JP5890067B2 - Absorbing structure for trough concentrator - Google Patents

Description

  The present invention relates to an absorbent structure for a trough concentrating plant according to the preamble of claim 1. In the solar thermal power generation plant, the above-mentioned type of trough concentrator is often used.

  Due to the unresolved drawbacks of photovoltaic technology, to date it has not been possible to produce solar electricity using this technology in a way that roughly covers the cost. On the other hand, for some time solar power plants have already produced electricity on an industrial scale at a price close to the normal commercial price for electricity produced by traditional methods compared to photovoltaic technology. .

  In a solar thermal power plant, solar radiation is reflected by the concentrator's concentrator and is focused to a location where high temperatures result. The collected heat can be used to operate a heat engine such as a turbine that drives a generator that produces electrical power.

  The three basic types of solar power plants currently in use are the dish / sterling system, the solar tower plant system and the parabolic trough system.

  Dish / Stirling systems as small units of up to 50 kW per module are not widely used.

  The solar tower plant system has a central absorber for solar light (on the “tower”) installed elevated. Sunlight is reflected towards the absorber by hundreds to thousands of independent mirrors. Thereby, the radiant energy of the sun is concentrated in a point-like manner on the absorber by a number of mirrors, i.e. concentrators, and with the high concentration that can be achieved, the temperature can reach up to 1300 ° C., which is , To help run downstream thermal engines (generally steam or fluid turbine power plants for power generation) effectively. Until now, however, solar tower power plants have not been popular (despite the advantageous high temperatures achievable) due to some technical difficulties inherent in them.

  However, parabolic trough systems are widespread and have a large number of trough concentrators with multiple long concentrators. These long concentrators have a small cross-sectional area, and therefore have no focal point but a focal line, and are essentially different in their design from dish stirling plants and solar tower power plants. These linear concentrators today have a length of 20 m to 150 m and at the same time the width can reach 5 m or more than 10 m. An absorption line for the collected heat (up to about 500 ° C.) is placed at the focal line and the medium flows through the absorption line. This medium absorbs heat and carries it through multiple lines to the machine hall of the power plant. For example, fluids such as thermal oil or superheated steam can be used as the heat transfer medium.

  In Southern California, nine parabolic trough plants together produce nearly 350 MW of output. The power plant “Nevada Solar One” connected to the distribution line in 2007 has trough concentrators with 182,400 curved mirrors, which are located in the area of 140 hectares and have 65 MW Produce output. Power plants Andasol 1-3 have a maximum output of 50 MW (Andasol 3 began to operate at the end of 2011). The maximum efficiency of the entire plant (undersols 1 to 3) is about 20%, and the annual average efficiency is about 15%.

  Inevitably, if an attempt is made to raise the temperature of the heat transfer medium to the maximum possible, e.g. the higher the temperature, the higher the efficiency of converting the heat obtained in the plant into electric power. Even when the solar power plant is for supplying heat for an industrial production process, the highest possible temperature is required.

  For the efficiency of the power plant, the release of heat through the line through which the heat transfer medium circulates, i.e. heat dissipation (heat loss) is taken into account. This heat loss can reach 100 W / m for line lengths up to 100 km, so that the heat loss across the line, including the rate of heat loss in the absorption pipes, is a factor of the overall efficiency of the power plant. Therefore, it becomes an important element that cannot be ignored. From the above information, of course, the total length of the trough concentrator, and thus the total length of the absorption pipe in such a solar thermal power plant, reaches several dozen kilometers, so its heat loss is relative to the efficiency of the entire plant. It cannot be ignored.

  Absorption line configurations are becoming increasingly complex to avoid such heat losses. Therefore, the conventional absorption line which extends over a wide area is composed of a metal pipe covered with glass, and a vacuum is applied between the glass and the metal pipe. A heat transfer medium is placed inside the metal pipe. The outer surface of the metal pipe absorbs incident light in the visible region well, but is coated with a deep emission rate for wavelengths in the infrared region. The surrounding glass pipe protects the metal pipe from cooling by wind and acts as an additional barrier to heat radiation. The surrounding glass wall has the disadvantage of partially reflecting or absorbing incident concentrated solar radiation, so that a reflection-reducing layer is applied to the glass.

