Plate heat exchanger

Abstract

A plate heat exchanger (1) in which a plurality of heat exchange blocks (10) are stacked, and adjacent blocks (5) are connected in a manner that a heat medium flows from a discharge port (72) of one block (5) to a supply port (71) of another block (5), a pipe (21) is inserted from one end side to the other end side in the stacking direction of the heat exchange blocks (10), the other end side end portion of the pipe (21) is inserted into either the supply port (71) or the discharge port (72) of the other end block (5) located at the other end side, and a standing wall (12g) is provided which protrudes from the opening edge (12h) toward the one end side.

Description

TECHNICAL FIELD

[0001] The present application relates to a plate heat exchanger which is configured by stacking a plurality of blocks having heat exchanging bodies. BACKGROUND

[0002] A plate heat exchanger having a plurality of heat exchanging bodies which are joined by an upper heat exchange plate and a lower heat exchange plate is proposed (for example, Patent Literature 1: Japanese Patent Publication No. 2020-85362). Each heat exchanging body has an internal space through which a heat medium flows between the upper heat exchange plate and the lower heat exchange plate, and a plurality of through holes which pass through the internal space in a non-communicating state and through which combustion exhaust gas flows in the vertical direction.

[0003] The plate heat exchanger in Patent Literature 1 is configured by stacking a plurality of blocks having at least one heat exchanging body in the vertical direction. In addition, the blocks adjacent in the vertical direction are communicated with each other in a manner that the heat medium flows. Furthermore, the adjacent blocks are configured in a manner that the flow direction of the heat medium flowing in the internal space of the heat exchanging body constituting one block is different from the flow direction of the heat medium flowing in the internal space of the heat exchanging body constituting the other block. Thus, the flow path of the heat medium flowing in the heat exchanger becomes longer according to the number of segments of the blocks, and the thermal efficiency can be improved.

[0004] In addition, in the above plate heat exchanger, an inflow pipe for supplying the heat medium is inserted through one opening of the most downstream heat exchanging body constituting the inlet port of the most downstream block located at the most downstream in the gas flow direction of the combustion exhaust gas. Furthermore, in the heat exchanging bodies on the upstream side of the most downstream heat exchanging body in the gas flow direction of the combustion exhaust gas, an opening is provided at a position corresponding to the other opening of the most downstream heat exchanging body. Then, an outflow pipe is inserted from the other opening of the most downstream heat exchanging body to one opening of the heat exchanging body constituting the outlet port of the most upstream block, and the internal space of the heat exchanging body having the outlet port is communicated with the outflow pipe. Thus, 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 from the outlet port of the most upstream block to the outflow pipe. Then, the heat medium flowing out to the outflow pipe flows out to the outside of the plate heat exchanger through the outflow pipe.

[0005] However, in the case of manufacturing the plate heat exchanger of Patent Document 1, a plurality of upper and lower heat exchange plates need to be stacked, and prescribed portions of the upper and lower heat exchange plates are joined by a joining means such as brazing material. Therefore, assembly errors are easily generated, and the length of the heat exchanger side through which the outlet pipe is inserted easily varies for each product with respect to the length of the outlet pipe. Therefore, there is a case where the upper end portion of the outlet pipe does not pass through the guide outlet of the most upstream block. If the heat medium is circulated in the heat exchanger in this state where the upper end portion of the outlet pipe does not reach the guide outlet of the most upstream block, the outlet pipe communicates with the internal space of the heat exchange body on the downstream side of the heat exchange body where the guide outlet of the most upstream block is provided in the gas flow direction of the combustion exhaust gas, and the heat medium short-circuits from the heat exchange body on the downstream side of the most upstream block to the outlet pipe and flows out. As a result, the inflow amount of the heat medium to the most upstream block decreases, and there is a problem that the thermal efficiency decreases. SUMMARY

[0006] An object of the present application is to provide a plate heat exchanger with high thermal efficiency.

[0007] According to the present application,

[0008] A plate heat exchanger is provided, which is configured by stacking a plurality of blocks each having at least one heat exchange body,

[0009] The heat exchange body is configured to perform heat exchange between a heat medium circulating in the internal space of the heat exchange body and combustion exhaust gas circulating outside the heat exchange body,

[0010] Each of the plurality of blocks has a guide inlet through which the heat medium is guided into the block, and a guide outlet through which the heat medium is guided out of the block,

[0011] The adjacent blocks among the plurality of blocks are connected in a manner that the heat medium circulates from the guide outlet of one of the adjacent blocks to the guide inlet of the other of the adjacent blocks,

[0012] The adjacent blocks among the plurality of blocks are connected in a manner that the flow direction of the heat medium circulating in the internal space of the heat exchange body of the one of the adjacent blocks is different from the flow direction of the heat medium circulating in the internal space of the heat exchange body of the other of the adjacent blocks,

[0013] A pipe is inserted through a portion of the plate heat exchanger from one end side to the other end side in the stacking direction of the heat exchange bodies,

[0014] The other end side end portion of the pipe on the other end side of the heat exchanger body is inserted into either one of the inlet port or the outlet port of the other end block body in a manner that the pipe communicates with the internal space of the heat exchanger body constituting the other end block body on the other end side,

[0015] In the opening of either one of the inlet port or the outlet port of the other end block body into which the other end side end portion of the pipe is inserted, a standing wall is provided which protrudes from an opening edge of the opening toward the one end side in the stacking direction of the heat exchanger body.

