JP2005321137A - Heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To actualize uniform temperature distribution on the whole surface of a core portion 2 even when hot water flows at an extremely low rate. <P>SOLUTION: A fluid passage in one upper side header tank 5 is formed in a double layer structure in the longitudinal direction of tubes 3, where a fluid inflow portion 7 and a fluid outflow portion 8 are provided in one outside fluid passage 5A and in the other inside fluid passage 5B, respectively. The tubes 3 are of two long and short types, and one long tube 3A communicates the outside fluid passage 5A with a turn-around fluid passage 6A in the other lower side header tank 6 and the other short tube 3B communicates the inside fluid passage 5B with the turn-around fluid passage 6A. The long tube 3A and the short tube 3B are approximately alternately arranged in the layering direction. The whole core portion 2 is divided into small blocks to wholly uniform a blow-off temperature even when a slight temperature gradient occurs in each U-turn portion. This actualizes uniform temperature distribution on the whole surface of the core portion 2 even when hot water flows at an extremely low rate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat exchanger suitable for use in a heater core of a vehicle air conditioner, and more particularly, to a heat exchanger configured with a tube and a header tank to achieve uniform temperature over the entire core portion. .

  Conventionally, in a vehicle air conditioning system of a reheat method (heating after cooling and dehumidifying air) adopted mainly by European carmakers, it is desirable that the blowing temperature of the heater core that heats the air be uniform over the entire surface. ing. The heater core used in this case often employs a front-rear U-turn flow heat exchanger.

  As a heat exchanger of this front-rear U-turn flow, a flat tube that forms a U-shaped channel in the front-rear direction of ventilation, a core portion that is formed by alternately laminating a plurality of corrugated fins, and a U-shaped flat tube A front and rear U-turn type (for example, a heater core described in Patent Document 1) provided with two tanks forming tank chambers connected to both ends of the mold flow path and a fluid inflow / outflow portion provided on the side surface of the tank. Proposed.

  FIG. 5 is a front view showing a heat exchanger 1 according to an embodiment of the prior art (Patent Document 1), and FIG. 6 is a schematic perspective view illustrating the flow of hot water in the heat exchanger 1 of FIG. A plurality of tubes 3 and corrugated fins 4 through which hot water circulates are alternately stacked in one direction, and air flows from outside the tubes 3 by flowing in from the direction substantially perpendicular to the longitudinal direction and the stacking direction of the tubes 3. The core part 2 which performs heat exchange between the hot water flowing through the tube 3 is formed.

  The tubes 3 are formed along the stacking direction and connected to both ends of the tubes 3 in the longitudinal direction to communicate with the inside. The hot water is distributed and supplied to the tubes 3, and the hot water flowing out from the tubes 3 is collected and recovered. Upper and lower header tanks 5 and 6 are provided. The tank portion in one upper header tank 5 is partitioned into two in the front-rear direction, and one inflow side tank portion 5A is further partitioned at the center by a separator 9, and fluid inflow portions 7A are provided at both ends. -7B is provided. Further, a fluid outflow portion 8 is provided in the other outflow side tank portion 5B.

Further, the fluid passage in the other lower header tank 6 is also partitioned at the center by the separator 9 to form left and right folded tank portions 6A. The warm water flows in from the fluid inflow portions 7A and 7B on both side surfaces of the inflow side tank portion 5A, descends the tubes 3a serving as a plurality of first paths communicating with the inflow side tank portion 5A, and the folded tank of the lower header tank 6 It reaches the section 6A, and this time, the tubes 3b serving as a plurality of second passes are raised and gathered in the outflow side tank section 5B, and flow out from the fluid outflow section 8.
JP 2003-106788 A

  As described above, the front-rear U-turn heat exchanger as described above is usually used when a uniform blowing temperature is required on the entire surface. However, when the flow rate of warm water is low, the temperature may not always be uniform. FIG. 7 is an isotherm diagram showing an example of the temperature distribution in the core 2 in the hot water flow of FIG. As shown in this figure, there is a problem that a temperature gradient is likely to occur because the flow rate of hot water is very low in the reheat control region.

