Hitachi, Ltd.

Katsuto Kashiwahara

Katsukuni Hisano

Hiroshi Matsumoto

Yoshio Sato

Haruo Urushidani

Ryoichi Kaneko

Shigeyoshi Kawano

Yoshiyuki Nakano

Fumio Kato

Yasuhiko Otawara

Yasuhiro Tennichi

Satoshi Ninomiya

Toshihiko Higashi

Hidesumi Kuwashima

Akira Okabe

Jube Matsumura

Hitoshi Isa

Ryosuke Arie

Yasuhiro Yamachi

Koichiro Fukushima

A main steam inlet structure of a steam turbine has two inlet tubes which are separable from an inner casing and an outer casing of the turbine and are arranged concentrically with a spacing therebetween to constitute an inflow passage for main steam are connected at one end to the outer casing and at the other end to the inner casing, by seal rings. Cooling steam extracted from turbine stage midway is supplied to a cooling steam passage of the spacing formed between the two inlet tubes, thereby cooling the inner inlet tube.

Main steam inlet structure for steam turbine

A combined plant including a gas turbine, a steam turbine and a waste heat recovery boiler using exhaust gases of the gas turbine as a heat source for producing steam serving as a drive source of the steam turbine further includes an ancillary steam source separate from and independent of the waste heat recovery boiler. At the time of startup of the plant, steam from the ancillary steam source is introduced into the steam turbine until the conditions for feeding air to the waste heat recovery boiler are set, to thereby avoid overheating of the steam turbine due to a windage loss.

Combined plant having steam turbine and gas turbine connected by single

A cross compound turbine apparatus and method of operating the same wherein the apparatus includes a first turbine generator having a high pressure turbine and a first low pressure turbine connected to a first generator driving shaft, with the second turbine generator having an intermediate pressure turbine connected to a second generator driving shaft. Driving steam is supplied to the high pressure turbine and a primary steam line communicates exhaust steam from the high pressure turbine to drive the intermediate pressure turbine during a steady state operation of the first and second turbine generator sections. A bypass steam line communicates steam from the system supplying driving steam to the high pressure turbine to the intermediate pressure turbine in a bypassing relationship to the high pressure turbine. A control arrangement controls the flow of steam in the primary and bypass steam lines during a starting operating of the turbine generator sections, with the control arrangement being adapted to maintain the relative speeds of the first and second generator driving shafts in a predetermined synchronsis ratio. A controllable vent arrangement is provided for venting a portion of the steam flow in the primary steam line during starting operations. By virtue of these features, a speed synchronization of multiturbine sections can be obtained in an efficient and inexpensive manner without causing excessive heat rise in the turbine blades.

Method and apparatus for operating a cross-compound turbine generator

The present stress in the turbine rotor is estimated at each control period, from the steam temperature and pressure at the turbine inlet. In addition, the future turbine inlet steam temperature or pressure is preestimated once every n.sub.T control cycles, for a given speed or load changing rate, making use of data concerning the changing rate of the turbine steam inlet temperature or pressure in relation with the change of the speed or load, which has been obtained by a learning of the past turbine operating condition. This future steam temperature or pressure at the turbine inlet is used as a factor for preestimating the future stress expected to be caused in the turbine rotor. The preestimation of the rotor stress is performed for a plurality of assumed speed or load changing rates. The turbine is controlled at the maximum speed increase-rate or load changing rate which would not cause the future stress preestimated over a given preestimation time to exceed a limit stress. An observation of the present stress is made at each control period to check whether the limit stress is not exceeded by the present stress.

Rotor-stress preestimating turbine control system

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Hitachi, Japan

Katsuto Kashiwahara