RU2804786C1 - Loop heat exchanger - Google Patents

Abstract

FIELD: heat engineering.

SUBSTANCE: invention can be used in recuperative heat exchange devices. The invention lies in the fact that the heat exchanger has a heat exchange matrix in the form of a cylindrical ring, made of a closed sheet, bent to form a loop, the flat parts of the walls of which are located in the radial planes of the cylindrical body, inside the heat exchange matrix there is a displacer, consisting of a cylindrical shell and connected to it the edges of the diametrical and conical partitions, along the common axis of the cylindrical body and the heat exchange matrix, a tightening rod passes, which with its ends is detachably fixed in the thrust rings located in the inlet and outlet nozzles for the first coolant and rigidly connected to the nozzles by means of radial connections, on the cylindrical body distributing and collecting collectors are installed, covering the cylindrical body along its perimeter, the cavities of the distributing and collecting collectors are connected to the inlets and outlets of the channels for the second coolant through windows in the wall of the cylindrical body, the inlet and outlet nozzles for the second coolant are connected to the distributing and collecting collectors, respectively, in channels for the first coolant there are spacers connected to the displacer shell, sealing gaskets are placed between the ends of the heat exchange matrix and the covers, spacer rings are fixed on the inner surface of the cylindrical body, at least one end of the tightening rod is threaded and equipped with a spring dressed on the rod and located between the outer end edge of the thrust ring and the clamping nut, there are corrugations on the flat parts of the surfaces of the loop of the heat exchange matrix.

EFFECT: simplification of the design of the device, ability to produce a heat transfer surface from a single sheet.

3 cl, 2 dwg

Description

The invention relates to recuperative heat exchange devices and can be used in the chemical, food industry, energy and other branches of technology for heating and cooling fluids.

A known plate heat exchanger [1] with a heat transfer surface made of thin heat-conducting sheets, forming slotted channels for the passage of coolants, differs from widely used tubular heat exchangers by being more compact and having lower specific material consumption. The disadvantages of the device [1] and other similar devices include the complexity of manufacturing, high hydraulic resistance to the movement of coolants, due to the large number of turns along the path of their movement.

In the known plate heat exchanger [2] with a sheet heat transfer surface, the hydraulic resistance is relatively small due to the single-pass movement of the coolants. The disadvantage is the complexity of the design and the large number of embedded sealing elements.

A known spiral heat exchanger with a heat transfer surface made of a sheet in the form of a two-way cylindrical spiral inside a housing [3]. This heat exchanger has an increased intensity of heat transfer of coolant flows. Disadvantages include the complexity of manufacturing and the difficulty of ensuring the tightness of the channels.

A heat exchanger is known that contains a cylindrical body, a sheet heat transfer surface placed inside the cylindrical body and forming a heat exchange matrix with alternating channels for the first and second coolants, covers detachably connected to the ends of the cylindrical body with inlet and outlet pipes for the first coolant, sealing gaskets, inlet and outlet pipes for the second coolant [4] - prototype. This heat exchanger is highly compact and can work with coolants in any phase state. Disadvantages include a large number of welds between the elements of the heat transfer surface, complexity and labor-intensive manufacturing.

The technical problem to be solved by the present invention is to simplify the design of the device and to be able to manufacture the heat transfer surface from a single sheet.

The problem posed is solved by the fact that the proposed loop heat exchanger contains a cylindrical body, a sheet heat transfer surface located inside the cylindrical body and forming a heat exchange matrix with alternating channels for the first and second coolants, detachably connected to the ends of the cylindrical body of the lid with inlet and outlet pipes installed on them for the first coolant, sealing gaskets, inlet and outlet pipes for the second coolant, has a heat exchange matrix in the form of a cylindrical ring, made of a closed sheet, bent to form loops, the flat parts of the walls of which are located in the radial planes of the cylindrical body, a displacer is placed inside the heat exchange matrix, consisting of a cylindrical shell and diametrical and conical partitions connected to it by the edges, a tension rod runs along the common axis of the cylindrical body and the heat exchange matrix, which at its ends is detachably fixed in thrust rings located in the inlet and outlet pipes for the first coolant and rigidly connected to the pipes using radial connections, a distributing and collecting manifold is installed on the cylindrical body, covering the cylindrical body along its perimeter, the cavities of the distributing and collecting manifolds are connected to the inlets and outlets of the channels for the second coolant through windows in the wall of the cylindrical body, the inlet and outlet pipes for the second coolant are connected with distributing and collecting manifolds, respectively, in the channels for the first coolant there are spacers connected to the displacer shell, sealing gaskets are placed between the ends of the heat exchange matrix and the covers, spacer rings are fixed on the inner surface of the cylindrical body, at least one end of the tension rod is threaded and equipped with a spring, dressed on a rod and located between the outer end edge of the thrust ring and the pressure nut, there are corrugations on the flat parts of the surfaces of the heat exchange matrix loop.

