Our Ref: 40141667 P/00/0 I I Regulation 3:2 AUSTRALIA Patents Act 1990 ORIGINAL COMPLETE SPECIFICATION INNOVATION PATENT Applicants: Simon Pointer and Chris Pearson Address for Service: DAVIES COLLISON CAVE Patent & Trade Mark Attorneys Level 10, 301 Coronation Drive Milton QLD 4064 Invention Title: "Solar thermal power station" The following statement is a full description of this invention, including the best method of performing it known to me:- C:\NRPonbI\DCC\UR\33R2073_1 DOC-23/12/2010 SOLAR THERMAL POWER STATION Background of the Invention This invention relates to a solar thermal power station, and in particular to the generation of electricity using an attached steam turbine electricity generating plant, which can be 5 configured for small or large scale applications and can be either installed in a permanent location or configured for mobile use. Description of the Prior Art Reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or 10 admission or any form of suggestion that the prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates. The traditional arrangement for Solar Thermal Power Generation is to have a large field of Reflectors focusing Sunlight upon either tubes containing water or tubes containing a thermal 15 medium. The heat harvested by the collectors is then converted to electricity or used as a heat source for other applications. The traditional arrangement is not easily scalable and once assembled cannot be transported to other locations. Accordingly, whilst traditional arrangements may be suitable for large scale use, they typically have many limitations when used for small-scale facilities such as 20 individual buildings or when used as a mobile facility in support of emergency services or the construction industries, or the like. Summary of the Present Invention In a first broad form the present invention seeks to provide a solar thermal generating apparatus including: 25 a) at least one heat trap including an housing having an optically transparent portion and containing one or more evacuated tubes containing a heat transfer medium, the heat transfer material being heated by solar radiation; C \NRPonb\DCC\LJR\3382073 -. DOC.2312/211t -2 b) a steam generator for generating steam using heat from the heated heat transfer medium; and c) a steam turbine for generating electricity from the steam. Typically the heat trap includes a double skinned insulated glass fronted box containing the 5 evacuated tubes and piping containing the heat transfer medium. Typically the piping runs along a floor of the heat trap and supports the evacuated tubes, thereby warming incoming heat transfer medium prior to entering the evacuated tubes. Typically the apparatus includes: a) a thermal collector array including a number of heat traps; 10 b) heat transfer medium pipes for transporting heat transfer medium through the thermal collector array and the steam generator; c) an electricity generator for generating electricity from rotation of the steam turbine; d) a condenser for condensing steam output from the steam turbine; e) steam pipes for transporting steam from the steam generator to the steam turbine and 15 then to the condenser; f) water pipes for transporting water from the condenser to the steam generator; and, g) a frame for supporting the thermal collector array, the heat transfer medium pipes, the steam pipes, the water pipes, the steam turbine and the condenser. In a second broad form the present invention seeks to provide a heat trap for a solar thermal 20 generating apparatus, the heat trap including a double skinned insulated glass fronted box containing evacuated tubes and piping containing a heat transfer medium, the heat transfer medium being heated by solar radiation for use in generating electricity. Brief Description of the Drawings An example of the present invention will now be described with reference to the 25 accompanying drawings, in which: Figure 1 is a schematic diagram of an example of a solar thermal power station; Figure 2 is a schematic exploded view of an example of a heat box; Figures 3A to 3C are schematic perspective, side and end views of an example of a steam generator; 30 Figure 4 is a schematic diagram of an example of a condenser; and, C:WRPotbl\DCC\LJR\33K2073_l DOC-2312/21)0) -3 Figures 5A and 5B are schematic front and rear views of an example of an assembly forming a scalable solar thermal generating apparatus. Detailed Description of the Preferred Embodiments The examples presented within this document are intended to give an impression of the 5 components and overall structure of the invention. Some Installations, as a result of climate or geographic conditions may result in a modification of the number of components or a modification of the arrangement of components. The purpose of the examples is to illustrate the key components in an ideal arrangement for climatic conditions likely to be found in South East Queensland. 