WO2013092394A2

WO2013092394A2 - Device for directly generating electrical energy from thermal energy

Info

Publication number: WO2013092394A2
Application number: PCT/EP2012/075443
Authority: WO
Inventors: Evert Houwman; Gregor Luthe; Tobias Stahl
Original assignee: Wind Plus Sonne Gmbh
Priority date: 2011-12-22
Filing date: 2012-12-13
Publication date: 2013-06-27
Also published as: DE102011056877A1; WO2013092394A3; DE102011056877B4

Abstract

The invention relates to a device (1) as per figure 1 for directly generating electrical energy from thermal energy, comprising at least one source of thermal energy (2), at least one heat pipe (3.1), at least one thermoelectric element (4), and at least one heat-dissipating device (5), wherein the heat pipe (3.1) is in thermally conductive contact with the source of thermal energy (2) at one end (3.1.1) of the heat pipe and is in electrically insulating, thermally conductive contact with the hot side (4.1) of the thermoelectric element (4) at the other end (3.1.2) of the heat pipe, and wherein the cold side (4.2) of the thermoelectric element (4) opposite the hot side (4.1) is in electrically insulating, thermally conductive contact (5.1) with the heat-dissipating device (5). The invention further relates to a method for directly generating electrical energy from thermal energy.

Description

Apparatus and method for direct generation of electrical energy from thermal energy

The present invention relates to a new apparatus and method for directly producing electrical energy from thermal energy.

State of the art

Methods and apparatus for directly generating electrical energy from thermal energy utilizing a temperature gradient (Seebeck effect) as well as suitable materials for the manufacture of such devices are known e.g. from US patent US 5,610,366, US patent application US 2010/02299911 A1, international patent application WO 97/44993, German patent application DE 101 12 383 A1 or the company publication of Hi-Z Technology Inc., "Use, Application and Testing of Hi-Z Thermoelectric Modules ", authors: FA Levitt, NB Eisner and JC Bass, known.

These devices are known to have so-called Peltier elements or thermoelectric elements (TEE). Basically, a TEE includes two legs made of different thermoelectric materials having different Seebeck coefficients electrically connected to one another at a pad or in a contact region. An elevated temperature in the contact area compared to the temperature of the other ends of the legs causes an electrical voltage (thermal voltage) between the two thermoelectric materials due to the thermoelectric effect. When the circuit is closed then flows an electric current. A TEE can be made up of several such Peltier elements, which can be shaded in series and / or in parallel to achieve a higher thermoelectric voltage or higher current. In most cases, a combination of both interconnections is used. When connected in series, there is a contact area on both sides of the legs, which must be electrically isolated from the other legs.

The known devices for the direct generation of electrical energy therefore generally comprise at least one TEE which is in thermal contact with a source of thermal energy in its contact region and in thermal contact with a heat absorbing device which removes the incoming thermal energy or with the opposite side otherwise uses. This configuration "source of thermal energy TEE / heat absorbing device" on the other hand, due to the high number of heat sources on the one hand and heat absorbing devices on the other hand, a variety of applications, especially as a self-sufficient, independent of an electrical distributor sources of electrical energy.

The sources of thermal energy are devices as diverse as: photovoltaic cells or solar cells heated by sofartherm; In general, the devices in question have the configuration

"Solar cell / electrically insulating heat-conducting layer / TEE / electrically insulating, heat-conducting layer / heat-absorbing device" (see US patent applications US 2011/0048488 A1 and US 2011/0048489 A1 or US patents US 7,875,795 B2, US 4,106,952 and US 3,956,017), - the waste heat of engine blocks, exhaust systems, flue pipes, flue gas, furnaces or containers with materials that provide thermal energy during phase transformations (see German Patent Application DE 199 46 806 A1, International Patent Applications WO 99/36735 and WO 01 / 80325 A1, the American patent application US 2006/0266404 A1 or the US patents US 6,232,545 B1, US 6,624,349 B1, US6,527,548 B1 and US 6,053,163) or US Pat

Sonnenkolfektoren, in particular flat plate collectors (see the American patent application US2010 / 0300504 A1, the European patent application EP 2 239 187 A1 or the German patent application DE 10 208 009 979 A1, DE 36

19 127 A1 and DE 37 04 559 A1) into consideration. Equally diverse are the heat absorbing devices. They range from river water, seawater or other liquids, air or other gases, Salt melts, cooling fins or heat exchangers up to tube cooling bodies (see the patents cited above).

These known devices for direct generation of electrical energy from thermal energy have the disadvantage that the conduction of the thermal energy from the source of heat to the "hot" side of the TEE and its discharge from the "cold" side of the TEE to the heat absorbing device (heat sink ) may be relatively ineffective, which reduces the efficiency of the known devices. The upper limit of the efficiency of a thermoelectric element that generates electricity namely given by the equation I in the equation I, the variables T _m , T _c and TH mean the mean temperature of the TEE, the temperatures of the hot side and the temperature at the cold Page. Equation I

_ generated electrical energy _

Heat energy absorbs on the hot side c ^ + zr _m ! /: T.

The Carnot efficiency rjc is given by Equation II:

Equation II

¹ H

The efficiency is also severely affected by the thermal resistance between the hot TEE electrode and the heat source with the temperature THH, and the resistance between the cold TEE electrode and the heat dissipation at the temperature Tcc- at the same thermal resistance Ri, the entire thermal Resistance indicated by the equation Iii, where RTEE = thermal resistance of the TEEs.

Equation III Total - 2Rl + RTEE!

This reduces the heat flow through the TEE according to Equations IV and V of

Equation IV

on

Equation V

This reduces the temperature drop across the TEE according to equations Vi and VII of

Equation VI

on

Equation VII

The most important factor influencing the efficiency of the TEE is according to equation VII! the Carnot efficiency. This therefore changes from equation II

Equation VII I

ηο = (THH-TCC) THH on ο - [1 / (1 + 2RI / RTEE)] [(THH-TCC) / THH3-

Thus for 2Ri = O. SRTEE η ₀ is reduced by 31% and for 2Ri = RTEE even by 47%,

The thermal resistance Ri is set according to equation IX from the contact or contact resistance Rhi between the TEE and the thermal conductor at one end, the contact or contact resistance Rh2 between the heat sealer and the Heat sources at the other end and the thermal resistance R _{L of} the heat conductor itself together.

Equation! X

The simplest thermal conductors are metal conductors with a large cross section AL, so that the line resistance according to equation X remains small. In the equation XI ki stands. for the Wärmeleitungszah! of the metallic conductor and L for its length.

Equation X

R _L = k _L / A _L.

Common, inexpensive materials with high k _L values are Cu or Al. So that the line resistance RL remains small enough, the cross section AL should be large.

The thermal contact resistance between solids is calculated according to equation X! determined by the close contact between the materials of the two sides of the contact, where all the influences are summarized in the thermal contact coefficient h _c , and the area A of the contact.

Equation XI

The thermal contact is generally improved, ie h _c increases, with the number of points of contact between the two contact surfaces. For this purpose, the thermal contact can be increased with high pressure by compressing the contact surfaces. Reduced surface roughness, cleaning of the contact surfaces and a surface of high quality and planarity also lead to a certain improvement. Frequently, a thermally highly conductive paste based on polymers containing metal-containing particles is used in order to remove the remaining "heat-dissipation holes" in the process Contact us.

The thermal contact resistance Rh between solids and liquids or gases is determined by the design of the heat sink, the properties of the gases and Liquids and the flow characteristics (forced flow, convection or turbulent or laminar flow) determined.

The disadvantages of using pressure are numerous.

Thus, a complex mechanical structure is necessary to achieve permanently sufficient pressure. In the case of the TEE, the entire assembly then consists of comparatively heavy metal thermal contacts and the TEE itself, which is predominantly made up of ceramic parts. When the hot side of the TEE is heated, the mechanical stresses change due to the different thermal expansion coefficients of the metallic and ceramic materials. This can lead to breakage of the TEE; In any case, the mechanical stresses lead to material fatigue. In addition, the thermal contact changes during heating, because the pressure changes. Applying a thermally conductive paste can only partially solve this problem.

