JPS6333603B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method in which the peripheral wall of the furnace or flue of a boiler is formed of an evaporation tube or a steam cooling tube, and a pipe header is provided on the upper part of the tube of the peripheral wall, and the furnace wall and the flue are In this type of heating pipe, the heating pipe connected to the inlet and outlet of the superheater, reheater, etc., which is constructed of heating pipes installed in the ceiling, penetrates the ceiling pipe part and is connected to the pipe header installed above the ceiling. This invention relates to improvements to steam generators.

Conventional steam generators are as shown in FIGS. 1 to 5. In Figures 1 and 2, 1 is an evaporation pipe forming the furnace and the furnace wall above the furnace, 2 is a cooling pipe forming a flue wall, 3 and 4 are each ceiling pipes, and 5 and 6 are each a side wall. upper header,
Reference numerals 7 and 8 denote a superheater and a reheater, each of which is constituted by a heating tube that passes through the ceiling tube and is suspended in the flue.
4 to 21 are headers provided at the inlet and outlet of the superheater and reheater, respectively; 22 is a backstay for reinforcing the furnace wall; 23 is a hanging rod for suspending and supporting each part of the steam generator; and 24 is a Hanging rod 2
3 is a spring interposed therein; 25 is a peripheral wall formed of a heat insulating material for keeping the upper part of the ceiling warm and an exterior plate; and 26 is a support building supporting the steam generator.

Generally, in recent large-scale steam generators, their weight is suspended and supported from the top of a support building 26 by a hanging rod 23.

In such a steam generator, it is necessary to satisfy the conditions for steam to be sent to a turbine, etc., but at the same time, the steam generator itself must be supported sufficiently and safely against various conditions.

That is, it must be able to safely support the amount of the steam generator, the gas pressure within the furnace that acts on the furnace wall during operation, and even when large horizontal forces such as earthquakes and wind pressure act unexpectedly.

Furthermore, since the temperatures of various parts of the steam generator are different during operation, differences in thermal expansion occur, but this must be freely allowed and undue stress must not be generated in the steam generator itself. The conventionally known steam generator described above is based on the above-mentioned requirements, but is constructed as described below and has many structural defects.

That is, as shown in FIGS. 1 and 2, the furnace wall tubes 1,
In the upper header 2, the corresponding wall pipes 1-1 and 1-2 are often bent toward the inside of the furnace to form a ceiling with these wall pipes, and the wall pipe header 7 is provided on the ceiling. Other corresponding side wall tubes 1-3, sometimes arranged perpendicular to the furnace wall,
1-4, the header 5-1 is slightly (approximately 1 meter) above the position of the ceiling pipes 3, 4.
5-2 is placed. As shown in Fig. 5, the wall pipes 1-3 and 1-4 are located near the ceiling pipe position.
Since a tie bar 27 is provided to attach the backstay 22 to prevent disturbance of the In order to allow for the difference in thermal expansion between header 1-3 and header 5, a considerable distance was provided above the ceiling position.

However, as shown in Figure 1, in this section, there are many heaters 9 to 13 that penetrate the ceiling and are suspended in the furnace, so the horizontal force caused by the earthquake in this section becomes extremely large. In addition, there is also a force that tries to bend the furnace wall outward from the furnace due to the gas pressure inside the furnace, resulting in a huge force.

For this reason, a backstay 22 having an extremely large cross section is required near this portion, which cannot be provided at low cost. Furthermore, even if the backstay 22 is quite large, its force is supported at both ends as shown in Figure 3, so at its center there is a force of δ ₁ (approximately several tens of millimeters) toward the outside of the furnace. This will cause deflection.

For this reason, the structure of the gas seal plate 28 in this part becomes complicated, and the seal plate 28 may be damaged due to undue stress, and the boiler operation must be frequently stopped to repair gas leaks. There is. Furthermore, since the backstay 22 in this part is large, a large moment _M1 is generated in the part related alloy 29 and the part attached to the wall pipe 1-3 because the backstay 22 is attached to the wall pipe 1-3. Unfavorable uneven stress occurs, causing wall tube 1-3
There is a risk of damaging it. In addition, in the engagement alloy 29, while freely allowing the difference in expansion between the wall tube 1-3 and the backstay 22, the huge force is transmitted to the backstay 22, and at the same time, the moment is
Since it must be able to withstand M ₁ sufficiently, the structure of the engagement alloy 29 is complicated, and furthermore, the installation and assembly are not easy.

