METHODS AND SYSTEMS FOR CONCENTRATED SOLAR POWER

• US 20130257056A1
• Filed: 04/02/2013
• Published: 10/03/2013
• Est. Priority Date: 04/02/2012
• Status: Active Grant

• Current Assignee: Alliance For Sustainable Energy LLC
• Original Assignee: Alliance For Sustainable Energy LLC
• Inventors: MA, Zhiwen
• Granted Patent: US 9,347,690 B2
• Time in Patent Office: Days
• US Class Current: 290/52
• CPC Class Codes: E02D 27/38 Foundations for large tanks, e.g. oil tanks
• CPC Class Codes: E04H 7/26 mainly of concrete, e.g. reinforced concrete or other stone-like materials
• CPC Class Codes: F03G 6/065 having a Rankine cycle
• CPC Class Codes: F24S 10/80 comprising porous material or permeable masses directly contacting the working fluids for conveying liquefied working fluid from evaporator sections to condenser sections with capillary force F24S10/95
• 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 60/10 using latent heat
• CPC Class Codes: F24S 70/10 characterised by the absorbing material absorbing coatings or surface treatment for increasing absorption F24S70/20
• CPC Class Codes: F24S 80/20 Working fluids specially adapted for solar heat collectors
• CPC Class Codes: F24S 90/00 Solar heat systems not otherwise provided for
• CPC Class Codes: F28C 3/10 one heat-exchange medium at least being a fluent solid, e.g. a particulate material
• CPC Class Codes: F28C 3/12 the heat-exchange medium being a particulate material and a gas, vapour, or liquid
• CPC Class Codes: F28D 13/00 Heat-exchange apparatus using a fluidised bed
• CPC Class Codes: F28D 20/0056 using solid heat storage material F28D20/0052 takes precedence
• CPC Class Codes: F28D 2020/0047 using molten salts or liquid metals
• CPC Class Codes: F28D 2021/0045 for granular materials
• CPC Class Codes: H02K 7/1823 structurally associated with turbines or similar engines
• CPC Class Codes: Y02E 10/40 Solar thermal energy, e.g. solar towers
• CPC Class Codes: Y02E 10/44 Heat exchange systems
• CPC Class Codes: Y02E 10/46 Conversion of thermal power into mechanical power, e.g. Rankine, Stirling or solar thermal engines
• CPC Class Codes: Y02E 60/14 Thermal energy storage

Abstract

Embodiments described herein relate to a method of producing energy from concentrated solar flux. The method includes dropping granular solid particles through a solar flux receiver configured to transfer energy from concentrated solar flux incident on the solar flux receiver to the granular solid particles as heat. The method also includes fluidizing the granular solid particles from the solar flux receiver to produce a gas-solid fluid. The gas-solid fluid is passed through a heat exchanger to transfer heat from the solid particles in the gas-solid fluid to a working fluid. The granular solid particles are extracted from the gas-solid fluid such that the granular solid particles can be dropped through the solar flux receiver again.

Claims

1. A method of producing energy from concentrated solar flux, the method comprising:

dropping granular solid particles through a solar flux receiver configured to transfer energy from concentrated solar flux incident on the solar flux receiver to the granular solid particles as heat;

fluidizing the granular solid particles from the solar flux receiver to produce a gas-solid fluid;

passing the gas-solid fluid through a heat exchanger to transfer heat from the solid particles in the gas-solid fluid to a working fluid; and

extracting the granular solid particles from the gas-solid fluid such that the granular solid particles can be dropped through the solar flux receiver again.

2. The method of claim 1, comprising:

slowing a flow of the granular solid particle through the solar flux receiver using one or more baffles in the solar flux receiver.

3. The method of claim 1, comprising:

pumping the gas-solid fluid from the heat exchanger to a height above the solar flux receiver such that after extracting the solid particles from the gas-solid fluid, the solid particles can be dropped through the solar flux receiver.

4. The method of claim 1, comprising:

storing the solid particles from the solar flux receiver in a hot particle silo before fluidizing the solid particles.

