Thermodynamic Modeling of Solar Thermal Power (Captive Power) and Water Desalination (With Single Ef

IJSRD - International Journal for Scientific Research & Development| Vol. 4, Issue 05, 2016 | ISSN (online): 2321-0613

Thermodynamic Modeling of Solar Thermal Power (Captive Power) and Water Desalination (with Single Effect) P.Ramakrishnan Assistant Professor CIT, Coimbatore 641014, Tamilnadu, India Abstract— In this paper thermodynamic modeling is used to assess the performance characteristics of a solar desalination system using concentrated parabolic solar trough. In this desalination system a single-effect flash evaporator is used to evaporate the fluid with a reduced pressure state. Instead of reducing pressure in the evaporation chamber the fluid’s evaporating temperature will be less.so that we can get more vapor withless temperature. Due to this kind of evaporators the instantaneous efficiency of the whole system is increased.

Although very few solar power plants have been set up in the last fifteen years, significant R&D advances have taken place in cylindrical parabolic collector technology.

Key words: solar water desalination; single effect flash evaporator; instantaneous efficiency I. INTRODUCTION Solar energy is a very large, inexhaustible source of energy.

The power from the sun intercepted by the earth is approximately 1.8×〖10〗^11MW which is many thousands of time larger than the present consumption rate on the earth of all commercial energy sources. Thus, in principle, solar energy could supply all the present and future energy needs of the world on continuing basis. This makes it one of the most promising of unconventional energy sources.

A. Why Solar Energy?

Using renewable energy sources is the necessity for reduce the pollution. Renewable energy commonly considered for desalination are solar, wind and geothermal energies.

Among these three energies solar energy occupies nearly 57% of renewable energy based desalination market.

