드럼보일러 증기발생기 수위 안정을 위한 급수펌프 유량제어특성 개선

Abstract

In Korea, since the beginning of the 1990s, there has been a surge in the construction of high-efficiency coal-fired once-through boilers for 500 MW standard thermal power plants rather than drum (D/M) type steam generators. Furthermore, Old D/M type boilers have been retired without life extensions, and the capacity factor of remaining coal-fired power plants has been lowered owing to a government emission regulation policy on coal-fired power plants to reduce particulate matter since 2019. Recently, several issues with control systems of D/M type steam generators have been reported, including weekly start-up and shut-down and large-rapid load swings rather than constant operating patterns. The D/M level control system is one of the most important control systems in power plants, as it is directly influenced by the performance of the feedwater (FW) flow control system in terms of pump speed, flow control valve opening, and load runback controls, all of which affect FW flow and D/M level status. This study demonstrates how to reduce the parasitic power consumption during normal operating and regulate the steam generator level during runback operation by incorporating differential pressure control logic for flow compensation.