Hitachi, Ltd.

Hitachi Engineering Co., Ltd.

Naoto Koizumi

Yoshiki Noguchi

Shinichi Hoizumi

Toshihiko Sasaki

Asao Takashi

Masanori Onuma

A steam turbine plant includes an extraction system and a control system for controlling the steam extraction. The extraction system includes an extraction steam flowmeter and a stop valve. The control system sets a warning flow and an extracted steam stop flow for the extracted steam. When the extracted steam flow reaches the warning flow, a warning is issued and after a lapse of a predetermined time period, the stop valve is opened to restrict the extracted steam flow. When the extracted steam flow reaches the extracted steam stop flow, the stop valve is closed to stop steam extraction. A steam turbine plant can thus exercise extraction control to stably supply extracted steam while avoiding turbine trip, even if not equipped with a high-performance and expensive valve device such as an extraction steam control valve.

Steam turbine plant

A pressurized fluidized bed combustion combined cycle power plant has a gas turbine unit of single spindle type in which a turbine, driven by combustion gas from burning of coal in a pressurized fluidized bed combustion boiler, drives an electrical generator at constant speed and drives a compressor supplying compressed combustion air to the boiler. To permit partial load operation, a control arrangement is provided to effect, in dependence upon an operating load of the boiler, control of at least one of the flow rate of the combustion air into the boiler, and the operating pressure in the combustion chamber of the boiler. The control arrangement may be, for example, a valve controlling a by-pass flow of the combustion air and/or inlet guide vanes of the compressor.

Pressurized fluidized bed combustion combined cycle power plant and

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Hitachi, Japan

Naoto Koizumi