Abb Research Ltd.

Asea Brown Boveri Ag

Abb Management Ag

Jurgen Haumann

Thomas Sattelmayer

Hans Peter Knopfel

Klaus Dobbeling

Christian Steinbach

Bettina Paikert

Thomas Ruck

Rudolf Tresch

Thomas Sattlemayer

Alfred Knopfli

Thomas Sattelamayer

When a boiler plant (100), which is equipped with an air plenum (104), is in operation, during the startup phase the admission pressure in this air plenum (104) is lowered in terms of time and amount via a blowoff device (106) with respect to combustion air (7) and startup air (105) made available from this air plenum (104). The air coefficient to the burner is consequently reduced. This ensures that, by means of such a near-stoichiometric fuel/air mixture, favorable ignition conditions are provided in the burner and the pollutant emissions during the startup phase are greatly reduced.

Method for operating a boiler plant

In a boiler plant for heat generation, which consists essentially of a combustion space and of a burner acting on the head side of the combustion space, this combustion space is divided into two parts (17,102a) by the insertion of an annular disk (103). A limited internal backflow zone (24) forms in the front part (17) in interaction with this disk (103). This disk (103) then causes external backflow zones (106) fed by recirculated flue gases (30) to form within the front part (17) of the combustion space, the flue gases of said external backflow zones being introduced into the combustion process of the burner, said backflow zones (24, 106) being in each case separated locally from one another. Better flame stabilization, lower pulsations and markedly lower pollutant emissions can thereby be achieved when the burner is operating.

Boiler plant for heat generation

In a method of operating a swirl-stabilized burner operated with gaseous and/or liquid fuels (12, 16), in which combustion air (7) or a mixture of recycled flue gas (30) and fresh air (29), which mixture is formed by injector delivery, and fuel (12, 16) are intensively mixed by means of a swirl generator (37) and then burned, in the course of which a backflow zone (24), which stabilizes the flame, is formed, starting air (38), which has at least a radial velocity component, is injected during the starting action at the downstream end of the swirl generator (37) in such a way as to be directed from the margin of the burner into the center. The injection of the starting air (38) is switched off after the end of the starting action, so that the burner works in such a way as to be unaffected in normal operation. The invention improves the ignition conditions, increases the flame stabilization, and reduces the pollutant emissions when the burner is being started.

Method of operating a swirl stabilized burner and burner for carrying

In a method and a device for burning fuels in a combustion air main stream, the combustion air is passed in a channel over at least one deltoid body. The deltoid body consists of at least one essentially triangular vortex generator area and a downstream, trapezoid flame stabilizer area. In the region of the vortex generator area, fuel is introduced into the turbulent combustion air. The vortex generator area is set via a half sweep angle and an angle of attack relative to the main stream in such a way that the spin of the longitudinal vortexes induced in the main stream is smaller than the critical spin for generating a recirculation zone. The flame stabilization area is set via a half sweep angle and an angle of attack relative to the stream in such a way that the spin of the longitudinal vortexes induced in the stream is greater than the critical spin, so that for each deltoid body, a pair of concave recirculation zones is generated, and the ignited combustion air-fuel mixture is stabilized.

Method and device for burning fuels

In a burner which consists of a swirl generator (100) on the oncoming-flow side, the flow (40) formed herein is passed smoothly into a mixing section (220). This is done with the aid of a transition geometry which is present at the start of the mixing tube (220) and consists of transition passages (201) which cover sectors of the end face of the mixing section (220), in accordance with the number of sectional bodies of the swirl generator (100), and run helically in the direction of flow. On the outflow side of these transition passages (201), prefilming bores (21) pass through the mixing section (220), which prefilming bores (21) initiate an increase in the flow velocity along the tube wall. Adjoining the mixing section (220) is a combustion chamber (30) in which a backflow zone (50) forms in the region of the jump in cross-section between mixing section (220) and combustion chamber (30).

Burner

In an apparatus for impingement cooling, in which a cooling surface and a cover surface are disposed parallel to one another, trapezoidal profiles that are open respectively on the narrow side and connected to one another at a constant distance from the cooling surface are disposed crosswise to the flow direction of the cooling air. A side of the trapezoid facing the cooling surface is provided with at least one row of perforations and forms a gap of a constant height with the cooling surface. Open sides of the trapezoid located opposite the cover surface form feed openings for the cooling air, and open sides of the trapezoids located opposite the cooling surface form overflow openings. The feed opening is much larger than the cross-section of a perforation. The cross-section of the return flow conduit is much larger than the overflow opening, and this opening is, in turn, much larger than the cross-section of the gap.

Apparatus for impingement cooling

In a process for low-pollutant combustion in a power station boiler (22) for steam generation, at least one precombustion chamber (24) acts at the boiler itself, which precombustion chamber is operated with at least one burner (25a-c). At least a part of the primary air (26) initially flows through a heat exchanger (24c) , in which a caloric treatment of this air takes place to give combustion air (26a). This combustion air (26a) then flows into the burner (25a-c), where a mixing, and subsequent combustion with fuel (12) or with another mixture takes place. A further air stream as secondary air (27) is injected directly into the precombustion chamber (24), this taking place directly before the actual join of the precombustion chamber (24) to the boiler (22). Downstream of the precombustion chamber (24), a tertiary air stream (29) is fed into the boiler (22). Using this configuration, a process with double air staging is proposed, the boiler (22) being operated with air deficiency. As a result of this substoichiometric operation of the boiler (22), nitrogen-containing fuel compounds can be reduced.

Growing community of inventors

Rekingen, Switzerland

Jurgen Haumann