JP5207053B2 - Heat exchanger and water heater - Google Patents

Description

  The present invention is configured by using a plurality of coil tube units, a heat exchanger that recovers heat from a heating medium such as combustion gas using the plurality of coil tube units, a hot water supply device including the heat exchanger, and the like It relates to the hot water device.

  An example of a conventional heat exchanger is described in Patent Document 1. In the heat exchanger described in the document, the heat transfer tubes are configured using a plurality of coil tube units, and the plurality of coil tube units are arranged in the axial direction in the casing. . Each coil tube unit has a coil tube portion in which a plurality of spiral loop portions are connected in series, and a pair of extended tube portions connected to both ends of the coil tube unit. It is possible to allow water to flow from the extended tube portion into the coil tube portion. On the other hand, when the combustion gas is supplied to the inner regions of the plurality of coil tube units, the combustion gas acts on the coiled tube portion while passing between the plurality of loop portions of the coil tube portion. . Therefore, it is possible to recover the heat from the combustion gas by the coiled tube portion and to heat the water flowing through the coil tube portion. If a heat transfer tube is configured using a plurality of coil tube units, the amount of heat recovered from the combustion gas can be changed as appropriate by increasing or decreasing the number of coil tube units, and the desired hot water heating capacity is exhibited. This makes it easier to design and manufacture the heat exchanger.

  However, the prior art has a problem to be solved as described below.

  That is, in the prior art, a coiled tube unit 9 as shown in FIGS. 9A and 9B is used. In the coil tube unit 9, first and second extending tube portions 91a and 91b extend in a tangential direction from both ends of a coil tube portion 90 as a circular spiral tube. A dimension L10 between the pair of extending tube portions 91a and 91b is as large as the inner diameter of the coil tube portion 90. In addition, a step h is generated between each of the extending tube portions 91a and 91b and the surface portion of the coil tube portion 90 located in the vicinity thereof. For this reason, as shown in FIG. 10, when the plurality of coil tube units 9 are arranged in the axial length direction, a gap 92 having a width L10 is formed in a region where they are adjacent to each other. In this case, when the combustion gas is supplied to the inside of each coil tube portion 90, most of the combustion gas passes through the gap 92, and the combustion gas is effectively applied to each coil tube portion 90. This causes a problem that the amount of heat recovery is reduced. In the example shown in FIGS. 9 and 10, the thickness of each part of the coiled tube body 90 is shown to be uniform, but in Patent Document 1, the thickness of each part of the coiled tube body is shown. A configuration is shown in which the gaps 92 are not generated as described above. However, in such a configuration, compared with the case where the thickness of each part of the coiled tube body part is formed uniformly, the manufacturing operation of the coiled tube body part becomes considerably troublesome and the manufacturing cost becomes high.

JP-T-2006-503260

  The present invention has been conceived under the circumstances as described above, and avoids the generation of large gaps in adjacent regions between a plurality of coiled tube units, and heating due to the existence of the gaps. It is an object of the present invention to provide a heat exchanger that can appropriately suppress a decrease in the amount of heat recovered from a working medium, and a hot water device including the heat exchanger.

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

  The heat exchanger provided by the first aspect of the present invention includes a plurality of coil tube units arranged in the axial length direction, and each of the coil tube units has a plurality of loop portions connected in series. A coil tube section, and first and second extending tube sections connected to both ends of the coil tube section and extending outward from the coil tube section; When the heating medium passes between the plurality of loop portions from one of the inner region and the outer region to the other, the fluid flowing through the coiled tube portion can be heated. In the heat exchanger, the first and second extending tube portions located in adjacent regions of the plurality of coil tube units are formed to extend in a substantially normal direction of the loop portions. It is characterized by being close to each other.

  According to such a configuration, in the adjacent region between the coil tube units, a gap formed between the first and second extending tube portions is reduced. Therefore, when passing the heating medium from one of the inner region and the outer region of the coiled tube portion toward the other, the heating medium is made to prevent most of the heating medium from passing through the gap. It is possible to efficiently act on the coiled tube body portion and increase the heat exchange efficiency. In the present invention, as means for reducing the gap formed between the first and second extending tube portions, both the first and second extending tube portions are connected to the loop portions. However, according to such means, unlike in Patent Document 1, the thickness of each part of the coil tube unit is formed unevenly. There is no need, and the manufacturing cost of the coil tube unit can be reduced.

