JPH06159863A - Condenser - Google Patents

Abstract

PURPOSE:To furnish a condenser not causing lowering of heat exchanger effectiveness and an increase of a refrigerant-side pressure loss irrespective of the number of groups of refrigerant passages. CONSTITUTION:A plurality of tubes 1 are disposed in parallel lines, while fins 2 are disposed between the adjacent tubes 1, and the end parts of each tube 1 are connected in communication to hollow headers 3 and 4. The cross-sectional area of a refrigerant passage of a refrigerant outlet pipe 6 connected to the header 4 is set to be 30% or above of the cross-sectional area of a final refrigerant passage group C constructed of the tubes 1 in a plurality through which a refrigerant flowing out of the outlet pipe 6 flows just before the outflow.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a condenser, and more particularly to a condenser for an air conditioner such as a car air conditioner or a room air conditioner.

[0002]

2. Description of the Related Art Conventionally, as a condenser for a car cooler, for example, a porous extruded flat tube called a harmonica tube is bent in a meandering shape, and fins are arranged between parallel portions to form a core portion. The type known as the serpentine type was generally used. However, in recent years, the use of a so-called multi-flow type condenser in place of this type of serpentine type condenser has been proposed and put into practical use.

This multi-flow type condenser is one in which a refrigerant is simultaneously passed through a plurality of tubes. The most common configuration is to arrange pipe headers on the left and right at a predetermined interval, and to arrange a large number of flat tubes in parallel with fins interposed between them, and to arrange each tube in parallel. By connecting both ends to the corresponding header and partitioning the inside of the header,
The refrigerant passage constituted by a tube is divided into a plurality of refrigerant passage groups to allow the refrigerant to flow in a meandering manner.

In such a multi-flow type condenser, the refrigerant in the gasified state, which is flowed in from the refrigerant inlet pipe connected to the upper part of the header, is formed in a meandering shape in a refrigerant passage group composed of a plurality of tubes. During the circulation, the heat is exchanged with the air to be condensed, and the condensed heat is discharged to the outside from the refrigerant outlet pipe connected to the lower part of the header.

By the way, in this type of multi-flow condenser, it is extremely important to improve the heat exchange efficiency and reduce the pressure loss of the refrigerant. Regarding this problem, the applicant of the present application, in the previous application, of the refrigerant passage cross-sectional area of the inlet side passage group in which the refrigerant is still gasified and the refrigerant passage cross-sectional area of the outlet side passage group in which the refrigerant is liquefied It was found that the heat exchange efficiency can be improved and the pressure loss of the refrigerant can be reduced by setting the ratio within the appropriate range, and the refrigerant passage cross-sectional area of the outlet side passage group relative to the inlet side passage group Has been proposed (see Japanese Patent Laid-Open No. 2-146476).

[0006]

However, even if the ratio of the passage cross-sectional areas of the outlet-side passage group and the inlet-side passage group is set within the appropriate range in this way, the number of passes that meanders, That is, when the number of refrigerant passage groups is small, it may not be possible to achieve the desired improvement in heat exchange efficiency and reduction in refrigerant-side pressure loss. That is, even if the condensers have the same size of core, it does not cause much problem when the number of passes is set relatively large, but when the number of passes is set small, the outlet side passage group is configured. In particular, it has been found that the refrigerant liquid accumulates in a part of the tubes located on the lower side and causes a deterioration in performance.

The present invention has been made to solve the above-mentioned problems, and condenses without reducing the heat exchange efficiency and increasing the pressure loss on the refrigerant side regardless of the number of refrigerant passage groups. The purpose is to provide a container.

[0008]

For the above-mentioned purpose, the inventor has analyzed and studied various multi-flow type condensers in order to investigate the cause of the above-mentioned inconvenience caused especially when the number of refrigerant passage groups is small. As a result of stacking, the refrigerant flowing out from the refrigerant outlet pipe has a relationship between the refrigerant passage cross-sectional area of the final refrigerant passage group and the refrigerant passage cross-sectional area of the refrigerant outlet pipe in which the refrigerant flows immediately before that closely affects the occurrence of the inconvenience. As a result of further elucidation based on such elucidation, the present invention has been completed.

Thus, in the present invention, the refrigerant passage cross-sectional area of the refrigerant outlet pipe is defined as the refrigerant passage cross-sectional area of the final refrigerant passage group consisting of a plurality of tubes through which the refrigerant flowing out from the outlet pipe circulates immediately before it. Is set to 30% or more.

