DE102010030566A1 - Solar heating device for use as thermo-solar device for heating liquid, has concentrator changed from spherical shape into parabolic shape, where absorber medium exhibits sectional and/or contact points with caustic curve of concentrator - Google Patents

Abstract

The device (100) has a concentrator (10) i.e. groove or trough-shaped mirror, changed from a spherical shape into a slightly parabolic shape. An absorber medium is located within a caustic curve of the concentrator. The absorber medium exhibits a sectional point and/or a contact point with the caustic curve of the concentrator. The absorber medium flows through a liquid tube (20) and heated by concentration of incident light by the concentrator. The tube is attached to a glass plate, acryl glass plate or Plexiglas(RTM: light, transparent, weather-resistant thermoplastic) plate. An independent claim is also included for a solar heating method for heating an absorber medium.

Description

Technical area

The The present invention relates to the technical field of solar thermal energy or Concentrated Solar Power (CSP).

The The present invention particularly relates to a solar thermal device for heating at least one absorber medium, in particular at least a liquid, by means of at least one concentrator, in particular by means of at least one channel or trough-shaped trained mirror.

The The present invention further relates, in particular, to a corresponding Solar thermal process for heating at least one absorber medium, in particular at least one liquid, by means of at least of a concentrator, in particular by means of at least one channel or trough-shaped mirror.

in this connection shall hereinafter be understood by incident light that light caused by the light rays from outside the device, in particular by the sun's rays striking from the outside, is formed.

In However, this relationship is within the scope of the present invention the term light is not only visible to the eye Area of electromagnetic radiation understood in a wavelength range of about 380 nanometers to about 780 nanometers (which corresponds to a frequency of about 789 terahertz down to about 385 terahertz).

• – der I[nfra]R[ot]-Bereich (Wellenlängenbereich bis zu etwa 2.000 Nanometer bzw. Frequenzbereich bis herab zu etwa 150 Terahertz) und
• – der U[ltra]V[iolett]-Bereich (Wellenlängenbereich bis herab zu etwa einem Nanometer bzw. Frequenzbereich bis zu etwa 300 Petahertz).

Rather, the term light is understood to mean the entire, ie also the electromagnetic wavelength or frequency spectrum which is not visible to the eye, in particular

• The I [nfra] R [ot] region (wavelength range up to about 2,000 nanometers or frequency range down to about 150 terahertz) and
• - The U [ltra] V [iolett] range (wavelength range down to about one nanometer or frequency range up to about 300 petahertz).

State of the art

Under Solar thermal or Concentrated Solar Power (CSP) is basically the conversion of solar energy into usable thermal energy Understood. Here, by means of mirrors, for example by means of Parabolic mirrors, focused on the sun, with one as possible high efficiency or the highest possible efficiency sought becomes.

• – auf die Druckschriften DE 28 47 433 A1 , EP 1 970 641 A1 , JP 59 11 93 10 A , WO 90/12989 A1 , WO 2004/025194 A1 , WO 2004/113801 A1 und WO 2008/034423 A2 ,
• – auf die Publikation ”Solaranlagen: Handbuch der thermischen Solarenergienutzung” von Frank Späte/Heinz Ladener, ökobuch-Verlag, 9. Auflage 2007, Seiten 66 und 67 ,
• – auf das Internetangebot unter http://www.powerfromthesun.net/Chapter9/Chapter9new.htm sowie
• – auf das Internetangebot unter http://www-m10.ma.tum.de/~vogel/Diffgeo/Cinderella/Kaustik_1.html

aufmerksam gemacht werden.The technological background of the present invention can be exemplified here

• - on the pamphlets DE 28 47 433 A1 . EP 1 970 641 A1 . JP 59 11 93 10 A . WO 90/12989 A1 . WO 2004/025194 A1 . WO 2004/113801 A1 and WO 2008/034423 A2 .
• - on the publication "Solar Systems: Handbook of Thermal Solar Energy Utilization" by Frank Späte / Heinz Ladener, Ökobuch-Verlag, 9th Edition 2007, pages 66 and 67 .
• - on the Internet offer under http://www.powerfromthesun.net/Chapter9/Chapter9new.htm such as
• - on the Internet offer under http://www-m10.ma.tum.de/~vogel/Diffgeo/Cinderella/Kaustik_1.html

to be made aware.

