JPH08145583A - Grooved tube for heat exchanger in air conditioner and refrigerator and corresponding exchanger - Google Patents

Abstract

PURPOSE: To permit economical and efficient assembly while maintaining the high heat exchanging capacity of a tube itself, by a method wherein a periodical profile comprising two pieces of ribs and having a specified height ratio and different in the heights of them is formed while the high rib is arranged between two pieces of flat bottom grooves. CONSTITUTION: In a tube for manufacturing a heat exchanger, whose external diameter De is 3-30 mm and which is equipped with (n) (n; 35-90) pieces of spiral ribs having the spiral angle of 5-50 degrees and the apex angle (α) of 30-60 degrees on the internal part of the same, a periodical profile comprising two pieces of ribs having different heights is formed. In this case, the height of a higher rib 2h is Hh and the height of the lower rib 2b is Hb while a ratio of Hb/Hh is 0.40-0.97 or preferably 0.6-0.95 and respective higher ribs 2h are arranged between two pieces of flat bottom grooves 3. Further, the ratio of Hh/De is 0.003-0.05 or preferably 0.015-0.04. The section of the flat bottom groove 3 is not truncated shape and the area S is 0.02-0.15 mm<2> or preferably 0.060-0.15 mm<2> when the tube is provided with the external diameter Dew of 7.93 mm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a fluid circulating inside a pipe and the heat used for producing heat exchangers in air conditioners and refrigeration systems, or for any other heating or cooling. The present invention relates to a tube that supports heat exchange with an atmosphere that circulates inside the exchanger.

[0002] The present invention is usually a pin (straight part +
Bending) copper, aluminum or steel tubes and made of copper or aluminum and in thermal contact with them, usually perpendicular to the straight parts of the tubes and exchanged with the atmosphere It also relates to said heat exchanger, which usually comprises an assembly with plates known as fins, which provides a large area for

[0003]

BACKGROUND OF THE INVENTION [0002] Tubes, usually copper and copper alloy tubes, are already known for a large number of variants and also for improving the heat exchange between the fluid circulating inside the tube and the external atmosphere. ing.

To show these variants, it is possible to cite US Pat. No. 4,480,684 and European patent application EP-A-148609, which describe internally grooved tubes.

In US Pat. No. 4,480,684,
Grooves are characterized by a combination of features such as:

-The helical angles with respect to the tube axis are 16 degrees and 35.
A spiral groove between degrees.

Grooves with a depth of between 0.1 mm and 0.6 mm.

Grooves with a pitch between 0.2 mm and 0.6 mm.

-A "V" -shaped cross section with angles of 50 degrees and 10
A groove between 0 degrees.

FIGS. 2 and 6 of the above patent each show a heat exchanger and a "V" groove separated by a "V" shaped rib of the same angle termed the apex angle (alpha) relative to the axis. Figure 3 shows a contoured section of the tube along a section that is vertical.

European Patent Application EP-A-14860
No. 9 also describes a grooved tube in which the spiral groove has a trapezoidal cross-section, the ribs have a triangular cross-section, and which is characterized by a combination of features such as:

The ratio of the groove depth H (or rib height H) to the inner diameter Di of the tube is between 0.02 and 0.03.

The groove helix angle is between 7 and 30 degrees.

The ratio of the cross-sectional area S of the groove to the depth H is 0.1
Between 5 mm and 0.40 mm.

-The apex angle of the rib is between 30 and 60 degrees.

[0016]

The importance of grooved tubes for increasing the heat exchange between the fluid circulating inside the tube and the tube itself has long been recognized by those skilled in the art.

For a typical copper tube having an outer diameter of 9.52 mm, there may be a sufficient number (45-65) of helical ribs / grooves (helix angle between 10 and 30 degrees). The person skilled in the art knows that it is preferable.

However, with respect to many other features related to the actual shape of the ribs and grooves, the prior art has found that those skilled in the art will reveal those features by analyzing the prior art. To ensure that a high performance heat exchanger is obtained, it does not give a uniform picture, ie a homogeneous teaching, which the person skilled in the art can turn to.