  In order to reduce expensive cleaning expenses for such absorption lines and to protect the glass from mechanical damage, the absorption lines can additionally be provided with mechanical protection pipes. This protective pipe must cover the glass pipe and provide an opening for incident solar radiation, while ensuring that the absorption line is protected.

  Such a design is complex and relatively expensive in both production and maintenance.

  International Application Publication No. WO 2010/076668 (herein included in this application as a reference) discloses an absorption pipe that is thermally insulated from the outside and has improved efficiency. The absorption pipe has an elongated thermal aperture for use in a trough concentrator, which is configured as a slot-type aperture and is optimized for heat loss. This thermal opening is reduced over the entire length of the absorption pipe according to the temperature rising along the longitudinal direction of the heat transfer medium flowing in the longitudinal direction through the absorption pipe. Although complex measurements to reduce the thermal aperture are only performed in a relatively small area of the absorption pipe, the thermal radiation increases with the fourth power of the temperature, so the total energy loss of the absorption pipe Most are prevented in this way.

International Publication WO 2010/076668

  An object of the present invention is to provide an absorption structure suitable for the high operating temperature of the heat absorption medium, and this absorption structure has low heat loss and can be manufactured at low cost.

  This object is achieved by an absorbent structure configured according to the features of claim 1.

  Since the heat exchanger structure is provided so that the heat transfer fluid flows through the cross flow, the absorption space can be at least one absorption space at a high temperature of 500 ° C. or higher, for example 650 ° C. or It can be constructed in a way that separates it from the heat exchanger through which the fluid flows at higher temperatures. The heat radiation that passes through the thermal aperture falls to a lesser extent, so that the efficiency of the overall heat exchanger structure is improved.

  The present invention will be described in more detail below with reference to the accompanying drawings.

1 shows a trough concentrator with a conventional type of absorption pipe. 2 shows a part of a first embodiment of an absorbent structure according to the invention. 2 shows a part of a second embodiment of an absorbent structure according to the invention. Fig. 4 shows a part of a third embodiment of an absorbent structure according to the present invention. Fig. 3 shows an absorption space formed by a part of the heat exchanger structure. Fig. 3 shows a cross-sectional view of a trough concentrator with an absorption structure according to the invention having at least two parallel absorption spaces extending longitudinally arranged adjacent to each other. FIG. 7 shows a cross-sectional view of the absorbent structure shown in FIG. 6.

  FIG. 1 shows a trough concentrator 1 of the conventional type. This concentrator 1 has a condensing device 2 whose section is curved radially (parabolic) and reflects incident sunlight. The reflected light beam 4 is collected in a focal region where the absorption pipe 5 is disposed. A heat transfer medium is supplied to the absorption pipe 5 through the supply line 6. The heat transfer medium flows through the absorption pipe 5 and is heated from the inlet temperature TE to the outlet temperature TA during processing and is finally discharged by the drain 7.

  The link 8 shown schematically allows the concentrator 2 to rotate about the axis 10, so that the concentrator 2 can always track the current position of the sun. become able to. The concentrator 2 and the support 11 for the lines 6 and 7 are likewise schematically shown.

  In the graph D, statistical data of the temperature T of the heat transfer medium over the length L of the absorption pipe 5 is qualitatively shown by the curve 15. The temperature curve 15 is essentially linear according to the heat supplied by the reflected light 4 evenly to the absorption pipe 5 over the length L (and thus to the fluid flowing longitudinally through the absorption pipe 5).

  The absorption pipe 5 has a thermal opening. This thermal aperture is not shown so as not to complicate the drawing. The light beam passes through the heat opening and enters the absorption pipe 5 to heat the heat transfer fluid. This type of structure is known to the person skilled in the art from the international publication WO 2010/076668 mentioned above. The interior of the absorption pipe 5 heated by the reflected light 4 (including the heated heat transfer medium) emits heat in the infrared region, and this thermal backside radiation, ie heat re-emission, leaks from the absorption pipe through the thermal opening. This back-emission, or re-emission, increases with the fourth power of the temperature that is effective inside the absorption pipe 5. The curve 16 qualitatively shows the statistical data of the radiation intensity passing through the thermal opening of the absorption pipe 5. In other words, the absorption pipe is continuously losing energy at the fourth power of its internal temperature, so a radically favorable further increase in outlet temperature TA from 500 ° C. to eg 650 ° C. or higher is difficult. . Also, among other reasons, after the length of the absorption pipe 5, there is no further increase in temperature in the fluid, since the back radiation or re-radiation is as high as the illumination by the reflected light 4.

