Ihi Corporation

Electric Power Development Co., Ltd.

Terutoshi Uchida

Toshihiko Yamada

Shuzo Watanabe

Shuuhei Terushita

Shinji Watanabe

Toru Ishii

Yoshiyuki Iso

Masami Sato

Nobuhiro Misawa

A combustion-support-gas bypass line is provided to cause combustion support gas to bypass a preheater. A combustion-support-gas flow control damper is provided in the combustion-support-gas bypass line. An inlet temperature of a deduster is measured by a temperature sensor and the inlet temperature measured by the temperature sensor is inputted to a controller and is compared with a set temperature more than an acid dew-point preliminarily set in the controller. On the basis of a comparison result, an opening-degree control signal is outputted from the controller to the combustion-support-gas flow control damper so as to make the inlet temperature to a set temperature more than an acid dew-point.

Method and apparatus for controlling inlet temperature of dedusting apparatus in oxygen combustion boiler equipment

Provided are regenerative rotary preheater having flue gas flow passage through which passed is flue gas from oxyfuel combustion boiler, primary-combustion-support-fluid flow passage adjacent to the flue gas flow passage and through which passed is primary combustion support fluid with pressure higher than that of the flue gas, secondary-combustion-support-fluid flow passage adjacent to the flue gas flow passage and through which passed is secondary combustion support fluid with pressure higher than that of the flue gas and oxygen flow passage between the primary- and secondary-combustion-support-fluid flow passages and through which oxygen is passed, and an oxygen mixing section mixing the fluid preheated through the secondary-combustion-support passage with oxygen preheated through the oxygen flow passage and supplies the mixture to the oxyfuel combustion boiler.

Combustion assisting fluid preheating device for oxygen combustion system

A combined heat exchanger including a flue gas cooler heat-transfer unit supplied with cooling fluid by a supply pump and an upstream GGH heat-transfer unit for circulation of circulating fluid with a downstream GGH by a circulation pump is arranged at an outlet of a gas air heater for heat exchange of flue gas from a boiler body for oxyfuel combustion with recirculation flue gases. A low-low temperature ESP is arranged at an outlet of the combined heat exchanger. A heat-exchange-duty adjustment device is arranged to regulate heats exchanged in the heat-transfer units in the heat exchanger such that at least flue gas temperature at the inlet of the low-low temperature ESP is kept to an inlet set temperature.

Oxyfuel combustion boiler system

A feed-water discharge side of a condenser is connected to a feed-water entry side of an flue gas cooler through a bypass line provided with a steam production preventive pump and with an inlet cutoff valve. A feed-water discharge side of the flue gas cooler is connected to the feed-water entry side of the condenser through a steam production preventive water circulation line provided with an outlet cutoff valve. When a boiler feed-water pump is stopped in boiler fuel cutoff, the inlet and outlet cutoff valves are opened and the steam production preventive pump is activated to cause water to flow through the bypass line into the flue gas cooler, is returned through the steam production preventive water circulation line to the condenser and is circulated.

Device for preventing steam from being produced in flue gas cooler for oxyfuel combustion boiler

A pulverized coal burner for an oxyfuel combustion boiler which attains uniform combustion from a pulverized coal burner and which constrains a temperature rise of an oxygen injection nozzle is provided. The burner includes burner inner and outer cylinders arranged to penetrate a wind box and come close to a throat portion. A pulverized coal feed passage is provided between the burner inner and outer cylinders. A plurality of oxygen injection devices are arranged outwardly of the burner outer cylinder so as to directly feed oxygen ahead of the burner outer cylinder.

Pulverized coal burner for oxyfuel combustion boiler

Provided are a method and an apparatus of controlling an oxygen supply in an oxyfuel combustion boiler capable of attaining stable oxyfuel combustion even when properties of coal are changed. A boiler-brought-in oxygen density is obtained when coal with a fuel ratio measured by fuel measuring meansis burned stably with oxygen in a boilerso that a relationship between the fuel ratio and/or carbon content of the coal and the boiler-brought-in oxygen density is obtained and inputted in advance into the controller. When the coal is changed to the new kind of coal, a total amount of gases recirculated is regulated such that a boiler-brought-in oxygen density becomes accordance with a fuel ratio and/or a carbon content which is measured in advance for the new kind of coal.

