JP2002340442A - Heat exchanger - Google Patents

Abstract

(57) Abstract: The present invention provides a heat exchanger capable of sufficiently exhibiting a heat exchange effect even when a liquid-phase refrigerant and a gas-phase refrigerant of a two-phase refrigerant are introduced into a heat exchange unit. is there. In particular, considering the flow state of the gas-phase refrigerant and the liquid-phase refrigerant in the heat exchange unit,
The flow of the gas-phase refrigerant in the heat exchange unit is reduced as much as possible, and the stagnation of the gas-phase refrigerant in the refrigerant passage of the heat exchange unit is reduced. A branch passage (17) is provided in an upper tank portion (6b) of a leeward heat exchange unit (2c), and a refrigerant supplied to the tank portion (6b) flows through a tube of the leeward heat exchange unit (2c). 3c and a flow flowing into the upper second tank 8b of the windward heat exchange unit 3c through the branch passage 17, and a refrigerant containing a large amount of gaseous refrigerant flows through the branch passage 17. The liquid refrigerant flows through the tube.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger constituted by connecting at least a plurality of heat exchange units having a refrigerant passage for evaporating a refrigerant.

[0002]

2. Description of the Related Art Conventionally, a heat exchanger 200 as disclosed in JP-A-09-170850 has been known. In this heat exchanger 200, as shown in FIG. 14, the heat exchange units have tank portions arranged at both upper and lower ends, and are stacked on the leeward side and the leeward side.

In this heat exchanger 200, a partition 207 is provided at the center of the lower tank 204 of the leeward heat exchanger 201.
And is divided into a first lower tank 204a and a second lower tank 204b. Similarly, windward heat exchanger 2
02, a partition portion 208 is provided at the center of the upper tank portion 205, and a first upper tank 205a and a second upper tank 2 are provided.
05b. A refrigerant inlet 214 is provided in the first lower tank 204a, and the first upper tank 205
The outlet part 215 is provided in a.

[0004] In this heat exchanger 200, the refrigerant flows into the inlet 2
14, the refrigerant enters the first lower tank 204 a, ascends the refrigerant passage in the tube, and is guided to the upper tank 203. Then, the gas flows right and left in the upper tank 203 and descends in the tube to reach the second lower tank 204b. Further, the refrigerant flows through the communication passage 218 to the second upper tank 20.
5b, from the inside of the tube, to the lower tank 206, and then to the left and right through the lower tank 206, and then rises in the tube to the first upper tank 20.
5a, the outlet 21 of the first upper tank 205a.
Exhausted from 5

[0005]

Problems to be Solved by the Invention Japanese Patent Laid-Open No. 09-1708
In the case of No. 50, the liquid-phase refrigerant and the gas-phase refrigerant of the gas-liquid two-phase refrigerant enter the first lower tank 204a from the inlet part 214, rise up the refrigerant passage in the tube, and are guided to the upper tank 203. At that time, as shown in FIG. 15, the gaseous refrigerant that easily flows tends to accumulate in the upper central portion of the refrigerant passage. Then, the refrigerant flows left and right through the upper tank 203 and then descends the refrigerant passage to reach the second lower tank 204b. When flowing through the upper tank 203 left and right, the liquid-phase refrigerant flows due to the flow inertia. As a result, the gas-phase refrigerant tends to accumulate in the lower central portion of the refrigerant passage. The same occurs in the windward heat exchange unit 202.

[0006] As described above, since the gas-phase refrigerant tends to concentrate on a part of the inside and stagnate, a uniform flow cannot be performed.
A uniform heat distribution cannot be obtained, and heat exchange in the heat exchange unit is insufficient. Therefore, increase the number of heat exchange units,
It is conceivable to increase the length of the refrigerant passage. In that case, the total capacity of the heat exchange unit increases, and a space problem occurs. It is also conceivable that the number of heat exchange units is increased by subdividing the heat exchange units, that is, the number of heat exchange units is increased. However, the path length of the refrigerant passage increases, the flow resistance increases, and the pressure loss increases.

An object of the present invention is to solve the above-mentioned problems of the prior art. In particular, even when a liquid-phase refrigerant and a gas-phase refrigerant of a two-phase refrigerant are introduced into a heat exchange unit, the heat exchange effect can be sufficiently improved. It is intended to provide a heat exchanger that can be used. In particular,
Considering the flow state of the gas-phase refrigerant and the liquid-phase refrigerant in the heat exchange unit, minimize the flow of the gas-phase refrigerant in the heat exchange unit, and allow the gas-phase refrigerant to flow in the refrigerant passage of the heat exchange unit. This is to reduce stagnation.

