CZ37536U1 - A countercurrent cylindrical recuperative heat exchanger, intended for ventilation of buildings - Google Patents

Description

Countercurrent cylindrical heat recovery exchanger intended for ventilation of buildings

Field of technology

The technical solution refers to a counter-current cylindrical heat recovery exchanger, intended mainly for ventilation of buildings. The exchanger includes a cylindrical countercurrent part, connected to two oppositely arranged distributors. The counterflow part contains a coaxially arranged inner and outer tube, between which the slats are arranged. The air inlets are arranged radially, or semi-radially, on the manifolds of the exchanger and radially relative to the longitudinal axis of the exchanger and connect to the inlet channels, arranged between the outer pipe and the inner pipe of the upstream part of the exchanger. The air outlets are arranged axially on the end distributors of the exchanger in a radial manner with respect to the longitudinal axis and connect to the outlet channels between the outer pipe and the inner pipe of the upstream part of the exchanger. If the flow directions are reversed, air inlets become air outlets and air outlets become air inlets.

Current state of the art

Patent CZ 300999 B6 (publ. 08.04.2009) describes a hexagonal-shaped counter-current recuperation exchanger. A counter-flow recovery heat exchanger includes a frame in which layers of thin lamellae are stored, with peaks and valleys. A single slat shape is used with a center section and opposite end sections. The counter-current central part, preferably rectangular, is used for the supply and discharge of media streams. Oppositely arranged end parts, preferably triangular, are provided with spacers. The countercurrent central part has parallel arranged grooves, guided in the longitudinal direction between the opposite end parts of the lamella, which show a rounded accordion-like profile in the cross-section of the central part, guided perpendicularly to the longitudinal direction of the lamella. All lamellas arranged in layers always have adjacent lamellas facing each other with their front sides and their reverse sides. All facing sides of adjacent lamellas abut one another in the central part only in the contact areas of the grooves with the smallest possible area. Between the contact areas of the grooves of the facing sides of the adjacent slats in the counter-current central area, a free intermediate space is defined for the flow of one stream of medium. Grooves of the central part showing the trajectory of the undulations of the grooves in the form of waves connected to each other or circular arcs connected tangentially one behind the other, or sine waves. Wavy grooves have an amplitude of the undulation of the groove trajectory greater than or equal to the pitch of the neighboring peaks or the depression of the grooves. The wavy grooves of the facing sides of the adjacent lamellae are phase-shifted with respect to each other in the longitudinal direction by half a period inclusive. The free intermediate space, in a cross-section perpendicular to the longitudinal direction in the direction of the two streams, shows a cross-section with a constant area size, but a variable cross-sectional shape, in the longitudinal direction in the sense of the two streams of the medium between the facing grooves.

The advantage of this solution is the improvement of the shape of the slats, when almost the entire surface of the slats is used as heat exchange surfaces and not just the contact areas with the smallest possible surface. The free space between the lamellas is passable for media over the entire surface of the lamellas, in the longitudinal direction and in the direction perpendicular to it.

The disadvantage is the hexagonal prismatic shape when applying the heat exchanger to the wall of the building. Another disadvantage is represented by the distance elements of the end triangular parts, which serve to maintain the distance between two adjacent slats and which cause an excessive such loss during the flow.

Patent CZ 303626 B6 (publ. 16.01.2013), corresponding to application WO 2013/041066 A2 and patent EP 2758738 B1, has the same owner 2VV s.r.o. Pardubice CZ, and the same originators Chlup Jaroslav and Hazuka Pavel, as in the previous patent CZ 300999 B6. Patent CZ 303626 B6 describes a counter-current recovery heat exchanger with multi-pass helical coiled heat exchange surfaces, intended especially for building ventilation equipment and represents an improved technical solution compared to the previous patent CZ 300999 B6. Recuperation heat exchanger according to the patent

- 1 CZ 37536 U1

CZ 303266 B6 has a cylindrical shape, an outer tube with a coaxially arranged inner tube, between which are located helical shaped heat exchange surfaces. Distributors for media input and output are located at both ends of the recovery exchanger. If the flow directions are reversed, media inputs become media outputs and media outputs become media inputs. The helix of the heat exchange surface is right-handed or left-handed and is twisted at a pitch angle that is greater than 0 degrees and less than 90 degrees relative to the longitudinal axis of the recovery exchanger. The heat exchange surfaces are separated from each other, coaxial, multi-pass, helically twisted between the outer tube and the inner tube. The heat exchange surfaces have the shape of the surface created by pulling the forming profile along the outer helices and the inner helices, where the profile has one shape, in a cross section perpendicular to the longitudinal axis of the heat exchanger , from the group including parts of straight lines, circles, spirals, involutes, parabolas and hyperbolas. Individual heat exchange surfaces, and therefore inlet channels and outlet channels, can have a constant helix pitch. The heat exchange surfaces can be connected on the inner and outer surfaces into inserts, whereby two adjacent heat exchange surfaces on the outer cylindrical surface and the following two adjacent heat exchange surfaces on the inner cylindrical surface are alternately connected. An inner tube is preferably inserted into the inner cylindrical surface and a protective tube is inserted into the outer cylindrical surface. Each distributor can be provided with an external separation surface and/or an internal separation surface for separating media input and output. The outer pipe or inserts, or the recovery exchanger, can be inserted into the protective pipe. Advantageously, the outer pipe is provided with holes for draining condensate and the protective pipe with means for collecting condensate.