The contact resistance Rh is also lowered by connecting the TEE and the heat conductor directly to each other by means of a soldering or welding connection. Due to the direct metallic compound, the h _c value is very large and thus R _{h is} small. R _h can not be reduced by increasing the contact area because this is limited by the dimensions of the TEE. During welding or soldering, high temperatures are generated which lead to stresses within the material at low operating temperatures. Likewise, the welded or soldered parts can not relax by relative movements against each other. In addition, you can not dismantle the system easily, for example for a repair or a later recycling.

In the US patent application US 2010/0300504 A1, a flat collector is proposed, which has a sun-facing front part with a Sonnenkol! Ektor, ie an absorber of solar energy, a middle part with TEE and a rear part with cooling elements. The solar collector can consist of materials as diverse as metal, cement, concrete, bricks, porcelain, ceramics or plastic. In addition, the solar panel can still be covered with a transparent material to use the greenhouse effect. To improve the conduction of the thermal energy to and from the individual parts, they are joined under pressure by fasteners. As is known, however, occur in such solar panels temperature differences between the front and the rear side of up to 400 ° C. However, since materials of different coefficients of thermal expansion are to be joined under duress in the solar vectors known from US 2010/0300504 A1, there is a high risk that the mechanical stresses caused by the high temperature differences and the different coefficients of thermal expansion sooner or later lead to damage which can lead solar panels, which is a major drawback.

In order to overcome the disadvantages associated with the application of pressure, US Pat. No. 6,322,545 B1 proposes a bifurcated electrical network arrangement comprising a terraced substrate, an insulating film, a copper metal layer and thermophotovoltaic cells. which are connected to the copper layer. In order to avoid mechanical stresses caused by different thermal expansion coefficients, materials with similar coefficients of expansion are used for the individual components of the network arrangement. For example, in the case of GaSb cells, Cu / Invar / Cu laminates or AlSiC are used as the substrate material. The disadvantage here is the limited choice of materials.

A heat pipe is a gas-tight component that can be used to transport thermal energy or heat very efficiently from one place to another. It can transport 100 to 1000 times higher thermal energy than a component of the same geometric dimensions made of solid copper. The heat pipe uses the physical effect that very large amounts of energy are converted when evaporating and condensing a liquid. The heat pipe is hollow inside and filled with a small amount of liquid, the "working" liquid. This is under its vapor pressure, which can be well below the atmospheric pressure at low temperatures. The inner wall of the heat pipe can be covered with a capillary structure - comparable to a wick. This capillary structure is saturated with a liquid heat transport medium, the "working" liquid. If energy is supplied at one point of the heat pipe, the "working" liquid from the capillary structure evaporates there. The steam flows in the direction of the temperature gradient and condenses everywhere by releasing the heat of vaporization, where energy is dissipated. The condensate, the liquefied heat transfer medium, is absorbed by the capillary structure, flows back to re-evaporate. It closes a cycle that yearns! circulating very effectively transported thermal energy.

The temperature difference between the evaporation and condensation zone in the heat pipe is very low, so that the heat dissipation can be done isothermally.

Depending on the temperature range used, different "working" liquids are used, such as water in the temperature range of about 170 to 600 ° K, ammonia in the temperature range of about 150 to 170 ° K, mercury in the temperature range of 400 to 800 ° K or lithium or silver in a temperature range above 1000 ° K. Heat pipes can be used, for example, in Peltier element heat pipe cooling systems.

Object of the present invention The object of the present invention was to propose a new apparatus and method for the direct production of electrical energy from thermal energy, which no longer has the disadvantages of the prior art, but the particularly efficient transport of the thermal Allow energy from the energy source to a thermoelectric element (TEE) as well as efficient dissipation of the supplied thermal energy from the TEE to a heat absorbing device. The selection of the materials used to construct the new device should be subject to less or no restrictions with regard to their thermal expansion coefficients. Nevertheless, no or only negligibly small, caused by different thermal expansion coefficients thermal stresses occur in the new device and the new method, all in all, the new device and the new method should have a higher efficiency than the devices and methods of the prior art, The inventive solution Accordingly, the new device (1) for the direct generation of electrical energy from thermal energy has been found which comprises at least one line of thermal energy (2), at least one heat pipe (3.1), at least one thermoelectric element (4) and - at least one heat-dissipating device ( 5), wherein the heat pipe (3.1) with its one end (3.1.1) in thermally conductive contact with the source of thermal energy (2) and with its other end (3.1.2) in electrically insulating, thermally conductive contact with the hot side (4.1) of the thermoelectric element (4) and wherein the hot side (4.1) opposite cold side (4.2) of the thermoelectric element (4) in electrically insulating, thermally conductive contact (5.1) with the heat dissipating device (5).

In the following, the new device for the direct generation of electrical energy from thermal energy is referred to as "device according to the invention".

In addition, the new method of directly producing electrical energy from thermal energy has been found, in which the thermal energy delivered by at least one source of thermal energy (2) by means of at least one heat pipe (3.1) to the hot side (4.1) of at least one thermoelectric element (4) is transported, by the supplied thermal energy in the at least one thermoelectric element (4) an electrical voltage is generated and the remaining supplied thermal energy from the hot side (4.1) opposite cold side (4.2) of the at least one thermoelectric element (4) via an electrically insulating, thermally conductive contact (5.1) of a heat dissipating device (5) is supplied. In the following, the new method for the direct generation of electrical energy from thermal energy is referred to as the "method according to the invention". Advantages of the invention

In view of the prior art, it was surprising and unforeseeable for the skilled person that the object underlying the present invention could be solved by means of the device according to the invention and the method according to the invention.

In particular, it was surprising that the device according to the invention and the method according to the invention no longer had the disadvantages of the prior art, but rather a particularly efficient transport of the thermal energy from the energy source to a thermoelectric element (TEE), as well as the efficient discharge of the remainder thermal energy from the TEE to a heat absorbing device. The selection of the materials used to construct the device according to the invention was subject to less or no restrictions with regard to their thermal expansion coefficients. Nevertheless, in the device according to the invention and in the method according to the invention, there were no or only negligibly small thermal stresses caused by different thermal expansion coefficients.

The device according to the invention also eliminated the problems of thermal contact between the source of thermal energy and the hot surface of the TEE and between the cold surface of the TEE and the heat absorbing device. Thus, in prior art devices, effective thermal contact was ensured only by mechanical pressure. As a result, there was the danger that the known devices were already mechanically damaged during assembly or in the course of their use. In addition, the quality and pianority of the contact surfaces in question had to be set high, otherwise, in particular, the temperature drop between the source of thermal energy and the hot side of the TEE became too high and thereby the efficiency of power generation was lowered.

Overall, the device according to the invention and the method according to the invention have a higher efficiency than the devices and methods of the prior art. The device according to the invention also had the significant advantage that their components could be combined with each other in a wide variety of spatial arrangements. As a result, the device according to the invention could be adapted to a wide variety of spatial and / or thermal conditions in a particularly flexible manner. In particular, the TEE could be arranged as an electrical component separate from heat-dissipating devices containing water or flammable liquids, which made the inventive device and the inventive method particularly safe.

In addition, the apparatus and method of the invention allowed the thermal energy to be concentrated to a few TEEs, thus ensuring that the temperature of the hot side of the TEE was always at or near the optimum range, and thus the efficiency of power generation high remained. Thus, the thermal energy generated on a large area can be concentrated to one or a few TEEs and then redistributed to a large area.

Detailed description of the invention

The device according to the invention serves for the direct generation of electrical energy from thermal energy by means of the Seebeck effect in thermoelectric elements (TEE). The thermal energy can be heat from different sources, in which it is selectively generated or obtained as waste heat that is not used or can not be used.

