Solar steam generator

Abstract

The invention relates to a solar absorber for steam generation, in particular for a concentrator module of a solar installation, the solar absorber comprising at least one pressure vessel (2), a capillary layer (3), wherein the capillary layer (3) lines at least some sections of an inner surface of the pressure vessel (2), a condensate space, which condensate space is connected to a condensate line (7.2), and an evaporation space, which evaporation space is at least partially surrounded by the capillary layer (3) and is connected to a steam line (7.1), wherein an end portion of the capillary layer (3) projects into the condensate space.

Description

DI Martin Hadlauer 26007P-WO 1 / 18 Solar steam generator

[0001] The invention relates to a solar absorber for a concentrator module for solar steam generation. The term "concentrator module" refers to the unit comprising a mirror and a solar absorber. Here, the radiation is focused by the mirror onto the solar absorber, which preferably has a glass casing. The solar absorber is heated with a high radiation intensity, which can be many times the normal solar irradiance (up to 20 times that of the Sun).

[0002] A key component of the solar absorber is a pressure vessel lined internally with an absorbent layer. This can be a porous capillary layer produced using a sintering process, similar to the coatings in conventional heat pipes. This coating, or capillary layer, absorbs condensate when dry. When the pressure vessel is heated externally (by solar radiation), the capillary layer heats up, causing the absorbed condensate to evaporate. New condensate then flows into the vapor-generating and thus drying zones via capillary action. The amount of evaporation automatically adjusts to the heating power. The capillary layer can be manufactured using a wide variety of metallic sintered materials. It is important to find the finest possible grain size. To closely mimic natural processes, the capillaries can have average gap widths of 5 to 50 nm.The finer the capillary, the greater the suction head. Aluminum alloys are particularly interesting due to their good thermal conductivity. These materials sinter well and are relatively corrosion-resistant to steam up to a temperature of 400°C. This corrosion resistance results from the formation of a thin patina. The sintering process allows for the joining of different materials. For example, the capillary or sintered layer can be made of an aluminum alloy, while the pressure vessel is made of high-strength carbon steel. It is also possible to use non-metals (ceramics, corundum, etc.) and sinter them. Technical task

[0003] Steam is transported from the solar absorber to a station (consumer) via a first line. Condensate is returned to the solar absorber via a second line. The heat transfer medium is in a closed loop. A preferred heat transfer medium is chemically pure water. The entire cycle should be DI Martin Hadlauer 26007P-WO 2 / 18 The system should start running automatically as soon as solar heat is applied to the solar absorber. The pressure difference between the condensate and the steam should be low (maximum 0.5 bar). If the pressure difference is higher, for example due to the geodetic height, the condensate can be pressurized accordingly. A suitable setup will be discussed in more detail later in this application. The condensate temperature in the pipes should be slightly lower than the steam temperature, as otherwise bubbles may form, disrupting the process. Key design criteria for the capillary layer are the mean path length for the capillary condensate flow and the evaporation rate relative to the surface area [W / m²]. 2 ]. State of the art

[0004] In the applicant's own earlier patent application WO 2023 / 175051 A1, a solar absorber for steam generation is shown. This absorber was intended to fulfill the technical requirements of the overall process. The application depicts a solar absorber with five tubes connected to a distribution unit. Condensate flows via the distribution unit to the tubes, which are lined internally with a capillary layer. Steam (preferably saturated steam) produced during solar heating is discharged. The original concept behind this design was to utilize existing heat pipe material and make adaptations.

[0005] As it turns out, no suitable heat pipes designed for the high power density required by this concentrator module are available on the market. This also applies to the consideration of a dual-flow system. The five-pointed distribution unit with flow channels for steam and condensate proves to be very complex. When fully populated, it forms an elongated cone with gaps where the radiation bypasses the heat pipes. This necessitates either a reflector plate to direct the lost radiation onto the heat pipes from the rear or encasing the heat pipes with heat-conducting plates. Another disadvantage is that the radiation strikes the absorber surfaces at a relatively oblique angle in the lower zone. A spherical or nearly spherical absorber surface proves to be significantly more favorable in terms of the radiation characteristics and, consequently, also the shape of the reflector (reduced depth).

