JPH0332944Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial field of application This invention relates to a condenser, particularly an aluminum condenser for a car cooler.

In this specification, the term aluminum is used to include aluminum alloys.

Conventional technology and its problems Heat exchangers such as those used as condensers for car coolers use relatively high-pressure gas as a refrigerant, so they must have excellent pressure resistance for safety reasons. requested.

For this reason, conventionally, a serpentine tube type heat exchanger is generally used. That is, a core is generally used by bending a multi-hole extruded flat tube called a harmonica tube into a meandering shape and arranging fins between its parallel parts.

However, one of the essential problems with such a serpentine condenser is that the refrigerant circuit is formed in a meandering manner from one end to the other within one tube. There is a problem that the flow resistance of the refrigerant becomes relatively large.
In order to reduce this flow resistance, it is considered to widen the width of the tube and increase the cross-sectional area of the flow path, but since the size of the condenser core is limited by its installation space, Countermeasures are difficult to apply.

In addition, to increase the heat exchange efficiency of the condenser,
In addition to increasing the width of the tubes to reduce the pressure loss of the refrigerant as described above, the distance between adjacent tubes, that is, the height of the fins, can be reduced to increase the number of fins interposed between the parallel portions of the tubes. It is also taken into consideration. However, because the radius of curvature of the bent portion of the tube material cannot be made smaller than a certain value due to processing, there is a limit to the improvement in heat exchange efficiency by narrowing the tube spacing.

By the way, in the case of a condenser, the refrigerant passage is roughly divided into a refrigerant condensing section near the inlet side where the refrigerant is still in a gasified state, and a supercooling section near the exit side where the refrigerant is in a liquefied state. . In order to ensure high heat exchange efficiency, it is generally necessary to ensure a large heat transfer area in the condensing part, and the heat transfer area in the supercooling part may be relatively small. However, in the case of the conventional serpentine tube type, the refrigerant passage is formed by a single tube, so it is essentially impossible to change the cross-sectional area of the passage between the condensing section and the supercooling section. be. As a result, a so-called liquid seal state occurs in which the liquefied refrigerant blocks the passage as it progresses from the inlet side to the outlet side in response to the phase change of the refrigerant from gas to liquid. This creates heat transfer resistance and reduces heat exchange efficiency. As a result, it is necessary to make the heat exchange tubes extra long. As described above, heat exchange in accordance with the phase change of the refrigerant is not possible, resulting in poor heat exchange efficiency, resulting in an increase in the size of the entire condenser and, in addition, the need for a large compressor.

As described above, due to the structure of the conventional serpentine condenser, there are limits to the design specifications that can be adopted in order to reduce pressure loss and improve heat exchange efficiency.

In addition, in terms of manufacturing, bending the tube into a serpentine shape is somewhat troublesome, and when assembling the tube and fins, the serpentine bending state of the tube tends to expand as the fins are inserted. Therefore, it is difficult to perform the assembly by automatic mechanical assembly means, resulting in low productivity and high costs.

Problems to be solved by this invention Therefore, this invention can ensure a large cross-sectional area of the refrigerant passage without increasing the size of the condenser core, thereby reducing pressure loss, and improving pressure resistance and heat exchange efficiency. The purpose is to provide a new type of condenser with excellent performance.

In addition, for another purpose, the present invention provides a condenser in which the cross-sectional area of each passage is changed between a condensing section that exclusively condenses refrigerant gas and a subcooling section where liquefied refrigerant mainly flows. That's true.

Still another purpose is to facilitate assembly and production;
It is an object of the present invention to provide a condenser that has good production efficiency and can reduce costs.