The advantage of this exchanger is its cylindrical surface, representing a structurally simple arrangement. A great advantage of the exchanger are the end distributors for radial or semi-radial media input and axial media output relative to the longitudinal axis of the recovery exchanger, enabling reliable separation of both media streams.

The disadvantage of this solution is the multi-pass helical arrangement of the heat exchange surfaces of the slats, the heat exchange insert and the separating surfaces of the distributors, the production of which is financially expensive, lengthy and unprofitable, and moreover difficult to produce with conventional technologies.

Application DE 2543326 A1 (publ. 07.04.1977) describes a plate heat exchanger which contains a cylindrical shell for conducting a gaseous heat-absorbing medium. Parallel flow channels for conducting the gaseous, heat-releasing medium, running parallel to the longitudinal axis of the cylindrical shell, are located in the cylindrical shell. Each flow channel is formed by two involute curved plates. The plates are welded to the collectors at their upper and lower ends. Inside the heat exchanger, a central tube is placed parallel to the longitudinal axis of the shell, which, together with the involutely curved plates and the shell, defines the flow channels. Involute plates can be welded from individual involute shaped pressed segments. The flow channels are reinforced with spacers that act as spacers. Spacers have a circular or elliptical shape. An additional outer cylindrical shell is arranged around the heat exchanger shell to form an annular channel in cross-section. The annular channel is blinded by two end surfaces in its central region. The annular channel is connected to the involute flow channels through slits in the casing of the upstream part.

This countercurrent heat exchanger is particularly suitable for use in systems where high temperatures occur on the heat exchange surfaces, e.g. in nuclear power plants. This heat exchanger is exposed to very high temperatures, as the inlet temperature of the primary or cooling gas is up to 950 °C. The outlet temperature of the medium circulating in the secondary circuit is up to 900 °C. Rolled sheets of highly heat-resistant material are used to produce involutely curved plates that serve as heat exchange surfaces. Inert helium is preferably used as a heat exchange medium for the primary and secondary circuit.

This robust cylindrical counter-current heat exchanger is designed for the specified special industrial applications. This exchanger is apparently expensive to manufacture and operate. The heat exchanger has a complex construction, e.g. it includes three cylindrical coaxial tubes, or pipelines, while the outer ring is

- 2 CZ 37536 U1 medium from the collectors to the upstream part of the exchanger. This exchanger is completely unsuitable for ventilation of buildings at normal temperatures.

The essence of the technical solution

The mentioned disadvantages are eliminated or substantially reduced in the case of a counter-flow cylindrical recuperative heat exchanger intended for building ventilation. The counter-current cylindrical heat recovery exchanger includes a counter-current cylindrical part connected to two oppositely arranged distributors. The heat exchanger contains a coaxially arranged inner tube and an outer tube, between which the lamellae are arranged. The air inlets are arranged radially or semi-radially on the manifolds of the exchanger and radially relative to the longitudinal axis of the exchanger and connect to the inlet channels arranged between the outer tube and the inner tube of the upstream part of the exchanger. The air outlets are arranged axially on the end distributors of the exchanger radially relative to the longitudinal axis and connect to the outlet channels between the outer pipe and the inner pipe of the upstream part of the exchanger. If the flow directions are reversed, air inlets become air outlets and air outlets become air inlets.

The essence of this technical solution lies in the fact that the lamellas are twisted into an involute shape in a cross-section perpendicular to the longitudinal axis of the exchanger, the involute lamellas are arranged parallel and coaxially behind each other with respect to the axis of the exchanger and with the same mutual distance between each other. A separate countercurrent involute air supply channel is defined by a pair of involute lamellas, and a separate countercurrent involute air outlet channel is defined by an adjacent pair of involute lamellas. Each countercurrent involute air supply channel connects to an external involute air inlet, and each countercurrent involute air outlet channel connects to an internal involute air outlet. All involute channels with air supply and exhaust, and all involute inlets and involute air outlets are arranged in an involute shape in a cross-section perpendicular to the longitudinal axis of the exchanger. Each distributor is equipped with an intermediate connecting pipe.

The main advantage of this technical solution is the maximum efficiency of the counter-current cylindrical heat recovery exchanger with minimum pressure loss at minimum cost, thanks to the filling of a large part of the counter-current part of the exchanger with profiled and wavy involute coiled lamellae, involute channels between them, involute air inlets and outlets, and also thanks to rigid and prestressed involute lamellas. This results in a small, cheap and available recuperation unit for ventilation of buildings with undemanding installation, simple and clear control, long service life and a simple and functional construction. Recovery saves heating costs and reduces energy losses through ventilation. Involute channels with essentially the same spacing allow the same pressure loss in both directions of air flow. The connecting intermediate pipe safely separates the air inlets and outlets in the manifolds. The wavy surface of the upstream part of the exchanger causes heat transfer to intensify.

Advantageously, the countercurrent part of the exchanger is corrugated in the transverse and longitudinal direction relative to the longitudinal axis of the exchanger, which contributes to increasing the efficiency of the exchanger and reducing pressure losses.

