FORM-2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2006
COMPLETE
Specification
(See Section 10 and Rule 13) A SOLAR CONCENTRATOR
THERMAX LIMITED
an Indian Company
of D-13, MIDC Industrial Area, R.D. Aga Road, Chinchwad, Pune - 411 019, Maharashtra, India.
INVENTORS:
1. JANG ADA JAYPRAKASH
2. AHMAD TANVEER 3.PATHAKANAGHA 4. ROHOM HEMANT 5.AGRAWALANKIT
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE NATURE OF THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED

FIELD OF THE DISCLOSURE
The present disclosure relates to the field of solar concentrators. Particularly, the present disclosure relates to the field of parabolic dish type solar concentrators for tracking the sun.
BACKGROUND
A majority of the world's current electricity supply is generated from traditional fossil fuels such as coal, oil and natural gas. However, these traditional energy sources face a number of challenges including rising prices, security concerns over dependence on imports from a limited number of countries having significant fossil fuel supplies and growing environmental concerns over the climate change risks due to pollution associated with power generation using fossil fuels. As a result governments, businesses and consumers are increasingly supporting the development of alternative energy sources and new technologies for generation of electricity over traditional energy sources. Renewable energy sources such as solar energy have emerged as potential alternatives which address the problems associated with traditional energy sources.
There are many different methods for producing heat and power from solar energy, but a more common and viable method includes a system which uses reflective surfaces to concentrate or focus the incident sunlight onto a receiver, where it is converted into electrical or thermal energy.

There are mainly three types of solar concentrators namely, heliostats or central receiver type, parabolic troughs or line focus type and paraboloid dishes or point focus type.
Heliostats include plane mirrors which are rotated so as to focus reflected rays of solar light towards a predetermined target, compensating for apparent motion of the sun. However, one disadvantage of the heliostats is that they are required to have tall towers supporting remote receivers which increase the cost.
The parabolic troughs are simple in construction with parabolic shaped mirrors or other reflective surface. The parabolic troughs concentrate solar light onto long receiver pipes. The disadvantages of the parabolic troughs include low concentration ratio, high receiver heat loss and high receiver cost. Both the heliostats and the parabolic troughs fail face sun directly and therefore have reduced performances due to cosine losses.
Solar dishes consist of stand-alone parabolic reflector that concentrates light onto a receiver positioned at the focal point of the parabolic reflector. The parabolic reflector enables tracking of the sun along two axes. Thus, the solar dishes help in achieving high concentration of solar rays and high efficiency as the parabolic reflector of the solar dishes faces the sun directly at all point of time. Thus, in the parabolic reflectors, incoming solar radiation of the sun parallel to the axis of the parabola forming the parabolic reflectors are incident on a predetermined focus. This increases the concentration of solar radiation on surface of the parabolic reflectors and thus maximizes the use of solar radiation for heating and power generation. The parabolic reflectors cooperates with tracking mechanisms to ensure

focusing the solar radiation on a receiver mounted at the focus to achieve maximum energy concentration, by synchronizing the position of the parabolic reflectors position with the position of the sun.
Several attempts have been made to develop solar dishes with parabolic reflectors.
Accordingly, United States patent US6485152 discloses a solar dish consisting of flexed glass mirror supported on a structural frame. The solar dish tracks the solar azimuth with a bicycle wheel and the solar zenith with a television satellite dish actuator. Further, a pair of counter weights is mounted for balancing the solar dish. However, the bicycle wheel for tracking the solar azimuth in US6485152 necessitates large space for operation of the solar dish thus, rendering the solar dish of US6485152 unsuitable for operation in locations having low footprint area for operation of solar dish. Further, the use of a pair of counter weights makes the system complex in operation and increases the cost.
Further, United States patent US6485152 discloses a reflector dish having at least one elongated mirror-surfaced reflector panels which are structurally integrated with a support framework. The reflector dish has a parabolic dish shape with short focal length, synthesized from a combination of the reflector panels. The reflector dish of US6485152 is complex in construction.
Thus, there was a need for a solar concentrator which enables overcoming the drawbacks of the prior art.

