KR100497847B1 - Evaporator - Google Patents

Abstract

An evaporator (1) comprises at least one evaporator unit (1A) including a pair of headers (2,3) arranged one above the other in parallel and spaced apart by a distance, and parallel refrigerant tubes (4) having a width oriented in a front-rear direction and opposite ends joined to the respect headers (2,3). The refrigerant tubes (4) are each in the form of a flat tube (17) comprising flat left and right walls (11,12), front and rear walls (13,14) positioned between and joined to front and rear side edges of the left and right walls (11,12), and a plurality of reinforcing walls (15) positioned between and joined to the left and right walls (11,12), extending longitudinally thereof and arranged at a predetermined interval between the front and rear walls (13,14), the flat tube (17) having parallel refrigerant channels (16) inside thereof. The reinforcing walls (15) are formed with a plurality of communication holes (19) for causing the parallel refrigerant channels (16) to communicate with one another. The flat tube (17) is formed by a platelike left component (21) having a left wall forming portion (23) and a platelike right component (22) having a right wall forming portion (28). The front and rear walls (13,14) of the flat tube (17) comprise rightward projecting walls (24) projecting rightward from the respective front and rear side edges of the left component (21) integrally therewith and brazed to the right component (22) and leftward projecting walls (29) projecting leftward from the respective front and rear side edges of the right component (22) integrally therewith and brazed to the left component (20). The reinforcing walls (15) of the flat tube each comprise a reinforcing wall forming portion (25) projecting inward from the left wall forming portion (23) of the left component (21) and having an outer end brazed to the right wall (28) forming portion of the other component (22).

Description

Evaporator {EVAPORATOR}

The present invention relates to an evaporator used in an air conditioner such as a vehicle air conditioner, an indoor air conditioner.

In this specification, the direction parallel to a ventilation direction is called front-back direction, and the direction orthogonal to this front-back direction is called left-right direction. For example, the left side of FIG. 3 is referred to as the front, the right side as the rear, the lower side as the left side, and the upper side as the right side.

Conventionally, the laminated type evaporator of Unexamined-Japanese-Patent No. 3-230064 was used as the evaporator for air conditioners for vehicles, for example. The laminated evaporator is formed by soldering a pair of longitudinally elongated plates made of a press-formed product in which a plurality of ribs extending upward and downward on an inner side face each other in an opposing state with the ribs inward and soldering at the periphery. A plurality of tube elements having a flat tube portion extending in the state is laminated in the thickness direction with the pins interposed therebetween, the tank portion connected to the flat tube portion on the upper and lower ends of the tube element is formed in a bulge (shape), each The tank parts of the tube elements are soldered in communication with each other. As shown in FIG. 18, the ribs 73, 74 of the longitudinally elongated plates 71, 72 of each tube element 70 project inwardly to be substantially U-shaped in cross section, and one longitudinally long one. The rib 73 of the plate 71 is located between the ribs 74 of the other longitudinally long plate 72, while the tip thereof is soldered to the other longitudinally long plate 72, and the other side thereof. A plurality of parallel coolant passages 75 are formed by soldering the tip of the rib 74 of the longitudinally long plate 72 to one of the longitudinally long plates 71.

However, the conventional evaporator has the following problem. That is, since the ribs 73 and 74 of the elongated plates 71 and 72 are U-shaped in cross section, when the width of the tube element 70 is made constant, as shown by reference numeral 76 in FIG. Likewise, a wasteful space portion which does not contribute to the circulation of the coolant is generated, and as a result, there is a limit in increasing the number of the coolant passages 75. In addition, there is a limit to the stretching of the material in the manufacturing process due to the constraints of the press technology. If the distance between the adjacent ribs 73 and 74 is reduced, cracks are generated in the plates 71 and 72, so that adjacent ribs The distance between the (73, 74) should be relatively large, and as a result, when the width of the tube element 70 is made constant, the equivalent diameter of the refrigerant passage 75 is reduced and the number of the refrigerant passages 75 is increased. It becomes impossible. Therefore, there is a limit in improving heat exchange performance, that is, evaporation performance of the refrigerant.

