Patent Application
20250198617
The present disclosure concerns a burner device for combustion of at least one fuel with at least one oxidizer. Furthermore, the present disclosure concerns a combustion chamber device with a burner device, and furthermore a thermal exhaust gas cleaning system with a burner device.
Ever more stringent legal requirements impose, for example in thermal exhaust air cleaning systems, a trend towards ever lower NOx values which are difficult to achieve with the former combustion devices or burners, since sometimes very high combustion chamber temperatures prevail with a low mass stream. Also, in conventional low NOx jet burners, the burner jet enters the flow region very deeply after the burner head, whereby larger recirculation zones occur at the side of this jet. Accordingly, attempts are made to achieve rapid homogenization of fuel and oxidizer with complex injection geometry, but in larger burners this rapidly leads to high investment levels. Finally, the present burners not designed for the use of hydrogen.
The present disclosure is therefore based on the object of creating a burner device of the type cited initially which can be produced easily and cheaply, achieves an even and rapid mixing of fuel and oxidizer, causes lower NOx emissions and/or is prepared at least for the use of hydrogen/methane mixtures.
This object is achieved according to examples disclosed herein in that a burner device is provided for combustion of at least one fuel with at least one oxidizer, wherein the burner device comprises a central longitudinal axis and a main flow direction which is at least approximately parallel to the central longitudinal axis, and wherein the burner device comprises the following:
The burner head comprises the following:
With the burner device according to examples disclosed herein, it may be advantageous that in comparison with conventional burner devices, significantly lower NOx values can be achieved with a more even combustion. A more even and faster mixing of fuel and oxidizer accelerates the corresponding thermal reactions, whereby the combustion chamber temperature can be reduced.
In particular, the use of the baffle plate preferably optimizes the recirculation zones, the flame anchoring and/or the stabilization. Preferably, also the injected fuel or oxidizer can be accelerated and/or an improved mixing of fuel and oxidizer achieved. As a result, as already stated, combustion can take place preferably at lower temperatures, whereby in particular the NOx emissions are lowered.
It is furthermore possible that each two adjacent baffle openings of the at least one baffle plate, and/or each two adjacent injection openings of the at least one injection device, are formed or arranged differently from one another in shape, dimensions and orientation relative to one another and/or relative to the main flow direction or central longitudinal axis.
It may also be provided that the arrangement of the at least one baffle plate on the at least one injection device means that these can be arranged in the immediate physical vicinity of one another relative to the main flow direction, without however thereby obstructing the flow of the oxidizer around the injection device through the baffle openings of the at least one baffle plate.
Furthermore, it is understood that the central longitudinal axis is preferably an axis of symmetry along the burner device, and the main flow direction, in particular parallel thereto, is an axial direction, i.e. any twist with respect to the main flow direction remains disregarded unless explicitly specified otherwise.
In an embodiment of examples disclosed herein, it is provided that the burner head furthermore comprises at least one swirl device for swirling the fuel and/or oxidizer supplied through the burner head, which device is arranged at least partially upstream of the at least one injection device relative to the main flow direction.
The through-flowing part of the oxidizer is thereby deflected only once for swirling and the flow speed can therefore preferably be used almost unchanged for mixing with the fuel. Injection of the fuel is preferably optimized by such a structure and optimally lower pressure losses and/or lower emissions are achieved.
In an embodiment of examples disclosed herein, it is provided that the at least one swirl device is connected to the at least one injection device or has a distance from the at least one injection device which is constant or variably adjustable.
It is conceivable that the at least one injection device is at least partially integrated in the at least one swirl device at a downstream end thereof relative to the main flow direction. However, a fixed distance between the at least one swirl device and the at least one injection device may also be advantageous. Furthermore, a variably adjustable distance allows reaction to changing peripheral conditions of the flow system of the burner device, so that the combustion process can be adapted in order to efficiently reduce the NOx emissions.
In an embodiment of examples disclosed herein, it is provided that the at least one swirl device is connected to the at least one baffle plate.
By connecting the at least one swirl device to the at least one baffle plate and the at least one injection device arranged between the two, advantageously a compact design of the burner device can be achieved.
In an embodiment of examples disclosed herein, it is provided that the swirl device comprises multiple swirl bodies which are each tilted relative to the main flow direction about a radial axis, relative to the central longitudinal axis, for swirling of the through-flowing fuel and/or oxidizer.
The swirl bodies may preferably have the form of straight or curved plates; however, wing profiles or similar are also conceivable.
It is advantageous if the swirl bodies are arranged equidistantly from one another in a circumferential direction relative to the central longitudinal axis, since this guarantees an even swirling of the through-flowing oxidizer, and no local pressure differences or losses occur at the swirl bodies.
