A discharge system for combustion gases

Abstract: Discharge system whereby one end of a discharge pipe (1) is connected to a gas turbine or the like. The other end of the discharge pipe is connected to a heat exchanger. A branch pipe (2), which extends transversely to the discharge pipe, is connected to the discharge pipe. A valve (3) is adjustable between a first position, in which the end of the branch pipe connecting to the discharge pipe is closed, and a second position, in which the discharge pipe is closed downstream of the connection of the branch pipe to the discharge pipe. The passage of the branch pipe is larger than that of the discharge pipe.

Description: The invention relates to a discharge system for combustion gases of a gas turbine or the like, whereby one end of the discharge pipe is connected to the gas turbine or the like, whilst the other end of the discharge pipe is connected to a heat exchanger or the like, and a branch pipe, which extends transversely to the discharge pipe, is connected to said discharge pipe, a valve means being disposed near the connection of the branch pipe to the discharge pipe, said valve means being pivotable about a pivot axis between a first position, in which the end of the branch pipe connecting to the discharge pipe is closed by the valve means extending at least substantially perpendicularly to the central axis of the branch pipe, and a second position, in which the discharge pipe is closed, said pivot axis being situated near and downstreams of said connection and outside the passage of the discharge pipe and outside the passage of the branch pipe and the construction of the valve means being such that in the second position of the valve means a flat upstream boundary surface of the valve means, which extends into the discharge pipe from the side of the discharge pipe close to the branch pipe, forms an angle of less than 90° with the longitudinal axis of the discharge pipe. Such discharge systems are e.g. known from GB-A-2,208,427 and DE-A-3,504,443. With the construction according to DE-A-3,504,443 closing means are provided, on either side of the valve, at the end of the valve remote from the pivot pin. In the position in which the valve closes the branch pipe the end of the valve supporting the closing means is located in a recess located beside the branch pipe. With the construction according to GB-A-2,208.427 the end of the valve remote from the pivot pin co-operates, in the position in which said valve closes the branch pipe, with a section disposed in the branch pipe. In these prior embodiments the passage of the branch pipe is therefore smaller, at least near its connection to the discharge pipe, than that of the discharge pipe. This relatively small diameter of the branch pipe makes for some additional resistance against the discharge of the combustion gases from the turbine, which experiences some resistance anyway as a result of the forced deflection of the gas flow upon being discharged through the branch pipe. According to the invention the passage of the branch pipe is larger than the passage of the discharge pipe, and the valve means is provided with at least two sealing lips at its end remote from the pivot axis, one of said sealing lips sealing the branch pipe in said first position and the other sealing the discharge pipe in said second position of the valve means, whereby the free end of the sealing lip being operative in said first positior is located at a larger distance from the pivot axis than the free end of the sealing lip being operative in the second position. By using the construction according to the invention an advantageous, comparatively large passage of the branch pipe may be accomplished in a simple manner, whilst an adequate sealing in both operating positions of the valve can be realised all the same. It is noted that from DE-A-2 920 608 there is known a system have a branch pipe with a passage greater than the passage of a discharge pipe. The valve means has a more or less U-shaped form and is adjustable about a pivot axis situated close to the longitudinal axis of the discharge pipe. Further DE-U-8702138 shows possibilities of sealing pipes. The invention will be explained in more detail hereafter with reference to a few possible embodiments of the construction according to the invention diagrammatically illustrated in the accompanying Figures. Figure 1 is a diagrammatic sectional view of one embodiment of a discharge system according to the invention. Figure 2 is a larger-scale view of the boxed part II of Figure 1. The discharge system shown in Figure 1 comprises a discharge pipe 1 and a branch pipe 2 extending perpendicularly thereto, of which branch pipe 2 only the connecting piece to the discharge pipe 1 is illustrated in Figure 1. When seen in Figure 1, the upstream end of the discharge pipe 1, which is located on the left in Figure 1, will be in communication with a gas turbine or the like, whilst the downstream end of the discharge pipe 1 (only partly shown), located on the right in Figure 1, will be connected to a heat exchanger or the like. The discharge system shown in Figure 1 is furthermore provided with a valve 3, which is built up of a frame 4, which on either side is lined with fire-resisting linings 5. As is apparent from Figure 1, at the bottom side of the valve the lining located to the left of the frame 4 thereby projects beyond the lining 5 located on the right. The valve 3 is pivotable about a pivot pin 6 defining a pivot axis, which crosses the longitudinal axis of the discharge pipe 1 perpendicularly, said pivot pin being disposed downstream of the branch pipe 2, near the connection of said branch pipe 2 to the discharge pipe 1. In the position shown in Figure 1 the valve 3 closes the discharge pipe 1 downstream of the connection of the branch pipe 2 to the discharge pipe 1, so that combustion gases from the gas turbine, flowing through the discharge pipe 1 in the direction indicated by the arrow A, will be forced to flow out through the branch pipe 2 in the direction according to the arrow B. As will be apparent from Figure 1, in particular the upstream boundary surface 7 of the valve 3 slopes upwards into the discharge channel from the side 8 of the discharge channel remote from the branch pipe, in such a manner that the parts of the boundary surface 7 located near the side 8 are located further upstream than parts of the boundary surface 7 located further away from the side 8. In the illustrated embodiment the boundary surface 7 includes an angle of about 70° with the longitudinal axis of the discharge pipe 1. It will be apparent that as a result of this sloping arrangement of the boundary surface 7 the gases flowing in the direction indicated by the arrow A will be gradually deflected in the direction of flow B. As is shown in more detail in Figure 2, sealing lips 9 are secured to the end of the valve 3 remote from the pivot pin 6, said sealing lips in the position illustrated in Figures 1 and 2 abutting against a U-shaped sealing section 10 attached to the side 8 of the discharge channel 1. As is furthermore apparent from Figure 2, near the sealing lips 9 further sealing lips 11 are secured to the valve 3, said further sealing lips extending at least substantially parallel to the sealing lips 9 and beyond the ends of the lips 9, when seen from the pin 6. In case it is desirable for the combustion gases to be supplied to the heat exchanger or the like connected to the upstream end of the discharge pipe 1, the valve 3 can be pivoted in the direction according to the arrow C, from the position shown in Figure 3, into an at least substantially horizontal position, in which the valve 3 releases the passage through the discharge pipe 1 and closes the end of the branch pipe 2 connecting to the discharge pipe 1, whereby the above-mentioned sealing lips 11 come into operation by co-operation with sealing strips provided near said connection, and similar to sealing section 10. It will be apparent that the dimension of the end of the branch pipe 2 connected to the discharge pipe 1 may be at least substantially equal to the dimension of the boundary surface 7 of the valve 3, which dimension is larger than that of the diameter of the discharge pipe 1. The fact that the dimension of the passage of the end of the branch pipe 2 connected to the discharge pipe 1 is larger than that of the diameter of the discharge pipe 1 itself, contributes substantially towards a rapid discharge of the combustion gases from the discharge pipe into the branch pipe.