[0016] According to the present application, even if an assembly error occurs in the manufacture of a plate heat exchanger, the other end side end portion of the pipe can be reliably inserted into the opening of the heat exchanger body constituting the other end block body. Thus, the internal space of the heat exchanger body of the other block body other than the other end block body can be inhibited from communicating with the pipe, and therefore a plate heat exchanger with high thermal efficiency can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a schematic partially cutaway perspective view showing a heat source machine having a heat exchanger according to an embodiment of the present application.

[0018] Figure 2 is a schematic partially exploded perspective view showing a heat exchanger according to an embodiment of the present application.

[0019] Figure 3 is a schematic diagram illustrating the flow of combustion exhaust gas and the flow of heat medium in a heat exchanger according to an embodiment of the present application.

[0020] Figure 4 is a schematic partially exploded perspective view showing two heat exchanger bodies in an upstream region of a gas flow path of combustion exhaust gas in a heat exchanger according to an embodiment of the present application.

[0021] Figure 5 is a schematic plan view showing an example of an upper surface of one heat exchange plate constituting a heat exchanger according to an embodiment of the present application.

[0022] Figure 6 is a schematic plan view showing an example of an upper surface of another heat exchange plate constituting a heat exchanger according to an embodiment of the present application.

[0023] Figure 7 is a schematic partially cross-sectional view showing a flow-out pipe side of a portion of a heat exchanger according to an embodiment of the present application. DETAILED DESCRIPTION

[0024] Hereinafter, a plate heat exchanger according to the present embodiment and a heat source unit provided with the plate heat exchanger will be described with reference to the drawings. Figure 1

[0025] As shown in FIG. 1, the heat source unit according to the present embodiment is a water heater that heats water (heat medium) flowing into the heat exchanger 1 from the inflow pipe 20 by combustion exhaust gas generated by the burner 31, and supplies the hot water to a hot water utilization side (not shown) such as a faucet or a shower through the outflow pipe 21. Although not shown, the water heater is assembled in a housing. In addition, other heat medium (for example, antifreeze) can be used as the heat medium. Figure 1

[0026] In the water heater, the burner body 3 that constitutes the outer shape of the burner 31, the combustion chamber 2, the heat exchanger 1, and the drain receiving portion 40 are sequentially arranged from the top. In addition, the fan housing 4 that has a combustion fan that sends a mixed gas of fuel gas and air into the burner body 3 is arranged at one side (right side in FIG. 1) of the burner body 3. In addition, the exhaust duct 41 that communicates with the drain receiving portion 40 is arranged at the other side (left side in FIG. 1) of the burner body 3. The exhaust duct 41 exhausts the combustion exhaust gas exhausted to the drain receiving portion 40 to the outside of the water heater. Figure 1 Figure 1

[0027] In addition, in the present specification, when the water heater is observed in a state where the fan housing 4 and the exhaust duct 41 are arranged at the sides of the burner body 3, the depth direction corresponds to the front-rear direction, the width direction corresponds to the left-right direction, and the height direction corresponds to the up-down direction.

[0028] The burner body 3 has a substantially oval shape in plan view, and is formed of, for example, a stainless steel metal. Although not shown, the burner body 3 is open downward.

[0029] A gas introduction portion that communicates with the fan housing 4 protrudes upward from the central portion of the burner body 3. The burner body 3 has the burner 31 that has a flat combustion surface 30 facing downward. By operating the combustion fan, the mixed gas is supplied into the burner body 3.

[0030] ​​​​Burner 31 is a primary air combustion burner. Burner 31 may be constructed, for example, of a ceramic combustion plate with multiple downward-facing flame holes (not shown), or a combustion pad woven from metal fibers into a mesh. The mixed gas supplied to the burner body 3 is ejected downwards from the downward-facing combustion surface 30 by the supply air pressure of the combustion fan. By igniting this mixed gas, a flame is formed on the combustion surface 30 of burner 31, generating combustion exhaust. Therefore, the combustion exhaust ejected from burner 31 is sent to heat exchanger 1 via combustion chamber 2. Then, the combustion exhaust passing through heat exchanger 1 is discharged to the outside of the water heater via drain receiver 40 and exhaust pipe 41.

[0031] That is, such as Figure 2 As shown by the dashed arrow, in this heat exchanger 1, the upper side where the burner 31 is installed corresponds to the upstream side of the combustion exhaust gas flow path, and the lower side of the side opposite to the side where the burner 31 is installed corresponds to the downstream side of the combustion exhaust gas flow path.

[0032] Combustion chamber 2 has a roughly elliptical shape when viewed from above. Combustion chamber 2 is formed, for example, from a stainless steel-like metal. Combustion chamber 2 is formed by bending a roughly rectangular metal plate and joining the two ends in an open-top and bottom manner.

[0033] like Figure 2 As shown, the heat exchanger 1 has a generally elliptical shape when viewed from above. The heat exchanger 1 is a plate heat exchanger with multiple (in this case, thirteen layers) thin plate-shaped heat exchange elements 10 stacked (layered, stacked) together. In addition, the heat exchanger 1 may also have a casing covering its surroundings.