Thus, as sources of thermal energy come as diverse devices as FiachkoSlektoren, evacuated tube collectors, photovoltaic cells, solar cells, radiators, components of ovens such as fire chambers, steel elements, natural stones, firebricks, furnace roofs, Hypokaustenzüge, stove tiles or smoke vents, underfloor heating, current transformers, the underside of automobiles, Engine blocks, exhaust pipes, flue pipes, flue gas chimneys, tanks containing materials that provide thermal energy during phase transformations, electrical resistors, hot water bags, biogas plants, human and animal bodies, or Sun concentrators, as used for example in concentrator photovoltaics (see the journal photovoitaik, 1 1, 2011, pages 58 to 67) into consideration.

Preferably, the Flachkoliektoren for Soiarthermie include a transparent cover, in particular from Gias, an absorber for the solar energy, in particular of copper, and heat-dissipating devices, in particular tube cooler. The end of the heat pipe is in heat-conducting contact with the back of the absorber. Preferably, the evacuated tube collectors comprise a transparent insulating vacuum tube as an outer envelope, a black absorber layer on the inside of the vacuum tube, a heat pipe, particularly copper, fixed by thermally conductive centering devices and a closure cap, a portion of the heat pipe projecting beyond the closure cap the end of which condenses the working fluid and transfers the thermal energy to heat rejecting devices. But there are also known condenser systems which operate with a liquid flowing therethrough which is heated.

The basic structure of photovoltaic cells or solar cells for the conversion of light into electricity is well known and need not be explained in detail here. Meanwhile, they are available in a variety of configurations. As is known, they can be produced on the basis of inorganic and organic semiconducting materials. When irradiated with sunlight, the solar cells heat up, which is why they can also be used as a source of thermal energy. This is because the conversion of the stray energy into electrical current, i. Energy conversion is not 100% efficient and the residual energy is converted into thermal energy. The sources of thermal energy are in at least one heat pipe in electrically isoiierendem, thermally conductive contact with the hot side of at least one thermoelectric element.

The operating principle has already been described at the beginning. It is essential that, depending on in which temperature range (low, medium, high) is worked, different working fluids can be used, such as water or salt solutions in the temperature range of about 170 to 600 ° K, ammonia in the temperature range of about 150 to 170 ° K, mercury in the temperature range from 400 to 800 ° K or lithium or silver in a temperature range above 1000 ° K.

The walls of the heat pipes can be constructed from a wide variety of materials. For the construction also flexible materials can be used. In addition, the heat pipes can be an integral part of flexible plastic films.

Examples of suitable materials are metals such as titanium, zirconium, Haftnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, rhenium, iron, rhenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, Gold, zinc, cadmium, aluminum, gallium, indium, silicon, germanium, tin and lead and their alloys with each other and / or with other metals and / or non-metals, non-metallic inorganic materials such as ceramics and plastics such as high temperature resistant plastics.

The materials of which the heat pipes are constructed, however, must be gas-tight in the temperature range given by the source of thermal energy, both chemically stable to the working fluid and to the external atmosphere, mechanically and thermally stable and stable in deformation. In addition, the materials should preferably have high thermal conductivity, at least in the areas where the thermal energy is absorbed or delivered, so that the thermal energy of the source can be effectively absorbed and effectively delivered to the hot side of the thermo-electric element. The other areas of the heat pipes need not be thermally conductive, but may be thermally insulating.

The heat pipes can have a great variety of lengths, which are directed in particular according to their intended use and the dimensions of the devices according to the invention. Thus, the lengths can range from a few microns to several meters and more. The heat pipes may have different cross sections such as squares, rectangles and triangles, which may have rounded corners and / or sides, ellipses, ovals or circles. The size of the cross sections can vary widely and also depends on the intended use of the heat pipes and the dimensions of the devices according to the invention. Accordingly, the cross sections may be in the range of a few microns to several centimeters.

In addition, the heat pipes may have different shapes in the longitudinal direction. Thus, they can be rectilinear, curved in the plane one or more times, spatially multiple curved, meandering or spiraling.

The heat pipes can still be coated after shaping to protect them from mechanical, chemical and / or thermal effects. Examples of suitable coating materials are thermally and / or curable with actinic radiation such as UV radiation or electron radiation, pigmented or non-pigmented powder coatings or water-based or solvent-based liquid coatings).

The capillary structure with wicking on the inside of the walls can also be made of a variety of materials. Essential for their selection are the temperature range given by the source of the thermal energy and the stability with respect to the working liquid. In addition, contact between the capillary structure and the walls should not cause corrosion under the influence of the working fluid. The person skilled in the art can therefore select the materials on the basis of the property profiles known to him.

The Kapiliarstruktur can be constructed of nanoparticles, fiber materials or nano- or microporous materials with appropriately sized pore sizes. In addition, the wicking by wire mesh, such as copper wire mesh or electrically non-conductive wire mesh and fiber bundles, such as ceramic, glass or high temperature resistant plastics, are generated inside the heat pipes. Furthermore, the wicking effect can also be generated by surface structures of elevations and depressions such as grooves, columns, spheres or cups on the inner walls of the heat pipes. The capillary structure with wicking can also be retrofitted. Examples of suitable methods are crystallization or precipitation mesoporous materials such as zeolites. This is particularly advantageous for the "open embodiment" described below, because in one step, a direct connection to an electrically insulating, thermally conductive, structured surface on the TEE on which the working fluid condenses out can be accomplished.

The end of the heat pipe, which is in thermally conductive contact with the source of thermal energy, need not necessarily be electrically isolated therefrom.

For example, the thermally conductive contact between the end of the heat pipe and the source of thermal energy through solder contacts, welding contacts, flange contacts, electrically and thermally conductive, metal particles containing Kiebschichten, screw, plug and terminal contacts, in which the end of the heat pipe into the source or screwed to the source of thermal energy, or plugged or plugged or clamped, pressure contacts, in which the end of the heat pipe is pressed by means of suitable devices to the source of thermal energy, hergesteilt. The heat-conducting contact can also be further improved by optionally containing metal particles Wärmeleitpasten.

In the case of sources of thermal energy that generate or use electrical power such as photovoltaic cells or solar cells, generators, electric motors and resistors, it is recommended that the contact between the end of the heat pipe and the source of thermal energy is also electrically insulating. Such insulation can be ensured, for example, by heatable ceramic layers, plastic layers or layers of aluminum oxide, aluminum nitride or silicon nitride. These layers can be applied to the respective surfaces to be converted, for example by sputtering, or applied as wafers. In the case of the sheet-like photovoltaic cells or solar cells, these heat-conductive layers are applied to the side of the cells facing away from the sun. On the other hand, it is imperative that the contact of the other end of the heat pipe with the hot side of the thermoelectric element is electrically insulating. The hot side of a thermoelectric element is the side that absorbs the thermal energy. On both sides of the TEE is also the contact area, in which the two different thermoelectric materials of the thermoelectric element electrically conductively connected to each other. The TEE may be electrically conductively connected to at least one other TEE. However, 100 or more such TEEs can also be connected in parallel and / or in series. The contact of the heat pipe with the hot side of the thermoelectric element is made by a suitable contact device. The selection of the materials for the construction of the contact device depends in particular on the temperature range predetermined by the source of the thermal energy. Preferably, the contact device comprises heat-conducting solder contacts, welding contacts, Fianschkontakte, adhesive layers, screw, plug and terminal contacts, in which the end of the heat pipe in or on located on the hot side corresponding operations on or screwed, plugged or on or is clamped. The thermal conductivity can be further improved by the use of thermal pastes, for example thermal pastes based on silicones.

If this contact device are still electrically conductive, the contact device comprises the above-described electrically insulating, heat-conducting layers. These layers are located directly on the hot side of the TEE. In general, they only need a few nuclear facilities to be strong. In order to enable soldering and welding, the heat-conductive insulating layers are covered on their outside with a thin metal layer. A particularly advantageous arrangement of this kind can be made by applying a metal oxide layer which gradually turns into a metal layer.

