KR100228503B1 - Tube element for laminated heat exchanger - Google Patents

Abstract

Bead width A, bead spacing B, tube element thickness H and forming plate thickness T are 2.0 A 3.0 , 3.5 B 6.3 , 1.9 H 2.7 , 0.25 T 0.47 Is determined to be within range.

Within this range, it is possible to provide an ideal tube element with an optimal balance of passage resistance, heat exchange performance, strength and the like. A plurality of bead rows running perpendicular to the direction in which the heat exchange medium passages are formed are installed in the tube element, and the beads are formed so that they are positioned at different intervals in adjacent bead rows or the areas where no beads are formed are different in the bead rows. It is positioned to form this continuum. This structure reduces the number of beads formed in the catchment area and reduces the passage resistance, thereby improving the flow of the heat exchange medium.

Description

Tube Element for Stacked Heat Exchanger

1 is an illustration of a stacked heat exchanger embodiment showing a front view A, a bottom view B. FIG.

FIG. 2 is a front view of a forming plate (Type 1) constituting a tube element used for the multilayer heat exchanger of FIG.

3 is an exemplary view showing the flow of the heat exchange medium in the stacked heat exchanger of FIG.

4 is an enlarged cross sectional view showing a lead in a tube element.

5 (a), 5 (b) and 5 (c) are exemplary views showing the relationship between the bead shape, the bead size A and the bead spacing B. FIG.

Figure 6 (a) is a characteristic diagram showing the ratio change of heat exchange performance and passage resistance when the bead size is changed.

Figure 6 (b) is a characteristic diagram showing the change in the ratio of heat exchange performance and passage resistance when the bead interval is changed.

Figure 6 (c) is a characteristic diagram showing the ratio change of heat exchange performance and passage resistance when the tube element thickness is changed.

7 is an illustration of a forming plate (type 2) constituting a tube element used for a laminated heat exchanger.

8 is an illustration of a forming plate (type 3) constituting a tube element for use in a laminated heat exchanger.

9 illustrates an apparatus used to measure the performance of a tube element.

10 (a) is a temperature distribution diagram of a type 1 tube element when the water flow rate is 5 cc / sec.

10 (b) is a temperature distribution diagram of type 2 tube element when the water flow rate is 5 cc / sec.

10 (c) is a temperature distribution diagram of type 3 tube element when the water flow rate is 5 cc / sec.

Figure 11 (a) is a temperature distribution diagram of type 1 tube element when the water flow rate is 10 cc / sec.

Figure 11 (b) is a temperature distribution diagram of type 2 tube element when the water flow rate is 10 cc / sec.

Figure 11 (c) is a temperature distribution diagram of type 3 tube element when the water flow rate is 10 cc / sec.

Figure 12 (a) is a temperature distribution diagram of a Type 1 tube element with a water flow rate of 20 cc / sec.

12 (b) is a temperature distribution diagram of type 2 tube element when the water flow rate is 20 cc / sec.

12 (c) is a temperature distribution diagram of type 3 tube element when the water flow rate is 20 cc / sec.

13 is an illustration of fluid flow through an obstruction.

* Explanation of symbols for main parts of the drawings

1: heat exchanger 2: fin

3: tube element 4: forming plate

5: tank 7: heat exchange medium passage

10: protrusion 21: passage

[Industrial use]

The present invention relates to tube elements that can be used in laminated heat exchangers such as evaporators, condensers, heater cores or radiators.

[Prior art]

In a conventional heat exchanger formed by alternately stacking fins and tube elements, a bead is used to increase the contact area with the heat exchange medium as a means for dispersing the flow of the heat exchange medium and at the same time improving the heat exchange performance. ) Is formed in the heat exchange medium passage of the tube element. This application also uses a tube element press-formed into a formed plate in which a plurality of round beads constitute the tube element, as disclosed, for example, in Japanese Patent Laid-Open No. 63-153397. Tube elements of known technology have a bead diameter of 3.8 , Minimum bead spacing 7.0 , Tube element thickness 2.9 And thickness of molded plate 0.57 Has According to an investigation by the applicant, the bead diameter or short diameter is 3.5 for products of other companies that use round or oval beads. 4.8 Range, tube element diameter is 2.8 3.4 Range, plate thickness of molded plate is 0.4 0.57 It is within range. Except for the bead spacing for which we do not have data, our tube elements are within this range.

