The condensate water temperature and quality

temperature and pressure in deaerator

and parameter variation of water pumps were investigated in an ultra supercritical 1 000MW unit during runback(RB)process.The results show that

during the fast load rejection process

the NPSHa of feedwater pumps falls by a significant margin and cavitation may occur in the booster pump.Thus

several suggestions were proposed

such as taking the RB condition as the standard to account the NPSHa drop value of booster pump to prevent the cavitation occurring when arranging the deaerator

setting the enthalpy of water in the deaerator as the enthalpy value of saturated water corresponding to pressure at middle point of the water tank when calculating the NPSHa values.