In the publication DE 25 56 725 A1 a solar energy collector is disclosed, which refers to a cylindrical concentrator with parabolic cross section, wherein in a parabolic mirror basically no caustic occurs. That according to the doctrine of DE 25 56 725 A1 the caustic is not used, is exemplary of their 1 This is because the light concentration in obliquely incident light rays is different there than in the case of a spherical mirror on the center line. In the DE 25 56 725 A1 For example, to effect an angular tolerance for obliquely incident light, defocusing of the parabolic mirror is utilized. The absorber is located as an elliptical tube around the focal point of the parabolic mirror (see. 1 of the DE 25 56 725 A1 ) and is chosen so large that it compensates for the focal point decay of the parabolic mirror with obliquely incident light to a certain angle.

The absorber surface is according to the teaching of DE 25 56 725 A1 now chosen so that their ratio to the mirror opening (receiving surface of the absorber) is 1 to 1.8, that is, the light concentration is 1.8 times. Will now according to 3 of the DE 25 56 725 A1 placed an equilateral triangle around the elliptical absorber tube, so the ratio of absorber surface to receiving surface of 1 to 1.8 reduced to 1 to 1.2, which is no significant concentration of light and the cost of a concentrator in question.

The result is that in the DE 25 56 725 A1 described the technical optics of the concentrator not the behavior of a spherical concentrator with its Kaustik, but a defocusing parabolic concentrator.

From the publication DE 103 58 327 A1 a device for generating energy by means of incident solar radiation is known; according to the teaching of DE 103 58 327 A1 However, the caustic is not used here.

• – die Absorber gemäß der CH 680 166 A5 liegen außerhalb der optisch aktiven Gebiete eines sphärischen Spiegels und haben damit keine Schnittpunkte mit der Kaustikkurve; und
• – die in der CH 680 166 A5 gezeichneten Strahlengänge sind insoweit optisch unzutreffend, als Einfallswinkel gleich Ausfallswinkel auch bei sphärischen Spiegeln gilt.

In the publication CH 680 166 A5 there is disclosed a sunlight receiver in which two zones form (see description column 1, lines 30 to 44, of FIG CH 680 166 A5 ). However, according to the teaching of CH 680 166 A5 both the concentration receiver and the pre-concentration receiver are located outside the caustic curve; this means in detail:

• The absorbers according to CH 680 166 A5 lie outside the optically active regions of a spherical mirror and thus have no points of intersection with the Kaustikkurve; and
• - in the CH 680 166 A5 drawn beam paths are visually inaccurate insofar as the angle of incidence is the same as the angle of reflection for spherical mirrors.

Illustration of the present invention: Task, solution, benefits

outgoing from the disadvantages and shortcomings set out above and in appreciation of the outlined prior art The present invention is based on the object, a solar thermal device as well as a solar thermal process in such a way that in the comparison to the conventional approach a higher efficiency or a higher efficiency is achieved.

These Task is by a solar thermal device with the in the claim 1 specified characteristics and by a solar thermal with solved the features specified in claim 7. advantageous Embodiments and expedient developments The present invention is defined in the subclaims characterized.

In at least one (in contrast to the publication CH 680 166 A5 from the prior art) the caustic use, in particular spherical or approximately spherical, concentrator is at least one in pipes, especially in heat pipes, flowing medium, in particular at least one absorber medium, for example at least one liquid heated by the light concentration.

in this connection is the medium, in particular as at least one absorber element and / or as at least one absorber liquid and / or as at least one absorber material can be formed within the Kaustikkurve, that is in the range of Kaustik arranged so that it coincides with the caustic curve of the concentrator or more common points, especially one or more Intersections and / or one or more touch points, Has.

