SOLAR DISH SOLAR DISH Under the Supervision of: Dr. Osayd abdel-fatttah Prepared by: Qsaem Malhis Qusai Abdel-rahman Odai Wahdan Malk Abbas May 2014 An-Najah National University Engineering Collage mechanical Engineering Department

Introduction Solar dish is the future alternative to the flat plate solar collector, we selected this project because ninety-five percent of water heating in Palestine depends mainly on solar radiation

Why choose solar dish Rooftops are always filled with flat plate solar collector To reduce this area, we selected the solar dish where area extends vertically and is also the best in terms of heating because it is always directed toward the sun.

Objective The aim of this project is to design Solar Dish Engine for heating water from the sun. Dish/engine systems convert the thermal energy in solar radiation to heating water, dish/engine systems use a mirror array to reflect and concentrate incoming direct normal isolation to a heat exchanger, in order to achieve the temperatures required to efficiently convert heat. This requires that the dish track the sun in two axes by two sensor at the dish one in the east and the other in the west. The concentrated solar radiation is absorbed by the receiver and transferred to a tank.

methodology We brought the raw materials to build a model to the concerns of the Faculty of Engineering. The base was formed by Steel Frame (2 * 2cm) and collected by welding took the form of box then brought inside a hollow shaft outer with diameter (6 cm) and installation of Bearings to allow him to rotate, leading to the movement of the dish X-direction, Then put in the middle of the base.

methodology We used copper as a material to absorb the heat, we have to bring a copper rod and roll on the pipe (2) inches to take the form of a spiral coil and put it at the center of the dish. Then cut glass was pasted on the dish by silicone material Adhesive. Put the dish on the main shaft with allowing him to move in Y-direction by two Bearings. Also been building a base for tank, then was to bring the two stepper motor and placed under brings to allow movement.

Mathematical Approach Design crank shaft:

Mathematical Approach A a : aperture area A a : aperture area a: semi-major axes a: semi-major axes b: semi-minor axes b: semi-minor axes F:force F:force m: weight m: weight g: gravity g: gravity

Mathematical Approach C: censorial axis C: censorial axis M: moment M: moment I: second-area moment I: second-area moment D: outside diameter D: outside diameter d: inside diameter d: inside diameter

Mathematical Approach T : torque T : torque r : inner radius r : inner radius J : polar second moment of area J : polar second moment of area

Mathematical Approach Aa=3.14*.40*.35=.4396 m 2 Aa=3.14*.40*.35=.4396 m 2 F=7*9.81=68.67 N F=7*9.81=68.67 N M=7.55 N\m↑ M=7.55 N\m↑ I=1.08*10 -6 I=1.08*10 -6

Calculating a Parabolic Dish’s Focal Point F = focal point of dish F = focal point of dishD=diameter d= depth

Results q u : useful thermal energy delivered q u : useful thermal energy delivered η= The efficiency η= The efficiency I b =The amount of radiation I b =The amount of radiation I b =I d = W/m 2 I b =I d = W/m 2 η = 0.5 η = 0.5 q u = 0.5 * *.4396 q u = 0.5 * *.4396 q u =157.5W q u =157.5W

Results where (m. w ) is the rate of heating the water and (c pw )is the specific heat capacity at constant pressure of the water where (m. w ) is the rate of heating the water and (c pw )is the specific heat capacity at constant pressure of the water q u =m. w *c pw (T w -T a )=μ*I D *A a q u =m. w *c pw (T w -T a )=μ*I D *A a

Results The energy(Pabs) absorbed by the absorber The energy(Pabs) absorbed by the absorber μ o = 0.65 (average of 0.6 and 0.7) The efficiency for absorber μ o = 0.65 (average of 0.6 and 0.7) The efficiency for absorber

Conclusion  Solar dish system is the developer of a Flat Plate it more efficient, but to achieve this should be a large-sized system.  The system could be developed for the production of steam and use steam to generate energy through turbines.  Was concave mirrors should be placed over the whole dish, because the mirrors chopped Break sunlight.

Recommendation  Improve concentrator geometry. This will make the largest deference in system efficiency.  Decrease cavity aperture size. With an improved concentrator,  Eliminate the absorber. Use only the cavity absorber and insulate all other surfaces on the receiver.  Add a pump.  Correct tracking system. Program safety procedures to keep tracking system from moving when clouds block sunlight.