JP2018112324A - Heat exchanger - Google Patents

Abstract

Even if the flow rate is small, the occurrence of temperature unevenness is suppressed.
A heat exchanger (1) includes a casing (2) through which combustion exhaust passes from the lower side to the upper side, and passes through the casing (2) in a straight line in the horizontal direction, and is arranged in parallel at equal intervals in a direction orthogonal to the penetration direction. The ends of the heat transfer tube portions 4, 4 that are inserted inside the casing 2 and the heat transfer tube portions 4, 4 that are adjacent to each other outside the casing 2 are staggered in plan view. A U-shaped connecting pipe part (bent part 5 and U-shaped pipe 6) connected in such a manner that the turbulent flow plate 10B is inserted vertically into the heat transfer tube part 4 to the turbulent flow plate 10B. Are formed by alternately raising and lowering a plurality of turbulent flow pieces 15 to the left and right, and all the turbulent flow pieces 15 are provided in a downward inclined posture toward the downstream side.
[Selection] Figure 3

Description

  The present invention relates to a heat exchanger provided in a water heater or the like.

  In a heat exchanger such as a water heater, a fluid such as water flows, and has a meandering pipe (fin pipe) having a plurality of fins at equal intervals on the outer periphery, and allows combustion exhaust of a burner to pass between the fins. Thus, heat is exchanged between the exhaust heat and the fluid in the pipe. In the pipe, as disclosed in Patent Documents 1 to 3, a baffle plate (turbulent flow plate) in which cut and raised pieces are formed for the purpose of preventing boiling noise due to local boiling in the pipe and increasing thermal efficiency. Has been inserted.

Japanese Patent No. 3678261 Japanese Patent No. 3678262 Japanese Patent No. 3687294

  Since the baffle plates of Patent Documents 1 to 3 are formed so that the cut-and-raised pieces are alternately upward and downward, the flow stays in the longitudinal direction when the flow rate is low or the fluid is highly viscous. There is a possibility that temperature unevenness may occur, resulting in poor thermal efficiency.

  Accordingly, an object of the present invention is to provide a heat exchanger capable of suppressing the occurrence of temperature unevenness and improving the thermal efficiency even when the flow rate is small.

In order to achieve the above object, the invention according to claim 1 is directed to a casing in which combustion exhaust passes from below to above, and through the casing in a straight line in a horizontal direction, in a direction orthogonal to the penetration direction. Connect a plurality of heat transfer tube parts arranged side by side at equal intervals and having turbulent flow plates inserted therein, and the ends of adjacent heat transfer tube parts outside the casing so that both ends are alternated in plan view. A heat exchanger including a U-shaped connecting pipe part, and a heat transfer pipe part and a connecting pipe part forming a series of pipes connected in a meandering manner,
The turbulent flow plate is inserted vertically into the heat transfer tube, and the turbulent flow plate is formed by alternately cutting a plurality of turbulent flow pieces to the left and right. It is provided in an inclined posture.

  According to the first aspect of the present invention, since the fluid is always directed downward by the turbulent piece in the downward inclined posture toward the downstream side, heat exchange with the combustion exhaust rising from below is efficiently performed even when the flow rate is small. Done. Therefore, temperature unevenness in the longitudinal direction of the heat transfer tube portion is suppressed, and thermal efficiency is improved.

