JP2001349502A - Steam generator and vertical water tube boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the manufacturing cost of a steam generator in which a plurality of evaporating pipes 3 vertically arranged with, providing an upper header and a lower header to the top ends and the bottom ends thereof and connecting the top ends to the upper header and the bottom ends to the lower header are arranged along a side wall section 11 or a vertical water tube boiler in which the inside space of the arranged evaporating pipes 3 is constituted as a combustion chamber and, at the same time, to improve the efficiency of heat transfer of the generator or boiler by making use of advantage of the compact constitution of the generator or boiler. SOLUTION: A cylindrical water tube group 4 is formed by arranging the evaporating pipes 3 at narrow intervals along a cylindrical surface formed along the side wall section 11 and the spaces among the adjacent water tubes 3 of the group 4 are formed as radial flow passages 5 through which a heat- source gas is made to flow outward. It is better to constitute the external surfaces of the evaporating pipes 3 facing an outer peripheral flow passage 6 which leads the heat-source gas to an outlet section O along the outer periphery of the water tube group 4 as a contact heat transfer section 9 that promotes contact heat transfer with the heat-source gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a plurality of vertical headers provided with an upper header and a lower header at the top and bottom, an upper end connected to the upper header, and a lower end connected to the lower header. A steam generator in which the evaporating tubes are arranged along a cylindrical side wall formed in a vertical direction, and a plurality of evaporating tubes are arranged along a cylindrical side wall formed in a vertical direction. The present invention relates to a vertical water pipe boiler in which a space inside the arranged evaporating tubes is configured as a combustion chamber and a combustor that forms a flame toward the combustion chamber is disposed. Above all,
The present invention is effective for small steam generators and vertical water tube boilers made of steel without applying refractories to the side walls.

[0002]

2. Description of the Related Art As a vertical water tube boiler, for example, JP-A-2000-18502 and JP-A-2000-391 are known.
As shown in Japanese Patent Publication No. 01, an annular upper header is provided at an upper portion of a cylindrical can body, and an annular lower header is provided at a lower portion of the can body, and an upper end portion is connected to the upper header,
A structure in which a plurality of evaporating tubes having a lower end connected to the lower header and provided in a vertical direction and arranged in two rows in a cylindrical shape has been previously proposed. In this configuration, an inner space of the cylindrically arranged evaporating tubes is configured as a combustion chamber, and an exhaust gas outlet is provided at one location on a side wall portion. The fin plates are welded between adjacent ones of the evaporating tubes arranged along the cylindrical surface to form a group of cylindrical water tubes composed of the plurality of evaporating tubes. Then, the fin plate is not attached between some of the evaporating tubes, and a portion between the evaporating tubes is formed as a radial flow path toward the outside of the combustion gas generated in the combustion chamber. A portion between the outer cylindrical water pipe group and the outer cylindrical water tube group is formed as a circumferential flow path of the combustion gas toward the exhaust gas outlet. In this vertical water tube boiler, heat is transferred from the combustion gas to the cylindrical water tube group in the circumferential flow path. The radial flow path guides the combustion gas generated in the combustion chamber to the circumferential flow path, and guides the combustion gas from the circumferential flow path to an outer circumferential flow path. This point is the same even in a steam generator configured similarly.

[0003]

By the way, in a steam generator having a similar configuration including the above vertical water tube boiler, a heat source gas passes through a plurality of circumferential flow paths along the cylindrical water tube group. Therefore, the heat source gas flow passes through a complicated path, and the problem that the flow resistance of the combustion gas flow path as the flow path of the heat source gas from the combustion chamber to the exhaust gas outlet cannot be avoided is increased. there were. Furthermore, if the fin plate is used to connect the evaporating tubes constituting the cylindrical water tube group as described above, the welding requires a great deal of time and labor, and the cost is increased even with a simple structure. have. In addition, if a double cylindrical water pipe group is formed, if the diameter is small, the process restriction that the inner cylindrical water pipe group must be assembled first and then the outer cylindrical water pipe group must be assembled. Also occurs.

