JP2022061054A - Plate heat exchanger - Google Patents

Abstract

To provide a plate heat exchanger with less assembly failure and high heat efficiency.SOLUTION: A plate heat exchanger 1 is composed of a plurality of heat exchange bodies 10 laminated together, and adjacent heat exchangers 10 are laminated so that an internal space 14 of one heat exchanger 10 and an internal space 14 of the other heat exchanger 10 communicate with each other via one opening 12e and the other opening 11e provided in each heat exchanger 10. The one heat exchanger 10 has an insertion wall 12j inserted into the opposite opening 11e of the other heat exchanger 10 at the peripheral part of the one opening 12e, and the tip part of the insertion wall 12j has a discontinuous protrusion height in a circumferential direction.SELECTED DRAWING: Figure 8

Description

The present invention relates to a plate heat exchanger configured by stacking a plurality of heat exchangers.

A plate-type heat exchanger including a plurality of heat exchangers in which an upper heat exchange plate and a lower heat exchange plate are joined has been proposed (for example, Patent Document 1). Each heat exchanger has a plurality of through holes through which the heat medium flows between the upper heat exchange plate and the lower heat exchange plate and the internal space in a non-communication state, and the combustion exhaust flows in the vertical direction. And have.

Each heat exchanger has at least one opening that communicates with the interior space. Further, each opening is arranged so as to face the opening of the adjacent heat exchanger. Therefore, the adjacent heat exchangers in the plate heat exchanger are communicated with each other so that the heat medium flows from the lower side to the upper side through the opening. Further, an inflow pipe for supplying a heat medium is inserted through one opening of the most downstream heat exchanger located at the most downstream of the gas flow path of the combustion exhaust. Further, an outflow pipe is inserted from the other opening of the most downstream heat exchanger to one opening of the most upstream heat exchanger. Therefore, in this plate heat exchanger, the heat medium flowing from the inflow pipe to the most downstream heat exchanger flows through the heat exchanger laminated from the most downstream heat exchanger toward the most upstream heat exchanger, and flows to the most upstream. It flows out to the outflow tube from the opening of the heat exchanger. This makes it possible to increase the thermal efficiency.

Japanese Unexamined Patent Publication No. 2020-85362

By the way, in the case of manufacturing the plate type heat exchanger of Patent Document 1, it is necessary to stack a large number of upper and lower heat exchange plates and join a predetermined portion of the upper and lower heat exchange plates by a joining means such as a brazing material. Therefore, an assembly error is likely to occur, and the openings of adjacent heat exchangers are likely to be displaced and arranged. When such a deviation of the opening occurs, there is a problem that the heat medium leaks from the internal space to the outside of the heat exchanger.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a plate heat exchanger having high thermal efficiency with few assembly defects.

According to the present invention
A plate-type heat exchanger composed of a stack of multiple heat exchangers.
Each heat exchanger is configured to exchange heat between a first fluid flowing through the internal space of the heat exchanger and a second fluid flowing outside the heat exchanger.
In the adjacent heat exchangers in the plurality of heat exchangers, the internal space of one heat exchanger and the internal space of the other heat exchanger are provided in one of the heat exchangers with one opening and the other. It is laminated so as to communicate with each other through the other opening provided in the heat exchanger of.
The one heat exchanger has an insertion wall inserted into the other opening when the one heat exchanger and the other heat exchanger are laminated on the peripheral edge of the one opening.
The insertion wall is provided with a plate heat exchanger in which the tip portion is formed so as to have a discontinuous protrusion height in the circumferential direction.

According to the plate heat exchanger, since the peripheral portion of one opening is provided with an insertion wall to be inserted into the other opening, when one heat exchanger and the other heat exchanger are laminated, when the other heat exchanger is laminated. When the facing one opening and the other opening are misaligned due to an assembly error, the insertion wall rides on the peripheral edge of the other opening. Therefore, the gap between adjacent heat exchangers is larger than that in a proper laminated state. This makes it possible to easily confirm the assembly failure.

On the other hand, the one opening and the other opening communicate with the internal space of each heat exchanger, and the insertion wall is inserted into the other opening, so that the insertion wall protrudes into the internal space of the other heat exchanger. Therefore, the insertion wall may increase the flow resistance of the first fluid flowing through the internal space near the other opening and reduce the thermal efficiency.

However, according to the plate heat exchanger, since the tip of the insertion wall has a discontinuous protruding height in the circumferential direction, a notch having a constant width is formed in the tip of the insertion wall in the circumferential direction. Therefore, even if the insertion wall protrudes into the internal space of the other heat exchanger, the first fluid flows through the notch, so that the decrease in the flow path of the first fluid near the other opening is small. As a result, it is possible to suppress an increase in the flow path resistance of the first fluid flowing through the internal space due to the insertion wall and prevent a decrease in thermal efficiency.

