JPH07167581A - Tube elements of lamination type heat exchanger - Google Patents

Abstract

PURPOSE:To improve tube elements, enhance the efficiency of heat exchange and further reduce the size. CONSTITUTION:The width A of beads 20, the pitch B of the beads formed in a tube element 3, the thickness H of the tube element 3, and the thickness T of a forming plate are determined in the following relational expressions: 2.0<=A<=3.0mm, 3.5mm<=B<=6.3mm, 1.9<=H<=2.7mm, 0.25mm<=T<=0.47mm. This construction makes it possible to provide the optimum tube element 3 which is well-balanced in terms of passage resistance, heat exchange efficiency and strength or the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tube element used in a laminated heat exchanger such as an evaporator, a condenser, a heater core and a radiator.

[0002]

2. Description of the Related Art In a heat exchanger in which fins and tube elements are alternately stacked, a bead is formed in the heat exchange medium passage of the tube element to increase the heat exchange efficiency, as a means for improving heat exchange efficiency. It has been considered to increase the contact area with the heat exchange medium while diffusing. The applicant of the present invention also discloses, for example, JP-A-63-1
As disclosed in Japanese Patent No. 53397, a molded plate forming a tube element is used in which a large number of round beads are integrally press-molded, and those conventionally commercialized have a bead diameter of 3.8 mm and a shortest bead pitch. 7.0
mm, the thickness of the tube element was 2.9 mm, and the thickness of the molding plate was 0.57 mm. According to the investigation by the applicant, there is no data on the shortest bead pitch for products of other companies using round beads or oval beads, but the bead diameter or the bead minor diameter is 3.5 mm to 4.8 mm, and the tube element is Had a thickness of 2.8 mm to 3.4 mm, the plate thickness of the molding plate was 0.40 mm to 0.57 mm, and the tube element of the present invention was within the above range except for the bead pitch.

[0003]

The more beads formed on the conventional tube element, the larger the contact area between the tube element and the heat exchange medium, and the higher the heat exchange efficiency. It is considered possible, but if the number of beads is simply increased, the passage area of the heat exchange medium passage is narrowed, the passage resistance increases, and the flow of the heat exchange medium deteriorates. On the contrary, if the beads are made small and small in order to reduce the passage resistance, the area in contact with the heat exchange medium cannot be gained, so the heat transfer rate to the fins is lowered and the heat exchange performance may be deteriorated. I know. However, it is necessary to meet the demands for higher performance and smaller size of the heat exchanger while considering these incompatible conditions, and further improvement of the tube element is required.

Further, for example, when a plurality of obstacles A are sequentially arranged in the traveling direction of the fluid as shown in FIG. 13, the flow of the fluid hitting a certain obstacle A is on both sides of the obstacle A. It is known that a so-called dead water region is formed by flowing without spreading and hitting the obstacle A at the rear, and the so-called dead water region is formed, and even in the bead of the conventional tube element, the dead water region is formed and does not contribute much to heat exchange. It is expected that there will be beads. In order to reduce the passage resistance, it is better not to have such a bead in the dead water region, and it is preferable to reduce the passage resistance to flow as much heat exchange medium as possible to promote heat exchange.

Further, in addition to the problem of the dead water region, the heat exchange medium tends to flow through the shortest flow path, and therefore has a U-shaped heat exchange medium passage 7 like the tube element of FIG. In the case of a thing, it tries to flow along the central ridge 10. In the conventional tube element, the beads are formed in the entire passage at a uniform density and at equal intervals.
There is no difference in the passage resistance as a whole passage, so that the heat exchange medium flows along the ridges, and a stagnant region of the heat exchange medium is formed like the upper side of the tube element.

From the above, there is room for further improvement in the bead arrangement of the tube element.

In view of the above, it is an object of the present invention to provide a tube element which can be improved in efficiency by improving the tube element and thus can downsize the heat exchanger. In addition, in addition to this, the bead arrangement of the tube element is improved while considering the point of reducing the dead water area and the point of diffusing the fluid by adjusting the passage resistance to improve the heat exchange efficiency. The challenge is to provide.

