JPH09138081A - Heat exchanger for mixed refrigerant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain necessary super cooling or superheating in spite of a small size by a method wherein the flow passage of a first row is connected to the flow passage of a final row mutually through a header so that non-azeotropic mixed refrigerant flows vertically to the flow of air while opposing and meandering. SOLUTION: All of fluid inlet ports 13 of the upper end opening of refrigerant flow passage 12A of a final row in respective flat tubes 3 are communicated by an inlet header 7 while all of fluid outlet ports 14 of the lower end opening of refrigerant passage 12D of an initial row are communicate with each other through an outlet header 9. Meandering refrigerant passages 12A, 12D for discharging out of the fluid outlet port 14 at the fore end lower part through the refrigerant passage 12D of the initial row, the formed. According to this method, meandering flows are repeated whereby the refrigerant is mixed, heat exchanging efficiency is improved, and necessary super cooling or superheating can be obtained in spite of the small size of the heat exchanger.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger for mixed refrigerant used in an indoor unit for room air conditioners, an outdoor unit and the like.

[0002]

2. Description of the Related Art Conventionally, for example, a cross fin type heat exchanger is known as a heat exchanger used as an indoor unit or an outdoor unit for a room air conditioner.

[0003]

When the heat exchanger is used as an indoor unit or an outdoor unit for a room air conditioner, the refrigerant liquid that has been concentrated is cooled to a saturation temperature or lower, or the evaporated refrigerant gas is saturated to a saturation temperature. In the above overheated state, it is necessary to discharge the refrigerant, but in the above conventional cross fin type heat exchanger, if it is attempted to obtain the required overcooled state or overheated state. However, there is a problem that the length of the heat exchange pipe becomes long and the heat exchanger becomes large. On the other hand, as HCFC22 can no longer be used as a refrigerant due to CFC regulations, HCFC22
22 instead of 22, for example HFC134a and HFC125
A non-azeotropic mixed refrigerant composed of a and HFC32 has come to be used. In such a heat exchanger for a non-azeotropic mixed refrigerant, since the phase change temperatures of the respective refrigerants are different, there is a problem that it will not function satisfactorily unless the passage length of the refrigerant is made longer than in the past. The type also has a low heat exchange efficiency due to the difference in the temperature distribution on the front surface of the heat exchanger core when compared to the counter-flow heat exchanger. It is no longer possible to deal with it.

An object of the present invention is to provide a heat exchanger for a mixed refrigerant, which is small in size but can sufficiently obtain necessary supercooling or overheating.

[0005]

A heat exchanger for mixed refrigerant according to the present invention comprises flat pipes arranged in parallel and corrugated fins interposed between adjacent flat pipes. , A meandering fluid passage consisting of a plurality of rows of fluid passages is formed, and one or a plurality of rows of fluid passages flowing in the same direction from the first row and one or a plurality of rows of fluid passages counted from the last row The fluid passages flowing in the same direction are connected by a header.

The mixed refrigerant is preferably a non-azeotropic mixed refrigerant.

It is preferable that the mixed refrigerant be made to flow in a state of being orthogonally opposed to the flow of air.

The flat tube is made of extruded shape, and the flat tube is provided with partition walls extending from one end to the front of the other end and partition walls extending from the other end to the front of the flat pipe alternately. Are preferably closed except for the fluid passage openings which are connected to the header.

A partition wall for dividing the fluid passage may be provided in at least one of the fluid passages.

In the flat tube, a pattern corresponding to a meandering fluid passage is printed on one surface of either one of the pair of aluminum plates with an anti-pressing agent, and the other aluminum plate is superposed on the printed surface and rolled. After that, it may be formed by bulging the non-crimped portion into a tubular shape by fluid pressure.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. In this specification, "aluminum" includes an aluminum alloy. In addition, in this specification, upper and lower sides, front and rear sides, and right and left sides are based on FIG. It may be used by turning left and right.

