JPH064164Y2 - Multi-tube once-through boiler - Google Patents

Description

TECHNICAL FIELD The present invention relates to a multi-tube once-through boiler, and more specifically, to a large number of inner-row heating tubes and a large number of inner-row heating tubes arranged upright around a combustion chamber. In a shell-and-tube once-through boiler having a combustion gas passage during outer row heating, the gas inlet portion of the combustion gas passage is improved.

2. Description of the Related Art Conventionally, a multi-tube once-through boiler has a combustion chamber, a large number of inner row heating pipes arranged upright around the combustion chamber, a plurality of similar outer row heating pipes, and the combustion chamber. Combustion gas emitted from the combustion chamber has a combustion gas passage passing between the inner row heating pipe and the outer row heating pipe, and an upper pipe side and a lower pipe side supporting the both heating pipes. The gas inlet portion of the passage is provided to the inner row heating pipe, and the gas outlet portion of the combustion gas passage is provided to the outer row heating pipe. And, for example, Shokai 6
No. 0-101505, there is no inner-row shield fin at the gas inlet of the combustion gas passage, and the inner-row heating pipe is open over the entire length, for example, , JP-B-58-41402
As described in Japanese Patent Laid-Open Publication No. JP-A No. 2003-242, it is known that the lower part, which is open over its entire length, is covered with a refractory material or the refractory material is provided with small holes.

Problems to be solved by the invention In a multi-tube once-through boiler, as is well known, water is supplied to the lower pipe side and steam is taken out from the upper pipe side. Yes, as it goes up, it becomes hot water, boils and becomes steam. That is, inside each heating tube, the lower the temperature is, the higher the temperature is. Therefore, in order to obtain a large amount of heat with a limited heat transfer area, it is desirable to make the lower temperature lower part of each heating tube contact a large amount of combustion gas. At the gas inlet of the gas passage, the conventional one having an opening over the entire length of the inner row heating pipes does not positively allow a large amount of combustion gas to pass through the lower portion of the heating pipes, and thus the limited heat transfer. In addition to being unfavorable in terms of effective heat transfer in the area, both radiant heat from the combustion chamber and contact heat due to passage of combustion gas are concentrated near the opening, that is, in-row heating on both sides of the opening. There is a problem in that the tubes, the outer row heating tubes at the back of the opening, and the outer row shield fins on both sides of the tube concentrate on each upper part. Moreover, as mentioned above, if the lower part of the opening is covered with refractory,
It is effective in changing the direction of the combustion gas flow, but in terms of effective heat transfer action in a limited heat transfer area, it is completely unfavorable, and there is a problem that the above heat concentration is remarkable. is there. In addition, between the upper side of the inner row heating tube and the upper tube side,
By providing means for preventing the inflow of the combustion gas from the combustion chamber and positively allowing the inflow of the combustion gas between the lower side of the inner row heating tubes and the vicinity of the lower tube, the heat concentration can be improved. Although it will be mitigated, a new problem will occur that the heat collection balance will not be uniform. The present invention aims to solve such problems.

Means for Solving the Problems At the gas inlet portion of the combustion gas passage between the inner row heating pipe and the outer row heating pipe, the inner row shield fin is provided between the upper side of the inner row heating pipe and the upper pipe side. And the inner row shield fins are not provided between the lower side of the inner row heating pipe and the lower tube side,
It was an opening. Further, the inner row shield fins and the openings are intermittently provided between the openings and the uppermost inner row shield fins.

Action At the gas inlet of the combustion gas passage, there is an inner row shield fin between the upper side and the upper tube side of the inner row heating pipe, and the lower side and the lower tube side of the inner row heating pipe are provided. In between
Since it has an opening, the high-temperature combustion gas flowing from the combustion chamber into the combustion gas passage is blocked by the inner-row shield fins on the upper side of the inner-row heating pipes, and the lower part of the inner-row heating pipes is positively blocked. From the side opening. Therefore,
The high-temperature combustion gas comes into contact with a lower temperature lower portion of each heating tube, and a relatively large amount of heat can be collected in a limited heat transfer area. Further, the concentration of heat in the portion that tends to become high in heat at the gas inlet portion is avoided, overheating of that portion is prevented, and thermal stress is relieved.
Moreover, since the inner-row shield fins and the openings are intermittently provided between the openings and the uppermost-side inner-row shield fins, a part of the combustion gas is intermittently provided in the openings. Flows into the middle part of the gas passage to bring the heat collection balance closer evenly.