  In a preferred embodiment of the present invention, each of the coil tube units has a plurality of coil tube portions that are substantially concentrically wound as the coil tube portions, and the plurality of coil tube bodies. The first and second extending tube portions formed so as to extend in the substantially normal direction of the loop portions are respectively connected to both ends of the portion, and the plurality of coil tube units are connected to each other. In the adjacent region, the first and second extending tube portions connected to the innermost coil tube portion interpose the other first and second extending tube portions therebetween. Are close to each other without.

  According to such a configuration, when a heating medium is applied to each coil tube unit, heat recovery is performed by each of the plurality of coil tube body portions that are substantially concentrically wound around each coil tube unit. In order to be carried out, it is more preferable to increase the heat exchange efficiency. On the other hand, according to the said structure, the clearance gap formed between the 1st and 2nd extending tubular-body parts connected with the innermost coil-tube part in the adjacent area | region between coiled-tube units is made small. be able to. For this reason, for example, when the heating medium is passed from the inner region of the innermost coil tube portion toward the outer region, most of the heating medium is prevented from passing through the gap. The heating medium can also be efficiently applied to the peripheral coil tube portion.

  In a preferred embodiment of the present invention, there is provided a header portion provided on a peripheral wall portion of a casing for accommodating the plurality of coil tube units therein, and having a water inlet and a hot water outlet, and each coil tube is provided in the header portion. By connecting the first and second extending tube portions of the unit, water can be passed from the header portion to each of the coil tube units, and adjacent to the plurality of coil tube units. The gap formed between the first and second extending tube portions located in the region is arranged to face the header portion, and the heating medium that has passed through the gap is placed in the header portion. It is set as the structure which can be made to act.

  According to such a configuration, using the heating medium that has passed through the gap formed between the first and second extending tube parts, the header part, and thus the hot water present in the header part is removed. It becomes possible to heat. Therefore, the heating medium that has passed through the gap can also be used effectively for hot water heating, which is more suitable for improving the heat exchange efficiency. Also, if the heating medium that has passed through the gap acts on the header portion, unlike the case where this heating medium acts on other parts of the casing, a part of the casing is heated to a high temperature by the heating medium. The problem that is solved is also solved appropriately.

  In a preferred embodiment of the present invention, it comprises a partition member that partitions the inner regions of the plurality of coil tube units into first and second space portions in the axial length direction, and the plurality of coil tube units are It is divided into a first heat exchanging part surrounding the first space part and a second heat exchanging part surrounding the second space part, and the heating medium is supplied to the first space part. The heating medium passes between the loop parts of the first heat exchange part and then passes between the loop parts of the second heat exchange part, and the first and second heat exchange parts. The exchange unit can sequentially recover sensible heat and latent heat from the heating medium.

  According to such a configuration, since sensible heat and latent heat can be recovered from the heating medium, respectively, it is more preferable for increasing the amount of heat recovery.

  In a preferred embodiment of the present invention, the plurality of coil tube units are provided side by side so that the axial length direction is a substantially horizontal direction, and the first and second extending tube portions are In addition, the drain generated on the outer surface of the coiled tube part in accordance with the latent heat recovery extends downward or obliquely downward from the coiled tube part so that the drain can be guided downward.

  According to such a configuration, when a drain generated due to the recovery of latent heat is generated on the surface of the coil tube body portion, the drain is positively guided downward by the first and second extending tube body portions. This eliminates the fact that a large amount of drain remains on the surface of the coiled tube portion. If many drains remain on the surface of the coiled tube part, it becomes difficult to directly contact the heating medium with the surface of the coiled tube part, resulting in a decrease in heat exchange efficiency. According to this, such a problem can be solved appropriately.

  In a preferred embodiment of the present invention, the header portion is located below the plurality of coil tube units and receives the drain guided by the first and second extending tube portions. It is possible and has a drain discharge port for discharging the received drain to the outside of the header portion.