The electrically insulating, thermally conductive contact can also be designed so that the hot side is in direct contact with the interior of the heat pipe, so that the working liquid condenses directly on the hot side and the thermal energy is transmitted directly. In the following, this embodiment will be referred to as an "open embodiment". In this open embodiment, the TEE itself forms the end of the heat pipe. In the open embodiment, the condensing tone of the working fluid and the transfer of thermal energy can be determined by means of a structured surface on the hot side, which is in direct contact with the inside of the heat pipe, can be further improved. The structured surface may be composed of nanoporous or microporous materials, nanoparticles, groove structures, pyramids, columns, wells, spheres, etc. If the structured surface is still electrically conductive, it is electrically insulated from the hot side of the TEE by one of the above-described electrically insulating, thermally conductive layers.

The return of the condensed working liquid to the other end, i. the end in contact with the source of thermal energy, the heat pipe can be made by gravity. For this, the heat pipe must be arranged with a tilt or vertically.

The return can also be due to the wicking of inserted wire mesh and fiber bundles, as described above, take place. These wire meshes and fiber bundles are arranged to be in direct contact with the condensed working liquid. In this embodiment, the heat pipe can be arranged arbitrarily spatially.

In the open embodiment, the contact device further comprises a gas-tight, adherent, electrically insulating connection between the wall of the heat pipes and the hot side of the TEE. This connection does not have to be heat-conducting. The connections are preferably solder contacts or welding contacts, which are electrically insulated to the hot side in the manner described above, or electrically insulating, high temperature resistant adhesive layers.

These connections may have different shapes depending on the arrangement of the heat pipes and depending on the outer shape of the TEE. Preferably, the compounds are rectangular, square or polygonal, such as hexagonal, when the TEEs have a rectangular, square or polygonal surface. Preferably, the compounds are round or oval, for example elliptical, when the TEEs have a round or oval surface. In addition, the connection of the planarity of the surface of the TEE may be adapted, for example, if it is bent outwards or inwards and / or has a regular or not regular roughness. This can be guaranteed will be that almost the entire surface of the TEE is used for the transmission of thermal energy.

The above applies mutatis mutandis to the electrically insulating, heat-conducting compounds in the embodiments of the device according to the invention, in which closed heat pipes are used.

In general, three temperature ranges are distinguished in the operation of TEE low temperature range, i. Temperatures up to 250 ° C,

Medium temperature range, i. Temperatures up to 600 ° C and

High temperature range, i. Temperatures up to 1000 ° C.

Depending on the work in soft Temperaturberetch, different materials are used in the device according to the invention. The choice can be made by a person skilled in the art on the basis of the known chemical and physical properties of the materials.

The legs of the TEE that are brought into electrical contact with each other are selected by their figure-of-merit according to Equation XII.

Equation XII

Z = σα ² / Λ.

In equation XII, α stands for the Seebeck coefficient, σ is the electrical conductivity, and λ is the thermal conductivity of the material in question.

Preferably, p- and n-doped semiconductor materials are used.

Examples of well-suited semiconductor materials for the low temperature range are bismuth teturide alloys (Bi ₂ Te3).

An example of a well-suited semiconductor material for the mid-temperature range is lead telluride (PbTe). Examples of well-suited semiconductor materials for the high temperature range are silicon germanium alloys and Zintl alloys.

Further examples of suitable curing materials are disclosed in US patent application US 2010/02291 A1, page 1, paragraphs [0003] to [001 1], or in US patent US 5,610,366, column 2, page 27, to column 3, page 32, known.

Conventional and known, commercially available TEEs can be used in the devices according to the invention. The term "thermoelectric element" in this case comprises a single TEE or an arrangement of several series or parallel connected TEEs in the form of a so-called thermopile.

Examples of suitable TEEs are described in detail in US patent US 5,610,366, US patent application US 2010/02299911 A1, international patent application WO 97/44993, German patent application DE 101 12 383 A1 or the company publication of Hi-Z Technology Inc., " Use, Application and Testing or Hi-Z Termoelectric Modutes ", authors: FA Levitt, NB Eisner and JC Bass.

For example, thermoelectric modules are used in "egggrate" configuration (egg-box configuration), as described, for example, in international patent application WO 97/44993, page 2, last paragraph, page 15, last paragraph, in conjunction with FIGS. 1A to 14 and 27 will be described.

However, other configurations are also possible, such as tubular TEEs with a hot outside and a cold inside.

In the device according to the invention, one or more TEEs can be thermally contacted simultaneously. In the devices according to the invention, the hot side opposite cold side of the TEE is in electrically insulating, thermally conductive contact with a heat-dissipating device. This serves to dissipate and optionally use the remaining supplied thermal energy. Such heat-dissipating devices are often referred to as "heat sinks". In a preferred embodiment, this contact is accomplished by at least one additional heat pipe, hereinafter the further heat pipe is referred to as a "second heat pipe". The second heat pipe is in one of its ends in electrically insulating, thermally conductive contact with the cold side of the TEE and at its other end in heat-conducting contact with the heat-dissipating device.

Preferably, the above-described heat pipes and contact devices are used. Since the heat pipes and cold side contact devices of the TEE are exposed to lower temperatures than those of the hot side of the TEE, materials other than the hot side may be used. The heat-dissipating devices can be of the most varied nature and construction.

In the context of the present invention, inorganic and organic gases such as air, nitrogen, oxygen, noble gases, gaseous carbon dioxide, gaseous ammonia, sulfur hexafluoride, hydrocarbons, fluorinated, chlorinated and / or brominated hydrocarbons or amines; inorganic and organic liquids such as water, salt solutions, ammonia, molten salts, ionic liquids, liquid ammonia, liquid metals and metal alloys, liquid hydrocarbons or liquid fluorinated, chlorinated and / or brominated hydrocarbons, and inorganic and organic sublimable solids such as sublimate, solid carbon dioxide, p Dichlorobenzoi, naphthalene or camphor heat-emitting devices according to the invention. Preferably, the remaining supplied thermal energy is transmitted via cooling fins on the cooling media. Accordingly, cooling fins are heat-dissipating devices in the context of the invention.

Preferably, however, the heat-dissipating devices are devices that allow the use of the residual thermal energy supplied. These are particularly preferably heat exchangers, tube cooling bodies, in particular tube cooling bodies for solar thermal systems, motors, turbines or systems for carrying out the Rankine cycle, in particular the organic Rankine cycle, in which comparatively low-boiling organic liquids are used as the working medium.

In addition, heat radiating radiators and large panel heaters, which can be installed under walls, ceilings or floors in the interior and exterior of buildings, are considered as heat dissipating devices. Devices according to the invention constructed in this way can operate their energy-consuming water circuits and circulation pumps themselves or support them in their operation.

The electric current generated by the TEEs of the devices of the invention can be used for a variety of purposes. So he can support the operation of the devices according to the invention itself, for example, to operate or support the control electronics.

Likewise, the current may assist the operation of the heat dissipating devices that utilize the residual applied thermal energy as well as the operation of their peripherals. As bet games are electrically operated pumps, cooling units that protect the Queilen thermal energy from overheating, and called motors. Likewise, the power can be used to charge electrical storage such as batteries, accumulators and electric storage heaters. Overall, the use of waste heat in this way results in significant energy savings.

The power can also be used for the operation of external electrical equipment of various kinds such as lighting systems, refrigerators and freezers, air conditioners, heat pumps, circulation pumps, consumer electronics, communication devices such as telephones or mobile phones, computers, laptops or iPads In the method according to the invention for direct production From electrical energy from thermal energy, the thermal energy delivered by at least one source of thermal energy is transported by means of at least one heat pipe to the hot side of at least one TEE, wherein an electrical voltage is generated in the TEE. The remaining applied thermal energy is supplied from the cold side of the TEE via an electrically insulating, thermally conductive contact to a heat dissipating device. It is a very particular advantage of the device according to the invention and of the method according to the invention that they can also be operated "reversed". Thus, the heat-rejecting device, such as a water-containing tube cooler or a heat accumulator, can transfer thermal energy to the TEE, ie the cold side now acts as a hot side. The originally hot side of the TEE now releases the thermal energy to the heat pipe or heat pipes as a cold side. With this method, roofs can be heated in winter, for example, to free them from snow loads. The heat pipes then serve as heating elements.