FIG. 1 is a heat exchanger used as an indoor unit or an outdoor unit for a room air conditioner using a non-azeotropic mixed refrigerant.
(1) is shown, the heat exchanger (1) is made of aluminum (including aluminum alloy), and the flat tubes (3) extending in the vertical direction are arranged in parallel on the left and right, and the adjacent flat tubes.
The core (2) consisting of corrugated fins (4) and a pair of left and right side plates (5), (5) interposed in the ventilation gap between (3), and provided at the upper and lower ends of the core (2). Flat tube
(3) A pair of upper and lower plates with the upper and lower ends inserted
(6) (6), an inlet header (7) provided at the upper rear end of the core (2), an inlet pipe (8) connected to the inlet header (7), and an outlet provided at the lower front end of the core (2). It has a header (9) and an outlet pipe (10) connected to it.

Each flat tube (3) is made of an extruded shape, and 10 partition walls (11A) (11B) extending in the vertical direction are provided inside the flat tube (3), so that each flat tube (3) is 11 rows of refrigerant passages
(12A) (12B) (12C) (12D) are formed. These refrigerant passages (12A) (12B) (12C) (12D) are formed so that the refrigerant flows in a meandering manner, as shown below with reference to FIGS. 2 and 3.

Each flat tube (3) is cut into a required length and then further processed as follows.

The refrigerant passage (12A) in the last row is the other passage (12B)
(12C) Flat tube (3) so that it projects above (12D)
The upper end of the refrigerant passage is cut except for the refrigerant passage (12A) in the last row, and the refrigerant passage (12D) in the front row is connected to the other passages (12A) (12B) (12
The lower end portion of the flat tube (3) is cut except for the refrigerant passage (12D) in the front row so as to project downward from C).
Further, the lower end portions of all odd-numbered partition walls (11A) and the upper end portions of all even-numbered partition walls (11B) are cut off later. The cut-off parts of the partition walls (11A) (11D) are adjacent fluid passages (12A) (12B) (12C) (12D)
It becomes a communication hole (25) (26) that allows them to pass through each other.

And, the refrigerant passage in the last row of each flat tube (3)
The upper end opening of (12A) serves as the fluid inlet (13), and the fluid inlets (13) of all flat tubes (3) are communicated with each other by the inlet header (7), and the front row of each flat tube (3) is connected. The lower end opening of the refrigerant passage (12D) serves as a fluid outlet (14), and the fluid outlets (14) of all the flat tubes (3) are communicated with each other by an outlet header (9).

Further, in each flat tube (3), all the upper and lower openings (15) (16) except the openings communicated by the inlet header (7) or the outlet header (9) are connected to the upper and lower lid members (17) ( It has been blocked by 18). In order to make it easier to fit the upper and lower lids (17) and (18) to the flat tubes (3), the upper end of all odd-numbered partition walls (11A) after the third,
Positioning protrusion (19) is formed and upper lid (17)
A positioning through hole (20) corresponding to these is formed in the. In addition, at the bottom of all even-numbered partition walls (11B) counting from the rear except for the front row, the positioning protrusion (2
1) is formed, and the lower lid member (18) is provided with positioning through holes (22) corresponding thereto.

In this way, in each flat tube (3), the refrigerant introduced from the fluid inlet (13) above the rear end into the refrigerant passage (12A) in the last row makes a U-turn at the lower end and the upper end. While
The even-numbered refrigerant passages (12B) flow upwards, and the odd-numbered refrigerant passages (12C) flow downwards, and the frontmost refrigerant passages (12D)
The meandering refrigerant passages (12A) (12B) (12C) (12D) discharged from the fluid outlet (14) below the front end are formed.

The inlet and outlet headers (7) and (9) have a circular cross section, and the lower surface of the inlet header (7) has holes for inserting the edges of the fluid inlets (13) of the flat tubes (3). (23) is opened,
On top of the outlet header (9) is the fluid outlet (1
There is a hole (24) for inserting the edge of 4). The refrigerant introduced from the inlet pipe (8) into the inlet header (7) flows in a meandering manner in each flat pipe (3), then is collected in the outlet header (9) and discharged from the outlet pipe (10). It

When the heat exchanger (1) is used as an indoor unit for a room air conditioner, during cooling, the condensed liquid refrigerant is introduced from the inlet pipe (8) so that the indoor unit functions as an evaporator. During heating, a gaseous refrigerant is introduced from the inlet pipe (8), and the indoor unit functions as a condenser. Air arrow
As indicated by (X), it flows from the front (outdoor) side to the rear (indoor) side of the figure.

