# US 2018/0320931 A1 · Solar thermal concentrator and method of forming same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0320931 A1 - Document ID: US20180320931A1 - Status: Published application - Kind: A1 - Application number: 15/967,413 - Filed: 2018-04-30 - Published: 2018-11-08 - Earliest claimed: 2012-07-12 - Assignees: The Regents of the University of California - Applicants: The Regents of the University of California - Inventors: Roland Winston; Lun Jiang - Web page: https://patentgrep.com/patent/US20180320931A1 ## CPC - F24S 10/45: {the enclosure being cylindrical} - B23P 15/26: heat exchangers {or the like (making heat exchangers by methods covered by other subclasses B21D53/02)} - F24S 10/70: the working fluids being conveyed through tubular absorbing conduits - F24S 10/75: with enlarged surfaces, e.g. with protrusions or corrugations (collectors comprising porous material or permeable masses directly contacting the working fluids F24S10/80) - F24S 10/95: having evaporator sections and condenser sections, e.g. heat pipes - F24S 23/74: with trough-shaped or cylindro-parabolic reflective surfaces - F24S 70/10: characterised by the absorbing material (absorbing coatings or surface treatment for increasing absorption F24S70/20) - F24S 20/20: Solar heat collectors for receiving concentrated solar energy, e.g. receivers for solar power plants - F24S 23/82: {characterised by the material or the construction of the reflector} - F24S 80/50: Elements for transmitting incoming solar rays and preventing outgoing heat radiation; Transparent coverings - F24S 2010/751: {Special fins} - F24S 2023/834: {trough-shaped} - Y02E 10/40: Solar thermal energy, e.g. solar towers - Y02E 10/44: Heat exchange systems - Y10T 29/49355: Solar energy device making - F24S: SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS (for producing mechanical power from solar energy F03G6/00) - B23P: METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS (arrangements for copying or controlling B23Q) - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A concentrator tube comprises a reflector portion having two walls; and an aperture closing an opening to the reflector portion. The aperture and the reflector portion extend longitudinally. The aperture is substantially flat relative to curvature of the reflector portion. ## Claims ### Claim at position 1 1-32. (canceled) ### Claim 33 A concentrator tube extending from a distal end to a proximal end comprising: a trough shaped reflector portion extending between the proximal end and the distal end and defining an upper opening, the reflector portion configured to concentrate light from a source onto an absorber; a light transmissive aperture member closing the upper opening of the trough shaped reflector portion, wherein the tube concentrates light incident through the aperture member at angles to an optic axis less than an acceptance angle with an optical efficiency greater than 80%; and the absorber located within the tube; wherein the reflector portion is configured such that substantially any radiation energy emitted from the absorber onto the reflector portion is either directed to the source or directed back to the absorber; and wherein each end of the tube is sealed. ### Claim 34 (depends on 33) The concentrator tube of claim 33, wherein the tube encloses a volume. ### Claim 35 (depends on 34) The concentrator tube of claim 34, wherein the volume is substantially evacuated. ### Claim 36 (depends on 34) The concentrator tube of claim 34, wherein the reflector portion is located on an interior wall of the volume. ### Claim 37 (depends on 34) The concentrator tube of claim 34, wherein the reflector portion is located outside of the volume. ### Claim 38 (depends on 33) The concentrator tube of claim 33, wherein the aperture member is less curved than the reflector portion. ### Claim 39 (depends on 33) The concentrator tube of claim 33, wherein the aperture member is substantially flat. ### Claim 40 (depends on 33) The concentrator tube of claim 33, wherein the absorber is positioned to accommodate refraction of light entering the concentrator tube through the aperture member. ### Claim 41 (depends on 33) The concentrator tube of claim 33, wherein the reflector portion is configured to accommodate refraction of light entering the concentrator tube through the aperture member. ### Claim 42 (depends on 41) The concentrator tube of claim 41, wherein the reflector portion is configured such that edge ray light rays refracted by the aperture member reflect from the reflector portion and contact the absorber. ### Claim 43 (depends on 33) The concentrator tube of claim 33, wherein the absorber is configured to have a thermal energy transfer fluid flowing therethrough. ### Claim 44 (depends on 43) The concentrator tube of claim 43, wherein the absorber comprises an input and an output for the thermal energy transfer fluid, and wherein both the input and the output extend through a first end of the concentrator tube. ### Claim 45 (depends on 43) The concentrator tube of claim 43, wherein the absorber has an end portion located proximal a second end of the concentrator tube, and wherein the end portion is free to move within the tube in response to thermal expansion or contraction. ### Claim 46 (depends on 43) The concentrator tube of claim 43, wherein the absorber comprises a plurality of minichannels configured