[0034] like Figure 3 as well as Figure 3As shown, the heat exchanger 1 is constructed by stacking multiple (in this case, four sections) blocks 5, each having one or more heat exchange elements 10, in the vertical direction. (Hereinafter, these blocks 5 are collectively referred to as "blocks 5". Furthermore, along the gas flow direction of the combustion exhaust, the uppermost block 5 is called "uppermost block 5a", the middle blocks 5 are sequentially called "first downstream block 5b" and "second downstream block 5c" from the upstream side, and the lowermost block 5 is called "lowest downstream block 5d"). The uppermost block 5a and the first downstream block 5b are each composed of one heat exchange element 10. The second downstream block 5c is constructed by stacking five heat exchange elements 10, and the lowest downstream block 5d is constructed by stacking six heat exchange elements 10. Alternatively, the heat exchanger 1 may be composed of three or fewer blocks 5, or five or more blocks 5. As described below, when a block 5 is composed of multiple heat exchangers 10, water flows side-by-side in the same direction within the internal space 14 of each heat exchanger 10 constituting the block 5. Furthermore, adjacent heat exchangers 10 in each block 5 are interconnected in a manner where water flows from bottom to top. Additionally, adjacent blocks 5 are interconnected in a manner where water flows from bottom to top. Furthermore, as... Figure 2 As shown by the solid arrow, two adjacent blocks 5 are configured such that the flow direction of water flowing within the internal space 14 of each heat exchanger 10 in one block 5 is opposite to the flow direction of water flowing within the internal space 14 of each heat exchanger 10 in the other block 5. Therefore, the heat exchanger 1 has four flow paths (four passages) corresponding to the number of segments of the blocks 5, with the water flow paths zigzagging between adjacent blocks 5. This creates long water flow paths within the heat exchanger 1, improving thermal efficiency.

[0035] Next, the structure of the heat exchanger 10 will be described. Except for some structural differences such as the positions of the upper and lower through holes and the presence or absence of water holes at the corners, each heat exchanger 10 is formed by overlapping a set of upper heat exchange plates 11 and lower heat exchange plates 12 with a common structure in the vertical direction and joining the specified portions (described later) using brazing filler metal or other joining methods. Therefore, the structure of one heat exchanger 10 will be mainly described below. Furthermore, the accompanying drawings do not necessarily represent actual dimensions and are not limited to specific embodiments.

[0036] like Figures 4-6 as well as Figure 7 As shown, the upper and lower heat exchange plates 11 and 12 have a generally elliptical shape when viewed from above. The upper and lower heat exchange plates 11 and 12 are formed, for example, from stainless steel plates of a specified thickness. The upper and lower heat exchange plates 11 and 12 each have: a plurality of upper through holes 11a and lower through holes 12a formed on approximately the entire surface of the plate except for the corners; and upper through hole flange portions 11c and lower through hole flange portions 12c formed on the periphery of the upper and lower through holes 11a and 12a.

[0037] Upper and lower peripheral edge engaging portions W1, W2 are formed in the peripheral edges of the upper and lower heat exchange plates 11, 12, respectively, which protrude upward. The upper and lower peripheral edge engaging portions W1, W2 are formed by inclined walls which extend upward at a prescribed angle with the upper end located on the obliquely upper outer side than the lower end, respectively. Therefore, when the upper and lower heat exchange plates 11, 12 are stacked, the upper heat exchange plate 11 is embedded in the lower heat exchange plate 12 in one heat exchange body 10. Further, the lower heat exchange plate 12 of the upper heat exchange body 10 is embedded in the upper heat exchange plate 11 of the lower adjacent heat exchange body 10. Therefore, if a plurality of upper and lower heat exchange plates 11, 12 are stacked, the upper and lower heat exchange plates 11, 12 are arranged in such a manner that the peripheral edge engaging portions W1, W2 coincide at a prescribed height in the gas flow direction of the combustion exhaust gas (refer to Figure 3 ).

[0038] The upper and lower heat exchange plates 11, 12 are configured so that, in one heat exchange body 10, when the lower peripheral edge engaging portion W2 is engaged with the lower surface peripheral edge of the upper heat exchange plate 11, the upper and lower heat exchange plates 11, 12 are separated with a prescribed height gap. Further, the upper and lower heat exchange plates 11, 12 are configured so that, when the upper peripheral edge engaging portion W1 is engaged with the lower surface peripheral edge of the lower heat exchange plate 12 of the upper adjacent heat exchange body 10, the upper heat exchange plate 11 of the lower heat exchange body 10 and the lower heat exchange plate 12 of the upper adjacent heat exchange body 10 are separated with a prescribed height gap.

[0039] Therefore, by engaging the upper and lower heat exchange plates 11, 12, an internal space 14 of a prescribed height is formed between the lower surface of the upper heat exchange plate 12 and the upper surface of the lower heat exchange plate 12 (refer to Figure 3 ). Further, by engaging a plurality of heat exchange bodies 10, an exhaust gas space 15 of a prescribed height is formed between the two heat exchange bodies 10 which are adjacent upward and downward (refer to Figure 7 ).

[0040] In the regions other than the peripheral edge regions of the upper and lower heat exchange plates 11, 12, the upper and lower through holes 11a, 12a of a substantially square shape in plan view are formed in a staggered manner at prescribed intervals in the front-rear and left-right directions. The upper and lower through hole flange portions 11c, 12c formed at the peripheral edge portions of the upper and lower through holes 11a, 12a of a substantially square shape in plan view extend substantially horizontally from the opening edges of the upper and lower through holes 11a, 12a to the outer side in the peripheral direction, and have a substantially square shape in plan view. In the peripheral edge regions of the upper and lower heat exchange plates 11, 12, the upper and lower through holes 11a, 12a of a substantially pentagonal shape in plan view are formed at prescribed intervals in the front-rear or left-right directions. The upper and lower through hole flange portions 11c, 12c formed at the peripheral edge portions of the upper and lower through holes 11a, 12a of a substantially pentagonal shape in plan view extend substantially horizontally from the opening edges of the upper and lower through holes 11a, 12a to the outer side in the peripheral direction, and have a substantially pentagonal shape in plan view. The upper and lower through holes 11a, 12a can also have other shapes such as a substantially circular shape or a substantially elliptical shape. Furthermore, all of the upper and lower through holes 11a, 12a can have the same size and shape, and all of the upper and lower through hole flange portions 11c, 12c can also have the same size and shape.

