JP2022044083A - Plate type heat exchanger - Google Patents

Abstract

To provide a plate type heat exchanger with high heat efficiency.SOLUTION: In a plate type heat exchanger 1 in which a plurality of heat exchangers 10 are laminated, adjacent blocks 5 are connected so that a heat medium flows from an outlet 72 of one block 5 to an inlet 71 of the other block 5; a pipe 21 is inserted from one end side to the other end side in a lamination direction of the heat exchangers 10; an end part on the other end side of the pipe 21 is inserted through an opening of either the inlet 71 or the outlet 72 of the other end block 5 located at the other endmost side; and the opening of the other end block 5 through which the end part on the other end side of the pipe 21 is inserted is provided with an upright wall 12g protruding from an opening edge 12h toward the one end side.SELECTED DRAWING: Figure 7

Description

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

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.

The plate heat exchanger in Patent Document 1 is configured by stacking a plurality of blocks having at least one heat exchanger in the vertical direction. Further, the blocks adjacent to each other in the vertical direction are communicated with each other so that the heat medium can flow. Further, the adjacent blocks are configured so that the flow path direction of the heat medium flowing through one block is different from that of the heat medium flowing through the other block. As a result, the flow path of the heat medium circulating in the heat exchanger becomes longer according to the number of stages of the block, and the thermal efficiency can be improved.

Further, in the above-mentioned plate heat exchanger, an inflow pipe for supplying a heat medium is inserted into one opening of the most downstream heat exchanger constituting the introduction port of the most downstream block located at the most downstream of the gas flow path of the combustion exhaust. Has been done. Further, the heat exchanger on the upstream side of the gas flow path of the combustion exhaust from the most downstream heat exchanger is provided with an opening at a position corresponding to another opening of the most downstream heat exchanger. Then, the outflow pipe is inserted from the other opening of the most downstream heat exchanger to one opening of the heat exchanger constituting the outlet of the most upstream block, and the internal space and outflow of the heat exchanger having the outlet are inserted. It communicates with the pipe. Therefore, in this plate heat exchanger, the heat medium flowing from the inflow pipe to the most downstream block flows from the most downstream block toward the most upstream block, and flows out to the outflow pipe from the outlet of the most upstream block. Then, the heat medium flowing out to the outflow pipe flows down the outflow pipe and flows out to the outside of the plate heat exchanger.

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 length of the heat exchanger side through which the outflow pipe is inserted may change for each product, and the upper end of the outflow pipe may not be inserted into the outlet of the most upstream block. If the heat medium flows through the heat exchanger with the upper end of the outflow pipe not reaching the outlet of the most upstream block, the outflow pipe will be more than the heat exchanger provided with the outlet of the most upstream block. The heat medium communicates with the internal space of the heat exchanger on the downstream side of the gas flow path of the combustion exhaust, and the heat medium is short-circuited from the heat exchanger on the downstream side of the most upstream block to the outflow pipe and flows out. As a result, there is a problem that the inflow amount of the heat medium to the uppermost stream block is reduced and the thermal efficiency is lowered.

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 with high thermal efficiency.

According to the present invention
A plate heat exchanger in which a plurality of blocks having at least one heat exchanger are laminated.
The heat exchanger is configured to exchange heat between a heat medium flowing through the internal space of the heat exchanger and combustion exhaust flowing outside the heat exchanger.
Each block in the plurality of blocks is provided with an introduction port for introducing the heat medium into each block and an outlet for deriving the heat medium from each block.
Adjacent blocks in the plurality of blocks are connected so that the heat medium flows from the outlet of one block to the inlet of the other block.
In the adjacent blocks, the flow path direction of the heat medium flowing through the internal space of the heat exchanger of the one block is different from that of the heat medium flowing inside the heat exchanger of the other block. Is configured as
A pipe is inserted from one end side to the other end side in the stacking direction of the heat exchanger so as to penetrate a part of the plate heat exchanger.
The other end of the pipe is the introduction port of the other end block or the introduction port of the other end block so as to communicate with the internal space of the heat exchanger constituting the other end block in which the pipe is located on the other end side. It is inserted through one of the outlets and is inserted into one of the outlets.
Provided is a plate heat exchanger provided with an upright wall projecting from the opening edge toward the one end side at the opening of the other end block through which the other end side end portion of the pipe is inserted. Will be done.

