JP2008134000A - Heat exchanger and water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger capable of reducing manufacturing costs with a simple structure, and achieving high heat exchanging efficiency while preventing enlargement as a whole. <P>SOLUTION: In this heat exchanger B comprising a case 7 in which a fluid for heating is introduced, and first and second heat transfer tubes Pa, Pb disposed in the case 7, and provided with an inflow port and outflow ports 62a, 63a for heated fluid of the first heat transfer tube Pa at one end side in the width direction, of the case 7, and an inflow port and outflow ports 62b, 63b for the heated fluid of the second heat transfer tube P2 at the other end side in the width direction of the case 7, the first and second heat transfer tubes Pa, Pb have first and second spiral tubular body portions 5A, 5B, and the first and second spiral tubular body portions 5A, 5B are stacked in the spiral shaft length direction, and have the spiral winding directions opposite to each other. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat exchanger used for heating a desired fluid by performing heat recovery from a heating gas such as a combustion gas using a heat transfer tube, and a hot water apparatus including the heat exchanger.

  This applicant has proposed the thing of patent document 1 as an example of the heat exchanger used for a hot water apparatus. The heat exchanger described in this document is called a thin tube type, and a plurality of thin tubular heat transfer tubes extending in a straight line are accommodated in a case into which combustion gas is introduced. A partition plate is provided in the case, and the plurality of heat transfer tubes are divided into a first heat exchange part below the partition plate and a second heat exchange part above the partition plate. Has been. The water inlet and outlet of the heat transfer pipe constituting the first heat exchange section are arranged on one end side in the width direction of the case, whereas the water inlet and outlet of the heat transfer pipe constituting the second heat exchange section are arranged. The gate is arranged on the other end side in the width direction of the case.

  According to such a configuration, it is possible to perform hot water heating using the first and second heat exchange units individually, for example, performing hot water heating for general hot water supply and hot water heating for floor heating individually. Can do. On the other hand, since the 1st and 2nd heat exchange part is accommodated in one case, compared with the case where they are separately accommodated in two cases, the enlargement of the whole is also suppressed. Moreover, since the thin tubes are used as the plurality of heat transfer tubes, the heat transfer rate is high, which is suitable for recovering latent heat from the combustion gas. Furthermore, since the inlet and outlet for the first heat exchange section and the inlet and outlet for the second heat exchanger are distributed to one end side and the other end side of the case, This is also convenient when connecting pipes to parts. For example, when the heat exchanger is used for latent heat recovery, two heat exchangers for sensible heat recovery are used separately from the heat exchanger, and one of these two heat exchangers is used. It is also possible to reduce the piping distance between them by making the water inlet and the hot water outlet of the first heat exchange section approach and the other approaching the water inlet and the hot water outlet of the second heat exchange section. is there.

  However, the prior art has problems to be improved as described below.

  That is, in order to increase the heat exchange efficiency of the heat exchanger, it is necessary to increase the number of heat transfer tubes. However, when the number of heat transfer tubes is increased in this way, the number of parts is increased, the structure becomes complicated, and the manufacturing work becomes complicated. In particular, when attaching a header for incoming and outgoing hot water to a large number of heat transfer tubes, the work of joining each of the large number of heat transfer tubes to the header becomes more complicated. As a result, the manufacturing cost is expensive, and there is room for improvement in this respect.

  In addition, as a conventional heat exchanger, there is one using a so-called spiral heat transfer tube as described in Patent Documents 2 to 4, for example, unlike the above-described heat exchanger. In this type of heat exchanger, since the heat transfer tubes are formed in a spiral shape, the heat transfer area of one heat transfer tube can be increased. Therefore, the present inventor intends to reduce the number of heat transfer tubes and simplify the structure by replacing the heat transfer tubes with a spiral type in the structure of the thin tube heat exchanger described above. Inspired. However, the helical heat transfer tube has a unique form in which a plurality of loop tube portions connected in series are stacked in a certain direction. Therefore, when two independent heat exchange parts are configured using such a helical tube part, there are problems inherent in reducing the overall size and improving the heat exchange efficiency. Therefore, it is desired to solve this problem appropriately.

Japanese Patent Laid-Open No. 2005-274043 Japanese Patent Laid-Open No. 62-288446 No. 6-8442 Japanese Patent No. 2835286

The present invention has been conceived under such circumstances. The structure is simple and the production cost can be reduced, and the overall enlargement is suppressed and high heat exchange efficiency is achieved. It is an object of the present invention to provide a heat exchanger that can be obtained and a hot water device including the heat exchanger.