5. The method of claim 4, comprising:

controlling an amount of solid particles from the hot particle silo that are fluidized and passed through the heat exchanger to adjust an amount of energy to be output.

6. The method of claim 1, comprising:

storing the solid particles after extracting and before passing through a solar flux receiver in a cold particle silo.

7. The method of claim 5, comprising:

mechanically lifting the solid particles from the cold particle silo to a drop position for the solar flux receiver.

8. The method of claim 7, comprising:

controlling an amount of solid particles lifted from the cold particle silo and dropped into the solar flux received based on an amount of solar flux incident on the solar flux receiver.

9. The method of claim 1, comprising:

recirculating gas from the gas-solid fluid for fluidizing the solid particles from the hot particle storage silo.

10. The method of claim 1, wherein extracting the solid particles from the gas-solid fluid includes cyclonically separating the solid particles from the gas-solid fluid.

11. The method of claim 1, wherein extracting the solid particles from the gas-solid fluid includes allowing the solid particles to settle out from the gas-solid fluid.

12. The method of claim 1, comprising:

driving a power turbine with the working fluid after the working fluid is heated in the heat exchanger.

13. A concentrating solar power system comprising:

a solar flux receiver configured to heat solid particles dropped therethrough using energy from concentrated solar flux incident on the solar flux receiver; and

a fluidized-bed heat exchanger configured to receive solid particles heated by the solar flux receiver, fluidize the solid particles to form a gas-solid fluid, and transfer heat from the gas-solid fluid to a working fluid.

14. The concentrating solar power system of claim 13, comprising:

a gas-solid separator configured to separate the solid particles from gas in the gas-solid fluid after the gas-solid fluid has passed through the fluidized-bed heat exchanger.

15. The concentrating solar power system of claim 14, wherein the gas-solid separator is a cyclone separator.

16. The concentrating solar power system of claim 14, comprising:

a cold particle silo configured to receive solid particles from the solid particle separator.

17. The concentrating solar power system of claim 16, wherein concrete is the primary structural material of the cold particle silo.

18. The concentrating solar power system of claim 16, comprising:

a lift mechanism configured to transport solid particles from the cold particle silo and drop the solid particles into the solar flux receiver.

19. The concentrating solar power system of claim 18, wherein the lift mechanism is a bucket conveyor.

20. The concentrating solar power system of claim 16, comprising:

a hot particle silo configured to receive the solid particles from the solar flux receiver, wherein solid particles are removed from the hot particle silo and transported to the fluidized-bed heat exchanger.

21. The concentrating solar power system of claim 20, wherein concrete is the primary structural material of the hot particle silo.

22. The concentrating solar power system of claim 20, wherein the hot particle silo is disposed lower in height than the solar flux receiver such that the solid particles can drop from the solar flux receiver into the hot particle silo.

23. The concentrating solar power system of claim 14, wherein the gas-solid separator is disposed at a height above the solar flux receiver such that the solid particles from the solid particle separator can drop from the gas-solid separator to the solar flux receiver.

24. The concentrating solar power system of claim 13, comprising:

a compressor configured to receive the gas from the solid particle separator, compress the gas, and provide the gas to the fluidized-bed heat exchanger for fluidizing the solid particles therein.

25. The concentrating solar power system of claim 13, wherein the solid particles include ash, sand, or a metal-oxide.

26. The concentrating solar power system of claim 13, wherein the fluidized-bed heat exchanger includes a stackup hybrid boiler having a stationary bed super heater with a turbulent bed evaporator on top of the stationary bed super heater, and a fast bed preheater on top of the turbulent bed evaporator;

and

a gas-solid separator configured to separate the solid particles from gas in the gas-solid fluid after the gas-solid fluid has passed through the fast bed preheater.

27. The concentrating solar power system of claim 26, wherein the solid particles enter the stationary bed super heater and are fluidized to form the gas-solid fluid, wherein the gas-solid fluid is forced upward through the turbulent bed evaporator and the fast bed preheater.

