JP2019049382A - Heat exchanger - Google Patents

Abstract

To provide a heat exchanger capable of restraining adhesion of soot onto a fin plate surface by keeping high heat exchanging efficiency.SOLUTION: A heat exchanger 18 comprises plural fin pipes 20 arranged on upper, lower, right and left sides at constant intervals, and plural fin plates 19 aligned at predetermined intervals in an axial line direction of the fin pipe 20. A gap 28 notched toward a downstream side of a flow direction of combustion gas from a lower edge is formed on the fin plate 19, and a tip side of the gap 28 is positioned at an approximate center part of a space surrounded by the fin pipes 20 arranged in a rectangular shape at upper and lower stages. A protrusion part 29 is provided at a tip side peripheral ledge of the gap 28, and a slight distance is provided from the tip edge of the protrusion part 29 to the adjacent fin plate 19 opposed to the tip edge of the protrusion part 29. A notch part 29c is formed at the protrusion part 29, and a ratio of a notch area S2 of the notch part 29c to a projection area S1 at an inner edge of the protrusion part 29 contacting the combustion gas when seen from a flow direction of the combustion gas is made to 1.63% to 4.67%.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a finned tube type heat exchanger.

  Conventionally, in this type of heat exchanger, as shown in FIG. 7, in the fin plate 102 connected to the fin pipe 101, a gap 103 is provided which is cut away from the lower edge of the fin plate 102 toward the downstream side of the combustion gas flow direction. And a raised portion 104 raised from the surface of the fin plate 102 on the tip side peripheral edge of the gap 103. (For example, refer to patent document 1.)

Japanese Utility Model Application Publication No. 3-546

  By the way, in such a heat exchanger, a plurality of fin plates 102 are arranged at predetermined intervals along the axial direction of the fin pipe 101, and combustion gas flows between adjacent fin plates 102. If the gap between the front edge of the raised portion 14 raised from the surface of the plate 102 and the back surface of the adjacent fin plate 102 opposite to the front edge of the raised portion 104 is large, combustion gas does not stay and passes easily. The heat absorption amount to the fin plate 102 decreases, and the heat exchange efficiency decreases. In order to improve the heat exchange efficiency, it is necessary to make the gap smaller, make the combustion gas stagnant and difficult to pass, and increase the heat absorption amount to the fin plate 102.

  However, when the gap is reduced, most of the combustion gas flows along the outer edge side of the raised portion 104 while passing through the raised portion 104, as shown by the broken line in FIG. In particular, since the combustion gas flowing along the outer edge side of the raised portion 104 among the combustion gas flowing along the outer edge side of the raised portion 104 is also reduced, the In the region T on the back side of the raised portion 104, the temperature of the combustion gas is low and the flow velocity is low, that is, in the region T, the kinetic energy of the soot particles in the combustion gas is reduced and the soot particles polymerize with each other And adhere easily to the surface of the fin plate 102. If soot adheres to the surface of the fin plate 102 and deposits, heat absorption from the combustion gas is impeded, which leads to adhesion of soot, Product was made of a factor causing a decrease in heat exchange efficiency.

  Therefore, an object of the present invention is to provide a heat exchanger capable of suppressing the adhesion and the deposition of the soot on the surface of the fin plate 102 while keeping the heat exchange efficiency high.

  In order to solve the above-mentioned problems, in the present invention, in particular, according to claim 1, a plurality of fin pipes disposed at regular intervals in the vertical and horizontal directions, and predetermined intervals along the axial direction of the fin pipes And a plurality of fin plates arranged in each of the plurality of fin plates arranged in the combustion can body, and the fin plate is formed with a gap cut away from the lower edge of the fin plate toward the downstream side in the flow direction of the combustion gas; The tip end side of the gap is located at a substantially central portion of a rectangular space surrounded by the fin pipes arranged in a rectangular shape in the upper and lower stages, and a protrusion raised from the surface of the fin plate is provided on the tip side peripheral edge of the gap. And the adjacent fin plate having a small distance from the leading edge of the raised portion to the adjacent fin plate opposed to the leading edge of the raised portion and entering from the lower edge side of the fin plate. In the heat exchanger configured to absorb the heat of the combustion gas flowing between the heat sinks through the fin plate to the fin pipe, a notch is formed in the raised portion, and viewed from the flow direction of the combustion gas. The ratio of the notched area of the notched portion to the projected area of the inner edge of the raised portion in contact with the combustion gas is set to 1.63% to 4.67%.