Keywords: 1.8×〖10〗^11MW; solar energy occupies nearly 57% of renewable energy

Ib

S

instantaneous = radiation, W hourly 2 /m

= icident solar flux absorbed,

W m2

Table 1: đ?‘‡ = đ?‘Ąđ?‘’đ?‘šđ?‘?đ?‘’đ?‘&#x;đ?‘Žđ?‘Ąđ?‘˘đ?‘&#x;đ?‘’, đ??ž đ?‘‡đ?‘Ž = đ?‘Žđ?‘šđ?‘?đ?‘–đ?‘’đ?‘›đ?‘Ą đ?‘Ąđ?‘’đ?‘šđ?‘?đ?‘’đ?‘&#x;đ?‘Žđ?‘Ąđ?‘˘đ?‘&#x;đ?‘’ âˆ? đ?‘‡đ?‘“ = đ?‘™đ?‘œđ?‘?đ?‘Žđ?‘™ đ?‘“đ?‘™đ?‘˘đ?‘–đ?‘‘ đ?‘Ąđ?‘’đ?‘šđ?‘?đ?‘’đ?‘&#x;đ?‘Žđ?‘Ąđ?‘˘đ?‘&#x;đ?‘’, = đ??ž đ?‘Žđ?‘?đ?‘ đ?‘œđ?‘&#x;đ?‘?đ?‘Ąđ?‘–đ?‘Łđ?‘–đ?‘Ąđ?‘Ś đ?‘œđ?‘“ đ?‘Žđ?‘?đ?‘ đ?‘œđ?‘&#x;đ?‘?đ?‘’đ?‘&#x; đ?‘ đ?‘˘đ?‘&#x;đ?‘“đ?‘Žđ?‘?đ?‘’ âˆ? đ?‘‡đ?‘“đ?‘– đ?‘Ž đ?‘ đ?‘œđ?‘™đ?‘Žđ?‘&#x; = đ?‘Ąđ?‘’đ?‘šđ?‘?đ?‘’đ?‘&#x;đ?‘Žđ?‘Ąđ?‘˘đ?‘&#x;đ?‘’ đ?‘œđ?‘“ đ?‘“đ?‘™đ?‘˘đ?‘–đ?‘‘ đ?‘Žđ?‘Ą = đ?‘–đ?‘›đ?‘™đ?‘’đ?‘Ą, đ??ž đ?‘Žđ?‘™đ?‘Ąđ?‘–đ?‘Ąđ?‘˘đ?‘‘đ?‘’ đ?‘Žđ?‘›đ?‘”đ?‘™đ?‘’ đ?›˝ = đ?‘ đ?‘™đ?‘œđ?‘?đ?‘’ đ?‘œđ?‘&#x; đ?‘Ąđ?‘–đ?‘™đ?‘Ą đ?‘‡đ?‘“đ?‘œ đ?›ž = đ?‘Ąđ?‘’đ?‘šđ?‘?đ?‘’đ?‘&#x;đ?‘Žđ?‘Ąđ?‘˘đ?‘&#x;đ?‘’ đ?‘œđ?‘“ đ?‘“đ?‘™đ?‘˘đ?‘–đ?‘‘ đ?‘Žđ?‘Ą đ?‘œđ?‘˘đ?‘Ąđ?‘™đ?‘’đ?‘Ą, đ??ž = đ?‘ đ?‘˘đ?‘&#x;đ?‘“đ?‘Žđ?‘?đ?‘’ đ?‘Žđ?‘§đ?‘–đ?‘šđ?‘˘đ?‘Ąâ„Ž đ?‘Žđ?‘›đ?‘”đ?‘™đ?‘’ đ?‘ˆ đ?›żđ?‘Š = đ?‘‘đ?‘’đ?‘?đ?‘™đ?‘–đ?‘›đ?‘Žđ?‘Ąđ?‘–đ?‘œđ?‘› = đ?‘œđ?‘Łđ?‘’đ?‘&#x;đ?‘Žđ?‘™đ?‘™ đ?‘™đ?‘œđ?‘ đ?‘ đ?‘?đ?‘œđ?‘’đ?‘“đ?‘“đ?‘–đ?‘?đ?‘–đ?‘’đ?‘›đ?‘Ą, đ?œƒ 2= đ?‘Žđ?‘›đ?‘”đ?‘™đ?‘’ đ?‘œđ?‘“ đ?‘–đ?‘›đ?‘?đ?‘–đ?‘‘đ?‘’đ?‘›đ?‘?đ?‘’ đ?‘š đ??ž đ?œƒđ?‘§ = đ?‘§đ?‘’đ?‘›đ?‘–đ?‘Ąâ„Ž đ?‘Žđ?‘›đ?‘”đ?‘™đ?‘’ đ?‘‰ đ?‘š đ?œŒ = đ?‘‘đ?‘’đ?‘›đ?‘ đ?‘–đ?‘Ąđ?‘Ś, đ?‘˜đ?‘” = đ?‘Žđ?‘Łđ?‘’đ?‘&#x;đ?‘Žđ?‘”đ?‘’ đ?‘¤đ?‘–đ?‘›đ?‘‘ đ?‘ đ?‘?đ?‘’đ?‘’đ?‘‘, đ?‘š3 đ?‘ đ?‘š đ?œ? = đ?‘Ąđ?‘&#x;đ?‘Žđ?‘›đ?‘ đ?‘šđ?‘–đ?‘ đ?‘ đ?‘–đ?‘Łđ?‘–đ?‘Ąđ?‘Ś đ?‘‰ = đ?‘Łđ?‘’đ?‘™đ?‘œđ?‘?đ?‘–đ?‘Ąđ?‘Ś, ∅ đ?‘ đ?‘Š = đ?‘Žđ?‘?đ?‘’đ?‘&#x;đ?‘Ąđ?‘˘đ?‘&#x;đ?‘’, đ?‘š = đ?‘™đ?‘Žđ?‘Ąđ?‘Ąđ?‘–đ?‘Ąđ?‘˘đ?‘‘đ?‘’; đ?‘?đ?‘™đ?‘Žđ?‘Ąđ?‘’ đ?‘’đ?‘“đ?‘“đ?‘’đ?‘?đ?‘Ąđ?‘–đ?‘Łđ?‘’đ?‘›đ?‘’đ?‘ đ?‘ đ?‘‹ = đ?‘Ąđ?‘Žđ?‘?đ?‘’ đ?‘Ąđ?‘¤đ?‘–đ?‘ đ?‘Ą đ?‘&#x;đ?‘Žđ?‘Ąđ?‘–đ?‘œ đ?œ‘ đ?‘ đ?‘˘ = đ?‘›đ?‘˘đ?‘ đ?‘ đ?‘’đ?‘™đ?‘Ą đ?‘›đ?‘˘đ?‘šđ?‘?đ?‘’đ?‘&#x; = đ?‘–đ?‘›đ?‘?đ?‘™đ?‘–đ?‘›đ?‘Žđ?‘Ąđ?‘–đ?‘œđ?‘› đ?‘œđ?‘“ đ?‘&#x;đ?‘’đ?‘“đ?‘™đ?‘’đ?‘?đ?‘Ąđ?‘œđ?‘&#x; đ?œ” = â„Žđ?‘œđ?‘˘đ?‘&#x; đ?‘Žđ?‘›đ?‘”đ?‘™đ?‘’

