JPH08285208A - Damping support structure of boiler - Google Patents

Abstract

PURPOSE: To provide a damping support structure of a boiler to increase the reduction effect of an earthquake response and reduce the weight of a support steel frame therealong by increasing a vibration mass exerted on a vibration damping device, in a damping support device for a boiler by a support steel frame. CONSTITUTION: A vibration damping device 8 is installed between a boiler body 2 and a support steel frame 1 and vibration damping devices 10, 12, and 14 are installed between an attendant apparatus, such as a denitrating device 4 and an air heater 5, and a support steel frame. Further, a resilient substance, such as lamination rubbers 9, 11, and 13 is placed between the attendant apparatus and the support steel frame, and the attendant apparatus is also functioned as a vibration mass serving to the vibration damping device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping support structure for a large boiler supported by a supporting steel frame such as a coal-fired boiler for power generation and a heavy oil-fired boiler.

[0002]

2. Description of the Related Art Large boilers such as coal-fired boilers for power generation and heavy oil-fired boilers are usually attached to and supported by a supporting steel frame together with auxiliary equipment such as a denitration device and an air heater.

FIGS. 4 (a) and 4 (b) are side views of a conventional example of such a supporting structure for a large-sized coal-fired boiler for power generation and auxiliary equipment. In FIG. 4 (a), 1 is a supporting steel frame, 2 is a boiler main body, and the boiler main body 2 is vertically suspended by being suspended from the top of the supporting steel frame 1 by a plurality of suspension rods 6 in the vertical direction. Supported by.

Reference numeral 3 denotes a coal bunker arranged in the front part of the supporting steel frame 1, and 4 and 5 are denitration devices and air heaters arranged in the rear part of the supporting steel frame 1. These accessories 3,
Numerals 4 and 5 are placed and fixed on the front and rear portions of the supporting steel frame 1 on the horizontal beam 1b constituting the supporting steel frame 1.

The supporting steel frame 1 is composed of a vertical column 1a, a horizontal beam 1b, a vertical brace 1c for connecting the nodes of the columns 1a and 1b, and a horizontal brace 1d (details will be described later). It has a structure that can withstand the weight of the direction and seismic force in the horizontal direction.

Reference numeral 7 denotes a horizontal steady rest mechanism which is interposed between the boiler body 2 and the supporting steel frame 1. The steady rest mechanism 7 has a support structure with low rigidity so that the boiler main body 2 can largely swing horizontally when an earthquake occurs.

That is, as shown in FIG. 4 (b), the steady rest mechanism 7 has a cantilever-like beam 7 a projecting from the boiler body 2 and having a flexible structure. The structure is such that it is sandwiched between the portions 7b.

Further, a plurality of vibration damping devices 8 such as hydraulic dampers are interposed between the supporting steel frame 1 and the boiler body 2, and the supporting steel frame 1 and the boiler body 2 are connected by the damping device 8 when an earthquake occurs. Vibration energy is absorbed by utilizing the difference in displacement (relative displacement).

On the other hand, auxiliary equipment such as the coal bunker 3, the denitration device 4, and the air heater 5 are placed on the beam 1b of the supporting steel frame 1 and fixed by bolts.

The weight ratio of the apparatus in the boiler supporting structure including the supporting steel frame 1 constructed as described above to the total weight of the apparatus is about 20% for the main body of the boiler and 3 = 2 for the coil bunker.
0%, denitration device 4 = 6%, air heater 5 = 4%, supporting steel frame 1 and other accessories = about 50%.

In the boiler support structure constructed as described above, when an earthquake occurs, the boiler main body 2 supported by the supporting steel frame 1 by the steady rest mechanism 7 is largely displaced with respect to the supporting steel frame 1 and is located between the two. A large relative displacement is generated, and the vibration energy due to this relative displacement is absorbed by the vibration damping device 8 interposed between the supporting steel frame 1 and the boiler body 2. This improves the damping capacity of the entire device and reduces the seismic response.

[0012]

In the conventional boiler supporting structure as described above, when an earthquake occurs, as described above, the boiler main body 2 having a weight of about 20% of the total weight of the apparatus is shaken. The boiler main body 2 is positively displaced (vibrated) by being horizontally supported by the stop mechanism 7, and the vibration energy is absorbed by the vibration damping device 8 provided together with the steady rest mechanism 7 to reduce the seismic response. .

The effect of reducing the seismic response increases as the weight of the heavy object to be displaced (vibrated) becomes heavier. However, in the above-mentioned conventional boiler support structure, as described above, only the mass of the boiler main body 2, which is about 20% of the entire apparatus, is used. Therefore, in order to improve the seismic response reduction effect, the mass surface can be improved. There was a limit.

