Refill refrigerant for cold storage system
The working procedure for charging refrigerant to the refrigeration system of the cold storage unit should be carried out after the vacuuming of the refrigeration system is completed to prevent the infiltration of air due to the internal vacuum of the system.
Before adding refrigerant to the refrigeration system of the unit, the circuit of the solenoid valve in the system should be connected to make it in the open state. When adding refrigerant for the first time, add liquid refrigerant from the shut-off valve of the unit's high-pressure valve or the liquid filling port on the accumulator. If possible, a filter drier can be installed on the filling pipe between the unit and the freon cylinder to prevent moisture and impurities in the refrigerant from entering the system.
The first filling amount of cold storage refrigerant can be filled according to 80% of the rated value of the refrigeration system demand, and the first filling amount should not be too much.
For large-scale ice machines or cold storage, after filling, the unit is stationary for about 30 minutes, and after the internal pressure of the refrigeration system of the standby group is stable, the compressor can be started (for water-cooled units, the cooling water system should be turned on first), and observe the refrigeration The operating state of the refrigerant can generally be judged by observing the refrigerant flow state from the system sight glass to determine whether the refrigerant filling amount is appropriate. If the refrigerant is insufficient, a proper amount of gaseous refrigerant can be filled from the low pressure detection port until the sight glass The medium bubbles disappear, the evaporator is covered with uniform frost, and the compressor return pipe is covered with thin frost, it can be determined that the refrigeration system is filled with the appropriate amount of refrigerant.
In most cases of cold storage refrigeration system, gas or liquid refrigerant can be charged from the low pressure side. When the refrigerant charge is large, the liquid charging method can also be used to charge the refrigerant from the high pressure side. requires attention! If the liquid refrigerant is charged from the low pressure side, it must be added slowly to avoid liquid shock! If you are afraid of liquid shock, it can also be filled in gaseous state.
The method of adding refrigerant from the low pressure side:
When charging gaseous refrigerant from the low-pressure side, first turn the low-pressure three-way stop valve counterclockwise to the end, and then connect the fluorine cylinder's fluorine cylinder to the bypass wire seat of the low-pressure three-way stop valve, and then open it For the bottle valve of the R22 fluorine bottle, loosen the joint of the bypass wire seat of the three-way stop valve slightly, and use R22 gas to drive out the air in the fluorine pipe. When you hear the sound of "sizzling" at the joint Immediately lock it, and refrigerant charging begins.
When the injection volume reaches the specified quality, close the fluorine bottle shut-off valve, turn the low-pressure three-way shut-off valve counterclockwise to the end, close the bottle valve of the R22 fluorine bottle, remove the fluorine pipe, and the fluorine addition work is complete.