JP7162875B2 - Heat exchanger - Google Patents

Description

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

A heat exchanger such as a water heater has a meandering pipe (finned pipe) in which a fluid such as water flows and a plurality of fins are provided at equal intervals on the outer circumference, and the combustion exhaust of the burner is passed 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 (turbulence plate) formed with cut-and-raised pieces is provided for the purpose of preventing boiling noise due to local boiling in the pipe and improving thermal efficiency. inserted.

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

Since the baffle plates of Patent Documents 1 to 3 are tightly fitted in the fin pipes, the baffle plates may move downstream due to the force of the fluid. In addition, when the flow rate of the fluid is low or when the fluid is highly viscous, such as antifreeze, the flow will stagnate at the contact part with the inner surface of the pipe, resulting in uneven temperature, and increased pressure loss due to increased turbulent action. There is a possibility that the heat transfer performance may be degraded.
Furthermore, the baffle plate is inserted in a substantially horizontal posture (sideways posture) in the straight portion of the pipe that is arranged horizontally with respect to the flow of the combustion exhaust from below, but the cut-and-raised pieces are inserted from upstream to downstream. Since the angle of inclination is set so that the slanted portion faces upward, it is necessary to consider the flow direction and the vertical direction during assembly work, which deteriorates assembly workability.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a heat exchanger that can improve heat transfer performance without causing temperature unevenness or an increase in pressure loss in the fluid in heat transfer tubes, and that has good assembling workability. It is what I did.

In order to achieve the above object, the invention according to claim 1 provides a casing through which combustion exhaust passes in the vertical direction, and a casing that penetrates the casing in a straight line in the horizontal direction and in a direction orthogonal to the through direction. A plurality of heat transfer tube portions arranged side by side at intervals, each having a turbulence plate inserted therein, and a U connecting the ends of adjacent heat transfer tube portions outside the casing so that both ends are staggered in a plan view. a letter-shaped connecting pipe portion, wherein the heat transfer pipe portion and the connecting pipe portion form a series of pipes connected in a meandering manner,
The turbulence plate is a belt-shaped body that is vertically inserted into the heat transfer tube portion, and at least one of the upper portion and the lower portion has a notch portion that allows communication between the left and right sides of the turbulence plate in the heat transfer tube portion. Formed at a plurality of locations at predetermined intervals in the longitudinal direction, a pair of blade pieces inclined to either the left or right of the turbulence plate are formed on the front and rear inner edges in the longitudinal direction of each notch so that the left and right sides are opposite to each other. It is formed by cutting and raising ,
The cutouts are formed in the upper and lower portions of the turbulence plate so as to be aligned in the vertical direction. is formed so as to be rotationally symmetric about the longitudinal central axis of the turbulence plate.
The invention according to claim 2 is characterized in that, in the configuration according to claim 1 , one of the upper and lower front blades and the other rear blade in each vertically overlapping notch are parallel to each other. and
The invention according to claim 3 is characterized in that, in the structure according to claim 1 or 2 , a projection is formed between the pair of blade pieces on the inner edge of each notch.
In order to achieve the above object, the invention according to claim 4 provides a casing through which combustion exhaust passes in the vertical direction, and a casing through which the combustion exhaust passes in a straight line in the horizontal direction, such as in a direction orthogonal to the through direction. A plurality of heat transfer tube portions arranged side by side at intervals, each having a turbulence plate inserted therein, and a U connecting the ends of adjacent heat transfer tube portions outside the casing so that both ends are staggered in a plan view. a letter-shaped connecting pipe portion, wherein the heat transfer pipe portion and the connecting pipe portion form a series of pipes connected in a meandering manner,
The turbulence plate is a belt-shaped body that is vertically inserted into the heat transfer tube portion, and at least one of the upper portion and the lower portion has a notch portion that allows communication between the left and right sides of the turbulence plate in the heat transfer tube portion. Formed at a plurality of locations at predetermined intervals in the longitudinal direction, a pair of blade pieces inclined to either the left or right of the turbulence plate are formed on the front and rear inner edges in the longitudinal direction of each notch so that the left and right sides are opposite to each other. It is formed by cutting and raising,
A protrusion is formed between the pair of blade pieces on the inner edge of each cutout.