That is, the present invention is a condenser in which a plurality of tubes are arranged in parallel, fins are arranged between adjacent tubes, and the ends of the tubes are connected to the hollow header for communication. The refrigerant passage cross-sectional area of the refrigerant outlet pipe connected to the header is 30 times the refrigerant passage cross-sectional area of the final refrigerant passage group constituted by a plurality of tubes through which the refrigerant flowing out from the outlet pipe circulates immediately before. The gist of the present invention is a condenser characterized by being set to at least%.

The most common multi-pass type condenser, that is, a plurality of tubes are arranged in parallel, fins are arranged between adjacent tubes, and both ends of each tube form a pair of hollow headers. A condenser in which the refrigerant inlet pipe and the outlet pipe are connected to each other and connected to a header, and the inside of the header is partitioned so that a refrigerant passage formed by the tubes flows from the refrigerant inlet pipe. At least the refrigerant is divided into at least two refrigerant passage groups including a first refrigerant passage group in which the refrigerant first flows and a final refrigerant passage group in which the refrigerant flowing out of the refrigerant outlet pipe flows immediately before the first refrigerant passage group. Even if it is configured to meander and flow one or more times, the refrigerant passage sectional area of the refrigerant outlet pipe is set to 30% or more of the refrigerant passage sectional area of the final refrigerant passage group. It shall be constant.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on illustrated embodiments applied to a car air conditioner condenser.

In the heat exchanger according to this embodiment, as shown in FIG. 1, a large number of flat tubes (1) are horizontally arranged with corrugated fins (2) interposed therebetween and are stacked in the thickness direction. Both ends of these tubes (1) are communicatively connected to the pair of left and right headers (3) and (4). The refrigerant inlet pipe (5) is connected to the left header (3), and the refrigerant outlet pipe (6) is connected to the right header (4).

The tube (1) is made of a flat extrusion mold material made of aluminum. The tube (1) is preferably a so-called harmonica tube for the purpose of improving pressure resistance and the like.

However, in order to further reduce the thickness of the tube (1) and improve the heat exchange performance, an electric resistance welded tube or the like may be used instead of the above extruded mold material. When an electric resistance welded pipe is used, an inner fin material formed into a corrugated shape in the width direction is separately inserted into the pipe, and the fin material is made to function as a reinforcing member by brazing and joining to both inner surfaces of the pipe wall, It is desirable to obtain the required pressure resistance.

The corrugated fins (2) arranged between the tubes (1) have substantially the same width as the tubes (1) and cover the surface of the tubes (1) or the surfaces of the fins (2). The formed brazing material is brazed and integrated with the tube (1). The corrugated fin (2) is also made of aluminum, and it is preferable to use a louver cut and raised. Note that instead of the corrugated fins, plate-shaped fins having a tube fitting notch on one side edge are used, and these are used as headers (3) (4).
The tubes (1) may be arranged in parallel with each other at predetermined intervals and the tubes (1) may be fitted in the cutouts.

The headers (3) and (4), to which the left and right ends of the tube (1) are connected in communication, are made of an aluminum hollow extruded material having a circular cross section and are formed to have high pressure resistance. Instead of such an extruded mold material, a double-sided or single-sided brazing sheet may be formed into a tubular shape, and a formed pipe in which the corresponding butt edges are joined by electric resistance welding or brazing may be used. Further, the cross-sectional shape of this type of header does not necessarily have to be a perfect circle, and in short, it is sufficient that it can withstand the internal pressure required for the condenser.

The headers (3) and (4) are provided with tube insertion holes (7) at predetermined intervals along the length direction thereof, and the tubes (1) corresponding to these insertion holes (7) are formed. ), The corresponding ends are inserted into the tube (1) and the header (3) by brazing in the inserted state.
And (4) are firmly brazed together. From the viewpoint of improving manufacturing efficiency, it is desirable that such brazing is performed by brazing the brazing material coated on the header (3) (4) or the tube (1) together. Upper and lower ends of the headers (3) and (4) are closed by a lid body (8).

On the left side header (3), a short length refrigerant inlet pipe (5) is inserted into the hole (9) formed in the header (3) at the upper part of the outer surface thereof. While being integrated by brazing in the state of being held, the right side header- (4) has a short refrigerant outlet pipe (6) at the lower portion of the outer surface thereof and a base end portion (6a) of the header (4). ) Is joined and integrated by brazing while being inserted into the hole (10) formed in (1). Note that (11) (1
2) are upper and lower side plates arranged outside the outermost corrugated fins (2) (2).

