JPH08327005A - Multitubular once-through boiler - Google Patents

Abstract

PURPOSE: To efficiently heat water tubes even if combustion gas temperature is low by providing heat absorbing fins perpendicular to the tube axial direction in the outer smoke passage port of an outer water tube row. CONSTITUTION: When a burner 10 is burnt, combustion gas is generated in a combustion chamber 9 to first heat the surface of an inner water tube row 3 at the chamber 9 side. Then, the gas reaches from an inner smoke passage port 5 a combustion gas passage 7 to heat the row 3 and an outer water tube row 4 faced with the passage 7 while flowing from above to below. The gas crosses the row 4 to heat it, flows along heat absorbing fins 11 to heat the fins 11, and to heat the row 4 via the fins 11. The waters in the rows 3 and 4 are heated by the heating of the tubes, output through an upper header 1 as steam, and the combustion exhaust gas lowered at its temperature is exhausted via a flue 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-tube through-flow boiler in which a combustion gas passage is provided between an inner water pipe row and an outer water pipe row, and the combustion gas flows in the combustion gas passage in a direction parallel to the pipe axis. It is about.

[0002]

2. Description of the Related Art An annular upper water pipe row and a lower water pipe row are connected by two rows of water pipes, an inner water pipe row and an outer water pipe row, and a part between the adjacent inner water pipe row and the adjacent outer water pipe row is removed. By closing it by forming a combustion gas passage between the inner water pipe row and the outer water pipe row, the combustion gas passage communicates with the combustion chamber by the inner smoke outlet provided between the water pipes of the inner water pipe row, A multi-tube once-through boiler is widely used in which an inner smoke outlet and an outer smoke outlet provided in an outer water pipe row on the opposite side in the axial direction of the pipe communicate with a flue. The boiler first heats the water pipe on the side facing the combustion chamber by the combustion gas generated in the combustion chamber surrounded by the inner row of water pipes, and then reaches the combustion gas passage through the inner smoke vent and then the inner side. The surfaces of the water tube row and the outer water tube row on the side facing the combustion gas passage are heated, and the combustion exhaust gas is discharged through the outer smoke outlet and the flue. In this case, since the combustion gas has its temperature lowered by heating the water pipe, the amount of heat absorbed by the water pipe decreases toward the downstream side of the combustion gas flow,
In particular, when a water pipe having irregularities on the surface is used and a large amount of heat is absorbed on the upstream side of the combustion gas flow, the amount of heat absorbed in the vicinity of the outer smoke vent becomes extremely low.

[0003]

SUMMARY OF THE INVENTION The problem to be solved by the present invention is to make it possible to absorb a large amount of heat even in the vicinity of the outer smoke vent having a low combustion gas temperature.

[0004]

[Means for Solving the Problems] An annular upper pipe header and a lower pipe header are connected by two rows of water pipes, an inner water pipe row and an outer water pipe row, and a part of each water pipe row between adjacent water pipes is removed. By closing the inner water pipe row with the inner water pipe row, a combustion gas passage is formed between the inner water pipe row and the outer water pipe row, and the combustion gas passage communicates with the combustion chamber by the inner smoke passage provided in the inner water pipe row. In a multi-tube through-flow boiler that communicates with a flue by an outer smoke outlet provided in an outer water pipe row on the axially opposite side, a heat absorption fin perpendicular to the pipe axis direction in the outer smoke outlet portion of the outer water pipe row. Is provided to absorb a large amount of heat in the outer smoke vent portion.

[0005]

By providing a heat absorbing fin perpendicular to the pipe axis direction at the outer smoke outlet portion of the outer water pipe array, more heat can be absorbed, so that the water pipe can be used even if the combustion gas temperature is low. Can be efficiently heated.

[0006]

An embodiment of the present invention will be described with reference to the drawings.
An annular upper header 1 is provided on the upper part of the can body, and an annular lower header 2 is also provided on the lower part, and an inner water pipe row 3 and an outer water pipe row 4 arranged in an annular shape are connected between the upper and lower pipe headers. There is. The inner water pipe row 3 and the outer water pipe row 4 are closed by a closing fin 8 parallel to the pipe axis direction between adjacent water pipes, and combustion gas is provided between the inner water pipe row 3 and the outer water pipe row 4. A passage 7 is formed. A portion surrounded by the inner water pipe array 3 is a combustion chamber 9, and a burner 10 is provided above the combustion chamber 9. Inner water tube row 3
A combustion chamber 9 and a combustion gas passage 7 are communicated with each other by an inner smoke vent 5 without a fin 8 for closing, and the outer water pipe array 4
A flue 12 for discharging combustion gas and a combustion gas passage 7 are communicated with each other through an outer smoke passage 6 without the lower closing fin 8. A large number of heat absorbing fins 11 are provided in the outer smoke outlet 6 portion of the outer water pipe array 4 perpendicularly to the pipe axis direction. The upper and lower pipe pulling parts are covered with the refractory material 14, and the entire can body is covered with the heat insulating material 15.

When the burner 10 is combusted, combustion gas is generated in the combustion chamber 9, and first, the combustion chamber 9 of the inner water pipe array 3 is generated.
Heat the side surface. Then, the combustion gas reaches the inside of the combustion gas passage 7 through the inner smoke outlet 5, and heats the inside water pipe row 3 and the outside water pipe row 4 facing the combustion gas passage 7 while flowing in the combustion gas passage 7 from the upper part to the lower part. To do. When the combustion gas reaches the portion where the heat absorbing fins 11 are provided, the combustion gas heats the outer water pipe rows by intersecting with the outer water pipe rows, and at the same time, flows along the heat absorbing fins 11 to absorb the heat absorbing fins. 11 is heated, and the outer water pipe array 4 is heated through the heat absorbing fins 11. The water in the inner water pipe row 3 and the outer water pipe row 4 is heated by heating the water pipes, becomes steam, and is taken out through the upper header 1. The flue gas whose temperature has dropped passes through the flue 12. Is discharged.

If the heat absorbing fins provided at the outer smoke vent 6 are made larger toward the downstream side of the combustion gas, the heat can be absorbed more effectively.

[0009]

By implementing the present invention, heat can be effectively absorbed even from the combustion gas having a lowered temperature, and the efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

2 is a sectional view taken along line AA of FIG.

[Explanation of reference numerals] 1 upper pipe head 2 lower pipe pipe 3 inner water pipe row 4 outer water pipe row 5 inner smoke outlet 6 outer smoke outlet 7 combustion gas passage 8 closing fin 9 combustion chamber 10 burner 11 heat absorption fin 12 Flue 13 Refractory 14 Insulation

Claims (1)

[Claims] 1. An annular upper and lower pipe header is connected by two rows of water pipes, an inner water pipe line and an outer water pipe line, and the adjacent water pipes of each water pipe line are closed except for a part thereof. , A combustion gas passage is formed between the inner water pipe row and the outer water pipe row, and the combustion gas passage communicates with the combustion chamber by the inner smoke passage provided in the inner water pipe row, and is opposite to the inner smoke passage in the axial direction of the pipe. In a multi-tube through-flow boiler that communicates with a flue by an outer smoke outlet provided in the outer water pipe row, a heat absorbing fin that is perpendicular to the pipe axis direction is provided in the outer smoke outlet portion of the outer water pipe row. A multi-tube once-through boiler characterized by.