[0008]

The applicant has found that the passage resistance increases as the bead size increases, and conversely, the passage resistance decreases as the bead size decreases, but if the bead size is too small, the heat exchange performance is relatively small. Points that decrease
The smaller the bead pitch, the larger the number of beads, which increases the passage resistance. Conversely, the larger the bead pitch, the smaller the number of beads, so that the heat exchange performance relatively decreases. Also, since the heat exchange medium passage becomes narrower as the thickness becomes smaller,
The passage resistance increases, and conversely, the larger the thickness, the smaller the passage resistance, but the heat exchange performance decreases because the heat exchange medium passes without sufficient heat exchange. The better the heat transfer rate,
In consideration of the fact that the corrosion resistance and strength become poor, and if the thickness of the forming plate is increased and the tube element has the same thickness, the heat exchange medium passage becomes narrower and the passage resistance becomes larger. We have found the optimum dimensional relationship among the bead pitch, the thickness of the tube element, and the thickness of the forming plate.

That is, the fins are alternately laminated in a plurality of stages,
In a tube element of a laminated heat exchanger in which a flow path for a heat exchange medium is formed by combining two molding plates and a bead is formed to project inside the flow path, the tube element is formed in the tube element. Bead width A
And bead pitch B is 2.0 mm ≦ A ≦ 3.0 m
m, 3.5 mm ≦ B ≦ 6.3 mm.

In addition to this, the thickness H of the tube element and the plate thickness T of the molding plate are set to 1.9 mm≤H≤2.
You may make it set in the range of 7 mm and 0.25 mm <= T <= 0.47 mm.

In addition to the above structure, a large number of bead rows orthogonal to the flow path forming direction of the heat exchange medium are provided, and adjacent bead rows have different bead intervals. The beads of the adjacent bead rows may be arranged so as not to overlap when projected in the flow channel forming direction, or a large number of bead rows orthogonal to the flow channel forming direction may be arranged. The bead rows adjacent to each other may have different bead-free portions, and the bead rows of the adjacent bead rows may be continuously connected.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, a laminated heat exchanger 1 is, for example, an evaporator of, for example, a 4-pass system in which fins 2 and tube elements 3 are alternately laminated in a plurality of stages, and the tube element 3 is formed of two sheets. The plates 4 and 4 are joined together at their peripheral edges, and two tanks 5 and 5 on the upstream side and the downstream side of the air are provided on one end side, and a heat exchange medium is passed through from this tank 5 to the other end side. Each has a medium passage 7.

The molding plate 4 is formed by pressing an aluminum plate. As shown in FIG. 2, two bowl-shaped tank forming bulges 8 and 8 are formed at one end. The bulging portion 9 for forming a passage is formed while being formed, and the bulging portion 9 for forming a passage is formed on the other end of the molding plate from between the two bulging portions 8 for forming a tank. A ridge 10 extending to the vicinity is formed. A mounting recess 11 for a communication pipe, which will be described later, is provided between the two tank forming bulges 8 and 8, and the other end of the molding plate 4 is provided at the time of assembly before brazing. A protrusion 12 (shown in FIG. 1) for preventing the fin 2 from falling off is provided. Each tank forming bulge 8 bulges larger than the passage forming bulge 9, and the ridge 10 is joined to the other ridge when the forming plate 4 is joined at the peripheral edge thereof, so that heat exchange is performed. The medium passage 7 is partitioned to the vicinity of the other end of the tube element 3 to form a U-shape as a whole.

Then, the tanks 5 of the adjacent tube elements 3 are butted against each other at the tank forming bulging portions 8 of the respective molding plates 4, except for the blind tank 5a on one side located substantially in the center in the stacking direction. The tank forming bulging portion 8 communicates with each other through a communicating hole 13 formed therein.