Therefore, in order to solve the above problem, at least one evaporator comprising a pair of headers arranged parallel to each other at a distance from each other and a parallel refrigerant flow pipe connected at both ends to the pair of headers, respectively. And an evaporator having a unit, wherein the refrigerant flow pipe is formed of a hollow extruded shape member having flat left and right walls and a plurality of reinforcing walls extending in the longitudinal direction and extending in the longitudinal direction at the same time. have. In such an evaporator, the number of refrigerant passages can be increased as compared with the flat tube portion of the tube element of the conventional evaporator described above, and the equivalent diameter of the refrigerant passage can be reduced. By the way, in order to improve the heat exchange efficiency, ie, the evaporation efficiency of the refrigerant, and to compact the evaporator, it is preferable that the refrigerant flow pipe is thin and the width in the left and right directions is as small as possible.

However, in the case of an extruded shape member, there are limitations in reducing the thickness of the tube with high dimensional accuracy and reducing the width in the left and right directions of the tube with high dimensional accuracy due to the limitations in the extrusion technique. In addition, in the case of an extruded shape member, communication holes through which parallel coolant passages, which are considered to be effective in improving performance, cannot be formed in the reinforcing wall.

The object of the present invention is to solve all the above-mentioned problems, improve the heat exchange performance, that is, the evaporation performance of the refrigerant compared to the conventional evaporator, and improve the heat exchange performance, that is, the evaporation performance of the refrigerant compared to the evaporator having a hollow extruded shape member. At the same time to provide a compact evaporator.

The evaporator according to the present invention comprises at least one evaporator comprising a pair of headers arranged parallel to each other at a distance from each other and a parallel refrigerant flow pipe connected at both ends to the pair of headers in a width direction forward and backward. The coolant flow pipe includes a flat left and right wall, front and rear side walls extending over both front and rear edges of the left and right walls, and a longitudinal side wall extending between the front and rear side walls and extending in the longitudinal direction, respectively. It has a plurality of reinforcing walls provided at intervals, and consists of a flat tube having a parallel refrigerant passage therein, the flat tube is formed of a metal plate, the reinforcing wall is integrally formed in the inner ridge form from the metal plate It consists of wall forming parts.

According to the evaporator of the present invention, the refrigerant flow pipes have a flat left and right walls, front and rear side walls that extend across the front and rear ends of these left and right walls, and extend in the longitudinal direction between the front and rear both side walls, and extend in the longitudinal direction, and have a predetermined distance from each other. It has a plurality of reinforcement walls provided in the form, and consists of a flat tube having a parallel refrigerant passage therein, the flat tube is formed of a metal plate, the reinforcement wall is integrally formed from the metal plate into the inner ridge reinforcement wall Since it consists of a formation part, compared with the flat tube part of the tube element of the conventional evaporator of Unexamined-Japanese-Patent No. 3-230064, the number of refrigerant paths can be increased and the considerable diameter of a refrigerant path can be made small. . Therefore, the heat exchange performance, that is, the evaporation performance of the refrigerant, is improved as compared with the evaporator described in the above publication. In addition, since the thickness of the refrigerant flow pipe can be made thinner with higher dimensional accuracy than that of the evaporator having a hollow extruded shape member, and the width of the right and left directions can be reduced with high dimensional accuracy, the heat exchange performance of the evaporator disclosed in the above publication. That is, the evaporation performance of the refrigerant is improved and at the same time compact.

In the evaporator, it is preferable that a plurality of communication holes are formed in the reinforcing wall to allow parallel refrigerant passages to pass through. These plurality of communication holes are preferably formed in a zigzag arrangement type when viewed from the left side. Moreover, it is good that the opening ratio which is a ratio which all the communication holes in each reinforcement wall occupy is 10 to 40%.