In a preferred embodiment, the swirl bodies extend only up to the inside of the flame tube. However, in a possible further embodiment, the swirl bodies may extend radially to the central longitudinal axis through slot-like openings of the flame tube, whereby firstly a compact design is possible and secondly, because of the portion of the swirl body radially protruding beyond the flame tube, the possibility of swirling is also made available for a particular region outside the flame tube.
In an embodiment of examples disclosed herein, it is provided that the swirl bodies have a protrusion at their upstream edges relative to the main flow direction.
It may be favorable with such protrusions that the through-flow region is exposed to variable flame heights, i.e. the flame height is influenced in the main flow direction depending on the concrete embodiment of the protrusion.
In an embodiment of examples disclosed herein, it is provided that the flame tube forms at least one diffuser at its downstream end relative to the main flow direction.
It may be advantageous if the diffuser promotes the recirculation of the inner flow, and/or because of the diffuser the geometry of the flame tube is stabilized, for example the corresponding end of the flame tube has increased stiffness in comparison with a cylindrical design. The diffuser preferably causes a spreading of the secondary part of the oxidizer or secondary air flowing along the outside of the flame tube. Spreading or widening of this part of the oxidizer may be particularly important for rapid mixing of fuel and oxidizer, which preferably leads to improved cleaning of exhaust air.
In an embodiment of examples disclosed herein, it is provided that the diffuser has a constant cross-sectional widening downstream relative to the main flow direction.
The necessary or desired speed of mixing can be set amongst others by the opening angle and the course of the cross-sectional widening, so that a constant cross-sectional widening is regarded as merely particularly advantageous.
The opening angle of the cross-sectional widening may be constant. It is however also possible that the opening angle of the cross-sectional widening increases or decreases.
If the diffuser is produced by means of an additive manufacturing process such as 3D printing, it is possible that steps are formed due to production. This stepped contour, which is not usually very pronounced, on the outside and/or inside of the diffuser should also be regarded as a constant cross-sectional widening.
In an embodiment of examples disclosed herein, it is provided that the at least one injection device has first injection openings, the central axes of which point at least approximately in the main flow direction.
Thus the fuel and/or oxidizer is injected into the combustion chamber at least approximately parallel to the main flow direction, wherein the central axis of an injection opening means its main outflow direction.
It is however also conceivable that the central axes of the injection openings and the main flow direction enclose an angle of more than zero, since it may be advantageous not to orient the injection openings in the direction of the main flow direction but, depending on further adjustable elements of the burner device, to specify an angle relative to the main flow direction, for example in order to optimize the mixing of the injected fuel and through-flowing oxidizer.
In an embodiment of examples disclosed herein, it is provided that at least one of the first injection openings has an injection nozzle protruding in the main flow direction.
It is favorable here that injection nozzles at the injection openings, depending on profile or geometry along the central axis, can increase the speed with which the fuel emerges from the injection opening.
In an embodiment of examples disclosed herein, it is provided that the at least one injection device has second injection openings, the central axes of which each enclose an angle of between 0 degrees and 90 degrees to the main flow direction.
In particular, it may be advantageous if the second injection openings enclose an angle different from zero with the first injection openings.
Additional injection openings which are not oriented in the main flow direction preferably allow local premixed combustion, or at least an increase in local mixing of fuel and oxidizer, and thereby overall, as well as an increased available fuel volume, the homogenization of the mixture is accelerated.
In a further possible embodiment of examples disclosed herein, it may be provided that the first and second injection openings are controllable independently of one another, i.e. either the first, the second or both the first and second injection openings can be activated or deactivated, whereby the volume flow of fuel can be adjusted. Furthermore, it is possible that different fuels can be injected via the first and the second injection openings. The first and the second injection openings of the at least one injection device may be arranged alternately or in groups.
In an embodiment of examples disclosed herein, it is provided that the at least one injection device is a tube ring, a star-shaped closed tube arrangement, a tube ring with a fluidically connected internal tube cross, or a tube cross.
In the context of examples disclosed herein, the injection devices are not restricted to a specific embodiment. Rather, depending on concrete application, a design different from a tube ring may be preferable. Thus e.g. the variant of a tube ring with fluidically connected internal tube cross offers the possibility of injecting more fuel into a central region via the additional injection openings.
A tube cross is an arrangement in which the number of cross webs and, associated therewith, the angle prevailing between the webs depends on the application. A tube cross in particular means also an arrangement of at least three tube portions which are arranged substantially as a jet around a common center point, preferably with an enclosed angle of 120° between each two adjacent tube portions. The three tube portions are connected fluid-conductively with at least one supply. The supply may be arranged both in the center and also at least partly surrounding the tube cross of the tube portions.
In an embodiment of examples disclosed herein, it is provided that the at least one injection device has a round or angular cross-section.
Round or rounded cross-sections include circular, oval and elliptical cross-sections.
