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Schlee (China) Refrigerating Equipment Manufacturing Co.,Ltd

Add:Jupu Road, Pukou Development Zone, Nanjing City, Jiangsu Province, China

Contact us:Cherry





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Water Cooled Chiller Requirements
- Jun 15, 2017 -

In the chiller operation, the evaporation temperature, evaporation pressure and cold water into the evaporator heat is closely related. When the heat load is large, the return water temperature of the evaporator is increased, causing the evaporator temperature to rise and the corresponding evaporation pressure is also increased. On the contrary, when the heat load is reduced, Water Cooled Chiller the cold water return temperature decreases, the evaporation temperature and evaporation pressure are reduced. In the actual operation of the air conditioning room to reduce the heat load, the cold water back to the water temperature decreases, the evaporation temperature and evaporation pressure equalization down.

In operation, to meet the requirements of the use of air conditioning, should be as much as possible to improve the cold water temperature. Under normal circumstances, the evaporation temperature is lower than the cold water temperature 2 ℃ ~ 4 ℃. Evaporation temperature is often controlled in the range of 3 ℃ ~ 5 ℃. Excessive evaporation temperature is often difficult to achieve the required air conditioning effect, and too low evaporation temperature, not only increased the energy consumption of the unit, but also easily lead to evaporation of the pipeline.

In the chiller, the pressure indicated by the high pressure gauge is called the condensing pressure, and the temperature corresponding to the pressure is called the condensation temperature. The level of condensation temperature, in the case of constant evaporation temperature, Water Cooled Chiller the unit power consumption is decisive. Condensation temperature increases power consumption increases, in addition, centrifugal refrigeration unit condensation pressure will cause the host surge. Conversely, the condensing temperature is reduced and the power consumption is reduced.

Therefore, in the operation of chillers operation, should pay attention to ensure that the cooling water temperature, water, water and other indicators in the qualified range. When the air is present in the condenser, the temperature difference between the condensation temperature and the outlet of the cooling water increases, and the cooling water inlet and outlet temperature difference is reduced, and the heat transfer effect of the condenser is not good. In addition, the condenser tube water side fouling and sludge on the heat transfer also play a considerable role.

The cold water flow of the evaporator is inversely proportional to the temperature difference between the supply and return water, that is, the larger the cold water flow is, Water Cooled Chiller the smaller the temperature difference is. The smaller the flow rate is, the greater the temperature difference. Therefore, the chiller unit conditions for cold water supply and return water temperature difference of 5 ℃, which is actually set the unit of cold water flow. This cold water flow control is manifested by the control of cold water through the evaporator.

Chillers in the standard operating conditions, Water Cooled Chiller the condenser back to the water temperature of 30 ℃, the temperature is 35 ℃. For the operation of the chiller, environmental conditions, load and cooling capacity have become fixed. At this time, the condensing heat load is undoubtedly the value. Standard provisions into the water temperature difference of 5 ℃, cooling water flow is bound to a certain value. And the flow rate is inversely proportional to the temperature difference between inlet and outlet water. Therefore, the chiller in the standard operating conditions, as long as the provisions of the cooling water into and out of the water temperature on the line. This flow is usually used to control the cooling water pressure of the condenser.

For centrifugal chillers, the condensing pressure is too high or too low to cause a surge. Centrifugal chillers encountered such a situation, it should be noted that the difference between condensing pressure and evaporation pressure can not be too small, should meet the requirements to prevent the occurrence of surge, or to surge. In the lower temperature of the fall, running reciprocating chillers is advantageous because the condensing pressure is low and the power consumption is reduced.

The suction temperature of the compressor, Water Cooled Chiller for the reciprocating compressor, refers to the temperature of the refrigerant gas in the compressor suction chamber; for the centrifugal compressor, the temperature of the refrigerant gas on the suction guide vane should be used. The level of inspiratory temperature, not only affect the level of the exhaust temperature, but also on the compressor volume cooling capacity has an important impact. Compressor suction temperature is high, the exhaust temperature is high, Water Cooled Chiller the refrigerant is inhaled when the specific capacity, this time the unit capacity of the compressor cooling capacity is small, which we do not want. In contrast, when the suction temperature of the compressor is low, the unit capacity is large.

For reciprocating chillers, the compressor suction superheat is taken as 5 to 10 ° C, and a dry evaporator is used. You can use the thermal expansion valve to control the inspiratory superheat, by adjusting the thermostatic expansion valve adjustment screw, you can adjust the size of superheat.

The exhaust temperature is higher than the condensation temperature, the direct impact of exhaust temperature is the compressor suction temperature, the two are proportional relationship. If the reciprocating compressor sucks, the exhaust valve is not tight or broken to cause leakage (internal leakage), the exhaust temperature will rise significantly. In the centrifugal refrigeration unit if the refrigeration system into the air, the suction temperature and exhaust temperature will rise.