Cooling Operation of Ammonia Refrigerated Cold Storage

Before cooling the cold storage, the control valves of the refrigeration system should be inspected and adjusted to ensure the smooth flow of the low-pressure system pipelines in the storage that needs cooling. The high-pressure pipelines, liquid storage devices, and high-pressure pressure regulating stations from the compressor to the condenser must also be opened. At the beginning of cooling, liquid should be properly delivered to the evaporator. After a certain amount of ammonia liquid exists in the system, the ammonia compressor should be started according to the normal startup procedure so that the machine can be put into normal production.

Adjust the amount of liquid supplied to the evaporator to keep the ammonia liquid operating normally in the system and gradually reduce the temperature of the storage tank. After the temperature of the storage reaches a certain level, the liquid supply stops, the compressor is shut down, and the temperature is paused. After a specified time, the temperature continues to drop until it meets the design requirements.
When cooling the cold storage, the storage door should be tightly closed to ensure good frosting of the evaporator tubes. The cold storage is mainly used as a constant-temperature cold storage air-conditioning equipment for food, dairy products, meat, aquatic products, chemicals, medicine, seedling cultivation, scientific experiments, etc. The cooling situation of the storage room should be well recorded. The temperature of the storage tank should reach the design requirements before cooling can be stopped. Observe and record the temperature rise.
Cooling means that if the temperature of the oil storage layer does not drop and cannot meet the design requirements, the reasons should be analyzed and appropriate treatment should be taken. The cold storage is mainly used for constant-temperature storage of food, dairy products, meat, aquatic products, poultry, fruits and vegetables, cold drinks, flowers, green plants, tea, pharmaceuticals, chemical raw materials, electronic instruments and meters, etc. The reasons for the drop in temperature of the storage tank are various, and the selection of the designed refrigeration system may also be unreasonable. For example, the capacity of the compressor is too small, the caliber of the throttle valve or the pipe diameter is unreasonable, and the evaporation surface of the evaporator in the warehouse is not enough. It may also be due to incorrect installation of the nozzle, improper installation location, partial blockage of the pipeline, no frosting of the evaporator, improper adjustment of valves in the operating system, insufficient liquid supply to the evaporator, etc. Specific analysis should be made according to specific circumstances for special treatment.

After cooling, if the temperature of the reservoir rises rapidly, it should be checked whether the insulation layer is uneven or damp and the construction quality is poor.