JP5888538B2 - Heat exchanger and hot water device provided with the same - Google Patents

Description

  The present invention relates to a heat exchanger having a configuration in which a heat transfer tube is accommodated in a case, and a hot water apparatus such as a hot water supply apparatus including the heat exchanger.

  Conventionally, as a specific example of a heat exchanger for a hot water supply apparatus, there is one described in Patent Document 1. In the heat exchanger described in the same document, the case for housing the heat transfer tube has a rectangular tube-shaped main body, and the main body joins two members formed in a predetermined structure. It is comprised by doing. According to such a configuration, it is possible to reduce the total number of components of the case and reduce the manufacturing cost of the heat exchanger.

  However, it is often highly desirable to further reduce the manufacturing cost of the heat exchanger. On the other hand, in the prior art, since the main body of the case is composed of two members and joined together, there are relatively many manufacturing processes in which the two members are separately manufactured and assembled. Thus, there is still room for improvement in reducing the manufacturing cost. In addition, the heat exchanger of the hot water supply apparatus is generally housed in an outer case together with a burner constituting the hot water supply apparatus. Conventionally, in such a case, an exhaust gas guide member (exhaust top) is separately provided at the exhaust port of the heat exchanger as a means for exhausting the exhaust gas after heat recovery by the heat exchanger to the outside of the outer case. It was customary to have attached. Therefore, the work of manufacturing such an exhaust top separately from the heat exchanger and attaching it to the heat exchanger becomes complicated, and there is a problem that the manufacturing cost is further increased accordingly.

JP 2009-180398 A

  The present invention has been conceived under the circumstances as described above, and includes a heat exchanger capable of reducing the manufacturing cost and improving the heat exchange efficiency compared with the conventional one, and the same. The problem is to provide a hot water apparatus.

  In order to solve the above problems, the present invention takes the following technical means.

The heat exchanger provided by the 1st side of the present invention is provided with a case which stores a heat exchanger tube inside, and this case has a square tube which has a plurality of wall parts surrounding the perimeter of the above-mentioned heat exchanger tube. A heat exchanger, wherein the case body is provided with an air supply port and an exhaust port for heating gas for heating the heat transfer tube. Has a side plate assembled to the end portion of the case main body portion so as to close the end opening of the case main body portion, and the side plate has pipe body portions near both ends on the inlet side and the outlet side of the heat transfer tube. Is formed in the lower wall portion of the case main body in an arrangement spaced upward from the side plate, and on the convex portion, the heat transfer tube On the other hand, the end opposite to the side plate is placed and supported In the region closer to the side plate than the convex part, a gap for allowing the heating gas to pass is formed between the lower part of the heat transfer tube and the lower wall part of the case body part, An upward stepped portion for reducing the gap is formed on the lower wall portion of the case main body portion, and the convex portion is provided on the stepped portion.

According to such a configuration, the following effects can be obtained.
Since the heat transfer tube is fixed using the side plate of the case, the structure for fixing the heat transfer tube is simplified, and the assembly workability of the heat exchanger is improved.
Based on the presence of the convex portion, an effect of further stabilizing the fixing state of the heat transfer tube can be obtained. In addition, since the heating gas can be passed through the gap formed between the lower part of the heat transfer tube and the lower wall part of the case main body, the lower part of the heat transfer tube is efficient for heat recovery from the heating gas. It is often used and is preferable for improving heat exchange efficiency.
By providing the stepped portion, the gap between the lower portion of the heat transfer tube and the lower wall portion of the case main body portion can be reduced, so that the heating gas does not easily act on the lower portion of the heat transfer tube, This is more preferable in increasing the exchange efficiency.

  In the present invention, preferably, in the lower wall portion of the case main body portion, a drain discharge port is provided at a position downstream of the step portion in the heating gas flow direction, and more than the step portion. First and second recesses extending in the left-right width direction of the lower wall portion are formed on the upstream side and the downstream side in the gas flow direction for heating, and the first side portion in the left-right width direction of the lower wall portion is provided with the first A third recess that connects one end of the first and second recesses is formed, and the drain that has flowed down from the heat transfer tube onto the lower wall portion is one of the first to third recesses. It is configured to flow and be guided to the drain outlet.