• – http://de.wikipedia.org/wiki/Kaustik_(Optik) ,
• – das von Carl Ernst Heinrich Grimsehl, Walter Schallreuter und Rudolf Seeliger verfasste ”Lehrbuch der Physik”, Band 3: Optik, Verlag Teubner, 14. Auflage (1962) ,
• – das von Henrik Wann Jensen verfasste Buch ”Realistic Image Synthesis Using Photon Mapping”, Verlag A. K. Peters, Wellesley (Juli 2001) oder
• – das Manuskript zum von Johannes Kofler, Institut für Angewandte Physik der Johannes-Kepler-Universität Linz, am 31. März 2005 gehaltenen Vortrag ”Lichtfokussierung durch Mikrokugeln” ).

In the case of spherical concentrator mirrors, this effect of heating the medium or the liquid by the spherical aberration and the resulting caustics as well as the wandering focus caused by the caustic is supported in a very substantial way (for the phenomenon of caustic see, for example

• - http://de.wikipedia.org/wiki/Kaustik_(Optik) .
• - that from Carl Ernst Heinrich Grimsehl, Walter Schallreuter and Rudolf Seeliger wrote "Textbook of Physics", Volume 3: Optics, Verlag Teubner, 14th Edition (1962) .
• - that from Henrik Wann Jensen authored "Realistic Image Synthesis Using Photon Mapping", published by AK Peters, Wellesley (July 2001) or
• - the manuscript of Johannes Kofler, Institute of Applied Physics, Johannes-Kepler-University Linz, lecture "Light focusing through microspheres" held on March 31, 2005 ).

The Exploiting the caustics of a spherical mirror based on the properties of the concentrating element, namely the spherical mirror with its "wandering" focus, but not on the properties of the absorber element and / or the absorber liquid and / or the absorber material; in this way is an application of the effect of Kaustik a spherical concentrator in thermosol technology possible.

In Appropriately, the (heat conduction) pipes on at least one cover, in particular on at least one (Ab-) cover plate or clamping surface or (upper) surface, For example, on at least one planar and / or transparent (Ab-) cover plate or clamping surface or even closed surface, such as at least one glass plate, acrylic sheet or Plexiglas plate arranged be.

Becomes before the liquid-carrying (heat-conducting) pipes According to a preferred embodiment of the present invention in the direction of the reflected (solar) light at least one refractive, in particular optically transparent, Element, for example at least one prism or at least one (e) Lens (nsystem), such as at least one converging lens, optionally also in combination with at least one diverging lens arranged [→ shifting the position of the (absorber) medium between the focal point and the center of the concentrator], so are the (Wärmeleit-) pipes Conveniently between the focal plane or Focal area or focal point of the mirror body and center of the mirror body.

In a preferred embodiment of the present invention, the refractive element is arranged below the absorber, that is different than for example in the document DE 103 58 327 A1 , ge according to which the lens system is arranged above the absorber. While the lens system of DE 103 58 327 A1 Thus, in order to optimally concentrate the light on the absorber, in the present invention, the tolerance angle of the reflected light across the refractive element can be increased. Thus, in the present invention, a completely different physical effect than in the prior art in the DE 103 58 327 A1 in front.

Also this arrangement in a spherical concentrator is independent from the absorber element and / or from the absorber liquid and / or the absorber material and can therefore in the Thermosolartechnik be applied.

In Particularly preferred embodiment of the present invention the concentrator in cross-section at least approximately spherical or at least approximately spherical in cross-section; In particular, the concentrator in cross section in its outer Border areas of a spherical shape in one, for example approaching or slightly parabolic.

These Deviation from the spherical shape to the parabolic shape is pertinently only so low that this mixed form between spherical and slightly parabolic shape yet shows the caustic effect. By such a configuration remains the focal point is stable, and a gain occurs (only) along the caustic curve, allowing a tracking of the concentrator is not required.

in this connection It should be remembered that the shape of a parabolic mirror at small opening angles well approximated by a spherical mirror shape becomes. A parabolic mirror has no true sense Caustic on, but also creates a burning surface, when the object to be illuminated is mounted below the focal point becomes.

in the In contrast, in the present invention, the Kaustikeffekt a spherical mirror or the mixed form of a spherical-parabolic Mirror used for concentrators.