  FIG. 2 schematically shows an absorption structure 20 according to the invention, which can be used in place of the absorption pipe 5 in the trough concentrator 1 (FIG. 1). Only the longitudinal portion 21 of the absorbent structure 20 is shown in the drawing. The drawing shows a longitudinal portion 21 starting from a cross-section at a predetermined position along the longitudinal direction of the absorbent structure 20 up to the next cutting line 22 of the transverse cross-section. The line 22 continues to the end of each trough concentrator. At present, absorption structures longer than 100 m, preferably longer than 150 m and reaching 200 m or more can be realized according to the present invention, corresponding length trough concentrators are allowed, Useful for industrial deployment of trough concentrators in power plants.

  As means for transferring the heat transfer medium, here a supply structure configured as pipelines 23 and 24 and a drain structure configured as pipeline 25 are illustrated, which are the absorption structure. They extend along the length L and are operatively connected to each other by lines configured here as pipelines 26. Here, the pipeline 26 consists of two rows 27 and 28 adjacent to each other to form a heat exchanger structure 29. Column 28 is indicated by the outline of pipelines 26 adjacent to each other, and column 27 is hidden in the drawing.

  Between the rows 27 and 28 of the pipeline 26 constituting the heat exchanger structure 29 is an absorption space 30 for condensing through the thermal aperture 35, ie for the reflected light 4. The wall 36 of the absorption space 30 absorbs heat incident from the light beam 4. Then, as shown in the drawing, the absorbed heat is transferred to the pipeline 26 constituting the heat exchanger structure 29 thermally connected thereto, for example, by direct contact with the wall 36.

  In operation, the heat transfer fluid passes through the inlet portion 38 of the pipelines 23 and 24 that make up the supply structure, into the pipeline 26 that makes up the heat exchanger structure 29, over the length L, at the inlet temperature. Supplied by TE. The fluid is heated in the pipeline 26 to the outlet temperature TA, at which temperature it passes from the outlet portion 39 to the pipeline 25 that forms the drain structure over the length L of the absorbent structure.

In other words, the following can be said.
In one embodiment of the present invention, the supply structure and the drain structure have supply pipes 23 and 24 and a drain pipe 25, and the pipes 23, 24 and 25 extend in parallel with each other and have at least one absorption space. 30 is arranged between the pipes 23, 24 and 25, and the absorption space extends over the length of the pipes 23, 24 and 25.
In one embodiment of the invention, the supply structure has supply lines 23 and 24 for fluid that is heated and supplied to the heat exchanger over its length, said supply line comprising an absorbent structure Extends over the length of the body. Supply lines 23 and 24 are preferably insulated over their length to the opening for heating fluid supply. This is advantageous when the inlet temperature TE is higher than the ambient temperature.
In one embodiment of the present invention, the drain structure has a collecting line 25 that extends the length of the absorption structure and extends from the heat exchanger structure 29 to its length. For the heating fluid supplied to it. The collecting line 25 is thermally insulated over its length up to the heating fluid supply opening.

  The heat transfer fluid flows longitudinally through the absorbent structure as described above, but it has one inlet temperature TE and one has an outlet temperature TA, as indicated by the arrows in the drawing. There are two separate flows. Furthermore, the heat transfer fluid is moved in a direction that intersects the longitudinal direction of the absorbent structure during heat absorption.

  However, in the heat exchanger structure, the fluid flows in a cross flow with respect to the length L, resulting in a fluid having an outlet temperature TA over the entire length L of the absorbent structure 20 in the line 25 of the drain structure. Will exist. This cross-flow principle results in the following effects.

  The absorption space 30 can be designed with regard to its shape by a person skilled in the art with respect to the known light collecting device 2 (see FIG. 1), mainly so that the light rays 4 strike the inlet region of the absorption space 30. In the inlet region close to the thermal opening 35, the fluid has a low temperature close to the inlet temperature TE, and the inlet region will be cooled, so its heat reflection / re-emission will be lowered accordingly.

