RU2069830C1 - Method of manufacture of tubeless heat exchanger - Google Patents

Abstract

FIELD: heat engineering; manufacture of heat exchange equipment in which increasing of outer and inner surfaces is required. SUBSTANCE: plates with holes with edging over perimeter are assembled into pack. Corrugated tapes with filler is corrugations are wound into coil which is fixed at end faces by end pieces, and combined plastic deformation is carried out to obtain a set diameter is equal to diameter of holes with edgings inplates. Instead of alignment of holes of adjacent plates, plates are fitted on set of corrugated tapes with fillers, and then fillers are taken out. Coil of corrugated tapes with fillers can be fixed by winding with wire whose diameter is less than thickness of tapes. Corrugations of tapes can be oriented rectilinear along longitudinal axis of set or along screw line. Fitted on plates, rings and corrugated tapes have layer of solder. Extraction of fillers is carried out first at solder melting temperature and than at solder solidification temperature. EFFECT: enlarged operating capabilities. 5 cl, 14 dwg

Description

 The invention relates to the field of processing materials by pressure to obtain products with internal and external fins, namely, with their highly developed inner and outer surfaces. This method can be used for the manufacture of various kinds of heat exchangers.

 An analogue of the present invention is a method for producing products with internal finning [1] comprising assembling a set of copper aluminum rods, introducing the set into a copper pipe, compressing them together, heating the deformed set to the sintering temperature of copper, then cutting it into tablets and immersing the latter in a solution for removal of aluminum fillers by etching them. As a result of these operations, products with a developed inner surface are obtained.

 The disadvantages of this analogue are the inevitability of using at least one pipe, the manufacture of which is relatively expensive, as well as the long time it takes to remove fillers from aluminum. In addition, the method by analogy does not allow to obtain products with external fins, which reduces the efficiency of heat transfer in them.

 As a prototype of the claimed invention, a method for producing a heat exchanger with external fins [2] is selected, which includes making rows of holes with flanges in the plates, assembling these plates in a bag, and aligning the holes of adjacent plates.

 The disadvantage of the prototype method is the limited development of internal fins due to the limitation of the area forming the inner surface of its structure, which also reduces the efficiency of heat transfer.

 The objective of the invention is to expand the technological capabilities of producing a tubeless heat exchanger with its highly developed internal and external surfaces to increase the efficiency of heat transfer using relatively inexpensive components, instead of pipes.

 The problem is achieved in that the method of producing a tubeless heat exchanger includes making rows of holes with flanges in the plates and assembling these plates in a package, according to the claimed invention, cylindrical corrugated tapes are preassembled into a roll, during which fillers are placed in the corrugation cavity in the form of rods of material based on paraffin, and the rods are arranged in concentric circles, then fix on the ends of the formed roll using the tips and they are crimped to a diameter equal to the diameter of the holes of the plates, after which the bag is inserted onto the crimped roll and the filler rods are removed; a roll of corrugated tapes with fillers is fixed by a winding of a wire whose diameter is less than the thickness of these tapes; corrugations of tapes are oriented parallel to the longitudinal axis of the roll; corrugations of tapes are oriented along a helix relative to the longitudinal axis of the roll; plates and tapes are coated with a layer of solder, and the removal of filler rods is carried out initially at the melting point of the solder, and then at the pour point of the solder.

 A significant difference of the claimed invention lies in the fact that it is possible to increase the development of both the outer and inner surfaces of the tubeless heat exchanger by finning it using components, namely, plates and tapes of various configurations, the manufacture of which requires less cost than the production of pipes.

 In FIG. 1, 2 shows a side view of a roll of corrugated tapes with fillers before they are crimped together; in FIG. 3, 4, 5 cross section of a roll of corrugated tapes with fillers before they are crimped together; in FIG. 6, 7, 8 cross section of a roll of corrugated tapes with fillers after they are crimped together; in FIG. 9, 10, 11 longitudinal section of a tubeless heat exchanger; in FIG. 12, 13, 14 is a cross section of a tubeless heat exchanger (where 1 corrugated tape, 2 filler, 3 tip, 4 wire, 5 plate with flanges at its holes, 6 straight channel, 7 screw channel).

 The technological process for producing a tubeless heat exchanger is as follows: corrugated tapes (1) with fillers (2) located in their corrugations are preassembled into a roll (see Fig. 1-5), then the formed roll is fixed with tips (3) or winding the wire (4) and crimping it to a diameter equal to the diameter of the flanged hole at the plates (5), the last of which are collected separately in a bag and are mounted on a crimped roll. In conclusion, the operation is carried out to remove the introduced fillers by heating all the components at the melting point or evaporation of these fillers, and in the presence of plates and tapes with a layer of solder, initially at the melting point of the solder, and then at the pour point of the solder. As a result of these operations, a tubeless heat exchanger with external and internal fins is obtained, the last of which forms through channels (6, 7).

 The presence of internal ribs formed by corrugated tapes after removal of fillers, significantly increases the development of the inner surface of the tubeless heat exchanger. The diameter of the channels formed by the inner ribs can vary from a few microns to several tens of millimeters; and the number of such channels reaches several thousand or more. The presence of helical channels creates an element of turbulization of the transmitted heat carriers in the tubeless heat exchanger, which also increases the efficiency of heat transfer in it.