In order to cope with the above problem, the cylindrical water pipe group formed by the evaporating pipe row is made single, and as shown in a plan sectional view of FIG.
Only those in the vicinity of the exhaust gas outlet E are closely contacted between adjacent ones, and the gap between the adjacent evaporating pipes 3 other than this point is defined as a radial flow path 5 directed outward of the combustion gas. It is conceivable to form a circumferential channel 15 between the evaporating tube 3 and the side wall 11. However, in this configuration, since the fin plate is not welded between the evaporating tubes 3, the manufacturing cost can be reduced.
As a result, the temperature of the combustion gas reaches the side wall portion 11 without decreasing so much.
However, there was a problem that the temperature of No. 1 increased, and this point was unsatisfactory. Therefore, as shown in FIG. 9, the cylindrical water pipe group 4 may be provided double inside and outside, and the combustion gas passing through the radial flow path 5 may be received by the outside cylindrical water pipe group. Although it is conceivable that the temperature of the combustion gas reaching the exhaust gas outlet is expected to be sufficiently low without increasing the temperature of the side wall portion 11, the above-described cost increase problem and the extension of the exhaust gas path have Problems remain with the increase in road resistance. Therefore, the inventors have paid attention to the point that the heat transfer efficiency is improved by reducing the gap in the radial flow path, and have attempted further improvement, thereby completing the present invention.

[0005] Therefore, the steam generator and the vertical water tube boiler according to the present invention provide means capable of reducing the manufacturing cost and improving the heat transfer efficiency while utilizing the features of the compact vertical water tube boiler. Aim.

[0006]

[Means for Solving the Problems]

The steam generator and the vertical water tube boiler according to the present invention are provided with an upper header and a lower header on the upper and lower sides, an upper end is connected to the upper header, and a lower end is connected to the lower part. Connected to the header, a plurality of vertically provided evaporator tubes are arranged along a cylindrical furnace wall formed in a vertical direction, a steam generator forming a cylindrical water tube group, or in addition thereto In a vertical water tube boiler in which the inner space of the cylindrical water tube group is configured as a combustion chamber and a combustor that forms a flame toward the combustion chamber is disposed, an adjacent space forming the cylindrical water tube group is provided. It is characterized in that the gap between the evaporating tubes is narrowly arranged, and each has the following features.

According to a first feature of the steam generator according to the present invention, as set forth in claim 1, the evaporating tubes are arranged at a narrow gap along a cylindrical surface along the furnace wall to form a cylindrical water tube group. And the gap between the evaporating pipes adjacent to the cylindrical water pipe group is formed as a radial flow path through which the heat source gas flows outward.

According to a second aspect of the steam generator according to the present invention, a heat source gas is formed between the side wall and the cylindrical water pipe group in the first aspect of the steam generator. Is formed along the outer periphery of the cylindrical water tube group to the outlet portion, and the outer surface of the evaporator tube facing the outer peripheral passage is used as a contact heat transfer portion that promotes contact heat transfer with the heat source gas. The point is that it is structured.

A first characteristic configuration of the vertical water tube boiler according to the present invention is that, as described in claim 3, the gap between adjacent ones of the evaporating tubes along a single cylindrical surface along the furnace wall is narrowed. An array of cylindrical water tubes is formed, the combustor is arranged on the ceiling to form a flame downward, and the combustion gas generated by the combustor is discharged to one side of the side wall. An exhaust gas outlet is provided, and the evaporating pipes in the vicinity of the exhaust gas outlet are closely arranged, and a gap between the evaporating pipes arranged in other parts is provided.
The combustion gas is formed as an outward radial flow path toward the side wall.

According to a second aspect of the vertical water pipe boiler according to the present invention, the vertical water pipe boiler includes a cylindrical water pipe group and a side wall portion in the first characteristic configuration of the vertical water pipe boiler.
Forming an outer peripheral flow path that guides the combustion gas flowing out from the radial flow path in the circumferential direction toward the exhaust gas outlet, and promotes the heat transfer in contact with the combustion gas on the outer surface of the evaporator tube facing the outer peripheral flow path. The point is that it is configured as a contact heat transfer section.

