Suspension for an annular gas turbine combustor

The invention relates to the suspension of an annular gas turbine combustor in the outlet area thereof according to a housing wall, the preamble of the main claim.

Ring-combustion chambers of gas turbines are usually in their front End by the protruding into the combustion chamber interior Brenner worn while she sucked in the rear end, the. Outlet region, suitable to a housing wall, the so-called. "combustion chamber outer casing ", are suspended. In particular, in case of effusion Combustion chamber wall with a plurality of cooling air openings, the so-called. effusion holes is to take care, that also the rear combustion chamber wall portion sufficient cooling learns. The support structure for the suspension of the combustion chamber may in this area thus does not hinder the effective cooling. A suspension and a support structure that meets these requirements is, for example, shown in the above mentioned EP 0564172 A1. This annular, formed bent arm structure relative to the gas turbine longitudinal axis an inner and an outer leg, is in Professional circles also known under the term "hair-pin" (hairpin). The inner Leg closes it with the outer leg at an acute angle a, as is the inner leg with respect to the combustion chamber wall inclined at an acute angle, whereby a wedge-shaped annular gap results between the inner leg and the combustion chamber wall, the direction of flow in the guided along on the outer side of the outer combustion chamber wall Cooling air flow considered is open. In this way, optimal Way cooling air access to the rearmost end of the combustion chamber wall.

In the prior art, in which these trained kinked Arm structure and the so-called. Hairpin / hair-pin on the outer wall of annular combustor is provided to this chamber supports only at the wall surrounding the combustion chamber via this arm structure Housing wall from, whereas the actual fastening of the combustion chamber via the inner wall of the annular combustor This can lead to undesirable large relative movements in the rear end portion of the combustion chamber to lead.

The closest prior art is shown in DE 196 00 837 A1. Out this publication is an axially-stepped annular combustor of a gas turbine is known in which the suspension formed by means of a kinked Arm structure takes place, at which the outer legs of arm a flange adjoined, via a releasable connecting element is connected to the housing wall.

An angled Armstrukturverlagerung an annular combustor further shows the GB 1578474 A. At their outside leg has this arm structure on recesses.

is just falling from US Patent 5,323,605 an angled arm structure previously known. This, however, is clamped at its outer edge region only, unsolvable screwed.

European Patent Application EP 521 687 A1 shows a storage annular gas turbine combustor, wherein an angled arm structure is formed integrally with the combustion chamber wall. The outer Edge of this arm structure between two components of the housing wall clamped. An additional flange is not provided.

The invention is based on the object, a suspension of an annular to provide gas turbine combustor of the type mentioned, which easily while avoiding the disadvantages of the prior art built, is reliable and usable be manufactured inexpensively can.

According to the invention the object is achieved by the features of the main claim solved the subclaims show further advantageous embodiments of the Invention.

be explained in detail, the invention is based on a preferred embodiment. It shows<dl tsize="7" compact="compact"><dt>Fig. 1</dt><dd>a partial section through a gas turbine annular combustor with an inventive suspension,</dd><dt>FIG. 2</dt><dd>view X from FIG. 1 as a partial settlement of the annular Arm structure, and</dd><dt>Fig. 3</dt><dd>essential elements of the view A in FIG. 1.</dd></dl>

The reference numeral 1 is an annular combustor of a gas turbine is indicated, which is embodied here as a stepped combustion chamber and thus in addition to a Plurality of annularly arranged burners pilot end face 2 further also arranged in a ring main burner 3. In exit area 4 of the combustion chamber 1 - to these, includes a plurality of Vanes 5 bearing guide vane 6 on - the combustion chamber 1 to a surrounding entire combustion chamber structure housing wall 7 hung. It is planned for this purpose an annular, bent trained Arm structure 8 which at the end portion of the outer combustion chamber wall 9a connects. Because of the bend along the likewise annular called. This folding line 10 has arm structure 8 with respect to the gas turbine longitudinal axis 11 an inner leg 8a and an outer leg 8b, which meet in the fold line 10 and between an acute Include angle. Likewise, is an acute angle between the outer Combustion chamber wall 9a and the inner leg 8a and between the Housing wall 7 and the outer legs 8b before.

At the of the fold line 10 opposite end of the outer leg 8b includes a radially extending flange 8c to which on a releasable connecting element 12 (in the form of a screw-nut connection) with a likewise in the radial direction, ie perpendicular to Gas turbine longitudinal axis 11 extending flange 7a of the housing wall 7 connected is. After about the periphery of the combustion chamber 1 and the Housing wall 7 distributed a plurality of such fasteners 12 are provided, is a safe and in particular unwanted relative movements preventive suspension of the combustion chamber 1 in the outlet area 4 ensured.