  According to such a configuration, the drain generated with heat recovery can be accurately discharged outside the case after being guided to the drain outlet using the first to third recesses, The presence of the stepped portion can prevent a problem that it becomes difficult to discharge the drain.

The hot water apparatus provided by the second aspect of the present invention includes the heat exchanger provided by the first aspect of the present invention.
According to such a configuration, the same effect as described for the heat exchanger provided by the first aspect of the present invention can be obtained.

  Other features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention with reference to the accompanying drawings.

It is a perspective view which shows an example of the hot water apparatus which concerns on this invention. It is II-II sectional drawing of FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 1. It is a perspective view of the heat exchanger (equivalent to an example of the heat exchanger which concerns on this invention) with which the hot water apparatus shown in FIG. 1 was equipped. It is a disassembled perspective view of the heat exchanger shown in FIG. It is a plane sectional view of the heat exchanger shown in FIG. It is a schematic plane cross section which shows the structure of the lower wall part of the case of the heat exchanger shown in FIG. It is a disassembled sectional view of the heat exchanger shown in FIG. It is a plane sectional view showing other examples of the heat exchanger concerning the present invention. It is principal part sectional drawing which shows the other example of the heat exchanger which concerns on this invention.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

  The hot water apparatus WH shown in FIG. 1 is configured as a hot water supply apparatus capable of two systems of hot water supply, and burners 3a and 3b capable of individually combusting fuel such as fuel gas and the burners 3a and 3b. Fan 31 for supplying combustion air, primary heat exchangers 1a and 1b for recovering sensible heat from the combustion gas generated by the burners 3a and 3b, and secondary heat for recovering latent heat from the combustion gas An exchange HE is provided. The secondary heat exchanger HE corresponds to an example of the heat exchanger according to the present invention, and the primary heat exchangers 1a and 1b do not correspond to a specific example of the heat exchanger according to the present invention. The secondary heat exchanger HE in the present embodiment is a single-can two-circuit system in which two heat transfer tubes T1 and T2 are accommodated in one case C, and has an external form as shown in FIG. The details will be described later.

  The primary heat exchangers 1 a and 1 b have a configuration in which, for example, heat transfer tubes 11 a and 11 b including a large number of fins 12 are arranged in the can 30 and partitioned by a partition wall 32. The combustion gas that has passed through the primary heat exchangers 1 a and 1 b is supplied to the secondary heat exchanger HE using the guide member 39. As shown in FIGS. 2 and 3, the combustion gas that has passed upward through the primary heat exchangers 1 a and 1 b passes through the guide member 39 and passes through the air supply ports 51 a and 51 b of the secondary heat exchanger HE. C flows into C and acts individually on the heat transfer tubes T1 and T2, and thereafter is discharged as exhaust gas from a common exhaust port 52 to the outside. Of course, the exhaust port 52 may have a configuration in which two are provided in the same manner as the air supply ports 51a and 51b.

  In FIG. 1, headers 80a and 80b for incoming water and headers 81a and 81b for hot water are connected to both ends of heat transfer tubes T1 and T2 of the secondary heat exchanger HE. The hot water supplied to the incoming header 80a passes through the heat transfer pipe T1 and is heated, and then is sent to the primary heat exchanger 1a via the outgoing hot water header 81a and the piping portion 82 to be further heated. Then, the hot water is discharged from the hot water outlet 14a. This hot water is used, for example, for general hot water supply, and is supplied to a kitchen or a washroom. On the other hand, the hot water supplied to the incoming header 80b passes through the heat transfer tube T2 and is heated, and then sent to the primary heat exchanger 1b via the outgoing hot water header 81b and the piping part 83. Heated and discharged from the outlet 14b. This hot water is used, for example, for heating or bath water supply. Antifreeze is also included in the hot water concept.

  Next, the configuration of the secondary heat exchanger HE will be described in more detail.