[0006] The subject of the present application is a completely new development with a solution to the technical problems without the restrictions imposed by the otherwise necessary reliance on existing heat pipe developments on the market. DI Martin Hadlauer 26007P-WÖ 3 / 18 Description of the invention

[0007] In particular, the design of the solar absorber is the subject of this invention. One objective is to enable simple and cost-effective manufacturing. Further objectives will become apparent from the description, the claims, and the drawings. Instead of the five tubes with which the concentrator module had to be equipped according to the prior art described above, a single pressure vessel is now provided. This vessel is ideally spherical, or at least approximately spherical, or at least partially (essentially) spherical, in order to withstand high pressure loads.

[0008] For manufacturing reasons, it can be advantageous if the pressure vessel of the concentrator module consists of two identical or nearly identical hemispherical domes. The domes are provided on the inside with a porous capillary or absorbent layer. Both domes may have openings at their poles, preferably in a round shape.

[0009] The individual hemispheres or caps can be identical parts. The two caps of the pressure vessel can be prefabricated to the extent that the capillary layers are applied to the inside, weld-in bodies with the hydraulic connections (steam and condensate) are welded into the pole-side recesses, and barrier plates are welded in, separating a condensate space from a steam space.

[0010] In its assembled state, the solar absorber can be designed to include a capillary inner lining, at least one, preferably two, sealed condensate chambers, and lines for condensate supply and vapor removal. When the two domes are joined to form a sphere, the two condensate chambers, which can connect to the weld-in inserts provided at the poles, can be fluidically connected via a sealing plug connection. This results in a dual flow (upper and lower evaporator dome) through the absorber. The average path length for the capillary condensate flow is thus almost halved. An annular flow pattern from the upper and lower condensate chambers provides optimal conditions for good flow through the capillary layer. To form the condensate chambers, the two weld-in inserts can be welded to the pole-side recesses of the spherical domes.These weld-in components can include piping for condensate supply and steam discharge, or be formed integrally with this piping. A barrier plate is provided, which is welded to the respective weld-in component. DI Martin Hadlauer 26007P-WO 4 / 18. Whether the components are soldered or not, a condensate chamber is formed, allowing a ring-shaped flow of condensate – following a direction of meridians running between the two poles – into the capillary layer. The modular, weld-in components lay the foundation for the simple production of the solar absorber with as many identical parts as possible.

[0011] This solar absorber can essentially comprise the following components before final assembly: Pressure vessel - 2x Capillary layer - 2x Plywood floor - 2x Weld-in body - 2x

[0012] The spherical design of the solar absorber offers the advantage of particularly high compressive strength in its final assembly (i.e., in a welded state, in which the solar absorber can be inserted into and / or used as intended in a concentrator module). For example, if a sphere with a diameter of 350 mm and a wall thickness of 2.5 mm is used, as is preferred here, the stress at 30 bar is approximately 100 N / mm². 2 Preferably, the spherical caps are therefore made of a steel with a tensile strength of over 450 N / mm². 2The pressure vessel can be externally coated with a (selective) coating that absorbs solar radiation. This (selective) coating largely prevents heat radiation due to the vessel's own temperature. A particularly preferred feature of the solar absorber is a glass encasement. This glass encasement can also consist of an upper part, preferably dome-shaped, and a lower part, preferably dome-shaped. The two glass parts can be slid over the pressure vessel and welded together. Coatings, in particular an outer and an inner anti-reflective coating, or at least an inner coating, can be applied to the glass parts before welding. Any interference zone that may form at the weld seam is negligible with regard to performance reduction. The glass suspension features a vacuum-tight glass-to-metal connection.A further metal-to-metal welding process to create a vacuum chamber completes the absorber's manufacturing. A vacuum chamber has now been created between the glass and the pressure vessel, preventing convective heat loss. DI Martin Hadlauer 26007P-WO 5 / 18. Disassembly of the solar absorber is not possible (at least not without damage).

[0013] Detailed information on the structure and function of the solar absorber or the concentrator module for solar steam generation or a solar steam generator can be found in the figure description.