  Moreover, in Claim 2, the said notch part shall be formed in the width direction center part of the said protruding part.

  In the third aspect of the present invention, the notch has a shape in which the length in the width direction of the notch is longer than the length in the height direction of the notch.

  Moreover, in Claim 4, the said notch is a notch which notched toward the surface of the said fin plate from the front end edge of the said protrusion, and the said notch does not penetrate the said fin plate, and the said protrusion is It is assumed to be left over.

  According to claim 1 of the present invention, in the heat exchanger having a minute distance between the leading edge of the ridge and the adjacent fin plate opposite to the leading edge of the ridge, the notch is formed in the ridge As a result, the flow path resistance of the ridge to the flow of combustion gas is reduced, and the combustion gas entering the gap can easily pass through the ridge and passes through the notch at a relatively high temperature. Even in the vicinity of the fin pipe on the downstream side, the temperature of the combustion gas is high, the flow velocity is high, the kinetic energy of the soot particles is difficult to decrease, and the soot particles become difficult to polymerize, and adhesion of soot to the fin plate surface Deposition can be suppressed, and the ratio of the notched area of the notch to the projected area of the inner edge of the raised portion with which the combustion gas contacts when viewed from the flow direction of the combustion gas is 1.63% to 4.4. 67% It is, while maintaining high heat exchange efficiency, is capable of suppressing the adhesion of soot on the fin plate surface, the deposition.

  According to the second aspect of the present invention, the notch is formed at the central portion in the width direction of the raised portion, so that the combustion gas is relatively generated at the central portion on the back side of the raised portion where the combustion gas hardly flows. Since it is led to the fin pipe side of the upper stage while passing through the notch at high temperature, the temperature of the combustion gas is high and the flow velocity is high even in the vicinity of the fin pipe of the upper stage which is the flow direction downstream side of the combustion gas The kinetic energy of the particles is also less likely to be reduced, and the soot particles are also less likely to be polymerized, and adhesion and deposition of the soot on the fin plate surface can be suppressed.

  According to the third aspect of the present invention, the notch has a shape in which the length in the width direction of the notch is longer than the length in the height direction of the notch, so that the combustion gas on the back surface side of the raised portion Since the combustion gas can be circulated at a relatively high temperature over a wide range even in the region where it is difficult to flow, adhesion and deposition of soot on the fin plate surface can be suppressed.

  According to the fourth aspect of the present invention, the notch is a notch cut from the tip end edge of the raised portion toward the surface of the fin plate, and the notch does not penetrate the fin plate and leaves excess thickness in the raised portion. It is possible to suppress adhesion of soot and deposition on the surface of the fin plate while minimizing the decrease in heat exchange efficiency due to the reduction of the surface area of the fin plate by reducing the surface area of the fin plate. It is possible to form the notches of the dimensions set in advance with high accuracy, and to easily manage the dimensional accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram of the hot-water supply apparatus provided with the heat exchanger of one Embodiment of this invention. Sectional drawing by the AA of FIG. The perspective view of the fin plate which comprises a heat exchanger. The figure which shows the flow of the combustion gas in the heat exchanger of one Embodiment of this invention. Sectional drawing by the BB line of FIG. The graph which shows the relationship between heat exchange efficiency and a weather resistance, and the ratio of notch area S2 with respect to projected area S1 of the combustion gas contact portion of the ridge inner part seen from the combustion gas flow direction. The figure which shows the conventional heat exchanger.

An embodiment of a heat exchanger according to the present invention will be described based on the drawings.
FIG. 1 is a schematic configuration diagram of a hot water supply apparatus provided with a heat exchanger according to an embodiment of the present invention, and the details will be described below.