Of the spherical or spherical parabolic mirrors Here, in a preferred manner, the shape of a groove or a Have spherical cap, wherein the migratory as a result of Kaustikeffekts Focus of the spherical or spherical-parabolic mirror is used for the benefit of the present invention.

Becomes So in a spherical or spherical-parabolic Concentrator mirror whose Kaustik exploited, so is a concentration the incident light without tracking the concentrator possible (so no extra costs for one any mirror tracking arise).

• – ohne Nachführung: Toleranzwinkel von etwa ±zehn Grad oder größer;
• – mit unterstützender (konzentrierender) Optik direkt vor dem photovoltaischem Material: Toleranzwinkel von etwa ±fünfzehn Grad oder größer.

The caustics of the spherical concentrator mirror in this case enables amplification factors up to the order of the geometry factors (where the geometry factor is the ratio of the opening area of the concentrating mirror and thus the maximum light incidence to the area of the absorber used in the mirror):

• - without tracking: tolerance angle of about ± ten degrees or greater;
• - with supporting (concentrating) optics directly in front of the photovoltaic material: tolerance angle of about ± fifteen degrees or greater.

The The present invention further relates to a solar thermal system, comprising at least one solar thermal device according to the set out above and / or working according to the method according to the kind set out above.

advantageously, The solar thermal systems forming the solar thermal system can through at least one common cover be summarized or below be arranged at least one common cover.

The The present invention finally relates to the use at least one solar thermal device according to set forth above and / or at least one solar thermal system according to the manner set out above as a thermo-solar device for efficiently heating at least one absorber medium, in particular at least one liquid.

According to the Principle of the present invention will be the operation of the spherical or spherical-parabolic concentrator in diffused light as a function, in particular by increasing its acceptance or tolerance angle improves regardless of the type of absorber, but depending on the form and arrangement in the concentrator, because that's the acceptance or tolerance angle affected. This is below the acceptance or tolerance angle understood the maximum angle of incidence, in which the radiation can be included.

On the basis of the invention essential fact that the Kaustik the spherical or spherical parabolic concentrator mirror allows a wandering focus of the incident light rays, the acceptance or tolerance of the direction of light incidence can be particularly large especially in diffuse (solar) light, which is particularly in nachführungsfreien Systems is advantageous because then regardless of the specific season-dependent position in the sun always very good Results are achievable.

Brief description of the drawings

As already discussed above, there are various possibilities for embodying and developing the teaching of the present invention in an advantageous manner. For this purpose, reference is made on the one hand to the claim 1 and the claim 7 subordinate claims, on the other hand, further embodiments, features and advantages of the present invention will be described below with reference to 1 to 4 illustrated embodiments explained in more detail.

It shows:

1 a schematic cross-sectional view of a first embodiment of a provided with a cover in the form of a cover plate solar thermal device according to the present invention, which operates according to the method according to the present invention;

2 in a schematic cross-sectional view of a second embodiment of a provided with a cover in the form of a cover plate solar thermal device according to the present invention, which operates according to the method according to the present invention;

3A in a schematic-perspective cross-sectional view of a third embodiment of a provided with a cover in the form of a cover plate solar thermal device according to the present invention, which operates according to the method according to the present invention;

3B in schematic perspective cross-sectional view of an embodiment of a provided with a common cover in the form of a common cover plate solar thermal system according to the present invention with several solar thermal devices 3A ; and

4 in a diagrammatic representation, the relationship between the tolerance angle plotted on the abscissa and the efficiency plotted on the ordinate in diffuse light incidence.

Same or similar embodiments, elements or features are in 1 to 4 provided with identical reference numerals.

Best way to execute of the present invention

As in 1 (= first embodiment) or in 2 (= second embodiment) or in 3A (= third embodiment), the liquid pipes are 20 respectively. 20 ' respectively. 20 '' at the solar thermal device 100 respectively. 100 ' respectively. 100 '' on a glass cover 30 appropriate.