Table 2: III. SYSTEM DESCRIPTION

This solar thermal power water desalination system consists of five major parts. Those are water feeding system, heat exchanger, concentrated cylindrical parabolic solar trough, Aa Ig Evaporator, Condenser. = effective aperture area instantaneous radiation = global C = concentration ratio A. Water Feeding System: hourly Cp = specific heat W For feeding the water into the system for the processes, a /, 2 Dci pumping unit is required. This water may -collected from the m = inner diameter of glass cover, k m depth part of the seas. The danger in collecting the water is to W avoid the other macro particles from the seas. The main thing Dco = thermal conductivity, 2 = outer diameter of glass cover, m m K to avoid is the jelly fishes, so the strainer should be effective Di L for fighting with the jelly fishes. = inner diameter of tube, m = length of cocentrator, m B. Heat Exchanger (4-5 & 11-13): kg Do m ̇ = mass flow rate, Heat in exhausting concentrated fluid wasted in environment, = outer diameter of tube, m s this heat energy also can be used to heat the water as much as Ě F n = day of the year possible. Inlet water for the heat exchanger is the water outlet Pr = prandtl number = collector efficiency factor of evaporator. This heat is transferred to the starting fluid and r FR = heat removal factor b the water gets preheated. = tilt factor beam radiation hf q = useful heat gain, W = heat transfer coefficient on inside u Re = reynold′ s number surface of tube, Wâ „m2 K II. LIST OF SYMBOLS USED

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Thermodynamic Modeling of Solar Thermal Power (Captive Power) and Water Desalination (with Single Effect) (IJSRD/Vol. 4/Issue 05/2016/066)

C. Solar Trough (6-7): This part is the main part of this system. Here cylindrical parabolic solar troughs are used. This is also referred as a linear parabolic collector. The basic elements making up a conventional collector are (i) the absorber tube located at the focal axis through which the liquid to be heated flows (ii) the concentric transparent cover, (iii) the reflector, and (iv) the support structure. Elements (i) and (ii) together constitute the receiver, while elements (iii) and (iv) constitute the concentrator.

The collectors are available over a wide range of aperture areas from about 1 to 60 m^2 and with widths ranging from 1 to 6 m. concentration ratios range from 10 to 80, and rim angles from 70 to 120°.

Preheated saline water is fed into solar troughs. In these troughs the passage pipe is placed in the focal point of the aperture mirrors. Due to this the temperature of the water increased significantly. The outlet -temperature of the water should enough for evaporate the water.

D. Flash-Evaporator (8-10): However the gained energy from solar trough is enough to evaporate, to increase the efficiency the water should be passed through flash evaporator. Flash evaporator is nothing but a chamber at where the evaporation is motivated. Here by reducing the chamber pressure below to the atmospheric pressure, the boiling temperature of the water id decreased, so that we can gain steam more than previous.

After evaporation the remaining concentrated salt containing water is fed into heat exchanger for preheating.

E. Condenser (2-3): Condenser is also nothing but a heat exchanger. This exchanges heat from cold water to the saturated steam, so that steam gets condensed and changes its phase into vapor to liquid. Here we can get purest distilled water.

