EP3499125A1 - Pipe combustion chamber with ceramic cladding - Google Patents

Abstract

The invention relates to a combustion chamber (1) comprising a jacket (3) arranged around a main axis (2) of the combustion chamber (1) and a ceramic tube (4) arranged within the jacket (3), wherein between the jacket (3) and ceramic tube (4 ) an intermediate layer (5) is arranged and the jacket (3) is at least partially conical and the ceramic tube (4) is axially braced in the jacket (3) along the main axis (2).

Description

The invention relates to a tube combustion chamber with a ceramic lining.

To produce a ceramic-lined tube combustion chamber, a material and assembly-compatible construction is necessary.

The careful integration of the break-sensitive ceramic monoliths in the metal environment is particularly important because the tube combustion chamber is exposed to strong combustion oscillations or vibrations. The vibration-damping, permanent storage of the ceramic is therefore a constructive main task. During storage, it is particularly important to ensure that the ceramic is exposed by the installation in the housing no critical tensile or shear stress. During operation, the ceramic insert experiences, in addition to the composite stresses caused by the storage, the load voltages resulting from the combustion. These stresses, together with the inherent stresses caused by the production, result in the total stress distribution, at which compressive stresses for the component can superimpose critical tensile stresses harmlessly.

The object of the invention is to carefully install such a ceramic insert in the metallic shell a combustion chamber and possibly to make an interface geometry of ceramic segments of such a combustion chamber with each other so that thermal expansions are not hindered. Furthermore, the interface geometry must fulfill various additional functions, such as the transmission of axial and radial composite loads, the clear definition of the position and rotation of the individual elements, the seal between the hot and cold gas side and the avoidance of tensile stresses in the interface area.

The invention solves the object directed to a combustion chamber by providing that in such a combustion chamber, comprising a jacket arranged around a main axis of the combustion chamber and a ceramic tube disposed within the jacket, an intermediate layer is arranged between the jacket and the ceramic tube, the jacket at least partially is conical and the ceramic tube is braced axially along the main axis in the mantle.

The important for the solution of the task realization of a compressive bias is thus achieved according to the invention by axial clamping of the one or more parts ceramic tube in a conical mating surface. About the axial bracing radial forces are generated, which are transmitted via resilient elements on the ceramic outer surface. In this way, an externally pressurized ceramic tube (e.g., cylinder, cone) is created.

In an advantageous embodiment of the invention, the jacket is metallic.

In a further advantageous embodiment, the ceramic tube made of refractory material.

It is advantageous if the intermediate layer is a ceramic swelling mat. Swelling mats are mineral fiber mats containing expandable particles. Due to their elastic restoring forces they exert a holding force on the ceramic tube.

Alternatively, it is advantageous if the intermediate layer comprises spring and / or damping elements. These can be ceramic or metallic.

In an advantageous embodiment, the jacket at the opening with the largest opening diameter fastening means, with the help of a counterpart to the opening can be pulled. For example, the axial clamping can be done by a non-positively and / or positively joined metal ring. The adhesion is made from the metal ring on the ceramic column and springs on the metallic conical counter surface.

With the aim of limiting the joining forces and lining variable geometries, it may be advantageous if the jacket comprises two conical partial shells, i. the jacket is then separated into two conical components (e.g., with a dividing plane shifted to the center).

The ceramic tube itself may conveniently be a solid cylinder or a full cone.

It is particularly advantageous if the ceramic tube is a composite of several heat shield segments. In the design with individual segments, these are held in position and force-locking in position (archway principle) and thus form a pressure-biased ceramic ring. Thermal expansions can be intercepted particularly advantageous here by the heat shield segments each have a hot side acted upon by a hot medium, one facing the hot side, the jacket facing cold side and a circulating between hot side and cold side edge, and in the cold state individual heat shield segments of a segment row on the Edge adjacent to the cold side contact surfaces and to the hot gas side opening column have. Thermal expansion differences namely occur in particular between hot and cold side of the ceramic segments. It is particularly advantageous if the column are sickle-shaped. The cold-side contact surfaces of the individual segments serve to transmit power in the tangential and axial directions. The crescent-shaped gaps which open to the hot side, similar to a tongue and groove connection, ensure unhindered thermal expansions and, on the other hand, a form fit and thus a position definition in the radial direction. The side and end face geometry is to be designed such that their Gap geometry is stretch-adjusted and thus minimizes the column realized during operation to avoid the ingress of hot gas as far as possible.

It is expedient if uneven end faces are provided between rows of segments, so that a positive connection between individual heat shield segments in the circumferential direction arises in the hot state. For the interface geometry, preferably obtuse angles and comparatively large radii are to be used in order to avoid tension-stressed zones.

