JP3883735B2 - Liquid heating equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In the present invention, a finned tube having a special structure excellent in heat resistance is arranged on the same circumference centering on an axis in a cylindrical casing having a combustion chamber for burning fuel, and combustion from the combustion chamber is performed. The present invention relates to a liquid heating apparatus that heats a liquid supplied into the finned tube by heating the finned tube with gas and radiant heat.
[0002]
[Prior art]
Conventionally, heat exchangers have the advantage that the finned tube can increase the heat transfer area and improve the thermal efficiency, so that a large number of finned tubes to which fins are attached are widely used. It was.
However, this finned tube has a problem in terms of heat resistance because the fin is fixed to the heat transfer outer peripheral surface of the tube main body by means such as brazing. It is currently used only when the temperature of the gas or liquid outside the tube is as low as 100 ° C. or less.
[0003]
In order to eliminate the disadvantages of such finned tubes, there are also finned tubes in which fins are integrally formed on the heat transfer outer peripheral surface of the tube body, but the fins of such finned tubes are thin. In addition, in terms of heat resistance, the gas or liquid outside the finned tube cannot be used when the temperature of the gas or liquid is high such as the combustion gas immediately after burning the fuel.
This is because, for example, as a device used to heat the liquid with which the finned tube is allowed to flow in the finned tube, it is used in a boiler economizer, and the combustion gas having a lowered temperature after heating the boiler body Is used only when using low-temperature waste heat such as that used to preheat water supplied to the boiler around the finned tube, or to heat the liquid positively As an example in which the tube is provided, it is clear from the fact that there is only an apparatus disclosed in, for example, Japanese Patent Laid-Open No. 10-220701.
[0004]
That is, in the apparatus disclosed in Japanese Patent Laid-Open No. 10-220701, two rows of water pipes, an inner water pipe row and an outer water pipe row, are arranged on the circumferences having different diameters, respectively. Between adjacent inner water pipes facing the combustion chamber is closed except for a portion forming an inner smoke vent on one end side in the longitudinal direction of the inner water pipe, and between adjacent outer water pipes is an inner water pipe from this inner smoke duct. A multi-tube once-through boiler that is closed except for a portion that forms an outer smoke vent on the other end side in the longitudinal direction of the outer water pipe in order to discharge the combustion gas flowing between the outer water pipe and the outer water pipe, It is the structure by which the fin is attached to the downstream of the combustion gas flow of the outer side water pipe in the passage of the combustion gas between the inner side water pipe and the outer side water pipe.
[0005]
However, since this multitubular once-through boiler is configured to burn fuel further inside the inner water tube, the inner water tube is heated by high-temperature combustion gas and radiant heat, and the water supplied into the inner water tube is heated. However, the fins for efficiently absorbing heat are not attached to the inner water pipe, and the combustion gas that has passed through the inner smoke vent is heated by lowering the temperature supplied to the water in the inner water pipe. The fin is attached only to the downstream side of the combustion gas flow of the outer water pipe that flows between the inner water pipe and the outer water pipe, and the fin cannot be attached to the inner water pipe that is in direct contact with the hot combustion gas. This is a suggestion.
[0006]
[Problems to be solved by the invention]
The present invention eliminates the drawbacks of the prior art described above, and arranges a finned tube with a special structure having heat resistance on the same circumference as the center of a combustion chamber for burning fuel on the axial center side in a cylindrical casing. Then, by directly heating the finned tube with the combustion gas and radiant heat from the combustion chamber, the liquid passing through the finned tube can be efficiently heated. Even in a small device, the liquid can be brought to a desired temperature. It is an object of the present invention to provide a liquid heating apparatus that can be heated efficiently.
[0007]
[Means for Solving the Problems]
As a result of intensive studies to solve such problems, the present inventors have heat resistance in an atmosphere of at least 500 ° C. on the same circumference centered on the axis in the cylindrical casing. A substantially trapezoidal fin body having a narrow width on the axial center side of the casing and a wide width on the opposite side to the axial center of the casing is integrally formed at one end of a fixed portion made of a short circular tube. The finned tube fixed in a state where there is no gap across the entire length on the outer peripheral surface is disposed so that the fins of the adjacent finned tube are close to each other, and the fin of the finned tube is fixed. A fixed end plate with one end fixed is fixed to the casing, and a sliding end plate with the other end fixed to which the fin is not fixed is slidably provided on the casing, so that the tube array with fins is provided. Formed And a supply port and a fin for supplying liquid to the finned tube on the outside of the casing of the fixed end plate and the sliding end plate, wherein the axial center side of the casing of the tube row with fins combusts fuel. The present invention has been completed by investigating that the above-mentioned problems can be solved if each of the outlets for discharging the heated liquid supplied into the attachment tube is provided.
