JP2004347046A - Sealing construction in damper gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a damper gear capable of being improved in sealing performance at low costs, and maintaining the sealing performance for the long time. <P>SOLUTION: The damper gear 1 is comprised of valve seats 18, 19 and a valve body 20 detachably midway along passages of ducts 7, 10, 13, formed to close the passages of the ducts 10, 13 by pressing the valve element 20 against the valve seats 18 and 19, and open the passages of the ducts 10 and 13 by pulling the valve element 20 apart from the valve seats 18, 19. Bearing surfaces 18a, 19a of valves 18, 19 are formed to shape along a concave circular face in the pressing direction P of the valve element 20 for the valve seats 18, 19. When the valve element 20 is pressed against the valve seats 18, 19, metal sheet plates 23, 23, which elastically deform along the bearing surfaces 18a, 19a, and close an opening H of the valve seats 18, 19, can be bent to attach to a damper blade 22 forming a main body of the valve element 20. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a seal structure in a damper device that performs, for example, switching of a flow path of a duct through which exhaust gas flows.
[0002]
[Prior art]
2. Description of the Related Art Generally, in a cogeneration system using exhaust gas such as a gas turbine, when there is demand for electricity but no heat demand, the exhaust gas is led to a heat recovery device by switching a damper device. Power generation is maintained by switching from the heat recovery flow path to an exhaust gas discharge flow path that directly guides exhaust gas to the chimney. When the exhaust gas discharge flow path is selected by the switching operation of the damper device, if the amount of leakage of the exhaust gas in the damper device is large, the heat recovery device continues to be heated even though there is no heat demand. Therefore, there is a problem that it is necessary to install a device for releasing the heat of the heat recovery device. Conversely, when the heat recovery flow path is selected by the switching operation of the damper device, the If the amount of leakage of the exhaust gas is large, a problem that sufficient heat cannot be recovered occurs.
[0003]
Conventionally, as a sealing means for preventing the leakage of the exhaust gas which causes these problems, those using a metal touch (for example, see Patent Document 1) and those using an air seal (for example, Patent Document 2) See, for example, those using gaskets (for example, see Patent Document 3).
[0004]
Here, as shown in FIG. 9, a sealing means using a metal touch according to Patent Document 1 includes a round bar 103 serving as a seat surface of a valve seat all around an inward flange 102 formed on a damper body 101. And a ring-shaped thin metal sheet plate 104 abutting on the round bar 103 is attached to the outer periphery of the valve body 105 so that the metal sheet plate 104 is elastically deformed by driving a four-bar rotating mechanism 106. The seal is formed by pressing against the round bar 103.
[0005]
[Patent Document 1]
Japanese Patent No. 3125831 [Patent Document 2]
JP-A-9-203468 [Patent Document 3]
JP-B-63-667 [0006]
[Problems to be solved by the invention]
However, in the metal touch type sealing means according to Patent Document 1, when the metal sheet plate 104 attached to the outer periphery of the valve body 105 is pressed against a seat surface formed by the round bar 103 to seal the metal sheet, The four sides of the plate 104 are elastically deformed by the pressing force while being in good contact with the round bar 103, but the four corners D (see FIG. 9B) of the metal sheet plate 104 are elastically deformed by the four sides. This causes a problem that a gap is formed between the four corners D and the seat surface, and the exhaust gas leaks. In addition, it is conceivable to prevent the leakage of the exhaust gas by strictly setting the shape and dimensions of the seat surface in consideration of the gap generated between the four corners D and the seat surface. There is a problem that causes an increase in the number. On the other hand, the air-sealing type sealing means according to Patent Document 2 has a problem that the cost is high because an air supply facility is separately required. On the other hand, in the gasket-type sealing means, a gasket that is normally preferably used to prevent gas leakage at a stationary portion is used for the purpose of preventing gas leakage when the flow path opening / closing section is closed. Therefore, there is a problem that the deterioration of the gasket is apt to proceed, so that the sealing performance is reduced at an early stage.
