Positive displacement refrigeration compressor: by changing the volume of the working chamber, the periodic inhalation of quantitative gas compression. Commonly used positive displacement compressor: piston type, rolling rotor type, scroll type, single screw type, double screw type
Centrifugal refrigeration compressor: relying on the role of centrifugal force, continuous compression of the inhaled gas.
Condenser: The high temperature and high pressure gaseous refrigerant discharged from the refrigeration compressor is cooled and liquefied so that the refrigerant can be recycled in the system.
Throttling mechanism: the high-pressure liquid refrigerant is throttled and reduced to ensure the pressure difference between the condenser and evaporator, so that the liquid refrigerant in the evaporator evaporates and absorbs heat at the required low pressure, so as to achieve the purpose of cooling and cooling; At the same time, the gaseous refrigerant in the condenser is thermally condensed under high pressure at each top. In addition, the refrigerant flow into the evaporator can be adjusted to adapt to the evaporator heat load change, so as to avoid some refrigerant in the evaporator is not vaporized.
Evaporator: Through the refrigerant evaporation (boiling), absorb heat, so as to achieve the purpose of refrigeration.
The difference between full liquid evaporator and non-full liquid (dry) evaporator: (dry) evaporator shell tube: the refrigerant of the evaporator flows in the tube, and the water flows outside the tube cluster. The flow of refrigerant usually has several processes, due to the gradual gasification of refrigerant liquid, usually the higher the flow, the more tubes. In order to increase the water side heat transfer, a number of baffle plates are arranged on the outside of the tube tube to make the water flow across the tube cluster many times.
Its advantages are:
Lubricating oil enters the compressor with the refrigerant, and there is generally no oil accumulation problem.
The refrigerant charged is less, generally only about 1/3 of the full liquid type;
When t0 is near 0 ° C, water will not freeze.
Full liquid evaporator: The evaporator moves water in the tube, and the refrigerant evaporates outside the tube cluster, so the heat transfer surface is basically in contact with the liquid refrigerant. Generally, the refrigeration dose charged in the shell is about 55% to 65% of the effective volume of the cylinder, and the refrigerant liquid is thermatively vaporized through the liquid separator at the top of the cylinder and returned to the compressor.
Advantages: compact structure, easy operation and management, high heat transfer coefficient.
Disadvantages:
When the evaporation temperature of refrigeration system is lower than 0℃, the water in the tube is easy to freeze, and the evaporation tube is damaged.
Large amount of refrigerant filling;
Affected by the height of the refrigerant liquid column, the evaporation temperature at the bottom of the cylinder is high.
Oil will accumulate in the lower part of the evaporator cylinder, and reliable oil return measures must be available.
Declaration: The content and template of this article are organized from the network, and the copyright belongs to the original author; If there is infringement, please inform in time and contact to delete.