KR100414852B1 - Refrigerant distributor for heat exchanger - Google Patents

Abstract

The refrigerant flow pipe for a heat exchanger is constituted by upper and lower walls, a flat tube having a plurality of reinforcing walls extending in the longitudinal direction over the upper and lower walls and spaced apart from each other at a predetermined interval and having parallel refrigerant passages therein, And a plurality of communication holes through which the parallel coolant passages pass are formed. The opening ratio of each reinforcing wall, which is a magnification with respect to the reinforcing wall of all the communication holes, is 10 to 40%.

Description

Refrigerant distributor for heat exchanger

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerant flow pipe for a heat exchanger, and more particularly, to a condenser or a refrigerant flow pipe for an evaporator used in a vehicle cooler.

Throughout this specification and claims, " aluminum " is intended to include both pure aluminum and aluminum alloys.

A condenser for a vehicle cooler as disclosed in Japanese Patent Application Publication No. 45300/91 comprises a pair of headers arranged in parallel left and right at a distance from each other and a pair of parallel flat coolers A corrugated fin disposed at a ventilation gap between the flow pipe and the adjacent refrigerant flow pipe and soldered to both refrigerant flow pipes; an inlet pipe connected to the upper end of the left header; and an outlet connected to the lower end of the right header, A left partition plate disposed inside the upper portion of the middle of the left header and a right partition plate disposed inside the lower portion of the right header, the number of the refrigerant circulation tubes between the inlet tube and the left partition plate, The number of refrigerant flow tubes between the left partition plate and the right partition plate, and the number of refrigerant flow tubes between the right partition plate and the outlet pipe are sequentially decreased from above Called parallel flow type or multiphase type condenser which flows in the condenser in a serpentine fashion until the gaseous refrigerant introduced from the inlet pipe flows out of the outlet pipe in a liquid state and flows out, , It is widely used as a high-performance, low-pressure loss, and compact device.

The flat-type refrigerant flow pipe used in the condenser is required to have pressure resistance to introduce a high-pressure gas refrigerant into the flat refrigerant flow pipe. In order to meet this demand and increase the heat exchange efficiency, a flat aluminum tube having upper and lower walls and reinforcing walls extending in the longitudinal direction over the upper and lower walls has been used as the refrigerant circulating tube.

However, when the reinforcing wall is provided in the refrigerant flow pipe, a separate refrigerant flow passage is formed in parallel inside the reinforcing wall. Since the air flows vertically through the parallel refrigerant passage, the heat exchange in the refrigerant passage at the inlet side is necessarily better than the refrigerant passage at the outlet side of the air. Therefore, in the refrigerant passage on the upstream side, the gaseous refrigerant is rapidly condensed (condensed) to collect the condensed liquid. On the other hand, in the case of the refrigerant distribution tube as a whole, since the gaseous refrigerant remains in the refrigerant passage on the downstream side, And the heat exchange efficiency is poor.

An object of the present invention is to provide a refrigerant flow pipe for a heat exchanger having a high heat exchange efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a flat refrigerant distribution tube according to a first embodiment of the present invention; FIG.

Fig. 2 is a partially enlarged view of the flat refrigerant flow pipe of Fig. 1; Fig.

3 is an enlarged sectional view taken along the line 3-3 in Fig.

4 is a cross-sectional view showing a state in which an aluminum plate for a refrigerant distribution tube of Embodiment 1 of the present invention is rolled and manufactured.

Fig. 5 is a cross-sectional view showing a state in which a notch is provided at the upper edge of the parallel-like ridge portion of the aluminum plate of Fig. 4;

6 is a sectional view taken along the line 6-6 in Fig.

7 is a longitudinal sectional view showing a state in which the raised portion and the notched portion at the upper edge thereof are formed in one step.

8 is an enlarged partial perspective view showing a state in which a flat type refrigerant distribution tube of the first embodiment of the present invention is manufactured.

