solar dish

SOLAR DISHSOLAR DISH

Under the Supervision ofUnder the Supervision of::

Dr. Osayd abdel-fatttahDr. Osayd abdel-fatttah

Prepared byPrepared by::

Qsaem MalhisQsaem Malhis

Qusai Abdel-rahmanQusai Abdel-rahman

Odai WahdanOdai Wahdan

Malk AbbasMalk Abbas May 2014

An-Najah National University Engineering Collage

mechanical Engineering Department

IntroductionIntroduction

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 dishWhy 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.

ObjectiveObjective 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 ApproachMathematical Approach

Design crank shaft:


AAaa: aperture area : aperture area a: semi-major axesa: semi-major axes b: semi-minor axesb: semi-minor axes

F:forceF:force m: weight m: weight g: gravity g: gravity


C: censorial axisC: censorial axis M: moment M: moment I: second-area momentI: second-area moment D: outside diameterD: outside diameter d: inside diameter d: inside diameter


T : torqueT : torque r : inner radiusr : inner radius J : polar second moment of areaJ : polar second moment of area


Aa=3.14*.40*.35=.4396 mAa=3.14*.40*.35=.4396 m22

F=7*9.81=68.67 NF=7*9.81=68.67 N M=7.55 N\mM=7.55 N\m↑↑ I=1.08*10I=1.08*10-6-6

Calculating a Parabolic Dish’s Calculating a Parabolic Dish’s Focal PointFocal Point

F = focal point of dishF = focal point of dishD=diameter D=diameter d= depth d= depth

ResultsResults

qquu: useful thermal energy delivered: useful thermal energy delivered ηη= The efficiency= The efficiency IIb b =The amount of radiation=The amount of radiation

IIbb =I =Idd = 716.6 W/m = 716.6 W/m22 ηη = 0.5 = 0.5 qquu= 0.5 * 716.6 * .4396= 0.5 * 716.6 * .4396

qquu=157.5W =157.5W

ResultsResults

where (mwhere (m..ww ) is the rate of heating the water ) is the rate of heating the water

and (cand (cpw pw )is the specific heat capacity at )is the specific heat capacity at constant pressure of the waterconstant pressure of the water

qquu=m=m..ww*c*cpwpw(T(Tww-T-Taa)= *Iμ)= *Iμ DD*A*Aaa

ResultsResults

The energy(Pabs) absorbed by the absorberThe energy(Pabs) absorbed by the absorber μ μ oo= 0.65 (average of 0.6 and 0.7) The = 0.65 (average of 0.6 and 0.7) The

efficiency for absorberefficiency for absorber

ConclusionConclusion

Solar dish system is the developer of a Flat Solar dish system is the developer of a Flat Plate it more efficient, but to achieve this Plate it more efficient, but to achieve this should be a large-sized system. should be a large-sized system.

The system could be developed for the The system could be developed for the production of steam and use steam to production of steam and use steam to generate energy through turbines .generate energy through turbines .

Was concave mirrors should be placed over Was concave mirrors should be placed over the whole dish, because the mirrors the whole dish, because the mirrors chopped Break sunlight.chopped Break sunlight.

RecommendationRecommendation

Improve concentrator geometry. This will make the Improve concentrator geometry. This will make the largest deference in system efficiency.largest deference in system efficiency.

Decrease cavity aperture size. With an improved Decrease cavity aperture size. With an improved concentrator, concentrator,

Eliminate the absorber. Use only the cavity absorber Eliminate the absorber. Use only the cavity absorber and insulate all other surfaces on the receiver.and insulate all other surfaces on the receiver.

Add a pump. Add a pump. Correct tracking system. Program safety procedures Correct tracking system. Program safety procedures

to keep tracking system from moving when clouds to keep tracking system from moving when clouds block sunlight.block sunlight.

solar dish

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