[0014] One object of the invention is solved by a solar absorber for steam generation, in particular for a concentrator module of a solar power plant, the solar absorber comprising at least one pressure vessel, a capillary layer, wherein the capillary layer lines at least a section of an inner surface of the pressure vessel, a condensate chamber, which condensate chamber is connected to a condensate line, and an evaporation chamber, which evaporation chamber is at least partially surrounded by the capillary layer and connected to a steam line, wherein the capillary layer projects into the condensate chamber with an end section.

[0015] According to a preferred embodiment, the evaporation chamber is provided to be gas-tightly sealed against the condensate chamber, preferably at least in one operating state of the solar absorber.

[0016] According to a preferred embodiment, the condensate space is lined with the capillary layer only in sections.

[0017] According to a preferred embodiment, the condensate chamber is provided to accommodate a distributor element, preferably cylindrical, which carries the steam line and the condensate line.

[0018] According to a preferred embodiment, the distribution element has a branch opening into the condensate chamber to connect the condensate line to the condensate chamber.

[0019] According to a preferred embodiment, the distributor element has an opening leading into the evaporation chamber for connecting the steam line to the evaporation chamber.

[0020] According to a preferred embodiment, the condensate line projects into the evaporation chamber via an intermediate piece, with one end of the intermediate piece facing away from the distribution element being connected to another distribution element. DI Martin Hadlauer 26007P-WÖ 6 / 18

[0021] According to a preferred embodiment, the further distribution element is provided to be housed in a further condensate chamber and has an outlet opening into the further condensate chamber for connecting the condensate line to the further condensate chamber.

[0022] According to a preferred embodiment, the distributor element is designed as a lower weld-in body and / or the further distributor element is designed as an upper weld-in body.

[0023] According to a preferred embodiment, a locking element, in particular a locking base, is provided on the lower weld-in body and / or on the upper weld-in body, which locking element projects from the respective weld-in body and extends substantially parallel to the inner surface of the pressure vessel.

[0024] According to a preferred embodiment, the barrier base is in contact with the capillary layer via a circumferential seal, in particular via a sealing ring, wherein preferably the seal is subjected to a spring force by means of the barrier base.

[0025] According to a preferred embodiment, the pressure vessel is arranged in a glass enclosure and separated from the glass enclosure by a vacuum gap, wherein the glass enclosure is preferably connected to a jacket tube connected to the pressure vessel, in particular welded.

[0026] According to a preferred embodiment, the pressure body is essentially spherical and / or composed of a lower pressure cap and an upper pressure cap, wherein the lower pressure cap is preferably welded to the upper pressure cap.

[0027] According to a preferred embodiment, the distributor element is inserted into an opening provided at a lower pole of the lower pressure dome and welded to the lower pressure dome, and / or the further distributor element is inserted into an opening provided at an upper pole of the upper pressure dome and welded to the upper pressure dome.

[0028] One object of the invention is also solved by a solar system comprising at least one concentrator module with a mirror, wherein the concentrator module comprises a solar absorber according to one of the embodiments described above, wherein the DI Martin Hadlauer 26007P-WO 7 / 18 The solar absorber is preferably arranged in the concentrator module such that its pressure vessel is located at a focal point of the mirror. Brief description of the characters

[0029] The invention is described in more detail below with reference to exemplary embodiments. However, the following explanations are neither intended to restrict nor to exhaustively present the inventive concept. The following are shown: Fig. 1, 1A, 1B, 1C shows the position of the solar absorber in the mirror system. Concentrator module; Fig. 2, 2A, 2B, 2C shows the setup for the evaporation function; Figs. 3, 3A, 3B show the structural design of the solar absorber with a view into the interior; Fig. 4 shows a detailed view of the lower condensate chamber; Fig. 5 shows a detailed view of the exit; Fig. 6 shows a parts list of all components; Figs. 7, 7A, 7B, 7C show the device for the pre-printing unit; and Fig. 8 shows a view inside the pre-printing unit. Ways to implement the invention

