JP3763271B2 - Heat exchange unit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat exchange device using a household or commercial combustion device, and more specifically, latent heat recovery heat exchange in which latent heat of steam in a combustion gas such as hot water supply or heating is recovered to greatly improve thermal efficiency. It relates to the device.
[0002]
[Prior art]
Conventionally, this type of heat exchange apparatus has been shown in FIG. 11 described in JP 2000-146304 A as a first example. In FIG. 11, 1 is a copper water pipe, 2 is a thick aluminum fin tube formed with fins 3 by cutting or rolling, 4 is a heat exchange chamber side plate surrounding the fin tube 2, and 5 is It is a copper U-shaped pipe joined to the water pipe 1. The fin tube 2 was surrounded by the heat exchange chamber side plate 4, and the water pipe 1 was inserted into the fin tube 2.
[0003]
In the above configuration, most of the heat is removed from the upstream side, and the combustion exhaust gas having a low temperature of 200 to 300 ° C. is further deprived of heat to the fin tube 2, and water vapor is condensed to generate condensed water. Furthermore, it is discharged as exhaust gas of 100 ° C. or less. Here, the finned tube 2 and the fin crest 3 are corroded by acidic dew condensation water containing carbonic acid and nitrate ions, but the aluminum finned tube 2 covering the water flow tube 1 is thick, so that the water flow tube 1 over time is reached. The corrosion progress was delayed to ensure a certain level of durability.
[0004]
As a second example, there is the one shown in FIG. 12 described in Japanese Patent Laid-Open No. 2000-146305. In FIG. 12, 6 is a copper water pipe, 7 is a heat receiving pipe formed of aluminum or stainless steel, 8 is a plate fin formed of aluminum or stainless steel planted on the outer periphery of the heat receiving pipe 7, Is a side plate constituting the heat exchange chamber. By inserting the water pipe 6 into the heat receiving pipe 7 and expanding the water pipe 6, the water pipe 6, the heat receiving pipe 7, and the fin plate 8 are integrally joined.
[0005]
The copper water pipe 6 is covered with a heat receiving pipe 7 made of aluminum or stainless steel, and a corrosion-resistant material such as aluminum or stainless steel is used for the portion in contact with the combustion gas. It became possible to protect the water pipe 6 from corrosion by acidic condensed water.
[0006]
[Problems to be solved by the invention]
However, in the configuration of the heat exchange device in the first conventional example, since the aluminum fin tube 2 having the fins 3 is used in the portion that comes into contact with the combustion gas, acidic dew condensation water due to water vapor in the combustion gas When aluminum adheres to the aluminum surface, aluminum hydroxide is formed and thermally expands to block the combustion gas passages between the fin crests 3. As time elapses, this blockage progresses and causes an exhaust failure. There existed a subject that generation | occurrence | production of complete combustion and the ignition failure of a combustion apparatus will generate | occur | produce. And there also existed a subject that a heat exchanger became large sized in order to make aluminum into a thick structure.
[0007]
Further, in the configuration of the heat exchange device in the second conventional example, a stainless steel fin plate 8 is planted on the outer periphery of the stainless steel heat receiving pipe 7 in a portion in contact with the combustion gas, and the pipe expansion method is performed. Therefore, due to the repetition of heating and cooling due to operation and stop, a gap is formed in the portion where the fin plate 8 and the heat receiving pipe 7 are joined, and the heat transfer is deteriorated. There is a problem that high thermal efficiency cannot be obtained. On the other hand, when brazing to prevent the occurrence of gaps, expensive stainless steel brazing material and furnace equipment in a high temperature range are required compared to copper, which greatly increases production costs. There was a problem.
[0008]
The present invention solves the above-described conventional problems, and provides a high-efficiency heat exchange device that prevents corrosion due to acidic dew condensation water, maintains desired performance, has good durability, and can be downsized. Objective.
[0009]
[Means for Solving the Problems]
In order to solve the above-described conventional problems, the present invention includes an inner tube and an exterior portion that covers the inner tube, and the inner tube and the exterior portion are integrated, and the outer tube includes the inner tube. Are formed integrally with a heat transfer plate having a heat transfer fin integrally therewith, and the heat transfer fin is a single-layer heat transfer fin composed of a single heat transfer plate. And a heat exchange unit comprising a plurality of heat transfer fins configured by overlapping a plurality of the heat transfer plates .
