冬季制冷设备的操作问题和对策
Operation problems and Countermeasures of refrigeration equipment in winter
In Winter、当室外温度潮湿且较低时，冷凝压力对制冷系统的性能影响很大。
当冷凝压力（或冷凝温度）较高时，压缩比增加。
并且压缩机的容积效率降低，导致制冷量减少，电耗增加。排气温度越高、冷凝压力越高，其不利影响越大。
凝结压力高的现象主要发生在夏季。 此时应尽可能降低冷凝压力，以保证系统运行的经济性和可靠性。
However, in winter, the condensation pressure of refrigeration equipment may be too low。
When the condensing pressure is too low, the pressure difference between the front and back of the expansion valve is too small, and the capacity of the expansion valve is reduced, resulting in the insufficient liquid supply capacity of the system refrigerant, the lack of liquid in the evaporator, and the refrigeration capacity of the system is greatly reduced, and the unit is protected under low pressure. Therefore, it is necessary to control the condensing pressure in a reasonable range, otherwise the refrigeration device will have frequent low-pressure alarm or low suction pressure alarm.
In order to avoid the winter operation risk of the cooling water system, we can start from ：the cooling tower equipment, cooling tower operation strategy and the end pipeline setting.
To avoid the winter operation risk through the equipment side anti freezing, cooling tower start-up and shutdown and pipeline optimization design.
1.There are TWO parts of antifreeze in the place of perennial operation or partial operation:
Spray Water System and Internal Circulating Water System (softened water)。
For the anti freezing problem of spray water system, an electric heater is usually added in the water pan, which is generally started when the spray water is lower than 5 ℃ and stops when the spray water is above 8 ℃.
The temperature probe transmits the signal to the control cabinet to automatically control the start and stop of the electric heater. The power selection of electric heater depends on circulating water volume and external air temperature.
2.Ethylene glycol solution or electric heating equipment can be added to prevent freezing of internal circulating water system.
The freezing point temperature of glycol solution should be selected below the local historical minimum temperature.
For the larger cooling system, we can consider digging a pool to put the spray water into it, which can save the power consumption due to electric heating operation.
