Date 10/03/22
Introduction:-Solar cooker is a device used to harvest thermal energy from the sun.It is used to cooking food in small scale.Cooking food using solar cooker is safe way to cook food.
Objectives:1)To refabrish solar cookers and make it working
. 2) To calculate cost of maintenance
. Firstly we saw the solar cookers having dust falls on it.and screws got corrode, insulation material and wooden planks got damaged . mirror got break down.
Problems Identify:
Adjustable screw not available
Rubber gaskets got damaged
Mirror breaks down of one solar cooker
Screws got corrode
Insulation material damaged
wooden blocks and wooden planks got damaged
Date 11/03/22
Drawing of solar cookers with their parts
Date 12/03/22
Making bill of material of solar cookers
Date 19/03/22
After Bill of material this day I start to repairing two solar cookers.l went to hardware and bring the screws.
Date 21/03/22
I took the mirror in scrap having square pipe attached with them. for separating mirror from Square pipe l use screw driver. After separating mirror,l cut the mirror by using scale,marker and cutter. on evening l try to attach mirror in solar cooker.on this time the mirror got break down at one corner.after that I joint the mirror using resin,hardner and hard paper chops.
Date 22/03/22
I try to remove the corrodile nut bolts from solar cooker.but not remove by me.then l remove the nut bolts using grinder.
Date 23/03/22
I went to hardware for bringing the nut bolts for mirror section of solar cooker.at that time l went to lakud vakhar in pabal for enquiry of wooden blocks.
Date 24/03/22
l remove the dust from links using polish paper.l bring the wooden blocks and cutting by hacksaw machine at same height of all blocks about 9.5 cm.The four wooden blocks required for solar cooker at four corners.
Date 25/03/22
l remove the dust from solar cooker handle,hooks,clamp by using files, polish wheel in grinder machine.
Date 28/03/22
I clean the metallic body of first solar cooker using water and cloth. after that I put to sun drying. After drying metal body,I polish the metal body using polish paper.
Date 29/03/22
I fit the wooden blocks at four corners of solar cooker.first l was drill the wooden blocks and fit them using screw.because screws better than Nails,they don’t damage wood.
Followings are the purpose of using wooden blocks:
1.As a standing support to wooden planks.
2.As compare to metal blocks, wood blocks have good insulator of heat.but another query is that the plastic has also insulator.The plastic is soft and breakable material so we not use this.
3.Creating gap between outer metal sheet and inner black absorbing tray for filling insulation material.
Date 30/03/22
l polish the hook, hinge, and small parts of second solar cooker.
Date 31/03/22
I took the big wooden plank from scrapyard, and cut down 7 planks from it using wood grinder.The dimensions of two planks are 60cm*3cm*2cm( l*b*t) and five are 52cm*3cm*2cm
Date 01/04/22
I remove the old gaskets from second solar cooker using hammer and chiesel.
I polish the wooden planks using polish papers.After that I fit the two wooden planks with each other using screws.I drill in two wooden planks using “Radial drill & piller type drill Machine” for attaching of screws having the purpose of straight drilling. While using hand drill machine,holes create diagonally or disturbed.
Date 02/04/22
I fit the all wooden planks with four wooden blocks using drill machine and screws.
Date 4/04/22
l cut the wooden planks using wood grinder
Date 5/04/22
l cut the four small m.s plates and drill it on two ends after that l drill the wooden planks and attach with the sheet having the plates attach to corners.
Date 6/04/22
I clean the spray paint gun.
Date 7/04/22
l paint the solar cookers
Date 8/04/22
l polish the two trays using polish wheel of grinder.
09/04/22
l remove the mirror in square tube and cut it accurately.l remove old rubber and attach new rubber on glass sheet.
Date 12/04/22
I paint the Two trays of solar cookers with black colour.
After painting the trays,I install the insulation of first solar cooker below the tray and fit the tray with screws.
Date 13/04/22
I open the glass cover and remove the damaged rubber from glass cover
After that I install the insulation in second solar cooker below the tray and fit the tray with screws.
Date 16/04/22
The one corner was break down of glass cover frame.for fitting the corner of glass cover frame, I cut the small M.S plate, mould it with moulding machine, drill it with drilling machine and attach to the corner of glass cover frame.
After this work was done, I joint the rubber in the glass cover frame for attaching glasses in the frame.
Date 19/04/22
By using resin and hardner (Araldite) I stick the rubber plates above the black absorbing tray.
Date 20/04/22
Bring the U channels for making glass cover frame for first solar cooker after that cut the U channels in proper size using grinder machine and make a frame using rubber in U channels.
Date 21/04/22
fitting the adjustable screw and compressing nut Bolts in second solar cooker.
Date 22/04/21
fitting all the parts of first solar cooker also fit the adjustable screw in this solar cooker.this solar cooker was completed.
Date 23/04/22
I put the first solar cooker in sun exposure area.after that took a steel tiffin box. In the tiffin box I pour the water having temperature 27°c at time 10 am after two hours at 12 pm water temperature was 88°c. Also I cut the sponge 2 cm thick and attached to the backsight area of second solar cooker mirror.
Mr.jadhav sir told me the cost of labor charges i.e 30 rs/hr. This rate I include in estimating the overall cost of solar cookers. I estimate the overall cost of solar cookers in below pdf:
Taking trials for calculating efficiency of solar cooker :
Date 25/04/22
Took the water temperature readings from 10 am to 12pm having 150 ml water.
M=Mass of water-150 ml=0.150 ltr
cp=specific heat of water=4.186 j
∆t=Temperature difference between maximum temperature of water and Inner temperature of tray 88-54=34°
Average solar radiation between 2 hrs.=556 w/m2
Aperture area of mirror and glass cover=0.5 m2
Time=2 hrs
Latent heat of water=2260 j
water loss=10 ml= 0.010 ltr
Efficiency=output/input
. (0.150×4.186×34)+(0.010×2260) /(556×0.5×2)
=0.079 ×100
. =7.9 % i.e 8 %
Conclusion :- I learn the hands on learning experience in maintainance of solar cooker.also calculate the overall maintenance cost of solar cookers.