[Problem to Solve Invention]

It has been commonly recognized in the art that the more beads in a tube element, the larger the contact area between the tube element and the heat exchange medium, and therefore, the better the heat exchange performance. However, if the number of beads is excessively increased, the passage area of the heat exchange medium passage decreases, which increases the passage resistance, which hinders the flow of the heat exchange medium. Conversely, if the beads are made smaller and the number is reduced in order to reduce passage resistance, the contact area with the heat exchange medium becomes inefficient, so that the reverse transfer speed to the fins is reduced and the heat exchange performance is deteriorated. However, these contradictory factors should be taken into account to meet the demand for small heat exchangers having excellent heat exchange performance. It is also essential to improve the tube element.

As shown in FIG. 13, when a plurality of obstacles A are continuously positioned in the passage direction of the fluid, the flow of fluid in contact with the obstacle A is redirected to the side of the obstacle A and collides with the obstacles. They will try to flow between successive obstacles, creating a so-called dead water region. In the case of the tube element according to the known art, it is inferred that there will be a large number of beads that do not contribute sufficiently to the heat exchange process because they are in the sandwater. The shooter's bead is not only useless but also increases passage resistance and must be removed. It is desirable to improve the heat exchanger by allowing the heat exchange medium to penetrate the passage as much as possible with minimal passage resistance.

Moreover, in addition to the above water catchment problem, the flow of the heat exchange medium takes the shortest path, and in the case of the tube element provided with the U-type heat exchange medium passage 7 as in the tube element shown in FIG. 2, the heat exchange medium has a central protrusion ( Will move along 10). Beads are formed in the traditional furnace at consistent densities in known tube elements, so the passage resistance is the same throughout the traditional furnace. Therefore, the heat exchange medium moves along the protrusion to leave a region where the heat exchange medium is stagnant, such as the upper side of the tube element.

All of these indicate that there is room for improvement in the bead arrangement in the tube element.

It is an object of the present invention to provide a tube element capable of improving the efficiency and producing a compact heat exchanger.

Yet another object is to provide a tube element with an improved bead arrangement that takes into account the need to reduce the number of beads in the catchment area to improve heat exchange performance and the need to disperse fluid flow by adjusting passage resistance.

[Means for solving the problem]

The present application considers the factors described below to determine the optimal dimensional relationship between bead size, bead spacing, tube element thickness and mold plate thickness:

(1) The larger the bead size, the larger the passage resistance. The smaller the bead size, the straighter the passage resistance. However, if the bead size is too small, the heat exchange performance decreases relatively.

(2) The smaller the bead spacing, the larger the number of beads and hence the passage resistance. Conversely, as the bead spacing increases, the number of beads decreases, thereby relatively reducing heat exchange performance.

(3) The smaller the thickness of the tube element, the narrower the heat exchange medium passage, which increases the passage resistance. The larger the tube element, the smaller the passage resistance. However, in the latter case, the heat exchange medium passes through without sufficient heat exchange, and thus the heat exchange performance deteriorates.

(4) The heat exchange rate is improved by reducing the thickness of the molded plate, but the corrosion resistance and strength are reduced. If the thickness of the formed plate increases and the thickness of the tube element is the same, the passage resistance increases by narrowing the heat exchange medium passage.

In summary, bead width A and bead spacing B are 2.0 A 3.0 , 3.5 B 6.3 A fluid path for a heat exchange medium is formed by adjoining a bead formed in a tube element and two forming plates one by one with a protrusion in the flow path so that the tube element and the fin are alternately stacked over a plurality of rows. will be.

In addition, the tube element thickness H and the platen thickness T are 1.9 H 2.7 , 0.25 T 0.47 You are in range.

By thus optimizing the optimal dimensional relationships for bead width A, bead spacing B, tube element thickness H and forming plate thickness T, an ideal tube element can be realized that provides the best combination of heat exchange rate, passage resistance and strength. It is possible to manufacture a heat exchanger smaller than t and maximize the heat exchange performance.

