JPH0711284Y2 - Multi-tube once-through boiler - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to a multi-tube once-through boiler which is improved so as to efficiently recover heat from combustion gas, and in particular, a multi-tube type having a double row of annular water tubes. It is about a once-through boiler.

2. Description of the Related Art Conventionally, in a generally used multi-tube through-flow boiler, as shown in FIG. 5 to FIG. 7, an annular upper pipe header (1) and a lower pipe header (2) are provided. Multiple vertical water pipes (3), (6) are connected to form a double row of annular water pipes. And the water pipe (6) of the outer water pipe row is arranged at a position facing the gap of the inner water pipe row with a space from the water pipe (3) of the adjacent inner water pipe row, and the water pipe (6) of the outer water pipe row is , The pitch angle (B) is equal to the pitch angle (A) of the water pipes (3) of the inner water pipe row, and the water pipes (3) are arranged with a shift of a half pitch angle from the position of the water pipes (3). Furthermore, the water tubes (6) of the outer water tube row have a smaller diameter than the water tubes (3) of the inner water tube row. A combustion chamber (4) is formed in the inner space of the inner water pipe array, and a burner (5) is attached to the center of the upper opening of the combustion chamber (4) so as to project downward in the combustion chamber (4). Has been.

Outside the outer water pipe array, between the upper pipe assembly (1) and the lower pipe assembly (2), a cylindrical outer wall (7) that surrounds the outer water pipe array over the entire length is spaced from the outer water pipe array. It is provided in advance. A combustion gas exhaust port (8) is formed in a part of the outer wall (7).

Also, the combustion chamber (4) and the outer space (9) of the outer water tube row.
Are communicated with each other by a combustion gas flow path (10) from the gap of the inner water pipe row to the gap of the outer water pipe row through the gap between the inner water pipe row and the outer water pipe row.

In the boiler having such a configuration, the water pipes (3) of the inner water pipe row are heated by the radiant heat of the flame of the burner (5) radiated into the combustion chamber (4) and the heat conduction of the convection of the combustion gas, while the outside The water pipe (6) of the water pipe array is
It is heated by the high temperature combustion gas passing through the combustion gas passage (10).

In this case, in order to make the heat load uniform between the water pipes (3) of the inner water pipe row and the water pipes (6) of the outer water pipe row, the diameter of the water pipe (6) is made smaller than that of the water pipe (3). Despite the fact that the heat load is not sufficiently uniformed, scale adhesion and corrosion concentrate on the water pipe (3), and further, from the combustion chamber (4) through the combustion gas flow path (10) to the outside. However, there is a problem that heat cannot be efficiently recovered from the combustion gas discharged to the exhaust gas and a considerable amount of fuel is wasted.

Therefore, in order to eliminate this drawback, the combustion gas flow path (1
A baffle plate can be attached to the inside of (0) to efficiently recover heat from the combustion gas, and the heat load can be made uniform between the water pipes (3) of the inner water pipe row and the water pipes (6) of the outer water pipe row. A multi-tube once-through boiler has been devised.

For example, in Japanese Utility Model Publication No. 62-185301, FIG.
In the multi-tube once-through boiler described with reference to FIG. 7, as shown in FIG. 8, water pipes (6) are provided on the left and right side surfaces of the water pipes (6) of the outer water pipe row facing the water pipes (3) of the inner water pipe row. ), A pair of baffle plates (11) extending substantially along the generatrix direction are provided. Each of these pairs of baffles (1
1) has a cross-sectional shape that protrudes in a V shape when viewed from the outside of the water pipe (6) and the tip reaches near the center of the gap of the outer water pipe array.

In this way, after the combustion gas passes through the gap between the water pipes (3) adjacent to each other, the combustion gas is divided into left and right, passes through the gap between the tips of the adjacent baffle plates (11), and is discharged to the outside. There is.