OBJECTS
Some of the objects of the solar concentrator of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to provide an efficient and low cost solar concentrator for directing solar radiation incident on a reflecting surface to a receiver.
Yet another object of the present disclosure is to enable tracking of the sun accurate in sunny condition and approximately in cloudy condition.
Still another object of the present disclosure is to provide a simple and compact solar concentrator.
An added object of the present disclosure is to provide a solar concentrator required reduced installation space.
Other objects and advantages of the present disclosure will be more apparent from the following description when read in conjunction with the accompanying figures, which are not intended to limit the scope of the present disclosure.
SUMMARY
In accordance with the present disclosure there is provided a solar concentrator comprising:
a solar dish including a reflector frame with a reflecting surface
mounted thereon;

a supporting arrangement adapted to support the solar dish on a
mounting location;
a displacement mechanism for biaxial displacement of the solar
dish with respect to a mounting location on the displacement
mechanism;
a sensing circuit adapted to sense the position of the sun to
produce a sensed data in real time;
a database adapted to store a calibrated stored data of the position
of the sun with respect to real-time; and
a controller adapted to control the biaxial displacement of the
solar dish alternately in accordance with the sensed data and the
calibrated stored data.
Generally, the supporting arrangement includes a supporting structure mounted on a support post anchored to the ground through a pedestal, the solar dish being adapted to be mounted on the supporting structure.
Typically, the supporting arrangement is reinforced by a plurality of stiffener plates positioned between the supporting arrangement and the pedestal, the stiffener plates having a shape selected from the group consisting of triangular shaped or T-shaped.
Preferably, the at least one reflector frame includes a plurality of tubes arranged to define a paraboloidal structure having a plurality of diagonals reinforced with a plurality of reinforcement tubes associated with the plurality of diagonals defining the sides of a quadrilateral therebetween.

Typically, the plurality of tubes is made of materials selected from the group consisting of aluminum, mild steel and lightweight steel.
Typically, the at least one reflecting surface is mounted on the reflector frame defined by a parabolic surface defining an focal axis of the solar dish, the solar dish defining a predetermined focus for concentrating the incoming solar radiations reflected from the at least one reflecting surface to form the position of the sun at the predetermined focus.
Typically, the at least one reflecting surface is made of reflecting material selected from the group consisting of solar grade mirror, white mirror, low iron glass and aluminum reflecting sheet, the at least one reflecting surface being adapted to have a length in the range of 0.8m to 3.6m, a thickness in the range of 0.3mm to 4mm.
Generally, the displacement mechanism is mounted on the supporting arrangement.
Preferably, the displacement mechanism includes an azimuth tracker driven by a gear drive means for angularly displacing the solar dish within a predetermined angle about the supporting arrangement, the azimuth tracker being operated for azimuth tracking of the sun.
Additionally, the displacement mechanism includes a concentrator tilting mechanism driven by a linear drive means for tilting the solar dish at the mounting location on the supporting arrangement, the concentrator tilting mechanism being operated for altitude tracking of the sun.

Preferably, a receiver is positioned at the predetermined focus, the receiver being mounted on a receiver support arrangement extending along the focal axis of the solar dish.
Typically, the controller includes a switching means adapted to transfer control for operation of the displacement mechanism between the sensed data and the calibrated stored data and vice versa.
Preferably, the sensing circuit provides an input signal to a processor for transmitting a corresponding output signal to control the operation of the gear drive means and the linear drive means, the processor being selected from the group consisting of microprocessor, ARM (Advanced RISC Machines) based processor and DSP (Digital Signal Processor).
Typically, at least one counter weight is mounted on the support arrangement, the counter weight being adapted to balance the solar concentrator.
Typically, the concentrator has a shape selected from the group consisting of a square, a rectangle, a hexagon and an oval.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
The solar concentrator of the present disclosure will now be described with the help of accompanying drawings, in which:
Figure 1 illustrates the solar concentrator in accordance with the invention;

Figure 2 illustrates a post assembly and direction of movement of the solar dish supported thereon for azimuth tracking of the sun;
Figure 3 illustrates supporting arrangement and direction of movement of the solar dish of the solar concentrator for altitude tracking of the sun; and
Figure 4 and Figure 5 illustrate reflector frame supporting the solar concentrator with four diagonals.
DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS
A preferred embodiment of the solar concentrator of the present disclosure will now be described in detail with reference to the accompanying drawings. The preferred embodiment does not limit the scope and ambit of the disclosure. The description provided is purely by way of example and illustration.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

