D series of pyrolysis, electrolysis and hydrolysis: comparison with DL, DD and DJ evaporators
Hot air thawing is the third technical alternative. Compared with electrolysis and D series water thawing, it is less used, but it has specific advantages for some types of industrial freezing rooms. Its working principle is to melt the frost on the wing of evaporator DL,DD or DJ by using hot steam from compressor.
In the hot gas thawing cycle, the evaporator fan is turned off, and the hot gas is transferred from the compressor to the evaporator pipeline. The heat inside the pipe melted the frost from the inside out. Do not use resistors or spray water.
Its main advantage is very low energy consumption. It uses the residual heat of the compressor, so the additional cost of each thawing cycle is obviously lower than that of electrolysis. Unlike D series hydrolysis, it does not need to install water pipes, filters or water supply systems.
It has important limitations. Hot gas defrosting needs to add additional components in the cooling circuit: exhaust valve, size pipes and specific controls. Compared with the other two solutions, the initial investment of refrigeration circuit is significantly increased.
When the temperature of the compressor is low, it is ineffective under the condition of very low load. If the gas does not reach enough temperature, the melting is incomplete and frost residue is left on the wings. Therefore, it is best to work in compressor facilities with medium and high heat load.
Quick comparison: Electrolysis is the simplest and most universal, and it is suitable for super freezer without water. D series hydrolysis emits light in a room with high humidity and moderate temperature. Hot gas defrosting is attractive for large facilities with many evaporators, in which it is sought to greatly reduce the defrosting power consumption.
Not all DL, DD and DJ evaporators can adapt to hot gas thawing. Special configuration of pipeline internal circuit that needs to be defined in the factory; You can't turn a standard evaporator into a job.
The condensers FNH,FNV,FNVT remain stationary or run at reduced speed during the hot air thawing cycle. System control should manage this stage to avoid abnormal pressure peak on the high pressure side.
FAQ
Where does the heat of hot gas thawing come from? It uses the hot steam discharged directly from the refrigeration compressor.
Do water pipes need to be thawed with hot gas? No, this is one of the advantages of its hydrolysis with D series.
What are its main limitations? It requires additional cooling circuit components and hot enough gas.
Can the standard evaporator be used for hot gas thawing? No, it needs special internal circuit configuration in the factory.
Which condensing devices play a role in the hot gas thawing process? The FNH, FNV and FNVT capacitors operate at low speed during the thawing cycle.
Key words: hot air thawing, electric thawing, D series water thawing, DL series air cooler, DD series air cooler, DJ series air cooler, FNH condenser, FNV condenser, FNVT condenser, thawing cycle.
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