Embodiment FIG. 1 shows an embodiment of the present invention, and FIGS. 2 and 3 show a part of it in an enlarged scale.

In FIG. 1, 1 is a combustion chamber, 2 is a large number of inner-row heating pipes arranged upright around the combustion chamber 1 and arranged in an annular shape, 3
Is a large number of outer row heating pipes arranged in the same manner on the outer circumference of the inner row heating pipe 2, and 4 is the combustion gas emitted from the combustion chamber 1 between the inner row heating pipe 2 and the outer row heating pipe 3. Combustion gas passages flowing along the annular shape, 5 is an upper pipe side supporting the upper portions of the inner row heating pipes 2 and the outer row heating pipes 3, and 6 is the inner row heating pipes 2 and the outer row heating pipes 3 Reference numeral 7 is a burner supporting the lower portion, and 7 is a burner.

In FIG. 2, 8 is an inner row shield fin, 9 is an outer row shield fin, 10 is a gas inlet portion of the combustion gas passage 4 provided in the inner row heating pipe 2, and 11 is the outer row heating pipe. 3 is a gas outlet portion of the combustion gas passage 4 provided on the side of FIG.

In FIG. 3, reference numeral 12 is a portion where the inner row shield fins 8 are not provided, that is, an opening.

That is, in the gas inlet portion 10 of the combustion gas passage 4, as shown in FIG. 3, the combustion gas from the combustion chamber 1 is provided between the uppermost side of the inner row heating pipe 2 and the upper pipe side 5. Has an inner-row shield fin 8 for preventing the inflow of the combustion gas, and positively allows the inflow of the combustion gas from the combustion chamber 1 between the lowermost portion of the inner-row heating pipe 2 and the lower pipe portion 6. Opening 12
Further, an inner row shield fin 8'and an opening 12 'are intermittently provided between the innermost shield fin 8 on the uppermost side and the opening 12 on the lowermost side.

In the multi-tube type once-through boiler configured as shown,
At the gas inlet portion 10 of the combustion gas passage 4, an inner row shield fin 8 is provided between the uppermost side of the inner row heating pipe 2 and the upper pipe side 5, and the lowermost side and lower portion of the inner row heating pipe 2 are provided. Since the opening portion 12 is provided between the pipe sections 6 and the inner row shield fins 8'and the opening portions 12 'which are intermittently provided in the middle portion, the combustion chamber 1 to the combustion gas passage 4 are provided. The high temperature combustion gas flowing into the inner row heating pipe 2 is blocked by the inner row shield fins 8 on the uppermost side, and only a part of the combustion gas flows into the combustion gas passage 4 through the opening 12 ′ in the intermediate portion. But
Most of the combustion gas flows into the combustion gas passage 4 through the lowermost opening 12. Therefore, the hot combustion gas is
Since the inner row heating pipes 2 and the outer row heating pipes 3 come into contact with lower portions of low temperature, a relatively large amount of heat can be collected in a limited heat transfer area. Further, as described above, since the high-temperature combustion gas makes a large contact with the lower portion having a low temperature, the inner row heating pipes 2 in the gas inlet portion 10 and the outer row heating pipes at the back of the gas inlet portion 10 which tend to concentrate heat in the past 3. Since heat does not concentrate on the upper portions of the outer row shield fins 9 on both sides, overheating of that portion is prevented and thermal stress is relieved.
Longer life. Moreover, since the upper part of the inner row heating pipe 2 and the upper part of the outer row heating pipe 3 in the gas inlet part 10 do not receive much contact heat due to the passage of the combustion gas, the water level is lowered at the time of starting the boiler with fast boiling. It is possible to prevent the boiling water from being taken out to the steam. Especially,
By providing the opening 12 'in the middle part, a part of the combustion gas flows into the middle part of the combustion gas passage 4 from the opening 12', so that the heat collection balance can be made closer evenly.