Further, in the multi-tube once-through boiler described in FIGS. 5 to 7, as shown in FIG. 9, each combustion gas passage (10) has substantially the same length as the water pipe (6) of the outer water pipe row. And a lateral cross-section that is branched from both sides while projecting outward from the central portion of the gap of the outer water pipe row and partially encircles adjacent water pipes (6) at equal intervals. A baffle plate (13) having a shape and a baffle plate (13) adjacent to each other over substantially the entire length along the generatrix direction of each water pipe (6) of the outer water pipe row, as shown in FIG. Attached to the water pipe (6) in a substantially tangential direction on the outer periphery of the outer water pipe row so as to close the gap of the outer water pipe row and attached at a tip end thereof to the adjacent water pipe (6). There is.

However, in the configuration of the baffle plate shown in FIG. 8 described above, the baffle plate (11) is heated by receiving the combustion gas passing through the combustion gas passage (10), The heat received by the baffle plate (11) is conducted from its base end to the water pipe (6) of the outer water pipe row, but on the other hand, the area of the water pipe portion directly heated by the combustion gas is reduced, which is effective. It cannot be said that it is a thing.

In the baffle plate (12) shown in FIG. 9, the combustion gas is guided by the baffle plate (12) and flows so as to surround the water pipe (6), and the water pipe (6) and the baffle plate (12) are Although it is effectively heated, the heat recovered from the combustion gas by the baffle plate (12) is not conducted to either the water pipe (3) of the inner water pipe row or the water pipe (6) of the outer water pipe row. It has drawbacks.

Further, in the case of the baffle plate (13) shown in FIG. 10, there is a drawback that effective heat transfer is performed only near the tip portion of the baffle plate (13).

Therefore, in view of the above, an object of the present invention is to provide a multi-tube once-through boiler equipped with a baffle plate having a simple structure, which is capable of efficiently recovering heat from combustion gas, instead of the conventional one. Is to provide.

Means for Solving the Problems To achieve the above object, the structure of the present invention has a double structure in which the upper header and the lower header are connected by a plurality of vertical water pipes spaced from each other. An annular water tube row is formed, and the water tubes of the outer water tube row are arranged at a position facing the gap of the inner water tube row with a space from the water tubes of the adjacent inner water tube row, and the inner space of the inner water tube row is used as the combustion chamber to burn. In a multi-tube once-through boiler in which the chamber and the outer space of the outer water tube row are connected by a combustion gas flow path from the gap of the inner water tube row to the gap of the outer water tube row through the gap between the inner water tube row and the outer water tube row , A pair of baffle plates extending along substantially the entire length along the generatrix direction is provided on the outer peripheral surface of each water pipe of the inner water pipe row, and each pair of the baffle plates is an inner water pipe row in the cross section of the boiler. From the water pipe to the outer water pipe After radially projecting into the gap between the rows, the water pipes of the adjacent outer water pipe rows extend to the outer space of the outer water pipe rows while partially encircling the water pipes from the adjacent outer water pipe rows, and partially encircling the baffle plate. The multi-tube once-through boiler is characterized in that the gap between the deflected outer water pipe row and the water pipe forms a part of the combustion gas passage.

In addition, the diameter of the water pipe of the inner water pipe row may be configured to be larger than the diameter of the water pipe of the outer water pipe row, and in this case, between the water pipe of the inner water pipe row and the water pipe of the outer water pipe row. It is possible to effectively equalize the heat load.

Action In the above configuration, the water tubes of the inner water tube row are heated by the radiant heat of the flame of the burner radiated into the combustion chamber and the convection of the combustion gas.

Further, the combustion gas enters the combustion gas passage from the gap of the inner water pipe row, passes through the gap between the baffle plate and the outer circumference of the water pipe of the outer water pipe row, and flows so as to surround the outer circumference of the water pipe of the outer water pipe row, It is discharged to the outside from the gap between the leading edges of the adjacent baffle plates. At this time, the combustion gas heats the water pipes and the baffle plates of the outer water pipe row. The heat received by the baffle plate is conducted from its base end portion to the water pipes of the inner water pipe row, and assists the heating of these water pipes.

In this case, generally, if the flow velocity of the combustion gas is higher,
Since the heat transfer effect from the combustion gas to the water pipes of the outer water pipe row and the baffle plate also becomes large, the distance between the baffle plate and the water pipes of the outer water pipe row and the length of the baffle plate should be set to the value of the combustion gas passing through the combustion gas flow path. It is preferable to preset the speed so that it increases as much as possible.