[0007]
The present invention has been made in order to solve such a problem, and a seal structure in a damper device capable of improving sealing performance at low cost and maintaining the sealing performance for a long period of time. It is intended to provide.
[0008]
[Means for Solving the Problems and Functions / Effects]
In order to achieve the object, a seal structure in the damper device according to the present invention is provided such that a valve seat and a valve body are provided to be able to freely contact and separate in the middle of the flow path of the duct, and by pressing the valve body against the valve seat, A seal structure in a damper device configured to close the flow path of the duct and to separate the valve body pressed against the valve seat from the valve seat to open the flow path of the duct,
A seating surface of the valve seat is formed in a shape along a concave arc surface in a pressing direction of the valve body against the valve seat,
When the valve body is pressed against the valve seat, a sheet-like member that elastically deforms along the seat surface of the valve seat and closes an opening of the valve seat is attached to the main body of the valve body in a bendable manner. (1st invention).
[0009]
According to the present invention, when closing the duct by pressing the valve body against the valve seat, the sheet-shaped member is elastically deformed along the seat surface of the valve seat, and the opening of the valve seat is closed by the sheet-shaped member. The seat is released by the repulsive force of the sheet-like member which is increased in the direction of warping of the seat surface of the valve seat formed so as to follow the concave arc surface in the pressing direction of the valve body against the valve seat. Since the shape member and the seat surface of the valve seat are strongly adhered to each other, it is possible to surely seal the closed duct without causing the fluid to leak into the closed duct. In addition, since the deformation of the sheet-like member at the time of sealing is performed in the elastic region of the sheet-like member, the sheet-like member hardly deteriorates, and thus the sealing performance can be maintained for a long time. . In addition, the valve seat distortion and shape dimensional error are absorbed by the elastic deformation and repulsive force of the sheet-like member, and the necessary and sufficient sealing performance can be secured even if the grade of processing accuracy is slightly reduced, so that the manufacturing cost is reduced. Can be reduced. Further, since special equipment such as air supply equipment in the conventional air seal type sealing means is not required, both initial costs and running costs can be significantly reduced.
[0010]
In the present invention, it is preferable that the sheet-like member is attached to a main body portion of the valve body via an elastic body (a second invention). With this configuration, even if there is a slight error in the mounting positional relationship between the valve seat and the valve element, the error is absorbed by the elastic body, so that the sealing performance can be stably maintained.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, a specific embodiment of a seal structure in a damper device according to the present invention will be described with reference to the drawings.
[0012]
FIG. 1 shows a schematic configuration diagram of an exhaust gas utilization system in a cogeneration system according to an embodiment of the present invention.
[0013]
In the cogeneration facility according to the present embodiment, as shown in FIG. 1, the exhaust gas discharged from a gas turbine (not shown) is guided directly to a chimney 2 via a damper device 1 as shown in FIG. 1. Flow path 3 (a flow path indicated by an alternate long and short dash line arrow in the figure) and a heat recovery flow path 5 (shown by a broken arrow in the figure) for guiding the exhaust gas to a chimney 2 via a damper device 1 and a heat recovery device 4. Shown flow path). Here, in the exhaust gas discharge passage 3, an exhaust gas outlet (not shown) of the gas turbine and an exhaust gas inlet 6 of the damper device 1 are connected by a duct 7, and one of the damper devices 1 is connected. The exhaust gas outlet 8 on the side and the exhaust gas inlet 9 of the chimney 2 are connected by a duct 10. On the other hand, in the heat recovery channel 5, the exhaust gas outlet 11 on the other side of the damper device 1 and the exhaust gas inlet 12 of the heat recovery device 4 are connected by a duct 13. An exhaust gas outlet 14 and a duct connection port 15 of the duct 10 are connected by a duct 16.