[0008]
In addition, a communicating portion that allows the ends of the finned tubes to communicate with each other is provided outside the casing of the fixed end plate and the sliding end plate so that the heated liquid gradually passes through the two or more finned tubes of the finned tube row. It has also been found that even a small device with a short length of each finned tube can substantially increase the liquid flow path and heat the liquid to a desired temperature.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the liquid heating apparatus according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is an explanatory perspective view showing an embodiment of a liquid heating apparatus according to the present invention, FIG. 2 is an illustration of a central cross section of FIG. 1, FIG. 3 is an illustration of a central vertical section of FIG. FIG. 5 is an explanatory perspective view showing the structure of the finned tube, and FIG. 6 is an explanatory view showing an installation example of the liquid heating apparatus according to the present invention.
[0010]
In the drawings, 1 is a cylindrical casing, and 2 is a finned tube that is arranged in a state in which fins 2a, which will be described later, are close to each other on the same circumference centered on the axis in the casing 1.
[0011]
As shown in FIG. 5, the finned tube 2 has a substantially trapezoidal fin main body 2aa having a narrow width on the axial center side of the casing 1 and a wide width on the opposite side to the axial center of the casing 1, and a fixed portion 2ab comprising a short circular tube. A fin 2a integrally formed at one end is fixed to the heat transfer outer peripheral surface of the tube main body 2b in a state where the fin 2a is disposed without a gap over the entire length by expanding the tube main body 2b.
[0012]
The fin 2a in which the fin main body 2aa is integrally formed at one end of the fixed portion 2ab formed of a short circular tube is exposed to a high-temperature atmosphere by the combustion gas and radiant heat of the fuel burned in the combustion chamber 5 described later. Therefore, it is made of, for example, stainless steel or heat resistant steel so as to have heat resistance in an atmosphere of at least 500 ° C., and the thickness thereof is usually made of a thick member of about 0.5 to 4 mm.
[0013]
Reference numeral 3 denotes a fixed end plate to which one end of the finned tube 2 to which the fin 2a is not fixed is fixed and is fixed to one end of the casing 1. Reference numeral 4 denotes the other end to which the fin 2a of the finned tube 2 is not fixed. The sliding end plate is fixed to the other end of the casing 1 so that it can slide freely. The finned tube 2 has both ends fixed to the fixed end plate 3 and the sliding end plate 4. Although the finned tube 2 is heated and expanded, the elongation generated on the end side fixed to the sliding end plate 4 in the longitudinal direction is absorbed by the sliding end plate 4 sliding in the casing 1. The
[0014]
Reference numeral 5 denotes a space on the axial center side of the casing 1 of the two rows of finned pipes 1 in which fuel is combusted. In the illustrated embodiment, the burner 5a is installed facing the combustion chamber 5. The finned tube 2 is heated by the high-temperature combustion gas that burns the fuel and the radiant heat of the flame from the burner 5a.
[0015]
6 is a supply port that is provided outside the casing 1 of the fixed end plate 3 and / or the sliding end plate 4 and supplies the liquid to be heated to the finned tube 2, and 7 is the fixed end plate 3 and / or the sliding end plate 4. A discharge port provided outside the casing 1 for discharging the heated liquid supplied into the finned tube 2 and having a supply port 6 on one end side of the casing 1 and a discharge port on the other end side. There is an aspect in which the supply port 6 and the discharge port 7 are provided on one end side of the casing 1.
[0016]
The former mode is shown in FIG. 4 when the liquid to be heated is configured to pass through one finned tube 2 or to pass through an odd number of finned tubes 2 in two rows of finned tubes. As shown in the figure, a communicating portion 8 is provided for communicating the ends of the finned tube 2 with each other. For example, each finned tube 2 having no supply port 6 on the side where the supply port 6 is provided is provided. Adjacent ends are communicated with each other by the communicating portion 8, and adjacent ends of the finned pipes 2 that are not provided with the exhaust port 7 are communicated with each other by the communicating portion 8. And a pump 10 or the like for forcibly feeding liquid into or forcibly discharging the liquid into one of the pipe connected to the supply port 6 or the pipe connected to the discharge port 7. The liquid to be heated is circulated through all the finned tubes 2 by It is possible to heat, it is possible to heat the liquid to be heated even with a small casing 1 to a high temperature.