[0010]
The above heat exchange unit is disposed in the combustion gas passage, passes through the inner pipe, covers the surface of the inner pipe with, for example, a corrosion-resistant exterior part, and the exterior part having the heat transfer fin is in contact with the combustion gas. With this configuration, the contact between the inner pipe and the combustion gas is blocked, and the inner pipe is prevented from being corroded by acid drain water, and the heat transfer fin formed by the exterior portion is provided on the combustion gas side having a low heat transfer coefficient. Therefore, heat exchange between the water passing through the inner pipe and the combustion gas flowing on the surface of the heat transfer fin can be performed efficiently.
[0011]
In this way, the heat transfer fins can be easily formed, and a highly efficient heat exchange device with good durability can be provided.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The heat exchange unit according to claim 1 includes an inner tube and an exterior part that covers the inner tube, and integrates the inner tube and the exterior part, and the exterior part has a substantially longitudinal direction of the inner tube. Are formed integrally with a heat transfer plate having a heat transfer fin integrally therewith, and the heat transfer fin includes a single-layer heat transfer fin composed of one heat transfer plate, and the heat transfer fin. A heat exchange unit including a plurality of heat transfer fins configured by stacking a plurality of heat plates.
[0013]
The heat exchange unit is disposed in the combustion gas passage, allows water to pass through the inner pipe, covers the surface of the inner pipe with, for example, a corrosion-resistant exterior part, and the exterior part having heat transfer fins contacts the combustion gas. With this configuration, the contact between the inner pipe and the combustion gas is blocked, and the inner pipe is prevented from being corroded by acid drain water, and the heat transfer fin formed by the exterior portion is provided on the combustion gas side having a low heat transfer coefficient. Therefore, heat exchange between the water passing through the inner pipe and the combustion gas flowing through the heat transfer fins can be performed efficiently.
[0014]
As described above, the heat transfer fins are easily formed, have high durability, and can provide a highly efficient heat exchange device.
[0015]
In the above heat exchange unit, a plurality of single-layer heat transfer fins can be stacked to form a multi-layer heat transfer fin, and conversely, a plurality of single-layer heat transfer fins can be peeled off to form a plurality of single-layer heat transfer fins If necessary, the optimum heat transfer fin area can be easily adjusted. Further, since the multilayer heat transfer fin has a fin thickness, the fin efficiency is improved and the heat transfer can be improved.
[0016]
The heat exchange unit according to claim 2 has a structure in which the heat transfer fins are wave-like in addition to the structure of claim 1 .
[0017]
In the above heat exchange unit, since the heat transfer fins of the exterior part are wave-like, the wave-like heat transfer fins placed in the combustion gas passage disturb the combustion gas flow and increase the heat transfer coefficient to improve heat transfer. Can do. Further, by making the heat transfer fins corrugated, more heat transfer area can be ensured in a finite space, so that heat transfer can be improved.
[0018]
In the heat exchange unit according to claim 3 , in addition to the structure of any one of claims 1 and 2 , the exterior portion is made of a corrosion-resistant material.
[0019]
In said heat exchange unit, since an exterior part is comprised with a corrosion-resistant material, the corrosion by acidic condensed water can be prevented and a highly efficient heat exchange unit with sufficient durability can be provided.
[0020]
According to a fourth aspect of the present invention , in addition to the structure of any one of the first to third aspects, the inner tube is made of a highly heat conductive material.
[0021]
In the above heat exchange unit, since the inner tube is made of a highly heat conductive material, heat transfer can be improved and a high efficiency heat exchange unit can be provided.
[0022]
In addition to the structure in any one of Claims 1-4 , the heat exchange unit which concerns on Claim 5 is filled with the high thermal conductivity material between the inner tube | pipe and the exterior part.
[0023]
By filling the inner tube and the exterior part with a high thermal conductivity material, there is no gap between the inner tube and the exterior part, so that the heat received by the exterior part can be efficiently transferred to the inner tube. An exchange unit can be provided.
[0024]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0025]
Example 1
1 is a system configuration diagram of a heat exchange device according to a first embodiment of the present invention, FIG. 2 is a perspective view of a heat exchange unit constituting the heat exchange device, and FIG. 3 is an exploded view of the heat exchange unit.