In addition to the above structure, a plurality of bead rows that cross the fluid passage direction of the heat exchange medium at right angles to each other in the direction in which the bead rows are arranged adjacent to each other with different spacings between the beads and are arranged adjacent to each other. Beads in adjacent bead rows are arranged in such a way that subsequent low pressure zones do not collide with subsequent beads. Alternatively, there may be a portion where beads exist in a plurality of bead rows in which the tube elements cross the fluid passage direction at right angles, and bead rows positioned adjacent to each other may have a structure in which a portion without beads forms a continuum. have.

With such a structure, the bead arrangement reduces the dead zone and passage resistance even though it is out of the optimal dimensional relationship due to the part where no beads are formed, thereby eliminating the stagnant region by uniformly distributing the heat exchange medium throughout the traditional furnace. Therefore, heat exchange performance is further increased due to the increase in the area where no beads are formed.

Also by combining these structures, a tube element can be obtained that provides the optimum bead shape and optimal bead arrangement.

These and other inventive features will be better understood by those skilled in the art by the detailed description in conjunction with the accompanying drawings which illustrate preferred embodiments.

EXAMPLE

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

In FIG. 1, the stacked heat exchanger 1 is a four-pass evaporator in which the fins 2 and the tube elements 3 are alternately stacked over a plurality of rows. Each tube element 3 is formed by adhering two forming plates 4 to their peripheral edges, and a pair of tanks 5 are provided at the upstream and downstream ends of the air flow. In addition, a heat exchange medium passage 7 through which the heat exchange medium flows from the tank 5 to the other end is provided.

Each molded plate 4 is made by press-molding an aluminum plate, as shown in FIG. 2, and includes two container-shaped extensions 8 and an extension 8 for forming a tank at one end. An extension 9 is formed which continuously forms the passage. A protrusion 10 extending from the two extensions 8 for forming the tank to the vicinity of the other end of the forming plate is formed in the extension 9 forming the passage. In addition, the mounting recess 11 for installing the connecting pipe, which will be described later, is installed between the extension portions 8, and a protruding piece 12 (see FIG. 1) is formed at one end of the forming plate 4 before brazing. It is installed to prevent the pin 2 from falling off during assembly. Each extension 8 swells more than the extension 9. When the periphery of the forming plate 4 is bonded, the protrusion 10 is bonded to the opposite protrusion, so that the protrusion 10 divides the heat exchange medium passage 7 into a portion except for the portion close to the other end of the tube element 3. It forms a U-shaped passage.

The tanks 5 of adjacent tube elements 3 are in contact with each other at the extension part 8 of each forming plate 4, and are blind-type tanks 5a positioned at one side at approximately the center in the stacking direction. Except for being connected to each other via a connection hole 13 formed in the extension (8).

In addition, the above-described mounting recess 11 is not installed in the tube element 3a positioned at a specific position from the center to one side, and one of the tanks 5b on which the blind tank 5a is installed is the opposite tank. Extends adjacent to. This extended tank 5b is connected with a connection pipe 15 installed on the mounting recess 11. In addition, an entrance 16 is provided at one end of the heat exchanger in the stacking direction farthest from the extended tank 5b. The inlet and outlet 16 are connected to the connecting part 17 for the expansion valve, the connecting part 18 connecting the connecting part 17 and the tank on the side where the blind tank is installed, and the connecting path 19 connected to the connecting pipe 15. Are installed in turn.

In this structure, the heat exchange medium is introduced through one of the connection passages, for example, through the connection passage 19 connected to the entrance 16. The introduced heat exchange medium flows through the connecting pipe 15 and the elongated tank 5b to a part of the tank 5 on the side of the blind tank 5a and then along the projection 10 to the heat exchange medium passage 7. It flows upwards of and flows downward by u-turn at the top of the projection 10 to finally reach the tank on the opposite side of the blind tank 5a. The heat exchange medium then moves horizontally to another tank 5 which is separated in about half. Thereafter, the heat exchange medium again flows along the protrusion 11 above the passage 7, and U-turns on the top of the protrusion 10 and flows downward. Finally, the heat exchange medium flows out from the tank 5 located on the side where the blind tank 5a is installed via the connecting passage 18 (see the flow path in FIG. 3). Because of this, the heat of the heat exchange medium is transferred to the fins 2 while the medium flows through the passages 7 and the heat of the fins is heat exchanged with the air passing between the fins.

