JP2015114003A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a heat exchanger capable of surely discharging water even in a case where the projection dimensions of heat absorption pipes in a header are different, with high productivity.SOLUTION: In a heat exchanger, heat absorption pipes 52 are arranged in a case where combustion exhaust flows, and one end part and the other end part of the heat absorption pipe 52 are connected to an inflow header 6a and an outflow header 6b provided in a side plate 51 of the case to heat water flowing into the heat absorption pipes 52 by combustion exhaust. In the inflow header 6a whose height position is on a low position side, a water discharge plate 7 is arranged, which has separation plates 70 separated so as to contact with each of a plurality of pipe end openings 52a while having elastic energization force.

Description

  The present invention relates to a heat exchanger that heats and heats water flowing into a heat absorption pipe via an inflow header and an outflow header by combustion exhaust.

  Even when the endothermic tube is narrowed for high thermal efficiency, the water film is prevented from being stretched at the end opening of the endothermic tube during the draining operation so that smooth drainage is possible. The present applicant has previously proposed a heat exchanger having a water draining plate 170 arranged continuously facing a plurality of pipe end openings 152a arranged in parallel in a header 160 as shown in FIG. In this heat exchanger, the gap between the pipe end opening 152a and the water draining plate 170 in the header 160 is less than or equal to the rising amount of the water film formed in the pipe end opening 152a due to the surface tension of water. By setting, a drain passage is formed between the pipe end opening 152a and the drain plate 170 to prevent water from remaining in the downstream portion in the flowing direction when draining (Patent Document 1).

JP 2010-175103 A

  However, when the heat exchanger is industrially produced, a manufacturing error in the length of the heat absorption tube 152, an assembly error when the heat absorption tube 152 and the header 160 are joined, and the like occur. Is inserted into the insertion port 163 provided in the header body 161, it is difficult to completely match the outgoing dimensions of the respective heat absorption tubes 152 protruding into the header 160 as seen in FIG. Therefore, in the drainage plate 170 continuously arranged opposite to the plurality of pipe end openings 152a as in Patent Document 1, the drainage plate 170 cannot follow the difference in the protruding size of the heat absorption tube 152. In addition, there is a problem in that there is a portion where the gap between the pipe end opening 152a and the drain plate 170 cannot be reduced below the rising amount of the water film. Further, even when a predetermined gap is formed between the pipe end opening 152a and the drain plate 170 at the time of assembly, a large load is applied during freezing and the portion of the drain plate 170 facing the pipe end opening 152a is deformed. In this case, since the drain plate 170 does not return to its original shape, there is a problem that the gap becomes large. In addition, the gap between the pipe end opening 152a and the drain plate 170 for forming the drain channel is formed by closing the header body 161 with the header lid 162. It is impossible to confirm whether or not the predetermined gap is formed due to the difference in dimensions, and it is not possible to adjust when the predetermined gap is not formed. Therefore, even if the distance between the header body 161 and the header lid 162 and the height of the drainage plate 170 are formed as designed, a drainage failure may occur.

  The present invention has been made to solve the above-described problems. When a drain plate of the heat absorption pipe is provided in the header, the water can be reliably drained even when the end dimensions of the heat absorption pipe in the header are different. Is to manufacture a simple heat exchanger with high productivity.

The present invention
A case where combustion exhaust flows,
A plurality of endothermic tubes disposed in the case;
An inflow header and an outflow header which are arranged on the side plate of the case, and are connected by inserting one end and the other end of each heat absorption tube,
A heat exchanger comprising: a drain plate for draining water that has been arranged in a header at a low position on the low position side and drains water that has reached a plurality of pipe end openings arranged in parallel when draining water in the heat absorption pipe Because
The drainage plate is a heat exchanger having a separation plate separated so as to come into contact with each of a plurality of pipe end openings with an elastic biasing force.