Preferably, in the plate heat exchanger,
Each of the heat exchangers is formed by joining a set of heat exchange plates.
One of the heat exchange plates in the set of heat exchange plates has an outer peripheral flange portion that stands on one side of the heat exchanger in the stacking direction on the peripheral edge.
The one heat exchange plate and the proximity heat exchange plate on the side close to the one heat exchange plate in the heat exchanger adjacent to the one side have the outer peripheral flange portion and the peripheral edge of the proximity heat exchange plate. The heat exchangers are laminated so as to overlap each other with a predetermined stacking allowance in the stacking direction.
The insertion wall is set so that the maximum protruding height of the tip portion is larger than the stacking allowance.

According to the plate heat exchanger, the insertion wall is set so that the maximum protrusion height of the tip portion is larger than the stacking allowance. Therefore, due to an assembly error, the tip portion of the insertion wall is the peripheral portion of the other opening. When riding on, a gap of a certain height is created between the peripheral edges of the adjacent heat exchangers. As a result, it is possible to reliably confirm the assembly failure.

Preferably, in the plate heat exchanger,
The insertion wall is formed so that the tip portion is located inward of the one-sided opening with respect to the proximal end portion.

According to the plate heat exchanger, the insertion wall is easily guided into the other opening during assembly. This makes it possible to further reduce assembly defects.

Preferably, in the plate heat exchanger,
The other heat exchanger has a recess on the peripheral edge of the other opening that is concave toward the one opening side.

According to the plate heat exchanger, the other heat exchanger has a recess in the peripheral edge of the other opening that is concave toward the one opening side, so that when the insertion wall is inserted into the other opening, the insertion wall It is possible to prevent the tip portion from protruding significantly into the internal space of the other heat exchanger. As a result, it is possible to suppress an increase in the flow path resistance of the first fluid flowing in the internal space near the other opening.

As described above, according to the present invention, it is possible to manufacture a plate-type heat exchanger having high heat efficiency with few assembly defects.

FIG. 1 is a schematic partially cutaway perspective view showing a heat source machine having a heat exchanger according to an embodiment of the present invention. FIG. 2 is a schematic partially disassembled perspective view showing a heat exchanger according to an embodiment of the present invention. FIG. 3 is a schematic schematic diagram illustrating a flow of combustion exhaust and a heat medium in the heat exchanger according to the embodiment of the present invention. FIG. 4 is a schematic exploded perspective view showing two heat exchangers in the upstream region of the gas flow path of the combustion exhaust in the heat exchanger according to the embodiment of the present invention. FIG. 5 is a schematic plan view showing an example of the upper surface of one of the heat exchange plates constituting the heat exchanger in the heat exchanger according to the embodiment of the present invention. FIG. 6 is a schematic plan view showing an example of the upper surface of the other heat exchange plate constituting the heat exchanger in the heat exchanger according to the embodiment of the present invention. FIG. 7 is a schematic partial perspective view showing an example of the lower surface of the other heat exchange plate of FIG. FIG. 8 is a schematic partial cross-sectional view showing the heat exchanger according to the embodiment of the present invention. FIG. 9 is a schematic partial cross-sectional view showing a heat exchanger according to another embodiment of the present invention.

Hereinafter, the plate heat exchanger according to the present embodiment and the heat source machine provided with the plate heat exchanger will be specifically described with reference to the attached drawings.

As shown in FIG. 1, in the heat source machine according to the present embodiment, water (heat medium), which is the first fluid flowing into the heat exchanger 1 from the inflow pipe 20, is generated by the burner 31 as a second fluid. It is a water heater that is heated by the combustion exhaust and supplied to a hot water utilization destination (not shown) such as a curan or a shower through an outflow pipe 21. Although not shown, the water heater is built into the casing. In addition, another heat medium (for example, antifreeze liquid) may be used as a heat medium.

In this water heater, a burner body 3, a combustion chamber 2, a heat exchanger 1, and a drain receiver 40, which form the outer shell of the burner 31, are arranged in this order from above. Further, on one side of the burner body 3 (on the right side in FIG. 1), a fan case 4 including a combustion fan for sending a mixed gas of fuel gas and air into the burner body 3 is arranged. Further, an exhaust duct 41 communicating with the drain receiver 40 is arranged on the other side of the burner body 3 (on the left side in FIG. 1). The exhaust duct 41 discharges the combustion exhaust discharged to the drain receiver 40 to the outside of the water heater.

In this specification, when the water heater is viewed with the fan case 4 and the exhaust duct 41 arranged on the sides of the burner body 3, the depth direction corresponds to the front-rear direction and the width direction corresponds to the left-right direction. Corresponding, the height direction corresponds to the vertical direction.

The burner body 3 has a substantially oval shape in a plan view, and is formed of, for example, a stainless-based metal. Although not shown, the burner body 3 is open downward.

The gas introduction portion communicating with the fan case 4 projects upward from the central portion of the burner body 3. The burner body 3 includes a planar burner 31 having a downward combustion surface 30. By operating the combustion fan, the mixed gas is supplied into the burner body 3.

The burner 31 is an all-primary air-combustion type, and comprises, for example, a ceramic combustion plate having a large number of flame holes (not shown) that open downward, or a combustion mat in which metal fibers are woven into a net. The mixed gas supplied into the burner body 3 is ejected downward from the downward combustion surface 30 by the supply pressure of the combustion fan. By igniting this mixed gas, a flame is formed on the combustion surface 30 of the burner 31, and combustion exhaust is generated. Therefore, the combustion exhaust gas ejected from the burner 31 is sent to the heat exchanger 1 via the combustion chamber 2. Next, the combustion exhaust gas that has passed through the heat exchanger 1 is discharged to the outside of the water heater through the drain receiver 40 and the exhaust duct 41.