Preferably, the above-described inventive devices are used for the inventive method.

The device 1 according to the invention will be explained below by way of example with reference to FIGS. 1 to 16. Figures 1 to 16 are schematic representations intended to illustrate the principle of the invention. The size ratios must therefore not correspond to the size ratios used in practice. Figure 1 shows the flow diagram of a device 1 according to the invention, wherein the source of thermal energy is connected via a heat pipe to the hot side of a thermoelectric element and the cold side of the TEEs is in electrically insulating, thermally conductive contact with a heat-dissipating device. FIG. 2 shows a detail of a device 1 according to the invention, wherein the one end of the heat pipe is in contact with the hot side of a TEE via a first embodiment of an electrically insulating, heat-conducting contact device. FIG. 3 shows a detail of a device 1 according to the invention, in which one end of the heat pipe is in contact with the hot side of a TEE via a second embodiment of an electrically insulating, heat-conducting contact device. FIG. 4 shows a section of a device 1 according to the invention, wherein the one end of the heat pipe is electrically connected via a third embodiment insulating, thermally conductive contact device with the hot side of a TEE is in contact.

FIG. 5 shows a section of a device 1 according to the invention, in which one end of the heat pipe is in contact with the hot side of two thermoelectric elements via a fourth embodiment of an electrically insulating, heat-conducting contact device.

FIG. 6 shows a detail of a device 1 according to the invention, wherein one end of the heat pipe is in contact with the hot side of two thermoelectric elements via a fifth embodiment of an electrically insulating, heat-conducting contact device.

FIG. 7 shows a device 1 according to the invention, in which the cold side of a TEE is in the middle of a second heat pipe with a heat-dissipating device in an electrically insulating, heat-conducting contact (5.1).

FIG. 8 shows a detail of a device 1 according to the invention, wherein the one end of the second heat pipe is in contact with the cold side of a thermoelectric element via a first embodiment of an electrically insulating, heat-conducting contact device.

FIG. 9 shows a detail of a device 1 according to the invention, wherein the one end of the second heat pipe is in contact with the cold side of a TEE via a second embodiment of an electrically insulating, heat-conducting contact device.

FIG. 10 shows a section of a device 1 according to the invention, in which one end of the second heat pipe is in contact with the cold side of a TEE via a third embodiment of an electrically insulating, heat-conducting contact device.

FIG. 11 shows a detail of a device 1 according to the invention, wherein the one end of the second heat pipe is in contact with the cold two thermoelectric elements via a fourth embodiment of an electrically insulating, heat-conducting contact device. FIG. 12 shows a section of a device 1 according to the invention, wherein the one end of the second heat pipe is in contact with the cold side of two thermoelectric elements via a fifth embodiment of an electrically insulating, heat-conducting contact device.

FIG. 13 shows a section of a device 1 according to the invention in a perspective view. FIG. 13a shows the sectional planes laid by FIG. 3 for the views of FIGS. 13b, 13c and 13d.

FIG. 13b shows the longitudinal section through the side view of the detail of the device 1 according to the invention according to FIG. 13.

FIG. 13c shows the cross section through the detail of the device 1 according to the invention according to FIG. 13.

FIG. 13 d shows the longitudinal section through the view from above onto the detail of the device 1 according to the invention according to FIG. 13.

FIG. 14 shows a detail of a vertical arrangement device 1 according to the invention. FIG. 15 shows a section of a device 1 according to the invention, in which the source of thermal energy is a vacuum tube co-octor.

FIG. 6 shows a detail of a device 1 according to the invention, in which the sources of thermal energy are oven tiles,

In FIGS. 1 to 16, the reference numerals have the following meaning.

1 Device according to the invention 2 source of thermal energy

2.1 Vacuum tube 2.2 absorber layer

2.3 heat-conducting centering devices for the heat pipe 3.1

2.4 Cap

heat pipe

first end of the heat pipe 3.1

second end of the heat pipe 3.1

Wall of the heat pipe 3.1

Capillary structure with wicking second heat pipe

first end of the heat pipe 3.2

second end of the heat pipe 3.2

Wall of the heat pipe 3.2

Wicking capillary structure

4 thermoelectric element

4.1 hot side of the thermoelectric element 4

4.1.1 electrically insulating, heat-conducting contact device

4.1.1.1 electrically insulating, thermally conductive distribution layer

4.1.4.2 Metal layer

4.1.4.3 soldering or welding contact

4.1.2 structured surface cold side of the thermoelectric element 4

electrically insulating, heat-conducting contact device

structured surface

5 heat-dissipating device

5.1 electrically insulating, thermally conductive contact between the cold side

4.2 of the TEE 4 and the heat-dissipating device 5

A-B-A'-B 'plane of the longitudinal section through the side view of the detail of a device 1 according to the invention according to FIG. 13

CD-C'-D 'plane of the cross section through the section of a device 1 according to the invention according to FIG. 13 EF-E'-F 'plane of the section through the top view of the section of a device 1 according to the invention according to FIG. 13

G gravity

h.v solar energy

FIG. 1 shows a flow chart which illustrates the functional principle of the device 1.

A source of thermal energy 2 was electrically insulated, thermally conductively connected to the hot side 4.1 of a TEE 4 via a heat pipe 3.1 shown in longitudinal section with the walls 3.1.3. For this purpose, the end 3.1.1 of the heat pipe was thermally conductively connected to the source of thermal energy 2. The other end

3.1.2 of the heat pipe 3.1 was thermally conductive and electrically insulating connected to the hot side 4.1. In the TEE 4, an electrical voltage was generated by the supplied thermal energy, with the help of which electricity could be generated. The remaining supplied thermal energy was supplied via the cold side 4.2 of the TEE 4 by means of an electrically insulating, thermally conductive contact 5.1 of a heat-dissipating device 5.

In the embodiment of the device 1 according to FIG. 2 (shown is the section of interest from the device 1), the end 3.1.2 of a heat pipe 3.1 (shown in longitudinal section) whose wall 3.1.3 was made of copper has an electrically insulating one , thermally conductive ceramic comprehensive, the end 3.1.3 adapted device 4.1.1 thermally conductively connected to the hot side 4.1 of the TEE 4. As working liquid 3.1 water of a maximum temperature of 250 ° C was used in the heat pipe. The end 3.1.2 was connected to the device 4.1.1 by means of a high temperature resistant adhesive layer (not shown) adherent. The remaining applied thermal energy was supplied via the contact 5.1 of the heat-dissipating device 5 (not shown). In the embodiment of the device 1 according to FIG. 3 (shown is the section of interest from the device 1) there was a direct contact between the hot side 4.1 of the TEE 4 and the interior of the heat pipe 3.1 with the wall

3.1.3 made of copper. As working liquid 3.1 water of a maximum temperature of 250 ° C was used in the heat pipe. The end 3.1.2 of the heat pipe 3.1 was thermally conductively connected to the hot side 4.1 of the TEE 4 via a rectangular, electrically insulating, thermally conductive ceramic device 4.1.1. there included the rectangular device 4.1.1 on its top nor a firmly adhered et alischicht to which the end was 3.1.2 adherent and gas-tight angeiötet. In this open embodiment, the working liquid could condense directly on the hot side 4.1, whereby the heat transfer to the TEE 4 was particularly effective. In addition, because of the rectangular configuration of the device 4.1.1, almost the entire surface of the TEE could be used for thermal energy transfer. The rest of the supplied thermal energy was supplied here via the cold side 4.2 via an electrically insulating, heat-conducting contact 5.1 of the heat-dissipating device 5 (not shown).