In an embodiment of examples disclosed herein, it is provided that the at least one injection device is formed undulating relative to a plane perpendicular to the central longitudinal axis.
An undulating or zigzag design of an injection device preferably allows an influence on the flame height, whereby additionally it may be provided that the orientation of the injection opening of such an injection device, relative to the main flow direction, may differ between the valleys and the peaks of the wave form.
In an embodiment of examples disclosed herein, it is provided that the at least one baffle plate has first baffle openings and second baffle openings.
Preferably, the first and second baffle openings are configured and/or arranged differently in form, dimensions and/or orientation relative to one another and/or relative to the main flow direction or central longitudinal axis, whereby the stabilization of the flames can be influenced.
In a possible further embodiment of examples disclosed herein, it is provided that the first baffle openings and the second baffle openings of the baffle plate are arranged alternately in the circumferential direction.
The alternating arrangement may offer the advantage that different combustion types and/or combustion modes can be set at the respective openings, and thus a mutual stabilization of combustion can be achieved at adjacent openings.
In an embodiment of examples disclosed herein, it is provided that the first baffle openings are circular baffle openings and the second baffle openings are elliptical, slot-like or kidney-shaped baffle openings.
The different geometries of the baffle openings create different zones on the baffle plate which preferably stabilize one another.
In an embodiment of examples disclosed herein, it is provided that the second baffle openings are at least partially covered downstream of the at least one baffle plate relative to the main flow direction, wherein the degree of coverage is adjustable.
Adjustable in this context firstly means a possibility of setting the degree of coverage of the second baffle openings depending on the variable combustion parameters, such as combustion chamber temperature, volume flows, pressures etc. In other words, control or adjustment of the coverage degree is possible. Secondly, the adjustability may relate to the adaptation of the coverage degree during production of the at least one baffle plate, or before commissioning, depending on the actual application case.
In an advantageous embodiment, the coverage of the second baffle openings may be adjusted mechanically via flap angles.
In an embodiment of examples disclosed herein, it is provided that fuel can be supplied to the combustion chamber through the first baffle openings from a respective one of the injection openings, and that fuel can be supplied to the combustion chamber through the second baffle openings from a respective two of the injection openings.
It may be favorable if different combustion stages or combustion types take place within a baffle plate. Whereas a richer combustion occurs at the circular first baffle openings with an assigned injection opening, a leaner combustion optimally prevails at the preferably slot-like second baffle openings, which in turn is stabilized via the richer combustion.
In an embodiment of examples disclosed herein, it is provided that the respective two injection openings which supply fuel to the combustion chamber through a second baffle opening are offset radially from a longitudinal central axis of the slot-like baffle opening relative to the central longitudinal axis.
This may have the advantage that the burner flame or combustion in the radially outer region is stabilized. This may be partly because a larger stream of oxidizer is produced through the radially offset arrangement of slot-like baffle opening and the two injection openings on the radially inner long side of the slot-like baffle opening, i.e. hotter flow paths occur on the radially outer long sides of the slot-like baffle openings, while the colder flow paths are preferably formed radially on the inside.
In other words, it is particularly advantageous if the center point of the corresponding baffle openings, or their central axis, relative to the circumferential direction of the baffle plate, is arranged radially further inward than the center point of the assigned injection opening or openings, because this leads to a stable flame on the outer edge of the baffle plate.
This effect may be furthermore achieved or promoted, alternatively or additionally to a radial offset of the baffle and injection openings, by constrictions or protrusions, widenings or similar on the outer and/or inner edge of the baffle plate.
In an embodiment of examples disclosed herein, it is provided that a diversion body for radial diversion of the fuel and/or oxidizer is arranged substantially centrally on the at least one baffle plate downstream relative to the main flow direction.
In a preferred embodiment, the diversion body may for example be frustoconical, whereby advantageously, at the downstream outlet from the at least one baffle plate, the fluid stream is guided or forced radially further outward by the frustoconical diversion body, promoting a fast mixing of fuel and oxidizer.
Other geometries are however also conceivable, e.g. a tube with a protruding terminating cover element on the downstream end.
In an embodiment of examples disclosed herein, it is provided that that the burner head has a first baffle plate, a second baffle plate, a first injection device and a second injection device.
In an embodiment of examples disclosed herein, it is provided that the first and second baffle plates are formed as a ring and the first and second injection devices as a ring tube, wherein the ring diameter of the second baffle plate and the second injection device is greater than the ring diameter of the first baffle plate and the first injection device, and wherein the second baffle plate and the second injection device are radially spaced from the first baffle plate and the first injection device relative to the central longitudinal axis.
In particular, the second baffle plate and the second injection device are arranged coaxially to the first baffle plate and the first injection device.