Furthermore, while conducting research into small batteries with improved thermal contact between the tube and the fin, the inventor used a structure known per se to generally pass the inside of the tube. With a mandrel bent, bend the conventional grooved tubes and crimp the grooves into them, thereby inflating the tube slightly against the edge of the end of the fin, thus making it expensive Excellent thermal contact could be obtained without the need for soldering or brazing techniques.

The inventor has found that inspection of the cross section of a crimped tube (a standard tube with 60 "V" ribs) causes the ribs to become crushed. This means that the depth H of the cross section S of the groove is extremely shallow.

Before caulking After caulking H 0.20 mm 0.13 mm S 0.060 mm ² 0.024 mm ² (60% reduction) As far as heat exchange between the fluid circulating inside the tube and the tube itself is concerned. The cross-sectional area S is 60 by the measurement performed for comparing the pipe parts after the tightening.
It was confirmed that the performance was deteriorated after caulking due to the decrease in%.

The inventor therefore concludes that, while taking into account the rib / groove deformation that occurs during tube and fin assembly, it is only useful in handling the tube and optimizing its performance. Reached

Therefore, the inventor can take into consideration caulking, thereby suppressing the adverse effects of caulking, but it is still advantageous in terms of heat exchange between the pipe and the fin, and is an economical assembly technique. The desired groove / rib contour was obtained.

[0024]

A first object of the present invention, a tube for use in manufacturing a heat exchanger by crimping a fin, has an outer diameter De of 3 to 30 mm,
Inside, there are n (n is between 35 and 90) spiral ribbed grooves having a helix angle of 5 to 50 degrees and an apex angle of 30 to 60 degrees,
The ribs form a periodic contour containing at least two ribs of different height, one rib known as a "high" rib has a height of Hh and is known as a "lower" rib. The height of the other rib is Hb, and the ratio Hb
/ Hh is between 0.40 and 0.97 and is characterized in that each "high" rib is located between two flat bottom grooves.

The periodic contour is a name given to a continuous arrangement of ribs and fins that is uniformly reproduced at each pitch p.

According to the test conducted by the inventor, the ratio Hb / H
It has been found that h of slightly less than 1 is sufficient for a large effect. However, the ratio Hb /
If Hh is between 0.6 and 0.95, the heat exchange capacity of the tubes after crimping the fins decreases beyond their limits,
It is preferable to further decrease beyond the limit of 0.40 to 0.97.

This solution is, on the one hand, different heights (H
h and Hb) have two basic features, a periodic profile comprising at least two ribs and, on the other hand, each “high” rib located between two flat-bottomed grooves with a cross-sectional area S. Including.

To produce a tube with a flat bottom groove, after crimping the tube with grooves and fins, the cross-sectional area is S '<S, but sufficient for efficient heat exchange. There are two elements that are important to the invention.

Unexpectedly, the inventors have found that after assembling tubes (straight and bent) and fins by caulking, the periodic contours of the invention are advantageous in terms of heat exchange capacity. Noticed.

In fact, the height that results in the ribs having different functions during the crimping operation ("high" ribs having "protective" or "sacrificial" functions, "lower" ribs being "protected"). This way of distinguishing ribs by means of which the results obtained according to the invention could not be predicted.

That is, the inventor was not satisfied with optimizing the internal construction of the tube which itself was considered with respect to the heat exchange characteristics of the tube (in the case of evaporation or condensation). Rather, the inventor also considered the manufacture of the tube itself, as well as the manufacture of a corresponding heat exchanger by assembling the fin with the tube using a crimping mandrel. It is within this range that the present invention is an effective solution to the challenges posed.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The periodic contours are interleaved with "high" ribs (2h) and "low" ribs (2b), represented by h / b, as shown in FIGS. 3a and 3b. Alternatively, as shown in Figures 7a and 7b, it is preferred to include a continuous arrangement of "high" ribs (2h) and two "low" ribs (2b), represented by h / b / b.

Of the contours h / b and h / b / b, the h / b of alternating "high" ribs (2h) and "low" ribs (2b) forming a flat bottom groove (3) between them. Is preferred.

