Enclosed Solar Thermal Energy Generation System and Methods of Operation

Abstract

The invention relates to enclosed solar parabolic trough reflector systems for thermal heat generation that can ultimately be used in various applications. The system includes a modular dual arch building design with a transparent building envelope and a reflector assembly connected within the building through a bearing assembly. The system is particularly suited for solar heat collection in harsh environment.

Claims

1. A solar reflector system comprising: a reflector assembly comprising a support frame and a parabolic reflector, wherein the support frame is configured to support the parabolic reflector via a plurality of support members interconnected by cross members, wherein the cross members are rotatably interconnected via one or more connector nodes such that the plurality of support members and cross members are (i) collapsible and (ii) expandable for forming the support frame, and wherein the parabolic reflector comprises a flexible membrane configured to reflect solar radiation; a tensioning system configured to tension the flexible membrane, wherein the tensioning system comprises at least one of the one or more connector nodes; an actuation system configured to move the reflector assembly; at least one sensor; at least one processor; and data storage having instruction code stored thereon that, when executed by one or more processors of the solar reflector system, causes the solar reflector system to: receive, via the at least one sensor, input data corresponding to a state of the reflector assembly; determine a desired position of the reflector assembly based on at least (i) the received input data and (ii) sun position data stored via the data storage; and cause, via the actuation system, the reflector assembly to move to the determined desired position.

2. The solar reflector system of claim 1, further comprising: a building formed at least in part from a plurality of structural members and a transparent membrane covering at least a portion of the plurality of structural members; and a thermal pipe supported in the building.

3. The solar reflector system of claim 2, wherein the actuation system is further configured to move the reflector assembly within the building in a manner suitable to move the parabolic reflector within the building while maintaining the reflector assembly at a distance from a thermal pipe that is sufficient for the parabolic reflector to focus solar radiation received by the parabolic reflector onto the thermal pipe.

4. The solar reflector system of claim 1, wherein the at least one sensor comprises one or more of (a) at least one pressure sensor and (b) at least one flow sensor, and wherein the state of the solar reflector system comprises one or more of (a) a pressure within a thermal pipe and (b) a flow within a thermal pipe.

5. The solar reflector system of claim 1, wherein the at least one sensor comprises at least one inclinometer, and wherein the state of the solar reflector system comprises a position of the reflector assembly.

6. The solar reflector system of claim 5, the data storage having further instruction code stored thereon that, when executed by one or more processors of the solar reflector system, causes the solar reflector system to: receive, via the at least one inclinometer, reflector-assembly position data; and determine, based on the received reflector-assembly position data, that the reflector-assembly is in a desired position.

7. The solar reflector system of claim 5, the data storage having further instruction code stored thereon that, when executed by one or more processors of the solar reflector system, causes the solar reflector system to: receive, via the at least one inclinometer, reflector-assembly position data; and determine, based on the received reflector-assembly position data, that the reflector assembly is correctly aligned along a length of the reflector assembly.

8. The solar reflector system of claim 5, the data storage having further instruction code stored thereon that, when executed by one or more processors of the solar reflector system, causes the solar reflector system to: receive, via the at least one inclinometer, reflector-assembly position data; determine, based on the received reflector-assembly position data, that the reflector assembly is not correctly aligned along a length of the reflector assembly; and based on the determination that the reflector assembly is not correctly aligned, determine a system fault.

9. The solar reflector system of claim 1, further comprising: one or both of a temperature sensor or a pressure sensor; and at least one pump configured to control a flow of fluid through a thermal pipe, wherein the data storage has further instruction code stored thereon that, when executed by one or more processors of the solar reflector system, causes the solar reflector system to: receive one or both (i) temperature data via the temperature sensor or (ii) pressure data via the pressure sensor; and at least in part via the at least one pump, cause the flow of fluid through the thermal pipe to match a desired flow based at least in part on one or both of the temperature data or the pressure data.

10. The solar reflector system of claim 1, further comprising: at least one pump configured to control a flow of fluid through a thermal pipe, wherein the data storage has further instruction code stored thereon that, when executed by one or more processors of the solar reflector system, causes the solar reflector system to: cause, at least in part via the pump, the flow of fluid through the thermal pipe to match a desired flow.

11. The solar reflector system of claim 1, wherein an individual connector node is both (i) lockable to hold one or more cross members in a set position and (ii) releasable to allow rotation of the one or more cross members relative to the individual connector node.

12. The solar reflector system of claim 1, wherein the reflector assembly is at least partially supported by a support post that is fixed to a foundation of a building formed at least in part from a plurality of structural members and a transparent membrane covering at least a portion of the plurality of structural members.

13. The solar reflector system of claim 1, further comprising a support base comprising a set of panels, wherein a given panel in the set of panels comprises one or more of a photovoltaic panel, a thermal energy storage system, and a reservoir panel.