The advantage with this embodiment may be the two-stage combustion with an inner pilot stage comprising the first injection device and the first baffle plate, and an outer main stage comprising the second injection device and the second baffle plate, wherein the injection devices can preferably inject the same or different fuels. Preferably, the two injection devices are connected to a respective assigned fuel supply such that a volume flow, pressure and/or duration of fuel supply to the respective injection device can be controlled or adjusted independently of one another.
Optionally, an embodiment with a further stage may be favorable in that a higher volume of combustible mixture is provided.
In an embodiment of examples disclosed herein, it is provided that the first baffle plate comprises or is connected to an internal circular disc. The internal circular disc is in particular arranged radially on the inside and/or spaced from the first baffle plate and/or connected thereto via webs.
By suitable dimensioning of the internal circular disc, the recirculation in the downstream zone before the burner head can be adapted. Also, the internal circular disc preferably serves as a heat shield against the fuel supply.
In an embodiment of examples disclosed herein, it is provided that the first baffle plate and the first injection device are arranged downstream or upstream of the second baffle plate and the second injection device, relative to the main flow direction.
In particular, an arrangement may be advantageous in which the first baffle plate and the first injection device are located downstream, because this promotes a spreading or opening of the flow and reduces a pressure fall.
In an embodiment of examples disclosed herein, it is provided that the number of baffle openings of the first baffle plate and the second baffle plate are different.
In an embodiment of examples disclosed herein, it is provided that the outer contour and/or inner contour of the first baffle plate and second baffle plate are different.
Both the different number of baffle openings and the different contours preferably ensure that the formation of eddy paths is suppressed, or the risk of their formation is minimized, whereby preferably also a periodic detachment and associated therewith an oscillation of the combustion are prevented. Without such a periodic detachment, the burnout is higher and hence the exhaust air cleaning is improved.
In an embodiment of examples disclosed herein, it is provided that the baffle plate, in particular the first baffle plate and/or the second baffle plate, comprises two or more segments which are arranged spaced apart from one another relative to the circumferential direction of the baffle plate.
In an embodiment of examples disclosed herein, it is provided that the first baffle plate is arranged spaced from the first injection device, and the second baffle plate is arranged spaced from the second injection device.
In an embodiment of examples disclosed herein, it is provided that the second baffle openings have at least one, preferably at least two bulges for partial constriction.
The term “bulge” in this description and in the appended claims means a region of the respective baffle plate, disc or similar which protrudes or projects. Such a protruding or projecting region partially constricts the baffle opening concerned, or partially reduces the distance between opposite elements of the burner device.
In an embodiment of examples disclosed herein, it is provided that the flame tube is arranged in a guide tube such that between the flame tube and the guide tube, a flow channel is formed through which part of the oxidizer can flow.
The division of the oxidizer stream into a primary part flowing through the burner head and flame tube, and a secondary part flowing through the annular flow channel between the guide tube and flame tube, preferably accelerates the rapid mixing of the fuel and oxidizer.
In a further possible embodiment of examples disclosed herein, it may be provided that the radial edges of the swirl body, relative to the central longitudinal axis, touch the inside the guide tube.
This may offer the advantage that the secondary part of the oxidizer flowing through the annular flow channel formed between the guide tube and the flame tube is completely swirled.
It is however also conceivable that the swirl bodies do not reach up to the inside of the first guide tube and thus, inside the annular flow channel, an unswirled flow path is created which runs substantially along the inside of the first guide tube, and a swirled flow path which runs substantially along the outside of the flame tube, wherein this preferably applies at least to the upstream inlet of the annular flow channel, and/or wherein preferably downstream the paths merge due to the flow dynamics.
In a further possible embodiment of examples disclosed herein, it may again be provided that the guide tube is arranged in a further second guide tube or casing tube, such that a second annular flow channel is formed between the guide tube and the casing tube, through which channel a part of the secondary oxidizer part can flow.
Thus in this second annular flow channel, a part of the secondary oxidizer part flows in an unswirled stream. In the end, the division of the secondary oxidizer part into a swirled and an unswirled part preferably reinforces the recirculation.
In an embodiment of examples disclosed herein, it is provided that at least one bypass injection device for injection of fuel is arranged in the flow channel between the flame tube and the guide tube.
The bypass injection device causes mixing of fuel with part of the oxidizer already in the flow channel. Thus the bypass injection increases the combustion, wherein the fuel which is injected by means of the bypass injection device may be the same fuel as the fuel injected via the injection device, but also a fuel different from this.
In an embodiment of examples disclosed herein, it is provided that at least one further swirl device for swirling the oxidizer is arranged in the flow channel between the flame tube and the guide tube.
This promotes the mixing of the fuel injected through the bypass injection device and the oxidizer part flowing through the flow channel.
In an embodiment of examples disclosed herein, it is provided that the bypass injection device is arranged downstream of the at least one further swirl device relative to the main flow direction.
Thus the fuel of the bypass injection device is injected into the swirled oxidizer part, which leads to improved mixing.
