Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
  • F24S30/00—Arrangements for moving or orienting solar heat collector modules
  • F24S30/40—Arrangements for moving or orienting solar heat collector modules for rotary movement
  • F24S30/45—Arrangements for moving or orienting solar heat collector modules for rotary movement with two rotation axes
  • F24S30/452—Vertical primary axis
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
  • F24S40/00—Safety or protection arrangements of solar heat collectors; Preventing malfunction of solar heat collectors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
  • F24S25/00—Arrangement of stationary mountings or supports for solar heat collector modules
  • F24S25/10—Arrangement of stationary mountings or supports for solar heat collector modules extending in directions away from a supporting surface
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
  • F24S40/00—Safety or protection arrangements of solar heat collectors; Preventing malfunction of solar heat collectors
  • F24S40/80—Accommodating differential expansion of solar collector elements
  • F24S40/85—Arrangements for protecting solar collectors against adverse weather conditions
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E10/00—Energy generation through renewable energy sources
  • Y02E10/40—Solar thermal energy, e.g. solar towers
  • Y02E10/47—Mountings or tracking

Definitions

• This invention relates to the field of solar energy collection, and in particular to solar energy transfer structure design and construction.
• Active systems use radiant energy collecting solar cells to convert the incident electo agne ic energy into usable electric, steam or other power sources.
• Solar collection units fall into two primary classifications, active solar units and passive solar units. To date the primary emphasis has been on the development of active solar collection units. In general, active solar collection units have a large number of solar collecting elements contained thereon. Such systems include those which make use of large reflectors to direct the radiant energy to a central absorber, those which have a plurality of direct solar absorbers and those providing direct solar energy conversion. In this application, the term "collector" will be used to describe all of these various types of solar collecting elements.
• the tracking structures have been comprised of a base or mounting pedestal upon which the remaining components are mounted, a drive mechanism, a plate or mounting surface upon which the individual reflecting elements are mounted and the individual collecting elements themselves.
• these tracking structures are tied to a sensing and control system, which provide a control signal for driving the tracking structure.
• the tracking structures then adjust the position of the collecting surfaces so as to keep the energy properly oriented relative to the sun. While this basic design is well known in the art, considerable effort has continued in the development of improved designs. The primary concern in the design and operation of solar energy conversion systems is the overall collection efficiency. While significant effort is continuing to be directed into the design of more efficient solar collecting elements themselves, other areas of development are also receiving considerable attention. Also, since significant numbers of these tracking structures are needed for each solar energy collection facility, the reduction in the cost of fabrication and maintenance of the structures is quite important.
• One means of increasing efficiency is to increase the density of solar collecting elements that are carried on a single solar energy transfer structure.
• the increased size presents several other problems which must be compensated for.
• the first problem is that the larger and heavier the structure, the larger and more powerful must be the drive motors which are installed. This creates significant problems in terms of control and cost.
• the larger the solar energy transfer structure the larger the motor requi ed to control the structure. Also, the larger the motor required, the more difficult it is for that motor to achieve fine motion and position control .
• This cost can be quite significant when multiplied by the relatively large number of solar energy transfer structures necessary for large energy farms. Added. to this cost is the necessity of larger drive motors, larger drive mechanisms and gearing.
• the prior art has attempted to address this problem by reducing the weight and inertia of the system by using stronger and lighter materials. This approach has met with some success.
• this does not address the second major problem in that regardless of how much effort is put into the improvement of the materials used, the basic moving surface of the solar energy transfer structure is planar shaped, and when placed in the outdoor environment, acts as an airfoil when the natural wind blows across it. That is, when in a substantially horizontal position, the wind blowing across the planar surface places lifting loads on the structure. Then, when it becomes necessary to adjust or otherwise maneuver the structure, a greater torque loading factor must be overcome before the unit can be moved by the drive mechanism.