Means for Solving the Problems For the above purpose, the aluminum condenser according to the present invention includes a pair of aluminum cylindrical headers arranged parallel to each other on the left and right with an interval between them, and a pair of aluminum cylindrical headers arranged parallel to each other at a distance from each other, and having both ends as described above. A plurality of heat exchange tubes are arranged horizontally and parallel to each other in communication with the header, and fins are arranged in air circulation gaps between adjacent tubes, and the tubes have a flat cross section and an inner It is constructed of a flat aluminum tube having a reinforcing wall extending between the upper and lower walls, and both ends of the tube are inserted into tube insertion holes drilled in the header and brazed in a liquid-tight state, and at least one The interior of the header is partitioned in the length direction by the partition means at predetermined positions in the length direction, so that the refrigerant passages constituted by the heat exchange tube group are separated from each other by a plurality of heat exchange tubes. The partition is divided into at least two or more passage groups including an inlet side passage group and an outlet side passage group, and the refrigerant is made to sequentially flow through each passage group in a meandering shape of two or more passes; The means includes a partition having a closing portion located transversely within the header and closing the internal space thereof, and a positioning portion located within a slit-like notch formed in the circumferential direction of the header to fill it. The partition plate is made of a plate, and the partition plate is inserted into the header through the notch, and the mutually adjacent parts are brazed and joined together.

Further, in a preferred embodiment of the partition means, the cut portion is formed over a range of more than half the circumference of the header in the circumferential direction, and the partition plate is formed in a small diameter portion having an outer diameter that fits the inner peripheral surface of the header. and a large-diameter portion having an outer diameter that matches the outer circumferential surface of the header and whose peripheral end fits into the notch.

Embodiment Next, an embodiment of this invention will be described along with its operation.

As shown in Fig. 2, the condenser according to this invention consists of a large number of tubes 1 arranged in parallel in the horizontal direction, corrugated fins 2 interposed between adjacent tubes 1, 1, and a group of tubes. A pair of left and right headers 3 and 4 are provided at both ends of the header 3 and 4, which are arranged in parallel and perpendicular thereto.

The tube 1 is made of a flat extruded aluminum material, and has a reinforcing wall 1a extending between the upper and lower walls at the center in the width direction, as shown in FIG. It is designed to withstand large internal pressures without any problems. The tube 1 may be of a porous type, such as a so-called harmonica tube. Alternatively, instead of using an extruded material, an electric resistance welded tube may be used, and a reinforcing member corresponding to the reinforcing wall 1a may be inserted and joined inside.

The corrugated fin 2 has approximately the same width as the tube 1, and is joined to the tube by brazing. The corrugated fins 2 are also made of aluminum, and preferably have louvers cut and raised.

The headers 3 and 4 are made of aluminum pipe material with a circular cross section. In this embodiment, a molded pipe made of a brazing sheet coated with a brazing material on one or both of its inner and outer surfaces is used as the pipe material. Note that the abutting portions of this formed tube may be electrically welded in advance and used as an electric resistance welding tube, or the abutting portions may be brazed at the same time as the tube and header are brazed to form a tubular shape. Good as a thing. Tube insertion holes 5 are bored in each header 3 and 4 at intervals along the length direction, and both ends of each tube 1 are inserted into the holes and firmly joined by brazing. connected. Further, a refrigerant inlet pipe 6 is connected to the upper end of the left header 3, and a refrigerant outlet pipe 7 is connected to the lower end of the left header 3.
are connected. Furthermore, closing lid pieces 12 and 13 are attached to the upper and lower ends of the right header 4, respectively. Note that 8 and 9 shown in FIG. 1 are upper and lower side plates arranged outside the outermost corrugated fins 2, 2.

Furthermore, the left header 3 is provided with a total of two partition plates 10, 10, one each at an upper position and a lower position from the central part in the length direction, so that the header has three compartments. On the other hand, the right header 4 is also provided with one partition plate 10 approximately in the center, and the inside of the header is partitioned into two upper and lower chambers. By installing such a partitioning means, all the refrigerant passages 14 (the fifth
(see figure) are inlet side passage group A and outlet side passage group C.
and two intermediate passage groups B located between them.
The refrigerant is divided into four passage groups: 1 and B2, and the refrigerant is made to flow in a meandering manner around each passage group. In addition, the inlet side passage group A and intermediate passage groups B1 and B2 include a larger number of tubes, that is, the number of refrigerant passages, than the outlet side passage group C, and the passage cross-sectional area thereof is larger than the passage cross-sectional area of the outlet side passage group C. It is set to something.

