JP3095547B2 - 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. 8 is a side view of a conventional laminated heat exchanger, and FIG. 9 is an enlarged cross section of the right side in FIG.

8 and 9, 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.

[0006] corrugated fin 4 is provided between the sub id 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.

[0008] The flat tube 1 will be described with reference to Figs.
Will be described. FIG. 10 is a front view of the plate 2 constituting the flat tube 1, and FIG. 11 is a view taken along line XI-XI 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. 12 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 above-mentioned evaporator 5, since the tube diameter of each group 21 to 23 is the same, the refrigerant is almost 80% liquid at the inlet of the evaporator. When it becomes 100% gas, the volume becomes
In order to solve the problem that the pressure loss (ΔPh) becomes several hundred times and the pressure drop (ΔPh) becomes very large, the performance is reduced.
The number of tubes in the downstream tube group is
It was necessary to increase the number of tubes in the group. Increasing the number of tubes has the effect of reducing pressure loss, but increasing the number excessively has an adverse effect on refrigerant distribution and refrigerant-side heat transfer.
And there is a disadvantage that the performance is reduced.

[0016]

According to the structure of the present invention, a pair of forming plates having a fluid inlet / outlet tank portion and a core portion forming a fluid flow path are provided on a fluid flow path portion. An inner fin is inserted to form a superimposed flat tube, and a plurality of the flat tubes and corrugated fins are alternately laminated, and the plurality of flat tubes are divided into a plurality of tube groups from the inlet side to the outlet side of the fluid. /> in the Tsu switching laminated heat exchanger, characterized by being larger than the fin pitch of the waveform inner fins of the inlet-side tube group fin pitch waveforms inner fins being inserted into the flat tube of the outlet-side tube group .

Further, a pair of forming plates having a fluid inlet / outlet tank portion provided at one end and a core portion forming a U-shaped fluid flow passage which turns at the other end are formed by a linear portion of the U-shaped flow passage. A corrugated inner fin is inserted into each to form a superimposed flat tube, and a plurality of the flat tubes and corrugated fins are alternately laminated, and these many flat tubes are formed into a plurality of tube groups from the inlet side to the outlet side of the fluid. in the stacked heat exchanger Tsu partition less when
The fin pitch of the corrugated inner fin inserted into the downstream flow path is larger than the fin pitch of the corrugated inner fin inserted into the upstream flow path of the U-shaped flow path of each flat tube of the one tube group. It is characterized by.

[0018]

According to the above construction, in addition to a slight increase in the number of tubes, the internal resistance at the outlet tube can be reduced, and the pressure loss of the refrigerant can be reduced without lowering the performance.

[0019]

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.
4 shows a detailed state of an arrow III part in FIG. 2, FIG. 4 shows a side view of the laminated heat exchanger, FIG. 5 shows the same plane, and FIG. 6 shows a cross section of a flat tube.

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 FIGS. 4 and 5, flat tubes 41 and corrugated fins 65 are alternately stacked, and the inlet / outlet tank section 43 is connected to form a stacked heat exchanger (evaporator) 66. In the figure, 69a is a piping for introducing a refrigerant as a fluid, and 69b is a piping for discharging the refrigerant. In this embodiment, the refrigerant is divided into three tube groups 53a to 53c from the inlet side to the outlet side of the refrigerant, and the number of tubes in the tube group 53c on the outlet side is the other tube group 53c.
The number of a and 53b is increased from six to seven. The entrance / exit tank section 43 is partitioned into an entrance section 44 and an exit section 45 in the plate width direction of the flat tube 41, and when the evaporator 66 is configured, the entrance / exit tank section 4 adjacent thereto is formed.
In 3, the inlet portions 44 and the outlet portions 45 are communicated by the communication holes 46.

The inner space of the plate 42 is divided 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.

The corrugated inner fins 52a to 52d are inserted into the chambers 48, 49 (linear portions) of the fluid passage 51, and flow along the length direction (vertical direction) of the chambers 48, 49 as shown in FIG. A plurality of roads are formed separately from each other.

Projecting walls 67 are formed in the chambers 48 and 49 so as to extend in parallel along the partition wall 47 and form a groove on the outside of the plate 42. When the two plates 42 are butted and joined, as shown in FIG. 6, the corrugated inner fins 52a to 52a-5
2d is positioned and fixed by the partition wall 47 and the protruding wall 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 exist on the outer surface of the flat tube 41. And the flow of the condensed water can be promoted to prevent dew dropping.

In this embodiment, as shown in FIG.
The inlet side of the tube group 53a, 53b to the inserted waveform Lee <br/> runner fins 52a~52d of the outlet side of the fin pitch tube group 53c in the inserted waveform inner fins 52a
The fin pitch of ~ 52d is set larger, and the internal resistance is reduced. From a similar point of view, not limited to FIG.
As shown in FIG. 7, the corrugated inner fin 52 located on the upstream side of the refrigerant flow in the tube group 53c on the outlet side.
The fin pitches of the corrugated inner fins 52a and 52b located downstream of the fin pitches of c and 52d may be set larger.

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

When the refrigerant flows between the chambers 48 and 49, the refrigerant flowing through the flow path outside the flat tube 41 in the width direction flows through the turn flow path 56 outside the U-turn part 50. The refrigerant flowing through the flow path inside the flat tube 41 in the width direction is U
It flows through the turn channel 56 inside the turn part 50. That is, the refrigerant in the flat tube 41 flows through the fluid passage 51 from inside to inside and from outside to outside.