The beads 20 are press molded into a part of the forming plate 4. In the case of the forming plate 4 shown in FIG. 2, the plurality of beads are arranged to be perpendicular to the flow direction of the heat exchange medium passing through the passage 7 in the plurality of bead rows, and each of the bead rows has a plurality of beads positioned at regular intervals ( 20) is installed. In the drawing, when n is composed of 4 beads, n + 1 is composed of 5 beads, n + 2 is composed of 4 beads, but the beads are adjacent to each other but flow path (vertical direction in the drawing) The low pressure zone created behind each bead in the direction in which is formed is located in the bead row so as not to collide with the next bead. Beads in every bead row are positioned to fit in the low pressure zones created behind each bead in the direction in which the flow path is formed. Eventually, the beads 20 are formed with uniform density.

As shown in FIG. 4, the beads 20 protrude from the inner surface of the formed plate to the inside of the heat exchange medium passage 7. The beads are bonded to the beads of adjacent forming plates to improve the heat exchange performance of the heat exchange medium passing through the passage 7. In the tube element 3, each bead bottom spacing (hereinafter referred to as bead size), which is considered to start at the point where the forming plate 4 starts to protrude into the passage 7, is adjacent to each other. The intervals (hereinafter, referred to as bead intervals) between B, the thickness of the tube elements constituting the heat exchange medium passages, H, and the thickness of the forming plate, T, are 2.0 of these ranges. A 3.0 , 3.5 B 6.3 , 1.9 H 2.7 , 0.25 T 0.47 to be.

For example, when circular beads having a truncated cone are arranged as shown in Fig. 2 (magnification of Fig. 5 (a)), i.e., a plurality of beads in a direction perpendicular to the direction in which the heat exchange medium passage is formed. When running at interval n in column n, the beads at column n + column 1 are placed at interval b in such a way that each of them is located at a distance from the nearest bead in column n. It becomes B. When the beads of FIG. 5 (a) are replaced with egg-shaped beads as shown in FIG. 5 (b), or when the beads are placed as shown in FIG. 5 (c), several bead centers (ie, long and short diameters) The shortest distance between two points) becomes B.

Generally speaking, it is desirable to minimize the heat resistance of the heat exchange medium passage 7 in the tube element 3 as large as possible. For example, passage resistance increases when bead size A increases, but passage resistance decreases when bead size decreases. However, if the bead size is too small, the heat exchange performance is relatively reduced. In addition, as the bead spacing B decreases, the number of beads increases and the passage resistance increases. Increasing the bead spacing decreases the number of beads and relatively decreases passage resistance, but simultaneously decreases heat exchange performance. In addition, in the thickness of the tube element 3, the smaller the thickness, the narrower the exchange medium passage 7, thereby increasing the passage resistance, and the larger the thickness, the passage resistance decreases. However, the smaller the passage through air, the lower the heat exchange performance.

In addition, as the thickness of the formed plate 4 decreases, the heat exchange medium passage 7 may be widened, thereby increasing heat exchange performance. However, if the plate thickness is too small, problems arise in terms of strength and corrosion resistance. Conversely, when the plate thickness increases, the heat exchange medium passage 7 narrows, thereby increasing passage resistance. All of this means that the relationship between heat exchange performance and passage resistance can be used as an index for evaluating the tube element 3, except for the thickness of the molded plate.

This evaluation can be obtained by placing the heat exchange performance / path resistance on the vertical axis and the bead size, bead spacing and tube element thickness on the horizontal axis, respectively, and are shown in FIG. The indicator (heat exchange performance / path resistance) has a bead size of 2.5 , Bead spacing 4.8 Tube element thickness 2.4 When was set to 100.

For the bead size, the bead size is 2.5, as shown in Figure 6 (a). The smaller or larger the indicator becomes smaller. However, the smaller the bead car, the harder the molding and at the same time the heat exchange performance deteriorates, so A ≥ 2 It is necessary to be. In addition, the larger the bead size, the larger the passage resistance, which is common in the known art. Note that when the bead size is increased, good indicators cannot be achieved, so the upper limit of the bead size is determined using the same indicators or better indicators as the lower limit of the bead size. 3.0 Is determined.