According to the steam generator and the vertical water tube boiler according to the present invention, the gap between adjacent evaporating tubes is narrowed to form a radial passage having high heat transfer efficiency. In addition, the number of assembling steps of the steam generator can be reduced to reduce the manufacturing cost, and at the same time, the thermal efficiency can be improved, and each has the following unique effects.

According to the first characteristic configuration of the steam generator according to the present invention, a narrow gap between the adjacent evaporating tubes is formed between the inner space and the outer space of the cylindrical water tube group in the radial flow path. By keeping the heat transfer efficiency in this radial flow path high, as a result, the temperature of the heat source gas reaching the side wall decreases, so that the temperature of the side wall can be sufficiently reduced without applying a refractory. Be able to maintain. Further, since the heat transfer tube group is constituted by a single cylindrical water tube group, there is no restriction on the order of assembling the evaporating tubes, and the assembling of the evaporating air is facilitated. In addition, since the evaporator tube does not need to be welded, labor and time for assembling the evaporator can be reduced.

According to the second characteristic configuration of the evaporator according to the present invention, the outer circumferential flow path formed along the outer circumference of the cylindrical water pipe group while exhibiting the operation and effect of the first characteristic configuration of the steam generator. By forming a contact heat transfer section on the outer surface of the evaporator tube facing
As a result of efficient heat exchange in the radial flow path, contact heat transfer with the heat source gas whose temperature has decreased is promoted, and the heat transfer efficiency can be further improved while having a compact structure.

According to the first characteristic configuration of the vertical water tube boiler according to the present invention, a single cylindrical water tube group is formed along the furnace wall, and the gap between adjacent evaporating tubes in the cylindrical water tube group is narrowed. And, by being formed as a radial flow path through which the combustion gas flows outward, the high heat transfer efficiency of this radial flow path can be utilized, and even in a narrow gap, the cylindrical water pipe group is formed. Since the total flow path cross-sectional area of the entire gap is sufficient,
The flow path resistance can be kept low. Further, by suppressing the flow resistance in the flow path of the combustion gas to be low, it is not necessary to increase the pressure of the combustor, and the cost can be reduced.
Furthermore, by configuring the evaporating tube group with a single cylindrical water tube group, there is no restriction on the mounting order of the evaporating tubes, improving the workability of assembling the vertical water tube boiler, and reducing the time and labor required for the assembly. Can be reduced.

According to the second characteristic configuration of the vertical water tube boiler according to the present invention, while exhibiting the operation and effect of the first characteristic configuration of the steam vertical water tube boiler, the temperature is sufficiently lowered and the combustion gas is discharged to the outer peripheral flow. Even on the road, the heat is efficiently transferred into the evaporator tube by contacting the contact heat transfer section.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of a steam generator and a vertical water tube boiler according to the present invention will be described with reference to the drawings for one example of a steam generator and two examples of a vertical water tube boiler. explain. Elements having the same or similar functions as the elements described with reference to FIGS. 8 and 9 are denoted by the same or similar reference numerals, and a part of the overlapping description will be omitted.

[First Embodiment]

As shown in FIGS. 1 and 2, the steam generator has an upper header 1 functioning as a steam drum disposed on a ceiling 12 and a lower header functioning as a water supply drum disposed on a bottom 13. 2, the upper end portion is connected to the upper header 1, the lower end portion is connected to the lower header 2, and a plurality of evaporating tubes 3 provided in a vertical direction are connected to a cylindrical side wall formed in a vertical direction. It is arranged and arranged along the part 11. Then, the evaporating tubes 3 are arranged with a narrow gap along a cylindrical surface along the side wall portion 11 to form a cylindrical water tube group 4.
To form The gap between the evaporating pipes 3 adjacent to the cylindrical water pipe group 4 is formed as a radial flow path 5 through which the heat source gas flows inward and outward. The gap is preferably narrow. However, if the gap is too narrow, the dust may block the gap. Also, if dew condensation occurs in the evaporating pipe 3, if the gap is too narrow, adjacent evaporation Water droplets connected to the outer surfaces of the pipes 3 may cause corrosion, and the gap should be at least 0.5 mm or more. In addition, this gap is 2 mm
If the distance exceeds the range, the heat transfer efficiency is undesirably reduced. An outer peripheral channel 6 that allows a heat source gas to flow in the circumferential direction along the cylindrical water pipe group 4 is formed, and an outer surface of the evaporating pipe 3 located at a portion facing the outer peripheral channel 6 facing the outer peripheral channel 6 is formed. ,
Heat absorbing fins 14 for promoting the contact heat transfer with the heat source gas are provided to constitute the contact heat transfer section 9. On one side of the cylindrical side wall 11 of the steam generator, an outlet O of the heat source gas is opened, and the lower header 2 is formed in an annular shape. The opening I of the heat source gas is open. In the vicinity of the outlet portion O in the circumferential direction of the cylindrical water tube group 4, the adjacent evaporating tubes 3 are kept in close contact with each other.

