The core problem of compressor oper
The temperature status and failure causes of the unit components of various commercial central air conditioning systems
As we all know, refrigerators are divided into screw refrigerators and other different types of refrigerators, but this is classified by compressors, and by the heat dissipation method and cooling system, the refrigerators can be divided into common air cooling and water cooling Of course, there are oil cooling and natural cooling, but z* common industrial refrigerators are water-cooled and air-cooled. Let’s talk about the difference between water-cooling and air-cooling systems of refrigerators. .
One, compressor discharge temperature
1, normal range:
When the compressor is in the cooling state in summer, the exhaust temperature is relatively high, so please don't touch it with your hands. For example, the exhaust temperature of R22 (refrigerant type) refrigeration system does not exceed about 125°C.
2, failure:
(1) The reason for the excessively high exhaust temperature is the excessively high suction temperature of the compressor or the excessively high condensation temperature, which must be paid attention to.
(2). The exhaust temperature is too low, and the exhaust pipe is not hot when touching the exhaust pipe by hand. This indicates that the suction temperature is extremely low, and the compressor may run on wet stroke or run with very little system refrigerant.
Compressor wet stroke operation is easy to damage the valve structure; the operation of the refrigerant is especially rare, which will affect the heat dissipation of the motor winding and accelerate the aging of the insulating material.
2. Compressor shell temperature
1. Normal range:
(1). The upper casing is affected by the inhalation of steam. The temperature is relatively low, and it is in the slightly hot or slightly cooler range. It is estimated to be around 30°C. There may be condensation on the surface of the casing around the suction pipe.
(2) The heat generated by the motor in the lower casing and the frictional heat carried by the refrigerating oil are mainly carried out of the casing by steam.
2, failure:
(1) The surface temperature of the case exceeds the normal range, mainly because the suction temperature of the refrigeration system is too high. Excessively hot steam bursts into the compressor, and after absorbing the heat in the casing, the temperature of the steam becomes higher, thereby increasing the temperature of the casing.
(2) The temperature of the shell surface is lower than the normal range, the reason is that the suction temperature is too low. It is beneficial to the cooling of refrigerating oil and motor windings, but the cooling capacity has decreased.
Three, the temperature of the condenser
1, normal range
Under normal circumstances, the front half of the radiating pipe is very hot, and its temperature tends to decrease gradually. Compared with the front half, the heat sensitivity of the rear half of the radiating pipe is greatly reduced.
2, failure:
The refrigerant in the second half of the condenser tube has gradually liquefied and reached the condensing temperature and supercooling temperature. When an abnormal situation occurs, the latter part is usually close to normal temperature (ambient temperature). The reason is that the refrigerant quantity of the compressor is insufficient; in addition, if the entire condenser tube is very hot, it is mostly due to excessive refrigerant quantity or low ventilation, or Caused by high ambient temperature.
Fourth, the temperature of the shell and tube water-cooled condenser
1, normal range
Normally, the upper part is relatively hot, and the lower part is warm.
2, failure:
If the entire shell is not too hot, it may be due to insufficient refrigerant; if the entire shell is very hot, it may be due to insufficient cooling water or poor heat dissipation (fouling in the water pipe).
5. The temperature of the filter
1, normal range
Under normal circumstances, the suction tube feels very cold to the touch with dew.
2, failure:
If the filter becomes cold, it may be because the filter mesh is blocked by sludge, which makes the filter not unblocked. When the refrigerant flows through the filter mesh, throttling occurs; if the filter is not hot, it is equivalent to the ambient temperature. It is because the filter is completely blocked and the refrigerant cannot flow.
Six, the temperature of the suction pipe
1, normal range
Under normal circumstances, the suction tube feels cold to the touch with dew.
2, failure:
If the suction pipe is cold and there is too much dew, which causes condensation on a large area, it is mostly because the refrigerant flow is too large, the liquid cannot be fully vaporized in the evaporator, and there is a phenomenon of liquid reflux. If the suction pipe is not cold, does not condense, and the casing is hot. It is mostly because the refrigerant flow is too small or the amount of refrigerant is insufficient. The consequence is that the exhaust temperature rises and the cooling capacity drops.
Seven, the temperature of the thermal expansion valve
1, normal range
Under normal circumstances, the lower half of the expansion valve is very cold with dew, and the sound of refrigerant flowing is dull.
2, failure:
If the valve body is relatively cold, there is more dew on the surface, or even frost, the flow of refrigerant is louder (gas flow). It is mostly because the filter screen is blocked or the refrigerant in the power box leaks, and the valve hole is not closed.
8. The temperature of the capillary
1, normal range
Under normal circumstances, the capillary is cold and accompanied by dew, and there is a sound of liquid flowing.
2, failure:
If the surface of the capillary tube is cold and condensing, but the flow sound is loud, it is mostly because of insufficient refrigerant; if the surface of the capillary tube is not cold or dew, the flow sound cannot be heard, and the filter screen is blocked or the capillary tube is blocked.
Nine, the temperature of the evaporator
1, normal range
Under normal circumstances, the outer surface of the evaporator is very cold, and its condensation water drops continuously, and the temperature of the outgoing wind is relatively high. The temperature range is generally 12℃~14℃
2, failure:
If the surface of the evaporator is not too cold, there is not much dew, or no condensation, you can hear the sound of refrigerant flowing very loudly, and the temperature difference between the inlet and outlet air is small. It is mostly due to insufficient refrigerant amount or small opening of the expansion valve.