  Since the water draining plate includes a separation plate that is separated so as to come into contact with each of the pipe end openings of the plurality of heat absorption tubes with an elastic biasing force, the dimensions of the heat absorption tubes in the header are different. Even in this case, the separation plate can absorb the difference in the protruding size, and the drain plate can be arranged in a state where at least a part of the separation plate is brought into contact with any of the pipe end openings. Therefore, since the gap between the pipe end opening and the separation plate can be narrowed, the drainage channel can be reliably formed from any pipe end opening. In addition, since the separation plate abuts the pipe end opening with an elastic biasing force, even if a load is applied to the separation plate during freezing, the gap between the pipe end opening and the separation plate is prevented from becoming large. be able to.

Preferably, in the heat exchanger,
The drainage plate includes a support portion that supports a plurality of separation plates,
Each separation plate is arranged such that when the drainage plate is installed so that the support portion is in the lower state before being arranged in the header, the free end of the separation plate is higher than the fixed end on the support portion side. Inclined.

If the position of the pipe end opening differs greatly between the endothermic pipe with the largest output dimension and the endothermic pipe with the smallest output dimension, it can be elastically deformed if the fixed end and free end of the separation plate are formed at the same height. Even if a separate separator plate is formed, it is difficult to bring the separator plate into contact with all the pipe end openings.
However, the drain plate includes a support portion that supports a plurality of separation plates, and each separation plate is inclined so that the free end is higher than the fixed end before being disposed in the header. Therefore, the free end of each separation plate is formed with an inclined surface closer to the pipe end opening in the header than the fixed end, and is elastically deformable when each separation plate abuts on the pipe end opening. The range becomes larger. As a result, even if the projecting dimensions of the respective heat absorption tubes are greatly different, the separation plate can be followed, and the separation plate can be reliably brought into contact with all the pipe end openings with an elastic biasing force.

  As described above, according to the heat exchanger according to the present invention, when industrially producing a heat exchanger in which a drainage plate is arranged in the header, the manufacturing error of the length of the heat absorption tube and the heat absorption tube Even if the heat sink tube exit dimensions in the header are different due to mounting errors with the header, etc., the difference in the output dimension can be absorbed by the water drain plate. It can be made to contact, and it can drain reliably. Therefore, it is not necessary to manage the length of the heat absorption tube and the positioning of the heat absorption tube at the time of attachment with high accuracy in consideration of drainage. Further, even when a load is applied to the separation plate due to freezing, it is possible to prevent the gap between the pipe end opening and the separation plate from becoming large. Therefore, it is possible to efficiently produce a heat exchanger that is unlikely to cause water drainage failure.

It is a schematic sectional drawing which shows the structure of the hot water supply apparatus provided with the heat exchanger which concerns on embodiment of this invention. It is the schematic perspective view which decomposed | disassembled the part of the inflow header of the subheat exchanger which concerns on embodiment of this invention. It is a schematic block diagram which shows the water draining plate which concerns on embodiment of this invention, (A) shows a front view, (B) shows sectional drawing. It is a schematic cross-sectional view which shows the internal structure of the inflow header which concerns on embodiment of this invention. It is a schematic block diagram which shows the conventional water draining board. It is a schematic cross-sectional view which shows the internal structure of the inflow header which has arrange | positioned the conventional water draining board.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
A hot water supply apparatus 1 shown in FIG. 1 is a latent heat recovery type hot water supply apparatus, and includes a combustion housing 3 containing a gas burner 31 in an outer case 2, a main heat exchanger 4 above the combustion housing 3, and a main heat exchanger. 4 and an auxiliary heat exchanger 5 above. An air supply fan 11 that supplies combustion air into the combustion housing 3 is installed below the combustion housing 3.