  1 is a hot water supply device for generating hot water used in a predetermined terminal (hot water supply valve etc.), 2 is an aluminum die-cast vaporizer for vaporizing fuel oil such as kerosene, 3 is provided in the vaporizer 2 and is capable of vaporizing fuel oil A vaporizer heater for heating up to a certain temperature, an aluminum die-casting mixing chamber 4 located at the lower part of the vaporizer 2 and premixing the vaporized gas vaporized by the vaporizer 2 with primary air And the mixing chamber 4 form the vaporizing unit 5 for vaporizing the fuel oil.

  6 is a combustion unit which is provided on the back side of the vaporizer 2 at the upper part of the mixing chamber 4 and which burns the premixed gas premixed in the mixing chamber 4 and which constitutes a burner by the combustion unit 6 and the vaporization unit 5 It is. Further, 7 denotes a plurality of heat absorption fins which are integrally formed with the carburetor 2 and project on the back of the carburetor 2 and onto the combustion unit 6 and feed back the heat of combustion as the heat of vaporization to the carburetor 2 during combustion. The amount of energization of the vaporizer heater 3 is minimized.

  8 is a nozzle for spraying fuel to the vaporizer 2, 9 is an electromagnetic pump for pumping fuel to the nozzle 8 through the oil feed pipe 10, 11 is a combustion fan, and the combustion fan 11 is for the vaporizer 2 via the air passage 12. The combustion air, which is in communication with the inlet and the air chamber 14 between the combustion unit 6 and the cover frame 13 and is sucked from the suction port 15, is supplied to the carburetor 2 as primary air for premixing, to the air chamber 14 Is supplied from the lower side of the mixing chamber 4 through the side of the vaporizer 2 as secondary air to be burned in the combustion section 6.

  A combustion can 16 has a combustion chamber 17 and a heat exchanger 18, and the heat exchanger 18 is a heat (combustion flame and combustion) generated by the combustion of the burner (combustion unit 6) in the combustion chamber 17 Heat from the gas is absorbed by the finned pipe 20 through the plurality of finned plates 19, and the finned pipe type heat exchanger is heated by water flowing through the finned pipe 20. The combustion gas that has passed through the heat exchanger 18 is exhausted to the outside of the machine from the exhaust port 22. The detailed configuration of the heat exchanger 18 will be described later.

  Reference numeral 23 denotes a water supply pipe for circulating water supplied from a water supply source to the inlet of the heat exchange channel in the heat exchanger 18, and 24 is connected to the outlet of the heat exchange channel in the heat exchanger 18 for heat exchange A hot water supply pipe for supplying hot water heated by the heater 18 to a hot water supply tap (not shown) provided at a predetermined location, 25 is a water supply bypass pipe branched from the water supply pipe 23, 26 is a hot water supply pipe 24 and a water supply bypass pipe 25 The mixing valve is provided at the connection portion of the water supply pipe 24 and mixes the hot water from the hot water supply pipe 24 and the water from the water supply bypass pipe 25 and can change the mixing ratio. The fin pipe 20, the U-shaped pipe 21, the water supply pipe 23, the hot water supply pipe 24, and the water supply bypass pipe 25 constitute a hot water supply circuit in which water flows.

Next, the detailed configuration of the heat exchanger 18 will be described with reference to FIGS.
2 is a cross-sectional view taken along the line A-A in FIG. 1 and is a front view of the main part of the heat exchanger 18, and FIG. 3 is a perspective view of the fin plate 19 constituting the heat exchanger 18.

  The heat exchangers 18 are disposed at regular intervals in the vertical and horizontal directions, and a plurality of fin pipes 20 (10 fin pipes 20 in this embodiment) through which water as a fluid to be heated flows and the fin pipes 20 The fin plate 19 is composed of a plurality of fin plates 19 arranged at predetermined intervals along the axial direction, and the fin plate 19 has a plurality of through holes 27 for passing the fin pipes 20 (from the surface of the fin plate 19). The burring 27a of the raised through hole 27 and the brazing material hole 27b for inserting the brazing material are also formed, and the fin pipe 20 is penetrated by the brazing material inserted into the brazing material hole 27b. The inner edge of the burring 27 a of each hole 27 is brazed and fixed to the fin plate 19. The same fluid to be heated, that is, water for hot water supply, circulates through the fin pipes 20 disposed vertically and horizontally.