Here are as liquid pipes 20 according to the first embodiment in 1 five rectangular in profile, in particular square, square tubes made of aluminum or copper laterally slightly offset from each other; according to the second embodiment in 2 are as liquid pipes 20 ' two square in profile, in particular square, square tubes made of aluminum arranged side by side; according to the third embodiment in 3A is the liquid pipe 20 '' flat or flat round.

These liquid pipes 20 respectively. 20 ' respectively. 20 '' are within the mirrored for the purpose of reflection of the (sun) light inside, a radius R having concentrator modules or concentrator elements 10 arranged. Here, the liquid pipes 20 respectively. 20 ' respectively. 20 '' be arranged at a distance R / 2 from the dome center M to the caustics of the spherical dome 10 optimally exploit. In certain applications, it is also useful to defocus the absorber means, that is slightly offset to the dome center M to arrange.

So in the tracking-free thermo-solar concentrator 100 (= first embodiment according to 1 ) respectively. 100 ' (= second embodiment according to 2 ) respectively. 100 '' (= third embodiment according to 3A ) the caustics of the spherical mirror (= concentrator modules or concentrator elements 10 ) and the associated traveling focus F of the spherical mirror 10 to use in an optimal way, that can be at least one liquid-carrying pipe 20 respectively. 20 ' respectively. 20 '' emulate the curve of the traveling focal point F with radius R / 2 (see in particular the illustration in FIG 1 according to which the liquid pipes 20 laterally slightly offset from each other along the half radius of the concentrator 10 lined up).

According to the second embodiment 2 is in front of the liquid-carrying pipes 20 ' in the direction of the reflective light, a refractive, optically transparent element 22 arranged in the form of a convex-plan lens; Accordingly, the liquid-carrying pipes 20 ' between the focal plane or focal plane F of the mirror body 10 and center M of the mirror body 10 arranged.

The thermo solar system (= solar thermal system 200 with planar surface 30 ) is in 3B realized as based on the Kaustik, not necessarily nachzuführundes concentrator system for thermovoltaics, in which one of the flat or flat-round heat pipes 20 '' (see third embodiment according to 3A ) flowing liquid heated, for example, evaporated, and the further use, in particular the energy conversion, for example, in a (steam) turbine, is supplied. Alternatively or additionally, a supply to a hot water tank is possible.

In the context of the present invention, such a solar thermal system can be 200 also with liquid-carrying pipes 20 according to the first embodiment (see. 1 ) or with liquid-carrying pipes 20 ' according to the second embodiment (see. 2 ) realize.

In this case with a spherical mirror 10 built concentrator system whose Nachführfreiheit a high acceptance angle of the concentrating element to obliquely incident light radiation. By location and shape of the absorber and by introducing optional additional optical elements, such as lenses (systems), prisms or the like, the acceptance or tolerance angle can be influenced or increased.

4 shows a typical curve for the dependence of the efficiency of the acceptance angle in diffused light, measured with different absorbers. In this case, the reference value for the efficiency value 100 percent is assumed to be a planar, non-concentrating element or module. The curve illustrating the substantially linear relationship between tolerance angle and diffuse light efficiency according to FIG 4 is removable as the efficiency increases with increase in the acceptance or tolerance angle. This high efficiency in diffused light makes the spherical concentrator very attractive.

This property distinguishes the spherical concentrator 10 in a very significant way from purely parabolic concentrators, which have only a very low acceptance or tolerance angle and therefore a relatively low efficiency in diffused light. The increase in efficiency with increase in the acceptance or tolerance angle is the applicable in photovoltaic property of a spherical concentrator, regardless of the absorber element and / or the absorber liquid and / or the absorber material.

As a result, the optional Nachuhrfreiheit the solar thermal device 100 respectively. 100 ' respectively. 100 '' a high acceptance or tolerance angle, which in turn causes good processing of diffused light or scattered light; This effect is also independent of the absorber medium or the absorber agent.