[0008]

According to the first aspect of the present invention, a pair of tanks, a refrigerant passage including a tube connected between the tanks, and a fin are provided between the tubes. A branch passage that includes a plurality of heat exchange units and supplies refrigerant to the tank unit of the downstream heat exchange unit, bypassing at least a part of the refrigerant passage of the upstream heat exchange unit, in one of the tank units of the upstream heat exchange unit. The refrigerant supplied to the tank portion of the upstream heat exchange unit flows through the refrigerant passage of the upstream heat exchange unit and flows into the other tank portion, and the downstream heat flows through the branch passage. The flow flowing into the tank unit of the exchange unit is formed, and the cross-sectional area of the branch passage is formed to be equal to or larger than the cross-sectional area of the tube of the upstream heat exchange unit.

With this configuration, the refrigerant having a large amount of the gaseous refrigerant can be reliably bypassed to the heat exchange unit.
The heat exchange variation in the heat exchange unit can be reduced, and the heat exchange function can be improved. In particular, since the cross-sectional area of the branch passage is formed to be equal to or larger than the cross-sectional area of the tube of the upstream heat exchange unit, the pipe passage resistance can be reduced, and the refrigerant having a large amount of gas-phase refrigerant can be separated and passed. .

According to a second aspect of the present invention, in the heat exchanger of the first aspect, the branch passage has a flow direction of the refrigerant in the branch passage substantially perpendicular to a flow direction of the tank portion provided with the branch passage. As a result, the heat exchange unit can be bypassed with a simple configuration for a refrigerant containing a large amount of gaseous refrigerant, and the heat exchange efficiency can be improved.

According to a third aspect of the present invention, in the heat exchanger according to the first or second aspect, the upstream heat exchange unit is installed on the leeward side, and the downstream heat exchange unit is connected to the upstream heat exchange unit. The branch passage is provided so as to overlap the windward side of the side heat exchange unit, and the branch passage is provided by connecting the tank portion of the leeward side heat exchange unit and the tank portion of the windward heat exchange unit, and flows through the branch passage. Is configured to bypass at least part of the refrigerant passages of the leeward heat exchange unit and the leeward heat exchange unit, so that heat exchange on the leeward and leeward sides can be effectively performed. Heat exchange efficiency can be greatly improved.

According to a fourth aspect of the present invention, in the heat exchanger according to the third aspect, each of the leeward heat exchange unit and the leeward heat exchange unit has upper and lower tank portions, and the branch passage is provided on the leeward side. Since the adjacent upper tank portions of the side heat exchange unit and the windward heat exchange unit are provided in communication with each other, a relatively light gas-phase refrigerant can be efficiently bypassed, and the heat exchange efficiency can be improved.

According to a fifth aspect of the present invention, in the heat exchanger according to the third or fourth aspect, the leeward heat exchange unit has two heat exchange units on the upstream side and the downstream side, and the first heat exchanger on the upstream side. An inlet portion for the refrigerant is provided in the upstream tank portion of the exchange unit, and the branch passage is provided by connecting the tank portion provided with the inlet portion and the tank portion of the windward heat exchange unit. Since the refrigerant flowing through the branch passage can bypass the first heat exchange unit and the second heat exchange unit of the leeward heat exchange unit, the heat exchange variation of the refrigerant on the leeward side is reduced, and the heat exchange efficiency is reduced. Is dramatically improved.

According to a sixth aspect of the present invention, in the heat exchanger according to the third or fourth aspect, the leeward heat exchange unit has two heat exchange units on the upstream side and the downstream side, and the first heat exchanger on the upstream side. An inlet portion for the refrigerant is provided in the upstream tank portion of the exchange unit, and the downstream tank portion of the first heat exchange unit on the upstream side and the upstream tank portion of the second heat exchange unit on the downstream side are connected to each other. The passage is provided by connecting the upstream tank portion of the second heat exchange unit and the tank portion of the windward heat exchange unit, and the refrigerant flowing through the branch passage is provided on the leeward side. Since the second heat exchange unit and the heat exchange unit on the windward side overlapped with the second heat exchange unit can be bypassed, heat is effectively exchanged on the windward and leeward sides, and the heat exchange efficiency is greatly improved. You.

