Central air conditioners can cool in summer and heat in winter, and work in cycles all year round, bringing comfortable temperatures to people’s lives. Today, let’s take a look at the refrigeration principle of central air conditioning and its common components.
I. Refrigeration principle
The compressor compresses the gaseous refrigerant into high temperature and high pressure gaseous refrigerant, which is sent to the condenser of the outdoor unit as liquid refrigerant, and the liquid refrigerant is throttled by the throttling mechanism. Then the refrigerant enters the evaporator to absorb the heat in the air and vaporize into gaseous refrigerant, and then the gaseous refrigerant returns to the compressor to continue compression and continue to circulate for refrigeration.
When heating, there is a four-way valve to make the refrigerant flow in the condenser and evaporator opposite to that during cooling, so when heating, it blows cold air outdoors and hot air indoors.
II.the main components of refrigeration and air conditioning
1. Compressors can be divided into centrifugal type, rotary type and rotary type
Common compressors are：
Totally enclosed piston compressor: 1-20 cold tons, used in commercial buildings or domestic facilities.
Semi-closed piston compressor: mostly used for refrigeration equipment
Rotor compressor: Now it is mostly used in refrigeration equipment with less than 7 horses. Rolling rotor compressor has few parts, simple structure, no suction valve, small clearance volume, light weight and stable operation.
Scroll compressor: The single unit capacity is 3HP~25HP, which is mainly used in central air conditioning (domestic and commercial). The scroll machine has the advantages of high efficiency, energy saving, low noise, small size, light weight, stable operation, small airflow pulsation and long service life.
Screw compressor: with a single unit capacity of 40HP~400HP, it is mainly used for commercial central air conditioners and other large equipment. Simple structure, less wearing parts, low exhaust temperature under large pressure difference and good gas transmission regulation performance.
Centrifugal compressor: a centrifugal refrigeration compressor, which depends on the change of kinetic energy to increase the vapor pressure during operation. The centrifugal compressor has the characteristics of large refrigerating capacity and stable operation.