  This is because a slight variation in the flow rate distribution at a low flow rate results in a variation in the amount of hot water flowing through the tube, which greatly affects the variation in the blowing temperature. The present invention has been made in view of the problems of the prior art, and an object of the present invention is to provide a heat exchanger that can obtain a uniform temperature distribution over the entire core portion even when the hot water flow is extremely low. is there.

In order to achieve the above object, the present invention employs technical means described in claims 1 to 4. That is, in the first aspect of the present invention, a plurality of tubes (3) through which a fluid flows are stacked in one direction, and the tubes (3) flow in from the longitudinal direction and the direction substantially perpendicular to the stacking direction. A core portion (2) that performs heat exchange between an external fluid that flows outside the tube (3) and an internal fluid that flows inside the tube (3), and is formed along the stacking direction of the tubes (3). First and second headers connected to both ends in the longitudinal direction of a plurality of tubes (3) to communicate with the inside, distribute and supply fluid to the tubes (3), and collect and collect fluids flowing out from the tubes (3) In a heat exchanger with tanks (5, 6),
The fluid passage in one of the first header tanks (5) has a two-layer structure in the longitudinal direction of the tube (3), the fluid inflow portion (7) and the other second fluid in the one first fluid passage (5A). The passage (5B) is provided with a fluid outflow portion (8), and the tube (3) is made into two types of long and short. One of the first tubes (3A) is composed of the first fluid passage (5A) and the other second header tank ( 6) The folded fluid passage (6A) and the other second tube (3B) are provided so as to communicate the folded fluid passage (6A) and the second fluid passage (5B), and further the first tube (3A). And the second tubes (3B) are arranged approximately alternately in the stacking direction.

  This is because the fluid passage in one of the first header tanks (5) has a two-layer structure, and by combining the long first tube (3A) and the short second tube (3B), the core portion (2) The local left and right U-turns are formed and a large number of these are arranged to make the blowing temperature uniform over the entire surface of the core part (2). That is, by dividing the entire core portion (2) into small blocks, even if a slight temperature gradient of the blowing temperature occurs in each U-turn portion, the entire core portion (2) is aimed to be uniformized.

  According to the first aspect of the present invention, the temperature distribution on the entire surface of the core portion (2) can be made uniform even when the hot water flow is extremely low. In addition, the structure of the present invention has no separator because the temperature distribution can be made uniform without partitioning the inflow side tank section at the center with a separator and flowing in warm water from both ends as in the conventional structure described above. The manufacturing cost can be reduced, and problems such as internal leakage caused by inserting a separator in the tank can be eliminated.

  In the invention according to claim 2, the fluid passages (5A, 5B, 6A) are partitioned by the partition member (9) at substantially the center in the stacking direction, and on both sides of the first fluid passage (5A) in the stacking direction. The first and second fluid inflow portions (7A, 7B) are provided, and the fluid outflow portion (8) is provided at a substantially central partition position in the stacking direction of the second fluid passage (5B).

  According to the second aspect of the present invention, the temperature difference between the left and right can be eliminated. Alternatively, by adjusting the flow rate of hot water between the left and right halves corresponding to the vehicle air conditioner with independent left and right temperature control, it is possible to adjust to different blowout temperatures, and as separate temperature settings for the left and right Also, the temperature can be made uniform on each half.

  Further, the invention described in claim 3 is characterized in that the ratio and arrangement of both tubes (3A, 3B) are changed in the whole area or a part in the stacking direction. According to the third aspect of the present invention, the distribution of the blowing temperature can be arbitrarily varied by changing the ratio and arrangement of both the tubes (3A, 3B) even in the same-sized core portion (2).