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

  The heat exchanger provided by the first aspect of the present invention includes a case in which a heating fluid is introduced, and first and second heat transfer tubes disposed in the case. The inlet and outlet of the fluid to be heated of the first heat transfer tube are arranged on one end side in the width direction of the case, and the inlet and outlet of the fluid to be heated of the second heat transfer tube are A heat exchanger disposed on the other end in the width direction of the case, wherein the first and second heat transfer tubes have first and second helical tube parts, The first and second helical tube portions are stacked in the longitudinal direction of the spiral axis, and the winding directions of the spirals are opposite to each other. In the present invention, the “spiral axis length direction” means the direction in which the spiral central axis of the spiral tube body extends.

  According to such a configuration, the following effects can be obtained. However, for ease of understanding, description will be made with reference to FIG.

  According to the present invention, for example, as shown in FIG. 1 (a), when the first helical tube portion is, for example, right-handed (plan view in the direction of traveling from below to above), the second helical tube The part is counterclockwise on the opposite side. In such a configuration, the first and second helical tube portions can be stacked close to each other without causing a large gap between the first and second helical tube portions. On the other hand, in the comparative example of FIG. 1B, both the first and second helical tube portions are right-handed. According to this comparative configuration, a large gap C is generated between the first and second helical tube portions. For this reason, according to the present invention, the overall height H1 of the first and second helical tube portions can be made lower than the comparative height H2, thereby achieving downsizing. In addition, as an important point, the gap C becomes a factor that causes uneven distribution of the flow of the heating fluid when the heating fluid is applied to the first and second helical tube portions, Reduces heat exchange efficiency. However, according to the present invention, it is also appropriately avoided that the heat exchange efficiency decreases due to such a gap C.

  Of course, according to the present invention, the inlet and the outlet of the heating fluid of the first and second heat transfer tubes are distributed to one end side and the other end side in the width direction of the case. When the heat exchanger is used for latent heat recovery and connected to two heat exchangers for sensible heat recovery, there is an advantage that the piping distance can be shortened. Moreover, since the heat transfer tube is configured as a so-called spiral heat transfer tube, the heat transfer area of one heat transfer tube is large. Therefore, it is possible to obtain high heat exchange efficiency without increasing the number of heat transfer tubes, simplifying the overall structure by reducing the number of heat transfer tubes, and reducing the manufacturing cost.

  In a preferred embodiment of the present invention, the first and second helical tube portions are interposed between the first and second helical tube portions, and the first and second helical tube portions are individually provided in the case. There are provided partition plates for partitioning the first and second space portions accommodated, and the case is provided with two supplies that can individually supply heating fluid to the first and second space portions. Mouth is provided.

  According to such a configuration, the heating fluid can be individually supplied to the first and second space portions in the case, and the heat exchange using the first and second helical tube portions individually. Processing can be executed appropriately.

  In a preferred embodiment of the present invention, the second spiral tube portion is stacked above the first spiral tube portion, and the case includes the first and second spirals. The bottom plate portion that receives the drain when the drain is dropped from the tube-shaped tube portion and is inclined so that the height becomes lower toward one end in the front-rear direction of the case, and the front and rear of the bottom plate portion Near one end of the direction, a discharge port for discharging the drain to the outside of the case is provided, and the spiral direction of the first spiral tube body is determined by the first spiral tube. Of the lower part of the body part, the winding direction is such that the other end side is higher than the one end side in the front-rear direction.

  When the heating fluid is a combustion gas and latent heat is recovered from the combustion gas, many drains (condensed water) are generated on the surface of the heat transfer tube. According to the above configuration, when such a drain is generated and dropped, the drain is received by the bottom plate portion of the case, guided to the discharge port by the tilting action of the bottom plate portion, and then discharged to the outside of the case. Can do. In addition, since the lower part of the first spiral tubular body part is inclined in the same direction as the bottom plate part of the case and has a step, the lower part of the first spiral tubular body part and the case It is also possible to prevent a large gap from being generated between the base plate portion and the bottom plate portion. If a large gap is formed in the above-described location, a large amount of heating fluid passes through the gap, resulting in a disadvantage that the amount of heat recovery is reduced and the vertical height of the case is increased. On the other hand, according to the said structure, such a disadvantage is avoided.

  The hot water apparatus provided by the second aspect of the present invention supplies the heat exchanger provided by the first aspect of the present invention and the combustion gas as the heating fluid into the case of the heat exchanger. And a combustor.

  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.

