JP2007064551A - Combustion apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact arrangement that recovers latent heat to enhance heat efficiency and achieve energy savings. <P>SOLUTION: A latent heat exchanger of a water-heating heat exchanger heated by a burner to exchange heat with hot water comprises a plurality of bellows pipes 27 and heat-transfer fin parts 25 mounted on the outsides of the plurality of bellows pipes. The heat-transfer fins are folded back and semicircular protrusions and cylindrical burring or the like are provided, whereby a high-efficiency heat exchange apparatus larger than an arrangement composed only of the bellows pipes 27 and the heat-transfer fins can be provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a heat exchange system that recovers not only sensible heat but also water vapor latent heat in combustion gas and improves thermal efficiency in a household or commercial combustion apparatus.

  Conventionally, as this type of latent heat recovery heat exchange device, for example, there has been one described in Patent Document 1. FIG. 9 shows a conventional latent heat recovery heat exchange device described in the publication.

  In FIG. 9, 1 is a burner, 2 is a gas pipe for supplying fuel gas to the burner 1, 3 is a fan for supplying combustion air to the burner 1, and 4 is hot water supply located downstream of the combustion gas generated by the combustion of the burner 1 The heat exchanger 5 is a reheating heat exchanger that is disposed on top of and below the hot water supply heat exchanger 4, 6 is a hot water transfer tube that forms the hot water heat exchanger 4, and 7 is a reheating heat exchanger. It is a reheating heat transfer tube. 8 is a hot water latent heat recovery heat exchanger installed downstream of the combustion gas of the hot water heat exchanger 4, 9 is a hot water latent heat transfer tube that forms a hot water latent heat recovery heat exchanger, and 10 is an outlet 9 b of the hot water latent heat transfer tube 9. It is a hot water pipe that connects the inlet 6 a of the hot water supply heat transfer pipe 6. 11 is a water supply pipe connected to the inlet 9a of the hot water latent heat transfer pipe 9, 12 is a hot water pipe connected to the outlet 6b of the hot water heat transfer pipe 6, 13 is a bath return pipe connected to the inlet of the additional heat transfer pipe 7, Is a bath outlet pipe connected to the outlet of the reheating heat transfer pipe 7.

The hot water supply heat exchanger 4 and the reheating heat exchanger 5 are heated by the common burner 1, and the water supplied from the water supply pipe 11 enters the hot water supply latent heat recovery heat exchanger 8, and the hot water supply heat exchanger 4 and the reheating heat exchanger are connected. The heated combustion gas is heated, enters the hot water supply heat exchanger 4 through the hot water pipe 10, further heated by the combustion gas generated by the burner 1, reaches a predetermined temperature, and flows out of the hot water supply pipe 12. In this hot water supply latent heat recovery heat exchanger 8, the condensation latent heat mainly contained in the water vapor in the combustion gas is recovered. Also, bath water (not shown) from the bath return pipe 13 enters the reheating heat exchanger 5 and is heated by the combustion gas, and then flows to the bath water tank (not shown) through the bath outlet pipe 14. . Thus, by providing the hot water supply latent heat recovery heat exchanger 8, it is possible to recover even the condensation latent heat of the water vapor in the combustion gas during the hot water supply operation, and high thermal efficiency is obtained (for example, see Patent Document 1).
JP-A-10-267414

  However, in the above conventional configuration, it is difficult to take a large heat transfer area due to the machining restriction of the bellows tube used for the heat transfer tube of the latent heat recovery heat exchanger. In order to increase the heat transfer area by increasing the size, the heat exchanger for recovering latent heat is inevitably increased, resulting in an increase in the size of the water heater casing.

  The present invention solves the above-described conventional problems, and constitutes a high-efficiency and space-saving latent heat recovery heat exchanger and is installed at an appropriate location in the combustion gas passage to improve combustion efficiency. An object is to provide an apparatus.

  In order to achieve the above object, in the combustion apparatus of the present invention, the latent heat recovery heat exchanger is configured by integrally attaching heat transfer fins to the outer circumferences of the plurality of bellows-shaped inner tubes, and the flow of combustion gas flows downward from above. It is designed to be installed in the combustion gas passage that is deflected to the right.

  According to the above invention, it is possible to provide a highly efficient and space-saving latent heat recovery heat exchanger having a heat transfer area increased by a bellows tube and a heat transfer fin, and by bypassing the combustion gas path, the combustion gas It is possible to efficiently recover the latent heat therein, and to improve the overall combustion efficiency and easily perform the dew condensation treatment configuration.