9 is a cross-sectional view of a flat refrigerant distribution tube according to Embodiment 2 of the present invention.

10 is a cross-sectional view of a flat type refrigerant distribution tube according to Embodiment 3 of the present invention.

11 is a cross-sectional view of a flat type refrigerant distribution tube according to Embodiment 4 of the present invention.

12 is a cross-sectional view of a flat type refrigerant distribution tube of Embodiment 5 of the present invention.

13 is a cross-sectional view of a flat type refrigerant distribution tube according to Embodiment 6 of the present invention.

14 is a graph showing the results of the evaluation test 1 and a graph showing the relationship between the average degree of drying X of the refrigerant and the heat transfer coefficient hA.

15 is a graph showing the results of the evaluation test 2 and showing the relationship between the average degree of drying X of the refrigerant and the thermal conductivity h.

16 shows the results of the evaluation test 3, and shows the relationship between the opening ratio and the heat transfer coefficient hA at the refrigerant average dryness X of 20%, 50% and 80% and the relationship between the opening ratio hA and the average dryness X A graph showing the relationship between the aperture ratio and the friction coefficient f.

Fig. 17 shows the results of the evaluation test 4, and shows the relationship between the opening ratio and the thermal conductivity h at 20%, 50% and 80% of the average dryness X of the refrigerant, And a friction coefficient f.

18 is a graph showing the results of the evaluation test 5 and showing the relationship between the refrigerant pressure loss DELTA Pr of the condenser using the refrigerant flow pipe and the heat radiation amount per unit area Q / Fa.

19 is a front view of a condenser in which a flat refrigerant flow tube is used;

Description of the Related Art

1: upper wall

2: Lower wall

5: reinforced wall

6: Refrigerant passage

7: flat aluminum tube

The present invention provides a refrigerant flow pipe for a heat exchanger that achieves the above object. The refrigerant flow pipe includes upper and lower walls, a plurality of reinforcing walls which extend over the upper and lower walls and extend in the longitudinal direction, Wherein the flat aluminum pipe is formed of an aluminum plate, and the reinforcing wall is composed of a ridge portion integrally formed in a protruding manner from an aluminum plate, and the reinforcing wall is provided with a parallel-type coolant passage And an opening ratio of 10% to 40%, which is a ratio of the total amount of the communicating holes to the surface area of the reinforcing wall of each reinforcing wall, is 10% to 40%.

The refrigerant flowing through the parallel refrigerant passages flows in the width direction of the flow pipe through the communication holes and is mixed over all of the refrigerant passages. Therefore, since the temperature difference does not occur in the refrigerant between the refrigerant passages, the refrigerant is equally condensed on the upstream side and the downstream side, and the refrigerant flows uniformly, thereby improving the heat exchange efficiency. The opening ratio, which is the magnification of all the reinforcing walls in each reinforcing wall with respect to the reinforcing wall, affects the heat transfer degree, but when the opening ratio is in the range of 10 to 40%, good heat transfer is obtained, Can be further improved. The reason why the aperture ratio is limited within the range of 10 to 40% is that if the heat transfer coefficient is less than 10%, the heat transfer coefficient does not increase, and if it exceeds 40%, the heat transfer coefficient does not increase. The aperture ratio is preferably 10 to 30%, more preferably about 20%, even in the range of 10 to 40%.

In addition, the cross-sectional area of the communication hole is such that the refrigerant in the neighboring coolant passage is sufficiently exchanged, and is not clogged by the flow of lead at the time of soldering, and does not decrease the pressure resistance of the coolant circulation pipe. In addition, the pitch of the communication holes is such that the flow of the refrigerant can be sufficiently performed without lowering the pressure resistance of the refrigerant flow pipe.

In addition, it is preferable that the communication holes formed in the plurality of reinforcing walls are in a staggered arrangement in plan view.

The pitch of the reinforcing wall in the tube width direction is preferably 4 mm or less. If the pitch of the reinforcing wall exceeds 4 mm, the heat exchange efficiency becomes poor.