According to the plate heat exchanger, the other end block has an upright wall that protrudes toward one end at the opening edge of the opening through which the other end of the pipe is inserted. Even if the other end does not reach the opening edge of the opening, the other end can be inserted through the erection wall. As a result, it is possible to suppress communication between the internal space of the heat exchanger of the other block other than the other end block and the piping. Therefore, it is possible to prevent a decrease in the amount of heat medium flowing into the other end block and obtain high thermal efficiency.

Preferably, in the plate heat exchanger,
The insertion length of the pipe from the one end block is restricted by the contact between the pipe side positioning portion provided on the pipe and the block side positioning portion provided on the one end block located on the one end side.
In the pipe, the first length L1 from the piping side positioning portion to the other end side opening is longer than the second length L2 from the block side positioning portion to the base end portion of the erection wall. Is set to.

According to the plate heat exchanger, the first length L1 from the piping side positioning portion to the other end side opening is longer than the second length L2 from the block side positioning portion to the base end portion of the erecting wall. Therefore, when the piping side positioning part comes into contact with the block side positioning part, the other end side opening of the pipe should be arranged on the other end side of the base end part of the vertical wall. Can be done. As a result, it is possible to reliably suppress the communication between the internal space of the heat exchanger other than the heat exchanger of the other end block and the piping.

Preferably, in the plate heat exchanger,
The other end block has a concave portion that becomes concave toward one end side at the peripheral edge portion of the opening through which the pipe is inserted.
The pipe is set so that the first length L1 is shorter than the total length (L2 + L3) of the second length L2 and the depth L3 of the recess.

According to the plate heat exchanger, the piping is set so that the first length L1 is shorter than the total length (L2 + L3) of the second length L2 and the depth L3 of the recess at the peripheral edge of the opening. Therefore, when the piping side positioning portion comes into contact with the block side positioning portion, it is possible to prevent the other end side opening of the pipe from protruding toward the other end side of the recess. As a result, the amount of protrusion of the pipe into the internal space of the heat exchanger provided with the opening is restricted, so that the other end of the pipe can be reliably inserted into the opening of the other end block. It is possible to suppress an increase in the flow path resistance of the heat medium flowing in the internal space near the opening.

As described above, according to the present invention, even if an assembly error occurs in the manufacture of the plate heat exchanger, the other end of the pipe can be reliably inserted into the opening of the other end block. As a result, communication between the internal space of the heat exchanger other than the heat exchanger of the other end block and the piping can be suppressed, so that a plate-type heat exchanger with high heat efficiency can be provided.

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 cross-sectional view on the outflow pipe side showing a part of the heat exchanger according to the 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) flowing into the heat exchanger 1 from the inflow pipe 20 is heated by the combustion exhaust generated by the burner 31, and the outflow pipe is used. It is a water heater that supplies hot water to a hot water usage destination (not shown) such as a burner or a shower through 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 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, in the upper and lower heat exchange plates 11 and 12, these peripheral edge joints W1 and W2 overlap each other at a predetermined height in the gas flow path direction of the combustion exhaust. Arranged (see Figure 7).

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 hole flanges 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. 7). 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. 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.

As shown in FIG. 7, the underwater hole 12e is opened by burring. Therefore, the lower heat exchange plate 12 has a burring portion (standing wall) 12 g that protrudes downward (downstream side of the gas flow path of the combustion exhaust) from the opening edge 12h of the lower water passage hole 12e. Therefore, the opening edge 12h of the lower water passage hole 12e constitutes the base end portion of the burring portion 12g. Further, when the upper and lower heat exchange plates 11 and 12 are overlapped with each other, the burring portion 12g projects downward from the upper water passage hole flange portion 11f of the upper heat exchange plate 11 of the heat exchanger 10 adjacent to the lower side. The downwardly projecting burring portion may be formed in the upper water passage hole 11e of the upper heat exchange plate 11 or may be formed in both the upper and lower water passage holes 11e and 12e.