The invention is used for tubes with an outer diameter De which can vary significantly between 3 and 30 mm. The "high" rib height Hh varies with De, but is not necessarily proportional to it.

Generally speaking, in order to maintain the optimum efficiency of the grooved tube after crimping, the ratio Hh / De is 0.003.
And 0.05, preferably between 0.015 and 0.04.

According to one aspect of the invention, the "high" ribs (2h) have a substantially triangular cross section and a height of Hh. As shown in Figures 3a and 3b, the term "substantially triangular in cross section" is used as shown, in particular in Figure 3a, which is a cross-sectional view of a real tube (illustrated as an example) taken from a photograph. As shown, it means a cross section with a relatively rounded apex.

According to another aspect, as shown in FIG.
The "high" ribs (2h) have a substantially trapezoidal cross section and a height of Hh.

As shown in FIGS. 3a and 3b, the "low" ribs (2b) preferably have a substantially triangular cross section and a height of Hb. Further, as described above regarding the meaning of the expression, "almost triangular" can be applied here.

According to the invention, it is flat-bottomed and not trapezoidal (H
The cross-sectional area of the groove is 0.020 to 0.1 (since h> Hb).
5 mm ^2, when the outside diameter De of at least 7.93mm tube is preferably 0.060～0.15Mm ^2, when the outside diameter De of 7.93mm smaller tube, 0.02
It is advantageous to choose a tube of 0 to 0.070 mm ^{2, which} is preferred. Those values are usually obtained for the following values.

* Height Hb is 0.10 to 0.20 mm. * Height Hh is 0.20 to 0.30 mm. * In the case of a standard tube with a length of 0.10 to 0.20 mm and an inside diameter (at the bottom of the groove) of the order of 8.8 mm, the pitch (pitch = flat bottom length and "high" rib A flat bottom (approximately flat, not taking into account the curvature of the tube) where the bottom half plus the bottom half of the "lower" ribs is typically 0.40 to 0.50 mm.

For shorter diameters (eg 7 mm), the heights Hb and Hh, in particular the height Hh, are lowered (see Examples 5 and 6).

With respect to the area S, its lower limit is set because it is necessary to sufficiently increase the heat exchange between the fluid circulating inside the tube and the external atmosphere.

On the other hand, the upper limit of the area S is first set in consideration of the size of a normal pipe and the number n of ribs (2h and 2b).
, As a result of geometrical considerations.

A second object of the invention is a heat exchanger made by crimping a fin and a grooved tube. After assembling the fin and the tube by inserting the crimping mandrel inside the tube and inflating the tube by the action of the mandrel, the rib forms a periodic contour including at least two ribs of different widths. One rib has a trapezoidal cross section and a wide width Lh at an intermediate height, and a “wide” rib (20).
h), another rib has a triangular or trapezoidal cross section and a narrow width Lb at intermediate height,
Known as "narrow" ribs (20b), the ratio (Lh-Lb) / D for tubes with an outer diameter of 9.52 mm.
e is at least equal to 0.003 and the value of Lh-Lb is usually at least equal to 0.03.

5a and 5b show the rib and groove contours before and after crimping. The "high" ribs (2h) before crimping become lower ribs (20h) after crimping, and the "low" ribs (2b) become ribs (20b) after crimping.
The symmetry-a symmetrical expression-is not significantly changed by the crimping operation (slightly flattened in Figure 5c, but unchanged in Figures 5a and 5c).

In the specific case where the "low" ribs (2b) are relatively high, or in the specific case where Hh-Hb is low, which after swaging has essentially the same result, the "wide" The ribs and the "narrow" ribs have almost the same height (H '
With h = H′b), the cross section of the area S ′ of the flat bottom groove (30) is trapezoidal.

The area S of the cross section of the groove (3) seems to be still smaller. After caulking, the area S is S '<
It becomes S. However, this reduction is limited by the present invention. Usually, the cross-sectional area S ′ of the flat bottom groove (30) is 0.0
In 15~0.060mm ^2, it is preferred when the outer diameter is 9.52mm tube is 0.35~0.60mm ^2.