10 An example solar thermal power station will now be described with reference to Figure 1. In this example, the Solar Thermal Power Station consists of a Thermal Collector Array (E 1), a Steam Generator (E-3), a Steam Turbine (E-4), an Electricity Generator (E-5), a Condenser (E-6), Heat Transfer Medium, Heat Transfer Medium Transport Piping (P-I and P-2), Steam Piping (P-3 and P-4), Liquid Water Piping (P-5), an Oil Pump (E-2) and a Water 15 Pump (E-7). Each Component can be modular in order to allow ease of replacement and to add additional components as and when required. Examples of the components will now be described in more detail. The Thermal Collector Array (E-1) typically consists of a two glass fronted insulated Heat 20 Boxes containing from twelve to twenty four Solar Evacuated Tubes and their associated plumbing. The Thermal Collection Arrays' purpose is to collect heat and transfer it to the Heat Transfer Medium. The number of Tubes selected and Thermal Collector Arrays used will vary dependent on the installation and may depend on parameters such as the environment, and in particular the available solar radiation, the amount of electricity to be 25 generated, or the like. In one example, the Heat Transfer Medium is a class Cl (Combustible Liquid) low viscosity mineral oil called Transformer Oil BSI (Caltex Product Code 1692). The Heat Transfer Medium is contained within the plumbing of the Thermal Collector Array (E-1) and the Heat Transfer Medium Transport Piping (P-1 and P-2). The Heat Transfer Medium is moved in a C:\NRPortbl\DCCkLJR\3382073 1.DOC.23/l2/2010 -4 clockwise direction via an Oil Pump (E-2), the speed of which can be controlled by an electronic controller, thereby allowing the flow rate of the heat transfer medium to be adjusted. The Heat Transfer Mediums purpose is to transfer heat from the Thermal Collector Array to the Steam Generator (E-3). 5 The Heat Transfer Medium Transport Piping (P-1 and P-2) can consist of 15 mm diameter copper piping. The Heat Transfer Medium Transport Piping's purpose is to act as a conduit for the Heat Transfer Medium. In one example, the Steam Generator (E-3) is a 13-chambered water boiler consisting of a length of coiled Heat Transfer Medium Transport Piping, a Gate Valve (for Steam Egress) 1o and a Swing Check Valve (for water ingress). The Steam Generators' purpose is to produce Steam to power the Steam Turbine (E-4). The Steam Turbine (E-4) can be any suitable Back Pressure Steam Turbine Generator and typically includes the Steam Turbine, a Gear Box, Generator (E-5), and Electrical Control Panels. The Steam Turbines' purpose is the generation of electricity. 15 The Condenser (E-6), typically includes a small tank of water with a connection from the exhaust steam pipe (P-4) Steam Turbine, and a Water Pipe (P-5) and Water Pump (E-7) connected to the Steam Generator. The purpose of the Condenser is to capture exhaust steam, liquefy it and feed it back into the Steam Generator. The Fittings for the Heat Transfer Medium Transport Piping and Water Piping can be any 20 suitable 5mm and 15mm Flare Compression Fittings or similar. The Thermal Collector Array includes one or more Heat Boxes containing a number (typically twelve or twenty-four) solar evacuated tubes. The structure of the Heat Box is illustrated in Figure 2 and will now be described in further detail. In this example, the heat box includes an Outer Casing (1), which may be formed from an 25 open topped folded and spot welded metal box with two diagonally separated circular (15mm diameter) holes for the Heat Transfer Medium Transport Pipes to enter and exit. The Outer Casing provides structural integrity, a container to hold the Glass Fibre Insulation, and a surface mounting for an assembly frame.
CWRPortbl\DCC\LJR\3132073_1 DOC-23112/20110 -5 The Glass Fibre Insulation (4) is typically a bed of Glass Fibre Insulation positioned on the floor and against the walls of the Outer Casing to reduce heat loss and to provide for the secure placement of the Inner Casing (3). In this example, the Inner Casing (3) is an Open topped folded and spot welded metal box 5 with a circular (15mm diameter) entry hole opposite the circular re-entry hole of the Outer Casing and an exit hole (15 mm diameter) opposite the exit hole of the outer casing. The Inner Casing contains the Heat Transfer Medium Transport Pipes (2) and the Solar Evacuated Tubes. The Heat Transfer Medium Transport Pipes connected to the piping coming from outside of the Thermal Collector Array allows the flow of Heat Transfer Medium to the Solar 10 Evacuated Tubes. The Heat Transfer Medium Transport Piping is positioned on the floor of the Inner casing in a series of loops and supports the weight of the Solar Evacuated Tubes. Heat loss from the pipes within the inner casing is absorbed by the Solar Evacuated Tubes. A Bridging Cover (5) is provided, which in one example is a square of welded metal, which connects the wall of the Inner Casing to those of the Outer Casing thus closing the metal box. 15 The Bridging Cover is welded to the walls of the two casings (4), Detail AA illustrates a Imm bevelled inner edge of the Bridging Cover. The purpose of the bevelled edge is the support a Glass cover to the Thermal Collector Array. The Glass Cover (6) can be a 5mm thick glass cover sits on the Imm bevel cut into the upper surface of the bridging cover and is held in place by Silicon sealant. The purpose the glass 20 cover is to seal the thermal array, protect the solar evacuated tubes and minimize heat loss back to the atmosphere. Whilst a glass cover is described, it will be appreciated that this is for the purpose of example only and that in practice any optically transparent material can be used for any portion of the housing, such as a wall, cover, or the like, to thereby permit solar radiation to enter the casing. 25 Depending on the Expected Power Output the Environmental and Geographical characteristics of the site the Scalable Solar Thermal Power Station can have 2 or more groupings of Thermal Collector Arrays (i.e. 2 x Thermal Collector Arrays, 4 x Thermal Collector Arrays, 6 x Thermal Collector Array ... etc). It will be appreciated however that any suitable configuration used, depending on the preferred implementation.