In the above configuration, the refrigerant flowing from the refrigerant inlet pipe 6 at the upper part of the left header 3 passes through each tube 1 of the inlet side passage group A and reaches the right header 4, and then is reversed. Intermediate passage group B
1 and B2 make a U-turn at the left header 3 and flow sequentially, then reverse at the right header 4, flow through each passage of the outlet side passage group C to the left header 3, and flow out from the outlet pipe 8 to the outside of the condenser. . While flowing through each passage group, heat exchange is performed with the air flowing through the air circulation gap including the corrugated fins 2 formed between the tubes 1 and 1. Although the refrigerant passing through the inlet-side passage group A is still in a gasified state with a large volume, the passage cross-sectional area of the inlet-side passage group A is set to be large, so that the heat transfer area is large. The refrigerant is efficiently condensed. The refrigerant passing through the intermediate passage groups B1 and B2 is partially liquefied in the inlet side passage group A, so it exhibits a gas-liquid mixed state, but the passage cross-sectional area of the intermediate passage groups B1 and B2 is also the same as that of the inlet side passage group A. Since it is set to the same level as the above, it is possible to perform the necessary and sufficient heat exchange and allow the refrigerant to pass through with less resistance. Then, when the refrigerant passes through the outlet side passage group C, most of the refrigerant is already in a liquid state and the volume is small, so the passage cross-sectional area may also be small. Since it is set to be smaller than the passage groups B1 and B2, no space is wasted in passing the refrigerant. In addition, since the refrigerant is subjected to a gas-liquid mixing action within the headers 3 and 4, it is effectively prevented that the passage becomes liquid-sealed due to being filled with liquid phase refrigerant.

In the embodiment described above, the cross-sectional area of the inlet-side passage group A and the intermediate passage groups B1 and B2 is the same, and only the passage cross-sectional area of the outlet-side passage group C is reduced. The cross-sectional area of the passages may be reduced in stages from the inlet side passage group A to the outlet side passage group C. Furthermore, in the above embodiment, a four-pass system was shown in which four passage groups were provided and the refrigerant was made to make three U-turns and meander four times; It is also applicable to a two-pass condenser that makes U-turns only once, and a meandering condenser that has five or more passes in which three or more intermediate passages are formed.

Incidentally, the partition plate 10 is attached to the headers 3 and 4 in the following manner. That is,
As shown in FIG. 1, the headers 3 and 4 have slit-shaped notches with a width approximately equal to the thickness of the partition plate 10 extending approximately half the way around the partition plate 10 in the outer circumferential direction at the intended attachment position of the partition plate 10. A portion 11 is formed. on the other hand,
The partition plate 10 has a closing portion that is located transversely within the headers 3 and 4 to close off the internal space thereof, and a positioning portion that is located within a slit-like notch formed in the circumferential direction of the header to fill it. It is considered to have the following. More specifically, it is formed into a small diameter portion 10a whose outer diameter is approximately equal to the inner diameter of the headers 3 and 4, and the remaining half circumference is a peripheral end bulge having an outer diameter equal to the outer diameter of the headers. It is formed in a large diameter portion 10b having a shape. As shown in FIG. 4, in the partition plate 10, the outer peripheral surface of the small diameter portion 10a is brought into contact with the inner peripheral surface of the headers 3 and 4, and the peripheral end of the large diameter portion 10b is brought into contact with the notch 11. The headers are inserted into the headers 3 and 4 from the notch 11 so as to fit into the headers 3 and 4, and are fixed by brazing in this state. Regarding this brazing, if a brazing sheet clad with a brazing material is used for the headers 3, 4 or the partition plate 10, brazing can be performed simultaneously with the fins 2, tubes 1, etc., and productivity can be further improved. After brazing, the partition plate 10 is joined and integrated with the headers 3 and 4 without any gaps, and the outer peripheral surface of the header and the partition plate 10 are
The outer circumferential surface of the large-diameter portion 10b coincides with the outer circumferential surface of the large diameter portion 10b, so that the curved surface has no irregularities and the appearance is not impaired.