According to a seventh aspect of the present invention, in the heat exchanger according to any one of the first to sixth aspects, the tank portion of the leeward heat exchange unit, the tank portion of the leeward heat exchange unit, and the leeward heat exchange unit are provided. Since the tube and the tube of the windward heat exchange unit are formed by a refrigerant plate integrally formed of the same member, a heat exchanger having a simple configuration, low cost, and excellent heat exchange efficiency can be obtained.

According to an eighth aspect of the present invention, in the heat exchanger of the seventh aspect, a partition wall is provided at an intermediate portion of the integrally formed refrigerant plate to form a partition between the leeward side and the leeward side tank. Since the branch passage is formed by removing a part of the wall, the branch passage can be formed at an arbitrary portion with a simple configuration, and the productivity is very excellent.

According to a ninth aspect of the present invention, there are provided a plurality of heat exchange units each including a pair of tank portions, a tube connected in a U-shape between the tank portions, and fins disposed between the tubes. An inlet portion for the refrigerant is provided in one tank portion of the upstream heat exchange unit, and a branch passage is provided for directly connecting the one tank portion and the other tank portion connected by the U-shaped tube, Through the branch passage and the flow of the refrigerant supplied to the one tank portion of the upstream heat exchange unit flows through the U-shaped tube and flows into the other tank portion,
The flow flowing into the other tank portion is formed, and the cross-sectional area of the branch passage is formed to be equal to or larger than the cross-sectional area of the tube of the upstream heat exchange unit.

In this configuration, the refrigerant having a large amount of the gaseous refrigerant can reliably bypass the heat exchange unit.
The heat exchange variation in the heat exchange unit can be reduced, and the heat exchange function can be improved. In particular, since the cross-sectional area of the branch passage is formed to be equal to or larger than the cross-sectional area of the tube of the upstream heat exchange unit, the pipe passage resistance can be reduced, and the refrigerant having a large amount of gas-phase refrigerant can be separated and passed. .

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. 1 to 4 show a heat exchanger 1 according to a first embodiment. As shown in FIG. 1, the heat exchanger 1 has a leeward heat exchange unit 2
It comprises a windward heat exchange unit 3. Each of the leeward heat exchange unit 2 and the leeward heat exchange unit 3 is formed by alternately stacking a refrigerant passage composed of a plurality of tubes 4 and wavy fins 5 for heat radiation, and above and below the stacked tubes 4 and wavy fins 5. The tanks 6, 7 and 8, 9 are provided.

In the first embodiment, as shown in FIG. 2, partition plates 10 and 12 are provided at intermediate positions in the left-right direction between the upper tank 6 of the leeward heat exchange unit 2 and the upper tank 8 of the leeward heat exchange unit 3. And the upper tank 6 is
The upper tank 8 is divided into an upper first tank 8a and an upper second tank 8b, into a tank 6a and an upper second tank 6b. Partition plates 11 and 13 are also provided at intermediate positions of the lower tanks 7 and 9 in the left-right direction. The lower tank 7 is provided in the lower first tank 7a and the lower second tank 7b, and the lower tank 9 is provided in the lower first tank 9a and the lower tank. It is divided into a second tank 9b. With this configuration, the leeward heat exchange unit 2 is divided into leeward heat exchange units 2a, 2b and 2c as shown in FIG. 3, and as shown in FIG.
Are divided into windward heat exchange units 3a, 3b, 3c.

A refrigerant inlet 14 is provided in the upper first tank 6a of the leeward heat exchange unit 2, and a refrigerant outlet 15 is provided in the upper first tank 8a of the leeward heat exchanger 3. .

As shown in FIG. 6, the upper second tank 6b of the leeward heat exchange unit 2b and the leeward heat exchange unit 2c
The upper second tank 6b is formed continuously and integrally as a tank portion, and a boundary portion thereof forms a communication passage 16. Immediately downstream of the communication passage 16, the upper second tank 6b
A branch passage 17 is provided substantially at right angles to the above.