For the bead spacing, the bead spacing was 4.8, as shown in Figure 6 (b). The smaller or larger the indicator becomes smaller. In the end, the desirable indicator is 3.5 6.3 Obtained when within range intervals. As B decreases, molding becomes more difficult and at the same time, passage resistance increases, so B is 3.5 It needs to be ideal. Preferably 3.8 in view of slight tolerances in molding Is good. Also, as B increases, the passage resistance will decrease, but the heat exchange performance will also decrease. Therefore, the upper limit of the bead interval is the lower limit of the bead interval (3.5 6.3 using an indicator equal to or better than It is decided as follows. Lower limit of bead interval (3.8 When the upper limit of the bead interval is determined using an indicator equal to or better than It is as follows.

As shown in Fig. 6 (c), the thickness H is 2.4. If smaller or larger, the index of the tube element decreases. The smaller H is, the more difficult the molding is, and at the same time, the heat exchange performance is reduced. H is 1.9. It needs to be ideal. 2.0 taking into account the tolerances in forming The above is preferable. In addition, the larger the thickness (H), the smaller the passage resistance but the smaller the heat exchange performance. Therefore, the upper limit of the thickness H is equal to or lower than the lower limit of the thickness. 2.7 , Preferably H 2.6 Is determined.

In the case of a molded plate, as mentioned above, the optimum plate thickness T needs to be determined in consideration of the strength, corrosion resistance, and passage resistance of the molded plate. Therefore, taking into account the strength and corrosion resistance, the lower limit is T ≥ 0.25 The upper limit is T in consideration of the deterioration of heat exchange performance due to the increase of furnace passage resistance. 0.47 It is necessary to decide.

As a result, the tube element in which the above condition range is obtained will be an optimally balanced tube element in consideration of two requirements, namely, an improvement in heat exchange performance and a decrease in passage resistance. In addition, in view of strength and other considerations, the tube element makes it possible to provide a heat exchanger which is much smaller and lighter than using a known tube element.

7 shows another embodiment (second embodiment) of the forming plate 4 constituting the tube element 3. Here, the beads 20 are formed in a plurality of bead rows that vertically cross the direction in which the heat exchange medium passages 7 are formed, and the intervals at which the beads are located are different from the adjacent bead rows. In this example, five beads are provided on the surface at equal intervals of L1 in rows n, three beads are provided at equal intervals of L2 in columns n + 1 and five beads are again provided at intervals L1 in columns n + 2. N + 3 columns are provided with three beads at intervals of L2. In short, bead rows provided with beads at the same interval L1 and bead rows provided with leads at the same interval L2 are alternately formed. The interval L2 is twice the length of L1.

Beads in all other bead rows are positioned in such a way as to be located between the low pressure zones created behind the beads in the direction in which the heat exchange medium passage 7 is formed (vertical direction on the drawing). In this embodiment, the beads are positioned at an angle of 30 ° in the direction in which the heat exchange medium passage 7 is formed from the given beads closest to the given beads in adjacent rows. As a result, a bead group of patterns appears when viewed at an angle of 30 °, with beads arranged alternately at intervals a and b.

The forming plate 4 constituting the tube element 3 has the structure of the embodiment (third embodiment) shown in FIG. 8, wherein the portion without beads is perpendicular to the direction in which the heat exchange medium passage 7 is formed. At different locations in the bead rows that are adjacent to each other. The portions in which beads in the beads rows adjacent to each other are not formed are connected to form passages 21, where the beads are in a direction different from the direction in which the heat exchange medium passages 7 are formed. In this embodiment, the portions (gaps) in which the beads 20 are not formed are continuously connected to each other in the direction of 30 ° angle in the direction in which the heat exchange medium passage 7 is formed, as opposed to the tube element of the known art in which the beads are formed consistently. Connected.

As a result, in the second and third embodiments, the number of beads located in the catchment area is reduced, and a portion having a small passage resistance is generated throughout the heat exchange medium passage 7 without reducing the heat exchange performance. The distribution of the heat exchange medium to the portion having low passage resistance is improved to avoid congestion and to distribute the heat exchange medium over the entire tube element. Moreover, by reducing beads, an improvement in heat exchange performance can be achieved.