It is a front view of a heat exchanger. It is the sectional view on the AA line of FIG. It is the BB sectional view taken on the line of FIG. It is CC sectional view taken on the line of FIG. It is a perspective view of a turbulent flow board. It is explanatory drawing of a turbulent flow board, (A) shows a side surface, (B) shows a bottom face, respectively. It is the schematic of a water heater. It is explanatory drawing which shows the flow of the water with respect to a turbulent flow board, (A) shows 10 A of turbulent flow boards, (B) shows the turbulent flow board 10B, respectively. It is a perspective view of the turbulent plate of the example of a change. It is explanatory drawing of the turbulent plate of the example of a change, (A) shows a side surface, (B) shows a bottom face, respectively. It is sectional drawing in the same position as FIG. 1B-B in the heat exchanger which inserted the turbulent flow board of the example of a change. It is the DD sectional view taken on the line of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 is a front view showing an example of a heat exchanger, FIG. 2 is a cross-sectional view taken along line AA, FIG. 3 is a cross-sectional view taken along line BB, and FIG. 4 is a cross-sectional view taken along line CC.
This heat exchanger 1 has a rectangular cylindrical casing 2 and a plurality of fins 3, 3... (In FIG. 3 and FIG. 4, intermediate layers) are stacked at equal intervals in the left-right direction. And a plurality of heat transfer tube portions 4, 4... That pass through the fins 3 and are arranged in parallel at equal intervals in the front-rear direction inside the casing 2. The heat transfer tube parts 4, 4 arranged in the front and rear are arranged in two upper and lower stages (here, four in the upper stage and five in the lower stage). A long pipe is bent at an intermediate portion, and the casing 2 and the fins 3, 3... Pass through the U-shaped bent part 5 as a connecting pipe part protruding outside the right side of the casing 2. Formed.

On the other hand, on the left side of the casing 2, the heat transfer tube portions 4 and 4 adjacent to each other at each stage are connected by plugging both ends of the U-shaped tube 6 as a connection tube portion to the end portions of the heat transfer tube portions 4 and 4. To be connected. However, the U-shaped tube 6 is arranged so that the bent portion 5 and the left and right are alternated in plan view. The uppermost rearmost heat transfer tube portion 4 and the lowermost rearmost heat transfer tube portion 4 are connected to each other by plugging and connecting both ends of the vertical U-shaped tube 6.
As a result, the four heat transfer tube portions 4 continue to meander from the heat transfer tube portion 4 in the uppermost frontmost position via the bent portion 5 and the U-shaped tube 6 to the upper part in the casing 2, From the heat transfer tube portion 4 at the position to the lower stage via the U-shaped tube 6, the five heat transfer tube portions 4 meander from the heat transfer tube portion 4 at the rearmost position at the lower stage via the bent portion 5 and the U-shaped tube 6. A series of tube bodies 7 are formed.

  A turbulent flow plate 10 is inserted in each heat transfer tube portion 4. As shown in FIG. 5, the turbulent flow plate 10 is a metal (for example, a nickel alloy-based strip material) that has high strength and thermal conductivity and excellent corrosion resistance and oxidation resistance, and is larger than the inner diameter of the heat transfer tube portion 4. It is formed in a strip shape with a slightly smaller width. One end portion in the longitudinal direction of the turbulent flow plate 10 is a square end portion 11 having a linear end, and the other end portion is a circular end portion 12 having a semicircular end. Two circular through holes 13 are formed in the circular end portion 12 side by side in the longitudinal direction.

  Further, as shown in FIG. 6, the turbulent flow plate 10 has a plurality of triangular holes 14, 14... That have an acute angle on the square end 11 side and increase in the vertical width toward the circular end 12. It is formed at intervals. Triangular turbulent flow pieces 15, 15... Are alternately projected to the left and right at the inclined edges of the respective triangular holes 14. Thus, it is bent so as to have a downward inclined posture. A small hole 16 is formed outside the wide end of each turbulent flow piece 15.

  This turbulent flow plate 10 is inserted vertically into each of the upper four heat transfer tube portions 4. Specifically, after inserting the turbulent flow plate 10 with the circular end 12 first from the left end of the heat transfer tube portion 4 before the U-tube 6 is plugged in, the U-tube 6 is plugged in. To do. However, between the four heat transfer tube portions 4, 4..., Even in the same vertical turbulent flow plate 10, as shown in FIG. The direction in which the flow piece 15 is inclined downward from the left to the right, hereinafter referred to as “10A” when distinguished from each other), and the acute angle portion is on the lower side as shown in FIG. Inserted by changing the orientation so that the orientation (the orientation in which the turbulent flow piece 15 is in a downward inclined posture from right to left, hereinafter referred to as “10B” when distinguished) is alternated. ing.