[0030] Fig. 1 shows the position of the solar absorber in the mirror system or in a concentrator module. As can be seen, all reflected rays from the direct irradiance strike a spherical body of the solar absorber almost perpendicularly. The irradiance is not concentrated at the center of the sphere. A special mirror geometry is used here, which ensures a largely uniform distribution of radiation intensity across the irradiation surface of the solar absorber. This would also be advantageous if the solar absorber were to be equipped with solar cells (cooled PV concentrator system). The diameter of the sphere, or absorber sphere, is relatively large compared to the mirror. This provides a sufficiently large evaporation surface to optimally absorb the power. Another advantage is that a high percentage of the diffuse irradiance (average capture steradian >9°) also strikes the absorber.The absorber unit, or solar absorber, has two outgoing pipes: a first pipe (steam line) 7.1 for steam removal and a second pipe (condensate line) 7.2 for condensate return. When mounted on the support arms of a collector system, these pipes are inserted into a sealing set of the respective concentrator module. (See DI Martin Hadlauer 26007P-WO 8 / 18.) Two suspensions 11 for a bayonet fitting are provided for securing the solar absorber in the concentrator module.

[0031] Figure 2 shows, in Figures 2A, 2B, and 2C, the structure of the solar absorber in a first embodiment for the evaporation function. Figures 2B and 2C are detailed views from Figure 2A. Figure 2A shows a half-section of the solar absorber, with an upper pressure dome and a lower pressure dome shown in half-section, allowing a view into the interior. The pressure vessel 2 (see Figure 3b) of the solar absorber is visible, comprising the two pressure domes, namely a lower pressure dome 2.1 and an upper pressure dome 2.2, each of which is lined internally with a capillary layer 3 (see Figure 2). 3B), namely with a lower capillary layer 3.1 and an upper capillary layer 3.2. Between the respective pressure dome of the pressure vessel 2 and the sealing plates 4 with gasket 4.1, an upper and a lower condensate chamber are formed. The condensate flows via the second pipe 7.2 into a distribution element 22, which here is designed as a lower weld-in body 8.1 with a branch 13.1 into the first condensate chamber. Thus, condensate from the condensate line 7.2 can enter the condensate chamber via the distribution element 22. The second partial flow is directed via the second pipe 7.2 or an intermediate piece 24 of the condensate line to a further distribution element 23, which here is designed as an upper weld-in body 8.2 with an outlet 13.2 into the second condensate chamber, and can thus enter the second condensate chamber.The fluidic connection of the second condensate chamber is established by a sealing insertion of the intermediate piece 24 into an inlet nozzle of the upper weld-in body 8.2. A key feature of this embodiment is the weld-in bodies 8.1 and 8.2, which form prefabricated compact units, each with a branch 13.1 or outlet 13.2. The prefabrication includes, among other things, the welding of the tubes 7.1 and 7.2 to a disc-shaped or cylindrical base body in the case of the lower weld-in body 8.1, and the welding of the inlet nozzle to a similarly disc-shaped or cylindrical base body in the case of the upper weld-in body 8.2.During evaporation, the condensate is drawn in two directions, namely from the lower condensate chamber and the upper condensate chamber, along the inner side of the respective pressure dome, i.e., in a circumferential direction of the sphere extending parallel to the meridians running between the poles of the sphere, via capillary layers 3.1 and 3.2 into a heating zone. In the heating zone, the capillary layers are in contact with saturated steam. The space enclosed by the capillary layer—essentially the interior of the sphere—is functionally referred to as the evaporation chamber. Condensate evaporating from the heating zone leads to the drying of capillary layers 3.1 and 3.2, which in turn produces new DI Martin Hadlauer 26007P-WO 9 / 18. Condensate is pumped from the condensate chambers. The process works particularly well when there is no air in the system and phase equilibrium exists.

[0032] The condensate recirculation process is purely heat-driven. If no heat of vaporization enters the solar absorber, the process ceases. The process only functions within a specific pressure range between the condensate chamber and the evaporation chamber. Thus, the evaporation chamber can be either pressurized or depressurized relative to the condensate chamber. If the pressure difference is too great, no condensate can be drawn in, or flooding will occur when the process is idled. A special device, described in Figures 7 and 8, can regulate this. If the geodetic height between the absorber and the consumer (where the vapor condenses) is within the physically permissible range of capillary forces, this device (also called a pre-pressure device) can be omitted. The system then operates naturally and begins working automatically when heat is introduced.If there is no heat, the process comes to a standstill without any further condensate flowing into the absorber. The seal 4.1 provided on the respective barrier plate 4 between the condensate chamber and the vapor chamber is crucial for its function. The purpose of the seal 4.1 is to prevent condensate from overflowing, especially since the flow is intended to occur exclusively via the capillaries. This seal 4.1 can also be omitted if the barrier plate 4 forms a direct connection with the capillary layer and this connection provides sufficient sealing between the condensate chamber and the vapor chamber. For example, soldering could be used, but it is important to ensure that only the uppermost layer of the capillaries is coated with solder. Under no circumstances should the solder completely fill the capillaries.

