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  1. 29-Jul-08 1RIZWAN MASOOD.
  2. DESIGN AND FABRICATION OF “PARABOLIC SOLAR CONCENTRATOR” with sole objective to define future projects to save natural gas 29-Jul-08 2RIZWAN MASOOD.
  3. RESEARCH TEAM Rizwan Masood, Student of Chemical Engineering Department, UET Lahore. Dr. A.R. Saleemi, Chairman, Department of Chemical Engineering, UET Lahore. Dr. A.H. Dilawari, Professor at SNGPL Chair on Gas Engineering. 29-Jul-08 RIZWAN MASOOD. 3
  4. . SYNOPSIS This presentation includes following topics. 1. Solar energy and it's importance in present era. 2. Potential for solar energy in Pakistan. 3. Introduction to “Solar Concentrating Collectors”. 4. Design of “Parabolic Trough Concentrator”. 5. Basic Parts and Structure. 6. Performance and efficiency calculations. 7. Applications in modern processes. 29-Jul-08 RIZWAN MASOOD. 4
  5. .  The sun has a surface temperature of 6000°C, maintained by continuous nuclear fusion reactions between hydrogen atoms within its interior. These nuclear reactions will gradually convert all of the hydrogen into heavier elements, but this is a relatively slow process and the sun should continue to supply power for another 5 billion years.  The sun radiates huge quantities of energy into the surrounding space, and the tiny fraction intercepted by the Earth's atmosphere, 150 million km away, is however equivalent to about 15,000 times humanity's present rate of use of fossil and nuclear fuels. 29-Jul-08 RIZWAN MASOOD. 5 1. SOLAR ENERGY.
  6. .  Even though approximately one-third of the intercepted energy is reflected away by the atmosphere before reaching the earth's surface, this still means that a continuous and virtually inexhaustible flow of power amounting to 10,000 times our current rate of consumption of conventional fuels is available in principle to human civilization. 29-Jul-08 RIZWAN MASOOD. 6 1. SOLAR ENERGY.
  7. .  In this figure the places in dark orange color are high solar insolation regions. 29-Jul-08 RIZWAN MASOOD. 7 2. Potential for solar energy in Pakistan.
  8. . Solar energy technologies have great potential to benefit our nation. They can diversify our energy supply, reduce our dependence on natural gas and imported fuels, improve the quality of the air we breathe, offset greenhouse gas emissions, and stimulate our economy by creating jobs in the manufacturing and installation of solar energy systems. 29-Jul-08 RIZWAN MASOOD. 8 2. Potential for solar energy in Pakistan.
  9. . 2. Potential for solar energy in Pakistan. MONTHLY AVG DAILY TOTAL RADIATION ON HORIZONTAL SURFACE FOR LAHORE. Month Day length(hr) Rad (cal/cm2) Rad (cal/m2) Rad (J/cm2) Rad(j/m2) flux(W/m2) JAN 10.2 256 2560000 1075.2 10752000 292.81046 FEB 10.9 333 3330000 1398.6 13986000 356.42202 MAR 11.8 435 4350000 1827 18270000 430.08475 APR 12.8 499 4990000 2095.8 20958000 454.81771 MAY 13.6 545 5450000 2289 22890000 467.52451 JUN 14 533 5330000 2238.6 22386000 444.16667 JUL 13.8 491 4910000 2062.2 20622000 415.09662 AUG 13.1 448 4480000 1881.6 18816000 398.98219 SEP 12.2 436 4360000 1831.2 18312000 416.93989 OCT 11.2 361 3610000 1516.2 15162000 376.04167 NOV 10.4 297 2970000 1247.4 12474000 333.17308 DEC 10 244 2440000 1024.8 10248000 284.66667 29-Jul-08 RIZWAN MASOOD. 9
  10. . 3. INTRODUCTION.  Concentrator: Concentrator are oriented to track the sun so that the beam radiation will be directed onto the absorbing surface. Collector that directs radiation onto the receiver.  Collector: The aperture of the concentrator is the opening through which the solar radiation enters the concentrator  Receiver: Radiation is absorbed and converted to some other energy form (e.g. heat). 29-Jul-08 10RIZWAN MASOOD.
  11. . 3. INTRODUCTION. Concentration Types a) Parabolic trough collector b) Linear Fresnel collector c) Central receiver system with dish collector and d) Central receiver system with distributed reflectors 29-Jul-08 11RIZWAN MASOOD.
  12. . a) Parabolic Trough Collector It is a principle of geometry that a parabolic reflector pointed at the sun will reflect parallel rays of light to the focal point of the parabola.  A parabolic trough is a one- dimensional parabola that focuses solar energy onto a line. Physically, this line is a pipe with a flowing liquid inside that absorbs the heat transmitted through the pipe wall and delivers it to the thermal load. 29-Jul-08 12RIZWAN MASOOD. 3. INTRODUCTION.