[0014]
Next, the structure and operation of the damper device 1 will be described below. FIG. 2 is a schematic structural explanatory view of the damper device in the present embodiment, and FIG. 3 is an operational explanatory diagram of the damper device.
[0015]
As shown in FIG. 2, the damper device 1 includes a housing 17 in which an exhaust gas inlet 6, an exhaust gas outlet 8 on one side, and an exhaust gas outlet 11 on the other side are arranged in three directions. A valve seat 18 on one side of a square tube (which may be cylindrical) formed in communication with the one side exhaust gas outlet 8 and protruding from the inner surface of the housing 17; A valve seat 19 on the other side of a quadrangular cylinder (which may be cylindrical) formed so as to communicate with the exhaust gas outlet 11 on the side and protrude from the inner side surface of the housing 17; The valve body 20 is rotatably disposed on the side, and the valve body 20 is rotated in one direction (right side in FIG. 2) to press the valve body 20 against the valve seat 18 on one side, thereby forming a duct. 3 is closed (see FIG. 3 (a)), and on the contrary, the valve body 20 is moved to the other side (the left side in FIG. 2). ) And direction by rotating the duct 13 by pressing the valve element 20 in valve seat 19 of the other side is closed and is configured to (see FIG. 3 (b)).
[0016]
As shown in FIGS. 2 and 4, the seat surfaces 18a and 19a of the respective valve seats 18 and 19 are arranged along a concave arc surface in the pressing direction P of the valve body 20 against the respective valve seats 18 and 19. It is formed in a suitable shape. Further, on the seat surfaces 18a, 19a of the valve seats 18, 19, the deformation of the metal sheet plates 23, 23 (to be described in detail later), which come into engagement with the respective seat surfaces 18a, 19a, The magnitude of the curvature is set so as to be performed in the elastic region of 23.
[0017]
The valve body 20 has a damper shaft 21 that is rotated by a drive mechanism that uses an electric motor (not shown) as a drive source in a range of θ = 0 ° to 90 °, and is welded and fixed to a peripheral surface of the damper shaft 21. A rectangular damper blade 22 that forms the main body of the valve body 20 is disposed on the one side surface and the other side surface of the damper blade 22 so as to face each other with a space therebetween. A set of metal sheet plates 23, 23 (sheet-like members) is provided.
[0018]
As shown in FIGS. 5 (a) and 5 (b), each of the one side surface and the other side surface of the damper blade 22 has a plurality (FIG. 5A) supporting the central portion of each of the metal sheet plates 23, 23. (5) stepped screw shafts 24, 24,... A compression coil spring 25, a spring seat 26, a metal sheet plate 23, a washer 27 and a nut 28 are sequentially fitted into each stepped screw shaft 24 as shown in FIG. A metal sheet plate 23 is attached between a spring seat 26 receiving an urging force and a washer 27 fixed to a stepped portion (not shown) of the stepped screw shaft 24 by tightening a nut 28. Have been. Here, the separation distance L between the damper blade 22 and each of the metal sheet plates 23, 23 is determined by the operation of pressing the valve body 20 against each of the valve seats 18, 19, so that each of the metal sheet plates 23, 23 has its own valve seat 18, 19. The length is set so that each metal sheet plate 23 does not interfere with the damper blade 22 even if it curves along the seating surfaces 18a, 19a. In the present embodiment, the compression coil springs 25,... Are interposed between the damper blade 22 and the metal sheet plates 23, 23, as shown in FIG. Even if there is some error (for example, poor parallelism) in the mounting positional relationship between the seats 18 and 19, the error is absorbed by the compression coil springs 25 and so that the sealing performance is stably maintained. Has been.