Advantageously, the distributors are beveled and are narrowed towards the longitudinal axis of the exchanger and towards the connecting intermediate pipes, which helps the favorable conduction of the air currents at the inlet and outlet of the distributors.

It is also advantageous if the distributors are flat, which represents a cheap and available exchanger at an acceptable price.

It is also advantageous if each involute lamella is attached at its ends to the inner tube and to the outer tube in the upstream part and to the distributor part of the distributors, preferably airtight, which ensures a safe separation of the involute channels in the upstream part of the exchanger and at the air inlets and outlets in the distributors.

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Advantageously, each involute lamella is self-supporting, is pre-tensioned, and thus maintains its shape during production and operation.

Furthermore, it is advantageous if the involute lamella has a central countercurrent part and both opposite end cross parts with a smooth surface, which brings about easy construction and production and makes the heat exchanger cheaper.

It is also preferred that each involute slat has a central upstream section profiled and corrugated and both opposite end cross sections have a smooth surface. This arrangement has been shown to yield very good results in heat transfer and pressure loss reduction.

In addition, it is advantageous if the involute lamella has its counterflow part of a rectangular shape, which fills the counterflow part and contributes to its greater efficiency. Opposite end cross parts of the lamella in the shape of a triangle or a rectangle are easy to manufacture, while they do not additionally contain spacer elements like the lamellas in patent CZ 303626 B1.

In addition, it is advantageous if the air supply inlets and air outlets of the distribution parts or distributors are equipped with internal blanks that ensure a safe separation of the air inlets and outlets, and they can also act as spacers.

External plugs at both ends of the inner tube prevent fake air from flowing into the exchanger.

Grooves on the inner surface of the inner tube and possibly on the outer surface of the outer tube or on the outer surface of the connecting intermediate tube enable easier fixation of the involute slats during production and operation.

Clarification of drawings

The technical solution is described in detail further on in non-limiting concrete exemplary embodiments of the cylindrical countercurrent recuperation exchanger, clarified in the attached schematic drawings.

Example 1 illustrates in the attached drawings an exchanger with a cylindrical counterflow part, connected integrally to opposite distributors with beveled air inlets and outlets, in which it represents:

Fig. 1 is an axonometric view with basic structural elements of the heat exchanger with views of one smooth involutely curved lamella, hexagonal in shape, formed by a rectangular smooth countercurrent part of the lamella, integrally connected to opposite smooth triangular cross sections;

Fig. 2 is an axonometric view of the heat exchanger with dividers and indicated flow directions and a view of the countercurrent part of the heat exchanger with two smooth involute curled lamellae;

Fig. 3 is a front view of the left exchanger manifold of Fig. 2, with the involute air inlets and outlets highlighted and with the manifold areas closed;

Fig. 4 is a front view of the front distributor from Fig. 2 without highlighted air inlets and outlets; Fig. 5 is a side view of the exchanger from Fig. 4 with its cylindrical countercurrent part cut away; and Fig. 6 is a cross section A-A from Fig. 5 of the upstream part of the exchanger.

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Example 2 is shown in the attached drawings of a corrugated plate heat exchanger, each plate consisting of a profiled corrugated countercurrent section in the shape of a rectangle and adjacent opposite end smooth cross sections in the shape of a triangle, and with beveled manifold inlets and outlets, in which it represents:

Fig. 7 is an axonometric view of the heat exchanger with one wavy involute coiled lamella in the view and in the left part in the view of the front distributor;

Fig. 8 is a front view of the front manifold of the exchanger of Fig. 7, with the air inlets and outlets shown and with the front manifold areas closed;

Fig. 9 is a side view of the heat exchanger from Fig. 8 with a cut-away of the upstream part of the cylindrical heat exchanger;

Fig. 10 cross-section B-B of the upstream part of the exchanger from Fig. 9;

Fig. 11 is an axonometric view of an inner tube with grooves and with one planar corrugated lamella; Fig. 12 is an axonometric view of an inner tube with grooves and with two planar corrugated lamellae;

Fig. 13 is an axonometric view of an inner tube with all planar corrugated lamellae;

Fig. 14 is an axonometric view of an inner tube with grooves and with two wavy coiled involute lamellae;

Fig. 15 is an axonometric view of the inner tube with all the involute coiled lamellae;

Fig. 16 is an axonometric view of the inner tube with all corrugated involute coiled lamellae inserted into the outer tube;

Fig. 17 is an axonometric view of an inner tube with grooves with two wavy involute curled fins and with a front and rear splitter;

Fig. 18 is an axonometric view of the inner tube with all involute coiled fins and both manifolds; and Fig. 19 is an axonometric view of the complete exchanger.