IV. THERMODYNAMIC MODELING Thermodynamic modeling for the given desalination system is developed using energy balancing concepts. Some values for the equations are constant, those parameters are mentioned below the equations. đ?‘‡â„Ž1 − đ?‘‡đ?‘?1 đ?‘™đ?‘› ( ) đ?‘‡â„Ž2 − đ?‘‡đ?‘?2 = đ?‘ˆđ?‘œ đ??´đ?‘œ đ?‘šđ?‘? đ?‘‡â„Ž1 − đ?‘‡đ?‘?1 = đ?‘’ đ?‘ˆđ?‘œ đ??´đ?‘œ đ?‘šđ?‘? đ?‘‡â„Ž2 − đ?‘‡đ?‘?2 đ?‘‡â„Ž2 − đ?‘‡đ?‘?2 đ?‘‡â„Ž1 − đ?‘‡đ?‘?1 = đ?‘ˆđ?‘œ đ??´đ?‘œ đ?‘šđ?‘? đ?‘’ đ?‘‡đ?‘?2 đ?‘‡â„Ž1 − đ?‘‡đ?‘?1 = − đ?‘ˆđ?‘œ đ??´đ?‘œ đ?‘šđ?‘? + đ?‘‡â„Ž2 đ?‘’ đ?‘‡đ?‘?2 đ?‘‡â„Ž1 − đ?‘‡đ?‘?1 = đ?‘‡â„Ž2 − đ?‘ˆđ?‘œđ??´đ?‘œ đ?‘šđ?‘? đ?‘’

đ?‘„ = đ?‘šĚ‡ â„Ž đ?‘?â„Ž (đ?‘‡â„Ž1 − đ?‘‡â„Ž2 ) = đ?‘šĚ‡ đ?‘? đ?‘?đ?‘? (đ?‘‡đ?‘?2 − đ?‘‡đ?‘?1 ) đ?‘šĚ‡ đ?‘? đ?‘?đ?‘? (đ?‘‡đ?‘?2 − đ?‘‡đ?‘?1 ) đ?‘‡â„Ž2 = đ?‘‡â„Ž1 − đ?‘šĚ‡ â„Ž đ?‘?â„Ž đ?‘šĚ‡ đ?‘? đ?‘?đ?‘? đ?‘‡đ?‘?2 = đ?‘‡â„Ž1 − ( ) (đ?‘‡đ?‘?2 − đ?‘‡đ?‘?1 ) đ?‘šĚ‡â„Ž đ?‘?â„Ž đ?‘‡â„Ž1 − đ?‘‡đ?‘?1 − đ?‘ˆđ?‘œ đ??´đ?‘œ đ?‘šđ?‘? đ?‘’ Where 1 đ??´đ?‘œ 1 đ?‘Ľđ?‘¤ đ??´đ?‘œ =( + + ) đ?‘ˆđ?‘œ â„Žđ?‘– đ??´đ?‘– â„Žđ?‘œ đ??žđ?‘¤ đ??´đ?‘¤ 1 1 đ?‘šđ?‘? = + đ?‘šĚ‡ â„Ž đ?‘?â„Ž đ?‘šĚ‡ đ?‘? đ?‘?đ?‘?

A. Heat Exchanger (4-5) & Condenser (2-3): đ?‘‡đ?‘?2 = đ?‘Ąđ?‘’đ?‘šđ?‘?đ?‘’đ?‘&#x;đ?‘Žđ?‘Ąđ?‘˘đ?‘&#x;đ?‘’ đ?‘œđ?‘“ đ?‘œđ?‘˘đ?‘Ąđ?‘™đ?‘’đ?‘Ą đ?‘?đ?‘œđ?‘™đ?‘‘ đ?‘“đ?‘™đ?‘˘đ?‘–đ?‘‘