  The main heat exchanger 4 includes a large number of endothermic fins 41 arranged in parallel in the body 40 through which the combustion exhaust gas of the gas burner 31 flows, and an endothermic pipe 42 penetrating the endothermic fins 41 in a meandering shape. ing. The auxiliary heat exchanger 5 is a latent heat exchanger, and includes a plurality of heat absorption tubes 52 arranged in a meandering manner in the case 50. The endothermic tube 52 is formed by bending a corrugated tube made of a corrosion-resistant metal such as stainless steel or titanium into a meandering shape. The side plate 51 on one side of the case 50 is provided with an inflow header 6a and an outflow header 6b. One end of a plurality of heat absorption tubes 52 is connected to the inflow header 6a, and the other end is connected to the outflow header 6b. It is connected. A water supply pipe 81 is connected to the inflow header 6a, and a connection pipe 83 connected to the upstream end of the heat absorption pipe 42 of the main heat exchanger 4 is connected to the outflow header 6b. A tapping pipe 82 is connected to the downstream end of the heat absorption pipe 42 of the main heat exchanger 4. The auxiliary heat exchanger 5 has an exhaust inlet 54 for combustion exhaust that has passed through the main heat exchanger 4 at the rear of the bottom plate 53, and exhausts the combustion exhaust that has passed through the auxiliary heat exchanger 5 on the front surface of the case 50. An exhaust port 55 is provided.

  When the outlet tap at the downstream end of the hot water pipe 82 is opened, water is passed from the water supply pipe 81 to the heat absorption pipe 52 of the auxiliary heat exchanger 5 and the heat absorption pipe 42 of the main heat exchanger 4, and the gas burner 31 is combusted. Is done. In the main heat exchanger 4, sensible heat is mainly absorbed from the combustion exhaust gas generated by the combustion of the gas burner 31, and the water flowing in the heat absorption pipe 42 is heat exchange heated. The auxiliary heat exchanger 5 condenses the water vapor in the combustion exhaust and absorbs latent heat to heat and heat the water in the heat absorption pipe 52. As a result, the hot water heated by the sub heat exchanger 5 and the main heat exchanger 4 is discharged from the hot water discharge pipe 82.

  The auxiliary heat exchanger 5 is installed with a slight inclination (about 5 °) in the rearward direction. Acidic drain water generated by the condensation of water vapor in the combustion exhaust gas in the auxiliary heat exchanger 5 is dropped on the inclined bottom plate 53, and passes through the drain drain pipe 57 from the drain recovery portion 56 at the lower position and is neutralized in the neutralizer 58. After being summed, it is drained into sewage.

  As shown in FIGS. 2 and 4, the inflow header 6 a and the outflow header 6 b in the auxiliary heat exchanger 5 are headers formed by recesses recessed inward of the case 50 by drawing a predetermined position of the side plate 51. A main body 61 and a header lid 62 that is disposed from the outside of the case 50 and defines a closed space 60 between the main body 61 and the header main body 61 are provided. In the header body 61, a plurality of insertion ports 63 for the heat absorption pipes 52 are provided in a staggered manner in two rows on the left and right sides corresponding to the plurality of heat absorption pipes 52, and the water supply pipe 81 and the connection pipe 83 are provided in the header lid 62. A single joint portion 64 is provided. The header lid 62 is formed in a shallow vessel shape in which the back side where the joint portion 64 is not provided forms a peripheral wall 65 on the entire periphery. The header lid 62 is fitted into the recess of the header body 61 with the back side of the header lid 62 facing the recess of the header body 61, and the recess inner wall 68 of the header body 61 and the outer surface of the peripheral wall 65 of the header lid 62 are overlapped. Each header 6a, 6b is formed by brazing.

  The position of the joint portion 64 of the inflow header 6a is provided on the lower side, and the position of the joint portion 64 in the outflow header 6b is provided on the upper side. And since the sub heat exchanger 5 is installed inclining, the inflow header 6a is arrange | positioned in the lower position in the height position.