14. The solar reflector system of claim 13, wherein a given panel in the set of panels comprises the thermal energy storage system, and wherein the thermal energy storage system comprises one or more of (a) a thermal mass and (b) a phase change material.

15. The solar reflector system of claim 1, further comprising a structural housing, wherein the structural housing comprises a channel configured to receive a housing membrane.

16. The solar reflector system of claim 15, further comprising the housing membrane, wherein the housing membrane comprises an edge element, wherein the channel is further configured to receive the edge element.

17. A solar reflector system comprising: a reflector assembly comprising a support frame and a parabolic reflector, wherein the support frame is configured to support the parabolic reflector via a plurality of support members interconnected by cross members, wherein the cross members are rotatably interconnected via one or more connector nodes such that the plurality of support members and cross members are (i) collapsible and (ii) expandable for forming the support frame, and wherein the parabolic reflector comprises a flexible membrane configured to reflect solar radiation; a tensioning system configured to tension the flexible membrane, wherein the tensioning system comprises at least one of the one or more connector nodes; a control system for causing the solar reflector system to: receive, via at least one sensor, input data corresponding to a state of the solar reflector system; determine a desired position of the reflector assembly based on at least (1) the received input data and (2) sun position data stored via data storage; and cause, via an actuation system, the reflector assembly to move to the determined desired position.

18. The solar reflector system of claim 17, further comprising: a building formed at least in part from a plurality of structural members and a transparent membrane covering at least a portion of the plurality of structural members; a thermal pipe supported in the building; and wherein the actuation system is further configured to move the reflector assembly within the building in a manner suitable to move the parabolic reflector within the building while maintaining the reflector assembly at a distance from a thermal pipe that is sufficient for the parabolic reflector to focus solar radiation received by the parabolic reflector onto the thermal pipe.

19. The solar reflector system of claim 17, wherein the at least one sensor comprises one or more of (i) at least one pressure sensor and (ii) at least one flow sensor, and wherein the state of the solar reflector system comprises one or more of (i) a pressure within a thermal pipe and (ii) a flow within a thermal pipe.

20. The solar reflector system of claim 17, wherein the at least one sensor comprises at least one inclinometer, wherein the state of the solar reflector system comprises a position of the reflector assembly, and wherein the data storage has further instruction code stored therein that, when executed by one or more processors of the solar reflector system, causes the solar reflector system to one or more: (i) receive reflector-assembly position data via the at least one inclinometer, and determine, that the reflector-assembly is in a desired position based on the received reflector-assembly position data; (ii) receive reflector-assembly position data via the at least one inclinometer, and determine that the reflector assembly is correctly aligned along a length of the reflector assembly based on the received reflector-assembly position data; (iii) receive reflector-assembly position data via the at least one inclinometer, determine that the reflector assembly is not correctly aligned along a length of the reflector assembly based on the received reflector-assembly position data, and determine a system fault based on the determination that the reflector assembly is not correctly aligned.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Various objects, features and advantages of the invention will be apparent from the following description of particular embodiments of the invention, as illustrated in the accompanying drawings. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of various embodiments of the invention. Similar reference numerals indicate similar components.

[0037] FIG. 1 shows two perspective overviews of a solar thermal energy conversion (STEC) system showing a typical modular deployment in accordance with one grade-mounted embodiment of the invention.

[0038] FIG. 1A is an isometric view of an STEC system in accordance with one embodiment of the invention.

[0039] FIG. 1B is a cross sectional view of an STEC system at line A-A from FIGS. 1A and 10 in accordance with one embodiment of the invention.

[0040] FIG. 1C is a side view of an STEC system in accordance with one embodiment of the invention.

[0041] FIG. 1D is an end view of an STEC system in accordance with one embodiment of the invention.

[0042] FIGS. 1E and 1F are perspective views showing details of a membrane attachment system in accordance with two embodiments of the invention.

[0043] FIG. 2 is an isometric view of a solar receiver support and collector rotation bearing system of an STEC system in accordance with one embodiment of the invention.

[0044] FIG. 2A is an isometric cross-sectional view of a solar receiver support and collector rotation bearing system of an STEC system in accordance with one embodiment of the invention.

[0045] FIG. 2B is an exploded view of a solar receiver support and collector rotation bearing system of an STEC system in accordance with one embodiment of the invention.

[0046] FIG. 3 is an isometric and cross-sectional view of a solar receiver support and collector rotation bearing system and thermal receiver pipe of an STEC system in accordance with one embodiment of the invention.

[0047] FIG. 3A is a side and cross-sectional view of a bearing system and thermal receiver pipe of an STEC system in accordance with one embodiment of the invention.

[0048] FIG. 3B is an isometric view of a thermal receiver pipe of an STEC system in accordance with one embodiment of the invention.

[0049] FIG. 4 is an isometric view of a first embodiment of a reflector system of an STEC system showing a reflector space frame with a partially installed reflector in accordance with one embodiment of the invention.

