1. Operation of the condenser

1) When the refrigeration system is running, all the other valves of the condenser should be opened except the oil drain valve and the air drain valve are closed.

2) The maximum condensing pressure of the water-cooled condenser should not exceed 1.5MPa, otherwise the cause should be found out and eliminated in time. The water supply to the condenser can be stopped only after the compressors are all shut down for 15 minutes. When stopping work for a long time in winter, the stored water should be drained to avoid freezing damage to the equipment.

3) Always check the temperature and water volume of the cooling water, the temperature difference between the inlet and outlet of the cooling water is about 2-4 points, and the condensing temperature is generally 3-5°C higher than the outlet temperature of the cooling water.

4) The dirt on the tube wall of the condenser should be regularly removed and the thickness of the dirt should not exceed 1mm, generally once a year.

5) Check whether there is ammonia in the effluent of the condenser every month. If there is ammonia in the water, it will turn red when it encounters phenolphthalein. When there is leakage in the fluorine condenser, there will be oil pollution. The leakage of the condenser should be found in time for timely maintenance.

6) The placement of the vertical shell and tube condenser water separator should be appropriate, the water should be evenly distributed along the inner wall of the pipeline, and the water volume should be sufficient.

7) The cooling water of the horizontal shell and tube condenser should be poured from the bottom to the top, and the cooling water should not be interrupted during operation.

8) When the evaporative condenser is running, the exhaust fan and the circulating water pump should be started first, and then the air inlet valve and the liquid outlet valve should be opened. The water spray nozzle should be unblocked, the water spray should be uniform, and the scale should be cleaned once a year.

9) Air-cooled condensers should always use compressed air to clean the accumulated dust on the tube wall and cooling fins to improve heat transfer efficiency.

10) When multiple condensers are used in combination, it is necessary to determine the number of condensers, the required amount of cooling water and the number of pumps to operate. It should be based on parameters such as the load of the compressor and the temperature of the cooling water, so as to achieve the economical and efficient operation of the refrigeration system. reasonable and safe operation.

Second, the operation of the evaporator

Cold storage cold room evaporators can be divided into two categories: air coolers and cooling exhaust pipes.

Air coolers are generally used in cooling rooms, freezing rooms and cooling-reduction rooms, and can be divided into floor-type air coolers and ceiling-type air coolers due to different installation locations. Cooling pipes are often used in freezer rooms for frozen materials, and general small refrigerators also use cooling pipe evaporators.

Operation of the air cooler. During normal operation, the surface of the evaporative coil of the air cooler should be frosted evenly. If it is found that the frosting is uneven, it means that the liquid supply is not normal, 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 the air circulation, reduce the heat exchange efficiency, and make it difficult to cool down the cold room. So when the frosting is too thick, it should be washed in time.

The cooling fan in the freezing room generally needs to be flushed regularly. When the cooling fan is stopped, the liquid supply valve should be closed first, and the liquid supply to the evaporative coil of the cooling fan should be stopped. After the pressure of the evaporating coil has dropped, the air return valve should be closed, the power supply of the fan motor should be cut off, and the operation of the cooling fan should be stopped.

Operation of the cooling pipe. When the cooling exhaust pipe is working normally, the surface of the exhaust pipe should be frosted evenly, and the amount of liquid supply can be judged according to the frosting situation. Too much liquid supply may cause wet stroke of the compressor, and too little liquid supply will cause frost on the surface of the exhaust 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 frost on the cooling exhaust pipe is too thick, it should be flushed in time to avoid affecting the heat exchange. When there is too much oil in the cooling exhaust pipe, the lubricating oil occupies the space of the refrigerant, and at the same time, an oil film is formed on the inner wall of the exhaust pipe, which seriously affects the heat exchange and makes it difficult to cool the cold room.