28. The concentrating solar power system of claim 13, wherein the fluidized-bed heat exchanger includes a cascading boiler having a stationary bed super heater with a turbulent bed evaporator beside the stationary bed super heater, and a bubbling bed preheater beside the stationary bed boiler, wherein the bubbling bed preheater outputs the solid particles separate from the gas.

29. The concentrating solar power system of claim 28, wherein the solid particles enter the stationary bed boiler and are fluidized to form the gas-solid fluid, wherein the gas-solid fluid is forced sideways through the turbulent bed evaporator and the bubbling bed preheater.

30. The concentrating solar power system of claim 13, wherein the fluidized-bed heat exchanger includes a pressurized system having a pressure chamber in which the solid particles are fluidized.

31. The concentrating solar power system of claim 30, wherein concrete is the primary structural material of the pressure chamber.

32. The concentrating solar power system of claim 13, comprising:

a power cycle configured to generate electricity from heat in the working fluid, wherein the power cycle comprises one of a supercritical steam Rankine cycle, an advanced supercritical-carbon dioxide Brayton cycle, a gas turbine cycle, or a gas turbine combined cycle.

33. A concentrating solar power system comprising:

a heat exchanger configured to transfer heat from solid particles to a working fluid;

a cold particle silo configured to receive and store cold particles from the heat exchanger, the cold particle silo disposed generally on the north side of the heat exchanger;

a solar flux receiver configured to heat solid particles passed therethrough using energy from concentrated solar flux, the solar flux receiver disposed on top of the cold particle silo and proximate an array of mirrors oriented to direct solar rays toward the solar flux receiver;

a lift mechanism configured to lift solid particles from a top of the cold particle silo and drop the solid particles into the solar flux receiver; and

a first hot particle silo configured to receive and store hot particles from the solar flux receiver, wherein the first hot particle silo is disposed generally on the south-west side of the cold particle silo, wherein the solar flux receiver is disposed higher than an entrance of the first hot particle silo such that solid particles can gravity flow from the solar flux receiver into the first hot particle silo.

34. The concentrating solar power system of claim 33, comprising:

a second hot particle silo configured to receive and store hot particles from the solar flux receiver, wherein the second hot particle silo is disposed generally on the south-east side of the cold particle silo; and

wherein first hot particle silo is configured to selectively receive hot or cold particles.

35. The concentrating solar power system of claim 33, wherein the cold particle silo has a generally flat floor and is configured to have solid particles placed therein and removed from a top thereof, wherein the hot particle silo has an inverted cone shaped bottom and is configured to have solid particles enter in the entrance on a top thereof and exit from the inverted cone shaped bottom.

36. The concentrating solar power system of claim 35, wherein the hot particle silo has a valve on an apex of the inverted cone shaped bottom to control an output flow of solid particles therefrom, wherein the valve comprises one of a tickle valve, J-valve, L-valve, loop seal, or plate control valve.

37. The concentrating solar power system of claim 33, wherein the cold particle silo and the hot particle silo have a height of a solid particle storage area that is at least twice as large as a diameter.

38. A silo for storage of high temperature solid particles, the silo comprising:

a concrete container having one or more generally vertical walls;

mineral wool insulation disposed on an outside of the one or more generally vertical walls;

calcium silicate insulation disposed on an inside of the one or more generally vertical walls; and

a refractory lining disposed on an inside surface of the calcium silicate insulation.

39. The silo of claim 38, wherein the refractory lining is composed of fire bricks.

40. A concentrating solar power system comprising:

a solar flux receiver configured to heat granular solid particles dropped therethrough using energy from concentrated solar flux incident on the solar flux receiver; and

a heat exchanger configured to receive solid particles heated by the solar flux receiver and transfer heat from the solid particles to a working fluid, wherein the heat exchanger is configured to have the solid particles dropped in a top thereof and to flow downward through the heat exchanger while contacting vertically oriented plates within the heat exchanger, wherein the vertically oriented plates are configured to transfer heat from the solid particles to the working fluid, wherein the solid particles exit from a bottom of the heat exchanger.