[0033] Fig. 3 shows the structural design of the solar absorber with an internal view in two half-sections. Fig. 3A shows the assembly of the solar absorber. Visible are a glass casing 1, the pressure vessel 2 with the capillary layer 3, the barrier plate or barrier base 4 with the seal 4.1, a jacket tube 6, an inner tube 5, the lower weld-in body 8.1, the steam and condensate lines or the first tube 7.1 and the second tube 7.2, the upper weld-in body 8.2 with the inlet nozzle, insulating sleeves 10, the suspension 11, and a groove 12 for an O-ring (not shown). Fig. 3B shows the lower pressure dome 2.1 of the pressure vessel 2 as a finished part before welding to the upper pressure dome 2.2. DI Martin Hadlauer 26007P-WO 10 / 18

[0034] The manufacturing process and assembly are as follows (order not mandatory): 1. Manufacturing of the base bodies of the weld-in body 8.1 and the weld-in body 8.2 together with the piping 7.1 and 7.2. 2. Manufacturing of the lower pressure dome 2.1 and the upper pressure dome 2.2 with drill holes at the poles. 3. Inner coating of the lower pressure dome 2.1 with the lower capillary layer 3.1 and of the upper pressure dome 2.2 with the upper capillary layer 3.2. 4. Manufacturing two barrier plates 4 and attaching the seals 4.1. 5. Welding of the barrier plates 4 and the pressure caps 2.1 and 2.2 to the base bodies of the weld-in bodies 8.1 and 8.2. 6. Applying the O-ring to groove 12 on the second pipe 7.2. 7. Assembling the upper and lower finished units with simultaneous insertion of the second tube 7.2 into the insertion nozzle of the upper weld-in body 8.2. 8. Welding the pressure caps 2.1 and 2.2 together to form a sphere, in order to obtain the pressure vessel 2. 9. Applying a selective coating to the outside of the pressure vessel 2. 10. Welding of the inner tube 5 to the pressure vessel 2. 11. Production of an upper and a lower glass dome 1.2 and 1.1. 12. Anti-reflective coating of the glass domes 1.1 and 1.2 inside and outside. 13. Welding of the lower glass dome 1.1 to the outer tube 6 at the edging. 14. Insertion of a sealing plug 9, thus positioning the inner tube 5 and outer tube 6. With the positioning of outer tube 6, the lower glass dome 1.1 is also positioned relative to the pressure vessel 2. This is a push-fit connection that can be easily disconnected. DI Martin Hadlauer 26007P-WO 11 / 18 15. Overlap of the upper glass dome 1.2 and welding with the lower glass dome 1.1. 16. Additional positioning of inner tube 5 relative to outer tube 6 in a device within a vacuum chamber using a welding or brazing device. Once tubes 5 and 6 are fixed relative to each other, the sealing plug 9 is extended. A vacuum is then drawn. Under vacuum, the sealing plug 9 is reinserted. The joints between inner tube 5 and outer tube 6 are welded or brazed using the sealing plug 9. 17. Pack securely to prevent damage.

[0035] The outgoing pipes 7.1 and 7.2 have different outer diameters. This prevents incorrect installation, as a 180° reversed installation in the collector system is thus impossible.

[0036] Fig. 4 shows a detailed view of the lower condensate chamber. Visible are the glass casing 1 at the rim, the pressure vessel 2, the (lower) capillary layer 3, the barrier plate or barrier base 4 with the seal 4.1, the inner tube 5, the outer casing 6, the steam and condensate lines 7.1 and 7.2, the (lower) weld-in body 8, the insulating sleeves 10, and the suspension 11.