The height of the reinforcing wall is preferably 2 mm or less. If the height of the reinforcing wall exceeds 2 mm, it is difficult to make the heat exchanger compact, and the resistance of the passing air increases, resulting in poor heat exchange efficiency.

The invention will now be described in more detail with reference to the accompanying drawings.

Fig. 19 shows a condenser used in a flat-type refrigerant flow pipe according to the present invention. The condensers have a pair of headers (61, 62) arranged in parallel left and right spaced from each other, a parallel flat type refrigerant flow pipe (63) connected to both the headers (61, 62) A corrugated fin 64 disposed at the ventilation gap between the flow channels 63 and soldered to the both refrigerant flow channels 63, an inlet pipe 65 connected to the upper end of the left header 61, A left partition plate 67 provided inside the upper portion of the middle of the left header 61 and a left partition plate 67 provided inside the middle of the right header 62 The number of the refrigerant circulation pipes 63 between the inlet pipe 65 and the left partition plate 67 and the number of the refrigerant circulation pipes 63 between the left partition plate 67 and the right partition plate 68, The number of the refrigerant circulation pipes 63 between the right partition plate 68 and the outlet pipe 66 is sequentially decreased from the top and the number of the inlet pipes 6 5) flows in the condenser in a serpentine form until the refrigerant in the gaseous state introduced from the outlet pipe (66) flows into the liquid state and flows out.

The present invention relates to a refrigerant flow pipe (63) used in the condenser. Specific examples of the refrigerant flow pipe according to the present invention will be described below. In the following concrete examples, the opening ratio, which is the magnification of all the reinforcing walls with respect to the reinforcing wall, is 10 to 40%. In addition, the communication holes formed in the plurality of reinforcing walls are all in a staggered arrangement when viewed from the top.

Example 1

This specific example is shown in Figs. The refrigerant circulation pipe T1 for the heat exchanger has flat upper and lower walls 1 and 2 and vertical left and right side walls 3 and 4 extending over both left and right side edges of the upper and lower walls 1 and 2, ) Having a plurality of reinforcing walls (5) extending in the longitudinal direction over the upper and lower walls (1, 2) and spaced apart from each other by a predetermined distance therebetween and having parallel refrigerant passages (6) (7), and the reinforcing wall (5) is formed with a plurality of rectangular communication holes (8) passing between the parallel coolant passages (6).

The flat aluminum tube 7 is formed by vertically bending both side edges of the lower aluminum plate 10 so that a hollow portion is formed by two upper and lower aluminum plates 9 and 10, And are joined to both side edges of the plate (9).

The reinforcing wall 5 is formed by joining a parallel ridge 11 protruding inwardly from the lower wall 2 to the inner surface of the upper wall 1. The rectangular communication hole 8 is formed by joining the ridge 11, A rectangular cut-away portion 12 provided at a predetermined distance from the upper edge of the upper side wall 1 is formed by blocking the opening portion of the upper side wall 1.

The refrigerant flow pipe T1 is manufactured as follows.

First of all, the upper roll 13 has a parallel annular groove 14 and a first small-diameter portion 15 (small-diameter portion) on both outer sides having a circumferential surface conforming to the groove bottom surface of the annular groove 14, And an upper roll (13) having a smaller diameter than the first small diameter portion (15) and having a second small diameter portion (16) wider than the first small diameter portion (15) A pair of upper and lower rolling rolls 13 and 17 are used by using a lower roll 17 provided on both outer sides of the large-diameter portion 18 having a smaller width than that of the second small- A single sheet of aluminum sheet material made of a brazing sheet having a thickness thicker than the upper and lower walls of the coolant circulation pipe to be manufactured and covered with a lead material layer is rolled, The plate material portion rolled by the planes to become the lower side wall 2 is peeled to a predetermined thickness to form the flat end portions 19, The annular groove 14 is formed by the protruding portion 11 integrally projecting from the flat end portion 19 and the inner end portion 20a having the same height as the protruding portion 11 and the thin end portion extending upward from the outer edge thereof. The rolled aluminum plate 21 is formed by forming the raised portions 20 having the convex portions 20b on both side edges thereof.