Example 3 illustrates in the accompanying drawings a heat exchanger with corrugated hexagonal fins, each consisting of a rectangular profiled counterflow section and triangular end cross sections, and with planar manifolds (without chamfers) in which it represents:

Fig. 20 is an axonometric view of a smooth inner tube with a single planar corrugated lamella in the developed state;

Fig. 21 is an axonometric view of a smooth inner tube with two corrugated planar fins in the developed state;

Fig. 22 is an axonometric view of the inner tube with all corrugated planar fins in the developed state;

Fig. 23 is an axonometric view of a smooth inner tube with two undulating involute coiled lamellae;

Fig. 24 is an axonometric view of the inner tube with all corrugated involute coiled fins;

Fig. 25 is an axonometric view of the inner tube with all corrugated involute coiled lamellae inserted into the outer tube;

Fig. 26 is an axonometric view of a smooth inner tube with two curled corrugated fins with both flat dividers;

Fig. 27 is an axonometric view of the inner tube with all corrugated involute fins and with both flat manifolds; and Fig. 28 is an axonometric view of a complete heat exchanger with a smooth inner tube with all corrugated involute fins inserted into the outer tube and with both flat manifolds.

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Examples of implementing a technical solution

Counterflow recovery heat exchangers (1, 1a, 1b), intended mainly for the ventilation of rooms in buildings, have the task of exchanging the polluted air in the room for clean outdoor air, while transferring heat from the polluted exhaust air to the incoming clean air.

Example 1 (Figs. 1 to 6)

Countercurrent cylindrical heat recovery exchanger 1 with smooth involutely curled lamellae 6 and with beveled inlets 11 and outlets 12 of air distributors 17, 18.

The simplest exemplary embodiment of the countercurrent cylindrical heat recovery exchanger 1 according to this technical solution is the solution shown in Fig. 1 to 6.

Fig. 1 shows the basic structural elements of the heat exchanger 1, consisting of a cylindrical counterflow part 2 and integrally following it two cross end distribution parts 3 of the distributors 17, 18 of the front distributor 17 and the rear distributor 18. The counterflow part 2 of the heat exchanger 1 contains an inner pipe 4 with a smooth outer surface, a coaxially arranged outer tube 5 and a hexagonal lamella 6. The smooth inner tube 4 represents the central supporting structural element of the exchanger 1, through which no medium flows, always air in exemplary embodiments. The outer tube 5 represents another supporting structural element and has the function of the outer shell of the exchanger 1. The lamella 6 is twisted in a cross-section, perpendicular to the axis 8 of the exchanger 1, into an involute shape 7, indicated in Fig. 1 by a double dashed line. In this exemplary embodiment, the involutely curled lamella 6 consists of a rectangular countercurrent part 15, which is integrally connected by two oppositely arranged triangular end cross parts 16.

In the following text, the term "involute coiled lamella 6" or "involute lamella 6" is used as appropriate in the text, both of which correspond to the same lamella 6 solution.

The involute lamella 6 in this exemplary embodiment has smooth heat exchange surfaces of its upstream part 15 without undulations. It represents the simplest form of lamella 6, easy to manufacture. The inner pipe 4 and the outer pipe 5 are coaxial with the longitudinal axis 8 of the exchanger 1. The distribution part 3 contains a connecting intermediate pipe 9 for connecting one air stream.

Giant. 2 shows an axonometric view of the heat exchanger 1 with all lamellas 6 and with two dashed smooth involute lamellas 6 in the view of the upstream part 2 of the heat exchanger 1. In the left part of Fig. 2, the front distributor 17 is shown in perspective, which includes the distributor part 3, involutely curled end the cross parts 16 of the lamellas 6, the connecting intermediate pipe 9, the plugs 10 and the end parts of the inner tube 4 and the outer tube 5, all integrally connected. In the front distribution part 3, involutely coiled lamellas 6 are shown, each of which two adjacent involutely coiled lamellas 6 are interspersed blinded by blanks 10, between which the outer involute air inlets 11 and the inner involute air outlets 12 are created, which are thus safely separated.

In Fig. 2, the direction of flow of air supply 13 is shown separately by arrows (ended straight) and by other arrows (ended in the shape of the letter "V") the direction of flow of air outlet 14 is shown separately, along the entire length of exchanger 1.

Giant. 3 shows a plan view of the front distributor 17, where blanks 10 for blinding the outer openings of the inner tube 4 are marked with cross hatching, external involute air inlets 11 with hatching from left-bottom to right-up and internal involute air outlets 12 with hatching from left-top to right- down.

The external involute air inlets 11 are arranged radially or semi-radially on the end distributors 17, 18 in a radial manner with respect to the longitudinal axis 8 of the heat exchanger 1, they connect to the involute air inlet channels 13 arranged separately between the inner tube 4 and the outer tube 5.

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The internal involute air outlets 12 are arranged axially on the end distributors 17, 18 and radially relative to the longitudinal axis 8 of the heat exchanger 1, they connect to the outlet involute channels of the air outlet 14 and are arranged separated from each other between the inner pipe 4 and the outer pipe 5.

In Fig. 3, the inner pipe 4 with the outer plug 10 to close its cavity, the outer pipe 5 and the connecting intermediate pipe 9 arranged between them are further marked, while all these pipes 4, 5, 9 are arranged coaxially with respect to the axis 8 of the exchanger 1.

Giant. 4 corresponds to Fig. 3 with the difference that only the blanks 10 are highlighted, namely the outer blank 10 for blanking the cavity of the inner tube 4 and the inner blank 10, which secures and separates the involute inlets 11 and outlets 12 of the air in the distributor 17. Between the blanks 10, the free external involute air inlets 11 and the internal involute air outlets 12 are visible.