Nevertheless, to a certain mobility of the combustion chamber 1 opposite the Housing wall 7 be given. this mobility is made possible by called. By interruptions 13 in the arm structure 8 or in the legs 8a, 8b. If these openings or perforations 13 in at least one of the legs 8a, 8b, but preferably in two legs 8a, 8b suitable dimensioned and arranged so the arm structure 8 acts like a Leaf spring with targeted designable spring characteristic. Best results were calculated by the below-explained design and arrangement scored by perforations 13 in the arm structure eighth

As Fig. 2 shows that by interruptions 13 are dovetailed designed and distributed similarly to the periphery of both legs 8a, 8b arranged, the narrowest sections of the perforations of each of the Fold line 10 of arm facing. 8 In addition, through interruptions are 13 to fold line towards open so that - after these perforations in the outer leg 8b, and the inner leg 8a in the representation 1 quasi superimposed by FIG -. Between each through refractive 13 in the outer legs 8b and the adjacent opening 13 the inner leg 8a exists a so-called. connection gap 14th With this Design results for a sufficient softness to expansions opposite the housing wall 7 to take the combustion chamber 1, on the other hand However, a sufficient strength to secure the combustion chamber 1 suspended from the housing wall. 7

As FIG. 3 shows are at the stepped annular combustor shown here 1 the pilot burner 2 and the main burner 3 circumferentially offset to each other. An optimal combustor inventive suspension arises with this arrangement when in the cutting plane 15 of each burner (this cutting plane 15 passes as usual through the Burner 2 and 3 themselves, and by the gas turbine longitudinal axis 11) at least in one of the legs 8a and 8b, respectively, but preferably in both the Legs 8a, 8b an opening 13 is provided, wherein in this Cutting plane 15 and the so-called. Connecting gap 14 comes to rest.

However, it is also possible for the openings 13 with respect to the burners 2 offset circumferentially to arrange, so that then the cutting planes 15 of the individual burners 2, 3, for example. Exactly centrally between two adjacent the openings 13 come to rest (not shown). but are also possible other desired intermediate positions of Perforations 13 with respect to the legs 8a and / or 8b of the torch-cutting planes 15th

In the embodiment shown here, with respect to each burner-sectional plane 15 in the two legs 8a, 8b exactly one opening 13 is provided, that is, a ratio of the number of perforations 13 in one of the legs 8a and 8b, respectively (over the entire periphery counted) and the total number of burners 2, 3 and results here exactly the value "1". alternative can this ratio "(number of perforations) / (total number accept the torch) "as well as other useful values, as eg. 0.5 or 1.5 or 2.5 but also 2 or 3, wherein the integer values ​​of this Quotient have the advantage of simple periodic repetition. In expressed in other words, this means that only half as many alternatively Apertures 13 in the legs 8a, 8b of the arm structure 8 is provided are as burners 2, 3 are available, or that three times as many openings 13 are available, are provided as the burner. In particular, is noted that in non-stepped combustors other numerical values for said quotient can be useful, as in stepped Combustion chambers (as shown here).

With the described construction and combustion chamber suspension is a optimal adjustment in terms of function, weight and life Annular combustor 1 possible. One reason for this is that by the periodic fuel injection via the burners 2, 3, a periodic mechanical stress on the combustion chamber walls (the outer combustion chamber wall 9a and 9b of the inner combustion chamber wall) is present, which in the described suspension of the combustion chamber 1 in continues. With this Described construction, each load peak, the corresponding structure required opposite. The last paragraph referred Division ratios or ratio with respect to the number of Perforations 13 relative to the number of the burner results in a be fixed repetitive relationship of thermal / mechanical stress the combustion chamber suspension in its entirety and each opening in the legs 8a, 8b due to the consequent mechanical State conditions.

As FIG. 1 shows, the inner combustion chamber wall 9b a receiving end 16 for adjoining the combustion chamber 1 guide vane ring 6, so that the latter via the combustion chamber 1 as well as their advantageous Suspension is also maintained in an optimum manner. Furthermore recognizes you between the end portion of the outer combustion chamber wall 9a to which the arm structure according to the invention connects 8, and the outer ring the guide vane ring 6 has a circumferential seal 17, the plurality via a is held by rivets 18 at the guide vane 6, but this may well a number of other details particular constructive type quite be designed differently from the illustrated embodiment without the departing from the inventive concept.

<u>LIST OF REFERENCE NUMBERS</u><dl tsize="2" compact="compact"><dt>1</dt><dd>Annular combustor</dd><dt>2</dt><dd>Pilot Burner</dd><dt>3</dt><dd>Main burner</dd><dt>4</dt><dd>exit region</dd><dt>5</dt><dd>vane</dd><dt>6</dt><dd>guide vane ring</dd><dt>7</dt><dd>housing wall</dd><dt>7a</dt><dd>flange</dd><dt>8th</dt><dd>arm structure</dd><dt>8a</dt><dd>inner limb of 8</dd><dt>8b</dt><dd>outer limb of 8</dd><dt>8c</dt><dd>flange</dd><dt>9a</dt><dd>outer combustion chamber wall</dd><dt>9b</dt><dd>inner combustion chamber wall</dd><dt>10</dt><dd>fold line</dd><dt>11</dt><dd>Gas turbine longitudinal axis</dd><dt>12</dt><dd>Connection element: Screw-nut connection</dd><dt>13</dt><dd>perforation</dd><dt>14</dt><dd>connecting gap</dd><dt>15</dt><dd>sectional plane</dd><dt>16</dt><dd>admission</dd><dt>17</dt><dd>poetry</dd><dt>18</dt><dd>rivet</dd></dl>