The following description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
Referring to the accompanied drawings, the solar concentrator, in accordance with the present disclosure is generally indicated by the reference numeral 10 and is particularly shown in Figure 1 of the drawing.
The solar concentrator 10 comprises a supporting arrangement, a displacement mechanism, a solar dish, a sensing circuit and a controller.
The solar dish comprises at least one reflector frame 120 with at least one reflecting surface 170 mounted thereon. The solar dish is supported on a mounting location on the supporting arrangement for transferring load of the solar dish to the ground.
The supporting arrangement includes a support post 100, illustrated in Figure 2, and a supporting structure 110, illustrated in Figure 3. The supporting arrangement enables in mounting a displacement mechanism

mounted thereon for biaxial displacement of the solar dish. The displacement mechanism includes an azimuth tracker 160 and a concentrator tilting mechanism 150. The support post 100 includes a main post 101 with one end cooperating with a pedestal 103 for anchoring the solar concentrator 10 to the ground. The pedestal 103 is a flat plate perpendicular to the main post 101. The pedestal 103 besides anchoring the solar concentrator 10 to the ground also enables transferring the load of the solar concentrator 10 to the ground. A plurality of stiffener plates 102, typically, triangular shaped or T-shaped, is positioned between the main post 101 and pedestal 103. The stiffener plates 102 are provided to support the solar concentrator 10 during windy/turbulent conditions. The azimuth tracker 160, typically a worm and wheel gear arrangement, cooperates with the end of the main post 101 distal from the pedestal 103 for azimuth tracking of the sun. The azimuth tracker 160 is driven by a gear drive means. In order to perform azimuth tracking of the sun, the azimuth tracker 160 causes the reflector frame 120 and hence the reflecting surface 170 to rotate about a first axis along the length of the support post 100 in the direction of movement of azimuth tracker 160 illustrated by arrows referenced by numerals 104a and 104b.
The supporting structure 110, illustrated in Figure 3, is mounted on the support post 100 and enables supporting the reflector frame 120 mounted thereon. The concentrator tilting mechanism 150 cooperates with the supporting structure 110 to enable rotation of the reflector frame 120, and hence the reflecting surface 170, about a second axis substantially perpendicular to the first axis. The concentrator tilting mechanism 150 enables in altitude tracking of the sun by tilting the reflector frame 120 and hence the reflecting surface 170 with respect to the mounting location on the

supporting arrangement in the direction illustrated by arrows referenced by numerals 104a and 104b. On tilting the reflector frame 120, the reflectors of the reflecting frame 170 are positioned orthogonal to the tilt direction and the direction of the incoming solar radiation. The concentrator tilting mechanism 150 is driven by a linear drive means.
The support post 100 and a supporting structure 110, illustrated in Figure 3is utilized for making low cost dual axis photovoltaic tracking system of the sun by mounting photovoltaic cells directly on the supporting structure 110 by means of a supporting frame.
The reflecting surface 170 of the solar dish is typically a paraboloidal reflecting surface mounted on the reflector frame 120. The reflector frame 120 is made of a plurality of tubes arranged to form a parabolic reflector frame 120 for supporting at least one reflector, preferably, glass mirrors, solar grade mirror, white mirror or low iron glass, having a length in the range of 0.8m to 3.6m, thickness in the range of 0.3mm to 4mm. The at least one reflector has a predetermined resilience. The plurality of tubes is typically made of aluminum, mild steel (MS) or lightweight steel and is typically circular in cross-section. The plurality of tubes are joined/fitted together to form the reflector frame 120. The reflector frame 120 defines four diagonals of the parabolic reflector frame 120 referenced by numerals 121a, 121b, 121c and 121d, illustrated in Figure 4 and Figure 5. The diagonals 121a, 121b, 121c and 121d are defined by a plurality of reinforcement tubes associated with the diagonalsl21a, 121b, 121c and 121d. The reinforcement tubes are typically straight or zig-zag in structure. The reinforcement tubes are arranged such that the reinforcement tube

