Patent Description:
Since the invention is characterized by its structure, it can also be designated F28F - structural elements of devices for heat exchange and transfer for general application.

The inventors aimed to improve the thermal performances of the heat exchanger core, primarily in a way that the essential parameters of the working fluids can be easily controlled.

Furthermore, using such an improved heat exchanger core, the inventors have designed a heat exchanger that is easy to manufacture, use and maintain, suitable for use in a variety of commercial and residential premises, and in a variety of industries. Also, the inventors aimed to design a heat exchanger that has a smaller mass in relation to the existing heat exchangers of the same power and the same material.

The inventors have consulted the patent databases and found that there are inventions of heat exchangers that include a structure that has helical tubes, a stepwise distance between the tubes, and a crossflow of fluids such as <CIT>) or <CIT> - Multiple concentric cylindrical co-coiled heat exchanger or <CIT> - Crossflow countercurrent heat exchanger with inner and outer-tube sections made up of closely packed coaxially nested layers of helicoidally wound tubes. A device according to the preamble of claim <NUM> is disclosed in <CIT>.

Some other similar inventions such as <CIT> - Counter-flow heat exchanger with helical tube bundle or <CIT>) - Improvements relating to the construction of tubular heat exchangers do not include crossflow of fluids or a stepwise distance between the tubes. None of the previous patents contains a counterflow and a crossflow heat exchanger, made by winding helical tubes (coils) into each other through structural reinforcements, which are an integral part of the heat exchanger core and which enable stepwise/zigzag arrangement of coils and arrangement of tubes of each coil exactly in the middle position and at the same distance between the tubes of adjacent coils in the entire heat exchanger core and together they make the heat exchanger surface. Also, none of these patents discloses structural reinforcements that would be made so that their inner and outer edge correspond to the required coil pitch and that the inner edge additionally follows the angle of the coil on which they are placed and that the outer edge follows the angle of the next coil.

The present invention is a design solution of a counterflow and crossflow heat exchanger, made by winding helical tubes (coils) successively through structural reinforcements, which are an integral part of the heat exchanger core, and which enable stepwise/zigzag arrangement of coils, and arrangement of tubes of each coil exactly in the middle position and at the same distance between the tubes of adjacent coils in the entire heat exchanger core, and together they make the heat exchanger surface.

Structural reinforcements are made so that their inner and outer edge correspond to the required coil pitch and that the inner edge additionally follows the angle of the coil on which they are placed and that the outer edge follows the angle of the next coil.

Two fluids, the first fluid and the second fluid, can pass through this energy exchange device. Furthermore, this device may include a central router with conical extensions and structural reinforcement support, wherein a basic structural reinforcement on which the first helical coil is wound is placed on the central router having conical extensions on both sides, and wherein the central router is to direct the flow of the first fluid towards the coils and prevent the passage of the first fluid through the central part of the heat exchanger core, and wherein the conical extensions direct the flow of the first fluid as close as possible to the outer walls of the coils through which the second fluid moves. All odd- numbered coils (the first, the third, the fifth,. ) are parallel to each other in both transverse and longitudinal planes of the heat exchange core, while also all even- numbered coils (the second, the fourth, the sixth,. ) are parallel to each other in both transverse and longitudinal planes of the heat exchange core. The diameters of the d pipes from which all the coils are made are the same. Each coil in the heat exchanger core has a different diameter, wherein all coils have the same coil pitch, and each coil has a different thread angle. The structural reinforcements have a sinusoidal or wavy or wavy-zigzag shape, whereby the shape of the structural reinforcements represents bearings on which the coils move when wound into the heat exchanger core.

Structural reinforcements comprise an inner edge and an outer edge, wherein they correspond to the required coil pitch, and wherein the inner edge additionally follows the thread angle of the coil on which they are placed, and the outer edge follows the angle of the next coil, wherein the first coil has the diameter, the pitch and the thread angle of the first coil. The first structural reinforcement, which is placed on the first coil and follows the pitch, additionally follows the angle of the first coil with the inner edge, and with the outer edge, it follows the angle of the next second coil and so on till the last wound coil.

At least two structural reinforcements are placed on each coil in turn, and most preferably three or more, arranged at equal distances along the diameters of the coils with structural reinforcements placed on each subsequent coil so that they are not in the same plane with the structural reinforcements of the previous coil.

