Five common problems of refrigeration system

1、 Treatment of insufficient refrigerant: 1 Fault phenomenon: The refrigeration effect of the whole machine is poor, the water outlet is only a little cold, and the pressure on the high-pressure side and the low-pressure side is found to be low by the manifold pressure gauge inspection (under the normal speed of the compressor, when the ambient temperature is about 35 ℃, the low-pressure gauge index is lower than 1kg / cm2, and the high-pressure gauge index is lower than 10kg / cm2) At the same time, bubble flow can be seen from the sight glass 2 Cause of failure: there is a refrigerant leakage point in the refrigeration system, which leads to insufficient refrigerant 3 Treatment method: 1) use electronic leak detector to find out the leakage point and repair or replace the parts 2) if the parts are not replaced, only appropriate amount of refrigerant shall be added; if the parts are replaced, appropriate amount of refrigerant oil shall be added as required, and sufficient refrigerant shall be added after the system is vacuumized Five common problems of refrigeration system, each broken! II Over filling of refrigerant: 1 Failure: poor refrigeration effect It is found that the pressure at high pressure side and low pressure side is too high when the manifold pressure gauge is used for inspection (when the compressor speed is normal and the ambient temperature is 35 ℃, the pressure at high pressure gauge is about 19kg / cm2, and the pressure at low pressure gauge is 2.3kg/cm2, and there is no bubble flow in the sight glass 2 Cause of failure: too much refrigerant is filled in the refrigeration system, so that the refrigeration capacity cannot be fully developed, resulting in poor refrigeration effect 3 Treatment method: connect the manifold pressure gauge in the system, slowly loosen the manual valve on the low-pressure side of the manifold pressure gauge, so that the refrigerant can be slowly discharged (it can not be discharged from the high-pressure side, because the refrigerant discharged from the high-pressure side will bring a large amount of refrigerant oil), until the high-low side pressure is normal, at the same time, the refrigerant can be seen clearly flowing from the sight glass, and occasionally there are bubbles flowing through III air mixed in the refrigeration system: 1 Fault phenomenon: The refrigeration capacity of the whole machine is reduced; when the manifold pressure gauge is used for inspection, it is found that the pressure on the high-pressure side is high, and sometimes the pressure on the low-pressure side is higher than the normal value (when the compressor speed is normal and the ambient temperature is 35 ° C, the pressure on the high-pressure side is higher than 20kg / cm2; the pointer of the high-pressure gauge swings; on the other hand, many bubbles flow can be seen from the sight glass 2 Fault cause: air is mixed in the system Mainly after assembly or overhaul, the vacuum pumping is not complete; when filling refrigerant or adding refrigeration oil, the air will be brought into the system, or when the system is working under negative pressure, the air will be mixed through the airtight place When there is air in the refrigerant, it has a certain pressure, and the refrigerant also has a certain pressure In a closed container, the total pressure of the gas is equal to the sum of the pressure of each part, so the readings of the high and low pressure gauges are higher than the normal values 3 Treatment method: 1) discharge the refrigerant (slowly discharge it from the low pressure side with the pressure gauge) 2) check the cleanliness of compressor oil 3) refill refrigerant after vacuumizing IV "ice jam" occurs in the refrigeration system 1 Failure: the refrigeration system periodically cools and does not cool During the operation, the pointer on the low-pressure side of the manifold pressure gauge often fluctuates between the negative pressure and the normal value 2 Fault cause: the refrigerant in the refrigeration system is mixed with water, because the water and refrigerant are insoluble, when the refrigerant flows through the throttle hole of the expansion valve, the temperature drops suddenly, and the water mixed in the refrigerant is easy to be in the throttle hole or Small ice particles are formed around the valve pinhole, which are spherical or hemispherical When the ice particles are formed to a certain extent, the throttling channel is blocked and ice blockage fault is formed When ice jam occurs, the refrigeration system can not work normally, and the refrigeration effect is obviously reduced, even no refrigeration At this time, the negative pressure appears on the low-pressure gauge, so the temperature at the ice blockage obviously rises, the ice particles in the ice blockage melt into water, so that the ice blockage disappears, the refrigeration system returns to normal operation, the refrigeration is good, and the pressure at the low-pressure side returns to normal After a while, the system appears ice jam again, and the system is not working normally 3 Treatment method: 1) since the desiccant is in the oversaturated state, it is necessary to replace the reservoir with desiccant and add 30ml of refrigeration oil 2) vacuum the system and add the specified amount of refrigerant V troubleshooting of dirty blockage: 1 Fault phenomenon: poor refrigeration effect or no refrigeration When the air conditioning system is running, the readings of the high / low pressure gauge on the manifold pressure gauge are all lower than the normal value, (when the compressor speed is normal and the ambient temperature is about 35 ℃, the pressure on the high pressure gauge side is lower than 9kg / cm2, and the pressure on the low pressure side is in the negative pressure state), and there is frost or condensation on the front and rear pipes of the filter and capillary 2 Fault cause: in the refrigeration system, the dust is bound or attached to the filter screen at the inlet of the filter, or at the interface between the capillary and the filter screen, which causes the local throttling phenomenon, namely, the temperature drops rapidly, and condensation or frosting occurs 3 Treatment method: if there is frosting at the inlet of the filter, and the intermittent air flow sound is heard, tap the filter body with a small wrench, the air flow sound will be changed At the same time, the frost layer in front of the filter and the capillary will melt, so it can be judged that the filter inlet screen is blocked At this time: ① remove the capillary, clean the filter screen and dry it, and then install it again Or replace the filter ②, vacuumize and fill the refrigerant to the specified amount.