That is, in this heat exchanger 1, the upper side where the burner 31 is provided corresponds to the upstream side of the gas flow path of the combustion exhaust, and the lower side opposite to the side where the burner 31 is provided corresponds to the gas flow of the combustion exhaust. Corresponds to the downstream side of the road.

The combustion chamber 2 has a substantially oval shape in a plan view. The combustion chamber 2 is made of, for example, a stainless steel. The combustion chamber 2 is formed by bending one substantially rectangular metal plate and joining both ends so as to open up and down.

As shown in FIG. 2, the heat exchanger 1 has a substantially oval shape in a plan view. The heat exchanger 1 is a plate-type heat exchanger in which a plurality of (here, 13 layers) thin plate-shaped heat exchangers 10 are laminated. The heat exchanger 1 may have a housing that covers the periphery thereof.

As shown in FIGS. 2 and 3, the heat exchanger 1 is configured by stacking a plurality of (here, four stages) blocks 5 having one or a plurality of heat exchangers 10 in the vertical direction (hereinafter, 4 stages). When these blocks 5 are collectively referred to, they are simply referred to as "block 5". Further, according to the gas flow path of the combustion exhaust, the uppermost block 5 is referred to as "uppermost flow block 5a", and the middle block 5 is sequentially referred to from the upstream side. "First downstream block 5b", "second downstream block 5c", and the lowest block 5 are referred to as "most downstream block 5d"). The most upstream block 5a and the first downstream block 5b are each composed of one heat exchanger 10. Further, the second downstream block 5c is configured by stacking five heat exchangers 10, and the most downstream block 5d is configured by stacking six heat exchangers 10. The heat exchanger 1 may be composed of three or less or five or more blocks 5. As will be described later, when one block 5 is composed of a plurality of heat exchangers 10, water flows in parallel in the same direction inside each heat exchanger 10 constituting the one block 5. Further, the adjacent heat exchangers 10 in each block 5 communicate with each other so that water flows from the lower side to the upper side. Further, the adjacent blocks 5 communicate with each other so that water flows from the lower side to the upper side. Further, in the adjacent blocks 5, the direction of the flow path of water flowing inside each heat exchanger 10 in one block 5 is opposite to the direction of the flow path of water flowing inside each heat exchanger 10 in the other block 5. It is configured to be in the direction. Therefore, the water flow path of each block 5 is folded back between the adjacent blocks 5 so that the heat exchanger 1 has four flow paths (4 paths) according to the number of stages of the blocks 5. As a result, a long water flow path is formed in the heat exchanger 1, and the thermal efficiency can be improved.

Next, the configuration of the heat exchanger 10 will be described. Each heat exchanger 10 exchanges lower heat with a set of upper heat exchange plates 11 having a common configuration, except that some configurations such as the positions of upper and lower through holes and the presence or absence of water passage holes in the corners are different. It is formed by superimposing the plate 12 in the vertical direction and joining a predetermined portion described later by a joining means such as a brazing material. Therefore, in the following, the configuration of one heat exchanger 10 will be mainly described. It should be noted that each drawing does not necessarily show the actual dimensions and does not limit the embodiment.

As shown in FIGS. 2 and 4 to 6, the upper and lower heat exchange plates 11 and 12 have a substantially oval shape in a plan view. The upper and lower heat exchange plates 11 and 12 are formed of, for example, a stainless steel metal plate having a predetermined thickness. The upper and lower heat exchange plates 11 and 12 have a large number of upper through holes 11a and lower through holes 12a formed on substantially the entire surface of the plate excluding the corners, and upper through holes 11a and 12a formed on the peripheral edges of the upper and lower through holes 11a and 12a, respectively. It has a hole flange portion 11c and a lower through hole flange portion 12c.

Upper peripheral edge joints W1 and lower peripheral edge joints W2 projecting upward as outer peripheral flanges are formed on the peripheral edges of the upper and lower heat exchange plates 11 and 12, respectively. The upper and lower peripheral edge joints W1 and W2 are each formed of an inclined wall that spreads upward at a predetermined angle so that the upper end portion is located diagonally upward and outward from the base end portion. Therefore, when the upper and lower heat exchange plates 11 and 12 are laminated, the upper heat exchange plate 11 is internally fitted in the lower heat exchange plate 12 in one heat exchanger 10. Further, the lower heat exchange plate 12 of the upper heat exchanger 10 is fitted inside the upper heat exchange plate 11 of the heat exchanger 10 adjacent to the lower side. Therefore, when a plurality of upper and lower heat exchange plates 11 and 12 are laminated, the peripheral joint portions W1 and W2 of the upper and lower heat exchange plates 11 and 12 overlap each other at a predetermined stacking allowance Hp in the stacking direction of the heat exchanger 10. (See FIG. 8).