[0050] FIG. 5A is a top perspective view of a second embodiment of a reflector system, showing a bearing system and thermal receiver pipe of a STEC system.

[0051] FIG. 5B is a bottom perspective view of the reflector system of FIG. 5A.

[0052] FIG. 5C is a side elevation view of the reflector system of FIG. 5A.

[0053] FIG. 5D is a bottom plan view of the reflector system of FIG. 5A.

[0054] FIG. 5E is an end elevation view of the reflector system of FIG. 5A.

[0055] FIG. 5F is bottom perspective view of the reflector system of FIG. 5A.

[0056] FIG. 5G is a detailed view of section A of FIG. 5F.

[0057] FIG. 5H is a detailed view of section B of FIG. 5F.

[0058] FIG. 6A is a top perspective view of a third embodiment of a reflector system, showing a bearing system and thermal receiver pipe of a STEC system.

[0059] FIG. 6B is a bottom perspective view of the reflector system of FIG. 6A.

[0060] FIG. 6C is a side elevation view of the reflector system of FIG. 6A.

[0061] FIG. 6D is a bottom plan view of the reflector system of FIG. 6A.

[0062] FIG. 6E is an end elevation view of the reflector system of FIG. 6A.

[0063] FIG. 6F is an end elevation view of the reflector system of FIG. 6A in a rotated position.

[0064] FIG. 6G is a partial elevation view of the reflector system of FIG. 6A, showing a rotatable pipe connection.

[0065] FIG. 7A is a top perspective view of the reflector system of FIG. 5A.

[0066] FIG. 7B is a perspective view of one embodiment of a reflector arch.

[0067] FIG. 7C is a side elevation view of the reflector arch of FIG. 7B.

[0068] FIG. 7D is a side cross sectional view of a section of reflector with bead and parabolic membrane with attachment system.

[0069] FIG. 8A is a perspective view of a connector node.

[0070] FIG. 8B is an exploded perspective view of the connector node of FIG. 8A.

[0071] FIG. 8C is a side elevation view of the connector node of FIG. 8A.

[0072] FIG. 8D is a perspective view of frame members and connector nodes in an extended position.

[0073] FIG. 8E is a perspective view of frame members and connector nodes in a collapsed position.

[0074] FIG. 9 is a perspective view of a further embodiment of a solar reflector system.

[0075] FIG. 9A is a perspective view of a further embodiment of a solar reflector system.

[0076] FIG. 9B is a perspective view of a further embodiment of a solar reflector system.

[0077] FIG. 9C is a perspective view of a further embodiment of a solar reflector system.

[0078] FIG. 10A is a perspective view of a first embodiment of a floor panel.

[0079] FIG. 10B is a perspective view of a second embodiment of a floor panel.

[0080] FIG. 10C is a perspective view of a third embodiment of a floor panel.

[0081] FIG. 11 is a schematic overview of an STEC installation in accordance with one embodiment of the invention.

[0082] FIG. 11A is an overview of an STEC control system in accordance with one embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0083] With reference to the figures solar thermal energy conversion (STEC) systems 10 are described.

[0084] All terms have definitions that are reasonably inferable from the drawings and description.

[0085] Various aspects of the invention will now be described with reference to the figures. For the purposes of illustration, components depicted in the figures are not necessarily drawn to scale. Instead, emphasis is placed on highlighting the various contributions of the components to the functionality of various aspects of the invention. A number of possible alternative features are introduced during the course of this description. It is to be understood that, according to the knowledge and judgment of persons skilled in the art, such alternative features may be substituted in various combinations to arrive at different embodiments of the present invention.

[0086] With reference to the Figures, an STEC system 10 is described. The system 10 includes an arched building structure 12 enclosing a parabolic solar collector assembly (PSCA) (also referred to herein as a solar receiver and collector assembly or reflector assembly) 14. The arched building structure includes pairs of arches 12 a connected together to form dual arch assemblies 12 b. A plurality of dual arch assemblies is aligned and spaced along a central axis 12 c to form supports for an external building envelope 23 (FIG. 1E) and the reflector assembly 14. Deployment of an STEC system 10 can be used for the generation of medium to high quality heating fluids including steam from solar radiation.

Building Structure

[0087] With reference to FIGS. 1A-1F, each arch 12 a, when assembled forms a dual arch assembly 12 b, designed to provide a shape and structure that both protects the reflector assembly from weather elements and support the reflector assembly 14 within the building envelope.

[0088] As shown, aligned pairs of arches form a barrel vault or gothic arch structure and preferably a pointed barrel vault or gothic arch characterized by arches having a substantially vertical exterior surface adjacent a lower end 12 d transitioning to an approximately 45 exterior surface adjacent an upper end 12 e.

