JP2519193B2 - Tubing with an inner region for hot gas induction, especially flame tubes - Google Patents

Description

The present invention relates to a tubing with an inner region for guiding hot gas in the flow direction and a heat shield consisting of a number of stones arranged in parallel towards this inner region.

This kind of pipe material is used in various ways as a flame tube especially in a combustion device of a gas turbine device. German patents B1173734 and C2523449 describe pipes with heat shields of this kind, each of which consists of a number of stones arranged in parallel, each stone containing 2 stones. It is clamped by supports on two opposite sides. The fixing of stones perpendicular to the direction of tightening is not explicitly mentioned, but if the pipes are vertical or at least oblique, a suitable support frame is required to support the stones. For tubing placed approximately horizontally, the heat shield must be sealed and supported at each end by a suitable frame. The corresponding support frame is generally made of metal. In order for the support frame to withstand as much of the operational heat load as the heat shield, the support frame must be sufficiently cooled.

For cooling the support frame, the support frame is provided with holes or similar channels through which cooling gas (in the case of a flame tube, part of the combustion air which is generally sent to the flame tube)
Is washed away. Proposals of this kind are described, for example, in German Patent DE-C 2523449. A frequent problem here is that the cooling air flows into the inner region of the tubing in the form of discrete flows. This results in the formation of vortices in the hot gas stream, which can cause the hot gases to vortex on the surface of the support frame directed to the inner region and damage this surface. Also, in some cases, the hot flow itself is hampered by the cooling gas flowing across it. To this end, some measures are taken by angling the channels to a certain degree rather than perpendicularly to the surface of the support frame. However, this solution is extremely expensive to manufacture and at least does not have a sufficient effect unless the angle is chosen such that it cannot be realized without considerable expense.

JP-A-59-41716 describes a flame tube with a wall of substantially conical ceramic segments which are fitted together while forming a slit for guiding the cooling gas.

The object of the present invention is therefore a heat shield reinforced tubing with at least one support frame for a heat shield that can be cooled efficiently and with as little savings as possible,
It is an object of the present invention to provide a pipe material capable of avoiding the danger of the obstruction of the flow of hot gas in the pipe material and the fine flow of hot gas impinging on the supporting frame in connection therewith.

According to the invention, the tubing comprises an inner region for guiding the hot gas in the vertical flow direction and is reinforced with a heat shield consisting of a number of stones arranged in parallel, which heat shield is directed towards the inner region. It is supported by at least one support frame, which is made of metal and comprises a number of channels for supplying cooling gas and a lip which surrounds the tubing while forming slits, in which the channels are inside It is almost covered towards the area.

The tubing according to the invention has a support frame with a slit around it, in which the cooling gas flowing through the channels is collected, where it becomes a uniform slow flow, which finally leads to the hot gas. Enter the inner area of the guide. This slow flow can create a sufficient cooling gas film above the support frame, which surely shields the support frame, but in this case the hot gas flow is unobstructed and does not cause vortices. . The cooling fluids guided through the channels are slowed down by impinging on the lips before entering the inner region and join together forming a uniform cooling fluid film. Further, effective collision cooling of the highly heat resistant portion of the support frame is achieved.

In order to achieve a particularly good collecting guidance of the cooling gas flow flowing out of the channel, the support frame is equipped with a collecting chamber or an array of collecting chambers surrounding the tubing, into which the channel opens, Cooling gas is guided from the collecting chamber through the slits to the inner region. Since the cooling gas flow is decelerated in the collecting chamber, a particularly uniform film can be formed over the entire circumference of the pipe material.

Providing the slits substantially parallel to the flow direction is particularly advantageous independent of otherwise forming. This produces a cooling gas flow which is substantially parallel or antiparallel to the flow direction and which has a velocity component as small as possible in the direction perpendicular to the flow direction. Further, the portion of the support frame having the highest heat resistance, that is, the portion directly facing the inner region is cooled efficiently. Efficient impingement cooling is achieved by the cooling gas flow from the channels by forming the thermally strongest part as a thin lip.

In another embodiment of the invention, the slits are advantageously provided in the support frame such that the slits open into the inner region near the inflow of the support frame. In this way, it is possible to form a cooling gas film which covers the entire support frame and which is shielded from the hot gas.

In a particularly advantageous embodiment of the invention, the tubing is substantially upright on an axis parallel to the flow direction. A further development of this is that the tubing is axially symmetric with respect to its axis, in particular cylindrical, which results in a particularly simple and low-cost embodiment of the invention.

A preferred application is to use the tubing according to the invention as a flame tube for gas turbine equipment. This tubing is extremely strong thermally and additionally requires only a small amount of cooling, which gives a great deal of structural freedom in installation in the gas turbine.

The detailed description of the invention is based on the exemplary embodiments shown in the drawings.

FIG. 1 is a pipe material including a heat shield and a support frame according to the present invention, FIGS. 2 and 3 are embodiments of a support frame according to the present invention, and FIG. 4 is particularly a pipe member including a heat shield and a support frame according to the present invention. An advantageous embodiment is shown.