Further, the tube element 3a at a predetermined position closer to one side from the center is not provided with the mounting recess 11, and the one tank 5b on the side having the blind tank 5a.
Has been enlarged to be closer to the other tank. A communication pipe 15 mounted in the mounting recess 11 is connected to the enlarged tank 5b. Further, of both ends in the stacking direction, an inlet / outlet portion 16 is provided at an end far from the expansion tank 5b, and this inlet / outlet portion 16 is connected to the expansion valve and a blind portion from the connection portion 17. A communication passage 18 connected to the tank on the side having the tank and a communication passage 19 connected to the communication pipe 15 are provided.

Then, one communication passage 1 of the entrance / exit portion 16
Assuming that the heat exchange medium is introduced from 9, the introduced heat exchange medium enters almost half of the tank 5 on the blind tank 5a side through the communication pipe 15 and the expansion tank 5b, and from there, the heat exchange medium passage 7 rises along the ridge 10, makes a U-turn above the ridge 10 and descends to reach the tank on the side opposite to the blind tank 5a side. After that, the remaining half of the tube element 3 is moved in parallel to the tank, and the heat exchange medium passage 7 is again moved up along the ridges 10 and is turned above the ridges 10 by making a U-turn to move down the blind tank 5a. It flows out from the tank 5 on the holding side through the communication passage 18 (see the flow in FIG. 3). Therefore, the heat of the heat exchange medium passes through the heat exchange medium passage 7
In the process of flowing through, the heat is exchanged with the air transmitted to the fins 2 and passing between the fins.

Further, the bead 2 is attached to the molding plate 4.
0 are integrally press-molded, and in the molding plate 4 shown in FIG. 2, a large number of bead rows that are perpendicular to the flow direction of the heat exchange medium flowing through the heat exchange medium passage 7 of the tube element 41 are formed, and the respective bead rows are formed. The row has a plurality of beads 20 arranged at equal intervals, and in the figure, when the n-th row is composed of four beads, the n + 1-th row has 5 beads.
The beads of the individual beads are provided so as to be repeated hereinafter, and the beads of the adjacent bead rows do not overlap when projected in the forming direction of the heat exchange medium passage 7 (vertical direction in the drawing). It is located in. Further, in every other bead row, all the beads are overlapped when projected in the formation direction of the heat exchange medium passages 7, and the beads 20 are formed with a uniform density as a whole.

As shown in FIG. 4, the bead 20 projects inward from the inner surface of the molding plate, is joined to the beads of the molding plates to be joined to each other, and forms the heat exchange medium flowing through the heat exchange medium passage 7. The heat exchange efficiency is improved. Then, the tube element 3 regards the bead from the hem portion that starts to protrude inside the molding plate 4, and defines the hem interval (hereinafter, referred to as bead size) as A, and the pitch of the closest adjacent bead (hereinafter referred to as bead pitch). B, thickness of the portion of the tube element constituting the heat exchange medium passage is H, and plate thickness of the forming plate is T, 2.0 mm ≦ A ≦ 3.0 mm, 3.5 mm ≦ B ≦
6.3 mm, 1.9 mm ≤ H ≤ 2.7 mm, 0.25 m
The relationship of m ≦ T ≦ 0.47 mm is satisfied.

For example, when round beads having a substantially truncated cone shape are arranged as shown in FIG. 2 (an enlarged view is shown in FIG. 5A), that is, in a direction perpendicular to the heat exchange medium passage forming direction. A plurality of beads at the nth stage are arranged at a predetermined interval b,
When the beads of the (n + 1) th stage are arranged so as to be equidistant from the adjacent beads of the nth stage with the predetermined distance b, the diameter of the bead hem is A and the predetermined distance b is B. Further, in the case of FIG. 5 (b) in which the bead of FIG. 5 (a) is replaced by an elliptical bead, or when the bead is arranged as shown in FIG. 5 (c), the hem portion of the bead is The minor axis is A, and the minimum distance between the centers of the beads (the part where the minor axis and the major axis intersect) is B.