defining the diagonal 121a is parallel to the reinforcement tube diagonal defining the diagonal 121c and the reinforcement tube defining the diagonal 121b is parallel to the reinforcement tube diagonal defining the diagonal 121d. The reinforcement tubes defining the diagonal 121a, 121b, 121c and 121d defines a quadrilateral, typically a square, a rectangle or a hexagon, therebetween and are arranged so as to partially cross over the adjacent tubes at a single point along the length of the reinforcement tubes. The arrangement of the tubes defining the diagonal 121a, 121b, 121c and 121d enables the solar concentrator 10 to withstand heavy wind and maintain the parabolic shape of the reflector frame 120 during moderate wind condition. Typically, the shape of the solar concentrator 10 is a square, a rectangle, a hexagon or an oval.
The size of the solar concentrator 10 can be increased by dividing the reflector frame 120 into four quadrants of equal size and shape to be joined/fitted together to define a parabolic shape. In order to further increase the size of the solar dish, each quadrant of the reflector frame 120 is subdivided into at least two parts. The size of each quadrant is dependent on the size of the tubes. The support post 100 and the supporting structure 110 are dependent on the size of reflector frame 120 and wind load condition at a particular location.
A receiver 140 is mounted on a receiver support arrangement 130 extending along the focal axis of the reflecting surface 170 such that the receiver 140 is located at the focus of the reflecting surface 170 of the solar concentrator 10, defined at a pre-determined distance from the reflecting surface 170. The azimuth tracker 160 and the concentrator tilting mechanism 150 enables in

positioning the reflector frame 120 and hence the reflecting surface 170 so as to direct the solar radiation normally sticking the reflecting surface 170 towards the receiver 140. The axis of the paraboloid formed by the reflector frame 120 is maintained parallel to the incoming solar radiation sticking the reflecting surface 170. The receiver 140 is typically an 'L' cavity type with "T" spiral coil having minimal insulation. A counter weight 180 is provided on the supporting structure 110 to enable balancing the solar concentrator 10 during biaxial displacement by the azimuth tracker 160 and the concentrator tilting mechanism 150 for azimuth tracking and altitude tracking of the sun respectively.
The sensing circuit, which includes at least one solar sensor, enables sensing the position of the sun and produces a sensed data for operation of the displacement arrangement in real time. The sensed data is stored in a database as a calibrated stored data of the position of the sun with respect to real-time. The calibrated stored data serves as future reference for solar tracking during cloudy weather with passive tracking routines. The sensing circuit provides an input signal to a processor (not shown in Figure) for transmitting a corresponding output signal to the gear drive means and the linear drive means for driving the azimuth tracker 160 and the concentrator tilting mechanism 150. The processor (not shown in Figure) is typically a micro-processor, an ARM (Advanced RISC Machines) based processor or a DSP (Digital Signal Processor). The solar sensor determines the time/position of the sun and the position of the reflecting surface 170 with respect to the time/position of the sun. The change in the position of the reflecting surface 170 is dependent on the lateral movement of the sun. The controller helps in controlling the biaxial displacement of the solar dish by

supplying input signals to the displacement mechanism alternately between the sensed data of the sun in real time and the calibrated stored data of the position of the sun in the absence of the sensed data. The controller includes a switching means which helps in transferring control for operation of the displacement mechanism between the sensed data of the sun in real time and the calibrated stored data in the database and vice versa.
Further, the processor (not shown in figure) enables in signaling the drive for the concentrator tilting mechanism 150 to displace the reflecting surface 170 such that in heavy storms and windy condition, the reflecting surface 170 is displaced to horizontal position so that wind facing area of the reflecting surface 170 is minimal.
The receiver 140, located at the focus of the solar dish, is filled with water or a desired fluid pumped into the receiver 140 through the receiver tubes. The sensing circuit senses the position of the sun. The processor (not shown in figure) calculates the desired position of the reflecting surface 170 with respect to the position of the sun and provides signal to the drive units for the azimuth tracker 160 and the concentrator tilting mechanism 150 so as to position the reflecting surface 170 normal to the incoming solar radiation. Based on the sensed data, the azimuth tracker 160 rotates the reflecting surface 170 around the axis of the support post 100 for adjusting the azimuth angle and the concentrator tilting mechanism 150 enables tilting the reflecting surface 170 along an axis substantially perpendicular to the axis of the support post 100 on a mounting location. When the reflecting surface 170 is positioned such that the incoming solar radiation is normal to the reflecting surface 170, the processor (not shown in figure) enables recording

the time, date and position of the reflecting surface 170 in real time into the database. The incoming solar radiations are reflected from the reflecting surface 170 to the receiver 140 positioned at the focus of the reflecting surface 170 and heat up the fluid stored therein to generate hot water/steam/hot fluids depending on a desired application.
TECHNICAL ADVANCEMENTS
The technical advancements offered by the present disclosure include the realization of:
• an efficient and low cost solar concentrator for directing solar radiation incident on a reflecting surface to a receiver;
• accurate tracking of the sun in sunny condition and at least partially in cloudy condition; and
• a simple and compact solar concentrator.
Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression "at least" or "at least one" suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.