  Each fin plate 19 is a gap 28 (one fin plate 19 in this embodiment) cut between the lower adjacent fin pipes 20 and from the lower edge of the fin plate 19 toward the downstream side of the combustion gas flow direction. Four gaps 28) are formed, and the tip end side of the gap 28 is located at a substantially central portion of a rectangular space surrounded by four fin pipes 20 disposed in a rectangular shape at the upper and lower stages of the plurality of fin pipes 20. Is wider than the gap 28 located between the adjacent lower fin pipes 20 and has a substantially diamond shape, and the fin plate 19 between the fin pipes 20 is locally formed by the formation of the gaps 28. It is possible to suppress excessive heating. Although the gap 28 is formed to the lower edge of the fin plate 19, the lower edge here is essentially the same as the lower edge according to the vertical direction of the drawing (FIG. 2). The lower edge of the fin plate 19 means the edge side of the fin plate 19 located upstream of the flow direction of the combustion gas.

  Further, on the tip side peripheral edge of the substantially rhombus-shaped gap 28, a raised portion 29 raised from the surface of the fin plate 19 is provided, and the raised portion 29 is a front surface of the fin plate 19 as shown in FIG. In the view (viewed from the axial direction of the fin pipe 20), it has straight portions 29a on four sides and a curved portion 29b connecting between the straight portions 29a, which together form a substantially rhombus shape It is The height of the raised portion 29 is a height slightly lower than the height of the burring 27a.

  Furthermore, among the protuberances 29, the protuberances 29 (here in the center of the width direction (the direction perpendicular to the axial direction of the fin pipe 20 and the flow direction of the combustion gas) of the combustion gas on the most downstream side Then, in the upper portion, the curved portion 29b located between the adjacent fin pipes 20 is made to flow the combustion gas which has entered into the gap 28 of the substantially rhombus shape downstream of the raised portion 29. A notch 29c is formed as a notch cut from the tip edge of the raised portion 29 toward the surface of the fin plate 19, and the notch 29c does not penetrate the fin plate 19, and the raised portion The excess thickness 29 d is left at 29, and the notch 29 c is wider than the length of the notch 29 c in the height direction of the fin pipe 20 in the same direction as the axial direction of the fin pipe 20. One in which people of the length of has become a long shape.

  Note that each of the four linear portions 29 a forming the raised portion 29 is substantially orthogonal to the linear portion 29 a of the four fin pipes 20 arranged in a rectangular shape so as to surround the tip end of the gap 28. The heat absorbed from the combustion gas by the raised portions 29 is directed to the fin pipes 20 which are respectively opposed from the straight portions 29 a of the four sides, since they are disposed to face the fin pipes 20 positioned in the direction. Since the heat is transferred via the fin plate 19, each fin pipe 20 can be absorbed uniformly without bias, and the heat exchange efficiency can be improved.

  Further, the left and right end edges of each fin plate 19 are bent in a perpendicular direction (the same direction as the direction in which the raised portion 29 bulges from the surface of the fin plate 19), and brazed to the inner wall of the combustion can 16. Side edge bent pieces 30 are provided, and at the upper edge of each fin plate 19 and at a position between adjacent fin pipes 20 in the upper stage, a right angle direction (protrusions 29 are raised from the surface of the fin plate 19 The upper edge bent piece 31 (in this embodiment, one fin plate 19) which is bent in the same direction as the direction in which the combustion gas is guided to the downstream side (the back side of the fin pipe 20) of the upper fin pipe 20 Four upper edge bent pieces 31) are provided. Here, although the upper edge bending pieces 31 are provided at the upper edge of the fin plate 19, the upper edge here is referred to as the upper edge according to the vertical direction of the drawing (FIG. 2). In essence, the upper edge of the fin plate 19 means the edge of the fin plate 19 located downstream of the flow direction of the combustion gas. Further, the height of the side edge bent pieces 30 and the height of the upper edge bent pieces 31 are slightly lower than the height of the burring 27 a of the through hole 27 and substantially the same as the height of the raised portion 29.