  For example, when the hot water has a low flow rate, the heat exchange ends in the middle of the first tube (3A) that is normally the first pass. Therefore, by changing the arrangement of the tubes to reduce the ratio of the first tube (3A) serving as the first path and increasing the ratio of the second tube (3B) serving as the second path, heat exchange is uniformly performed in both paths. Will be able to.

  Further, the first tube (3A) serving as the first pass is disposed in a portion where the blowing temperature is desired to be relatively high, and conversely, the second tube (3B) serving as the second pass is located in the portion where the blowing temperature is desired to be relatively low. ), It is possible to generate a temperature gradient as intended.

  Further, the invention according to claim 4 is characterized in that a large flow passage (10) is provided in a part of both the tubes (3A, 3B). According to the fourth aspect of the present invention, the hot water is directly bypassed into the second header tank (6) on the lower side using the large flow passage (10) provided in an arbitrary portion. As a result, the distribution of the blowing temperature can be arbitrarily varied. Incidentally, the reference numerals in parentheses of the above means are examples showing the correspondence with the specific means described in the embodiments described later.

(First embodiment)
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1: shows the heat exchanger 1 in 1st Embodiment of this invention, (a) is a perspective schematic diagram, (b) is the fragmentary sectional view of the AA direction in (a), (c) is (a It is sectional drawing of a BB direction. The heat exchanger 1 of the present embodiment is used, for example, in a heater core of a vehicle air conditioner, and exchanges heat between engine cooling water heated by an engine water jacket and air blown into the vehicle interior of the vehicle. It heats the air.

  The heat exchanger 1 is formed in a predetermined shape using a metal material such as an aluminum alloy, for example. The heat exchanger 1 is roughly divided into a core portion 2 that performs heat exchange between engine coolant and air, and the core portion 2 is illustrated in the drawing. The upper header tank (first header tank) 5 and the lower header tank (second header tank) 6 connected to the upper and lower end portions of the upper and lower ends are manufactured by integral brazing.

  As one of the features of the present invention, the fluid passage in one upper header tank 5 has a two-layer structure in the longitudinal direction (vertical direction in the drawing) of the tube 3. Specifically, as shown in the partial cross-sectional view of FIG. 1B, a first (inner side) that forms a conventional tank space on a sheet metal 51 having a tube insertion hole 51a into which an end of the tube 3 is inserted. ) A two-layer structure is formed by placing a capsule 52 and covering a second (outer) capsule 53 that forms another tank space thereon.

  An inlet pipe 7 is provided as a fluid inflow portion in one outer fluid passage (first fluid passage) 5A, and an outlet pipe 8 is provided as a fluid outflow portion in the other inner fluid passage (second fluid passage) 5B. Further, in the other lower header tank 6, one folded fluid passage 6 </ b> A is formed. Although not specifically shown, like the sheet metal 51 and the first capsule 52 of the upper header tank 5, the sheet metal is formed. 61 and a capsule 62. The sheet metal 51, 61 and the capsules 52, 53, 62 are made of an aluminum alloy material (cladding material) coated with a brazing material on one side and both sides.

  Next, the core part 2 is configured by alternately stacking a plurality of tubes 3 and corrugated fins 4. The plurality of tubes 3 are flat flow channel tubes that exchange heat between the engine coolant flowing inside and the air passing between the two adjacent tubes 3. The header tanks 5. 6 are stacked in the longitudinal direction. Further, as one of the features of the present invention, the tube 3 is of two types, long and short.

  One long tube (first tube) 3A is provided to communicate the outer fluid passage 5A in the upper header tank 5 with the folded fluid passage 6A in the lower header tank 6, and the other short tube (first tube) 3A. 2 tube) 3B is provided so that the folded fluid passage (6A) and the inner fluid passage 5B in the upper header tank 5 communicate with each other. Therefore, a tube insertion hole 52a into which only the end of the long tube 3A is inserted is formed in the first capsule 52 of the upper header tank 5 described above. And as one of the characteristics of this invention, the long tube 3A and the short tube 3B are alternately arrange | positioned in the lamination direction.