In an embodiment of examples disclosed herein, it is provided that the oxidizer enters the flow channel with a speed of 50 m/s to 70 m/s, in particular 60 m/s.
This may advantageously implement a jet stream at the combustion chamber inlet.
The object is furthermore achieved according to examples disclosed herein by the use of a burner device as described above. The burner device is in particular used for exhaust gas cleaning and/or exhaust air cleaning.
The object is furthermore achieved according to examples disclosed herein by a method for operation of a burner device, wherein the method comprises the following steps:
The object may furthermore be achieved according to examples disclosed herein by a combustion chamber system with at least one combustion chamber and at least one burner device as described above, wherein the outer periphery of the burner device is connected to a floor of the combustion chamber device.
In an embodiment of examples disclosed herein, it is provided that the burner device is inserted in the combustion chamber and attached outside the combustion chamber, wherein between the outer periphery of the burner device and the combustion chamber, a flow channel is formed through which a part of the oxidizer can flow.
In particular in a burner device with guide tube, part of the oxidizer flows firstly through the flow channel between the flame tube and guide tube, and secondly through the annular gap between the guide tube and the corresponding insertion region of the combustion chamber device. This annular gap may be formed asymmetrically as a result of production tolerances or due to thermal deformations. The provision of a guide tube nonetheless ensures that a symmetrical flow from the flame tube to the opening of the combustion chamber device prevails.
The object may furthermore be achieved according to examples disclosed herein by a thermal exhaust gas cleaning plant with a burner device as described above.
Further preferred features and/or advantages of examples disclosed herein are the subject of the following description and the illustration of exemplary embodiments in the drawings.
The same or functionally equivalent elements carry the same reference signs in all figures.
The further elements or assemblies of the burner device 100 and base unit 300 are described in more detail in connection with
A burner device, designated as a whole by 100 and shown in
The burner device 100 is formed substantially rotationally symmetrically about a central longitudinal axis 102, wherein a main flow direction 104 runs at least approximately parallel to the central longitudinal axis 102. With reference to the illustration of the burner device 100 in
The burner device 100 comprises a flame tube 106, a burner head 108 and a guide tube 110. The burner head 108 is arranged in the flame tube 106 such that the flame tube 106 protrudes downstream beyond the burner head 108.
At its downstream end, the flame tube 106 has a diffuser 112. The diffuser 112 is characterized by a constant cross-sectional widening, for example at least around 15°, preferably at least around 25°, and/or at most around 60°, in particular at most around 45°.
The flame tube 106 is arranged in the guide tube 110 which, for reasons of visibility of elements arranged below this, is shown transparently in
An annular flow channel 114 is formed between the flow tube 106 and the guide tube 110; optionally, a bypass injection device can inject fuel into said channel in order to mix the fuel with the through-flowing oxidizer part.
The burner head 108 comprises a first baffle plate 116, a second baffle plate 118, a first injection device 120, a second injection device 122, a swirl device 123 with multiple swirl bodies in the form of swirl plates 124, and a central hollow body 126 which is not completely visible in
Further details of the burner head 108 are described below with reference to
The swirl plates 124 extend from the central hollow body 126 through the slot-like openings 128 in the flame tube 106 up to the inside of the guide tube 110. Also, at their upstream edges, the swirl plates each have a protrusion 130 which adjoins the inside of the guide tube 110.
These protrusions 130 on the swirl plates 124, which could also be described as fins, load the through-flow region, i.e. the annular flow channel 114, at variable heights, i.e. the flame height is influenced in the main flow direction 104 in order to reinforce the enveloping hot zone.
A primary part of the oxidizer, e.g. primary air, flows through the flame tube 106 and burner head 108. A secondary part of the oxidizer, e.g. secondary air, flows through the annular flow channel 114.
The secondary part of the oxidizer flowing through the annular flow channel 114 is swirled by the portion of the swirl plates 124 present in the annular flow channel 114, and deflected or spread outward, i.e. away from the central longitudinal axis 102, by the shape of the diffuser 112.
This spreading directly at the downstream end of the burner device 100 causes a rapid homogenization of the combustion mixture, and also preferably lateral cold streams in the main flow downstream of the burner device 100 are eliminated.
Because of the cooperation of the diffuser 112 with the swirl plates 124, less swirling is required, i.e. a smaller slope angle of the swirl plates 124, which leads to a lower pressure loss.
It is furthermore conceivable the volatile organic compounds (VOC) are injected between the flame tube 106 and guide tube 110, and/or between the guide tube 110 and the casing tube.
Furthermore, the first injection device 120 and the second injection device 122 are supplied by fuel supply lines 134.
The second baffle plate 118 has teeth 136 on its outer contour which touch the inside of the flame tube 106.
