EP0774636A2 - Heat exchanger, more particularly evaporator - Google Patents

Abstract

The heat exchanger consists of a stack of assembled discs (2) forming tubes and two stamped plates (3,4) forming a hollow zone between them. All the plates of the heat exchanger have flush and aligned mounting openings (17), for a fixing rod (13) to be inserted through them. The mounting openings are outside the stamped shapes (7,8), but close to them on a symmetrical axis. The plates are made of solder plated aluminium and the fixing rod is an aluminium wire.

Description

The invention relates to a heat exchanger, in particular a refrigerant evaporator of the type specified in the preamble of claim 1.

US-A-5,176,206 describes a heat exchanger which consists of a plurality of flat, tubular elements, the tubular elements each being formed from two embossed plates. As a result, the tubular elements have the shape of disks, which are assembled to form a stack with the interposition of corrugated ribs, a side part being arranged at both ends of the stack. The sheet metal plates from which the disks are made have, at one end of their longitudinal extent, features with openings arranged therein, the features being directed towards the respectively adjacent tube element, so that the successive disks are in contact with one another with their features. The openings in the forms form passages to the cavity of the next disk in each case, so that a flow channel is formed for the fluid flowing through the heat exchanger.

In the known arrangement, the surfaces on which two plates, which form a tubular element, lie against each other are flat. Likewise, the adjacent panes lie with only flat surfaces to each other, so that the stack composed of disks and corrugated ribs must be handled with extreme care until after the soldering a displacement of the plates relative to one another is impossible. However, such a treatment of a stack consisting of disks cannot be carried out in practice, so that complex fixing and tensioning devices are necessary to secure the individual sheets or disks in their relative position with respect to the overall arrangement. However, such clamping devices are expensive and complicate the manufacturing process, which ultimately has an impact on the manufacturing costs of the heat exchanger.

In US-A 5,086,832 a heat exchanger consisting of stacked disks is known, in which the disks form flat tubular elements, each consisting of two embossed sheets. The sheets have spacing and locking deformations at one end, so that the respectively adjacent plates are fixed to the adjacent plate at this end. However, this requires an appropriate shape, which leads to an increased use of materials, to a complication of the manufacturing process and to a higher weight of the heat exchanger. Ultimately, such complex measures are also reflected in the price of the heat exchanger.

The present invention has for its object to provide a heat exchanger of the type referred to in the preamble of claim 1, in which the manufacturing quality is improved despite simple disk configuration.

This object is achieved by a heat exchanger with the features of claim 1.

The main advantages of the invention can be seen in the fact that the heat exchanger can be manufactured more simply and therefore more cost-effectively with increased manufacturing quality, because no expensive fixing means have to be molded onto the sheets forming the disks, and also no clamping devices are required for fixing the stack of disks.

An advantageous further development of the subject matter of the invention is seen in the fact that the openings are arranged outside the forms, but in the vicinity thereof. In this way, the means for fixing are located outside the fluid-carrying heat exchange channels, i. H. no additional solder joints are created in the area of the channels. The fact that the fixing means are arranged close to the features also has the advantage that these features and also the openings therein for connecting the cavities of the respective adjacent panes are surely congruent one above the other and thus the entire soldering area surrounding the openings is available. So that a uniform type of embossed sheets can be used when forming the stack of sheets for producing the heat exchanger consisting of disks, it is advantageous that the fixing openings lie in an axis of symmetry running in the longitudinal direction of the disks.

Usually, the first and last plate of a heat exchanger consisting of a plate stack are provided on both sides with corrugated fins, these outer corrugated fins being covered by a side part. In order to include this side part in the fixation of the entire stack of disc elements, it is advantageous that fixing openings are also provided in the side parts, which are congruent with the fixing openings of the disks. The fixing openings of the sheets forming the disks and of the side parts preferably have a circular cross section, as does the fixing rod.