[0041] The upper and lower through holes 11a, 12a and the upper and lower through hole flange portions 11c, 12c are formed at positions corresponding to each other when the upper and lower heat exchange plates 11, 12 are overlapped. Furthermore, the upper and lower through holes 11a, 12a and the upper and lower through hole flange portions 11c, 12c are formed on the bottom surfaces of the stepped portions projecting inward by drawing processing in a manner in which the facing upper and lower through hole flange portions 11c, 12c contact each other when the upper and lower heat exchange plates 11, 12 are overlapped.

[0042] Therefore, in the state in which the upper and lower heat exchange plates 11, 12 are overlapped, if the upper and lower through hole flange portions 11c, 12c are joined by a joining means such as brazing material, a flange portion 16 that occludes the internal space 14 is formed by the upper and lower through hole flange portions 11c, 12c (refer to FIG. 2). Figure 7 Furthermore, the through holes 13 that pass through the internal space 14 in a non-communicating state are formed by the upper and lower through holes 11a, 12a. That is, the internal space 14 does not communicate with the inside of the through holes 13.

[0043] The upper and lower through water holes 11e, 12e are provided at at least one corner portion of the upper and lower heat exchange plates 11, 12 other than the upper heat exchange plate 11 of the uppermost layer heat exchange body 10 (hereinafter referred to as "uppermost flow heat exchange body 10a"). The upper and lower through water holes 11e, 12e provided at at least one corner portion of the upper and lower heat exchange plates 11, 12 that form one heat exchange body 10 are opened in a manner that communicates with the internal space 14 formed between the upper and lower heat exchange plates 11, 12 when the upper and lower heat exchange plates 11, 12 are overlapped.

[0044] The upper water passage 11e and the upper water passage flange portion 11f are formed at positions corresponding to the lower water passage 12e and the lower water passage flange portion 12f of the lower heat exchange panel 12 of the heat exchange body 10 positioned above, respectively, when the two heat exchange bodies 10 are overlapped. Further, the upper water passage 11e and the upper water passage flange portion 11f are formed on the upper surface of the step portion protruding toward the outside, by drawing processing, so as to be in surface contact with the lower water passage flange portion 12f of the heat exchange body 10 positioned above, when the upper heat exchange panel 11 and the lower heat exchange panel 12 of the heat exchange body 10 positioned above are overlapped. Similarly, the lower water passage 12e and the lower water passage flange portion 12f are formed on the bottom surface of the step portion protruding toward the outside, by drawing processing, so as to be in surface contact with the upper water passage flange portion 11f of the heat exchange body 10 positioned below, when the lower heat exchange panel 12 and the upper heat exchange panel 11 of the heat exchange body 10 positioned below are overlapped.

[0045] Therefore, in a state where the upper heat exchange panel 11 of the heat exchange body 10 positioned below and the lower heat exchange panel 12 of the heat exchange body 10 positioned above are overlapped, when the upper and lower water passage flange portions 11f, 12f are joined by a joining means such as solder, a water passage flange portion 64 is formed that closes the exhaust space 15 between the two heat exchange bodies 10 by the upper and lower water passage flange portions 11f, 12f. Further, a water passage 63 that communicates with the internal space 14 is formed by the upper and lower water passages 11e, 12e of the two heat exchange bodies 10 positioned above and below, respectively. Further, the internal space 14 of the peripheral portion of the upper and lower water passages 11e, 12e extends in the vertical direction, more than the other internal spaces 14 other than the peripheral portion of the upper and lower water passages 11e, 12e. Therefore, an upper recessed portion 65 recessed upward is formed in the peripheral portion of the upper water passage 11e of each heat exchange body 10, and a lower recessed portion 66 recessed downward is formed in the peripheral portion of the lower water passage 12e of each heat exchange body 10.

[0046] As Figure 3As shown, the lower water passage 12e is formed by a flanged process. Therefore, the lower heat exchange plate 12 has a flanged portion (vertically installed wall) 12g protruding downwards (downstream of the combustion exhaust gas flow direction) from the opening edge 12h of the lower water passage 12e. Thus, the opening edge 12h of the lower water passage 12e constitutes the base end of the flanged portion 12g. Furthermore, when the upper and lower heat exchange plates 11 and 12 overlap, the flanged portion 12g of the lower water passage 12e of the lower heat exchange plate 12 of one heat exchanger 10 protrudes downwards more than the upper water passage flange 11f of the upper heat exchange plate 11 of the heat exchanger 10 adjacent below. Moreover, the downwardly protruding flanged portion can be formed in the upper water passage 11e of the upper heat exchange plate 11, or it can be formed in both the upper and lower water passages 11e and 12e.