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 burring portion 12g are omitted in FIG.

In the lower water passage hole 12e of the corner portion on the right front side of the lower heat exchange plate 12 forming the heat exchanger 10 (hereinafter referred to as "most downstream heat exchanger 10s") located at the most downstream of the gas flow path of the combustion exhaust. Is connected to the inflow pipe 20. 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. Therefore, in the present embodiment, the most downstream heat exchanger 10s side corresponds to one end side of the heat exchanger 10 in the stacking direction, and the most upstream heat exchanger 10a side corresponds to the other end side of the heat exchanger 10 in the stacking direction. The upstream block 5a corresponds to the other end block on the farthest end side, and the most downstream block 5b corresponds to the one end block on the farthest end side. Further, the outlet 72 of the most upstream block 5a corresponds to an opening through which the other end of the pipe is inserted.

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, the heat exchanger 10 (hereinafter referred to as "second heat exchanger 10b") of the first downstream side block 5b is referred to 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 burring portion 12g of the lower water passage hole 12e 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 which is the first pipe 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 which is the second pipe is inserted upward from the lower water passage hole 12e on the right rear side of the most downstream heat exchanger 10s through the other 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.

FIG. 7 is a schematic partial cross-sectional view on the outflow pipe 21 side showing a part of the heat exchanger 1 of the present embodiment. Although FIG. 7 shows only the configuration of the upstream and downstream regions of the gas flow path of the combustion exhaust, the configuration of the midstream region is also the same. As shown in FIG. 7, the outflow pipe 21 has a small diameter portion 21a having a constant outer diameter from the upper end portion to the vicinity of the lower end portion and a large diameter portion having an outer diameter larger than the outer diameter of the small diameter portion 21a near the lower end portion. Has 21b and. The small diameter portion 21a of the outflow pipe 21 has an outer diameter substantially the same as the inner diameters of the upper and lower water passage holes 11e and 12e. Further, the large diameter portion 21b of the outflow pipe 21 has an outer diameter larger than the outer diameter of the burring portion 12g. Therefore, when the outflow pipe 21 is inserted from the lower side to the upper side, the upper end of the large diameter portion 21b is a burring portion provided in the lower water passage hole 12e of the lower heat exchange plate 12 of the most downstream heat exchanger 10s. It abuts on the lower end of 12 g. As a result, the insertion length of the outflow pipe 21 to the heat exchanger 1 is restricted. Therefore, the upper end of the large diameter portion 21b of the outflow pipe 21 constitutes the piping side positioning portion, and the lower end of the burring portion 12g constitutes the block side positioning portion.

Further, in the present embodiment, the first length L1 of the small diameter portion 21a from the upper end of the large diameter portion 21b to the upper end of the outflow pipe 21 is the lower water passage of the lower heat exchange plate 12 of the most downstream heat exchanger 10s. The second length from the lower end of the burring portion 12g provided in the hole 12e to the opening edge 12h of the lower water passage hole 12e of the lower heat exchange plate 12 of the uppermost flow heat exchanger 10a forming the outlet 72 of the uppermost flow block 5a. It is set to be longer than the L2 and shorter than the total length (L2 + L3) of the second length L2 and the depth L3 of the lower recess 66 at the peripheral edge of the lower water hole 12e.