Since the fixing rod does not lead to a noticeable increase in the weight of the heat exchanger, it is expedient to leave it in the heat exchanger and to connect the fixing rod to the disks and the side parts in a cohesive manner during the soldering process. It is considered particularly advantageous here that the fixing openings are surrounded by passages formed from the material of the sheets, so that there is a sufficient soldering area between the fixing rod and the sheets. Such soldering between the sheets and the fixing rod leads to an increase in the strength of the heat exchanger and in particular to an increase in the bursting pressure. Since the sheets are stacked in pairs to form a disc, which are mirrored together, the passages of two sheets that form a disc are directed in opposite directions. In order to avoid a separate solder application, the sheets are made of solder-plated aluminum, so that the contact surfaces between the passages and the fixing rod made of aluminum wire provide a sufficient amount of solder. Depending on the design of the heat exchanger, the strength of the fixing rod can be dimensioned, it being considered advantageous that the fixing rod and, accordingly, also the fixing openings receiving it have a diameter of approximately 2 mm to 5 mm, preferably 3 mm.

Fig. 1

einen aus Scheiben gebildeten Wärmetauscher,

Fig. 2

einen Ausschnitt eines geprägten Bleches zur Bildung der Scheiben,

Fig. 3

einen Schnitt entlang der Linie III-III in Fig. 2,

Fig. 4

einen Schnitt entlang der Linie IV-IV in Fig. 2,

Fig. 5

einen Schnitt entlang der Linie V-V in Fig. 2,

Fig. 6

einen Ausschnitt eines Seitenteils,

Fig. 7

einen Schnitt entlang der Linie VII-VII in Fig. 6,

Fig. 8

eine vergrößerte Darstellung der Einzelheit VIII in Fig. 1, teilweise geschnitten,

Fig. 9

einen Ausschnitt des Endbereichs eines Wärmetauschers mit Anschlußrohr in perspektivischer Darstellung,

Fig. 10

einen Schnitt durch ein Seitenteil und ein Anschlußrohr.

An embodiment of the heat exchanger according to the invention is explained below with reference to the drawing. The drawing shows:

Fig. 1

a heat exchanger made of disks,

Fig. 2

a section of an embossed sheet to form the disks,

Fig. 3

2 shows a section along the line III-III in FIG. 2,

Fig. 4

2 shows a section along the line IV-IV in FIG. 2,

Fig. 5

3 shows a section along the line VV in FIG. 2,

Fig. 6

a section of a side part,

Fig. 7

6 shows a section along the line VII-VII in FIG. 6,

Fig. 8

2 shows an enlarged view of detail VIII in FIG. 1, partially in section,

Fig. 9

a section of the end region of a heat exchanger with a connecting pipe in a perspective view,

Fig. 10

a section through a side part and a connecting pipe.

In Fig. 1, a heat exchanger 1 is shown, which consists of a plurality of parallel plates 2, 2 ', 2''. These slices 2, 2 ', 2''are stacked, whereby a corrugated fin 5 is arranged between two successive disks 2, 2 ', 2''. A side part 6 runs parallel to the outermost disc 2, the distance between the side part 6 and the outermost disc 2 being equal to the distance between two adjacent discs 2, 2 ', 2'', so that also between the side part 6 and the outermost one Disk 2 a corrugated fin 5 can be arranged. Each of the disks 2, 2 ', 2''is formed from two embossed sheets 3 which, due to their shape, enclose cavities between them which serve to guide a heat exchanger fluid, preferably a refrigerant of an air conditioning system. The sheets 3 and 4 are of identical design and are placed mirror-inverted against each other, so that they have the same configuration on both flat sides.