  The plurality of corrugated fins 4 are joined to the tubes 3 using joining means such as brazing while being sandwiched between the two adjacent tubes 3, and the engine cooling water flowing in the tubes 3 and the adjacent 2 The heat exchange efficiency with the air passing between the two tubes 3 is improved. In addition, the corrugated fin 4 of this embodiment is obtained by bending a band-like and extremely thin plate material (for example, a metal plate such as an aluminum alloy) into a corrugated shape.

  Next, for example, a method for assembling the heat exchanger 1 used in the heater core of the vehicle air conditioner will be briefly described with reference to FIG. First, the upper and lower ends of the plurality of tubes 3A and 3B are inserted into oval tube insertion holes 51a and 61a formed in a large number in the sheet metal 51 and 61, and between two adjacent tubes 3A and 3B. The core part 2 of the heat exchanger 1 is configured by temporarily assembling the corrugated fins 4. Next, the first capsule 52 and the second capsule 53 are fitted to the upper sheet metal 51 in the figure, and the capsule 62 is fitted to the lower sheet metal 61 in the figure.

  Furthermore, the connection side portions of the inlet pipe and the outlet pipe are inserted into the first capsule 52 and the second capsule 53. Thus, the temporary assembly of the heat exchanger 1 in which the header tanks 5 and 6 are installed at the upper and lower ends of the core portion 2 in the drawing and the two inlet / outlet pipes are connected to both side surfaces of the header tank 5 is completed. Next, the heat exchanger 1 is put in a furnace and heated at a temperature equal to or higher than the melting temperature of the brazing material, whereby each joint portion of the heat exchanger 1 is brazed and the heat exchanger 1 is manufactured.

  Next, for example, the fluid flow in the heat exchanger 1 used in the heater core of the vehicle air conditioner will be briefly described with reference to FIG. The engine coolant warmed by the engine water jacket flows into the outer fluid passage 5 </ b> A in the upper header tank 5 from the inlet pipe 7 attached to the side surface of the upper header tank 5. And it flows in from the upper end of several long tube 3A connected to the outer fluid channel | path 5A, and goes to the return fluid channel | path 6A of the lower header tank 6 (1st path | pass).

  Next, it flows in from the lower end of the short tube 3B through the folded fluid passage 6A and heads toward the inner fluid passage 5B of the upper header tank 5 (second pass). Then, it flows on both sides of the tube 3 in the inner fluid passage 5B, flows out from the outlet pipe 8 attached to the other side surface of the upper header tank 5, and flows toward the water jacket of the engine. Thus, when flowing through the plurality of tubes 3A and 3B, the engine cooling water exchanges heat with the air passing between the two adjacent tubes 3 to heat the air. As a result, the passenger compartment of the vehicle is heated.

Next, features and effects of this embodiment will be described. A plurality of tubes 3 in which a fluid flows are stacked in one direction, and the inside of the tube 3 and the external fluid flowing from outside the tube 3 by flowing in from the direction substantially perpendicular to the longitudinal direction and the stacking direction of the tubes 3. The core 2 that exchanges heat with the flowing internal fluid and the tubes 3 are formed along the stacking direction of the tubes 3 and connected to both ends in the longitudinal direction of the plurality of tubes 3 to communicate with the inside. In a heat exchanger provided with upper and lower header tanks 5 and 6 for collecting and collecting fluid flowing out from the tube 3 while distributing and supplying,
The fluid passage in one upper header tank 5 has a two-layer structure in the longitudinal direction of the tube 3, and an inlet pipe 7 is provided in one outer fluid passage 5A and an outlet pipe 8 is provided in the other inner fluid passage 5B. The long tube 3A is connected to the outer fluid passage 5A and the folded fluid passage 6A in the other lower header tank 6, and the other short tube 3B is connected to the folded fluid passage 6A and the inner fluid passage 5B. Further, the long tubes 3A and the short tubes 3B are arranged substantially alternately in the stacking direction.

