Solar thermal aerogel receiver and materials therefor
A silica aerogel having a mean pore size less than 5 nm with a standard deviation of 3 nm. The silica aerogel may have greater than 95% solar-weighted transmittance at a thickness of 8 mm for wavelengths in the range of 250 nm to 2500 nm, and a 400° C. black-body weighted specific extinction coefficient of greater than 8 m 2 /kg for wavelengths of 1.5 μm to 15 μm. Silica aerogel synthesis methods are described. A solar thermal aerogel receiver (STAR) may include an opaque frame defining an opening, an aerogel layer disposed in the opaque frame, with at least a portion of the aerogel layer being proximate the opening, and a heat transfer fluid pipe in thermal contact with and proximate the aerogel layer. A concentrating solar energy system may include a STAR and at least one reflector to direct sunlight to an opening in the STAR.
1. A solar thermal aerogel receiver comprising:
an opaque frame defining an opening;
an aerogel layer disposed in the opaque frame, with at least a portion of the aerogel layer being disposed proximate the opening; and
a heat transfer fluid pipe in thermal contact with and proximate the aerogel layer.
2. The solar thermal aerogel receiver of claim 1 , wherein the aerogel layer comprises silica aerogel.
3. The solar thermal aerogel receiver of claim 2 , wherein the silica aerogel defines a porous material with pores having a mean radius of less than 5 nm with a standard deviation of 3 nm.
4. The solar thermal aerogel receiver of claim 1 , wherein the aerogel layer comprises an absorber layer.
5. The solar thermal aerogel receiver of claim 1 , wherein the aerogel layer comprises silica aerogel having (i) greater than 95% solar-weighted transmittance at a thickness of 8 mm for wavelengths selected from the range of 250 nm to 2500 nm; and (ii) a 400° C. black-body weighted specific extinction coefficient of greater than 8 m 2 /kg for wavelengths selected from the range of 1.5 μm to 15 μm.
6. The solar thermal aerogel receiver of claim 5 , wherein the opaque frame further comprises an insulating layer.
7. The solar thermal aerogel receiver of claim 1 , wherein the heat transfer fluid pipe comprises a black absorber layer.
8. The solar thermal aerogel receiver of claim 1 further comprising a transparent outer layer disposed in the opening in the opaque frame.
9. The solar thermal aerogel receiver of claim 8 , wherein the transparent outer layer comprises at least one of glass and a transparent polymer.
10. The solar thermal aerogel receiver of claim 8 , wherein the transparent outer layer forms at least a portion of a flat bottom surface of the opaque frame.
11. The solar thermal aerogel receiver of claim 8 , wherein the aerogel layer is in direct contact with the transparent outer layer.
12. The solar thermal aerogel receiver of claim 8 , wherein the transparent outer layer and the aerogel layer define an air gap therebetween.
13. The solar thermal aerogel receiver of claim 1 , wherein the receiver has a maximum solar-to-exergy conversion efficiency of greater than 35% at an optical concentration of 40 suns.
14. A concentrating solar energy system comprising:
a solar thermal aerogel receiver comprising:
an opaque frame defining an opening,
an aerogel layer disposed in the opaque frame, with at least a portion of the aerogel layer being disposed proximate the opening, and
a heat transfer fluid pipe in thermal contact with and proximate to the aerogel layer; and
at least one reflector configured to direct sunlight to the opening.
15. The concentrating solar energy system of claim 14 , wherein the aerogel layer comprises an absorber layer.
16. The concentrating solar energy system of claim 14 , wherein the aerogel layer comprises silica aerogel.
17. The concentrating solar energy system of claim 16 , wherein the silica aerogel defines a porous material with pores having a mean radius of less than 5 nm with a standard deviation of 3 nm.
18. The concentrating solar energy system of claim 14 , wherein the aerogel layer comprises silica aerogel having (i) greater than 95% solar-weighted transmittance at a thickness of 8 mm for wavelengths selected from the range of 250 nm to 2500 nm; and (ii) a 400° C. black-body weighted specific extinction coefficient of greater than 8 m 2 /kg for wavelengths selected from the range of 1.5 μm to 15 μm.
19. The concentrating solar energy system of claim 14 , wherein the heat transfer fluid pipe comprises a black absorber layer.
20. The concentrating solar energy system of claim 14 , wherein the opaque frame further comprises an insulating layer.
21. The concentrating solar energy system of claim 14 , wherein the solar thermal aerogel receiver has a maximum solar-to-exergy conversion efficiency of greater than 35% at an optical concentration of 40 suns.
22. The concentrating solar energy system of claim 14 further comprising a transparent outer layer disposed in the opening.
23. The concentrating solar energy system of claim 22 , wherein the transparent outer layer comprises at least one of glass and a transparent polymer.
24. The concentrating solar energy system of claim 22 , wherein the aerogel layer is in direct contact with the transparent outer layer.
25. The concentrating solar energy system of claim 22 , wherein the transparent outer layer and the aerogel layer define an air gap therebetween.
26. The concentrating solar energy system of claim 22 , wherein the transparent outer layer forms at least a portion of a flat bottom surface of the opaque frame.