JP6752023B2 - Boiler with spiral heat transfer tube - Google Patents

Description

The present invention relates to a boiler having a spiral heat transfer tube, and more specifically, by making a coil, which is a cylindrical heat transfer tube wall in which the heat transfer tube is spirally wound, double, to form an inner coil. The present invention relates to a boiler having a spiral heat transfer tube having an annular combustion gas passage between the outer coils and allowing combustion gas to flow through the combustion gas passage to heat the inner coil and the outer coil.

As described in Japanese Patent Application Laid-Open No. 52-29642, there is known a boiler in which a can body is formed by a cylindrical heat transfer tube wall in which a heat transfer tube is spirally wound. This boiler has a double coil, which is a cylindrical heat transfer tube, and is installed with a gap between the inner coil and the outer coil to provide an annular combustion gas passage between the inner coil and the outer coil. .. The central part of the can body surrounded by the coil is used as a combustion chamber, and combustion is performed in the combustion chamber by a combustion device provided in the upper part of the combustion chamber, and the heat medium in the heat transfer tube is heated by the heat generated by the combustion. The lower part of the inner coil is installed with a space between it and the bottom of the combustion chamber, and the upper part of the outer coil is installed with a space between it and the upper part of the boiler, so that the combustion gas passage between the inner and outer coils is centered at the bottom. It connects to the combustion chamber on the side and connects to the exhaust stack that connects to the outside of the boiler at the top. The combustion gas generated in the combustion chamber enters the combustion gas passage from the bottom of the combustion chamber, and when it flows upward in the combustion gas passage, it heats the heat transfer tube facing the combustion gas passage and from the upper part of the combustion gas passage. It is discharged to the outside of the boiler.

In the boiler described in Japanese Patent Application Laid-Open No. 52-29642, a spacer having the same width as the passage is installed in the combustion gas passage. In a boiler that has a combustion gas passage between the inner coil and the outer coil installed in duplicate, the inner coil and the outer coil are assembled eccentrically, and if the width of the combustion gas passage differs depending on the location, the flow of the combustion gas is biased. , The amount of heat absorbed by the heat transfer tube is significantly reduced. If a spacer is installed and the distance between the inner coil and the outer coil is unified to the width of the spacer, the distance between the inner coil and the outer coil can be made constant, and the uneven flow of the combustion gas flow in the combustion gas passage is eliminated. The heat transfer tube facing the combustion gas passage can be efficiently heated.

When assembling this boiler, the heat transfer tube is usually bent by a pipe bender to make an inner coil and an outer coil, and the can body is formed by combining the inner coil and the outer coil. When installing a spacer between the inner and outer coils, either fix the spacer on the outside of the inner coil and then cover the outer coil, or insert the spacer after assembling the inner and outer coils. If the width is the same as the width of the combustion gas passage, there is a problem that the workability of assembly is deteriorated. On the other hand, if the width of the spacer is narrower than the width of the combustion gas passage, the effect as a spacer is reduced, and if the inner and outer coils are eccentric, the heat transfer efficiency is reduced.

Jikkai Sho 52-29642

An object to be solved by the present invention is to provide a boiler having a spiral heat transfer tube capable of both preventing eccentricity of the inner and outer coils and improving workability at the time of assembly.

It has an inner coil and an outer coil, which are double cylindrical heat transfer tube walls in which the heat transfer tube is wound spirally, and the central part of the can body surrounded by the double coils is used as the combustion chamber, and it is generated in the combustion chamber. Combustion gas is burned in the combustion gas passage in the boiler that heats the heat medium flowing in the heat transfer tube by passing through the combustion gas passage provided between the inner coil and the outer coil. The heat transfer tube at the end of the inner coil, which is the start point of the combustion gas passage sandwiched between the inner coil and the outer coil, and the end of the outer coil, which is the end point of the combustion gas passage, are elongated in the vertical direction, which is the gas flow direction. The spacer first member, which is a rod-shaped member having a length that reaches both of the heat transfer tubes, and the plate-shaped member, which has a shorter vertical length than the first spacer member, which is the direction of combustion gas flow in the combustion gas passage. A spacer composed of a spacer second member, which is a member, is installed. The spacer first member and the spacer second member are thinner than the width of the combustion gas passage, respectively, and the spacer first member and the spacer second member are used. By overlapping, the width of the combustion gas passage is obtained, and by overlapping the spacer first member and the spacer second member, a predetermined distance is secured between the inner coil and the outer coil. And.

By implementing the present invention, in a boiler having a spiral heat transfer tube, eccentricity during assembly of the inner and outer coils can be prevented, and workability during assembly is also improved, so that both prevention of eccentricity and improvement of workability can be achieved. ..

Longitudinal sectional view of the can body portion of the boiler in which the present invention is carried out. Top view of the can body portion of the boiler in which the present invention is carried out. Perspective view of the spacer of the present invention extracted

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a vertical sectional view of a can body portion of a boiler in which the present invention is carried out, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is a perspective view of the spacer of the present invention extracted. The boiler 1 is composed of a heat transfer tube wall in which a heat transfer tube is spirally wound to form a can body. The heat transfer tube wall is a double coil, and the inner coil is the inner coil 3 and the outer coil is the outer coil 4. The inner coil 3 and the outer coil 4 are installed at intervals, and an annular combustion gas passage 7 is provided between the inner coil 3 and the outer coil 4. The central portion of the can body surrounded by the inner coil 3 is used as the combustion chamber 8, and the combustion device 2 is provided above the combustion chamber 8. The combustion device 2 generates a flame downward, and by performing combustion in the combustion device 2, heat is generated in the combustion chamber 8 to heat the heat transfer tube.

