What is the reason for ice blockage of 200 ton chiller?

What is the reason for ice blockage of 200 ton chiller?

Air-cooled screw water chiller and water-cooled screw water chiller are two commonly used water chillers. During the use of LC -25°C ~ -5°C Low Temperature Chillers, there may be “ice blockage” phenomenon, which is usually caused by water freezing at the throttling device of thermal expansion valve.

Due to the blockage, the exhaust pressure will increase, the sound of the machine will increase, there is no refrigerant flowing into the evaporator, the frosting area will gradually decrease, the temperature will gradually increase, and the capillary temperature will also rise, so the ice will start to melt, and the refrigerant can start to circulate again at this time.

If ice blockage occurs again after a period of time, it will form periodic ice blockage.

The main reason for the ice blockage failure of screw chiller is that there is a large amount of water in the refrigeration system.

With the continuous circulation of refrigerant, the water in the refrigeration system will gradually concentrate at the outlet of the capillary.

Because the temperature at the outlet of the capillary is relatively low, the water will become ice and gradually expand. To a certain extent, the capillary will be completely blocked, and finally the refrigerant can not be circulated.

The main source of moisture in the cooling system of the chiller is that the insulating paper of the motor in the compressor contains moisture, which is the main source of moisture in the system.

In addition, the residual moisture in the components and connecting pipes of the refrigeration system due to insufficient drying;

The refrigerant oil and refrigerant contain more than the allowed amount of water; During assembly or maintenance, the pipeline is under development for a long time, resulting in moisture in the air being absorbed by motor insulating paper and refrigerant oil.

As a result of the above reasons, the water content of the refrigeration system exceeds the allowable amount of the refrigeration system, thus causing ice blockage.

On the one hand, ice blockage causes the refrigerant to be unable to circulate and the refrigerator to be unable to cool normally;

On the other hand, water will also react with refrigerant to generate hydrochloric acid and hydrogen fluoride, which will cause corrosion to metal pipes and components, and even lead to insulation damage of motor winding.

At the same time, it will also cause deterioration of refrigerant oil and affect the lubrication of compressor. Therefore, the moisture in the system must be controlled to a minimum.