Next, as shown in Figs. 5 and 6, rectangular projections 23 are formed at predetermined intervals in positions corresponding to the parallel annular grooves 14 of the upper rolling roll 13 in the previous process A rectangular cutout 12 is formed at an upper edge of each ridge 11 at a predetermined interval by passing the rolled aluminum plate 21 between the upper roll 22 and the lower roll 24 installed, The plate 10 is obtained.

The plurality of protrusions 23 are disposed in the upper edge of the parallel-like ridge portion 11 as gratings so as to obtain a notched portion 12 of a staggered arrangement as viewed in plan.

In the method of manufacturing the lower aluminum plate 10, a two-step process is required to obtain the protruding portion 11 formed with the cut-out portion 12. However, as shown in Fig. 7, in the parallel annular groove 14, If the upper roll 26 having the protrusions 25 formed lower than the groove depth at intervals is used in combination with the lower rolls 17 of the first step, the protrusions 11 formed with the cutouts 12 in the one- Can be obtained.

On the other hand, a flat upper aluminum plate 9 made of a brazing sheet whose both surfaces are covered with a lead material layer is formed. The upper surfaces of both side edges of the upper side aluminum plate 9 are formed on the inclined surface 27 inclined outwardly downward as shown in Fig. The side edges of the upper aluminum plate 9 are placed on the end portions 20a of the raised portions 20 of the lower aluminum plate 10 and the thin skin 20b is folded And is attached to the inclined surface 27 of the upper side aluminum plate 9 by bending. The end portion 20a of the rising portion 20 of the lower side aluminum plate 10 and the front end of the raised portion 11 are soldered to the lower surface of the lower side aluminum plate 9 to obtain the refrigerant flow path T1.

When a concave-convex portion having a triangular-shaped cross-sectional shape is provided on the peripheral surface of the upper rolling roll 13 or knurling is performed, the concave / convex portion extending in the longitudinal direction is formed on the entire inner surface of the lower- Concave and convex portions having a negative or lattice shape can be obtained and the surface area of the lower side wall 2 can be increased.

Specific Example 2

9, the refrigerant circulating tube T2 for a heat exchanger has a double structure of the left and right side walls 28, 29, and the communicating hole 30 has an inverted trapezoidal shape, Except that a plurality of heat transfer area increasing projections 31 extending at a relatively low height at predetermined intervals along the longitudinal direction are integrally formed in the upwardly projecting shape. The trapezoidal communication hole 30 can be obtained by forming a notched portion 32 having a trapezoidal shape at the upper edge of the raised portion 11.

The flat aluminum tube 33 forming the refrigerant flow pipe 72 is formed by bending both side edges of both aluminum plates 34 and 35 so that a hollow portion is formed by two upper and lower aluminum plates 34 and 35, As shown in Fig.

The side walls 28 and 29 are specifically formed as follows. In other words, a rising portion 36 having the same height as the reinforcing wall 5 is formed on both sides of the upper aluminum plate 35, and a sloped surface 38 inclined upward outward is formed at the bottom edge of the rising portion 36 . On the other hand, on both sides of the upper side aluminum plate 34, a vertical lower portion 37 which abuts against the outer side surface of the rising portion 36 and protrudes slightly downward beyond the lower surface of the lower side wall 2, . The lower protruding portion 37a of the vertical lower portion 37 is bent and attached to the inclined surface 38 of the lower aluminum plate 35 and the mutual contact portions of the upper and lower aluminum plates 34 and 35 are soldered.

