Double slope desalination of sea water by using solar with film

Double slope desalination of sea water by using solar with film

1. Double slope desalination of sea water by using solar stills with film Project members Harish kumar S ( Reg.no : 16TB0422) Muralidaran M ( Reg.no : 16TBL036) Arivalan K ( Reg.no : 16TB0411) Kazhalvannan C ( Reg.no : 16TB0432) Under the Guidance of Mr. D. Nagasundaram Asst.Professor Department of Mechanical Engineering RGCET, Puducherry .

2. Objective To increase efficiency of sea water by solar stills To increase evaporation by using film To reduce the heat loss

3. Introduction Increases of world population, the fresh water resources are getting low, about 71% of earth surface us covered with water, 97%of earth is in ocean as sea water remaining 3% of water is available as fresh water Population growth and urbanisation cause depletion and population of fresh water resource Desalination and water recycling are carried out to over come the water scarcity in many part of the world Solar desalination is type of distillation method for desalination, solar distillation is carried out in solar still

4. Solar desalination systems have low operating and maintenance costs and require large installation areas and high initial cost There are two different types of solar stills, those are; active solar still and passive solar still Active solar stills contain mechanical component, whereas passive solar still does not require mechanical components. Among these passive solar still gets more attractive compared to active solar still. In this present work, focus is made on passive solar still because passive solar stills are more economic then active solar still In this paper we study solar still with film. By implementing film to increase the evaporation

5. Abstract Desalination by solar still is one of the simple method for desalination. The main objective for this project is to increase the evaporation area by using solar film. And to increase the efficiency and to reduce the heat loss. So in this project we are going to use film in solar desalination system to increase the efficiency by increasing the evaporation area. First theoretical analysis of solar still without using film was done. Then film is implemented in solar still theoretical model and compared with results obtained from theoretical model of solar still without film. Then film installed still is fabricated and tested experimentally.

6. SOLAR DESALINATION Solar desalination is a technique to desalinate water using solar energy. There are two basic methods of achieving desalination using this technique; direct and indirect. Sunlight may provide heat for evaporative desalination processes, or for some indirect methods, convert to electricity to power a membrane process.

7. Literature Review

8. Year Author Investigation Details Journal name,vol.no:pp 2008 Abhay singh & Abhishek gaikwad This journal has discussed a relation for the predicting convective and evaporative heat transfer coefficient and distillate output or 200 mm and 160 mm depth of water. The sides of the wall of the condensing cover are made up of FRP sheet to avoid heat losses from sides and to provide the desired inclination to the cover to the bath. Effect of water depth at 30 degree inclined condensing cover in the performance of a water distillation JOURNAL 1

9. Year Author Investigation Details Journal Name, Vol.No ; PP 2012 Gang Xiao & Fei Wang A review on solar stills for brine desalination

10. Year Author Investigation Details Journal Name, Vol.No ; PP 2013 Amitava Bhattacharyya Direct sunlight has been utilized long back for desalination of water. Solar desalination plants are used for supplying desalinated water to small communities nearby coastal remote areas. Solar stills are easy to construct, can be done by local people from locally available materials, simple in operation by unskilled personnel, no hard maintanence requirements and almost no operation costs But they have the disadvantage of high initial cost If there is no sunshine, the productivity is almost zero for conventional basin type modal However,from the simplest basin type models of solar still in ealier days, researches haveprogressed a lot to increase its efficiency Solar stills for desalination of water in rural households

11. Year Author Investigation Details Journal Name, Vol.No ; PP 2010 N panchal A device which converts the unwanted water into drinkable water with the help of solar energy is called solar still It is very simple device and it is also very cheap Here, three absorbers plates have taken like galvanized iron sheets, copper sheets and mild sheet It has been observed that the yield is very ow upto noon but increased at after noon. For reducing the cost of solar still, wood chip has used as insulator in the solar still Experimental analysis of different absorber plates on performance of double slope solar still

12. WORK PLAN Selection of material Collection of material Fabrication Theoretical analysis basin wood aluminium glass Black paint film Report submission

13. Time Line Topic selection July Journal collection Selection of materials Fabrication Collection of materials Analysis Report submission August August December October April February

14. Experimental setup

15. Basic components A basic still consists of the following basic components: A basin Support structures Glass A distillate Insulation Film Black paint

16. Basin: The basin, contains the saline water that will undergo distillation. So, it must be waterproof and dark to absorb sunlight. The basin should be construct using aluminium , wood and thermocol . Aluminium used to absorb the sunlight, wood is used to fix the glass and thermocol used to used to reduce heat loss.

17. Glass: Glass are arranged at the top of the still which will allow the solar radiation to enter in to the basin. Dimensions of the glasses are 53.55cm*100cm*4mm

18. Film: Films are somewhat like mosquito net which are made in aluminium material which can absorb more amount of heat energy from the radiation of the sun and makes the evaporation rate high. The films are arranged in the solar basin using tubes. Nearly 3 tubes will arranged for every 9 cm in 30cm height of the basin

19. Dimensions of model

20. 3D models:

21. THEORETICAL ANALYSIS OF SOLAR STILL WITH FILM Incoming solar radiation to the glass Q' = I(t) x A Area of set up A = 0.8x0.8 = 0.24m Energy supplied to water Qs = α x Q (W or J/Sec) Mass of water in base plate (aluminium) m= ρ x v Mass of water with focus point of Fresnel lens m= ρ x v Heat required for vapourisation for water mass Qr = mx LH of water. Energy loss of base plate q b = h x (T b -T a .) Hourly distillate output Mass of evaporation water without Film m ew = ( q ewg / L g ) x 3600. Evaporation of heat loss q ewg = h ew ( T v -T g ) Evaporation loss of heat transfer coefficient h ew =16.273x10 h ew ( p w -P g )/( T w - T g ))

22. Convective loss heat coefficient h ew = 0.884[(T w - T g )+ ( p w - P g )(T w + 273)/(268.9x10 -3 - pw ))] Partial pressure of water ( p w ) = exp [ 25.317 – (5144 /(T w + 273))] Partial pressure of glass ( p g ) = exp [ 25.317 - (5144 /( T f +273))] Hourly distillate output Mass of evaporation water with glass m ew = ( qewf /LI) x 360. Temperature of film T f = 39 ⁰c Temperature of water T w = 62°c Evaporation of heat loss q ewf = h ew (T w – T f ) Evaporation loss of heat transfer coefficient h ew = 16.273x10 -3 x h ew (( P w -P f ) ( T w – T f )

23. Convective loss heat coefficient h ew = 0.884[(T w – T f ) + (( P w – P f )( T w + 273)/(268.9x10 -2 – p w )] Partial pressure of water ( P w ) = exp [ 25.317(5144 /( T w + 273)] Partial pressure of Fresnel lens ( p g ) = exp [ 25.317(5144 /(T f +273)] Efficiency of distillate water Mass of evaporation with Film - Mass of evaporation of without film

24. Thank You