Improving the efficiency of vapor refrigerating machine with screw compressors at capacity control
DOI: 10.21047/1606-4313-2017-16-2-38-42
UDC 621.514
Noskov A.N., Tarasenkov D.S.
Keywords: refrigeration screw compressor, cooling capacity, condensation temperature, throttling device, pump.
UDC 621.514
Improving the efficiency of vapor refrigerating machine with screw compressors at capacity control
For citation: Noskov A.N., Tarasenkov D.S. Improving the efficiency of vapor refrigerating machine with screw compressors at ca-pacity control. Vestnik Mezhdunarodnoi akademii kholoda. 2017. No 2. p. 38-42
Abstract
When using an air chiller condenser in refrigerating machine condensing temperature depends on the outside air parameters significantly. To ensure stable operation of the throttling device a condensation temperature not below a certain value is maintained artificially. This results in unnecessary energy costs for steam compression in the compressor. The article shows a diagram of the chiller with screw compressors that enables reducing energy costs for cold production by decreasing condensing pressure when the ambient temperature is lowered and the installing the pump in front of the throttling device. The operation of chiller with screw oil-flooded compressors at full and partial capacity in different modes has its specific features. The article describes the control of screw compressor consisting of a valve and two butterfly valves. This design allows adjusting geometric compression ratio at full capacity and obtaining arbitrary laws of variation when the capacity is decreased. The article shows the dependences of cooling, effective capacity, and coefficient of performance at full and 50% capacity of the screw compressor when condensing temperature is decreased. Experimental and computational characteristics of oil-filled refrigeration screw compressor operating on R22 Freon were used. The use of vapor refrigerating system with screw compressors and a pump in front of the throttle valve allows significant improving the energy-efficiency of the system.
Abstract
When using an air chiller condenser in refrigerating machine condensing temperature depends on the outside air parameters significantly. To ensure stable operation of the throttling device a condensation temperature not below a certain value is maintained artificially. This results in unnecessary energy costs for steam compression in the compressor. The article shows a diagram of the chiller with screw compressors that enables reducing energy costs for cold production by decreasing condensing pressure when the ambient temperature is lowered and the installing the pump in front of the throttling device. The operation of chiller with screw oil-flooded compressors at full and partial capacity in different modes has its specific features. The article describes the control of screw compressor consisting of a valve and two butterfly valves. This design allows adjusting geometric compression ratio at full capacity and obtaining arbitrary laws of variation when the capacity is decreased. The article shows the dependences of cooling, effective capacity, and coefficient of performance at full and 50% capacity of the screw compressor when condensing temperature is decreased. Experimental and computational characteristics of oil-filled refrigeration screw compressor operating on R22 Freon were used. The use of vapor refrigerating system with screw compressors and a pump in front of the throttle valve allows significant improving the energy-efficiency of the system.
Keywords: refrigeration screw compressor, cooling capacity, condensation temperature, throttling device, pump.
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