In contrast to the known device [4], the design of the heat exchange matrix in the form of a cylindrical ring made of a closed sheet, bent to form loops, the flat parts of the walls of which are located in the radial planes of the cylindrical body, simplifies the design and increases its manufacturability. The heat transfer surface can be made of a single sheet, which is closed by, for example, welding its two opposite edges. Placing a displacer inside the heat exchange matrix, consisting of a cylindrical shell and diametrical and conical partitions connected to it by the edges, ensures the distribution of the first coolant flow along parallel channels in the heat exchange matrix. The presence of spacers in the channels for the first coolant, fixed to the displacer shell, increases the rigidity of the heat exchange matrix and helps maintain its shape and dimensions during operation of the device. The distribution of the flow of the second coolant along adjacent parallel channels of the heat exchange matrix is ensured by placing distribution and collecting manifolds around the cylindrical body with inlet and outlet pipes for the second coolant installed on them, respectively, and by the presence of windows in the cylindrical body that connect the cavities of the distributing and collecting manifolds with the inlets and outlets of the channels for the second coolant. The placement of sealing gaskets between the ends of the heat exchange matrix and the covers ensures the separation of the channels for the first and second coolants and their sealing. The presence of spacer rings attached to the inner surface of the cylindrical body creates an annular gap between the wall of the cylindrical body and the heat exchange matrix, which promotes more complete and dense contact of the sealing gaskets with the edges of the heat exchange matrix loop. The quality of sealing with gaskets is also improved by the presence of a tension rod running along the common axis of the cylindrical body and the heat exchange matrix, which at its ends is detachably secured in thrust rings located in the inlet and outlet pipes for the first coolant and rigidly connected to the pipes using radial connections. Tightening the clamping nut and compressing the spring at the threaded end of the tension rod, together with tightening the flange connectors of the cylindrical body and covers, ensures that the sealing gasket is tightly pressed to the heat exchange matrix over the entire area of their contact. The presence of a spring, put on the rod and located between the outer end edge of the thrust ring and the clamping nut, also makes it possible to compensate for the thermal expansion of the device elements during its operation due to the compression and decompression of the spring. The presence of corrugations on the flat parts of the surfaces of the loops of the heat exchange matrix intensifies the heat exchange of coolant flows in the channels and, as a result, makes it possible to increase the compactness and reduce the material consumption of the heat exchanger.

Thus, the set of distinctive features of the invention allows us to solve the problem posed.

A comparative analysis of the claimed technical solution with the prototype shows that the claimed device meets the invention criterion of “novelty”.

Known similar devices [1, 2, 3] are structurally more complex and less technologically advanced to manufacture.

All this allows us to conclude that the proposed technical solution meets the invention criterion of “significant differences”.

Figure 1 shows a schematic representation of the proposed loop heat exchanger; Fig.2 - section A-A in Fig.1.

The loop heat exchanger contains a cylindrical body 1 with a heat exchange matrix 2 located inside it in the form of a cylindrical ring, made of a closed sheet, bent to form a loop 3 and alternating flow channels 4 for the first and 5 for the second coolant. The inlet 6 and outlet 7 pipes for the first coolant are installed respectively on the covers 8 and 9, connected by flange connectors to the ends of the cylindrical body 7. Between the covers 8 and 9 and the ends of the heat exchange matrix 2 there are sealing gaskets 10. Inside the heat exchange matrix 2 there is a displacer 11, consisting from a cylindrical shell 12 and diametrical 13 and conical 14 partitions connected to it by the edges. Axisymmetrically with the displacer 11, the heat exchange matrix 2 and the cylindrical body 1 there is a tightening rod 15, the ends of which are placed in the thrust rings 16, secured by means of connections 17 in the nozzles 6 and 7 for the first coolant. The threaded end (or both ends) of the tension rod 75 is fitted with a spring 18 and is equipped with a clamping nut 19. In the channels 4 for the first coolant there are spacers 20 secured to the shell 12 of the displacer 11. Spacer rings 21 are attached to the inner surface of the cylindrical body 1. On the outside The cylindrical body 1 is enclosed along its perimeter by distributing 22 and collecting 23 manifolds, the cavities of which are connected through windows 24 in the wall of the cylindrical body 1, respectively, with the inputs and outputs of channels 5 for the second coolant in the heat exchange matrix 2. On the distributing 22 and collecting 23 manifolds, the input 25 and outlet 26 pipes for the second coolant. On the flat parts of the surfaces of the loop 3 of the heat exchange matrix 2 there are corrugations 27.

The loop heat exchanger works as follows.

The first coolant enters the heat exchanger through the inlet pipe 6 and is distributed along parallel channels 4 of the heat exchange matrix 2 through their side openings in the area between the cover 8 and the displacer 11. The width of the side openings of the channels 4 is determined by the size of the spacers 20 located in them, mounted on the cylindrical shell 12 of the displacer 11. Displacer 11, consisting of a cylindrical shell 12 and diametrical 13 and conical 14 partitions connected to it by the edges, is impenetrable to the flow of coolant and forms parts of the walls of channels 4. Moving along channels 4, the first coolant exchanges heat with the walls of loops 3, participating in the process in the process of heat transfer through the walls with the second coolant. At the opposite end of the heat exchange matrix 2, the first coolant exits the parallel channels 4 through their side openings in the area between the cover 9 and the displacer 11 and is removed from the heat exchanger by a common flow through the outlet pipe 7.