C:\NRPonbl\DCC\LR\3382(073_ DOC-23/122011 -6 An example Steam Generator will now be described in more detail with reference to Figures 3A to 3C. In this example, the Steam Generator includes a multiple chambered water boiler consisting of a length of coiled Heat Transfer Medium Transport Piping, a Gate Valve (for Steam 5 Egress), a Swing Check Valve (for water ingress). The role of the Steam Generator is to produce Steam at sufficient temperature and pressure in order to drive a Steam Turbine. The Steam Generator consist of the following: The steam generator typically includes an external case (310) made from steel in the shape of a cylinder with end plates, which in one example has a length 1000mm, width 500mm and 10 height 500mm. As shown in Figure 3B, external connections to the Steam Generator can include a Steam Outlet pipe which is connected to a Gate Valve located at point (a), the Heat Transfer Medium Transport Pipe entry at point (b), a Heat Transfer Medium Transport Pipe exit point at point (c), and a Water Ingress pipe entry at point (d) in Figure 3B. The Water Ingress pipe 15 can include a 30mm diameter copper pipe providing a continuous feed of water into the boiler via a Swing Check Valve. In one example, the Heat Transfer Medium Transport Pipe connects to a series of coiled 15mm Copper pipe within the heat chambers of the Steam Generator (e). The flow of the Heat Transfer Medium along the coiled copper pipe follows the red arrows in Figure 3B. 20 Heat is transferred to the first heat chamber as the Heat Transfer Medium moves through the coils, gradually depositing heat in successive heat chambers until the exit point (c). This establishes a thermal cycle within the steam generator, as shown by the blue and red arrows in Figure 3C, which permits continuous mixing of hot and warm water. This gradually increases the temperature and the pressure with each successive movement of Heat Transfer 25 Medium through the coils. When steam of sufficient temperature and pressure (180*C / 0.8 Mpa) is attained steam is released into the Steam Pipe (P-3) and enters the Steam Turbine. Two cool water/steam entry chambers flank each central heating chamber. The cool water/steam entry chambers sit flush with the lower internal sides of the Steam Generator and 30 allow cool water/steam to enter the central heating chamber via the cool water/steam vents.
C :NRPonbrlDCC\LJR\3382073_I.DOC.23/12/2010 -7 A Vortex Generating Chamber is formed by the space above the central heating chambers and cool water/steam entry chambers (f). This chamber has no internal structures and is the central water storage and mixing chamber within the Steam Generator. Vortexes are generated by hot water/steam rising out of the central heating chambers and striking the 5 ceiling of the Vortex Generating Chamber. This causes the stream of hot water/steam to split and travel down along the walls of the chamber until it enters the cool water/steam entry chambers. During this passage down the chamber wall the water/steam will mix with water/steam from the other chambers. This mixing will initially cause vortexes due to differing thermal characteristics of the fluid. 10 In one example, the Steam Turbine (E-4) is a Back Pressure Steam Turbine Generator, such as a Shandong Zerchen Group Model B0.005-0.8/0.11. The Steam Turbine accepts steam from the Steam Generator via its Steam Inlet Valve. Steam temperature / pressure at the Steam Inlet Valve are no less than the minimum temperature and pressure to propel the turbine and therefore generate power within the specific Steam Turbine Generator installed. 15 The design is capable of accepting a range of Zerchen Back Pressure Steam Turbine Generators from the 5kw to 500kw. Used steam is exhausted via the Steam Outlet Valve. The used steam travels along a Steam Pipe (P-4) to the Condenser, an example of which will now be described in more detail with reference to Figure 4. 20 The Condenser 400 is a single chamber device intended to convert the exhaust steam from the Steam Turbine Generator into hot water suitable for re-ingestion into the Steam Generator. The Condenser consists of a water tank (420) with the exhaust pipe (410) from the turbine terminating above the floor of the tank. This allows steam to directly enter the water as shown by the red arrow thereby heating the water and condensing the steam. The 25 condenser outlet pipe (440), returns hot water as shown by the blue arrow to the Steam Generator via the Hot Water Inlet pipe. When required additional water can be transported to the Steam Generator via the condenser. The condenser is un-pressurized and is progressively toped up via a water pipe connection to an external water supply (430). An example of an Assembly in the form of a Scalable Solar Thermal Power Station will now 30 be described with reference to Figures 5A and 5B.
