Application of an integral large small feedwater control valve to nighttime low-load operation

摘要

This paper introduces a feedwater control valve developed for variable-pressure boilers, which are subjected to severe operating conditions during nighttime low load operation and boiler start-up, as well.In the paper, the problems of the conventional feedwater control valves under high differential pressure at low-load operation, and the features of the valve developed to solve them are described, as well as its design concept, detailed structure, working principles, and its application results to the actual plants.With its unique embodiment of an integrated large-and-small valve structure, the developed valve is capable of controlling fluid flow both in low-load, small flow rate, under high differential pressure region and in high-load, large flow rate, lowdifferential pressure region.