[0026]
In FIG. 1, reference numeral 10 denotes a burner for burning fuel gas. A drum can 12 constituting a combustion chamber 11 is provided on the downstream side of the burner 10, and a drum water pipe 13 is bonded to the outer periphery of the drum can 12. On the downstream side of the combustion chamber 11, a sensible heat exchanger 15 containing the fin tube 14 and an exhaust chamber 16 are provided in close contact with each other. An exhaust passage adjusting plate 17 is provided on the downstream side of the exhaust chamber 16, and the exhaust gas A is bent by the exhaust passage adjusting plate 17 and guided to the combustion gas passage 18. A downstream portion of the combustion gas passage 18 faces downward and communicates with the discharge passage 21. In the discharge passage 21, the exhaust gas B is bent and guided to the lead-out passage 22 and is discharged from the exhaust port 23. Further, a dew condensation water discharge unit 24 is connected to the discharge passage 21.
[0027]
Here, the combustion gas passage 18 is provided with a heat exchange device 20 in which a large number of heat exchange units 19 are connected. As shown in FIGS. 2 and 3, the heat exchange unit 19 includes two heat transfer plates 25 a and 25 b that are stacked to form a plate-shaped heat transfer fin 25, such as a corrosion resistant material such as stainless steel, or a surface treatment. The outer portion 26 made of the material covered with the material covers the inner tube 27 made of a material having high thermal conductivity such as copper, and these are integrated.
[0028]
The operation and action of the heat exchange apparatus configured as described above will be described below.
[0029]
The high-temperature combustion gas formed in the combustion chamber 11 by the combustion of the burner 10 heats the preheated water flowing in the fin tube 14 by the sensible heat exchanger 15 and then becomes low-temperature combustion gas and flows into the exhaust chamber 16. To do. Further, on the downstream side of the exhaust chamber 16, the low-temperature exhaust gas A is deflected in the downward flow direction while passing through the combustion gas passage 18 and passes through the heat exchange device 20. At this time, in the heat exchange device 20, by preheating water flowing in the inner pipe 27 through the heat transfer fins 25, the exhaust gas becomes an even lower temperature exhaust gas B, and the water vapor in the combustion exhaust gas is deprived of condensation latent heat. And becomes condensed water on the surface of the exterior portion 26. Since gas such as CO2 and NOx is dissolved in this condensed water, it shows acidity (pH = 2 to 4). The generated condensed water flows downward together with the combustion gas that has become lower in temperature, and is discharged from the condensed water discharge unit 24. On the other hand, the exhaust gas B having a lower temperature is deflected by the discharge passage 21, flows again through the outlet passage 22, and is discharged from the exhaust port 23 to the atmosphere. Water, which is a heating fluid, is introduced into the inner pipe 27 of the heat exchange device 20 from a water supply port (not shown), takes steam latent heat from the low-temperature exhaust gas A, and becomes preheated water having a slightly higher temperature than during water supply, Derived from the heat exchange device 20. Then, the preheated water is led to a drum water pipe 13 that winds around the outer periphery of the drum can 12, reaches the fin pipe 14 while cooling the outer periphery of the drum can 12, and is heated to a predetermined temperature by the sensible heat exchanger 15 and then discharged from the hot water. Is done.
[0030]
As described above, the heat exchange unit 19 configured to be integrated with the inner pipe 27 by using the exterior portion 26 integrally formed with the heat transfer fins 25, the exterior portion 26 is made of a corrosion-resistant material such as stainless steel, The anticorrosion treatment protects the inner tube 27 from the corrosion of the acidic dew condensation water caused by the dissolution of CO2 and NOx contained in the combustion gas without the need to set up heat transfer fins with different materials or means, thereby improving durability. Can be improved.
[0031]
Further, the heat exchange device 20 exchanges heat with the low-temperature heating fluid on the upstream side by the low-temperature combustion gas on the downstream side, and the sensible heat exchanger uses the high-temperature heating fluid on the downstream side with the high-temperature combustion gas on the upstream side. By adopting the opposed heat exchange system in which heat is exchanged by 15, a temperature difference between the heating fluid and the combustion gas is ensured, and effective heat transfer is performed to realize a small heat exchange system.
[0032]
(Example 2)
FIG. 4 is a perspective view of a heat exchange unit according to the second embodiment of the present invention.
[0033]
In the second embodiment, the difference from the first embodiment is that, as shown in FIG. 4, the heat exchange unit 19 is configured by superimposing the single-layer heat transfer fins 28 and the heat transfer plates 25 a and 25 b with the heat transfer plates 25 a or 25 b. The multilayer heat transfer fin 29 is provided.
[0034]
In addition, the thing of the same code | symbol as Example 1 has the same structure, and abbreviate | omits description.