[0047] like Figure 3 As shown, the through holes 13 of the heat exchangers 10 are arranged such that the through holes 13 of one heat exchanger 10 and the through holes 13 of the other heat exchanger 10 are staggered in a left-right direction, perpendicular to the gas flow direction of the combustion exhaust. That is, the two adjacent heat exchangers 10 are arranged such that the projected plane of the through hole 13 of one heat exchanger 10 does not coincide with the through hole 13 of the other heat exchanger 10. Therefore, as shown by the dashed arrow, the combustion exhaust flowing from the upstream side (the upper combustion chamber 2) flows through the through hole 13 of one heat exchanger 10 and then flows out into the exhaust space 15 between that heat exchanger 10 and the heat exchanger 10 adjacent to it on the downstream side. 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 it on the downstream side and flows further downstream through the through hole 13 of the heat exchanger 10 adjacent to it on the downstream side. That is, when the combustion exhaust flows from the upstream side to the downstream side in the heat exchanger 1, a serrated 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 is increased.

[0048] Next, refer to Figure 3 The flow of combustion exhaust gas and water in heat exchanger 1 will be described. Each block 5 has an inlet 71 for introducing water into the interior of the block 5 and an outlet 72 for discharging water to the exterior of the block 5. The inlet 71 is formed by a predetermined lower water passage 12e of the heat exchanger 10 located downstream of the combustion exhaust gas flow direction in each block 5. The outlet 72 is formed by a predetermined upper water passage 11e of the heat exchanger 10 located upstream of the combustion exhaust gas flow direction in each of the blocks 5b, 5c, and 5d (excluding the upstream block 5a), and a predetermined lower water passage 12e of the heat exchanger 10 in the upstream block 5a. Furthermore, to avoid complexity, Figure 3 The structure of parts such as the flange 16 and the folded edge 12g is omitted.

[0049] In the lower water passage hole 12e formed in the right front corner portion of the lower heat exchange plate 12 of the heat exchanger 10 located at the most downstream side in the gas flow direction of the combustion exhaust gas (hereinafter referred to as "the most downstream heat exchanger 10s"), the inflow pipe 20 is connected. In addition, in the lower water passage hole 12e formed in the right rear corner portion of the lower heat exchange plate 12 of the most downstream heat exchanger 10s, the outflow pipe 21 extending from the most downstream heat exchanger 10s toward the upper side to the most upstream heat exchanger 10a is inserted in a manner of passing through a portion of the heat exchanger 1. The upper end portion of the outflow pipe 21 is inserted in the lower water passage hole 12e formed in the right rear corner portion of the lower heat exchange plate 12 of the most upstream heat exchanger 10a. Therefore, in the present embodiment, the most downstream heat exchanger 10s side corresponds to one end side in the stacking direction of the heat exchangers 10, and the most upstream heat exchanger 10a side corresponds to the other end side in the stacking direction of the heat exchangers 10. In addition, the most upstream block 5a corresponds to the other end block on the other end side, and the most downstream block 5d corresponds to the one end block on the one end side. In addition, the guide outlet 72 of the most upstream block 5a corresponds to the opening through which the other end side end portion of the supply pipe is inserted.

[0050] The upper end opening portion of the other end side end portion of the outflow pipe 21 communicates with the internal space 14 of the most upstream heat exchanger 10a. In addition, if the outflow pipe 21 is inserted from the most downstream heat exchanger 10s to the most upstream heat exchanger 10a, the outflow pipe 21 passes through the internal spaces 14 of the heat exchangers 10 other than the most upstream heat exchanger 10a and all of the exhaust gas spaces 15 between the adjacent two heat exchangers 10 in a non-communicating state. That is, the outflow pipe 21 does not communicate with the internal spaces 14 of the heat exchangers 10 other than the most upstream heat exchanger 10a and all of the exhaust gas spaces 15 between the adjacent two heat exchangers 10.

[0051] 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 (the guide inlet 71) of the right front corner portion flows in one direction (from the right side to the left side) in the left-right direction within the internal space 14. In addition, the water flowing into the internal space 14 of each heat exchanger 10 of the second downstream side block 5c from the upper and lower water passage holes 11e, 12e (the guide outlet 72 and the guide inlet 71) of the left front and rear corner portions flows in one direction (from the right side to the left side) in the left-right direction within the internal space 14. Figure 3 Figure 3 ​water flowing in the interior space 14 of the second downstream-side block 5c flows in the opposite direction to the water flowing in the second upstream-side block 5b. Further, the water flowing in the interior space 14 of the second downstream-side block 5c flows in the opposite direction to the water flowing in the most downstream block 5d. Further, the water flowing in the interior space 14 of the second downstream-side block 5c flows in the opposite direction to the water flowing in the most upstream block 5a. Figure 3 water flowing in the interior space 14 of the second upstream-side block 5b flows in the opposite direction to the water flowing in the second downstream-side block 5c. Further, the water flowing in the interior space 14 of the second upstream-side block 5b flows in the opposite direction to the water flowing in the most upstream block 5a. Figure 7 water flowing in the interior space 14 of the second upstream-side block 5b flows in the opposite direction to the water flowing in the second downstream-side block 5c. Further, the water flowing in the interior space 14 of the second upstream-side block 5b flows in the opposite direction to the water flowing in the most upstream block 5a.

[0052] Next, the manufacturing method of the heat exchanger 1 of the present embodiment will be described. The lower frame plate 101, the upper and lower heat exchange plates 11, 12, and the upper frame plate 102 are stacked while supplying a brazing material or the like to predetermined portions of the plates. Although not shown, the outer diameter of the flange 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.