Example 3

10, and a flat aluminum tube 39 constituting a refrigerant flow tube T3 for a heat exchanger is constituted by a single aluminum plate 40 made of a solder sheet whose one surface is covered with a lead material layer, And is formed by bending into the shape of a hair pin at the central portion of the width so as to form a hollow portion with the material layer out, and bending and folding both side edges in half-moon shape. The left and right side walls 41, 42 are thus arcuate. The butt joint portions 43 are inclined in cross section in order to increase the joining area.

The reinforcing wall 44 is formed by joining a downward protruding portion 44a formed in the inner protruding shape from the upper side wall 1 and an upward protruding portion 44b formed in the inner protruding shape from the lower side wall 2, 45 are formed by joining a pair of trapezoidal notch portions 45a, 45b provided at predetermined intervals to the lower edge of the downwardly raised portion 44a and the upper edge of the upwardly raised portion 44b, respectively.

Example 4

11, and the reinforcing wall 46 of the refrigerant flow pipe T4 for a heat exchanger is formed by a downward protruding portion 46a formed in an inner protruding shape from the upper wall 1, 2), and two types of upper ridges 46b, which are formed by joining the upper ridge 46b formed in the inner ridge from the lower side wall 2, to the inner surface of the flat upper side wall 1, The trapezoidal communication holes 47 are formed by trapezoidal notch portions 47a and 47b provided at predetermined intervals on the lower edge of the downwardly raised portion 46a and the upper edge of the upwardly raised portion 46b in the upper and lower walls 1, 2 is formed by blocking the opening portion from either one of the walls.

Example 5

12, and the reinforcing wall 48 of the refrigerant circulation pipe T5 for a heat exchanger is formed by a downward protruding portion 48a formed in an inner protruding shape from the upper wall 1, The trapezoidal communication hole 49 is formed by forming a trapezoidal notch 49a provided on the lower edge of the raised portion 48a at a predetermined interval to block the opening portion of the lower side wall 2 Was the same as that of the specific example 3.

Embodiment 6

13, and the flat aluminum tube 50 of the refrigerant circulating tube T4 for a heat exchanger is constituted by two upper and lower aluminum plates 51, 52 whose outer surfaces are covered with a lead material layer, And both sides of the upper and lower side edges are folded in a half-moon shape and are butt-joined to each other. The butt joint portions 53, 54 on the left and right sides have the same transverse section inclination as in the third embodiment.

In this embodiment, an aluminum extrusion type material having a predetermined cross-sectional surface may be used instead of the aluminum plate provided with the ridge portion and the like.

Hereinafter, examples of the present invention will be described together with comparative examples. The cross-sectional shapes of the refrigerant flow pipe of the examples and the comparative examples are as shown in Fig.

Example 1

A height of 1 mm between the upper and lower walls 1 and 2, a number of reinforcing walls 5 of 6, a pitch of reinforcing walls 5 of 2.4 mm, a height of reinforcing wall 5, Having a thickness of 0.3 mm and a pitch P of 1.6 mm of the communicating hole 8 and a length L of 0.8 mm of the communicating hole 8 and a height H of 0.2 mm of the communicating hole 8 and an opening ratio of 10% .

Example 2

The same refrigerant flow tube as in Example 1, except that the height of the communication hole was 0.4 mm and the opening ratio was 20%.

Example 3

The same refrigerant flow tube as in Example 1 except that the height of the communication hole was 0.6 mm and the opening ratio was 30%.

Example 4

The same refrigerant flow tube as in Example 1, except that the height of the communication hole was 0.8 mm and the opening ratio was 40%.

Comparative Example

The refrigerant flow pipe according to the first embodiment is the same as the first embodiment except that no reinforcing wall is formed with a communication hole.

