Thermoelectric module for residual heat utilization

Abstract

A thermoelectric module (1) for the use of waste heat, comprising at least some heat acquisition means (2), some energy generation means (4), and some heat dissipation means (5), and in particular adapted to be installed on an industrial pipe (3), wherein said collection means comprises a lower collector formed by an arched piece, an upper collector formed by an inverted pyramid piece, and a fixing device adapted to the aforementioned lower collector in contact with the heat source pipe, characterized in that said thermoelectric module (1).

Description

Technical Field

[0001] The present invention relates to a thermoelectric module for residual heat use, which is particularly adapted to be installed on a pipe functioning as a heat source or an industrial surface.

Background Art

[0002] Fossil fuels have been misused as a means of obtaining energy for many years, resulting in serious consequences such as global warming in the world we live in. Fossil fuels are finite, and their extraction, conversion, or utilization emits gases that are harmful to the environment and organisms, among other drawbacks.

[0003] Currently, humans are increasingly recognizing the need to protect the environment by researching and developing other energy sources such as renewable energy sources. For example, in addition to using energy in a more intelligent and sustainable way, avoiding wasteful consumption, and making equipment more efficient to reduce consumption, renewable energies such as solar, wind, geothermal, and other energies are beginning to be introduced.

[0004] Among these types of developments for optimizing energy resources, one of the new technologies today addressed by the present invention is thermoelectricity. As the name indicates, thermoelectricity is a field of physics that studies the direct conversion of thermal energy into electrical energy, or vice versa. Thermoelectricity was discovered more than 180 years ago, but there is currently increasing interest in its application and utilization for optimizing energy resources.

[0005] Primarily, the interest in thermoelectrics is due to its ability to convert residual heat into electrical energy that can be used as an energy source for other applications. Residual heat is the heat that is wasted in industrial or non-industrial processes and is later released into the environment without being used. This is, a priori, less useful than the original energy source and can be considered low-energy heat, which makes thermoelectrics a promising technology for recovering lost heat and improving performance. Avoiding environmentally harmful waste.

[0006] The pioneer of thermoelectric properties was the German scientist Thomas Johann Seebeck (1770 - 1831). In 1822, he summarized the results of his experiments in a paper titled "The Magnetic Polarization of Metal and Ores Produced by Temperature Difference". Seebeck experimented with how a magnetic needle would deflect when placed near a closed circuit formed by two conductors when one of the junctions of the two conductors was heated. He incorrectly concluded that the interaction was due to a magnetic phenomenon and continued with this idea, attempting to relate the Earth's magnetism to the temperature difference between the equator and the poles. Seebeck was unable to accurately define the effect but investigated the phenomenon in a number of materials, including some of what are now known as semiconductors.

[0007] Several years later, in 1834, the Peltier effect was discovered, which is complementary to the Seebeck effect. This effect occurs when an electric current passes through a circuit with two different conductors, and depending on the direction of the current, the junction of the two conductors can either release heat or absorb heat. This effect was discovered by the French physicist Jean Charles Athanase Peltier (1785 - 1845). Similar to Seebeck, Peltier was unable to evaluate the basis of his observations and relate the effect to Seebeck's findings, so he misinterpreted the results of his research. In 1838, Emily Lenz (1804 - 1865) demonstrated that the Peltier effect is an autonomous physical phenomenon consisting of the release or absorption of additional heat at the junction of conductors when an electric current passes through them, and she demonstrated this by freezing water and then reversing the direction of the current to melt the resultant.

[0008] Twenty years later, William Thomson wrote a comprehensive explanation of the Seebeck and Peltier effects and described their relationship. Additionally, he predicted the existence of a third thermoelectric effect, the Thomson effect, which is related to heating or cooling in a homogeneous conductor when there is a temperature gradient as an electric current passes through it.

[0009] These discoveries led to the development of a new field of engineering, thermoenergy engineering, which studies the process of converting thermal energy into electrical energy (the Seebeck effect) and thermoelectric heating and cooling (the Peltier effect).