  According to such a structure, a drain can be appropriately discharged | emitted outside the header part and a casing using a header part. Moreover, since the header part is provided with a water inlet, a hot water outlet, and a drain outlet, it is possible to consolidate connection pipes for these.

  A hot water apparatus provided by the second aspect of the present invention includes a burner and a heat exchanger for performing heat recovery from the combustion gas generated by the burner to perform hot water heating. However, the heat exchanger provided by the first aspect of the present invention is used as the heat exchanger.

  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.

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

  1-7 has shown an example of the heat exchanger with which this invention was applied, a hot water apparatus provided with the same, and the structure relevant to these. As clearly shown in FIG. 1, the hot water device WH of the present embodiment includes a burner 1 and a heat exchanger HE. The burner 1 is, for example, a gas burner. A gas mixture of combustion air and fuel gas is supplied to the burner 1 using a fan (not shown), and this gas mixture is ignited by an ignition plug (not shown). Combustion is performed by operation. The burner 1 is disposed in a first space portion 7A described later of the heat exchanger HE.

  The heat exchanger HE includes a casing 2 and a plurality of coil tube units U (U1 to U3) as heat transfer tubes accommodated in the casing 2. The casing 2 has a peripheral wall portion 20 surrounding the periphery of the plurality of coiled tube units U, and at both ends in the horizontal direction, an insertion opening 21 for the burner 1 and a combustion gas discharge port 22 for which heat recovery has been completed. Is formed. In addition, a header portion 5 for allowing water to flow through the plurality of coil tube units U is provided at the lower portion of the peripheral wall portion 20. A specific configuration of the header unit 5 will be described later.

  As shown in FIGS. 4 and 5, each coil tube unit U has two coil tube portions 3 (3A, 3B) having different winding diameters and having the same height in the axial length direction. ) Has a concentric lap winding configuration. Each coil tube portion 3 has a configuration in which a plurality of circular spiral loop portions 30 are connected in series, and a gap for allowing combustion gas to pass between the plurality of loop portions 30 is formed. Yes. First and second extending tube portions 4A and 4B are connected to both ends of each coil tube portion 3. In the present embodiment, each coiled tube portion 3 and the first and second extending tube portions 4A and 4B connected to the coiled tube portion 3 are formed by bending a single metal tube. The coil tube portions 3 and the first and second extending tube portions 4A and 4B are integrally connected. However, unlike this, the first and second extending tube portions 4A and 4B can be formed by using tubes separate from the coil tube portions 3 and connected to each other. .

  As clearly shown in FIG. 5, the first and second extending tube portions 4A and 4B extend in substantially the same direction as the normal line NL of the loop portion 30 so that they are substantially parallel to each other. It is bent and the first extending tube portion 4A and the second extending tube portion 4B are close to each other. In addition, the first and second extending tube portions 4A and 4B connected to the inner peripheral side coil tube portion 3A are provided between the first and second extended tube portions 3B. It is provided so that the interval L1 in the tangential direction of the loop portion 30 can be reduced without interposing the extending tube portions 4A and 4B. The distance L1 is small enough not to cause any trouble in connecting the first and second extending tube portions 4A and 4B to the header portion 5 described later.

  As shown in FIGS. 6 and 7, the plurality of coil tube units U1 to U3 are arranged so as to approach each other in the axial length direction (in the hot water apparatus WH of FIG. 1, the plurality of coil tube units U1 to U3 are arranged in a substantially horizontal direction, but for convenience, FIGS. 6 and 7 show the postures arranged in the vertical direction. Among the plurality of coil tube units U1 to U3, the first and second extending tube portions 4A located in the adjacent region between the coil tube units U1 and U2 and the adjacent region between the coil tube units U2 and U3, 4B extends in the same direction as one normal line (not shown) of the loop portion 30 and is close to each other. The opening width of the gap 6 formed between the first and second extending tube portions 4A and 4B is, for example, the same small dimension as the interval L1 shown in FIGS. 6 is preferable for reducing the amount of combustion gas passing through the cylinder 6.

