Several important reasons that affect the cooling effect of the refrigeration system of the computer room

Several important reasons that affect the cooling effect of the refrigeration system of the computer room

From the perspective of operation and maintenance, the specific factors that affect the cooling effect of the air conditioner include the evaporation temperature, the opening degree of the expansion valve, and the condensation pressure.

1. The evaporating temperature of the refrigeration system: the evaporating temperature of the refrigeration in the evaporator should be lower than the air temperature, so that the heat in the computer room can be transferred to the refrigerant, and this temperature difference is a combination of the investment cost of the air conditioner and the energy consumption during the cooling operation. And it is determined comprehensively. In computer room air conditioners, this temperature difference is generally 12C° to 14C°. If the temperature difference cannot be guaranteed due to various adverse factors, the operating energy consumption will increase. Through calculation, the evaporating temperature of the refrigerant in the evaporator in the refrigeration system is reduced by 1°C. To produce the same cold capacity, the power consumption increases by about 4%.

2. The opening degree of the expansion valve is incorrect: the expansion valve opening is too large or too small, which will cause the refrigerant flow to be too large or too small, and the working state of the expansion valve deviates from the optimal working condition, causing the cooling efficiency to decrease, and even the equipment Damage, causing unnecessary waste. Therefore, it is necessary to regularly measure the superheat of the expansion valve, and adjust the opening degree of the expansion valve according to the superheat. The degree of superheat is the difference between the evaporator outlet temperature t1 and the temperature t2 corresponding to the evaporator outlet pressure. The superheat of the expansion valve should be within a certain range, if it exceeds the normal range, it needs to be adjusted.

　　3. Condensing pressure of the refrigeration system: When the condenser heat exchange is poor, the condensing pressure will increase, and the cooling efficiency will decrease at this time. To achieve the same amount of cooling, power consumption will increase. Every time the condensation pressure increases by 9.8Pa (1Kgf/cm²), the power consumption increases by 6%-8%. Sundries and dust stick to the condenser fins, causing the air to be unable to pass through the condenser in a large flow, and the thermal resistance increases, resulting in a decrease in the condensation effect and an increase in the condensation pressure. If the cooling system is equipped with a small condenser, the heat exchange capacity is not enough, which will cause the condensation pressure to be too high.