Furthermore, when the diameter of the water pipes of the inner water pipe row is made larger than the diameter of the water pipes of the outer water pipe row, the heat load between the water pipes of the inner water pipe row and the water pipes of the outer water pipe row is more effectively equalized. be able to.

Embodiment An embodiment of the present invention is an improvement of the structure of the baffle plate in the conventional double water pipe array structure already described with reference to FIGS. 5 to 7. Therefore, only the structure of the baffle plate will be described, and the same components as those of the conventional example will be denoted by the same reference numerals and description thereof will be omitted.

FIG. 1 and FIG. 2 are cross-sectional views showing an embodiment of the present invention, in which the outer portion of each water pipe (3) of the inner water pipe array extends substantially along the generatrix direction of the water pipe (3). A pair of extending deflecting plates (14) are provided. Each of the pair of baffles (14) radially projects through the gap between the outer water pipe rows, and the water pipes (6) of the outer water pipe rows adjacent to each other at the tip end thereof are
The water pipe (6) has a cross-sectional shape that is partially bent to the front of the center of the portion forming the outer water pipe row outer periphery while gradually narrowing the interval with the water pipe (6). Thus
The combustion gas is guided by the baffle plate (14) and passes through the combustion gas passage (10) at a substantially constant flow velocity.

In the above configuration, the water pipe (3) of the inner water pipe row is heated by the radiant heat of the flame of the burner radiated into the combustion chamber and the convection of the combustion gas, as in the conventional example.

Combustion gas flows from the gap in the inner water tube row to the combustion gas flow path (10).
Enters the inside, flows through the gap between the baffle plate (14) and the outer circumference of the water pipe (6) of the outer water pipe row, and flows so as to surround the outer circumference of the water pipe (6). Is released to. At this time, the combustion gas heats the water pipe (6) and the baffle plate (14). The heat received by the baffle plate (14) is transferred from the base end portion to the water pipe (3) of the inner water pipe row, and assists the heating of the water pipe (3).

In this case, generally, if the flow velocity of the combustion gas is higher,
Since the heat transfer effect from the combustion gas to the water pipe (6) and the baffle plate (14) is also increased, the baffle plate (14) and the water pipe (6)
It is preferable to preset the interval between and and the length of the baffle plate so that the velocity of the combustion gas passing through the combustion gas passage is increased as much as possible.

In this way, heat can be efficiently recovered from the combustion gas passing through the combustion gas flow path (10), fuel can be saved, and between the water pipe (3) of the inner water pipe row and the water pipe (6) of the outer water pipe row. Thus, the heat load can be made uniform, and scale adhesion and corrosion can be prevented from concentrating on the water pipes (3) of the inner water pipe row.

FIG. 3 is a sectional view showing another embodiment of the present invention,
A pair of baffle plates (15) extending over substantially the entire length along the generatrix direction of the water pipes (3) are provided on the outer portion of each water pipe (3) of the inner water pipe row. Each of these pair of baffles (15) protrudes so that the gaps between the outer water pipe rows are parallel to each other, and the water pipes (6) of the adjacent outer water pipe rows are connected to each other at their tip portions by the outer water pipe rows in the water pipe (6). It has a cross-sectional shape that partially bends to a position in front of the center of the portion that forms the outer periphery while keeping the same interval as the water pipe (6).

In this embodiment, the design and installation of the baffle plate is easier than in the embodiment of FIGS. 1 and 2.

FIG. 4 shows still another embodiment of the present invention, in which a pair of a pair of water pipes (3) extending along the generatrix direction of the water pipes (3) extend over substantially the entire length of the inner water pipe row. A baffle plate (16) is provided. Each of the pair of baffles (16) protrudes so that the gap between the outer water pipe rows becomes substantially V-shaped, and the water pipe (6) that is adjacent to the water pipe (6) once at the tip thereof.
Crossing that bends to the side and partially encircles the water pipe (6) to a position in front of the center of the portion of the water pipe (6) that forms the outer circumference of the outer water pipe row while maintaining a predetermined distance from the water pipe (6). It has a surface shape.