The basic structural reinforcements are connected by welding to the central router and each subsequent structural reinforcement to the next wound coil in turn in the heat exchanger core, where the structural reinforcements also enable stepwise or zigzag arrangement of coils, and the arrangement of tubes of each coil exactly in the middle position and at the same distance between the tubes of adjacent coils in the entire heat exchanger core, transverse to the second fluid. This energy exchange device may further comprise structural reinforcement supports, on which holes are drilled so that one end of the structural reinforcement is inserted into each hole, wherein each of the structural reinforcement supports has as many holes drilled both vertically and horizontally as necessary to place at least two structural reinforcements on each coil.

The advantage of the present invention is reflected in simple manufacture, improved thermal performances, simple control of essential parameters of the working fluids, easy modularity for application in commercial, residential premises, and in various industries, and easy modularity for smaller/higher powers.

The invention is described in detail on the example of the draft where:.

The energy exchange device between media with improved structure and performances in one embodiment contains the following parts: sheath <NUM>, shield <NUM>, commutator (collector) <NUM>, coils or helical tubes <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, tubes with expansions <NUM>, central router <NUM> with conical extensions <NUM>, structural reinforcements <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and structural reinforcement support <NUM>.

Usually, basic structural reinforcements <NUM> are placed on both sides of the central router <NUM> with conical extensions on which the first helical tube (coil) <NUM> will be wound. The task of the central router <NUM> ist to direct the flow of the first fluid <NUM> towards the coils <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and to prevent the passage of the first fluid <NUM> through the central part of the heat exchanger core <NUM>. Conical extensions <NUM> direct the flow of the first fluid <NUM> as close as possible to the outer walls of the coils <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> through which the second fluid moves <NUM>. Central router <NUM> is made of pipes of a defined diameter to which conical extensions <NUM> are welded on both sides.

Coils of the heat exchanger core <NUM> are formed on the tools. A tool can be a cylinder of a defined diameter and length, made of plastic or metal with channels that correspond to the required coil and its characteristics, whereby helical tubes (coils) of given parameters are produced by turning the tool. All coils with an odd number e.g. <NUM>, <NUM> to <NUM> are parallel in both transverse and longitudinal planes of the heat exchanger core <NUM>. The same applies to even- numbered coils <NUM>, <NUM>, etc. The diameters of d pipes <NUM>, from which all coils are made, are all the same. Each coil <NUM> to <NUM>, <NUM> has a different diameter, and so is the diameter of the first coil <NUM>, the diameter of the penultimate coil <NUM>, and the diameter of the last coil <NUM> defined. All coils have the same coil pitch, but a different thread angle, so the first coil has a thread angle <NUM>, the thread angle of the penultimate coil is <NUM>, while the angle of the last coil is <NUM>, therefore the tool is different for each coil. Coils can also be made on modified tools for pipe bending, e.g., three-cylinder, drum-like tools, and other tools known from the prior art. The pipes from which the coils are made can be made of copper, aluminum, stainless steel, dual metals, etc. The heat exchanger core <NUM> can be connected to the heating or cooling systems vertically or horizontally.

Structural reinforcements <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> enable coil winding into the heat exchanger core <NUM>. Structural reinforcements <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> have a sinusoidal/wavy/wavy-zigzag shape. This form of structural reinforcements enables bearings on which the coils <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> move when wound into the heat exchanger core <NUM>. They are placed parallel to the longitudinal axis <NUM>, and the inner edge <NUM> and the outer edge <NUM> are designed to fit the required coil pitch <NUM>. Since the thread angle of coils <NUM>, <NUM>, <NUM> for each coil <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> is different, all structural reinforcements are different, made so that the inner edge <NUM> additionally follows the thread angle of the coil on which they are placed, and the outer edge <NUM> follows the angle of the next coil. So the first coil <NUM> has a diameter <NUM>, a thread pitch <NUM>, a diameter of d pipe of which the coil <NUM> is made, a thread angle <NUM> and the first structural reinforcement <NUM>, and so on for each subsequent coil successively. Likewise, the first structural reinforcement <NUM> placed on the coil <NUM> that follows the pitch <NUM>, additionally follows the angle of the coil <NUM> for the first coil <NUM> with the inner edge <NUM> and with the outer edge <NUM> it follows the angle <NUM> of the next second coil <NUM> and so on to the last wound coil. At least two structural reinforcements <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and most preferably three or more, arranged at equal distances along the diameters of the coils <NUM>, <NUM>,<NUM> are placed on each coil in turn. On each subsequent coil, the structural reinforcements are placed so that they are not in the same plane as the reinforcements of the previous coil. The basic structural reinforcement <NUM> is connected by welding to the central router <NUM>, and each subsequent structural reinforcement <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> to the next wound coil in turn into the heat exchanger core <NUM>. Structural reinforcements also enable a stepwise/zigzag arrangement of the coils and the arrangement of the tubes of each coil exactly in the middle position and at the same distance between the tubes <NUM> (transverse to the second fluid <NUM>) of adjacent coils in the entire heat exchanger core <NUM>. After placing the structural reinforcements on the last wound coil <NUM> or <NUM>, a cylindrical sheath <NUM> of the heat exchanger is placed on them. The basic structural reinforcements <NUM> and the last structural reinforcements <NUM>, can also be flat, without zigzag waves, and other aforementioned characteristics, and can be flush with the structural reinforcement of the next coil, which applies to the basic structural reinforcements <NUM>, or with the structural reinforcement of the previous coil, which applies to the last structural reinforcements <NUM>. Also, the coils <NUM>,<NUM>,<NUM> with their pair of structural reinforcements <NUM>, <NUM>, <NUM> in turn, can be welded, before being wound into the heat exchanger core <NUM>, and then individually wound into the heat exchanger core successively.