Giant. 5 shows a side view of the heat exchanger 1 from Fig. 4 with the interruption of the upstream part 2, with two opposite end distributors 17, 18 with the outer tube 5 and with the connecting intermediate tubes 9, with the ends of the involute lamellas 6 shown, with the outer plugs 10 and with the axis 8.

Giant. 6 shows the cross-section A-A from Fig. 5 of the countercurrent part 2 of the exchanger 1 with the outer tube 5 and the inner tube 4, between which the involute lamellas 6 define separate countercurrent involute air supply channels 13 hatched in the direction from left-bottom to right-up and countercurrent involute discharge channels 14 air hatched from left-top to right-bottom. The involute channels are safely separated from each other and have the same spacing between them.

From Fig. 2 to 6, it is clear that each inlet countercurrent involute channel with air supply 13 is arranged between the outer pipe 5 and the connecting intermediate pipe 9 and in the direction of air flow between the outer pipe 5 and the inner pipe 4. Each outlet countercurrent involute channel with discharge 14 of air is arranged between the outer pipe 5 and the connecting intermediate pipe 9 and in the direction of the air flow between the outer pipe 5 and the inner pipe 4.

All involute channels with air supply 13 and air outlet 14, and all involute air inlets 11 and involute air outlets 12 are arranged in an involute shape 7 in a cross-section perpendicular to the longitudinal axis 8 of the heat exchanger 1. All involute slats 6 are self-supporting and prestressed.

The ends of the involutely twisted slats 6 are firmly and airtightly connected to the inner tube 4, to the outer tube 5 and to the connecting intermediate tube 9.

This type of cylindrical counter-flow exchanger 1 with smooth heat exchange surfaces of involutely curled lamellae 6 represents the technically, manufacturing and commercially simplest design of the exchanger 1 for use in ventilation of residential buildings with heat recovery.

Example 2 (Fig. 7 to 19)

Countercurrent cylindrical heat recovery exchanger 1a with curled wavy involute fins 6a and with external beveled involute air inlets 11 and internal involute air outlets 12 of distributors 17a, 18a.

The most advantageous exemplary embodiment of the countercurrent cylindrical heat recovery exchanger 1a according to this technical solution represents the solution shown in Fig. 7 to 19.

The exchanger 1a shown in Fig. 7 in an axonometric view has a cylindrical central countercurrent part 2a, and two cross end distributors of parts 3a connected to it. The counterflow part 2a comprises an inner tube 4a with a grooved outer surface, an outer tube 5 and all corrugated, involute 5 coiled fins 6a-2. The connecting intermediate pipe 9 and the outer pipe 5 can be provided with grooves not shown on the outer surface. One is shown as a dashed line in the viewport

- 7 CZ 37536 U1 lamella 6a-2, twisted in a cross-section, perpendicular to the longitudinal axis 8 of the exchanger 1a, into an involute shape 7. The inner tube 4a and the outer tube 5 are coaxial with the longitudinal axis 8 of the exchanger 1a. Both distribution parts 3a contain 10 connecting intermediate pipe 9 for air connection. In Fig. 7, the front distributor 17a is captured in perspective on the left and partially the rear distributor 18a on the right. Unlike the previous example 1, the two distributors 17a, 18a are not integral with the countercurrent part 2a of the exchanger 1a. Both distributors 17a, 18a are made separately, and then the front distributor 17a and the rear distributor 18a are connected to the cylindrical counterflow part 2a so that the involute air inlets 11 and outlets 12 connect to the air inlets 13 and air outlets 14 of the connected involute channels.

Giant. 8 shows a front view of the front distributor 17a, where the outer blanks 10a for closing the inner tube 4a are marked with cross-hatching, the outer involute air inlets 11 and the inner involute air outlets 12 shown in the views with a visible touch of the wavy parts of the slats 6a-2. Fig. 8 further shows the inner pipe 4a with plugs 10a, the outer pipe 5 and the connecting intermediate pipe 9.

Giant. 9 shows a side view of the heat exchanger 1a from Fig. 7, for easier orientation of the reader, by simplification and with interruption of the upstream part 2a, with two end distribution parts 3a, with the outer tube 5, with the connecting tubes 9, with the ends of the involute slats 6a shown, with the inner with blanks 10a and with axis 8 exchanger 1a.

Giant. 10 shows a cross-section B-B from Fig. 9 of the countercurrent part 2a of the exchanger 1a with the outer tube 5 and the inner tube 4a, between which the involute lamellas 6a-2 define separate countercurrent involute air supply channels 13 and air outlet channels 14.

Fig. 11 shows one lamella 6a-1 in the unfolded state, attached to the inner tube 4a with grooves. The lamella 6a-1 comprises three parts, namely a middle profiled and wavy countercurrent part 15a-1 in the shape of a rectangle and two opposite end cross parts 16a-1 of a triangular shape with a smooth surface.

The counter-flow part 15a-1 fully corresponds to the counter-flow part of the slats according to patent CZ 303626 B6. Thus, the upstream part 15a of the lamella 6a-1 contains grooves of an accordion profile, having in cross-section a peak on the front side, corresponding to a depression on the reverse side. The grooves show both on the front side and on the reverse side a wavy trajectory of the grooves in the longitudinal direction between the opposite end smooth cross parts 16a-1 of each lamella 6a-1. Thus, the countercurrent portion 15a-1 is formed, which is profiled and corrugated.