Method and apparatus of controlling oxygen supply in oxyfuel combustion boiler

In an oxygen mixer for an oxygen combustion boiler, circulating exhaust gas heated in a rotary preheater is mixed with oxygen. Resultant mixed gas is guided to a boiler furnace through a combustion gas duct having bends. At the bend closest to the rotary preheater in the combustion gas duct, an oxygen injection nozzle is arranged to have a plurality of injection ports for injection of oxygen into circulating exhaust gas.

Oxygen mixer for oxygen combustion boiler

An apparatus of controlling oxygen supply for a boiler having wind boxesandarranged on left and right of a boiler bodyis configured to control supply balance of oxygen by adjusting oxygen supply opening degrees of the left and right oxygen distribution dampersandin accordance with a oxygen supply flow rate and left and right actually measured oxygen concentrations when controlling the oxygen supply amounts and to control the exhaust gas flow rates by correcting an exhaust gas flow rate set value corresponding to a boiler load demand in accordance with an oxygen concentration set value corresponding to a boiler load demand, left and right actually measured exhaust gas flow rates and left and right actually measured oxygen concentrations and adjusting left and right exhaust gas introduction opening degrees of the left and right exhaust gas introduction dampersandwhen controlling the exhaust gas flow rates.

Method and apparatus of controlling oxygen supply for boiler

In an apparatus of controlling an exhaust gas in an oxyfuel combustion boiler having the boilerprovided with burnersand a two-stage combustion port, a primary recirculation linethrough which pulverized coal obtained by a millis fed to the burnersof the boilerby the primary recirculating exhaust gas, a secondary recirculation linethrough which another portion of the exhaust gas in recirculation is fed to a wind boxof the boiler, an oxygen producer, a direct supply linethrough which a portion of oxygen produced by the oxygen produceris directly fed to the burnerand a secondary oxygen mixing linethrough which another portion of oxygen produced by the oxygen produceris fed to the secondary recirculation line, the apparatus comprises an oxygen supply linethrough which oxygen is fed to the two-stage combustion port of the boilerand a flow rate regulatorin the oxygen supply line for adjusting oxygen density.

Method and apparatus of controlling exhaust gas in oxyfuel combustion boiler

Provided are a method and an apparatus of controlling exhaust gas in an oxyfuel combustion boiler which can attain stable combustion of the boiler while an amount of unburned combustibles and a NOdensity in exhaust gas are maintained in their allowable ranges. A rate of supply of directly supplied oxygen to burnersto a total amount of oxygen produced by an air separation unitis regulated in an operating range where the NOdensity in the exhaust gas is below a NOx limit value and the amount of unburned combustibles in the exhaust gas is blow an unburned combustible limit value to thereby attain stable combustion of the oxyfuel combustion boiler.

Provided are a method and an apparatus of controlling a flow rate of a primary recirculating exhaust gas in an oxyfuel combustion boiler, capable of realizing a stable combustion by a burner in oxyfuel combustion. Weight ratio of flow rate of primary recirculating exhaust gas [ton/h] to amount of pulverized coal from a mill [ton/h] is defined as G/C, and the flow rate of primary recirculating exhaust gas is controlled so that the G/C falls within a given range.

Method and apparatus of controlling flow rate of primary recirculating exhaust gas in oxyfuel combustion boiler

Provided are fuel feed means, an air separation unitair feed means, a combustion furnacewith a burnerfor combustion, an exhaust gas linefor leading an exhaust gas from the combustion furnaceto outside of the combustion furnace, exhaust gas treatment meansandincluded in the exhaust gas line, and a recirculation linefor circulating a portion of the exhaust gas at least exhaust gas treatment meansandfor recirculation of a portion of the exhaust gas at least dust-removed by the exhaust gas treatment meansandto the burner. Further provided are exhaust gas capture meansfor taking out carbon dioxide gas from a remaining non-recirculating exhaust gas, and carbon dioxide gas feed meansandfor introducing carbon dioxide gas to equipmentsandof the oxyfuel combustion boiler facility.

Growing community of inventors

Tokyo, Japan

Terutoshi Uchida