The numerical values given of various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher or lower than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the disclosure unless there is a statement in the specification to the contrary.
Wherever a range of values is specified, a value up to 10% below and above the lowest and highest numerical value respectively, of the specified range, is included in the scope of the disclosure.
The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

We claim:
1. A solar concentrator comprising:
a solar dish including a reflector frame with a reflecting surface
mounted thereon;
a supporting arrangement adapted to support said solar dish on a
mounting location;
a displacement mechanism for biaxial displacement of said solar
dish with respect to a mounting location on said displacement
mechanism;
a sensing circuit adapted to sense the position of the sun to
produce a sensed data in real time;
a database adapted to store a calibrated stored data of the position
of the sun with respect to real-time; and
a controller adapted to control said biaxial displacement of said
solar dish alternately in accordance with said sensed data and said
calibrated stored data.
2. The concentrator as claimed in claim 1, wherein said supporting arrangement includes a supporting structure mounted on a support post anchored to the ground through a pedestal, said solar dish being adapted to be mounted on said supporting structure.
3. The concentrator as claimed in claim 1, wherein said supporting arrangement is reinforced by a plurality of stiffener plates positioned between said supporting arrangement and said pedestal, said stiffener plates having a shape selected from the group consisting of triangular shaped or T-shaped.

4. The concentrator as claimed in claim 1, wherein said at least one reflector frame includes a plurality of tubes arranged to define a paraboloidal structure having a plurality of diagonals reinforced with a plurality of reinforcement tubes associated with said plurality of diagonals defining the sides of a quadrilateral therebetween.
5. The concentrator as claimed in claim 4, wherein said plurality of tubes are made of materials selected from the group consisting of aluminum, mild steel and lightweight steel.
6. The concentrator as claimed in claim 1, wherein said at least one reflecting surface is mounted on said reflector frame defined by a parabolic surface defining an focal axis of said solar dish, said solar dish defining a predetermined focus for concentrating the incoming solar radiations reflected from said at least one reflecting surface to form the position of the sun at said predetermined focus.
7. The concentrator as claimed in claim 1, wherein said at least one reflecting surface is made of reflecting material selected from the group consisting of solar grade mirror, white mirror and low iron glass, said at least one reflecting surface being adapted to have a length in the range of 0.8m to 3.6m, a thickness in the range of 0.3mm to 4mm.
8. The concentrator as claimed in claim 1, wherein said displacement mechanism is mounted on said supporting arrangement.

9. The concentrator as claimed in claim 1, wherein said displacement mechanism includes a azimuth tracker driven by a worm and wheel gear arrangement for angularly displacing said solar dish within a predetermined angle about said supporting arrangement, said azimuth tracker being operated for azimuth tracking of the sun.
10. The concentrator as claimed in claim 1, wherein said displacement mechanism includes a concentrator tilting mechanism driven by a linear drive means for tilting said solar dish at said mounting location on said supporting arrangement, said concentrator tilting mechanism being operated for altitude tracking of the sun.
11. The concentrator as claimed in claim 1, wherein a receiver is positioned at said predetermined focus, said receiver being mounted on a receiver support arrangement extending along said focal axis of said solar dish.
12. The concentrator as claimed in claim 1, wherein said controller includes a switching means adapted to transfer control for operation of said displacement mechanism between said sensed data and said calibrated stored data and vice versa.
13. The concentrator as claimed in claim 1, wherein said sensing circuit provides an input signal to a processor for transmitting a corresponding output signal to control the operation of said gear drive means and said linear drive means, said processor being selected from the group consisting of microprocessor, ARM (Advanced RISC Machines) based processor and DSP (Digital Signal Processor).

14. The concentrator as claimed in claim 1, wherein at least one counter weight is mounted on said support arrangement, said counter weight being adapted to balance the solar concentrator.
15. The concentrator as claimed in claim 1, wherein said concentrator has a shape selected from the group consisting of a square, a rectangle, a hexagon and an oval.