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

In the following description, the same parts and the same parts are denoted by the same reference numerals throughout the drawings, and description thereof is omitted.

1 shows the overall configuration of a first embodiment of the evaporator according to the present invention, FIG. 2 shows the flow of the refrigerant, and FIGS. 3 to 5 show the configuration of its main parts. In addition, the same code | symbol is attached | subjected to the same thing and the same part through the whole drawing, and the duplicate description is abbreviate | omitted.

In addition, in the following description, the term "aluminum" shall include an aluminum alloy in addition to pure aluminum.

In Fig. 1, the evaporator 1 is a pair of headers 2 and 3 arranged in parallel in the vertical direction at intervals from each other, and in parallel with both ends connected to these headers 2 and 3 in the width direction back and forth, respectively. Two evaporator units (1A), which are arranged in the ventilation gap between the flat refrigerant flow pipe (4) and the adjacent refrigerant flow pipe (4), and which are made of aluminum corrugated fins (5) soldered to both refrigerant flow pipes (4). ). These two evaporator units 1A are arranged in parallel back and forth at intervals from each other. A communication tube in which the upper headers 2 and the lower headers 3 of the two evaporator units 1A are connected to the central portion of the length of the length of both upper headers 2 and the central portion of the length of both lower headers 3, respectively. It is communicated by (6, 7). The inlet tube 8 of the refrigerant is connected to the lower portion of the central portion of the lower communication tube 7, and the outlet tube 9 of the refrigerant is connected to the upper portion of the central portion of the length of the upper communication tube 6. As shown in FIG. 2, the liquid refrigerant flowing into the lower communication tube 7 from the inlet tube 8 is separated into the lower header 3 of the both evaporator units 1A, and then flows into each refrigerant distribution tube. (4) It flows into the upper header 2 while flowing inside, and flows out into the outlet pipe 9 through the upper communication pipe 6 afterwards.

As shown in FIGS. 3 to 5, the refrigerant flow pipe 4 includes flat left and right walls 11 and 12 and front and rear side walls 13 and 14 that extend across front and rear edges of the left and right walls 11 and 12. ) And a plurality of reinforcing walls 15 extending from the left and right walls 11 and 12 between the front and rear side walls 13 and 14 and extending in the longitudinal direction and provided at predetermined intervals from each other, and parallel to the inside thereof. It consists of the flat tube 17 made from aluminum which has the refrigerant | coolant path | route 16 of the type | mold.

In the part between the reinforcement walls 15 which adjoin the inner surface of the left side wall 11 of the flat pipe 17 made from aluminum, the some processus | protrusion 18 is right at intervals in the longitudinal direction for the purpose of increasing the heat transfer area. They are each formed integrally in a raised form. The reinforcing wall 15 is provided with a plurality of communication holes 19 through which the parallel coolant passages 16 pass. These communication holes 19 have a zigzag arrangement in the left view. When the communication holes 19 are open, the fluids flowing through the parallel fluid passages 16 respectively flow in the width direction of the flat tube 17 through the communication holes 19 and are spread widely in all the fluid passages 16. It is mixed, and there is no temperature difference in the fluid between the fluid passages 16. Therefore, the heat exchange efficiency, that is, the evaporation efficiency of the refrigerant is improved. The opening ratio, which is the ratio of the entire communication holes 19 in each reinforcing wall 15, is preferably in the range of 10 to 40%, particularly 10 to 30%, preferably about 20%. In this case, the effect of improving heat exchange efficiency becomes remarkable by forming the communication holes 19.

