JP6787574B2 - Heat exchanger - Google Patents

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 a meandering pipe (fin pipe) having a plurality of fins at equal intervals is provided on the outer periphery, and a burner combustion exhaust is passed between the fins. As a result, heat is exchanged between the exhaust heat and the fluid in the pipe. As disclosed in Patent Documents 1 to 3, a baffle plate (turbulent flow plate) in which cut-up pieces are formed is provided in the pipe for the purpose of preventing boiling noise due to local boiling in the pipe and improving thermal efficiency. It 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 pieces alternate upward and downward, the flow stays in the longitudinal direction when the flow rate is low or when the fluid has high viscosity. Temperature unevenness may occur and thermal efficiency may deteriorate.

Therefore, 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 has a casing in which the combustion exhaust passes from the bottom to the top, and the inside of the casing is linearly penetrated in the horizontal direction in a direction orthogonal to the penetration direction. Connect a plurality of heat transfer tubes that are arranged side by side at equal intervals and have turbulent flow plates inserted inside, and the ends of adjacent heat transfer tubes outside the casing so that both ends are staggered in a plan view. A heat exchanger in which a U-shaped connecting tube portion is included, and a series of tubular bodies connected in a serpentine shape are formed by the heat transfer tube portion and the connecting tube portion.
The turbulent plate is vertically inserted into the heat transfer tube portion, and a plurality of turbulent pieces are alternately cut up and raised to the left and right on the turbulent plate, and all the turbulent pieces are directed downward to the downstream side. It is characterized in that it is provided in an inclined posture.

According to the invention of claim 1, since the fluid is always directed downward by the turbulent flow piece in the downward inclined posture toward the downstream side, heat exchange with the combustion exhaust rising from below is efficient even when the flow rate is small. Will be 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. FIG. 1 is a cross-sectional view taken along the line AA of FIG. It is sectional drawing BB of FIG. FIG. 3 is a cross-sectional view taken along the line CC of FIG. It is a perspective view of a turbulent flow plate. In the explanatory view of the turbulent plate, (A) shows the side surface and (B) shows the bottom surface. It is a schematic diagram of a water heater. In the explanatory view showing the flow of water with respect to the turbulent plate, (A) shows the turbulent plate 10A, and (B) shows the turbulent plate 10B. It is a perspective view of the turbulent flow plate of the modified example. In the explanatory view of the turbulent flow plate of the modified example, (A) shows the side surface and (B) shows the bottom surface. It is sectional drawing at the same position as FIG. 1BB line in the heat exchanger in which the turbulent flow plate of the modified example is inserted. FIG. 10 is a cross-sectional view taken along the line DD 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 sectional view taken along line AA, FIG. 3 is a sectional view taken along line BB, and FIG. 4 is a sectional view taken along line CC.
This heat exchanger 1 has a square tubular casing 2, and a plurality of fins 3, 3 ... (Intermediate in FIGS. 3 and 4) in which a plurality of fins are laminated at equal intervals in the left-right direction on the upper portion of the casing 2. It has a plurality of heat transfer tube portions 4, 4, ... Which are arranged in parallel at equal intervals in the front-rear direction inside the casing 2 so as to penetrate each fin 3). The heat transfer tube portions 4, 4, which are lined up 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), and the heat transfer tube portions 4, 4 adjacent to each other in the front and rear in each stage are arranged. A long pipe is bent at an intermediate portion, and the U-shaped bent portion 5 as a connecting pipe portion is projected to the outside on the right side of the casing 2 and penetrates the casing 2 and the fins 3, 3, ... Is formed.