• a solar energy transfer structure spoiler is comprised of a base for supporting the remaining elements of the invention, an azimuth and elevation drive mechanism, a moving structure frame, a plurality of energy collecting elements, a first spoiler and a second spoiler.
• energy collecting elements is meant to include direct solar absorbers elements, solar direct conversion elements, and solar reflector elements.
• the first end of the base is fixedly secured to the ground, and the second end is attached to the azimuth and elevation drive mechanism.
• the drive mechanism is comprised of an azimuth drive motor, -the associated azimuth drive gearing, the elevation drive motor and the associated elevation drive gearing.
• the moving structure is trans!atably attached to the azimuth and elevation gears for free gimboling movement by the drive mechanism.
• the moving structure is a rigid planar shaped frame having disposed thereon a plurality of energy reflecting elements.
• the frame is a rectangular shaped frame.
• the planar shape of the moving structure allows for each collecting element to be fully exposed to the sun for efficient radiant energy collection.
• the first spoiler attached to the leading edge of the moving structure frame is the first spoiler, or pair of spoilers if the frame is of the split unit design.
• the leading spoiler is attached across each leading edge of the moving structure frame such that center of the plane upon which the solar collecting elements are mounted substantially bisects the midpoint of the widthwise dimension of the first spoiler.
• the second spoiler Attached to the trailing edge of the frame or to each unit of the moving structure frame if split units are used, is the second spoiler.
• the second pair of spoilers are mounted such that the center of the plane upon which the solar collecting elements are mounted also substantially bisects the midpoint of the widthwise dimension of said second spoiler or pair of spoilers.
• the spoilers are mounted to the frame such that the lower edge of each spoiler intersects the plane of the frame.
• the spoilers are projecting upward from the plane of the frame when the structure is in its operational mode.
• a third and a fourth spoiler are mounted to the left and the right sides of the frame respectively.
• the third and fourth spoilers are attached in order to account for shifts and variations in the wind direction passing through the farm.
• the third and fourth spoilers also accommodate the use of reflecting elements, in that when reflecting elements are used, they must be disposed in a circle substantially around the absorber, with each structure pointed toward the central absorber. Having spoilers on all four sides allows for more uniformity in structure design and ease in placement.
• FIGURE 1 is a side pictorial representation of the preferred embodiment of the disclosed invention, a solar energy transfer structure spoiler for reduced wind generated torque, showing the spoiler structure with the plane of the frame approximately equidistant to the width of both of the leading and trailing spoilers.
• FIGURE 2 is a side pictorial representation of the alternative embodiment of the disclosed invention, showing the spoiler structure with the plane of the frame approximately equal with the lower edge of both of the leading and trailing spoilers.
• FIGURE 3 is a isometric presentation of the alternative embodiment of the disclosed invention, showing two units of the frame with the spoilers attached in the fully rotated stored position.
• FIGURE 4 is a pictorial graph contrasting the torque forces experienced by the frame with no spoiler and the torque forces experienced by the frame with a small preferred embodiment spoiler.
• FIGURE 5 is a pictorial graph contrasting the torque forces experienced by the frame with no spoiler and the torque forces experienced by the frame with a large preferred embodiment spoiler.
• FIGURE 6 is a pictorial graph contrasting the torque forces experienced by the frame with no spoiler and the torque forces experienced by the frame with an alternative embodiment spoiler.
• a solar energy transfer structure and spoiler assembly 1 is comprised of a base 2 for supporting the remaining elements of the assembly 1, an azimuth and elevation drive mechanism 3, a moving structure frame 4, a plural ty of energy collecting elements 5, a wind spoiler assembly comprised of a first spoiler 6 and a second spoiler 7.
• solar energy collection systems include those which make use of large reflectors to direct the radiant energy to a central absorber, those systems which have a plurality of direct solar absorbers elements and those systems having direct solar conversion elements.
• solar collecting elements is intended to encompass all of these various types of elements.
• the first end of the base 2 is fixedly secured to the ground 8 or to some other permanent structure.
• the second end has the azimuth and elevation drive mechanism 3 attached thereto.
• the drive mechanism 3 is comprised of an azimuth drive motor and associated azimuth drive gearing 9, and the elevation drive motor and associated elevation drive gearing 10.
• the azimuth drive motor and gearing 9 are fixedly attached to the base 2, with the elevation motor and gearing 10 attached for rotation about an axis which is vertical relative to the axis of the azimuth motor and gearing 9.