The embodiment of the device 1 according to FIG. 4 (shown is the section of interest from the device 1) corresponded to the embodiment according to FIG. 3, except that a structured surface 4.1.2 was still arranged on the hot side 4.1. The structured surface 4.1.2 was formed by thermally conductive grooves made of copper. The thermally conductive grooves were electrically insulated from the hot side 4.1 by a few atomic layers of insulating oxide layer (not shown).

The embodiment of the device 1 according to FIG. 5 (shown is the section of interest from the device 1) has a heat pipe 3.1 (shown in longitudinal section) with a wall 3.1.3 made of copper and with water having a maximum temperature of 250 ° C. as a working liquid on. Its end 3.1.2 was as in the open embodiment of Figure 3 with an electrically insulating, heat-conductive contact device 4.1.1 in the form of a plate of thermally conductive ceramic adhesive and gas-tight connected. The plate 4.1.1 made of thermally conductive ceramic was on its opposite side in heat-conducting contact with the hot side of at least two TEE 4, In this way, through the heat pipe 3.1 supplied thermal energy could be distributed efficiently to several TEE. The remaining supplied thermal energy was also supplied here via the cold side 4.2 of the TEE via electrically insulating, heat-conducting contacts 5.1 of the heat-dissipating device 5 (not shown).

The embodiment of the device 1 according to FIG. 6 (shown is the section of interest from the device 1) corresponds to the embodiment of the device 1 according to FIG. 5, except that on the surface of the plate 4.1.1 made of thermally conductive ceramic there is still a structured surface 4.1. 2 was arranged. The structured Surface 4.1.2 was formed by thermally conductive rivets of copper. This has further increased the efficiency of heat transfer.

FIG. 7 shows a flow chart which illustrates the functional principle of a preferred embodiment of the device 1.

A source of thermal energy 2 was connected via a heat pipe 3.1 shown in longitudinal section with the walls 3.1.3 electrically insulating, wärmeieitend with the hot side 4.1 of a TEEs 4. For this purpose, the end of the heat pipe 3.1.1 thermally conductive and optionally electrically insulating with the source of thermal energy 2 was connected. The other end 3.1.2 of the heat pipe 3.1 was connected to the hot side 4.1 electrically insulating. In the TEE 4, an electrical voltage was generated by the supplied thermal energy, with whose Hiife power could be generated. The remaining supplied thermal energy was connected via the cold side 4.2 of the TEEs 4 by means of a second heat pipe 3.2 with the wall 3.2.3 as an electrically insulating, heat-conducting contact 5.1 with a heat-dissipating device 5. In this case, the end 3.2.1 of the heat pipe with the cold side 4.2 was electrically insulating, thermally conductively connected, and the end 3.2.2 was connected to the heat-dissipating device 5 thermally conductive and optionally electrically insulating. The working liquid of the heat pipe 3.2 was vaporized at its end 3.2.1 by the transferred from the cold side 4.2 residual thermal energy supplied and condensed again at the end of 3.2.2, whereby the electrically insulating, heat-conducting contact 5.1 with the heat-dissipating device 5 closed was transferred and the remaining supplied thermal energy to the device 5 for further use.

In the embodiment of the device 1 according to FIG. 8 (shown is the section of interest from the device 1), the end 3.2.1 of the heat pipe 3.2 (shown in longitudinal section), whose wall 3.2.3 was made of copper, has an electrically insulating, thermally conductive ceramic comprehensive, the end 3.2.1 adapted device 4.2.1 thermally conductively connected to the cold side 4.2 of the TEEs 4. As working liquid, 3.2% of water at a maximum temperature of 250 ° C was used in the heat pipe. The end 3.2.1 was connected to the device 4.2.1 by means of a high temperature resistant adhesive layer (not shown) adherent. The heat pipe 3.1 could with the hot side 4.1 of the TEE 4 in the at previously described embodiments according to the figures 2, 3 or 4 shown manner are connected.

In the embodiment of the device 1 according to FIG. 9 (shown is the section of interest from the device 1) there was direct contact between the cold side 4.2 of the TEE 4 and the interior of the heat pipe 3.2 with the wall 3.2.3 made of copper. As working liquid 3.2 water of a temperature of maximum 250 ° C was used in the heat pipe. The end 3.2.1 of the heat pipe 3.2 was heat-conductively connected to the cold side 4.2 of the TEU 4 via a device 4.2.1 comprising a ring-shaped, electrically insulating, thermally conductive ceramic. In this case, the ring-shaped device 4.2.1 still included on its upper side an adherent bonded metal layer (not shown) to which the end 3.2.1 had been adhesively bonded and gas-tight. In this open embodiment, the working liquid could evaporate directly on the cold side 4.2, whereby the heat transfer to the heat-dissipating device 5 (not shown) was particularly effective. The remaining applied thermal energy was supplied to the heat-dissipating device 5 (not shown). The heat pipe 3.1 could be connected to the hot side 4.1 of the TEE 4 in the manner shown in the embodiments described above according to the figures 2, 3 or 4.

The embodiment of the device 1 according to FIG. 10 (shown is the section of interest from the device 1) corresponded to the embodiment according to FIG. 9, except that a structured surface 4.2.2 was still arranged on the cold side 4.2. The structured surface 4, FIG. 2.2 was formed by thermally conductive grooves made of copper. The thermally conductive grooves 4.2.2 were electrically insulated from the cold side 4.2 by a few atomic layers of insulating oxide layer (not shown). By the thermally conductive grooves 4.2.2, the evaporation rate of the working liquid and thus the efficiency of the transfer of the remaining applied thermal energy to the heat-dissipating device 5 (not shown) could be further increased.

The embodiment of the device 1 according to FIG. 11 (shown is the section of interest from the device 1) has a heat pipe 3.2 (shown in longitudinal section) with a wall 3.2.3 made of copper and with water at a maximum temperature of 250 ° C. as a working liquid on. His end was 3.2.1 as in the open embodiment according to the figure 9 with an electrically insulating, thermally conductive contact device 4,2.1 in the form of a plate made of thermally conductive ceramic adherent and gas-tight. The plate 4.2.1 made of thermally conductive ceramic was on its opposite side in heat-conducting contact with the cold side 4.2 at least two TEE 4. In this way, the remaining supplied thermal energy of several TEE 4 on the heat pipe 3.2 of the heat-dissipating device 5 (not shown ). The supply of the thermal energy from the source 2 to the hot side 4.1 of the TEE was carried out by means of the embodiment according to FIG. 5.

The embodiment of the device 1 according to FIG. 12 (shown is the section of interest from the device 1) corresponded to the embodiment of the device 1 according to FIG. 11 except that a structured surface 4.2.2 on the surface of the plate 4.2.1 was still made thermally conductive ceramic was arranged. The structured surface 4.2.2 was formed by thermally conductive grooves made of copper. In this way, the evaporation rate of the working liquid could be further increased, and the efficiency of transferring the residual supplied thermal energy to the heat-dissipating device 5 (not shown) could be further increased. The embodiment of the device 1 according to FIG. 13 (the section of interest from the device 1 shown) had a heat pipe 3.1 with a wall of copper 3.1.3 and water at a maximum temperature of 250 ° C. as a working liquid. The wall 3.1.3 was coated inside the heat pipe 3.1 with a wicking capillary structure 3.1.4 constructed of a nanoporous material. The capillary structure 3.1.4 served the return transport of the condensed at the end 3.1.2 of the heat pipe 3.1 working liquid to its end 3.1.1 (not shown), where it is re-evaporated by the thermal energy from the source 2 (not shown) supplied thermal energy has been. In the area of its end 3.1.2 day, the heat pipe 3.1 horizontally connected to the hot side 4.1 of a TEE 4 via the contact device 4.1.1 electrically insulating and thermally conductive and adherent and gas-tight. The contact device 4.1.1 comprised a sheet-like soldering contact (not shown), which was insulated from the hot side 4.1 by a strong, electrically insulating oxide layer (not shown) that had a few atomic amounts. FIG. 13a shows the slicing planes AB-A'-B ', CD-C'-D' and EF-E'-F 'produced by the device 1 according to FIG. 13 for producing FIGS. 13b, 13c and 13d. The sectional planes AB-A'-B 'here mean the plane of the longitudinal section through the side view of the detail of a device 1 according to the invention according to FIG. 13,

the plane of the cross section through the section of a device 1 according to the invention according to Figure 13 and

the plane of the section through the top view of the section of a device 1 according to the invention according to FIG. 13.