Although not shown, the branch passage 17 is connected substantially at right angles to the outlet side of the upper second tank 8b of the windward heat exchange unit 3b arranged adjacent to the windward side of the upper second tank 6b. . As shown in FIG. 3, the branch passage 17 is connected to bypass the refrigerant passage (tube 4) of the leeward heat exchange unit 2c and the leeward heat exchange unit 3c. Therefore, the introduction of the gas-phase refrigerant to the leeward heat exchange units 2c and the leeward heat exchange units 3c arranged as stacked is reduced as much as possible, and the heat distribution in the leeward and leeward heat exchange units is reduced. Is extremely reduced, and a material having extremely excellent heat exchange efficiency can be obtained.

The flow of a normal refrigerant will be described. The refrigerant composed of the liquid-phase refrigerant and the gas-phase refrigerant is introduced into the upper first tank 6a from the normal inlet 14 and the refrigerant passage 4 formed of a tube.
It is introduced into the lower first tank 7a and flows through the leeward heat exchange unit 2a. After that, it flows in the lower first tank 7a in the longitudinal direction, and the leeward heat exchange unit 2
b, and rises in the tube 4 to move to the upper second tank 6b.
Will be introduced.

The liquid-phase refrigerant mainly flows in the upper second tank 6b in the longitudinal direction, and flows in the upper second tank 6b of the leeward heat exchange unit 2c.
It descends from inside the tube 4 from the tank 6b and reaches the lower second tank 7b. On the other hand, the gas-phase refrigerant mainly flows through the branch passage 17 to the upper second tank 8 of the windward heat exchange unit 3c.
b.

The branch passage 17 is provided in the upper second tank 6b.
And the direction of the refrigerant changes substantially perpendicularly to the flow direction of the refrigerant, and the liquid-phase refrigerant in the refrigerant hardly enters the branch passage due to the inertia of the flow direction. Flows downward in the tube 4 of the leeward heat exchange unit 2c.

On the other hand, the gas-phase refrigerant flows without being entrained by the liquid-phase refrigerant, and because it is light, is guided to the branch passage 17 and tends to flow to the upper second tank 8b of the windward heat exchange unit 3c. In particular, since the cross-sectional area of the branch passage 17 is equal to or greater than the cross-sectional area of the tube of the upper second tank 6b, the gaseous refrigerant flows into the branch passage 17 more than flows through the tube 4.
It is easy to flow toward.

The refrigerant flowing through the leeward heat exchange unit 2c is guided to the lower second tank 9b of the leeward heat exchange unit 3c arranged on the leeward side of the leeward heat exchange unit 2c, and rises in the tube 4 here. To the upper second tank 8b. Then, it merges with the refrigerant from the branch passage 17 and flows in the upper second tank 8b in the longitudinal direction, so that the windward heat exchange unit 3
b, descends in the tube 4, and moves to the lower first tank 9a.
Leads to.

The refrigerant flows in the lower first tank 9a in the longitudinal direction, is guided to the windward heat exchange unit 3a, rises in the tube 4 and is guided to the upper first tank 8a, and the outlet therefrom. The heat is discharged outside the heat exchanger 1 through the heat exchanger 15.

In the first embodiment, the branch passage is connected by a branch passage 17 by utilizing the point that the upper tank of the leeward heat exchange unit and the upper tank of the leeward heat exchange unit are installed in parallel. Gas phase refrigerant in the refrigerant flows separately from the liquid phase refrigerant, reducing the variation in heat distribution in the heat exchange unit with a simple configuration and changing the total capacity of the heat exchanger The heat exchange efficiency can be significantly improved without performing.

In the first embodiment, the branch passage 17 is provided not in the lower tank but in the upper tank, so that the gas-phase refrigerant that has risen in the tube does not descend but flows easily from the upper tank to the branch passage. Therefore, the gas-phase refrigerant and the liquid-phase refrigerant are easily separated and passed.

FIGS. 7 and 8 relate to the second embodiment.
8 shows a diagram similar to FIG. 2, FIG. 8 shows a diagram similar to FIG. 5, and portions similar to those in the first embodiment are denoted by the same reference numerals. The second embodiment has a configuration corresponding to a heat exchanger in which the leeward heat exchange unit 2a and the leeward heat exchange unit 3a of the first embodiment are removed.

In the second embodiment, the leeward heat exchange unit 2b
An inlet 14a is provided in the lower first tank 7a, and an outlet is provided in the lower first tank 9a of the windward heat exchange unit 3b. In this embodiment, as in the first embodiment, there is a branch passage 17a that bypasses the leeward heat exchange unit 2c and the leeward heat exchange unit 3c. The refrigerant is introduced into the leeward heat exchange unit 2b from the inlet 14a, rises in the tube of the leeward heat exchange unit 2b, and is guided to the upper second tank 6b of the leeward heat exchange unit 2c. Thereafter, the liquid-phase refrigerant mainly descends in the tube of the leeward heat exchange unit 2c, and the gas-phase refrigerant is introduced into the upper second tank portion of the leeward heat exchange unit 3c mainly through the branch passage.

