FIELD OF INVENTION:

The invention relates to the field of utilizing solar energy to generate electricity. It is well known that when sun's rays are concentrated at a focal point, high temperatures in the range of 80 to 500 degrees of Celsius are reached. The heat is transferred by heat exchangers to generate steam which is used for driving turbines.

Parabolic reflectors in the form of troughs have been used to have a line which will have the focal points along the length of the trough. A pipe carrying a thermic fluid is run along the path of foci of parabolas. Parabolic reflectors are known to be highly efficient in terms of cost per unit of power.

An important consideration is the ability of the parabolic system is to ensure that maximum sunrays are concentrated at the focal point and the whole apparatus is designed to track the sun during its journey from east to west to gather the maximum amount of rays throughout the day. The parabolic structure consisting of reflectors and their supporting structures need to be rotated. It requires motors, hydraulic/pneumatic power systems and these have to be monitored continuously.

BACKGROUND OF THE INVENTION:

India with its burgeoning population and its demand for power to meet global needs in this age of competition requires that the required power is generated by perennially available source like sun, sea and the air instead of depending on the limited and depleting fossil fuels or the limited and unreliable water (hydro) sources or the hazardous nuclear reactors. In this direction generation of electricity using Concentrated Solar Power is being done for nearly sixty years.

The principle is to focus the solar rays - which can be taken to fall on the surface of earth as parallel. Mirrors made of glass using circular sections have limitations as the diameter will be a limiting factor for the width of the ray collecting area. So parabolas became popular, because they have no limitation of the surface closing in when the diameter is reached. To have stability in terms of keeping the shape over a long period metallic (aluminum or steel) structures are constructed.

The silicon based glass reflectors add a lot of weight. To make collection of solar energy efficient, the whole apparatus has to be rotated to track the sun's path during the day. Thus rotating the structures needs power, pivotal support and sometimes hydraulic systems have to be provided. The concentrated solar power is collected by the liquid that flows through the pipe, and heat exchangers are used to generate super heated steam under pressure which drive turbines to generate electric power.

PRIOR ART AND THEIR LIMITATIONS

At present parabolas are manufactured by using glass reflectors which are very heavy - which weigh l0Kg. Per sqm. The supporting structures and the movement mechanisms also needs to be stronger and heavier. The support structures and the moving systems need greater strength in the present invention 4mjn thick aluminum reflectors which are to be fixed to heavier structures by welding, screwing which introduce inaccuracies in the shape frequent corrective maintenance and shorter life cycle.

They are very heavy thus needing steel structures to support them. These add to the weight of the system and need high power requirements to move them to track the sun. All the parabolas in the world move by means of hydraulic cylinders which require heavy power consumption. Hydraulic jacks complicated circuitry, sensors and control mechanism are used to making the parabolas to obtain the required movement. They are supported at the ends of the array of parabolas - nearly 8 metres apart - weighing more than a ton. The parabolas being open ended aluminum structures - troughs -being 5 metres wide at extremity are subjected to great wind forces. Thus they get distorted and the foci of the parabolas are lost and collection of sun energy is reduced greatly. This makes the system highly inefficient. The absorbing pipe carries the oil which gets heating owing to the focused sunrays has its ends connected with swivel joints which are prone to leaks and causes a lot of maintenance problems.

In the existing systems, because of their great weight, the parabolas need to be individually driven for tracking. They even need hydraulic movements which area powered by heavy duty motors.

OBJECT OF INVENTION:

The primary object of the invention is to obtain heat energy by converting light energy honeycomb sheets and planetary movement of parabolas. The further object of the invention is to eradicate heavy hydraulic movements by providing light wire rope in triangle suspension for tracking.

The further object of the invention is to reduce the weight of comparable parabolas having equivalent area of surface to sunlight of 630 kgs by using aluminium extrusion, aluminium die casting & gravity casting wherein the reflection sheet is also aluminium with honeycomb sheet instead of heavy silicon based glass sheets.

The further object of the invention is to obtain great stability and uninterrupted focusing of the sunrays exactly on the focal line

STATEMENT OF INVENTION:

Accordingly the present invention provides a novel assembly of honeycomb sheets and planetary movement of parabolas for concentrated solar power, having honeycomb sheets to support the anodized and polished aluminum reflecting hollow parabolas reducing weight and moving an array of the parabolas, which are joined by extruded aluminum components crimping them without welding and rotating the entire system by a stainless chain in triangular shape driven by a fractional hp motor by using planetary motion to track of the sun and attaining maximum absorption of solar energy.
Description of Drawings:

Fig 1 illustrates the novel assembly of the parabola assembled wwith Main Horizontal Aluminum Tube (1), with Main Horizontal Holder - Aluminum Alloy casting (2), Honeycomb hollow top - extrusion top (3) , with Honeycomb locking clip - aluminum extrusion ( 4), Honeycomb - Alumiiiim sheet (5), Parabola Holder - Aluminum Casting ( 6), Steel Rope Holder - for tracking (7), Parabola Drive Guide Ring - Aluminum Extrusion (8), Receiving Tube (9), Parabola Bottom Holder - Aluminum Extrusion ( 10), Base Plate (11), DC Drive tracking motor ( 12), Stainless Steel Rope (13), Main Vertical Support (14), RoUer (15), Purlin Support - Aluminum Extrusion ( 16) Honeycomb sheet support - Aluminum Extrusion Tube (17).

Fig 2 illustrates the front view of the assembly.