C:NRPortbl\DCC\UR\3182073_1.DOC-23/12/2010 -8 In this example, a Frame, which supports the assembled structure, is made from metal tubing and metal sheets. The arrangement of the frame is dependent of the installation, and will vary from facility to facility. The Scalable Solar Thermal Power Generator includes the Thermal Collector Array 510, 5 containing the Solar Evacuated Tubes, the Heat Transfer Medium Transport Pipe 520 connecting the Thermal Collector Array pipe exit point to the Steam Generator pipe entry point, and the Heat Transfer Medium Transport Pipe 530 connecting the Thermal Collector Array pipe entry point to the Steam Generator pipe exit point. The Scalable Solar Thermal Power Generator also includes the Steam Generator 540, the 10 Steam Turbine Generator 550, the Condenser 560 and the Assembly Frame 570. It will be appreciated that the above described arrangement can be used to provide a scalable solar thermal power plant capable of generating electricity. The system utilises heat boxes containing evacuated tubes, used to transport a heat transfer medium, such as a thermal oil, to a steam generator. The generated steam can then be used to generate electricity, for example 15 using a steam turbine. The heat boxes are cheap and easy to construct, whilst being robust and capable of protecting the evacuated tubes from the environment. Furthermore, by increasing the number of heat boxes and/or evacuated tubes per heat box, the amount of heat energy available to heat the thermal oil can be increased, thereby increasing the steam generating capacity of the steam generator, and hence the amount of electricity produced. It 20 will therefore be appreciated that this allows the capacity of the system to be adjusted to suit a wide range of applications. The traditional arrangement for Solar Thermal Power Generation is to have a large field of Reflectors focusing Sunlight upon either tubes containing water or a boiler, which then uses the heat to produce steam and drive a turbine generator. The traditional arrangement is good 25 for large-scale applications such as a town, but is not easily scalable and cannot be transported. In contrast to this, the above described system provides a scalable and transportable solar thermal power station, which can be used in a traditional field array arrangement capable of powering a small town, domestically as a single unit providing electricity to a family, or as a transportable unit to provide electricity to remote sites for 30 mining, construction and other activities.
C \NRPonbliDCCUR\3382073_I.DOC-2311212010 -9 This allows a scalable and portable Solar Thermal Electricity Generating system to be deployed using commercial off the shelf components, and can provide enough electricity and capacity to power various domestic, industrial and urban installations. In one particular example, the Scalable Solar Thermal Power Station consists of a Thermal 5 Collector Array, for light and heat conversion, piping for heat collection and transportation using a heat transfer medium, a Steam Generator, and a commercially available steam turbine generator, to generate electricity. The Thermal Collector Array is composed of Solar Evacuated Tubes contained within one or more Insulated Glass fronted heat traps and linked by an array of Copper pipes. The copper 10 pipes contain a Heat Transfer Medium, which is exposed to Solar Thermal Heating within the Solar Evacuated Tubes. The Heat traps, containing the Solar Evacuated Tubes and Copper Piping with its internal Heat Transfer Medium consist of double skinned insulated glass fronted boxes. The Copper Piping runs along the floor of the Heat Trap and supports the Solar Evacuated Tubes. The 15 purpose of the heat trap is to ensure that only minimal thermal loss occurs and that incoming Heat Transfer Medium is warmed prior to entering the Solar Evacuated Tubes. The Solar Evacuated Tubes are an array of commercially sourced Solar Thermal tubes connected via Copper Piping to a Spine consisting of Copper Pipes. The Solar Evacuated Tubes have an internal carriage system for the Heat Transfer Medium. The Solar Evacuated 20 Tube arrays are contained within the Heat Traps and connected directly to the Copper Piping supporting them. The Heat Transfer Medium moves from the cooler side of the array to the hotter side within the Heat Trap. The Hot Heat Transfer Medium temperature is further boosted in any supplemental Thermal Collector Arrays, should they be required. The Number of Solar Evacuated Tubes within each Heat Trap and the number of Thermal 25 Collector Arrays used depends on the Latitude of the installation. In Tropical Climates Less Tubes and Heat