JP2015224804A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide heat exchangers reduced in resistance of water passage and manufacturing cost and having a simple structure with which a turbulent flow generating member can be partially mounted to a heat transfer pipe.SOLUTION: The heat exchanger 10 includes: the heat transfer pipe 12; and the turbulent flow generating member 13 inserted into the heat transfer pipe 12 and generating a turbulent flow inside the heat transfer pipe 12. The heat transfer pipe 12 includes: multiple straight pipe parts 15 arranged in parallel; multiple coupling parts 16 for coupling end parts of the multiple straight pipe parts 15 to each other. The turbulent flow generating member 13 is partially mounted to straight pipe parts 15a, 15b of the multiple straight pipe parts 15.

Description

  The present invention relates to a heat exchanger, and more particularly to a heat exchanger equipped with a turbulent flow generating member for generating turbulent flow in a heat transfer tube.

  2. Description of the Related Art Conventionally, a combustion apparatus that combusts a gas has been widely spread as a heat source apparatus such as a hot water supply apparatus and a heating device. This type of combustion apparatus includes a blower fan that takes in combustion air from the outside, a multistage burner unit that mixes and burns combustion air and fuel gas, and high-temperature combustion gas and water flowing through a heat transfer tube. It has a heat exchanger that heats and heats the water, an exhaust pipe for discharging the exhaust gas after the heat exchange to the outside, and the like.

  As the above heat exchanger, generally, a heat exchanger tube and a fin tube heat exchanger composed of a plurality of fins fixed to the heat exchanger tube so as to be capable of heat transfer are employed. The thing which comprised, and the thing which comprised the heat exchanger tube and the fin with the copper material are employ | adopted widely.

  By the way, in the case of the heating operation for supplying heat to the heating equipment, since the first stage combustion is often performed without using all the combustion stages of the burner unit, the heat transfer tubes of the heat exchanger are partially heated for a long time. In addition, since the hot water temperature returning from the heating device to the heat exchanger also increases, there is a problem that boiling occurs in the local area of the heat transfer tube.

  In order to solve such a problem of local boiling, for example, in the single can two-circuit type heat exchanger of Patent Document 1, a plurality of straight pipe portions close to the burner among the plurality of straight pipe portions of the heat transfer tubes are used. A structure is disclosed in which local boiling is prevented by inserting turbulent coils over the entire length, and generating turbulent flow in the straight pipe portion with the turbulent coils to equalize the temperature.

Japanese Patent No. 3687140

  However, if the turbulent flow coil is inserted over the entire length of the straight tube portion of the heat transfer tube as in the single-can two-circuit heat exchanger of Patent Document 1, the water flow resistance of the heat transfer tube is greatly increased. There is a problem in that the ability of the heat exchanger is reduced due to the difficulty in forming a water flow in the passage on the output side of the heat exchanger. Moreover, when a turbulent coil is mounted over the entire length of the heat transfer tube, the manufacturing cost for manufacturing the turbulent coil increases, and as a result, the manufacturing cost of the heat exchanger increases.

  An object of the present invention is to provide a heat exchanger that reduces water flow resistance and manufacturing cost, and that can easily attach a turbulent flow generating member to a heat transfer tube with a simple structure. It is to be.

  The heat exchanger according to claim 1 is a heat exchanger including a heat transfer tube and a turbulent flow generation member inserted into the heat transfer tube and generating a turbulent flow in the heat transfer tube. A plurality of straight pipe portions arranged in parallel; and a plurality of connection pipe portions that connect ends of the plurality of straight pipe portions; and the turbulent flow generation member includes the plurality of straight pipe portions. It is characterized by being partially attached to at least one straight pipe portion.

  The heat exchanger according to claim 2 is the invention according to claim 1, wherein the straight pipe portion to which the turbulent flow generation member is partially attached is connected to a small diameter pipe portion and an end portion of the small diameter pipe portion; A large-diameter pipe portion having a larger diameter than the small-diameter pipe portion, the turbulent flow generation member is attached to the large-diameter pipe portion, and one end portion of the turbulent flow generation member is connected to the small-diameter pipe portion and the large-diameter pipe portion. It is characterized by being in contact with the inner stepped portion at the boundary with the diameter pipe portion.