[0010] In the mid - 20th century, thermoelectrics resurfaced with the discovery of synthetic semiconductors with high Seebeck coefficients. However, since semiconductors had not improved compared to metals, interest waned. It was not until the 1950s that compound semiconductors were obtained, thermoelectric improvements were achieved, and the potential for military applications was stimulated.

[0011] In the early 1960s, space exploration and the exploration of Earth resources in adverse locations required self - contained power sources. Thermoelectricity, due to the absence of moving parts, its reliability and its quiet operation, which offset its relatively high cost and low efficiency, was presented as an ideal technology for these cases. Thus, radioisotope thermoelectric generators were developed for the Apollo space program and lunar communications, and most of the materials used in current commercial generators were derived from them.

[0012] Currently, thermoelectric research has increased significantly for the search for alternative energy for large - scale production. Currently, thermoelectric generators (known as TEGs) are manufactured from various semiconductor materials, and the results vary.

[0013] A thermoelectric generator is composed of one or more thermoelectric modules. A thermoelectric module or Peltier cell (trademark name) directly converts heat into electricity. Heat induces the circulation of an electric current flowing through the thermoelectric generator (heat generator) from a heat source.

[0014] To generate electricity by the thermoelectric effect, a Peltier cell and a temperature difference across its two sides are required. Since the generated electrical energy is proportional to the thermal energy passing through the cell, the high - temperature source and the low - temperature source need to continuously supply and dissipate heat to maintain this thermal difference.

[0015] A Peltier cell is composed of two ceramic plates that function as a base for thermoelectric couples or thermo - elements (type P and type N) made of semiconductor materials, which also provide mechanical stability and function as electrical insulators.

[0016] Conventional modules are composed of several thermoelectric couples (P - and N - doped semiconductor elements), are electrically connected in series, and thermally connected in parallel if there are empty spaces, and both semiconductors are connected via high - conductivity metal junctions. A Peltier cell is composed of 100 - 600 thermo - elements.

[0017] These modules are quiet, have no moving parts, and require no maintenance. In addition, their size and weight are small, and they can be used in a wide temperature range. However, they have the major drawback of being inefficient.

[0018] This efficiency is related to the semiconductor material forming the thermoelectric junction and is currently under study for improvement, but the process is slow. Therefore, in order to improve performance, it is necessary to optimize the heat exchange system located on both sides of the cell to increase the generated electric power. This is achieved, in part, when the temperature of the cold or hot source is the same as that of the source of generation.

[0019] To provide a more efficient alternative, the Applicant has already devised the solution described in Patent Application No. P202100024. However, a more specific solution for industrial pipes is needed.

Summary of the Invention

Problems to be Solved by the Invention

[0020] Taking into account the current state of the art, the object of the present invention is to obtain a thermoelectric module that improves the coupling to industrial pipes and is capable of generating sufficient energy to utilize the residual heat of the system to power the monitored electronic devices or industrial sensors.

Means for Solving the Problems

[0021] For the use of industrial heat, in particular to provide a technical solution for industrial pipes, and due to the increasing need to monitor various parameters of the operation of machines and processes in the industry, a thermoelectric module for using residual heat is disclosed that is particularly adapted to be installed on pipes, ducts, and surfaces in the industry, which comprises at least heat acquisition means, energy generation means, and heat dissipation means. This enables this monitoring without the need for wiring or batteries using the associated electronic equipment presented later.

[0022] Essentially, the thermoelectric module comprises at least one lower heat collector, wherein the heat collection means is essentially formed by an arched piece of thermally conductive material adapted on its inner surface to contact the surface of a heat source external to the thermoelectric module; an upper heat collector, essentially formed by an inverted pyramid piece of thermally conductive material adapted to contact the lower collector at its lower base and to contact heat dissipation means at its upper base; a fastener adapted to firmly fasten the lower collector to the pipe of the heat source; and energy generation means adapted to convert heat into electrical energy, comprising at least one thermoelectric generator disposed between the upper collector and the heat dissipation means. The heat dissipation means comprises at least one base coupled to the upper collector and a heat sink having a plurality of fins for dissipating as much heat as possible from the thermoelectric generator coupled via the base.