With respect to re-emission, the thermal opening 35 is located on the opposite side of the inlet region and is not as great as the (far farthest) wall of the absorption space 30 heated to the outlet temperature TA, but overwhelmingly the inlet region. "to see".

The absorption space shown in the drawing is beneficially configured in this respect. It should be noted here that, of course, it is advantageous for all embodiments according to the invention to cover the thermal opening, for example with a glass cover, in order to reduce heat reflection / re-emission. is there.

On the other hand, it is true that the person skilled in the art can expand the heat exchange surface by forming an absorption space (here mainly its height, its depth when viewed from the direction of the ray 4). is there. For example, it is true that the entire inner surface of the pipeline 26 of the heat exchanger structure is used as a heat exchange surface.
Even if only one side of the pipeline 26 is irradiated by radiation 4, the pipeline 26 may be made of a material of the pipeline 26 (for example, a material with good thermal conductivity, such as copper, Due to the heat conduction in a suitable alloy that conducts well, the entire circumference is heated substantially uniformly, so that the heat exchange surface is correspondingly large. A large heat conversion surface is used for efficient heat transfer to the heat transfer fluid, so that the heat conversion surface can be substantially prevented from being locally overheated.

  Here, according to Applicant's insight, in conventional absorption pipes, in the end region (the region where the temperature of the fluid is high), the walls heated by the radiation are often overheated, and as a result, The reflection will be greatly increased. This is due to the fact that in the hot region of conventional absorption pipes and heat exchange walls, it is already in the longitudinal flow of the fluid to be superheated, which itself is strongly heated, so that the fluid passes through the end region. During a short time, the walls of the end regions can no longer be cooled sufficiently. (The mass flow rate must reach its set temperature TA by heat from the reflected radiation 4, and the mass flow rate to be increased can no longer reach this temperature, so it is impossible to increase the mass flow rate. is there.)

  As a result, in the case of the absorbent structure according to the invention, a heat reflection or re-emission corresponding to the outlet temperature TA is used due to the thermal opening 35, and little overheating occurs due to the cross-flow principle. It is true that the absorption structure according to the invention results in less energy loss compared to the conventional absorption pipe as a whole. Thus, an absorbing structure can be realized with virtually any desired length L without adverse effects on thermal radiation. In addition, compared to conventional absorption pipes, due to the shape of the absorption pipes, the heat reflections corresponding to the outlet temperature TA of the relevant part of the wall from which heat is reflected or re-emitted are kept cold.

  According to the present invention, the associated wall region of the absorption pipe located near the heat opening is kept cool and the heat exchange surface overheating is substantially reduced compared to the conventional absorption pipe. The

  In this example, depending on the design of the absorption pipe, it can be added that the physical opening to the absorption space according to FIG. 2 is specified using the term “thermal opening”. The term “thermal aperture” also consists of a physically closed area in the case of other designed absorption spaces, which is designed for the heat path of the concentrated solar radiation. The Here, for example, by applying a suitable coating at the location of the heat radiation, the reflection of heat can be minimized. This type of design is known to those skilled in the art. Nevertheless, at the location of the heat opening, eventually it is inevitable if it is impossible to achieve good insulation, so the corresponding associated heat loss due to heat reflection is acceptable. It must be.

  Furthermore, it can be added that the absorbing structure according to the invention can be used in a trough concentrator for a short distance from its edge after the fluid has reached a temperature of 100 ° C. or somewhat higher. However, the absorption structure according to the present invention preferably extends over the entire length of the trough concentrator.

  Here, it can be explained that the pipeline 26 of the heat exchange structure 29 can replace the wall of the absorption space 30 at least up to a certain length, resulting in the advantage that the pipeline 26 is directly irradiated, In other words, the advantage is obtained that the interruption of heat transfer to the heat transfer fluid is minimized. Furthermore, according to the invention, at least some part of the wall of the at least one absorption space is formed by a heat exchanger, ie its pipeline. Furthermore, according to the invention, the heat exchanger has fluid line portions adjacent to each other, which form at least one wall portion for at least one absorption space.