In summary and in contrast to the discussed in the description section above The prior art should be noted that the Kaustik in the present Invention does not compensate for erroneous behavior of a spherical Mirror is, but represents the feature essential to the invention, exploited in the applications described in this invention becomes.

It should be noted that purely parabolic mirrors concentrate the reflected light at their focus and show no causticity. Spherical mirrors focus the reflected light on the caustic curve. Spherical-parabolic concentrator hybrid forms show neither automatically nor generally a Kaustikeffekt, but can only under certain boundary conditions also show a Kaustikeffekt:
If the shape close to the axis is spherical and the off-axis shape is parabolic, no caustic effect occurs. If, on the other hand, the paraxial shape and the off-axis shape are spherical, a caustic effect can be observed, with the off-axis areas of the concentrator being essential for the appearance of the caustic. If there is only a slight deviation from the spherical shape in the direction of a parabolic shape in the area away from the axis, a caustic effect is likewise to be observed.

requirement for the occurrence of the Kaustikeffektes is the dominance the spherical shape in the off-axis areas of the concentrator. Thus, when reference is made in the prior art is on the appearance of caustics, so the shaping must be far away Concentrator areas be described, because otherwise is not ensured that a Kaustik ever occurs.

100

Solar thermal device (= first embodiment according to 1 )

100 '

Solar thermal device (= second embodiment according to 3 )

100 ''

Solar thermal device (= third embodiment according to 3A . 3B )

10

concentrator in particular spherical or spherical-parabolic Concentrator, for example trough-shaped or trough-shaped mirror

20

Pipe, in particular heat pipe, for example, rectangular, such as square, square tube made of aluminum or copper (= first embodiment according to 1 )

20 '

Pipe, in particular heat pipe, for example, rectangular, such as square, square tube made of aluminum (= second embodiment according to 2 )

20 ''

Pipe, in particular heat pipe, for example, flat or flat-round liquid pipe (= third embodiment according to 3A . 3B )

22

refractive, in particular optically transparent element, for example prism or lens (nsystem), such as convex lens, optionally in combination with diverging lens

30

Cover, in particular (Ab-) cover plate or clamping surface or (top) surface, for Example planar and / or transparent (Ab-) cover plate or clamping surface or even closed surface, such as glass plate, Acrylic glass plate or Plexiglas plate

200

Solar thermal system (= third embodiment according to 3B )

F

focus

M

Focus

R

radius

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 2847433 A1 [0008]
• EP 1970641 A1 [0008]
• - JP 59119310 A [0008]
• WO 90/12989 A1 [0008]
• WO 2004/025194 A1 [0008]
• WO 2004/113801 A1 [0008]
• - WO 2008/034423 A2 [0008]
• - DE 2556725 A1 [0009, 0009, 0009, 0009, 0010, 0010, 0011]
• - DE 10358327 A1 [0012, 0012, 0022, 0022, 0022]
• - CH 680166 A5 [0013, 0013, 0013, 0013, 0013, 0016]

Cited non-patent literature

• - "Solar Plants: Handbook of Thermal Solar Energy Utilization" by Frank Späte / Heinz Ladener, Ökobuch-Verlag, 9th Edition 2007, pages 66 and 67 [0008]
• - http://www.powerfromthesun.net/Chapter9/Chapter9new.htm [0008]
• - http://www-m10.ma.tum.de/~vogel/Diffgeo/Cinderella/Kaustik_1.html [0008]
• - http://en.wikipedia.org/wiki/Kaustik_(Optik) [0018]
• - Carl Ernst Heinrich Grimsehl, Walter Schallreuter and Rudolf Seeliger wrote "Lehrbuch der Physik", Volume 3: Optics, Verlag Teubner, 14th Edition (1962) [0018]
• - Henrik Wann Jensen authored book "Realistic Image Synthesis Using Photon Mapping", published by AK Peters, Wellesley (July 2001) [0018]
• - Johannes Kofler, Institute of Applied Physics, Johannes-Kepler-University Linz, lecture "Light focusing by microspheres" held on March 31, 2005 [0018]

Claims (10)