As described above, in the plate heat exchanger 1 configured by laminating a large number of upper and lower heat exchange plates 11 and 12, depending on the product, under the lower heat exchange plate 12 of the most downstream heat exchanger 10s due to an assembly error. The length from the water passage hole 12e to the lower water passage hole 12e of the lower heat exchange plate 12 of the uppermost flow heat exchanger 10a (that is, the outlet 72 of the uppermost flow block 5a) is likely to change. Therefore, when the outflow pipe 21 having a single diameter is used, even if the outflow pipe 21 is inserted into the heat exchanger 1 having a predetermined length, the upper end of the outflow pipe 21 is the most upstream heat exchanger 10a depending on the product. It may not reach the lower water passage hole 12e of the lower heat exchange plate 12. Therefore, the internal space 14 of the heat exchanger 10 on the downstream side of the most upstream block 5a and the outflow pipe 21 communicate with each other, and water is short-circuited from the internal space 14 of the heat exchanger 10 on the downstream side to the outflow pipe 21. leak. As a result, the inflow amount of water flowing into the most upstream block 5a is reduced, and the thermal efficiency is lowered.

However, according to the present embodiment, the lower heat exchange plate 12 of the uppermost flow heat exchanger 10a forming the outlet 72 of the uppermost flow block 5a is directed downstream from the opening edge 12h of the lower water passage hole 12e. Since it has a protruding burring portion 12g, even if the upper end portion of the outflow pipe 21 is inserted only to a position below the opening edge 12h of the lower water passage hole 12e due to an assembly error, the upper end portion of the outflow pipe 21 is burred. It can be inserted through the portion 12g. As a result, it is possible to prevent water from short-circuiting to the outflow pipe 21 from the heat exchanger 10 on the downstream side of the most upstream block 5a and flowing out. Therefore, it is possible to prevent a decrease in the amount of water flowing into the most upstream block 5a and obtain high thermal efficiency.

Further, it is conceivable to lengthen the insertion length of the outflow pipe 21 to the heat exchanger 1, but due to an assembly error, the most upstream heat is exchanged from the lower water hole 12e of the lower heat exchange plate 12 of the most downstream heat exchanger 10s. The length to the lower water passage hole 12e of the lower heat exchange plate 12 of the body 10a may be shortened. Therefore, when the insertion length of the outflow pipe 21 is lengthened, the outflow pipe 21 greatly protrudes into the internal space 14 of the most upstream heat exchanger 10a and closes the internal space 14. As a result, the flow path resistance of water may increase and the thermal efficiency may decrease.

However, according to the present embodiment, the upper end of the large diameter portion 21b provided near the lower end portion of the outflow pipe 21 is provided in the lower water passage hole 12e of the lower heat exchange plate 12 of the most downstream heat exchanger 10s. By contacting the lower end of the burring portion 12g, the insertion of the outflow pipe 21 into the heat exchanger 1 is restricted. The first length L1 of the small diameter portion 21a of the outflow pipe 21 is a burring provided in the lower water passage hole 12e of the lower heat exchange plate 12 of the most downstream heat exchanger 10s with which the upper end of the large diameter portion 21b abuts. It is longer than the second length L2 from the lower end of the portion 12g to the opening edge 12h of the lower water passage hole 12e of the lower heat exchange plate 12 of the uppermost flow heat exchanger 10a. Therefore, the small diameter portion 21a of the outflow pipe 21 is heat exchanged until the upper end of the large diameter portion 21b abuts on the lower end of the burring portion 12g provided in the lower water passage hole 12e of the lower heat exchange plate 12 of the most downstream heat exchanger 10s. When inserted into the vessel 1, the upper end opening of the outflow pipe 21 is arranged at least above the opening edge 12h of the lower water passage hole 12e. As a result, even if an assembly error occurs, it is possible to reliably prevent water from short-circuiting to the outflow pipe 21 from the heat exchanger 10 on the downstream side of the most upstream block 5a and flowing out.

Further, according to the present embodiment, the first length L1 of the small diameter portion 21a of the outflow pipe 21 is the second length L2 and the depth L3 of the lower recess 66 of the peripheral edge portion of the lower water passage hole 12e. It is set to be shorter than the total length (L2 + L3). Therefore, when the upper end of the large diameter portion 21b abuts on the lower end of the burring portion 12g provided in the lower water passage hole 12e of the lower heat exchange plate 12 of the most downstream heat exchanger 10s, the upper end opening of the outflow pipe 21 is the maximum. It is arranged above the opening edge 12h of the lower water passage hole 12e of the lower heat exchange plate 12 of the upstream heat exchanger 10a and below the upper end of the lower recess 66. As a result, even if the outflow pipe 21 protrudes into the internal space 14 of the upstream heat exchanger 10a, the heat exchanger of the upstream block 5a is smoothly prevented from increasing the flow path resistance of the water flowing through the internal space 14. Water can be discharged from the 10 to the outflow pipe 21. Thereby, the thermal efficiency can be further improved.