[0019]
Each of the metal sheet plates 23, 23 has a relatively small thickness (0... 0) so that the metal sheet plates 23, 23 can be easily deformed along the respective seat surfaces 18a, 19a when the valve body 20 is pressed against the respective valve seats 18, 19. (Approximately 5 to 1 mm), and the external dimensions are set so that the openings H (see FIG. 4) of the respective valve seats 18 and 19 can be closed when deformed along the respective seat surfaces 18a and 19a. When the valve body 20 is pressed against the valve seats 18, 19, the metal sheet plates 23, 23 are elastically deformed along the respective seat surfaces 18a, 19a, and are pressed against the valve seats 18, 19 on the contrary. Since it is necessary to return to the original state when the valve body 20 is separated, the valve body 20 is made of a material having a high elasticity even with a thin thickness such as spring steel. In the case where the metal sheet plates 23 are used in a gas atmosphere having a corrosiveness at a high temperature as in the present embodiment, a stainless material (for example, SUS304) is used as the material of the metal sheet plates 23. Is preferred.
[0020]
In the damper device 1 configured as described above, when there is an electric demand but no heat demand, as shown in FIG. 3B, the valve body 20 is moved to the other side (the left side in FIG. 2). The duct 13 is closed by rotating the valve body 20 in the direction and pressing the valve body 20 against the valve seat 19 on the other side, whereby the heat recovery flow path 5 is switched to the exhaust gas discharge flow path 3. At this time, the metal sheet plate 23 is elastically deformed along the seat surface 19a of the valve seat 19 on the other side, so that the opening H of the valve seat 19 on the other side is closed by the metal sheet plate 23 and the metal sheet plate 23 on the other side. Due to the repulsive force of the metal sheet plate 23, which increases as the seat surface 19a of the valve seat 19 moves upward in the warp direction T, the metal sheet plate 23 and the seat surface 19a of the valve seat 19 on the other side are strongly adhered. On the other hand, when the heat demand increases, as shown in FIG. 3A, the valve body 20 is rotated in one direction (the right side in FIG. 2) to move the valve body 20 to the one side valve seat. By pressing against the duct 18, the duct 10 is closed, thereby switching from the exhaust gas discharge channel 3 to the heat recovery channel 5. At this time, the metal sheet plate 23 is elastically deformed along the seating surface 18a of the valve seat 18 on one side, so that the opening H of the valve seat 18 on one side is closed by the metal sheet plate 23 and The metal sheet plate 23 and the seat surface 18a of the valve seat 18 on one side are strongly adhered to each other due to the repulsive force of the metal sheet plate 23 that increases as the seat surface 18a of the valve seat 18 in the warp direction T rises. .
[0021]
According to the present embodiment, when the valve bodies 20 are pressed against the valve seats 18 and 19 to close the ducts 10 and 13, the metal sheet plates 23 and 23 are seated on the seat surfaces 18a and 19a of the valve seats 18 and 19, respectively. , So that the exhaust gas can be reliably sealed without leaking into the closed duct. Therefore, it is possible to reliably prevent the heat recovery device 14 from continuing to be heated even though there is no heat demand due to the leakage of the exhaust gas, or to prevent the heat recovery device 14 from recovering sufficient heat. You.
[0022]
Further, according to the present embodiment, there are the following advantages (1) to (5).
(1) Since the deformation of each metal sheet plate 23, 23 at the time of sealing is performed in the elastic region of each metal sheet plate 23, 23, these metal sheet plates 23, 23 hardly deteriorate, so that the sealing performance is reduced. It can be maintained for a long time.
(2) The distortion and shape dimensional error of each valve seat 18, 19 are absorbed by the elastic deformation and repulsion of each metal sheet plate 23, 23, and a necessary and sufficient sealing performance is ensured even if the grade of processing accuracy is slightly lowered. Therefore, the manufacturing cost can be reduced.
(3) Since special equipment such as air supply equipment in the conventional air seal type sealing means is not required, both initial costs and running costs can be significantly reduced.