  The heat exchanger 18 has the above-described configuration, in particular, having the raised portion 29 so that the amount of heat absorbed from the combustion gas in the raised portion 29 is transmitted to the fin pipe 20 through the fin plate 19 to obtain a fin pipe It can be used to heat the water flowing inside.

  Next, the flow of the combustion gas passing through the heat exchanger 18 will be described with reference to FIG. 4. Here, the flow of the combustion gas entering the substantially rhombus-shaped gap 28 which is the tip side of the gap 28 and the flow The flows of combustion gases other than the combustion gas flow will be described respectively, and the flow of combustion gas entering the substantially rhombus-shaped gap 28 will be indicated by alternate long and short dashed lines, and the flow of combustion gases other than combustion gas entering the approximately rhombus-shaped gap 28 will be described. It shall be indicated by a broken line.

  First, the flow of the combustion gas other than the combustion gas entering the substantially rhombus-shaped gap 28 will be described. The combustion gas generated by the combustion in the burner (the combustion unit 6) flows into the heat exchanger 18, and the substantially rhombus is formed. The combustion gases other than the combustion gas entering the interspace 28 rise from the upstream side to the side of the lower fin pipe 20 as shown by the broken line, and As it passes through between the straight part 29a of the opposing raised portion 29 and the fin pipe 20 at the lower stage, it collides in the vicinity of the X mark located between the adjacent raised portions 29 and rises while being turbulent, The upper edge of the fin plate 19 passing through between the straight portion 29a of the raised portion 29 opposed to the pipe 20 and the fin pipe 20 of the upper stage is the upper edge of the fin plate 19 and the adjacent fin of the upper and upper stages of the substantially rink-shaped gap 28 Pipe 20 By an edge bent piece 31 on which is positioned between, it is guided to the downstream (rear) side of the upper fin pipe 20, in which flows out from the heat exchanger 18.

  Here, the substantially rhombus shaped gap 28 corresponding to the tip side of the gap 28 is viewed vertically from the upper edge side to the lower edge side of the fin plate 19 in plan view (or from the lower edge side of the fin plate 19 to the upper edge side) , And at least a portion thereof overlaps with the fin pipe 20, that is, the substantially rhombus-shaped gap 28 is rectangular in the upper and lower portions so as to surround the substantially rhombus-shaped gap 28. 4 and the fin pipe 20 disposed at the bottom of the heat exchanger 18 so as to flow into the heat exchanger 18 as shown by the broken line in FIG. The combustion gas which has progressed between the fin pipe 20 of the lower part is directed toward the center (the top of the lower fin pipe 20) on the downstream (rear) side of the lower fin pipe 20, and the downstream side of the lower fin pipe 20. It is smoothly guided to a substantially central portion, absorbed on the downstream side of the lower fin pipe 20, and the heat absorption amount in the lower fin pipe 20 increases, and the approximately central portion on the upstream side of the upper fin pipe 20 (upper stage Since the lower end portion of the fin pipe 20 is also smoothly guided, the heat absorption is performed on the upstream side of the upper fin pipe 20, and the heat absorption amount in the upper fin pipe 20 is also increased. The combustion gases can be reliably hit against each other (the position indicated by x in FIG. 4), and the turbulent flow of the combustion gases is promoted, so that the heat exchange efficiency can be improved. As a matter of course, the combustion gas which has entered into the substantially rhombus-shaped gap 28 is also turbulent by colliding with the inner edge of the raised portion 29, which contributes to the improvement of the heat exchange efficiency. Further, by providing the upper edge bent piece 31, the combustion gas which has passed between the raised portion 29 and the fin pipe 20 of the upper stage is guided to the downstream (rear) side of the fin pipe 20 of the upper stage. Heat is absorbed also on the downstream side of the fin pipe 20, and the amount of heat absorbed by the fin pipe 20 in the upper stage is also increased, and the heat exchange efficiency can be improved.