[0089] In various embodiments, the lower slope angle between a horizontal axis and the lower outer end surface 12 d is 90 degrees or greater, preferably between about 90 degrees and 110 degrees, and more preferably between about 90 degrees and 100 degrees, and the upper slope angle between the outer upper end surface 12 e and a horizontal axis is greater than 40 degrees, preferably between about 40-60 degrees and most preferably about 45 degrees.

[0090] As such, the dual arch shape provides a high-slope upper outer envelope surface that progressively increases to a substantially vertical surface towards the lower end. This structure substantially prevents/minimizes the accumulation of snow/water on the envelope with angles that will generally prevent or minimize environmental solids, such as dust, sand and/or accumulating snow accumulating on the envelope.

[0091] Optionally, the building structure 12 can include one or more peripheral, external drainage channels to direct collected water from rain and snow, said water which in turn can be directed to an integrated reservoir or drainage system. The drainage channels can be formed into the arches 12 a themselves, or can be formed by means of texturing of the envelope material, or the drainage channels can be separate channels mounted to one or both of the arches 12 a or the envelope material.

[0092] The symmetric dual arch structure also provides a modular design wherein any reasonable number of arch pairs can be assembled along an axis to create STEC systems of varying lengths and system capacity. These repeating assembly units enable both efficient manufacturing and construction at a deployment site.

[0093] As shown, each arch pair 12 b are inter-connected by a top gusset 13 and may be connected to a foundation structure 15 via bottom gussets 13 a. A typical arch pair ranges in base width from about 3 m to 9 m and total height of about 3 m to 9 m maintaining a 1:1 ratio.

[0094] As shown in FIG. 1A, adjacent arch pairs 12 b are interconnected via a ridge member 16 a at the apex of each arch pair. Horizontal stringers 16 spaced between each arch provide additional attachment points for envelope material and the reflector assembly. Spacing between arch pairs is variable and will consider the span of the envelope material described below to enable proper snow/wind loading while also seeking to minimize shadowing effects from the arch pairs over the reflector assembly 14 (typically 3-9 m centers or 4.5-6 m).

[0095] Suitable arch materials include pre-formed metal arches and laminated wooden arches, however any other suitable material, including plastics, could be used which can be formed to the desired shape and angle of the arches 12 a, which is suitably weather-resistant, and which can either be formed with a means to support the envelope, or onto which can be mounted means to support the envelope. Such means can include a Keder-style track system or other systems, as described further below.

[0096] The building includes appropriate access doors 18 a constructed in end walls 18 as shown in FIG. 1D.

[0097] The foundation 15 of the building may be constructed as required by local building codes and may include fully excavated and supported concrete structures, screw piles, and floating on grade foundations as may be appropriate for a particular location and size of building.

[0098] In a further alternate embodiment illustrated in FIGS. 9A and 10B, the support base 15 may be built to include photovoltaic (PV) panels 15 a that can be energized from solar power such that the system 10 forms a hybrid PV and thermal system.

[0099] In other embodiments as illustrated in FIGS. 9B and 10A, the support base may include one or more panels that serves as a modular thermal energy storage system 15 b, in which thermal fluids are directed to run in floor panels of the support base containing a thermal mass or phase change material (PCM) capable of charging or discharging heat energy from/to the thermal fluid. In one example, for rapid system start-up or stabilized energy delivery, thermal fluids may be partially pre-heated by directing passage through the thermal energy storage system, having stored heat produced the previous day through a reverse process, prior to introduction to the main heating system as described below.

[0100] The foundation/flooring system may also include one or more panels that serve as a reservoir 15 d for liquids collected by the external drainage system described above. Such reservoir panels are illustrated in FIGS. 10C.

[0101] It would be understood by a person of skill in the art that the foundation/flooring system can include of any combination of PV panels 15 a, thermal energy storage panels 15 b or reservoir panels 15 d or plain panels.

[0102] In another embodiment for scaled system configuration and design, the thermal energy storage system is stacked in a separate structure.

[0103] As shown in FIG. 1E, the outer surface of the structure (i.e. the building envelope) is a material 23 that is transparent or substantially transparent to solar radiation. That is, the envelope material is selected to maximize solar radiation into the building whilst providing sufficient structural properties for sealing the building to water and to provide sufficient wind and snow loading. The surface properties of the envelope may also be provided with low friction properties to further assist in snow shedding.

[0104] Suitable envelope materials include a tensioned membrane such as ethylene tetrafluoroethylene (ETFE), polycarbonate (PC), polyethylene (PE), polyethylene terephthalate (PET), or other suitable polymers that are configured to be held and received in Keder-type extrusion tracks 22 mounted on and connected to the arches 12 a. The membrane material 23 is provided with an edge bead 22 b that is held within an appropriate recess in the track 22 a to provide support and tension to the membrane 23 between arches of the building.

[0105] Other envelope materials include acrylic, PVC, polycarbonate or other suitably transparent materials 23 a that may be attached to the exterior of the building with slotted tracks 24 as shown in FIG. 1F.

