[Troubleshooting method] After the refrigerant leaks, you should not rush to fill the system with refrigerant, but find the leak point immediately, and then fill the refrigerant after repairing.
-
②Too much refrigerant charged after maintenance
[Fault analysis] The amount of refrigerant charged in the repaired refrigeration system exceeds the capacity of the system, and the refrigerant will occupy a certain volume of the condenser, reducing the heat dissipation area, reducing the cooling efficiency, and generally high suction and exhaust pressures. Below the normal pressure value, the evaporator is not frosted solid, and the cooling is slow.
[Troubleshooting method] According to the operating procedures, the excess refrigerant must be released at the high-pressure stop valve after a few minutes of shutdown, and the residual air in the system can also be released at this time.
-
③Air in the cooling system
[Fault analysis]Air in the refrigeration system will reduce the refrigeration efficiency. The prominent phenomenon is that the suction and exhaust pressure increase (but the exhaust pressure has not exceeded the rated value), and the temperature between the outlet of the compressor and the inlet of the condenser increases significantly. Due to the presence of air in the system, the exhaust pressure and exhaust temperature increase.
[Troubleshooting method] After a few minutes after the shutdown, air can be released from the high-pressure stop valve several times in a row, and some refrigerant can also be properly charged according to the actual situation.
-
④low compressor efficiency
[Fault analysis] The low efficiency of the refrigeration compressor means that under the condition of constant working conditions, the actual displacement decreases, resulting in a corresponding decrease in cooling capacity. This phenomenon often occurs on compressors that have been used for a long time. The wear and tear is large, the fitting clearance of each component is large, and the sealing performance of the air valve is reduced, resulting in a decrease in the actual displacement.
【Method of exclusion】
◆ Check whether the cylinder head paper gasket is broken down and cause leakage, and replace it if any.
◆ Check whether the high and low pressure exhaust valves are not tightly closed, and replace them if necessary.
◆ Check the matching gap between the piston and the cylinder, and replace it if the gap is too large.
-
⑤The frost on the surface of the evaporator is too thick
[Fault analysis]The evaporator that has been used for a long time should defrost regularly. If it does not defrost, the frost layer on the evaporator pipeline will accumulate thicker and thicker. When the entire pipeline is wrapped into a transparent ice layer, it will seriously affect the heat transfer and cause The temperature in the storage room did not fall within the required range.
[Troubleshooting method]Shut down the machine to defrost, open the warehouse door to let the air circulate, or use a fan to speed up the circulation and reduce the defrost time.
-
⑥Refrigerated oil in the evaporator line
[Fault analysis] During the refrigeration cycle, some refrigerated oil remains in the evaporator pipeline. After a long period of use, when there is more residual oil in the evaporator, it will seriously affect its heat transfer effect and cause poor refrigeration.
[Treatment method] Clear the refrigerating machine oil in the evaporator. Remove the evaporator, blow it out and then dry it. If it is not easy to disassemble, a compressor can be used to pump air and blow dirt from the evaporator inlet.
-
⑦The refrigeration system is not smooth
【Fault analysis】Because the refrigeration system is not cleaned cleanly, after a certain period of use, the dirt gradually accumulates in the filter, and some meshes are blocked, resulting in a decrease in the refrigerant flow rate and affecting the cooling effect. In the system, the expansion valve and the filter screen at the suction port of the compressor are also slightly blocked.
[Treatment method] The micro-blocking parts can be removed, cleaned, dried and then installed.
[Fault analysis ]The desiccant has been used for a long time and becomes a paste to seal the filter, or dirt gradually accumulates in the filter to cause blockage.
[Remedy] Remove the filter, clean it, dry it, replace it with a new desiccant, and install it into the system.
-
⑨Refrigerant leakage in the temperature sensing bag of the expansion valve
[Fault analysis] After the temperature-sensing agent in the temperature-sensing package of the expansion valve leaks, the two forces below the diaphragm push the diaphragm to move upward, which means that the valve hole is closed, and the refrigerant in the system cannot pass through, resulting in no refrigeration. At this time, the expansion valve does not close Frost, the low pressure is a vacuum, and the sound of airflow cannot be heard in the evaporator.
[Troubleshooting method] Stop the machine and close the shut-off valve, remove the expansion valve to check whether the filter is blocked, if not, use your mouth to blow the inlet of the expansion valve to see if it is ventilated. It can also be visually inspected or disassembled for inspection, and replaced if damaged.
-
⑩Condenser heat dissipation is not good
[Fault analysis] If the condenser does not dissipate heat well, it will cause the cooling capacity of the refrigeration equipment to drop, or even not to cool.
[Troubleshooting method] Clean the condenser, pay attention to cleaning the stolen goods inside the fins, and pay attention to avoid obstacles at the air outlet of the condenser. If it is a water-cooled condenser, clean the scale.
|