  2-9 has shown an example of the hot water supply apparatus as a specific example of the hot water apparatus with which this invention was applied, and the structure relevant to this. As clearly shown in FIG. 2, the hot water supply apparatus A of the present embodiment includes two combustors 3 a and 3 b, two primary heat exchangers 1 a and 1 b, and a secondary heat exchanger B. . The secondary heat exchanger B corresponds to an example of a heat exchanger to which the present invention is applied.

  Each of the combustors 3a and 3b is a positive combustion type gas burner, and is arranged in the can bodies 30a and 30b, and is configured such that fuel gas is supplied from the outside via the pipes 32a and 32b. In the cans 30a and 30b, combustion air is blown upward from the two blower fans 31 below. The primary heat exchangers 1a and 1b are for recovering sensible heat from the combustion gas generated by the combustors 3a and 3b, and the heat transfer tubes 11a and 11b having a plurality of fins 12 are can bodies 30a and 30b. It has a structure arranged inside.

  The secondary heat exchanger B is for recovering latent heat from the combustion gas from which sensible heat has been recovered by the primary heat exchangers 1a and 1b, and is disposed above the primary heat exchangers 1a and 1b. And it is connected to can bodies 30a and 30b via auxiliary can bodies 19a and 19b. The secondary heat exchanger B includes a case 7 in which combustion gas is introduced, a plurality of first and second heat transfer tubes Pa and Pb, and two sets of headers 60a and 60b for entering and discharging hot water. 61a and 61b are provided. The first and second heat transfer tubes Pa, Pb have first and second helical tube portions 5A, 5B, and these first and second helical tube portions 5A, 5B are: The case 7 is stacked in the vertical height direction (vertical direction) of the case 7, which is the direction of the length of the spiral axis.

  The case 7 has a hollow, substantially rectangular parallelepiped shape. As clearly shown in FIG. 4, a partition plate 78 is disposed inside the case 7. By this partition plate 78, the inside of the case 7 has a first space part 79a in which the first spiral tube part 5A is arranged and a second space part in which the second spiral tube part 5B is arranged. 79b. Two supply ports 71a and 71b and a discharge port 72 for combustion gas are provided in the rear wall portion 70a and the front wall portion 70b of the case 7. Combustion gases that have passed through the primary heat exchangers 1a and 1b and have traveled above them individually pass through the auxiliary can bodies 19a and 19b, respectively, and are supplied from the supply ports 71a and 71b to the first and second space portions 79a. , 79b and act on the first and second helical tube portions 5A, 5B. The discharge port 72 is shared, and any combustion gas that has traveled through the first and second space portions 79 a and 79 b passes through the discharge port 72 and is discharged to the outside of the case 7. The discharge port 72 has, for example, a substantially rectangular shape as shown in FIG. The same applies to the supply ports 71a and 71b.

  When latent heat is recovered from the combustion gas by the first and second helical tube portions 5A and 5B, drains (condensed water) are generated on the surfaces thereof and dripped downward. In contrast, the case 7 has a bottom wall portion 70d, and a drain outlet 73 is provided at a position near the front end of the bottom wall portion 70d. Further, the bottom wall portion 70d is inclined in a front-down manner. As a result, when the drain drops from the surface of the first and second helical tube portions 5A and 5B onto the bottom wall portion 70d, the drain then flows into the discharge port 73 and is discharged to the outside of the case 7. .

  Each of the first spiral tubular body portions 5A has a plurality of loop portions 50a connected in a series of substantially oval shapes in plan view through a plurality of gaps 59, as shown well in FIGS. It is the structure laminated | stacked on the up-down height direction. The plurality of first spiral tubular body portions 5A are formed so that the sizes of the respective loop portions 50a are different from each other, and these are arranged in a substantially concentric overlapping shape. The spiral winding direction of the plurality of first spiral tubular body portions 5A is right-handed (plan view in a direction of proceeding from the lower portion to the upper portion of the first spiral tubular body portion 5A). Accordingly, as shown in FIG. 4, the lower end of the first spiral tubular body portion 5A is higher at the rear end portion 5A ″ than at the front end portion 5A ′ side.

  As shown in FIGS. 5 and 8, each second spiral tubular body portion 5 </ b> B includes a plurality of loop portions 50 b connected in a series of substantially oval shapes in plan view through a plurality of gaps 59. It has the structure laminated | stacked on the up-down height direction, and they are distribute | arranged to the substantially concentric overwrapping shape. These points are common to the first spiral tubular body portion 5A. However, the winding direction of the spiral of the second spiral tubular body portion 5B is left-handed (plan view in a direction from the lower portion to the upper portion of the second spiral tubular body portion 5B). 1 is different from the spiral tubular body portion 5A. The technical significance of this will be described later.