Generally, the higher the heat exchange performance, the better, and the lower the passage resistance of the heat exchange medium passage 7 of the tube element 3, the better. For example, the larger the bead size A, the larger the passage resistance becomes.
Is smaller, the passage resistance is smaller, but if the bead size is too small, the heat exchange performance is relatively lowered. Also, as the bead pitch B becomes smaller, the number of beads increases, so that the passage resistance increases, and as the bead pitch B increases, the bead number decreases, so that the passage resistance becomes smaller, but the heat exchange performance is relatively high. Decrease. Also,
As for the thickness of the tube element 3, the smaller the thickness, the narrower the heat exchange medium passage 7, so that the passage resistance increases.
The larger the thickness H, the smaller the passage resistance, but the passage through which air passes becomes narrower, so the heat exchange performance deteriorates. Further, as for the thickness of the molded plate, the thinner the thickness, the wider the width of the heat exchange medium passage 7, so that the heat exchange performance is improved. However, when the thickness of the molded plate is reduced, there is a problem in strength and corrosion resistance. On the contrary, if the plate thickness is made thicker, the heat exchange medium passage 7 becomes narrower, so that the passage resistance becomes larger. from these things,
Excluding the plate thickness of the molded plate, the ratio of the heat exchange performance and the passage resistance can be used as an index for evaluating the tube element 3.

Therefore, the heat exchange performance / passage resistance may be used as the vertical axis, and the bead size, bead pitch, and tube element thickness may be evaluated as the horizontal axis. These are shown in FIG. 2.5 mm, bead pitch 4.8 mm, tube element thickness 2.
The index (heat exchange performance / passage resistance) in the state of 4 mm is 100.

In the bead size, as shown in FIG. 6 (a), the index decreases when the size is smaller or larger than 2.5 mm, but the smaller the size, the more difficult the processing becomes and the lower the performance. Therefore, it is necessary to secure A ≧ 2 mm. Also, the larger the bead size, the greater the passage resistance, and if the conventional bead size is increased to 3.8 mm, a good index cannot be obtained. From this, if the upper limit of the bead size is set with an index equal to or lower than the lower limit of the bead size as a guide, A ≦
It becomes 3.0 mm.

Further, as shown in FIG. 6 (b), the bead pitch becomes lower when the pitch is smaller than 4.8 mm or larger, but a good index is obtained in the pitch range of 3.5 mm to 6.3 mm. Is obtained. The smaller B is, the more difficult it is to process and the passage resistance is significantly increased. Therefore, it is necessary to set B to 3.5 mm or more. With a certain processing margin, B is set to 3.8 mm or more. Is preferred. Also, as B increases, the passage resistance decreases, but the heat exchange performance deteriorates. Therefore, set the upper limit of the bead pitch based on an index equal to the lower limit value of the bead pitch (3.5 mm) or a better index. Then, B is 6.3.
If the upper limit of the bead pitch is set with an index equal to or less than 3.8 mm or an index better than 3.8 mm as a guide,
It will be 8 mm or less.

Next, the tube element is shown in FIG. 6 (c).
As shown in, the index decreases when the thickness H is smaller or larger than 2.4 mm, but the smaller the thickness, the more difficult the processing becomes and the lower the performance. Therefore, H ≧ 1.9.
It is necessary to secure mm, and it is preferable that H ≧ 2 mm with a certain processing margin. Also, it has been found that the larger the thickness H, the smaller the passage resistance and the smaller the heat exchange efficiency. Therefore, the upper limit of the thickness H is set with an index equal to the lower limit value of the thickness or a better index. If so, H ≦ 2.7 mm, preferably H ≦ 2.6 m
m.

By the way, in the molded plate, as described above, it is necessary to set the optimum plate thickness T from the relationship between the strength and corrosion resistance of the molded plate and the passage resistance, and the lower limit is set in consideration of strength and corrosion resistance. It is necessary to satisfy T ≧ 0.25 mm, and it is desirable that the upper limit is T ≦ 0.47 mm in consideration of deterioration of heat exchange performance due to increase in passage resistance.

Therefore, the tube element obtained in the above range is the best obtained by considering both the improvement of heat exchange efficiency and the reduction of passage resistance, and further the strength and the like. A heat exchanger smaller and lighter than a heat exchanger using an element can be provided.

