Claims
- 1. A thermophotovoltaic generator comprising a burner, a combustion air guide leading to the burner, a low NOx radiant tube burner extending upwards around the burner, an infrared emitter spaced outward from the tube burner, a photovoltaic cell array spaced outward from the emitter, an exhaust guide connected to the generator for exhausting combustion gases, a recuperator connected to the combustion air guide and to the exhaust guide for preheating combustion air with exhaust gases, and a fold-back emitter support tube extending along the recuperator.
- 2. The generator of claim 1, further comprising inert gas disposed between the emitter and the photovoltaic cell array.
- 3. The generator of claim 2, further comprising a hermetic seal between the support tube and the array for sealing the inert gas between the support tube and the array.
- 4. The generator of claim 1, further comprising end mirrors at opposite ends of the array for reflecting infrared rays toward the array.
- 5. The generator of claim 1, wherein the recuperator comprises fins extending into the combustion air guide and into the exhaust guide, the recuperator further comprising dual coaxial recuperator assembly.
- 6. The generator of claim 5, wherein the coaxial recuperator elements are formed of an inner stack and an outer stack.
- 7. The generator of claim 6, wherein each stack is formed of disks having inward and outward extending fins and rings interconnecting the disks.
- 8. A thermophotovoltaic generator comprising a burner, a combustion air guide leading to the burner, a low NOx radiant tube burner extending from around the burner, an infrared emitter spaced outward from and surrounding the tube burner, a photovoltaic cell array spaced outward from the emitter, an exhaust guide connected to the generator for exhausting combustion gases, and inert gas disposed between the emitter and the photovoltaic cell array.
- 9. The generator of claim 8, further comprising a hermetic seal between the support tube and the array for sealing the inert gas between the support tube and the array.
- 10. The generator of claim 8, further comprising end mirrors at opposite ends of the array for reflecting infrared rays toward the array.
- 11. The generator of claim 8, wherein the burner tube comprises a tapered burner tube for controlling spacing between the tapered burner tube and the emitter.
- 12. A thermophotovoltaic generator comprising a burner, a combustion air guide leading to the burner, a low NOx radiant tube burner extending from the around the burner, an infrared emitter spaced outward from the tube burner, a photovoltaic cell array spaced outward from the emitter, an exhaust guide connected to the generator for exhausting combustion gases, and end mirrors at opposite ends of the array for reflecting infrared rays toward the array.
- 13. The generator of claim 12, wherein the tube burner comprises a tapered burner tube for controlling spacing between the tapered burner tube and the emitter.
- 14. A thermophotovoltaic generator comprising a burner, a combustion air guide leading to the burner, a low NOx radiant burner tube extending from the around the burner, an infrared emitter spaced outward from the tube burner, a photovoltaic cell array spaced outward from and surrounding the emitter, an exhaust guide connected to the generator for exhausting combustion gases, and wherein the burner tube comprises a tapered burner tube for controlling spacing between the tapered burner tube and the emitter.
- 15. A thermophotovoltaic generator comprising a burner, a combustion air guide leading to the burner, a low NOx radiant tube burner extending around the burner, an infrared emitter spaced outward from and surrounding the tube burner, a photovoltaic cell array spaced outward from the emitter, an exhaust guide connected to the generator for exhausting combustion gases, a fold back emitter support tube having an inner portion connected to the emitter having a middle portion extending away from the emitter then outward and then in the direction of the emitter and then outward for connecting to an enclosure for reducing conduction heat flow from the emitter along the emitter support tube to the enclosure.
- 16. The generator of claim 15, further comprising inert gas disposed between the emitter and the photovoltaic cell array.
- 17. The generator of claim 16, further comprising a hermetic seal between the support tube and the array for sealing the inert gas between the support tube and the array.
- 18. The generator of claim 15, further comprising end mirrors at opposite ends of the array for reflecting infrared rays toward the array.
- 19. The generator of claim 15, wherein the burner tube comprises a tapered burner tube for controlling spacing between the tapered burner tube and the emitter.
- 20. The generator of claim 15, further comprising a recuperator having coaxial elements with an inner stack positioned inside the middle portion and having an outer stack positioned outside the middle portion.
- 21. The generator of claim 20, wherein the middle portion of the emitter support tube and the recuperator turnaround plate form the exhaust guide and further comprising a porous portion of the turnaround plate for leaking combustion air into the exhaust guide.
- 22. The generator of claim 21, further comprising catalyst coatings on at least some of the fins extending into the exhaust guide and cooperating with leaked combustion air for completing combustion of the exhaust gases.