đ?‘‡đ?‘?1 = đ?‘–đ?‘›đ?‘™đ?‘’đ?‘Ą đ?‘Ąđ?‘’đ?‘šđ?‘?đ?‘’đ?‘&#x;đ?‘Žđ?‘Ąđ?‘˘đ?‘&#x;đ?‘’ đ?‘œđ?‘“ đ?‘?đ?‘œđ?‘™đ?‘‘ đ?‘“đ?‘™đ?‘˘đ?‘–đ?‘‘ đ?‘‡â„Ž1 = đ?‘–đ?‘›đ?‘™đ?‘’đ?‘Ą â„Žđ?‘œđ?‘Ą đ?‘“đ?‘™đ?‘˘đ?‘–đ?‘‘ đ?‘Ąđ?‘’đ?‘šđ?‘?đ?‘’đ?‘&#x;đ?‘Žđ?‘Ąđ?‘˘đ?‘&#x;đ?‘’ đ?‘‡â„Ž2 = đ?‘œđ?‘˘đ?‘Ąđ?‘™đ?‘’đ?‘Ą đ?‘Ąđ?‘’đ?‘šđ?‘?đ?‘’đ?‘&#x;đ?‘Žđ?‘Ąđ?‘˘đ?‘&#x;đ?‘’ đ?‘œđ?‘“ â„Žđ?‘œđ?‘Ą đ?‘“đ?‘™đ?‘˘đ?‘–đ?‘‘ B. Solar Trough: đ?‘šđ??śđ?‘? (đ?‘‡đ?‘œ − đ?‘‡đ?‘– ) =

