The adiabatic index of freon is smaller than that of ammonia. The exhaust temperature of industrial water chiller is still very low at a higher compression ratio. On the one hand, the compressor will not overheat and the service life will be prolonged. On the other hand, the lubricating oil will hardly be damaged, so the crankshaft clamp of regenerative compressor is not needed. At the same time, there is no need to worry about properly increasing the suction temperature (the suction temperature is not allowed to exceed 15 ℃) and causing too high exhaust temperature, so freon refrigeration circulating system of chiller often uses regenerator to improve refrigeration efficiency. The use of regenerative circulation is characteristic of the freon system.
The heat exchanger is used to make the high temperature and high pressure remission phase refrigerant before entering the expansion valve and the low temperature and low pressure gas preparation from the evaporator heat exchange, so that the liquid under cooling, gas overheating refrigeration cycle is called the regenerative cycle. From the refrigeration principle, when the liquid refrigerant in front of the expansion valve has a large degree of subcooling, the temperature difference between the refrigerant before and after the throttle valve can be reduced, so that the refrigerant vapor after throttling is reduced, and the purpose of reducing throttling loss is also achieved.
The application of heat recovery cycle can not only improve the cooling capacity and co-efficient of refrigeration system, but also eliminate harmful overheating. Liquid refrigerant in the evaporator heat evaporation after the formation of the refrigerant vapor in saturated state, when the flow in the muffler road to absorb heat, make oneself of the temperature, the formation of superheated steam, so that the power consumed by a refrigerator, the refrigeration co-efficient of refrigeration system is reduced, this is the so-called harmful to overheat. The use of heat recovery cycle not only makes the liquid refrigerant in front of the throttle valve reach super cooling, but also makes the temperature of the gas refrigerant rise, reduces the temperature difference between the gas refrigerant and the external dead gas, and restrains harmful overheating. In addition, it can prevent the compressor from inhaling wet vapor and wet compression.
Using the same heat cycle to greatly improve the suction temperature of chiller, its exhaust temperature will inevitably rise. In order to prevent the decomposition of fluorocarbon and a large amount of carbonization of lubricating oil, it is necessary to control the super heat of compressor return gas to a certain extent. The general suction temperature is not allowed to exceed 15 ℃.