[0053] Next, the upper end portion of the inflow pipe 20 as the first pipe is inserted through the lower water passage 12e on the right front side of the most downstream heat exchanger 10s via the opening of the lower frame plate 101. In addition, the outflow pipe 21 as the second pipe is inserted toward the upper side from the lower water passage 12e on the right rear side of the most downstream heat exchanger 10s via the other opening of the lower frame plate 101. Then, the outer peripheral surface of the inflow pipe 20 inserted through the lower water passage 12e on the right front side of the most downstream heat exchanger 10s and the outer peripheral surface of the outflow pipe 21 inserted through the lower water passage 12e on the right rear side of the most downstream heat exchanger 10s are supplied with a brazing material or the like as a joining means to make an assembly. By performing a brazing process by placing the assembly in a furnace, the heat exchanger 1 can be manufactured.

[0054] Figure 7 is a schematic partial cross-sectional view of the outflow pipe 21 side of a portion of the heat exchanger 1 of the present embodiment. In addition, in Figure 7 , only the structure of the upstream and downstream areas of the gas flow path of the combustion exhaust gas is shown, but the structure of the midstream area is the same. As ​ indicated, the outflow pipe 21 has a small-diameter portion 21a having a certain outer diameter from the upper end portion as the other end side end portion to the vicinity of the lower end portion as the one end side end portion, and a large-diameter portion 21b having an outer diameter larger than that of the small-diameter portion 21a in the vicinity of the lower end portion. 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 passages 11e, 12e. In addition, the large-diameter portion 21b of the outflow pipe 21 has an outer diameter larger than that of the flange portion 12g. Therefore, when the outflow pipe 21 is inserted from the lower side toward the upper side, the outer peripheral upper end of the large-diameter portion 21b abuts against the lower end of the flange portion 12g provided to the lower water passage 12e of the lower heat exchange plate 12 of the most downstream heat exchanger 10s. Thereby, the insertion length of the outflow pipe 21 into the heat exchanger 1 is limited. Therefore, the outer peripheral upper end of the large-diameter portion 21b of the outflow pipe 21 constitutes a pipe side positioning portion, and the lower end of the above-described flange portion 12g constitutes a block side positioning portion.

[0055] In addition, in the present embodiment, a first length L1 from the upper end of the large-diameter portion 21b to the small-diameter portion 21a of the upper end portion of the outflow pipe 21 is set to be longer than a second length L2 from the lower end of the flange portion 12g provided to the lower water passage 12e of the lower heat exchange plate 12 of the most downstream heat exchanger 10s to the opening edge 12h of the lower water passage 12e of the lower heat exchange plate 12 of the most upstream heat exchanger 10a forming the guide outlet 72 of the most upstream block 5a, and shorter than the total length (L2+L3) of the second length L2 and the depth L3 of the lower recessed portion 66 of the peripheral edge portion of the lower water passage 12e.

[0056] As described above, in the plate heat exchanger 1 configured by stacking a plurality of upper and lower heat exchange plates 11, 12, the length from the lower water passage hole 12e of the lower heat exchange plate 12 of the most downstream heat exchange body 10s to the lower water passage hole 12e of the lower heat exchange plate 12 of the most upstream heat exchange body 10a (i.e., the outlet port 72 of the most upstream block 5a) is likely to vary in each product due to assembly errors. Therefore, in the case where the outlet pipe 21 of a single diameter is used, even if the outlet pipe 21 is inserted into the heat exchanger 1 at a prescribed length, there is a case where the upper end portion (the other end side end portion) of the outlet pipe 21 does not reach the lower water passage hole 12e of the lower heat exchange plate 12 of the most upstream heat exchange body 10a depending on the product. In such a case, the internal space 14 of the heat exchange body 10 of the block 5b on the downstream side from the most upstream block 5a is communicated with the outlet pipe 21, and water flows out from the internal space 14 of the heat exchange body 10 of the block 5b on the downstream side to the outlet pipe 21 by short-circuiting. As a result, the inflow amount of water into the most upstream block 5a decreases, and the thermal efficiency decreases.

[0057] However, according to the present embodiment, the lower heat exchange plate 12 of the most upstream heat exchange body 10a that forms the outlet port 72 of the most upstream block 5a has a flange portion 12g that protrudes toward the downstream side from the opening edge 12h of the lower water passage hole 12e. Therefore, even in the case where the upper end portion (the other end side end portion) of the outlet pipe 21 is inserted only to a position below the opening edge 12h of the lower water passage hole 12e due to assembly errors, the upper end portion (the other end side end portion) of the outlet pipe 21 can be inserted to the flange portion 12g. Thereby, it is possible to suppress water from flowing out from the heat exchange body 10 of the block 5b on the downstream side from the most upstream block 5a to the outlet pipe 21 by short-circuiting. Therefore, the decrease in the inflow amount of water into the most upstream block 5a is prevented, and a higher thermal efficiency can be obtained. Further, it is preferable that the protruding height of the flange portion be below the depth of the recess formed in the opening peripheral edge portion of the adjacent heat exchange plate of the adjacent heat exchange body 10 when the plurality of heat exchange bodies 10 are overlapped.

[0058] In addition, it is also considered to extend the insertion length of the outlet pipe 21 into the heat exchanger 1. However, if there are assembly errors, there is a case where the length from the lower water passage hole 12e of the lower heat exchange plate 12 of the most downstream heat exchange body 10s to the lower water passage hole 12e of the lower heat exchange plate 12 of the most upstream heat exchange body 10a is shorter than the set length. Therefore, if the insertion length of the outlet pipe 21 is extended, the outlet pipe 21 protrudes significantly into the internal space 14 of the most upstream heat exchange body 10a, and the outlet pipe 21 occludes the internal space 14. As a result, the flow path resistance of water increases, and the thermal efficiency can decrease.