Next, to support the load on the wall pipe 1-3, a hanging hardware 30 is attached to the header 5,
It is suspended and supported from the boiler support iron pipe by the hanging rod 23, but the support point of the wall pipe 1-1 in the direction perpendicular to the wall pipe 1-3 or the ceiling pipe 3 and the heaters 9 to 13 in that part is Since the vertical positions are different, the lengths of the hanging rods are different, resulting in a difference in thermal expansion during boiler operation. For this reason, in order to absorb the difference in expansion, a spring 24 may be interposed at the joint between the hanging rod 23 and the building 26. However, since the spring 24 has some load fluctuation due to the expansion and contraction of the spring 24, the furnace wall tube 1-3
The load will be transferred to the furnace wall tube 1-1 through the corner a, which is undesirable because force is applied to the joint at the corner.

Furthermore, heating pipes 9 to 9 arranged in the furnace (flue)
13 and headers 14 to 21 installed above the ceiling.
As shown in FIGS. 2 and 5, side wall pipes 1-3, 1-
Since the headers 5 and 6 of No. 4 and 2 are located vertically above the communication pipes 9' to 13', the end pipes of the communication pipes 9' to 13' must be arranged in a detour. Further, for this reason, the distance between the headers 14 to 21 and the ceiling pipe 3 must be increased to accommodate the distance required for this detour. However, since most of the heating pipe connecting pipes 9' to 13' are high-temperature parts, the materials used therefor are high-grade and expensive. From above, it is not the part that performs heat exchange, but the heating pipes 9 to 13 and header 1.
4 to 21, and there are only secondary elements, making it unnecessarily long is pointless and uneconomical.

Furthermore, increasing the length of the connecting pipe increases pressure loss due to frictional resistance of the internal fluid, and in order to maintain the steam pressure at the boiler outlet, the water supply pressure must be increased accordingly, increasing the design pressure of the entire boiler. This is uneconomical and undesirable.

Furthermore, as mentioned above, the pipe headers 14 to 21 and the ceiling pipe 3
Increasing the distance from the boiler support building 26 requires increasing the height of the boiler support building 26, which is not preferable.

Moreover, the installation and assembly of this part is not easy because the side wall headers 5, 6, etc. become obstacles.

As mentioned above, in conventional steam generators, the backstay in the ceiling becomes large, resulting in an uneconomical design.Also, the header of the heating pipe placed in the flue is placed in the ceiling, but the back stay of the heating pipe becomes large. Because the length of the non-heating part is so long that there is a gap between it and the side wall header,
It has drawbacks such as a long and uneconomical design, and its development was necessary in order to reduce costs.

The present invention solves the above-mentioned drawbacks of the conventional device, and involves bending the furnace side wall tube of a boiler approximately horizontally toward the outside of the furnace at approximately the ceiling position to form a substantially horizontal tube, and also forming a substantially horizontal tube. An upper header of the furnace side wall tube is arranged outward on the extension of the axis, and a support plate for supporting the side wall load is fixed to the bent portion of the furnace side wall tube, and this support plate is suspended by a hanging rod. In addition, a ceiling tube support metal fitting is fixed to the upper part of the ceiling tube, which is formed by bending the front wall tube and the cooling tube of the boiler approximately horizontally toward the inside of the furnace at approximately the ceiling position, so as to be perpendicular to the ceiling tube. Both ends are connected to the support plate, and the ceiling tube support hardware is suspended by another hanging rod at substantially the same support position as the hanging rod of the support plate.

The present invention can be widely applied to power generation boilers and industrial boilers.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 6 to 10. In the upper part of the side wall of the steam generator as explained in the conventional apparatus,
The wall pipes 1-3 and 1-4 are bent substantially horizontally toward the outside of the furnace at substantially the ceiling position to form a substantially horizontal pipe 1-3'. -3', arranged at an appropriate distance outward on the axis line extension,
A support plate 31 that connects the side wall tubes 1-3 to the bent portion of the side wall tubes 1-3 is attached from the inside of the side wall tubes 1-3, so that the front wall tubes 1-1 and the cooling tubes 2 of the boiler are at approximately the ceiling position. The ends of the ceiling tube support metal fittings 32 fixed perpendicularly to the upper part of the ceiling tube 3 formed by bending it approximately horizontally in the direction of the furnace interior are welded or attached to the corresponding support plates 31, respectively. Connected by bolts.

