The cooling capacity of the water chiller is directly r […]
The cooling capacity of the water chiller is directly related to the operating status of the system. For compressors of the same structure, the same speed, and the same refrigerant type, due to changes in operating conditions, different cooling capacity and energy consumption, their operation management is also different, and changes with it.
1. As the evaporation temperature decreases, the compression ratio of the compressor increases, and the unit energy consumption of production cooling increases. When the evaporation temperature decreases by 1 ° C, it consumes 3% to 4%. Therefore, minimizing the evaporation temperature difference and increasing the evaporation temperature not only save energy consumption, but also increase the relative humidity of the cold room.
2. As the condensing temperature increases, the compressor compression ratio increases, and the energy consumption per unit cooling capacity increases. The condensation temperature is between 25 ° C and 40 ° C. For every 1 ° C increase, the power consumption increases by about 3.2%.
3. When the heat exchange surface of the condenser and the evaporator is covered with an oil layer, the condensation temperature increases and the evaporation temperature decreases, resulting in a reduction in cooling capacity and an increase in power consumption. When a 0.1mm thick oil layer accumulates on the inner surface of the condenser, the compressor's cooling capacity will be reduced by 16.6 and the power consumption will be increased by 12.4. When the oil is a 0.1 mm thick inner surface evaporator, in order to maintain the predetermined low temperature requirement, the evaporation temperature drops by 2.5 ° C and the power consumption increases by 9.7.
4. When air accumulates in the condenser, the pressure of the condenser will rise. When the partial pressure of non-condensable gas reaches 1.96105Pa, the power consumption of the compressor needs to be increased by 18.
5. When the scale of the condenser wall reaches 1.5 mm, the condensing temperature rises by 2.8 ° C before the temperature calibration, and the power consumption increases by 9.7.
6. The surface of the evaporator is covered with a layer of frost, which reduces the heat transfer coefficient. Especially the frosted outer surface of the fin tube not only increases the heat transfer resistance, but also makes the air flow between the fins difficult, reducing the appearance. Heat transfer coefficient and heat dissipation area. When the indoor temperature is lower than 0 ° C, when the temperature difference between the two sides of the evaporator tube group is 10 ° C, the heat transfer coefficient of the evaporator is about 70 for one month before frosting.
7. The gas sucked by the compressor allows a certain degree of overheating, but the overheating is too large, the specific volume of the sucked gas increases, the cooling capacity decreases, and the relative power consumption increases.
8. When compressing the frost, quickly close the small suction valve, drastically reduce the cooling capacity, and increase the power consumption relatively.