The vacuum extraction system of condenser has remarkable energy saving potential. It is still lack of an effective method to optimize the various technical solutions

because of the wide difference on the condenser air extraction system's actual operating condition. By taking the transformation scheme of three typical vacuum pumping system as the research object

such as water ring-roots vacuum pump group

water-ring vacuum pump working fluid deep-cooling and steam jet vacuum pumping system

this paper detects and investigates the effects of condenser tightness

circulating water inlet temperature and unit load rate on energy saving benefits of the retrofitting schemes. Moreover

the results were compared with the original water ring vacuum pump. It shows that

when the condenser tightness is excellent

only the water ring-roots vacuum pump group retrofitting scheme can produce energy saving benefits. When the suction of the original water ring vacuum pump is insufficient

the schemes of water ring-roots vacuum pump group

water-ring vacuum pump working fluid deep-cooling and steam jet vacuum pumping system can produce energy saving benefits

and the benefits increase when the unit load rate decreased and the condenser tightness got worse. On this basis

this paper gives out a method for optimizing the three energy-saving modification schemes according to the actual operation state of the condenser vacuum pumping system

which provides an important reference for feasibility study and implementation of energy-saving retrofitting for condenser vacuum pumping system.