In addition, to deal with the load on the side wall 1-3, the support plate 31 is suspended and supported by the steam generator support building 26 using a hanging rod 23-1.
Next, the ceiling gas seal plate 28 is attached by welding directly to the support plate 31 at the side wall end, and by welding to the ceiling pipe support hardware 32 and other similar ceiling pipe support hardware 33 at other parts. . In addition, in the wall 1-1 in the direction perpendicular to the side wall 1-3, if the ceiling is formed by the wall pipe 1-1 as a ceiling pipe, the part is outside the wall pipe as shown in FIG. A support plate 34 is provided from the side, and the gas seal plate 28 is attached to the support plate 34.

Next, in the method shown in FIGS. 11 and 12, in the structure of the present invention in which the side wall tube 1-3 is bent outward substantially horizontally, the header 5 and the support plate 3 provided at the bent portion are
According to the present invention, the connecting pipes 1-3' are crossed with each other to form a truss beam structure in order to strengthen the effect as a support beam by the connecting pipes 1-3' connecting the parts. This is a method according to another embodiment.

Next, to explain the structure of the present invention described above from the perspective of force action, as mentioned earlier, in a steam generator, it is necessary to fully satisfy the steam conditions for sending to a turbine etc. At the same time, the steam generator itself must be safely supported under various conditions.

That is, it must be supported sufficiently safely even when the weight of the steam generator, the gas pressure inside the furnace that acts on the furnace wall during operation, and unexpected large horizontal forces such as earthquakes and wind pressure act.

Additionally, in a steam generator, differences in thermal expansion occur due to differences in temperature or length of each part during operation, but this must be freely allowed so that undue stress does not occur in the steam generator itself. . Moreover, it is preferable that the elongation difference does not occur as much as possible.

Generally, in recent large boilers, a structure is adopted in which the weight is suspended from the top of the support building 26 by a hanging rod 23, and in particular, in the ceiling of the boiler, the weight is suspended inside the furnace (inside the flue). Heater 9
- 13 are placed and suspended through the ceiling, the horizontal force caused by earthquakes and the like will be an extremely large force, but the structure must be able to withstand such a huge force. First, regarding the vertical load applied to the furnace wall tube 13, the wall tube 1-3
The building 26 is supported by the hanging rod 23-1 via the support plate 31 attached to the bent portion bent outward.
suspended from the top of the

In addition, as for the weight of the heaters 9 to 13, which are disposed in the furnace (inside the flue) by penetrating the ceiling pipe 3 and the ceiling pipe group, the weights of the heaters 9 to 13, which are disposed in the furnace (inside the flue) through the ceiling pipe 3 and the ceiling pipe group, are determined by It is suspended from the top of the support building 26 by a hanging rod 23-2 in the same manner as described above.
In this case, the lengths of the hanging rods 23-1 on the side wall 1-3 and the hanging rods 23-2 on the ceiling are approximately the same, so there is no difference in thermal expansion, so the force is biased towards the connecting part of the part. will have no effect.

Next, in the case of a boiler that uses the forced draft method, during operation the pressure inside the furnace reaches several hundred millimeters of water, creating a large force on the furnace walls 1-3 that tends to curve the furnace walls outward. However, this force causes the wall tube 1-3 to bend outward, and is transmitted to the portion formed into a set of beams by the header 5 and support plate 31 provided outward, and the force is A part of the force is transmitted to a support plate 31 provided on the furnace wall 1-3, and the other part of the force is transmitted to a plurality of support metal fittings 32 and 33 attached to the ceiling pipe 3, respectively. It will be done. In addition, a similar effect occurs in the wall tube 1-4 corresponding to the wall tube, and is transmitted to the support plate 31-1 and the supporting hardware 32, 33, respectively, but in this case, the reaction acting on the other corresponding furnace wall Since the magnitudes of the forces are the same, just in opposite directions, balance can be achieved by the support plates 31, 31' and the support metal fittings 32, 33, respectively. In addition, furnace wall tube 1
-3, the ceiling tube 3 is connected to the support plates 32, 3 provided on the corresponding walls, respectively.
3, a reaction force acts on the ceiling pipe 3, and each can be balanced in the same manner as described above.

