JP2004003502A - Silencer for gas turbines - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a silencer for gas turbines of a splitter form which can reduce stress generated by heat differential expansion with enclosed frame in sieve plate and acoustic material(heat insulating material) of a silencer panel. <P>SOLUTION: The silencer of the splitter form is formed in duct for pumpings of the gas turbine. The silencer includes a sieve plate 10 slidable in relation to a frame 11, slidably inserted by a grooved metal presser 23 long enough to be held by a plurality of studs 22 fixed to the frame 11, having prongs 25 for the stud 22 movably inserted to a stud insertion section as a compatible thing, and a heat expansion absorbing section established at the time of gas turbine operation. <P>COPYRIGHT: (C)2004,JPO

Description

[Industrial applications]
The present invention relates to a gas turbine silencer provided in an intake / exhaust portion of a gas turbine.
[Prior art]
2. Description of the Related Art In recent years, gas turbines have been increasing in size with the development of high-efficiency combined cycle power plants, and their intake and exhaust air volumes have been increasing. In addition, as the inlet temperature of the gas turbine is raised to increase the efficiency, the exhaust temperature also increases, and the gas temperature at the outlet of the gas turbine becomes 600 ° C. or higher.
With the increase in capacity of the gas turbine, noise and energy level at the gas turbine outlet have become a serious problem (reaching 130 dB at the gas turbine outlet), and an exhaust silencer with a large volume reduction has been attached to the gas turbine outlet. However, it has been pointed out that the reliability with respect to temperature rise and size increase has been reduced, and further improvement in durability has been required.
In addition, conventional gas turbines played an important role as emergency power supply equipment, but high-efficiency combined-cycle power plants combining steam turbines and gas turbines were more powerful than conventional thermal and nuclear power plants. Because of their high efficiency and excellent starting characteristics, they tend to be used in load-following DSS (daily start / stop) operation.
FIG. 5 illustrates a configuration of a combined cycle power plant. The exhaust gas from the gas turbine 1 is introduced into the exhaust heat recovery boiler 3 through the silencer 2, and the steam generated by the exhaust heat recovery boiler 3 drives the steam turbine 4. Generators 5 and 6 are connected to the gas turbine 1 and the steam turbine 4, respectively, and power is generated by the outputs of the turbines 1 and 4. 3a is a chimney for discharging waste gas. The exhaust silencer 2 of the gas turbine 1 is required to have a structure that is capable of eliminating thermal expansion and contraction due to daily startup and shutdown and an exhaust gas flow having a large flow velocity distribution.
The configuration of a conventional silencer is illustrated in FIGS. This silencer 2 is a splitter type silencer. As shown schematically in FIG. 6 and FIG. 7, a plurality of flat silencer panels 8 are attached to a silencer duct 7 constituting a part of an exhaust duct in a direction orthogonal to the gas flow. They are arranged side by side.
As shown in FIG. 8, the silencer panel 8 has a configuration in which a streamlined bull nose 8B is provided at a front end of a flat main body 8A. As shown in FIGS. 9 to 11, the silencer panel 8 has an assembling structure in which a perforated plate 10 in which a number of through holes 9 are formed in a heat-resistant steel plate is attached to a lattice-shaped frame 11 in a tile shape. The frame 11 is filled with a sound absorbing material block 12.
The sound absorbing material block 12 has a block structure in which the sound absorbing material 13 is protected by a cloth 14 and a mat 15, as shown in FIGS. It is configured by sewing.
References relating to the prior art include "New Proposals and Pollution Prevention Measures [Noise and Vibration Edition] Published by the Japan Association of Industrial Pollution Prevention" or "Noise Countermeasures Handbook, published by Japan Acoustic Materials Association, Gihodo."
[Problems to be solved by the invention]
By the way, in order to increase the size of the gas turbine and reduce noise due to environmental problems, in recent years, there has been a strong demand for increasing the length of the silencer panel 8 in the gas flow direction. Due to restrictions, the silencer panel 8 and the silencer duct 7 need to be divided into a plurality in the gas flow direction.
FIGS. 13 and 14 show a splitter-type silencer structure for meeting such a demand. The upstream silencer panel 8a and the downstream silencer panel 8b divided in the gas flow direction are fastened to the upstream silencer duct 7a and the downstream silencer duct 7b via stoppers 17 for preventing slippage, respectively. I have.