(4) The metal sheet plate 23 is sandwiched between the spring seat 26 receiving the urging force from the compression coil spring 25 and the washer 27 fixed to the stepped portion of the stepped screw shaft 24 by tightening the nut 28. Because of the mounting structure, there is no adverse effect such as thermal deformation in the case of mounting by welding, and no factor that impairs the sealing performance occurs during the manufacturing stage.
(5) Even if the metal sheet plate 23 needs to be replaced, the metal sheet plate 23 can be easily removed by releasing the fastening of the nut 28, so that maintenance is easy.
[0023]
In the present embodiment, an example in which the present invention is applied to a three-way switching damper device that switches between the exhaust gas discharge passage 3 and the heat recovery passage 5 has been described. For example, as shown in FIG. 7, the flow path of the exhaust gas sent out from each of the boilers 29, 29 according to the respective operating conditions of the plurality of boilers 29, 29 installed in parallel (in FIG. The present invention can also be applied to the two-way switching damper devices 30, 30 that open and close the respective flow paths (shown).
[0024]
Further, in the present embodiment, an example is shown in which the elastic body interposed between the damper blade 22 and the metal sheet plates 23 in the valve body 20 is the compression coil spring 25,. The valve body 20A is not limited to this, and the elastic body is a corrugated leaf spring 31, 31 as shown in FIG. 8 (a), or the elastic body is made of rubber as shown in FIG. 8 (b). The cushioning members 32,... Of the valve body 20B can basically provide the same functions and effects as those of the present embodiment. In the case where the shape and dimensions of the valve seats 18, 19 and the dimensions of the mounting position between the valve seats 18, 19 and the valve body 20 can be set with high precision, FIG. It is also possible to employ a valve body 20C having a structure in which spacers 33,... Are interposed between the damper blade 22 and each of the metal sheet plates 23, 23.
[0025]
Further, in the present embodiment, the example in which the present invention is applied to the damper device that switches the flow path of the exhaust gas is described, but the present invention is also applied to a damper device that switches the flow path of the air and other fluids. Needless to say, it can be done.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an exhaust gas utilization system in a cogeneration facility according to an embodiment of the present invention.
FIG. 2 is a schematic structural explanatory view of a damper device in the present embodiment.
FIG. 3 is an explanatory diagram of an operation of the damper device.
FIG. 4 is an external perspective view illustrating the shape of a valve seat.
FIG. 5 is a view as seen from the direction of the arrow A in FIG. 2 (a) and a view as viewed from the direction of the arrow B in FIG. 2 (a).
FIG. 6 is a functional explanatory view of an elastic body provided in the valve body.
FIG. 7 is a schematic configuration diagram of an exhaust gas utilization system using a damper device of another embodiment to which the present invention can be applied. FIGS. 8 (a) to 8 (c) show valves. It is a figure showing the other example of a body.
FIGS. 9A and 9B are explanatory diagrams of a structure of a damper device having a seal structure according to a conventional technique, and FIGS.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Damper device 7,10,13 Duct 18 One side valve seat 19 Other side valve seat 18a Seat surface (one side valve seat)
19a Seat (other side valve seat)
20 valve element 23 metal sheet plate (sheet-like member)
H Opening P Pressing direction

Claims (2)

A valve seat and a valve element are provided to be able to freely contact and separate in the middle of the flow path of the duct, and by pressing the valve element against the valve seat, the flow path of the duct is closed and the valve pressed against the valve seat A seal structure in a damper device configured to open a flow path of the duct by separating a body from the valve seat,
A seating surface of the valve seat is formed in a shape along a concave arc surface in a pressing direction of the valve body against the valve seat,
When the valve body is pressed against the valve seat, a sheet-like member that elastically deforms along the seat surface of the valve seat and closes an opening of the valve seat is attached to the main body of the valve body in a bendable manner. A seal structure in a damper device. The seal structure according to claim 1, wherein the sheet-shaped member is attached to a main body of the valve body via an elastic body.

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