[0106] Tensioned membranes such as ETFE are advantaged over various transparent materials by providing a balance between optical, thermal, and physical properties. ETFE is more transparent to solar radiation while remaining lightweight with excellent abrasion resistance, thermal and UV stability, and good tear/puncture resistance compared to other materials. A comparison to other materials shows that ETFE can have a transmissivity of up to 94% compared to polycarbonate which has a transmissivity up to 90% and polyethylene which has a transmissivity up to 83%.

Parabolic Solar Collector Assembly (PSCA)/Reflector Assembly

[0107] As shown in FIG. 1B, in one embodiment the building arches 12 b support the parabolic solar collector assembly (PSCA)/reflector assembly 14 within the building. The reflector assembly 14 includes a parabolic reflector 14 a having a support frame 14 b. The reflector 14 a and support frame 14 b are supported by rigid reflector stays 14 c and bearing assembly 20. Bearing assembly 20 is suspended and supported from the building frame by rigid bearing stays 20 a. As shown, the reflector stays 14 c are configured to multiple connection points on the support frame 14 b to provide support and rigidity to the reflector and support frame as it is rotating as described below. The bearing stays 20 a are preferably connected to three or more separate positions on an arch pair including the apex and an upper side surface of each arch. As shown, the bearing stays may include rigging screws/turnbuckles 20 b to enable system adjustment during assembly and if required during maintenance.

[0108] In an alternate embodiment as illustrated in FIGS. 6A to 6G and 9 to 9C, the thermal pipe 25 is connected to the reflector assembly 14 by means of rigid supports 25 c connected between thermal pipe 25 ends and ends of the reflector assembly 14. The rigid supports 25 c are in turn connected by a support post 15 c that is fixed to the foundation 15 of the building. In this embodiment no relative rotation is allowed between the thermal pipe 25 and the reflector assembly 14. Instead, the thermal pipe 25 and the reflector assembly 14 are rigidly connected to one another such that both rotate together along a common axis of rotation, said common axis of rotation including the bearing assemblies 20, as will be described in further detail below.

[0109] The parabolic reflector 14 a and support frame 14 b are designed to be relatively light weight to reduce material costs, manufacturing costs, operating costs, the physical size and density of support materials and reflector tracking system, and energy demand of the reflector tracking control system. The reflector and frame assembly must be sufficiently rigid to enable accurate operation and movement of the assembly within the building, but it is not required to withstand hail, wind and snow loads.

[0110] The reflector may be constructed of a combined reflector (e.g. silver reflective film), honeycomb support (e.g. expanded aluminum honeycomb cell) and a backing (e.g. a thin aluminum panel). Other lightweight reflectors may also be utilized.

[0111] As shown in FIG. 4, the frame assembly 14 b includes parabolic support members 14 e and cross-members 14 f to interconnect each parabolic support member 14 e. Collectively, the parabolic reflector 14 a and frame assembly 14 b are designed to provide sufficient rigidity whilst minimizing weight. The frame assembly can be manufactured from lightweight steel/aluminum/plastic in the form of structural trusses. The reflector stays 14 c are connected to the frame assembly at their lower end.

[0112] In an alternate embodiment illustrated in FIGS. 5A to 6G, the reflector assembly 14 includes a parabolic reflector having a reflective surface configured to underlying support members 14 e (FIG. 7B), cross members 14 f and a deployable space frame assembly 14 b that collectively provide a rigid and lightweight parabolic structure. As shown for example in FIG. 5B, the frame assembly includes a plurality of rods 14 g interconnected through nodes 80 (FIG. 8A, 8B, 8C) that lock individual rods at various angles with respect to one another to create a lightweight frame structure supporting the reflective surface.

[0113] As illustrated in FIGS. 8A to 8C, the rods 14 g are connectable by use of one or more node connectors 80. The node connector 80 can receive a plurality of connector pegs 80 a configured to an end of each of the members/rods 14 e, 14 f, 14 g. The pegs 80 a may be threaded to be received into mating threads inside the ends of the support members or vice versa.

[0114] The pegs 80 a are rotatable/pivotable in the node connector 80 via a ball 80 b that engages within the node connector and allows for rotation/pivoting of the peg 80 a within the node. The movement between the ball and node connectors in turn allows for the support members to extend at a variety of angles and orientations to facilitate connection, orientation and tensioning between the various support members. The balls 80 b are sandwiched between clamshell halves 80 c/80 d of the node connector 80 such that the balls 80 b can rotate/pivot while being held securely. A clamping handle 80 e clamps clamshell halves 80 c/80 d together once the orientations of the pegs 80 a and support members are set, to thereafter prevent movement of the balls 80 b within the connector node 80.

