Optimization on Blowdown Flow Regulation Characteristics of Steam Generator in a Nuclear Power Plant

Abstract

During the operation of a nuclear power plant, the blowdown flow measurement signal of the steam generator fluctuates frequently, which interferes with the automatic adjustment function of the flow control valve. When the signal fluctuation reaches the alarm value, the flow control valve will be closed automatically, isolating the steam generator blowdown system, and affect the water quality regulation of the secondary circuit. Through the analysis of the system design, operating conditions and equipment structure, it is shown that due to the blocked flow of the flow regulating valve, the flowmeter is affected by the two-phase flow. In view of the problems, this paper proposes improvement measures from the rationality of flowmeter selection, the optimization of system control logic parameters, and the system multistage depressurization.