Evaluation test 1

The relationship between the average degree of drying of the refrigerant (the mass ratio of the middle phase in the refrigerant) X and the heat transfer coefficient hA (h (heat transfer coefficient, A: heat transfer area in the refrigerant circulation tube)) was examined using the refrigerant flow tube of Example 2 and Comparative Example Respectively. The measurement method is as follows. That is, the refrigerant circulation pipe is disposed in the cooling water passage to allow the refrigerant made of HFC134a to flow in the refrigerant flow pipe, and the cooling water is allowed to flow in the cooling water passage. After a predetermined time, the mass velocity G of the refrigerant is 400 kg / Was set at 65 DEG C and the heat flow rate between the coolant and the cooling water was set at 8 kW / m < ₂ >, and the flow rate of cooling water was set at 1500 Reynolds number to measure the heat transfer rate hA Respectively.

The results are shown in Fig. 14, when the through holes are formed in the reinforcing wall, it can be seen that the heat transfer degree hA is larger in any average degree of drying X than in the case where the through holes are not formed.

Evaluation Test 2

The relationship between the average degree of drying X of the refrigerant and the heat transfer rate h was examined in the same manner as in Evaluation Test 1, using the refrigerant flow tube of Example 2 and Comparative Example. The results are shown in Fig.

15, it can be seen that the heat transfer rate h becomes larger in any mean dryness X than in the case where the through holes are formed in the reinforcing wall, as compared with the case where the through holes are not formed.

Evaluation Test 3

Using the refrigerant flow tubes of Examples 1 to 4 and Comparative Example, the relationship between the opening ratio and the heat transfer coefficient hA at 20%, 50% and 80% of the average dryness X of the refrigerant in the same manner as in the evaluation test 1, (Reynolds number of refrigerant = 104) between the opening ratio and the friction coefficient f in the state where X is 50%. The results are shown in Fig.

16, in the case where the communication hole is formed in the reinforcing wall, the heat transfer degree hA becomes larger at any average degree of drying X than in the case where no communication hole is formed, and in particular, the heat transfer degree hA becomes larger at the opening ratio of 20% .

Evaluation Test 4

Using the refrigerant flow tubes of Examples 1 to 4 and Comparative Example, the relationship between the opening ratio and the heat transfer coefficient h at the average dryness X of the refrigerant at 20%, 50% and 80% and the average dryness X (Reynolds number of refrigerant = 104) between the opening ratio and the friction coefficient f in a state where the refrigerant temperature is 50%. The results are shown in Fig.

In the case where a communication hole is formed in the reinforcing wall in FIG. 17, it is understood that the heat transfer rate h becomes larger in any average drying degree X, and the heat transfer rate h becomes larger at an opening ratio of 20%, as compared with the case where no communication hole is formed have.

Evaluation Test 5

Three types of capacitors of the multiphase type shown in Fig. 19 were assembled by using the refrigerant flow tube of Example 2 and the comparative example. That is, a core portion having a width of 326 mm, a height of 330.5 mm, and a total area of 0.108 m 2 was formed by using 37 refrigerant distribution tubes, a corrugated fin having a width of 22 mm, a height of 7 mm and a fin pitch of 1 mm, and both ends of each refrigerant distribution tube were connected Respectively. In Type I capacitors, partition plates are not installed in the right and left headers (1 pass). In the type II condenser, a partition plate is provided on the upper side of the middle of the left header and on the lower side of the middle of the right side header, and the number of refrigerant flow tubes existing above the partition wall of the left header is 20, The number of refrigerant flow tubes existing in the plate was 11, and the number of refrigerant flow tubes existing below the partition plate in the right header was 6 (3 passes). In the type III capacitor, partition plates are provided at the upper and lower positions of the left header, respectively, and at the middle height position of the two partition plates of the left header in the right header and at the positions lower than the lower partition plate of the left header The number of the refrigerant flow tubes existing above the upper partition wall of the left header is set to 12 and the number of the refrigerant flow tubes existing between the upper partition plate of the left header and the upper partition plate of the right header is set to 9 The number of the refrigerant flow tubes existing between the upper partition plate of the right header and the lower partition plate of the left header is 7 and the number of the refrigerant flow tubes existing between the lower partition plate of the left header and the lower partition plate of the right header, And the number of refrigerant flow tubes existing below the lower partition plate of the right header was set to four (five passes). Then, the relationship between the refrigerant pressure loss? Pr of each condenser and the heat radiation amount per unit area Q / Fa was examined. The results are shown in Fig.