The flat aluminum plate 17 made of aluminum comprises the left wall member 11, the front and rear side walls 13 and 14, and the reinforcing wall 15, and is formed of a plate-shaped left structural member 21 and a right wall 12. And the right and right structural members 22 made of aluminum that constitute the front and rear side walls 13 and 14. The left structural member 21 includes a left wall forming portion 23, a right protruding wall 24 integrally formed at right front and rear sides of the left wall forming portion 23 in a right ridge shape, and a left wall forming portion. It consists of the reinforcement wall formation part 25 integrally shape | molded by the inner side ridge type in (23). A plurality of notches 26 are formed at the right edge of the reinforcing wall forming portion 25 at intervals in the longitudinal direction, and the tip of the reinforcing wall forming portion 25 is soldered to the right wall 12, and the notches 26 are formed. The communication hole 19 is formed by the opening part of the () being blocked by the right side wall 12. The inclined surface 27 which inclined to the right toward the front-back direction outer side is formed in the front-back both edges of the outer surface of the left structural member 21.

The right structural member 22 consists of the right side wall forming part 28 and the left side protruding wall 29 integrally formed by the left raised form at the front and back both edges of this right wall forming part 28. As shown in FIG. The height of the left protruding wall 29 is slightly larger than the original height of the reinforcing wall forming portion 25 of the left structural member 21 plus the thickness of the left wall forming portion 23 (see dashed line in FIG. 4). ). The front and rear side walls 13 and 14 of the flat tube 17 are formed by the right protruding wall 24 of the left structural member 21 and the left protruding wall 29 of the right structural member 22.

The left structural member 21 is formed of an aluminum brazing sheet having a brazing material layer only on its outer surface, and the right structural member 22 is formed of an aluminum brazing sheet having a brazing material layer on both surfaces.

The left structural member 21 and the right structural member 22 are formed so that the left protruding wall 29 of the right structural member 22 comes outside the right protruding wall 24 of the left structural member 21 and overlaps them. And the left end portion of the left protruding wall 29 is bent inward and backward inward so that the inner bent portion 29a is closely engaged with the inclined surface 27 so that both constituent members 21 and 22 are temporarily fixed. While the right protruding wall 24 and the left protruding wall 29 are soldered to each other, the tip of the reinforcing wall forming portion 25 is soldered to the right wall forming portion 28, and the inner bent portion 29a is the inclined surface 27. ), The flat tube 17 is formed.

The left structural member 21 is molded by rolling, and the right structural member 22 is formed by roll forming. Rolling of the left structural member 21 is performed using a normal rolling mill. Further, the rolling of the left structural member 21 is performed by a plurality of satellite work rolls which are arranged at equal intervals in the circumferential direction around the center work roll and the center work roll, and which rotate at the same circumferential speed as the center work roll. It may be performed using the rolling mill which consists of. On the peripheral surface of one of the center work roll and each satellite work roll, an annular groove for forming the right protrusion wall and an annular groove for forming the reinforcing wall forming portion are provided over the entire circumference, and for forming the adjacent reinforcing wall forming portion. A plurality of projection forming recesses are provided between the annular grooves at intervals in the circumferential direction, and a notch forming convex portion is provided on the bottom surface of the annular groove for forming the reinforcing wall forming portion. Then, when the aluminum brazing sheet is continuously passed between such a center work roll and all the satellite work rolls, each of the grooves, the recesses and the convex portions are completely transferred to the aluminum brazing sheet to obtain the left constituent member 21 having the desired shape. .

6 and 7 show a second embodiment of the evaporator of the invention.

In Fig. 6, the difference between the evaporator 30 and the evaporator 1 of the first embodiment described above is that the inlet tube 31 of the refrigerant is connected to the upper portion of the center of the length of the upper communication tube 6, The outlet pipe 32 of the refrigerant is connected to the lower portion of the center portion of the length of the communication tube 7. The other structure is the same as that of a 1st specific example.

As shown in FIG. 7, the liquid refrigerant flowing into the upper communication tube 6 from the inlet tube 31 is separated into the upper header 2 of the non-evaporator unit 1A, and then flows into each refrigerant distribution tube. (4) It flows into the lower header 3 while flowing inside, flows into the lower header 3, and then flows out through the lower communication tube 7 to the outlet tube 32.

8 and 9 show a third embodiment of the evaporator of the invention.