  The case C of the secondary heat exchanger HE has a substantially rectangular parallelepiped shape, and is a rectangular tube (rectangular tube) case main body 5 having both left and right ends opened, and side plates 6a and 6b that close the end openings 53a and 53b. And have. As shown in FIGS. 2 and 3, the case main body 5 includes an upper wall portion 50 a, a lower wall portion 50 b, a front wall portion 50 c, as a plurality of wall portions surrounding the entire circumference of the heat transfer tubes T <b> 1 and T <b> 2. And a rear wall 50d. The air supply ports 51a and 51b are provided in the rear wall portion 50d, and the exhaust port 52 is provided in the front wall portion 50c. As shown in FIG. 5, the case main body portion 5 is a single plate member 5 ′ having regions (same as those of the wall portions 50 a to 50 d) corresponding to the plurality of wall portions 50 a to 50 d. Is bent into a rectangular tube shape. The plate material 5 ′ is formed by forming the above-described air supply ports 51a and 51b and the exhaust port 52 on a metal plate made of stainless steel, for example, and further appropriately pressing predetermined portions described later.

As shown in FIG. 2 and FIG. 3, the case body 5 has the front wall 50c and the rear wall 50d standing upward from the front and rear end edges of the lower wall 50b and bending, and the upper end of the rear wall 50d. The upper wall portion 50a is bent substantially horizontally from the edge. A bent piece 50e that is bent upward is integrally formed at the tip edge of the upper wall 50a. The bent piece portion 50e and the upper end edge of the front wall portion 50c are overlapped with each other, and the overlapped portion is, for example, a joint portion J1 subjected to welding. The joint portion J1 corresponds to an example of “a joint portion between both edge portions of the plate material” in the present invention. When welding is performed on the plate material 5 ′, the corrosion resistance of the welded portion may be lowered, but in the present embodiment, the joint portion J <b> 1 is located at the uppermost portion of the case main body portion 5 or at a height close thereto. According to such a configuration, the strongly acidic drain generated with the recovery of latent heat from the combustion gas becomes difficult to contact the joint J1, which is preferable in preventing corrosion of the joint J1. In the vicinity of the upper edge of the front wall portion 50c, a convex portion 55a protruding toward the inside of the case C is integrally formed, and the leading edge of the upper wall portion 50a abuts on the upper surface portion of the convex portion 55a. Thus, positioning in the vertical direction is possible. Preferably, the convex portions 55a are provided in a pair on the left and right sides with an interval in the width direction of the case main body portion 5, the surfaces in contact with the upper wall portion 50a are flat, and the heights thereof are the same. It is aligned. Thereby, the end surfaces of the bent piece portions 50e of the front wall portion 50c and the upper wall portion 50a can be accurately aligned.

  The front wall 50c of the case main body 5 is integrally formed with a protruding portion 56 having a form in which a part of the region protrudes forward from its peripheral portion. An exhaust port 52 and an auxiliary opening 54 are provided. As shown in FIGS. 4 and 5, the protruding portion 56 has a form extending in the left-right width direction of the front wall portion 50 c, and the exhaust port 52 has an elongated shape extending in the left-right width direction as well. The protrusion 56 serves as an exhaust top and serves to guide the exhaust gas to the outside of the exterior case 90 that surrounds each part of the hot water device WH, as shown in FIGS.

  In the auxiliary opening 54, the drain generated due to the recovery of latent heat is not discharged from the drain discharge port 22 to the outside of the case C due to some trouble, and the water level of the drain accumulated in the case C has risen abnormally. In this case, the drain is a part for discharging the drain to the outside of the case C. The auxiliary opening 54 is provided at a position lower than the exhaust port 52, but is further provided at a height lower than the lower edge portions of the air supply ports 51a and 51b. As a result, when the drain is unreasonably collected in the case C, it is possible to prevent the drain from flowing into the air supply ports 51a and 51b.

  In the front part of the case C, silencers 7a and 7b and a seal material 7c are provided supported by brackets 70 and 71, respectively. Although these components are omitted in FIGS. 4 to 7, at least the silencers 7 a and 7 b and the seal material 7 c are provided in a form extending in series in the left-right width direction of the case C. The brackets 70 and 71 are formed by bending a stainless plate or the like, and are fixed to the case C by spot welding, for example. The silencers 7a and 7b are for reducing the exhaust noise of the combustion gas. However, the silencer 7a and the bracket 70 located in the vicinity of the joint portion J1 prevent the drain from scattering to the joint portion J1. Also plays a role. The sealing material 7c plays a role of restricting the combustion gas from proceeding toward the auxiliary opening 54, thereby preventing a large amount of exhaust gas from being discharged from the auxiliary opening 54 to the outside. In addition, since the sound deadening materials 7a and 7b and the sealing material 7c are arranged in front of the heat transfer tubes T1 and T2, when the outside air temperature is lowered when the operation of the water heater WH is stopped, the heat exchanger HE Due to the cold air blown from the front, the effect of suppressing the problem that the front portions of the heat transfer tubes T1 and T2 are cooled and frozen is also obtained.

