As an important component of the cold storage refrigeration system, the air cooler plays the role of directly generating cold capacity and reducing the temperature of the cold storage. The efficiency of the cold output of the air cooler directly affects the temperature of the cold storage and the quality of the storage. The Guangzhou Bingquan CBFI technical team found that in actual use, there are many factors that affect the efficiency of the cooling capacity of the air cooler. Among them, frosting on the evaporator is one of the important factors, and it is also a key issue that cannot be avoided in actual use.
In actual conditions, there is no situation that the air does not contain moisture. Therefore, when the air cooler works at a temperature below 0°C and below the dew point of the air, frost begins to form on the surface of the evaporator. As the operating time increases, The frost layer will become thicker. A thicker frost layer will cause two main problems: one is the increase in heat transfer resistance, and the cold in the evaporator coil cannot be effectively transferred to the cold storage through the tube wall and frost layer; the other problem: thicker frost The layer forms a larger wind resistance to the fan motor, which leads to a decrease in the air volume of the air cooler and also reduces the heat transfer efficiency of the air cooler.
1. The relative humidity in the cold storage is large, causing serious frosting of the evaporator
Reasons for frosting: The door of the cold storage is frequently opened and closed when loading goods, and the door is opened for a long time each time, causing a large amount of external hot air to continuously invade the storage.
Suggested measures: install a curtain or air curtain at the door of the cold storage to isolate the intrusion of external hot air, and at the same time regulate the use of the cold storage, so as to close the door in time; in addition, it is recommended that the large and variable spacing models should be selected when selecting the air cooler, and increase The electric fan heater protects the safe operation of the motor.
2. The incorrect installation position of the air cooler causes serious frost on the evaporator
Cause of frosting: The air cooler is installed above the door of the cold storage. When the door is opened, if the air cooler is running, the hot air outside the cold storage is directly sucked into the inside of the cooler, and water vapor is also condensed on the air cooler shell and the fan grille. .
Suggested measures: Install the air cooler far away from the cold storage door to avoid direct external hot air being sucked into the air cooler when the door is opened.
3. Poor defrosting leads to icing on the evaporator surface
Cause of frosting: Due to the insufficient defrosting time and the unreasonable position of the defrosting reset probe, the evaporator will be turned on when the defrosting is not clean. The local frost layer of the evaporator will freeze and accumulate after multiple cycles .
Suggested measures: electric defrost model-reset the defrost cycle and defrost time, and allow enough drainage time and check whether the defrost reset probe position is correct; water flush model-adjust the defrost water volume and confirm the water pipe Whether the diameter is reasonable, make sure that every frosted part on the evaporator is washed thoroughly by water.
4. The drain pipe of the air cooler has no backwater bend outside the warehouse
Cause of frosting: The drain pipe of the air cooler is out of the warehouse without a backwater bend, which leads to the cooling operation of the warehouse. If other warehouses are not in use, hot air from other warehouses will be sucked into the lower part of the cooling fan drain plate to form frost and ice. phenomenon.
Recommended measures: The drain pipe of each air cooler must be made an independent backwater bend to prevent the intrusion of external hot air during cooling operation.