On the other hand, on the left side of the casing 2, the heat transfer tube portions 4, 4 adjacent to each other in the front and rear at each stage are connected by inserting both ends of the U-shaped tube 6 as the connection tube portion into the ends of the heat transfer tube portions 4, 4. It is connected by doing. However, the U-shaped tube 6 is arranged so that the bent portion 5 and the left and right sides are staggered in a plan view. Further, the heat transfer tube portion 4 at the innermost stage of the upper stage and the heat transfer tube portion 4 at the innermost stage of the lower stage are connected by inserting and connecting both ends of the vertically oriented U-shaped tube 6.
As a result, four heat transfer tube portions 4 are meanderingly continuous from the heat transfer tube portion 4 at the uppermost front position via the bent portion 5 and the U-shaped tube 6 to the upper portion in the casing 2, and are rearmost. The heat transfer tube portion 4 at the position moves to the lower stage via the U-shaped tube 6, and the five heat transfer tube portions 4 meandering from the heat transfer tube portion 4 at the rearmost position of the lower stage via the bent portion 5 and the U-shaped tube 6. A series of tubular bodies 7 are formed.

A turbulent plate 10 is inserted into each heat transfer tube portion 4. As shown in FIG. 5, the turbulent plate 10 is a metal having high strength and thermal conductivity and excellent corrosion resistance and oxidation resistance (for example, a nickel alloy-based strip material), which 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 of the turbulent plate 10 in the longitudinal direction has a square end 11 having a linear end, and the other end has a circular end 12 having a semicircular end. Two circular through holes 13 and 13 are formed side by side in the longitudinal direction at the circular end portion 12.

Further, as shown in FIG. 6, the turbulent plate 10 has a plurality of triangular holes 14, 14, ... The square end portion 11 side has an acute angle and the vertical width increases toward the circular end portion 12 side. It is formed at intervals. At the inclined edge of each triangular hole 14, triangular turbulent pieces 15, 15 ..., Which are shaped like an acute-angled portion and whose width expands toward the circular end 12, project alternately to the left and right. It is bent so as to be in a downwardly inclined posture. A small hole 16 is formed on the outer side of the tip of each turbulent piece 15 on the wide side.

The turbulent plate 10 is vertically inserted into each of the four heat transfer tube portions 4 in the upper stage. Specifically, the turbulent plate 10 is inserted from the left end of the heat transfer tube portion 4 before the U-shaped tube 6 is inserted and connected with the circular end portion 12 first, and then the U-shaped tube 6 is inserted and connected. To do. However, between the four heat transfer tube portions 4, 4, ..., the acute-angled portion of the triangular hole 14 is located on the upper side (turbulence) even in the same vertical turbulent plate 10 as shown in FIG. 8 (A). The direction in which the flow piece 15 is tilted downward from left to right, hereinafter referred to as "10A" when distinguishing between them), and as shown in Fig. (B), the acute-angled portion is on the lower side. Inserted in different directions so that the positions (the direction in which the turbulent piece 15 is in a downward tilted posture from right to left, hereinafter referred to as "10B" when distinguishing) alternate. ing.

Then, as shown in FIGS. 3 and 4, the insertion ends 6a and 6a of each U-shaped tube 6 abut on the square ends 11 and 11, respectively, and the turbulent plates 10 and 10 are brought into contact with the circular ends 12 and 12. Push it in until it is inserted into the bent portion 5 on the right side. As a result, in each turbulent plate 10, 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 plate 10 is in contact with the lower inner surface of the heat transfer tube portion 4, and the tips of the turbulent pieces 15 are 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 regulated.

