There are 10 circulating water pumps in Changshan Thermal Power Plant

among them

6 pumps of 24sh-19 type were installed in pump house No 1

the other 4 pumps of 48sh-22 type were installed in pump house No 2

The operational practice shows

the designed effective head of pumps of this two types was high

but the flow of them was low.When 10 circutating wter pumps were putting into operation all together in summer season

the shortage of circulating water flow has still been 1 000 t/h.In such case

the operational point of each pump was far away from the optimal point

making operation effciency to be low and energy consumption to be high.Keeping the pumps’casing in its original state

only the impellers and sealing rings had been retrofitted

enabling the maximum efficiency of 24sh-19G type and 48sh-22G type of pumps to reach 87.26% and 88.28% respectively.After retrofit

the water flow has been increased

effective head lowered

and operation efficiency heightened

resulting in enormous reduction of energy consumption.The total annual practical energy-saving of 10 pumps added up to 8.21×10 6 kW·h.