During cooling, the liquid refrigerant exchanges heat with air to gradually evaporate and become a gas phase, and at the fluid outlet (14), it is heated to a temperature 3 to 5 ° C. higher than the saturation temperature and becomes an overheated state. . On the other hand, the heat of the air is taken by the refrigerant to become cold air, which is blown out into the room. The gaseous refrigerant discharged from the fluid outlet (14) of each flat tube (3) collects in the outlet header (9) and the
It is discharged from 0) to the outdoor unit side. At this time, each flat tube (3)
The refrigerant flowing inside is meandering through the refrigerant passages (12A) (12B) (12C) (12D), is orthogonal to the air, and further flows in a stepwise opposed manner to the air. Will be distributed to. Therefore, the temperature of the refrigerant on the air inlet side of the heat exchanger core is high, while the temperature of the refrigerant on the air outlet side of the heat exchanger core is low, while the air is also high on the air inlet side of the heat exchanger core. Since the temperature of the air outlet side of the heat exchanger core is low, the same effect as the counterflow type heat exchanger can be obtained and the heat exchange efficiency is excellent. Moreover, by repeating the meandering flow, the refrigerant is agitated to promote the destruction of the liquid film formed on the inner surface of the flat tube (3), and the heat exchange efficiency is further improved.

During heating, the gaseous refrigerant exchanges heat with air and gradually condenses into a liquid phase. At the fluid outlet (14), it is supercooled to a temperature 3 to 5 ° C. lower than the saturation temperature. It becomes a state. On the other hand, the air receives heat from the gaseous refrigerant, becomes warm air, and is blown out into the room. The liquid refrigerant discharged from the fluid outlet (14) of each flat pipe (3) is collected in the outlet header (9) and discharged from the outlet pipe (10) to the outdoor unit side. At this time, as in the case of cooling, the refrigerant flowing in each flat pipe (3) is meandering through the refrigerant passages (12A) (12B) (12C) (12D), is orthogonal to the air, and is further gradually air-cooled. Flow toward each other, and are circulated orthogonally to the flow of air, the refrigerant temperature on the air inlet side of the heat exchanger core is low, and the refrigerant temperature on the air outlet side of the heat exchanger core is high. On the other hand, in the case of air, the temperature on the air inlet side of the heat exchanger core is low and the temperature on the air outlet side of the heat exchanger core is high, and it is as if the same effect as the counterflow heat exchanger. It is obtained and has excellent heat exchange efficiency. Moreover, by repeating the meandering flow, the refrigerant is agitated to promote the destruction of the liquid film formed on the inner surface of the flat tube (3), and the heat exchange efficiency is further improved.

FIG. 8 shows the refrigerant of the heat exchanger (1) as
The graph for comparing the coefficient of performance between the case where a conventional single refrigerant is used and the case where a non-azeotropic mixed refrigerant is used is shown. In the graph of the figure, when the condensation start temperature is T, the entropy at that time is b, the entropy at the end of condensation is a, and the evaporation start temperature is T ₀ , the coefficient of performance ε of the heat pump of a single refrigerant is ε = freezing Effect / work from the outside = T ₀ (ba) / (T-T ₀ ) (ba) = T ₀ / (T-T ₀ ).

When a non-azeotropic mixed refrigerant is used, during the evaporation process, the refrigerant with the lowest evaporation temperature evaporates first and finally the evaporation temperature during the meandering flow in each flat tube (3). The highest refrigerant evaporates. During this time, the temperature of the mixed refrigerant gradually rises. When this rising temperature is ΔT, the refrigerating effect = (T ₀ + 1/2 × ΔT) (ba), and the refrigerating effect is improved. On the other hand, during the condensing process, while flowing in a meandering manner in each flat tube (3), all the refrigerants with the highest condensation temperature are condensed first, and finally the refrigerant with the lowest condensation temperature is condensed. The temperature of the refrigerant gradually decreases. Therefore, work from the outside = (T−T ₀ −ΔT)
(Ba), which means less work from outside. Eventually, the power in the shaded areas below and above the graph will be reduced. The coefficient of performance ε ′ of the heat pump of the non-azeotropic mixed refrigerant is ε ′ = (T ₀ + 1/2 × ΔT) / (T−T ₀ −ΔT), which is higher than the coefficient of performance of the heat pump of the single refrigerant. To do.