  Then, as shown in FIGS. 3 and 4, the insertion end portions 6 a and 6 a of the U-tubes 6 abut against the square end portions 11 and 11, respectively, so that the turbulent flow plates 10 and 10 are replaced with the circular end portions 12 and 12. Is pushed to the position where it is inserted into the bent portion 5 on the right side. Thereby, each turbulent flow plate 10 is in a state where the circular end portion 12 is close to the inner surface of the bent portion 5 and the square end portion 11 is in contact with the insertion end portion 6a of the U-shaped tube 6 in the longitudinal direction. Movement is restricted. At this time, the lower edge of the turbulent flow plate 10 is in contact with the lower inner surface of the heat transfer tube portion 4, and each turbulent flow piece 15 is in a state of being in contact with the left and right inner surfaces of the heat transfer tube portion 4, The rotation of the turbulent plate 10 is also restricted.

  For example, as shown in FIG. 7, the heat exchanger 1 configured as described above is assembled in an upper portion of a burner unit 22 in which a plurality of burner groups are provided in a housing 21 of a water heater 20. An exhaust hood 23 is assembled on the top of the heat exchanger 1. As a result, a combustion chamber (inner cylinder) is formed in which the combustion exhaust from the burner group in the burner unit 22 rises in the casing 2 of the heat exchanger 1 and passes between the fins 3 and 3 to reach the exhaust hood 23. Is done. In addition, an inlet pipe 24 connected to an external water pipe is connected to the upstream end of the pipe body 7 of the heat exchanger 1, and a hot water outlet connected to a pipe connected to the hot water tap is connected to the downstream end of the pipe body 7. A tube 25 is connected. 26 is a fan for supplying air to the burner unit 22, and 27 is a controller.

  In this water heater 20, when the hot water tap is opened and water is passed through the appliance, the water passes through the water inlet pipe 24 to the tube body 7 of the heat exchanger 1, and each heat transfer pipe section 4.4. Pass in order. On the other hand, the controller 27 detects water flow and ignites the burner group in the burner unit 22 and rotates the air supply fan 26 to supply combustion air to the burner group. The combustion exhaust of the burner group is exchanged with the water passing through the heat transfer pipe section 4 by rising in the casing 2 of the heat exchanger 1 and passing between the fins 3 and 3. Therefore, hot water of a predetermined temperature is discharged from the hot water discharge pipe 25 and supplied from the hot water tap.

In each heat transfer tube portion 4, water passes in the direction of the solid arrow shown in FIG. 3. Here, when water flows from the square end 11 side through the U-shaped tube 6, the turbulent flow plate 10 </ b> A. A part of the water that has contacted the turbulent flow pieces 15 and 15 while passing through the left and right sides of the turbulent flow is guided downward by a downward inclined posture of the turbulent flow pieces 15 as indicated by a two-dot chain line arrow in FIG. Therefore, it collides with the lower inner surface of the heat transfer tube portion 4 to generate turbulent flow. Even through the small holes 16 of the turbulent flow pieces 15, the flow velocity is partially changed to generate turbulent flow. Further, part of the water passes through the triangular hole 14 so as to go to the left and right of the turbulent flow plate 10A to generate turbulent flow.
Further, when water flows from the circular end 12 side through the bent portion 5, the water enters the heat transfer tube portion 4 outside the circular end portion 13 of the turbulent flow plate 10 </ b> B or through the through holes 13 and 13. Flowing. Then, a part of the water that is in contact with the turbulent flow pieces 15 and 15 while flowing on the left and right of the turbulent flow plate 10B is inclined downward as shown by a two-dot chain line arrow in FIG. Is caused to collide with the lower inner surface of the heat transfer tube section 4 to generate turbulent flow. Even through the small holes 16 of the turbulent flow pieces 15, the flow velocity is partially changed to generate turbulent flow. Further, a part of the water passes through the triangular hole 14 so as to go to the left and right of the turbulent flow plate 10B to generate turbulent flow.