According to the first aspect of the invention, by adopting a turbulent flow plate having a notch and a pair of blade pieces provided on the inner edge thereof, a swirl flow can be generated without stagnation of the flow inside the heat transfer tube. can. Therefore, temperature unevenness does not occur, and heat transfer performance can be improved without increasing pressure loss of water in the heat transfer tube portion. In addition, since there is no forward/backward or vertical directionality, there is no need to consider the front/rear and vertical directions during assembly work, and the assembly workability is improved.
In particular , notches are formed in both the upper portion and the lower portion of the turbulence plate so as to align their positions in the vertical direction, and the pair of upper and lower blade pieces are arranged around the longitudinal central axis of the turbulence plate. Since they are formed so as to be rotationally symmetrical, the tips of the upper and lower blades do not face each other in a tapered manner, and the blades can be formed so as not to hinder the flow of the swirling flow.
According to the second aspect of the invention, in addition to the above effect, one of the upper and lower upstream blades and the other downstream blade of each vertically overlapping notch are parallel to each other. , two swirling flows can be effectively generated without disturbing the flow.
According to the inventions of claims 3 and 4 , in addition to the above effects, by forming a projection between the pair of blade pieces in each cutout, the projection is added to the flow of water when passing through the cutout. Interference can be made to generate turbulence and improve the stirring effect.

It is a front view of a heat exchanger. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1; FIG. 2 is a cross-sectional view taken along line BB of FIG. 1; 4 is a cross-sectional view taken along line CC of FIG. 3; FIG. Fig. 2 is a perspective view of a turbulence plate; It is explanatory drawing of a turbulence plate, (A) is a side surface, (B) is a plane, (C) is a bottom surface, (D) is a front surface, (E) is a back surface, respectively. FIG. 4 is a partial exploded view of a turbulence plate; 1 is a schematic diagram of a water heater; FIG. It is explanatory drawing which shows the flow of the water in a heat-transfer tube part, (A) shows a perspective, (B) shows a side surface, (C) shows a plane, respectively.

BEST MODE FOR CARRYING OUT THE INVENTION 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 along the line A--A, FIG. 3 is a cross-sectional view along the line B--B, and FIG. 4 is a cross-sectional view along the line CC.
This heat exchanger 1 has a rectangular cylindrical casing 2. In the upper part of the casing 2, a plurality of fins 3, 3... , and a plurality of heat transfer tube portions 4 , 4 . The heat transfer tube portions 4, 4, . A long pipe is bent at an intermediate portion, and a U-shaped bent portion 5 as a connection pipe portion is protruded to the outside of the casing 2 on the right side, and penetrates the casing 2 and the fins 3, 3, . . . formed by

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 a U-shaped tube 6 as a connection tube portion into the end portions of the heat transfer tube portions 4, 4. It is connected by doing. However, the U-tube 6 is arranged so that the left and right sides of the bent portion 5 are staggered in plan view. In addition, the innermost heat transfer tube portion 4 in the upper stage and the innermost heat transfer tube portion 4 in the lower stage are connected to each other by inserting and connecting both ends of the vertical U-shaped tube 6 .
As a result, in the upper part of the casing 2, four heat transfer tube portions 4 continue in a meandering manner from the heat transfer tube portion 4 at the foremost position in the upper stage through the bent portion 5 and the U-shaped tube 6, From the heat transfer tube part 4 at the rearmost position of the lower stage to the lower stage through the U-shaped tube 6, five heat transfer tube parts 4 are meandering through the bent part 5 and the U-shaped tube 6. A continuous series of tubes 7 are formed.

A turbulence plate 10 is inserted in each heat transfer tube portion 4 . As shown in FIG. 5, the turbulence plate 10 is made of a metal (for example, a nickel alloy strip material) having high strength, high thermal conductivity, and excellent corrosion resistance and oxidation resistance. It is formed in a band plate shape with a slightly smaller width. One end in the longitudinal direction of the turbulence plate 10 has a square end 11 with a linear end, and the other end has a circular end 12 with a semicircular end. Three circular through holes 13, 13, . . .
In the description of the single turbulence plate 10 shown in FIG. 5, the square end portion 11 side is the front side, the circular end portion 12 side is the rear side, and the direction intersecting the turbulence plate 10 is left and right.