By the way, a partition plate (13) is provided at an intermediate portion in the vertical direction of the left header (3) so as to traverse the header (3), and a lower portion of the right header (4) in the vertical direction. Similarly, one partition plate (14)
The partition plates (13) and (14) divide the headers (3) and (4) into upper and lower two chambers, respectively. By installing the partition plates (13) and (14), the entire refrigerant passage constituted by the tube group is constituted by a plurality of tubes (1) through which the refrigerant introduced from the refrigerant inlet pipe (5) first flows. First refrigerant passage group (A)
And a final refrigerant passage group (C) constituted by a plurality of tubes (1) through which the refrigerant flowing out of the refrigerant outlet pipe (6) flows immediately before, and a plurality of tubes (1) located in the middle thereof. Of the intermediate refrigerant passage group (B) and the intermediate refrigerant passage group (B), and the refrigerant flows in a meandering manner through the passage groups (A), (B) and (C) in sequence. .

Here, the intermediate refrigerant passage group (B) is smaller than the refrigerant passage sectional area of the first refrigerant passage group (A), and the final refrigerant passage group (C) is the intermediate refrigerant passage group (B).
Is set to be smaller than the refrigerant passage cross-sectional area.
This is because the refrigerant passage cross-sectional area corresponding to the volume change of the refrigerant is ensured so that the refrigerant can be efficiently condensed and the pressure loss on the refrigerant side can be reduced as much as possible. In particular, when the refrigerant passes through the final refrigerant passage group (C), the refrigerant is already in a liquefied state and has a small volume, but the refrigerant passage cross-sectional area of the final refrigerant passage group (C) is as described above. Since the refrigerant passage has a corresponding cross-sectional area, the refrigerant passes through while performing necessary and sufficient heat exchange and suppressing the refrigerant-side pressure loss.

From this point of view, it is most preferable to gradually reduce the refrigerant passage cross-sectional area of the refrigerant passage group from the first refrigerant passage group (A) to the final refrigerant passage group (C). However, even if the refrigerant passage groups are not reduced stepwise in this way, it is possible to set the refrigerant passage sectional area of the final refrigerant passage group (C) smaller than the refrigerant passage sectional area of the first refrigerant passage group (A). A sufficient practical effect can be achieved, and in this case, it is desirable to set the latter in the range of 30 to 60% of the former, particularly preferably in the range of 35 to 50%.

By the way, even if the refrigerant passage cross-sectional areas of the respective refrigerant passage groups (A), (B), and (C) are set in a suitable range as described above, depending on the number of passes, that is, the number of refrigerant passage groups, the entire condenser may be changed. In some cases, it may not be possible to improve the expected heat exchange performance. Therefore, in order to obtain the desired heat exchange performance regardless of the number of passes, the refrigerant passage cross-sectional area of the refrigerant outlet pipe (6) is set to the refrigerant passage cross-sectional area of the final refrigerant passage group (C) [each The value obtained by multiplying the refrigerant passage cross-sectional area of the tube (1) by the number of tubes forming the final refrigerant passage group (C)] needs to be set to 30% or more. The reason for this is as follows.

That is, even in a condenser having the same number of tubes, if the number of partitions of the headers (3) and (4) is reduced and the number of refrigerant passage groups is set to be smaller, the number of partitions is increased to increase the number of refrigerant passages. As compared with the case where the number of groups is set to be large, the number of tubes forming the final refrigerant passage group (C) is increased and the flow rate of the refrigerant flowing through the final refrigerant passage group (C) is increased.

Particularly in this case, if the relationship between the refrigerant passage cross-sectional area of the final refrigerant passage group (C) and the refrigerant passage cross-sectional area of the refrigerant outlet pipe (6) is not appropriate, the refrigerant is abruptly drawn in the refrigerant outlet pipe (6). As a result of the flow passage being reduced and the refrigerant flow resistance being significantly increased, the liquefied refrigerant will stay in the lower tube (1) forming the final refrigerant passage group (C).
Therefore, in order to eliminate such inconvenience, the refrigerant outlet pipe (6)
It is necessary to set the cross sectional area of the refrigerant passage of 30% or more of the cross sectional area of the refrigerant passage of the final refrigerant passage group (C). Desirably, it is set to 60% or more.