Fig. 12 shows a tube 4a with grooves to which two lamellae 6a-1 are attached in the unfolded state. Each of these slats 6a-1 has a central countercurrent part 15a-1 in the shape of a rectangle and two opposite end cross parts 16a-1 in a triangular shape.

Fig. 13 shows a grooved tube 4a with all lamellae 6a-1 in the unfolded state, which are clamped in the grooves of the tube 4a and radially arranged to the center of the longitudinal axis 8.

Fig. 14 shows a grooved tube 4a to which 2 lamellas 6a-2 twisted into an involute shape 7 are attached. Each of these involutely twisted lamellas 6a-2 has a middle counter-current part 15a-2 in the shape of a rectangle and two opposite end cross parts 16a-2 triangular shape.

Fig. 15 shows a grooved tube 4a with all lamellae 6a-2, twisted into an involute shape 7, clamped in the grooves of the tube 4a and radially arranged to the center of the longitudinal axis 8.

Giant. 16 shows the arrangement from Fig. 15 supplemented by an outer tube 5.

Giant. 17 shows the arrangement from Fig. 14 supplemented with a front distributor 17a and a rear distributor 18a.

Giant. 18 shows the arrangement from Fig. 15 supplemented with a front distributor 17a and a rear distributor 18a.

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The picture shows the undulation of the involute lamellas 6a-2 in the upstream part 2a of the exchanger 1a.

The external involute air inlets 11 of the distributors 17a, 18a, the external involute outputs 12 of the distributors 17a, 18a, the air inlets 13 and the air outlets 14 into the involute channels of the countercurrent part 2a of the exchanger 21a, are arranged similarly to the previous Example 1. The involute coiled lamellas 6a-2 are firmly and air-tightly attached at their ends to the inner tube 4a, to the outer tube 5 and to the connecting intermediate tube 9.

Giant. 19 shows the arrangement from Fig. 16 supplemented with a front distributor 17a and a rear distributor 18a and thus represents a complete exchanger 1a.

In an exemplary embodiment, the exchanger 1b is made of hard plastic.

The involute lamella 6a-2 has a thickness of 0.1 to 0.5 mm, preferably 0.2 to 0.4 mm, most preferably 0.25 mm.

The pitch between the lamellae is preferably 1 to 5 mm, preferably 3.5 mm. The number of lamellae 6a-2 is 20 to 50, preferably 20 to 40, most preferably 30.

The inner tube 4a has an inner diameter of 20 to 100 mm, preferably 30 to 70 mm, most preferably 50 mm.

The outer tube 5 has an inner diameter of 100 to 300 mm, preferably 200 mm.

The length of the inner tube 4a and the outer tube 5 is 200 to 600 mm, preferably 300 to 15,500 mm, most preferably 250 mm.

Example 3 (Figs. 20 to 28)

Countercurrent cylindrical heat recovery exchanger 1b with curled wavy involute lamellas 6b and with flat air inlets 11 and air outlets 12 of distributor parts 3.

An exemplary embodiment of the counter-current cylindrical heat recovery exchanger 1b according to this technical solution represents the optimal solution of this exchanger 2b, shown in Fig. 20 to 28. The structural arrangement corresponds to the previous Example 2 with the difference that the inner tube 4 has a smooth surface, the lamellae 6b-1, 6b-2 have end cross sections 16b-1. 16b-2 of a rectangular shape with a smooth surface, so that the slats 6b-1, 6b-2 have a rectangular shape, and furthermore it is essential that both distributors, the front distributor 17b and the rear distributor 18b are flat, not beveled as in the previous Examples 1 and 2.

Fig. 20 shows one lamella 6b-1 in the unfolded state, air-tightly attached to the smooth tube 4. The lamella 6b-1 comprises three parts, namely a middle profiled wavy counter-current part 15b-1 in the shape of a rectangle, and two opposite end cross parts 16b-1 rectangular shape with a smooth surface.

Fig. 21 shows a smooth tube 4 to which two lamellae 6b-1 are attached in the unfolded state. Each of these slats 6b-1 has a middle countercurrent portion 15b-1 of rectangular shape and two opposite end cross portions 16b-1 of rectangular shape.

Fig. 22 shows a smooth tube 4 with all lamellae 6b-1 in the unfolded state, which are hermetically attached to the smooth tube 4 and radially arranged to the center of the longitudinal axis 8 of the exchanger 2b.

Fig. 23 shows a smooth tube 4 to which two lamellae 6b-2 are attached. curled into an involute shape 7. Each of these involute lamellas 6b-2 10 has a middle countercurrent portion 15b-2 in the shape of a rectangle and two opposite end cross portions 16b-2 in a rectangular shape.

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Fig. 24 shows a smooth tube 4 with all lamellae 6b-2 twisted into an involute shape 7, which are attached to the smooth tube 4 and radially arranged to the longitudinal axis 8 of the exchanger 2b.

Giant. 25 shows the arrangement from Fig. 24 supplemented by the outer tube 5.

