How do ammonia evaporators work?

How do ammonia evaporators work?

An ammonia evaporator is a type of refrigeration equipment that utilises ammonia as a cooling medium and works based on the principles of evaporative cooling and heat transfer. The following are the basic principles and working process of an ammonia evaporator:

Compressor: The work of an ammonia evaporator begins with the compressor. The compressor draws in the low-temperature, low-pressure ammonia gas and makes it into a high-temperature, high-pressure gas through compression.

Condenser: After the high temperature and high pressure ammonia gas is discharged from the compressor, it enters the condenser. The cooling medium in the condenser (usually water or air) comes into contact with the ammonia gas, which releases heat and condenses into a high-pressure liquid.

Expansion Valve: The high pressure liquid enters the expansion device through the expansion valve, which controls the flow and pressure of the liquid and converts it into low temperature and low pressure ammonia gas.

Evaporator: The low-temperature, low-pressure ammonia gas enters the evaporator and comes into contact with outside air or objects. In the evaporator, the ammonia absorbs the surrounding heat, which causes the ammonia to evaporate, achieving a cooling effect.

Fans: The back of the evaporator is usually equipped with one or more fans to pass air through the evaporator, accelerating the evaporation process of the ammonia and transferring the cooled air to the target area.

Recirculation: The ammonia evaporator redirects the cooled ammonia air to the compressor through a recirculation system, thus creating a continuous refrigeration cycle.

Overall, the basic principle of an ammonia evaporator is to utilise the process of phase change of ammonia, i.e. the evaporation of liquid to gas, to absorb the surrounding heat to achieve the cooling effect. The role of the compressor and expansion valve is to control the pressure and flow of ammonia, the condenser is used to cool the high temperature and high pressure gas into a high pressure liquid, while the evaporator uses the evaporation of ammonia to absorb heat to achieve cooling. The role of the fan is to promote the evaporation process, increase air flow and heat exchange efficiency. By working in this way, ammonia evaporators are able to provide effective cooling and refrigeration.