That is, the refrigerant containing a large amount of gaseous refrigerant bypasses the leeward heat exchange unit 2c and the leeward heat exchange unit 3c as shown in FIG. Discharged from the unit. Therefore, also in the second embodiment, a heat exchanger having an excellent heat exchange effect can be obtained as in the first embodiment.

FIGS. 9 to 12 relate to the third embodiment.
9 and 10 show views similar to FIGS. 7 and 8 of the second embodiment, and FIGS. 11 and 12 are sectional views taken along line AA of FIG.
FIG. In the third embodiment, unlike the second embodiment, the inlet 14b and the outlet 15b are provided in the upper first tank 6a of the downstream heat exchange unit 2b and the upper first tank 8a of the windward heat exchange unit 3b, respectively. A partition member 10b is provided between the upper first tank 6a and the upper second tank 6b of the leeward heat exchange unit 2b, and the upper first tank 8a and the upper second tank of the leeward heat exchange unit 3b are provided.
A partition member 12b is provided between the tank and the tank 8b.

Upper first tank 6a and upper second tank 8b
And the partition member 10b and the partition member 12b are wrapped in the stacking direction of the leeward and leeward heat exchange units.
It is arranged so as to be shifted in a direction perpendicular to the laminating direction. As shown in FIG. 12, a branch passage 17b is provided so that the wrapped tank portions communicate with each other.

As shown in FIGS. 11 and 12, the tubes of the leeward heat exchange unit, the upper and lower tank units, the tubes of the leeward heat exchange unit, and the upper and lower tank units are integrally formed.
They are stacked with fins in between. FIG. 11a shows a tube,
FIG. 11b is a front view of the upper and lower tank parts, FIG. 11b is a side view of the tube and the upper and lower tank parts, and a side view of the fins. FIG. 12a and 12b
FIG. 12C shows a front view, a side view, and a plan view of the tube, the upper and lower tank portions, respectively.

In the third embodiment, the refrigerant flows through the inlet 14b.
Is guided to the upper tank 6a of the leeward heat exchange unit 2b, the refrigerant containing a large amount of liquid layer refrigerant descends in the tube, is guided to the lower tank 7, and flows in the lower second tank 7a in the longitudinal direction. Inside the leeward heat exchange unit 2
c is guided to the upper second tank portion 6b. Thereafter, the windward heat exchange unit 3c once goes outside, is guided to the upper second tank portion 8b of the windward heat exchange unit 3c, descends in the tube of the windward heat exchange unit 3c, and is introduced into the windward heat exchange unit 3b. It is discharged from the outlet 15b. On the other hand, the refrigerant having a large amount of gaseous refrigerant does not descend in the tube, but is guided from the upper tank 6 to the upper second tank portion 8b of the windward heat exchange unit 3c via the branch passage 17b.

In the third embodiment, after the gas-phase refrigerant is introduced into the heat exchange unit, it is immediately bypassed from the upper tank to the next heat exchanger via the branch passage without descending in the tube. The refrigerant in the heat exchange unit of the above is less biased and has excellent heat exchange efficiency.

FIG. 13 shows a fourth embodiment, and is similar to FIG. The downstream heat exchange unit 102 and the windward heat exchange unit 103 are stacked. The downstream heat exchange unit 102 and the windward heat exchange unit 103 are provided with upper tanks 106 and 108, respectively, and the upper tank 106 is separated from the upper first tank 106 by a partition member 127.
a, is partitioned into an upper second tank 106b.

The tube 104 is connected to the downstream heat exchange unit 1
02 upper tank 106 and windward heat exchange unit 103
The upper tank 108 has a substantially U-shape. The inlet 114 is provided in the upper tank 106a, and the outlet is provided in the upper tank 106b. Branch passage 117
Is connected at a substantially right angle to the upper tank 106a and the upper tank 108, and has a cross-sectional area equal to or greater than the cross-sectional area of the tube 104.

