1. Refrigerant leakage
[fault analysis] After the refrigerant leak in the system, the cooling capacity is insufficient, the suction and exhaust pressure are low, and the expansion valve can hear much larger intermittent “squeak” air flow than usual.The evaporator is not frosted or with a small amount of frosting. If the expansion valve hole is enlarged, the suction pressure remains unchanged.After the shutdown, the equilibrium pressure in the system is generally lower than the saturation pressure corresponding to the same ambient temperature.
2. Too much refrigerant is filled after maintenance
[fault analysis] When the refrigerating dose filled in the refrigeration system after maintenance exceeds the capacity of the system, the refrigerant will occupy a certain volume of the condenser, reduce the heat dissipation area, and reduce its refrigeration efficiency. Generally, the suction and exhaust pressure are higher than the normal pressure value, the evaporator is not frosted, and the temperature in the warehouse is slow.
3. Air in the refrigeration system
[fault analysis] The air will reduce the refrigeration efficiency in the refrigeration system. The prominent phenomenon is the increase of suction and exhaust pressure (but the exhaust pressure has not exceeded the specified value). The temperature of the compressor at the inlet of the condenser is significantly increased.
4. Low compressor efficiency
[fault analysis] The low efficiency of refrigerating compressor refers to the reduction in the response of refrigerating volume due to the decrease of the actual exhaust volume under the condition that the working condition remains unchanged.This phenomenon usually occurs on compressors that have been used for a long period of time, with large wear and tear, large clearance of all components, and decreased sealing performance of air valves, which results in the decrease of actual air discharge.
5. The surface of evaporator is frosted too thick
[fault analysis] Long-term use of cold storage evaporator should be regularly defrosted. If the frost is not defrosted, the frost layer on the evaporator tube becomes thicker and thicker. When the whole pipeline is encased in transparent ice, the heat transfer will be seriously affected, causing the temperature in the reservoir to fall below the required range.
6. There is frozen oil in the evaporator pipeline
[fault analysis] During the refrigeration cycle, some frozen oil remains in the evaporator pipeline. After a long period of use, a large amount of oil remains in the evaporator, which will seriously affect its heat transfer effect and lead to poor refrigeration.
7. The refrigeration system is not smooth
[fault analysis] Because the refrigeration system is not clean, after several hours of use, the dirt is gradually silted up in the filter and some mesh holes are blocked, resulting in the reduction of refrigerant flow and affecting the refrigeration effect.
In the system the expansion valve, the compressor suction nozzle at the filter screen also has a small plug phenomenon.
8. The filter is blocked
[fault analysis] When the desiccant is used for a long time, it becomes paste to seal the filter, or the dirt gradually accumulates in the filter, causing blockage.
9. Leakage of refrigerant in the expansion valve sensible temperature package
[fault analysis] After the leakage of the temperature sensor in the expansion valve’s temperature sensor package, two forces under the diaphragm push the diaphragm upward. It is the valve hole closed.
10. Cold air cooling condenser has poor cooling effect in the cold storage
[fault analysis]
⑴The fan is not on.
⑵Parliamentary fan motor damaged.
⑶Torque fan reverse.
⑷high ambient temperatures (40 ℃ above).
⑸Flow of condenser cooling fins blocked by oil and dust.
11. The cooling effect of water-cooled condenser is poor
[fault analysis]
⑴The cooling water valve is not opened or opened too small, and the inlet pressure is too low
⑵Potassium water regulating valve fails.
⑶The scale on the wall of the condenser pipe is thicker.
12. Too much refrigerant is added into the system
[fault analysis] Too many refrigerants lead to a significant increase in the exhaust pressure, exceeding the normal value.
13. Residual air in the system
[fault analysis] The air circulation in the system will lead to excessive exhaust pressure, high exhaust temperature, hot exhaust pipe, poor refrigeration effect, the compressor will operate soon, and the exhaust pressure will exceed the normal value.
14. Stop when the suction pressure is too low
[fault analysis] When the suction pressure in the system is lower than the set value of the pressure relay, its contact action will cut off the power supply.
15. The temperature controller is out of control
[fault analysis] The thermostat fails to adjust or the temperature sensor package is improperly installed.
16. Sudden stop caused by other reasons
[fault analysis] In the process of use and maintenance, it is often necessary to open, close the exhaust, inhale, and store the liquid, etc.
Welcome to HERO-TECH !!
Post time: Dec-14-2018