  As shown in FIG. 1, the plurality of coil tube units U are arranged in the casing 2 in a state where they are arranged side by side so that their axial length directions are substantially horizontal directions. As positioning means for the plurality of coil tube units U, a set of spacers 29a, 29b and other members (not shown) that sandwich them in the horizontal direction are appropriately used. A partition member 28 is provided between the coil tube units U2 and U3, and an inner region of the coil tube units U1 to U3 includes a first space portion 7A in which the burner 1 is disposed, and combustion gas. The second space portion 7 </ b> B communicating with the discharge port 22 is partitioned. As a result, the two coil tube units U1, U2 serve as a first heat exchanging portion H1 surrounding the first space portion 7A, and the remaining coil tube units U3 define the second space portion 7B. It becomes the surrounding 2nd heat exchange part H2. When the burner 1 is driven to generate combustion gas in the first space portion 7A, the combustion gas passes between the loop portions 30 of the first heat exchange portion H1 and passes through the first heat exchange portion H1. , After passing between the loop portions 30 of the second heat exchange portion H2, flows into the second space portion 7B, and thereafter is discharged from the discharge port 22 to the outside of the casing 2. . In such a process, sensible heat and latent heat are sequentially recovered from the combustion gas by the first and second heat exchanging units H1 and H2.

  As clearly shown in FIG. 2, the first and second extending tube portions 4 </ b> A and 4 </ b> B of each coil tube unit U both extend downward and are connected to the header portion 5. As shown in FIG. 1, the header portion 5 has a water inlet 50 and a hot water outlet 51, and a plurality of hot water communicating with the inside of the first and second extending tube portions 4 </ b> A and 4 </ b> B inside. The inflow chamber 57 is formed. When water is supplied from the outside to the water inlet 50, the water flows through each coil tube unit U and is heated, and the hot water generated by heating is discharged from the hot water outlet 51 to the outside. The order of water flow to the plurality of coiled tube units U using the header portion 5 is, for example, the order shown by the arrows in FIG. 6, but is not limited to this. Preferably, non-heated low-temperature water is supplied to the coil tube unit U3 used for latent heat recovery, thereby increasing the amount of latent heat recovery. Preferably, the hot water finally passes through the coil tube part 3A on the inner peripheral side of the coil tube units U1, U2 heated to the highest temperature by the burner 1. If it does in this way, it will become advantageous in preventing the hot water in the coil pipe part 3A on the inner circumference side (innermost circumference) that becomes the highest temperature from boiling.

  When latent heat recovery is performed by the second heat exchange unit H2, water vapor in the combustion gas is condensed, and a drain (condensed water) is generated and attached to the surface of the coiled tube part 3 of the second heat exchange unit H2. . On the other hand, since the first and second extending tube portions 4A and 4B extend downward from the coil tube portion 3 as described above, the drain is connected to the first and second extensions. It becomes easy to flow downward along the surface of the pipe body parts 4A and 4B. As shown in FIG. 3, the upper surface side of the header part 5 is made into the shape which can receive the drain which flowed from upper direction. The header portion 5 is provided with drain discharge ports 58 and 59 for allowing the received drain to flow into a predetermined region in the header portion 5 and then discharging the drain to the outside of the header portion 5 and the casing 2. Further, as shown in FIG. 2, the header portion 5 is disposed so as to face the gap 6 between the first and second extending tube portions 4 </ b> A and 4 </ b> B. When passing through the gap 6 from the inner region toward the outer region, the combustion gas can act on the header portion 5.

  Next, the operation of the hot water device WH provided with the above-described heat exchanger HE will be described.

  First, when the burner 1 is driven to generate combustion gas in the first space portion 7A, as described above, this combustion gas passes between the loop portions 30 of the first heat exchange portion H1. After passing around the first heat exchanging portion H1, passes between the loop portions 30 of the second heat exchanging portion H2 and flows into the second space portion 7B, and then the casing 2 through the outlet 22 Is discharged outside. The first and second heat exchanging parts H1 and H2 are each configured by using coil tube parts 3A and 3B having a double winding structure, and each loop part 30 of the coil tube parts 3A and 3B. Are arranged in the flow direction of the combustion gas, so that the coil tube portions 3A and 3B are formed using circular tubes (tubes having a circular cross-sectional shape), but the heat from the combustion gas is It is possible to increase the recovery amount and obtain high heat exchange efficiency.