Since the water is always directed downward by the turbulent flow piece 15 inclined downward in this way, even when the flow rate is small, heat exchange with the combustion exhaust rising from below is efficiently performed, and the heat transfer tube portion 4 in the longitudinal direction Temperature unevenness can be suppressed.
On the other hand, as the water passes through the heat transfer tube portion 4 in contact with the turbulent flow piece 15 in this way, the turbulent flow plate 10 is urged to the downstream side of the water, but flows in from the square end portion 11 side. In this case, the turbulent flow plate 10 has its circular end 12 abutted against the inner surface of the bent portion 5 and is restricted from moving. When the turbulent flow plate 10 flows from the circular end 12 side, the square end 11 of the turbulent flow plate 10 has a U-shaped tube 6. The movement is restricted by coming into contact with the insertion end 6a. Therefore, the turbulent flow plate 10 does not move or rotate in the heat transfer tube portion 4.

(Effect of invention relating to movement and rotation regulation of turbulent plate by circular end)
Thus, according to the heat exchanger 1 of the said form, one edge part of the turbulent flow board 10 is inserted in the connection pipe part (the bending part 5 or the U-shaped pipe 6), and the said connection pipe part is connected. Since it is the semicircular circular end portion 12 that is close to or in contact with the inner surface, the turbulent flow plate 10 is not moved or rotated by the flow of water. In addition, it is only necessary to form the circular end 12 on the turbulent flow plate 10 and insert it into the connecting pipe portion, and no fixing means such as brazing is required. The structure is also good.

In particular, here, since the through holes 13 and 13 are formed in the insertion portion of the turbulent flow plate 10 into the connecting pipe portion, even if the circular end portion 12 is inserted into the connecting pipe portion, the inflow of water is more than necessary. There is no hindrance.
Moreover, since the turbulent flow plate 10 is provided with a plurality of turbulent flow pieces 15 and 15 which are alternately cut and raised to the left and right, the occurrence of temperature unevenness in the longitudinal direction of the heat transfer tube portion 4 can be suppressed. it can.

In addition, in the said form, although the insertion end part of a U-shaped tube is utilized for the movement restriction | limiting of the square end part of a turbulent flow board, it protruded on the inner surface of not only this but a heat-transfer tube part or a U-shaped tube. A protrusion, a rib, or the like may be used. When the inner surface of the heat transfer tube portion is used, the square end portion side does not need to be a separate U-shaped tube.
However, it is not limited to a structure in which only one end of the turbulent flow plate is a circular end, but as in the turbulent flow plate 10 shown in FIGS. May be provided. In this case, in the heat transfer tube portion 4, as shown in FIGS. 11 and 12, one circular end portion 12 is close to the inner surface of the bent portion 5, and the other circular end portion 12 is close to the inner surface of the U-shaped tube 6. By inserting in such a manner, movement in the longitudinal direction within the heat transfer tube portion 4 can be regulated.
With this structure, the movement of the turbulent flow plate 10 can be restricted without using the insertion end of the U-shaped tube 6.

Moreover, in this invention, the number and shape of a through-hole and the number and shape of a triangular hole and a turbulent flow piece can also be changed suitably.
Furthermore, in the above embodiment, the turbulent flow plate is inserted vertically into the heat transfer tube portion of the tube meandering in the horizontal direction, but when the upper and lower heat transfer tube portions are connected by the vertical connection tube portion, the turbulent flow You may make it insert a board | plate sideways and insert one end or both ends of a longitudinal direction in a connection pipe part. Also in this case, the movement in the longitudinal direction can be restricted by the circular end portion approaching or abutting against the inner surface of the vertically connecting pipe portion.