  Each of the heat transfer tubes T1 and T2 has a configuration in which a plurality of helical tubes having an oval shape in plan view are arranged in a substantially concentric wrapping shape. The portions near the lower end and the upper end of the heat transfer tube T1 are straight pipe portions 20a and 20b extending substantially horizontally, and the portions near the outer ends of the straight pipe portions 20a and 20b penetrate the side plate 6a of the case C. In this through portion, the heat transfer tube T1 and the side plate 6a are joined and fixed to each other. The relationship between the heat transfer tube T2 and the side plate 6b is the same as described above, and the straight tube portions 21a and 21b extending substantially horizontally near the lower end and the upper end of the heat transfer tube T2 pass through the side plate 6b of the case C, and In this through portion, the heat transfer tube T2 and the side plate 6b are joined and fixed to each other.

  The side plates 6a and 6b are fitted into both end openings 53a and 53b of the case main body 5, and are joined to the peripheral edges of the both end openings 53a and 53b. As a result, the side plates 6a and 6b are fixed to the case body 5, and the heat transfer tubes T1 and T2 are also fixed. As clearly shown in FIG. 8, a plurality of convex portions 55 b protruding inwardly are integrally formed on the case main body 5 at the periphery of both end openings 53 a and 53 b of the case main body 5. When the side plates 6a and 6b are fitted into the opening portions 53a and 53b, the side plates 6a and 6b can be positioned by bringing the side plates 6a and 6b into contact with the convex portions 55b. Preferably, of the plurality of convex portions 55b, the portions that come into contact with the side plates 6a and 6b are flat, and are configured to be positioned appropriately by surface contact with the side plates 6a and 6b. In the case C, a partition plate 68 is interposed between the heat transfer tubes T1 and T2.

  As shown in FIGS. 2 and 3, the upper wall portion 50a of the case C is provided with a downward-facing step portion 50a ′ for reducing the gap c1 between the upper portions of the heat transfer tubes T1 and T2 and the upper wall portion 50a. It has been. Similarly, the lower wall portion 50b of the case C is provided with an upward step portion 50b ′ for reducing the gap c2 between the lower portions of the heat transfer tubes T1 and T2 and the lower wall portion 50b. When the gaps c1 and c2 are thus reduced, the combustion gas that has flowed into the case C from the air supply ports 51a and 51b passes through the gaps c1 and c2 and is transferred to the heat transfer tubes T1 and T2. It is possible to efficiently act on the upper part and the lower part.

  An upward convex portion 57 for supporting the heat transfer tube T1 is further provided on the step portion 50b ′ of the lower wall portion 50b. The convex portion 57 is formed in an appropriate size separated from the side plates 6a and 6b so as not to block the entire length of the gap c2, and the end of the heat transfer tube T1 opposite to the side plate 6a is , And is supported on the convex portion 57. Thus, more stable support of the heat transfer tube T1 is achieved. In the present embodiment, no means corresponding to the convex portion 57 is provided at the place where the other heat transfer tube T2 is disposed. The reason is that since the heat transfer tube T2 is relatively small and lightweight, stable support can be achieved without providing means corresponding to the convex portion 57. However, unlike the present embodiment, a convex portion for supporting the heat transfer tube T2 may be provided on the lower wall portion 50b.