[0115] The support members/rods 14 g of FIG. 5G are preferably configured such that the length of a member/rod can be extended or shortened. This can include being interconnectable via end-to-end connectors such that multiple support members/rods can be connected to achieve a desired overall length of support member for supporting the reflector 14 a. Further, a threaded connector 14 j can be used to connect threaded ends of the support members such that the threaded connector 14 j can be rotated to extend or contract the length of a support member/rod to provide appropriate tensioning of the overall support frame and/or for desired adjustment of the length of a member/rod.

[0116] Furthermore, as illustrated in FIGS. 8D and 8E, the rotatable connection between frame members and the node connector 80 allows for the overall space frame structure to be collapsed and reduced in size for transport to site, where the space frame can again be extended and arranged for supporting a reflective membrane 14 a, all without having to disconnect support members from the nodes 80. This forms a prefabricated frame that simplifies the transportation process to the extent that each frame may be collapsed for shipping reducing shipping volume and greatly speeds up the set up and take down process.

[0117] As shown in FIG. 5 H cross members 14 f are connected to parabolic members 70 b to provide a fixed spacing between adjacent parabolic members wherein the configured rods 14 g lengthened/tensioned via the threaded connectors and nodes to provide tensioning to overall support frame and reflector.

[0118] In one embodiment, as illustrated in FIGS. 7A to 7D, the parabolic members 14 e also include an attachment and tensioning system 70 for attaching a flexible reflective membrane 14 a to the parabolic members 14 e. In this embodiment, the reflective membrane includes an edge bead 70 a to interface with tracks 70 b formed with or mounted on the parabolic support members 14 e. Thus, a reflective surface, which may be somewhat flexible and having a bead 70 a along opposite edges, may be inserted into tracks 70 b and then tensioned by adjustment of the support frame members as described above.

Bearing Assembly

[0119] As shown in FIGS. 1 to 5F, the STEC system is designed to heat a thermal fluid within a solar thermal pipe 25, specifically designed for solar thermal heating, positioned at the focal point of the reflector system. The efficiency of the thermal pipe can be aided by coating the pipe in an absorptive coating and enclosing the pipe in an evacuated glass cylinder 26. FIGS. 3 and 3A shows a section of the parabolic reflector system and a corresponding section of thermal pipe 25. In one embodiment, as shown in FIG. 1, the thermal pipe is fixed relative to the building structure, or alternatively as shown in FIG. 6A to 6G and FIGS. 9 to 9C, the thermal pipe 25 is connected to the building foundation 15, allowing thermal fluid to flow from one end of the building to another.

[0120] In order to enable the reflector assembly 14 to focus on the thermal pipe 25, In the embodiments of FIGS. 1 to 5F, the bearing assemblies 20 both support the thermal pipe in its fixed position whilst allowing the reflector assembly to be rotated about the thermal pipe. In FIGS. 6A to 6G and FIGS. 9 to 9C, the bearing assemblies 20 support the thermal pipe 25 together with the reflector assembly 14, whilst allowing rotation about the central bearing axis.

[0121] FIG. 2 shows a bearing assembly 20 together with reflector stays 14 c and bearing stays 20 a without an installed thermal pipe. FIG. 2A shows a cross section of a bearing assembly and FIG. 2B is an exploded assembly drawing of the bearing assembly. FIGS. 3 and 3A show the bearing assembly with a partially installed thermal pipe 25. FIG. 3B shows an embodiment where a thermal pipe 25 has a flange 25 b that is used to connect pipe sections together or to other pipes 25 d, such other pipes can be rigid pipes, flexible hoses or flexible pipes. FIGS. 5A to 5E also show the bearing assembly together with reflector stays 14 c and bearing stays 20 a.

[0122] Each bearing assembly 20 includes a stationary portion 50 a and a pivoting portion 50 b. Generally, a thermal pipe is supported by non-rotating support plates 50 c on either side of the bearing assembly. The support plates are connected to the bearing stays 20 a and are thus supported by the building.

[0123] The pivoting portion 50 b includes a bearing race 50 d operatively connected between the support plates and that engages against the fixed thermal pipe 25 such that the reflector assembly 14 is suspended from and can rotate about the thermal pipe.

[0124] As shown, the bearing assembly 20 is designed to facilitate installation in sections within a building and whilst a building is being assembled. The bearing assembly 20 is described with reference to the steps of installation which includes the following general steps:

[0125] Bearing stay 20 a installation as per FIGS. 1 to 3B and 5A to 5EThree bearing stays 20 a are connected to upper stay connector 50 e. The bearing stays 20 a are connected to the building and adjusted to the correct height and position within the building with turnbuckles 20 b.