FIG. 7 shows another example (second embodiment) of the molding plate 4 constituting the tube element 3, and the beads 20 are a large number of bead rows orthogonal to the forming direction of the heat exchange medium passages 7. The adjacent bead rows have different bead intervals. In this embodiment, assuming that five beads are provided on the n-step surface at equal intervals L1, three beads are provided on the n + 1-th step at equal intervals L2, and n + 2 steps. The five beads with the interval L1 are again in the eye, and the interval L2 is in the n + 3th row.
The bead row at the interval L1 and the bead row at the interval L2 are repeatedly formed, such as the three beads. Moreover, the distance L2 is twice as large as the distance L1.

Each bead 20 in the adjacent bead row is
The heat exchange medium passages 7 are arranged so that they do not overlap when projected in the forming direction of the heat exchange medium passages 7 (vertical direction in the figure). In this embodiment, the closest bead of one bead to the next row is the heat exchange medium. The beads are arranged so as to be inclined at 30 degrees with respect to the passage forming direction, and even when viewed in the 30 degrees direction, bead groups arranged at intervals a and bead groups arranged at intervals b. A regular pattern in which and appear alternately is formed.

As still another embodiment (third embodiment) of the molded plate 4 constituting the tube element 3, as shown in FIG. 8, in adjacent bead rows orthogonal to the direction in which the heat exchange medium passages 7 are formed. , A region where no bead 20 is formed is different, and a region where no bead is formed in an adjacent bead row is connected to form a passage 2 where no bead exists.
1 may be formed in a direction different from the direction in which the heat exchange medium passage 7 is formed. In this embodiment, the bead 2 is inclined in a direction inclined by 30 degrees with respect to the direction in which the heat exchange medium passage 7 is formed, as compared with the conventional tube element in which beads are evenly formed.
Areas where 0 is not formed are connected continuously.

Therefore, in each of the second and third embodiments, the bead in the dead water region is reduced, so that the region having a small passage resistance is provided in the entire heat exchange medium passage 7 without impairing the heat exchange efficiency. The heat exchange medium can be formed to promote the flow of the heat exchange medium to the region having a small passage resistance, and the heat exchange medium can be spread over the entire tube element without stagnating, and conversely, the heat exchange efficiency can be improved.

To evaluate the tube element having the above bead arrangement in comparison with the tube element in which the beads are arranged at a uniform density, the present applicant tried the following experiment.

A tube element of the type shown in FIG. 2 in which beads are arranged at a uniform density (hereinafter referred to as type 1), a tube element of the second embodiment (hereinafter referred to as type 2), and a tube element of the third embodiment ( Less than,
9), as shown in FIG. 9, a heat generating plate 22 is attached to one entire surface of one of the passage forming bulging portions 9 by using a silicon adhesive, and a heat insulating material is provided so as to cover the entire surface. 30 is provided, an AC power source is connected to the heat generating plate 22, and a certain amount of heat is applied to each tube element 4,
Heat evenly. And a certain amount of tap water is 500
It is supplied to the tube element 4 through the inlet pipe 23 of mm, guided from one tank to the other tank through the heat exchange medium passage, and discharged from the outlet pipe 24. The tap water supplied from the inlet pipe 23 is detected by the flow meter 25, and is 5cc / sec, 10cc / sec, 20cc / s.
The surface temperature of each tube element was measured by changing the flow rates of ec and tap water. The result is shown in FIG.
Through thermographics in FIG. The numbers in FIGS. 10 to 12 represent temperatures (° C.).

In addition, tap water 5cc / sec, 10cc / sec, 2
Instead of 0 cc / sec, thermocouples 26, 2 provided at the inlet and outlet of the tube element 4 in each case
7, the temperature reading device 28 causes the water temperature difference between the inlet and the outlet (°
C) was measured. The results are shown in Table 1.

[0035]

[Table 1]

The inlet static pressure hole 31 formed in the inlet pipe 23 and the outlet static pressure hole 3 formed in the outlet pipe 24.
The pressure at the inlet and outlet of the tube element 4 was measured via the pressure gauge 33 to determine the water resistance (mmHg) of the tube element 4. The results are shown in Table 2.