Giant. 26 shows the arrangement of Fig. 23 supplemented by the front splitter 17b and the rear splitter 18b, which are not bevelled, they are smooth. Both distributors 17b, 18b contain a connecting intermediate pipe 9, internal plugs 10b securing and separating the involute inlets 11 and outlets 12 of air in the distributors 17b, 18b. Between the blanks 10b, free external involute air inlets 11 and internal involute air outlets 12 are visible. In this case, the opposite ends of the outer tube 5 and the inner tube 4b extend into both distributors 17b, 18b.

Giant. 27 shows the arrangement from Fig. 24 with all the involute lamellas 6b-2 supplemented by the front distributor 17b and the rear distributor 18b.

Giant. 28 shows the arrangement from Fig. 27 supplemented with the outer tube 5 and thus represents a complete exchanger 1b.

Example 4 (Fig. 11, 12, 13, 15, 16, 19)

Production of a counter-current cylindrical heat recovery exchanger 1a with wavy involute fins 6a and with bevelled involute air inlets 11 and involute air outlets 12 of distributor parts 3.

The production of this exchanger 1a according to Example 2 consists of several steps.

First, the individual components of the exchanger 1a are prepared, e.g. from thermoplastic.

The inner tube 4a and the outer tube 5 are prepared to the desired length, e.g. by cutting.

The lamellas 6a-1 in the developed state are prepared while hot, e.g. by vacuum injection and hot pressing into a mold, including trimming.

This is followed by the assembly of these individual components into the semi-finished assembly.

The individual lamellas 6a-1 in the unfolded state are glued radially to the inner tube 4a, namely the left and right lamellas 6a-1 interspersed. face to face, reverse to reverse of lamella 6a-1.

Subsequently, this assembly semi-finished product is inserted into a special rolling device, with the help of which all lamellas 6a-1 are rolled at once into the desired involute shape 7.

The assembly blank thus obtained is placed inside the outer tube 5, internally provided with glue to fix all the involute lamellae 6a-2 between the inner tube 4a and the outer tube 5. Then both ends of this assembly are provided with the front distributor 17a and the rear distributor 18a using glue so that the front distributor 17a and the rear distributor 18a must be positioned so that the outer involute air inlets 11 of both distributors 17a, 18a and the inner involute air outlets 12 open into the corresponding involute channels of the countercurrent part 2a of the exchanger 1a. This completes exchanger 1a.

3D printing is an alternative way of manufacturing exchanger 1, 1a, 1b. It represents a more expensive method of production.

In the case of metal material for the exchanger 1, 1a, 1b, such as e.g. aluminum, production by welding individual components is possible. Metal involute lamellas 6, 6a-2, 6b-2 can be pressed from a thin foil by cold forming.

- 10 CZ 37536 U1

Industrial applicability

The recovery exchanger 1, 1a, 1b represents an air-technical element of the ventilation system, maintaining heat or cold in the room during ventilation in the building. It is an air-to-air heat exchanger 1, 1a, 1b, which is intended for installation mainly in the perimeter wall of the building, but also in the ventilation duct.

Claims (23)