The object of the present invention is to increase the vibration mass applied to the vibration damping device, thereby increasing the effect of reducing the seismic response, and at the same time, reducing the weight of the supporting steel frame. Is to provide.

[0015]

SUMMARY OF THE INVENTION According to the present invention, a vibration damping device is interposed between a boiler main body supported by a supporting steel frame through a horizontal steady rest mechanism and the supporting steel frame, and the supporting steel frame is mounted on the supporting steel frame. A vibration damping device is also installed between the supporting steel frame and auxiliary equipment such as a denitration device and an air heater, and an elastic body such as laminated rubber is installed between the auxiliary equipment and the supporting steel frame. In addition, the gist is that the auxiliary equipment is also configured to function as a vibration mass applied to the vibration damping device. As the vibration damping device, known devices such as a hydraulic damper and a dashpot are used.

[0016]

Since the present invention is configured as described above, when an earthquake occurs, the auxiliary equipment, which has become an independent vibrating mass, vibrates together with the boiler body, and acts on the vibration damping device more than the conventional one. The vibrating mass is greatly increased and the amount of vibration energy absorbed is increased. This will increase the seismic response reduction effect.

[0017]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 shows a vibration damping support structure for a coal-fired boiler for power generation according to an embodiment of the present invention, and FIG. 2 shows a plan view (a line AA view) of FIG.

In FIGS. 1 and 2, 1 is a supporting steel frame, 2 is a boiler main body, and the boiler main body 2 is suspended from the top of the supporting steel frame 1 by a plurality of suspension rods 6 from the top thereof. It is supported vertically.

The supporting steel frame 1 is a column 1 extending in the vertical direction.
a, a beam 1b extending in the horizontal direction, a vertical brace 1c connecting the nodes of the columns 1a and 1b, and a horizontal brace 1d, and has a structure capable of withstanding its own weight in the vertical direction and seismic force in the horizontal direction.

Reference numeral 7 denotes a horizontal steady rest mechanism which is interposed between the boiler body 2 and the supporting steel frame 1. The steady rest mechanism 7 has a supporting structure with low rigidity so that the boiler main body 2 can largely swing horizontally when an earthquake occurs. As shown in FIG. 4B, the steady rest mechanism 7 is The cantilever beam 7a having a flexible structure protruding from the boiler main body 2 is sandwiched by the claw portions 7b provided on the supporting steel frame 1.

Reference numeral 8 denotes a vibration damping device such as a hydraulic damper provided between the supporting steel frame 1 and the boiler main body 2, and a difference in horizontal displacement between the supporting steel frame 1 and the boiler main body 2 (relative Displacement) is used to absorb vibration energy. As the vibration damping device, known devices such as a hydraulic damper and a dashpot are used.

The above construction is similar to the conventional one shown in FIG.

Reference numeral 3 denotes a coal bunker provided in the front portion of the supporting steel frame 1, and 4 and 5 are denitration devices and air heaters provided in the rear portion of the supporting steel frame 1.

The coal bunker 3, the denitration device 4, and the air heater 5 are mounted on the horizontal beam 1b of the supporting steel frame 1 via laminated rubbers 9, 11, and 13. In consideration of ensuring the static stability of each of the accessory devices 3, 4, and 5, the laminated rubbers 9, 11, and 13 should be installed at four corners of each device (see FIG. 2). It is suitable.

The laminated rubbers 9, 11 and 13 are used in the seismic isolation structure of a building and have a high rigidity in the vertical direction and a large load-bearing capacity, while being flexible in the horizontal direction. It has rigidity and large horizontal deformability.

In place of the laminated rubbers 9, 11, 13 described above,
An elastic body such as a spring or a single material rubber pad may be used.

Between the bottoms of the auxiliary devices 3, 4, 5 and the beam of the supporting steel frame 1, vibration damping devices 10, 12, 14 including hydraulic dampers are provided. These vibration damping devices 10, 12, 14 are arranged on both sides of each device in order to prevent the occurrence of twisting of each device.

In the boiler supporting structure constructed as described above, when an earthquake occurs, the boiler main body 2 supported by the supporting steel frame 1 through the horizontal steady rest mechanism 7 and the vibration damping device 8 and the supporting steel frame 1 are supported. Laminated rubber 9, 11, 13
The coal bunker 3, the denitration device 4, and the air heater 5, which are supported via the vibration damping devices 10, 12, and 14, vibrate with respect to the supporting steel frame 1 with a relative displacement larger than this.

The mass of this vibration system is the mass of the boiler main body 2, the coal bunker 3, the denitration device 4 and the air heater 5, and only the conventional vibration system shown in FIG. It has 2.5 times the mass of the vibrating system that acts. This improves the effect of absorbing vibration energy.