[0023] Advantageously, when disposed on a pipe or surface, the thermoelectric module can generate electrical energy that can be used in other devices using its residual heat. With this configuration, the collection surface increases from the lower collector and is used more efficiently by the energy generation means via the upper collector. In addition, by using the base of the dissipation medium and the heat sink, a more efficient module is achieved that more appropriately optimizes the thermal energy obtained from the pipe and converts it into electrical energy for consumption in other applications or services, all of which increase the overall energy efficiency.

[0024] According to another feature of the invention, the thermoelectric module is characterized in that it comprises a component of a thermal material specifically adapted to reduce the thermal resistance by the contact between the lower collector and the upper collector. This component is intended to be made of a material basically made of tin and to have an essentially flat washer shape.

[0025] According to another feature of the present invention, the thermoelectric module is characterized in that it comprises a component of a thermal material specifically adapted to reduce the thermal resistance by contact between the lower collector and the upper collector. This component is basically made of a material made of tin and is intended to have an essentially flat washer shape.

[0026] Advantageously, this component improves the performance of this thermoelectric module by reducing the thermal resistance due to contact, making the temperature transfer more efficient, and promoting heat transfer.

[0027] According to a preferred embodiment of the present invention, the thermoelectric module is characterized in that the thermoelectric generator has at least one heat generating cell, the high temperature side of which is in contact with the upper collector, while the low temperature side is in contact with the base of the dissipation means, and thus, heat energy is conducted between the high temperature conduit and the thermoelectric generator. Due to the temperature difference occurring between the opposing surfaces of the surface in contact with the collector and the surface in contact with the heat sink, this cell, or as known in the art, the TEG cell, obtains heat energy that can be converted into electrical energy.

[0028] According to another feature of the present invention, the thermoelectric module is characterized in that the heat sink is provided with a plurality of vertical fins having branches that increase the contact surface with the environment, making it possible to remove excess heat more quickly by natural convection.

[0029] According to another feature of the present invention, the thermoelectric module is characterized in that the base of the dissipation means is formed by an inverted cone adapted to concentrate the flow from the larger surface of the upper collector to the smaller surface and towards the heat sink.

[0030] In a preferred embodiment of the present invention, the thermoelectric module is characterized in that it comprises an elastomer between the upper collector of the collection means and the base of the dissipation means and surrounds the thermoelectric generator.

[0031] Advantageously, this elastomer has two additional functions in addition to its function as a sealing element. One is that the heat from the upper collector needs to reach the base of the heat sink and prevent it from being contaminated and interfering with its function. On the other hand, the present system has the purpose of surrounding the assembly of the thermoelectric generator with a frame and fixing its position between the collecting means and the dissipating means.

[0032] According to another feature of the present invention, the thermoelectric module can accommodate, inside itself, an electronic box having the role of managing the electrical energy coming from the thermoelectric generator, can acquire data from sensors, and is characterized by including an electronic box that transmits data using long-distance wireless communication.

[0033] Advantageously, this thermoelectric module of the present invention enables the monitoring of any machine without adding energy by using the residual heat of the machine itself or other residual sources of heat in the environment to which the module is applied.

[0034] To complete the description being carried out and to facilitate the understanding of the features of the present invention, by way of example and not limitation, a set of drawings is attached to this illustrative report showing an embodiment of the thermoelectric module of the present invention. Specifically, the following is shown.

Brief Description of the Drawings

[0035]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying out the Invention

[0036] Figures 2 and 3 show a thermoelectric module 1 for residual heat use installed in an industrial pipe 3. The exploded view of Figure 1 can be referred to for an easy understanding of its components. Also, for the improvement of the understanding of the readers of the present invention, a cross-sectional view of the thermoelectric module 1 is shown in Figure 4, with different lines depicting the flow of temperature exchange drawn on it.

[0037] The aforementioned thermoelectric module 1 includes a heat collection means 2, an energy generation means 4, and a heat dissipation means 5.

