The high and low temperature damp heat test machine refrigeration system is a sealed circulation system. The refrigerant circulating in the system requires clean and impurity-free, but it is impossible to completely clean in actual operation, which is related to the working conditions and the refrigerant that is added to the system is not clean enough. . The impurities are: lubricating oil, air, water, etc. These impurities enter the high and low temperature damp heat test machine refrigeration system is very unfavorable for the work of the refrigeration device, and should be eliminated in time.
1, water
Water entering the high and low temperature damp heat tester system will lead to an increase in evaporation temperature. Freon is a high-low temperature damp heat tester refrigeration system with refrigerant. Freon contains water and corrodes the metal (allows 0.0025%); due to Freon sparing Into the water, it is also easy to cause ice plugs in the expansion valve and the like. Ways and preventive measures for water to enter the system:
(1) The air is not evacuated during installation or overhaul, or the evacuation is not complete. Precautions: Air is evacuated during installation or overhaul and a dryer is installed.
(2) Entering from an unsealed location. Precautions: Do not have leaks and avoid negative pressure operation.
(3) There is moisture in the oil or refrigerant. Precautions: Strictly control the moisture content of the added oil or refrigerant. In addition, since the oil is absorbing water, the long-term open storage tank will absorb moisture and the oil drum should be closed.
2, air
When air enters the refrigeration system, the pressure of the condensate in the high and low temperature damp heat tester system increases, the total pressure rises, and the air forms a gas layer on the surface of the condenser, generating additional thermal resistance, which reduces the heat transfer efficiency and causes the condensation pressure. And the condensing temperature rises, the power consumption increases by about 6~8% for every 1kg/cm2 of condensing pressure. In addition, the adiabatic index of air (k=1.41) lies in the adiabatic index of the refrigerant, which causes the temperature of the exhaust gas to rise, and air should be released in time.
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