  In the embodiment shown in FIG. 3, the absorption space may be formed, for example, by a line 42 consisting of a heat exchanger structure, which bends so as to be adjacent to each other, preferably inside the absorption space. Cover completely.

  FIG. 3 shows a further embodiment of an absorbent structure 40 according to the invention, which basically corresponds to the embodiment of FIG. 2 except for the configuration of the heat exchanger structure 41. doing. The lines of the heat exchanger structure 41 configured as pipelines 42 are arranged in this embodiment so as to draw a small loop, in other words they are longer in any case. Composed. Despite extending in a loop in the longitudinal direction, the heat exchange fluid flows through the heat exchanger structure 41 in a direction across the longitudinal direction L. In order to be able to see the pipeline 42, the pipe 24 (FIG. 2) is omitted in FIG.

The long pipeline 42 has the advantage that the heat exchanger surface is enlarged for a partial flow of fluid, but has the disadvantage that the pressure drop in the pipeline 42 is large. In practice, one skilled in the art can determine the flow and thermodynamic design of the pipeline 42. Fundamentally, the heat exchanger structure performs the transfer in its main direction, orthogonal to the longitudinal direction L, so long as the fluid is heated during operation from the inlet temperature to the operating temperature in the transverse direction. Any suitable transfer of heat transfer fluid by the vessel structure is compatible with the present invention.
Similarly, any suitable line structure in the heat exchanger structure according to the invention used for the passage of fluid conforms to the invention.

  A small flow arrow 44 indicates the flow direction of the heat transfer fluid.

  FIG. 4 shows a further embodiment of an absorbent structure according to the invention, which essentially corresponds to the embodiment shown in FIG. 2 except for the configuration of the heat exchanger structure 51. Corresponding lines configured like the pipeline 52 are arranged as small coils 53 in this embodiment, in other words, longer in each case. The coil 53 is only schematically shown in FIG. 4 and is shown in detail in FIG.

  The coil 53 formed from the pipeline 52 is open toward the bottom, and as a result, the space portion is surrounded by them, so that an absorption space 54 is formed. As a result, the heat exchanging surface for this space and the heat exchanging surface over the length of the absorbent structure are substantially larger and have the advantages as described above for FIG. The region of the coil 53 that opens at the bottom forms a thermal opening 59.

  Due to the illustrated arrangement of the coils 53, the absorption spaces 54 are arranged in one row 55.

  Further, in FIG. 4, the pipeline 24 is omitted so as not to complicate the drawing, and as a result, the configuration above the coil 53 is clarified.

  The absorbent structure 50 in the embodiment shown in the drawing is configured such that the supply structure and drain structure have supply pipes 23 and 24 and a drain pipe 25. Here, the pipes 23, 24 and 25 extend in parallel with each other, and a plurality of absorption spaces each formed by the coil 53 are arranged between the pipes 23 to 25, and these spaces are formed in the absorption structure 50. Stretches over the length of.

  FIG. 5 shows one of the coils 53 shown only schematically in FIG. 4, which is wound around a heat exchanger structure 51 according to the invention configured as a pipeline 52. It is formed from a line. Here, the coil 53 has an axis of symmetry, surrounds the absorption space 54 for the incident radiation 4, and the end of the coil 53 opens at the bottom to form a thermal opening 59. The heat transfer medium having the inlet temperature TE flows into the coil 53 through the connecting member 57 of the pipeline 52 and passes through the end portion 58 of the pipeline 52 at the outlet temperature TA. Here, the heat transfer medium is constituted by the pipeline 25. Enter the collecting line.

  In the absorption structure shown in FIG. 4, the supply structure and the drain structure have supply pipes 22 and 24 and a drain pipe 25, and these pipes 23, 24, and 25 extend in parallel with each other, and a large number of absorption structures are provided. Spaces 54 are provided and the absorption spaces 54 are arranged in at least one row 55 extending between the pipes 23, 24 and 25, with at least one row 55 extending over the length of the pipe. Thus, advantageously, a plurality of (any desired shape) absorption spaces are generally provided, which are connected in parallel between the supply and drain structures.