6 and 7, the ratio of the refrigerant passage cross-sectional areas of the refrigerant outlet pipe (6) and the final refrigerant passage group (C) is changed, and the heat exchange amount and the refrigerant side pressure loss at each ratio are measured. The results are shown schematically. From the figure, when the refrigerant passage cross-sectional area of the refrigerant outlet pipe (6) is less than 30% of the refrigerant passage cross-sectional area of the final refrigerant passage group (C), the heat exchange efficiency decreases and the pressure loss on the refrigerant side decreases. It can be seen that the number is significantly increasing. By the way, in the condenser according to the above-mentioned embodiment, the left and right headers (3) and (4) are respectively attached to the condenser side for the purpose of attaching the condenser to the attachment side of the vehicle body or the like so that accessory parts can be attached to the condenser. Brackets (15), (15), (15) and (15) are attached one by one.

These brackets (15) are attached to the header-
(3) In addition to having a holding portion (16) which can be properly fitted to the outer peripheral surface of the outer peripheral surface of the outer peripheral surface excluding the side surface on the tube insertion side of (4) for more than a half circumference, Parallel plate-shaped tube side contact part (17)
(17) is extended. These tube side contact parts (17) (17) are attached to the tube (1) when mounted.
It is brought into contact with the side surface of the holding section (16) and acts to regulate the rotation of the holding section (16) with respect to the headers (3) and (4).

Further, the holding portion (16) is provided with a plate-shaped mounting portion (18) extending on the outer surface opposite to the tube side surface contact portions (17) (17). A fastening member such as a bolt can be inserted into the hole (18a) formed in the portion (18) and fixed to the mounting side or the like.

The bracket (15) is shown in FIG.
As shown in, the holding portion (16) is attached to the header (3).
(4) is fitted to the tube side contact part (1
7) and (17) are brazed to the headers (3) and (4) with the side surfaces of the tube (1) abutting.

The bracket (15) is attached to the header (3)
It is desirable that temporary fixing can be easily performed when mounting to (4) and that brazing does not occur in the header (3) and (4) contacting portions with the jig after brazing. Be done. Therefore, in the bracket (15), slits (17a) (17a) are formed in the tube side contact portions (17) (17) along the vertical direction, and the slits (1)
As shown in FIG. 5, a part of a jig (19) made of a bent rod-shaped material is fitted into 7a) and (17a), and the tube (1) is locked and held by the bracket (1).
5) is temporarily fixed. The jig (1
9) does not come into contact with the headers (3) and (4) coated with the brazing filler metal, the surface of the headers (3) and (4) is not contacted by the jig after brazing. There is an advantage that it is possible to avoid the inconvenience such as the occurrence of a wax accumulation due to

The bracket (15) is provided for the purpose of preventing the so-called wax shrinkage phenomenon, in which the brazing material does not sufficiently wrap around at the connection between the headers (3) and (4) and the tube (1). For the header (3) (4)
Header (3) (4) when attached to
The shape is such that a void (a) is formed in the vicinity of the connecting portion between the tube and the tube (1).

8 to 10 show a modification of the bracket.

The bracket (25) shown in FIG. 8 has a fitting portion (26) of a corresponding shape which can be fitted to a part of the outer peripheral surface of the header (3) (4) and a mounting portion extending from one end edge thereof. (2
8) and. In the juxtaposition part (26),
A cutout portion (26a) is formed at the upper end edge thereof, and a hole portion (26b) is formed at an intermediate portion. The notch (26a) and the hole (26b) are provided for spot welding when the bracket (25) is temporarily fixed to the headers (3) and (4),
This has an advantage that the effective welding length can be increased and the temporary fixing strength can be improved as compared with the case where there is no such cutout portion (26a) or hole portion (26b). Of course, it is desirable to provide both the notch portion (26a) and the hole portion (26b), but the purpose can be sufficiently achieved even if only one of them is provided. In the figure, (28a) is the mounting portion (2
It is a hole for inserting a fastening member such as a bolt formed in 8).

The bracket (3 shown in FIGS. 9 and 10
5) has a side portion (36) and a mounting portion (38) similar to those in the above-mentioned embodiment. A hole (36a) is formed in the juxtaposition part (36), and a hole (b) is also formed in the headers (3) and (4) correspondingly.
Then, the bracket (35) is temporarily fixed to the headers (3) and (4) as follows. First, the bracket (35) is arranged in the juxtaposed state with respect to the headers (3) and (4) in such a manner that the holes (36a) and (b) of both are aligned. Then, in that state, the both hole portions (36a)
In (b), an aluminum alloy bolt-shaped insertion member (3
9) is inserted and arranged, and a hole (39a) is formed in the insertion member (39) from its head to a predetermined depth.
A tapping screw (4) having a tapered shaft portion (40a).
0) is forcibly driven. As a result, the bolt-shaped insertion member (39) is expanded in diameter in the holes (39a) (a), and the bracket (35) is temporarily fixed to the headers (3) and (4).

