Influencing factors of air entering the refrigeration system during cold storage operation

Influencing factors of air entering the refrigeration system during cold storage operation

In addition to the refrigerant, there are inevitably some mixed gases in the fresh-keeping cold storage refrigeration system. The main component is air, and there are some gases that are decomposed by oil and refrigerant at high temperatures. These gases will not condense under the condensation temperature and pressure of the refrigerant and are called non-condensable gases. Although the quantity is not necessarily large, it has a relatively large impact on the refrigeration system, and the system needs to be released in time. .

　　The factors that cause air to enter the refrigeration system when the cold storage is in use are:

　　 1. The refrigeration system was not completely evacuated before being put into production or after repair, so that some air remained in the system after the cold storage was installed.

　　2. When the Shandong cold storage is operating in the low-pressure system or the pressure in the crankcase is lower than the atmospheric pressure, air infiltrates into the system from the valve, shaft seal, etc. not tight.

　　3. When the cold storage is in operation, the compressor discharge temperature is too high, and some refrigerants and refrigerating machine oils have poor thermal stability, which will also decompose non-condensable gases.

　　4. When the cold storage device is used for daily repairs, some pipes and equipment are directly put into work without vacuuming.

　　5. When adding refrigerant and refrigerating oil, some air was brought in due to irregular operations, such as not thoroughly sweeping the air in the fluorine-filled tube.

　　The influence of air on the refrigeration system during cold storage operation:

If there is a small amount of air in the refrigeration system, it will accumulate in the condenser and the high-pressure accumulator to form an inert gas, which will cause thermal resistance to the heat transfer of the condenser, reduce the heat transfer power, and increase the condensation pressure and temperature, which will eventually lead to The cooling capacity of the refrigeration compressor has decreased and the power consumption has increased. At the same time, because air enters the system, the water content of the system is added, which corrodes the cold storage system pipes and equipment. When Shandong cold storage uses Freon to enter the air in the refrigeration system, it is more harmful.Because the presence of water vapor in the air can cause ice blockage, moisture can also chemically change with the refrigerant and adversely affect it, and it can be burned in severe cases. machine. In addition, if there is air in the system after the cold storage device is built, when the exhaust temperature is high, accidents are likely to occur when encountering oil vapor. Therefore, no matter what kind of refrigeration system, it is very necessary to sweep the air in the system.