Examples All the tubes described in the examples below are provided with external grooves (ribs to be obtained on the inner surface of the tube and grooves and ribs on the outer surface of the mandrel corresponding to the grooves).
Manufactured by a known method using a floating mandrel having The method is of the type described in US Pat. No. 4,373,366.

Examples 1,3,5,6,8,9 are according to the invention and the tube profile is as shown in Figures 3a and 3b. Examples 2, 4 and 7 are from the prior art taken for comparison.

In all examples, the tubes are standard NFA.
It was made of copper (Cubl-DHP) according to 51123 (= ASTM B68 and 280).

Examples 1 and 2 Tubes were produced which were internally grooved and had an outer diameter De of 9.52 mm and a groove bottom thickness Ep of 0.30 mm.

Other Characteristics of Produced Tube Example 1 Example 2 (Invention) (Prior Art) Rib Height (High Rib of Example 1) 0.23 mm 0.20 mm Rib Height (Low Rib of Example 1) 0.16 mm 0.20mm Rib apex angle (alpha) 40 ° 50 ° Helix angle (beta) 18 ° 18 ° Number of ribs n 60 60 Groove cross-sectional area 0.070mm ² 0.060mm ² Then shown in Figures 6a and 6b Fins were attached to these types of tubes using a mandrel.

Example of Crimped Tubes Taken to Determine Geometrical Properties of Inner Ribs and Grooves: Properties after Crimping Example 1 Example 2 (Invention) (Prior Art) Rib Height ("Example 1""High"(H'h)) 0.20mm 0.13mm Next rib height ("Low"(H'b) in Example 1) 0.16mm 0.13mm Rib width Lh at intermediate height (Rib 20h in Example 1) 0.096 mm 0.25 mm Width Lb of adjacent rib at intermediate height (rib 20b of Example 1) 0.048 mm 0.25 mm Groove cross-sectional area S'0.042 mm ² 0.024 mm ² Finally, the mass flow rate is 160 kg / m ² . s. Of the standard chlorofluorocarbonated frozen liquid (Freon R22 (R)) during condensation (vapor content = 50%, saturation temperature = 30 ° C.) and evaporation (vapor content = 30%, saturation temperature = 10 ° C.) A comparative evaluation of the performance of the tubes in Examples 1 and 2 before and after caulking was performed by measuring the average heat exchange efficiency (W / m ² .K) at the time.

The following values were found.

At evaporation time At condensation time Before caulking * According to example 1 9500 W / m ² . K 9400 W / m ² . K * according to example 2 8500 W / m ² . K 9600 W / m ² . K Tube after caulking * According to example 1 5700 W / m ² . K 5640 W / m ² . K * according to example 2 3400 W / m ² . K 3840 W / m ² . K By comparing the tubes, the tube of the invention is only slightly superior to the conventional tube taken for comparison (at the time of condensation and evaporation respectively), but after caulking It can be seen that the tube of the invention is clearly superior to the conventional tube, which shows the importance of the present invention.

Examples 3 and 4 Tubes were produced which were grooved inside and had an outer diameter De of 7 mm and a groove bottom thickness Ep of 0.25 mm.

Another characteristic of the tube produced Example 3 Example 4 (invention) (prior art) Rib height (high rib of Example 3) 0.18 mm 0.18 mm Height of adjacent rib (Low of Example 3) Rib) 0.15 mm 0.18 mm Rib apex angle (alpha) 40 ° 40 ° Helix angle (beta) 18 ° 18 ° Number of ribs n 44 50 Groove cross-sectional area S 0.060 mm ² 0.053 mm ² Then, Fins were attached to these types of tubes by crimping using the mandrel shown in Figures 6a and 6b.

The tubes were tested before and after crimping the fins on the tube. As a result, the same performance change as that observed in Examples 1 and 2 was observed.

Before staking: The performance of the tubes in Examples 3 and 4 is close.

After crimping: tube in example 4 (prior art)
The performance of the tube in Example 3 (invention) is higher than that of

Similar to Examples 1 and 2, Examples 3 and 4
Then, it can be seen that the deterioration of the performance caused by crimping the fin on the tube is smaller in the tube of the present invention.