As described above, the headers (3) and (4)
The brackets (25) and (35) temporarily fixed to
As in the past, it is brazed and fixed by brazing in the furnace.

The present invention is not limited to the multi-pass type condenser as shown in the above embodiment, but can be applied to a one-pass type condenser in which a header is not provided with a partition. is there.

[0037]

As described above, the heat exchanger according to the present invention has a plurality of tubes arranged in parallel and
A heat dissipation fin is arranged between adjacent tubes, and an end of each tube is connected to a hollow header to be a condenser, and the refrigerant passage cross-sectional area of the refrigerant outlet pipe connected to the header is the outlet pipe. Since the refrigerant flowing out of the final refrigerant passage group is set to 30% or more of the refrigerant passage cross-sectional area of the final refrigerant passage group formed by a plurality of tubes flowing immediately before the inside of the tubes forming the final refrigerant passage group. It is possible to reduce or eliminate the retention of the refrigerant in the. Therefore, it is possible to prevent the effective heat exchange area from being reduced due to the retention of the refrigerant in the final refrigerant passage group, and consequently to prevent the heat exchange performance from being deteriorated, and also to prevent the refrigerant-side pressure loss from increasing.

[Brief description of drawings]

FIG. 1 is an overall front view of a condenser.

FIG. 2 is a plan view of the condenser.

FIG. 3 is a left side view of the condenser.

FIG. 4 is an enlarged sectional view taken along line IV-IV of FIG.

FIG. 5: V of FIG. 4 showing a temporarily fixed state with a jig attached
It is an expanded sectional view of the -V line.

FIG. 6 is a graph schematically showing a relationship between a ratio (%) of a refrigerant passage cross-sectional area of a refrigerant outlet pipe and a refrigerant passage cross-sectional area of a final refrigerant passage group, and an exchange heat amount.

FIG. 7 is a graph schematically showing a relationship between the refrigerant side pressure loss and the ratio (%) of the refrigerant passage sectional area of the refrigerant outlet pipe and the refrigerant passage sectional area of the final refrigerant passage group.

FIG. 8 is a perspective view showing a modified example of the bracket and showing a separated state before the bracket is attached to the header.

9 is a perspective view corresponding to FIG. 8, showing another modified example of the bracket.

10 is a cross-sectional view showing a state where the bracket shown in FIG. 9 is attached to a header.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Tube 2 ... Fin 3 ... Header 4 ... Header 5 ... Refrigerant inlet pipe 6 ... Refrigerant outlet pipe A ... First refrigerant passage group B ... Intermediate refrigerant passage group C ... Final refrigerant passage group

Claims (2)

[Claims] 1. A plurality of tubes (1) are arranged in parallel, fins (2) are arranged between adjacent tubes (1), and the ends of each tube (1) are hollow headers.
(3) In the condenser connected to (4), the refrigerant passage cross-sectional area of the refrigerant outlet pipe (6) connected to the header (4) is such that the refrigerant flowing out from the outlet pipe (6) is A condenser characterized by being set to 30% or more of the refrigerant passage cross-sectional area of the final refrigerant passage group (C) constituted by a plurality of tubes (1) flowing immediately before that. 2. A plurality of tubes (1) are arranged in parallel, fins (2) are arranged between adjacent tubes, and both ends of each tube (1) are a pair of hollow headers.
(3) Connected in communication with (4), and further header (3)
A condenser in which a refrigerant inlet pipe (5) and an outlet pipe (6) are connected to (4), and the refrigerant passage constituted by the tube (1) is formed by partitioning the inside of the header. The first refrigerant passage group (A) in which the refrigerant flowing in from the refrigerant inlet pipe (5) first flows, and the final refrigerant passage group (C) in which the refrigerant flowing out from the refrigerant outlet pipe (6) circulates immediately before that. At least two or more refrigerant passage groups (A) containing
By being divided into (B) and (C), the refrigerant is made to meander and flow at least once, and the refrigerant passage cross-sectional area of the refrigerant outlet pipe (6) is the final refrigerant passage group. A condenser characterized by being set to 30% or more of the cross-sectional area of the refrigerant passage of (C).