JP2984480B2 - Stacked heat exchanger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated heat exchanger for an air conditioner.

[0002]

2. Description of the Related Art A conventional laminated heat exchanger will be described with reference to FIGS. FIG. 7 shows a side view of a conventional laminated heat exchanger, and FIG. 8 shows an enlarged cross section of the right side in FIG.

In FIGS. 7 and 8, reference numeral 1 denotes a flat tube, and the flat tube 1 is formed by abutting two press-formed plates 2. An entrance / exit tank portion 3 is formed at one end (upper end in the figure) of the flat tube 1.

[0004] The flat tubes 1 and corrugated fins 4 are alternately stacked, and the inlet / outlet tank portion 3 is connected to form a stacked heat exchanger (evaporator) 5.

The outer side of the flat tubes 1a located at both ends is an end plate 6, and a flow hole 7 is provided in the end plate 6 of the entrance / exit tank portion 3. One of the flow holes 7 is connected to a refrigerant introduction pipe 8, and the other flow hole 7 is connected to a refrigerant discharge pipe 9.

The introduction pipe 8 and the discharge pipe 9 are fixed by a side plate 10, and a corrugated fin 4 is provided between the side plate 10 and the end plate 6.

The inlet / outlet tank section 3 is divided into an inlet section 11 and an outlet section 12 in the plate width direction of the flat tube 1, and when the evaporator 5 is constructed, the adjacent inlet / outlet tank sections 3 are connected to each other. These are communicated with each other by the communication hole 13.

The flat tube 1 will be described with reference to FIGS. FIG. 9 is a front view of the plate 2 constituting the flat tube 1, and FIG. 10 is a view taken along line XX in FIG.

An entrance / exit tank section 3 is provided at the upper end of the plate 2.
Is formed, and the inner space of the plate 2 is partitioned into two chambers 16 and 17 by a partition wall 15 extending vertically in the center. A lower end of the partition wall 15 is absent, and a lower end of the plate 2 is a U-turn portion 18 for making a U-turn of the refrigerant. By abutting the two plates 2, the entrance / exit tank portion 3 is partitioned by the partition wall 15 into an inlet portion 11 and an outlet portion 12, and a chamber 16 continuous with the inlet portion 11 and a chamber continuous with the outlet portion 12. 17 and is divided. Further, the chambers 16 and 17 are U
Fluid passages are formed in the chambers 16 and 17 and the U-turn part 18 so as to communicate with each other at the turn part 18.

A large number of ribs 19 project from the chambers 16 and 17, and the inside of the chambers 16 and 17 is subdivided into a maze. A guide rib 20 protrudes from the U-turn portion 18, and the refrigerant flows from the chamber 16 to the chamber 17 by the guide rib 20 (U-turn).
Will be guided.

The evaporator 5 described above with reference to FIG.
Will be described. FIG. 11 shows the flow state of the refrigerant.

The evaporator 5 has three groups 21, 22, 2
3 and the arrangement of the inlet 11 and the outlet 12 in the groups 21 and 23 to which the introduction pipe 8 and the discharge pipe 9 are connected are the same, and the inlet 11 and the outlet 1 in the group 22 are the same.
The arrangement of 2 is reversed. The entrance / exit tank unit 3 facing between the groups 21 and 22 and between the groups 22 and 23 is group 2
1 and the inlet 11 of the group 22 communicate with each other.
The outlet 12 of the group 23 and the inlet 11 of the group 23 communicate with each other. The inlet 11 of the group 21 is connected to the introduction pipe 8 by the flow hole 7 of the end plate 6, and the outlet 12 of the group 23 is connected to the discharge pipe 9 by the flow hole 7 of the end plate 6.

The refrigerant 31 introduced into the evaporator 5 from the introduction pipe 8 is sent from the inlet 11 of the group 21 to the U-turn part 18 through the chamber 16, is U-turned by the U-turn part 18, and passes through the chamber 17. To the outlet 12. The refrigerant 31 sent to the outlet 12 of the group 21 is sent to the inlet 11 of the group 22 and sent to the group 23 in the same flow as the group 21,
Is discharged from the discharge pipe 9 through the fluid passages (chambers 16, 17 and the U-turn portion 18).

During this time, the air 3 is placed between the corrugated fins 4.
2 is sent, and the air 32 is cooled using the latent heat of evaporation of the refrigerant 31.