  The combustion apparatus of the present invention can provide a highly efficient and space-saving latent heat recovery heat exchanger with a heat transfer area increased by a bellows tube and heat transfer fins, and also burns by bypassing the combustion gas path The latent heat recovery in the gas can be efficiently performed, and the overall combustion efficiency can be improved and the dew condensation water treatment configuration can be easily performed.

  The first invention is provided in a burner, a hot water heat exchanger that is heated by the burner and exchanges heat with hot water, and is provided in a combustion gas passage on the downstream side of the hot water heat exchanger to recover latent heat of condensation of water vapor in the combustion gas. A latent heat recovery heat exchanger; and an exhaust passage for discharging combustion gas via the latent heat recovery heat exchanger. The latent heat recovery heat exchanger has heat transfer fins integrally formed on the outer periphery of a plurality of bellows-shaped inner tubes. And is installed in a combustion gas passage in which the flow of the combustion gas is deflected downward from above.

  In addition, it is possible to provide a highly efficient and space-saving latent heat recovery heat exchanger that increases the heat transfer area by means of a bellows tube and heat transfer fins, and also recovers latent heat in the combustion gas by bypassing the combustion gas path. Therefore, it is possible to improve the overall combustion efficiency and to easily perform the dew condensation water treatment configuration.

  According to a second aspect of the present invention, the latent heat recovery heat exchanger is characterized in that folding is provided on the heat transfer fin portion attached to the outside of the plurality of bellows tubes.

  And the heat transfer area can be further increased by providing the end faces of the heat transfer fins, and the latent heat recovery can be performed more effectively.

  A third invention is characterized in that the latent heat recovery heat exchanger is provided with a semicircular protrusion on a heat transfer fin portion attached to the outside of the plurality of bellows tubes.

  Further, by providing a semicircular projection on the end face of the heat transfer fin, the heat transfer area can be further increased, and latent heat recovery can be performed more effectively.

  The fourth invention is characterized in that the latent heat recovery heat exchanger is provided with a cylindrical burring in a heat transfer fin portion attached to the outside of the plurality of bellows tubes.

  Then, by providing a cylindrical burring on the heat transfer fin, the exhaust flow can be more efficiently guided to the bellows tube, so that heat can be exchanged more effectively.

  According to a fifth aspect of the present invention, the latent heat recovery heat exchanger is characterized in that the heat transfer fin portion attached to the outside of the plurality of bellows tubes is provided with a cut-and-raised portion on the bridge.

Then, by providing the heat transfer fins with the cut and raised portions on the bridge, it is possible to more effectively exchange heat by diffusing the exhaust flow and guiding it more efficiently to the bellows tube.
According to a sixth aspect of the present invention, the latent heat recovery heat exchanger is characterized in that a wave-shaped bend is provided on the entire heat transfer fin attached to the outside of the plurality of bellows tubes.

  And, the heat transfer fin is provided with a corrugated bend throughout. It is possible to exchange heat more effectively by increasing the endothermic area by providing a corrugated bend as a whole.

  According to a seventh aspect of the present invention, the latent heat recovery heat exchanger is characterized in that a wedge-shaped cut and raised portion is provided in a heat transfer fin portion attached outside the plurality of bellows tubes.

  Then, by providing a V-shaped cut and raised on the heat transfer fin, the exhaust flow can be efficiently guided to the bellows tube, so that heat can be exchanged more effectively.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the present embodiment.

(Embodiment 1)
FIG. 1 is a system configuration diagram of a heat exchange device according to Embodiment 1 of the present invention, FIG. 2 is a perspective view of a heat exchange unit constituting the heat exchange device, and FIG. 3 is a cross-sectional view of the heat exchange unit.

  In FIG. 1, reference numeral 10 denotes a burner that burns fuel gas. A drum can 12 that constitutes a combustion chamber 11 is provided on the downstream side of the burner 10, and a drum water pipe 13 is attached to the outer periphery of the drum can 12 in close contact. Yes. 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. 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 FIG. 2, the heat exchanging unit 19 has a heat transfer mechanism for fixing the bellows-like inner tube 27 to the outer periphery of the bellows-like inner tube 27 using a corrosion-resistant material such as stainless steel or a surface-treated material. The fin 25 is integrally formed.