In order to prevent a rotation in the circumferential direction between the rows of segments, the end faces are not flat, but to be designed so that a positive connection between the ceramic individual segments in the circumferential direction. For this purpose, the interface geometry is preferably carried out in a wavy geometry or any other formschlussgewährleistenden geometry. Again, preferably obtuse angles and comparatively large radii are to be used.

For the lining of a tube combustion chamber, a ceramic composite of several refractory heat shield segments or a ceramic solid cylinder or cone is provided. The resulting ring or cone made of refractory ceramic is supported by means of a resilient intermediate layer in a metallic housing. The attachment of the ceramic segments is realized via the external pressure, so that a construction without gaps arises.

With the invention, basic design principles of a ceramic-metal composite in combination with a component and cost-reduced design can be realized. With the creation of pressure biases in the ceramic lining, it is possible to increase the strength of the ceramic. The use of refractory ceramics in a tube combustion chamber leads to a reduction of the new part and life cycle costs (by increasing the service life compared to the metallic solution). In addition, an increase in Temperature resistance and a reduction of the cooling air consumption possible.

Figur 1

einen Ausschnitt einer Verbundlösung für eine Brennkammer aus den Elementen Mantel, Keramikrohr und Zwischenschicht,

Figur 2

eine Darstellung der wirkenden Kräfte der Verbundlösung der Figur 1 in der Seitensicht und

Figur 3

eine Darstellung der wirkenden Kräfte der Verbundlösung der Figur 1 in der Längssicht,

Figur 4

axiales Spannen am Beispiel eines Metallrings in geöffnetem Zustand und

Figur 5

axiales Spannen am Beispiel eines Metallrings in geschlossenem Zustand,

Figur 6

das Prinzip zweier konischer Komponenten mit mittiger Trennebene,

Figur 7

eine aufgeschnittene Rohrbrennkammer mit Übergangsstück,

Figur 8

eine Nut-Feder-ähnliche Verbindung von Hitzeschildsegmenten mit Anlagefläche im kalten Zustand,

Figur 9

eine Nut-Feder-ähnliche Verbindung von Hitzeschildsegmenten mit Anlagefläche und geschlossenem Spalt im heißen Zustand und

Figur 10

eine wellenförmige Geometrie zwischen verschiedenen Segmentreihen als Verdrehsicherung.

The invention will be explained in more detail by way of example with reference to the drawings. Shown schematically and not to scale:

FIG. 1

a detail of a composite solution for a combustion chamber of the elements sheath, ceramic tube and intermediate layer,

FIG. 2

a representation of the forces acting on the composite solution of FIG. 1 in the side view and

FIG. 3

a representation of the forces acting on the composite solution of FIG. 1 in the longitudinal direction,

FIG. 4

axial clamping on the example of a metal ring in the open state and

FIG. 5

axial clamping using the example of a metal ring in the closed state,

FIG. 6

the principle of two conical components with a central parting plane,

FIG. 7

a cut pipe combustion chamber with transition piece,

FIG. 8

a tongue and groove-like connection of heat shield segments with contact surface in the cold state,

FIG. 9

a tongue and groove-like connection of heat shield segments with contact surface and closed gap in the hot state and

FIG. 10

a wavy geometry between different rows of segments as anti-rotation.

FIG. 1 shows schematically and by way of example a composite solution of three elements for a combustion chamber 1 with jacket 3, arranged in a shell 3 ceramic tube 4 made of refractory material and a high temperature resistant intermediate layer 5, which is disposed between the shell 3 and ceramic tube 4.

The careful integration of the ceramic tube 4, be it in one piece or in several pieces, in the metal environment is particularly important. FIG. 2 illustrates for this purpose the inventive By axial clamping 18 of the ceramic tube in the direction of the main axis 2 of a conical metallic mating surface, ie the shell, radial forces 19 are generated, which via resilient elements, ie the intermediate layer 5, on the ceramic outer surface be transmitted. In this way, a ceramic composite under external pressure is produced.

In the embodiment with individual heat shield segments 10, these are positively and non-positively held in position (archway principle) and thus form a pressure-biased ring of ceramic heat shield segments 10, as in the FIG. 3 is shown as segment row 14.

The FIGS. 4 and 5 show by way of example how the axial bracing 18 can be effected by a force and / or form-fitting joined metal ring as a fastening means 7 in the region of the larger opening 6 of the cone. The frictional connection is made from the metal ring on the ceramic column and springs on the metallic conical mating surface of the shell. 3

With the aim of limiting the joining forces and lining variable geometries, the metallic component can be separated into two conical components (for example with a dividing plane 20 displaced in the middle, as shown in FIG FIG. 6 is shown). The respective other part jacket 9 with the corresponding ceramic tube 4 acts here as a counterpart 8 for the axial tension 18th

FIG. 7 shows a longitudinally cut tube combustion chamber 1 with transition piece 21, in which a lining, as in FIG. 6 presented, offers.

