Results of Analysis on the Characteristics of the New Steam Temperature Control System for Supercritical Once Thru Boilers

Abstract

New steam temperature control logic for supercritical once thru boilers was developed from the view point of simplicity similar to the conventional sub-critical drum type boilers. Water wall outlet steam temperature can be controlled more easily due to larger specific heat capacity of steam than superheater outlet steam temperature. Dividing temperature control into two parts, one at water wall outlet by fuel flow and another at superheater outlet by spray water flow, boiler steam temperature control was much improved. This paper introduces results of analysis on the characteristics of the new steam temperature control system for supercritical once thru boilers.