When the lower peripheral edge joint portion W2 and the lower peripheral edge of the upper heat exchange plate 11 are joined to each other in one heat exchanger 10, the upper and lower heat exchange plates 11 and 12 have a predetermined height. It is set so that there is a gap between them. Further, the upper and lower heat exchange plates 11 and 12 are above the lower heat exchanger 10 when the upper peripheral edge joint portion W1 and the lower peripheral edge of the lower heat exchange plate 12 of the heat exchanger 10 adjacent above are joined. The heat exchange plate 11 and the lower heat exchange plate 12 of the heat exchanger 10 adjacent to the upper side are set so as to have a gap of a predetermined height.

Therefore, by joining the upper and lower heat exchange plates 11 and 12, an internal space 14 having a predetermined height is formed (see FIG. 3). Further, by joining the plurality of heat exchangers 10, an exhaust space 15 having a predetermined height is formed between the heat exchangers 10 adjacent to the top and bottom (see FIG. 3).

In the region excluding the peripheral region of the vertical heat exchange plates 11 and 12, the vertical through holes 11a and 12a having a substantially square shape in a plan view are provided in a staggered manner at predetermined intervals in the front-rear and left-right directions. The upper and lower through hole flange portions 11c and 12c formed on the peripheral portions of the upper and lower through holes 11a and 12a having a substantially square shape in a plan view extend substantially horizontally outward in the circumferential direction from the opening edges of the upper and lower through holes 11a and 12a and are flat. It has a substantially square outer shape. Further, in the peripheral region of the upper and lower heat exchange plates 11 and 12, upper and lower through holes 11a and 12a having a substantially pentagonal shape in a plan view are provided at predetermined intervals in the front-rear direction or the left-right direction. The upper and lower through hole flange portions 11c and 12c formed on the peripheral edges of the upper and lower through holes 11a and 12a having a substantially pentagonal shape in a plan view extend substantially horizontally outward in the circumferential direction from the opening edges of the upper and lower through holes 11a and 12a and are flat. It has a substantially pentagonal outer shape. The upper and lower through holes 11a and 12a may have other shapes such as a substantially circular shape and a substantially elliptical shape. All the upper and lower through holes 11a and 12a may have the same size and shape, and all the upper and lower through hole flange portions 11c and 12c may have the same size and shape.

The upper and lower through holes 11a and 12a and the upper and lower through hole flange portions 11c and 12c are formed at positions corresponding to each other when the upper and lower heat exchange plates 11 and 12, respectively. Further, the upper and lower through holes 11a and 12a and the upper and lower through hole flange portions 11c and 12c are in surface contact with the upper and lower through hole flange portions 11c and 12c facing each other when the upper and lower heat exchange plates 11 and 12 are overlapped by drawing. As described above, it is formed on the bottom surface of the stepped portion protruding inward.

Therefore, when the upper and lower through-hole flange portions 11c and 12c are joined by a joining means such as a brazing material in a state where the upper and lower heat exchange plates 11 and 12 are overlapped, the upper and lower through-hole flange portions 11c and 12c create the internal space 14. A flange portion 16 to be closed is formed (see FIG. 8). Further, the upper and lower through holes 11a and 12a form a through hole 13 that penetrates the internal space 14 in a non-communication state.

Except for the upper heat exchange plate 11 of the uppermost heat exchanger 10 (hereinafter referred to as "uppermost flow heat exchanger 10a"), the upper and lower heat exchange plates 11 and 12 each have upper water flow through at least one corner portion. It has a hole 11e and a lower water passage hole 12e. The upper and lower water passage holes 11e and 12e provided in at least one corner of the upper and lower heat exchange plates 11 and 12 forming one heat exchanger 10 are used to heat up and down when the upper and lower heat exchange plates 11 and 12 are overlapped. It is open so as to communicate with the internal space 14 formed between the exchange plates 11 and 12.

On the peripheral edges of the upper and lower water passage holes 11e and 12e, the upper water passage hole flange portion 11f and the lower water passage hole flange that extend substantially horizontally outward from the opening edges 11h and 12h of the upper and lower water passage holes 11e and 12e, respectively. The portion 12f is formed. The upper water passage hole 11e and the upper water passage hole flange portion 11f interact with the lower water passage hole 12e and the lower water hole flange portion 12f of the adjacent heat exchanger 10 when the adjacent heat exchangers 10 are overlapped with each other. It is formed at the position corresponding to. Further, the upper water passage hole 11e and the upper water passage hole flange portion 11f face each other when the upper heat exchange plate 11 and the lower heat exchange plate 12 of the heat exchanger 10 adjacent to the upper side are overlapped by the drawing process. The upper and lower water passage holes flange portions 11f and 12f are formed on the upper surface of the stepped portion protruding outward so as to be in surface contact with each other. Similarly, the lower water passage hole 12e and the lower water passage hole flange portion 12f face each other when the lower heat exchange plate 12 and the upper heat exchange plate 11 of the heat exchanger 10 adjacent to the lower side are overlapped by the drawing process. The upper and lower water passage holes flange portions 11f and 12f are formed on the bottom surface of the stepped portion protruding outward so as to be in surface contact with each other.