  FIG. 6 shows a cross-sectional view of a trough concentrator 60 with an absorption structure 61 according to the invention, in which two concentrators 62 and 63 are provided, for example, Constructed in accordance with International Publication No. WO 2010/037243 (included as a reference in this application). The framework of the trough concentrator 60 is configured according to, for example, International Publication No. WO2009 / 135330.

  According to the concentrating devices 62 and 63, the absorption structure 61 has at least two absorption spaces 64 and 65, which extend over the length L of the absorption structure 61. However, it is also included in the present invention that two rows of absorption spaces are arranged side by side as in the embodiment according to FIGS. 3 to 5 in which a plurality of rows of absorption spaces are shown. Similarly, for trough concentrators having concentrating devices that are even more adjacent to each other, it is also included in the present invention to provide two or more rows of absorbing spaces in the absorbing structure.

  FIG. 7 shows a cross-sectional view of the absorbent structure 61 shown in FIG. A line of supply structure for heat transfer fluid configured as a pipeline 72, a heat exchanger structure 74 having two lines in this embodiment, and a pipeline 25 forming a drain structure for heat transfer fluid. In this embodiment, a heat insulating material 70 is provided as a collecting line. In the illustrated embodiment, the heat exchanger structure 74 comprises two rows 75 of spirals 53 arranged side by side, which are similar to those shown in FIG. The fluid passes through the line 72 at the inlet temperature TE and enters the connecting member 57 and, as a result, enters each coil 53, through these coils 53, through the end portion 58 of the pipeline 52, and the outlet temperature TA. To exit the coil 53 and enter the pipeline 25 of the drain structure. Preferably, auxiliary concentrators 73 known to those skilled in the art as trumpets are provided, which extend in a suitable manner along the thermal opening 59 over the length L of the absorbent structure 61 and are therefore troughs. In the transverse direction of the concentrator, the radiation already collected by the concentrators 62 and 63 is collected twice in succession, making it possible to reduce the width of the thermal aperture.

  The frame structural element 71 supports the structure as shown in the drawings and can be appropriately configured by a person skilled in the art in an existing manner.

  For the embodiments not shown in these drawings, a number of absorption spaces arranged in a row are provided over the length of the absorption structure, these absorption spaces being at a distance from each other, Spaced apart. In such an embodiment, radiation reflected by at least one concentrator (FIG. 1) or a plurality of concentrators 62, 63 (FIG. 6) is further upstream in the longitudinal direction of the absorbing structure. It is advantageous if the light is collected by another longitudinal collector structure, so that instead of the focal line area, a number of focal areas (here, one or more longitudinally extending focal lines) Is possible), and a higher concentration is obtained.

  Similarly, an improved coil compared to the coil 53 shown in FIG. 5 is included in the present invention. These can, for example, form an elliptical or polygonal absorption space instead of a circular absorption space, and a wall facing the thermal opening by means of a simple lid instead of a coil consisting of the pipe 52 shown in FIG. It can be terminated with a part. (Similarly, the absorption space may be constituted by a single box in each embodiment, for example, instead of a space formed by lines.)

  Similarly, coils whose symmetry axis is tilted with respect to the thermal aperture (not perpendicular for the embodiment of FIG. 5) are included in the present invention, and such coils have a skew angle range. Has the advantage of being advantageous. The skew angle is known per se to those skilled in the art and specifies the angle at which the sun pours light onto a concentrator aimed at the sun.

  In summary, according to the present invention, the heat exchanger structure and thus at least one absorption space can be adapted and configured in terms of design according to the thermodynamic requirements that actually exist, The exchange fluid is heated in cross flow to the operating temperature, i.e. to the outlet temperature TA, so that the drain structure is supplied with fluid at the outlet temperature TA over its length L. Those skilled in the art can combine the features described in the various embodiments described above, depending on the actual requirements, and are not limited to each illustrated embodiment. Similarly, the heat exchanger structure may not be formed by the pipeline but may be formed by other suitable structures.

  Finally, according to another embodiment of the present invention, splitting the supply structure is also advantageous for pressure supply reasons, where each segment has a connection to a fluid source. As a result, energy loss due to pressure drop in long lines is minimized.