[0015]

In the evaporator 5 described above, the chambers 16 inside the plate 2 of the flat tube 1 are provided.
Although a large number of ribs 19 are provided on 17 to increase the heat transfer area of the refrigerant, it is still insufficient, and further improvement in the heat transfer coefficient has been desired.

[0016]

Configuration of the present invention for solving the above object, according to an aspect of the, and a core portion that forms the entrance tank and the fluid passage of the fluid therebetween butting two plates obtained by press molding In a laminated heat exchanger in which a flat tube is formed by sandwiching an inner fin and a plurality of the tubes and the fins are alternately laminated, the plate and the inner
And fine embossing is applied to a plate portion of the fluid passage formed by the fins .

[0017]

According to the above construction, the heat transfer coefficient is further improved by further expanding the heat transfer area of the refrigerant and promoting turbulence.

[0018]

FIG. 1 is an exploded perspective view of a flat tube in a laminated heat exchanger according to an embodiment of the present invention. FIG. 2 is a front view showing a joining surface of plates constituting the flat tube.
2 shows a detailed state of an arrow III part in FIG. 2, FIG. 4 shows a side view of the stacked heat exchanger, FIG. 5 shows a view taken along a line VV in FIG. 4, and FIG. The perspective view of the main part is shown.

The flat tube 41 is formed by abutting two press-formed plates 42. An inlet / outlet tank part 43 is formed at one end (the upper end in FIG. 2) of the flat tube 41.

As shown in FIG. 4, the flat tubes 41 and the corrugated fins 65 are alternately stacked, and the inlet / outlet tank section 43 is connected to form a stacked heat exchanger (evaporator) 66.
Is configured. In the figure, 69a is a piping for introducing a refrigerant as a fluid, and 69b is a piping for discharging the refrigerant. Doorway tank part 4
3 is divided into an inlet portion 44 and an outlet portion 45 in the plate width direction of the flat tube 41 to constitute an evaporator 66.
Adjacent entrance / exit tank portions 43 have inlet portions 44 and outlet portions 45 communicating with each other through communication holes 46.

The inner space of the plate 42 is partitioned into two chambers 48 and 49 by a partition wall 47 extending vertically in the center. A lower end of the partition wall 47 is absent, and a lower end of the plate 42 is a U-turn portion 50 for making a U-turn of the refrigerant. By abutting the two plates 42,
The partition wall 47 allows the entrance / exit tank portion 43 to be connected to the entrance portion 44
And an outlet 45, and a chamber 48 connected to the inlet 44 and a chamber 49 connected to the outlet 45. Further, the chamber 48 and the chamber 49 are communicated by a U-turn part 50, and a fluid passage (core part) 51 is formed by the chambers 48, 49 and the U-turn part 50.

Corrugated inner fins 52 and 53 are inserted into the chambers 48 and 49 (linear portions) of the fluid passage 51. As shown in FIG. 5, the corrugated inner fins 52, 53 are provided with flow paths 5 along the longitudinal direction (up-down direction) of the chambers 48, 49.
A plurality of waveforms 52a and 53a along the length direction are formed so that a plurality of sections 4 and 55 are separately formed.

In the chambers 48 and 49, a protruding wall 67 is formed which extends parallel to the partition wall 47 and has a groove-like outside of the plate 42. When the two plates 42 are butted and joined, as shown in FIG.
Is mounted with its central portion sandwiched between the projecting walls 67.

By forming a groove on the outside of the plate 42 by the protruding wall 67, a groove formed by the partition wall 47 and a groove formed by the protruding wall 67 are present on the outer surface of the flat tube 41. And the flow of the condensed water can be promoted to prevent dew dropping.

The inner surface of the core portion 51 of the plate 42 is embossed, and a large number of minute projections 70 are formed on the core portion 5.
1 is protruded. This embossing is not limited to the minute protrusion 70, and as shown in FIG.
A) or meandering ridge 71b (b in FIG. 6)
But it is good. In FIG. 5, the minute projections 70 are omitted because the drawing is complicated. In the illustrated example, embossing is performed on the inner surface of the core portion 51, but may be performed on the inner surface of the entrance / exit tank portion 43.

