What are the cold room refrigeration equipment?
Thermal expansion valve: the pressure at the outlet of the evaporator is felt under the membrane of the external balanced expansion valve. The thermal expansion valve is divided into internal balance expansion valve and external balance expansion valve. The inlet pressure of evaporator is felt under the inner balance expansion valve diaphragm;
In selection, ammonia refrigeration compressor can also be considered, because the power of ammonia refrigeration compressor is large, and one machine can be used for multiple purposes. Generally, the small refrigerator selects the fully enclosed compressor. A semi-enclosed compressor or screw compressor is selected for large cold storage. However, installation and management are rather cumbersome. Semi-closed compressors are generally used in medium-sized refrigerators.
Oil separator: generally, when the airflow speed is less than 1 m / s, the oil particles with a diameter of more than 0.2 mm in the steam can be separated. According to the principle of oil separation, which can reduce the velocity of airflow and change the direction of airflow, the oil particles in high-pressure steam can be separated under the action of gravity. The commonly used oil separators are washing type, centrifugal type, packing type, and filter type. Its function is to separate the lubricating oil in the high-pressure steam discharged from the refrigeration compressor, to ensure the safe and efficient operation of the device.
Evaporator: the evaporation exhaust pipe made of a seamless steel pipe is mainly used in the medium and low-temperature cold storage, which is characterized by good constant temperature effect and timely cold storage. Generally, the fan is used as an evaporator in the high-temperature storehouse, which is characterized by fast cooling speed, but easy to cause water loss of cold collection;
Solenoid valve: when the cold storage temperature reaches the set value, the temperature controller acts, the solenoid valve loses power, and when the low pressure reaches the set value of shutdown, the compressor stops. When the temperature in the cold storage rises to the set value, the temperature controller acts, the solenoid valve is powered, and when the low pressure rises to the set value of the compressor startup, the compressor starts. Prevent the high-pressure refrigerant liquid from entering the evaporator when the compressor is shut down, avoid the high low-pressure when the compressor is started next time, and prevent the liquid hammer of the compressor.
Condenser: air cooling is only used in small cold storage equipment, while water cooling condenser can be used in all forms of refrigeration system. Condenser has air cooling, water cooling and air and water combined cooling mode.
How to maintain the cold room refrigeration equipment after installation
1. The method is to install a pressure gauge with a range of 0 ~ 2.5MPa on the standby channel of the high-pressure stop valve of the compressor, and a pressure gauge with a range of - 0.1 ~ 1.6Mpa on the multi-purpose channel of the low-pressure stop valve of the compressor. Connect the spare port of low-pressure stop valve of the compressor with nitrogen cylinder, connect the pressure pipeline, use the interface of the dry filter as the test port, open the nitrogen cylinder valve, use the nitrogen with 0.6MPa gauge pressure to blow the low-pressure section of the system, still use white paper to put on the air outlet to check whether there is any dirt, after confirming that there is no dirt, after the completion of the blowdown process, the refrigeration system of small cold storage shall be pressurized Leakage test.
2. Then quickly pull out the wooden plug and use the high-speed airflow to discharge the dirt in the system. Put a piece of white paper on the air outlet to check whether there is any dirt. It depends on the cleanliness. If the white paper is clean, it means that there is no dirt washed out with the gas. Stop blowing. Connect the spare port of high-pressure stop valve of compressor and nitrogen cylinder with pressure pipe, remove the drying filter from the system, open the nitrogen cylinder valve, blow the high-pressure section of the system with nitrogen with a gauge pressure of 0.6MPa, and stop charging after the pressure reaches gauge pressure of 0.6MPa.
The procedure of the cold room refrigeration equipment and installation company is to blow the dirt of the high-pressure part of the refrigeration system first, and then the dirt of the low-pressure part of the refrigeration system. After the refrigeration system is installed, the method of purging is to purge the refrigeration system in sections. The drain outlet of the refrigeration system shall be selected at the lowest point of each section, and the drain outlet of each section shall be fastened with a wooden plug in advance.