  According to a third aspect of the present invention, there is provided the heat exchanger according to the first aspect, wherein the turbulent flow generating member is constituted by a turbulent coil, and one end of the turbulent flow coil is partially attached to the turbulent flow coil. It is characterized by being locked to one end of the straight pipe portion.

  According to the first aspect of the present invention, since the turbulent flow generating member is partially attached to at least one of the plurality of straight pipe portions, the turbulent flow generating member allows the turbulent flow generating member to The water flow at the place where the turbulent flow generating member is attached is disturbed, and the heat in the vicinity of the wall surface of the straight pipe portion is diffused to prevent local boiling at the place where the turbulent flow generating member of the straight pipe portion is attached. it can.

  Therefore, by attaching the turbulent flow generating member to a part where the possibility of local boiling of the straight pipe portion is high, it is compared with the conventional structure in which the turbulent flow generating member is mounted over the entire length of the straight pipe portion. Thus, the water flow resistance of the straight pipe portion is reduced, the capacity of the heat exchanger is improved, and the manufacturing cost is reduced by configuring the turbulent flow generation member to be short.

  According to the invention of claim 2, the straight pipe portion on which the turbulent flow generation member is partially attached is connected to the small diameter pipe portion and the end of the small diameter pipe portion and has a larger diameter than the small diameter pipe portion. The turbulent flow generating member is attached to the large diameter pipe portion, and one end of the turbulent flow generating member is in contact with the inner stepped portion at the boundary between the small diameter pipe portion and the large diameter pipe portion. Therefore, when the turbulent flow generating member is mounted on the straight pipe portion, the turbulent flow generating member can be easily positioned by the inner stepped portion, and therefore the turbulent flow generating member can be partly connected to the straight pipe portion with a simple structure. Can be installed.

  According to the invention of claim 3, the turbulent flow generating member is constituted by a turbulent coil, and one end of the turbulent coil is related to one end of the straight pipe portion to which the turbulent coil is partially attached. Therefore, when the turbulent coil is attached to the straight pipe portion, the turbulent coil can be easily positioned by one end of the straight pipe portion. Can be partially attached to the part.

It is a schematic block diagram of the combustion apparatus incorporating the heat exchanger which concerns on the Example of this invention. It is a longitudinal cross-sectional view of a heat exchanger. It is a top view of the upper stage heat exchange area | region of a heat exchanger. It is sectional drawing of the heat exchanger tube of the upper stage heat exchange area | region of a heat exchanger. It is a principal part enlarged view of FIG. It is a principal part expanded sectional view of the heat exchanger tube of the heat exchanger which concerns on a 1st modification. It is a principal part expanded sectional view of the heat exchanger tube of the heat exchanger which concerns on a 2nd modification. It is a principal part expanded sectional view of the heat exchanger tube of the heat exchanger which concerns on a 3rd modification. It is a partial front view of the turbulent flow production | generation member which concerns on a 4th modification. It is a fragmentary perspective view of the turbulent flow production | generation member which concerns on a 5th modification.

  Hereinafter, modes for carrying out the present invention will be described based on examples.

First, the whole structure of the combustion apparatus 1 incorporating the heat exchanger 10 of this invention is demonstrated.
As shown in FIG. 1, a combustion apparatus 1 is applied as a heat source device such as a hot water supply apparatus or a heating device, and burns fuel gas and heats water or hot water using heat contained in the combustion gas. It constitutes a gas water heater that performs.

  That is, as shown in FIG. 1, the combustion apparatus 1 includes a blower fan 2 for supplying combustion air, a burner unit 3 for burning fuel gas, and heat exchange between the combustion gas and water by the burner unit 3. Heat exchanger section 4, exhaust pipe 5 that discharges exhaust gas after heat exchange by this heat exchanger section 4, various pipes such as water inlet pipe 6 a and hot water outlet pipe 6 b, and electrical parts that drive and control various devices, etc. ing.

  The burner unit 3 comprises a burner unit 7 that mixes and burns fuel gas supplied from a fuel supply pipe (not shown) and combustion air supplied from the blower fan 2, and a burner can containing the burner unit 7. The body 8 is provided. A blower fan 2 is provided at the lower end of the burner can body 8.

