大型冷凍機の運転中、冷却能力と作業条件が電力消費の主な問題となるが、無駄な電力消費を避けるためには、明確に理解する必要がある。規模が大きくなると、消費電力は大きくなる。

When the scale on the tube wall of the condenser of the large-size refrigeration unit reaches 1.5mm, the condensing temperature will increase by 2.8°C compared with the temperature before the scale, and the power consumption will increase by 9.7. The surface of the large-scale refrigeration unit evaporator is covered with a layer of frost, which reduces the heat transfer coefficient, especially when the outer surface of the fin tube is frosted, which not only increases the heat transfer resistance, but also makes the air flow between the fins difficult and reduces The surface heat transfer coefficient and heat dissipation area. When the ambient temperature is lower than 0°C and 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 before frosting after one month of operation.

The gas sucked in by the compressor of a large-size refrigeration unit allows a certain degree of superheat, but the superheat is too high, the specific volume of the sucked gas increases, its cold production is reduced, the relative power consumption increases, the compressor is frosted, and the suction is quickly turned off. The valve drastically reduces the cooling capacity and relatively increases the power consumption.

As the evaporation temperature of the large-size refrigeration unit decreases, the compression ratio of the compressor increases, and the energy consumption per unit of cold production increases. When the evaporation temperature drops by 1℃, it will consume 3%-4% more electricity. Therefore, reduce the evaporation temperature difference as much as possible and increase the evaporation temperature, which not only saves power consumption, but also increases the relative humidity of the cold room.

As the condensing temperature of large-size refrigeration units increases, the compression ratio of the compressor increases, and the energy consumption per unit of cold production increases. When the heat exchange surface of the condenser and evaporator of a large refrigeration unit is covered with an oil layer, it will cause the condensation temperature to rise and the evaporation temperature to decrease, resulting in a decrease in cold production and an increase in power consumption. When the air accumulates in the condenser, it will cause the condensing pressure to rise, and the power consumption of the compressor will increase.

If the same large-size refrigeration unit has the same structure and speed, the cooling capacity and power consumption are different if the operating conditions are different. Therefore, the operator will perform the operation after understanding it clearly to avoid the increase in the operating cost of the enterprise.