The above formula is based on the assumption that the refrigerant completely changes its phase, and since the mixed refrigerant contains the refrigerant which is relatively hard to evaporate or condense, it is necessary to take a sufficient passage length of the refrigerant. . In the conventional heat pump heat exchanger, if the passage length of the refrigerant is sufficiently long to try to make the air flow in the opposite direction, the outer dimension of the heat exchanger becomes large, which is far from making the room air conditioner compact. Will end up. On the other hand, in the heat exchanger (1) of the present invention, while ensuring a passage length capable of performing a sufficient phase change, and by allowing air to flow in a cross counterflow, the effect of using a mixed refrigerant is sufficiently exerted. be able to.

Whether a single refrigerant, an azeotropic mixed refrigerant or a non-azeotropic mixed refrigerant is used, a liquid film is formed in the flat tube (3), which causes a decrease in heat exchange efficiency. However, in the case of single refrigerants and azeotropes, flat tubes
(3) Since the refrigerant that is in contact with the inner surface can easily evaporate and condense, the reduction in heat exchange efficiency can be small. When the mixed refrigerant is a non-azeotropic mixed refrigerant, the refrigerant with a low boiling point forms a liquid film in the flat tube and sticks to the inner surface of the flat tube (3), which is more than that of the single refrigerant and the azeotropic mixed refrigerant. As a result, the amount of decrease in heat exchange efficiency increases. Therefore, the margin for improving the heat exchange efficiency by destroying the liquid film by repeating the meandering flow is larger than that of the single refrigerant and the azeotropic mixed refrigerant, and is non-coincident with the heat exchanger (1). The use of the boiling mixed refrigerant has a unique effect of significantly improving the coefficient of performance of the heat pump.

When the heat exchanger (1) is used as, for example, an evaporator, it is of course possible to introduce a liquid refrigerant from the outlet pipe (10). In this case, the flow of the refrigerant is an arrow. From the outlet pipe (10) to the outlet header
The refrigerant introduced into (9) flows in a meandering manner in each flat pipe (3), is then collected in the inlet header (7), and is discharged from the inlet pipe (8). In this case, the air flows in the opposite direction of the arrow (X) from the rear side to the front side of the figure.

In the above, the dimensions of the flat tubes (3) and the number of partition walls (11A) (11B) are determined according to the performance required of the heat exchanger (1). The inlet header (7) and the outlet header (9) may be provided above or below the core (2).

To manufacture the above heat exchanger (1), first,
Only the core (2) is brazed, then the upper and lower plates (6) (6) are welded to the core (2) and the upper and lower lids (17) (18) are attached to each flat tube (3) by torch brazing. Fixed, the inlet and outlet headers (7) (9) are fixed to the core (2) by torch brazing.

In the above embodiment, the cross-sectional area of the refrigerant passage is constant from the fluid inlet (13) to the fluid outlet (14), but the cross-sectional area of the refrigerant passage can be changed midway. An example of this is shown in FIG.

In this embodiment, the original flat tube (3) is the same as that of the above embodiment, but the cross-sectional area of the refrigerant passage is changed in the middle by changing the processing method as shown below. Have changed.

The upper end portion of the flat pipe (30) is arranged so that the refrigerant passage (32A) in the last row and the refrigerant passage (32B) adjacent to the last passage protrude above the other passages (32C) (32D) (32E). Is cut, 2
The upper end openings of the three refrigerant passages (32A) (32B) are used as the fluid inlet (33). And the fluid inlet (33) of all flat tubes (30)
The two are communicated with each other by a large-diameter inlet header (37).
On the other hand, the fluid outlet side is the same as that of the above embodiment,
The frontmost refrigerant passage (32E) is connected to the other refrigerant passages (32A) (32B) (32
C) The lower end portion of the flat tube (30) is cut so that (32D) projects further downward, and only the lower end opening of the refrigerant passage (32E) in the front row serves as the fluid outlet (34). .. The fluid outlets (34) of all the flat tubes (30) are communicated with each other by the outlet header (39). Also, the first partition wall (31C) and the second, sixth and ninth partition walls (31
The bottom part of (A) is cut off, and the third, fifth and seven
The upper and lower end portions of the third partition wall (31D) are cut off, and the upper end portions of the fourth, eighth and tenth partition walls (31B) are cut off.