As shown in FIG. 7, for example, the heat exchanger 1 configured as described above is assembled in the housing 21 of the water heater 20 on the upper portion of the burner unit 22 in which a plurality of burner groups are provided. An exhaust hood 23 is assembled on the upper part of the heat exchanger 1. As a result, the combustion chamber (inner body) of the burner group in the burner unit 22 rises in the casing 2 of the heat exchanger 1, passes between the fins 3 and 3, and reaches the exhaust hood 23. Will be done. Further, a water 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 pipe connected to a hot water tap is connected to the downstream end of the pipe body 7. The pipe 25 is connected. Reference numeral 26 is an air supply fan for 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 device, water passes through the water inlet pipe 24 and reaches the pipe body 7 of the heat exchanger 1, and each heat transfer pipe portion 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 rises in the casing 2 of the heat exchanger 1 and passes between the fins 3 and 3, so that the heat is exchanged with the water passing through the heat transfer tube portion 4. Therefore, hot water having a predetermined temperature is discharged from the hot water 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, but when water flows in from the square end portion 11 side through the U-shaped tube 6, the turbulent flow plate 10A A part of the water that has come into contact with the turbulent pieces 15 and 15 while passing through the left and right sides of the water is guided downward by the downward inclined posture of the turbulent piece 15 as shown by the two-dot chain arrow in FIG. 8 (A). Therefore, it collides with the lower inner surface of the heat transfer tube portion 4 to generate turbulence. The flow velocity is partially changed by passing through the small holes 16 of each turbulent piece 15, and turbulent flow is generated. Further, a part of the water passes through the triangular hole 14 and moves back and forth to the left and right of the turbulent plate 10A to generate turbulent flow.
Further, when water flows in from the circular end portion 12 side through the bent portion 5, the water flows into the heat transfer tube portion 4 through the outside of the circular end portion 13 of the turbulent plate 10B or through the through holes 13 and 13. It flows. Then, a part of the water flowing to the left and right of the turbulent plate 10B and coming into contact with the turbulent pieces 15 and 15 is in a downwardly inclined posture of the turbulent piece 15 as shown by the two-dot chain arrow in FIG. 8 (B). It is guided downward by and collides with the lower inner surface of the heat transfer tube portion 4 to generate turbulence. The flow velocity is partially changed by passing through the small holes 16 of each turbulent piece 15, and turbulent flow is generated. Further, a part of water passes through the triangular hole 14 and moves back and forth to the left and right of the turbulent plate 10B to generate turbulent flow.

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

(Effect of the invention relating to the movement and rotation regulation of the turbulent plate by the circular end)
As described above, according to the heat exchanger 1 of the above-described embodiment, one end of the turbulent plate 10 is inserted into the connecting pipe portion (bent portion 5 or U-shaped pipe 6) of the connecting pipe portion. Since the semicircular end portion 12 is in close proximity to or in contact with the inner surface, the turbulent plate 10 does not move or rotate due to the flow of water. Further, it is sufficient to form a circular end portion 12 on the turbulent flow plate 10 and insert it into the connecting pipe portion, and since fixing means such as brazing is not required, the structure is simple with a small number of parts and the assembly work. It also has a good structure.

In particular, here, since the through holes 13 and 13 are formed in the insertion portion of the turbulent 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. It does not interfere.
Further, since the turbulent plate 10 is provided with a plurality of turbulent pieces 15 and 15 formed by alternately cutting and raising to the left and right, it is possible to suppress the occurrence of temperature unevenness in the longitudinal direction of the heat transfer tube portion 4. it can.

In the above embodiment, the insertion end of the U-shaped tube is used to regulate the movement of the square end of the turbulent plate, but the present invention is not limited to this, and is projected on the inner surface of the heat transfer tube or the U-shaped tube. Protrusions, ribs, etc. may be used. When the inner surface of the heat transfer tube portion is used, the square end side does not need to be a separate U-shaped tube.
However, the structure is not limited to a structure in which only one end of the turbulent plate has a circular end, and through holes 13 and 13 have circular ends 12 and 12 at both ends as in the turbulent plate 10 shown in FIGS. 9 and 10. 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 the heat transfer tube portion 4 in such a manner, it is possible to restrict the movement in the longitudinal direction in the heat transfer tube portion 4.
With this structure, the movement of the turbulent plate 10 can be regulated without using the insertion end of the U-shaped tube 6.