  This is because the fluid passage in one upper header tank 5 has a two-layer structure, and by combining the long tube 3A and the short tube 3B, a local left and right U-turn is formed in the core portion 2, By arranging a large number, the blowout temperature is made uniform over the entire surface of the core part 2. That is, by dividing the entire core portion 2 into small blocks, even if a slight temperature gradient of the blowing temperature occurs in each U-turn portion, the entire core portion 2 is aimed to be uniformized.

  According to this, even if the hot water flow is an extremely low flow rate, the temperature distribution on the entire surface of the core portion 2 can be made uniform. In addition, the structure of the present invention has no separator because the temperature distribution can be made uniform without partitioning the inflow side tank section at the center with a separator and flowing in warm water from both ends as in the conventional structure described above. The manufacturing cost can be reduced, and problems such as internal leakage caused by inserting a separator in the tank can be eliminated.

(Second Embodiment)
FIG. 2 is a cross-sectional view showing the heat exchanger 1 in the second embodiment of the present invention. The difference from the above-described embodiment is that each of the fluid passages 5A, 5B, and 6A is partitioned by a separator (partition member) 9 at a substantially center in the stacking direction, and the left inlet pipe (first (Fluid inflow portion) 7A and a right inlet pipe (second fluid inflow portion) 7B are provided, and an outlet pipe 8 is provided at a substantially central partition position in the stacking direction of the inner fluid passage 5B.

  According to this, the temperature difference between left and right can be eliminated. Alternatively, by adjusting the flow rate of hot water between the left and right halves corresponding to the vehicle air conditioner with independent left and right temperature control, it is possible to adjust to different blowout temperatures, and as separate temperature settings for the left and right Also, the temperature can be made uniform on each half. Note that the separator 9 may not be integrated as shown in FIG.

(Third embodiment)
FIG. 3 is a cross-sectional view showing the heat exchanger 1 in the third embodiment of the present invention. The difference from the above-described embodiment is that the ratio of both tubes 3A and 3B is changed in the entire region in the stacking direction. According to this, even in the core part 2 having the same size, the distribution of the blowing temperature can be arbitrarily varied by changing the ratio of both the tubes 3A and 3B.

  For example, when the hot water has a low flow rate, the heat exchange ends in the middle of the first tube 3A that is normally the first pass. Therefore, in the embodiment shown in FIG. 3, by changing the arrangement of the tubes, the ratio of the long tubes 3A serving as the first path is reduced, and the ratio of the short tubes 3B serving as the second path is increased, so that the heat is uniformly distributed in both paths. It can be exchanged.

  Although not shown, the long tube 3A serving as the first pass is disposed at a portion where the blowing temperature is desired to be relatively high, and conversely, the short tube 3B serving as the second pass is disposed at a portion where the blowing temperature is desired to be relatively low. By arranging them in such a manner, a temperature gradient can be generated as intended. Such a variable may be performed only in a part in the stacking direction.

(Fourth embodiment)
FIG. 4 is a cross-sectional view showing the heat exchanger 1 in the fourth embodiment of the present invention. The difference from the above-described embodiment is that a large flow passage 10 is provided in a part of both the tubes 3A and 3B. According to this, the distribution of the blowing temperature can be arbitrarily varied by using the large flow passage 10 provided in an arbitrary portion and allowing the hot water to directly flow into the lower header tank 6 and flow in. it can.

(Other embodiments)
In the above-described embodiment, the example in which the present invention is used for the heater core of the vehicle air conditioner has been described. The heat exchanger may be used for other purposes. In the above-described embodiment, the outer fluid passage 5A is made to flow from the left and right sides as the inflow side, and the inner fluid passage 5B is made to flow out from the center portion as the outflow side. 5A may be used as the outflow side, or may be a flow method in which the flow is caused to flow in from the center and flow out to the left and right sides.