 The plates and corrugated tapes can be fastened together by jamming, welding or soldering them. The application of a layer of solder on the plates and corrugated tapes is able to provide high-quality contact of these components to reduce contact thermal resistance.

 As fillers, a material can be used whose melting or evaporation temperature should be lower than the melting temperature of the selected plates and corrugated tapes. One of the representatives of such fillers is paraffin-based material.

Examples of individual versions of a tubeless heat exchanger:
Example 1. A method of obtaining a tubeless heat exchanger from copper steel.

 First, corrugated tapes (1) of steel with a layer of copper solder are assembled into a roll, into the corrugations of which a filler (2) is introduced in the form of a rod of paraffin-based material, as shown in FIG. 3. This roll is fixed at the ends with tips (3). At the same time, in the center is a tape with one corrugation; and in the annular layer there is a tape with corrugations of 6 pcs. and ribbons with one corrugation of 3 pcs. All corrugations of the tapes have a rectilinear orientation relative to the longitudinal axis of the roll (see Fig. 1). A fixed roll of these components is subjected to compression on a rolling mill to a diameter equal to 20 mm (Fig. 6). Then, in a steel plate (5) with a layer of copper solder, a hole with a diameter of 20 mm is made with flanges that are collected in a package. This bag is mounted on a compressed roll, and in conclusion, all assembled components are heated to a temperature of 1473 K, during which the filler and copper solder melt; then, at a temperature of 1123 K, the molten solder solidifies and the filler evaporates; resulting in through channels.

 The resulting copperless tubeless heat exchanger is shown in FIG. 9, 12, contains external fins and internal ribs forming straight channels with a diameter of 6 mm and a quantity of 7 pcs.

 Example 2. A method of obtaining a copper tubeless heat exchanger.

 Corrugated tapes (1) made of 0.5 mm thick copper with fillers introduced into their corrugations (2) from a paraffin-based material of 19 pieces are collected separately. (Fig. 4), and in the center is a tape with one corrugation; in the first annular layer one tape with corrugations of 6 pcs. and 3 tapes with one corrugation, and in the second ring layer one tape with corrugations of 18 pcs. and tapes with one corrugation of 9 pcs. The assembled tapes with fillers in a roll (Fig. 4) are twisted along a helical line relative to its longitudinal axis and are fixed by winding a steel wire (4) with a diameter of 0.2 mm. After crimping the fixed roll to a diameter of 15 mm (Fig. 7), a packet of copper plates (5) with one hole with a diameter of 15 mm and flanges is mounted on it. All assembled components are heated in a hydrogen medium at a temperature of 1123 K, as a result of which the filler evaporates, and in the joints of the plates and tapes one-piece joints are formed due to the mutual diffusion of surface copper atoms.

 The resulting tubeless copper heat exchanger is shown in FIG. 10, 13, which contains the outer and inner ribs, the last of which form helical channels with a diameter of 2 mm and a quantity of 19 pcs.

 Example 3. A method of obtaining a tubeless heat exchanger from aluminum.

 Three rolls of corrugated tapes (1) from aluminum with filler (2) introduced from their corrugations from a material based on paraffin are collected separately. In this case, one roll contains a total number of fillers of 7 pcs. (Fig. 3), the second 19 pcs. (Fig. 4), and the third 37 pcs. (Fig. 5). These rolls are fixed by winding steel wire and are separately crimped by rolling to a diameter of 5 mm (see Fig. 6, 7, 8). Then, a pack of aluminum plates (5) containing four holes with a diameter of 5 mm with flanges is mounted on crimped rolls. After heating all the collected components in air at a temperature of 823 K, a tubeless aluminum heat exchanger was obtained for evaporating the filler (Figs. 11, 14), containing external fins, one rectilinear channel with a diameter of 5 mm, forming the surface of the plates at the flanges and internal ribs; forming straight channels with a diameter of 0.5 mm (37 pcs.), 0.7 mm diameter (19 pcs.), 1.2 mm diameter (7 pcs.).

 Thus, the use of relatively inexpensive components in the form of flanging plates at their holes and corrugated tapes expands the technological capabilities of producing a tubeless heat exchanger with its highly developed outer and inner surfaces.

Claims (5)

 1. A method of producing a tubeless heat exchanger by making rows of holes with flanges in the plates and assembling these plates into a package, characterized in that they are pre-assembled into a roll of cylindrical corrugated tapes, during which fillers are placed in the corrugation cavity in the form of rods made of paraffin-based material moreover, the rods are arranged in concentric circles, then they are fixed at the ends of the formed roll using tips and crimped to a diameter equal to the diameter of the holes p lining, after which the package of plates is mounted on the compressed roll and the filler rods are removed.  2. The method according to claim 1, characterized in that the roll of corrugated tapes with filler is fixed by a winding of a wire whose diameter is less than the thickness of these tapes.  3. The method according to claim 1, characterized in that the corrugations of the tapes are oriented parallel to the longitudinal axis of the roll.  4. The method according to claim 1, characterized in that the corrugations of the tapes are oriented along a helical line relative to the longitudinal axis of the roll.  5. The method according to PP. 1 to 4, characterized in that the plates and tapes are coated with a layer of solder, and the removal of the filler rods is carried out initially at the melting point of the solder, and then at the pour point of the solder.

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