Further, in the present invention, the number and shape of through holes, the number and shape of triangular holes and turbulent flow pieces can be changed as appropriate.
Further, in the above embodiment, the turbulent plate is vertically inserted into the heat transfer tube portion of the tube body that meanders 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 The plate may be inserted sideways so that one or both ends in the longitudinal direction are inserted into the connecting pipe portion. In this case as well, movement in the longitudinal direction can be restricted by the circular end portion approaching or abutting on the inner surface of the vertically oriented connecting pipe portion.

(Effect of the invention relating to a turbulent piece in a downwardly inclined posture)
According to the heat exchanger 1 of the above embodiment, the turbulent flow plate 10 is vertically inserted into the heat transfer tube portion 4, and a plurality of turbulent flow pieces 15, 15 ... Are alternately left and right in the turbulent flow plate 10. In addition to being cut and raised, each turbulent piece 15 is provided in a downwardly inclined posture toward the downstream side, so that the water is always directed downward by the downwardly inclined turbulent piece 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 embodiment, the turbulent plate 10 of the same form is used and inserted into each heat transfer tube portion 4 in different directions, but a turbulent piece that guides the flow of water downward is provided. If it is, turbulent plates having different shapes of through holes, triangular holes, and the number and shape of turbulent pieces may be used alternately or for each heat transfer tube portion.

(Effect of the invention relating to the movement regulation of the turbulent plate by the U-shaped tube)
According to the heat exchanger 1 of the above embodiment, a plurality of connecting pipe portions in the tube body 7 are formed as separate U-shaped tubes 6 in which both ends are inserted and connected to the ends of the adjacent heat transfer tube portions 4 and 4. , The turbulent plate 10 is positioned by the insertion end 6a of the U-shaped pipe 6 coming into contact with the end of the turbulent plate 10 on the side to which the U-shaped pipe 6 is inserted and connected. The movement of the turbulent plate 10 can be effectively regulated by a simple structure using the pipe 6 and having good assembly workability.

In the above embodiment, the heat transfer tubes are connected to each other by using a U-shaped tube only on the left side in a plan view, but the U-shaped tubes are also connected to the right side, and both ends of the turbulent plate are connected by the U-shaped tube. The movement of the turbulent plate may be restricted as if it is sandwiched between the insertion ends.

And, in common with each invention, the water heater provided with the heat exchanger is also a latent heat recovery type having an auxiliary heat exchanger, a two-can type having a heat exchanger for reheating the bath 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 the two-can type, the present invention may be applied to both heat exchangers installed side by side.
Of course, not only the water heater but also other appliances such as a load heater can adopt the heat exchanger of the present invention as long as it has a heat exchanger that exchanges heat between the fluid and the combustion exhaust.

1 ... heat exchanger, 2 ... casing, 3 ... fins, 4 ... heat transfer tube part, 5 ... bent part, 6 ... U-shaped 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 ...・ Water heater, 21 ・ ・ casing, 22 ・ ・ burner unit, 23 ・ ・ exhaust hood, 24 ・ ・ water inlet pipe, 25 ・ ・ hot water outlet pipe.

Claims (1)

A casing through which combustion exhaust passes from below to above,
A plurality of heat transfer tube portions that penetrate the casing in a straight line in the horizontal direction, are arranged side by side at equal intervals in the direction orthogonal to the penetration direction, and each has a turbulent flow plate inserted therein.
The heat transfer tube portion and the connection tube portion include a U-shaped connection tube portion that connects the ends of the heat transfer tube portions that are adjacent to each other outside the casing so that both ends are staggered in a plan view. It is a heat exchanger that forms a series of pipes that are connected in a meandering manner.
The turbulent plate is vertically inserted into the heat transfer tube portion, and a plurality of turbulent pieces are alternately cut up and raised to the left and right on the turbulent plate, and all the turbulent pieces are downstream. A heat exchanger characterized in that it is provided in a downwardly inclined posture toward the side.

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