Examples 5, 6 and 7 In the case of Examples 5 and 7, a tube having a groove inside was used and the outer diameter De
Of 9.52 mm and the thickness Ep of the bottom of the groove was 0.30 mm.

In the case of Example 6, a tube having a groove inside is
Outer diameter De is 7.93 mm, groove bottom thickness Ep is 0.25
A tube that is mm is manufactured.

Other characteristics of manufactured pipe Example 5 Example 6 Example 7 (Invention) (Invention) (Invention) Rib height (high rib of Examples 5 and 6) 0.23 mm 0.18 mm 0.20 mm Next rib Height (Low ribs in Examples 5 and 6) 0.16mm 0.15mm 0.20mm Rib apex angle (alpha) 40 ° 40 ° 40 ° Helix angle (beta) 18 ° 18 ° 18 ° Number of ribs n 54 46 60 Area S (of groove cross section) 0.075 0.061 0.062 Freon flow rate 110 kg / m ² . s and 10-60
The pressure drop (ie loss of fill) before and after crimping was measured for a steam content of wt.%.

The loss of fill in the tubes of the invention in Examples 5 and 6 was 1 before that of the tubes in Example 7 before crimping.
It was found to be 5% less and after caulking 13% less than that of the tube in Example 7.

Examples 8, 9 and 10 Tubes having grooves inside were produced, with an outer diameter De of 12.70 mm and a groove bottom thickness Ep of 0.36 mm.

Other Characteristics of Produced Tubes Example 8 Example 9 Example 10 (Invention) (Invention) (Invention) Rib height (high ribs in Examples 5 and 6) 0.25 mm 0.25 mm 0.25 mm Next rib Height (Low ribs in Examples 5 and 6) 0.22mm 0.22mm 0.25mm Rib apex angle 50 ° 50 ° 50 ° Helix angle (beta) 18 ° 30 ° 0 ° Number of ribs n 65 65 65 Area S (groove) 0.089 0.089 0.082 Helical angle beta of the pipe after crimping (18 degrees for the pipe in the case of test 8, 30 degrees for the pipe in the case of test 9,
For test 10, the heat exchange efficiency (W / m ² .K) was calculated as a function of 0 ° to the tube.

The measurements were carried out for various flow values of Freon R22 in the case of condensation.

Result = heat exchange efficiency value (W / m ² .K) Freon flow rate kg / s Example 8 Example 9 Example 10 0.08 2000 3450 1750 0.10 2700 4300 2150 0.12 3500 4950 2500 0.14 4500 5600 3000 0.16 5000 6400 3500 0.18 5800 7300 4000 0.20 6550 8000 4450 The manufacturing speed tends to decrease as the helix angle increases. Even though the intent was to increase heat exchange efficiency, those tests and other tests performed for cases with apex angles higher than 30 degrees showed that the apex angle was at least 30 degrees, preferably 30-50 degrees. It turned out to be desirable to choose.

However, if the intention is to improve the production speed, it is preferable to select the helix angle to be 5 to 30 degrees.

[0071]

Therefore, the main advantage of the present invention is that it limits the loss of performance (especially heat exchange efficiency) when assembling tubes and fins by crimping to make a heat exchanger.

Thus, according to the invention and of a periodic profile with at least two ribs of different height, another rib being "sacrificed" during the crimping operation to "protect" the lower rib. The concept makes it possible to use economical and efficient assembly methods while maintaining the high heat exchange capacity of the tubes themselves.

Furthermore, the tube of the present invention is less expensive than conventional tubes because the tube of the present invention does not require any means other than the usual means of producing standard grooved tubes.

The grooved tube of the present invention is compared to conventional grooved tubes in applications where the groove of the original tube is unchanged or slightly modified, such as in heat exchangers with soldered or brazed fins. Without reducing efficiency,
It is particularly suitable for producing fin-clad heat exchangers.

In particular, it is important to note the very certain effect of the invention on the loss of fill, as shown in Examples 5, 6 and 7.

Significant reduction in tube diameter (tube outer diameter in Example 5 = 9.52 mm and tube outer diameter in Example 6 =
(7.93 mm), despite the loss of fill amount that occurred in the prior art, no significant increase in the loss of fill amount was brought about.