  On the other hand, the flow of the combustion gas entering the substantially rhombus-shaped gap 28 will be described. The combustion gas generated by the combustion in the burner (the combustion unit 6) flows into the heat exchanger 18 and the approximately rhombus-shaped gap 28 The combustion gas entering the inside is formed at the most downstream side in the flow direction of the combustion gas and at the center in the width direction of the gap 28 from the substantially rhombus-shaped gap 28 to the ridge 29 as shown by the dashed dotted line. Through the notched portion 29c and behind the raised portion 29 at the position where the notched portion 29c is formed, and passing through the shaded area T in FIG. Is guided to the downstream (rear) side of the fin pipe 20 of the upper stage by the upper edge bending pieces 31 provided at the upper side of the substantially rhombus-shaped gap 28 and between the adjacent fin pipes 20 of the upper stage. Flow out of the exchanger 18 Ku is intended.

  Here, in the conventional heat exchanger shown in FIG. 7, in the vicinity of the upper fin pipe 101, which is the downstream side of the flow direction of the combustion gas, the heat exchange with water flowing in the lower fin pipe 101 is rapid. Since the combustion gas whose temperature is lowered flows and the flow velocity of the combustion gas near the fin pipe 101 in the upper stage decreases with the temperature decrease, the kinetic energy of the soot particles in the combustion gas decreases, and the soot particles polymerize each other In the heat exchanger 18 of this embodiment, the notch 29c is provided in the raised portion 29, so that the flow passage resistance of the raised portion 29 to the flow of the combustion gas is reduced, and the heat sink 18 has a substantially rhombus shape. The combustion gas entering into the gap 28 easily passes through the raised portion 29 and passes through the notch 29c in a relatively high temperature even in the region T where the flow of the combustion Then, since it is led to the upper fin pipe 20 side, the temperature of the combustion gas is high and the flow velocity is fast, and the kinetic energy of the soot particles is also near the upper fin pipe 20 which is the flow direction downstream side of the combustion gas. It becomes difficult to lower the viscosity, and the soot particles also become difficult to polymerize, so that adhesion and deposition of soot on the surface of the fin plate 19 can be suppressed, and adhesion and deposition of soot on the surface of the fin plate 19 is suppressed. Thus, the decrease in heat exchange efficiency can be suppressed.

  However, FIG. 5 (FIG. 5 is a cross-sectional view taken along the line B-B in FIG. 4 and is a view of the raised portion 29 in the same direction as the flow direction of the combustion gas. As shown in the two drawings for the purpose of illustration only, the minute distance D3 between the tip edge of the ridge 29 and the back surface of the adjacent fin plate 19 opposite to the tip edge of the ridge 29 In the heat exchanger 18 having (for example, 0.1 mm or less), the height direction length D1 of the raised portion 29 and the width direction of the inner edge of the raised portion 29 with which the combustion gas contacts when viewed from the flow direction of the combustion gas. The projected area S1 of the inner edge of the raised portion 29 with which the combustion gas contacts when viewed from the flow direction of the combustion gas, which is calculated by the product of the maximum length L1, the length D2 in the height direction of the notch 29c, and the notch 29c Calculated by multiplying with the length L2 in the width direction of the The balance of the notch area S2, or heat exchange efficiency is deteriorated, there is a case where soot to the fin plate 19 surface may become easily adhere.

  Therefore, in the heat exchanger 18 of the present embodiment, which has a small distance D3 (for example, 0.1 mm or less) between the tip edge of the raised portion 29 and the opposite back surface of the adjacent fin plate 19 as described above. And the results as shown in FIG. 6 were obtained. FIG. 6 is a graph showing the relationship between S2 / S1, which is the ratio of the notched area S2 to the projected area S1, heat exchange efficiency, and weathering resistance which indicates the degree of adhesion of the fins to the fin plate 19; Yes, the broken line in FIG. 6 indicates the heat exchange efficiency m of the heat exchanger used in the conventional water heater, and in terms of heat exchange efficiency, if S2 / S1 is 4.67% or less, It can be seen that the heat exchange efficiency is higher than the heat exchange efficiency m of the conventional one, and regarding the heat resistance, if S2 / S1 is 1.63% or more, the heat resistance is good and wrinkles on the surface of the fin plate 19 It turns out that it is difficult to attach.