However, in this case, a gap Z is generated between the upstream silencer panel 8a and the downstream silencer panel 8b.
As shown in FIG. 15, the gap Z causes a vortex in the gas flow in the silencer, which causes a pressure loss to increase.
FIG. 16 shows the temperature change of each part when the exhaust gas of the gas turbine flows into the splitter type silencer according to the conventional technology. In FIG. 16, a indicates a change in the gas temperature at the gas turbine outlet, that is, the temperature of the exhaust gas flowing into the silencer panel 8. b indicates a change in the temperature of the perforated plate 10 welded and fixed to the surface of the silencer panel 8. c indicates a change in the temperature of the frame 11 constituting the silencer panel 8. d indicates a temperature difference between the perforated plate 10 and the frame 11.
When the gas turbine is started, the exhaust gas temperature at the gas turbine outlet rises rapidly and rises to 650 ° C. in a short time. The temperature of the perforated plate 10 rises slightly later than the temperature of the exhaust gas at the gas turbine outlet because of the heat capacity of various members provided in the gas passage portion and the perforated plate itself.
Further, the temperature of the frame 11 of the silencer panel 8 rises later than the perforated plate 10 due to the filling of the sound absorbing material block 12 and the small contact area with the gas. As a result, a temperature difference occurs between the perforated plate 10 and the frame 11 due to a difference in temperature rising speed. Since the perforated plate 10 and the frame 11 are fixed by welding, the difference in thermal expansion due to this temperature difference cannot be escaped, and the surface of the perforated plate 10 is cracked or the perforated plate 10 is deformed and wrinkled. There are problems such as occurrence of.
The present invention has been made in view of such circumstances, and a splitter-type gas capable of reducing stress generated due to a difference in thermal expansion between a perforated plate of a silencer panel and a frame surrounded by a sound absorbing material (heat insulating material). An object of the present invention is to provide a silencer for a turbine.
[Means for Solving the Problems]
In order to achieve the above object, the present invention is a splitter-type silencer provided in a gas intake / exhaust duct of a gas turbine, a frame formed in a lattice shape, and a sound absorbing material filled in the frame, A silencer panel comprising a perforated plate serving as a cover for a sound absorbing material attached to the frame, wherein the perforated plate is slidable relative to the frame, and a plurality of studs fixed to the frame. The perforated plate is slidably sandwiched by a groove-shaped holding member having a length that is collectively held by the perforated plate, and each perforated plate has a stud play insertion hole in the stud insertion portion. , Wherein a thermal expansion absorbing portion is set during operation of the gas turbine.
[Action]
According to the present invention, the perforated plate can be slid with respect to the frame constituting the silencer panel, so that thermal expansion due to heating during operation can be absorbed and stress can be reduced.
【Example】
An embodiment of the present invention will be described below with reference to FIGS. The same parts as those in the conventional configuration are also referred to FIGS.
The gas turbine silencer 2 according to the present embodiment is a splitter-type silencer provided in a gas intake / exhaust duct of a gas turbine, and includes a frame 11 formed in a lattice shape, and a sound absorption filled in the frame 11. A silencer panel is composed of a sound absorbing material block 12 made of a material and a perforated plate 10 provided as a cover for the sound absorbing material attached to the frame 11.
In this apparatus, a perforated plate 10 is slidable with respect to a frame 11 and is perforated by a groove-shaped holding member 23 having a length held collectively by a plurality of studs 22 fixed to the frame 10. The plate 10 is slidably held, and each of the porous plates 10 has a hole 25 for loose insertion of a stud in a stud insertion portion, and a thermal expansion absorbing portion during gas turbine operation is set.
More specifically, the silencer 2 of the present embodiment includes an upstream silencer tact and a downstream silencer duct serving as an exhaust duct of a gas turbine, and an upstream silencer panel 8a and a silencer panel 8a arranged in series along the gas flow direction. It has a downstream silencer panel 8b connected to it (see FIGS. 13 and 14). Each silencer panel 8a, 8b is fixed to each silencer duct 7 via a silencer panel stopper (see FIGS. 6 and 7).
