JPH1130401A - Boiler having fin for heat absorption crossing combustion gas flow - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cause absorption of quantities of heats by devising the shape and arrangement of fins for heat absorption. SOLUTION: Two water tube walls each composed of a plurality of water tubes 4 arranged in parallel and a fin 8 for closure closing a space between the water tubes 4 are formed. A part nipped between the two water tube walls forms a combustion gas passage and combustion gas is caused to flow through a combustion gas passage in parallel to the water tube axis of the water tube 4 to absorb heat. In a so formed boiler, Two or more trains of fin trains for heat absorption formed in a way that fan sheet-form fins 11 for heat absorption are arranged in a number of stages in a direction extending vertically to a water tube axis and crossing a combustion gas flow are arranged at a part 15 fronting on the combustion gas passages of the water tubes 4, and a combustion gas main flow part 14 having no fin for heat absorption is arranged between the fin trains for heat absorption paralleling each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boiler provided with heat absorbing fins crossing a combustion gas flow.

[0002]

2. Description of the Related Art When a combustion gas is caused to flow on the surface of a water pipe and heat of the combustion gas is absorbed by the water pipe, a heat absorbing fin may be provided on the surface of the water pipe in order to absorb more heat. When the heat absorbing fins are attached in a direction crossing the flow of the combustion gas, if the interval between the heat absorbing fins is larger than a predetermined value, as shown in FIG. A vortex is formed at the point past the tip, and the flow of combustion gas from the tip of the heat absorbing fin to the water pipe surface is increased, so the heat absorption increases, but the distance before and after the heat absorbing fin is required to be wide Therefore, only a small number of heat absorbing fins can be installed, and there is a limit to an increase in heat absorption.
Further, as shown in FIG. 7, when the distance between the front and rear of the heat absorbing fins is reduced and the number of heat absorbing fins is increased, the combustion gas reaches the next heat absorbing fin before forming a vortex. As a result, since the combustion gas flows in a portion away from the water pipe, the heat absorption efficiency of the heat absorption fins is poor, and even if a large number of heat absorption fins are installed, the heat absorption amount increases only slightly. .

[0004]

The problem to be solved by the present invention is to make it possible to absorb more heat into the water pipe by devising the shape and arrangement of the heat absorbing fins. .

[0005]

A water pipe wall comprising a plurality of water pipes provided in parallel and a closing fin for closing between the water pipes is formed on two surfaces, and a portion sandwiched between the two water pipe walls is formed. In the boiler which absorbs heat by flowing the combustion gas in the combustion gas passage parallel to the water pipe axis of the water pipe in a combustion gas passage, a portion of the water pipe facing the combustion gas passage is perpendicular to the water pipe axis. At least two rows of heat absorbing fins formed by providing a plurality of fan-shaped heat absorbing fins in a direction intersecting with the combustion gas flow are provided in parallel with each other. A main flow portion of the combustion gas having no heat absorbing fin is provided therebetween.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. An annular upper header 1 is provided at the upper part of the can body, and an annular lower header 2 is also provided at the lower part. The inner water pipe 3 and the outer water pipe 4 are arranged in an annular shape between the upper and lower headers.
The connection between the water pipe and the header is covered with a refractory material 13. The inner water pipe 3 and the outer water pipe 4 are formed by a closing fin 8 parallel to the pipe axis direction between the adjacent water pipes at portions other than the end of the water pipe where the inner smoke port 5 and the outer smoke port 6 are provided. It is closed, and a combustion gas passage 7 is formed between the inner water pipe 3 and the outer water pipe 4. The central portion of the boiler surrounded by the inner water pipe 3 is a combustion chamber 9, and a burner 10 is provided above the combustion chamber 9. At the lower part of the inner water pipe, an inner smoke passage 5 not provided with the closing fin 8 is provided so as to surround the combustion chamber 9, and the combustion chamber 9 and the combustion gas passage 7 are connected by the inner smoke passage 5. The combustion exhaust gas sent through the combustion gas passage 7 by the outer smoke passage 6 without the closing fin 8 at the upper part of the water pipe is discharged in the circumferential direction of the boiler.
2 to discharge.