- 23. A thermophotovoltaic generator apparatus comprising a radiant tube burner running in low NOx flameless oxidation mode, an array of low bandgap photovoltaic cells surrounding the burner for converting infrared radiant energy to electricity.
- 24. The apparatus of claim 23, wherein the tube burner is a recuperative radiant tube burner comprising a first and largest diameter outer SiC tube closed at an hot end, a second inner SiC flame tube inside the outer SiC tube at the hot end, a third SiC recuperator tube assembly inside the first outer tube and located toward the cold end, a larger diameter coaxial emitter support tube, wherein the outer SiC tube is bonded to the larger diameter coaxial emitter support tube and wherein the emitter support tube comprises a fold back section folded back toward the hot end of the outer SiC tube and terminating in a flange.
- 25. The apparatus of claim 24, further comprising a photovoltaic container having a complementary flange on one end forming a seal with the flange on the end of the emitter support tube.
- 26. The apparatus of claim 25, wherein the seal forms a space between the emitter tube and the photovoltaic array and an inert gas back-filling the space.
- 27. The apparatus of claim 26, wherein the folded back coaxial emitter support tube forms an elongated path for limiting thermal conduction along cylindrical walls of the emitter tube from a very hot emitter section to a cooled seal flange section.
- 28. The apparatus of claim 26, wherein the recuperator assembly is a two stage folded back recuperator assembly comprising two coaxial recuperator sections.
- 29. The apparatus of claim 28, wherein each recuperator section comprises a stack of large finned disks on one section, and wherein the one section is disposed outside the emitter support tube and another section is disposed inside the fold back section of the first SiC tube.
- 30. The apparatus of claim 29, wherein the two coaxial recuperator comprises hot and cool sections wherein the hot section is inside the cool sections.
- 31. The apparatus of claim 24, further comprising an infrared AR/RM emitter.
- 32. The apparatus of claim 31, further comprising inert gas between the infrared AR/RM emitter and the photovoltaic array.
- 33. The apparatus of claim 31, further comprising a hermetic seal between the emitter support tube and the photovoltaic cell array.
- 34. The apparatus of claim 31, wherein the emitter support tube is a fold back coaxial emitter support tube disposed within the dual coaxial recuperator assembly.
- 35. The apparatus of claim 34, further comprising end mirrors for confining infrared energy.
- 36. The apparatus of claim 31, further comprising a tapered inner flame tube for tailoring an emitter temperature uniformity.
- 37. The apparatus of claim 36, further comprising a gap between the inner flame tube and the recuperator for exhaust gas re-circulation for low NOx.
- 38. The apparatus of claim 37, further comprising an insulation along rounded ends of the emitter support tube.
- 39. A thermophotovoltaic generator apparatus comprising a low NOx radiant tube burner comprising an integrated SiC assembly having an inner SiC flame tube, an SiC recuperator, a gap between the inner flame tube and the recuperator for increasing energy conversion efficiency, and a photovoltaic cell array surrounding the tube burner for converting infrared radiant energy to electric power.
- 40. The apparatus of claim 39, further comprising an emitter and an emitter support tube around the burner tube, mirrors at ends of the array for confining infrared energy between the emitter and the array.
- 41. The apparatus of claim 40, wherein the burner tube within the emitter support tube is tapered for optimizing emitter temperature profile along a length of the emitter.
- 42. The apparatus of claim 41, wherein the mirrors and the tapered burner tube provide uniform illumination of cells in the array enabling all the cells in a series string to generate a similar current.
- 43. The apparatus of claim 42, wherein the generator is adapted for integration in a home cogenerator for operating with low NOx.
- 44. The apparatus of claim 43, further comprising a fuel and air mixture close to a stoichiometric mixture for operating the generator and for de-localizing a flame and allowing for combustion at a lower temperature in larger volumes of the mixture.
- 45. The apparatus of claim 44, wherein the gap between the recuperator and the inner flame tube allows for exhaust gas recirculation to complete combustion.
- 46. The apparatus of claim 45, wherein the generator is a cylindrical thermophotovoltaic generator for low NOx.
- 47. The apparatus of claim 45, further comprising coupling infrared radiation to the photovoltaic array for preventing heat loss at an end of the radiant tube burner.
- 48. The apparatus of claim 47, further comprising heat shields or insulation disposed around the outer SiC tube except in areas proximal the AR/RM emitter.
Parent Case Info
[0001] This application claims the benefit of U.S. Provisional Application No. 60/329,761, filed Oct. 18, 2001.
Provisional Applications (1)
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Number |
Date |
Country |
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60329761 |
Oct 2001 |
US |