Next, in the case of an earthquake, the horizontal force generated in the heating pipes 9 to 13 that make up the superheater and reheater will be enormous, but the horizontal force will be transmitted through the heating pipes 9 to 13 and penetrate the ceiling. will be communicated to. Therefore, an extremely large horizontal force acts on the ceiling pipe section.

For this reason, in conventionally known boilers, the backstay 22 having an extremely large cross section is disposed outside the peripheral wall of the part as described above, and has various drawbacks, but in the present invention, the backstay 22 has various disadvantages. As shown in FIG.
By connecting the ceiling support metal fittings 32 and 33 to this support plate 31, it is possible to support the ceiling support plate 31 in a sufficient and safe manner, without causing uneven stress even in response to a huge horizontal force generated in the support plate 31.

First, to explain the horizontal force C shown in FIG. 8, the force C generated at the ceiling part and the heating pipe penetration part is
Tensile force is transmitted to the supporting metal fittings 32 and 33, respectively, and one of the tensile forces is transmitted to the supporting plates 31 and 31' provided on both sides.
One side is transmitted as a compressive force, which is transmitted through the rigid body formed by the side wall header 5, the wall pipe connecting pipe 1-3' and the support plate 31, and is then transmitted to the fixed point via the side wall header 5 provided at both ends. , is transmitted from the bottom part to the building 26. Also, a part of the force is directly transmitted from the ceiling wall to the side wall pipe header 5 due to the rigidity of the ceiling wall formed by the ceiling pipe 3, the gas seal plate 28, and the supporting metal fittings 32, 33, and is transferred to the side wall pipe header 5 at the same fixed point as above. B,
It is transmitted to the building 26 from B'.

Regarding the horizontal force A, a part of this horizontal force A is transmitted to the support plate 34 through the ceiling pipe 3, and is transmitted to both ends by the back stays 22 provided on the wall pipe 1-1 and the cooling pipe 2 (this In this case, the force is extremely small, so a small backstay is sufficient)
The majority of the force is transmitted to the building 26 from the ceiling pipe 3, the gas seal plate 28, and the support hardware 3.
The rigidity of the ceiling wall formed by 2 and 33 is directly transmitted to the support plate 34, and is transmitted to and supported by the building 26 via fixing points 2 and 2'.

As described above, according to the structure of the present invention, backstays for reinforcing the wall are not required in the side wall tubes 1-3 of the ceiling portion. That is, by arranging the header 5 outward at approximately the ceiling position, a backstay effect is produced due to the rigidity of this portion, as described above. Furthermore, due to the furnace internal pressure, the side wall pipes 1-3, 1
According to the structure of the present invention, both ends of the plurality of supporting metal fittings 32 and 33 attached to the upper part of the ceiling pipe 3 are connected to the support plate 1. Since the support plate 31 is attached to the support hardware 32,
33, and the fixing intervals are narrow, so that outward deflection of the side wall tubes 1-3, 1-4 and header 5 is almost eliminated. Therefore, the space between the ceiling pipe 3 and the side wall pipes 1-3, 1-4 is always kept constant during operation and cooling, and there is no expansion or contraction, so the ceiling gas seal in this area is maintained. The plate 28 can be welded directly to its support plate and will not be damaged.

Also, by directly connecting the support plate portion 31 to the support hardware 32, 33 and the seal plate 28, the ceiling wall can be connected to the ceiling pipe 3, the support hardware 32, 33, and the seal plate 28.
Together, the rigidity against horizontal forces increases significantly, resulting in a structure in which the ceiling wall itself can be expected to have a sufficient effect as a support beam against horizontal forces.