Traps are required than in Temperate and Polar climates. Providing a closed circuit from the Thermal Collector Arrays to the Steam Generator and back into the Solar Thermal Arrays. The movement of the Heat Transfer Medium is achieved via a pressure differentiation established by the thermal difference across the System. Hot 30 Heat Transfer Medium travels towards the cold Heat Transfer Medium generating current C:\NRPortbl\CCRR320731 .DOC-23112/2010 - 10 within the Heat Transfer System. Alternatively a pump can be used to ensure Heat Transfer Medium flow. The Heat Transfer Medium exits the Solar Thermal Array and enters the Steam Generator via an Insulated Copper Pipe. The Steam Generator is a boiler based on the Fire Box boiler 5 design. The Heat Transfer Medium is maintained within Copper Pipes inside the Steam Generator. The Steam is produced by the exposure of the water to the surface area of the hot Copper Pipes within the barrel of the Boiler. The Heat Transfer Medium becomes cooler as it travels through the Steam Generator and exits at a lower temperature. The Heat Transfer Medium is then fed back into the Thermal 10 Collector Array, thus completing the cycle. Each time the Heat Transfer Medium Travels through the Steam Generator more heat is deposited into the water contained within. As the water boils steam is generated and the pressure within the boiler increases. When the steam reaches the desired Temperature and Pressure it is released into a Commercially Available small Steam Turbine Generator. The Commercially Available small Steam Turbine Generator 15 uses the Steam from the Steam Generator to power an electric generator. The used steam is fed into a condenser and returned to the Steam Generator. Accordingly, a Scalable Solar Thermal Power Station can be constructed which uses Solar Evacuated Tubes as the heat source. The Scalable Solar Thermal Power Station can be a single unit construction with all components making up an integral package, which can be 20 moved as a single unit. The Scalable Solar Thermal Power Station can be scaled up by simply connecting additional Scalable Solar Thermal Power Stations up to a single distribution system to meet any power demands for any facility or urban area, or operated individually for small-scale electricity requirements. The Scalable Solar Thermal Power Station can be mounted on a trailer or flat bed vehicles and operated in remote locations or areas where 25 electricity supply has been disrupted. The Scalable Solar Thermal Power Station does not need to be permanently fixed in a single geographical location in order to function. The Scalable Solar Thermal Power Station can be assembled using a mixture of commercially available Solar Evacuated Tubes and a Back Pressure Steam Turbine Generator and a bespoke Steam Generator and Heat Box. Typically the Thermal Collector Array can 30 generate sufficient heat and can transfer that heat to a Heat Transfer Medium, which can C:NRPnbl\DCCUR\33H2073_I.DOC-23112/2010 - 11 deliver sufficient heat to a Steam Generator to produce steam at the appropriate temperature and pressure to drive a Back Pressure Steam Turbine Generator. The design of the Scalable Solar Thermal Power Station can be modular to allow the installation of additional Thermal Collector Arrays or there removal, and larger or smaller 5 Steam Turbine Generators depending on need of the installation. There is no set design for the Assembly frame, and the arrangement can depend on the Geographic, Environmental and Power requirements of each installation. Persons skilled in the art will appreciate that numerous variations and modifications will become apparent. All such variations and modifications which become apparent to persons 10 skilled in the art should be considered to fall within the spirit and scope of the invention broadly appearing and described in more detail herein. It is to be appreciated that reference to "one example" or "an example" of the invention is not made in an exclusive sense. Accordingly, one example may exemplify certain aspects of the invention, whilst other aspects are exemplified in a different example. These examples are 15 intended to assist the skilled person in performing the invention and are not intended to limit the overall scope of the invention in any way unless the context clearly indicates otherwise. Features that are common to the art are not explained in any detail as they are deemed to be easily understood by the skilled person. Similarly, throughout this specification, the term "comprising" and its grammatical equivalents shall be taken to have an inclusive meaning, 20 unless the context of use clearly indicates otherwise.