In the present embodiment, water flows into the most downstream block 5d from the inflow pipe 20 connected to the introduction port 71 of the most downstream block 5d, which is the one end block on the farthest end side, and the other end block on the farthest end side. Water flows out from the outflow pipe 21 connected to the outlet 72 of the most upstream block 5a. However, the flow of the heat medium may be in the opposite direction. That is, the heat medium may flow into the most upstream block 5a and flow out from the most downstream block 5d. In this case, the inflow pipe 20 constitutes the outflow pipe, and the outflow pipe 21 constitutes the inflow pipe. Further, the lower water passage hole 12e of the lower heat exchange plate 12 of the uppermost flow heat exchanger 10a constitutes an introduction port.

(Other embodiments)
(1) In the above embodiment, the most upstream block is formed from one heat exchanger. However, the most upstream block may be formed from a plurality of heat exchangers. In this case, a predetermined underwater hole of the heat exchanger located at the most downstream of the plurality of heat exchangers constituting the most upstream block forms an outlet. Also in this heat exchanger, preferably, the first length L1 of the pipe is longer than the second length L2 and shorter than the total length (L2 + L3) of the second length L2 and the depth L3 of the recess. Set. As a result, it is possible to prevent an increase in the flow path resistance of the heat medium and allow the heat medium to smoothly flow out to the pipe from the internal space of the heat exchanger located at the most downstream of the upstream block.

(2) 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.

(3) 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.

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

1 Plate type heat exchanger 5 blocks 10 heat exchanger 12h Opening edge 14 Internal space 21 Outflow pipe 71 Inlet port 72 Outlet port

Claims (3)

A plate heat exchanger in which a plurality of blocks having at least one heat exchanger are laminated.
The heat exchanger is configured to exchange heat between a heat medium flowing through the internal space of the heat exchanger and combustion exhaust flowing outside the heat exchanger.
Each block in the plurality of blocks is provided with an introduction port for introducing the heat medium into each block and an outlet for deriving the heat medium from each block.
Adjacent blocks in the plurality of blocks are connected so that the heat medium flows from the outlet of one block to the inlet of the other block.
In the adjacent blocks, the flow path direction of the heat medium flowing through the internal space of the heat exchanger of the one block is different from that of the heat medium flowing inside the heat exchanger of the other block. Is configured as
A pipe is inserted from one end side to the other end side in the stacking direction of the heat exchanger so as to penetrate a part of the plate heat exchanger.
The other end of the pipe is the introduction port of the other end block or the introduction port of the other end block so as to communicate with the internal space of the heat exchanger constituting the other end block in which the pipe is located on the other end side. It is inserted through one of the outlets and is inserted into one of the outlets.
A plate heat exchanger provided with an upright wall projecting from the opening edge toward the one end side at the opening of the other end block through which the other end side end portion of the pipe is inserted. In the plate heat exchanger according to claim 1,
The insertion length of the pipe from the one end block is restricted by the contact between the pipe side positioning portion provided on the pipe and the block side positioning portion provided on the one end block located on the one end side.
In the pipe, the first length L1 from the piping side positioning portion to the other end side opening is longer than the second length L2 from the block side positioning portion to the base end portion of the erection wall. Plate heat exchanger set in. In the plate heat exchanger according to claim 2,
The other end block has a concave portion that becomes concave toward one end side at the peripheral edge portion of the opening through which the pipe is inserted.
The pipe is a plate heat exchanger in which the first length L1 is set to be shorter than the total length (L2 + L3) of the second length L2 and the depth L3 of the recess.

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