How to remove the icing fault of the evaporator of the chiller?

During the daily use of the chiller, the evaporator of the chiller may freeze. Why does the refrigerator freeze? How to eliminate the fault?

How to eliminate icing fault of evaporator of chiller? Through many years of industry experience, the summary is as follows:

1. Insufficient refrigerant

Refrigerant leakage or leakage may occur due to insufficient refrigerant, equipment or long service time of the refrigerator and other reasons. After the refrigerant in the refrigeration system is reduced, the evaporation pressure is too low, causing the evaporator to freeze. The freezing positions are located in front of the evaporator. The troubleshooting method is to deal with the leaking part first, add enough refrigerant, and the fault will be eliminated.

2. The compressor efficiency is low

The compressor efficiency is low, the compressor has been used for a long time due to failure, the tightening effect of the compressor is reduced, or the compressor valve system is damaged, resulting in too low pressure and icing. Screw chillers can be divided into water-cooled screw chillers and air-cooled screw chillers according to different heat dissipation modes: 1. Overview of screw chillers The selection of chillers should be considered according to the cooling load and use. In order to deal with the refrigeration system under low load operation for a long time, it is recommended to select multi head plug compressor or screw compressor, which is convenient for adjustment and energy saving. The icing position is also partially located in front of the evaporator. The former is supplemented with some refrigerant, and the fault can be eliminated. If the fault persists, the compressor must be replaced.

3. More refrigerants

Too much refrigerant. Due to leakage and other reasons, the refrigerator was refilled with refrigerant, and the maintenance personnel improperly added too much refrigerant, which led to too much refrigerant flowing into the evaporator and local evaporation and icing. This ice is mainly formed around the evaporator and compressor return pipe to release excess refrigerant. Troubleshooting.

4. The heat exchanger is dirty

The heat exchanger is dirty. If the evaporator is used in the chiller for a period of time, the dust in the air or the microorganisms generated by the evaporator will accumulate on the evaporator, preventing the air flow, resulting in reduced heat exchange, low evaporator temperature and freezing. The refrigeration equipment is used as the transmission medium for the lubrication and hydraulic cooling of CNC machine tools, coordinate boring machines, grinders, machining centers, modular machine tools and various precision machine tool spindles. It can accurately control the oil temperature, effectively reduce the thermal deformation of the machine tools, and improve the machining accuracy of the machine tools. The freezing position is located behind the evaporator. To dissolve in ice, flush the evaporator with water, brush along the fins with a soft brush, and be careful not to wet the electrical parts. After cleaning, the fault will be eliminated.

5. The temperature setting is too low

If the temperature is set too low, the evaporator will freeze. The cooler provides cooling water device with constant temperature, constant current and constant pressure. The return water temperature of the chiller shall not be higher than 40 ℃. The higher the return water temperature, the greater the damage to the compressor. This kind of ice mainly starts from the evaporator. The fault can be eliminated only when the temperature is set higher.

6. Poor temperature probe or improper position of temperature probe device

The temperature control is effective due to poor temperature probe or improper position of temperature probe device. The gas pressure in the temperature sensing package of the mechanical temperature controller changes with the temperature, thus driving the contact of the temperature controller. Due to the contact adhesion and insufficient spring elasticity, the contact is usually closed, and the cooler continues to open, leading to icing. Replace the thermostat and the fault has been eliminated.