  The burner unit 7 is configured in a multi-stage system including a plurality of (for example, three) combustion stages 7a to 7c (see FIGS. 1 and 4). Each of the combustion stages 7a to 7c includes, for example, five, two, and three combustion tubes, respectively, and can be controlled independently by a control unit (not shown), and is a combustion stage that is combusted according to various operations. The number of stages 7a to 7c is adjusted.

  The heat exchanger unit 4 includes a heat exchanger 10 that recovers the heat of the combustion gas, a heat exchanger can 11 that accommodates the heat exchanger 10, and the like. An exhaust pipe 5 is provided at the upper end of the heat exchanger can body 11. The lower end portion of the heat exchanger can body 11 and the upper end portion of the burner can body 8 are joined by caulking or screw fastening. The heat exchanger can body 11 is composed of a front side plate 11a, a rear side plate 11b, a left side plate 11c, and a right side plate 11d in a rectangular frame shape in plan view (see FIG. 3).

Next, the heat exchanger 10 of the present invention will be described.
As shown in FIGS. 2 to 5, the heat exchanger 10 includes a heat transfer tube 12, a turbulent flow generation member 13 that is inserted into the heat transfer tube 12 and generates turbulent flow in the heat transfer tube 12, and the heat transfer tube. The fin tube type heat exchanger which consists of the several fin 14 etc. which were fixed to 12 so that heat transfer was possible was comprised. The heat transfer tubes 12 and the fins 14 are made of copper, but are not particularly limited to this material, and may be made of stainless steel.

  As shown in FIG. 2, in the heat exchanger can 11, the heat exchanger 10 includes an upper stage heat exchange region 10 </ b> A on the upper stage side (downstream side of the combustion gas flow) and a lower stage side (upstream side of the combustion gas stream). ) Lower heat exchange region 10B.

  As shown in FIGS. 3 and 4, the heat transfer tube 12 includes a plurality of straight pipe portions 15 arranged in parallel over two stages and a plurality of ends that connect the ends of the plurality of straight pipe portions 15. Connecting pipe part 16. Four straight pipe portions 15 are disposed in the upper heat exchange region 10A, and four straight tube portions 15 are disposed in the lower heat exchange region 10B. The downstream end of the water intake pipe 6a is connected to the straight pipe part 15 on the upstream side (back side) of the lower heat exchange area 10B, and the straight pipe part 15a on the downstream side (front side) of the lower heat exchange area 10B is connected to the upper stage. The straight pipe part 15b connected to the straight pipe part 15 on the upstream side (front side) of the heat exchange area 10A via the connecting pipe part 16 and the straight pipe part 15b on the downstream side (back side) of the upper stage heat exchange area 10A is located upstream of the outlet pipe 6b. Connected to the side edge.

  In each of the upper stage heat exchange region 10A and the lower stage heat exchange region 10B, the heat transfer tube 12 is configured in a meandering shape in plan view. That is, in the upper heat exchange region 10A, the four straight pipe portions 15 are disposed so as to extend in the left-right direction and at equal intervals in the front-rear direction, and the ends of the straight pipe portions 15 are substantially U-shaped. Are connected to each other via the connecting pipe portions 16 in a staggered manner. Similarly, in the lower heat exchange region 10B, the four straight pipe portions 15 are arranged so as to extend in the left-right direction and at equal intervals in the front-rear direction, and the ends of the straight pipe portions 15 are substantially U-shaped. Are connected to each other via the connecting pipe portion 16 (see FIGS. 3 and 4).

  As shown in FIG. 3, the plurality of fins 14 are each configured in a plate shape extending in the front-rear direction, and are disposed in the heat exchanger can 11 at small intervals in the left-right direction. Each of the plurality of straight pipe portions 15 penetrates the plurality of fins 14 and the left side plate 11c and the right side plate 11d of the heat exchanger can 11 and brazed to the plurality of fins 14, the left side plate 11c and the right side plate 11d. It is fixed. The plurality of fins 14 transmit heat absorbed from the combustion gas to the straight pipe portion 15, and water or hot water flowing in the straight pipe portion 15 is heated.