Structural reinforcements ensure the stability of the entire heat exchanger core <NUM>, reduction of vibrations, and a uniform distance between the coil tubes <NUM>. They additionally increase the heat exchange surface and together with the coils they form the total exchange surface. Other modifications are also possible in the way of bonding structural reinforcements besides welding e.g. soldering, gluing, etc..

Structural reinforcements are most preferably made of the same type of material as the coils. Structural reinforcements are made of full section materials, strips, wires, etc., or capillary tubes (microchannel tubes). They are made in their molds or are being cut, for example by laser cutting, to obtain a specific shape that ensures that the coils are easily wound, successively, into the heat exchanger core. The thickness <NUM> of the material from which the structural reinforcements are made is one of the reasons that affect the size (interspace-gap) of the distance <NUM>. Each structural reinforcement has the same thickness <NUM> of the material from which it is made. By changing the thickness <NUM> of their material, the size of the distance <NUM> decreases or increases, but always ensures a stepwise/zigzag arrangement of coils, and the arrangement of tubes of each coil exactly in the middle position and at the same distance <NUM> between the tubes of adjacent coils in the entire heat exchanger core <NUM>.

To avoid welding or gluing of structural reinforcements, all structural reinforcements can be inserted into symmetrical supports <NUM>. <FIG> show examples of the heat exchanger core <NUM> with supports <NUM> with eight coils <NUM> to <NUM>. All structural reinforcements that are inserted into the supports <NUM> are made according to the previously described principle. Each of the supports <NUM> is, most preferably, made of two identical pipes or round bars with a full section, which are welded at their centers at right angles. Structural reinforcements are inserted between the supports <NUM> in the holes <NUM> drilled therein. In the above example, the last structural reinforcement is the eighth structural reinforcement <NUM>. The supports <NUM> are made of the same type of material as the central router <NUM>, with a diameter not larger than the diameter of the d coil pipe <NUM>. Each of the supports <NUM> has as many holes drilled both vertically and horizontally as necessary to place at least two structural reinforcements on each coil. The supports <NUM> can be welded to the central router <NUM> before welding its conical extensions <NUM>. After inserting all structural reinforcements into the supports <NUM>, <FIG> show, coils <NUM> to <NUM> being rotated in turn, forming the heat exchanger core <NUM>. Also, structural reinforcements can be inserted into the supports <NUM> individually in turn, after winding each coil.

Based on the required power of the heat exchanger core <NUM>, type, speed, and temperature of working fluids <NUM> and <NUM>, and the required pressure drop of working fluids, the length <NUM> and the diameter <NUM> of the heat exchanger core are determined, the diameter of d pipe <NUM> for making coils, wall thickness <NUM> of pipes from which coils are made, the diameter of the first coil <NUM> to the diameter of the last coil <NUM> in turn, the number of coils and the required distance <NUM> are defined. By changing the coil pitch <NUM> and structural reinforcements, while retaining the aforementioned principle and the characteristics of their manufacture, the distance <NUM> is easily regulated, which enables simple control of the desired fluid pressure drop <NUM>. The length of each coil depends on the diameter of each coil, as well as the length <NUM> of the core itself.