Therefore, when the upper and lower water passage flange portions 11f and 12f are joined by a joining means such as a brazing material in a state where the upper and lower heat exchange plates 11 and 12 of the adjacent heat exchanger 10 are overlapped with each other, the upper and lower water passage hole flanges are joined. The portions 11f and 12f form a water passage flange portion 64 that closes the exhaust space 15 between the adjacent heat exchangers 10 (see FIG. 8). Further, the water passage holes 63 communicating with the internal space 14 are formed by the vertically opposed upper and lower water passage holes 11e and 12e in the adjacent heat exchanger 10. Further, the internal space 14 at the peripheral edges of the vertical water passage holes 11e and 12e is wider in the vertical direction than the other internal spaces 14. Therefore, a concave upper recess 65 is formed upward on the peripheral edge of the upper water passage hole 11e, and a concave lower recess 66 is formed downward on the peripheral edge of the lower water passage hole 12e.

The underwater hole 12e is opened by burring. Therefore, as shown in FIGS. 7 and 8, the lower water passage hole 12e has an insertion wall 12j protruding downward (downstream side of the gas flow path of the combustion exhaust) from the opening edge 12h. Further, the lower water passage hole 12e and the other heat exchanger 10 of the lower heat exchange plate 12 of the heat exchanger 10 (hereinafter referred to as “the most downstream heat exchanger 10s”) located at the most downstream of the gas flow path of the combustion exhaust. The insertion wall 12j of the lower water passage hole 12e excluding the lower water passage hole 12e on the right rear side of the lower heat exchange plate 12 has a tubular portion 12 m extending downward from the opening edge 12h of the lower water passage hole 12e and a tubular portion. It has a plurality of claw portions 12n protruding downward at a predetermined angle (for example, 120 degrees) in the circumferential direction from the lower end of 12 m. Therefore, the tip portion of the insertion wall 12j has a discontinuous protruding height in the circumferential direction, and has a notch 12p having a constant width between the claw portions 12n.

Further, the insertion wall 12j has the maximum protruding height of the tip portion protruding downward from the upper water passage hole 11e when the upper and lower heat exchange plates 11 and 12 are overlapped (that is, the protruding height of the lower end portion of the claw portion 12n). Hs exchanges heat between the lower peripheral edge joint W2 of the lower heat exchange plate 12 provided with the insertion wall 12j and the lower adjacent heat exchanger 10 having the upper water passage hole 11e into which the insertion wall 12j is inserted. It is set to be larger than the overlap margin Hp between the upper peripheral edge joint portion W1 of the plate 11. The insertion wall 12j may have 2 or less or 4 or more claw portions 12n. Further, when a plurality of claw portions 12n are provided, the heights of the claw portions 12n may be different. Further, the insertion wall 12j may be composed of only the claw portion 12n without the tubular portion 12m.

The tubular portion 12m of the insertion wall 12j has an outer diameter slightly smaller than the inner diameter of the facing upper water passage hole 11e, and the tip portion of the claw portion 12n has an outer diameter slightly smaller than the tubular portion 12m. Therefore, the insertion wall 12j is formed so that the tip end portion is located inward from the base end portion.

Therefore, in a state where the upper and lower heat exchange plates 11.12 are properly laminated, the insertion wall 12j formed in the lower water passage hole 12e of the lower heat exchange plate 12 is the upper heat exchange of the heat exchanger 10 adjacent to the lower side. It is inserted into the upper water passage hole 11e of the plate 11, and the tip end portion of the insertion wall 12j protrudes below the upper water passage hole flange portion 11f. That is, in the present embodiment, the lower water passage hole 12e corresponds to one opening, and the upper water passage hole 11e corresponds to the other opening. The upper water passage hole 11e of the upper heat exchange plate 11 may also be formed by burring.

As shown in FIG. 3, in each of the through holes 13 of the heat exchanger 10, the through hole 13 of one heat exchanger 10 in the adjacent heat exchanger 10 burns with the through hole 13 of the other heat exchanger 10. It is arranged so as to be displaced in the left-right direction, which intersects perpendicularly with the gas flow path direction of the exhaust. That is, the heat exchangers 10 adjacent to each other on the upper and lower sides are arranged so that the projection surface of the through hole 13 of one heat exchanger 10 does not overlap with the through hole 13 of the other heat exchanger 10. Therefore, the combustion exhaust flowing from the upstream side passes through the through hole 13 of one heat exchanger 10 and then enters the exhaust space 15 between the heat exchanger 10 and the heat exchanger 10 adjacent to the downstream side. It flows out. Then, the combustion exhaust flowing into the exhaust space 15 collides with the upper heat exchange plate 11 of the heat exchanger 10 adjacent to the downstream side, and flows further downstream from the through hole 13 of the heat exchanger 10 adjacent to the downstream side. .. That is, when the combustion exhaust flows in the heat exchanger 1 from the upstream side to the downstream side, a zigzag gas flow path is formed in the heat exchanger 1. As a result, the contact time between the combustion exhaust in the heat exchanger 1 and the upper and lower heat exchange plates 11 and 12 increases.

