Hitachi, Ltd.

Hitachi Engineering Co., Ltd.

Babcock-Hitachi Kabushiki Kaisha

Shigehisa Sugita

Kazuhito Koyama

Yoshiki Noguchi

Shinichi Hoizumi

Seiichiro Sakaguchi

Toshihiko Sasaki

Shinya Marushima

Motoaki Utamura

Tetsuo Sasada

Takashi Ikeguchi

Seiichi Kirikami

Nobuhiro Seiki

Yuji Makino

Yasushi Takeda

Hideaki Komatsu

Takeshi Suzumura

Kazuhiro Gonda

Shozo Nakamura

Michio Kuroda

Satoshi Tsukahara

Nobuo Nagasaki

Asao Hanzawa

Masato Takeuchi

Yoshihiro Uchiyama

Shigeyoshi Kawano

Kazuo Ikeuchi

Zensuke Tamura

Tadao Arakawa

Ryoichiro Oshima

Youichi Hattori

Taro Sakata

Koji Shiina

Kenji Yokosuka

Kojiro Kaneko

Yasuaki Akatu

To improve the thermal efficiency when an exhaust heat recovery type combined cycle plant having a gas turbine and a steam turbine in combination is operated at a partial load, the gas turbine exhaust is recirculated and returned to the compressor, and the combustion temperature is prevented from being lowered at the partial load. Preferably, the temperature is maintained constant. In this way, the thermal efficiency during operation at partial load can be improved.

Gas turbine exhaust recirculation method and apparatus

Exhaust recirculation type combined plant

A cylindrical fuel reforming apparatus covered with a thermal insulating layer 16 comprises a fuel flow passage 1 contoured by a cylindrical contour wall 2 in its central axial direction and a reforming catalyst bed 3 in the middle of the flow passage for reforming gas to be reformed flowing from the upstream of the fuel flow passage 1 into a proper reformed gas. A cooling jacket 10 is arranged in the upstream of the reforming catalyst bed 3 so as to surround the fuel flow passage 1 and to be supplied with steam 11 for cooling the cylindrical contour wall 2. There are provided in the cylindrical contour wall 2 in the upstream of the reforming catalyst bed 3 a plurality of injection nozzles 15 communicating the cooling jacket 10 with the fuel flow passage 1 so that the steam 11 introduced into the cooling jacket 10 is allowed to flow into the fuel flow passage 1.

Fuel reforming apparatus and electric power generating system having the

A cylindrical fuel reforming apparatus covered with a thermal insulating layer 16 has a fuel flow passage 1 contoured by a cylindrical contour wall 2 in its central axial direction, and a reforming catalyst bed 3 is disposed in the middle of the flow passage for reforming gas, flowing from the upstream end of the fuel flow passage 1, into a proper reformed gas. A cooling jacket 10 is arranged upstream of the reforming catalyst bed 3 so as to surround the fuel flow passage 1 and the cooling jacket is supplied with steam 11 for cooling the cylindrical contour wall 2. There are provided in the cylindrical contour wall 2 upstream of the reforming catalyst bed 3 a plurality of injection nozzles 15 for effecting communication between the cooling jacket 10 and the fuel flow passage 1 so that the steam 11 introduced into the cooling jacket 10 is allowed to flow into the fuel flow passage 1.

A combined cycle power plant has a plurality of gas turbine units each having a gas turbine and a heat recovery boiler for generating steam from heat from exhaust gas from the gas turbine. The gas turbine of a first one of the gas turbine units is a steam-cooled gas turbine. Steam turbines are driven by steam from the heat recovery boilers. For start-up of the first gas turbine unit, cooling steam generated in a heat recovery boiler different from not being the heat recovery boiler of the first gas turbine unit is fed to the steam-cooled gas turbine to effect cooling thereof during at least part of the start-up operation of the first gas turbine unit.

Combined cycle power plant

A pressurized fluidized-bed boiler power plant comprises: a pressurized fluidized-bed boiler including a fluidized-bed boiler and a pressure vessel containing the fluidized bed; a single-shaft gas turbine including a gas turbine, an air compressor and an electric generator; and a steam turbine unit in which steam generated by the pressurized fluidized-bed boiler drives a turbine so that electricity is generated. In the power plant, an air cooler is situated on a duct for conveying the compressed air from the compressor to the boiler or at an inlet of the compressor. Alternatively, there may be provided a device for conveying the compressed air from the compressor by way of the air cooler to a space formed by the fluidized-bed boiler and the pressure vessel of the pressurized fluidized-bed boiler. During operation, the compressed air is cooled to a temperature level allowable for the pressure vessel before it is supplied to the boiler.