As shown in FIG.
The height P of the edge portions 52c and 53c of the
The press forming depth Q of the portion where the second chambers 48 and 49 are formed is smaller than the press forming depth Q. Thereby, the corrugated inner fins 52, 53
Are arranged in the chambers 48 and 49 and the two plates 42 are abutted and joined to each other, so that the edges 52 c and 53 c of the corrugated inner fins 52 and 53 are not sandwiched between the joining edges 42 a of the plates 42. In addition, the edge portions 52c, 53c of the corrugated inner fins 52, 53 are not pushed by the joining edge 42a of the plate 42, so that the corrugated inner fins 52, 53 do not shift.

Therefore, the corrugated inner fins 52, 53
By using, the corrugated inner fins 52 and 53 can be reliably and easily arranged at predetermined positions in the chambers 48 and 49 formed by the two plates 42.

In the U-turn section 50 of the fluid passage 51, a plurality of U-shaped flow paths 56 for guiding the U-turn of the refrigerant are separately formed. The U-shaped channel 56 is formed by a plurality of U-shaped beads 57 press-formed on the abutting surface of the plate 42, and the U-shaped channel 56 has a U-shape that conforms to the shape of the plate 42.

When the refrigerant flows between the chambers 48 and 49, the refrigerant flowing through the channels 54 and 55 on the outside in the width direction of the flat tube 41 flows through the U-shaped channel 56 on the outside of the U-turn part 50. Further, the flow path 54 on the inner side in the width direction of the flat tube 41,
The refrigerant flowing through 55 flows through a U-shaped channel 56 inside the U-turn part 50. That is, the refrigerant in the flat tube 41 passes from the inside to the inside and from the outside to the outside, and passes through the fluid passage 51.
Flows through.

In the flat tube 41 described above, the inlet 4
The refrigerant as the fluid flowing from 4 is guided to the U-turn section 50 through the flow path 54 defined by the corrugated inner fin 52, and is U-turned in the U-shaped flow path 56 defined by the U-shaped bead 57. , And flows to the outlet 45 through a flow path 55 defined by the corrugated inner fins 53. An example of the flow of the refrigerant and the air in the entire evaporator in which the flat tubes 41 and the corrugated fins are alternately stacked is the same as the situation shown in FIG.

Since the refrigerant flowing in the flat tube 41 flows through the divided flow paths 54 and 55 and the U-shaped flow path 56, the refrigerant flows from the inside to the inside of the fluid passage 51 and from the outside to the outside. The separation of the gas-liquid two-phase flow refrigerant due to the centrifugal force at 50 is limited only to the U-shaped flow path 56, and the distribution of the gas-liquid distribution of the two-phase flow refrigerant is reduced. Also, U
Since the U-shaped flow path 56 of the turn portion 50 has a U-shape that follows the shape of the plate 42, no stagnation occurs in the flow of the refrigerant.

As a result, the distribution of the gas-liquid distribution amount of the refrigerant is reduced, so that the thermal efficiency is not easily reduced due to the bias, and the flow of the refrigerant does not stagnate and the heat exchange amount does not become uneven.

In this embodiment, the core 51
Since a large number of minute projections 70 are provided on the inner surface, the heat transfer area of the refrigerant can be increased, and the generation of turbulent flow of the refrigerant is promoted. As a result, the heat transfer coefficient on the refrigerant side is further improved.

As shown in FIG. 3, the projection 6 is formed on the joint edge 42a of the plate 42 and the U-turn portion 50 side of the partition wall 47.
1 is press-formed. The projections 61 position the corrugated inner fins 52, 53 in the chambers 48, 49, and the lower edges 52b, 52b, of the corrugated inner fins 52, 53 with respect to the upper end position of the U-shaped flow path 56 (U-shaped bead 57).
The position of 53b is regulated.

The gap S between the upper end of the U-shaped channel 56 and the lower edges 52b, 53b of the corrugated inner fins 52, 53 is set to 0.5 mm to 5 mm.

When the gap S is less than 0.5 mm, the pitch of the flow paths 54 and 55 formed by the corrugated inner fins 52 and 53 and the pitch of the U-shaped flow path 56 are different. The flow path 5 that matches the U-shaped bead 57 to be formed
The refrigerant passing through 4, 55 becomes difficult to flow.