As shown in the figure, the cylindrical water pipe group 4 is formed in a single layer, and the heat source is located at a gap between the evaporating pipes 3 in a circumferential area of the cylindrical water pipe group 4 except for the vicinity of the outlet O. A radial flow path 5 for gas is formed, and the cylindrical side wall portion 11 and the cylindrical water pipe group 4 are provided on both sides from the radial flow path 5.
Is formed between the evaporating tube 3 and the evaporating tube 3. Among the evaporating pipes 3 facing the outer peripheral flow path 6, the evaporating pipes 3 near the outlet O are arranged such that adjacent ones are in close contact with each other. As shown in FIG. 2, heat absorbing fins 14 are thermally connected to and attached to the outer surface forming the outer periphery of the cylindrical water tube group 4 over the entire length of the evaporating tubes 3 closely arranged in this manner, as shown in FIG. The heat transfer section 9 is configured. That is, the heat source gas is introduced into the cylindrical water pipe group 4 from below the steam generator, and flows out of the cylindrical water pipe group 4 from the radial flow path 5 formed between the evaporation pipes 3. Then, it flows between the side wall portion 11 and the cylindrical water tube group 4 in the circumferential direction, and flows out from the outlet portion O. Incidentally, since the radial flow path 5 passes through the narrow gap between the evaporating tubes 3, the heat transfer efficiency is good, and the temperature of the heat source gas is sufficiently lowered. Therefore, since the difference between the temperature of the evaporator tube 3 and the temperature of the heat source gas becomes smaller, the contact heat transfer portion 9 is formed on the outer surface of the evaporator tube 3 facing the outer peripheral flow path 6 near the outlet portion O. Thus, heat absorption by the heat absorbing fins 14 is achieved, and the overall heat transfer efficiency is further improved.

In this steam generator, when the heat source gas is introduced into the inner space of the cylindrical water pipe group 4 at about 1000 ° C., the heat retained by the heat source gas flowing out to the outer peripheral flow path 6 is converted into the radial flow. About 36% is transmitted to the evaporating tube 3 by a passage 5,
Its temperature drops below 300 ° C. Then, since it becomes difficult to recover the heat of the heat source gas in the outer peripheral flow path 6, the contact heat transfer section 9 recovers the heat. The heat absorbing fins 14 provided in the contact heat transfer section 9 are respectively attached to the evaporating tubes 3 by welding. The gap between the evaporating pipes 3 is set so that the total cross-sectional area of the radial flow path 5 is smaller than that of the exhaust path. Make it bigger. Therefore, the steam generator has extremely good thermal efficiency, and the radial flow path 5 may be extremely short, so that the flow resistance is low.

[Second Embodiment]

As shown in FIGS. 3 and 4, the vertical water tube boiler is provided with an upper header 1 functioning as a steam drum and a lower header 2 functioning as a water supply drum at the upper and lower portions of a boiler main body 10. The upper end is connected to the upper header 1, the lower end is connected to the lower header 2, and a plurality of evaporating tubes 3 provided in a vertical direction are arranged along a cylindrical side wall 11 formed in a vertical direction. At the same time, the internal space of the evaporating pipes 3 arranged as the combustion chamber 8
The basic configuration is a configuration in which a combustor 7 that forms a flame inward is arranged. Then, the upper header 1 is formed in an annular shape, and the combustor 7 is arranged so as to form a flame downward on the ceiling portion 12 of the inner space of the upper header 1,
An exhaust gas outlet E for discharging the combustion gas generated in the combustor 7 is provided on one side of the side wall 11.

