Babcock-hitachi Kabushiki Kaisha

Mitsubishi Hitachi Power Systems, Ltd.

Babcock-hitachi K.k.

Hidehisa Yoshizako

Hiroaki Kanemoto

Katsumi Shimohira

Masayuki Taniguchi

Hirofumi Okazaki

Hironobu Kobayashi

Kenji Kiyama

Akira Baba

Yoshitaka Takahashi

Toshikazu Tsumura

Kouji Kuramashi

Akihito Orii

Takahiro Marumoto

Takanori Yano

Hisayuki Orita

Naoki Oda

Toshihiko Mine

Satoshi Tadakuma

Pauli Dernjatin

Yutaka Takeno

Yoshinori Ohtani

Yuki Kamikawa

Noriyuki Ohyatsu

Noriyuki Imada

Kenso Arita

Yoshio Shimogori

Noriyuki Ooyatsu

Shinichirou Nomura

Yoshiaki Mitsui

Shinji Tsuda

Hitoshi Okimura

Seishi Miyake

An oxygen combustion system includes a boiler to burn fuel using combustion gas composed of oxygen-rich gas and circulating flue gas, a dust remover disposed in a flue through which flue gas discharged from the boiler flows, a second flue leading the combustion gas to the boiler, the combustion gas being made by mixing the circulating flue gas extracted downstream of the dust remover with the oxygen-rich gas, a combustion gas heater exchanging heat between the flue gas flowing between the boiler and dust remover and the combustion gas flowing through the second flue, and a flue gas cooler disposed between the heater and the dust remover to cool the flue gas. A control unit controls at least one of a flow rate and cooling medium temperature of the flue gas cooler such that temperature of the flue gas introduced into the dust remover will be between 90&#xb0; C. and 140&#xb0; C.

Oxygen combustion system and method for operating same

In an exhaust gas treatment device provided with: an exhaust gas treatment unit in which an oxygen combustion boilerusing coal as fuel, a denitration device, an air preheater, a dust-collection device, a desulfurization device, and a carbon dioxide recovery deviceare sequentially arranged from the upstream side to the downstream side of an exhaust gas duct; and an exhaust gas circulation unit which branches off from the exhaust gas duct at an outlet of the dust-collection deviceor an outlet of the desulfurization deviceand through which the exhaust gas is preheated by the air preheaterand returned to the oxygen combustion boiler, a heat-recovery heat exchangerthat adjusts a gas temperature at an inlet of the dust-collection deviceto be not greater than an acid dew point of SOand not lower than a water dew point is provided between the air preheaterand the dust-collection device, a reheating heat exchangerthat adjusts a gas temperature to be not lower than the acid dew point of SOis provided in the vicinity of a branch of the exhaust gas circulation unit, adjusting the gas temperature at the inlet of the dust-collection deviceto be not greater than the acid dew point of SOmakes it possible to prevent corrosion of pipes in the exhaust gas circulation unit and to avoid a decrease in fluidity or combustibility of the pulverized coal in the pipes in the mill.

Exhaust gas treatment device for an oxygen combustion system

A pulverized coal-fired boiler efficiently supplies air to a central part of a furnace and the neighborhood of a furnace wall, thereby promoting mixture with combustion gas, and reducing both NOx and CO. The main after air ports are structured so as to jet air having a large momentum for enabling arrival at the central part of the furnace, and the sub-after air ports are structured so as to jet air having a small momentum to the neighborhood of the wall face of the furnace, and a sectional center of each of the sub-after air ports is within a range from 1 to 5 times of a caliber of the main after air ports from a sectional center of each of the main after air ports.

Pulverized coal-fired boiler and pulverized coal burning method

A fuel supply duct, which supplies a mixed fluid of a solid fuel and carrier gas to one or more burners provided on the walls of a furnace, is provided with a branching part, and each of a plurality of branch ducts, which branch out from the branching part, is connected to a corresponding burner. Also a damper, with which the tilt angle with respect to the direction of flow of the mixed fluid can be changed, is positioned in the fuel supply duct at the upstream side of the branching part so that a mutual difference will arise in the solid fuel concentrations of the mixed fluid supplied to the respective branch ducts. A fuel distributor for fuel supply duct is thus arranged. The tilt angle of the above-mentioned damper is adjusted to increase the concentration of solid fuel in the mixed fluid supplied to a specific burner. At a burner to which the high solid fuel concentration is supplied, stability of ignition and stable combustion of the ignited flame can be obtained during low load operation.

Fuel distribution device for fuel feed ducts and method of operating distribution device

Growing community of inventors

Kure, Japan

Hidehisa Yoshizako