[0126] Outer support plate 50 a positioningOne of the outer support plates 50 a is attached to the bearing stays through stay connector 50 e. As shown, each outer support plate 50 a includes two halves 50 f, 50 g which can each connect to stay connector 50 e. Support plate 50 f may be installed initially. Depending on installation protocol, second half 50 g may be connected to stay connector 50 e or the thermal pipe is lifted and held in position against support plate 50 f prior to connection of support plate half 50 g. Either way, once thermal pipe 25 is in position and secured with support plates 50 a, 50 b, 50 f, 50 g multiple sections of thermal pipe 25 can be installed with support provided by the support plates. As shown in FIG. 3, the end of thermal pipe section 25 may protrude slightly beyond the support plate wherein adjacent sections of thermal pipe abut one another between the support plates. This provides support and alignment of the pipe sections 25 during installation.

[0127] Each thermal pipe section 25 preferably includes a beveled end 25 a allowing a weld bead (not shown) to be placed within a recess defined by beveled edges 25 a between two abutting pipe sections, to attach and seal each pipe section together. At this stage the bearing race 50 h, 50 i is not installed thus providing access for welding.

[0128] After installation and welding of pipe sections, the bearing race 50 h, 50 i is installed within the bearing assembly and around the thermal pipe 25. Each bearing race includes a rotating outer portion 50 h and an inner non-rotating portion 50 i. Each portion is comprised of two half sections 50 h 1, 50 h 2, and 50 i 1, 50 i 2 enabling installation within the support plates and around the thermal pipe 25.

[0129] The rotating outer portion 50 h of the bearing assembly is connected to reflector connector 51 and reflector stays 14 c, in the embodiment of FIGS. 1 to 3B and 5A to 5E. In the case of FIG. 6A to 6G, the rotating outer portion 50H is connected to rigid bearing supports 20C connected in turn to the reflector assembly 14. Fixed portion 50 i of the bearing race is connected to plates 50 c which rest on the outer surface of the thermal pipe.

[0130] Reflector assembly 14 InstallationA section of reflector assembly (i.e. the reflector and support frame) are lifted into position and connected to cable stays 14 c, in the case of FIGS. 1 to 3B and 5A to 5E to be suspended from the bearing assembly. Alternately the reflector assembly is supported by support post 15 c that is fixed to the foundation 15 of the building, as illustrated in FIGS. 6A to 6G and 9 to 9C.

[0131] The bearing race includes high temperature materials such as graphite impregnated bronze that provide proper lubrication of the running surfaces at maximum operating temperature.

Reflector System Actuation

[0132] The reflector assembly of FIGS. 1 to 3B and 5A to 5E is pivoted about the bearing assembly by an actuation system consisting of a wire rope 61 and motor drive 63 as shown in FIG. 1B. A wire rope has first 61 a and second 61 b ends fixed to the support frame 14 b with wire rope passing through a series of pulleys 63 a positioned on the support frame and building frame such that when the motor 63 is actuated the support frame 14 b is lifted thereby rotating the reflector assembly 14 about the bearing assembly 20. A tensioning mechanism 62 is used to take up slack and maintain tension on the wire rope 61.

[0133] Thus, the reflector assembly can be oriented relative to incoming solar radiation to position the reflector assembly such that incoming solar radiation can be focused on the thermal pipe.

[0134] In an alternate embodiment as illustrated in FIGS. 6A to 6G and 9 to 9C, the actuation system 90 includes a central single axis geared system connected to a drive motor 63 a where actuation of the motor rotates the thermal pipe 25 and reflector assembly 14. In FIGS. 6A to 6G and FIGS. 9 to 9C, the rigid support 25 c connects the thermal pipe 25 to and the reflector assembly 14 and support post 15 c rotatably connects to the rigid support 25 c and supports the assembly on the foundation 15. A drive motor 63 a and gear actuation system 90 connected between the support post 15 c and the rigid support 25 c causes rotation of the rigid support 25 c together with the reflector assembly 14 and the thermal pipe 25 about an axis of rotation defined by the connection of the support post 15 c and the rigid support 25 c. This is illustrated in FIG. 6F. The gear actuation system 90 can be a worm gear or a slew drive or similar system. A slew drive for the present purposes can be interpreted as containing an integrated geared actuation system and a bearing support system. Bearing assembly 20, also located at the connection of support post 15 c and rigid support 25 c also relative rotation of the reflector assembly 14/thermal pipe 25 relative to support post 15 c.

[0135] In the arrangement of FIGS. 6A to 6G and FIGS. 9 to 9C, the thermal pipe 25 can be connected to a flexible hose 25 d or otherwise flexible pipe 25 d to allow for rotation of the thermal pipe 25 with the reflector assembly 14. With reference FIG. 6G which is a partial elevation view of the assembly and FIGS. 9 to 9C, the other pipe 25 d may be rigid, but includes a rotatable pipe connection 25 e to allow for rotation of the thermal pipe 25 with reflector assembly 14. The rotatable pipe connection 25 e is more preferably located in the same axis of rotation as that of the thermal pipe 25 and reflector assembly 14.