1. Counterflow cylindrical heat recovery exchanger (1; 1a; 1b), intended for ventilation of buildings, including a cylindrical counterflow part (2; 2a; 2b) connected to two oppositely arranged distributors (17,18; 17a, 18a; 17b, 18b) ), the heat exchanger (1; 1a; 1b) contains a coaxially arranged inner pipe (4, 4a) and an outer pipe (5), between which the lamellas (6) are arranged, the air inlets (11) are arranged radially or semi-radially on the distributors (17) ,18; 17a, 18a; 17b, 18b) of the exchanger (1; 1a; 1b) and radially relative to the longitudinal axis (8) of the exchanger (1; 1a; 1b) and connect to the inlet channels arranged between the outer pipe (5) and the inner through the pipe (4; 4a; 4b) of the upstream part (2; 2a; 2b) of the exchanger (1; 1a; 1b), the air outlets (12) are arranged axially on the end distributors (17,18; 17a, 18a; 17b, 18b) of the exchanger (1; 1a; 1b ) radially with respect to the longitudinal axis (8) and connect to the outlet channels between the outer pipe (5) and the inner pipe (4; 4a; 4b) of the upstream part (2; 2a; 2b) of the exchanger (1; 1a; 1b) and if the flow directions are reversed, the air inlets become air outlets and the air outlets become air inlets, characterized by the fact that the slats (6; 6a-2; 6b-2) are twisted into an involute shape (7) in a cross-section perpendicular to the longitudinal axis (8) of the exchanger (1; 1a; 1b). 2. Countercurrent cylindrical recuperation exchanger (1; 1a) according to claim 1, characterized in that the involute lamellas (6; 6a-2; 6b-2) twisted into the involute shape (7) are arranged parallel and coaxially behind each other with respect to the axis (8) exchanger (1; 1a; 1b) with the same mutual distance between each other. 3. Countercurrent cylindrical recuperation exchanger (1; 1a) according to claim 2, characterized in that a separate countercurrent involute supply channel (13) is defined by a pair of involute lamellas (6; 6a-2; 6b-2) with a mutual pitch between them. of air and an adjacent pair of involute lamellas (6; 6a2; 6b-2) with a mutual pitch between them defines a separate counter-current involute channel for air removal (14). 4. Countercurrent cylindrical recuperation exchanger (1; 1a) according to claim 3, characterized in that each countercurrent involute air supply channel (13) connects to the external involute air inlet (11) and each countercurrent involute air outlet channel (14) connects to internal involute outlet (12) of air. 5. Countercurrent cylindrical recuperation exchanger (1; 1a; 1b) according to claim 4, characterized in that all involute channels with air supply (13) and exhaust (14) and all involute inlets (11) and involute outlets (12) of air are arranged in an involute shape (7) in a cross-section perpendicular to the longitudinal axis (8) of the exchanger (1;1a;1b). 6. Countercurrent cylindrical recovery exchanger (1; 1a) according to claim 1, characterized in that the exchanger (1; 1a; 1b) has a central countercurrent part (2; 2a; 2b) corrugated in the transverse and longitudinal direction with respect to the longitudinal axis (8 ) of the exchanger (1; 1a; 1b). 7. Countercurrent cylindrical recovery exchanger (1; 1a) according to claim 1, characterized in that the exchanger (1; 1a; 1b) has each distributor (17, 18; 17a, 18a; 17b, 18b) equipped with a connecting pipe (9) . 8. Countercurrent cylindrical recuperation exchanger (1; 1a; 1b) according to claim 6, characterized in that each inlet countercurrent involute channel with air supply (13) is arranged between the outer pipe (5) and the connecting intermediate pipe (9) and in the direction air flow between the outer tube (5) and the inner tube (4; 4a); and each outlet countercurrent involute channel with an air discharge (14) is arranged between the outer pipe (5) and the connecting intermediate pipe (9) and in the direction of the air flow between the outer pipe (5) and the inner pipe (4; 4a). - 12 CZ 37536 U1 9. Countercurrent cylindrical recovery exchanger (1; 1a) according to claim 6, characterized in that the distributors (17, 18; 17a, 18a) are beveled and are narrowed to the longitudinal axis (8) of the exchanger (1; 1a; 1b) and towards the connecting intermediate pipes (9). 10. Countercurrent cylindrical recovery exchanger (1b) according to claim 6, characterized in that the distributors (17b; 18b) are flat. 11. Countercurrent cylindrical recuperation exchanger (1, 1a, 1b) according to claim 1, characterized in that each involute lamella (6; 6a-2; 6b-2) is self-supporting. 12. Countercurrent cylindrical recuperation exchanger (1; 1a; 1b) according to claim 1, characterized in that each involute lamella (6; 6a-2; 6b-2) is attached to the inner tube (4; 4a; 4b) by its ends. and to the outer pipe (5) in the upstream part (2; 2a; 2b) and to the distributor part (3; 3a) of the distributors (17,18; 17a, 18a; 17b, 18b). 13. Countercurrent cylindrical recuperation exchanger (1) according to claim 1, characterized in that the involute lamella (6) has a central countercurrent part (15) and both opposite end cross parts (16) with a smooth surface. 14. Countercurrent cylindrical recuperation exchanger (1a; 1b) according to claim 1, characterized in that each involute lamella (6a-2; 6b-2) has a central countercurrent part (15a-2; 15b-2) profiled and corrugated and both the opposite end cross parts (16a-2, 16b-2) have a smooth surface. 15. Countercurrent cylindrical recuperation exchanger (1, 1a) according to claim 1, characterized in that the involute lamella (6; 6a-2) is hexagonal and has a countercurrent part (15; 15a-2) of rectangular shape and opposite end cross parts ( 16a-2; 16b-2) in the shape of a triangle. 16. Countercurrent cylindrical recuperation exchanger (1b) according to claim 1, characterized in that the involute lamella (6b-2) is rectangular and has its countercurrent part (15b-2) of a rectangular shape and its opposite end cross part (16b-2) in the shape of a rectangle. 17. Countercurrent cylindrical recuperation exchanger (1, 1a, 1b) according to claim 1, characterized in that the air supply inlets (13) and air outlets (14) of the distribution parts (3; 3a) are equipped with internal plugs (10, 10a, 10b). 18. Countercurrent cylindrical heat exchanger (1, 1a, 1b) according to claim 1, characterized in that the inlets of the air supply (13) and the outlets (14) of the air in the distributors (17, 18; 17a, 18a; 17b, 18b) are equipped with internal plugs (10, 10a, 10b). 19. Countercurrent cylindrical recuperation exchanger (1, 1a, 1b) according to claim 1, characterized in that the inner tubes (4, 4a) are provided with outer plugs (10, 10a, 10b) at their outer ends. 20. Countercurrent cylindrical recuperation exchanger (1, 1b) according to claim 1, characterized in that the inner tube (4; 4b) has a smooth surface. 21. Countercurrent cylindrical recuperation exchanger (1, 1a, 1b) according to claim 1, characterized in that the inner tube (4a) is provided with grooves on the outer surface. 22. Countercurrent cylindrical recuperation exchanger (1, 1a, 1b) according to claim 1, characterized in that the outer tube (5) is provided with grooves on the inner surface. 23. Countercurrent cylindrical recuperation exchanger (1, 1a, 1b) according to claim 1, characterized in that the connecting intermediate pipe (9) pipe (5) is provided with grooves on the outer surface.