  In order to increase the amount of heat recovery, it is desirable to have a configuration in which a large gap for releasing the combustion gas is not generated in the adjacent region between the plurality of coil tube units U. On the other hand, in the heat exchanger HE of the present embodiment, as described with reference to FIGS. 6 and 7, the first and second extending positions located in the adjacent region between the coil tube units U <b> 1 and U <b> 2. The tube portions 4A and 4B and the first and second extending tube portions 4A and 4B located in the adjacent regions of the coil tube units U2 and U3 are substantially the same as the normal direction of each loop portion 30. It extends in the direction and is close to each other, and the opening width of the gap 6 between them is reduced. Therefore, as a result of appropriately preventing a large amount of combustion gas from passing through the gap 6, the amount of combustion gas that normally passes between the loop portions 30 is increased, and a large amount of combustion gas is passed through the coil tube portion 3. It becomes possible to make combustion gas act effectively.

  When a part of the combustion gas passes through the gap 6, as described above, this combustion gas acts on the header part 5 facing the gap 6, and the hot water existing in the header part 5 is heated. Is done. Therefore, the combustion gas that has passed through the gap 6 is also effectively used for hot water heating, and is more preferable for increasing the heat recovery amount. Unlike this embodiment, when the combustion gas that has passed through the gap 6 acts on a portion of the casing 2 where the header portion 5 is not provided, this portion may be heated to a high temperature and cause damage. However, according to the present embodiment, such a fear can be appropriately eliminated.

  When the latent heat is recovered from the combustion gas, a drain is generated and attached to the surface of the coil tube portion 3, and as described above, the drain extends in the first and second directions extending downward from the coil tube portion 3. It is guided onto the header portion 5 through the second extending tube portions 4A and 4B. The drain is then smoothly discharged to the outside of the casing 2 through the drain discharge ports 58 and 59. If many drains are attached to the surface of the coiled tube part 3, the heat exchange efficiency is lowered. However, according to the heat exchanger HE of the present embodiment, the drains can be excluded from the coiled tube part 3. It is promoted and the possibility that the heat exchange efficiency is lowered due to the presence of the drain is also preferably suppressed.

FIG. 8 shows 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 the figure, the first and second extending tube portions 4A and 4B extend obliquely downward from the coil tube portion 3. Even with such a configuration, it is possible to guide the drain generated on the surface of the coiled tube body portion 3 to flow downward by the first and second extending tube body portions 4A and 4B, and to eliminate the drain. Can be promoted.

  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 varied in design in various ways.

  For example, the tubular body constituting the coil tube unit is not limited to a tubular body having a circular cross section, and for example, a tubular body having an elliptical cross section or a flat tubular body similar to Patent Document 1 can be used. The specific cross-sectional shape is not limited. In addition, as the coil tube unit, either one in which a plurality of coil tube portions are formed in a substantially concentric wrapping shape or a single layer structure in which such wrapping is not performed can be used. In the case of the former lap winding structure, it is possible to have a lap winding structure of triple winding or more. When recovering latent heat from combustion gas, an acidic drain is generated. Therefore, it is preferable to make the coil tube unit a material having excellent acid resistance, such as stainless steel, but the specific material of the coil tube unit is also used. It is not limited to this.

  When a plurality of coil tube units are provided side by side as in the above-described embodiment, each loop portion of the coil tube body portion is in an upright vertical position, which is generated along with latent heat recovery. Although an advantage that the drain can easily flow downward from each loop portion is obtained, the present invention is not limited to this. In this invention, it can also be set as the structure which put in order in the attitude | position which laminated | stacked the several coil tube unit in the up-down direction (substantially perpendicular direction), or in the inclined attitude | position. The total number of coil tube units should just be plural, and the concrete number is not ask | required.

  As the heating medium in the present invention, for example, high-temperature waste gas other than the combustion gas can be used. Also, the fluid to be heated (fluid supplied into the coil tube unit) can be a fluid other than water. 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. It is a concept that includes a wide range of equipment for producing hot water.