Furthermore, regarding the load related to the furnace wall 1-3, by suspending the support plate 31 by the hanging rod 23-1, the vertical position of the support point of the wall tube 1-1 in the direction perpendicular to the wall tube 1-3 can be adjusted. Since the vertical position is approximately the same as that of other hanging points on the ceiling, the length of the hanging rod is also approximately the same, and there is no difference in thermal expansion between the hanging rods of each part even during boiler operation, so the hanging point of that part is approximately the same. There is no need to install a spring or the like in the rod 23-1 at all.

Therefore, by not installing a spring, there is no load fluctuation between the hanging rods of each part, whether the boiler is cold or operating, so there is no load movement at the joints at the corners of the furnace wall, etc. , the force will not be biased toward the corners. Furthermore, at the positions of the heater headers 14 to 21 arranged above the ceiling, by arranging the side wall headers 5 substantially outside the ceiling position, the ceiling The arrangement of the heating pipe communication pipes 9' to 13' arranged above the pipes is not obstructed at all.

For this reason, there is no need to bypass the heater connecting pipes 9' to 13' for the side wall header 5 as in conventionally known devices, so the positions of the heater headers 14 to 21 are extremely low compared to conventional devices. can be placed. Most of the connecting pipes 9' to 13' in this section are high-temperature parts and are made of high-grade special materials, but this means that the connecting pipes 9' to 13' can be made as short as possible. Furthermore, since the height of the steam generator is reduced, the support building can also be lowered, so it can be provided at a much lower cost than conventional devices.

Furthermore, since the side wall header 5 is located outward at approximately the ceiling position, the header 5 does not become an obstacle during the installation and assembly of the above-mentioned portion, making the work easier.

In addition, by shortening the communication pipe of the heater, pressure loss due to frictional resistance of the internal fluid is reduced.
Plant efficiency will also improve.

As described above, the present invention eliminates various drawbacks of conventional devices in the ceiling portion of a steam generator, and can be provided at a much lower cost than conventional devices.

[Brief explanation of the drawing]

1 to 5 show the upper part of a conventionally known steam generator, FIG. 1 is a side view thereof, FIG. 2 is a sectional view taken along the - arrow in FIG. Action diagram when force is applied in the cross section seen by arrows, No. 4
The figure is a sectional view taken along the - arrow in FIG. 3, FIG. 5 is an enlarged front view of section A in FIG. 2, FIGS. Similar to FIG. 1, a top side view of the steam generator of the present invention, FIG. 7 is a sectional view taken along the - arrow in FIG. 6, FIG. 7 is an enlarged front view of part B, FIG. 10 is a perspective view seen from the direction of arrow C in FIG. 9, FIGS. 11 and 12 show another embodiment of the present invention, and FIG. is an enlarged plan view of section D in FIG. 8, and FIG. 12 is a sectional view taken along the - arrow in FIG. 11. 1... Evaporation tube, 1-1, 1-2, 1-3, 1-
4...Wall pipe, 1-3'...Wall pipe, 2...Cooling pipe,
3, 4... Ceiling pipe, 5, 6... Upper pipe header, 7,
8...Ceiling pipe header, 9, 10, 11, 12, 1
3...superheater and reheater, 9', 10', 11',
12', 13'... Heating pipe connecting pipe, 14, 15, 1
6, 17, 18, 19, 20, 21...header,
22...back stay, 23...hanging rod, 23-
1, 23-2...hanging rod, 24...spring, 2
5... Peripheral wall, 26... Support building, 27... Tie bar, 28... Gas seal plate, 29... Engagement alloy,
31...Support plate, 32...Support hardware, 33...Heating tube penetration part hardware, 34...Support plate.

Claims (1)

[Claims] 1. Bend the furnace side wall tube of the boiler approximately horizontally toward the outside of the furnace at approximately the ceiling position to form a substantially horizontal tube, and
Arranging the upper header of the furnace side wall tube outwardly on the axial extension of the substantially horizontal tube, and fixing a support plate for supporting the side wall load to the bent portion of the furnace side wall tube,
This support plate is suspended by a hanging rod, and the front wall tube and the cooling tube of the boiler are bent approximately horizontally toward the inside of the furnace at approximately the ceiling position. Both ends of the ceiling pipe support hardware fixed to are connected to the support plate, and the ceiling pipe support hardware is suspended by another hanging rod at substantially the same support position as the support position of the hanging rod of the support plate. A steam generator characterized by: