JP2017142012A - Boiler with spiral heat transfer tubes - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a boiler having a spiral heat transfer tube which can prevent eccentricity of inner and outer coils and improve workability at the time of assembly. SOLUTION: A combustion chamber 8 has an inner coil 3 and an outer coil 4 which are double cylindrical heat transfer tube walls in which a heat transfer tube is spirally wound, and a central portion of a can body surrounded by the double coils is formed. The combustion gas generated in the combustion chamber 8 is passed through the combustion gas passage 7 provided between the inner coil and the outer coil to heat the heat medium flowing in the heat transfer tube in the boiler 1. A spacer composed of a spacer first member 5 which is a vertically elongated member and a spacer second member 6 which is a member shorter in the vertical direction than the spacer first member is installed in the spacer 1. Each of the member 5 and the spacer second member 6 is thinner than the width of the combustion gas passage 7, and by overlapping the spacer first member 5 and the spacer second member 6, a predetermined space is formed between the inner coil 3 and the outer coil 4. A boiler with a spiral heat transfer tube, which is characterized by ensuring a space between the two. [Selection diagram] Fig. 1

Description

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

As described in Japanese Utility Model Laid-Open No. 52-29642, there is known a boiler in which a can body is constituted by a cylindrical heat transfer tube wall in which a heat transfer tube is spirally wound. This boiler has an annular combustion gas passage between the inner coil and the outer coil by doubling the coil, which is a cylindrical heat transfer tube, with a space 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 the upper part of the boiler and the combustion gas passage between the inner and outer coils is centered at the bottom. It is connected to the combustion chamber on the side, and at the top is connected to an exhaust pipe that leads to the outside of the boiler. Combustion gas generated in the combustion chamber enters the combustion gas passage from the bottom of the combustion chamber, and heats a heat transfer tube facing the combustion gas passage when flowing upward in the combustion gas passage, thereby It is discharged outside the boiler.

In the boiler described in Japanese Utility Model Publication No. 52-29642, a spacer having the same width as the passage is installed in the combustion gas passage. In a boiler having a combustion gas passage between a double-installed inner coil and an outer coil, the inner coil and the outer coil are assembled eccentrically, and if the width of the combustion gas passage varies depending on the location, the flow of the combustion gas is biased. The heat absorption amount of the heat transfer tube is significantly reduced. If a spacer is installed and the interval between the inner coil and the outer coil is unified to the width of the spacer, the interval between the inner coil and the outer coil can be made constant, and there is no drift of the combustion gas flow in the combustion gas passage. The heat transfer tube facing the combustion gas passage can be efficiently heated.

When assembling this boiler, a heat exchanger tube is usually bent by a pipe bender to create an inner coil and an outer coil, and a can body is formed by combining the inner coil and the outer coil. When installing a spacer between the inner and outer coils, either the outer coil can be covered after fixing the spacer on the outer side of the inner coil, or the spacer is inserted after assembling the inner and outer coils. When the width is the same as the width of the combustion gas passage, there is a problem that the workability of the assembly is deteriorated. However, if the width of the spacer is made narrower than the width of the combustion gas passage, the effect as the spacer is reduced, and the heat transfer efficiency is reduced when the inner and outer coils are eccentric.

Japanese Utility Model Publication No. 52-29642

  The problem to be solved by the present invention is to provide a boiler having a helical heat transfer tube that can achieve both prevention of eccentricity of inner and outer coils and improvement of workability during assembly.

It has an inner coil and an outer coil, which are double cylindrical heat transfer tube walls with spirally wound heat transfer tubes, and the center part of the can surrounded by the double coils is the combustion chamber and is generated in the combustion chamber The combustion gas is a member that is vertically elongated in the combustion gas passage in the boiler that heats the heat medium flowing in the heat transfer tube by passing the combustion gas passage provided between the inner coil and the outer coil. A spacer comprising a spacer first member and a spacer second member having a length shorter than that of the spacer first member is installed. The spacer first member and the spacer second member each have a width of the combustion gas passage. It is thinner and 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.