  In the sub heat exchanger 5 in the present embodiment, eight heat absorption tubes 52 (for example, caliber: φ10 mm) are arranged in a case 50. Thereby, many heat absorption pipes 52 are arranged in a limited space, the size is reduced, and the heat transfer area of the heat absorption pipes 52 is increased, thereby achieving high thermal efficiency. One end portion and the other end portion of these heat absorption tubes 52 are respectively inserted into the insertion ports 63 of the header main body 61 of the inflow header 6a and the outflow header 6b, and the heat absorption tubes 52 protruded into the recesses of the header main body 61. The pipe end openings 52a are arranged in a staggered manner in two rows on the left and right.

  As shown in FIGS. 2 to 4, in the inflow header 6 a arranged on the low position side, a drain plate 7 for forming a drain channel with the pipe end opening 52 a at the time of draining is arranged. It is installed. The drain plate 7 according to the present embodiment is formed by molding a single metal plate (for example, made of SUS304, thickness: about 0.5 mm). A plurality of separation plates 70 (eight in the present embodiment) supported by the left and right lower edges are provided. The support portion 71 is formed in a plate shape having a groove portion formed by bending a metal plate, and each separation plate 70 is elastic to the pipe end opening 52a when the drainage plate 7 is disposed in the inflow header 6a. It is formed in a thin plate shape having a fixed end 76 supported by the support portion 71 and a free end 75 on the opposite side to the support portion 71 so as to be able to come into contact with a specific urging force. The support portion 71 may be formed to support the left and right separation plates 70.

  The separation plates 70 are provided in a staggered manner in two rows on the left and right sides around the support portion 71 in accordance with the arrangement position of the pipe end opening 52 a protruding into the recess of the header body 61. In addition, the separation plate 70 positioned in a staggered manner other than the uppermost and lowermost separation plates 70 has a fixed end 76 and a free end 75 formed in a substantially rectangular shape having the same width. The separation plates 70 positioned at the upper and lowermost positions are each formed in a substantially trapezoidal shape with the upper and lower edges inclined according to the shape of the inner wall 68 of the header body 61.

  The drain plate 7 has a size substantially along the bottom of the header body 61 so that the pipe end opening 52a and the separation plate 70 face each other in a positioned state. Each separation plate 70 is not particularly limited as long as it covers at least a part of the pipe end opening 52a where water tends to remain when draining, but preferably, when the separation plate 70 faces the pipe end opening 52a. In addition, the pipe end opening 52 a is formed to be slightly larger than the diameter of the opposed pipe end opening 52 a so that the entire pipe end opening 52 a is covered with the separation plate 70. Note that the width of the notch 77 that separates the separation plates 70 can be set as appropriate according to the size of the separation plate 70 and the interval between the pipe end openings 52a adjacent in the vertical direction.

  Moreover, as shown in FIG. 3, the separation plate 70 of the present embodiment is free when the drain plate 7 is installed so that the support portion 71 is positioned downward in the state before being arranged in the inflow header 6a. The end 75 is formed to be higher than the fixed end 76 connected to the support portion 71. That is, the separation plate 70 is connected to the support portion 71 at an obtuse angle larger than 90 ° in a state where no load is applied to the separation plate 70, and the left and right separation plates 70 have the support portion 71 as the center of the bag. It is formed to spread in a fan shape. As a result, the free end 75 can be brought closer to the pipe end opening 52 a than the case where the fixed end 76 and the free end 75 are formed at substantially the same height with respect to the support portion 71, and the separation plate 70. The permissible range of elastic deformation can be expanded.

  Further, a bent portion 73 that is bent toward the support portion 71 is formed on the free end 75 side of the separation plate 70. As will be described later, the bent portion 73 has a distal end of a peripheral wall 65 of the header lid 62 facing the pipe end opening 52a of the heat absorption pipe 52 having a large output dimension when the drain plate 7 is disposed in the inflow header 6a. It is provided in contact with the upper end surface (FIG. 4).