In FIG. 8, the right ends of the upper headers 2 of the two evaporator units 1A of the evaporator 35 are communicated by the communication tube 36 connected at both ends to the upper headers 2. In addition, the lower headers 3 of the both evaporator units 1A do not communicate. The refrigerant inlet pipe 37 is connected to the left end of the lower header 3 of the rear evaporator unit 1A, while the refrigerant outlet pipe 38 is connected to the left end of the lower header 3 of the front evaporator unit 1A. ) Is connected. The other structure is the same as that of the 1st specific example mentioned above.

And, as shown in Fig. 9, the liquid refrigerant flowing into the lower header 3 of the rear evaporator unit 1A from the inlet pipe 37 flows upward through the inside of each refrigerant distribution pipe 4, and the upper header ( 2) and then through the communication tube 36 to the upper header (2) of the front evaporator unit (1A), and then flows down inside each refrigerant flow pipe (4) to the lower header (3) In the gas phase, the gas flows out to the outlet pipe 38.

10 and 11 show a fourth embodiment of the evaporator of the present invention.

In FIG. 10, the upper and lower headers 2 and 3 of the two evaporator units 1A of the evaporator 40 have communication tubes 41 each having both ends connected to both upper header 2 and both lower header 3, respectively. 42) the left ends communicate with each other. The inlet tube 43 of the refrigerant is connected to the left side of the center portion of the length of the lower communication tube 42, and the outlet tube 44 of the refrigerant is connected to the left side of the center portion of the length of the upper communication tube 41. The other structure is the same as that of the 1st specific example mentioned above.

As shown in FIG. 11, the liquid refrigerant flowing into the lower communication tube 42 from the inlet tube 43 flows into the lower header 3 of the both evaporator units 1A, and then flows into both evaporators. While flowing inside each refrigerant distribution pipe 4 of the unit 1A, the gas phase flows into the upper header 2 and flows out through the upper communication pipe 41 to the outlet pipe 44.

12 and 13 show a fifth embodiment of the evaporator of the present invention.

In FIG. 12, center portions of the lengths of the upper headers 2 of the two evaporator units 1A of the evaporator 45 pass through the communication tube 6, and the lower headers 3 do not communicate with each other. At the lower header 3 of the rear evaporator unit 1A, the inlet pipe 46 of the refrigerant is connected to the lower portion of the central portion of the length, and at the center of the length of the lower header 3 of the front evaporator unit 1A. The outlet pipe 47 of the refrigerant is connected below. The other structure is the same as that of the 1st specific example mentioned above.

And, as shown in FIG. 13, the liquid refrigerant flowing into the lower header 3 of the rear evaporator unit 1A from the inlet pipe 46 flows upwards inside each refrigerant flow pipe 4 so as to raise the upper header ( 2), and then into the upper header (2) of the front evaporator unit (1A) through the communication tube (6), and then flows downward into the lower header (3) inside each refrigerant flow pipe (4), The gaseous phase is discharged to the outlet pipe 47.

14 and 15 show a sixth embodiment of the evaporator of the present invention.

In FIG. 14, center portions of the lengths of the upper headers 2 of the two evaporator units 1A of the evaporator 50 pass through the communication tube 6, and the lower headers 3 do not communicate with each other. The refrigerant inlet pipe 51 is connected to the left end of the lower header 3 of the rear evaporator unit 1A, and the refrigerant outlet pipe 52 is connected to the left end of the lower header 3 of the front evaporator unit 1A. ) Is connected. The other structure is the same as that of the 1st specific example mentioned above.

As shown in FIG. 15, the liquid refrigerant flowing into the lower header 3 of the rear evaporator unit 1A from the inlet pipe 51 flows upwardly through the inside of each coolant distribution pipe 4 so that the upper header ( 2) and then through the communication tube (6) to the upper header (2) of the front evaporator unit (1A), and then flows down inside each refrigerant flow pipe (4) to the lower header (3) In the gas phase, the gas flows out to the outlet pipe 52.