(Effect of the invention relating to the turbulent piece in the downward inclined posture)
According to the heat exchanger 1 of the said form, the turbulent flow plate 10 is inserted vertically into the heat exchanger tube part 4, and the turbulent flow plate 10 has a plurality of turbulent flow pieces 15, 15,. Since all the turbulent flow pieces 15 are provided in a downwardly inclined posture toward the downstream side, the water is always directed downward by the downwardly inclined turbulent flow pieces 15 even when the flow rate is small. Heat exchange with the combustion exhaust rising from below is efficiently performed. Therefore, the temperature unevenness in the longitudinal direction of the heat transfer tube portion 4 is suppressed, and the thermal efficiency is improved.

  In the above-described embodiment, the turbulent flow plate 10 having the same configuration is used, and the turbulent flow pieces 10 are alternately inserted into the respective heat transfer tube portions 4. As long as it is a thing, you may use the turbulent flow board from which the shape of a through-hole, a triangular hole, and the number and shape of a turbulent flow piece differ, or for every heat exchanger tube part.

(Effect of invention relating to movement restriction of turbulent plate by U-shaped tube)
According to the heat exchanger 1 of the said form, the several places of the connection pipe part in the pipe body 7 are set as the separate U-shaped pipe 6 by which both ends are inserted and connected to the edge part of the adjacent heat transfer pipe parts 4 and 4. The turbulent flow plate 10 is positioned by the contact of the insertion end 6a of the U-shaped tube 6 with the end of the turbulent flow plate 10 on the side where the U-shaped tube 6 is inserted and connected. The movement of the turbulent plate 10 can be effectively restricted with a simple structure using the tube 6 and good assembly workability.

  In addition, in the said form, although the heat exchanger tube parts are connected only using the U-shaped tube on the left side in a plan view, the right side is also connected using the U-shaped tube, and both ends of the turbulent flow plate are connected to the U-shaped tube. You may make it perform movement restriction | limiting of a turbulent flow board as appearance put on an insertion edge part.

In common with each invention, the water heater provided with a heat exchanger is also a latent heat recovery type having a sub-heat exchanger, a two-can type with a heat exchanger for bathing and floor heating, and the like. However, the present invention can be applied. In the latent heat recovery type, the present invention may be applied to at least the main heat exchanger, and in the case of a two-can type, the present invention may be applied to both heat exchangers provided side by side.
Of course, the heat exchanger of the present invention can be used not only for the water heater but also for other equipment such as a road heater as long as it has a heat exchanger for exchanging heat between the fluid and the combustion exhaust.

  1. Heat exchanger 2. Casing 3. Fin 4. Heat transfer tube 5. Folding 6. U-tube 6a ... Insertion end 7. Tube Body 10 ... Turbulent plate 11, Square end 12 ... Circular end 13 ... Through hole 14 ... Triangular hole 15 ... Turbulent piece 16 ... Small hole 20 ... -Hot water heater, 21-Housing, 22-Burner unit, 23-Exhaust hood, 24-Water inlet pipe, 25-Hot water pipe.

Claims (1)

A casing through which combustion exhaust passes from below to above;
A plurality of heat transfer tube portions, which pass through the casing in a straight line in the horizontal direction, are arranged in parallel at equal intervals in a direction orthogonal to the penetration direction, and each has a turbulent flow plate inserted therein.
A U-shaped connecting pipe part that connects the ends of the heat transfer pipe parts adjacent to each other outside the casing so that both ends thereof are alternated in a plan view, and the heat transfer pipe part and the connecting pipe part And a heat exchanger that forms a series of pipes connected in a meandering manner,
The turbulent flow plate is inserted vertically into the heat transfer tube portion, and a plurality of turbulent flow pieces are alternately formed on the left and right sides of the turbulent flow plate, and the turbulent flow pieces are all downstream. A heat exchanger characterized by being provided with a downwardly inclined posture toward the side.

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