There are three types of defrosting methods currently used in refrigeration systems, water defrosting, hot gas defrosting, and electric defrosting.

Ⅰ Situation analysis：

The original system uses ammonia refrigerant, and the defrosting method is water defrosting, which causes serious water accumulation in the cold storage room, and the temperature of the room is -18~-22℃, and the accumulation of water is frozen, which affects the storage of the products.

a) Analyze the causes:

①Because of incomplete defrosting, the chiller enters the cooling mode without completing the defrosting process, resulting in ice blockage of the cooler, and condensate overflows from the water catch pan to the ground.                                                                                                                        Solution 1: Check the frosting situation, stop the cooling mode operation, carry out complete frosting, after the frosting is completely finished, start the operation.

② The condensate pipe of the cooler is congested, and the condensate produced cannot be discharged and overflows to the ground.
Solution 2: Check the condensate piping drainage, whether piping congestion occurs, exclude piping congestion, and then start operation.

③ Frosting water was splashed when the water was frosted, and no water-blocking measures were set up.
Solution 3: Add water blocking device to the existing cooler or replace the cooler.

(Hot ammonia frosting + water frosting photos

Red markings are water blocking device )

II Selection of defrosting methods

Option 1; Choose thermal ammonia frosting

Advantage:

①The existing water defrosting system can be utilized to realize the combined defrosting method of water+thermal ammonia, which is more effective.

②Thermo-ammonia frosting uses the hot gas discharged from the refrigeration system without the use of electricity, which can save the use of electric power resources and reduce costs.

Disadvantages：

①Due to technical requirements, the choice of thermo-ammonia defrosting requires 3 unit cooler, (2 of which run in defrosting mode, and 1 of which goes into cooling mode)

②Installation is complicated and requires additional thermal ammonia piping.

Option 2; Choose electrified frosting

Advantages:

①Electric frost only need two large-sized cooler(electric frost chiller can be based on the design parameters of the system, enter the frost program by itself, without the need to assign the operation of the action), low cost

②Electric frost does not need to increase the pipeline, the installation of chiller equipment, linked to the power supply and control program can be used.

Disadvantage:

Cannot use the existing water frosting equipment, but only rely on electric heating for frosting.