| 摘要 |
PROBLEM TO BE SOLVED: To always stably control the temperature of reheated steam by suppressing the temperature fluctuation which occurs immediately after a load change starts. SOLUTION: A reheating type boiler sends the exhaust steam of a high- pressure turbine to an intermediate/low-pressure turbine of the poststage by reheating the steam with its reheating heat transfer surface. In this case, the temperature of the reheated steam sent to the intermediate/low-pressure turbine is controlled by adjusting the flow rate of the combustion gas of the boiler supplied for heating the exhaust steam on the reheating heat transfer surface, and twice differentiated signal components 92 and 97 are generated by twice differentiating the load signal 51 of a plant and added to flow rate adjusting signals 77 and 78 which adjust the flow rate of the combustion gas of the boiler. The flow rate adjustment of the combustion gas is performed by increasing or decreasing the opening amounts of a gas distributing damper which changes the proportions of flow rates of the combustion gas to the reheating heat transfer surface and other heat transfer surfaces and a boiler gas circulating damper which again feeds back the combustion gas to a furnace.
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