Next, the turbulent flow generation member 13 will be described.
As shown in FIGS. 2 and 4, the turbulent flow generating member 13 includes an upper stage heat exchange and a right side portion of the downstream side (front side) straight pipe part 15a among the plurality of straight pipe parts 15 in the lower stage heat exchange region 10B. Each of the plurality of straight pipe portions 15 in the region 10A is partially attached to the right side portion of the downstream (back side) straight pipe portion 15b. The turbulent flow generation member 13 is formed in a coil shape having a length of about 1/3 of the total length of the straight pipe portions 15a and 15b. The turbulent flow generating member (turbulent coil) 13 is formed of a stainless steel wire, but is not particularly limited to this material.

  Since the straight pipe portions 15a and 15b to which the turbulent flow generating member 13 is partially attached have the same structure, only the straight pipe portion 15a will be described. As shown in FIGS. Includes a small-diameter pipe portion 17 having the same diameter as the other straight pipe portions 15, and a large-diameter pipe portion 18 connected to the end of the small-diameter pipe portion 17 and having a slightly larger diameter than the small-diameter pipe portion 17. . The large-diameter pipe portion 18 has a length of about 1/3 of the entire length of the straight pipe portion 15 so as to correspond to the left and right width of the combustion stage 7c of the burner unit 7.

  The turbulent flow generating member 13 has the same length as the large-diameter pipe portion 18 and an outer diameter that is substantially the same as the inner diameter of the large-diameter pipe portion 18, and the inside of the large-diameter pipe portions 18 of the straight pipe portions 15 a and 15 b. Each end of the turbulent flow generation member 13 is in contact with the inner step portion 19 at the boundary where the inner diameter of the small-diameter pipe portion 17 and the large-diameter pipe portion 18 changes. (See FIG. 5).

  When attaching the turbulent flow generating member 13 to the straight pipe portions 15a and 15b, respectively, the turbulent flow generating member 13 is inserted from the large diameter pipe portion 18 side opening of the straight pipe portions 15a and 15b before the connecting pipe portion 16 is attached. Then, each end of the turbulent flow generating member 13 is positioned by contacting the inner stepped portion 19 so that the turbulent flow generating member 13 is mounted on the straight pipe portions 15a and 15b, respectively, and then the connecting pipe portion 16 is attached. In addition, the side edge part connected to the large diameter pipe part 18 of the straight pipe parts 15a and 15b of the connection pipe part 16 is comprised larger diameter than the opposite side edge part to the straight pipe parts 15a and 15b.

Next, the operation and effect of the heat exchanger 10 of the present invention will be described.
In the combustion apparatus 1, fuel gas is supplied to the burner unit 7 from the fuel supply pipe and combustion air is supplied from the blower fan 2, and the fuel gas is mixed with the air and burned. The combustion heat (combustion gas) of this flame Then, the water in the heat exchanger 10 is heated, and then the exhaust is discharged to the outside through the exhaust tube 5 from the exhaust port.

  On the other hand, in the heat exchanger 10, when water is supplied from an external water source to the water intake pipe 6a, the water first flows through the heat transfer pipe 12 in the lower heat exchange region 10B of the heat exchanger 10, and then Then, the heat flows through the heat transfer pipe 12 in the upper heat exchange region 10A of the heat exchanger 10, and the water is heated in the heat exchanger 10 to become hot water as described above, and is discharged from the hot water discharge pipe 6b to the outside.

  By the way, in a present Example, when performing heating operation, the 1st stage combustion which uses only the right side combustion stage 7c among the combustion stages 7a-7c of several stages is performed. For this reason, at the time of heating operation, the right side portion of the plurality of straight pipe portions 15 of the heat transfer tube 12 is heated for a long time, and the hot water temperature returning to the heat exchanger 10 is also high. The first stage combustion spot in the downstream straight pipe portion 15a among the plurality of straight pipe portions 15 of the lower heat exchange region 10B that is directly blown by the flame of the burner unit 7 and the hot water temperature is high, and the hot water temperature is the highest. There is a high possibility that boiling occurs in the first-stage combustion portion of the straight pipe portion 15b of the upper-stage heat exchange region 10A on the most downstream side of the heat transfer tube 12 to be formed.

