Cold storage after replacing expansion pneumatic valve must be emptying technology performance impact adjustment operation

expansion pneumatic valve is an important part of refrigeration system, cooling system, general installation between the liquid storage tube evaporator and evaporator. Expansion pneumatic valve make medium temperature high pressure liquid refrigerant through the throttle into low temperature low pressure wet steam, then the refrigerant in the evaporator absorbs heat cooling effect, expansion pneumatic valve to control by the end of the evaporator superheat changes flow pneumatic valve, preventing evaporator area is underutilized and knocking phenomenon. Cold storage after replacing expansion pneumatic valve in the original system refrigerant were recycled to the accumulator or condenser, emptying operations must be conducted.

replace expansion pneumatic valve, the original system of refrigerants were recycled to the accumulator or in the condenser. Replacement after emptying of operation is as follows:

accumulator or condenser of a hydraulic pneumatic valve remains closed, open the compressor suction pneumatic valve, vent pneumatic valve closed compressor, open the exhaust pneumatic valve beside his, start the compressor, the accumulator or condenser after the hydraulic pneumatic valve to the air compressor for his discharge from the exhaust of the pneumatic valve, after waiting for low pressure stable in a vacuum or exhaust pneumatic valve beside his no gas discharge, close vent pneumatic valve beside his downtime, emptying after operation.

if you have any pressure control, the low pressure short row of unprecedented should be the controller run, so they don't jump when the vacuum.

emptying after operation should be all pneumatic valve and the controller according to the normal operation of the recovery.

see you above a few can lead to the body outside the refrigeration machine pneumatic valves, pneumatic valves on the top is often used to air, pneumatic valves are often used to row on the bottom of the water. Because you change the pneumatic valve, possible into the air inside the exhaust pipe, can be divided into many times. Specific operation:



normal start the machine, when the exhaust table pointer and shaking, show the body with the air, and then shut down, shut down all pneumatic valves, from the highest to pneumatic valve on the outside of the body after a hose ( General water pipe, the other side of the hose into containers of water, open the pneumatic valve, begins to appear a bubble in the water pipe, this is the air, behind no bubble, gradually close the pneumatic valve, a drain end, generally no more than a minute.

according to this method, multiple operation, the exhaust pressure gauge has a relatively stable at work, illustrate exhaust air in the system, can work normally.

the stand or fall of expansion pneumatic valve technical performance, can directly affect the normal adjustment operation. Usually prone to filter blockage, heat leakage fault. Caused by adjusting reaction insensitive, regulation or cannot adjust, etc. When there is frost expansion at the inlet of the pneumatic valve ( Or pneumatic valve cover frost, the temperature of the liquid into the tube is lower than normal temperature, even condensation; The compressor suction pressure is lower than the library under the temperature corresponding to the pressure, machine high temperature and exhaust temperature, cooling temperature decrease slowly or not, enough to illustrate expansion pneumatic valve filter blockage, there are dirty or ice blocking phenomenon.

processing methods: closed fluid for total pneumatic valve, open the compressor operation, inspiratory pressure is stable in the following, vent pneumatic valve closed compressor, stop at the end of the closed compressor work ( Fluorine is. Open expansion pneumatic valve inlet fluid inlet, remove the filter back into refrigerator export after cleaning, dry and replace infusion filtering agent or filters, check the infusion after recovery performance of pneumatic valve ( Check is clean. Open the compressor exhaust beside his ( Other are still closed state of fluorine in, boot operation, let the total pneumatic valve to the compressor body fluid for all his spare from the exhaust air, stay inspiratory pressure stability when under vacuum ( Extraction and closed his exhaust, open compressor exhaust pneumatic valve, pneumatic valve and fluid for total system resumed

pressure generally greater than the suction pressure. — 。 Mpa, and also check the suction of frosting condition. Evaporating pressure is too high. Rime and knot to the suction of the end of the pneumatic valve, said inflation through traffic is too big, should be a little down at this time. Whereas evaporating pressure is too low, rime knot not breathe in the front-end pneumatic valve, said expansion pneumatic valve flow small, at this time should be slightly larger. At the discretion of the judge evaporating pressure, cannot too impatient, only when the equipment operation for a period of time ( At least more than an hour the evaporating pressure there will be no big change, and frozen and refrigerated indoor heat load under the condition of little change, is the right temperature and pressure.

if expansion pneumatic valve flow xiaoke it manually later. If the suction pressure rise is not big may be expanding the mesh of the front-end pneumatic valve block, according to the provisions of after cleaning can be ruled out.