[0038] The heat collection means 2 includes a lower collector 21, an upper collector 22, and a fastener 23. The lower heat collector 21 is formed by an essentially arch-shaped piece of thermally conductive material, as a result of which its inner surface comes into contact with the heat source outside the thermoelectric module 1, in this case the surface of the pipe 3. The arch-shaped shape of the lower collector 21 facilitates its coupling with the shape of the pipe 3. The upper heat collector 22 is formed by an essentially pyramidal piece in the shape of an inverted cone made of a thermally conductive material that comes into contact with the lower base of the lower collector 21 and the heat dissipation means 5 on its upper surface. The fastener 23 firmly fixes the aforementioned lower collector 21, and thus the entire thermoelectric module 1, to the pipe 3. The pipe 3 is, in this example, an external heat source used for the module to convert into electrical energy. The fastener 23 in the example of the drawing consists of two straps that surround the pipe 3 and are attached to the lower collector 21. It is contemplated that the aforementioned straps of the fastener 23, or similar ones, may have tightening means or locking means regardless of the presence or absence of fixing means such as a padlock.

[0039] The energy generation means 4 having the mission of converting the acquired heat into electrical energy includes a thermoelectric generator 41 disposed between the upper collector 22 and the heat dissipation means 5.

[0040] The heat dissipation means 5 includes a base 51 coupled to the upper collector 22 and a heat sink 51 having a plurality of fins 52 for absorbing the maximum possible heat coming from the thermoelectric generator 41 coupled via the base 51. To reduce the thermal resistance due to contact between the main elements constituting this thermoelectric module 1, a component 25 made of a thermally conductive material (in this case, tin or the like, in the shape of a washer) is disposed between the lower collector 21 and the upper collector 22 of the heat collection means 2, and another component 55 made of a thermally conductive material (made of tin and in the shape of a washer) is disposed between the heat sink 52 and the base 51 of the heat dissipation means 5.

[0041] In this case, the thermoelectric generator 41 is a heat generation cell 41' of the TEG Peltier cell type, whose high-temperature surface contacts the upper collector, while its low-temperature surface contacts the base of the dissipation means 5, thus conducting thermal energy between the pipe 3 and the radiator 52, and thus, using this temperature difference, it can generate electrical energy.

[0042] To promote more rapid removal of excess heat by natural convection, the heat sink 52 of the heat dissipation means 5 is provided with a plurality of vertical fins 53 having branches that increase the contact surface with the environment, in this case air. Thus, in this way, the captured heat flow and exchange are achieved (see Figure 4), which is used by the thermoelectric generator 41 to generate electricity through the said temperature difference and it reaches the electronic box 9, and the electronic box 9 has the role of managing the generated electrical energy for different uses or applications.

[0043] To concentrate the flow from the larger surface of the upper collector 22 to the smaller surface of the heat sink 52, the base 51 of the dissipation means 5 is formed by an inverted cone. That is, these shapes prevent the collector from being cooled at its edges, which could lead to poor heat conduction and cause performance degradation or malfunction, and prevent the heat sink and the electronic box from being heated more than necessary by convection.

[0044] The thermoelectric module 1 of the present embodiment includes an elastomer 90 surrounding a thermoelectric generator 41 between the upper collector 22 of the collection means 2 and the base 51 of the dissipation means. The function of this elastomer 90 is to seal the cell 41' from external agents, which also functions as an insulator to prevent thermal bridges and ultimately functions as a structural component for arranging the aforementioned cell 41'.

[0045] The thermoelectric module 1 is contemplated to have a role of managing electrical energy coming from the thermoelectric generator 41 and to include an electronic box 9 for accommodating an electronic device capable of acquiring data from a sensor and transmitting the data using long-distance wireless communication.

[0046] To understand the thermal operation of the aforementioned thermoelectric module 1, the heat flow is represented by different arrows in FIG. 4, and for ease of understanding, the heat flow is represented in red and the cooling flow is represented in blue. Accordingly, the following sequence and situations can be observed.