Solar thermal device ( 100 ; 100 '; 100 '' ) for heating at least one absorber medium, in particular at least one liquid, by means of at least one concentrator ( 10 ), in particular by means of at least one trough-shaped or trough-shaped mirror, characterized in that - the absorber medium in the area of action of the caustic of the concentrator ( 10 ), in particular within the caustic curve of the concentrator ( 10 ), for example at least one point of intersection and / or at least one point of contact with the caustic curve of the concentrator ( 10 ), - that the concentrator ( 10 ) is tracking-free due to its caustics and / or the resulting traveling focus, and - that the efficiency of the solar thermal device ( 100 ; 100 '; 100 '' ) at, in particular diffuse, light incident on the concentrator ( 10 ) as a function of the acceptance angle or tolerance angle, in particular as the acceptance angle or tolerance angle increases. Solar thermal device according to claim 1, characterized in that the concentrator ( 10 ) in cross-section at least approximately spherical, in particular at least approximately spherical in cross-section, is, for example in cross-section in its outer edge regions of a spherical shape in one, for example approximately or slightly, parabolic shape passes. Solar thermal device according to claim 1 or 2, characterized by at least one tube containing the absorber medium ( 20 respectively. 20 ' respectively. 20 '' ), in particular by at least one heat pipe, in which the absorber medium flows and by the concentration of the incident light by means of the caustic use concentrator ( 10 ) is heated. Solar thermal device according to at least one of claims 1 to 3, characterized in that the tube ( 20 respectively. 20 ' respectively. 20 '' ) at least one cover ( 30 ), in particular at least one (ab) cover plate or clamping surface or (top) surface, for example at least one planar and / or transparent (cover) cover plate or clamping surface or flat closed surface, such as at least one glass plate, acrylic sheet or Plexiglas plate, is assigned, in particular that the pipe ( 20 respectively. 20 ' respectively. 20 '' ) on the cover ( 30 ), for example attached, is. Solar thermal device according to at least one of claims 1 to 4, characterized in that in the direction of the reflected light in front of the tube ( 20 respectively. 20 ' respectively. 20 '' ) at least one refractive, in particular optically transparent, element ( 22 ), for example at least one prism or at least one lens (nsystem), such as at least one converging lens, optionally also in combination with at least one diverging lens, so that the position of the absorber medium between the focal point and the center of the Concentrator ( 10 ) shifts. Solar thermal system ( 200 ), comprising at least one solar thermal device ( 100 ; 100 '; 100 '' ) according to any one of claims 1 to 5. Solar thermal process for heating at least one absorber medium, in particular at least one liquid, by means of at least one concentrator ( 10 ), in particular by means of at least one trough-shaped or trough-shaped mirror, characterized in that - the absorber medium in the area of action of the caustic of the concentrator ( 10 ), in particular within the caustic curve of the concentrator ( 10 ), for example at least one point of intersection and / or at least one point of contact with the caustic curve of the concentrator ( 10 ), - that the concentrator ( 10 ) is free of tracking due to its caustics and / or the resulting moving focus and - that the efficiency at, in particular diffuse, light incident on the concentrator ( 10 ) as a function of the acceptance angle or tolerance angle, in particular as the acceptance angle or tolerance angle increases. Solar thermal method according to claim 7, characterized in that the absorber medium in at least one tube ( 20 respectively. 20 ' respectively. 20 '' ), in particular in at least one heat pipe, flows and in this pipe ( 20 respectively. 20 ' respectively. 20 '' ) by the concentration of the incident light by means of the caustic-use concentrator ( 10 ) is heated. Solar thermal method according to claim 7 or 8, characterized in that the acceptance angle or tolerance angle by moving the absorber medium from the focal point or from the focal surface of the concentrator ( 10 ) is increased. Use of at least one solar thermal device ( 100 ; 100 '; 100 '' ) according to at least one of claims 1 to 5 and / or at least one solar thermal system ( 200 ) according to claim 6 as a thermal solar device for efficiently heating at least one absorber medium, in particular at least one liquid.