�� 1000

â„Žđ?‘“ = đ?‘ đ?‘˘ Ă—

đ?‘˜ đ??ˇđ?‘–

đ?‘‡đ?‘œ = đ?‘‡đ?‘’đ?‘šđ?‘?đ?‘’đ?‘&#x;đ?‘Žđ?‘Ąđ?‘˘đ?‘&#x;đ?‘’ đ?‘œđ?‘“ đ?‘œđ?‘˘đ?‘Ąđ?‘™đ?‘’đ?‘Ąđ?‘ đ?‘˘ đ?‘“đ?‘™đ?‘˘đ?‘–đ?‘‘ đ??źđ?‘›đ?‘ đ?‘Ąđ?‘Žđ?‘Ąđ?‘Žđ?‘›đ?‘’đ?‘œđ?‘˘đ?‘ đ?‘’đ?‘“đ?‘“đ?‘–đ?‘?đ?‘–đ?‘’đ?‘›đ?‘?đ?‘Ś = 5.172 [1 đ?‘žđ?‘˘ = đ??źđ?‘? đ?‘&#x;đ?‘? đ?‘Šđ??ż 0.7 0.5 đ?‘…đ?‘’ 1.78 đ??źđ?‘? + 0.005484 {Pr ( ) } ] = đ?‘–đ?‘›đ?‘Ąđ?‘’đ?‘›đ?‘ đ?‘–đ?‘Ąđ?‘Ś đ?‘œđ?‘“ đ?‘?đ?‘’đ?‘Žđ?‘š đ?‘&#x;đ?‘Žđ?‘‘đ?‘–đ?‘Žđ?‘Ąđ?‘–đ?‘œđ?‘› đ?‘‹ đ?‘&#x;đ?‘? = đ?‘‡đ?‘–đ?‘™đ?‘Ą đ?‘“đ?‘Žđ?‘?đ?‘Ąđ?‘œđ?‘&#x; đ?‘‹ = đ?‘‡đ?‘¤đ?‘–đ?‘ đ?‘Ąđ?‘’đ?‘‘ đ?‘Ąđ?‘Žđ?‘?đ?‘’ đ?‘&#x;đ?‘Žđ?‘Ąđ?‘–đ?‘œ đ?‘žđ?‘˘ = đ?‘˘đ?‘ đ?‘’đ?‘“đ?‘˘đ?‘™ â„Žđ?‘’đ?‘Žđ?‘Ą đ?‘”đ?‘Žđ?‘–đ?‘› đ?‘ đ?‘˘ = đ?‘ đ?‘˘đ?‘ đ?‘ đ?‘’đ?‘™đ?‘Ą đ?‘›đ?‘˘đ?‘šđ?‘?đ?‘’đ?‘&#x; đ?‘žđ?‘˘ đ?‘ƒđ?‘&#x; = đ?‘ƒđ?‘&#x;đ?‘Žđ?‘›đ?‘‘đ?‘Ąđ?‘™ đ?‘›đ?‘˘đ?‘šđ?‘?đ?‘’đ?‘&#x; = đ??šđ?‘… (đ?‘Š − đ??ˇđ?‘œ )đ??ż đ??śđ?‘? đ?‘Łđ?œŒ đ?‘ˆ = đ?‘˜ ∗ [đ?‘† − (đ?‘‡đ?‘– − đ?‘‡đ?‘Ž )] đ??ś đ?‘…đ?‘’ = đ?‘…đ?‘’đ?‘Śđ?‘›đ?‘œđ?‘™đ?‘‘đ?‘ đ?‘›đ?‘˘đ?‘šđ?‘?đ?‘’đ?‘&#x; đ??šđ?‘… đ?‘‰đ??ˇđ?‘– = = â„Žđ?‘’đ?‘Žđ?‘Ą đ?‘Ł − đ?‘…đ?‘’đ?‘šđ?‘œđ?‘Łđ?‘Žđ?‘™ đ?‘“đ?‘Žđ?‘?đ?‘Ąđ?‘œđ?‘&#x; đ??´đ?‘Łđ?‘’đ?‘&#x;đ?‘Žđ?‘”đ?‘’ đ?‘‰đ?‘’đ?‘™đ?‘œđ?‘?đ?‘–đ?‘Ąđ?‘Ś đ?‘‰ đ?‘† = đ??´đ?‘?đ?‘ đ?‘œđ?‘&#x;đ?‘?đ?‘’đ?‘‘ đ?‘“đ?‘™đ?‘˘đ?‘Ľ đ?‘šĚ‡ =đ?œ‹ 2 đ?‘ˆ = đ?‘œđ?‘Łđ?‘’đ?‘&#x;đ?‘Žđ?‘™đ?‘™ â„Žđ?‘’đ?‘Žđ?‘Ą đ?‘™đ?‘œđ?‘ đ?‘ đ??ˇ đ?œŒ 4 đ?‘– đ??ś = đ?‘?đ?‘œđ?‘›đ?‘?đ?‘’đ?‘›đ?‘Ąđ?‘&#x;đ?‘Žđ?‘Ąđ?‘–đ?‘œđ?‘› đ?‘&#x;đ?‘Žđ?‘Ąđ?‘–đ?‘œ đ?‘Ł, đ?‘˜, đ?œŒ, đ??śđ?‘? đ?‘Łđ?‘Žđ?‘™đ?‘˘đ?‘’đ?‘ đ?‘Žđ?‘&#x;đ?‘’ đ?‘Ąđ?‘Žđ?‘˜đ?‘’đ?‘› đ?‘“đ?‘&#x;đ?‘œđ?‘š đ?‘”đ?‘&#x;đ?‘Žđ?‘?â„Ž đ??ˇđ?‘œ đ?‘‡đ?‘– đ?‘† = đ??źđ?‘? đ?‘&#x;đ?‘? Ă— đ?œ?đ?›ź [đ?œŒđ?›ž + ] đ?‘Š − đ??ˇđ?‘œ = đ?‘“đ?‘™đ?‘˘đ?‘–đ?‘‘ đ?‘–đ?‘›đ?‘™đ?‘’đ?‘Ą đ?‘Ąđ?‘’đ?‘šđ?‘?đ?‘’đ?‘&#x;đ?‘Žđ?‘Ąđ?‘˘đ?‘&#x;đ?‘’ đ?‘&#x;đ?‘? đ?‘‡đ?‘Ž đ?‘?đ?‘œđ?‘ đ?œƒ = đ??´đ?‘šđ?‘?đ?‘–đ?‘’đ?‘›đ?‘Ą đ?‘‡đ?‘’đ?‘šđ?‘?đ?‘’đ?‘&#x;đ?‘Žđ?‘Ąđ?‘˘đ?‘&#x;đ?‘’ = sin ∅ sin đ?›ż +cos ∅ cos đ?›ż cos đ?œ” đ??šĚ 1 đ??šđ?‘… = đ??š [1 − exp(− )] đ??š cos đ?œƒ = [1 − đ?‘?đ?‘œđ?‘ 2 đ?›żđ?‘ đ?‘–đ?‘›2 đ?œ”]2 360 1 đ?›ż = 23.45đ?‘ đ?‘–đ?‘› [ (284 đ??šĚ = 1 đ??ˇđ?‘œ 365 đ?‘ˆ[ + ] đ?‘ˆ đ??ˇđ?‘– â„Žđ?‘“ + đ?‘›)] đ?‘šĚ‡đ??śđ?‘? đ??š= đ??śđ?‘œđ?‘›đ?‘?đ?‘’đ?‘›đ?‘Ąđ?‘&#x;đ?‘Žđ?‘Ąđ?‘–đ?‘œđ?‘› đ?‘…đ?‘Žđ?‘Ąđ?‘–đ?‘œ đ??ś đ?œ‹đ??ˇđ?‘œ đ?‘ˆđ??ż đ?‘Š − đ??ˇđ?‘œ đ?‘ˆ = đ?‘Žđ?‘ đ?‘ đ?‘˘đ?‘šđ?‘?đ?‘Ąđ?‘–đ?‘œđ?‘› = đ?œ‹đ??ˇđ?‘œ Table 3: V. EFFECT OF VARIOUS PARAMETERS WITH THE EFFICIENCY A. Effect of Inlet Temperature: As the fluid inlet temperature increases, the temperature of the absorber tube surface also increases. As a result, losses due to re-radiation and convection to the surroundings increase, resulting in a decrease in efficiency.