The performance of the condenser using the refrigerant flow tube in which the communication hole is formed in the reinforcing wall at the opening ratio of 20% is improved as compared with the performance of the condenser using the refrigerant flow tube in which the communication hole is not formed in the reinforcing wall, It can be seen that it is improved.

According to the refrigerant flow pipe for a heat exchanger of the present invention, since the opening ratio, which is the magnification of all the communication holes in each reinforcing wall, is within the range of 10 to 40%, the heat exchanging efficiency of the heat exchanger using the same is extremely excellent. Further, according to the condenser for a vehicle cooler of the present invention, the heat exchange efficiency is extremely excellent.

Claims (12)

And a flat aluminum tube having parallel walls and upper and lower walls and a plurality of reinforcing walls extending in the longitudinal direction and extending in the longitudinal direction and spaced apart from each other by a predetermined distance, Wherein the reinforcing wall is formed of a raised portion integrally formed in a protruding manner from an aluminum plate, and the reinforcing wall is provided with a plurality of communication holes communicating with parallel refrigerant passages, and in the reinforcing wall, Wherein the open area ratio of the open area of the reinforcing wall to the surface area of the reinforcing wall is 10 to 40%. The refrigerant flow pipe for a heat exchanger according to claim 1, wherein the opening ratio is 10 to 30%. The refrigerant flow pipe for a heat exchanger according to claim 1, wherein the opening ratio is about 20%. The refrigerant flow pipe for a heat exchanger according to any one of claims 1 to 3, wherein the shape of the communication hole is a rectangle or a trapezoid. The refrigerant flow pipe for a heat exchanger according to any one of claims 1 to 3, wherein the communication holes formed in the plurality of reinforcing walls are staggered in relation to the adjacent reinforcing walls. The refrigerant flow pipe for a heat exchanger according to claim 1, wherein the aluminum plate comprises a brazing sheet having a lead material layer on at least one side of both surfaces. The flat aluminum tube according to claim 1, wherein at least one side of the flat aluminum tube is formed by bending both side edges of the both aluminum plates so that the hollow portion is formed by two upper and lower aluminum plates, And a refrigerant flow pipe for the heat exchanger. The refrigerant flow pipe for a heat exchanger according to claim 1, wherein the flat aluminum tube is formed by bending both side edges of both aluminum plates so that the hollow portion is formed by the upper and lower aluminum plates, and the overlapping portions are joined to each other. The flat aluminum tube according to claim 1, wherein the flat aluminum tube is bent in a central portion of the width so that one aluminum plate is formed in a hollow portion, and at least one side edge of the plate is bent so that the bent edge is brought into contact with another edge, The refrigerant flow tube for a heat exchanger. [2] The apparatus according to claim 1, wherein the reinforcing wall is formed by joining a downward protruding portion formed integrally with the upper protruding portion from the upper protruding portion and an upward protruding portion formed integrally with the lower protruding portion from the lower protruding portion, And a pair of notches formed at an upper edge of the ridge portion at a predetermined interval are joined to each other. [2] The apparatus of claim 1, wherein the reinforcing wall is formed by joining the lower bump portion formed integrally with the upper bump from the upper side wall to the flat lower side wall inner surface, and the upper bump portion integrally formed from the lower side wall, And the communicating hole has a notch formed at a predetermined distance from the lower edge of the downward bulging portion and the upper edge of the upward bulging portion from one of the upper and lower walls, Wherein the refrigerant flow path is formed by blocking the refrigerant flow path. [2] The apparatus according to claim 1, wherein the reinforcing wall is formed by joining a raised portion formed integrally from one of the upper and lower walls to a flat inner surface of the flattened portion, Is formed by blocking an opening portion of any one of the upper and lower walls of the refrigerant flow tube.