JP5393606B2 - Heat exchanger - Google Patents

Description

  The present invention relates to a heat exchanger having left and right headers and heat transfer tubes provided between the headers. More specifically, the heat exchange efficiency is improved by flowing a fluid along the axial direction outside the heat transfer tubes. The present invention relates to a heat exchanger that is improved.

  Conventionally, various heat exchangers using multiple tubes have been proposed. FIG. 8 shows the structure of a general heat exchanger having multiple tubes. In FIG. 8, reference numeral 83 is a coaxial tube, and an inner tube 85 is coaxially provided inside the outer tube 84. As this multiple tube, there are, for example, those in which a large number of fins along the axial direction are provided on the outer peripheral portion of the inner tube, and those in which spiral fins are provided on the outer peripheral portion of the inner tube (Patent Documents 1 to Patent). Reference 3). When the heating fluid is cooled using such a coaxial tube, the heating fluid is passed through the inner tube 85 and the cooling fluid is passed through the gap between the outer tube 84 and the inner tube 85, thereby the inner tube 85. The heated fluid is cooled from the outer periphery.

  Further, as another heat exchanger using a multiple tube, a structure as shown in FIG. 9 is also known (Patent Document 4). In FIG. 9, reference numerals 210 </ b> L and 210 </ b> R are headers provided on the left and right sides, and reference numeral 210 is a heat transfer tube provided across the left and right headers. The heat transfer tube 210 is provided with an outer tube 212 at the center thereof, and a fin (not shown) is provided between the outer tube 212 and the inner tube 211 so that heat can be diffused. On the other hand, reference numeral 213 is a chamber partitioned between the left and right headers, and allows fluid to pass from the inlet 214 to the outlet 215. And when cooling the 1st fluid 6 using such a heat exchanger, the 1st fluid 6 is made to flow in from one header 210L, and is made to flow out to the other header 210R side via the inner pipe 211. On the other hand, at the same time, the second fluid 7 is introduced from the inlet 214 of the chamber 213, heat exchange is performed through the second fluid 7 in the gap between the outer tube 212 and the inner tube 211, and the heat is discharged from the outlet 215. I have to.

Japanese Patent Laying-Open No. 2005-083667 JP 2007-163092 A JP 2008-69993 A Japanese Patent Laid-Open No. 07-133993

  However, when heat exchange is performed using such a multiple tube, the following problems occur. That is, in the heat exchanger as shown in FIG. 8 or FIG. 9, since the fluid to be heat exchanged is passed through the thin inner tube, the inner tube is made thicker if a large flow rate is to be secured. Must be. However, if the inner tube is made thicker in this way, heat exchange can be performed only on the outer surface of the inner tube, resulting in a problem that the efficiency of heat exchange deteriorates.

  In addition, as shown in FIG. 9, when the second fluid 7 is allowed to flow through the central chamber 213, the second fluid 7 passes in the direction indicated by the thick solid line, so the portion indicated by the solid line In other regions (for example, near the corner of the chamber 213 or near the wall surface), there is a problem that heat exchange cannot be performed so much.

  Therefore, in order to solve the above-described problems, an object of the present invention is to provide a heat exchanger that can efficiently perform heat exchange in a heat exchanger that performs heat exchange using multiple tubes.

That is, in order to solve the above problems, the present invention uses a heat transfer tube having an outer tube and an inner tube, and between the first fluid flowing in the gap between the outer tube and the inner tube and the second fluid flowing in the inner tube. In the heat exchanger for exchanging heat with the header unit, the both ends of the inner pipe are extended from the outer pipe, and the first fluid is circulated from the outer peripheral portion of the extending inner pipe to the gap with the outer pipe, A second header for allowing a second fluid to flow through an inner pipe extending from the header unit, a plurality of the header units, a stack of the header units and the header units so as to have a gap, and the second header The second fluid from is passed through the inside of the inner tube and also through the outer surface of the outer tube along the axial direction through the gap.