Next, with reference to FIG. 3, the flow of combustion exhaust gas and water in the heat exchanger 1 will be described. Each block 5 has an introduction port 71 for introducing water into the block 5 and an outlet 72 for leading water to the outside of the block 5. Each of the introduction ports 71 is composed of a predetermined underwater hole 12e of the heat exchanger 10 located at the most downstream of the gas flow path of the combustion exhaust of each block 5. Further, the outlet 72 is a predetermined upper water passage hole 11e of the heat exchanger 10 located at the uppermost stream of the gas flow path of the combustion exhaust in each block 5b, 5c, 5d other than the uppermost stream block 5a, and the uppermost stream block. It is composed of a predetermined underwater hole 12e of the heat exchanger 10 in 5a. In addition, in order to avoid complication, some configurations such as the flange portion 16 and the insertion wall 12j are omitted in FIG.

The inflow pipe 20 is connected to the lower water passage hole 12e at the corner portion on the right front side of the lower heat exchange plate 12 forming the most downstream heat exchanger 10s. Further, in the lower water passage hole 12e of the corner portion on the right rear side of the lower heat exchange plate 12 forming the most downstream heat exchanger 10s, from the most downstream heat exchanger 10s so as to penetrate a part of the heat exchanger 1. An outflow pipe 21 extending upward to the most upstream heat exchanger 10a is inserted. The upper end of the outflow pipe 21 is inserted into the lower water passage hole 12e of the corner portion on the right rear side of the lower heat exchange plate 12 forming the uppermost flow heat exchanger 10a.

The upper end opening of the outflow pipe 21 communicates with the internal space 14 of the uppermost flow heat exchanger 10a. Further, when the outflow pipe 21 is inserted from the most downstream heat exchanger 10s to the most upstream heat exchanger 10a, the outflow pipe 21 is connected to the internal space 14 of the heat exchanger 10 other than the most upstream heat exchanger 10a and the adjacent heat exchange. It penetrates all the exhaust spaces 15 between the bodies 10 in a non-communication state.

Therefore, the water flowing into the internal space 14 of each heat exchanger 10 of the most downstream block 5d from the lower water passage hole 12e (introduction port 71) of the corner portion on the right front side is unidirectional in the internal space 14 in the left-right direction. It flows from the right side to the left side in Fig. 3. Further, the water flowing into the internal space 14 of each heat exchanger 10 of the second downstream block 5c through the upper and lower water passage holes 11e and 12e (outlet port 72 and introduction port 71) of both the front and rear corners on the left side It flows in one direction (from the left side to the right side in FIG. 3) in the left-right direction in the internal space 14. The direction of the flow path of water flowing through the internal space 14 of the heat exchanger 10 of the second downstream block 5c is opposite to that of the most downstream block 5d. Further, it is referred to as a heat exchanger 10 (hereinafter referred to as "second heat exchanger 10b") of the first downstream block 5b via the upper and lower water passage holes 11e and 12e (outlet port 72 and introduction port 71) of the corner portion on the right front side. ), The water flowing into the internal space 14 flows in one direction (from the right side to the left side in FIG. 3) in the left-right direction in the internal space 14. The flow path direction of the water flowing through the internal space 14 of the second heat exchanger 10b is opposite to that of the second downstream block 5c. Further, the water flowing into the internal space 14 of the most upstream heat exchanger 10a through the upper and lower water passage holes 11e and 12e (outlet port 72 and introduction port 71) of both the front and rear corners on the left side flows into the internal space 14. It flows in one direction in the left-right direction (from the left side to the right side in FIG. 3). The direction of the flow path of water flowing through the internal space 14 of the most upstream heat exchanger 10a is opposite to that of the second heat exchanger 10b. Then, the water flowing in the internal space 14 of the upstream heat exchanger 10a is passed through the outflow pipe 21 inserted into the lower water passage hole 12e (outlet port 72) of the corner portion on the right rear side of the upstream heat exchanger 10a. leak. The water flowing out to the outflow pipe 21 flows down the outflow pipe 21 and flows out to the outside of the heat exchanger 1. As described above, in the upstream heat exchanger 10a and the second heat exchanger 10b in the upstream region of the gas flow path of the combustion exhaust, all the water flowing into the inside of the second heat exchanger 10b is the upstream heat exchanger 10a. They are connected in series so that they flow into. Further, the plurality of heat exchangers 10 of the most downstream block 5d are connected in parallel so as to form a plurality of parallel flow paths. The second downstream block 5c also has the same configuration as the most downstream block 5d.

Next, a method of manufacturing the heat exchanger 1 of the present embodiment will be described. These plates are laminated while supplying a joining means such as a brazing material to a predetermined position of one lower frame plate 101, a predetermined number of upper and lower heat exchange plates 11 and 12, and one upper frame plate 102. Although not shown, the outer diameter of the tubular portion 12m of the lower water passage hole 12e of the lower heat exchange plate 12 of the most downstream heat exchanger 10s is set to be slightly smaller than the inner diameter of the opening of the corresponding lower frame plate 101. ..