On its downstream edge, i.e. on the edge pointing to the right in
The first injection device 120 is arranged between the swirl plates 124 and the first baffle plate 116 in the corresponding receivers 138 of the swirl plates 124, and the second injection device 122 is arranged between the swirl plates 124 and the second baffle plate 118 in the corresponding receivers 138 of the swirl plates 124.
The first injection device 120 can also be described as a pilot stage, and the second injection device 122 as the main stage.
The advantage of swirl generation or swirling of the oxidizer close to the injection point is to minimize pressure losses, leading in turn to lower emissions. In other words, by the combination of swirl plates with injection devices 120, 122, the speed of the oxidizer can be used directly by single deflection, which allows a more compact design.
It is advantageous if the first injection device 120 is arranged downstream of the second injection device 22 along the central longitudinal axis 102, i.e. the first injection device 120 or the pilot stage is arranged before the second injection device 122. As a result, the radial opening of the flow is promoted and the pressure fall reduced further.
It is also conceivable that a body protruding into the combustion chamber of the flame tube 106 adjoins the internal circular disc 142 downstream of the first injection device 120; this is preferably a frustoconical body, the smaller diameter side of which points upstream. This additional frustoconical body further promotes the radial widening or deflection of the flow. Also, such a body reduces the recirculation at the outlet of the burner head 108, or blocks a part of the recirculation zone, thus suppressing a merging of the burner flame at the first and second injection devices 120, 122.
The first baffle plate 116 and the second baffle plate 118 are each spaced apart from and releasably attached to the first injection device 120 or second injection device 122 respectively by means of multiple connections 140, preferably screw connections.
The combination of second baffle plate 118 and second injection device 122 has a greater diameter than the combination of first baffle plate 116 and first injection device 120. Also, the two combinations are arranged radially spaced apart from one another and/or coaxially aligned with one another.
Preferably an internal circular disc 142, which is connected to the first baffle plate 116 via multiple webs 144, preferably eight webs 144, is arranged radially on the inside with respect to the first baffle plate 116 and in the same plane.
In its central position, the internal circular disc 142 serves preferably as a heat shield with respect to the fuel supply in the recirculation zone.
The first baffle plate 116 and the second baffle plate 118 each comprise multiple first baffle openings 146, which are for example formed circular, and multiple second baffle openings 148 of different geometry and formed for example as slots. The circular baffle openings 146 and the slot-like baffle openings 148 are arranged preferably alternately along the circumference of the baffle plates 116, 118.
The baffle area of the circular baffle openings 146 is smaller than that of the slot-like baffle openings 148.
Because of the different size of the baffle areas of the baffle openings 146, 148, small and large flames are produced and consequently hot and colder zones. This may offer the advantage that the methane values in the combustion chamber are drastically reduced.
In particular with respect to
In addition, the injection openings 132 of the circular baffle openings 146 are centered relative thereto, whereas the injection openings 132 of the slot-like baffle openings are preferably offset radially outward relative to the longitudinal axis of the slot-like baffle openings, since the bending radius of the respective injection device 120, 122 is greater that the bending radius of the associated slot-like baffle openings 148. The latter ensures that combustion in the outer region of the burner device 100 is stabilized.
Because of the different number of active injection openings 132 of the circular and slot-like baffle openings 146, 148, there are two different combustion ratios within the baffle plates 116, 118. At the circular baffle openings 146, combustion is richer, whereas at the slot-like baffle openings 148, it is leaner, wherein the leaner combustion is stabilized via the richer.
The baffle plates 116, 118 promote recirculation in that they accelerate the oxidizer in the vicinity of the injection devices 120, 122, leading to a greater mixing of the oxidizer and fuel. The increased mixing allows combustion at lower temperature, which leads to a lower NOx emission. Combustion close to the baffle plates 116, 118 stabilizes the volume combustion.
It is clear from
In contrast, the first baffle plate 116 has round recesses 154 along its outer contour or outer periphery.
It is understood that both the outer contour and/or the inner contour of the first baffle plate 118, and the outer contour of the first baffle plate 116, may alternatively or additionally have a constant course, such as e.g. an undulating course, which reduces or enlarges in portions the distance from the flame tube or the distance between the first and second baffle plates 116, 118 respectively. As a result, there is less mutual reinforcement of flow instabilities.
It is furthermore found that the numbers of circular and slot-like baffle openings 146, 148 in the first and second baffle plates 116, 118 are different.
Because of the differences in outer or inner contour and the number of baffle openings 146, 148, it is guaranteed that no eddy paths occur and there are no periodic detachments which could lead to oscillation in combustion. The result is a higher burnout and hence improved exhaust air cleaning.
The illustrations in
In
Whereas in
Furthermore, the mixing can be controlled if the injection opening 132 slopes relative to the main flow direction 104, i.e. encloses an angle therewith as shown in
An embodiment is also possible in which an injection nozzle 166 or injection lance is arranged on the injection opening 132, the inner cross-section of which tapers for example relative to the main flow direction 104, whereby the flow speed of the outflowing fuel is increased and a greater or faster mixing occurs.