The tube 1 and the headers 3, 4 are joined by brazing with a brazing material layer coated on either the inner surface and/or the outer surface of the header in advance. That is, a clad tube, which is an aluminum tube whose inner surface is coated with a brazing metal layer, is used as the header component, and tube insertion holes 5 are arranged in a row in the clad tube.
After the end of the tube 1 is inserted into the insertion hole 5 to be temporarily assembled, they are joined together by vacuum brazing or the like. The clad pipe is generally manufactured by electric resistance welding, but it may also be manufactured by extrusion or other methods. In addition, the brazing material layer is generally made of Si.
An Al-Si alloy having a content of approximately 6 to 13 wt% is used. After brazing, headers 3 and 4
A sufficient fillet is formed at the connection portion between the headers 3, 4 and the tube 1, and the headers 3, 4 and the tube 1 are firmly joined and integrated without any gaps. When fixing the header and the tube by soldering, a brazing sheet coated with a brazing material is used as the material for the corrugated fin 2, or a clad tube whose outer surface is coated with a layer of brazing material is used as the material for the tube 1. If so, headers 3 and 4
It is possible to solder tube 1 and corrugated fin 2 at the same time as tube 1.
The productivity of the heat exchanger can be further improved.

Effect of invention This invention has the following effects.

(1) First, the pressure loss of the refrigerant can be significantly reduced.

That is, in the condenser according to this invention, a large number of heat exchange tubes are arranged in communication between a pair of headers arranged in parallel on the left and right, and gas introduced from the refrigerant inlet of one header is connected. It is constructed as a so-called multi-flow type heat exchanger that distributes and circulates refrigerant into multiple tubes at the same time. The pressure loss due to refrigerant flow can be greatly reduced. Therefore, it is possible to improve the heat exchange efficiency and reduce the required capacity of the compressor.

(2) It also has excellent pressure resistance and high safety.

That is, as a multi-flow type heat exchanger, there is a type generally known as a conventional radiator. However, this known heat exchanger has many aspects such as the structure of the tank, the joint structure between the tube and the tank, and the structure of the tube.
When used as a condenser that is subjected to a considerable internal pressure, it is difficult to ensure sufficient pressure resistance to withstand the use. However, in this invention, the header is inserted through the notch and reinforced with a partition plate that is joined by brazing, and the heat exchange tube with a flat cross section is inserted into the reinforcing wall between the upper and lower walls. Furthermore, as a communication connection structure between the tube and the header, the end of the tube is inserted into a hole drilled in the peripheral wall of the header and brazed. The headers, tubes, and their connecting parts can all have sufficiently excellent pressure resistance, and have sufficient safety and durability without fear of liquid leakage.

(3) It has excellent heat exchange efficiency and can be significantly downsized.

That is, in the condenser of this invention, a partition is provided inside one or both headers, so that the refrigerant passage formed by the tubes is divided into two inlets each consisting of a plurality of tubes. The header is divided into at least two passage groups including a side passage group and an outlet side passage group, and the refrigerant is made to make one or more U-turns within the header to flow in a meandering pattern of two or more passes. Therefore, depending on the position of the partition, the condensing section and the subcooling section each have a necessary and sufficient amount of water that reasonably corresponds to the change in the phase state of the refrigerant, that is, the phase change from the gas state to the liquid state. It becomes possible to ensure the required and sufficient length of the refrigerant passage from the inlet to the outlet while ensuring the passage cross-sectional area. In addition, the refrigerant is subjected to a gas-liquid mixing action when making a U-turn within the header, and is then distributed and introduced into the next refrigerant passage for further cooling. Therefore, as in the case of a conventional serpentine condenser, the liquid phase refrigerant condensed in the refrigerant passage blocks the refrigerant passage especially as it approaches the outlet side, which effectively creates a so-called liquid seal state. The front surface area of the core can be utilized to the maximum as an effective area for heat exchange, and the heat exchange capacity can be improved.
In addition, unlike conventional serpentine condensers, there is no inconvenience such as the tube pitch being limited by the radius of curvature of the bending part, and the tube pitch can be freely selected, reducing the number of meanderings and overall length of the refrigerant passage. If they are the same, by reducing the tube pitch, the number of corrugated fins interposed between adjacent tubes can be significantly increased, and the fin efficiency can be improved. Therefore, it is possible to improve the heat exchange efficiency, and the overall size of the condenser can be reduced, making it ideal as a condenser for vehicles that are especially applied in narrow spaces. The amount of refrigerant CFC, which has become a social problem as a pollution factor, can be significantly reduced by more than 30% compared to conventional serpentine condensers.