to allow flow therethrough of the thermal energy transfer fluid. ### Claim 47 (depends on 33) The concentrator tube of claim 33, wherein the tube concentrates through the aperture member at angles to the optic axis less than the acceptance angle with the optical efficiency greater than 90%. ### Claim 48 (depends on 33) The concentrator tube of claim 33, wherein the tube concentrates through the aperture member at angles to the optic axis less than the acceptance angle with the optical efficiency greater than 95%. ### Claim 49 (depends on 33) The concentrator tube of claim 33, wherein the tube concentrates through the aperture member at angles to the optic axis less than the acceptance angle with the optical efficiency greater than 99%. ### Claim 50 (depends on 33) The concentrator tube of claim 33, wherein the acceptance angle is greater than 10 degrees. ### Claim 51 (depends on 33) The concentrator tube of claim 33, wherein the acceptance angle is greater than 20 degrees. ### Claim 52 (depends on 33) The concentrator tube of claim 33, wherein the acceptance angle is greater than 25 degrees. ### Claim 53 (depends on 33) The concentrator tube of claim 33, wherein the acceptance angle is greater than 35 degrees. ### Claim 54 (depends on 33) The concentrator tube of claim 33, wherein the absorber comprises a heat pipe. ### Claim 55 (depends on 43) The concentrator tube of claim 43, wherein the absorber comprises a u-shaped tube coupled to an absorber fin. ### Claim 56 (depends on 33) The concentrator tube of claim 33, wherein the aperture member has an optical power of substantially zero. ### Claim 57 (depends on 33) The concentrator tube of claim 33, wherein the aperture member does not change a direction of the light from the source. ### Claim 58 (depends on 33) The concentrator tube of claim 33, wherein the reflector portion is configured to compensate for aberrations in the light entering the concentrator tube due to refraction by the aperture member. ### Claim 59 (depends on 33) The concentrator tube of claim 33, wherein the absorber has a tapered form factor. ### Claim 60 (depends on 33) The concentrator tube of claim 33, wherein the reflector portion is configured such that a gap exists between the absorber and a bottom section of the reflector portion. ### Claim 61 (depends on 33) The concentrator tube of claim 33, wherein the reflector portion is configured such that substantially all radiation energy emitted from the absorber onto the reflector portion is directed to the source. ### Claim 62 (depends on 33) The concentrator tube of claim 33, wherein a cross section of the reflector portion has a compound parabolic shape. ### Claim 63 (depends on 33) The concentrator tube of claim 33, wherein the reflector portion and the aperture member are formed by rolling a mandrel on an outside surface of a softened glass tube. ### Claim 64 A method of forming a concentrator tube extending from a distal end to a proximal end, comprising: forming a trough shaped reflector portion extending between the proximal end and the distal end and defining an upper opening, the reflector portion configured to concentrate light from a source onto an absorber; forming a light transmissive aperture member closing the upper opening of the trough shaped reflector portion; and positioning the absorber located within the tube; wherein the reflector portion is configured such that substantially any radiation energy emitted from the absorber onto the reflector portion is either directed to the source or directed back to the absorber, and wherein the reflector portion is further configured to compensate for aberrations in the light entering the concentrator tube due to refraction by the aperture member. ### Claim 65 (depends on 64) The method of claim 64, wherein the reflector portion and the aperture member are formed by rolling a mandrel on an outside surface of a softened glass tube ### Claim 66 (depends on 64) The method of claim 64, further comprising: forming a seal at each end of the tube to form a substantial vacuum within the tube. ### Claim 67 (depends on 66) The method of claim 66, wherein the seal on at least one end is a metal-to-glass seal. ### Claim 68 A method comprising: receiving light from a source through a light transmissive aperture member of a concentrator tube extending from a distal end to a proximal end; reflecting and concentrating at least a portion of the light to an absorber of the concentrator tube by a trough shaped reflector portion of the concentrator tube, wherein the reflector portion extends between the proximal end and the distal end, the reflector portion defines an upper opening that is closed by the light transmissive aperture member, and the reflector portion has a cross section of a compound parabolic shape; and absorbing the light by the absorber located in the tube, wherein the reflector portion is configured such that substantially any radiation energy emitted from the absorber onto the reflector portion is either directed to the source or directed back to the absorber, wherein the absorber comprises a plurality of minichannels configured to have a thermal energy transfer fluid flowing therethrough. ### Claim 69 (depends on 68) The method of claim 68, further comprising: converting energy from the light into a thermal energy in the absorber. ### Claim 70 (depends on 68) The method of claim 68, wherein the source is the sun.