The disks 2 have at the lower ends 11 only a bent sheet metal edge, but no additional features, so that the fluid channels formed in the cavities of the disks are deflected in the lower area of the disk. At their upper ends 12, the sheets 3 and 4, each of which forms a disk 2, have oppositely directed shapes 7 and 8, with each shape 7 of a disk 2 having a shape 8 of the subsequent disk 2 'or 2'' mutual investment comes. Openings are provided in these versions 7 and 8, all openings of the stacked panes 2 being congruent and creating a connection between the cavity of the respective pane 2 and the cavity of the adjacent pane 2 'and 2'', respectively. In this way, one or more collecting spaces are created by the large number of forms 7 and 8 of the stacked panes 2, the axis of a collecting space being designated by 10 in the exemplary embodiment in FIG. 1.

In the upper ends 12 of the panes 2, 2 ′, 2 ″, a fixing rod 13 runs orthogonally to the plane of the disc through the entire heat exchanger 1, one end 14 of the fixing rod 13 protruding through a cranked section 9 of the side part 6 onto the outside. The cranked section 9 of the side part 6 lies against the shape 7 of the sheet 3 of the pane 2 and is tightly soldered to it in order to close off the collecting space formed in the upper end 12 of the panes 2, 2 ′, 2 ″.

Fig. 2 shows the upper section with the end 12 of the embossed sheet 3 in an enlarged view. This plate 3 is designed such that, in relation to an axis of symmetry 16 which runs in the longitudinal direction of the plate 3, mirror-image arrangements of features are present. Between a central web 23 and outer edges 24, 24 'there are shallow depressions 25, 25', through which the cavities for the fluid-carrying channels are formed by two joined sheets 3, 4, the flat edges 24, 24 'and web 23 of which lie against one another will. A plurality of wart-shaped elevations 22 are arranged in these shallow depressions 25, 25 ', which come to rest with wart-shaped elevations of the further sheet of the same pane and are connected to them in a materially-bonded manner. In this way, not only the flow within the cavities formed by the flat recesses 25, 25 'is influenced, but also tie rods are formed which prevent the disks from inflating due to the fluid pressure prevailing within the cavities.

Near the upper end 12 of the sheet 3, two shapes 7, 7 'are formed, in which punched out openings 15 are located, which are surrounded by a contact surface 18, 18 'running parallel to the disk plane. These contact surfaces 18, 18 'serve to contact corresponding surfaces of the adjacent pane and at the same time form a soldering surface which tightly seals the cavities formed within the panes or the collecting tubes formed through the openings 15 of all panes. In the axis of symmetry 16 of the sheet 3 there is a fixing opening 17 at the upper end 12, which serves to receive the fixing rod shown in FIG. 1. This fixing opening 17 is located outside of the features 7, 7 'and thus also outside of the fluid-carrying cavities or the manifolds formed by the openings 15, 15'.

FIG. 3 shows a section along the line III-III in FIG. 2. From this representation it can be seen that the lateral edges 24, 24 'and the central web 23 run in one plane and in this way serve as a contact surface 26 for a further sheet, which forms a disc together with the sheet 3. The features 7 and 7 ', from which openings 15, 15' are punched out, are arranged between the central web 23 and the lateral edges 24, 24 '. These openings 15, 15 'are each surrounded by a contact surface 18, 18' running parallel to the wafer plane 26, which serves as a soldering surface when in contact with the next subsequent wafer. A passage 19 is provided between the forms 7, 7 ', which surrounds the fixing opening shown in FIG. 2 and which protrudes from the sheet metal plane 26 in the same direction as the forms 7 and 7'.

FIG. 4 shows a section along the line IV-IV in FIG. 2. The section runs through the axis of symmetry located fixing opening 17 which is surrounded by the passage 19. The shape 7 'rises much more strongly from the sheet metal plane 26, the shape 7' being followed by the flat depression 25, which forms the fluid channel within the disk.

Fig. 5 shows a section along the line V-V in Fig. 2, i. H. the section runs through the shape 7 of the sheet 3. From this illustration it can be seen that the flat recess 25 extends into the shape 7 and in this way a cavity connected to the collecting tube is formed within the disk by two sheets forming a disk. The passage 19 hidden in FIG. 5 is shown with dashed lines.