In addition, with respect to the configuration of one silencer panel, a reduction in stress due to a difference in thermal expansion between components is achieved.
That is, FIGS. 1 and 2 show the configuration of the upstream silencer panel 8a. The silencer panel 8a has a structure in which a frame 11 formed in a lattice shape is filled with a sound absorbing material block 12, and a plurality of perforated plates 10 are attached and fixed vertically and vertically (see FIG. 9). . In this embodiment, as shown in FIG. 2, the perforated plate 10 is slidable in contact with a frame 11 at a sliding portion 11a. Then, as shown in FIG. 3, each perforated plate 10 is supported by a plurality of studs 22 fixed to the frame 11 by a horizontally long holding member 23 made of a channel steel having a length which is held together. Are interposed via a washer 24. Each of the perforated plates 10 has a slot 25 as a long hole or a large hole having a room for stud movement in the stud insertion portion, and a thermal expansion absorbing portion during gas turbine operation is set. A hole 26 for absorbing thermal expansion is also formed in the holding member 23.
Also, as shown in FIG. 4, holes 27 for absorbing heat elongation are formed at the ends of the perforated plates 10 which are the joints in the vertical and horizontal directions, so that sliding in a superposed state is possible. ing. Thus, the sliding surface due to thermal deformation can be tolerated without the buckling of the contact surface of the perforated plate 10 with the frame 11. The stud 22 is fixed to the frame 11 and the washer 24 by welding.
According to such a configuration, the perforated plate 10 directly exposed to the exhaust gas can expand and contract in accordance with the exhaust gas temperature in the process of starting and stopping the gas turbine. That is, the frame 11 surrounded by the sound absorbing material block 12 does not restrain the perforated plate 10, and the perforated plate 10 slides on the contact surface with the frame 11 and is generated between the perforated plate 10 and the frame 11. Thermal stress due to a difference in thermal expansion can be reduced.
【The invention's effect】
As described above, according to the present invention, the perforated plate can be slid as a frame constituting the silencer panel, so that thermal expansion due to heating during operation can be absorbed and stress can be reduced.
[Brief description of the drawings]
FIG. 1 is a side view of an entire panel showing one embodiment of the present invention.
FIG. 2 is a sectional view taken along line CC of FIG. 1;
FIG. 3 is an enlarged sectional view taken along line DD of FIG. 1;
FIG. 4 is an enlarged sectional view taken along line EE of FIG. 1;
FIG. 5 is a diagram showing a configuration of a gas turbine with a silencer in a combined cycle.
FIG. 6 is a diagram showing a conventional example of a silencer in a cross section taken along line FF of FIG.
FIG. 7 is a sectional view taken along line GG of FIG. 6;
FIG. 8 is a perspective view showing a conventional silencer panel.
FIG. 9 is an exploded perspective view showing a conventional silencer panel.
FIG. 10 is an enlarged side view showing a conventional silencer panel.
FIG. 11 is a sectional view taken along line HH of FIG. 10;
12 (A) and (B) are perspective views showing a sound absorbing material block in a conventional example.
FIG. 13 is a plan view showing an arrangement configuration of a silencer panel in a conventional example.
FIG. 14 is a side view of FIG.
FIG. 15 is an operation explanatory view (plan view) of a conventional example.
FIG. 16 is a graph showing characteristics of a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Gas turbine 2 Silencer 3 Exhaust heat recovery boiler 3a Chimney 4 Steam turbine 5, 6 Generator 7 Silencer duct 7a Upstream silencer duct 7b Downstream silencer duct 8 Silencer panel 8A Flat body 8B Bullnose 9 Through hole 10 Perforated plate 11 Frame 12 Sound-absorbing material block 13 Sound-absorbing material 14 Cross 15 Mat 16 Wire mesh 16a Stainless wire 17 Stopper 22 Stud 23 Holder 24 Washer 25, 26, 27 hole

Claims (1)

A splitter-type silencer provided in a gas intake / exhaust duct of a gas turbine, which serves as a frame formed in a lattice shape, a sound absorbing material filled in the frame, and a cover for the sound absorbing material attached to the frame. A silencer panel formed by a perforated plate, wherein the perforated plate is slidable with respect to the frame, and has a groove shape having a length which is collectively held by a plurality of studs fixed to the frame; While holding the perforated plate slidably with the presser fitting, each perforated plate has a hole for stud play insertion in the stud insertion portion, and a thermal expansion absorbing portion at the time of gas turbine operation is set. A silencer for a gas turbine, comprising:

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