Hitachi, Ltd.

Hitachi Engineering Co., Ltd.

Takeshi Ueno

Shozo Nakamura

Tadao Arakawa

Toyohiko Masuda

Yoji Nagai

Hiroshi Tsunematsu

Shinichi Hoizumi

Tsuguo Hashimoto

Hitoshi Ishimaru

Kunio Hodozuka

Keiichi Toyoda

Norio Abe

A reheat steam turbine power plant having a boiler with a superheater and reheater disposed therein, a high pressure steam turbine, an intermediate pressure steam turbine, a low pressure turbine, and a condenser condensing a steam exhausted through the low pressure turbine to a condensate. A turbine bypass pipe is provided with a bypass valve. A branch pipe branches off a cold reheater pipe between the check valve and the reheater is connected to the condenser for introducing steam flowing through the turbine bypass pipe. A control valve is arranged in the branch pipe and a controller controls the bypass valve and the control valve. When the turbine bypass line is operational in one of a start-up or an auxiliary operation of the power plant, the control valve and the bypass valve are controlled by the controller so that the quantity of reheat steam introduced into the reheater is controlled and excess or surplus steam is discharged to the condenser through the branch pipe.

Steam turbine plant having a turbine bypass system

An apparatus for controlling an operation of a turbine plant on a reduction of the load on a turbine operates to compute a saturation pressure corresponding to the temperature in the downcomer pipe by using the detected values representing the conditions of the plant, and to control the reduction of the turbine to maintain the pressure in the downcomer pipe higher than the computed saturation pressure so as to prevent an occurrence of flashing.

Method and apparatus for controlling an operation of plant

Condensation system for use in a power plant. The condensate system includes side stream condenser defining therein first and second hot wells. Condensate is delivered from the first to second hot well through a condensate feed line. Condensate is introduced from the condensate feed line into a tank through a first spill-over line. Condensate is supplied from the second hot well to the power plant through a main condensate feed line. Condensate is introduced from the main condensate feed line into the tank through a second spill-over line. Actuator is operative in response to signal from a level detector detecting level of condensate in the first hot well, to regulate opening degree of a supplementary feed valve in the supplementary feed line, to close one of first and second spill-over valves in the first and second spill-over lines, respectively, and to open the other spill-over valve.

Condensation system for power plant

A side stream type condenser which has a first hot well for condensing steam exhausted from a turbine and storing the condensed water and a second hot well for storing the purified condensed water to prepare for water feed to a main system includes a partition plate for defining the two hot wells. The partition plate is formed with a weir portion so that part of the condensed water in the second hot well may overflow to keep a fixed water level. The weir portion is constructed in the shape of a labyrinth and is formed with a passage normally filled up with the condensed water, and a space in the upper part of the second hot well communicates with the upper space of the first hot well through this passage only. The condensed water in the first hot well is fed to a purifying system disposed outside, and is purified therein. It is thereafter fed to the second hot well when the main system requires the feed water and to the first hot well when not, through pipe means constructed so as to feed the water selectively to the first hot well and the second hot well. The water level of the first hot well is controlled by causing the condensed water to overflow from the weir portion. On the other hand, the water level of the second hot well is controlled in such a way that the actual water level is detected by a water level gauge disposed in the second hot well, that the quantities of water in an inlet and outlet of a tank for storing the feed water of the main system are controlled in accordance with the detected water level, and that the feed water of the tank is caused to flow into the first hot well.

Side stream type condensing system and method of operating the same

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Hitachi, Japan

Takeshi Ueno