POWER GENERATING GAS TURBINE EXHAUST GAS CONTROL DEVICE AND CONTROL METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To regulate an exhaust gas rate according to load fluctuation of steam by forming a space formed between an exhaust gas valve guide arranged on the flow outlet side of a bypass duct and the flow outlet side of an exhaust gas boiler and the valve element of three way switching damper, and enlarging the space in compliance with the opening of a valve. SOLUTION: In a three way switching damper, a valve body 11 rotated by a motor is arranged on the square part formed between the flow outlet of a bypass duct and the flow outlet of an exhaust gas boiler. A valve seat 12 is arranged on the flow outlet of exhaust gas of the bypass duct, and a valve seat 13 is arranged on the flow outlet of the exhaust gas boiler. The valve body 11 is rotated between the valve seat 12 and the valve seat 13. A spaceΔ1 is formed between the exhaust gas valve guide 15 and the valve body 11 of the valve seat 12 side, and a spaceΔ1 is formed between the exhaust gas valve guide 14 and the valve body 11 of the valve seat 13 side. Since the spaceΔ1 is enlarged in compliance with the opening of a valve, it is possible to make proportional characteristics of a relation between a damper opening degree and an exhaust gas flow rate.