In the refrigeration system, the evaporator, the condenser, the compressor and the throttle valve are the four essential parts in the refrigeration system, among which the evaporator is the equipment for conveying the cooling capacity. The refrigerant absorbs the heat of the object to be cooled in it to achieve refrigeration. The compressor is the heart and plays the role of inhaling, compressing and transporting the refrigerant vapor. The condenser is a device that emits heat, and transfers the heat absorbed in the evaporator together with the heat converted by the compressor work to the cooling medium to take away.

The throttle valve acts as a throttling and depressurization function for the refrigerant, and at the same time controls and adjusts the amount of refrigerant liquid flowing into the evaporator, and divides the system into two parts: the high-pressure side and the low-pressure side. In the actual refrigeration system, in addition to the above four components, there are often some auxiliary equipment, such as solenoid valves, distributors, dryers, collectors, fusible plugs, pressure controllers and other components, which are to improve the operation. for economy, reliability and safety.

Air conditioners can be divided into two types according to the condensation form: water-cooled and air-cooled, according to the purpose of use.

It is divided into two types: single cooling type and cooling heating type. No matter which type of structure is used, it is composed of the following main components.

The necessity of the condenser is based on the second law of thermodynamics - according to the second law of thermodynamics, the spontaneous flow direction of thermal energy inside a closed system is one-way, that is, it can only flow from high heat to low heat, and in the microscopic world, the microscopic particles that carry thermal energy can only from order to disorder.

Therefore, while a heat engine has energy input to do work, the downstream must also release energy, so that there will be a gap in thermal energy between upstream and downstream, the flow of thermal energy will be possible, and the cycle will continue.

The choice of condenser includes the choice of form and model, and determines the flow and resistance of cooling water or air flowing through the condenser. The choice of condenser type should consider the local water source, water temperature, climatic conditions, as well as the size of the total cooling capacity of the refrigeration system and the layout requirements of the refrigeration room. On the premise of determining the type of condenser, the heat transfer area of the condenser is calculated according to the condensation load and the heat load per unit area of the condenser, so as to select a specific type of condenser.