Example <NUM>: Example of an optimized heat exchanger according to the present invention for a required power of 1850W air-water:.

Basic parameters for manufacturing a heat exchanger core
First fluid <NUM>:
air.

The required pressure drop of the first fluid is <NUM> Pa and of the second fluid <NUM> kPa
An optimized heat exchanger core according to the present invention: technical characteristics of the manufacture.

The following essential parameters were obtained:.

All the aforementioned constructional and functional characteristics of the invention and the described example have been successfully tested by the inventor on the developed prototype. By changing the described geometrical parameters-technical characteristics of the heat exchanger core manufacture, it is possible to apply it to residential facilities (of lower power) as well as commercial facilities (of higher power) and various industry branches for cooling, heating, or recovery systems.

In the described example of the optimized heat exchanger core of small dimensions and lightweight, a high heat capacity (<NUM> W) is achieved, which enables a simple and flexible installation in a small space.

To facilitate coil winding into the heat exchanger core <NUM>, each is cut at its beginning and end in such a way that all coils of the heat exchanger core reach the same normal plane on axis <NUM>. At the beginning and end of each coil, tubes <NUM> with expansions of the same length are then placed on each coil individually. Holes <NUM> for the passage of tubes <NUM> with expansions that further enter straight into the commutator (collector) <NUM> are drilled on sheath <NUM>. Tubes with expansions <NUM> can be welded, glued, etc., to coils. Shield <NUM> is placed between the core sheath <NUM> and the tubes with expansions <NUM> to prevent the first fluid <NUM> flow outside the heat exchanger core <NUM>. Tubes with expansions <NUM> are most preferably made of the same material and diameter of d pipe <NUM> as the coils and are widened at one end where they will be drawn on the coils with standard pipe expansion tools. The commutator (collector) <NUM> additionally has openings <NUM> for venting the heat exchanger core <NUM>.

The first fluid <NUM> moves around the coils and the second fluid <NUM> through the coils. The inlet <NUM> of the first fluid <NUM> concerning the inlet <NUM> of the second fluid <NUM> is located on the opposite side of the heat exchanger core, whereby the fluids move in opposite directions. Thus, the temperature difference in the entire heat exchanger core <NUM> is big and the heat exchange on the entire device is high. The first fluid <NUM> further moves approximately perpendicularly (crosswise/ normally) concerning the axis of the coil tube. In this arrangement coils greatly interfere with the flow of the first fluid <NUM>, so there is continuous turbulence of the first fluid <NUM> around the coils. This enhances the heat exchange but also increases the pressure drop of the first fluid <NUM>. Since the coils are arranged stepwise (stepwise arrangement of coils) in the heat exchanger core by placing in their bearings on structural reinforcements, the tubes of each coil are exactly in the middle position and at the same distance <NUM> (transverse to the second fluid <NUM>) between the tubes of adjacent coils, the first fluid <NUM> is forced to move near the walls of the coil tubes.

In a stepwise arrangement, the tube of, e.g., the fifth coil <NUM>, as shown in <FIG>, is located exactly in the middle position between the adjacent tubes of the fourth coil <NUM> and the sixth coil <NUM>. The flow of the first fluid <NUM>, which passes between the fourth coil <NUM> and the sixth coil <NUM> directly strikes the tube of the fifth coil <NUM>. The flow of the first fluid <NUM>, which passes between the fourth coil <NUM> and the sixth coil <NUM> does not release or receive sufficient heat because it is located in the middle of the passage between the fourth coil <NUM> and the sixth coil <NUM>, at the first point <NUM>. But it further passes near the pipe wall of the fifth coil <NUM> at the second point <NUM>, where a lot of heat is released or received.

The heat transfer can be improved by reducing the distance from the pipe walls to the first fluid <NUM>, i.e., by reducing the distance <NUM>. If the distance <NUM> is very small, the flow of the first fluid <NUM> is forced to pass very closely to the pipe walls, therefore is the heat transfer higher. Basically, the thermal resistance of the flow of the first fluid <NUM> is proportional to the distance <NUM>, so the heat transfer rate is proportional to the inverse length of the distance <NUM> between the coil tubes: Q̃ ∝ Lg-<NUM>.

However, if the distance <NUM> between the coils is too small, the first fluid <NUM> is forced to pass through narrow passages, so more mechanical work is necessary to overcome the resistance, i.e., there is an increase in pressure drop of the first fluid <NUM> through the heat exchanger core <NUM>. This is an undesirable effect because part of the pressure is lost. The pressure drop of the first fluid <NUM> increases proportionally to the inverse cubic of the distance <NUM>, i.e., △PfluidsS∝Lg-<NUM>.

