Solar collector system

• US 4,117,682 A
• Filed: 11/01/1976
• Issued: 10/03/1978
• Est. Priority Date: 11/01/1976
• Status: Expired due to Term

• Current Assignee: Otto J.M. Smith
• Original Assignee: Otto J.M. Smith
• Inventors: Smith, Otto J. M.
• Primary Examiner(s): Ostrager, Allen M.
• Assistant Examiner(s): Husar, Stephen F.
• Application Number:
  US05/737,489
• Time in Patent Office: 701 Days
• Field of Search: 60/659, 60/641, 60/676, 60/679, 60/651, 60/671, 60/670, 126/270, 126/271
• US Class Current: 60/641.8
• CPC Class Codes: F03G 6/065 having a Rankine cycle
• CPC Class Codes: F24S 20/20 Solar heat collectors for receiving concentrated solar energy, e.g. receivers for solar power plants
• CPC Class Codes: F24S 2023/87 Reflectors layout
• CPC Class Codes: F24S 23/745 flexible
• CPC Class Codes: Y02E 10/40 Solar thermal energy, e.g. solar towers
• CPC Class Codes: Y02E 10/46 Conversion of thermal power into mechanical power, e.g. Rankine, Stirling or solar thermal engines

Abstract

A solar collector system uses a hexagonal field module of heliostatic mirrors with each heat receptor tower being located outside of its associated module. Each mirror includes a reflecting film held down electrostatically (for easy replacement) and protected by wind guards.

Claims

1. A solar collector system comprising:

a plurality of solar receptors supported on towers;

a plurality of heliostatic mirrors, a predetermined plurality of such mirrors laid out in a geometric pattern forming a field module with a unique associated tower on which such field module concentrates solar energy, each of said field modules being substantially contiguous to one another and interlocked, said unique tower being located outside of its associated field module.

2. A system as in claim 1 in which said geometric pattern is a hexagon.

3. A system as in claim 2 where said hexagon is non-regular.

4. A system as in claim 1 where each mirror comprises:

a substantially cylindrical surface; and

a relatively thin flexible reflecting sheet laid on said surface; and

means for retaining said sheet on said surface.

5. A system as in claim 4 where said retaining means includes an electrostatic hold-down grid.

6. A system as in claim 1 where each mirror comprises:

a substantially planar surface; and

a relatively thin reflecting sheet laid on said surface; and

means for retaining said sheet on said surface.

7. A system as in claim 6 where said retaining means includes an electrostatic hold-down grid.

8. A system as in claim 6 where said retaining means includes wind guard means extending upwardly from the edge of said planar surface.

9. A system as in claim 1 together with a thermal power plant having fluids at at least two different temperature ranges and where one of said field modules provides heating for a fluid of one temperature range and another field module for the other temperature range.

10. A system as in claim 1 where each mirror comprises:

a substantially paraboloid surface; and

a relatively thin flexible reflecting sheet laid on said surface; and

means for retaining said sheet on said surface.

11. A system as in claim 10 where said retaining means includes an electrostatic hold-down grid.

12. A system as in claim 10 where said reflecting sheet is a portion of a longer sheet available for future replacement.

13. A system as in claim 1 including power plant means having a turbine and heat exchanger means connected to said plurality of solar receptors said heat exchanger means receiving a pressurized first liquid from said solar receptors and providing a working fluid for said turbine, means for pumping said pressurized first liquid through said heat exchanger;

means for superheating said working fluid;

heat energy sensor means for the said superheated working fluid at the throttle of said turbine, and control means for controlling said pumping means to maximize said heat energy sensed by said sensor means.

14. A system as in claim 13 together with first liquid storage means intermediate said heat exchanger means and said solar receptor including second pumping means, means for sensing said liquid temperature, and control means responsive to said temperature for adjusting said second pumping means to maintain said temperature constant.

15. A system as in claim 13 where said turbine drives an electrical generator together with means for sensing the output of said generator, said control means being responsive to said output to maximize such output by controlling said pumping means.

16. A system as in claim 13 where said first liquid is water and said working fluid is water.

17. A system as in claim 1 including power plant means having a turbine, generator, and heat exchanger means connected to said plurality of solar receptors said heat exchanger means receiving a first liquid from said solar receptors and providing a working fluid for said turbine, means for pumping said first liquid through said heat exchanger, means for sensing the electrical output of said generator, and control means for controlling said pumping means to maximize said electrical output sensed by said sensing means.

18. A system as in claim 17 where said first liquid flows between two glass panes of a double-paned window on one of said receptors.

19. A system as in claim 17 where said first liquid flows in metal pipes in the interior of one of said receptors.

20. A system as in claim 19 where said first liquid is water.

21. A system as in claim 19 where said metal pipes are coated with a black solar-energy-absorbing coating.

22. A system as in claim 1 in which said towers form first rows in approximately a north-south direction, and said towers form second rows in approximately an east-west direction, and said towers form third rows in approximately a northwest-southeast direction, the distance between adjacent towers in one of said second rows being greater than the distance between adjacent towers in one of said third rows.

23. A system as in claim 22 where the distance between adjacent towers in one of said third rows is greater than the distance between adjacent towers in one of said first rows.

24. A system as in claim 1 together with a thermal power plant having fluids at at least two different pressures, and where one of said field modules provides heating for a first liquid at a first pressure, and another field module provides heating for a second fluid at a second pressure.

25. A system as in claim 24 where said first and second fluids are different phases of a single fluid where said first phase is superheated steam which flows to a high-pressure turbine in said thermal power plant, and where said second phase is the low-pressure steam from said turbine being reheated.

