关键词: 燃煤电厂, 烟气脱硫, 石膏, 循环冷却水, 阻垢剂

Abstract: Since the desulfurization system was put into operation in Heyuan Power Plant, the rise of moisture content of desulfurized gypsum have been observed several times with the maximum value as much as 50%, which has severely affected the dehydration, storage, transportation and utilization of the gypsum. In consideration of the design and operation of the desulfurization system, the probable causes are analyzed and finally the root cause is identified as the scale inhibitor in the drainage of the circulating water which is supplemented to the desulfurization process water. By replacing the process water temporarily and adding gypsum crystal seeds, the gypsum quality deterioration is now under control. Furthermore, by removing the scale inhibitor from the circulating water drainage, the problem has been completely solved. Consequently, the original water balance of the power plant is recovered with normal gypsum quality and zero wastewater discharge, and the technical level of environmental protection and the economic efficiency of the power plant are all improved.

Key words: coal-fired power plant, flue gas desulfurization, gypsum, circulating cooling water, scale inhibitor