Fig 3 illustrates the top view of the assembly.

Fig 4 illustrates the rotation of the assembly at 6. 00 A. M.

Fig 5 illustrate the rotation of the assembly at 9. 00 A. M.

Fig 6 illustrate the rotation of the assembly at 12. 00 P. M.

Fig 7 illustrate the rotation of the assembly at 3. 00 P. M.

Fig 8 illustrate the rotation of the assembly at 6. 00 P. M.

DETAILED DESCRIPTION OF INVENTION:

The reflective sheet (5) is joined to honey-comb formation to gain the self certaining strength & rigidity. The reflective sheet is fixed to main frame by means of specially designed clips made of aluminum extrusion. The entire parabola rotates on twelve rollers (15) made out of bakelite material which has very high wear resistance.

The parabola moves as per sun direction (known as tracking) .The parabola is pulled from the bottom by means of 10mm steel wire rope (13). The guided ring (15) which rollers on the rollers is fixed with a A type section designed and it is aluminium alloy extrusion. The entire parabolas movement is known as planetary movements which requires very low torque. The outer ring (8) has been fixed and positioned to suit into the two vertical pillars (14) which guides with twelve rollers. In the absence of welding, assembly of parabola and all the sections are interlocked, crimped and fixed by means of specially designed aluminium section known as 'dovetail' section for firm and rigid fixing. This will withstand vibration and facilitate easy assembly.

The total parabola is manufactured by local material which is re-cycleable & eco friendly. Very less torque is required to move the parabola for purposes of tiacking the sun. Hence the whole parabola is made out of hollow aluminium extrusion & honeycomb sheet. The present invention contemplates using honeycomb shape formed by 0.176mm aluminum.

Though the sheet is thin because of the honeycomb shape gives great strength to support 2mm LDPE sheet, over which 0.3mm thick reflective aluminum sheet is bonded. Beneath the honeycomb (corrugation) shaped aluminum sheet one more 0.3mm aluminum sheet with a protective PVDF protective coating is provided. The depth of the corrugation is nearly 8mm adding structural strength, trough having minimal weight.

This unique construction makes the weight of the entire structure light, thus needing a small fractional HP motor (12) to effect the movement required for tracking the sun. The weight of the entire system which moves is only 630 Kgs. This method helps in connecting the parabolas to be connected in chain formation for collective tracking.
One more feature of the invention is the use of planetary gear system to automatically effect the slow tracking movement of the entire system. The stainless rope (13) of 10mm which is driven by this system runs over the brackets which are fixed to the drum which is supported on three rollers (15) which are fixed to the supporting columns which are grouted to the ground and the beam.

The advantage of having twelve rollers for each parabola is that they help in retaining the position and shape of the parabola even when subjected to wind forces during the day. This retention helps is ensuring that all sunrays during the whole day is focuses on the line of the line of the absorbing pipe throughout its length and achieving maximum efficiency.

One more unique and facilitating feature of present invention provides for the collection of water formed by the dew during night. As the early morning sun hits the parabolas the dew water flows down into the top gutter which is formed in the extruded tube which is located at the bottom of the parabolas. The water can be collected in tank or container at one end of the array.

Detailed description of the invention with of the drawings:

The array of six parabolas (Fig 2) formed by highly polished anodized aluminum sheets area supported by honeycomb sheets ( 5) -to add structural strength. The movement for the parabolas (10) during the day comes from the rope in the guide (8) moving at a slow pace keeping the parabola (10) looking at the sim so that the focal points of the entire array of parabolas line on the absorbing tube (9). The planetary gear system attached to the motor (12) ensures that requisite RPM is delivered to have the required rotary motion of the parabolic system through the steel rope (13) that runs through the guide ring (8). It can be observed that the parabola gets the support of the rollers (15) placed at three positions - two on the columns and one on the beam. This will take care of the wind load on the parabolic trough. The absorbing tube at the focal line is made of special material and construction so that all the heat waves that fall on it during the day are absorbed and heats up the oil that run through it. The hot oil is used to generate steam to run turbines to produce electricity.

I Claim:
1. A novel assembly of honeycomb sheets (5) and planetary movement of parabolas for concentrated solar power, comprising of honeycomb sheets (5) to support the anodized and polished aluminum reflecting hoUow parabolas reducing weight and moving an array of the parabolas (figl & 2), which are joined by extruded aluminum components crimping them without welding and rotating the entire system by a stainless rope (13) in triangular shape driven by a fractional hp motor (12) by using planetary motion to track of the sun and attaining maximum absorption of solar energy.

2. A novel assembly as claimed in preceding claims, wherein with parabolas are of aluminium based reflective sheet in deep curvature shape with honeycomb aluminum padding with parabolas.

3. A novel assembly as claimed in proceeding claims, wherein the parabolas are connected in chain formation for collective tiacking (fig 2).

4. A novel assembly as claimed in preceding claims, wherein the twelve rollers (15) are fixed to the supporting columns (14) which are grouted to the ground and the beam, ensures stability and uninterrupted focusing sunrays on the focal line of absorbing pipe attaining maximum absorbtion of solar energy during the entire course of planetary movement of parabolas.

5. A novel assembly as claimed in preceding claims, wherein the enter assembly is light in weight of 630Kgs, cost effective, non corrosive, easily installed, replaced and of high tracking accuracy.

6. A novel assembly of honeycomb sheets and planetary movement of parabolas for concentrated solar power is substantially as described in the description along with accompanying drawings.