  The separation plate 70 has four large hole portions 74a having a large diameter opened at the central portion, and two small hole portions 74b having a small diameter opened at the top and bottom thereof. The diameters of these holes 74a and 74b are smaller than that of the pipe end opening 52a. When the separating plate 70 faces the pipe end opening 52a, all of the large holes 74a and the small holes 74b are formed. Is located in the pipe end opening 52a. Thereby, even if substantially the entire surface of the separation plate 70 abuts on the pipe end opening 52a, water can smoothly pass through the separation plate 70, and to the heat absorption pipe 52 via the inflow header 6a during normal use of the auxiliary heat exchanger 5. Smooth distribution of water.

  In the present embodiment, the support portion 71 is provided so as to be positioned between the pipe end openings 52a juxtaposed side by side when the drain plate 7 is disposed in the inflow header 6a. The height of the support portion 71 is such that when the drain plate 7 is disposed in the concave portion of the header body 61 and the header lid 62 is fitted into the header body 61 and at least a part of the separation plate 70 contacts the pipe end opening 52a, The apex of the support portion 71 is formed so as to contact the bottom surface 67 of the header lid 62. In addition, although the opening is not formed in the support part 71, you may provide an opening similarly to the separating plate 70. FIG.

  In disposing the drain plate 7 in the inflow header 6 a, the pipe end opening 52 a of the heat absorption pipe 52 is led out into the recess of the header body 61 through the insertion port 63 of the header body 61, A brazing material is applied to the boundary with the outer peripheral surface of the heat absorption tube 52 and temporarily fixed. Next, the drainage plate 7 is disposed in the recess of the header body 61 and is fitted until the peripheral wall 65 of the header lid 62 contacts the inner wall 68 of the header body 61. At this time, due to a manufacturing error in the length of the endothermic tube 52 or an assembly error of the endothermic tube 52 to be derived when the endothermic tube 52 and the header body 61 are joined together, for example, as shown in FIG. In 6a, the heat sink tubes 52 adjacent to each other are formed with different projecting dimensions. Therefore, in the case of a rigid single metal plate, such as the conventional water drain plate 170 that is continuously disposed vertically opposite to the plurality of pipe end openings 52a, a part of the endothermic tubes with a small output dimension. The clearance gap between the pipe end opening 52a of 52 and the drainage plate 170 becomes large. Further, when a small amount of remaining water is frozen and a large load is applied to the drainage plate 170 to cause plastic deformation, the drainage plate 170 does not return to its original shape, and therefore the gap becomes larger than that during assembly. As a result, a water film due to the surface tension of water is formed between the pipe end opening 52a and the drain plate 170 during drainage, and water further remains in the downstream portion in the flowing direction when draining the heat absorption pipe 52. It becomes easy.