In the fourth embodiment, the refrigerant is introduced into the upper tank 106a from the inlet 114, the liquid-phase refrigerant flows mainly through the U-shaped tube 104 and is guided to the upper tank 108, and the gas-phase refrigerant is It is led directly to the upper tank 108 mainly through the branch passage 117. Both refrigerants are in the upper tank 10
8 flows in the longitudinal direction, flows through the U-shaped tube 104, reaches the upper tank 106b, and is discharged from the outlet 115.

Also in the fourth embodiment, since the gas-phase refrigerant bypasses the tube, the uneven flow of the refrigerant in the tube is reduced, the variation in heat exchange is reduced, and the heat exchange efficiency is improved.

In the first embodiment, the refrigerant passage is formed by combining flat halves of a flat tube. However, the present invention is not limited to this shape, and may be an extruded flat tube or the like.

[0045]

According to the first aspect of the present invention, at least one of the refrigerant passages of the upstream heat exchange unit is bypassed to one of the tank portions of the upstream heat exchange unit, and the refrigerant is supplied to the tank portion of the downstream heat exchange unit. Is provided, and the refrigerant supplied to the tank portion of the upstream heat exchange unit flows through the refrigerant passage of the downstream heat exchange unit and flows into the other tank portion through the branch passage. And the flow flowing into the tank portion of the downstream heat exchange unit is formed, and the cross-sectional area of the branch passage is formed to be equal to or larger than the cross-sectional area of the tube of the upstream heat exchange unit. Since the refrigerant having a large amount of the gaseous refrigerant can be reliably bypassed to the heat exchange unit, the heat exchange variation in the heat exchange unit can be reduced, and the heat exchange function can be improved. In particular, since the cross-sectional area of the branch passage is formed to be equal to or larger than the cross-sectional area of the tube of the upstream heat exchange unit,
By reducing the pipe resistance, the refrigerant having a large amount of the gaseous refrigerant can be reliably separated and passed.

In the case where the flow direction of the refrigerant in the branch passage is provided so as to be substantially perpendicular to the flow direction of the tank portion provided with the branch passage, the liquid refrigerant flows along the flow of the refrigerant. In addition, the gas-phase refrigerant can be guided to the branch passage with a simple configuration, and the heat exchange efficiency can be improved.

In particular, in the case where the branch passage 17 is provided not in the lower tank but in the upper tank, the gas-phase refrigerant flows from the upper tank to the branch passage without descending in the tube. And the separation is effectively performed.

In the case where the leeward heat exchange unit and the leeward heat exchange unit are stacked and the branch passage connects the upper tanks of the leeward and leeward heat exchange units at substantially right angles, the gas-phase refrigerant is effective. At the branch passage,
The heat exchange efficiency is dramatically improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a heat exchanger according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a flow of the heat exchange medium of the first embodiment.

FIG. 3 is an explanatory diagram of a leeward heat exchange unit of the first embodiment.

FIG. 4 is an explanatory diagram of a windward heat exchange unit of the first embodiment.

FIG. 5 is a developed view showing a flow of the heat exchange medium of the first embodiment.

FIG. 6 shows a partial view of the heat exchanger of the first embodiment.

FIG. 7 shows a view similar to FIG. 2, according to a second embodiment.

FIG. 8 shows a view similar to FIG. 5, according to a second embodiment.

FIG. 9 shows a view similar to FIG. 2, according to a third embodiment.

FIG. 10 shows a view similar to FIG. 5, according to a third embodiment.

FIG. 11 is a sectional view taken along the line AA of FIG. 9;

FIG. 12 is a sectional view taken along line BB of FIG. 9;

FIG. 13 shows a view similar to FIG. 2, according to a fourth embodiment.

FIG. 14 shows a prior art heat exchanger.

FIG. 15 is a diagram illustrating a distribution state of a liquid-phase refrigerant and a gas-phase refrigerant in the heat exchanger of FIG. 14;

[Explanation of symbols]

 Reference Signs List 1 heat exchanger 2 leeward heat exchange unit 2a leeward heat exchange unit 2b leeward heat exchange unit 2c leeward heat exchange unit 3a leeward heat exchange unit 3a leeward heat exchange unit 3b leeward heat exchange unit 3c leeward heat Replacement unit 4 Tube (refrigerant passage) 5 Fin 6 Upper tank 6a Upper first tank 6b Upper second tank 7 Lower tank 7a Lower first tank 7b Lower second tank 8 Upper tank 8a Upper first tank 8b Upper first 2 tank 9 lower tank portion 9a lower first tank 9b lower second tank 10 partition member 11 partition member 12 partition member 13 partition member 14 inlet 15 outlet 16 communication passage 17 branch passage 17a branch passage 17b branch passage 117 branch passage