B. Effect of Mass Flow Rate: An increase in the mass flow rate of the thermic fluid increases the value of the inside heat transfer coefficient h_f.

Due to this, the collector efficiency factor and the collector heat-removal factor increase and the efficiency increases.

C. Effect of Concentration Ratio: The effect of increasing the concentration ratio by decreasing the size of the absorber tube.

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Thermodynamic Modeling of Solar Thermal Power (Captive Power) and Water Desalination (with Single Effect) (IJSRD/Vol. 4/Issue 05/2016/066)

VI. ADVANCES IN CYLINDRICAL PARABOLIC COLLECTOR TECHNOLOGY

A consortium of European companies and research laboratories called EuroTrough has developed a new design of the concentrator structure. This is based on the torque box concept and eliminates some problems associated with the Luz concentrator which had a truss design [1, 2]. The new design results in less weight and wind loading.

The material of the reflector is another key element of a parabolic concentrator. Although a number of materials have been proposed, thick silvered glass is the only material which has been successfully used so far [3].

The other component on which considerable developmental work has been done in the receiver. The evacuated glass tube is modified by the molybdenum-alumina coating which is stable and durable in an evacuated at high temperatures up to 350°C [4].

Fig. 3: VII. RESULT AND DISCUSSION A. Conclusion: From this thermodynamic modeling we can conclude that the efficiency of the whole system is depends upon these following parameters, so that we can improve the efficiency of this system by modifying these parameters.

1) Inlet temperature of working fluid to the solar trough 2) Mass flow rate of the thermic fluid 3) Concentration ratio of the trough 4) Suitable tracking modes 5) Evacuated absorber tube 6) Pressure drop in the flash chamber 7) Modification in the heat exchangers & evaporator

Fig. 1:

Fig. 4: schematic of desalination system REFERENCES

Fig. 2:

[1] Price, H, Luepfert, E., Kearney, D., Zarza, E., Cohen, G., Gee, R. and Mahoney, R.2002.Advances in parabolic trough solar power technology, Journal of solar Energy Engineering, Trans. ASME, 124: 109.

[2] Schiel, W., Schweitzer, A., Kracht, O. and Hunt, B. 2006. Collector development for parabolic trough power plants at Schlaich Bergermann und partner, Proc. Of solar PACES, June 20-23, Seville, Spain.

[3] Fend, T., Hoffsschmidt, B., Jorgensen, G., Kuester, H., Krueger, D., pitz-pall, R., Rietbrock, P. and Riffelmann,

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Thermodynamic Modeling of Solar Thermal Power (Captive Power) and Water Desalination (with Single Effect) (IJSRD/Vol. 4/Issue 05/2016/066)

K.2003.comparative assessment of solar concentrator materials, solar Energy, 74: 149.

[4] Lanxner, M. and Elgat, z.1990. solar selective absorber coating for high service temperatures produced by plasma sputtering. Proc. Photo-opt. Instrum. Engr. 1272: 240.

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