Pressurized fluidized-bed boiler power plant

A fuel reforming apparatus includes a reaction tube for causing endothermic reaction for converting a fuel gas with hydrocarbon, steam, and the like mixed therein into a hydrogen-enriched gas using a catalyst, a combustor for generating a combustion gas for heating the reaction tube, a heat insulating layer for preventing the radiation of the combustion gas, and a combustion gas passage disposed around the reaction tube and allowing the combustion gas to flow therethrough, and a passage for air or fuel gas disposed around the fuel gas passage, a heat insulating layer being disposed around the outer peripheral surface of this passage.

Fuel reforming apparatus

This invention relates to a favorable method of starting a fuel cell power generation system in which fuel is used directly as a heating medium for raising the temperature of said system. Namely, the present invention relates to a method of starting a fuel cell power generation system composed of (a) a reformer which is composed of a reforming part packed with reforming catalyst and a heating part and in which a fuel is fed to the reformer inlet and the fuel is combusted at the heating part, thereby to heat the reforming part and (b) the above-mentioned fuel cell in which the fuel which has been passed through said reformer reforming part is introduced to the anode and the exhaust gas produced at said reformer heating part is fed to the cathode, comprising the step of starting the fuel cell power generation system to ignite the fuel present at the reformer heating part only when the reformer reforming part has been filled with fuel.

Method of starting fuel cell power generation system

An integrated power plant based on a molten carbonate type fuel cell and a gas turbine combined plant comprising a gas turbine, a steam turbine and a common generator driven by the gas turbine and the steam turbine is disclosed, where a reformer for a fuel gas to the anode of the fuel cell is heated through heat exchange with the cathode off-gas from the fuel cell to obtain the necessary heat for the reforming, and a portion of the anode off-gas from the fuel cell is combusted in a separate burner to form a CO.sub.2 recycle to the cathode, while most of the remaining anode off-gas is supplied to the gas turbine combustor. The existing gas turbine combined plant can be used, as it is, without any substantial modification, and the present fuel cell power generation plant can be simply added thereto as an auxiliary unit.

Integrated power plant and method for operating the plant

A fuel cell power plant comprising a fuel cell employing a molten carbonate as an electrolyte, a reformer for reforming fuel into a reactive gas to be supplied into the anode of the cell, an expansion turbine connected to a compressor, a combustor for burning a gas exhausted from the anode and introducing the combustion gas into the cathode of the fuel cell along with a gas compressed by the compressor, and a waste heat recovery system. The power plant is characterized by the provision of another combustor on the passage through which cathode exhaust gas is sent from the cathode to the turbine and a passage for leading a part of the anode exhaust gas to the combustor, whereby unburned gas, included in the anode exhaust gas, is burned with the cathode exhaust gas supplied as oxygen source so that the temperature of the turbine driving gas is raised, as a result, the overall thermal efficiency of the power plant increases.

Fuel cell power plant

In combustion of gasified fuel by gasifying a low quality fuel and combusting the gasified fuel in a combustor, combustion of gasified fuel is controlled by sampling the gasified fuel at a constant flow rate at the upstream side of the combustor, combusting the sampled gasified fuel, detecting an overall energy level of sensible heat and heating value possessed per unit weight of the gasified fuel on the basis of the combustion temperature of the sampled gasified fuel, and controlling the flow rate of gasified fuel to be led to the combustor in accordance with a fluctuation in the detected overall energy level. Unstable combustion due to a fluctuation in the heating value of the gasified fuel and blow-out due to deficiency of the heating value can be prevented.

Method and apparatus for controlling combustion of gasified fuel

A power generating plant which includes a direct contact-type heat exchanger. A low-boiling point medium such as freon and a heat-source medium such as heated oil, are injected from a lower portion of the heat exchanger so that the two media are brought into direct contact with each other thereby vaporizing the gaseous low-boiling point medium. The low-boiling medium acts as a working fluid while it circulates through a closed cycle of the plant which includes a turbine and a condenser. The heat-source medium, circulates in a closed cycle of the plant which includes a heating unit.

Power-generating plant having increased circulating force of working

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Hitachi, Japan

Shigehisa Sugita