The sections AB-A'-B 'according to FIG. 13b, CD-C'-D' according to FIG. 13c and EF-E'-F 'according to FIG. 13d show that the device 1 according to FIG was an open embodiment in which the hot side 4.1 of the TEEs 4 was in direct contact with the inside of the heat pipe 3.1 (open embodiment). The heat pipe 3.1 had a wall 3.1.3 made of copper, a capillary structure 3.1.4 with wicking and water of a maximum temperature of 250 ° C as a working liquid. In the area of the opening of the heat pipe 3.1 was on the hot side 4.1 a structured surface 4.1, 2, which was formed by grooves made of thermally conductive ceramic. If the hot side of the TEEs still contained electrically conductive structures, the electrically insulating, heat-conducting contact device 4.1.1 also extended below the structured surface 4.1.2. This increased the evaporation rate of the condensed working fluid and increased the efficiency of transmitting the thermal energy delivered by the source of thermal energy 2 (not shown). The electrically insulating, thermally conductive contact 5.1 of the cold side 4.2 of the TEE 4 with the heat dissipation device 5 (not shown) could be produced as described in the embodiments described above according to FIGS. 8, 9 and 10. Since the grooves 4.1.2 made of thermally conductive ceramics were not in direct contact with the capillary structure 3.1.4 with wicking, so that the condensed working liquid not by capillary forces from the end 3.1.2 of the heat pipe 3.1 for re-evaporation to the end 3.1.1 (not drawn) could be transported away, the device 1 could be operated according to Figure 13 only in inclined or vertical orientation, so that the return transport of the condensing working liquid was carried out by gravity. However, instead of a capillary structure 3.1.4 attached to the inside of the wall 3.13 of the heat pipe 3.1, it was possible to fill up the entire interior of the heat pipe 3.1 with a capillary structure 3.1.4 formed from electrically insulating ceramic fibers, so that a direct contact between the heat pipes 3.1 Grooves 4.1.2 and Kapiliarstruktur 3.1.4 existed. As a result, the condensed working fluid could be transported away by Kapilfarkräfte, which is why this embodiment of the device 1 could be operated in accordance with Figure 13 in any spatial arrangement.

The embodiment of the device 1 according to FIG. 14 (only the section of interest is shown) had on the hot side 4.1 of the TEU 4 a heat pipe 3.1 which, as described in the open embodiment of FIGS. 13 and 13b, 13c and 13d, in FIG electrically insulating, thermally conductive contact with the hot side was 4.1. As in the embodiment of FIG. 13, the heat pipe 3.1 served to transmit the thermal energy delivered by the source of thermal energy 2 (not shown) to the TEE 4. The electrically insulating, thermally conductive contact 5.1 between the cold side 4.2 of the TEU 4 and the heat-dissipating device 5 {not shown) was taken over by the heat pipe 3.2 with the wall 3.2.3 of copper and water of a maximum temperature of 250 ° C as a working liquid. The heat pipe 3.2 was connected in the region of its end 3.2.1 with the cold side 4.2 via the contact device 4.2.1 electrically insulating and thermally conductive. The embodiment of the heat pipe 3.2 and its contact with the cold side 4.2 corresponded exactly to the open embodiment of Figures 13 and 13b, 13c and 13d. This can be illustrated in a simple manner, if in FIG. 13b the reference numbers relating to the heat pipe 3.1 and the hot side 4.1 are replaced by the reference numbers referring to the heat pipe 3.2 and to the cold side 4.2. The reference numerals correspond to each other as follows: 3.1 = 3.2,

3.1 »2 3.2, i

3.1.3 = 3.2.3,

3.1.4 = 3.2.4,

4.1 = 4.2,

4.1.1 = 4.2.1 and

4.1.2 = 4.2.2. In the open embodiment of Figure 14, the grooves 4.1.2 and 4.2.2 of thermally conductive ceramic were not in direct contact with the capillary structures 3.1.4 and 3.2.4 with wicking. Therefore, the condensed working liquid could not be transported away by capillary forces from the end 3.1.2 of the heat pipe 3.1 to the re-evaporation to the end 3.1.1 (not shown). The device 1 according to FIG. 14 could therefore only be operated in a vertical orientation, so that the return transport of the condensed working liquid in the heat pipe 3.1 was effected by gravity.

In contrast, the working liquid condensed at the end 3.2.2 of the heat pipe 3.2 (not shown) could be transported back to the end 3.2.1 via the capillary structure 3.2.4 for evaporation, so that the heat pipe 3.2 could be spatially arbitrarily aligned.

However, it was also possible in the embodiment according to Figure 14, instead of a mounted on the inside of the wall 3.1.3 of the heat pipe 3.1 capillary 3.1.4 fill the entire interior of the heat pipe 3.1 with a formed of electrically insulating ceramic fibers capillary 3.1.4, so that there was a direct contact between the grooves 4.1.2 and the Kapiilarstruktur 3.1.4. As a result, the condensed working liquid could be transported away by capillary forces, which is why this embodiment of the device 1 according to FIG. 14 could be operated in any desired spatial arrangement. The embodiment of the device 1 according to FIG. 15 has a vacuum tube collector as the source of the thermal energy 2. The vacuum tube co-former 2 comprised a vacuum tube 2.1 as a thermally insulating jacket. On its inside was a black absorber layer 2.2 for the solar energy hv attached. The absorber layer 2.2 was thermally and mechanically connected to the heat pipe 3.1 via heat-conducting centering devices 2.3. The interior of the vacuum tube collector 2 was closed by the cap 2.4. The heat pipe 3.1 had a wall 3.1.3 made of copper, on the inside of the wall 3.1.3 a capillary structure 3.1.4 with wicking and water of a maximum temperature of 250 ° C as working liquid. The over the cap 2.4 protruding part of the heat pipe 3.1 was connected by means of the contact device 4.1.1 with the hot side 4.1 of the TEEs electrically insulating and thermally conductive. The Contacting device 4.1, 1 comprised a soldering contact 4.1.1.3, a metal layer 4.1.1.2 and an electrically insulating, heat-conducting body (4.1.1.1 made of ceramic.) The metal layer 4.1.1.2 was adhesively bonded to the distributor layer 4.1.1.1 Insulating, thermally conductive contact 5.1 of the cold side 4.2 of the TEE 4 with the heat dissipating device 5 (not shown) could, as described in the embodiments described above according to Figures 8 to 12, are prepared.

In the embodiment of the device 1 according to the invention according to FIG. 16 (only the section of interest is shown), the source of the thermal energy 2 comprised several (here four) oven tiles. These had on their back each a meandering heat pipe 3.1 with the ends 3.1. and 3.1.2 on. The heat pipes 3.1 were connected at their ends 3.1.2 with the hot side 4.1 of a TEE electrically insulating and thermally conductive. The contact could, as described in the embodiments according to Figures 2 to 6, are produced. The electrically insulating, thermally conductive contact 5.1 of the cold side 4.2 of the TEEs 4 with the heat-dissipating device 5 (not shown) could, as described in the embodiments described above according to Figures 8 to 12, are prepared. The devices according to the invention, in particular the devices 1 according to FIGS. 1 to 16, have numerous surprising advantages.

