摘要:
The radiation selective absorber coating of the invention includes two or more barrier layers arranged over each other on a substrate surface, an infrared-range reflective layer arranged on the two or more barrier layers, and at least an absorption layer arranged over the infrared-range reflective layer and a final antireflection layer arranged over the absorption layer. The absorber pipe, especially for a parabolic trough collector, is a steel pipe, on whose outer side the radiation selective absorber coating is applied. In the method of making the absorber pipe a first oxide barrier layer is provided on the outer side of the steel pipe by thermal oxidation, and then a second barrier layer, an infrared-range reflective layer, an absorption layer and a final antireflection layer are applied by gas-phase physical deposition.
摘要:
A tubular radiation absorbing device (1) designed for a solar heating application is described. The tubular radiation absorbing device has a metal central tube (3) and a glass tubular jacket (2) surrounding the central tube (3). A folding bellows (11) is connected between the central tube (3) and the tubular jacket (2), so that the tubular jacket and the central tube are movable relative to each other. A connecting element (20) connects an inner end of the folding bellows (11) with the central tube (3) and extends from the inner end of the folding bellows (11) through an inner annular space (30) between the folding bellows (11) and the central tube (3). The connecting element includes at least a part of a hydrogen window (50). A getter (6) is arranged in an outer annular space (33) between the folding bellows (11) and the tubular jacket (2).
摘要:
The absorber pipe (1), especially for a parabolic collector for a solar heat collecting apparatus, is described. The absorber pipe (1) includes central metal pipe (3), a glass sleeve tube (2) surrounding the nine so that an annular space (4) is formed between them and an expansion compensating device connecting the central metal nine and a glass-metal transitional element (5) on a free end of the sleeve tube (2). The expansion compensation device (10) connects the metal pipe and sleeve tube, so that they can slide relative to each other, and includes folding bellows (11) for that purpose. Furthermore it also includes a connecting element (15), which has either a cylindrical or a conical section (17,18,18″) and which connects an interior end of the folding bellows with the metal pipe.
摘要:
The radiation-selective absorber coating (20) has two barrier layers (24a, 24b), an IR-reflecting layer (21) arranged thereon, an absorption layer (22) arranged above the IR-reflecting (21) and an antireflection layer (23) over the absorption layer (22). The absorber tube (13) is a steel tube (1) with the radiation-selective absorber coating (20) applied to the outside thereof. In the process of coating the absorber tube (13) a first oxide barrier layer (24a) is applied to a steel tube by thermal oxidation; a second barrier layer (24b) is then applied by physical gas phase deposition of silicon with supply of oxygen; the IR-reflecting layer (21) is then applied by gas phase deposition of gold, silver, platinum or copper; the absorption layer (22) is then applied by deposition of aluminum and molybdenum; and a final antireflection layer (23) is applied by deposition of silicon with supply of oxygen.
摘要:
The tubular radiation absorbing device (1) for solar thermal applications has a central tube (2) and a glass tubular jacket (3) surrounding the central tube (2) so that a ring-shaped space (4) is formed between the central tube (2) and the tubular jacket (3). The ring-shaped space (4) contains at least one inert gas with a partial pressure of 3 to 200 mbar. Alternatively in another embodiment a gas-tight closed container (10) filled with at least one inert gas is arranged in the ring-shaped space (4). The container (10) has a device for supplying inert gas to the ring-shaped space (4) in order to compensate for increased heat losses due to diffusion of hydrogen into the ring-shaped space (4) from the heat carrier medium.
摘要:
The solar absorber is equipped with an absorber body (10) that absorbs incident solar energy (12) and converts it to heat. The absorber body has a selective absorption layer (17) on a side (36) oriented toward the concentrator (13) and another selective absorption layer (18) on an opposite side (38) oriented away from the concentrator (13). The selective absorption layers (17, 18) have threshold wavelengths below which solar radiation is absorbed and above which a reradiation capacity of the absorber body is suppressed. The threshold wavelength of the selective absorption layer (17) on the side (36) of the absorber body that is oriented toward the concentrator is greater than the other threshold wavelength of the other selective absorption layer(18) on the opposite side (38) of the absorber body oriented away from the concentrator.
摘要:
The radiation selective absorber coating of the invention includes two or more barrier layers arranged over each other on a substrate surface, an infrared-range reflective layer arranged on the two or more barrier layers, and at least an absorption layer arranged over the infrared-range reflective layer and a final antireflection layer arranged over the absorption layer. The absorber pipe, especially for a parabolic trough collector, is a steel pipe, on whose outer side the radiation selective absorber coating is applied. In the method of making the absorber pipe a first oxide barrier layer is provided on the outer side of the steel pipe by thermal oxidation, and then a second barrier layer, an infrared-range reflective layer, an absorption layer and a final antireflection layer are applied by gas-phase physical deposition.
摘要:
The tubular radiation absorbing device (1) for solar thermal applications has a central tube (2) and a glass tubular jacket (3) surrounding the central tube (2) so that a ring-shaped space (4) is formed between the central tube (2) and the tubular jacket (3). The ring-shaped space (4) contains at least one inert gas with a partial pressure of 3 to 200 mbar. Alternatively in another embodiment a gas-tight closed container (10) filled with at least one inert gas is arranged in the ring-shaped space (4). The container (10) has a device for supplying inert gas to the ring-shaped space (4) in order to compensate for increased heat losses due to diffusion of hydrogen into the ring-shaped space (4) from the heat carrier medium.
摘要:
The invention relates to a solar collector comprising an absorber tube (13) supported by supports. Radiation-per-meable cladding tubes (15) are located between the supports and surround the absorber tube (13). Compensation pieces (17) are provided between the cladding tubes (15) due to the fact that the absorber tube (13) and the cladding tubes (15) have different expansion behaviors. In order to also capture radiation that strikes the connection area (50), at least one mirror collar (20) is provided that reflects the solar radiation into the area of the active absorber tube surface. This mirror collar (20) is capable of reflecting the concentrated solar radiation coming from different directions from the parabolic mirrors even at different solar angles of incidence upon the active absorber surface.
摘要:
An absorber tube, especially for solar collectors in solar thermal power plants with at least one collector mirror, is provided. The absorber tube includes a metal tube for supplying and heating a heat transfer medium, a sheath tube surrounding the metal tube to form an annular space that can be evacuated, a wall extending through the sheath tube and the metal tube to seal the annular space, and a getter material binding free hydrogen in the annular space. The absorber tube has a temperature variation device that changes the temperature of the getter material and the wall.