Claims (14)

An elongated absorbent structure (20, 40, 50, 61) for a trough concentrator (1, 60) that receives radiation (4) collected over its length during operation,
In an absorbent structure comprising means for transferring a heat transfer fluid through the absorbent structure (20, 40, 50, 61),
The absorption structure (20, 40, 50, 61) comprises at least one fluid-free absorption space (30, 54, 67) for the condensed radiation (4);
The absorption space has a thermal opening (35, 59, 66) leading to the inside thereof and a wall (36) for absorbing heat incident therein;
Means for transferring fluid comprises a supply structure and a drain structure, which are operatively connected to each other by a heat exchanger structure through which fluid flows;
The heat exchanger structure is
Extending along the length of the absorbent structure (20, 40, 50, 61),
The fluid is configured to flow through in a transverse flow relative to the length of the absorbent structure (20, 40, 50, 61); and
Thermally connected to at least one absorption space (30, 54, 67);
Absorbent structure, characterized in that the fluid is heated from the inlet temperature TE to the operating temperature TA during operation in cross flow and reaches the drain structure at this temperature. A large number of absorption spaces (30, 54, 67) are arranged in a line over the length of the absorption structure (20, 40, 50, 61),
The elongate absorbent structure according to claim 1, wherein the absorption spaces are directly adjacent to each other. A large number of absorption spaces (30, 54, 67) are arranged in a line over the length of the absorption structure (20, 40, 50, 61),
The elongate absorbent structure according to claim 1, wherein the absorption spaces are spaced apart from each other. The elongate absorbent structure according to claim 1, characterized in that at least a part of the wall of the at least one absorbent space (54, 67) is formed by a heat exchanger structure (51, 64). The heat exchanger structure has mutually adjacent line portions for fluid, the line portions forming at least one wall portion for at least one absorption space. An elongated absorbent structure. An absorption space is formed by the line (52) of the heat exchanger structure (51, 64),
6. The lines according to claim 2 and 5, characterized in that the lines are wound adjacent to each other and are preferably configured to completely enclose the interior of the absorption space (54, 67). Elongate absorbent structure. The drain structure has collecting lines (25, 65);
The collecting line extends over the length of the absorbent structure (20, 40, 50, 61);
Heat is supplied from the heat exchanger structure (29, 41, 51, 64) to the collecting line over the length of the absorption structure,
The elongate absorbent structure according to claim 1, characterized in that the collecting line (25, 65) is insulated over its length to an opening for the supply of heated fluid. The supply structure has a feed line (23, 24, 62) for the fluid to be heated and fed over its length to the heat exchanger structure;
The feed line extends over the length of the absorbent structure;
The elongate absorbent structure according to claim 1, characterized in that the supply line (23, 24, 62) is insulated over its length to an opening for the supply of heated fluid. The supply structure and the drain structure have a supply pipe (23, 24, 62) and a drain pipe (25, 75);
Pipes (23-25, 62, 75) run parallel to each other
At least one absorption space (30, 54, 67) is arranged between these pipes (23-25, 62, 75), preferably over the entire length of the absorption structure (20, 40, 50, 61). The elongate absorbent structure according to claim 1, wherein the elongate absorbent structure extends. The supply structure and the drain structure have a supply pipe (23, 24, 62) and a drain pipe (25, 75);
Pipes (23-25, 62, 75) run parallel to each other
A plurality of absorption spaces (54, 67) are arranged to extend in at least one row between the pipes (23-25, 62, 75);
The elongate absorbent structure according to claim 1, wherein the at least one row preferably extends over the entire length of the pipe. The elongate absorption structure according to claim 1, wherein a plurality of absorption spaces (54, 67) are provided so as to be connected in parallel between the supply structure and the drain structure. The supply structure has a plurality of supply pipes (23, 24, 62) divided into segments;
The elongated absorbent structure according to claim 1, wherein each segment includes a connecting portion for a heat transfer fluid source. The elongated absorbent structure according to claim 1, wherein the length is longer than 100 m, preferably longer than 150 m, more preferably longer than 200 m. A second light collecting device is provided,
The elongate absorption structure according to claim 1, wherein the second light collecting device condenses incident radiation in the longitudinal direction of the absorption structure upstream of at least one absorption space.

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