Thus, the temperature drop in a device 1 was almost completely across the TEE 4. That is, the temperature of the hot side 4.1 of the TEEs 4 was equal to or nearly equal to the temperature of the heat source or the source of thermal energy 2, so that the condition T _H = T _{HH was} fulfilled. The same applied to the cold side 4.2, so that the condition Tc = Tcc was also fulfilled. The line resistance RL was equal to or nearly equal to 0. Thus, all the thermal energy was available for conversion to electrical power. This increased the yield of electrical energy because the Carnot efficiency r \ _{c was} maximal (see equation il).

Instead of having to clamp a conventional massive metathic heat conductor on the TEE 4, the TEEs could now be provided directly with thermally highly conductive, structured surfaces 4.1.2 such as layers of nanoparticles or groove-like heat exchangers, on which the hot side 4.1 of the TEE 4 Condensation and on the cold side 4.2 of the TEE 4 the evaporation of the working liquid took place. Because the rilies or the nanoparticles! 4.1.2 was not a massive system, there were no problems with different coefficients of expansion. Since the housings of the heat pipes 3.1 and 3.2 were hollow, they could be formed to exert only small mechanical forces on the TEE 4, and therefore the resulting mechanical stresses and thus material fatigue could be minimized.

In addition, metallic heat exchangers 4.1.2 could be soldered directly to the surfaces 4.1 and 4.2 of the TEE 4, whereby the contact resistance could be further reduced. This opens up further new possibilities for the optimization of the devices according to the invention.

Since the line resistance R _{L of} the heat pipes 3.1 and 3.2 could be practically neglected, it was no longer dependent on the immediate spatial proximity of the sources of thermal energy 2 and TEE 4 on the one hand and the heat-dissipating devices 5 and TEE 4 on the other hand, but the TEE could be mounted in the devices 1 to structurally favorable Stelien. Thus, the TEEs 4 as electrical components could be better separated from any liquids present in the heat-dissipating devices 5. As a result, the safety of the devices 1 could be significantly increased. This was particularly important in the case of electrically conductive liquids such as water in order to avoid grounding of the device 1. In addition, the maintenance and cleaning of the fluid channel of such heat dissipating devices 5 as well as the associated electrical systems has been simplified. Further advantages and novel design possibilities arise for the devices 1 through the use of flexible heat pipes 3.1 and 3.2. In particular, the heat pipes could still be coated with suitable coating materials after their shaping. Because of the excellent thermal conductivity of the heat pipes 3.1 and 3.2, the devices 1 could be made much lighter and smaller and thus cheaper than prior art devices with comparable thermal and electrical performance. The thermal insulation of the components of the devices 1 and the devices 1 as a whole could be significantly simplified because of all these advantages. Not least, the use of hollow components such as the heat pipes and 3.1 and 3.2, the occurrence of thermal stresses in the device 1 could be avoided.

Overall, the use of heat pipes 3.1 and 3.2 in the devices brought numerous technical and thus financial benefits that compensated for the higher cost of the heat pipes 3.1 and 3.2 by far. In addition, the various sizes and models of heat pipes 3.1 and 3.2 were and are commercially available, which simplifies the implementation of the devices 1.

Claims

claims

1. Device (1) for the direct production of electrical energy from thermal energy, comprising at least one source of thermal energy at least one heat pipe (3.1), - at least one thermoelectric element (4) and at least one heat-dissipating device (5), wherein the heat pipe ( 3.1) with its one end (3.1.1) in thermally conductive contact with the source of thermal energy (2) and with its other end (3.1.2) in electrically insulating, thermally conductive contact with the hot side (4.1) of the thermoelectric element (4 ) and wherein the hot side (4.1) opposite cold side (4.2) of the thermoelectric element (4) in electrically insulating, heat-conducting contact (5.1) with the heat-dissipating device (5).

Device (1) according to claim 1, characterized in that at least one second heat pipe (3.2) comprises, wherein the second heat pipe (3.2) with its one end (3.2.1) in electrically insulating, thermally conductive contact with the hot side (4.1 ) opposite cold side (4.2) of the thermoelectric element

(4) and with its other end (3.2.

2) is in heat-conducting contact with the heat dissipating device (5), so that the contact (5.1) is accomplished.

3. Device (1) according to claim 1 or 2, characterized in that the sources of thermal energy (2) flat plate collectors, Vakuumrohrenko! Lectors, photovoltaic cells, solar cells, radiators, components of ovens underfloor heating, current transformers, underside of automobiles, engine blocks, exhausts, flue pipes, flue gas stacks, containers with materials that provide thermal energy during phase transformations, electrical resistors, hot water bags, biogas plants, human and animal bodies or

Solar concentrators are.

4. Device (1) according to one of claims 1 to 3, characterized in that the end (3.1.2) of the heat pipe (3.1) via an electrically insulating, heat-conducting contact device (4.1.1) with the hot side (4.1) of thermoelectric element (4) is in contact.

5. Device (1) according to claim 4, characterized in that in the region of the contact device (4.1.1) on the surface of the hot side (4.1) or the contact device (4.1.1) itself a structured surface (4.1.2) located in direct contact with the interior of the heat pipe (3.1) and its working fluid.

6. Device (1) according to one of claims 1 to 5, characterized in that the end (3,1.2) of the heat pipe (3.1) via a contact device (4.1.1) with the hot side of at least two thermoelectric elements (4) in electrically insulating, thermally conductive contact is.

7. Device (1) according to one of claims 1 to 6, characterized in that at least two thermoelectric elements (4) are joined together to form a thermopile.

8. Device (1) according to one of claims 1 to 7, characterized in that the heat-dissipating devices (5) inorganic and organic gases, inorganic and organic Flüssigkesten, inorganic and organic sublimable solids, cooling fins, heat exchangers, tube heat sinks, motors, turbines, Devices for performing the Rankine cycle, heat radiating radiators and large surface heating are.

9. Device (1) according to one of claims 3 to 8, characterized in that the inorganic and organic gases include air, nitrogen, oxygen, noble gases, Carbon dioxide, gaseous ammonia, sulfur hexafluoride, hydrocarbons, fluorinated, chlorinated and / or brominated hydrocarbons or amines; the inorganic and organic liquids, water, salt solutions, Saizschmelzen, ionic liquid chains, liquid ammonia, liquid metals and metal alloys, liquid hydrocarbons or liquid fluorinated, chlorinated and / or brominated hydrocarbons and the inorganic and organic sublimable solids sublimate, solid carbon dioxide, p-dichlorobenzene , Naphthalene or camphor; and that the components of furnaces are fire chambers, steel elements, natural stones, firebricks, furnace roofs, hypocausal pulls, oven tiles or smoke vents.

Device (1) according to one of claims 2 to 9, characterized in that the end (3.2.1) of the heat pipe (3.2) via an electrically insulating, heat-conducting contact device (4.2.1) with the cold side (4.2) of the thermoelectric element is in contact,

Device (1) according to claim 10, characterized in that on the surface of the cold side (4.2) or the contact device (4.2.1) is a structured surface (4.2.2), with the interior of the heat pipe (3.2) and whose working fluid is in direct contact.

Device (1) according to one of claims 2 to 11, characterized in that the end (3.2.1) of the heat pipe (3.2) via a contact device (4.1.1) with the cold side of at least two thermoelectric elements (4) in electrically insulating , thermally conductive contact stands.

Device (1) according to one of claims 2 to 12, characterized in that at least two thermoelectric elements (4) are joined together to form a thermopile.

Method for the direct production of electrical energy from thermal energy, characterized in that the thermal energy delivered by at least one source of thermal energy (2) is conveyed to the hot side (4.1) of at least one thermoelectric element (4) by means of at least one heat pipe (3.1). is transported, by the supplied thermal energy in the at least one thermoelectric element (4) an electrical voltage is generated and the remaining applied thermal energy from the hot side opposite cold side (4.2) of the at least one thermoelectric element (4) via an electrically insulating, thermally conductive contact (5.1) device (5) is supplied.

A method according to claim 13, characterized in that a device (1) according to one of claims 1 to 13 is used.