[0059] However, according to the present embodiment, the outer peripheral upper end of the large diameter portion 21b provided near the lower end portion of the outflow pipe 21 abuts against the lower end of the flange portion 12g of the lower water passage hole 12e of the lower heat exchange plate 12 of the most downstream heat exchanger 10s, thereby limiting the insertion length of the outflow pipe 21 into the heat exchanger 1. Also, the first length LI of the small diameter portion 21a of the outflow pipe 21 is longer than the second length L2, which is the length from the lower end of the flange portion 12g of the lower water passage hole 12e of the lower heat exchange plate 12 of the most downstream heat exchanger 10s, against which the outer peripheral upper end of the large diameter portion 21b abuts, to the opening edge 12h of the lower water passage hole 12e of the lower heat exchange plate 12 of the most upstream heat exchanger 10a. Therefore, if the small diameter portion 21a of the outflow pipe 21 is inserted into the heat exchanger 1 until the outer peripheral upper end of the large diameter portion 21b abuts against the lower end of the flange portion 12g of the lower water passage hole 12e of the lower heat exchange plate 12 of the most downstream heat exchanger 10s, the upper end opening portion of the outflow pipe 21 is disposed at least above the opening edge 12h of the lower water passage hole 12e of the lower heat exchange plate 12 of the most upstream heat exchanger 10a. Thus, even if an assembly error occurs, water flowing out from the heat exchangers 10 of the block 5b on the downstream side of the most upstream block 5a to the outflow pipe 21 can be reliably suppressed.

[0060] Also, according to the present embodiment, the first length LI of the small diameter portion 21a of the outflow pipe 21 is set to be shorter than the total length (L2+L3) of the second length L2 and the depth L3 of the lower recessed portion 66 of the peripheral edge portion of the lower water passage hole 12e. Therefore, when the outer peripheral upper end of the large diameter portion 21b abuts against the lower end of the flange portion 12g of the lower water passage hole 12e of the lower heat exchange plate 12 of the most downstream heat exchanger 10s, the upper end opening portion of the other end portion of the outflow pipe 21 is disposed above the opening edge 12h of the lower water passage hole 12e of the lower heat exchange plate 12 of the most upstream heat exchanger 10a and below the upper end of the lower recessed portion 66. Thus, even if the outflow pipe 21 protrudes into the internal space 14 of the most upstream heat exchanger 10a, an increase in the flow path resistance of water flowing in the internal space 14 can be prevented, and water can flow smoothly from the heat exchangers 10 of the most upstream block 5a to the outflow pipe 21. Thus, the thermal efficiency can be further improved.

[0061] Further, in the present embodiment, water flows into the most downstream block 5d from the inflow pipe 20 connected to the inlet port 71 of the most downstream block 5d, which is the block on the one end side, and water flows out from the outflow pipe 21 connected to the outlet port 72 of the most upstream block 5a, which is the block on the other end side. However, the flow of the heat medium can also be in the reverse direction. That is, the heat medium can also be caused to flow into the most upstream block 5a and to 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 through water hole 12e of the lower heat exchange plate 12 of the most upstream heat exchanger 10a constitutes the inlet port.

[0062] (Other Embodiments)

[0063] (1) In the above-described embodiment, the most upstream block is formed by one heat exchanger. However, the most upstream block can also be formed by a plurality of heat exchangers. In this case, the prescribed lower through water hole of the heat exchanger located most downstream among the plurality of heat exchangers constituting the most upstream block forms the outlet port. In this heat exchanger, the first length LI of the pipe is preferably set to be 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. Thereby, it is possible to prevent an increase in the flow path resistance of the heat medium and to cause the heat medium to smoothly flow out from the internal space of the heat exchanger located most downstream among the most upstream block to the pipe.

[0064] (2) In the above-described embodiment, the burner having the downward combustion surface is disposed above the heat exchanger. However, the burner having the upward combustion surface can also be disposed below the heat exchanger. In this case, since the gas flow direction of the combustion exhaust gas is reversed upside down, the uppermost heat exchanger corresponds to the most downstream heat exchanger, and the lowermost heat exchanger corresponds to the most upstream heat exchanger. Further, the combustion exhaust gas can also flow through in the left-right direction in the plate heat exchanger.

[0065] (3) In the above-described embodiment, the plurality of heat exchangers are stacked in the up-down direction. However, the plurality of heat exchangers can also be stacked in the left-right direction.

[0066] (4) In the above-described embodiment, a water heater is used, but a heat source machine such as a boiler can also be used.

[0067] The above has been described in detail, but if the present application is summarized, it is as follows.

[0068] According to the present application,

[0069] A plate heat exchanger is provided, which is configured by stacking a plurality of blocks having at least one heat exchanger,

[0070] the heat exchanger is configured to exchange heat between a heat medium flowing through an internal space of the heat exchanger and combustion exhaust gas flowing through an outside of the heat exchanger,

[0071] Each of the plurality of blocks has an inlet port through which the heat medium is introduced into the block and an outlet port through which the heat medium is discharged from the block,

[0072] Adjacent blocks among the plurality of blocks are connected in a manner that the heat medium flows from the outlet port of one of the adjacent blocks to the inlet port of the other of the adjacent blocks,

[0073] The adjacent blocks among the plurality of blocks are connected in a manner that a flow direction of the heat medium flowing in an inner space of the heat exchange body of the one block is different from a flow direction of the heat medium flowing in an inner space of the heat exchange body of the other block,

[0074] A pipe is inserted through a portion of the plate heat exchanger from one end side to the other end side in a stacking direction of the heat exchange bodies,

[0075] The other end side end portion of the pipe located on the other end side in the stacking direction of the heat exchange bodies is inserted into either one of the inlet port or the outlet port of the other end block located on the other end side in a manner that the pipe communicates with the inner space of the heat exchange body constituting the other end block,

[0076] An erected wall is provided in the opening of either one of the inlet port or the outlet port of the other end block through which the other end side end portion of the pipe is inserted, the erected wall protruding from an opening edge of the opening toward the one end side in the stacking direction of the heat exchange bodies.

