The chiller ice blockage failure occurs mainly because the refrigeration system contains excessive moisture. As the refrigerant continues to circulate, the water in the refrigeration system gradually concentrates at the capillary outlet. Since the temperature at the capillary outlet is the lowest, the water becomes ice. And gradually increase, to a certain extent, the capillary is completely blocked, the refrigerant can not be circulated, and the refrigerator is not cooled.
The main source of moisture in the chiller refrigeration system is that the motor insulation paper in the compressor contains moisture, which is the main source of moisture in the system. In addition, the residual parts of the refrigeration system components and connecting pipes are insufficient due to insufficient drying; the refrigerating machine oil and refrigerant contain more than the allowable amount of moisture; during the assembly or maintenance process, the pipeline is in development for a long time, causing moisture in the air to be Absorbed by motor insulation paper and refrigeration oil. Due to the above reasons, the water content of the refrigeration system exceeds the allowable amount of the refrigeration system, and ice blockage occurs. On the one hand, the ice block can cause the refrigerant to not circulate, and the refrigerator can not normally cool; on the other hand, the water will chemically react with the refrigerant to generate hydrochloric acid and hydrogen fluoride, causing corrosion of the metal pipes and components, and even causing the motor windings. Insulation damage, but also cause deterioration of the refrigeration oil, affecting the lubrication of the compressor. Therefore, the moisture in the system must be kept to a minimum.
The performance of ice plugging in the screw chiller refrigeration system is normal in the initial stage, frosting in the evaporator, heat dissipation in the condenser, stable operation of the unit, and clear and stable refrigerant activity in the evaporator. With the formation of ice blockage, the audible airflow becomes weaker and intermittent, and when the blockage is severe, the airflow sound disappears, the refrigerant cycle is interrupted, and the condenser gradually cools. Due to the blockage, the exhaust pressure is increased, the machine operation sound is increased, no refrigerant flows into the evaporator, the frosting area is gradually reduced, the temperature is gradually increased, and the capillary temperature is also raised together, so that the ice cube begins to melt, this The refrigerant begins to recirculate again. After a period of time, the ice block occurs again, forming a periodic phenomenon of plugging.