The evaporator is a heat exchanging device, and the evaporator is a heat absorbing device. In the evaporator, due to the gasification of the low pressure liquid refrigerant, the heat is absorbed from the object or the space which needs to be cooled, thereby reducing the temperature of the cooled object or space and achieving the purpose of refrigeration. Therefore, an evaporator is a device for generating and outputting a cold quantity in a refrigeration device.
According to the different types of cooling medium, the evaporator can be divided into two categories:
1. cooling liquid refrigerant for cooling liquid refrigerant, water, salt water or glycol water solution. This kind of evaporator is commonly used in horizontal evaporator, vertical tube evaporator and spiral tube evaporator.
2. the evaporator of the cooling air cooling evaporator and cooling fan.
Horizontal evaporator is also called horizontal shell and tube evaporator. It is similar to the structure of the horizontal shell and tube condenser. According to the mode of liquid supply, it can be divided into two types: shell and tube evaporator and dry evaporator.
Vertical tube and spiral tube evaporator characteristics of common tube and spiral tube evaporator is the evaporation of the refrigerant in the tube, the entire evaporator tube immersed in the refrigerant laden group Sheng (or in the pool and the tank), in order to ensure the refrigerant cycle at a certain speed in the box, box is welded with a longitudinal baffle and a spiral agitator. The coolant flow rate is 0.3 ~ 0.7m/s, in order to enhance heat transfer.
The two evaporator can only be used in the open cycle system, the refrigerant must be non volatile substances, commonly used is saline and water etc.. Such as the use of salt water, the evaporator tube is easy to be oxidized, and easy to absorb moisture and reduce the concentration of brine. The two evaporator can directly observe the flow of refrigerant, is widely used in brine system with ammonia as refrigerant.