[0035]
Next, the operation and action will be described. The single-layer heat transfer fin 28 composed of a part of the heat transfer plate 25a or 25b is more combusted than the multi-layer heat transfer fin 29 formed by superimposing the heat transfer plates 25a and 25b. Large heat transfer area in contact with gas. Further, the multi-layer heat transfer fin 29 is composed of a plurality of heat transfer plates and has a fin thickness, so that fin efficiency is higher than that of the single-layer heat transfer fin 28. As a result, the endothermic effect of the heat exchange unit 19 is improved, and a more compact heat exchange apparatus can be realized as compared with the first embodiment.
[0036]
Example 3
FIG. 5 is a perspective view of a heat exchange unit according to a third embodiment of the present invention, and FIG. 6 is an exploded perspective view of the heat exchange unit.
[0037]
The third embodiment is different from the first embodiment in that the exterior portion 26 of the heat exchange unit 19 is composed of a single heat transfer plate 30 as shown in FIGS. 5 and 6.
[0038]
In addition, the thing of the same code | symbol as Example 1 has the same structure, and abbreviate | omits description.
[0039]
Next, the operation and action will be described. In this embodiment, as shown in FIG. 6, the heat exchange unit 19 is formed by bending one heat transfer plate 30 at a predetermined position to cover the inner tube 27, so that there is little. A low-cost heat exchange device can be provided that can be processed with the number of parts.
[0040]
(Example 4)
FIG. 7 is a perspective view of a heat exchange unit according to the fourth embodiment of the present invention.
[0041]
The fourth embodiment is different from the first embodiment in that the heat transfer fins 31 of the heat exchange unit 19 are waved as shown in FIG.
[0042]
In addition, the thing of the same code | symbol as Example 1 has the same structure, and abbreviate | omits description.
[0043]
Next, the operation and action will be described. Since the heat transfer fins 31 are wave-like, the wave-like heat transfer fins 31 placed in the combustion gas passage disturb the combustion gas flow and increase the heat transfer coefficient to improve heat transfer. be able to. Further, by making the heat transfer fins corrugated, more heat transfer fins can be secured in a finite space, so that heat transfer can be improved.
[0044]
(Example 5)
FIG. 8 is a perspective view of a heat exchange unit according to the fifth embodiment of the present invention.
[0045]
The fifth embodiment is different from the first embodiment in that the heat transfer fins 25 of the heat exchange unit 19 are configured by overlapping the heat transfer plates 25a and 25b and intimately contacting them with the spot welding means 32 as shown in FIG. It is.
[0046]
In addition, the thing of the same code | symbol as Example 1 has the same structure, and abbreviate | omits description.
[0047]
Next, the operation and action will be described. Since the heat transfer plates 25a and 25b are fixed and intimately bonded by the spot welding means 32, the exterior portion 26 can be integrated with the inner tube 27, and the dew condensation water exchanges heat. It is possible to prevent permeation into the inner pipe 27 of the unit 19 and improve durability.
[0048]
(Example 6)
In the present Example 6, the exterior part 26 of the heat exchange unit 19 shown in each Example is comprised with corrosion-resistant material, such as stainless steel. The present embodiment will be described with reference to the drawings of the first embodiment.
[0049]
Next, the operation and action will be described. Since the surface of the exterior part 26 comes into contact with the combustion gas and also comes into contact with acidic condensed water condensed from the water vapor in the low-temperature combustion gas, the use of a corrosion resistant material such as stainless steel makes the exterior part 26 The inner pipe 27 can be protected from acidic corrosion without worrying about the surface being corroded, and durability can be improved.
[0050]
(Example 7)
In the seventh embodiment, the inner tube 27 of the heat exchange unit 19 shown in each first embodiment is made of a highly heat conductive material such as copper. The present embodiment will be described with reference to the drawings of the first embodiment.
[0051]
Next, the operation and action will be described. By making the inner tube 27 of a highly heat conductive material, heat transfer on the inner and outer walls of the inner tube 27 is improved, the heat transfer effect is improved, and high efficiency heat is achieved. An exchange device can be provided.
[0052]
(Example 8)
FIG. 9 is a sectional view of a heat exchange unit according to the eighth embodiment of the present invention.
[0053]
In the eighth embodiment, the difference from the first embodiment is that a high heat conductive material 33 is filled between the inner tube 27 and the exterior portion 26 constituting the heat exchange unit 19 as shown in FIG.
[0054]
In addition, the thing of the same code | symbol as Example 1 has the same structure, and abbreviate | omits description.