• the moving structure frame 4 is then fixedly attached to the elevation motor and gearing 10 such that the moving structure frame is free to be moved by the drive mechanism in a horizontally rotating and vertical tilting manner.
• the moving structure frame 4 is a rectangularly shaped support having disposed thereon a plurality of uniformly oriented, energy collecting elements 5.
• the planar shape of the moving structure frame 4 allows for each collecting elements 5 to be fully exposed to the sun and able to direct its reflected beam to a collector (not shown).
• the base 2 displaces the frame 4 far enough of the ground 8 or other permanent structure to allow for the full 360 degree rotation of the frame 4.
• This allows the solar energy transfer structure assembly 1 to be oriented toward the sun regardless of the angle at which the energy arrives at the assembly 1.
• the preferred embodiment of the moving structure frame 4 is comprised of two separate units 4a and 4b, one attached to each side of the elevation drive motor and gearing 10 mechanism. It should be noted that this construction also ' allows the moving structure frame 4 to be rotated to a stowed position with the collecting elements 5 rotated to a protected downward facing posi ion.
• the first spoiler 6 is attached to the leading edge or edges 11 of the moving structure frame 4 such that center of the plane upon which the solar collecting elements 5 are mounted substantially bisects the midpoint of the widthwise dimension of said first spoiler 6. In this preferred embodiment, the first spoiler 6 is substantially perpendicular to the plane of the moving structure frame 4. As shown in Figures 1, 2 and 3, attached to the trailing edge or edges 12 of each unit 4a and 4b of the moving structure frame 5 is the second spoiler 7.
• the second spoiler 7 is mounted such that the center of the plane upon which the solar collecting elements 5 are mounted substantially bisects the midpoint of the widthwise dimension of the second spoiler 7.
• the particular offset of the first and the second spoilers 6 and 7 is dependent upon the particular configuration of the frame 4 and in general this must be determined by empirical testing and evaluation. However, testing has shown that the lenghtwise dimension of the first spoiler 6 and the second spoiler 7 should be at least that of the width of the leading and trailing edge or edges of the frame 4 respectively, that both first spoiler 6 be oriented perpendicular the plane of the frame 4, and that the plan of the second spoiler 7 be parallel to the plane of the first spoiler 6.
• an alternative embodiment of the disclosed invention has the first spoiler 6 and the second spoile 7 projecting downward from the plan of the frame 4 such that when the moving structure frame is in the stowed position, the spoilers 6 and 7 are projecting upward. This configuration provides additional disruption of the air flow when the assembly 1 is in the stowed position.
• the effectivity of the assembly 1 is shown by the graphs presented in Figures 4, 5 and 6.
• the horizontal axis indicates the angle of attack of the air over the frame 4, while the vertical axis shows the torque in inch-pounds.
• the solid line 13 indicates the torque on the frame at various angle of attack without a set of spoilers 6 and 7 attached.
• the dotted line 14 shows the torque with the spoilers 6 and 7 in place.
• Figure 4 is a graph contrasting the difference in the lifting force, and correspondingly the torque, placed on a frame 4 not having a spoiler and the lifting force placed on a frame with a smaller sized version of the preferred embodiment spoilers 6 and 7.
• Figure 5 represents the torque difference with a larger preferred embodiment spoiler
• Figure 6 indicates the difference in torque when the alternative embodiment spoilers 6 and 7 are used.
• a third and a fourth spoiler are mounted to the left and the right sides of the frame respectively. ' These third and fourth spoilers are attached to the sides of the frame in order to accommodate shifts and variations in the direction of the wind as the wind passes through the farm.
• This second alternative embodiment also accommodates for the use of reflecting elements, in that when such reflecting elements are used, the tracking structures must be disposed in a circle substantially around the absorber. Having spoilers on all four sides allows for more uniformity in tracking structure design and ease in placement of the structures.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Life Sciences & Earth Sciences (AREA)
• Sustainable Development (AREA)
• Sustainable Energy (AREA)
• Thermal Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Photovoltaic Devices (AREA)

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• 1987
  • 1987-10-22 WO PCT/US1987/002748 patent/WO1988003635A1/en not_active Application Discontinuation
  • 1987-10-22 EP EP87907392A patent/EP0328545A1/de not_active Withdrawn
  • 1987-10-22 JP JP62506920A patent/JPH02500996A/ja active Pending
  • 1987-11-04 ES ES8703159A patent/ES2008310A6/es not_active Expired
  • 1987-11-04 CN CN87107688A patent/CN1010882B/zh not_active Expired

Non-Patent Citations (1)

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