Abstract: The influencing factors of water consumption, water saving methods and water balance are analyzed for the limestone/lime-gypsum wet FGD system. Moreover, the comparison between the water consumption of the FGD system before and after the low-temperature economizer modification in the phase II project of a power plant of Datang Group is conducted. It indicates that the water consumption in the FGD system is associated with the evaporated water in the absorber; the evaporated water can be decreased by reducing the gas temperature difference between the absorber inlet and outlet to realize in-depth water saving. According to the situation that water consumption in the wet FGD system of air-cooling units takes a large proportion of the overall water consumption of the plant in the west region, measures to keep the water balance are proposed.

Key words: fossil-fired power plant, wet-FGD, limestone/lime-gypsum method, water consumption, water balance, water saving