  13. . Parabolic Trough Collector (con) A trough captures sunlight over a large aperture area and concentrates this energy onto a much small receiver area, multiplying the intensity of the sun by a concentration ratio in the range of 10-80. It is the process of concentration that allows troughs to delivery high temperature thermal energy.  However, to achieve such concentration, a trough tracks the sun in one axis continually throughout the day. The required tracking accuracy is within a fraction of a degree. 29-Jul-08 RIZWAN MASOOD. 13 3. INTRODUCTION.
  14. .  Parabolic Geometry (CON) A parabola is the locus of a point that moves so that its distances from a fixed line and a fixed point are equal. The equation of a parabola is as follow. X2 = 4a Y where, 4a = lattice rectum a = Focus point 29-Jul-08 RIZWAN MASOOD. 14 4. Design of “Parabolic Trough Concentrator”.
  15. .  Parabolic Geometry (CON) This may be found for a particular parabola from Equation by integrating a differential segment of this curve and applying the limits x = h and y = d/2 as pictured in Figure. where d is the distance across the aperture of the parabola as shown in figure and h is the distance from the vertex to the aperture. 29-Jul-08 RIZWAN MASOOD. 15 4. Design of “Parabolic Trough Concentrator”.
  16. .  Parabolic Geometry (CON) From the Figure the result is where S= length of parabolic arc.  The cross sectional area of the space enclosed between a parabola and a line across its aperture and normal to the axis is given by  Reflecting surface area of a parabolic trough can be calculated as follow. As = S . L where , L = length of through. 29-Jul-08 RIZWAN MASOOD. 16 4. Design of “Parabolic Trough Concentrator”. (CON)
  17. . There are basically five major part of a parabolic trough concentrator system, which are as follow; a) Reflecting surface. b) Absorber. c) Support structure. d) Tracking system. e) Pumping system. 29-Jul-08 RIZWAN MASOOD. 17 5. Basic Parts and Structure.
  18. . 29-Jul-08 RIZWAN MASOOD. 18 5. Basic Parts and Structure (CON) a) Reflecting surface.
  19. . 29-Jul-08 RIZWAN MASOOD. 19 b) Absorber. 5. Basic Parts and Structure (CON)
  20. . c) Support structure. 29-Jul-08 RIZWAN MASOOD. 20 5. Basic Parts and Structure (CON)
  21. . d) Tracking system. 29-Jul-08 RIZWAN MASOOD. 21 5. Basic Parts and Structure (CON)
  22. . e) Pumping system. 29-Jul-08 RIZWAN MASOOD. 22 5. Basic Parts and Structure (CON)
  23. . PERFORMANCE There are basically two types of performances which are to be considered during design . a. Optical performance. b. Thermal performance. a) Optical performance optical performance of a solar concentrator depends on the optical characteristics of reflecting surface, glass envelope, absorber and also on geometry of parabola 29-Jul-08 23RIZWAN MASOOD. 6. Performance and Efficiency Calculations.
  24. . PERFORMANCE a) Optical performance absorbed radiation per unit area of unshaded aperture is given by: S=Ibρ(γτα) Kγτα Where Ib is effective incident beam radiation on the plane of aperture, ρ is the reflectance of the concentrator, γ is intercept factor, τ is transmittance, and α is absorptance. Kγτα is an incidence angle modifier that can be used to account for deviations from the normal of the angle of incidence of the radiation on the aperture 29-Jul-08 RIZWAN MASOOD. 24 6. Performance and Efficiency Calculations.
  25. .  PERFORMANCE b. Thermal performance The actual useful energy gain: Where Aa is the unshaded area of the concentrator aperture and Ar is the area of the receiver, S is the absorbed solar radiation per unit of aperture area, Ti and Ta are inlet fluid temperature and ambient temperature FR is the collector heat removal factor. 29-Jul-08 25RIZWAN MASOOD. 6. Performance and Efficiency Calculations.
  26. .  OVER ALL EFFICIENCY Over all efficiency of a solar collector is based on the optical and thermal performances. the over all efficiency can be calculated as; η = (Qu / Ib) × 100 29-Jul-08 26RIZWAN MASOOD. 6. Performance and Efficiency Calculations.
  27. . Solar Concentrating Collector are currently used for Cooling and air-conditioning Steam generation (for electricity power-plants) Desalination of sea water Production of hot water for domestic and industrial use Production of hydrogen gas 29-Jul-08 RIZWAN MASOOD. 27 7. Applications
  28. THANK YOU 29-Jul-08 RIZWAN MASOOD. 28