Evaporator frosting will increase thermal resistance and decrease heat transfer coefficient. It will affect the normal use of cold storage. So we should pay attention to the maintenance of the evaporator in the cold storage. How to defrost in time?
1. Manual defrosting
Advantage: Simple and easy operation and small impact on storage temperature
Disadvantage: High labor intensity and incomplete defrosting
2. Water defrosting, spray the water to the evaporator surface through the spray device to make the frost layer melt, and then discharge the water through the drainage pipe
Advantage:High efficiency, simple operation procedure and small fluctuation of storage temperature
Disadvantage: It is easy to cause fog in the cold storage, water dripping on the ceilin panel, reducing the service life
3. Hot gas defrosting, using the heat from the compressor to melt the frost layer on the evaporator surface
Disadvantage: The defrosting time is longer, which has a certain influence on the cold storage temperature
4. Electric defrosting: defrost by heating electric elements
Advantage: It is easy to operate and realize automation
Disadvantage: It consumes a lot of power.
When the actual scheme is determined, a defrosting scheme can be used, or different schemes can be combined. For example, the cold storage shelving pipe, the wall and the top pipe can be manual defrosting combined with hot gas defrosting. The manual defrosting can be carried out at ordinary times, and the hot air defrosting can be carried out regularly, so as to thoroughly remove the frost that is not easy to be removed by manual defrosting and discharge the accumulated oil in the pipeline. The air cooler is flushed with water defrosting and hot gas defrosting . Hot gas defrosting combined with water defrosting can be used for frequent defrosting in cold storage.