[0017]
The latter mode is a case where a communicating portion 8 is provided that allows the ends of the finned tubes 2 to communicate with each other so that the heated liquid passes through the even number of finned tubes 2 in the two rows of finned tubes. Since the supply port 6 and the discharge port 7 are provided on one end side of the casing 1, for example, the supply port 6 and the discharge end plate 7 provided with the supply port 6 and the discharge port 7 are connected to, for example, the supply port. 6 and the adjacent ends of the finned tubes 2 where the discharge ports 7 are not provided communicate with each other through the communication portion 8, and on the side where the supply ports 6 and the discharge ports 7 are not provided, When adjacent end portions are communicated with each other by the communication portion 8, the liquid is forcibly fed into either one of the pipe connected to the supply port 6 or the pipe connected to the discharge port 7, or the liquid Heating as shown in FIG. 8 by providing a pump 10 or the like forcibly discharging. Since the liquid to be heated by passing through circulating all the the finned tubes 2, it is possible to heat the liquid to be heated even with a small casing 1 to a high temperature.
[0018]
In other words, the liquid flow path has a configuration in which the communication portion 8 is provided to allow the ends of the finned tubes 2 to communicate with each other so that the heated liquid passes through at least two finned tubes 2. Even a small device in which the length of each finned tube 2 is configured to be short can be heated to a desired temperature, which is preferable.
[0019]
9 is an exhaust port through which the combustion gas combusted in the combustion chamber 5 heats the finned tube 2 and exhausts it as exhaust gas having a lowered temperature. In the illustrated embodiment, the exhaust port 9 is provided on the side surface of the casing 1. It has been.
[0020]
In order to heat the liquid by the liquid heating apparatus according to the present invention configured as described above, the fuel is burned in the combustion chamber 5 on the axial center side of the casing 1 of the two rows of finned tubes, and the combustion gas of this fuel And a liquid is supplied and heated to each finned tube 2 heated by the radiant heat of the flame.
[0021]
As described above, in the liquid heating apparatus according to the present invention, the finned tube 2 is directly heated by the combustion gas of the fuel burned in the combustion chamber 5 on the axial center side of the casing 1 and the radiant heat of the flame. The pipe 2 has a substantially trapezoidal fin body 2aa made of a heat-resistant material, and a fin 2a formed integrally with one end of a fixed portion 2ab formed of a short circular pipe is formed on the heat transfer outer peripheral surface of the pipe body 2b over the entire length. Since it has a heat-resistant structure in an atmosphere of at least 500 ° C. and is fixed in a state where it is arranged without any gaps, a phenomenon in which the fins 2a are burned out or melted does not occur.
[0022]
Each finned tube 2 is heated and expands in the longitudinal direction due to thermal expansion. Since one end is fixed to the fixed end plate 3 and the other end is fixed to the sliding end plate 4, The elongation generated in the attached tube 2 is absorbed by the sliding end plate 4 sliding in the casing 1 in accordance with the elongation, thereby preventing the generation of thermal stress.
[0023]
Further, since each finned tube 2 is arranged on the same circumference centered on the axis of the casing 1 to form two rows of finned tubes, each finned tube 2 is radiated heat of high-temperature combustion gas and flame. Is heated almost uniformly.
Further, the fin 2a of the finned tube 2 has a narrow width on the axial center side of the casing 1, that is, on the high temperature side facing the combustion chamber 5, and on the opposite side to the axial center of the casing 1, that is, on the low temperature side opposite to the combustion chamber 5. Since the fin 2a is formed in a substantially trapezoidal shape having a wide width and the heat transfer area of the fin 2a on the low temperature side is large, the liquid supplied to the tube main body 2b can be heated by efficiently absorbing heat from the low temperature side.