Between the square end portion 11 and the circular end portion 12 of the turbulence plate 10, as shown in FIG. The cutouts 14, 14 . An upward mountain-shaped projection 15 is formed at the center of each upper notch 14 in the front-rear direction, and a downward mountain-shaped projection 15 is formed at the center of each lower notch 14 in the front-rear direction. formed.
A pair of blade pieces 16, 16 inclined to either the left or the right are cut and raised on the front and rear inner edges of each notch 14 so that the left and right sides are opposite to each other.
As shown in the partially developed view of FIG. 7, the blades 16 are tapered and flat plate-shaped, which are punched out from the front and rear inner edges of the notch 14 in opposite directions in the front-rear direction. At positions 17, 17, they are formed by folding back to the opposite left and right sides. Therefore, the pair of blade pieces 16, 16 are parallel to each other in plan view and cross each other in side view.

Furthermore, in each of the vertically overlapping notches 14, 14, a pair of upper blade pieces 16A, 16A (when distinguishing between the upper and lower sides, the upper side is denoted as 16A and the lower side is denoted as 16B) and a lower pair of blades The pieces 16B, 16B are formed to be rotationally symmetrical about the central axis O in the longitudinal direction of the turbulence plate 10, and the upper and lower blade pieces 16A, 16B are in a twisted positional relationship.
Moreover, in each notch 14, 14 which overlaps vertically, the upper front blade 16A and the lower rear blade 16B (blade 16A, 16B positioned diagonally in a side view) are parallel to each other. It is cut and raised. Similarly, the upper rear wing piece 16A and the lower front wing piece 16B are cut and raised so as to be parallel to each other.

The turbulence plate 10 is vertically inserted into each of the upper four heat transfer tube portions 4 . Specifically, from the right end of the heat transfer tube portion 4 before the U-shaped tube 6 is inserted and connected, the turbulence plate 10 is inserted with the circular end 12 first, and then the U-shaped tube 6 is inserted and connected. do. At this time, since the top and bottom of the turbulence plate 10 are symmetrical, it is only necessary to pay attention to the left and right direction when inserting.
Then, as shown in FIGS. 3 and 4, the insertion ends 6a, 6a of each U-shaped tube 6 come into contact with the square ends 11, 11, respectively, so that the turbulence plates 10, 10 are brought into contact with the circular ends 12, 12. is inserted into the bent portion 5 on the right side. As a result, each turbulence plate 10 has its circular end portion 12 close to the inner surface of the bent portion 5 and its square end portion 11 in contact with the insertion end portion 6a of the U-shaped tube 6, thereby extending in the longitudinal direction. movement is restricted. At this time, the upper and lower edges of the turbulence plate 10 come into contact with the inner surface of the heat transfer tube portion 4 , and the tips of the vane pieces 16 come into contact with or close to the inner surface of the heat transfer tube portion 4 .

The heat exchanger 1 configured as described above is assembled in a housing 21 of a hot water heater 20 on top of a burner unit 22 in which a plurality of burner groups are provided, as shown in FIG. 8, for example. An exhaust hood 23 is attached to the upper portion of the heat exchanger 1 . As a result, the combustion exhaust from the burners in the burner unit 22 rises in the casing 2 of the heat exchanger 1, passes between the fins 3, 3, and reaches the exhaust hood 23 to form a combustion chamber (inner shell). be done. In addition, a water inlet pipe 24 connected to an external water pipe is connected to the upstream end of the tubular body 7 of the heat exchanger 1, and a hot water outlet pipe connected to a hot water tap is connected to the downstream end of the tubular body 7. A tube 25 is connected. 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 supply valve is opened to allow water to flow through the appliance, the water passes through the water inlet pipe 24 and reaches the tubular body 7 of the heat exchanger 1, and the heat transfer pipe portions 4, 4, . . . pass in order. On the other hand, the controller 27 detects the passage of water, ignites the burners in the burner unit 22, and rotates the air supply fan 26 to supply combustion air to the burners. Combustion exhaust gas from the burner group rises in the casing 2 of the heat exchanger 1 and passes between the fins 3 , 3 to exchange heat with water passing through the heat transfer tube portion 4 . Therefore, hot water of a predetermined temperature is discharged from the hot water discharge pipe 25 and supplied from the hot water tap.