Furthermore, the reduction in fill loss observed with the tubes of the present invention compared to conventional tubes is very practical in terms of reduced cost, reduced size and weight of the compressor used in the refrigerator. is important.

[Brief description of drawings]

FIG. 1a is a transverse cross section of a prior art grooved tube (1) perpendicular to the tube axis, which has ribs (2) with a triangular cross section, an apex angle of 90 degrees and a groove of substantially triangular cross section. It is sectional drawing which shows a part of surface. The bright parts of the photo on the dark background correspond to the tubes.

FIG. 1b is a substantially triangular cross section with an apex angle close to 50 degrees,
1 is a cross-sectional view showing a part of a cross section perpendicular to the tube axis of a prior art grooved tube (1) having ribs (2) with a trapezoidal section in between. The bright parts of the photo on the dark background correspond to the tubes.

FIG. 2 shows the flattened and deformed ribs (20) after crimping the fins on the tube during battery installation, FIG.
FIG. 5 is a view of a prior art tube corresponding to b. The bright parts of the photo on the dark background correspond to the tubes.

FIG. 3a: “High” ribs (2h) and “Low” ribs (2)
FIG. 4 is a cross-sectional view showing a part of a cross section perpendicular to the tube axis of the grooved tube (1) of the present invention formed by the alternating arrangement of b). The bright parts of the photo on the dark background correspond to the tubes.

FIG. 3b shows two types of ribs of heights Hh and Hb (2h and 2b).
3b is a diagram corresponding to FIG. 3a of a tube having a groove (3) with a cross-sectional area S, an outer diameter De and a tube thickness Ep (thickness at the bottom of the groove), which shows b). The pitch p of the periodic contour is "high" rib (2h) / flat bottom groove (3) / "low" rib (2).
b) / flat bottom groove (3) and the like. If the description is limited to ribs, the contour can be represented by "h / b". Here, h indicates "high" ribs and b indicates "low" ribs.

FIG. 4a is a view corresponding to FIG. 3a after crimping the fin and the tube. The rib (2h) of height Hh (before crimping) becomes a trapezoidal rib (20h) of height Hh '(after crimping),
The height Hh 'after crimping is lower than the height Hh before crimping,
The rib (20b) corresponds to the initial rib (2b). The height of the rib hardly changed by the caulking (Hb '
= Hb).

FIG. 4b is a view corresponding to FIG. 3b after the fins and tubes have been turned up. New groove (3 with cross section S '<S
It is a figure which shows 0).

5a is a view similar to FIG. 4b showing different features of the invention. Two types of ribs (2h) before crimping (2b) outline (thick line) and ribs (20h) and (20) after crimping
b) contours (thin lines) and corresponding widths Lh and Lb at intermediate height and grooves (3) and (3) before and after caulking.
The cross-sectional areas S and S'of 0) are shown. In this figure, the rib (2h) has a trapezoidal cross section, and after crimping, the height H'h of the high rib is higher than the height H'b of the low rib, and the height of the lower rib is crimped. The same applies to the front Hb and the rear H'b.

FIG. 5b is a view similar to FIG. 4b showing different features of the invention. Two types of ribs (2h) before crimping (2b) outline (thick line) and ribs (20h) and (20) after crimping
b) contours (thin lines) and corresponding widths Lh and Lb at intermediate height and grooves (3) and (3) before and after caulking.
The cross-sectional areas S and S'of 0) are shown. In this figure, the rib (2h) has a triangular cross section and an apex angle of 50 degrees, and the rib (2b) has a triangular cross section and an apex angle of 30 degrees. After the caulking, the height H'h of the high rib is close to the height H'b of the low rib, and the height of the lower rib is the same before and after the caulking.