More specifically, the first wall surface holds the vicinity of the end of the outer tube, the second wall surface facing the first wall surface holds the inner tube extending from the outer tube, and the first wall surface In the space surrounded by the second wall surface, the second fluid is circulated through the header unit that circulates the first fluid through the gap between the inner tube and the outer tube, and the inner tube that extends from the second wall surface of the header unit. A first inflow / discharge portion, a plurality of the header units, a stack of the header unit and the header unit so as to have a gap, and a second fluid from the first inflow / discharge portion to the inside of the inner pipe. In addition to passing through, the outer surface of the outer tube is also passed along the axial direction through the gap.

  In this way, the first fluid flowing in the gap between the outer tube and the inner tube can be heat-exchanged with the second fluid from the inside and the outside, and the first fluid is allowed to flow along the axial direction of the heat transfer tube. Therefore, heat exchange can be performed over the entire outer tube.

  In such an invention, a gap forming member is sandwiched between the stacked header units and the header unit to form a gap.

  In this way, the width of the gap can be changed by changing the thickness of the gap forming member, and the optimum gap width can be easily set.

  Alternatively, a convex portion or a concave portion is formed integrally with the header unit, and a gap portion is formed between the convex portion and the concave portion.

  In this way, the gap portion can be formed simply by stacking the header units having convex portions and concave portions, and adhesion of the gap forming member in the assembling process becomes unnecessary.

  Further, fins are provided along the axial direction of the heat transfer tubes between the upper layer and the lower layer heat transfer tubes of the stacked header units.

  If it does in this way, the 2nd fluid which flowed in via the crevice part can be branched to the surface side of a heat exchanger tube via a fin, and the 2nd fluid is made to flow near the surface of a heat exchanger tube, and heat exchange is carried out. Efficiency can be improved.

  Further, it is possible to provide a fin that forms a gap between the upper and lower header units in a state where the upper and lower heat transfer tubes are in contact with each other.

  With this configuration, the gap can be formed by sandwiching the fins between the heat transfer tubes of the header unit, and since the fins are in contact with the heat transfer tubes, more heat diffusion is achieved by heat conduction. Can also be performed.

According to the present invention, a heat exchanger using a heat transfer tube having an outer tube and an inner tube, and exchanging heat between the first fluid flowing through the gap between the outer tube and the inner tube and the second fluid flowing through the inner tube. A header unit that extends both ends of the inner tube from the outer tube, and circulates the first fluid through a gap between the outer tube and the outer tube, and an inner portion that extends from the header unit. A second header for circulating a second fluid in the pipe , a plurality of the header units, a stack of the header units and the header units so as to have a gap , and the second fluid from the second header In addition, the first fluid flowing in the gap between the outer tube and the inner tube is passed through the inner tube and the outer surface of the outer tube through the gap portion along the axial direction. Heat exchange with the second fluid from the outside, and By passing the first fluid along the axial direction of the heat pipe, it is possible to heat exchange throughout the outer tube.

Schematic of a heat exchanger showing an embodiment of the present invention A-A schematic cross-sectional view in FIG. BB cross-sectional schematic in FIG. The perspective view which shows the vicinity of the header in 1st embodiment The figure which shows the convex part of the header unit which shows 2nd embodiment of this invention The figure which shows the other convex part of the header unit which shows 2nd embodiment of this invention Schematic of a heat exchanger showing a third embodiment of the present invention Figure showing a conventional heat exchanger using multiple tubes Figure showing a conventional heat exchanger using multiple tubes

  <First embodiment>

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the heat exchanger 1 in the present embodiment includes a first header 2 a for passing a fluid (first fluid) to be subjected to heat exchange through a gap between the inner tube 41 and the outer tube 42, The second header 2 b is provided on both outer sides of the first header 2 a and allows the second fluid to pass through the inner pipe 41. Characteristically, the first header 2a is stacked such that a plurality of header units 21 are vertically provided with gaps W, and the second fluid is passed through the gaps W from outside and inside of the outer tube 42. Heat exchange is performed along the axial direction of the heat transfer tube 4. Hereinafter, the structure of the heat exchanger 1 in this Embodiment is demonstrated in detail.