The above phenomenon will be described in detail with reference to FIGS.

FIG. 3 (a) is a simple model of the support structure between the boiler body 2, the call bunker 3, the denitration device 4, the air heater 5 and the support steel frame 1 in order to obtain the natural vibration characteristic. .

That is, the supporting steel frame 1 has an equivalent beam element and a concentrated mass of 1 m, the boiler body 2 has an equivalent beam element and a concentrated mass of 2 m, and the call bunker 3, the denitration device 4, and the air heater 5 have the same equivalent beam. Element and concentrated mass 3
It is modeled with m, 4m, and 5m.

Further, the steady rest 7 for connecting the supporting steel frame and the boiler main body 2 is a spring element 7, and the laminated rubbers 9, 11, 13 for connecting the supporting steel frame 1, the call bunker 3, the denitration device 4, and the air heater 5 together. Similarly, the spring elements 9, 11, 13 are modeled.

Next, FIGS. 3 (b) and 3 (c) schematically show the calculation results when the natural vibration calculation is performed on the model of FIG. 3 (a).

FIG. 3B shows the vibration mode of the primary vibration, in which the supporting steel frame 1, the boiler body 2, the call bunker 3, the denitration device 4 and the air heater 5 are moving in the same direction, and the supporting steel frame 1 The displacement of the boiler main body 2 and the auxiliary equipment 7 is large with respect to the displacement of 1, and the vibration mode becomes a large relative displacement with the supporting steel frame 1.

FIG. 3 (c) also shows the vibration mode of the secondary vibration, in which the supporting steel frame 1, the boiler body 2, the call bunker 3, the denitration device 4 and the air heater 5 are displaced in the opposite directions, and the primary vibration occurs. Similar to the vibration, the vibration mode causes a large relative displacement with the supporting steel frame 1.

Although not shown, this tendency also applies to higher-order vibrations, and both of them are vibration modes in which a large relative displacement is generated between the supporting steel frame 1 and the boiler main body 2 and the auxiliary equipments 3, 4 and 5.

Due to such natural vibration characteristics, even when an earthquake occurs, a large relative displacement occurs between the supporting steel frame 1, the boiler body 2, the call bunker 3, the denitration device 4, and the air heater 5.

At this time, the damping devices 8 and 1 provided side by side
The vibration energy supplied by the earthquake is absorbed by 0, 12, and 14, the damping property of the entire structure is improved, and the seismic response is greatly reduced. That is, the horizontal earthquake force acting on the supporting steel frame 1 is reduced, and the forces acting on the columns 1a, the beams 1b, and the vertical braces 1c of the supporting steel frame 1 are reduced, so that the cross-sections of these members can be reduced. It is possible to obtain an economical boiler vibration damping support structure.

[0040]

As described above, according to the present invention, the vibration damping device is interposed between the boiler body and the supporting steel frame, and the vibration is also generated between the supporting steel frame and auxiliary equipment such as a denitration device and an air heater. Since a damping device was installed and an elastic body such as laminated rubber was installed between the auxiliary equipment and the supporting steel frame, when the earthquake occurred, the auxiliary equipment became an independent vibrating mass. Since it vibrates together with a certain boiler body, the vibrating mass acting on the vibration damping device is significantly increased as compared with the conventional one.

As a result, the amount of vibration energy absorbed is increased and the damping performance of the entire support structure is significantly improved, so that the seismic load generated on the support steel frame can be reliably reduced.

Further, since the seismic horizontal force acting on the supporting steel frame is reduced, it is possible to make the constituent members of the supporting steel frame thin and lightweight, and it is possible to obtain a low cost boiler supporting structure.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a vibration damping support structure of a coal-fired boiler for power generation according to an embodiment of the present invention.

FIG. 2 is a view (plan view) taken along the line AA of FIG.

FIG. 3 is an explanatory view of a vibration damping action in the above embodiment.

FIG. 4 is a response diagram of FIG. 1 showing a conventional example.

[Explanation of symbols]

 1 Support Steel Frame 2 Boiler Main Body 3 Coal Bunker 4 Denitration Device 5 Air Heater 7 Steady Stop Mechanism 8, 10, 12, 14 Vibration Damper 9, 11, 13 Laminated Rubber

Claims (1)

[Claims] 1. A boiler support structure in which a boiler main body is supported by a supporting steel frame through a horizontal steadying mechanism, and auxiliary equipment such as a denitration device and an air heater is mounted on the supporting steel frame. A vibration damper such as a hydraulic damper is installed between the main body and the supporting steel frame together with the steady rest mechanism, and a vibration damper such as a hydraulic damper and an elastic body such as laminated rubber are interposed between the auxiliary equipment and the supporting steel frame. Boiler damping support structure characterized by being equipped.