When the heat exchanger operates in a counterflow scheme, the second coolant enters through the inlet pipe 25 into the distribution manifold 22 and through windows 24 in the cylindrical body 1 is distributed along channels 5 of the heat exchange matrix 2. Moving along the channels 5, the second coolant exchanges heat with the walls of the loop 3 and participates in in the process of heat transfer through the walls with the first coolant. Having passed through channels 5, the second coolant through the corresponding windows 24 in the cylindrical body 1 enters the collecting manifold 23 and is removed from the heat exchanger through the outlet pipe 26 in one common flow.

Sealing gaskets 10 made of elastic material between the planes of covers 8 and 9 and the ends of the heat exchange matrix 2 ensure the tightness of channels 4 and 5 and eliminate the flow of coolants between the channels. Improving the quality of the seal and its reliability during operation of the heat exchanger is facilitated by the presence of a tightening rod 15, the ends of which are placed in thrust rings 16, secured by means of connections 17 in the nozzles 6 and 7. By compressing the spring 18 placed on the tightening rod 15 with a clamping nut 19, the required according to the conditions of tightness, pressing the sealing gasket 10 to the ends of the heat exchange matrix 2 over the entire area of their contact. Spring 18 also serves as a compensating element for thermal expansion of individual parts of the heat exchanger having different temperatures.

The corrugations 27 on the flat parts of the surfaces of the loop 3, being a means of intensifying the heat exchange of coolants in channels 4 and 5, also increase the rigidity of the walls of the heat transfer surface, which expands the permissible pressure difference between the first and second coolants in channels 4 and 5.

The heat exchanger is easy to disassemble and assemble. It is possible to mechanically clean the heat exchange surfaces in channels 4 and 5 from contamination, as well as replace the heat exchange matrix 2. If liquid coolants are used, then a vertical arrangement in the space of the loop heat exchanger may be preferable, which makes it possible to naturally drain the coolants from channels 4 and 5 of the heat exchange matrix 2 during long breaks in work.

The proposed loop heat exchanger has the following advantages over analogues:

- the heat transfer surface is made of one closed sheet with a minimum number of welded joints;

- the design is simple and technologically advanced to manufacture;

- complete disassembly and subsequent reassembly is possible without loss of working qualities;

- mechanical cleaning of heat exchange surfaces in the channels of the heat exchange matrix is possible;

- the possibility of free temperature expansion and contraction of heat exchanger elements due to spring compensation;

- high compactness and low material consumption.

INFORMATION SOURCES

1. Machines and apparatus for chemical production / A.S. Timonin, B.G. Boldin, V.Ya. Borshchev, Yu.I. Gusev and others // Under general. ed. A.S. Timonina. - Kaluga: Publishing house N.F. Bochkareva, 2008. p. 486, fig. 6.1.3.1.

2. Patent RU No. 2094726 C1. IPC F28D 9/00, F28F 3/02. Publ. 10/27/1997.

3. Patent RU No. 2687669 C1. IPC F28D 1/047. Publ. 05/15/2019. Bull. No. 14.

4. Baranovsky N.V., Kovalenko L.M., Yastrebenetsky A.R. Plate and spiral heat exchangers. M.: Mechanical Engineering, 1973. p. 33, fig. 20b.

Claims (3)

1. A loop heat exchanger containing a cylindrical body, a sheet heat transfer surface placed inside the cylindrical body and forming a heat exchange matrix with alternating channels for the first and second coolants, covers detachably connected to the ends of the cylindrical body with inlet and outlet pipes for the first coolant installed on them, sealing gaskets, inlet and outlet pipes for the second coolant, characterized in that the heat exchange matrix has the shape of a cylindrical ring and is made of a closed sheet, bent to form loops, the flat parts of the walls of which are located in the radial planes of the cylindrical body, a displacer consisting of of the cylindrical shell and the diametrical and conical partitions connected to it by the edges, a tension rod runs along the common axis of the cylindrical body and the heat exchange matrix, which at its ends is detachably fixed in thrust rings located in the inlet and outlet pipes for the first coolant and rigidly connected to the pipes using radial connections, distributing and collecting manifolds are installed on the cylindrical body, covering the cylindrical body along its perimeter, the cavities of the distributing and collecting manifolds are connected to the inputs and outputs of the channels for the second coolant through windows in the wall of the cylindrical body, the inlet and outlet pipes for the second coolant are connected to the distributing and collecting manifolds, respectively, in the channels for the first coolant there are spacers connected to the displacer shell, sealing gaskets are placed between the ends of the heat exchange matrix and the covers, spacer rings are fixed on the inner surface of the cylindrical body. 2. Loop heat exchanger according to claim 1, characterized in that at least one end of the tension rod is threaded and equipped with a spring, put on the rod and located between the outer end edge of the thrust ring and the pressure nut. 3. Loop heat exchanger according to claim 1, characterized in that there are corrugations on the flat parts of the surfaces of the loop of the heat exchange matrix.

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