This boiler has a flue in which a reducing agent supplying device and a selective reduction catalyst are provided, a bypass flow path bypassing economizers is provided, and a first closing device partially closing the bypass flow path and a second closing device partially closing the flue are also provided. A plurality of first closing members, serving as the first closing device, are provided along the direction in which exhaust gas flows through the flue at a predetermined spacing in the width direction of the flue. A plurality of second closing members, serving as the second closing device are provided along the vertical direction at a predetermined spacing in the width direction of the flue. The first closing members and the second closing members are arranged so as to be displaced from each other in the width direction of the flue.

A circular fluidizing bed combustion system with uniform airflow distributing device is provided. The system comprises a fluidizing bed and a uniform airflow distributing device. The fluidizing bed is comprised of a fluidizing bed boiler body, an airflow distributing plate and a plurality of air caps, wherein, the airflow distributing plate is provided inside the fluidizing bed boiler body and divides the inner space of the fluidizing bed boiler body into a fluidizing chamber which is located in the upper portion of the boiler body and an air chamber which is located in the lower portion of the boiler body, and the plurality of air caps are arranged on the airflow distributing plate for injecting the fluidizing air into the fluidizing chamber. The inner space of the air chamber is divided into a distributing chamber that is located under the airflow distributing plate and an air inlet chamber that is located on one side of the distributing chamber by means of a perforated plate. The distributing chamber is comprised of a front wall, two side walls, a top wall that extends upwards obliquely from the upside of the front wall, and a bottom wall extends downwards obliquely from the downside of the front wall. A first guide plate, a second guide plate and a third guide plate are installed in the distributing chamber. This system makes the flow of the fluidizing air entered into the fluidizing chamber through each air cap uniform, and enhances the combusting efficiency of the coal powder in the fluidizing chamber.

A combustion system includes a combustion chamber, a plurality of fuel introduction locations in the combustion chamber where fuel and air are provided to the combustion chamber for combustion, a fluid flow control device associated with each fuel introduction location, each fluid flow control device being controllable to vary an amount of the air supplied to each fuel introduction location, a plurality of sensing devices configured to monitor a plurality of operational parameters of the combustion system, and a control unit configured to control each fluid flow control device to control the amount of air supplied at each fuel introduction location independent of the amount of air supplied at the other fuel introduction locations, and to control the amount of air provided to all other air introduction locations, in dependence upon at least one of the plurality of operational parameters to minimize excess air provided to the combustion chamber.

A burner includes: an inner gas nozzle which extends along an axis while surrounding the axis, and which is capable of supplying a furnace with an inner combustion oxygen containing gas; a fuel supply nozzle surrounding the inner gas nozzle as seen in a direction along the axis, the fuel supply nozzle being capable of supplying the furnace with a fluid mixture of a solid powder fuel and a carrier gas; an outer gas nozzle surrounding the fuel supply nozzle as seen in the direction along the axis, the outer gas nozzle being capable of supplying the furnace with an outer combustion oxygen containing gas; and a flow-velocity-ratio adjustment apparatus capable of adjusting a relative flow velocity ratio of a discharge flow velocity of the inner combustion oxygen containing gas to a discharge flow velocity of the outer combustion oxygen containing gas.

A heat and hydrogen generation device comprising a burner combustion chamber (3), a burner (7) for feeding fuel and air into the burner combustion chamber (3), and a reformer catalyst (4). The target value of the O.sub.2/C molar ratio of air and fuel which are made to react in the burner combustion chamber (3) is preset as the target O.sub.2/C molar ratio. The actual O.sub.2/C molar ratio at the time of warm-up operation is estimated from the rate of temperature rise of the reformer catalyst (4) etc., when performing warm-up operation. When the estimated actual O.sub.2/C molar ratio deviates from the target O.sub.2/C molar ratio at the time of warm-up operation, the ratio of feed between the amount of feed of air for burner combustion and the amount of feed of fuel for burner combustion is corrected, in a direction making the estimated actual O.sub.2/C molar ratio approach the target O.sub.2/C molar ratio at the time of warm-up operation.

A combustion chamber assembly unit, for a vaporizing burner, includes a combustion chamber housing with a circumferential wall extending in a direction of a combustion chamber housing longitudinal axis (L) and a bottom area (14), together defining a combustion chamber (16). The bottom area (14) includes an evaporating medium carrier (18) and on a side facing the combustion chamber (16), a porous evaporating medium (20). A first flame diaphragm (36), with a first diaphragm opening (38), is provided on the circumferential wall (12). A second flame diaphragm (40), with a second diaphragm opening (42), is provided at an axial distance to the first flame diaphragm (36) on an axial side facing away from the porous evaporating medium (20). An air admission opening arrangement (44) is provided in the circumferential wall (12) and includes an air admission opening (46) between the first flame diaphragm (36) and the second flame diaphragm (40).

In a suction fan type combustion apparatus, when an air supply/exhaust path of a combustion and heating unit is clogged, a combustion fan has a degraded fan current for the same fan rotation speed. Furthermore, the suction fan type configuration has the combustion and heating unit's internal pressure reduced as the combustion fan rotates faster. A combustion burner supplies fuel gas with a pressure applied thereto, which is regulated by a gas proportional valve. A degree of opening of the gas proportional valve is corrected in a direction allowing the pressure to be reduced, in accordance with a rate of degradation of a fan current relative to a reference current following a reference current characteristic. This control for correction is done with the fan current degradation rate smoothed (or low-pass filtered) in a time base direction.

Combustion systems configured to achieve, and methods of operating combustion systems to attain, enhanced high turndown operation, are disclosed herein. In one example embodiment, a combustion system includes an air flow tube, an air inlet damper, a gas train, a mixing chamber, a burner, and a blower. A flow of air via the tube into the mixing chamber is governed at least in part by a status of the air inlet damper. Further, the air inlet damper includes a damper plate having an outer perimeter with a first edge portion that is complementary to an inner surface of the tube and one or more additional edge portions that define a first inwardly-extending cutout. In another example embodiment, the combustion system includes a control device configured to cause a control signal for receipt by the damper motor to vary nonlinearly in response to variation of a modulation signal.

Combustion systems configured to achieve, and methods of operating combustion systems to attain, enhanced high turndown operation, are disclosed herein. In one example embodiment, a combustion system includes an air flow tube, an air inlet damper, a gas train, a mixing chamber, a burner, and a blower. A flow of air via the tube into the mixing chamber is governed at least in part by a status of the air inlet damper. Further, the air inlet damper includes a damper plate having an outer perimeter with a first edge portion that is complementary to an inner surface of the tube and one or more additional edge portions that define a first inwardly-extending cutout. In another example embodiment, the combustion system includes a control device configured to cause a control signal for receipt by the damper motor to vary nonlinearly in response to variation of a modulation signal.

A furnace-heating combustion apparatus that allows adjustment of a ratio between the amount of primary air and the amount of secondary air. A double-tube elongate burner extends through a rear wall portion of an air box disposed away from a furnace wall. The leading end portion of the burner is disposed inside a tube section such that a secondary air conduit is formed between an outer circumferential face of the leading end portion and an inner circumferential face of the tube section. A primary air conduit is provided at the leading end portion of the burner to introduce the air inside the air box from the rear end portion and cause it to flow toward the leading end portion. A burner supporting means is provided for to allow adjustment of the position of the burner in the longitudinal direction relative to the rear wall of the air box.