  The structure of the first header 2a constituting the heat exchanger 1 will be described. The first header 2a is configured by laminating a header unit 21 holding a heat transfer tube 4 having an inner tube 41 and an outer tube 42. . As shown in FIG. 4, the header unit 21 is configured such that a pair of upper and lower unit separators 22 are vertically opposed to each other, and a first wall surface 23 on the side where an end portion of the outer tube 42 is attached is attached to the outer tube. The first concave portion 28a is formed by halving the outer shape of 42, and the outer shape of the inner tube 41 is also halved on the second wall surface (rear surface 26) facing the first wall surface 23 in the axial direction. A second recess 28b is formed to sandwich the outer tube 42 and the inner tube 41. The divided surfaces 20 of the first wall surface 23 and the second wall surface are divided by a plane parallel to the axial surface of the heat transfer tubes 4 arranged in a row, and the first recessed portion 28 a and the second recessed portion are formed on the divided surface 20. The open part of 28b is made to face. Further, a continuous side surface and a bottom surface are provided from the first wall surface 23 and the second wall surface, and an opening 27 is formed on one side surface to allow the first fluid to flow from there. . When the header unit 21 is formed using the unit separator 22 configured as described above, the unit separator 22 is vertically opposed so that the first recess 28a sandwiches the vicinity of the end of the outer tube 42, and from there The vicinity of the end portion of the extended inner tube 41 is sandwiched between the second recesses 28 b so that the first fluid flows between the outer tube 42 and the inner tube 41. When stacking the header units 21 sandwiching the heat transfer tubes 4 in this way, the gap forming member 8 is used to form a predetermined gap W in the vertical direction, and in this state, the opening 27 of each header unit 21 is formed. A header cover 3a is attached so as to cover the first fluid, and the first fluid is caused to flow in from the inflow port 31a. When the gap portion W is formed using the gap forming member 8, the gap forming member 8 having a dimension corresponding to the gap width is prepared and attached to the upper surface or the lower surface side of the header unit 21 to form the gap. .

  Next, the structure of the second header 2b will be described. The second header 2b is configured to allow the second fluid to flow in from the inner tube 41 extending from the second recess 28b. In this embodiment, the second header 2b is a single piece that covers the first header 2a and the header cover 3a. It consists of a header cover 3b. In this embodiment, the header cover 3b has a housing structure that covers all of the left and right first headers 2a and the heat transfer tubes 4 at the center thereof, and has inlets 31b and exhausts provided at both ends. The second fluid is allowed to flow in and out from the outlet 32b. When the second fluid is introduced through the inlet 31b of the second header 2b configured as described above, the second fluid flows from the end of the inner pipe 41, and the gap portion of the header unit 21 It flows along the outer peripheral part of the outer tube 42 from W.

  In such a heat transfer tube 4, two inner tubes 41 are inscribed in the outer tube 42 so that their axial surfaces coincide with each other, and the inner tube 41 swells at a high pressure. Even if it exists, the inner tube 41 is inscribed in the outer tube 42 so that the expansion of the inner tube 41 can be prevented. When configuring such a heat transfer tube 4, in order to improve the efficiency of heat exchange, for example, the outer diameter of the outer tube 42 is 0.8 mm to 2.0 mm, preferably 0.9 mm to 1.5 mm, The inner diameter is set to 0.7 mm to 1.9 mm, preferably about 0.8 mm to 1.4 mm.

  Further, the fins 9 are attached to the region of the heat transfer tube 4 in the gap between the header units 21 and the header units 21 arranged in layers in this way. The fin 9 is provided so as to be in contact with the outer peripheral portion of the heat transfer tube 4, and allows the second fluid that has flowed in through the gap W to approach the outer peripheral portion of the heat transfer tube 4. That is, if the fin 9 is not present, the second fluid that has flowed through the gap W may flow in a gap space in which the heat transfer tube 4 does not exist, and heat exchange efficiency may deteriorate. Therefore, the fin 9 is attached to the gap space where the heat exchange is not required to bring the second fluid closer to the heat transfer tube 4 side, and the heat from the heat transfer tube 4 is diffused to improve the efficiency of the heat exchange. ing. When attaching the fins 9 in this way, as shown in FIGS. 2 and 3, when viewed from the axial direction of the heat transfer tube 4, the fins 9 are parallel to the layered header unit 21, and the gap W Install in an overlapping position.

  Next, an effect | action at the time of using the heat exchanger 1 comprised in this way is demonstrated.