FIG. 5c is a view similar to FIG. 4b showing different features of the invention. Two types of ribs (2h) before crimping (2b) outline (thick line) and ribs (20h) and (20) after crimping
b) contours (thin lines) and corresponding widths Lh and Lb at intermediate height and grooves (3) and (3) before and after caulking.
The cross-sectional areas S and S'of 0) are shown. In this figure, the ribs (2h) and the ribs (2b) have a triangular cross section. After crimping, the height H'h of the rib is high and the height H'b of the rib is low.
The height H'b of the rib, which is closer to the lower side, is higher in the pre-crimping H'b than in the post-crimping H'b.

FIG. 6a is a sectional view along the axis of the grooved tube (1) of the crimping operation of the fin (4) by the mandrel (5) before the start of crimping.

FIG. 6b is a sectional view along the axis of the grooved tube (1) during the crimping operation of the fin (4) with the mandrel (5) during the crimping operation.

FIG. 7a shows a contour according to the invention.

FIG. 7b shows another contour according to the invention.

Claims (13)

[Claims] 1. An n (n is between 35 and 90) spiral rib (2) having an outer diameter De of 3 to 30 mm, a spiral angle of 5 to 50 degrees, and an apex angle (alpha) of 30 to 60 degrees. In a tube (1) for caulking a peripheral fin (4) for producing a heat exchanger, the rib (2) having at least two ribs of different heights in a periodic profile. And the height of one rib known as the "high" rib (2h) is Hh, and the height of the other rib known as the "low" rib (2b) is Hb, Ratio Hb
/ Hh between 0.40 and 0.97, each "high" rib (2h) being arranged between two flat-bottomed grooves (3). 2. The ratio Hb / Hh is preferably 0.6 and 0.
The tube of claim 1, wherein the tube is between 95. 3. The periodic contour is represented by h / b, alternating "high" ribs (2h) and "low" ribs (2b), or represented by h / b / b. A tube according to any one of claims 1 or 2, characterized in that it comprises a continuous structure of "high" ribs (2h) and two "low" ribs (2b). 4. The periodic contours are "high" ribs (2).
h) and “lower” ribs (2b), characterized by being constituted by said alternating h / b of “high” ribs (2h) and “low” ribs (2b) forming a flat bottom groove (3). The tube according to claim 3, wherein 5. The height of the "high" ribs (2h) is Hh.
And as a result Hh / De is between 0.003 and 0.05, preferably between 0.015 and 0.04. tube. 6. The "high" rib (2h) has a substantially triangular cross section and a height of Hh.
The tube described in. 7. A tube according to claim 5, characterized in that the "high" ribs (2h) have a substantially trapezoidal cross section and a height of Hh. 8. The "low" rib (2b) has a substantially triangular cross section and a height of Hb.
The tube according to any one of 1 to 7. 9. The flat bottom groove (3) has a non-trapezoidal cross section, an area S between 0.020 and 0.15 mm ² , and an outer diameter D.
7. Tube according to any one of claims 1 to 6, characterized in that in the case of a tube in which e is at least 7.93 mm, it is preferably between 0.060 and 0.15 mm ² . 10. A heat exchanger manufactured by caulking a grooved tube according to any one of claims 1 to 9 and a fin, wherein the fin and the fin are passed through a caulking mandrel inside the tube. After assembling the tube, the ribs form a periodic contour containing at least two ribs of different widths, one rib being “wide” with a trapezoidal cross section and a wide width Lh at the intermediate height. The other rib, known as a rib (20h), is triangular or trapezoidal in cross section and has a narrow width Lb at the intermediate height and a "narrow" rib (20h).
A heat exchanger known as b), characterized in that the ratio (Lh-Lb) / De is at least equal to 0.003. 11. The "wide" rib (20h) and the "narrow" rib (20), wherein the periodic contour is represented by 1 / e.
b) interleaved, or represented by l / e / e,
2. A continuous arrangement of one "wide" rib (20h) and two "narrow" ribs (20b).
The exchanger according to 0. 12. The "wide" rib (20h) and the "narrow" rib (20b) have substantially the same height (H'h = H'b).
The exchanger according to claim 11, characterized in that the cross section of the flat bottom groove (30) is trapezoidal with an area S '. 13. The cross-sectional area S ′ of the flat bottom groove (30).
Exchanger according to claim 10, characterized in that is between 0.015 and 0.060 mm ² .