| 摘要 |
PURPOSE:To reduce the discharge of NOX upon starting, by closing shut-off valves in inlet and outlet pipe lines to remote water in an evaporator, then opening a bypass valve to remove steam in a superheater, and by filling dilute ammonia gas to a denitration catalyst (DeNOX). CONSTITUTION:Before starting of a gas turbine, shut-off valves 23, 26 are closed while a blow valve 25 is opened to remove all of water in a preevaporator 10, and a bypass valve 22 is opened while a valve 29 is fully closed to remove steam in a superheater 9. Further, when the gas turbine starts, the amount of heat-exchange between the superheater 9 and the preevaporator 10 is decreased so that exhaust gas from the turbine slightly decreases its temperature and reaches a DeNOX section 11 to maintain the operating temperature Td of the section 11 at a higher value, and therefore, the operating temperature T2 of the DeNOX upon starting is raised to enhance the rate of denitration. Further, dilute ammonia gas is filled after the gas turbine is ignited, to reduce the discharge of NOX. |