[Procedure amendment]

[Submission date] May 28, 2001 (2001.5.2)
8)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 4

[Correction method] Change

[Correction contents]

FIG. 4

Claims (9)

[Claims] A plurality of heat exchange units each including a pair of tank portions, a refrigerant passage formed of tubes connected between the tank portions, and fins disposed between the tubes; In one of the tank portions of the unit, a branch passage for supplying a refrigerant to the tank portion of the downstream heat exchange unit bypassing at least a part of the refrigerant passage of the upstream heat exchange unit is provided, and the branch passage of the upstream heat exchange unit is provided. The flow of the refrigerant supplied to the tank portion flows through the refrigerant passage of the upstream heat exchange unit and flows into the other tank portion, and the flow flowing into the tank portion of the downstream heat exchange unit via the branch passage. A heat exchanger, wherein the cross-sectional area of the branch passage is formed to be equal to or larger than the cross-sectional area of the tube of the upstream heat exchange unit. 2. The branch passage according to claim 1, wherein a flow direction of the refrigerant in the branch passage is substantially perpendicular to a flow direction of the tank provided with the branch passage. 1
The heat exchanger as described. 3. The leeward heat exchange unit is disposed on the leeward side of the upstream heat exchange unit, the downstream heat exchange unit is disposed on the leeward side of the upstream heat exchange unit, and the branch passage is disposed on the leeward side of the leeward heat exchange unit. A refrigerant unit that is connected to a tank unit of the unit and a tank unit of the leeward heat exchange unit, and the refrigerant flowing through the branch passage is at least a part of the refrigerant of the leeward heat exchange unit and the leeward heat exchange unit. The heat exchanger according to claim 1, wherein the heat exchanger is configured to bypass the passage. 4. The leeward heat exchange unit and the leeward heat exchange unit have upper and lower tank portions, respectively, and the branch passage is adjacent to the leeward heat exchange unit and the leeward heat exchange unit. 4. The heat exchanger according to claim 3, wherein the heat exchangers are provided so that the tank portions communicate with each other. 5. The leeward heat exchange unit has two upstream and downstream heat exchange units, an upstream tank portion of the upstream first heat exchange unit is provided with a refrigerant inlet, and The heat exchanger according to claim 3 or 4, wherein the branch passage is provided by connecting the tank portion provided with the inlet portion and a tank portion of the windward heat exchange unit. 6. The leeward heat exchange unit has two upstream and downstream heat exchange units, an upstream tank portion of the upstream first heat exchange unit is provided with a refrigerant inlet, and The downstream tank portion of the first heat exchange unit on the side is connected to the upstream tank portion of the second heat exchange unit on the downstream side, and the branch passage is connected to the upstream tank portion of the second heat exchange unit. The heat exchanger according to claim 3, wherein the heat exchanger is provided so as to be connected to a tank of the windward heat exchange unit. 7. A refrigerant in which a tank portion of the leeward heat exchange unit, a tank portion of the leeward heat exchange unit, a tube of the leeward heat exchange unit, and a tube of the leeward heat exchange unit are integrally formed of the same member. The heat exchanger according to any one of claims 1 to 6, wherein the heat exchanger is formed of a plate. 8. A partition wall is provided at an intermediate portion of the integrally formed refrigerant plate to form a partition between a leeward side and an upwind side tank, and a part of the partition wall is removed to form a branch passage. The heat exchanger according to claim 7, characterized in that: 9. A plurality of heat exchange units each comprising a pair of tank portions, a tube connected in a U-shape between the tank portions, and fins arranged between the tubes, An inlet portion for the refrigerant is provided in one tank portion of the unit, and a branch passage is provided for directly connecting the one tank portion and the other tank portion connected by the U-shaped tube, and the upstream heat exchange unit is provided. The flow supplied to the one tank portion of the refrigerant flows through the U-shaped tube and flows into the other tank portion, and the flow flowing into the other tank portion through the branch passage is formed. A heat exchanger, wherein a cross-sectional area of the branch passage is formed to be equal to or larger than a cross-sectional area of a tube of the upstream heat exchange unit.