  The lower and upper extending tube portions 51b and 52b extending to the plurality of second spiral tube portions 5B pass through one side wall 70f of the case 7 and are drawn out of the case. It is connected to the headers 60b and 61b for hot water (see FIGS. 8 and 9). On the other hand, as shown in FIG. 6 and FIG. 7, the lower and upper extending tube portions 51a and 52a of the first spiral tube portions 5A extend in the opposite direction to the case 7 It penetrates the other side wall 70e and is connected to headers 60a and 61a for water entry and hot water.

  As shown in FIG. 2, the outlets 63a and 63b of the headers 61a and 61b are connected to the inlets 13a and 13b of the heat transfer tubes 11a and 11b via appropriate pipes 90a and 90b. A water supply pipe (not shown) is connected to the water inlet 62a of the header 60a. The water supplied to the water inlet 62a sequentially passes through the first spiral tubular body 5A and the heat transfer pipe 11a and is heated, and then supplied from the hot water outlet 14a to a desired hot water supply destination. On the other hand, a water supply pipe (not shown) is also connected to the water inlet 62b of the header 61b, and the water supplied to the water inlet 62b sequentially passes through the second spiral tubular body portion 5B and the heat transfer pipe 11b. It is heated and then supplied from the hot water outlet 14b to a desired hot water supply destination. In addition, when this hot water supply apparatus A is used as a heating source for floor heating, for example, an antifreeze liquid is preferably supplied as a fluid to be heated.

  Next, the effect | action of the secondary heat exchanger B and the hot water supply apparatus A provided with this is demonstrated.

  In FIG. 2, first, sensible heat is recovered from the combustion gas generated by the combustor 3a by the primary heat exchanger 1a, and then the latent heat is generated by the first helical tube portion 5A of the secondary heat exchanger B. Can be recovered. Similarly, sensible heat and latent heat can be recovered from the combustion gas generated by the combustor 3b by the primary spiral heat exchanger 1b and the second helical tube portion 5B of the secondary heat exchanger B. Therefore, hot water heating can be performed efficiently by such heat recovery. As described above, the drain generated along with the latent heat recovery is appropriately discharged from the discharge port 73 to the outside of the case 7. In the present embodiment, the drain outlet 73 is provided near the front end of the case 7, but in this way, pipe connection work to the outlet 73 is facilitated. In addition, since the distance between the discharge port 73 and the air supply port 71a is increased, the hot water supply device A vibrates in the state where the drain is accumulated around the discharge port 73 due to clogging. Even if it is inclined, an effect of preventing the drain from flowing into the air supply port 71a and flowing down onto the primary heat exchanger 1a can be expected.

  As described above, the spiral winding directions of the first and second helical tube portions 5A and 5B are different. For this reason, as shown in FIG. 4, the upper part of 5 A of 1st spiral tube parts and the lower part of the 2nd spiral tube part 5B can be made to approach. That is, according to the present embodiment, it is possible to prevent a large gap corresponding to the proportional gap C described with reference to FIG. For this reason, the dimension s1 between the first and second spiral tube portions 5A and 5B is reduced, and the overall vertical height of the first and second spiral tube portions 5A and 5B, and consequently The height dimension of the case 7 can be reduced.

  Further, if the above-described dimension s1 is reduced, even if a relatively thin plate material is used as the partition plate 78, each of the first and second helical tube portions 5A and 5B, the partition plate 78, and The size of the gaps C1 and C2 can be reduced. In this way, the flow rate of the combustion gas passing through the gaps C1 and C2 can be reduced, and the combustion gas passing through the gaps C1 and C2 acts on the first and second helical tube portions 5A and 5B. The effect which becomes easy is acquired and it becomes suitable for improving heat exchange efficiency. Further, at the lower part of the first spiral tubular body part 5A, the rear end part 5A ″ is higher than the front end part 5A ′, which matches the inclination of the bottom wall part 70d of the case 7. The size of the gap C3 between the lower portion of the first spiral tubular body portion 5A and the bottom plate portion 70d is also reduced, and the heat exchange efficiency can be further increased. Unlike the bottom wall portion 70d, it is not necessary to consider draining of the drain and the like, so that the gap with the upper portion of the second spiral tubular body portion 5B can be appropriately inclined.