Next, the upper end portion of the inflow pipe 20 is inserted into the lower water passage hole 12e on the right front side of the most downstream heat exchanger 10s through the opening of the lower frame plate 101. Further, the outflow pipe 21 is inserted upward from the lower water passage hole 12e on the right rear side of the most downstream heat exchanger 10s through another opening of the lower frame plate 101. Then, it is inserted into the outer peripheral surface of the inflow pipe 20 inserted into the lower water passage hole 12e on the right front side of the most downstream heat exchanger 10s and the lower water passage hole 12e on the right rear side of the most downstream heat exchanger 10s. A subassembly is prepared by supplying a joining means such as a brazing material to the outer peripheral surface of the outflow pipe 21. The heat exchanger 1 can be manufactured by putting this subassembly into a furnace and performing a brazing process.

As described above, the vertically opposed upper and lower water passage holes 11e and 12e in the adjacent heat exchanger 10 form a water passage hole 63 which is a communication passage for communicating the internal space 14 of the adjacent heat exchanger 10. .. On the other hand, in the plate type heat exchanger 1 in which a large number of upper and lower heat exchange plates 11 and 12 are laminated, the upper and lower water passage holes 11e and 12e facing each other are likely to be displaced and arranged due to an assembly error. Therefore, there is a possibility that the upper and lower heat exchange plates 11 and 12 may not be properly joined at the water passage hole flange portion 64 at the peripheral portion of the water passage hole 63, resulting in an assembly failure. When such an assembly failure occurs, the internal space 14 and the exhaust space 15 communicate with each other, and water leaks from the peripheral portion of the water passage hole 63 to the exhaust space 15.

However, according to the present embodiment, since the insertion wall 12j extending downward is provided on the peripheral edge of the lower water passage hole 12e forming the water passage hole 63, the heat exchanger 10 is appropriately laminated. If not, the insertion wall 12j projecting downward from the peripheral edge of the lower water passage hole 12e rides on the upper surface of the upper heat exchange plate 11 at the peripheral edge of the upper water passage hole 11e, and the lower heat exchange plate 12 adjacent above the upper surface. Is tilted. This makes it possible to easily confirm the assembly failure.

Further, in the present embodiment, since the claw portion 12n is formed at the tip end portion of the insertion wall 12j so that the protruding height is discontinuous in the circumferential direction, one claw portion 12n passes downward. Even if it is arranged in the water hole 11e, if another claw portion 12n rides on the peripheral portion of the upper water passage hole 11e due to an assembly error, the lower heat exchange plate 12 adjacent to the upper side is similarly tilted. As a result, it is possible to reliably confirm the assembly failure.

Further, according to the present embodiment, since the insertion wall 12j projects into the internal space 14 of the adjacent heat exchanger 10 via the upper water passage hole 11e, when water flows in the vicinity of the upper water passage hole 11e. , The water flow path resistance tends to increase due to the insertion wall 12j. However, according to the present embodiment, since the tip portion of the insertion wall 12j has a discontinuous protruding height, a notch 12p is formed at the tip portion of the insertion wall 12j. Therefore, even if the insertion wall 12j protrudes into the internal space 14 of the adjacent heat exchanger 10, the water flows through the notch 12p, so that the decrease in the water flow path in the vicinity of the upper water passage hole 11e is small. .. Therefore, it is possible to suppress an increase in the flow path resistance of the water flowing through the internal space 14 due to the insertion wall 12j. In particular, in the present embodiment, since the concave upper recess 65 is formed upward on the peripheral edge of the upper water passage hole 11e into which the insertion wall 12j is inserted, the insertion wall 12j is inside the other heat exchanger 10. It is possible to prevent a large protrusion into the space 14, and further suppress an increase in water flow path resistance. Therefore, water can be smoothly circulated from the internal space 14 of one heat exchanger 10 to the internal space 14 of the other heat exchanger 10. This makes it possible to suppress a decrease in thermal efficiency.

Further, according to the present embodiment, in the plurality of heat exchangers 10, the bottom peripheral edge of the lower heat exchange plate 12 is attached to the upper peripheral edge joint portion W1 which is the outer peripheral flange portion provided on the peripheral edge of the upper heat exchange plate 11. The bottom peripheral edge of the upper heat exchange plate 11 is internally fitted into the lower peripheral edge joint W2 which is the outer peripheral flange portion provided on the peripheral edge of the lower heat exchange plate 12. Then, if the insertion wall 12j is properly inserted into the upper water passage hole 11e, the upper and lower heat exchange plates 11 and 12 are laminated so as to overlap each other with a predetermined stacking allowance Hp. On the other hand, the maximum protruding height Hs at the tip of the insertion wall 12j is larger than the stacking allowance Hp. Therefore, when the insertion wall 12j rides on the peripheral edge of the upper water passage hole 11e due to an assembly error, a gap is generated between the peripheral edges of the adjacent heat exchangers 10. That is, in the present embodiment, the upper heat exchange plate 11 of one heat exchanger 10 corresponds to one heat exchange plate, and the lower side of the heat exchanger 10 adjacent to the upper side close to the upper heat exchange plate 11. The heat exchange plate 12 corresponds to the proximity heat exchange plate. In particular, in the present embodiment, since the water passage hole 63 is provided in the corner portion on the peripheral edge of the heat exchanger 10, the gap is easily confirmed in appearance. As a result, it is possible to reliably confirm the assembly failure.