[0047] a) The pipe functions as a heat source, b) This heat is captured along the contact points of the lower collector, and the heat is transmitted to the temperature collection medium at its bottom, c) The heat flow distribution, d) The high-temperature side (Tho) of the Peltier cell is heated, e) Heat dissipation to the environment, involving heat exchange with the air surrounding the thermoelectric module 1, f) The concentration of the heat flow towards the surface in contact with the heat sink, g) Heat exchange conduction between the pipe with the collection medium and the dissipation medium, due to the cooling of the low-temperature surface (Tcol) of the Peltier cell, h) A cable path with power. According to the thermoelectric principle, the temperature difference is converted into electrical energy. i) A structural element for fixing the electronic box. j) The electronic box, and k) A sealing gasket for waterproof and heat insulation protection.

[0048] By way of the examples described herein of the preferred embodiments, the objects of the present invention are more particularly understood, whereby a new thermoelectric module can be provided that improves the coupling to industrial pipes and, for example, can generate sufficient energy to utilize the residual heat of a monitored machine or process to power other electronic devices or industrial sensors. The configurations of the constituent elements described herein, their shapes, and characteristics achieve more optimal heat exchange and improve the overall performance compared to previous versions by the same applicant.

Claims

**Claim 1** A thermoelectric module (1) for the use of residual heat, comprising at least some heat acquisition means (2), some energy generation means (4), and some heat dissipation means (5), and in particular adapted to be installed on an industrial pipe (3), wherein the heat collection means (2) comprises at least one lower heat collector (21), which is essentially formed by an arched piece of heat conductive material adapted to contact the surface of a heat source outside the thermoelectric module on its inner surface, the at least one lower heat collector (21); an upper heat collector (22), which is essentially formed by an inverted pyramid piece of heat conductive material adapted to contact the lower collector at its lower base and the heat dissipation means at its upper surface, the upper heat collector (22); and a fastener (23) adapted to firmly fasten the lower collector to the pipe (3) of the heat source, wherein the energy generation means (4) adapted to convert heat into electrical energy comprises at least one thermoelectric generator (41) disposed between the upper collector (22) and the heat dissipation means (5), wherein the heat dissipation means (5) comprises a base (51) coupled to the upper collector (22), and a heat sink (51) having a plurality of fins (52) for absorbing the maximum possible heat coming from the thermoelectric generator (41) coupled through the base (51), characterized in that, the thermoelectric module (1). **Claim 2** The thermoelectric module (1) according to the preceding claim, characterized in that a component (25) of a heat material is provided between the lower collector (21) and the upper collector (22), which is particularly adapted to reduce the thermal resistance due to contact between the two. **Claim 3** The thermoelectric module (1) according to any one of the preceding claims, characterized in that a component (55) of a heat material is provided between the heat sink (52) and the base (51), which is particularly adapted to reduce the thermal resistance due to contact between the two. **Claim 4** The thermoelectric module (1) according to any one of claims 2 or 3, characterized in that the component (25 and / or 55) is made of a material essentially formed of tin. **Claim 5** The thermoelectric module (1) according to the preceding claim, characterized in that the component (25 and / or 55) has an essentially flat washer shape.

6. The thermoelectric generator (41) is at least one heat generating cell (41'), the high temperature side of the heat generating cell (41') is in contact with the upper collector, while its low temperature side is in contact with the base of the dissipation means, thus conducting heat energy between the high temperature pipe and the thermoelectric generator. The thermoelectric module (1) according to any one of the preceding claims, characterized in that.

7. The heat sink (52) is provided with a plurality of vertical fins (53) having branches that increase the contact surface with the environment, enabling more rapid removal of excess heat by natural convection. The thermoelectric module (1) according to any one of the preceding claims, characterized in that.

8. The base (51) of the dissipation means (5) is formed by an inverted cone adapted to concentrate the flow from the larger surface of the upper collector (22) to the smaller heat sink (52). The thermoelectric module (1) according to any one of the preceding claims, characterized in that.

9. An elastomer (90) is provided between the upper collector (22) of the collection means (2) and the base (51) of the dissipation means (5) and surrounds the thermoelectric generator (41). The thermoelectric module (1) according to any one of the preceding claims, characterized in that.

10. The thermoelectric module (1) according to any one of the preceding claims, characterized in that it comprises an electronic box (9) capable of housing therein an electronic device having a role of managing the electrical energy coming from the thermoelectric generator (41), acquiring data from sensors, and transmitting the data using long-distance wireless communication.

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