[0037] Fig. 5 shows a detailed view of the outlet. Visible are the inner pipe 5, the outer casing pipe 6, the steam and condensate lines 7.1 and 7.2, the insulating sleeves 10, and the sealing plug 9.

[0038] Fig. 6 shows a parts list of all components. As can be seen, the entire unit can be manufactured from just a few parts. Parts 2, 3, and 4 are provided in duplicate or as identical parts.

[0039] Fig. 7 shows the device for the pre-pressure or pre-pressure device. This is a pressure regulating valve. The base is a cube 15 with two flange connections 16, 17. Opening the locking nut 14 provides access to an adjusting screw. This allows the spring preload to be set. This, in turn, regulates the pressure of the condensate relative to the steam (p2) in the collectors. Thus, the pressure of the incoming condensate in the collectors can be set independently of the pre-pressure in the line. This is particularly important when several collectors are connected to a common condensate line, but the pressure at the extraction point on the respective collectors varies. DI Martin Hadlauer 26007P-WO 12 / 18 different condensate pressures A p1 have (e.g. due to different geodetic heights).

[0040] Fig. 8 shows a view inside the pre-pressure unit. This is a system with three chambers A, B, and C. Chamber A is at the pre-pressure of the feed line. Chamber B receives the appropriate pressure for the automatic evaporation function through the adjustment of the spring preload. Chamber C is at steam pressure. The bellows spring 18 has steam pressure on the outside and the pressure of the middle chamber B on the inside. Depending on the pressure difference, the spring connection 20 rises and falls. The control valve 19 is attached to the spring connection 20 via a screw connection. The control valve 19 is mounted in a conical seat and, in conjunction with the spring preload, can open or close from a certain pressure difference A p2. The control valve has a screw slot 21 for adjusting the appropriate pressure. The pressure automatically adjusts to the consumption by opening and closing at intervals. When condensate is consumed (evaporated in the collector), the pressure drops.Above a certain pressure difference p2, the valve opens and increases the pressure again.

[0041] One object of the invention is also solved by a solar steam generator consisting of a pressure vessel (2), wherein the latter is made of two preferably identical spherical shells (2.1 and 2.2), wherein boreholes are provided at the poles of the spherical shells, wherein a weld-in body 8.1 with the tubes 7.1 and 7.2 and an outlet (13) is welded into the spherical shell 2.1 and a weld-in body 8.2 with an insertion nozzle and an outlet (13) is welded into the spherical shell 2.2.

[0042] According to a preferred embodiment, the calottes (2.1 and 2.2) are provided or coated on the inside with a capillary layer (3).

[0043] According to a preferred embodiment, it is provided that locking plates (4), preferably with a seal (4.1), are welded or sealed to the weld-in bodies (8.1 and 8.2).

[0044] According to a preferred embodiment, an inner tube (5) is welded to the pressure vessel (2).

[0045] According to a preferred embodiment, a lower glass dome is sealedly connected or welded to a jacket tube (6), wherein DI Martin Hadlauer 26007P-WO 13 / 18 the outer tube (6) is sealed to the inner tube (5) via a vacuum seal (9) or is welded or soldered.

[0046] According to a preferred embodiment, a pre-pressure device is provided with a sealing screw (14) which provides access to a control valve (19) which is rotatably connected in a screw thread to a spring connection (20).

[0047] According to a preferred embodiment, a pressure device includes a spring (18) which separates a steam chamber C from a condensate chamber B. DI Martin Hadlauer 26007P-WO 14 / 18 Reference symbol list 1 glass casing 1.1 Lower glass dome 1.2 Upper glass dome 2 pressure vessels 2.1 Lower pressure dome 2.2 Upper pressure dome 3 capillary layer 3.1 Lower capillary layer 3.2 Upper capillary layer 4. Plywood / Plyboard 4.1 Seal 5 inner tube 6 Sheathing tube 7.1 First pipe (steam exhaust) 7.2 Second pipe (condensate feed) 8.1 Lower weld-in body 8.2 Upper weld-in body 9 sealing plugs 10 insulating sleeves 11. Bayonet fitting 12 Grooves for O-ring 13.1 Branch 13.2 Outlet 14 Locking nut (pre-pressure device) 15 Cube (housing of the pre-pressure device) 16 Flange connection (first) 17 Flange connection (second) 18 bellows spring 19 Control valve 20 Spring connection 21 Screw slot on the control valve 22 Distributor element 23 additional distribution element 24 Intermediate piece