Claims: A discharge system for combustion gases of a gas turbine or the like, whereby one end of the discharge pipe (1) is connected to the gas turbine or the like, whilst the other end of the discharge pipe (1) is connected to a heat exchanger or the like, and a branch pipe (2), which extends transversely to the discharge pipe (1), is connected to said discharge pipe (1), a valve means (3) being disposed near the connection of the branch pipe (2) to the discharge pipe (1), said valve means being pivotable about a pivot axis (6) between a first position, in which the end of the branch pipe (2) connecting to the discharge pipe (1) is closed by the valve means (3) extending at least substantially perpendicularly to the central axis of the branch pipe (2), and a second position, in which the discharge pipe (1) is closed, said pivot axis (6) being situated near and downstreams of said connection and outside the passage of the discharge pipe (1) and outside the passage of the branche pipe (2) and the construction of the valve means (3) being such that in the second position of the valve means a flat upstream boundary surface (7) of the valve means (3), which extends into the discharge pipe (1) from the side of the discharge pipe close to the branch pipe, forms an angle of less than 90° with the longitudinal axis of the discharge pipe (1), characterized in that the passage of the branch pipe (2) is larger than the passage of the discharge pipe (1), and that the valve means (3), at its end remote from the pivot pin (6), is provided with at least two sealing lips (9, 11), one of said sealing lips (11) sealing the branch pipe in said first position and the other (9) sealing the discharge pipe in said second position of the valve means, whereby the free end of the sealing lip (11) being operative in said first position is located at a larger distance from the pivot axis (6) than the free end of the sealing lip (9) being operative in the second position.

Inventors: KOUDIJS PHILIP RIJK, KOUDIJS, PHILIP RIJK
Applicants: KOUDIJS PHILIP RIJK, KOUDIJS, PHILIP RIJK
Application year: 1992
Main classification: F23L11
IPC codes: F23L11, F16K1, F24F13, F22B35, F16K11