  First, when the first fluid is introduced from the inlet 31a of the first header 2a, the first fluid flows into each header unit 21 via the header cover 3a, and then branches from there to each heat transfer tube 4. And discharged from the discharge port 32a. At this time, since only the end portion of the outer tube 42 is opened in the header unit 21, the first fluid flows between the outer tube 42 and the inner tube 41.

  In parallel with this, the second fluid is caused to flow from the inlet 31b of the second header 2b. Then, the second fluid flows into the inner tube 41 from the space surrounded by the header cover 3 b and flows along the axial direction of the inner tube 41. Further, the second fluid that has not flowed into the inner tube 41 flows in the axial direction of the heat transfer tube 4 through the gap W of the header unit 21. Then, the second fluid is branched into the upper and lower heat transfer tubes 4 by fins 9 provided in the gaps of the heat transfer tubes 4, and contacts the outside of the heat transfer tubes 4 to contact the first fluid and the heat. Let them exchange.

  As described above, according to the above-described embodiment, the header unit 21 is stacked with the predetermined gap portion W, and the second fluid is also passed from the gap portion W along the axial direction of the heat transfer tube 4. Heat can be exchanged over the entire heat pipe 4.

  Further, in this embodiment, since the fins 9 that contact the surface of the heat transfer tube 4 are provided along the axial direction, the second fluid that has flowed in from the gap W is brought closer to the surface side of the heat transfer tube 4. Thus, the efficiency of heat exchange can be further improved.

  <Second Embodiment>

  Next, a second embodiment of the present invention will be described. In the first embodiment, the gap portion W is formed by using the gap forming member 8, but in the second embodiment, as shown in FIG. A convex portion 25a or a concave portion 25b is formed, and the second fluid is passed through the gap. In addition, in this Embodiment, what attached | subjected the same code | symbol as 1st Embodiment shall have the same structure as 1st Embodiment.

  The unit separator 22 constituting the header unit 21 in this embodiment has a plate-like or fixed thickness 25a raised from the lower side of the bottom surface, and the convex portions 25a and 25a A gap portion W is formed by forming a concave portion 25b therebetween. Here, the convex portion 25a is integrally formed when the unit separator 22 is manufactured. As for this convex portion 25a, when the header units 21 are stacked one above the other, as shown in FIG. 5, the convex portion 25a interferes with the upper and lower convex portions 25a. When the height is set to “d / 2”, the height of the convex portion 25a is set to “d / 2”, so that the gap width can be set to “d” when the convex portion 25a interferes with the upper layer and the lower layer. Keep it like that.

  Alternatively, as shown in FIG. 6, the convex portion 25a is formed of a thin plate-like body along the axial direction of the heat transfer tube 4, and the upper or lower convex portions 25a are overlapped with each other. Also good. When configured in this way, the opening 27 of the upper header unit 21 and the lower header unit 21 are shifted by the thickness of the plate, but when the header cover 3a is attached to the opening 27, The gap may be filled with brazing material.

  As described above, according to the second embodiment, since the convex portion 25a (or the concave portion 25b) is integrally formed on the header unit 21, when the header unit 21 is stacked, a gap forming member is formed. It becomes unnecessary to attach 8, and the operation | work at the time of a lamination process can be simplified.

  In this embodiment, the concave portion 25b is formed in the gap by forming the convex portion 25a, but conversely, the concave portion 25b is formed by scraping the bottom surface portion of the unit separator 22. Alternatively, a convex portion 25a may be formed between the concave portion 25b and the concave portion 25b.

  <Third embodiment>

  Next, a third embodiment will be described. In the first and second embodiments, the gap portion W is formed by the gap forming member 8 and the convex portion 25a. However, in this embodiment, as shown in FIG. The gap portion W can be formed by the fins 9 sandwiched between the heat transfer tubes 4. Also in this embodiment, the same reference numerals as those in the first embodiment have the same configurations as those in the first embodiment.

  The heat exchanger 1 of this embodiment is configured in a state where the gap forming member 8 in FIG. 4 does not exist, and a fin 9 having a thickness is attached between the heat transfer tubes 4 between the left and right header units 21. The gap W is formed in the upper and lower header units 21 by sandwiching them so as to contact the heat transfer tubes 4.