Claims

DI Martin Hadlauer 26007P-WÖ 15 / 18 Patent claims 1. Solar absorber for steam generation, in particular for a concentrator module of a solar power plant, the solar absorber comprising at least a pressure vessel (2), a capillary layer (3), wherein the capillary layer (3) lines at least a section of an inner surface of the pressure vessel (2), a condensate chamber, which condensate chamber is connected to a condensate line (7.2), and an evaporation chamber, which evaporation chamber is at least partially surrounded by the capillary layer (3) and is connected to a steam line (7.1), wherein the capillary layer (3) projects into the condensate chamber with an end section.

2. Solar absorber according to claim 1, characterized in that the evaporation chamber is sealed gas-tight against the condensate chamber, preferably at least in one operating state of the solar absorber.

3. Solar absorber according to claim 1 or 2, characterized in that the condensate space is lined only section by section with the capillary layer (3).

4. Solar absorber according to one of claims 1 to 3, characterized in that the condensate chamber accommodates a, preferably cylindrical, distribution element (22), which distribution element (8) carries the steam line (7.1) and the condensate line (7.2).

5. Solar absorber according to claim 4, characterized in that the distribution element (22) has a branch (13.1) opening into the condensate chamber for connecting the condensate line (7.2) to the condensate chamber.

6. Solar absorber according to one of claims 4 or 5, characterized in that the distributor element (22) has an opening leading into the evaporation chamber for connecting the steam line (7.1) to the evaporation chamber.

7. Solar absorber according to one of claims 4 to 6, characterized in that the condensate line (7.2) projects into the evaporation chamber with an intermediate piece (24), wherein an end of the intermediate piece (24) facing away from the distributor element (22) is connected to a further distributor element (23).

8. Solar absorber according to claim 7, characterized in that the further distribution element (23) is accommodated in a further condensate chamber and has a DI Martin Hadlauer 26007P-WÖ 16 / 18 has an outlet (13.1) leading into the further condensate chamber for connecting the condensate line (7.2) to the further condensate chamber.

9. Solar absorber according to one of claims 4 to 8, characterized in that the distributor element (22) is designed as a lower weld-in body (8.1) and / or that the further distributor element (23) is designed as an upper weld-in body (8.2).

10. Solar absorber according to claim 9, characterized in that a locking element, in particular a locking base (4), is provided on the lower weld-in body (8.1) and / or on the upper weld-in body (8.2), which locking element projects from the respective weld-in body and extends substantially parallel to the inner surface of the pressure vessel (2).

11. Solar absorber according to claim 10, characterized in that the barrier base (4) is in contact with the capillary layer (3) via a circumferential seal (4.1), in particular via a sealing ring, wherein preferably the seal (4.1) is subjected to a spring force by means of the barrier base (4).

12. Solar absorber according to one of claims 1 to 11, characterized in that the pressure vessel (2) is arranged in a glass enclosure (1) and is separated from the glass enclosure (1) by a vacuum gap, wherein preferably the glass enclosure (1) is connected to a jacket tube (6) connected to the pressure vessel (2), in particular welded.

13. Solar absorber according to one of claims 1 to 12, characterized in that the pressure body (2) is essentially spherical and / or is composed of a lower pressure dome (2.1) and an upper pressure dome (2.2), wherein the lower pressure dome (2.1) is preferably welded to the upper pressure dome (2.2).

14. Solar absorber according to claim 13, characterized in that the distribution element (22) is inserted into an opening provided at a lower pole of the lower pressure dome (2.1) and welded to the lower pressure dome (2.1) and / or the further distribution element (23) is inserted into an opening provided at an upper pole of the upper pressure dome (2.2) and welded to the upper pressure dome (2.2). DI Martin Hadlauer 26007P-WO 17 / 18 15. Solar system comprising at least one concentrator module with a mirror, wherein the concentrator module comprises a solar absorber according to one of claims 1 to 14, wherein the solar absorber is preferably arranged in the concentrator module such that its pressure vessel (2) is located at a focal point of the mirror.

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