The inner coil 3 is installed with a space between the inner coil 3 and the bottom of the combustion chamber 8, and the outer coil 4 is installed with a space between the inner and upper parts of the boiler, so that the combustion gas passage 7 between the inner and outer coils burns at the bottom. It is connected to the chamber 8 and is connected to the exhaust pipe 9 connected to the outside of the boiler at the upper part. The combustion gas generated in the combustion chamber 8 enters the combustion gas passage 7 from the bottom of the combustion chamber 8 and heats the heat transfer tube facing the combustion gas passage 7 when flowing upward in the combustion gas passage 7. A heat medium is allowed to flow in the heat transfer tube, and the heat medium in the heat transfer tube is heated by heating the heat transfer tube.

A certain distance is provided between the inner coil 3 and the outer coil 4, and a spacer is installed between the inner coil 3 and the outer coil 4. The spacer is composed of a spacer first member 5 which is a vertically long round bar member and a spacer second member 6 which is a plate-shaped member which is shorter in the vertical direction than the spacer first member 5.

By setting the thickness of the spacer first member 5 to be slightly thinner than the width of the combustion gas passage 7, the spacer first member 5 can be moved into the combustion gas passage 7 even after the inner coil 3 and the outer coil 4 are assembled. It should be easy to insert. The length of the spacer first member 5 substantially occupies the portion of the combustion gas passage 7 sandwiched between the inner coil 3 and the outer coil 4, and when the spacer first member 5 is inserted into the combustion gas passage 7 and fixed. The lower end of the spacer first member 5 is located near the lower end of the inner coil 3, and the upper end of the spacer first member 5 is located higher than the height of the upper end of the outer coil 4. The spacer first member 5 is fixed to the outside of the inner coil 3 facing the combustion gas passage 7 by welding.

When the thickness of the spacer first member 5 is smaller than the width of the combustion gas passage 7, the workability of assembling the can body can be improved, but the spacer first member 5 alone is used only for the inner coil 3 and the outer coil. The eccentricity of the coil 4 cannot be completely prevented. Therefore, at the end of assembling the can body, the spacer second member 6 is inserted between the spacer first member 5 and the outer coil 4. The thickness of the spacer second member 6 shall be the width of the combustion gas passage 7 when added to the spacer first member 5. Further, in order to absorb manufacturing errors, a spacer second member 6 having a plurality of thicknesses may be prepared, and a spacer having an appropriate thickness may be selected and used.

Since the spacer second member 6 is vertically short, the spacer second member 6 can be inserted between the spacer first member 5 and the outer coil 4 without much effort. The spacer first member 5 and the spacer second member 6 are each thinner than the width of the combustion gas passage 7, and the width of the combustion gas passage 7 is widened by overlapping the spacer first member 5 and the spacer second member 6. By setting the value to, eccentricity during assembly of the inner and outer coils can be prevented, and both eccentricity prevention and workability improvement can be achieved at the same time. Further, when the spacer is installed at a position where the combustion gas passage 7 is divided into three equal parts as shown in FIG. 2, the distance between the inner coil 3 and the outer coil 4 is aligned on the entire circumference of the combustion gas passage 7. be able to.

The present invention is not limited to the embodiments described above, and many modifications can be made by a person having ordinary skill in the art within the technical idea of the present invention.

1 boiler
2 Combustion device
3 Inner coil 4 Outer coil 5 Spacer 1st member 6 Spacer 2nd member 7 Combustion gas passage 8 Combustion chamber 9 Exhaust pipe 10 Insulation material

Claims (1)

It has an inner coil and an outer coil, which are double cylindrical heat transfer tube walls in which the heat transfer tube is wound spirally, and the central part of the can body surrounded by the double coil is used as the combustion chamber, and it is generated in the combustion chamber. Combustion gas is burned in the combustion gas passage in the boiler that heats the heat medium flowing in the heat transfer tube by passing through the combustion gas passage provided between the inner coil and the outer coil. The heat transfer tube at the end of the inner coil, which is the start point of the combustion gas passage sandwiched between the inner coil and the outer coil, and the end of the outer coil, which is the end point of the combustion gas passage, are elongated in the vertical direction, which is the gas flow direction. The spacer first member, which is a rod-shaped member having a length that reaches both of the heat transfer tubes, and the plate-shaped member, which has a shorter vertical length than the spacer first member, which is the direction of combustion gas flow in the combustion gas passage. A spacer composed of a spacer second member, which is a member, is installed, and the spacer first member and the spacer second member are thinner than the width of the combustion gas passage, respectively, and the spacer first member and the spacer second member are used. The width of the combustion gas passage is obtained by overlapping them, and it is characterized in that a predetermined distance is secured between the inner coil and the outer coil by overlapping the spacer first member and the spacer second member. A boiler with a spiral heat transfer tube.

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