The evaporator is one of the four major components of t […]
The evaporator is one of the four major components of the refrigeration system and is the ultimate expression of cooling efficiency and efficiency. The evaporator is generally designed and equipped by the manufacturer of the chiller, and the user does not have to choose. However, in order to better maintain the refrigeration system and ensure its efficient operation, the following points should be noted:
Due to the influence of the height of the chiller refrigerant liquid column, the evaporation temperature at the bottom of the flooded evaporator is higher than the evaporation temperature of the liquid surface. Different refrigerants have different effects on the evaporating temperature of different liquid levels depending on the height of the hydrostatic fluid. Regardless of the refrigerant, the lower the evaporation temperature of the liquid surface, the greater the effect of the hydrostatic height on the evaporation temperature. Therefore, the effect of the hydrostatic height on the evaporation temperature can be ignored only when the evaporation pressure is high. When the evaporation temperature is low, it cannot be ignored. That is to say, it is uneconomical to use a flooded evaporator at this time.
If the evaporation temperature is lower than the solidification temperature of the brine, the brine may freeze. In the latter process of the coolant*, the temperature of the brine is low*, and the possibility of freezing is large*. When water is used as the brine, it is theoretically possible that the inner wall temperature of the tube can be as low as 0 °C. However, for safety reasons, the inner wall temperature of the tube at the outlet end of the latter process is usually kept above 0.5 °C. In the case of brine as a coolant, according to the same principle, the inner wall temperature of the pipe should be higher than the solidification temperature of the brine by more than 1 °C.
When the refrigerant flows through the evaporator, the pressure loss is caused, and the pressure p2 of the refrigerant at the outlet of the evaporator is inevitably lower than the pressure p1 at the inlet, thereby lowering the suction pressure of the compressor, resulting in a decrease in the refrigeration capacity. According to different models, the choice of evaporator is different, such as box type chiller, using water tank coil evaporator; open chiller and screw chiller, shell and tube evaporator; Acid-base chiller, you can choose titanium tube evaporator or stainless steel plate exchanger. A chiller can have a variety of options, of course, can be customized according to user needs.