  The lower wall part 50b of the case C is provided with means for positively guiding the drain toward the drain discharge port 22. That is, as shown in FIG. 7, the drain outlet 22 is provided at a position near the front wall portion 50c of the case C and on one end side in the width direction of the case C (in the present embodiment, on the side plate portion 6b side). It has been. On the other hand, the first and second recesses 23a and 23b (width Sa and Sb portions) of the case C are located at a position closer to the rear wall 50d and a position closer to the front wall 50c than the step 50b ′. It is formed extending in the left-right width direction. Further, on one end side in the width direction of the case C, a third recess 23c (a portion of the width Sc) that connects one end portions of the first and second recesses 23a and 23b is provided. These first to third recesses 23a to 23c are connected in a U shape in a plan view, and serve to guide the drain to flow in the direction indicated by the arrow N1 in FIG. Preferably, the bottom surfaces of the first to third recesses 23a to 23c are configured to be inclined so that the height thereof decreases as the direction of the arrow N1 proceeds. The step portion 50b ′ of the lower wall portion 50b can smoothly flow the drain into the first to third recesses 23a to 23c when the drain flows down from the heat transfer tubes T1 and T2 to the upper surface portion thereof. It is a form.

  Next, the operation of the hot water device WH will be described.

First, the case C of the secondary heat exchanger HE has the case body 5 formed by bending a single plate member 5 'into a rectangular tube shape. Can be reduced. In particular, in the present embodiment, as a means for joining both end edges of the plate material 5 ′, the bent piece portion 50e formed at the front end edge of the upper wall portion 50a and the upper end edge of the front wall portion 50c are overlapped. Therefore, it is possible to accurately join these portions to a state with good sealing performance so as not to cause leakage of combustion gas from these portions to the outside. Further, as described above, the joint portion J1 is disposed on the upper portion of the case C, and the effect that the drain does not easily come into contact with the joint portion J1 is obtained.

  The protrusion 56 provided on the front wall 50c of the case C functions as an exhaust top for guiding the exhaust gas to the outside of the exterior case C as described with reference to FIGS. The portion 56 is formed integrally with the front wall portion 50c. Therefore, compared with the case where the exhaust top is separately prepared and assembled to the case C, the manufacturing operation of the secondary heat exchanger HE is considerably simplified. The heat transfer tubes T1 and T2 are joined to the side plates 6a and 6b, and the side plates 6a and 6b are assembled to the case body 5 and at the same time, the heat transfer tubes T1 and T2 are assembled into the case C and fixed. . In particular, the heat transfer tube T1 can be stably supported by using the convex portion 57 integrally formed with the lower wall portion 50b. For this reason, the production of the secondary heat exchanger HE is facilitated, and the production cost of the secondary heat exchanger HE, and thus the overall production cost of the hot water device WH can be reduced.

  In addition, according to the present embodiment, as described above, the drain generated in the secondary heat exchanger HE is smoothly guided to the drain outlet 22 using the first to third recesses 23a to 23c. It is possible. It is also possible to appropriately avoid such a problem that the drain is blocked by the convex portion 57 and the step portion 50b 'and it becomes difficult to discharge the drain.

  9 and 10 show another embodiment of the present invention. In the figure, the same or similar elements as those in the above embodiment are given the same reference numerals as in the above embodiment.

  In the embodiment shown in FIG. 9, the secondary heat exchanger HE contains only the heat transfer tube T1 in the case C, and does not contain the heat transfer tube corresponding to the heat transfer tube T2. For this reason, the side plate 6b is not configured to be joined to the heat transfer tube, but is simply configured as a member that closes the end opening 53b. As can be understood from the present embodiment, the heat exchanger according to the present invention can be a one-can one-circuit system instead of the one-can multiple-circuit system. In addition, when using two one-can / one-circuit heat exchangers and using two burners corresponding to them, a configuration in which one fan for supplying combustion air is provided corresponding to each burner. It can be.

  In the embodiment shown in FIG. 10, the side plate 6 a of the case C is attached in a state in which the flange portion 60 formed on the outer peripheral edge is externally fitted to the end portion of the case main body portion 5. Even with such a configuration, the side plate 6 a can be accurately positioned and attached to the end portion of the case body 5.

  The present invention is not limited to the contents of the above-described embodiment. The specific configuration of each part of the heat exchanger and the hot water apparatus according to the present invention can be variously modified within the intended scope of the present invention.

In the above-described embodiment, the front wall portion 50c and the upper wall portion 50a of the case C are not directly connected to each other at the end edge portions, and these portions are joint portions (joint portions J1). However, the present invention is not limited to this. For example, after the edge portions of the upper wall portion 50a and the rear wall portion 50d are not directly connected to each other (in this case, the upper wall portion 50a and the front wall portion 50c are directly connected in a bent state). ), The end edge portions of the upper wall portion 50a and the rear wall portion 50d may be joined to each other. Even in this case, the junction can be arranged at the uppermost part of the case C or at a height close to the upper part of the case C to make it difficult to contact the drain. Of course, in the present invention,
A place other than the above can be used as a joint place.

