JPS5932801Y2 - Multi-tube once-through boiler - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a multi-tube once-through boiler with improved heat transfer.

Conventionally, in a multi-tube once-through boiler, the upper and lower ends of the internal water pipe group and the external wood pipe group were connected to the upper and lower headers to form an appropriate space between the water pipe groups, and the adjacent wood pipes in each water pipe group were connected. A space is created between the circumferential sides of the reduced diameter parts of the adjacent water pipe groups by bringing the circumferential sides as close as possible and using a part of each wood pipe of the internal wood pipe group and one end of each water pipe of the external water pipe group as a diameter reducing part, respectively. The boiler which formed this is publicly known (Japanese Utility Model Publication No. 44-2803).

The purpose of this invention is to provide a multi-tubular once-through boiler with good heat transfer by improving the conventionally known structure.

The multi-tube through boiler of this invention connects the inner and outer water tubes with a spacer, and provides a large number of protrusions for promoting heat transfer on the surface of the water tube facing the combustion gas flow path to direct the combustion gas in the tube axis direction. This feature is characterized by the fact that the flow is made to flow smoothly.

Examples of this invention will be described below based on the drawings.

Fig. 1 is a longitudinal sectional view showing an embodiment of this invention, Fig. 2 is a II-II sectional view, Fig. 3 is an enlarged cross-sectional view of the main part, Fig. 4 is an enlarged side view of the main part, and Fig. 5 is ■-V sectional view, Figure 6 is v
It is a sectional view taken along I-v■.

A plurality of internal water pipes 1 are vertically arranged at slight intervals in a state surrounding a combustion chamber 3.

A smoke vent 13 is provided near the lower end of at least a portion of the first group of internal water pipes.
An internal spacer 2 is provided in the gap to close it, leaving a gap to form a combustion chamber 3 inside.

Of course, the spacer 2 may be composed of a fin.

A plurality of external water pipes 4 are vertically arranged on the outer periphery of the smoke port 13 at slight intervals.

A smoke vent 14 is provided near the upper end of at least a portion of the 4 groups of external water pipes.
An external spacer 5 is provided in the gap to close the gap, and a combustion gas flow path 6 extending in the tube axis direction is formed between the first group of internal wood pipes and the fourth group of external water pipes.

Of course, the spacer 5 may be composed of a fin.

A large number of heat transfer promoting protrusions 7 are provided on the surface of the water pipe 1.4 in the portion facing the combustion gas flow path 6 side.

This protrusion 7 is preferably provided so as to disturb the temperature boundary layer of the combustion gas flow path 6.

The upper and lower ends of the first group of internal wood pipes and the four groups of external water pipes are communicated with an upper header 8 and a lower header 9, respectively.

A combustion device 10 is arranged inside the upper header 8.

Reference numeral 11 denotes a boiler casing that surrounds one group of internal water pipes and four groups of external wood pipes, and a flue 12 is provided in a part of the casing.

Thus, the combustion chamber communicates with the flue 12 through the smoke vent 13, the combustion gas flow path 6, and the smoke vent 14.

In addition, in the case of such a boiler, the smoke vent 13 of the first group of internal wood pipes
It is also possible to change the structure by vertically inverting the positions of the smoke vents 14 of the four groups of external wood pipes, the combustion device 10, etc.

In the multi-tubular once-through boiler according to this invention, the combustion device 1
The combustion gas generated at 0 first undergoes radiant heat transfer within the combustion chamber 3.

This combustion gas passes through the smoke port 13 of the internal water pipe 1 and reaches the combustion gas flow path 6.

Further, the combustion gas rises through the flow path 6 while heating the water pipes 1 and 4, passes through the smoke port 14 of the external water pipe 4, and enters the casing 1.
It is discharged to the outside through a flue 12 provided in a part of 1.

Combustion gas flow path 6 formed by internal water pipe 1 and external water pipe 4
In this case, due to the spacers 2 and 5, a dead area of combustion gas (an area where gas stagnates between wood pipes arranged at a slight interval) is not generated, and heat transfer is good.

In addition, the water pipes 1 and 4 in the portion facing the combustion gas flow path 6 side are
Since a large number of protrusions 7 are provided on the surface, the temperature boundary layer is disturbed and heat transfer there is also good.

As explained above, this invention can provide a small and highly efficient multi-tubular once-through boiler with good heat transfer.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view showing an embodiment of this invention, Fig. 2 is a II-II sectional view, Fig. 3 is an enlarged cross-sectional view of the main part, Fig. 4 is an enlarged side view of the main part, and Fig. 5 is ■-■ cross-sectional view, Figure 6 is V
It is an I-VI sectional view. 1... Internal woodwind, 2... Internal spacer, 3... Combustion chamber, 4... External woodwind,
5...External spacer, 6...Combustion gas flow path, 7...Protrusions for promoting heat transfer, 8...
... Upper header, 9... Lower header, 13.
...Smoke vent, 14...Smoke vent.

Claims (1)

[Claims for Utility Model Registration] (a) A plurality of internal water pipes 1 are arranged vertically with slight intervals surrounding the combustion chamber 3. (b) A smoke vent 13 is left near the lower end of at least a portion of the group of internal wood pipes 1, and an internal spacer 2 is provided in the gap to close it. (c) A plurality of external water pipes 4 are vertically arranged on the outer periphery of the smoke vent 13 at slight intervals. (d) A smoke vent 14 is left near the upper end of at least a portion of the four groups of external wood pipes, and an external spacer 5 is provided in the gap to close it, and the pipe axis is provided between the first group of internal wood pipes and the external water pipes 4. A combustion gas flow path 6 extending in the direction is formed. (E) Water pipe 1 in the portion facing the combustion gas flow path 6 side
, 4 are provided with a large number of protrusions 7 for promoting heat transfer. (f) The upper and lower ends of the first group of internal woodwinds and the four groups of external woodwinds are communicated with the upper header 8 and the lower header 9, respectively. A multi-tube once-through boiler configured as described above.