41. A concentrated solar power receiver comprising:

a plurality of open ended solar flux absorbers, the plurality of absorbers configured to have solar flux from a solar field enter into an open end thereof such that the solar flux enters into the absorber and is absorbed by an interior surface of the absorber, wherein the plurality of absorbers are spaced apart from one another such that a heat transfer material can pass between the absorbers.

42. The concentrated solar power receiver of claim 41 comprising:

a housing around a backside of the plurality of absorbers; and

structure disposed between the open ends of the absorbers thereby closing off any space between the open ends, wherein the closed off space between the respective open ends and the housing enclose a void about a body of the plurality of absorbers such that the heat transfer material can flow through the void and contact the plurality of absorbers.

43. The concentrated solar power receiver of claim 42, wherein the structure disposed between the open ends of the absorbers includes beveled surfaces extending from the open ends of the absorbers forming a wider opening, wherein the beveled surfaces of a first absorber abut the beveled surfaces adjacent absorbers to close off any space between adjacent absorbers.

44. The concentrated solar power receiver of claim 43, wherein the beveled surfaces extend in a hexagon shape, wherein each of the six beveled surfaces of the hexagon shape abut and align with a beveled surface of an adjacent absorber.

45. The concentrated solar power receiver of claim 43, wherein the absorbers comprise a mouth portion and a body portion, the mouth portion comprising the beveled surfaces that extend from the open end of the absorber, and the body portion extending from the mouth portion, the body portion comprising a hollow body.

46. The concentrated solar power receiver of claim 45, wherein the body portion comprises a tube having an open end abutting the mouth portion and closed end opposite the mouth portion, wherein the tube has a smaller diameter than the mouth portion.

47. The concentrated solar power receiver of claim 46, wherein the body portion of adjacent absorbers are spaced apart from one another such that the heat transfer material can flow between outer surfaces of the body portions of the adjacent absorbers, wherein the body portion of the absorbers are configure to absorb energy from the solar flux and release the energy as heat to the heat transfer material.

48. The concentrated solar power receiver of claim 46, wherein the plurality of absorbers are staggered such that the body portions slow the flow of the heat transfer material therethrough by causing the heat transfer material to change directions of flow as the heat transfer material flows through the plurality of absorbers.

49. The concentrated solar power receiver of claim 46, wherein the body portions of the plurality of absorbers include a plurality of features extending from an outside surface thereof, the plurality of features configured to slow the flow of the heat transfer material therethrough and cause blending of the heat transfer material as the heat transfer material flows through the plurality of absorbers.

50. The concentrated solar power receiver of claim 46, wherein at least a first subset of the plurality of absorbers are disposed such that the mouth portion is downward from the body portion in order to receive light from near field solar reflectors and to force the heat transfer material to flow towards the mouth portion of the absorbers.

51. The concentrated solar power receiver of claim 46, wherein an interior surface of the mouth portion of the absorber has a reflective surface to reflect solar flux incident thereon farther into the absorber, wherein at least a portion of an interior surface of the body portion of the absorber has an absorptive surface configured to absorb solar flux incident thereon.

52. The concentrated solar power receiver of claim 51, wherein a forward section of the interior surface of the body portion of the absorber has a reflective surface, the forward section proximate the mouth portion, and a back section of the interior surface of the body portion of the absorber has the absorptive surface.

53. The concentrated solar power receiver of claim 46, wherein an aspect ratio of a length of the body portion over a diameter of the body portion of the absorber is between 1 and 15.

54. The concentrated solar power receiver of claim 46, wherein a closed end of the body portion of the absorbers is attached to the housing, and wherein abutting edges of adjacent beveled surfaces are bonded together.

55. The concentrated solar power receiver of claim 54, comprising:

at least one support structure extending from the housing to the mouth portion of one or more of the plurality of absorbers, the at least one support structure configured to provide mechanical support for the open end of the one or more absorbers.

56. The concentrated solar power receiver of claim 42, comprising:

one or more orifice plates configured to control the flow of solid particles through the receiver.

57. The concentrated solar power receiver of claim 56, wherein the one or more orifice plates comprise two or more orifice plates adjacent to one another, the two or more orifice plates configured to control a flow of solid particles into a respective section of the plurality of absorbers.