  In this hot water supply apparatus A, as shown in FIG. 2, the headers 60a and 61a of the secondary heat exchanger B and the primary heat exchanger 1a can be brought close to each other. Similarly, the headers 60b and 61b and the primary heat exchanger 1b can be brought close to each other. Therefore, a piping system that performs hot water heating using the heat transfer pipe Pa and the primary heat exchanger 1a is clearly distinguished from a piping system that performs hot water heating using the heat transfer pipe Pb and the primary heat exchanger 1b. The pipe structure can be made orderly. There is also an advantage that the dimensional length of the pipes 90a and 90b is shortened.

  The present invention is not limited to the embodiment described above. 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.

  The loop shapes of the first and second spiral tubular body portions are not limited to a substantially oval shape, and may be other various shapes such as a substantially long rectangular shape, a substantially regular rectangular shape, or a circular shape. it can. Moreover, the lamination direction of the 1st and 2nd spiral tube parts should just be those spiral axis length directions, and is not limited to a perpendicular direction. For example, the first and second helical tube portions may be stacked so as to be arranged in the horizontal direction. The specific number of the first and second heat transfer tubes is not limited. Although it is not very realistic, it is possible to use one first heat transfer tube and one second heat transfer tube. As the fluid to be heated supplied to the heat transfer tube, a fluid other than water or antifreeze can be applied, and a medium other than the combustion gas can be applied as the heating fluid. The case may be any case as long as it accommodates the heat transfer tube and into which a heating fluid such as combustion gas flows, and its specific shape is not limited. When supplying the heating fluid into the case, instead of supplying the heating fluid from behind the case, for example, the heating fluid may be supplied from the front side of the case and discharged to the back of the case. it can.

  In the embodiment described above, the present invention is not applied to the primary heat exchanger for sensible heat recovery, but the heat exchanger according to the present invention may be of any type for sensible heat recovery and latent heat recovery. . The heat exchanger according to the present invention can also be used for sensible heat recovery.

  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.

(A) is explanatory drawing which shows the basic effect | action of this invention, (b) is explanatory drawing which shows contrast. It is a schematic front sectional view showing an example of a hot water supply device as a hot water device to which the present invention is applied. It is a principal part front view of the hot-water supply apparatus shown in FIG. It is IV-IV sectional drawing of FIG. It is front sectional drawing of the secondary heat exchanger of the hot water supply apparatus shown in FIG. It is a plane sectional view of a portion in which the 1st heat exchanger tube of the secondary heat exchanger shown in Drawing 5 is provided. FIG. 7 is a right side view of FIG. 6. FIG. 6 is a plan sectional view of a portion where the second heat transfer tube of the secondary heat exchanger shown in FIG. 5 is provided. FIG. 9 is a left side view of FIG. 8.

Explanation of symbols

A Hot water supply device (hot water device)
B Secondary heat exchanger (heat exchanger)
Pa, Pb First and second heat transfer tubes 3a, 3b Combustors 5A, 5B First and second spiral tube portions 7 Case 62a, 62b Water inlet (inlet for fluid to be heated)
63a, 63b Hot water outlet (outlet of fluid to be heated)
70d Bottom wall (of the case)
71a, 71b supply port (for combustion gas)
72 outlet (for combustion gas)
73 Discharge port (for drain)
78 divider

Claims (4)

A case in which a heating fluid is introduced inside, and first and second heat transfer tubes arranged in the case, and
The inlet and outlet of the heated fluid of the first heat transfer tube are arranged on one end side in the width direction of the case, and the inlet and outlet of the heated fluid of the second heat transfer tube are the case. A heat exchanger disposed on the other end in the width direction of
The first and second heat transfer tubes have first and second helical tube parts,
These first and second helical tube parts are stacked in the direction of the length of the spiral axis, and the winding directions of the spirals are opposite to each other. . First and second spaces that are interposed between the first and second spiral tube portions and in which the first and second spiral tube portions are individually accommodated in the case. It has a partition plate that divides into parts,
2. The heat exchanger according to claim 1, wherein the case is provided with two supply ports capable of individually supplying a heating fluid to the first and second space portions. The second helical tube portion is stacked above the first helical tube portion,
The case receives a drain when the drain drops from the first and second spiral tubular body portions, and has a bottom plate portion that is inclined so that the height is lowered toward one end in the front-rear direction of the case. And having a discharge port for discharging the drain to the outside of the case near the one end of the bottom plate portion in the front-rear direction,
The spiral winding direction of the first spiral tube portion is a winding direction in which the other end side of the lower portion of the first spiral tube portion is higher than the one end side in the front-rear direction. The heat exchanger according to claim 1 or 2.   Hot water comprising: the heat exchanger according to any one of claims 1 to 3; and a combustor that supplies combustion gas as the heating fluid into a case of the heat exchanger. apparatus.

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