The evaporating tubes 3 are arranged along a cylindrical surface substantially concentric with the side wall portion 11 to form a single cylindrical water tube group 4. The evaporating tubes 3 forming the cylindrical water tube group 4 are:
They are arranged at a narrow interval, and only the evaporating pipes 3 near the exhaust gas outlet E are arranged so that adjacent ones are in close contact with each other. That is,
A narrow gap between the evaporating tubes 3 is formed as a radial flow path 5 for guiding the combustion gas generated in the combustor 7 outward toward the side wall portion 11, and the cylindrical water pipe group 4 and the An outer peripheral passage 6 for guiding the combustion gas in the circumferential direction is formed between the outer peripheral passage 6 and the side wall 11. On the outer surface of the evaporating pipe 3 near the exhaust gas outlet E facing the outer peripheral flow path 6, heat absorbing fins 14 for promoting heat transfer in contact with the combustion gas are provided.
The outer surface of the evaporating tube 3 opposed to is formed as a contact heat transfer section 9. Combustion gas generated in the combustion chamber 8 formed in the inner space of the cylindrical water pipe group 4 in the combustor 7 flows out of the cylindrical water pipe group 4 through the radial flow path 5, and a large amount of gas flows during this time. After the heat exchange of the portion is completed, the heat reaches the exhaust gas outlet E via the outer peripheral flow path 6 between the cylindrical water pipe group 4 and the cylindrical side wall portion 11.

In the combustion chamber 8, the temperature of the combustion gas generated in the combustor 7 is maintained at about 1000 ° C., and about 47% of the retained heat is formed by the radiant heat to form the cylindrical water tube group 4. To the evaporating tube 3. And the combustion gas is
As described above, about 36% of the retained heat is transmitted to the evaporating tube 3 in the radial flow path 5 which has a very short distance but has a high heat transfer efficiency as described above, and the temperature decreases from about 1000 ° C. to about 350 ° C. is there. Therefore, the outer peripheral flow path 6 near the exhaust gas outlet E
The outer surface of the evaporating tube 3 facing the air is formed as the contact heat transfer section 9, and the heat absorbing fins 14 recover heat from the combustion gas whose temperature has decreased, thereby improving the overall heat transfer efficiency. is there. Here, about 7% of the remaining heat is absorbed from the combustion gas, and the temperature of the combustion gas reaching the exhaust gas outlet E is about 280 ° C.

The heat absorbing fins 14 are attached to the evaporating tubes 3 by welding. As described above, since the temperature of the combustion gas reaching the side wall portion 11 is low, the side wall portion 11 can be formed of a steel shell provided with no refractory. Further, the gap between the evaporating tubes 3 constituting the radial flow path 5 can be set in the same manner as described in the first embodiment, and the total flow path cross-sectional area of the radial flow path 5 can be set, The cross-sectional area of the outer peripheral flow path 6 can be set to be larger than the cross-sectional area of the downstream flow path. Since the road resistance can be suppressed and the back pressure of the generated combustion gas can be reduced, the combustor 7 can be inexpensive. In addition, since the evaporating tubes 3 form a single cylindrical water tube group 4, the evaporating tubes 3 are mounted between the upper header 1 and the lower header 2.
The order is not restricted. For example, in a small vertical water tube boiler that is a main object of the present invention, if the cylindrical water tube group 4 is doubled, at least one of the cylindrical water tube groups 4 must be assembled first. Therefore, a vertical water tube boiler having a simple structure, a reduced production cost, and high performance can be configured.

[Other Embodiments] Other embodiments of the steam generator and the vertical water tube boiler according to the present invention not shown in the above embodiment will be described below.