  The operation and action of the heat exchange apparatus configured as described above will be described below.

  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 the water flowing through the bellows-like inner tube 27 through the heat transfer fins 25 and the bellows-like inner tube 27, the exhaust gas becomes a lower temperature exhaust gas B, and the combustion exhaust gas The water vapor 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 from a water supply port (not shown) into the bellows-like inner tube 27 of the heat exchange device 20, and takes steam latent heat from the low-temperature exhaust gas A to become preheated water having a slightly higher temperature than that at the time of 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.

As described above, the heat exchange unit 19 configured using the bellows-shaped inner tube 27 integrally formed with the heat transfer fins 25 for fixing the plurality of bellows-shaped inner tubes 27 has the heat configured by the bellows-shaped inner tube 27 alone. More heat exchange area can be obtained for the exchange unit.

  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.

(Embodiment 2)
FIG. 3 shows a cross-sectional view of the heat exchange unit in the second embodiment of the present invention.

  In the present embodiment, the difference from the first embodiment is that the heat exchange unit 19 is provided with a turn on the end face of the heat transfer fin 25 as shown in FIG.

  Next, the operation will be described. The heat exchange unit constituted by the heat transfer fins 25 provided with the folded back 25b on the end face is in contact with the combustion gas as compared with the heat exchange unit constituted by the heat transfer fins not provided with the folded back 25b on the end face. As a result, a large heat transfer area can be obtained and resistance to the upward exhaust flow 25 </ b> C can be increased, thereby extending the heat transfer time. That is, by this, the heat absorption effect of the heat exchange unit 19 is improved, and a heat exchange device that is smaller than that of the first embodiment can be realized.

(Embodiment 3)
FIG. 4 shows a cross-sectional view of the heat exchange unit in the third embodiment of the present invention.

  In the present embodiment, the difference from the first embodiment is that the heat exchange unit 19 is provided with a semicircular protrusion 25b on the end face of the heat transfer fin 25 as shown in FIG.

  Next, the operation will be described. The heat exchange unit constituted by the heat transfer fins 25 provided with the semicircular protrusions 25b on the end face is heat exchange constituted by the heat transfer fins not provided with the semicircular protrusions 25b on the end face. Compared to the unit, the heat transfer area in contact with the combustion gas can be increased. Further, the exhaust gas is agitated by the semicircular protrusion 25b. That is, by this, the heat absorption effect of the heat exchange unit 19 is improved, and a smaller heat exchange device than that of the first embodiment can be realized.

(Embodiment 4)
5A and 5B are a cross-sectional view and a perspective view of a heat exchange unit according to the fourth embodiment of the present invention.

  The present embodiment is different from the first embodiment in that the heat exchange unit 19 is provided with a circular burring 25b on the heat transfer fin 25 as shown in FIG.

  Next, the operation will be described. The heat exchange unit constituted by the heat transfer fins 25 provided with the circular burring 25b is in contact with the combustion gas as compared with the heat exchange unit constituted by the heat transfer fins not having the circular burring 25b. A large heat transfer area can be obtained. Further, the exhaust can be more efficiently guided to the bellows-like inner tube 27 by the circular burring 25b. That is, by this, the heat absorption effect of the heat exchange unit 19 is improved, and a smaller heat exchange device than that of the first embodiment can be realized.

(Embodiment 5)
6A and 6B are a sectional view and a perspective view of a heat exchange unit according to the fifth embodiment of the present invention.

  In the present embodiment, the difference from the first embodiment is that the heat exchange unit 19 is provided with a rectangular bridge 25b on the heat transfer fin 25 as shown in FIG.

  Next, the operation will be described. The heat exchange unit constituted by the heat transfer fins 25 provided with the rectangular bridge 25b is in contact with the combustion gas as compared with the heat exchange unit constituted by the heat transfer fins not having the rectangular bridge 25b. A large heat transfer area can be obtained. Further, the exhaust can be more efficiently guided to the bellows-shaped inner tube 27 by the rectangular bridge 25b. That is, by this, the heat absorption effect of the heat exchange unit 19 is improved, and a smaller heat exchange device than that of the first embodiment can be realized.

(Embodiment 6)
FIG. 7 shows a sectional view of a heat exchange unit according to the sixth embodiment of the present invention.

  In the present embodiment, the difference from the first embodiment is that the heat exchange unit 19 is provided with a wave-shaped bend 25b in the heat transfer fin 25 as shown in FIG.