[0037]

[Table 2]

Further, in order to see how the heat exchange varies in the direction perpendicular to the direction in which the heat exchange medium passage 7 is formed, the surface of the tube element 4 (the surface opposite to the side provided with the heat generating plate). The average of the temperature difference (° C) in the direction perpendicular to the flow direction of the fluid was measured by the thermocouple group 29 provided at a predetermined plurality of places (24 places). The results are shown in Table 3.

[0039]

[Table 3]

With respect to the temperature difference between the inlet and outlet, the larger the value, the more active the heat exchange. According to the experimental results, both type 2 and type 3 are type 1.
Is almost the same as or slightly larger than 5 cc / sec or 20
For a flow rate of cc / sec, Type 1 has a larger temperature difference than Type 2.

In terms of water resistance, Type 2 and Type 3
Even at 5cc / sec, it became larger than Type 1, but 10cc
In view of the fact that the flow rates of / cc and 20 cc / sec are smaller than Type 1 and the actual flow velocity in the heat exchanger is around 10 cc / sec, it can be considered that the passage resistance has decreased in both cases. Further, the type 3 has a smaller water flow resistance than the type 2.

Further, if the isothermal lines in FIGS. 10 to 12 are horizontal (right angle to the heat exchange medium passage) or the temperature difference is smaller as seen from Table 3, heat is uniformly exchanged. It is desirable that Type 2 and Type 3 are both superior to Type 1.

Therefore, these experimental data show that Type 2 and Type 3 have better heat exchange characteristics even though the number of beads is smaller than Type 1, and these Type 2 It can be said that the tube elements of Nos. 3 and 3 have a bead arrangement in which the bead in the dead water area is reduced and the heat exchange medium is spread over the entire passage without stagnating, as compared with the type 1.

From this fact, the bead size A, the closest adjacent bead pitch B, the thickness H of the tube element, and the plate thickness T of the forming plate are 2.0 mm ≦.
A ≦ 3.0 mm, 3.5 mm ≦ B ≦ 6.3 mm, 1.9
mm ≦ H ≦ 2.7 mm, 0.25 mm ≦ T ≦ 0.47 m
When the bead is thinned out as shown in FIG. 7 or FIG. 8 after satisfying the relation of m, the thinned portion deviates from the above dimensional relation. The heat exchange performance can be further improved by further enhancing the effect of thinning the beads.

Although the tube element used for the evaporator has been described in this embodiment, the tube element under the same condition may be used for a laminated heat exchanger such as a heater core, a condenser and a radiator. However, it goes without saying that higher efficiency and smaller size can be achieved. Further, the present invention can be similarly applied regardless of whether the tank portion is integrally formed with the tube element or a separate tank portion is attached.

[0046]

As described above, according to the inventions of claims 1 and 2, the width A of the bead formed on the tube element, the pitch B of the bead, or in addition to this, the thickness of the tube element. H, plate thickness T of forming plate
Since the optimum dimensional relationship of is determined, it is possible to provide an optimal tube element in which heat exchange efficiency, passage resistance, strength, etc. are balanced, and a highly efficient heat exchanger can be provided.
It is possible to reduce the size of the heat exchanger.

Further, according to the invention of claim 3, the bead intervals of the adjacent bead rows are made different, and the beads of the adjacent bead rows are arranged so as not to overlap when projected in the passage forming direction. According to the invention of claim 4, the bead rows of the adjoining bead rows are made different from each other, and the bead rows of the adjoining bead rows are made to be continuous. It is possible to provide a bead arrangement that reduces the dead water area and passage resistance, although it is outside the optimum size range by looking at the thinned part, and spreads the heat exchange medium throughout to eliminate stagnation, and consequently thins the bead. In addition, the heat exchange efficiency can be further increased. That is, according to claim 3 or 4, it is possible to provide a tube element having both an optimum bead shape and an optimum bead arrangement at the same time.