Further, in each flat pipe (30), all the upper and lower openings (35) (36) except the openings communicated by the inlet header (37) or the outlet header (39) are the upper and lower lid members (17) ( It has been blocked by 18).

In this way, in each flat tube (30), the fluid is introduced from the fluid inlet (33) above the rear end into the refrigerant passage (32A) in the last row and the refrigerant passage (32B) next to it, Refrigerant passages with two rows each, making a U-turn at the lower and upper ends
A meandering refrigerant passage that flows through (32C) together, becomes one row in the middle, and is discharged from the fluid outlet (34) below the front end through the one row refrigerant passage (32D) and the first row refrigerant passage (32E). (32A) (32
B) (32C) (32D) (32E) are formed. And the inlet pipe
Refrigerant introduced from (38) to the inlet header (37) is
(3) After flowing in a meandering manner, it is collected in the outlet header (39) and discharged from the outlet pipe (40).

In the heat exchanger having the flat tube (30) shown in FIG.
When the gaseous refrigerant is introduced from the fluid inlet (33), the gaseous refrigerant is condensed before reaching the fluid outlet (34) and its volume is reduced, but with this, the cross-sectional area of the passage is also reduced. , The flow velocity is kept almost constant, and the heat exchange efficiency is improved. Therefore, a high performance condenser is obtained.

In the heat exchanger having the flat tube (30) shown in FIG.
It is of course possible to introduce the refrigerant from the outlet pipe (40), in this case, the refrigerant passage is in the opposite direction to the arrow, and the refrigerant introduced from the outlet pipe (40) to the outlet header (39) is After flowing in the flat pipe (30) in a meandering manner, it is collected in the inlet header (37) and discharged from the inlet pipe (38). In this heat exchanger,
When a gaseous refrigerant is introduced from the fluid inlet (34), the gaseous refrigerant condenses before reaching the fluid outlet (33) and its volume decreases, but with this, the passage cross-sectional area also decreases. , The flow velocity is kept almost constant, and the heat exchange efficiency is improved. Therefore, a high performance evaporator can be obtained.

In the above embodiment, the refrigerant passages are initially arranged in two rows and then in one row in the middle. However, the refrigerant passages are variously changed within a range in which the passages are meandering as a whole. It is possible. Although not shown in the drawings, the extruded shape of the flat pipe (3) shown in FIG. 3 is used as a reference, and the cross-sectional area of the refrigerant passage on the side close to the fluid inlet is large, and the passage of the refrigerant passage on the side close to the fluid outlet is cut off. By making the area small, it is possible to change the cross-sectional area of the refrigerant passage on the way.

FIG. 5 shows a flat tube (50) which makes it possible to omit the upper and lower lid members for closing the upper and lower openings.
Shows a method for manufacturing the flat tube (50).

As shown in FIG. 6, this flat tube (50) is similar to the embodiment shown in FIGS. 2 and 3, and the refrigerant passage (12A) in the last row is the other passage (12B). The upper end portion of the flat pipe (50) is cut except for the refrigerant passage (12A) in the last row so as to project above (12C) and (12D) (see FIG. 6 (a)), and the refrigerant in the front row is cooled. The aisle (12D) is the other aisle (12A) (12B) (1
2C), the lower end of the flat tube (50) is cut except for the refrigerant passage (12D) in the front row, and all the odd numbered partition walls (11A) counted from the rear. The lower end portion and the upper end portions of all even-numbered partition walls (11B) are cut off (see FIG. 6 (b)). After that, all the upper and lower openings except the fluid inlet / outlet ports (13) and (14) are closed by crushing (see FIG. 6 (c)), and further arc welding (52) is applied to the crushing portion (51). Then, the upper and lower ends of the partition wall (11A) that slightly protruded during the crushing process are smoothed (see FIG. 6D). As a result, a flat tube having exactly the same function as the flat tube (3) shown in FIGS. 2 and 3.
(50) is obtained.

The above-mentioned processing can be easily performed because the flat tube (50) is made of an extruded profile. In addition, the above-mentioned processing is performed as a single flat tube (50) before brazing the core (2), and the flat tube (3) is covered with the upper and lower cover materials (17) (1).
It has the following advantages over the torch brazing process of 8).