Applicants conducted experiments for evaluating tube elements characterized by the bead arrangement as compared to tube elements in which beads are provided at a constant density.

The following tube elements were tested. Tube elements of the type shown in FIG. 2 in which beads are provided with a certain density (hereinafter referred to as type 1), tube elements of the second embodiment (hereinafter referred to as form 2) and tube elements of the third embodiment (hereinafter referred to as form 3) ). As shown in FIG. 9, the heating plate 22 is attached with a silicone adhesive over one entire surface of the extension 9.

After that, the heat insulating material 30 is placed on the pre-assembly and the AC power is connected to the heating plate 22 to uniformly supply a certain amount of heat to the tube element. Next, a certain amount of water is 500 It is supplied to the tube element via the inflow pipe 23 of length. Water flows from the tank through the heat exchange medium passage to the next tank and is discharged to the outlet pipe 24. The amount of water supplied through the inlet pipe 23 was adjusted by the flow meter 25 and the flow rates of the flow rates were adjusted to 5 cc / sec, 10 cc / sec and 20 cc / sec. The surface temperature of the tube elements at different flow rates was measured. The result is the tenth Shown at 12 degrees. 10th At 12 degrees, the figure indicates temperature in degrees Celsius.

In addition, the flow rate was changed to 5 cc / sec, 10 cc / sec and 20 cc / sec, and the temperature difference at the inflow and outflow was determined from the thermocouples 26 and 27 installed at the inlet and outlet of the forming plate 4 and the reader (29). Was measured. The results are shown in Table 1.

TABLE 1

In addition, the pressure at the inlet and outlet ports is the pressure gauge 33 through the inlet and outlet stop pressure holes 31 and 32 formed in the inlet and outlet pipes 23 and 24 to determine the flow resistance (mmHg) of water in the tube element 3. Was measured. The results are shown in Table 2.

TABLE 2

The temperature difference (in degrees Celsius) between the flow direction of the fluid and its orthogonal direction is also determined in order to determine the degree of inconsistency in the heat exchange between the direction in which the thermal bridge medium passage 7 is formed and the orthogonal direction in this direction. It was measured with a thermocouple 29 provided at a specific position (position 24) on the surface opposite the side on which the heating plate was installed. The results are shown in Table 3.

TABLE 3

The difference in temperature between the inlet and the outlet indicates that more aggressive heat exchange takes place as the difference increases, and the experimental results show that the temperature difference is not significant but is larger in Types 2 and 3 than in Type 1. For Type 1, the temperature difference was greater at flow rates of 5 cc / sec and 20 cc / sec compared to Type 2.

For the flow resistance of water, Type 2 and 3 were larger than Type 1 at 5 cc / sec, but Type 2 and 3 were smaller at 10 cc / sec and 20 cc / sec. Thus, considering the actual flow rate of the heat exchanger at about 10 cc / sec, it can be concluded that Types 2 and 3 have lower flow resistance. It should also be noted that the flow resistance of water was lower in Type 3 than in Type 2.

It is preferable that the isotherms of FIGS. 10 to 12 degrees are horizontal (perpendicular to the heat exchange medium passage). That is, it is preferable to minimize the temperature difference in Table 3, which means that the heat exchange is performed consistently. In this respect, Forms 2 and 3 are better than Form 1.

In conclusion, the data obtained from the experiments indicate that the heat exchange characteristics of Types 2 and 3 were improved even though the number of beads in these types was smaller than that of Type 1, and the number of beads in the shooter area decreased in the tube elements of Types 2 and 3 Therefore, it can be said that a bead arrangement has been realized that allows the heat exchange medium to be more completely distributed throughout the passage without the stagnant portion than in Type 1.

From all of these, the bead size A, the bead spacing B between the adjacent neighboring beads, the tube element thickness H and the thickness T of the forming plate are 2.0 A 3.0 , 3.5 B 6.3 , 1.9 H 2.7 , 0.25 T 0.47 When in the range, the number of beads is reduced as shown in FIGS. 7 and 8, and even if the beads are out of the dimensional range at the portion where the number of beads is reduced, the heat exchange characteristics are improved as shown in the above experiments, and the number of beads It can be concluded that the additive effect improves heat exchange performance.