[Brief description of drawings]

FIG. 1 shows an embodiment of a laminated heat exchanger,
(A) is a front view of a heat exchanger, (b) is a bottom view.

FIG. 2 is a front view of a forming plate (type 1) constituting a tube element used in the laminated heat exchanger of FIG.

FIG. 3 is an explanatory diagram illustrating a flow of a heat exchange medium of the laminated heat exchanger of FIG.

FIG. 4 is an enlarged sectional view showing a bead of a tube element.

5 (a), (b), and (c) are explanatory diagrams showing the relationship between the bead shape formed on the tube element and the bead size A and bead pitch B. FIG.

FIG. 6 (a) is a characteristic diagram showing changes in the ratio of heat exchange performance and passage resistance when the bead size is changed, FIG.
6B is a characteristic diagram showing a change in the ratio of heat exchange performance and passage resistance when the bead pitch is changed, and FIG.
It is a characteristic diagram which shows the change of the ratio of heat exchange performance and passage resistance when changing the thickness of a tube element.

FIG. 7 is a diagram showing an example of a molded plate (type 2) used for a tube element of a laminated heat exchanger.

FIG. 8 is a view showing another example of a molded plate (type 3) used for the tube element of the laminated heat exchanger.

FIG. 9 is a diagram showing an experimental apparatus for evaluating the performance of a tube element.

[Fig. 10] Fig. 5 is a thermograph of a tube element when the flow rate of tap water is 5 cc / sec.
(A) shows a type 1 tube element, (b) shows a type 2 tube element, and (c) shows a type 3 tube element.

FIG. 6 is a thermograph of the tube element when the flow rate of tap water is 10 cc / sec,
(A) shows a type 1 tube element, (b) shows a type 2 tube element, and (c) shows a type 3 tube element.

FIG. 12 is a thermographic view of a tube element when the flow rate of tap water is 20 cc / sec,
(A) shows a type 1 tube element, (b) shows a type 2 tube element, and (c) shows a type 3 tube element.

FIG. 13 is an explanatory diagram showing a fluid flow when an obstacle is present.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Laminated heat exchanger 2 Fins 3 Tube element 4 Forming plate 7 Heat exchange medium passage 20 Bead

Claims (4)

[Claims] 1. A laminated type in which fins are alternately laminated in a plurality of stages, two molding plates are combined to form a flow path for a heat exchange medium, and a bead is formed to project inside the flow path. In the tube element of the heat exchanger, the width A of the bead formed on the tube element and the pitch B of the bead satisfy the relationship of 2.0 mm ≦ A ≦ 3.0 mm 3.5 mm ≦ B ≦ 6.3 mm. A tube element for a laminated heat exchanger, which is characterized in that 2. A laminated type in which fins are alternately laminated in a plurality of stages, two molding plates are combined to form a flow path for a heat exchange medium, and a bead is formed to project inside the flow path. In the tube element of the heat exchanger, the width A of the bead formed on the tube element, the bead pitch B, the thickness H of the tube element, and the plate thickness T of the forming plate are 2.0 mm ≦ A ≦ 3. 0.0 mm 3.5 mm ≤ B ≤ 6.3 mm 1.9 mm ≤ H ≤ 2.7 mm 0.25 mm ≤ T ≤ 0.47 mm A tube element of a laminated heat exchanger characterized by the following: 3. A plurality of bead rows that are orthogonal to the flow path of the heat exchange medium are provided in the formation direction of the heat exchange medium, and the adjacent bead rows have different bead intervals, and the bead rows of the adjacent bead rows are different from each other. The tube element of the laminated heat exchanger according to claim 1 or 2, wherein the tube elements are arranged so as not to overlap when projected in the forming direction of the flow path. 4. A plurality of bead rows that are orthogonal to the flow path of the heat exchange medium are provided in the direction in which the heat exchange medium is formed, and each adjacent bead row is different in a portion where no bead is formed. The tube element of the laminated heat exchanger according to claim 1 or 2, wherein a portion of the row where the beads are not formed is continuous.