(4) Easy to manufacture and has excellent productivity.

That is, the condenser of this invention can be assembled and manufactured by, for example, first inserting a partition plate into the header through a pre-formed notch in the header, and then inserting both ends of the tube into the tube insertion hole of the header. A frame-shaped skeleton is constructed, and fins are fitted between adjacent tubes to temporarily assemble the whole, or tubes and fins are arranged alternately and then combined with a header to temporarily assemble, and then assembled in a furnace. It can be easily performed by batch brazing, and productivity can be improved and manufacturing costs can be reduced as a result. In particular, by configuring the header partitioning means as described above, the header can be divided into one
It can be manufactured as a single piece using a single pipe, and the installation position of the partition plate can be easily and correctly determined.An alternative method is to consider, for example, installing multiple short header units separately in the middle. Compared to the case of joining with a partition plate interposed therebetween, the number of parts can be reduced and the assembly manufacturing process can be simplified.

Further, as in claim (2), by fitting the partition plate into the slit-like cut portion as having a small diameter portion and a large diameter portion,
Correct positioning of the partition plate and airtight connection to the header can be easily and reliably performed.

[Brief explanation of the drawing]

The drawings show a condenser as an embodiment of this invention. Fig. 1 is a perspective view showing the header, tube, and partition plate in a separated state, Fig. 2 is an overall front view, and Fig. 3 is a side view. FIG. 4 is a sectional view taken along the - line in FIG. 2, and FIG. 5 is a refrigerant circuit diagram. 1... Tube, 1a... Reinforcement wall, 2... Corrugated fin, 3, 4... Header, 10... Partition plate, 10a... Small diameter part, 10b... Large diameter part, 1
1... Cut portion, 14... Refrigerant passage, A... Inlet side passage group, B1, B2... Intermediate passage group, C... Outlet side passage group.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A pair of aluminum cylindrical headers arranged parallel to each other on the left and right with an interval between them, and a pair of aluminum cylindrical headers that are connected to the headers at both ends so as to be horizontal and parallel. A plurality of heat exchange tubes are arranged, and fins are arranged between adjacent tubes for air circulation. Both ends of the tube are inserted into tube insertion holes drilled in the header and brazed in a liquid-tight state, and the inside of at least one header is The refrigerant passages constituted by the heat exchange tube group are partitioned in the length direction by partition means at predetermined positions of The refrigerant is divided into at least two passage groups including at least two passage groups, and the refrigerant is made to flow in a meandering manner of two or more passes sequentially around each passage group, and the partition means is arranged in a transverse manner within the header. an occluding portion that is positioned to obstruct the internal space;
It consists of a partition plate having a positioning part located in and filling a slit-shaped notch formed in the circumferential direction of the header, and the partition plate is inserted into the header from the notch and is in contact with each other. A condenser characterized in that its parts are integrally joined by brazing. (2) The cut portion in the partition means is formed over a range of more than half the circumference of the header in the circumferential direction, while the partition plate has a small outer diameter portion that fits the inner circumferential surface of the header and a portion of the header. 2. The condenser according to claim 1, further comprising a large diameter portion having an outer diameter that fits the outer circumferential surface and a peripheral end portion of which fits into the notch.