In the flat tube 41 described above, the inlet 4
The refrigerant as the fluid flowing from the U-turn portion 5 passes through a flow path defined by the corrugated inner fins 52a and 52b.
0, and is U-turned in the turn flow path 56 defined by the U-shaped bead 57, and the corrugated inner fins 52c, 52d
And flows to the outlet 45 through the flow path defined by. 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 partitioned flow path and the turn flow path 56, the refrigerant flows from the inside to the inside of the fluid passage 51 and from the outside to the outside. As a result, the gas-liquid two-phase refrigerant is separated only in the turn channel 56, and the distribution of the gas-liquid distribution of the two-phase refrigerant becomes smaller. The U-turn section 50
Since the turn flow path 56 has a U-shape conforming to 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 become stagnant, so that the heat exchange amount is not uniform.

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 52a to 52d in the chambers 48 and 49, and regulate the position of the lower edge of the corrugated inner fins 52a to 52d with respect to the upper end position of the turn flow path 56 (U-shaped bead 57). .

The gap S between the upper end position of the turn channel 56 and the lower end edges of the corrugated inner fins 52a to 52d is 0.5 mm to 5 mm.
is set to mm.

When the gap S is smaller than 0.5 mm, the pitch of the flow path formed by the corrugated inner fins 52a to 52d and the pitch of the turn flow path 56 are different.
Therefore, it becomes difficult for the refrigerant to flow through the flow path that matches the U-shaped bead 57 that forms

On the other hand, if the gap S exceeds 5 mm, when the plate 42 is brazed and joined, the brazed 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. Corrugated inner fins 52 a to 52 d are arranged in chambers 48 and 49 formed by two plates 42,
Are crimped and the two plates 42 are caulked by the caulking stopper 68 so that the corrugated inner fins 52 a to 52
The flat tube 41 into which d is 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 a to 52 d 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 a flat tube 41 as an assembly.

A plurality of flat tubes 41 and corrugated fins 65 are assembled alternately in a stacked state, and these are brazed in a furnace 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-described structure, the flow paths in the longitudinal direction of the chambers 48 and 49 of the flat tube 41 are separated and formed by the corrugated inner fins 52a to 52d. Can be increased. Also, the corrugated inner fins 52a to 52
In (d), the fin pitch of the tube group 53c on the outlet side is made larger than the fin pitch of the tube groups 53a and 53b on the inlet side to reduce the internal resistance as much as possible. 1 tube
Together with the increase, the pressure loss of the refrigerant can be reduced without lowering the performance.

[0042]

According to the laminated heat exchanger of the present invention, the number of tubes in the tube group on the outlet side is slightly increased and the fin pitch of the corrugated inner fin is increased as much as possible, so that the pressure loss of the refrigerant is effectively reduced. it can.

[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 plan view of the stacked heat exchanger.

FIG. 6 is a sectional view of a flat tube.

FIG. 7 is a sectional view of a modification of the flat tube.

FIG. 8 is a side view of a conventional laminated heat exchanger.

FIG. 9 is an enlarged sectional view of the right side in FIG. 8;

FIG. 10 is a front view of a plate constituting the flat tube.

FIG. 11 is a view taken along line XI-XI in FIG. 10;

FIG. 12 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 52a-52d Waved inner fin 56 Turn flow path 57 U-shaped bead 65 Corrugated fin 66 Evaporator 68 Pre-staking part

Continued on the front page (72) Inventor Hidenao Kawai 1 Nagoya Laboratory, Iwazuka-cho, Nakamura-ku, Nagoya-shi, Aichi Nagoya Research Laboratory Mitsubishi Heavy Industries, Ltd. (56) References JP-A-4-254170 (JP, A) JP-A-3-207969 (JP, A) JP-A-61-55565 (JP, A) JP-A-48-100746 (JP, A) JP-A-61-173097 (JP, A) (JP, U) Jikkai Sho 56-28587 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F25B 39/02 F28F 1/40

Claims (2)

(57) [Claims] A flat tube is formed by superimposing a pair of forming plates having a fluid inlet / outlet tank portion and a core portion forming a fluid flow path by inserting a corrugated inner fin into the fluid flow path portion to form a flat tube. with a large number laminated and corrugated fins alternately, partition Tsu multiple tube group toward the outlet side a number of flat tubes them from the inlet side of the fluid
In the stacked heat exchanger, the laminated heat exchanger, characterized in that larger than the fin pitch of the waveform inner fins of the inlet-side tube group fin pitch waveforms inner fins being inserted into the flat tube of the outlet-side tube group vessel. 2. A pair of forming plates having a fluid inlet / outlet tank part provided at one end and a core part forming a U-shaped fluid flow path turning at the other end, and a linear portion of the U-shaped flow path. A corrugated inner fin is inserted into each to form a superimposed flat tube, and a plurality of the flat tubes and corrugated fins are alternately laminated, and these many flat tubes are formed into a plurality of tube groups from the inlet side to the outlet side of the fluid. in the stacked heat exchanger Tsu partition, at least a
The fin pitch of the corrugated inner fin inserted into the downstream flow path is larger than the fin pitch of the corrugated inner fin inserted into the upstream flow path of the U-shaped flow path of each flat tube of the two tube groups. Stacked heat exchanger.