At this time, water passes through each heat transfer tube portion 4 in the direction of the solid arrow shown in FIG. 3. Here, as shown in FIG. Thus, from the left and right of the turbulence plate 10, it passes between the upper and lower blades 16A and 16B, turns around to the left and right opposite sides at the position of the notch 14, and again passes between the upper and lower blades 16A and 16B. Swirling flows F1 and F2 are generated.
As the water passes through the heat transfer tube portion 4 while spirally swirling around the turbulent flow plate 10, the swirling flows F1 and F2 pass through the lower notch portion 14 where the temperature rises due to the combustion exhaust rising from below. The passing water stream and the water stream passing through the notch 14 on the upper side flow alternately and are agitated. Further, when each water flow passes through the notch 14, interference with the protrusion 15 also causes turbulence.
Therefore, heat exchange between the water passing through the heat transfer tube portion 4 and the combustion exhaust gas is efficiently performed, and temperature unevenness in the longitudinal direction of the heat transfer tube portion 4 is suppressed.

As the water passes through the heat transfer tube portion 4 while being in contact with the blade pieces 16, the turbulence plate 10 is urged toward the downstream side of the water. , the circular end 12 of the turbulent plate 10 abuts against the inner surface of the bent portion 5 and movement is restricted. The movement is restricted by contacting the insertion end 6a. Therefore, the turbulence plate 10 does not move or rotate within the heat transfer tube portion 4 .

Thus, according to the heat exchanger 1 of the above-described configuration, the turbulence plate 10 is a belt-like member vertically inserted into the heat transfer tube portion 4, and the upper portion and the lower portion of the turbulence plate 10 are provided with a heat transfer plate. A plurality of notches 14 are formed in the heat tube portion 4 so that the left and right sides of the turbulence plate 10 communicate with each other at predetermined intervals in the longitudinal direction of the turbulence plate 10 . In addition, the pair of blade pieces 16, 16 inclined to either the left or right side of the turbulence plate 10 are cut and raised so that the left and right sides are opposite to each other. Flows F1 and F2 can be generated. Therefore, temperature unevenness does not occur, and heat transfer performance can be improved without increasing the pressure loss of water in the heat transfer tube portion 4 . In addition, since there is no directionality in the vertical direction except for the direction in which the square end portion 11 and the circular end portion 12 are inserted, there is no need to consider the vertical direction during assembly work, and the assembly workability is improved.

In particular, here, the cutouts 14 are formed in both the upper portion and the lower portion of the turbulent flow plate 10 so as to be aligned in the vertical direction, and the upper pair of blade pieces 16A, 16A in the vertically overlapping cutouts 14 are formed. and the lower pair of blades 16B, 16B are formed so as to be rotationally symmetrical about the longitudinal central axis O of the turbulence plate 10, so that the upper and lower blades 16A, 16B The vane pieces 16 can be formed so that the tips do not face each other in a tapered manner and the swirling flows F1 and F2 are not obstructed.
In addition, since the blade piece 16 on the front side of one of the upper and lower sides of each vertically overlapping notch 14 and the blade piece 16 on the rear side of the other are parallel to each other, the two swirl flows F1, F2 can be effectively generated.
Furthermore, since the projections 15 are formed between the pair of blade pieces 16, 16 at the inner edge of each cutout 14, the projections 15 interfere with the water flow when passing through the cutouts 14, resulting in a turbulent flow. can be generated and the stirring effect can be improved.