  However, since the turbulent flow generating member 13 is attached to the first stage combustion portion (large diameter pipe portion 18) of the two straight pipe portions 15a and 15b having the possibility of local boiling, the turbulent flow By agitating the generating member 13, the water flow in the large-diameter pipe portion 18 is intentionally disturbed to promote turbulent flow, and the heat in the vicinity of the wall surface is diffused so as to equalize the temperature. 18 local boiling can be prevented.

  As described above, the turbulent flow generating member 13 is partially attached to a portion of the straight pipe portion 15 where there is a high possibility of local boiling, so that the turbulent flow generating member 13 is extended over the entire length of the conventional straight pipe portion 15. Compared with the mounting structure, the water flow resistance of the straight pipe portion 15 is reduced, the capability of the heat exchanger 10 is improved, and the turbulent flow generation member 13 is configured to be short, thereby reducing the manufacturing cost.

  Further, the straight pipe portions 15 a and 15 b to which the turbulent flow generation member 13 is partially attached are connected to the small diameter pipe portion 17 and the end of the small diameter pipe portion 17 and have a larger diameter than the small diameter pipe portion 17. The turbulent flow generation member 13 is mounted on the large diameter pipe portion 18, and one end of the turbulent flow generation member 13 is located at the boundary between the small diameter pipe portion 17 and the large diameter pipe portion 18. Since the turbulent flow generating member 13 is attached to the straight pipe portions 15a and 15b, the turbulent flow generating member 13 can be easily positioned by the inner stepped portion 19 because it is in contact with the inner stepped portion 19 respectively. The turbulent flow generation member 13 can be partially attached to the straight pipe portion 15 with a simple structure. When the inner step portion 19 is on the downstream side of the turbulent flow generation member 13, it is possible to prevent the turbulent flow generation member 13 from moving due to the water flow.

Next, a mode in which the above embodiment is partially changed will be described.
[1] In the above embodiment, the turbulent flow generating member 13 is partially attached to the large-diameter pipe portion 18 by abutting one end of the turbulent flow generating member 13 against the inner stepped portion 19. 6, as shown in FIG. 6, one end (upstream end) 13 a of the turbulent flow generation member 13 configured by a turbulent coil is replaced with one end (upstream end) of the straight pipe portion 15 </ b> A. ), The structure may be such that the turbulent flow generating member 13 is attached to the straight pipe portion 15A. In the case of this structure, it is not necessary for the straight pipe portion 15A to have a structure in which the diameters of the small diameter pipe portion 17 and the large diameter pipe portion 18 are different.

  According to this structure, the turbulent flow generating member 13 is configured by a turbulent coil, and one end portion 13a of the turbulent flow generating member 13 is a straight pipe portion 15A to which the turbulent flow generating member 13 is partially attached. Since the turbulent flow generation member 13 is attached to the straight pipe portion 15A, the turbulent flow generation member 13 can be easily positioned by the one end portion 22 of the straight pipe portion 15A. The turbulent flow generating member 13 can be partially attached to the straight pipe portion 15A with a simple structure. When the one end portion 22 of the straight pipe portion 15A is an upstream end portion, it is possible to prevent the turbulent flow generation member 13 from moving due to the water flow.

[2] In the above embodiment, the turbulent flow generating member 13 has a structure in which one end of the turbulent flow generating member 13 is in contact with the inner stepped portion 19. However, the present invention is not limited to this structure, and as shown in FIG. Even if the rib is processed, an annular protrusion 21 that protrudes inwardly is provided on the inner peripheral wall portion of the straight pipe portion 15B, and one end portion of the turbulent flow generation member 13 is brought into contact with the protrusion 21. good. In the case of this structure, similarly to the above, it is not necessary to make the straight pipe part 15B a structure in which the diameters of the small diameter pipe part 17 and the large diameter pipe part 18 are different.