In
Alternatively, an injection device 120, 122 may be formed as a star as shown in
Looking at
Secondly, the first baffle plate 116 is also divided, this time into four equal segments 174, which are also arranged spaced apart from one another relative to the circumferential direction of the first baffle plate 116.
The number of segments of the first and second baffle plates 116, 118 may also be greater or less than five or four respectively, since the number of segments depends in particular on the ease of manufacture and installation.
The segments 172 and 174 are separated from one other, preferably in the region of the second slot-like baffle opening 148.
It is also conceivable that the first baffle plate 116 is divided into more than four segments 174 or fewer than four segments 174, wherein the segments 174 of the first baffle plate 116 may be the same or different from one another. The same applies accordingly to the second baffle plate 118, which may also be divided into more or fewer than five segments 172, wherein these segments 172 may also be the same or different.
Because of the decoupled arrangement of segments 172 and 174, as a whole less thermal expansion occurs. Also, in the production of the comparatively smaller segments 172, 174, less waste material occurs than in production of a cohesive first or second baffle plate 116, 118. In addition, more connections 140 are required for attaching the segments 172, 174, whereby the fixing of the first and second baffle plates 116, 118 is improved and a defect or failure of a single connection 140 can be better compensated.
In this particularly preferred embodiment of the connections 140, the connections 140 each comprise a screw 176, a nut 178 and a spacer 118 formed as a sleeve.
Preferably, each segment 172, 174 is attached to the first or second injection device 120, 122 respectively by two or more pairs of connections 140, wherein the connections 140 of the individual pairs are arranged on mutually opposite sides of the injection device 120, 122.
The nuts 178 are attached, preferably welded, to the side of the first and second injection devices 120, 122.
The desired distance between the injection device and the baffle plate can be adjusted via the spacers 180, which are preferably interchangeable or exchangeable. Thus the oxidizer stream around the injection devices 120, 122 and through the baffle plates 116, 118 can be adjusted.
Because of the spacing of the baffle plates 116, 118 and the lateral attachment of the nuts 178, weld seams or weld points on the downstream-side hot surface of the injection devices 120, 122 are avoided.
The screws 176 are screwed into the associated nuts 178 for attachment of the respective segments 172, 174, wherein the bore 152 provided in the baffle plates 116, 118 for the respective connection 140 may additionally have a thread corresponding to the screw 176.
In the third embodiment, the connections 140 are also arranged in pairs on mutually opposite sides of the first or second injection device 120, 122.
In the third embodiment, the connections 140 also comprise a screw 176, a nut 178 and a sleeve-like spacer 180.
Each screw 176 of a connection pair extends through one of the segments 172, 174 into an assigned U-shaped bracket 182, which is guided against the first or second injection device 120, 122 on the upstream side and at least partially surrounds this. The two screws 176 are secured to the assigned U-shaped bracket 182 by means of the respective nuts 178. The two associated spacers 180 of the connection pair are arranged between the ends of the U-shaped bracket 182 and the corresponding segment, whereby the distance between this segment and the first or second injection device 120, 122 is set.
The brackets 182 may be fixed to the respective injection device 120, 122, e.g. by one or more weld points.
Alternatively, the brackets 182 are at least partially displaceable in the circumferential direction of the first or second injection device 120, 122, whereby a further degree of freedom is provided to reduce thermal stress. The movability of non-fixed brackets 182 in the circumferential direction may be limited by stops (not shown) which are attached to the first and second injection devices 120, 122.
The brackets 182 are preferably made of a metal.
The friction resistance between the bracket 182 and the first or second injection device 120, 122 may be adjusted via the width of the non-fixed brackets 182. Thus the risk of tilting of the associated, indirectly attached segment 172, 174 about the circumferential axis of the first or second injection device 120, 122 is reduced.
The bores 152 for the connections 140 in the first and second baffle plates 116, 118, and also the sleeve-like spacers 180, may be provided with an internal thread corresponding to the screws 176.
It is conceivable that the spacers 180 and/or the transverse webs 184 are attached to the first or second injection device 120, 122.
Furthermore, the friction resistance between the transverse web 184 and the first or second injection device 120, 122 can be set via the size of the contact area of the transverse web.
Alternatively or additionally, the segments 172, 174 may be secured to the first or second injection device 120, 122 by multiple U-shaped plates (not shown). These U-shaped plates, like the brackets 182 from
Firstly, the second slot-like baffle openings 148 of the segments 172, 174 of the first and second baffle plate 116, 118 are attached to the first or second injection device 120, 122 on both sides, i.e. at the slot inner web 156 and at the slot outer web 158, by one or two pairs of connections 140, which prevents or at least reduces flow-induced oscillations at the slot inner web 156 and the slot outer web 158.
