The relationship between cooling capacity and energy consumption

1. Impact of evaporation temperature: As the evaporation temperature decreases, the compression ratio of the compressor increases, leading to an increase in energy consumption per unit of cooling output. Specifically, for every 1°C decrease in evaporation temperature, power consumption increases by 3%-4%. Therefore, to save energy and increase the relative humidity in the cold room, it is advisable to minimize the evaporation temperature difference and raise the evaporation temperature as much as possible.

2. Impact of condensing temperature: An increase in condensing temperature will also lead to an increase in the compression ratio of the compressor, thereby increasing the energy consumption per unit of cooling output. Within the condensing temperature range of 25°C to 40°C, the power consumption will increase by approximately 3.2% for every 1°C increase.

3. Impact of oil layer on heat exchange surface: When the heat exchange surfaces of the condenser and evaporator are covered with an oil layer, it can lead to an increase in condensation temperature and a decrease in evaporation temperature, thereby reducing the cooling capacity and increasing power consumption. For example, if the inner surface of the condenser is coated with a 0.1mm thick oil layer, it will result in a 16.6% decrease in the compressor's cooling capacity and a 12.4% increase in power consumption; similarly, if the inner surface of the evaporator is coated with a 0.1mm thick oil layer, in order to maintain the established low temperature requirement, the evaporation temperature will drop by 2.5°C and power consumption will increase by 9.7%.

4. Impact of air accumulation: The accumulation of air within the condenser can lead to an increase in condensing pressure, subsequently increasing power consumption. When the partial pressure of non-condensable gas reaches 1.96×10^5 Pa, the power consumption of the compressor will increase by 18%.