[3] In the above-described embodiment, the straight pipe portion 15 includes the large-diameter pipe portion 18 having substantially the same length as that of the turbulent flow generation member 13, but it is not necessary to be limited to this structure, as shown in FIG. In addition, the straight pipe portion 15C includes a large-diameter pipe portion 18C longer than the turbulent flow generation member 13, and a small-diameter pipe portion 17C connected to the end of the large-diameter pipe portion 18C and shorter than the large-diameter pipe portion 18C. It may be.

  In the case of this structure, the turbulent flow generating member 13 is inserted into the large diameter pipe portion 18C, and one end of the turbulent flow generating member 13 is contacted with the inner step portion 19C at the boundary between the small diameter pipe portion 17C and the large diameter pipe portion 18C. The turbulent flow generating member is formed by forming a plurality of protrusions 23 protruding inward from the outside at equal intervals in the straight pipe portion 15C near the other end of the turbulent flow generating member 13 in contact with each other. 13 is attached to the straight pipe portion 15C.

[4] Instead of the coiled turbulent flow generating member (turbulent flow coil) 13 of the above-described embodiment, as shown in FIG. 9, a strip-shaped stainless steel material is 180 degrees at predetermined intervals as the turbulent flow generating member 13A. A twisted spiral baffle plate may be used. Moreover, you may use together the turbulent flow production | generation member (turbulent flow coil) 13 and the turbulent flow production | generation member (baffle board) 13B.

[5] Instead of the coil-shaped turbulent flow generating member (turbulent flow coil) 13 of the above-described embodiment, as shown in FIG. 10, as a turbulent flow generating member 13B, a strip-shaped stainless material is alternately formed at predetermined intervals. A baffle plate having a plurality of cut and raised pieces 25 formed by cutting and raising may be used. Moreover, you may use together the turbulent flow production | generation member 13 (turbulent flow coil) and the turbulent flow production | generation member (baffle board) 13B.

[6] In the above-described embodiment, the turbulent flow generation member 13 is mounted on each of about 1/3 of the total length from the right end of the straight pipe portions 15a and 15b, but it is not necessary to limit to this structure. As long as there is a possibility of local boiling, a structure in which the turbulent flow generation member 13 is partially attached to the left end portion or midway portion of the straight pipe portions 15a and 15b may be used.

  In addition, the turbulent flow generation member 13 is partially attached to the straight pipe portions 15a and 15b, respectively. However, the structure is not limited to this structure and is attached to only one straight pipe portion 15a. As long as it is attached to at least one straight pipe portion 15a, the number of straight pipe portions 15 to which the turbulent flow generation member 13 is partially attached can be changed as appropriate.

[7] In addition, those skilled in the art can implement the present invention by adding various modifications without departing from the spirit of the present invention, and the present invention includes such modifications. It is.

DESCRIPTION OF SYMBOLS 10 Heat exchanger 12 Heat exchanger tube 13, 13A, 13B Turbulent flow generation member 15, 15A-15C Straight pipe part 16 Connecting pipe part 17 Small diameter pipe part 18 Large diameter pipe part 19 Inner level | step difference part

Claims (3)

In a heat exchanger comprising a heat transfer tube and a turbulent flow generation member inserted into the heat transfer tube and generating turbulent flow in the heat transfer tube,
The heat transfer tube includes a plurality of straight tube portions arranged in parallel and a plurality of connection tube portions that connect ends of the plurality of straight tube portions,
The heat exchanger according to claim 1, wherein the turbulent flow generating member is partially attached to at least one straight pipe portion of the plurality of straight pipe portions. The straight pipe portion to which the turbulent flow generation member is partially mounted includes a small-diameter pipe portion and a large-diameter pipe portion connected to an end of the small-diameter pipe portion and having a larger diameter than the small-diameter pipe portion. ,
The turbulent flow generating member is attached to the large diameter pipe portion, and one end portion of the turbulent flow generating member is in contact with an inner stepped portion at a boundary between the small diameter pipe portion and the large diameter pipe portion. The heat exchanger according to claim 1. The turbulent flow generation member is composed of a turbulent coil,
2. The heat exchanger according to claim 1, wherein one end portion of the turbulent coil is locked to one end portion of the straight pipe portion to which the turbulent coil is partially attached.