Secondly, the second baffle openings 148 of the first or second baffle plates 116, 118 have one or more constrictions.
The constrictions are produced by pairs of opposite bulges 186 of the respective baffle plates 116, 118 which may be formed with constant or non-constant inner or outer contour, such as e.g. toothed or similar, wherein preferably the number of constrictions and hence also the number of bulges 186 of two adjacent baffle openings 148 differs along the circumferential direction of the first and second baffle plates 116, 118.
In
The bulges 186 may lie directly opposite one another or may also be arranged offset to one another.
Furthermore, further bulge elements (not shown) may protrude into the annular gap 188 between the first and second baffle plates 116, 118.
Thirdly, preferably also the internal circular disc 142 is provided with bulges 186 along its outer circumference, so that constricted portions are formed in the annular gap 190 between the internal circular disc 142 and the first baffle plate 116.
Further measures for noise reduction are conceivable which cause the formation of symmetrical and/or asymmetrical constrictions in the region of the annular gaps 188, 190 and along the second baffle openings 148.
At a second baffle opening 148 formed by two adjacent segments 172 or two adjacent segments 174, the slot inner web 156 and the slot outer web 158 are each divided by a gap. The resulting free ends or part pieces of the webs 156, 158 vibrate due to the oxidizer flow and thereby generate noise.
To reduce this noise, an upstream bent extension 192, which at least at least partly overlaps or protrudes beyond the other part piece 196 of the slot outer web 158, is provided on a part piece 194 of the slot outer web 158. The extension 192 is preferably a portion of the part piece 194.
As an alternative,
Additionally or alternatively, it is conceivable that the gaps between the part pieces of the slot inner web 156 and slot outer web 158 of a second baffle opening 148 are covered on the downstream surface by a common plate-like transverse element (not shown). The plate-like transverse element is accordingly oriented at least approximately perpendicularly to the circumferential direction of the respective baffle plate 116, 118.
As evident for example in the second embodiment in
The floating mounting, which preferably connects together two adjacent segments 172, 174, is created in that two mutually opposing angle elements 200 are fixed, preferably by means of a weld connection 202, to the respective injection device 120, 122 at the adjacent ends of two neighboring segments 172, 174.
The angle elements 200 preferably have three portions, of which, relative to the image plane in
The angle elements 200 receive the associated segment 172, 174 on the downstream side, preferably via the respective part pieces of the slot inner web 156 and slot outer web 158.
The part pieces of the slot inner web 156 and slot outer web 158 have a recess on the inside, i.e. a partial cutout of the segment. The radial depth of the recess may for example amount to half the respective web 156, 158, whereas the extent of the recess in the circumferential direction of the respective segment 172, 174 is preferably a multiple of the radial depth.
On the downstream side, the adjacent part pieces of the slot inner web 156 are covered by a plate segment 204, which is preferably connected to the two associated angle elements 200 of the slot inner web 156 by means of a weld connection 202.
Similarly, the adjacent part pieces of the slot outer web 158 are covered on the downstream side by a further plate segment 204, which is preferably connected to the two associated angle elements 200 of the slot outer web 158 by means of a weld connection 202.
The plate segments 204 are furthermore connected to the associated two angle elements 200 on the inside of the webs 156, 158 by means of a bolt 206 or similar.
The plate segments 204 contribute to noise reduction by covering the gap between the part pieces of the webs 156, 158.
Such a floating mounting of two adjacent ends of two segments 172, 174 allows a movement of the segments 172, 174 in the circumferential direction, whereby thermal expansion, in particular in the circumferential direction of the baffle plates 116, 118, can be compensated.
The igniter device 302 reaches from the base unit 300 into the burner device 100 and, with respect to the direction of gravity g, preferably lies from above on the first baffle plate 116. Particularly preferably, the igniter device 302 is received by a round recess 154 of the first baffle plate 116.
Because the igniter device 302 rests on the first baffle plate 116, it is guaranteed that the distance from the first baffle plate 116 is as short as possible, which at least hinders an ignition of false air.
The igniter device 302 is ideally arranged such that, relative to the direction of gravity g, it is arranged higher in the base unit 300 than in the burner device 100, whereby the igniter device 302 encloses an angle α with the central longitudinal axis 102. This oblique position prevents any possible condensate, contamination or similar from the burner device 100 being able to flow back through the igniter device 302.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2022 106 816.1 | Mar 2022 | DE | national |
This application is a national phase of international application No. PCT/DE2023/100230 filed on Mar. 23, 2023, and claims the benefit of German application No. 10 2022 106 816.1 filed on Mar. 23, 2022, which are incorporated herein by reference in their entirety and for all purposes.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/DE2023/100230 | 3/23/2023 | WO |