1 shows an upright tube 1 with a region 2 in which hot gas is to be guided in a flow direction 3 indicated by an arrow. This pipe material is lined with heat shields 4 made of stone materials 5 arranged in parallel and vertically. The stone material is fixed inside the pipe material 1 by a suitable fixing material. The type of fixing material and how to handle it are clear from the prior art and are not shown in the drawings. The pipe material 1 is provided with a support frame 6 at its lower end, and a stone material 5 is supported thereon. This support frame 6 is a pipe member 1 in this embodiment.
Is attached directly to. Of course, this support frame can be made separately if necessary, and can be connected to the pipe material 1 later by a method considered appropriate.

The support frame 6, like the rest of the tubing, is made of metal and is therefore less thermally stronger than the heat shield 4. Correspondingly, the support frame 6 has a special cooling part. A channel 7 is provided around the outer periphery of the support frame 6, through which cooling fluid, in particular cooling air, can be guided to the inner region 2 of the tubing 1. However, according to the invention, the channels 7 do not open directly into the inner region 2 but rather the slits 8 surrounding the tubing 1 in the support frame 6.
The slit is open towards the inner region 2 of the tubing 1 and is formed by the lip 9 surrounding the tubing 1. The cooling air streams coming out of the channels 7 merge in this slit 8 for the formation of a low-speed and uniform cooling air film, and this cooling air film comes out of the slit 8 and comes to the support frame 6.
It acts as a reliable heat shield while protecting the top. Towards the inner region 2 of the tubing 1, the channel 7 is substantially covered by the lip 9 of the support frame 6. The cooling air flow induced via the channels 7 impinges on this lip 9 and provides additional impingement cooling on the areas in the inner area 2 of the support frame 6 which are in direct contact with the hot gas.

Another embodiment of the support frame 6 according to the invention is shown in FIGS. For simplification, both figures are referred to here simultaneously. Here too, a cooling support frame 6 is provided for the support of the stone 5, which cooling air is guided through the channels 7 into the slits 8 surrounding the pipe 1 and from there to the inner region 2. To be cooled. In order to avoid as much as possible the formation of vortices in the hot gas flow induced through the inner region 2, the slits 8 open parallel to the flow direction 3 rather than perpendicularly. This achieves a further deceleration of the cooling air film, the structure to be cooled, in particular the lip 9
Cooling is accelerated. In the embodiment of FIG. 2, the hot gas stream is guided first to the support frame 6 and then to the stone 5. Correspondingly, the slit 8 faces the inner region 2 near the inflow portion 11 of the support frame 6 so that the cooling air film exiting from the slit 8 can enter as completely as possible between the support frame 6 and the hot gas flow. Open.

Another embodiment according to the present invention is shown in FIG. The support frame 6 is shown here as a separate component, which is flanged to the other parts of the tubing 1. The cooling of the support frame 6 is effected by cooling air which is guided through the channels 7 and the slits 8 into the inner region 2, but likewise the slits 8 close to the inlet 11 of the support frame 6 into the inner region. By opening towards, a cooling air film is obtained which covers the entire support frame 6 as much as possible and flows in the flow direction 3. In particular, the support frame 6 comprises between the channel 7 and the slit 8 a collecting chamber 10 which surrounds the tubing 1 into which cooling air flows from the channel 7 before passing through the slit 8 into the inner region 2. The collecting chamber 10 serves to further homogenize the cooling fluid exiting the slit 8. The collecting chamber can be formed as a composite part. The slit 8 is formed between the inflow portion 11 and the lip portion 9. In this lip, effective impingement cooling is provided by the cooling fluid flowing into the channel 7. The lip 9 is not of course made in one piece with the support frame in the case shown, but can be connected to the support frame 6 as a separate component. This gives rise to certain disadvantages in terms of manufacturing technology, but makes it possible for the support frame 6 to have various material choices. The part of the support frame 6 including the channel 7 is an economical and easily processed material,
For example, it can be made of ferritic steel, whereas the lip 9 can be made of a particularly strong material, for example a high heat resistant nickel alloy. In the meantime, the worrisome financial inconveniences can be solved in this way.

The heat shield protected tubing according to the invention is particularly resistant to heat and allows a more unimpeded induction of the flow of hot gases. This is particularly useful for use in combustion devices such as gas turbine combustion chambers.

Claims (7)

(57) [Claims] 1. An inner region (2) for guiding hot gas in the flow direction (3) and a number of stones (5) arranged in parallel.
A heat shield (4) consisting of a heat shield (4) supported by at least one metal support frame (6) towards the inner region (2) and having a number of channels () for supplying cooling gas. In a pipe material (1) having 7), a metal support frame (6) is provided with a lip portion (9) surrounding the pipe material (1) while forming a slit (8),
Tubular material, characterized in that the channel (7) is substantially covered by this lip towards the inner region (2). 2. Tubing according to claim 1, characterized in that the slits (8) extend substantially parallel to the flow direction (3). 3. The support frame (6) according to claim 1 or 2, comprising a collecting chamber (10) surrounding the pipe (1), said collecting chamber connecting the channel (7) to the slit (8). Pipe material. 4. The support frame (6) comprises an inlet (11) for hot gas, the slit (8) being open in the inner region (2) at this inlet (11). The pipe material described in 1. 5. Tubing according to claim 1, wherein it is substantially upright with respect to an axis (12) parallel to the flow direction (3). 6. Tubing according to claim 5, which is axially symmetric with respect to the axis (12), in particular cylindrical. 7. A flame tube for a gas turbine device, comprising a tube (1) according to one of claims 1 to 6.