The above-mentioned method of the present invention manufacture achieves the maximum heat exchange for the default pressure drop of the first fluid <NUM>. This design enables the manufacture of an axial helical countercurrent (of opposite direction) and crossflow heat exchanger core <NUM>, and a stepwise arrangement of coils, which is simply made by winding helical tubes (coils) successively over structural reinforcements, thus achieving high heat performances and simple control of the most important parameters.

An additional advantage of the present heat exchanger core <NUM> is the mechanism of "self-cleaning" of the interior of the coils. Scale, other sediments, and contaminants inside the coils cause a localized increase in the speed of the second fluid <NUM>, which increases the "pushing" of the impurity by friction between the second fluid <NUM> and the impurity, in such a way the inner surface of the coil cleans "itself".

The diameters <NUM> of the inlet of the first fluid <NUM> and the outlet of the first fluid <NUM>, as well as the diameter <NUM> of the inlet of the second fluid <NUM> and the outlet of the second fluid <NUM> of the heat exchanger core, as shown in <FIG>, can be reduced or increased for connection to standard connectors.

The increase of the required power of the present invention can also be accomplished by binding lower powers of the heat exchanger core <NUM> made according to the same principle.

<FIG> shows an example of binding multiple heat exchanger cores <NUM> of lower powers made according to the present invention to provide a single higher power heat exchanger. <FIG> shows an embodiment of the heat exchanger core <NUM> in section with <NUM> coils <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> so that it can be seen that first comes the basic structural reinforcement <NUM>, then the first coil <NUM>, then the first structural reinforcement <NUM> on it, and then the second coil <NUM>, which is placed in the recesses <NUM>, and on the bulges <NUM> of the first structural reinforcement <NUM> comes the third coil <NUM> on which comes the third structural reinforcement <NUM> on which comes the fourth coil <NUM>, which is placed in the recess <NUM> of the third structural reinforcement <NUM>, and on the bulges <NUM> of the third structural reinforcement <NUM> comes the fifth coil <NUM> on which comes the fifth structural reinforcement <NUM>, and on it the sixth coil <NUM>, which is placed in the recesses <NUM>, and on the bulges <NUM> of the fifth structural reinforcement <NUM> comes the seventh coil <NUM>, on which comes the seventh structural reinforcement <NUM>, and on it the eighth coil <NUM>, which is placed in the recesses <NUM> of that seventh structural reinforcement <NUM>, and on the eighth coil <NUM> comes the last eighth structural reinforcement <NUM>.

The present invention can be industrially applied in commercial, residential premises, and various branches of industry. <FIG> illustrates one of the applications of the invention in the automotive industry on a complete heat exchanger for cooling (intercooler) highly compressed hot air, where its purpose is to lower the air temperature with as little pressure loss as possible.

Although the present invention has been described in the most preferred embodiment, to allow a better understanding of the invention, we should bear in mind that various modifications are possible.

Claim 1:
The counterflow and crossflow energy exchange device between media with improved structure and performances, that contains coils (<NUM>, <NUM>, <NUM>,<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) made from tubes and structural reinforcements (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>), wherein the coils (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>,<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) and structural reinforcements (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) form the heat exchanger core (<NUM>), and wherein the coils (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) are successively wound over structural reinforcements (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>), wherein the coils have a stepwise/zigzag arrangement, and wherein the arrangement of the tubes of each coil is exactly in the middle position and at the same distance between the tubes of adjacent coils in the entire heat exchanger core (<NUM>) wherein the first fluid (<NUM>) and the second fluid (<NUM>) can pass through said energy exchange device, characterized in that it further comprises a central router (<NUM>) with conical extensions (<NUM>), structural reinforcement support (<NUM>) and a basic structural reinforcement (<NUM>), wherein a basic structural reinforcement (<NUM>) is placed on both sides of the central router (<NUM>) having conical extensions (<NUM>) to which the first helical coil is wound (<NUM>), and wherein the central router (<NUM>) directs the flow of the first fluid (<NUM>) towards the coils (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) and prevents the passage of the first fluid (<NUM>) through the central part of the heat exchanger core (<NUM>), and wherein the conical extensions (<NUM>) direct the flow of the first fluid (<NUM>) to the outer walls of the coils (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) through which the second fluid (<NUM>) moves.