JPH0318803Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a water tube boiler, and in particular aims to strengthen the wall surface of the flue so that the water tube wall surrounding the flue can firmly support the group of heat transfer tubes arranged in the vertical flue. Regarding ivy independent water tube boilers.

In a self-supporting water tube boiler, the furnace and the flue are separated by a partition wall made of water tubes, and a group of heat transfer tubes such as a superheater and a economizer are placed inside the flue, and the support for these heat transfer tube groups is Various improvements have also been made to this. FIG. 1 shows an example of this heat exchanger tube support method. In the figure, the self-supporting boiler body 1 itself is connected to a furnace 2 and a flue 6 by a partition wall 5 formed of water pipes.
In the flue 6, a group of heat exchanger tubes of a economizer 3 and a superheater 4 are arranged. Reference numeral 7 denotes a sling pipe suspended from the economizer inlet header 18. The sling pipe 7 supports the load of the economizer 3, and the superheater 4 located above it is also connected to the sling pipe 7. The sling tube 7 supports all the loads of the connected heat exchanger tubes placed in the flue. Since the partition wall 5 itself cannot be reinforced with backstays or the like, the load of the heat transfer tube group is supported by the flue side wall 6a via the sling tube 7. However, as the boiler becomes larger, each heat exchanger tube group also becomes larger and heavier, and the above-mentioned support method
This has become a problem as a large compressive stress is applied to the material. For this reason, a support method as shown in FIG. 2 has been proposed and actually used. This method consists of a partition wall 5 and a flue rear wall 8 located opposite to the partition wall 5.
The support 9 supports the load of the superheater 4 and the economizer 3, disperses this load, and prevents extreme compressive stress from being applied to the flue side wall, etc. ing. However, in this method, part of the load is borne on the partition wall 5, which has low strength, so the partition wall 5 tends to bend toward the furnace 2 side, resulting in a situation where each heat exchanger tube group falls off from the support 9. is also occurring.

In addition, in a free-standing water tube boiler, the vertical flue is constructed from the water pipe wall, and the flue is made up of multiple vertical small pipes by welding and connecting multiple vertical water pipes to a membrane bar (elongated iron plate). A device has been proposed in which a flue is divided into flues (referred to as unit flues) and a drum is supported by the flue (Japanese Patent Application Laid-open No. 32201/1983).
However, when the membrane that forms this partition is subjected to vibrations such as earthquakes, repeated compression or tensile force due to thermal stress, there are many opportunities for cracks to occur due to stress at the welds between the water pipe and the membrane bar. In addition, as for the stress along the surface of the membrane, since the surface is not a true plane, it is extremely vulnerable to buckling, which expands and deforms when compressive force is applied, and the drag force decreases at an accelerated rate. In addition, since the drum is supported directly above the flue, the load increases the risk of membrane cracking, deformation, and water leakage.

The purpose of this invention is to provide a boiler that can increase the strength of the walls forming the flue and effectively support the load of the heat exchanger tube group.

In short, this idea divides a vertical flue with a rectangular cross section whose long side is the furnace water pipe wall into multiple unit flues by a water pipe partition wall made up of multiple water pipes, and inserts a group of heat transfer tubes into each unit flue. In the self-standing water tube boiler, a plurality of meandering water tubes are interposed between the furnace water tube wall and the opposing wall surface, and the bent portions of the water tubes are each welded to the opposing wall surface. This is a self-supporting water tube boiler with the following characteristics.

Examples of this invention will be described below.

FIG. 3 shows a cross section of the self-supporting boiler according to this invention. In the figure, reference numeral 10 denotes a water pipe forming the rear wall 8 of the flue, which is partially extended toward the opposing partition wall 5 (hereinafter referred to as the "extending pipe"), and the tip 10a is located at the partition wall. 5 by a strong method such as welding. As a result, the expansion tube 10
acts as a support member that reinforces the wall surface constituting the flue, and in particular the strength of the partition wall 5, which has a problem in terms of strength, is greatly improved. Figure 4 shows the expansion tube 1 shown in Figure 3.
0, the tip end 10a of the extending pipe 10 is attached to the water pipe 11 constituting the partition wall 5 by welding 12. Also this exhibition tube 1
0 may be attached to a membrane bar 13 interposed between each water pipe 11.