By implementing the present invention, in a boiler having a helical heat transfer tube, eccentricity at the time of assembling the inner and outer coils can be prevented and workability at the time of assembling can be improved, so that both prevention of eccentricity and improvement of workability can be achieved. .

The longitudinal cross-sectional view of the can body part of the boiler which is implementing this invention The top view of the can part of the boiler which is implementing this invention The perspective view which extracted the spacer of this invention

  An embodiment of the present invention will be described with reference to the drawings. 1 is a longitudinal sectional view of a can body portion of a boiler embodying the present invention, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is a perspective view of a spacer of the present invention extracted. The boiler 1 comprises a can body with a heat transfer tube wall in which a heat transfer tube is wound spirally. The heat transfer tube wall is a double coil, the inner coil being the inner coil 3 and the outer coil being the outer coil 4. The inner coil 3 and the outer coil 4 are installed with a space therebetween, 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 a combustion chamber 8, and the combustion device 2 is provided above the combustion chamber 8. The combustion device 2 generates a downward flame. When combustion is performed by 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 bottom of the combustion chamber 8 and the outer coil 4 is installed with a space between the upper portion of the boiler and the combustion gas passage 7 between the inner and outer coils is burned at the bottom. It connects with the chamber 8, and connects with the exhaust pipe 9 connected outside the boiler in 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 constant interval is provided between the inner coil 3 and the outer coil 4, and a spacer is provided between the inner coil 3 and the outer coil 4. The spacer includes a spacer first member 5 that is a vertically long round bar member and a spacer second member 6 that is a plate-like member that is shorter in the vertical direction than the spacer first member 5.

The thickness of the spacer first member 5 is set to be slightly smaller than the width of the combustion gas passage 7, so that 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 a portion sandwiched between the inner coil 3 and the outer coil 4 of the combustion gas passage 7, and when the spacer first member 5 is inserted and fixed to the combustion gas passage 7, The lower end of the spacer first member 5 is in the vicinity of the lower end portion of the inner coil 3, and the upper end of the spacer first member 5 is positioned higher than the upper end height 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. The eccentricity of the coil 4 cannot be completely prevented. Therefore, the spacer second member 6 is inserted between the spacer first member 5 and the outer coil 4 at the end of the can assembly. The thickness of the spacer second member 6 is the width of the combustion gas passage 7 when added to the spacer first member 5. Further, in order to absorb manufacturing errors, a plurality of thicknesses may be prepared as the spacer second member 6, and one having an appropriate thickness may be selected and used.

Since the spacer second member 6 is short in length, it is possible to insert the spacer second member 6 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 made thinner than the width of the combustion gas passage 7, and the width of the combustion gas passage 7 is obtained by overlapping the spacer first member 5 and the spacer second member 6. By doing so, eccentricity at the time of assembling the inner and outer coils can be prevented, and both prevention of eccentricity and improvement in workability can be achieved. Further, when the spacer is installed at a position where the combustion gas passage 7 is equally divided as shown in FIG. 2, the distance between the inner coil 3 and the outer coil 4 is made uniform over 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 those having ordinary knowledge in the art within the technical idea of the present invention.

1 boiler
2 Combustion device
3 Inner coil 4 Outer coil 5 Spacer first member 6 Spacer second member 7 Combustion gas passage 8 Combustion chamber 9 Exhaust tube 10 Heat insulating material

Claims (1)

It has an inner coil and an outer coil, which are double cylindrical heat transfer tube walls with spirally wound heat transfer tubes, and the center part of the can surrounded by the double coils is the combustion chamber and is generated in the combustion chamber The combustion gas is a member that is vertically elongated in the combustion gas passage in the boiler that heats the heat medium flowing in the heat transfer tube by passing the combustion gas passage provided between the inner coil and the outer coil. A spacer comprising a spacer first member and a spacer second member having a length shorter than that of the spacer first member is installed. The spacer first member and the spacer second member each have a width of the combustion gas passage. It has a helical heat transfer tube that is thinner and has a predetermined interval between the inner coil and the outer coil by overlapping the spacer first member and the spacer second member. Boiler.

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