[0024]
【The invention's effect】
As described in detail above, the liquid heating apparatus according to the present invention has heat resistance in an atmosphere of at least 500 ° C. on the same circumference centering on the axis in the cylindrical casing. The fin body, which is integrally formed at one end of the fixing portion made of a short circular tube, has a substantially trapezoidal fin body with a narrow width on the axial center side and a wide width on the opposite side to the axial center of the casing. The finned tube that is fixed in a state where it is disposed on the surface without any gaps is disposed so that the fins of the adjacent finned tubes are close to each other, and the fins of the finned tube are not fixed A fixed end plate with one end fixed is fixed to the casing, and a sliding end plate with the other end fixed to which the fin is not fixed is slidably provided on the casing to form a tube array with fins. Has been An axial center side of the casing of the finned tube row forms a combustion chamber in which fuel is combusted, and a supply port for supplying liquid to the finned tube on the outside of the casing of the fixed end plate and the sliding end plate and an inside of the finned tube Since the discharge ports for discharging the heated liquid supplied to each are provided, the finned pipes arranged around the combustion chamber are directly heated by the radiant heat of the flame that burns the fuel and the high-temperature combustion gas In addition, the fins are formed in a substantially trapezoidal shape, and the low temperature side opposite to the combustion chamber is wide, so the amount of heat on this low temperature side can be absorbed efficiently, and the heat efficiency is very excellent, It can be made small with a short finned tube.
[0025]
When elongation occurs in the finned tube that is supported by the fixed end plate at one end and the sliding end plate at the other end, the sliding end plate slides in the casing in accordance with the elongation, and thermal stress Occurrence is prevented and durability is excellent.
[0026]
In addition, if a communicating portion is provided to allow the ends of the finned tubes to communicate with each other so that the heated liquid gradually passes through the two or more finned tubes of the finned tube row, the liquid flow path is lengthened. The liquid can be heated to a desired temperature even in a small device in which the length of each finned tube is further shortened.
[0027]
As described above, the liquid heating apparatus according to the present invention that exhibits various effects has a very large industrial value.
[Brief description of the drawings]
FIG. 1 is an explanatory perspective view showing an embodiment of a liquid heating apparatus according to the present invention.
FIG. 2 is an explanatory diagram of a central cross section of FIG. 1;
FIG. 3 is an explanatory diagram of a central longitudinal cross section of FIG. 1;
4 is an enlarged end view taken along line AA in FIG. 3. FIG.
FIG. 5 is an explanatory perspective view showing a structure of a finned tube.
FIG. 6 is an explanatory view showing an installation example of a liquid heating apparatus according to the present invention.
[Explanation of symbols]
1 Casing 2 Finned tube
2a Fin
2aa Fin body
2ab fixed part
2b Tube body 3 Fixed end plate 4 Sliding end plate 5 Combustion chamber
5a Burner 6 Supply port 7 Discharge port 8 Communication part 9 Exhaust port
10 Pump

Claims (2)

It has heat resistance in an atmosphere of at least 500 ° C. on the same circumference centered on the axis in the cylindrical casing (1), and the casing (1) has a narrow axial center side and the casing A fin (2a) integrally formed at one end of a fixing portion (2ab) formed of a short circular tube is formed in a substantially trapezoidal fin body (2aa) whose width opposite the axis of (1) is wide. The finned tube (2), which is fixed in a state where there is no gap across the entire length of the outer peripheral surface of the heat transfer), is disposed so that the fins (2a) of the adjacent finned tube (2) are close to each other. The fixed end plate (3) to which one end of the finned tube (2) to which the fin (2a) is not fixed is fixed is fixed to the casing (1) and the fin (2a) is fixed A sliding end plate (4) to which the other end is not fixed is slidably provided on the casing (1) to form a finned tube (2) row. The axial center side of the casing (1) of the finned tube (2) row forms a combustion chamber (5) in which fuel is combusted, and the fixed end plate (3) and / or the sliding end plate ( The supply port (6) for supplying the liquid to the finned tube (2) and the discharge port (7) for discharging the heated liquid supplied into the finned tube (2) are provided outside the casing (1) of 4). A liquid heating apparatus, each of which is provided. The communicating part (8) for connecting the ends of the finned tube (2) to each other so that the heated liquid gradually passes through the two or more finned tubes (2) in the finned tube (2) row is a fixed end plate The liquid heating device according to claim 1, wherein the liquid heating device is provided outside the casing (1) of the (3) and / or the sliding end plate (4).

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