Effect of the Invention The present invention is directed to the upper side of the inner row heating pipes and the upper tube side of the inner row heating pipes at the gas inlet portion of the combustion gas passage through which combustion gas flows between the inner row heating pipes and the outer row heating pipes in a multi-tube once-through boiler. Has an inner-row shield fin that blocks the inflow of the combustion gas from the combustion chamber, and positively allows the inflow of the combustion gas between the lower side of the inner-row heating pipe and the vicinity of the lower pipe. Since it has an opening portion, the high temperature combustion gas flowing into the combustion gas passage from the combustion chamber is blocked by the inner row shield fins on the upper side of the inner row heating pipe, and the combustion gas is actively It flows into the combustion gas passage from the opening on the lower side of the row heating pipe. Therefore, the high-temperature combustion gas comes into contact with the lower temperature lower portions of the inner row heating pipes and the outer row heating pipes, and a relatively large amount of heat can be obtained in a limited heat transfer area. it can. Further, it is possible to prevent heat from concentrating on a portion that tends to become hot at the gas inlet portion, prevent overheating of that portion, reduce thermal stress, and provide a long-life boiler. Moreover, it is possible to lower the set water level at the time of starting the boiler, and it is possible to provide a boiler that does not bring out boiling water to the steam at the time of starting. Particularly, in the present invention, since the inner row shield fins and the openings provided intermittently are provided between the openings and the uppermost inner row shield fins, there is an intermittent discontinuity in the vertical middle portion of the gas passage. Since the opening is provided in the combustion chamber, a part of the combustion gas flows into the combustion gas passage intermediate portion from the intermittently provided opening, and therefore it is possible to equalize the heat collection balance. Become,
The thermal efficiency is improved, and it is possible to provide a boiler having a long life.

[Brief description of drawings]

FIG. 1 is a sectional front view showing an embodiment of the present invention, FIG. 2 is an enlarged sectional plan view taken along the section line II-II in FIG. 1, and FIG. 3 is an arrow line III-III in FIG. It is a partially notched deployment front view seen. 1 ... Combustion chamber, 2 ... Inner row heating tube, 3 ... Outer row heating tube,
4 ... Combustion gas passage, 5 ... Upper pipe, 6 ... Lower pipe, 7 ... Burner, 8, 8 '... Inner row shield fin,
9 ... Outer row shield fin, 10 ... Gas inlet, 11
...... Gas outlets, 12, 12 '... Openings.

Continued Front Page (72) Inventor Yukinobu Kawaoka 4-41 Showa-cho, Kure-shi, Hiroshima Within Ishikawajima General-purpose Boiler Co., Ltd. (56) References (JP, B2)

Claims (1)

[Scope of utility model registration request] 1. A large number of inner row heating pipes and a plurality of outer row heating pipes which are erected upright around a combustion chamber and arranged in an annular shape, and which are supported by an upper pipe side and a lower pipe side. Then
Moreover, the combustion gas flowing out from the combustion chamber has a combustion gas passage flowing between the inner row heating pipe and the outer row heating pipe, and the gas inlet portion of the combustion gas passage is closer to the inner row heating pipe. And the gas outlet portion of the combustion gas passage is provided at the gas inlet portion of the combustion gas passage in the multi-tube type once-through boiler, which is provided toward the outer row heating pipe. Between the upper side and the upper tube side, there is an inner row shield fin for blocking the inflow of combustion gas from the combustion chamber, between the lower side of the inner row heating tube and the lower tube side, An inner row shield fin and an opening which are provided intermittently between the opening and the uppermost inner row shield fin are provided to positively allow the inflow of combustion gas from the combustion chamber. A multi-tube once-through boiler, characterized by having a section.