  However, in the present embodiment, the drain plate 7 has the separation plates 70 supported on the left and right of the support portion 71 so as to face each pipe end opening 52a. When the header lid 62 is fitted into the header main body 61 in a state where the 7 is disposed, as shown in FIG. 4, the separation plate 70 is inserted into the pipe end opening 52a at the location where the heat absorption pipe 52 having a large output dimension is disposed. The separator 70 is pressed and elastically deformed so that the separation plate 70 comes into contact with substantially the entire surface of the pipe end opening 52 a, and the bent portion 73 comes into contact with the upper end surface of the peripheral wall 65 of the header lid 62. Further, at the place where the heat absorption tube 52 with a small projecting dimension is disposed, the separation plate 70 is similarly elastically deformed by being pressed by the pipe end opening 52a. However, since the deformation amount is small, a part on the free end 75 side is provided. Only the pipe end opening 52a abuts, and the bent portion 73 is spaced from the upper end surface of the peripheral wall 65 of the header lid 62 so that the free end 75 is positioned closer to the pipe end opening 52a than the fixed end 76. . At this time, the apex of the support portion 71 is in contact with the bottom surface of the header lid 62, and the support portion 71 is fixed in a direction in which the header body 61 and the header lid 62 face each other. At least a part of the separation plate 70 is brought into contact with both the opening 52a and the pipe end opening 52a of the heat absorption pipe 52 having a small projecting dimension with an elastic biasing force. Thereby, the clearance gap between any pipe end opening 52a and the separating plate 70 can also be narrowed. Therefore, even if the water head pressure due to the height difference of the heat absorption pipe 52 is reduced during the water draining operation, it is difficult to form a water film due to the surface tension of the water at the pipe end opening 52a. The reached water flows along the separation plate 70 and flows below the drain plate 7, and the water in the downstream direction in the flowing direction when draining the heat absorption pipe 52 can be smoothly drained. Thus, according to the present embodiment, even if a manufacturing error occurs in the length of the heat absorption pipe 52 or an attachment error occurs when the heat absorption pipe 52 is attached to the inflow header 6a, those errors are reduced. It can be absorbed by the drain plate 7. Furthermore, even if a small amount of water remains and a large load is applied to the separation plate 70 during freezing, the separation plate 70 can be elastically deformed, so that a gap between the pipe end opening 52a and the separation plate 70 becomes large due to freezing. Can be prevented. Therefore, it is not necessary to carry out strict production management with respect to the length of the heat absorption pipe 52 and its output dimension, and the auxiliary heat exchanger 5 capable of reliably draining water can be manufactured with high productivity.

  In particular, the separation plate 70 in the present embodiment is formed with an inclined surface so that the free end 75 is higher than the fixed end 76 in a state where no load is applied to the separation plate 70, and the free end 75 is the pipe end. Since it is provided close to the opening 52a and the allowable range in which the separation plate 70 can be elastically deformed is widened, it is ensured that at least one of the separation plates 70 is ensured even when the difference in the projecting dimensions of the heat absorption tubes 52 is large. The portion can be brought into contact with the pipe end opening 52a.

  Furthermore, in this embodiment, since the separating plate 70 is elastically abutted against the opposing pipe end opening 52a, the drain plate 7 when the water flows through the inflow header 6a during normal use. It can also prevent rattling.

In addition, this invention is not limited only to the said embodiment, A various change is possible within the scope of the present invention.
For example, the pipe end openings 52a of the heat absorption tubes may be arranged in a line in the header. Further, the endothermic tube 52 may be arranged in a spiral shape, a spiral shape, or the like instead of the horizontal meandering shape.
Further, the heat exchanger is not limited to the hot water supply device, and may be used for various heat exchange devices.

DESCRIPTION OF SYMBOLS 1 Hot-water supply apparatus 2 Exterior case 3 Combustion housing 4 Main heat exchanger 5 Sub heat exchanger 6a Inflow header 6b Outflow header 7 Drain plate 42 Heat absorption pipe 50 Case 51 Side plate 52 Heat absorption pipe 52a Pipe end opening 61 Header main body 60 Closed space 62 Header lid 63 Insert port 70 Separation plate 71 Support part 75 Free end 76 Fixed end

Claims (2)

A case where combustion exhaust flows,
A plurality of endothermic tubes disposed in the case;
An inflow header and an outflow header which are arranged on the side plate of the case, and are connected by inserting one end and the other end of each heat absorption tube,
A heat exchanger comprising: a drain plate for draining water that has been arranged in a header at a low position on the low position side and drains water that has reached a plurality of pipe end openings arranged in parallel when draining water in the heat absorption pipe Because
The water draining plate is a heat exchanger having a separating plate separated so as to abut each of the plurality of pipe end openings with an elastic biasing force. The heat exchanger according to claim 1,
The drain plate has a support portion for supporting a plurality of separation plates,
Each separation plate is arranged such that when the drainage plate is installed so that the support portion is in the lower state before being arranged in the header, the free end of the separation plate is higher than the fixed end on the support portion side. An inclined heat exchanger.

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