[0055]
Next, the operation and action will be described. Since the inner tube 27 and the exterior portion 26 are integrated, the front surface of the inner tube 27 and the back surface of the exterior portion 26 are in close contact. However, as shown in FIG. When the heat plate 25a and the heat transfer plate 25b are overlapped, the edge portion 34 of the heat transfer plate 25a and the edge portion 35 of the heat transfer plate 25b create a gap between the exterior portion 26 and the inner tube 27, If air or the like enters this gap, a thermal resistance is generated and the flow of heat is obstructed. In this embodiment, the gap is filled with a highly heat conductive material 33, for example, a viscous copper powder, thereby eliminating the gap, improving the heat transfer property, and providing a highly efficient heat exchange device.
[0056]
In the present embodiment, the gap between the edge portions 34 and 35 is filled with the high thermal conductivity material 33. However, the entire surface of the inner tube 27 or the back surface of the exterior portion 26 is coated with the high thermal conductivity material and then integrated. As a result, the surface of the inner tube 27 and the back surface of the exterior portion 26 can be intimately brought into close contact with each other, heat conductivity is improved, and a highly efficient heat exchange device can be provided.
[0057]
Example 9
FIG. 10 is a perspective view of a heat exchange unit according to the ninth embodiment of the present invention.
[0058]
In the ninth embodiment, the difference from the first embodiment is that, as shown in FIG. 10, the end portion of the heat transfer plate 25a constituting the heat transfer fin 25 is bent and the caulking portion 36 covering the end portion of the heat transfer plate 25b. It is to have.
[0059]
In addition, the thing of the same code | symbol as Example 1 has the same structure, and abbreviate | omits description.
[0060]
Next, the operation and action will be described. Since the end portion of the heat transfer plate 25a is bent and the end portion of the heat transfer plate 25b is caulked, the end portion of the heat transfer fin 25 is caulked. It is possible to prevent water from penetrating into the inner tube 27 portion of the heat exchange unit 19 through the joint between the heat transfer plate 25a and the heat transfer plate 25b at the end, and the durability can be improved.
[0061]
In each of the above embodiments, the sensible heat exchanger 15 uses the fin tube 14, but the same effect can be realized even if the fin tube 14 is replaced with the heat exchange unit 19.
[0062]
In addition, although fuel gas was demonstrated in the said each Example, the same effect can be implement | achieved also when petroleum fuel and another fuel are used.
[0063]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a high-efficiency heat exchange device that prevents corrosion due to acidic dew condensation water, maintains desired performance, has good durability, and can be downsized. .
[Brief description of the drawings]
FIG. 1 is a system configuration diagram of a heat exchange device in Embodiment 1 of the present invention. FIG. 2 is a perspective view of a heat exchange unit constituting the heat exchange device. FIG. 3 is an exploded view of the heat exchange unit. FIG. 5 is a perspective view of a heat exchange unit in Embodiment 2 of the present invention. FIG. 5 is a perspective view of a heat exchange unit in Embodiment 3 of the present invention. FIG. 6 is an exploded perspective view of the heat exchange unit. FIG. 8 is a perspective view of a heat exchange unit in Example 5 of the present invention. FIG. 9 is a cross-sectional view of a heat exchange unit in Example 8 of the present invention. The perspective view of the heat exchange unit in Example 9. [FIG. 11] The principal part sectional view of the conventional heat exchange apparatus. [FIG. 12] The principal part sectional view of the other conventional heat exchange apparatus.
DESCRIPTION OF SYMBOLS 19 Heat exchange unit 25 Heat transfer fin 25a, 25b Heat transfer plate 26 Exterior part 27 Inner pipe 28 Single layer heat transfer fin 29 Multi-layer heat transfer fin 30 Heat transfer plate 31 Heat transfer fin 32 Welding means 33 High heat conductive material

Claims (5)

An inner tube and an exterior portion covering the inner tube, the inner tube and the exterior portion are integrated, and the exterior portion is integrally formed with heat transfer fins along a substantially longitudinal direction of the inner tube , The exterior part is composed of a heat transfer plate integrally including heat transfer fins, and the heat transfer fin is a composite layer composed of a single layer heat transfer fin composed of one heat transfer plate and a plurality of the heat transfer plates. Heat exchange unit consisting of layer heat transfer fins . The heat exchange unit according to claim 1 , wherein the heat transfer fins are corrugated. The heat exchange unit according to claim 1 or 2, wherein the exterior portion is made of a corrosion-resistant material. The heat exchange unit according to any one of claims 1 to 3 , wherein the inner tube is made of a highly heat conductive material. The heat exchange unit according to any one of claims 1 to 4 , wherein a high thermal conductivity material is filled between the inner tube and the exterior part.

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