How to deal with frosting on the compressor of a pre-cooler
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As shown in the figure, the outlet temperature of the pre-cooler is 4.0°C, which is on the low side; moreover, the cooling water flow has also been reduced, but it seems that this hasn’t had much effect. If it’s necessary to adjust the expansion valve, should it be opened up or closed?
There are several methods for dealing with frosting on the compressor of a pre-cooler: 1. Check whether the refrigeration cycle is functioning properly, including whether there is sufficient refrigerant and whether the evaporator and condenser are clean； 2. Adjust the expansion valve – try opening it slightly more to increase the cooling capacity, thereby reducing the outlet temperature ； 3. Melt the frosty areas. Regarding the issue you raised, it is first necessary to determine the cause of the low outlet temperature of the pre-cooler. If it is due to insufficient cooling capacity, options such as increasing the cooling capacity (for example, by enlarging the area of the evaporator) or adjusting the opening degree of the expansion valve can be considered. If it is caused by low water temperature, it is necessary to raise the water temperature or slightly increase the inlet and outlet valves to boost the water flow rate. .
It is recommended to contact the manufacturer to resolve the issue. Typically, such devices should have automatic temperature control, and it is sufficient to set the parameters according to the device’s requirements. It is best not to adjust this via the throttle on the device; this is for reference only.
Hello, when you say increase the water flow rate, doesn’t that mean making the outlet temperature lower? I’m a bit confused
The temperature setting for chiller units is based on the physical properties of water, and it is usually set at 5–6°C; if the temperature is too low, the water in the evaporator can freeze. During use, it must be operated within the specified range of process parameters. A common problem is low water flow into the condenser; a clogged water filter is a frequent cause of this issue. The water flow rate to the evaporator is too low, which can cause shutdown. If it is summer or the air pressure is low with high humidity, frosting at the throttle valve is also normal. Wrapping this section of pipe with insulating foam can solve this problem. For reference.