Further, according to the present embodiment, since the insertion wall 12j is formed so that the tip end portion is located inside the upper water passage hole 11e with respect to the base end portion, a plurality of heat exchange plates 11 and 12 are provided. When laminating, the insertion wall 12j is easily guided into the upper water passage hole 11e. This makes it possible to further reduce assembly defects.

In this embodiment, the insertion wall provided at the peripheral edge of the lower water passage hole is inserted into the facing upper water passage hole. However, the insertion wall provided at the peripheral edge of the upper water passage hole may be inserted into the opposite lower water passage hole. In this case, the upper water passage hole corresponds to one opening, and the lower water passage hole corresponds to the other opening.

(Other embodiments)
(1) In the above embodiment, each of the upper and lower heat exchange plates has an upper and lower peripheral edge joint portion which is an outer peripheral flange portion. However, as shown in FIG. 9, only one of the upper and lower heat exchange plates 11 and 12 may have an outer peripheral flange portion that stands on one side of the heat exchanger 10 in the stacking direction. In this case, as in the above embodiment, the insertion wall 12j has a maximum protrusion height Hs of the tip portion in the outer peripheral flange portion W1 of the upper heat exchange plate 11 on one side and the heat exchanger 10 adjacent to one side. Overlapping allowance Hp between the lower heat exchange plate 12 (that is, in the heat exchanger 10 adjacent to one side, the lower heat exchange plate 12 on the side closer to the upper heat exchange plate 11 of the lower heat exchanger 10). Is set to be larger than.

(2) In the above embodiment, the heat exchanger has a plurality of blocks in which the flow path directions of the first fluid are different. However, the heat exchanger may consist of one block. In this case, the first fluid circulates in all heat exchangers in the same direction.

(3) In the above embodiment, a burner having a downward combustion surface is arranged above the heat exchanger. However, a burner with an upward combustion surface may be disposed below the heat exchanger. In this case, since the flow path of the combustion exhaust is reversed upside down, the uppermost layer heat exchanger corresponds to the most downstream heat exchanger and the lowermost layer heat exchanger corresponds to the most upstream heat exchanger. Further, the combustion exhaust may flow through the plate heat exchanger in the left-right direction.

(4) In the above embodiment, the insertion wall extends from the opening edge of one opening toward the other opening. However, if the insertion wall can be inserted into the other opening, the insertion wall may extend from a predetermined position outward of the opening edge of one opening toward the other opening.

(5) In the above embodiment, the heat medium is used as the first fluid flowing through the internal space of the heat exchanger, and the combustion exhaust is used as the second fluid flowing outside the heat exchanger. However, a combustion exhaust may be used as the first fluid, and a heat medium may be used as the second fluid.

(6) In the above embodiment, a plurality of heat exchangers are stacked one above the other. However, a plurality of heat exchangers may be stacked on the left and right.

(7) In the above embodiment, a water heater is used, but a heat source machine such as a boiler may be used.

1 Plate heat exchanger 10 Heat exchanger 11e Upper water passage hole 12e Lower water passage hole 12j Insertion wall 14 Internal space 65 Upper recess

Claims (4)

A plate-type heat exchanger composed of a stack of multiple heat exchangers.
Each heat exchanger is configured to exchange heat between a first fluid flowing through the internal space of the heat exchanger and a second fluid flowing outside the heat exchanger.
In the adjacent heat exchangers in the plurality of heat exchangers, the internal space of one heat exchanger and the internal space of the other heat exchanger are provided in one of the heat exchangers with one opening and the other. It is laminated so as to communicate with each other through the other opening provided in the heat exchanger of.
The one heat exchanger has an insertion wall inserted into the other opening when the one heat exchanger and the other heat exchanger are laminated on the peripheral edge of the one opening.
The insertion wall is a plate heat exchanger in which the tip portion is formed so as to have a discontinuous protrusion height in the circumferential direction. In the plate heat exchanger according to claim 1,
Each of the heat exchangers is formed by joining a set of heat exchange plates.
One of the heat exchange plates in the set of heat exchange plates has an outer peripheral flange portion that stands on one side of the heat exchanger in the stacking direction on the peripheral edge.
The one heat exchange plate and the proximity heat exchange plate on the side close to the one heat exchange plate in the heat exchanger adjacent to the one side have the outer peripheral flange portion and the peripheral edge of the proximity heat exchange plate. The heat exchangers are laminated so as to overlap each other with a predetermined stacking allowance in the stacking direction.
The insertion wall is a plate-type heat exchanger in which the maximum protruding height of the tip portion is set to be larger than the stacking allowance. In the plate heat exchanger according to claim 1 or 2.
The insertion wall is a plate heat exchanger in which the tip portion is formed so as to be located inside the one opening with respect to the base end portion. In the plate heat exchanger according to any one of claims 1 to 3.
The other heat exchanger is a plate-type heat exchanger having a recess on the peripheral edge of the other opening, which is concave toward the one opening side.

Images