  Therefore, in the heat exchanger 18 of the present embodiment, which has a small distance D3 (for example, 0.1 mm or less) between the tip edge of the raised portion 29 and the opposite back surface of the adjacent fin plate 19 as described above, By setting S2 / S1 to 1.63% or more and 4.67% or less, adhesion of soot to the surface of the fin plate 19 and deposition can be suppressed while keeping the heat exchange efficiency high.

  Further, in the present embodiment, the notch 29c is formed at the central portion in the width direction of the raised portion 29, so that the back side central portion (region T) of the raised portion 29 which is most difficult to burn the combustion gas Also, since the combustion gas passes through the notch 29c at a relatively high temperature and is led to the fin pipe 20 side of the upper stage, the combustion gas is near the fin pipe 20 on the downstream side in the flow direction of the combustion gas as well. The temperature of the water is high, the flow velocity is high, the kinetic energy of the soot particles is difficult to lower, the soot particles are also difficult to polymerize, and adhesion and deposition of soot on the surface of the fin plate 19 can be suppressed. By suppressing the adhesion and the deposition of the wrinkles to the surface of the fin plate 19, it is possible to suppress the decrease of the heat exchange efficiency.

  Furthermore, in the present embodiment, the notch 29c has a length L2 in the width direction of the notch 29c more than a length D2 in the height direction of the notch 29c in the same direction as the axial direction of the fin pipe 20. Since the combustion gas can be circulated at a relatively high temperature over a wide range also to the region T where the combustion gas flow is the most on the back side of the raised portion 29 by the long shape of The adhesion of soot and deposition can be suppressed, and the reduction of heat exchange efficiency can be suppressed by inhibiting adhesion and deposition of soot on the surface of the fin plate 19.

  Moreover, in the present embodiment, the notch 29 c is cut from the tip edge of the raised portion 29 toward the surface of the fin plate 19 without penetrating the fin plate 19, leaving the excess thickness 29 d in the raised portion 29. Thus, it is possible to suppress the adhesion and the deposition of the soot on the surface of the fin plate 19 while minimizing the decrease in the heat exchange efficiency due to the surface area reduction of the fin plate 19.

  The notches 29c are formed by being punched out of the fin plate 19 before being burred to raise the raised portions 29 from the surface of the fin plate 19, and located inside the bending position by the burring. Therefore, the notch 29c of the dimension set in advance is precisely formed on the tip end side of the raised portion 29c because the dimension of the notch 29c is not changed without being affected by the expansion of the material due to bending. It is possible to easily manage the dimensional accuracy.

  Further, in the heat exchanger 18, a plurality of fin plates 19 are arranged at predetermined intervals along the axial direction of the fin pipe 20, and the raised portions 29, the side edge bending pieces 30, and the upper edge bending pieces 31. The combustion gas entering from the lower edge side of the fin plate 19 arranged in a plurality is arranged between the fin plate 19 and the burring 27a of the through hole 27 since the height of the through hole 27 is only slightly lower than the height of the burring 27a. Since the fuel gas flows in the combustion gas flow path formed between the raised portion 29, the side edge bent pieces 30 and the upper edge bent pieces 31, the flow velocity is uniformed overall, and the combustion gas proceeds along the surface of the fin pipe 20. The heat exchange efficiency can be improved, and the notch 29c is provided in the raised portion 29, whereby the flow Since the combustion gas flow path is formed such that the gas flows from the substantially diamond-shaped gap 28 through the notch 29c, it further contributes to the equalization of the flow velocity of the combustion gas, whereby the surface of the fin plate 19 is formed. Temperature deviation is suppressed, local heating is reduced, and silicon adhesion to the surface of the fin plate 19 can also be suppressed.