For example, in the embodiment of FIG. 2, when the inner fluid passage 5B is the inflow side and the outer fluid passage 5A is the outflow side, problems such as the tube 3 becoming a problem in the initial fluid distribution remain, but the outlet pipe 8 Is simply attached to the second capsule 53, and the position of the outlet pipe 8 need not be the partition position. Further, since the outer fluid passage 5A on the outflow side can omit the partition portion, the separator portion can be simplified.

The heat exchanger 1 in 1st Embodiment of this invention is shown, (a) is a perspective schematic diagram, (b) is the fragmentary sectional view of AA direction in (a), (c) is B- in (a). It is sectional drawing of a B direction. It is sectional drawing which shows the heat exchanger 1 in 2nd Embodiment of this invention. It is sectional drawing which shows the heat exchanger 1 in 3rd Embodiment of this invention. It is sectional drawing which shows the heat exchanger 1 in 4th Embodiment of this invention. It is a front view which shows the heat exchanger 1 in one conventional embodiment. It is a perspective schematic diagram explaining the flow of the warm water in the heat exchanger 1 of FIG. It is an isotherm figure which shows an example of the temperature distribution in the core part 2 in the warm water flow of FIG.

Explanation of symbols

2 ... Core part 3 ... Tube 3A ... Long tube (first tube)
3B ... Short tube (second tube)
5. Upper header tank (first header tank)
5A: outer fluid passage (first fluid passage)
5B ... Inner fluid passage (second fluid passage)
6 ... Lower header tank (second header tank)
6A: Folded fluid passage 7: Inlet pipe (fluid inflow part)
7A ... Left inlet pipe (first fluid inflow part)
7B ... Right inlet pipe (second fluid inflow part)
8 ... Outlet pipe (fluid outflow part)
9 ... Separator (partition member)
10 ... Large flow passage

Claims (4)

A plurality of tubes (3) through which a fluid flows are stacked in one direction, and flow from outside the tubes (3) by flowing in from the longitudinal direction of the tubes (3) and a direction substantially perpendicular to the stacking direction. A core (2) for exchanging heat between an external fluid and an internal fluid flowing in the tube (3);
The tube (3) is formed along the stacking direction, is connected to both ends in the longitudinal direction of the plurality of tubes (3) and communicates with the inside, distributes and supplies the fluid to the tube (3), and In the heat exchanger comprising first and second header tanks (5, 6) for collecting and collecting the fluid flowing out from the tube (3),
The fluid passage in one of the first header tanks (5) has a two-layer structure in the longitudinal direction of the tube (3), the fluid inflow portion (7) and the other first fluid passage (5A) A fluid outflow part (8) is provided in the two fluid passage (5B), and
The tube (3) is of two types, long and short. One of the first tubes (3A) is the first fluid passage (5A) and the other folded fluid passage (6A) in the second header tank (6), The second tube (3B) is provided to communicate the folded fluid passage (6A) and the second fluid passage (5B);
Further, the heat exchanger is characterized in that the first tubes (3A) and the second tubes (3B) are arranged substantially alternately in the stacking direction.   Each of the fluid passages (5A, 5B, 6A) is partitioned by a partition member (9) at substantially the center in the stacking direction, and the first and second fluids flow into both sides of the first fluid passage (5A) in the stacking direction. The part (7A, 7B) is provided, and the fluid outflow part (8) is provided at the partition position substantially at the center in the stacking direction of the second fluid passage (5B). Heat exchanger.   The heat exchanger according to claim 1 or 2, wherein a ratio and an arrangement of the two tubes (3A, 3B) are changed in the whole area or a part in the stacking direction.   The heat exchanger according to claim 1 or 2, wherein a large flow passage (10) is provided in a part of the row of both the tubes (3A, 3B).

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