What are the classifications of refrigerators?


Refrigerating machine (refrigerating machine) A machine that transfers the heat of the object to be cooled with a lower temperature to the environment medium to obtain cold energy. The heat transferred from a lower temperature object is traditionally called coldness. The working fluid in the refrigerator that participates in the change of the thermal process (energy conversion and heat transfer) is called refrigerant. The temperature range of refrigeration is usually above 120K, and below 120K belongs to the range of deep cryogenic technology. Refrigerators are widely used in industrial and agricultural production and daily life.
According to the working principle, the refrigerator can be divided into:
 ① Compression type refrigerator. Rely on the action of the compressor to increase the pressure of the refrigerant to realize the refrigeration cycle. According to the type of refrigerant, it can be divided into vapor compression refrigerator (based on hydraulic evaporative refrigeration, the refrigerant needs to undergo periodic gas-liquid phase change) and There are two types of gas compression refrigerators (based on high-pressure gas expansion and refrigeration, the refrigerant is always in a gas state).
 ② Absorption refrigerator. Relying on the role of the absorber-generator group (thermochemical compressor) to complete the refrigeration cycle, it can be divided into three types: ammonia absorption, lithium bromide absorption and absorption diffusion.
 ③Steam jet refrigerator. Rely on the steam ejector (ejector compressor) to complete the refrigeration cycle.
 ④ Semiconductor refrigerator. The thermoelectric effect of semiconductors is used to produce cold energy.

       The main performance indicators of refrigerators include operating temperature (evaporation temperature and condensation temperature for vapor compression refrigerators, and temperature of the object to be cooled and temperature of cooling medium for gas compression refrigerators and semiconductor refrigerators), cooling capacity (refrigeration The heat removed from the object to be cooled per unit time), power or heat consumption, refrigeration coefficient (a measure of the economics of a compression refrigerator, refers to the amount of cold that can be obtained by consuming a unit of work), and thermal coefficient (a measure of absorption And the economic index of steam jet refrigerator, refers to the amount of cold that can be obtained by consuming a unit of heat) and so on. Modern refrigerators are the most widely used vapor compression refrigerators.
An air conditioner is a room air conditioner, which is a unit used to provide processing air to a room (or enclosed space or area). Its function is to adjust the temperature, humidity, cleanliness and air flow rate of the air in the room (or enclosed space, area) to meet the requirements of human comfort or technological process.