The phenomenon of ice jam in low temperature chiller system is mainly due to the excessive water in the refrigeration system. With the continuous circulation of refrigerants, the water in the refrigeration system gradually concentrates at the outlet of expansion valve. Because the outlet of expansion valve has the lowest temperature, the water turns into ice and the ice enlarges gradually. To a certain extent, the expansion valve will be completely blocked, resulting that the refrigerant can not be recycled, and the cold storage will not refrigerate.

The phenomenon of ice jam in low temperature chiller system is normal in the initial stage. There is frost in the evaporator, heat dissipation of the condenser, stable operation of the unit, clear and stable movement of refrigerant in the evaporator. With the formation of ice jam, the air flow is gradually weakened and intermittent. When the jam becomes serious, the sound of air flow  completely disappears. The refrigerant cycle is interrupted. And the condenser is gradually cooled.
Because of the blockage, the exhaust pressure rises. The sound of the machine increases. There is no refrigerant flowing into the evaporator. The frost area decreases gradually. The temperature increases gradually, and the temperature of the expansion valve rises together, so the ice begins to melt. At this time, the refrigerant begins to recycle again. After a period of time, ice blockage occurs again, forming a periodic phenomenon of through-blockage.

Troubleshooting of Ice Block

The ice jam failure of low temperature chiller system is due to excessive moisture in the system, so the whole refrigeration system must be dried. There are two ways to deal with it:

1. Heat and dry the components of the refrigerant system in a drying box. Remove the compressor, condenser, evaporator, expansion valve and return pipe in the refrigerant system  from the cold storage and put them into the drying box for heating and drying.

2. Remove the water content of each part of the refrigeration system by heating and secondary vacuum extraction.