Cold storage central air conditioning

Working Principle:

Cooling principle of central air conditioning in Qinghai

Liquid vaporization refrigeration utilizes the heat absorption during liquid vaporization and the heat release during condensation to achieve refrigeration. Liquid vaporizes to form steam. When a liquid (refrigerant) is in a closed container, there are no other gases in the container except for the liquid and the vapor generated by the liquid itself. The liquid and vapor will reach equilibrium at a certain pressure, and the vapor at this point is called saturated vapor, the pressure is called saturated pressure, and the temperature is called saturated temperature. At equilibrium, the liquid no longer vaporizes. If a portion of the vapor is extracted from the container, the liquid must continue to vaporize to produce a portion of the vapor to maintain this equilibrium. When a liquid vaporizes, it absorbs heat, which is called latent heat of vaporization. The latent heat of vaporization comes from the cooled object, causing it to cool down. To ensure the continuity of this process, it is necessary to continuously extract steam from the container, condense it into a liquid, and then return it to the container. If the steam extracted from the container is directly condensed into a liquid, the temperature of the required cooling medium is lower than the evaporation temperature of the liquid. We hope that the condensation of the steam is carried out at room temperature, so we need to increase the pressure of the steam to the saturation pressure at room temperature.

The refrigerant will evaporate at low temperature and low pressure, producing a cooling effect; And condense at room temperature and high pressure, releasing heat to the surrounding environment or cooling medium. Steam condenses into high-pressure liquid at room temperature and high pressure, and its pressure needs to be reduced to the evaporation pressure before it can enter the container.

The liquid vaporization refrigeration cycle consists of four processes: refrigerant vaporization, steam boosting, high-pressure steam condensation, and high-pressure liquid depressurization.