The FIGS. 8 to 10 show details of the geometry between individual ceramic heat shield segments 10 in an externally pressurized ceramic-metal composite.

The FIG. 8 shows two adjacent heat shield segments 10 in the installed state. The heat shield segments 10 each have a hot side 11 which can be acted upon by a hot medium, a cold side 12 facing the hot side 11, facing the jacket 3, and an edge 13 which extends between hot side 11 and cold side 12. The heat shield segments 10 have on the edge 13 to the cold side 12 subsequent contact surfaces 15, which serve for transmitting power in the tangential and axial direction, and the hot gas side 11 toward opening column 16. The hot gas side opening gaps 16 are crescent-shaped, similar to the function of a tongue and groove joint. The gap 16 itself ensures unobstructed thermal expansion, the shape of the gap 16 allows a positive connection and thus a position definition in the radial direction.

FIG. 9 shows the same two heat shield segments 10, as FIG. 8 , The difference is that the heat shield segments 10 of the FIG. 8 in cold he FIG. 9 are in the hot state and the gap 16 is closed due to the thermal expansion 22.

In order to prevent rotation in the circumferential direction between the segment rows 14 of heat shield segments 10 arranged in the circumferential direction, the end faces 17 of the heat shield segments 10 are not planar but to be designed such that a positive connection between the individual ceramic heat shield segments 10 in the circumferential direction. For this purpose, the interface geometry is preferably in a wavy geometry, as in FIG. 10 represented, or any other formschlussgewährleistenden geometry. FIG. 10 shows a section through a combustion chamber 1 with two rows of segments 14. The flow direction 23 of the hot gases in operation is also indicated.

The side and end face geometry is of course designed to be stretch-adapted, so that a minimization of the gap 16 and also between the rows of segments 14 during the Operation is realized in order to avoid the penetration of hot gas as far as possible. In this case, preferably obtuse angles and large radii are to be used in order to avoid tension-stressed zones.

Claims (15)

Combustion chamber (1) comprising a jacket (3) arranged around a main axis (2) of the combustion chamber (1) and a ceramic tube (4) arranged inside the jacket (3), characterized in that between jacket (3) and ceramic tube (4) an intermediate layer (5) is arranged and the jacket (3) is at least partially conical and the ceramic tube (4) along the main axis (2) in the jacket (3) is axially braced. A combustor (1) according to claim 1, wherein the jacket (3) is metallic. Combustion chamber (1) according to one of claims 1 or 2, wherein the ceramic tube (4) consists of refractory material. Combustion chamber (1) according to one of the preceding claims, wherein the intermediate layer (5) is a ceramic swelling mat. Combustion chamber (1) according to one of claims 1 to 3, wherein the intermediate layer (5) comprises spring and / or damping elements. Combustion chamber (1) according to claim 5, wherein the spring and / or damping elements are ceramic. Combustion chamber (1) according to claim 5, wherein the spring and / or damping elements are metallic. Combustion chamber (1) according to one of the preceding claims, wherein the jacket (3) at the opening (6) having the largest opening diameter fastening means (7), by means of which a counterpart (8) can be pulled against the opening (6). Combustion chamber (1) according to one of the preceding claims, wherein the jacket (3) comprises two conical partial shells (9). Combustion chamber (1) according to one of the preceding claims, wherein the ceramic tube (4) is a solid cylinder. Combustion chamber (1) according to one of claims 1 to 8, wherein the ceramic tube (4) is a full cone. Combustion chamber (1) according to one of the preceding claims, wherein the ceramic tube (4) is a composite of a plurality of heat shield segments (10). Combustion chamber (1) according to claim 12, wherein the heat shield segments (10) each have a hot side (11) which can be acted upon by a hot medium, a cold side (12) facing the hot side (11) facing the shell (3) and a hot side (11 ) and cold side (12) peripheral edge (13), and in the cold state individual heat shield segments (10) of a segment row (14) on the edge (13) to the cold side (12) adjoining bearing surfaces (15) and the hot gas side (11 ) have opening column (16). A combustor (1) according to claim 13, wherein the gaps (16) are crescent shaped. Combustion chamber (1) according to one of claims 13 or 14, wherein uneven end faces (17) are provided between rows of segments (14), so that in the hot state, a positive connection between individual heat shield segments (10) is formed in the circumferential direction.

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