It is sectional drawing which shows an example of the heat exchanger which concerns on this invention, and a warm water apparatus provided with the same. 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 which shows the coiled tube unit used with the heat exchanger shown in FIG. FIG. 5 is a plan view of FIG. 4. It is a perspective view which shows the arrangement | sequence state of the some coiled tube unit used with the heat exchanger shown in FIG. FIG. 7 is a front view of FIG. 6. It is a schematic sectional drawing which shows the other example of this invention. (A) is a top view which shows an example of the conventional coiled tube unit, (b) is the perspective view. FIG. 10 is a front view showing a state in which a plurality of coil tube units shown in FIG. 9 are arranged.

Explanation of symbols

WH Hot water apparatus HE Heat exchanger U Coil tube unit NL Normal line 1 Burner 2 Casing 3 Coil tube portions 4A and 4B First and second extending tube portions 5 Header portion 6 Clearance (first and second extension) (Between tube parts)
7A, 7B 1st and 2nd space part 20 Perimeter wall part (casing)
30 Loop part 50 Water inlet 51 Hot water outlet 58, 59 Drain outlet

Claims (7)

It has a plurality of coil tube units arranged in the axial direction,
Each of the coil tube units includes a coil tube portion in which a plurality of loop portions are connected in series, and first and second portions that are connected to both ends of the coil tube portion and extend outward of the coil tube portion. And an extended tube part,
The heating medium passes between the plurality of loop portions from one of the inner region and the outer region of the coil tube portion toward the other, so that the fluid flowing through the coil tube portion can be heated. A heat exchanger,
The first and second extending tube portions located in the adjacent regions of the plurality of coil tube units are formed so as to extend in a substantially normal direction of the loop portions and are close to each other. And a heat exchanger. Each of the coil tube units has a plurality of coil tube bodies that are substantially concentrically wound as the coil tube body, and the loop portions are provided at both ends of the coil tube bodies. The first and second extending tube portions formed so as to extend in a substantially normal direction are connected to each other,
In the adjacent region between the plurality of coil tube units, the first and second extended tube portions connected to the innermost coil tube portion are the other first and second portions between them. The heat exchanger according to claim 1, wherein the heat exchangers are close to each other without interposing an extended tube portion. Provided on the peripheral wall portion of the casing that accommodates the plurality of coil tube units therein, and includes a header portion having a water inlet and a hot water outlet,
By connecting the first and second extending tube portions of each coil tube unit to this header portion, water can be passed from the header portion to each coil tube unit.
The gap formed between the first and second extending tube portions located in the adjacent region between the plurality of coil tube units is arranged to face the header portion and passes through the gap. The heat exchanger according to claim 1, wherein the heating medium is configured to be able to act on the header portion. A partition member that partitions inner regions of the plurality of coil tube units into first and second space portions in the axial length direction;
The plurality of coil tube units are divided into a first heat exchange part surrounding the first space part and a second heat exchange part surrounding the second space part,
When the heating medium is supplied to the first space portion, the heating medium passes between the loop portions of the first heat exchange portion, and then the loop portions of the second heat exchange portion are connected to each other. 4. The heat exchanger according to claim 3, wherein the sensible heat and the latent heat can be sequentially recovered from the heating medium by the first and second heat exchange units. The plurality of coiled tube units are provided side by side so that the axial direction is substantially horizontal.
The first and second extending tube portions are directed downward or obliquely downward from the coil tube portion so as to be able to guide the drain generated on the outer surface of the coil tube portion in accordance with latent heat recovery. The heat exchanger according to claim 4, which extends.   The header portion is located below the plurality of coiled tube units and can receive the drain guided by the first and second extending tube portions, and the received drain can be received by the header portion. The heat exchanger according to claim 5, further comprising a drain discharge port for discharging to the outside of the header portion. A hot water apparatus comprising a burner and a heat exchanger for performing heat recovery from combustion gas generated by the burner to perform hot water heating,
A hot water apparatus, wherein the heat exchanger according to any one of claims 1 to 6 is used as the heat exchanger.

Images