System Modularity and Maintenance

[0136] The system has been created with consideration of the DFMSA (Design for Manufacturing, Shipping, and Assembly) engineering methodology and modular design to reduce time and cost in manufacturing, assembly, and maintenance. Each of the components including the foundation structures, arches, membranes, thermal pipes, reflector assembly and bearing assembly can be manufactured with consistent dimensions as a single module enabling larger capacity systems to be assembled by interconnecting a number of modules. The modular design further enables simplified maintenance as may be required by enabling particular components to be removed/replaced by identical or upgraded components.

[0137] The modularity of the system allows for the system to be taken apart, collapsed, and easily shipped to other locations for set up.

[0138] For example, a single module may include a fixed number of arches and envelope material to cover that number of arches. As shown in FIG. 1A, a module may include multiple arch pairs (e.g. 2-6) designed to be spaced on appropriate centers, corresponding pre-cut to length Keder channels, pre-cut membrane with welded edge beads cut to an appropriate width, ridge members and fixed length stringers.

[0139] A reflector assembly module may include two bearing assemblies and stays, fixed length thermal pipe and sufficient reflector and frame materials to assemble a fixed length reflector assembly for the module. Reflector assemblies may be comprised of smaller or larger reflector panels and cross members as required.

[0140] Accessory modules may include other components including flooring, TES modules, PV panels, water collection and drainage channels, water storage modules, doors, end covers, and foundation equipment.

Control Equipment May Also be Provided in Modules

[0141] As such, the design and deployment of a particular installation can be simplified by utilizing multiples of the above modules.

Deployment and Operation

[0142] The STEC system will usually be deployed along an east-west or north-south axis to enable the reflector assemblies to track the sun perpendicular to deployment orientation. Deployment orientation may be favored to either extend the system thermal generation over more months into the shoulder seasons or provide a higher peak thermal generation output during the summer. Generally, if the system is east-west aligned, at dawn and sunset, with the sun low to the horizon, the reflector assembly will be lifted from a lower neutral position to enable the reflector assembly to be focused on the thermal pipe. As the sun rises in the sky, the system will adjust and be lowered towards the neutral position and as the sun lowers in the sky, the system will adjust and be lifted as sunset approaches.

[0143] As shown in FIG. 11A, the control of the system is automated via a controller that receives data from various sensors. Such sensors may include one or more inclinometers on the reflector assembly, temperature sensors deployed along the thermal pipe, pressure and/or flow sensors within each thermal pipe.

[0144] The controller may operate under a range of control schemes to optimize heat collection efficiency.

[0145] In one embodiment, the system will utilize sun position data for each day of the year (including hour and minute data) for the geographic location and adjust the angle of inclination based on the sun's position. That is, the controller will raise or lower the reflector assembly based on the known sun's position at a particular minute and hour of each day.

[0146] Confirmation that the system is at the correct angle may be confirmed by inclinometers. The inclinometers may also provide system fault checking data to ensure that a longer reflector assembly is correctly aligned along its entire length and not experiencing torsion.

[0147] The flow of thermal fluid through the thermal pipe is controlled by external pumps that may increase or decrease flow through the pipe based on measured temperatures along the length of the thermal pipe and may take into account local weather. Continuous thermal fluid circulation may be utilized for freeze-protection together with thermal storage. Material of manufacture of the thermal pipe, as well as choice of, thermal fluid, chemical treatment of thermal fluid, and inclusion of additives such as freezing point depressors can also be used individually or in combination to manage cold temperature operation.

Applications

[0148] As described above, an STEC system allows for the heating of a thermal fluid within the thermal pipe.

[0149] In one application, solar thermal energy is transferred to the thermal fluid that is used directly for commercial and industrial applications that require heat in their processes or building HVAC systems as shown in FIG. 11.

[0150] In one application, the STEC integrates with existing industrial processes through direct steam generation (DSG) and the use of lower grade process water as the thermal fluid. This allows for minimal integration infrastructure or process disruption to the many industrial applications that use steam directly as a heating medium through the elimination of heat exchangers or other equipment with thermal losses and a transition between different thermal fluids and heating loops.

[0151] The system is designed to be economically deployable in harsh climates where conventional systems are not feasible. These harsh conditions include both high and low temperatures, heavy snow and rainfall, high humidity, strong winds, dust and sandstorms and high frequencies of hail.

[0152] The foregoing design provides advantages over previous systems including effective protection of the reflector assembly to the environment. The high slope building enclosure minimizes the risk of snow/dust/sand accumulation and thereby reduces down-time due to fouled and/or shaded reflectors.

[0153] The building envelope enables utilization of a light-weight reflector assembly that reduces overall material and manufacturing costs. The modular design provides efficiency in the manufacture, assembly and maintenance of the system.

[0154] The bearing assembly enables ready access to the thermal pipe for maintenance or replacement.

[0155] Although the present invention has been described and illustrated with respect to preferred embodiments and preferred uses thereof, it is not to be so limited since modifications and changes can be made therein which are within the full, intended scope of the invention as understood by those skilled in the art.