6 shows a section of the side part 6 with the cranked section 9. FIG. 7 shows a section along the line VII-VII in FIG. 6. As is clear from the section in FIG. 7, two bulges 20 are provided in the cranked section 9, which in the direction from the plane of the side part 6 are formed, which faces the adjacent plate of the heat exchanger. This is intended to cause the bulges 20 to protrude into the openings 15, 15 'of the outer disk when the heat exchanger is stacked from disks. 6 and 7, there is a fixing opening 21, which has at least approximately the same cross section as the fixing opening in the metal sheets which form the disc, in the cranked section 9 of the side part 6. Due to the material thickness of the side part 6, there is sufficient surface within the fixing opening 21 for soldering to a fixing rod, so that a passage, as is present in the sheet metal forming the disks, can be dispensed with.

FIG. 8 shows an enlarged illustration of the detail VIII from FIG. 1. The area adjacent to the end 12 of the disks 2 is broken open, so that the arrangement of the fixing rod 13 within the sheets 3 and 4 forming the disks 2 is visible. The forms 7 and 8 of the disks 2, 2 ', 2' 'form a manifold 10' shown with dashed lines. Depending on the arrangement of the inlet and return connections for the heat exchanger fluid, d. H. an opening and a connecting piece may be provided on the cranked section 9 of the side part 6 instead of the curvature 20.

In a plane lying outside the collecting pipe 10 ', the sheets 3 and 4 of the disks 2, 2', 2 '' each have the passages 19, 19 'pointing in opposite directions, which surround the fixing openings 17. The fixing openings 17 and thus also the passages 19, 19 'of all sheets 3, 4 are aligned such that they lie congruently one above the other, as is the fixing opening 21 in the cranked section 9 of the side part 6. Through all the disks 2 of the stacked sheets 3, 4 and the side part 6 extends a fixing rod 13, the cross section of which is matched to the cross section of the fixing openings 17 and 21. In this way, there is a contact surface between the passages 19, 19 'or the cranked section 9 and the fixing rod 13, so that when the heat exchanger is soldered, a material connection between all the sheets 3, 4 and the side part 6 with the fixing rod 13 is produced. The length of the fixing rod 13 corresponds to the stack of the disks 2, only one end 14 of the fixing rod 13 being slightly different protrudes from the cranked section 9 of the side part 6.

Both the sheets 3, 4 and the side part 6 are preferably made of solder-plated aluminum, it being sufficient for the side part 6 to provide one-sided solder plating. The sheets 3, 4, on the other hand, are solder-plated on both sides, since they have soldering surfaces on the mutual contact surfaces to form a disk and also on the contact surfaces for the next disk in each case, on which a corresponding solder supply is to be provided. The fixing rod 13 expediently consists of an aluminum wire which is soldered to the metal sheets 3, 4 due to the solder plating inside the passages 19, 19 '. Due to the soldering, the fixing rod not only has the effect of precisely aligning all the sheets, but also leads to an increase in the strength of the disks 2, 2 ', 2' 'in this area located between the collecting tubes 10'. The cross section of the fixing openings and the fixing rod can be dimensioned according to the strength requirements, a diameter of approximately 2 mm to 5 mm being considered. A cross section with a diameter of 3 mm is regarded as a particularly preferred embodiment.

In Fig. 9, a section of the heat exchanger is shown in perspective, on which a connecting pipe is fastened by soldering, this soldering taking place simultaneously with the soldering of the heat exchanger, that is to say a so-called complete soldering. The heat exchanger 1 consists of disks 32, which are formed from sheets 33 and 34 joined together, and corrugated fins 35 arranged therebetween. The side end of the heat exchanger forms a side part 36, one Includes cranked section 39, in which an opening is formed with a passage 40 surrounding it and oriented orthogonally to the plane of the side part. The passage 40 points away from the adjacent pane 32. The end of a connecting pipe 30 is soldered into the passage 40. The sheets 33 and 34 are provided with features 37 and 38, the structure of the heat exchanger therefore essentially corresponds to the illustration already described in FIG. 1. A fixing rod is also used in the subject of FIG. 9, but it is not in this illustration visible.

