Precautions for operation of cold storage evaporator

Precautions for operation of cold storage evaporator

Cold storage evaporators can be divided into two categories: air coolers and cooling pipes. Air coolers are generally used in cooling rooms, freezing rooms and cooling reduction rooms for cooling objects. Due to different installation positions, they can be divided into floor-mounted air coolers and ceiling-mounted air coolers. Cooling pipes are often used in refrigeration rooms for frozen objects, and cooling pipe evaporators are also used in general small refrigerators.

　　 1. Operation of air cooler

　　 The air cooler should be in good condition before starting, the anchor bolts of the fan and the motor should not be loosened, the blades and the protective cover and the air duct should not be rubbed, the rotation should be flexible, and the bearing should be well lubricated.

　　 Before starting the air cooler, open the return valve of the evaporator coil and then open the liquid supply valve. Then turn on the power and start the air cooler to run. It should be noted that the rotation speed of the fan should be normal during operation, and there should be no noise when the fan and motor are running, the working current of the motor should not exceed the rated current value, and the temperature of the motor and the motor bearing should not be too high.

　　 During normal operation, the surface of the cooling fan's evaporation coil should be evenly frosted. If it is found that the frosting is uneven, it means that the liquid supply is abnormal, and it should be adjusted, and the liquid supply valve should be opened appropriately to increase the liquid supply. If the frost layer is too thick, the fin gap of the evaporation coil will be blocked by the frost layer, which will hinder air circulation, reduce heat exchange efficiency, and make it difficult to cool the cold room. So when the frost is too thick, you should rinse it in time. The air cooler in the freezing room should be frosted regularly.

　　 When the air cooler is stopped, the liquid supply valve should be closed first, and the liquid supply to the evaporating coil of the air cooler should be stopped. After the pressure of the evaporating coil drops, the air return valve should be closed to cut off the power of the fan motor and stop the operation of the air cooler.

　　2, the operation of the cooling pipe

　　 The cooling pipe is a natural air convection heat exchange evaporator. Except for the operation without a fan, the liquid supply operation procedure is basically the same as that of the air cooler. When the cooling pipe is running, first open the air return valve and then slowly open the liquid supply valve to supply liquid to the cooling pipe.

　　 When the cooling pipe is working normally, the surface of the pipe should be evenly frosted, and the size of the liquid supply can be judged according to the frosting situation. Excessive liquid supply may cause the compressor to produce a wet stroke, and too little liquid supply will not completely frost the surface of the pipe, which will affect the cooling of the cold room. Therefore, the opening degree of the liquid supply valve should be adjusted frequently according to the actual situation. When the cooling pipe is too thick, it should be frosted in time to avoid affecting heat exchange.

　　 When too much oil accumulates in the cooling pipe, the lubricating oil occupies the space of the ammonia liquid and at the same time forms an oil film on the inner wall of the pipe, which seriously affects the heat exchange and makes it difficult to cool the cold room. At this time, the frost should be flushed in time to take the oil out of the cooling pipe, or it can be discharged from the special oil drain pipe to the low-pressure oil collector for treatment.

　　 When the cooling pipe stops running, the liquid supply valve should be closed first to stop the liquid supply, and the return air valve should be closed after the pressure drops.