In the case of this embodiment, the design and installation of the baffle plate are easy, and the same effect as that of the embodiment described in FIG. 2 can be obtained.

As described above, according to the present invention, the combustion gas discharged from the combustion chamber through the combustion gas flow path to the outer space of the outer water tube row is guided by the baffle plate and is discharged from the water tube of the outer water tube row. By flowing so as to surround the outer circumference, the water pipes of the outer water pipe row are efficiently heated. At the same time, the baffle plate itself is also heated by the combustion gas, and the heat received by the baffle plate from the combustion gas is transferred from the base end of the baffle plate to the water pipes in the inner water pipe row, and the water pipes in the inner water pipe row are heated. Assist.

In this way, heat can be efficiently recovered from the combustion gas, fuel can be saved, and heat load can be made uniform between the water pipes of the inner water pipe row and the water pipes of the outer water pipe row. As a result, it is possible to prevent scale adhesion and corrosion from concentrating on the water pipes of the inner water pipe row.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a partially enlarged view of FIG. 1, and FIG. 3 is a sectional view showing another embodiment of the present invention. FIG. 5 is a sectional view showing still another embodiment of the present invention, FIG. 5 is a vertical sectional view showing a conventional multi-tube once-through boiler, and FIG. 6 is a cross-sectional view of the conventional multi-tube once-through boiler. Fig. 7, Fig. 7 is a partially enlarged view of Fig. 6, Fig. 8 is a sectional view showing the structure of a conventional deflector, and Fig. 9 is a sectional view showing another structure of the conventional deflector. FIG. 10 is a cross-sectional view showing still another configuration of the conventional baffle plate. (1) …… Upper heading (2) …… Lower heading (3) …… Inner water tube row water tube (4) …… Combustion chamber (6) …… Outer water tube row water tube (9) …… Outer space (10) …… Combustion gas flow path (14), (15), (16) …… Baffle plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shigehiro Watanabe 7 Horie-cho, Matsuyama-shi, Ehime Prefecture Miura Kogyo Co., Ltd. (72) Inventor Norio Anno 7 Horie-cho, Matsuyama-shi, Ehime Pref. Miura Kogyo Co., Ltd. (56) References: Actual Development Sho 61-192103 (JP, U)

Claims (2)

[Scope of utility model registration request] 1. An upper part header (1) and a lower part header (2)
Are connected to each other by a large number of vertical water pipes (3) and (6) arranged at intervals to form a double annular water pipe row, and the water pipes of the outer water pipe row are located at positions facing the gaps of the inner water pipe row ( 6) is arranged at a distance from the water pipes (3) of the adjacent inner water pipe rows, and the inner space of the inner water pipe rows serves as a combustion chamber (4), and the combustion chamber (4) and the outer water pipe row are outside. A multi-tube type in which a space (9) is communicated by a combustion gas flow path (10) from the gap of the inner water pipe row to the gap of the outer water pipe row through the gap between the inner water pipe row and the outer water pipe row. In a once-through boiler, a pair of baffle plates (1) extending over substantially the entire length along the generatrix direction on the outer peripheral surface of each water pipe (3) of the inner water pipe row.
4), (15), (16) are provided, wherein each pair of the baffles (14), (15), (16) is a water pipe of the inner water pipe row in a cross section of the boiler. After radially projecting from (3) into the gap of the outer water pipe row, the water pipe (6) of the adjacent outer water pipe row is partially encircled and spaced apart from the water pipe (6), and the outer space of the outer water pipe row is partially bent. It extends to (9), and the baffle plates (14), (15),
The gap between the (16) and the water pipe (6) of the outer water pipe row which is partially surrounded by this is defined by the combustion gas flow path (1).
A multi-tube once-through boiler characterized by being a part of (0). 2. The multi-tube flow-through according to claim 1, wherein the diameter of the water pipe (3) of the inner water pipe row is larger than the diameter of the water pipe (6) of the outer water pipe row. boiler.