In the torch brazing of the upper and lower lid materials (17) (18),
Welding is from the side of the flat tube (3), which tends to cause the failure of melting the flat tube (3), whereas as shown in Fig. 6 (d), welding is from the top of the flat tube (50). Since the heat is evenly transmitted and the flat tube (50) can be worked without being melted, both the defective rate and the workability are improved. Further, since the flat tube (50) can be welded as a single piece, the workability is further improved.

Although the flat tubes (3), (30) and (50) made of extruded shape are used in the above two embodiments, two flat tubes are used to form a meandering fluid passage in the flat tube. It may be composed of a single plate. FIG. 7 shows an example thereof.

In FIG. 7, each flat tube (60) is a roll bond panel, and one side of either one of the pair of aluminum plates (61) (61) is provided with a meandering fluid passage. It is formed by printing a corresponding pattern with an anti-pressing agent, stacking the other aluminum plate (61) on the printed surface and rolling it, and then bulging the non-pressing section into a tubular shape by fluid pressure. The serpentine fluid passages consist of multiple rows of fluid passageways (6
2A) (62B) (62C), the fluid passages (62A) in the first row and the fluid passages (62C) in the last row of the flat tubes (60) are respectively connected by the headers (7) and (9). It is connected.

By using each flat tube (60) as a roll bond panel, the fluid passage can be variously changed by changing the printing surface. For example, the fluid passages (62A) (62B) (62C) are provided with bypass passages. It is also possible to easily obtain a flat tube according to the required performance of the heat exchanger.

Instead of using the flat tube as a roll bond panel, a meandering recess is formed in each of a pair of plates by press working, and these plates are joined so that the recesses face each other. You may make it obtain a flat tube of the same shape.

In the embodiment, the headers (7) (9) (37) (39)
The heat exchangers (1) are arranged so that the refrigerant flows vertically in a meandering manner, but the headers are arranged in the left and right vertical directions so that the refrigerant flows in a meandering direction from side to side. A heat exchanger may be arranged.

[0047]

According to the heat exchanger for mixed refrigerant of the present invention, the fluid introduced into the header on the inlet side is distributed to each flat tube and flows meanderingly through the fluid passage in each flat tube, and then the outlet. It is collected and discharged in the header on the side, but the total length of the meandering fluid passage can be increased without increasing the size of the heat exchanger by increasing the number of fluid passages in each flat tube.
Moreover, by repeating the meandering flow, the refrigerant is agitated and the destruction of the liquid film formed on the inner surface of the flat tube is promoted, heat exchange efficiency is further improved, and supercooling is required despite the small size. Alternatively, sufficient overheating can be obtained.

When the mixed refrigerant is a non-azeotropic mixed refrigerant, the refrigerant having a low boiling point forms a liquid film in the flat tube and sticks to the inner surface of the flat tube, but this liquid film is destroyed. The amount of improvement in heat exchange efficiency is large compared to the case where the refrigerant in contact with the inner surface of the flat tube is easily evaporated and condensed, and the coefficient of performance of the heat pump is It has a unique effect that it can be greatly improved.

In the case where the mixed refrigerant is made to circulate in a state of being orthogonally opposed to the flow of air, it is possible to obtain the same effect as that of the counterflow type heat exchanger, and the heat exchange efficiency is excellent. There is.

The flat pipe is made of extruded shape, and the flat pipe is provided with partition walls extending from one end to the front of the other end and partition walls extending from the other end to the front of the flat pipe alternately. However, if the fluid passage is closed except for the opening of the fluid passage connected to the header, the length of the fluid passage in the flat tube can be easily lengthened and the manufacture is easy.

Further, in the case where at least one of the fluid passages is provided with a partition wall for fluid passage division,
Since a plurality of rows of parallel passages flowing in the same direction can be formed in the meandering fluid passage, the degree of freedom in designing the fluid passage is increased.

In the flat tube, a pattern corresponding to a meandering fluid passage is printed on one surface of either one of the pair of aluminum plates with an anti-pressing agent, and the other aluminum plate is superposed on the printed surface and rolled. After that, it is formed by bulging the non-pressure-bonded portion into a tubular shape by fluid pressure.However, various meandering fluid passages can be formed by changing the printing surface, and the required performance of the heat exchanger can be improved. A corresponding flat tube can be easily obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a heat exchanger for mixed refrigerant according to the present invention.

