For the low-temperature chiller using ethylene glycol solution, we
call it glycol chiller. Its outlet water temperature is generally below - 10 ℃, and the specific temperature requirements shall be subject to the
needs of users. Glycol chillers are common in chemical plants. In order to
ensure the safe and stable operation of equipment, many chemical plants will
strictly require water chillers to take explosion-proof measures, that is, what
we often call explosion-proof water chillers.
The structural composition of the water chiller is roughly the same, which is composed of compressor, evaporator, condenser, throttling element and electric control system. However, the glycol chiller adopts low-temperature compressor and is equipped with economic separator and other components, which are still different.
1、In order to keep the pressure in the evaporator low enough to ensure that the refrigerant evaporates at a sufficiently low boiling temperature, a compressor is used to extract the evaporated refrigerant gas, that is, the refrigerant steam with low temperature and low pressure is compressed into a refrigerant gas with high temperature and high pressure. When the suction speed of the compressor is greater than the evaporation speed of the refrigerant, the evaporation pressure and evaporation temperature will decrease. Conversely, the suction speed of the compressor is less than that of the refrigerant, and the evaporation temperature and pressure will rise accordingly.
2、 High temperature and high pressure refrigerant is condensed into liquid in the condenser. In the condenser, the refrigerant releases heat to air or water lower than its temperature. This part of heat includes the heat absorbed when the refrigerant evaporates in the evaporator and the heat converted when the compressor compresses. Special attention: the temperature of air or water must be lower than that of refrigerant, otherwise the refrigerant cannot release heat, that is, the temperature of cooling medium (cooling tower water or air) must be lower than that of refrigerant gas at the outlet of compressor.
3、Through the restrictor, the pressure of the refrigerant drops from the condensation pressure to the evaporation pressure. The liquid from the condenser is stored in the liquid reservoir. At this time, the refrigerant is in the state of normal temperature and high pressure. After passing through the expansion valve, the boiling point decreases due to the decrease of pressure. After entering the evaporator, the liquid is easy to absorb heat and evaporate.