In addition, the number of notches is not limited to the above-described form, and can be appropriately increased or decreased according to the length of the heat transfer tube portion or the like.
Also, the shape of the blade piece may not be tapered, or may be curved or twisted instead of being flat.
Furthermore, in the above embodiment, the notch and the blade piece are provided on the upper and lower portions of the turbulence plate, respectively. good. The shape of the protrusion can also be changed, and can be omitted.
As for the shape of the front and rear ends of the turbulence plate, the number of through-holes may be increased or decreased at the circular end, or may be omitted. Directionality may be lost by direction.

On the other hand, the water heater provided with a heat exchanger can also be a latent heat recovery type having a sub heat exchanger, or a two-can type with a heat exchanger for reheating a bath or floor heating. . In the case of 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. Also, the present invention can be applied to a reverse combustion type heat exchanger in which the combustion exhaust flows from the top to the bottom of the casing.
Of course, the heat exchanger of the present invention can be employed not only in water heaters, but also in other appliances such as road heaters, as long as they have a heat exchanger that exchanges heat between fluid and combustion exhaust gas.

DESCRIPTION OF SYMBOLS 1... Heat exchanger, 2... Casing, 3... Fin, 4... Heat transfer tube part, 5... Bent part, 6... U-shaped tube, 6a... Insertion end part, 7... Tube Body 10 Turbulence plate 11 Square end 12 Circular end 13 Through hole 14 Notch 15 Projection 16 Blade piece 20 Hot water supply 21: Housing 22: Burner unit 23: Exhaust hood 24: Water inlet pipe 25: Hot water outlet pipe F1, F2: Swirling flow.

Claims (4)

a casing through which combustion exhaust passes vertically;
a plurality of heat transfer tube portions that penetrate the casing in a straight line in the horizontal direction, are arranged in parallel in a direction orthogonal to the penetration direction at equal intervals, and have turbulence plates inserted therein;
a U-shaped connecting tube portion connecting the ends of the heat transfer tube portions adjacent outside the casing so that both ends are alternate in a plan view, the heat transfer tube portion and the connecting tube portion A heat exchanger in which a series of tubular bodies connected in a meandering manner is formed by
The turbulence plate is a belt-shaped body that is vertically inserted into the heat transfer tube portion, and at least one of the upper portion and the lower portion has a notch portion that allows communication between the left and right sides of the turbulence plate in the heat transfer tube portion, formed at a plurality of locations at predetermined intervals in the longitudinal direction of the turbulence plate,
A pair of blade pieces inclined to either the left or right side of the turbulence plate are cut and raised so as to be opposite to each other on the front and rear inner edges in the longitudinal direction of each of the notch portions.with
The cutouts are formed in the upper and lower portions of the turbulence plate so as to be aligned in the vertical direction. The pair of blade pieces are formed so as to be rotationally symmetric about the central axis of the turbulence plate in the longitudinal direction. A heat exchanger characterized by: 2. The heat exchanger according to claim 1 , wherein the blade piece on the front side of one of the upper and lower sides of each of the vertically overlapping notches and the blade piece on the rear side of the other are parallel to each other. 3. The heat exchanger according to claim 1, wherein a projection is formed between the pair of blade pieces on the inner edge of each cutout. a casing through which combustion exhaust passes vertically;
a plurality of heat transfer tube portions that penetrate the casing in a straight line in the horizontal direction, are arranged in parallel in a direction orthogonal to the penetration direction at equal intervals, and have turbulence plates inserted therein;
a U-shaped connecting tube portion connecting the ends of the heat transfer tube portions adjacent outside the casing so that both ends are alternate in a plan view, the heat transfer tube portion and the connecting tube portion A heat exchanger in which a series of tubular bodies connected in a meandering manner is formed by
The turbulence plate is a belt-shaped body that is vertically inserted into the heat transfer tube portion, and at least one of the upper portion and the lower portion has a notch portion that allows communication between the left and right sides of the turbulence plate in the heat transfer tube portion, formed at a plurality of locations at predetermined intervals in the longitudinal direction of the turbulence plate,
A pair of blade pieces inclined to either the left or the right side of the turbulence plate are cut and raised so as to be opposite to each other on the front and rear inner edges in the longitudinal direction of each of the notches, and
A heat exchanger according to claim 1, wherein a projection is formed between the pair of blades on the inner edge of each cutout.

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