According to different models, the choice of evaporators for low-temperature experiment special instruments is also different, such as box-type low temperature experiment special instruments, using water tank coil evaporator; open low temperature experiment special instrument and screw type refrigerator, then choose Shell and tube evaporator; for special instruments for acid and alkali resistance low temperature experiments, titanium tube evaporator or stainless steel plate exchanger can be selected. An ice water machine can have a variety of options, of course, can be customized according to user needs.
The temperature condition of the evaporator of the low-temperature experiment special instrument: under normal circumstances, the outer surface of the evaporator is very cold, and the condensation water droplets are continuously dripped, and the temperature of the inlet and outlet air is relatively large, usually Δt can be 12~14 ° C. The surface of the evaporator is not too cool, there is not much dew, or condensation, and the sound of the refrigerant flow is very loud, and the temperature difference between the inlet and outlet is small. The reason is that the refrigerant amount is insufficient, or the expansion valve opening degree is small.
The factors that affect the evaporation temperature of the device are as follows:
Evaporator pipe oiling: Under normal circumstances, due to the mutual solubility of lubricating oil and refrigerant, oil film will not form on the surface of the heat exchanger, and the thermal resistance of the oil film may be disregarded. However, in the case of additional lubricating oil, it must be the same as the original one. Lubricating oil to prevent the formation of oil film. Air filter plugging: The filter must be replaced regularly to ensure the required air circulation for the air conditioner. Dry filter plugging: In order to ensure the normal circulation of the cooling enthalpy, the refrigeration system must be kept clean and dry. If the system has impurities, the drying filter will be blocked, the system will be difficult to supply liquid, and the cooling effect will be affected. Too little refrigerant, additional refrigerant.
In the low temperature experiment special instrument, the evaporator also has certain requirements in terms of quality. The brand has a certain quality guarantee, so that the operation of the special instrument for low temperature experiment will be more stable.