In Fig. 10 is an enlarged view of a section through the side part 36 and the attached connecting tube 30. The side part 36 comprises the cranked section 39, which is used to bear against the shape 37 of the sheet 33 shown in FIG. 9. An opening 42 is provided in the cranked section 39, which is surrounded by the passage 40. This opening 42 overlaps with the opening 50 in the shape 37. On the side 41 facing the heat exchanger block, the side part 36 is provided with a solder plating, so that the passage 40 formed from the cranked section 39 has a sufficient amount of solder on its inner surface for soldering with a tapered section 29 of the connecting pipe 30. The tapered section 29 can be produced, for example, by roller burnishing and has a cone 28 at its front end which serves as an insertion aid when inserting the connecting pipe into the passage.

Claims (11)

Heat exchanger (1), in particular refrigerant evaporator, with a plurality of disks (2, 2 ', 2'', 32) assembled to form a stack, which are designed as tubular elements and each consist of two embossed sheets (3, 4, 33, 34), which enclose a cavity between them and near at least one end (12) of the disks (2, 2 ', 2'', 32) a shape (7, 8, 7', 37, 38) with an opening (15, 15 ') is provided, the expression (7, 8, 7', 37, 38) abutting the next disc (2, 2 ', 2'', 32) and via the opening (15, 15') with the latter Cavity is connected and with corrugated ribs (5, 35) arranged between each two adjacent disks (2, 2 ', or 2', 2 ''), characterized in that
that all sheets (3, 4, 33, 34) of the heat exchanger (1) are provided with a congruent fixing opening (17) so that the stacked disks (3, 4, 33, 34) of the heat exchanger (17) 1) a fixing rod (13) can be used. Heat exchanger according to claim 1, characterized in
that the fixing openings (17) are arranged outside the formations (7, 8, 7 ', 37, 38), but in the vicinity thereof. Heat exchanger according to claim 2, characterized in
that the fixing openings lie in an axis of symmetry (16) extending in the longitudinal direction of the sheets (3, 4, 33, 34) forming the disks (2, 2 ', 2'', 32). Heat exchanger according to one of the preceding claims, characterized in that
that at each end of the stack of disks (2, 2 ', 2'', 32) there is a side part (6, 36) in which there is also one with the fixing openings (17) of the disks (2, 2', 2 '', 32) congruent fixing opening (21) is provided. Heat exchanger according to one of the preceding claims, characterized in that
that the fixing openings (17, 21) and the fixing rod (13) have a circular cross section. Heat exchanger according to one of the preceding claims, characterized in that
that the fixing rod (13) is soldered to the washers (2, 2 ', 2''). Heat exchanger according to one of the preceding claims, characterized in that
that the fixing openings (17) are formed by passages (19,) made of the material of the metal sheets (3, 4, 33, 34) 19 ') are surrounded, the passages (19, 19') of two sheets (3, 4), which form a disc (2), are preferably directed in opposite directions. Heat exchanger according to one of claims 1 to 7, characterized in that
that the sheets (3, 4, 33, 34) consist of solder-plated aluminum and the fixing rod (13) is an aluminum wire. Heat exchanger according to claim 5, characterized in
that the fixing openings (17, 21) and the fixing rod (13) have a diameter of about 2 mm to 5 mm, preferably 3 mm. Heat exchanger according to claim 4, characterized in
that the side part (36) consists of a one-sided solder-plated material, the solder-plated side (41) facing the adjacent disc (32). Heat exchanger according to claim 4 or 10, characterized in that
that the side part (36) has an opening (42) surrounded by a passage (40) which is flush with the opening (15) in the recess (37), and that a connecting tube 30 is provided which has a tapered section (29 ), which lies in the passage (40) of the side part (36).

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