Figure 16 shows a seventh embodiment of the evaporator of the present invention.

In Fig. 16, the evaporator 55 consists of one evaporator unit 55A. The evaporator unit 55A has a pair of headers 56 and 57 arranged at intervals up and down, and is disposed at intervals in the front and rear directions and both ends of the pair of headers 56 and 57 facing the width direction forward and backward. A plurality of refrigerant flow pipe groups 58 made up of a plurality of connected refrigerant flow pipes 4, for example, are provided. These coolant flow pipe groups 58 are arranged in parallel at intervals in the horizontal direction.

The upper header 56 is composed of a box-shaped header main body 59 opened downward, and a header plate 60 closing the lower opening of the header main body 59. The upper end of 4) is connected.

The lower header 57 is upside down with the upper header 56, and the lower end of the refrigerant flow pipe 4 is connected to the header plate 60. The partition wall 61 is provided in the center part of the length of the lower header 57, and the inside of the lower header 57 is divided into two divisions by this. The inlet pipe 62 of the coolant is connected to the right side of the partition wall 61 on the lower side of the lower header 57, and the outlet pipe 63 of the coolant is similarly connected to the left side.

And in this evaporator 55, the liquid refrigerant | coolant which flowed in from the inlet pipe 62 to the right rather than the partition wall 61 of the lower header 57 is located in all the refrigerant | coolant distribution pipes located in the right side rather than the partition wall 61 ( 4) It flows upward inside and flows into all the refrigerant | coolant distribution pipes 4 located on the left side of the partition wall 61 through the upper header 56, and flows downward inside these refrigerant | coolant distribution pipes 4, and lower header. It flows into the left side of the partition wall 61 of 57, and flows out into the exit pipe 63 in a gaseous phase.

Example 1

This embodiment is carried out using the evaporator 55 of the seventh embodiment.

The length L in the left-right direction of the evaporator 55 was 227 mm, the width W of the front-back direction was 60 mm, and the height H was 235 mm. In addition, the width | variety of the front-back direction of the flat pipe 17 used as each refrigerant | coolant distribution pipe 4 is 18 mm, and the thickness of the left-right direction is 1.7 mm, and the number of the refrigerant | coolant distribution pipe groups 58 which consist of three refrigerant | coolant distribution pipes 4 is shown. Was set to 22.

Then, first, the air side heat transfer area A (m ² ) and the refrigerant side heat transfer area B (m ² ) were obtained. In addition, using HFC134a as a refrigerant, the air inlet temperature (dry bulb: 25 ° C., wet bulb: 17.8 ° C.), pressure before expansion valve: 16.5 kg / cm ² G, subcool: 5 deg, evaporator outlet pressure: 1.8 kg / cm ^The heat exchange amount Q (kcal / h) and the air-side ventilation resistance ΔPa (wet) (mmAq) were measured under conditions of ² G, superheat: 5 deg, and inlet air flow rate: 450 m ³ / h.

Comparative Example 1

This comparative example is carried out using an evaporator using a refrigerant flow pipe made of an aluminum hollow extruded shape member instead of the refrigerant flow pipe made of the flat pipe of the above embodiment. That is, the size of the evaporator is the same as the size of the evaporator of the above embodiment, and the size of the refrigerant flow pipe made of the hollow extruded shape member is also the same as the size of the flat tube of the embodiment.

Then, first, the air side heat transfer area A (m ² ) and the refrigerant side heat transfer area B (m ² ) were obtained. In addition, using HFC134a as the refrigerant, the heat exchange amount Q (kcal / h) and air-side air permeation resistance ΔPa (wet) (mmAq) were measured under the same conditions as in the above example.

Comparative Example 2

This comparative example is the structure described in Unexamined-Japanese-Patent No. 3-230064, and it carried out using the thing of the same size as the evaporator of the said Example except the width of the front-back direction is 75 mm.