The water pipe heat transfer surface 15, which is the surface of the outer water pipe 4 facing the combustion gas passage, is surrounded by two concentric arcs having different radii and the same arc angle, and two radii passing through both ends of each arc. The fan-shaped heat absorbing fins 11 are provided in multiple stages so that the fan-shaped surface intersects the combustion gas flow. The arc angle of the heat absorbing fins 11 is smaller than half the arc angle of the water pipe heat transfer surface.
Two rows of heat absorbing fins 1 are provided in parallel on the water pipe heat transfer surface of one water pipe, and there is no heat absorbing fin 11 between the two rows of heat absorbing fins. A combustion gas main flow portion 14 which is a space is provided.

When the burner 10 is burned, high-temperature combustion gas is generated in the combustion chamber 9, and first, the surface of the inner water pipe 3 on the combustion chamber 9 side is heated. Subsequently, the combustion gas is supplied to the inner smoke vent 5
The inner water pipe 3 and the outer water pipe 4 heat the surfaces of the inner water pipe 3 and the outer water pipe 4 while flowing into the combustion gas passage 7 from the lower part to the upper part. At this time, the combustion gas mainly flows through the combustion gas main flow portion 14, and the combustion gas flows into the portion between the front and rear heat absorption fins 11 in the heat absorption fin row provided on the left and right of the combustion gas main flow portion 14. be introduced. The combustion gas introduced from the combustion gas main flow portion 14 to the portion between the heat absorbing fins 11 flows in the lateral direction, and the space between the heat absorbing fins 11 may obstruct the formation of a vortex. Since there is no vortex, a vortex is formed in the lateral direction. Therefore, the combustion gas comes into contact with the upper and lower surfaces of the heat absorbing fins 11 and the water pipe heat transfer surface 15 at a portion between the heat absorption fins 11, and the heat absorption fin 11 and the water pipe heat transfer surface 15 transfer heat of the combustion gas. A large amount can be absorbed, and the heat absorption amount of the outer water pipe 4 can be increased. In the case where the combustion gas main flow portion 14 is provided to form a vortex in the lateral direction between the heat absorbing fins 11 as described above, a large number of heat absorbing fins can be provided, so that the heat absorption amount is very small. More. The flue gas whose temperature has been reduced by heating the water pipe is discharged to the outside smoke outlet 6,
Discharged through the flue 12.

In the heat absorbing fin row, the heat absorbing fins 11 may be shifted by a half pitch at the same pitch as the adjacent heat absorbing fin row as shown in FIG.

[0010]

According to the present invention, the amount of heat absorbed by the water pipe can be increased.

[Brief description of the drawings]

FIG. 1 is a perspective view of a heat absorbing fin obtained by extracting a part of an outer water pipe according to the present invention.

FIG. 2 is a perspective view of a heat absorbing fin in which a part of an outer water pipe is extracted in another embodiment.

FIG. 3 is a longitudinal sectional view showing one embodiment of the present invention.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a partially enlarged view of FIG. 4;

FIG. 6 is an explanatory view of a flow of a combustion gas in the case of a conventional heat absorbing fin.

FIG. 7 is an explanatory view of a flow of a combustion gas in the case of a conventional heat absorbing fin.

[Explanation of symbols]

 Reference Signs List 3 inner water pipe 4 outer water pipe 5 inner smoke port 6 outer smoke port 7 combustion gas passage 8 blockage fin 9 combustion chamber 11 heat absorption fin 12 flue 14 combustion gas main flow section 15 water pipe heat transfer surface

Claims (2)

[Claims] 1. A water pipe wall comprising a plurality of water pipes provided in parallel and a closing fin for closing between the water pipes, and two water pipe walls are formed.
The part of the surface between the water pipe walls is used as a combustion gas passage,
In a boiler that absorbs heat by flowing a combustion gas in a combustion gas passage parallel to a water pipe axis of the water pipe, a portion of the water pipe facing the combustion gas passage is perpendicular to the water pipe axis and is directed to the combustion gas flow. At least two rows of heat absorbing fins formed by arranging a large number of fan-shaped heat absorbing fins in the direction crossing each other are provided in parallel with each other, and the heat absorbing fins are arranged between the parallel heat absorbing fin rows. A boiler provided with heat absorbing fins intersecting the combustion gas flow, wherein a combustion gas main flow portion having no flow is provided. 2. A boiler having heat absorbing fins crossing the combustion gas flow according to claim 1, wherein the heat absorbing fins of the heat absorbing fin row are arranged at the same pitch as the adjacent heat absorbing fin row. A boiler provided with heat absorbing fins crossing a combustion gas flow, wherein the heat absorbing fins intersect with a combustion gas flow.