26. A system as in claim 1 wherein each of said receptors comprises a cavity with an optical opening, and means for reflecting said solar energy through said opening by reflective shields adjacent to and outside of the boundaries of said opening.

27. A system as in claim 26 wherein said optical opening is a double-paned window.

28. A system as in claim 27 including means for circulating a coolant fluid in the interpand space of said double-paned window.

29. A system as in claim 28 wherein said fluid as an optical refractive index substantially similar to that of the panes of said double-paned window.

30. A system as in claim 1 wherein each of said receptors comprises a cavity with an optical opening, and means for reducing convective air flows near said opening by convection shields adjacent to and outside of the boundaries of said opening.

31. A system as in claim 30 wherein said optical opening is a double-paned window.

32. A system as in claim 31 including means for circulating a coolant fluid in the interpane space of said double-paned window, said fluid having an optical refractive index substantially similar to that of the panes of said double-paned window.

36. A system as in claim 1 where each mirror comprises:

a substantially paraboloid surface; and

a relatively thin reflecting sheet laid on said surface; and

means for retaining said sheet on said surface.

37. A system as in claim 1 where said geometric pattern forming a field module is a function of the time of day, and means for changing said geometric pattern with respect to said unique associated tower.

38. A system as in claim 37 where said field module lies to the north and west of said unique tower in the morning, and said field module lies to the north of said unique tower at noon, and said field module lies to the north and east of said unique tower in the afternoon.

33. A solar collector system comprising:

a plurality of solar receptors supported on towers;

a plurality of heliostatic mirrors, a control system for one of said mirrors which is associated with a first and a second of said receptors for selected predetermined times of day, means for reflecting solar light from said mirror toward said first receptor before said predetermined time, and means for reflecting solar light from said mirror toward said second receptor after said predetermined time.

34. A system as in claim 33 where all of the heliostatic mirrors which are reflecting solar light toward said first reflector at any one time form a first field module with a geometrical pattern which is hexagonal, and all of the heliostatic mirrors which are reflecting solar light toward said second reflector at said time form a second geometrical field module pattern which is hexagonal.

35. A system as in claim 34 where said first and said second field modules are contiguous.

39. A system as in claim 33 where substantially all of the heliostatic mirrors which are reflecting solar light toward said first reflector at a predetermined time form a first field module with a geometrical pattern which is substantially hexagonal, and substantially all of the heliostatic mirrors which are reflecting solar light toward said second reflector at said predetermined time form a second geometrical field module pattern which is substantially hexagonal.

40. A system as in claim 39 where said first and second field modules are contiguous.

41. A system as in claim 33 where said mirrors have a substantially planar surface, with a relatively thin reflecting sheet laid on said surface, and means for retaining said sheet on said surface.

42. A system as in claim 33 wherein said mirrors have a substantially paraboloid surface, with a relatively thin flexible reflecting sheet laid over said surface, and means for retaining said sheet on said surface.

43. A system as in claim 33 wherein one of said receptors has window means consisting of two visibly transparent panes and means for circulating a transparent fluid between said panes.

44. A system as in claim 43 wherein said solar light from said mirror toward said first receptor is transmitted through said window.

45. A system as in claim 44 wherein said fluid has an optical refractive index substantially similar to that of said visibly transparent panes.

46. A solar collector system comprising:

a plurality of heliostatic mirrors, a first windowed solar receptor on a tower, a second windowed solar receptor on a second tower, a predetermined plurality of said mirrors concentrating solar energy on said first solar receptor, another predetermined plurality of said mirrors concentrating solar energy on said second solar receptor, first heat absorbing pipes within said first receptor, second heat absorbing pipes within said second receptor, a thermodynamic system containing a turbine, and means for circulating a first fluid through said first pipes to provide heat energy for said turbine, and means for circulating a second fluid through said second pipes to provide additional heat energy to said thermodynamic system.

47. A system as in claim 46 where said first fluid is dry steam for the inlet of said turbine and where said second fluid is liquid water.

48. A system as in claim 46 together with a heat-exchanger-boiler, and a circulating pump, where said second fluid is pumped by said pump through said second pipes and back at high temperature through said heat-exchanger-boiler, means for providing feed water to said boiler, and means for providing the steam produced by said boiler as said first fluid into said first pipes.

49. A system as in claim 46 together with a first and a second heat exchanger, a first and a second circulating pump, and a feed water supply, where said first fluid is pumped by said first pump through said first pipes and said first heat exchanger to increase the thermal energy of a flow of feed water from said feed water supply through said first heat exchanger to an outlet port, and where said second fluid is said feedwater which is pumped by said second pump through said second pipes and said second heat exchanger to increase the thermal energy of the flow from said output port through said second heat exchanger.

50. A solar collector system comprising:

a plurality of heliostatic mirrors, a first windowed solar receptor on a first tower, a second windowed solar receptor on a second tower, a predetermined plurality of said mirrors concentrating solar energy on said first solar receptor, another predetermined plurality of said mirrors concentrating solar energy on said second solar receptor, first heat absorbing pipes within said first receptor, second heat absorbing pipes within said second receptor, a thermodynamic system containing a turbine, and means for circulating through said first pipes a first phase of a working fluid for said turbine, and means for circulating through said second pipes a second phase of said working fluid.

51. A system as in claim 50 where said first phase is saturated steam from a boiler in said thermodynamic system, and wherein said second phase is low pressure dry steam from the exhaust of said turbine being reheated.

52. A system as in claim 50 wherein said first phase is boiler feed water and wherein said second phase is steam.