronic automatic controller. After the power is turned on, the axial fan of the heat pump starts to operate, and the outdoor air exchanges heat through the evaporator. The air after the temperature is lowered is exhausted by the fan, and the heat of the internal combustion of the heat pump is sucked into the compressor. The compressor compresses the low-pressure working gas into a high-temperature, high-pressure gas and sends it to the condenser. The water forced to be circulated by the water pump also passes through the condenser, is heated by the working medium and sent to the user for use, and the working medium is cooled to a liquid. The liquid is throttled by the expansion valve and then flows into the evaporator of the heat pump again. The cycle is repeated, and the heat energy in the air is continuously sent to the water, so that the water temperature in the heat preservation tank gradually rises, and finally reaches 55 ° C, which is suitable for people. Bathing, this is the basic working principle of air source heat pump water heaters.
The compressor of the heat pump is a high-temperature and high-pressure gas, which is converted into a high-pressure low-temperature vapor-liquid mixture through the heat exchange of the condenser. The lost heat is taken away by the hot water to supply heat to the user, and becomes a low-pressure low-temperature gas into the heat pump through the liquid storage tank and the expansion valve. The evaporator evaporates and absorbs heat, absorbing low-grade heat from the outside (can be rivers, lakes, groundwater, underground soil layers, air, etc., which we call water source, ground source, air source heat pump), and finally the evaporator of the heat pump comes out. The low pressure gas enters the compressor to complete the cycle.