58. The concentrated solar power receiver of claim 57, wherein the one or more orifice plates can be controlled based on the available solar flux such that when less solar flux is available a subset of the orifice plates are opened to allow solid particles to flow through a subset of the sections of the absorbers and when more solar flux is available additional orifice plates can be opened to allow solid particles to flow through additional sections of the absorbers.

59. The concentrated solar power receiver of claim 42, wherein the housing is composed of silicon carbide.

60. The concentrated solar power receiver of claim 41, wherein a second subset of the plurality of absorbers are disposed horizontally.

61. The concentrated solar power receiver of claim 60, wherein the second subset of the plurality of absorbers is disposed below the first subset.

62. The concentrated solar power receiver of claim 61, comprising:

a tube extending into a region proximate the junction of the first subset of the plurality of absorbers and the second subset of the plurality of the absorbers, the tube configured to introduce a gas into the receive to partially fluidize solid particles flowing through the receiver.

63. The concentrated solar power receiver of claim 62, comprising:

one or more orifice plates configured to control the flow of solid particles through the receiver, wherein the one or more orifice plates are disposed proximate the junction of the first subset of the plurality of absorbers and the second subset of the plurality of absorbers in order to control the flow of particles from the first subset into the second subset.

64. The concentrated solar power receiver of claim 41, wherein the plurality of absorbers are oriented to capture solar flux from multiple sides.

65. The concentrated solar power receiver of claim 41, comprising:

a hollow central portion proximate a backside of the absorbers, the hollow central portion extending vertically through the receiver and opening above the absorbers such that a lift mechanism configured to lift solid particles can lift the solid particles through the hollow central portion and drop the solid particles onto the plurality of absorbers.

66. The concentrated solar power receiver of claim 41, comprising:

one or more movable covers configured having a closed position in which the open ends of the plurality of absorbers are covered from the external environment, and an open position in which the open ends of the plurality of absorbers are exposed to the external environment and able to receive solar flux from a reflector field.

67. The concentrated solar power receiver of claim 41, wherein at least a subset of the plurality of absorbers are composed of metal.

68. The concentrated solar power receiver of claim 67, wherein the at least a subset of the plurality of absorbers include a coating of dual-band absorptive material on at least a portion of an interior surface thereof.

69. The concentrated solar power receiver of claim 41, wherein at least a subset of the plurality of absorbers are composed of a ceramic.

70. The concentrated solar power receiver of claim 69, wherein the at least a subset of the plurality of absorbers are composed of silicon carbide.

71. The concentrated solar power receiver of claim 41, wherein the heat transfer material is one of granular solid particles, gas, or a liquid.

72. A concentrated solar power receiver comprising:

a front member having an absorbing surface configured to absorb a majority of the solar flux from a solar field incident on the absorbing surface; and

a back member spaced apart from the front member and at least partially defining a void between at least a portion of an inside surface of the front member and the back member, wherein the inside surface of the front member is reverse of the absorbing surface, and wherein the void is configured to have granular solid particles dropped therethrough, wherein the granular solid particles can be heated by thermal radiation from a backside of the front member.

73. The concentrated solar power receiver of claim 72, comprising:

a plurality of baffles disposed in the void, the void configured to have granular solid particles dropped therethrough, wherein a first subset of the plurality of baffles extends from the back member and a second subset of the plurality of baffles extends opposite the first subset of baffles, is vertically offset from the first subset, extends interstitially between baffles of the first subset such that the solid particles weave downward through the plurality of baffles.

74. The concentrated solar power receiver of claim 73, wherein the absorbing surface has a waved shape to reduce reflection of solar flux.

75. The concentrated solar power receiver of claim 74, comprising:

an intermediate member disposed between the back member and outward arced portions of the front member, and defining a second void between a first side of the intermediate member and the inside surface of the outward arced portions of the front member, wherein the void at least partially defined by the back member and at least a portion of the inside surface of the front member is defined by the back member, the at least a portion of the inside surface of the front member, and a second side of the intermediate member, the second side reverse of the first side, wherein the second void is configured to have granular solid particles dropped therethrough.