[0077] According to the plate heat exchanger described above, since the opening edge of the opening through which the other end side end portion of the pipe is inserted has the erected wall protruding toward the one end side, even in a case where the other end side end portion of the pipe does not reach the opening edge of the opening of the heat exchange body of the other end block due to an assembly error, the other end side end portion can be inserted into the erected wall provided in the opening edge of the opening. Thus, the inner space of the heat exchange body of the other block other than the other end block can be prevented from communicating with the pipe. Therefore, a decrease in the amount of inflow of the heat medium into the other end block can be prevented, and a higher thermal efficiency can be obtained.

[0078] Preferably, in the plate heat exchanger described above,

[0079] The pipe has a pipe side positioning portion,

[0080] The one end block located on the one end side in the stacking direction of the heat exchange bodies has a block side positioning portion,

[0081] The pipe is restricted in length of insertion into the plate heat exchanger from the one end block by abutment of the pipe-side positioning portion of the pipe with the block-side positioning portion of the one end block,

[0082] The pipe is set in a manner that a first length L1 from the pipe-side positioning portion to a second end-side opening portion of the second end is longer than a second length L2 from the block-side positioning portion to a base end portion of the standing wall.

[0083] According to the above plate heat exchanger, since the first length L1 of the pipe from the pipe-side positioning portion to the second end-side opening portion is set to be longer than the second length L2 from the block-side positioning portion to the base end portion of the standing wall, when the pipe-side positioning portion and the block-side positioning portion abut, the second end-side opening portion of the pipe can be disposed more on the second end side than the base end portion of the standing wall. Thus, the communication of the internal space of the heat exchanging body of the other block than the one end block with the pipe can be reliably suppressed.

[0084] Preferably, in the above heat exchanger,

[0085] The other end block has a recessed portion recessed toward the one end side in a peripheral portion of the opening constituting any one of the guide inlet or the guide outlet for the second end-side end portion of the pipe to be inserted,

[0086] The pipe is formed in a manner that the first length L1 is shorter than a total length (L2+L3) of the second length L2 and a depth L3 of the recessed portion.

[0087] According to the above plate heat exchanger, since 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 recessed portion of the peripheral portion of the opening, when the pipe-side positioning portion and the block-side positioning portion abut, the second end-side opening portion of the pipe can be prevented from protruding more on the second end side than the recessed portion. Thus, the amount of protrusion of the pipe into the internal space of the heat exchanging body provided with the opening for the second end-side end portion of the pipe to be inserted is limited. Therefore, the second end-side end portion of the pipe can be reliably inserted into the opening of the heat exchanging body of the other end block, and an increase in flow path resistance of the heat medium flowing in the internal space in the vicinity of the opening can be suppressed.

Claims

1. A plate heat exchanger, characterized in that a plurality of blocks each having a heat exchange body are stacked, the heat exchange body is configured to exchange heat between a heat medium flowing in an internal space of the heat exchange body and combustion exhaust gas flowing outside the heat exchange body, each of the plurality of blocks has a guide inlet through which the heat medium is guided into the block and a guide outlet through which the heat medium is guided out of the block, adjacent blocks of the plurality of blocks are connected in a manner that the heat medium flows from the guide outlet of one of the adjacent blocks to the guide inlet of the other of the adjacent blocks, the adjacent blocks of the plurality of blocks are connected in a manner that a flow direction of the heat medium flowing in the internal space of the heat exchange body of the one block is different from a flow direction of the heat medium flowing in the internal space of the heat exchange body of the other block, a pipe is inserted through a portion of the plate heat exchanger from one end side to the other end side in a stacking direction of the heat exchange bodies, the other end side end portion of the pipe on the other end side of the heat exchange bodies in the stacking direction is inserted into either one of the guide inlet or the guide outlet of the other end block on the other end side in a manner that the pipe communicates with the internal space of the heat exchange body of the other end block, an erected wall protruding from an opening edge of the opening of either one of the guide inlet or the guide outlet of the other end block is provided toward the one end side in the stacking direction of the heat exchange bodies, the pipe has a pipe side positioning portion, one end block on the one end side of the heat exchange bodies in the stacking direction has a block side positioning portion, an insertion length of the pipe into the plate heat exchanger from the one end block is limited by abutment of the pipe side positioning portion of the pipe and the block side positioning portion of the one end block, the pipe is configured in a manner that a first length (L1) from the pipe side positioning portion to the other end side opening portion of the other end side end portion is longer than a second length (L2) from the block side positioning portion to a base end portion of the erected wall.

2. The plate heat exchanger according to claim 1, wherein the other end block has a recessed portion recessed toward the one end side in a peripheral portion of the opening of either one of the guide inlet or the guide outlet through which the other end side end portion of the pipe is inserted, the pipe is configured in a manner that the first length (L1) is shorter than a total length (L2+L3) of the second length (L2) and a depth (L3) of the recessed portion.

Images