The stable operation of refrigeration units is crucial for maintaining a suitable temperature environment. However, in actual operation, refrigeration systems often encounter various blockage problems, especially ice blockage and dirty blockage. These blockage phenomena not only affect the circulation of refrigerant, but also may lead to abnormal operation of compressors.
Taking the blockage of the expansion valve as an example, as an important regulating component in the refrigeration system, once the expansion valve is blocked, it will block the flow channel of the refrigerant from the high pressure side to the low pressure side. At this time, the compressor has to face the problem of continuously increasing pressure on the high pressure side and continuously decreasing pressure on the low pressure side under continuous pushing, which may cause the load and compression ratio of the compressor to continuously increase, ultimately leading to the activation of the compressor's overload protection mechanism.
On the high-pressure side, due to the blockage of the expansion valve, the compressor can only slowly push the refrigerant into the condenser and high-pressure pipe. With the accumulation of refrigerant on the high-pressure side, the condensation pressure and exhaust pressure gradually increase, and the corresponding condensation temperature also increases, resulting in an increase in energy consumption of the refrigeration unit.
On the low-pressure side, due to the blockage of the expansion valve, the refrigerant on the high-pressure side cannot flow smoothly into the evaporator. At the same time, the refrigerant inside the evaporator gradually decreases under the continuous extraction of the compressor, resulting in a continuous decrease in pressure on the low-pressure side. The decrease in evaporation pressure and suction pressure is proportional to pressure and temperature, which leads to a decrease in evaporation temperature and greatly reduces the refrigeration effect inside the evaporator.
Due to the reduction of refrigerant in the evaporator, the evaporated refrigerant vapor will continue to absorb heat, resulting in an increase in superheat, which in turn will push up the suction temperature of the compressor. The increase in suction temperature will also lead to an increase in the discharge temperature of the compressor, causing problems with the carbonization temperature of the refrigeration oil.
For compressors, the blockage of expansion valves leads to a significant increase in high pressure, a decrease in low pressure, and an increase in compression ratio, resulting in a significant increase in the load and power consumption of the compressor. As power consumption increases, the heat converted by the compressor also increases, leading to a continuous rise in exhaust temperature, which may ultimately trigger the compressor's overload protection mechanism.
It should be noted that the blockage of the expansion valve is usually characterized by low pressure and high pressure, which is significantly different from the situation of insufficient refrigerant. When the refrigerant is insufficient, both high and low pressure will show a low state. Therefore, when diagnosing refrigeration system problems, it is necessary to carefully distinguish between these two situations in order to take the correct maintenance measures.
In summary, the issue of blockage in the refrigeration system cannot be ignored. To ensure the stable operation of the refrigeration system, we need to regularly maintain and inspect the system, promptly identify and address potential blockage issues. At the same time, targeted maintenance measures need to be taken for different types of blockage phenomena to ensure the normal operation and cooling effect of the system.