  The fin 9 is made of a metallic member having a high thermal conductivity, and diffuses the heat of the heat transfer tube 4 by contacting the surface of each heat transfer tube 4 and transmits the second fluid flowing in from the gap W. The heat is exchanged by branching toward the heat tube 4 side.

  In addition, when such a fin 9 is comprised with a metal member, the clearance gap between the upper and lower header units 21 is determined by the thickness of the fin 9, and there is an error in the deflection of the heat transfer tube 4 or the thickness of the fin 9. The gap width of the header unit 21 changes. And the position of the opening part 27 of the header unit 21 changes with the fluctuation | variation of the clearance gap width, and it may become difficult to attach the header cover 3a. Therefore, only the upper layer and the lower layer of the fin 9 may be made of a metal member, and the intermediate layer may be made of an elastic material having relatively elasticity such as urethane. If it does in this way, the bending of the heat exchanger tube 4 etc. can be absorbed by the elasticity of the elastic material, and when attaching header cover 3a, it is made to perform alignment with opening 27 easily. it can.

  In addition, this invention can be implemented in various aspects, without being limited to each said embodiment.

  For example, in each of the above embodiments, the fins 9 are configured in parallel with the layered header unit 21 and are sandwiched between the heat transfer tubes 4. However, even if the fins 9 are not present, high heat If the exchange rate can be secured, the fins 9 need not be attached.

  In the above embodiment, the two inner tubes 41 are provided inside the circular outer tube 42. However, various shapes and numbers of inner tubes are adopted for the outer tube. Can do. That is, as long as the first fluid is configured to exchange heat from the inside and the outside, it may have any shape or number.

1 ... heat exchanger 2a ... first header 2b ... second header)
3a, 3b ... header cover 4 ... heat transfer tube (41 inner tube, 42 outer tube)
8 ... Gap forming member 9 ... Fin 21 ... Header unit 22 ... Unit separator 23 ... First wall surface 25a ... Convex part 25b ... Concave part

Claims (6)

In a heat exchanger that uses a heat transfer tube having an outer tube and an inner tube, and performs heat exchange between the first fluid that flows through the gap between the outer tube and the inner tube, and the second fluid that flows in the inner tube,
A header unit that extends both ends of the inner pipe from the outer pipe, and circulates the first fluid from the outer periphery of the extending inner pipe to the gap between the outer pipe, and
A second header for allowing the second fluid to flow through the inner pipe extending from the header unit;
A plurality of the header units are provided,
Laminating the header unit and the header unit so as to have a gap,
A heat exchanger characterized in that the second fluid from the second header passes through the inside of the inner tube and also passes through the outer surface of the outer tube along the axial direction through the gap. In a heat exchanger that uses a heat transfer tube having an outer tube and an inner tube, and performs heat exchange between the first fluid that flows through the gap between the outer tube and the inner tube, and the second fluid that flows in the inner tube,
The first wall holds the vicinity of the end of the outer tube, and the second wall facing the first wall holds the inner tube extending from the outer tube, and is surrounded by the first wall and the second wall. A header unit that circulates the first fluid in a gap between the inner pipe and the outer pipe within the space,
A first inflow / exhaust part for allowing the second fluid to circulate through the inner pipe extending from the second wall surface of the header unit;
A plurality of the header units are provided,
Laminate the header unit and the header unit so as to have a gap,
A heat exchanger characterized in that the second fluid is passed from the first inflow / exhaust portion to the inside of the inner tube and also to the outer surface of the outer tube through the gap portion along the axial direction. . The heat exchanger according to claim 1 or 2, wherein the gap is formed by sandwiching a gap forming member between the header unit and the header unit to be stacked. The heat exchanger according to claim 1 or 2, wherein the gap is formed by a convex portion or a concave portion formed integrally with the header unit. The heat exchanger according to claim 1 or 2, wherein fins along the axial direction of the heat transfer tube are provided between the header unit and the heat transfer tube in the header unit. The heat according to claim 1 or 2, wherein a fin is provided between the header unit and the heat transfer tube in the header unit so as to form a gap portion between the header unit and the header unit in contact with the upper and lower heat transfer tubes. Exchanger.

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