Causes and elimination of air intake in the refrigeration system of industrial chillers

Causes and elimination of air intake in the refrigeration system of industrial chillers

Water-cooled industrial chillers and air-cooled industrial chillers are generally used in long-term working conditions. If there is a little leakage in the refrigeration system, air will enter the refrigeration system of the industrial chiller over time. Due to the industrial chiller The low-temperature refrigerant in the refrigeration system will not condense into liquid with the heat dissipation of the air, which will affect the heat dissipation effect of the condenser, cause the condensation pressure to rise, and cause the industrial chiller to fail to operate normally. Therefore, the air in the industrial chiller needs to be exhausted to maintain the normal operation of the industrial chiller.

　　 One, the operation steps of the industrial chiller of the Freon system

　　 1. Close the outlet valve of the accumulator or the outlet valve of the condenser;

　　2. Start the compressor and collect the refrigerant in the low-pressure section into the condenser or accumulator;

　　 3. After the low pressure system pressure drops to a stable vacuum state, it will stop;

　　4. Loosen the screw plug of the bypass hole of the exhaust shut-off valve and turn it about half a turn. The exhaust valve stem makes the valve into a three-way shape, allowing high-pressure gas to escape from the bypass hole. Block the exhaust airflow with the palm of your hand. When you feel cold air and oil stains on your hands, it means that the air has been basically exhausted. Tighten the screw plug, reverse the exhaust valve stem, and close the bypass hole.

　　 5. It should be noted that the time of each deflation should not be too long, and it can be performed continuously for 2 to 3 times to avoid wasting refrigerant. If the top of the condenser or reservoir is equipped with a backup shut-off valve, the air can also be discharged directly from the valve.

　　 2. Operation steps of industrial chiller venting of refrigerant refrigeration system

　　1. When using an air separator to discharge air, place the return valve of the air separator in a normally open state to reduce the pressure of the air separator to the suction pressure, and other valves should be closed.

　　2. Properly open the mixed gas inlet valve to allow the mixed gas in the chiller refrigeration system to enter the air separator.

　　3. Slightly open the liquid supply valve to throttle the refrigerant into the air separator to vaporize and absorb heat to cool the mixed gas.

　　4. Connect the rubber hose used for the air release valve interface and insert one end into the water in the water container. When the refrigerant in the mixed gas is cooled into ammonia liquid, frost will form on the bottom of the air separator. At this time, the air valve can be slightly opened to discharge the air through the water container. If the bubbles are round in the process of rising in the water and there is no volume change, the water is not turbid and the water temperature does not rise, then air is released. At this time, the opening of the air release valve should be appropriate.

　　 5. The refrigerant in the mixed gas is gradually condensed into refrigerant liquid and accumulated at the bottom. The liquid level can be seen from the frosting of the shell. When the liquid level reaches 12, close the liquid supply throttle and open the liquid return throttle. The bottom refrigerant liquid is returned to the air separator to cool the mixed gas. When the bottom frost layer is about to melt, close the liquid return throttle valve and open the liquid supply throttle valve.

　　6. ​​When stopping the air release, first close the air release valve to prevent the refrigerant from leaking out, and then close the liquid supply throttle valve and the mixed gas inlet valve. In order to prevent the pressure in the air release device from increasing, the return valve should not be closed.

　　 Three, the refueling method of industrial chiller rotary compressor

　　 When adding refrigerating oil to the rotary compressor, the low-pressure pipe of the compressor should be sealed (or closed the low-pressure valve) first, and the refrigerated oil should be poured into the oil cup. Connect the middle hose of the composite pressure gauge to the high-pressure exhaust pipe of the compressor, the high-pressure hose of the composite pressure gauge is connected to the vacuum pump, and the low-pressure hose is inserted into the oil cup. Start the vacuum pump first to evacuate the inside of the compressor, and then close the high-pressure valve of the compound pressure gauge. Then open the low pressure valve of the compound pressure gauge, so that the refrigerated oil in the oil cup is sucked into the compressor. When the oil is sucked to the specified amount, close the low pressure valve and stop refueling