FIG. 5 shows another embodiment. In this embodiment, the distal end 10a of the extending tube 10 is disposed within the water tube group of the partition wall 5, and the partition wall 5 is integrated. FIG. 6 shows a cross section taken along line A--A in FIG.

In all of the above-illustrated pipes, the pipe body extends from the flue rear wall 8 toward the partition wall 5, but the pipe body is not limited to this, and may be extended from the partition wall 5 toward the flue rear wall. Furthermore, the tube bodies may be alternately extended from both wall surfaces toward the opposing wall surface.
Further, if the arrangement of the heat exchanger tubes is possible, the tube bodies may be extended from the side wall 6a toward the other opposing side wall.

FIG. 7 shows yet another embodiment. In this embodiment, instead of extending the pipe body from one wall surface to the other wall surface, there is a separate pipe body between two opposing wall surfaces (in the illustrated case, the partition wall flue front wall 5 and flue rear wall 8). A pipe body 15 is interposed to reinforce both wall surfaces, and the fluid flowing in the water pipes on both wall surfaces mixes.

FIG. 8 is a cross-sectional view of FIG. 3, and a plurality of the above-mentioned extension pipes 10 are arranged in the flue 6 to further increase the strength of the wall surface.

As shown in FIG. 2, the load of a group of heat transfer tubes such as a superheater or a economizer placed in the flue 6 is supported by the wall surface constituting the flue using a support 9 or the like. In this case, the wall surfaces constituting the flue, especially the partition wall 5, have significantly improved strength and can sufficiently withstand the load of the heat exchanger tube group, and will not bend toward the furnace side.

By implementing this idea, the opposing wall surface of the flue is a bent part of a bent water pipe, or a horizontally inclined straight pipe through which boiler water passes, and the inclination is alternately changed and the opposing wall surface is welded and connected. The structure has a truss structure, and its strength can be greatly improved, so it can support the heat exchanger tubes arranged in the flue while dispersing the load, and can fully cope with larger boilers.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views of a self-supporting boiler showing how the heat transfer tube group is supported by the conventional method, FIG. 3 is a cross-sectional view of the self-supporting boiler according to this invention, and FIGS. 4 and 5 are expanded views. FIG. 6 is a sectional view taken along line A-A in FIG. 5, and FIG. 7 is a perspective partial view of the partition wall showing the state of connection between the outlet pipe and the partition wall. FIG. The schematic diagram shown in FIG. 8 is a sectional view taken along the line B--B in FIG. 3. 1... Boiler body, 5... Partition wall, 6... Flue, 8... Flue rear wall, 10... Expansion pipe, 11...
Water pipe.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A vertical flue with a rectangular cross section whose long side is the wall surface of the furnace water pipe is divided into a plurality of unit flues by a water pipe partition wall made up of a plurality of water pipes, and each unit flue is divided into a plurality of unit flues. In a self-supporting water tube boiler in which a group of heat transfer tubes is located, a plurality of water tubes inclined with respect to the horizontal are interposed between the furnace water tube wall and the wall surface facing thereto, and each of the water tubes has a plurality of meandering lines, and the bent portions of the water tubes are arranged so as to face each other. A free-standing water tube boiler characterized by being welded to the wall. 2. Scope of Utility Model Registration In the self-supporting water tube boiler according to claim 1, a part of the water tubes constituting the wall surface is exposed from at least one wall surface to the opposing wall surface, and this exhibition A self-supporting water tube boiler constructed by welding the exposed water tube to the opposing wall. 3 In the free-standing water tube boiler described in claim 2 of the utility model registration claim, the water tube on the front wall of the flue that partitions the furnace and the flue and the water tube on the rear wall of the flue located opposite thereto are inclined with respect to the horizontal. A self-supporting water tube boiler is a self-supporting water tube boiler in which multiple tubes are welded and connected in alternating directions, and the boiler water flows through the tubes.