<1> In the first embodiment, the lower header 2 is formed in an annular shape, and the lower header 2
The example in which the heat source gas introduction portion I is opened in the bottom portion 13 inside the above has been described.
Is formed in an annular shape, and a ceiling portion 1 inside the upper header 1 is formed.
2 may be opened.

<2> In the first embodiment, the introduction portion I is opened in the bottom portion 13 inside the lower header 2, and the outlet portion O is opened on one side of the side wall portion 11. The example in which the heat source gas flows outward from the inside of the cylindrical water tube group 4 has been described. For example, as shown in FIG. 5, the outlet O is opened to the ceiling 12 above the upper header 1. You may let me. Further, the introduction section I and the exit section O may be arranged upside down. In short, the radial flow path 5 may be a path through which the heat source gas flows from the inside of the cylindrical water pipe group 4 to the outside.

<3> In the first embodiment, among the evaporating pipes 3 facing the outer peripheral flow path 6, the evaporating pipes 3 near the outlet O are closely arranged. Has been described with reference to FIG. 1, the closely arranged region may be expanded toward the opposite side of the outlet portion O.

<4> In the first embodiment, the outer surface of the evaporating pipe 3 facing the outer peripheral flow path 6 of the cylindrical water pipe group 4 is configured as the contact heat transfer section 9 provided with the heat absorbing fins 14. Although the example has been described, the heat absorbing fins 14 may be provided over a wider range, and may be provided on the outer surface of all the evaporating tubes 3 on the side facing the side wall portion 11 so as to cover the entire circumference of the cylindrical water tube group 4. The outer surface of the evaporating tube 3 may be configured as the contact heat transfer section 9 over the range.

<5> In the second and third embodiments, the flame is formed so that the combustor 7 is directed downward to the ceiling 12 in the inner space of the upper header 1. Although the arrangement example has been described, the combustor 7 may be provided on the bottom 13 inside the lower header 2 having an annular shape so as to form a flame upward.

<6> In the second embodiment, an example in which a single cylindrical water pipe group 4 is provided has been described. For example, as shown in FIGS. The side wall portion 1 is provided outside the cylindrical water tube group 4 in the embodiment.
The exhaust pipe 3 may be disposed along the exhaust pipe E, and a cut-out cylindrical water pipe wall 4A formed in a C-shaped cross section without the evaporative pipe may be provided at the exhaust gas outlet E. In this case, the evaporating pipes 3 arranged on the cylindrical water pipe wall 4A are connected to each other with a fin plate P between adjacent ones. Then, an outer peripheral flow path 6 that guides the combustion gas in the circumferential direction toward the exhaust gas outlet E is formed outside the inner cylindrical water pipe group 4 and between the cylindrical water pipe wall 4A. The cylindrical water pipe group 4 and the cylindrical water pipe wall 4A facing the outer peripheral flow path 6
Heat absorbing fins 14 which are thermally connected to the outer surfaces of
And the outer surface of the evaporating tube 3 facing the outer peripheral flow path 6 is configured as a contact heat transfer section 9.

With this configuration, while utilizing the high heat transfer efficiency of the radial flow path 5 in the cylindrical water pipe group 4, even if the temperature of the combustion gas passing through the radial flow path 5 is reduced, The combustion gas is received by the cylindrical water pipe wall 4A, and the contact heat transfer portion 9 is formed in the outer peripheral flow path 6 formed between the cylindrical water pipe wall 4A and the cylindrical water pipe group 4. Thus, the overall heat recovery efficiency can be made sufficiently high. Further, by forming the side wall portion 11 with the cylindrical water tube wall 4A, the outer wall temperature can be further reduced. Therefore, the thermal efficiency can be improved.

<7> In the second embodiment, the example in which the exhaust gas outlet E is provided on one side of the side wall portion 11 has been described, but the exhaust gas outlet E is provided below the lower header 2. It may be opened. Further, the combustor 7 may be provided at the bottom 13, and the exhaust gas outlet E may be opened above the upper header 1.