  Next, the operation will be described. The heat exchange unit constituted by the heat transfer fins 25 provided with the corrugated bend 25b on the end face is changed to the heat exchange unit constituted by the heat transfer fin not having the corrugated bend 25b on the end face. In comparison, the heat transfer area in contact with the combustion gas can be increased. Further, the exhaust gas is agitated in the corrugated bend 25b. That is, by this, the heat absorption effect of the heat exchange unit 19 is improved, and a heat exchange device that is smaller than that of the first embodiment can be realized.

(Embodiment 7)
8A and 8B are a sectional view and a perspective view of a heat exchange unit according to the seventh embodiment of the present invention.

  In the present embodiment, the difference from the first embodiment is that the heat exchanging unit 19 is provided with a wedge-shaped cut and raised portion 25b in the heat transfer fin 25 as shown in FIG.

  Next, the operation will be described. The heat exchange unit constituted by the heat transfer fins 25 provided with the wedge-shaped cut and raised portions 25b is compared with the heat exchange unit constituted by the heat transfer fins not having the wedge-shaped cut and raised portions 25b. A large heat transfer area in contact with the combustion gas can be obtained. Further, the exhaust can be more efficiently guided to the bellows-like inner tube 27 by the wedge-shaped cut and raised portion 25b. That is, by this, the heat absorption effect of the heat exchange unit 19 is improved, and a smaller heat exchange device than that of the first embodiment can be realized.

  As described above, the combustion apparatus of the present invention can provide a latent heat recovery apparatus that is more compact and highly efficient than conventional ones, and can therefore be applied as a heat exchange apparatus for gas and oil water heaters.

Sectional drawing of the combustion apparatus in Embodiment 1 of this invention A perspective view of a heat exchange unit of the combustion apparatus The perspective view of the heat exchange unit in Embodiment 2 of this invention The perspective view of the heat exchange unit in Embodiment 3 of this invention (A) (b) Cross section and perspective view of a heat exchange unit according to Embodiment 4 of the present invention (A) (b) Cross-sectional view and perspective view of heat exchange unit according to Embodiment 5 of the present invention The perspective view of the heat exchange unit in Example 6 of this invention (A) (b) Cross section and perspective view of a heat exchange unit in Embodiment 7 of the present invention Cross-sectional view of a conventional combustion device

Explanation of symbols

10 Burner 15 Sensible heat exchanger (hot water heat exchanger)
18 Combustion gas passage 19 Heat exchange unit (latent heat recovery heat exchanger)
25 Heat transfer fin (latent heat recovery heat exchanger)
27 Bellows tube (latent heat recovery heat exchanger)

Claims (7)

A burner, a hot water heat exchanger that is heated by the burner and exchanges heat with hot water, a latent heat recovery heat exchanger that is provided in a combustion gas passage on the downstream side of the hot water heat exchanger and recovers the latent heat of condensation of water vapor in the combustion gas; An exhaust passage for discharging combustion gas via the latent heat recovery heat exchanger, and the latent heat recovery heat exchanger is configured by integrally attaching heat transfer fins to the outer periphery of a plurality of bellows-shaped inner tubes. A combustion apparatus installed in a combustion gas passage in which the flow of the combustion gas is deflected downward from above. The combustion apparatus according to claim 1, wherein the latent heat recovery heat exchanger is provided with folds on heat transfer fin portions attached to the outside of the plurality of bellows tubes. The combustion apparatus according to claim 1, wherein the latent heat recovery heat exchanger is provided with a semicircular projection on a heat transfer fin portion attached to the outside of the plurality of bellows tubes. The combustion apparatus according to claim 1, wherein the latent heat recovery heat exchanger is provided with a cylindrical burring in a heat transfer fin portion attached to the outside of the plurality of bellows tubes. The combustion apparatus according to claim 1, wherein the latent heat recovery heat exchanger is provided with a cut-and-raised portion on the bridge in a heat transfer fin portion attached to the outside of the plurality of bellows tubes. The combustion apparatus according to claim 1, wherein the latent heat recovery heat exchanger is provided with a wave-shaped bend in the entire heat transfer fin attached to the outside of the plurality of bellows tubes. The combustion apparatus according to claim 1, wherein the latent heat recovery heat exchanger is provided with a wedge-shaped cut and raised at a heat transfer fin portion attached to the outside of the plurality of bellows tubes.

Images