FIG. 2 is an exploded perspective view of the main part.

FIG. 3 is a vertical sectional view showing a refrigerant passage in a flat tube.

FIG. 4 is a vertical cross-sectional view showing another example of the refrigerant passage in the flat tube.

FIG. 5 is a perspective view of a flat tube obtained by different manufacturing methods.

6A to 6C are schematic views sequentially showing a manufacturing process of the flat tube shown in FIG.

FIG. 7 is an exploded perspective view of a main part of a heat exchanger using a flat tube obtained by another manufacturing method.

FIG. 8 is a diagram showing a graph for comparing the coefficient of performance when a mixed refrigerant is used in the heat exchanger for mixed refrigerant according to the present invention with that when a single refrigerant is used.

[Explanation of symbols]

 (1) Heat exchanger (3) Flat tube (4) Corrugated fins (7) Inlet header (9) Outlet header (12A) (12B) (12C) (12D) Refrigerant passage (30) Flat tube (31A) ( 31B) Partition wall (31C) (31D) Partition wall (for dividing fluid passage) (32A) (32B) (32C) (32D) (32E) Refrigerant passage (37) Inlet header (39) Outlet header (50) Flat pipe (60) Flat tube (61) Aluminum plate (62A) (62B) (62C) Refrigerant passage

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinro Nagaro 1 20-20 Kitakousan, Otaka-cho, Midori-ku, Nagoya City Chubu Electric Power Co., Inc. Technology Development Headquarters Electricity Research Institute (72) Inventor Shoichi Watanabe Sakai Sakai 6-224, Umiyama-cho, Ichiyama, Showa Aluminum Co., Ltd. (72) Inventor Takayuki Anbu 6-224, Kaiyama-cho, Sakai Showa Aluminum Co., Ltd. Within Arminium Co., Ltd.

Claims (6)

[Claims] 1. Flat tubes (3) (30) (50) arranged in parallel.
(60) and corrugated fins (4) interposed between the adjacent flat tubes (3) (30) (50) (60), and each flat tube (3) (30) (50) Multiple rows of fluid passages (12A) in (60)
(12B) (12C) (12D) (32A) (32B) (32C) (32D) (32E) (62A) (62B)
A meandering fluid passage for mixed refrigerant composed of (62C) is formed, and fluid passages (12A) (32A) (62A) between the first row and one or a plurality of rows counting from the first row and flowing in the same direction and the last row Heat for mixed refrigerant in which one or more rows of fluid passages (12D) (32E) (62C) counting from the eyes are connected by headers (7) (37) (9) (39) Exchanger. 2. The heat exchanger for mixed refrigerant according to claim 1, wherein the mixed refrigerant is a non-azeotropic mixed refrigerant. 3. The heat exchanger for mixed refrigerant according to claim 1, wherein the mixed refrigerant is circulated so as to be orthogonally opposed to the flow of air. 4. The flat tubes (3) (30) (50) are made of extruded profile, and the flat tubes (3) (30) (50) have a partition wall (11A) extending from one end to the front of the other end. (31A) and partition walls (11B) and (31B) extending from the other end to the front are alternately provided, and the flat pipe
Both ends of (3) (30) (50) are connected to the headers (7) (37) (9) (39) except for the openings of fluid passages (12A) (32A) (12D) (32E). The heat exchanger for mixed refrigerant according to claim 1, which is closed. 5. Fluid passages (12A) (12B) (12C) (12D) (32A)
The partition wall (31C) (31D) for dividing a fluid passage is provided in at least one of (32B) (32C) (32D) (32E).
Heat exchanger for mixed refrigerant. 6. The flat tube (60) comprises a pair of aluminum plates (6).
1) Either one of the aluminum plate (61) is printed on one surface of a pattern corresponding to a meandering fluid passage with an anti-pressing agent, and after the other surface of the printed aluminum plate (61) is rolled and rolled, The heat exchanger for mixed refrigerant according to claim 1, wherein the heat exchanger for a mixed refrigerant is formed by bulging a non-pressure-bonded portion into a tubular shape by fluid pressure.