<8> The contact heat transfer section 9 described above
It is desirable to provide the evaporating pipes 3 in which adjacent ones are closely arranged. When the direction of the flow of the outer peripheral flow path 6 is set to the circumferential direction, each of the evaporating pipes 3 facing the outer peripheral flow path 6 is provided. It may be provided on all outer surfaces.

<9> In each of the above-described embodiments, an example in which both the upper header 1 and the lower header 2 are formed in a ring shape has been described with reference to the drawings, but the shape of the header is arbitrary. An arbitrary shape can be selected in accordance with the arrangement of the evaporating tubes 3, except in the case where the introduction part I or the outlet part O is provided in any of them.

[0038]

As described above, according to the present invention,
The manufacturing cost was reduced and the heat transfer efficiency was improved while maintaining a compact structure.

[Brief description of the drawings]

FIG. 1 is a cross-sectional plan view illustrating a configuration of an example of a steam generator according to the present invention.

FIG. 2 is a longitudinal sectional view illustrating the configuration of the steam generator shown in FIG.

FIG. 3 is a cross-sectional plan view illustrating a configuration of an example of a vertical water tube boiler according to the present invention.

FIG. 4 is a longitudinal sectional view illustrating the configuration of the vertical water tube boiler shown in FIG.

FIG. 5 is a longitudinal sectional view illustrating the configuration of another example of the evaporator according to the present invention.

FIG. 6 is a cross-sectional plan view illustrating the configuration of another example of the vertical water tube boiler according to the present invention.

FIG. 7 is a longitudinal sectional view illustrating the configuration of the vertical water tube boiler shown in FIG.

FIG. 8 is a plan sectional view showing an example of a conventional vertical water tube boiler.

FIG. 9 is a plan sectional view showing another example of a conventional vertical water tube boiler.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper header 2 Lower header 3 Evaporation pipe 4 Cylindrical water pipe group 5 Radial flow path 6 Outer flow path 7 Combustor 8 Combustion chamber 9 Contact heat transfer part 11 Side wall part 12 Ceiling part E Exhaust gas outlet O Exit part

Claims (4)

[Claims] An upper header and a lower header are provided at the top and bottom, an upper end is connected to the upper header, and a lower end is connected to the lower header.
A steam generator arranged along a cylindrical side wall formed in a vertical direction, wherein the evaporating pipes are arranged with a narrow gap along a cylindrical surface along the side wall, and a cylindrical water pipe is provided. A steam generator in which a group is formed and a gap between adjacent evaporating tubes of the cylindrical water tube group is formed as a radial flow path through which a heat source gas flows outward. 2. An outer peripheral flow path is formed between the side walls along the cylindrical water pipe group to guide the heat source gas to an outlet along the outer circumference of the cylindrical water pipe group. The steam generator according to claim 1, wherein an outer surface of the facing evaporating tube is configured as a contact heat transfer unit that promotes contact heat transfer with the heat source gas. 3. An upper header and a lower header are provided at the top and bottom, an upper end is connected to the upper header, and a lower end is connected to the lower header.
Along with the cylindrical side wall formed in the vertical direction, a combustor that forms a flame toward the combustion chamber by forming a space inside the arranged evaporator tubes as a combustion chamber is disposed. A vertical water tube boiler, wherein the evaporating tubes are formed into a group of cylindrical water tubes in which a gap between adjacent ones of the evaporating tubes is narrowed along a single cylindrical surface along the side wall portion. An exhaust gas outlet for discharging combustion gas generated in the combustor is provided on one side of the side wall so as to be arranged on the ceiling to form a flame downward, and an evaporating pipe near the exhaust gas outlet is provided. Is a vertical water tube boiler which is closely arranged and has a gap between evaporating tubes arranged at other portions as an outward radial flow path for the combustion gas toward the side wall portion. 4. An outer peripheral flow path is formed between the cylindrical water pipe group and the side wall to guide a combustion gas flowing out of the radial flow path in a circumferential direction toward the exhaust gas outlet. 4. The vertical water tube boiler according to claim 3, wherein an outer surface of the evaporator tube facing the flow path is configured as a contact heat transfer unit for promoting contact heat transfer with the combustion gas.