First, the air side heat transfer area A (m ² ) and the refrigerant side heat transfer area B (m ² ) were obtained. In addition, using HFC134a as the refrigerant, the heat exchange amount Q (kcal / h) and the air-side air permeation resistance ΔPa (wet) (mmAq) were measured under the same conditions as in the above example.

The results are summarized in the table below.

In the above table, each value of the air-side heat transfer area A, the refrigerant-side heat transfer area B, the heat exchange amount Q and the air-side airflow resistance ΔPa (wet) means a ratio when the comparative example 2 is 100.

As is apparent from the above table, the evaporator of the example has a smaller width in the front-rear direction than the evaporator of Comparative Example 2, and despite the small size as a whole, the amount of heat exchange is equivalent. This is considered to be because the refrigerant-side heat transfer area is larger than the comparative example 2 despite the smaller width in the front-rear direction. In addition, the air-side ventilation resistance of the example is smaller than that of the comparative example 2, and as a result, it is possible to flow more air, in which case the heat exchange amount further increases. In addition, although the size of the evaporator of the comparative example 1 is the same as that of an Example, heat exchange amount is small compared with the case of an Example. This is considered to be because the refrigerant-side heat transfer area is smaller than that of the embodiment, and no communication hole is formed in the reinforcing wall to allow the parallel refrigerant passages to pass through.

Example 2

This Example investigated the relationship between the average dryness (mass ratio of steam in the refrigerant) X (%) of the refrigerant composed of HFC134a and the heat transfer rate h using the refrigerant distribution pipe 4 of Example 1. The measuring method is as follows. That is, the refrigerant flow pipe is disposed in the cooling water passage, the refrigerant made of HFC134a flows inside the refrigerant flow pipe, and the cooling water flows in the cooling water passage, and after a predetermined time has elapsed, the flow rate of the refrigerant is 400 kg / m ² · s, The heat flux between the cooling water was set to 8 kW / m ² , the saturation temperature T of the refrigerant was set to 40 ° C., and the amount of cooling water was set to 1500 to Reynolds number, and the thermal conductivity h was measured while changing the average dryness of the refrigerant.

Comparative Example 3

In this comparative example, the relationship between the average dryness X (%) of the refrigerant composed of HFC134a and the thermal conductivity h was investigated in the same manner as in Example 2, using the refrigerant flow pipe of Comparative Example 1.

The results of Example 2 and Comparative Example 3 are shown in FIG.

As is apparent from Fig. 17, in the case of Example 2 in which the refrigerant-side heat transfer area is large and the communication hole is formed in the reinforcing wall, the comparative example is smaller in the refrigerant-side heat transfer area and the communication hole is not formed in the reinforcement wall. Compared to the case 3, the heat transfer rate h is increased.

According to the present invention, the heat exchange performance, that is, the evaporation performance of the refrigerant, is improved as compared with the conventional evaporator, and the heat exchange performance is also improved compared to the evaporator having the hollow extruded shape, and a compact evaporator is provided.

BRIEF DESCRIPTION OF THE DRAWINGS The perspective view which shows the whole structure of the 1st specific example of the evaporator which concerns on this invention.

Fig. 2 is a diagram showing the flow of refrigerant in the evaporator of the first embodiment.

3 is a partial perspective view of a part of notch of the refrigerant flow pipe in the evaporator of the first embodiment.

4 is a partially enlarged cross-sectional view of the refrigerant flow pipe.

5 is a cross-sectional view taken along the line V-V in FIG. 4.

6 is a perspective view showing the overall configuration of a second embodiment of the evaporator according to the present invention;

7 shows a flow of a refrigerant in the evaporator of the second embodiment.

8 is a perspective view showing the overall configuration of a third embodiment of the evaporator according to the present invention;

Fig. 9 is a diagram showing the flow of refrigerant in the evaporator of the third embodiment.

10 is a perspective view showing the overall configuration of a fourth embodiment of the evaporator of the present invention.

11 is a view showing a flow of a refrigerant in the evaporator of the fourth embodiment.