Although tube elements used in the evaporator have been described in these embodiments, tube elements satisfying the same conditions can be used in all types of stacked heat exchangers such as heater cores, condensers, radiators, etc., and higher heat exchange performance and miniaturization are also realized in the present application. It can be natural. In addition, the present invention can be applied to the case where the tank portion is installed on the tube element as a part or a separate unit of the tube element.

Claims (11)

A tube element that is laminated with a plurality of stages alternately with a fin to form a stacked heat exchanger. The tube element is formed by facing two bonded plates face to face, and a pair of tanks formed at one end in the longitudinal direction thereof, and a pair And a protruding portion extending from between tanks to the vicinity of the other end in the longitudinal direction, and a flow path of a heat exchange medium formed around the protruding portion and communicating with the pair of tank portions, the protruding portion from each forming plate. In forming a plurality of beads formed so as to be formed, one bead row is formed according to a plurality of beads arranged at a first interval perpendicular to the longitudinal direction of the tube element, beads adjacent to the one bead row The rows are arranged according to a plurality of beads arranged at a second interval larger than the first interval in a direction perpendicular to the longitudinal direction of the tube element. The one bead row and the bead row adjacent thereto are arranged alternately from the vicinity of a pair of tanks to one end portion in the longitudinal direction along the projection, and at the same time, the bevel rows are uniformly spaced in the bead, and the extension line of the projection The tube element according to claim 1, wherein an approximately long elliptical bead is formed in a portion between the longitudinal direction one end of the protruding portion and the other end of the tube element. The width (A) of the beads and the pitch (B) of the beads constituting the bead row are 2.0. A 3.0 3.5 B 6.3 Laminated tube heat exchanger element, characterized in that within the range of. The thickness H of the tube element in the stacking direction and the thickness T of the formed plate are 1.9. H 2.7 0.25 T 0.47 Laminated tube heat exchanger element, characterized in that within the range of. The tube element for a laminated heat exchanger according to claim 1 or 2, wherein all of the beads constituting the bead rows are circular in shape. 3. The tube element according to claim 1 or 2, wherein all of the beads constituting the bead row are substantially elliptical in shape. A tube element, which is extracted from a plurality of stages alternately with a fin and constitutes a stacked heat exchanger, is formed by joining two molded plates face-to-face, a pair of tanks formed at one end in the longitudinal direction, and a pair of A projection extending from between tanks to the vicinity of the other end in the longitudinal direction, and a heat exchange medium flow path formed around the projection and communicating with the pair of tanks, the flow path being formed to protrude from each molded plate. In the case where a plurality of beads are formed, the bead rows are configured according to the plurality of beads arranged perpendicularly to the longitudinal direction of the tube element, and the bead rows are spaced at intervals where no beads are formed at predetermined positions. Bead rows are arranged from the vicinity of the pair of tanks to one end portion in the longitudinal direction along the protrusions, The gap in which no beads were formed continued continuously in the oblique direction, and many passages in which no beads existed were formed, and as an extension line of the protrusion, the portion between the one end in the longitudinal direction of the protrusion and the other end of the tube element. The tube element for a laminated heat exchanger, characterized in that a bead of an approximately elliptic shape is formed in a short direction of the tube element. The width (A) of the beads and the pitch (B) of the beads constituting the bead row are 2.0. A 3.0 3.5 B 6.3 Laminated tube heat exchanger element, characterized in that within the range of. The thickness H of the tube element in the stacking direction and the thickness T of the formed plate are 1.9. H 2.7 0.25 T 0.47 Laminated tube heat exchanger element, characterized in that within the range of. The tube element according to claim 6 or 7, wherein all of the beads constituting the bead row have a circular shape. The tube element according to claim 6 or 7, wherein all of the beads constituting the bead row are substantially elliptical in shape. The tube element for a laminated heat exchanger according to claim 6, wherein the passage in which no beads are present is formed in a direction inclined at 30 degrees with respect to the longitudinal direction of the tube element.