  The case main body portion of the heat exchanger according to the present invention is formed in a rectangular tube shape, but the rectangular tube shape referred to in the present invention is a cylindrical shape that does not have a corner portion such as a cylindrical shape or an elliptical cylindrical shape. In other words, it does not have to be a cylinder having an accurate rectangular cross-sectional shape. Further, in the heat exchanger according to the present invention, the formation positions of the air supply port and the exhaust port can be changed as appropriate. For example, contrary to the above-described embodiment, the air supply port may be provided in the front wall portion of the case, and the exhaust port may be provided in the rear wall portion of the case. In this case, it goes without saying that the protruding portion serving as the exhaust top is formed on the rear wall portion of the case. By providing the air supply port in the bottom wall portion of the case, it is possible to adopt a configuration in which the combustion gas that has passed through the primary heat exchanger located therebelow directly flows into the air supply port. Of course, the protruding portion may be formed in a cylindrical shape, a rectangular tube shape, or the like other than the shape protruding in an elongated shape.

  The heat transfer tube is not limited to a tube using a spiral tube, and may be configured to use, for example, a U-shaped tube or a meandering flexible tube. As the heating gas in the present invention, a gas other than the combustion gas can be used. For example, exhaust gas discharged from a fuel cell of a cogeneration system or a gas engine can be used. The heat exchanger according to the present invention can be used not only for latent heat recovery but also for sensible heat recovery, and the type thereof is not limited. The hot water device as used in the present invention means a device having a function of generating hot water, and is used for various types of hot water supply devices for general hot water supply, bath hot water supply, heating, snow melting, and the like, and hot water supply. Widely includes equipment for producing hot water.

WH water heater HE secondary heat exchanger (heat exchanger according to the present invention)
C Case J1 Joint part T1, T2 Heat transfer tube c1, c2 Crevice 5 Case body part 5 'Plate material 6a, 6b Side plate 22 Drain outlets 23a-23c First to third recesses 50a Upper wall part 50b Lower wall part 50b 'Step part 50c Front wall part 50d Rear wall part 50e Bending piece part 51a, 51b Air supply port 52 Exhaust port 53a, 53b End part opening (of case main-body part)
55b Convex part 57 Convex part

Claims (3)

It has a case that houses the heat transfer tube inside,
This case has a rectangular tube-like case main body portion having a plurality of wall portions surrounding the entire periphery of the heat transfer tube in the vertical direction, and the case main body portion is used for heating to heat the heat transfer tube. A heat exchanger provided with a gas inlet and an outlet,
The case has a side plate that is assembled to the end of the case main body so as to close the end opening of the case main body, and the side plates include pipes on both ends of the heat transfer pipe on the inlet side and the outlet side. The body part penetrates and is fixed,
On the lower wall portion of the case body portion, an upward convex portion is provided so as to be separated from the side plate, and on the convex portion, an end of the heat transfer tube opposite to the side plate is provided. While the portion is mounted and supported, the heating gas passes between the lower portion of the heat transfer tube and the lower wall portion of the case body in the region closer to the side plate than the convex portion. A gap is formed to allow
A heat exchanger characterized in that an upward step portion for reducing the gap is formed on the lower wall portion of the case main body portion, and the convex portion is provided on the step portion. . The heat exchanger according to claim 1,
A drain discharge port is provided in a lower wall portion of the case main body portion on the downstream side in the heating gas flow direction with respect to the step portion, and an upstream side in the heating gas flow direction with respect to the step portion. The first and second recesses extending in the left-right width direction of the lower wall portion are formed on the downstream side, and the first and second recesses are formed on one end side in the left-right width direction of the lower wall portion. A third recess is formed connecting the one end portions,
The heat exchanger is configured such that the drain that has flowed down from the heat transfer tube onto the lower wall portion flows through any of the first to third recesses and is guided to the drain outlet. A hot water apparatus comprising the heat exchanger according to claim 1 or 2.

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