An Experienced Craftsman Summarizes the Common Problems of Cold Storage Equipment, It's Really Comprehensive!

2025-04-09

The installation of refrigeration system equipment and refrigerant pipelines, as well as the overall design of the cold storage and its daily use, must all be carried out in strict accordance with the specifications. Any situation of non-standard design, installation, use, or maintenance will lead to poor operation of the refrigeration system, and may even cause malfunctions and damage to the machinery.

The refrigeration compressor unit is not installed with vibration damping, or the vibration damping effect is poor. According to the installation specifications, the entire unit should be equipped with a vibration damping device. If the vibration damping is not standardized or there are no vibration damping measures, the machine will vibrate violently, which can easily cause the pipeline to crack, the equipment to be damaged, and even the machine room to be damaged.
The refrigerant pipeline has no or lacks an oil return bend. When the pipeline transporting the refrigerant turns upward from the horizontal direction, it must be made into a small bend that first droops downward and then goes upward, that is, a U-shaped bend. Only in this way is the pipeline qualified when it goes upward again. It cannot be directly made into a 90-degree turn and go upward. Otherwise, the oil in the system cannot return to the compressor well, but will accumulate in the air cooler in large quantities, preventing the air cooler and the entire system from functioning properly, and even damaging the air cooler and the unit equipment.
Uneven connection of refrigerant pipelines. When the unit pipelines are connected to a group of multiple compressors, to evenly distribute the oil return to each compressor, the interface of the main pipeline must be set in the middle position among multiple compressor heads, and then some branch pipelines should be set on both sides respectively, allowing the oil return to flow evenly into the branch pipes of multiple compressors.
Moreover, valves should be installed on each branch pipe to adjust the amount of oil return. If not, and multiple downward branch pipes are successively led out from different parts of the main pipeline and connected to multiple compressors, the oil return will be uneven. The oil return of the first compressor is always the fullest, and the oil return of the subsequent compressors gradually decreases in turn. In this way, the first compressor may experience operational failures, such as huge vibrations, excessive oil pressure, overheating of the unit, and even accidents like the compressor cylinder being damaged or seizing up, resulting in the damage of the equipment.
The pipeline is not insulated. Without insulation materials, the cold pipeline will frost under the ambient temperature, thus affecting the refrigeration effect, increasing the load of the unit, and then making the unit operate beyond its strength, reducing the service life of the unit.
Regularly check various technical indicators and adjust them in a timely manner. The operating temperature and pressure of the system, as well as the amounts of lubricating oil and refrigerant, should all be checked and adjusted in a timely manner. The system should have automatic control and compressor alarm devices. Once there is a problem, it will issue an alarm prompt or automatically shut down the compressor for protection.
Maintenance of the unit. Lubricating oil and filters should be replaced regularly. Refill the refrigerant as needed. The condenser should be cleaned at any time to keep it clean, to prevent dust, sediment, or flying floc and debris from affecting the refrigeration effect. Some people believe that as long as the lubricating oil has no impurities, it can be continuously used, and even if it has been used for more than two years, there is no need to replace it. This is obviously wrong. The lubricating oil has been operating at a high temperature in the system for a long time, and its performance may have changed, and it can no longer play its due role such as lubrication. If it is not replaced, it will cause the operating temperature of the machine to rise, and even damage the machine.
The filter should also be replaced regularly. We know that general machines have "three filters" that also need to be replaced regularly.
The refrigeration compressor system may not have "three filters", but only an oil filter, which should also be replaced regularly. If you think that the filter is made of metal and there is no need to replace it as long as it is not damaged, this view is groundless and untenable.
Installation environment and maintenance issues of the air cooler. The position and environment of the air cooler inside the cold storage will affect its operation. Generally, the air cooler near the cold storage door is prone to condensation and frosting. Because its environment is at the door position, when the door is opened, the hot air flow outside enters. When it encounters the air cooler, it condenses and frosts, or even freezes. Although the air cooler can automatically heat and defrost regularly, if the door is opened too frequently and for too long, and the hot air flow enters for a long time and in a large amount, the defrosting effect of the air cooler will not be good.
Because the defrosting time of the air cooler cannot be too long, otherwise the refrigeration time will be relatively shortened, the refrigeration effect will be poor, and the temperature in the storage cannot be guaranteed.
In some cold storages, due to too many doors, high door opening frequency, long opening time, lack of thermal insulation measures at the door, and no partition wall inside the door, the cold and hot air flows inside and outside are directly exchanged, and the air cooler near the door will inevitably encounter serious frosting problems.
The drainage problem of the water melted during the defrosting of the air cooler.
This problem is related to the severity of frosting. Due to serious frosting on the air cooler, a large amount of condensed water will inevitably be generated. If the water receiving tray of the air cooler cannot bear it and the drainage is not smooth, the water will leak and flow onto the ground inside the storage. If there are goods stored below, the goods will be soaked. In this case, a water receiving tray can be added, and a thicker guide pipe can be installed to drain the condensed water.
Some air coolers have the problem of water being blown out from the fan and sprayed onto the goods stored in the storage. This is also a frosting problem of the air cooler in a hot and cold exchange environment. It is mainly the condensed water generated by the fan blades of the air cooler in a hot environment, rather than a problem of the defrosting effect of the air cooler itself. To solve the problem of condensed water in the air cooler, the environment must be improved. If there is a partition wall inside the storage door in the design, the partition wall cannot be removed. If the partition wall is removed for the convenience of loading and unloading goods, the environment of the air cooler will change, and the refrigeration effect cannot be achieved, the defrosting effect will not be good, and even the air cooler will malfunction frequently and the equipment will have problems.
Problems of the condenser fan motor and the electric heating tube of the air cooler.
These are vulnerable components. The fan motor that operates for a long time in a high-temperature environment may malfunction and be damaged. If it is very important to ensure the temperature of the cold storage, some vulnerable parts should be ordered for timely maintenance. The electric heating tube of the air cooler also needs to have spare parts for greater safety.
Problems of the cold storage temperature and the cold storage door. The area of a cold storage, the inventory quantity, the number of doors, the opening and closing time and frequency of the doors, the inventory entry and exit frequency, and the cargo throughput are all factors that affect the temperature inside the storage.
Fire safety problems of the cold storage. The temperature in a cold storage is generally around minus 20 degrees. Due to the low ambient temperature, it is not suitable to install a fire sprinkler system. Therefore, more attention should be paid to fire prevention inside the cold storage. Although the ambient temperature in the cold storage is low, if there is a fire and there are combustibles in the storage, especially the goods are often packaged in cartons and wooden boxes, which are very easy to burn. Therefore, the fire hazard in the cold storage is also very high, and fireworks are strictly prohibited in the cold storage.
At the same time, the air cooler, its wire box, power cord, and electric heating tube should also be regularly checked to eliminate potential electrical fire hazards.
The ambient temperature problem of the condenser. The condenser is generally installed on the roof of the building outdoors. In the environment with high temperatures in summer, the temperature of the condenser itself is very high, increasing the operating pressure of the unit. If there are many hot days, a canopy can be built on the roof above the condenser to block the sunlight, reducing the temperature of the condenser, so as to reduce the pressure on the machine, protect the unit equipment, and ensure the temperature in the cold storage. Of course, if the unit has sufficient capacity to ensure the storage temperature, a canopy may not be necessary.