  The present invention is not limited to the embodiment described above, and in the present embodiment, the hot water supply device 1 for generating hot water used in a predetermined terminal (hot water supply valve etc.) according to the present invention Although the exchanger 18 is applied, the heat exchanger 18 of the present invention is also applied to a hot water heating apparatus for generating hot water used in a heat radiation terminal such as a floor heating panel for heating an air conditioned space as a predetermined terminal. The fuel used in the hot water supply apparatus 1 or the hot water heating apparatus may be a gas fuel such as city gas or propane gas instead of the fuel oil such as kerosene.

  Further, in the present embodiment, the flow of the combustion gas passing through the heat exchanger 18 is such that the lower edge side of the fin plate 19 having the gap 28 is upstream and the upper edge side of the fin plate 19 having the upper edge bent piece 31 is downstream. The combustion gas is flowing from the bottom to the top in the drawing (FIG. 4), but the burner is provided above the heat exchanger 18, and the combustion gas passing through the heat exchanger 18 is at the top. In the case of a so-called reverse-combustion type which flows from the bottom to the bottom, the heat exchanger 18 shown in FIG. 2 is turned upside down, the gap 28 is on the upper edge side of the fin plate 19, and the upper edge bent piece 31 is It may be disposed on the lower edge side of the fin plate 19, and the edge side having the gap 28 of the fin plate 19 is the upstream side in the flow direction of the combustion gas, and the edge side of the fin plate 19 having the upper edge bending pieces 31 is burned. If destroying the relationship that the downstream side of the flow direction of the gas, is capable of exerting the effect of the heat exchanger 18 of the present invention described above has.

  Further, in the present embodiment, the notch 29c is provided in the ridge portion 29 at the periphery of the gap 28 having a substantially rhombus shape that contacts the tip side of the gap 28, but the notch 29c is shown in FIG. 7 as a conventional heat exchanger. The gap 28 may be provided on the ridge portion of the gap periphery in a substantially circular shape, and the shape of the tip end side of the gap 28 is not particularly limited, and in the present embodiment, the notch is not limited. 29c is shown as a horizontally long rectangular shape in which the length L2 in the width direction of the notch 29c is longer than the length D2 in the height direction of the notch 29c, as shown in FIG. It is not necessary to have a rectangular shape, as long as the relationship that the length L2 in the width direction of the notch 29c is longer than the length D2 in the height direction is not required, and is not particularly limited.

Reference Signs List 16 combustion can 18 heat exchanger 19 fin plate 20 fin pipe 28 gap 29 raised portion 29 c notch 29 d excess thickness

Claims (4)

  A plurality of fin pipes arranged at regular intervals in the vertical and horizontal directions and a plurality of fin plates arranged at regular intervals along the axial direction of the fin pipes are provided in the combustion can, and A space is formed by cutting away from the lower edge of the fin plate toward the downstream side in the flow direction of the combustion gas, and the tip side of the space is a rectangle surrounded by the fin pipes arranged in a rectangular shape in upper and lower stages A protruding portion located at a substantially central portion of the space and provided on the tip side peripheral edge of the gap is provided with a raised portion protruding from the surface of the fin plate, and the adjacent one facing the leading end edge of the protruding portion from the leading end edge of the raised portion. The heat from the combustion gas flowing from the lower edge side of the fin plate to the space between the adjacent fin plates having a minute distance to the fin plate is transferred through the fin plate to the fin plate. In the heat exchanger adapted to be absorbed by the heat pipe, a notch is formed in the raised portion, and the notch with respect to the projected area of the inner edge of the raised portion which the combustion gas contacts when viewed from the flow direction of the combustion gas. The heat exchanger characterized in that the ratio of the notched area is set to 1.63% to 4.67%.   The heat exchanger according to claim 1, wherein the cutout portion is formed at a widthwise central portion of the raised portion.   The heat exchanger according to claim 1 or 2, wherein the notch has a shape in which the length in the width direction of the notch is longer than the length in the height direction of the notch.   The notch is a notch cut from the tip edge of the raised portion toward the surface of the fin plate, and the notch does not penetrate the fin plate and leaves excess thickness in the raised portion. The heat exchanger according to any one of claims 1 to 3, characterized by

Images