On the other hand, if the gap S exceeds 5 mm, when the plate 42 is brazed and joined, the brazing portion becomes large and the pressure resistance is insufficient.

As shown in FIG. 2, crimping stoppers 68 are provided at four positions on the joining edge 42a of the plate 42. The corrugated inner fins 52 and 53 are arranged in the chambers 48 and 49 formed by the two plates 42, and the plates 42 are butted against each other by the caulking portion 68.
By caulking, the flat tube 41 into which the corrugated inner fins 52 and 53 are inserted is configured as an assembly.

A method of manufacturing the evaporator 66 using the flat tube 41 having the above configuration will be described.

A chamber 48 formed by two plates 42,
The corrugated inner fins 52 and 53 are inserted into 49, the plates 42 are butted against each other, and the two plates 42 are integrated by the caulking portion 68 to form the flat tube 4 as an assembly.
Let it be 1.

A plurality of flat tubes 41 and corrugated fins 65 are assembled alternately in a stacked state and brazed in an oven to produce an evaporator 66.

The evaporator 66 manufactured by the method described above.
Since the flat tube 41 is manufactured as an assembly in advance, the flat tube 41 can be manufactured with high reliability, and no refrigerant leakage occurs.

In the evaporator 66 having the above structure, the flow paths 54, 55 in the longitudinal direction of the chambers 48, 49 of the flat tube 41 are provided.
Are formed separately by the corrugated inner fins 52 and 53, so that the flow of the refrigerant can be made smooth and the flow path area can be increased. Also, the corrugated inner fins 52, 5
Since the height P of the edge portions 52c, 53c of the plate 3 is smaller than the press forming depth Q of the chambers 48, 49 of the plate 42, the edge portions 52c, 53c are
When the plate 42 is joined by riding on 2a, the joining edge 4
The edge portions 52c and 53c are not sandwiched between 2a. Further, the edge portions 52c, 53c are not pushed by the joining edge 42a when the plate 42 is joined, so that the corrugated inner fins 52, 53 do not shift.

[0044]

As described above, the stacked heat exchanger of the present invention is capable of
Press forming the mouth tank and the core forming the fluid passage
Butt the two plates and insert the inner
To form a flat tube.
Stack heat exchanger consisting of multiple layers
And the fluid formed by the plate and the inner fin
That the plate part of the passage was finely embossed
Because of this feature, the heat exchange efficiency is improved by the inner fins.
The heat exchange efficiency of the upper and fine embossing
A synergistic effect of improvement is obtained, and the heat transfer area can be improved by further expanding the heat transfer area of the refrigerant and promoting turbulence.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a flat tube in a laminated heat exchanger according to one embodiment of the present invention.

FIG. 2 is a front view showing a joint surface of a plate constituting the flat tube.

FIG. 3 is a detailed view of an arrow III part in FIG. 2;

FIG. 4 is a side view of the stacked heat exchanger.

FIG. 5 is a view taken along line VV in FIG. 4;

FIG. 6 is an essential part perspective view of a plate showing a modification of embossing.

FIG. 7 is a side view of a conventional laminated heat exchanger.

FIG. 8 is an enlarged sectional view of the right side in FIG. 7;

FIG. 9 is a front view of a plate constituting the flat tube.

FIG. 10 is a view taken along line XX in FIG. 9;

FIG. 11 is an explanatory diagram of a flow state of a refrigerant.

[Explanation of symbols]

 41 Flat tube 42 Plate 42a Joining edge 43 Inlet / outlet tank part 44 Inlet part 45 Outlet part 46 Communication hole 47 Partition wall 48, 49 chamber 50 U-turn part 51 Fluid passage 52, 53 Corrugated inner fin 52c, 53c Edge 54 Passage 56 U-shaped flow path 57 U-shaped bead 65 corrugated fin 66 evaporator 68 caulking stopper 70 minute projection 71a, 71b ridge

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F28D 1/03 F28F 3/00-3/14

Claims (1)

(57) [Claims] 1. A flat tube formed by pressing two plates formed by press-forming a fluid inlet / outlet tank portion and a core portion forming a fluid passage , sandwiching an inner fin therebetween, and alternately forming the flat tube. In the stacked heat exchanger having a large number of layers, the plate and the inner
A laminated heat exchanger in which a fine embossing is applied to a plate portion of a fluid passage formed by the heat exchanger.