12 is a perspective view showing an overall configuration of a fifth embodiment of the evaporator of the present invention.

FIG. 13 is a view showing a flow of a refrigerant in the evaporator of the fifth embodiment. FIG.

14 is a perspective view showing the overall configuration of a sixth specific example of an evaporator according to the present invention;

Fig. 15 is a diagram showing the flow of refrigerant in the evaporator of the sixth embodiment.

16 is a perspective view of some notches showing the entire configuration of a seventh embodiment of an evaporator according to the present invention;

17 is a graph showing the results of Example 2 and Comparative Example 3. FIG.

18 is a cross sectional view of a tube element of a conventional evaporator.

<Description of the symbols for the main parts of the drawings>

1: evaporator

2, 3: header

4: refrigerant distribution pipe

6, 7: communication tube

8: entrance tube

9: outlet pipe

15: reinforcement wall

17: flat tube

21: left member

22: right member

23: left wall forming part

24: right protrusion wall

25: reinforcing wall forming part

Claims (10)

At least one evaporator unit comprising a pair of headers arranged parallel to each other and spaced apart from each other, and parallel refrigerant flow pipes of which both ends are connected to each of the headers in a width direction forward and backward, The evaporator unit is provided with a plurality of refrigerant flow pipe group consisting of a plurality of refrigerant flow pipes arranged at intervals in the front and rear direction, these refrigerant flow pipe groups are arranged in parallel in the left and right directions, The refrigerant flow pipe may include a plurality of flat left and right walls, front and rear side walls extending over both front and rear edges of the left and right walls, and a plurality of horizontally extending intervals between the front and rear side walls and extending in a longitudinal direction. An evaporator having a reinforcing wall, comprising a flat tube having a parallel coolant passage therein, wherein the flat tube is formed of a metal plate, and the reinforcing wall is formed of a reinforcing wall forming unit integrally molded from the metal plate into an inner ridge. The evaporator according to claim 1, wherein the reinforcing wall is provided with a plurality of communication holes through which the parallel refrigerant passages pass. The evaporator according to claim 2, wherein the plurality of communication holes are formed in a zigzag arrangement when viewed from the left side. The evaporator of Claim 2 or 3 whose opening ratio which is a ratio which the whole communication hole occupies in each reinforcement wall is 10 to 40%. According to claim 1, wherein the two evaporator units are arranged in parallel at intervals back and forth, the upper headers and the lower headers of the two evaporator units are respectively communicated by a communication tube, the refrigerant inlet to one communication tube An evaporator in which an outlet tube of refrigerant is connected to the other communicating tube while the tube is connected. According to claim 1, wherein two evaporator units are arranged in parallel at intervals back and forth, the upper headers of the two evaporator units are communicated by a communication tube, the inlet pipe of the refrigerant to the lower header of one evaporator unit An evaporator in which the outlet pipe of the refrigerant is connected to the lower header of the other evaporator unit while being connected. The said flat tube is formed of the plate-shaped left structural member which has a left wall formation part, and the plate-shaped right structural member which has a right wall formation part, The front and rear both side walls of the said flat tube are the said left structural member. The right protruding wall integrally molded at the right and left both edges of the front and rear edges of the right structural member and soldered to the right structural member, and the left protruding wall integrally molded at the front and rear both edges of the right structural member and soldered to the left structural member. And a reinforcing wall of the flat tube is integrally molded in at least one of a left side wall forming portion of the left constituting member and a right side wall forming portion of the right constituting member, and at the tip thereof An evaporator comprising a reinforcing wall forming portion soldered to the other side. 8. The evaporator according to claim 7, wherein the reinforcing wall is provided with a plurality of communication holes through which parallel coolant passages pass. The evaporator according to claim 8, wherein the plurality of communication holes are formed in a zigzag arrangement when viewed from the left side. The evaporator of Claim 8 or 9 whose opening ratio which is the ratio which the whole communication hole occupies in each reinforcement wall is 10 to 40%.

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