control to those who who are President over here and the webinar on solar thermal desalination Technologies which is going to deliver by Mr President of his PhD scholar at the department of storage and Water Conservation engineering junagad Agriculture University he completed his bachelor degree at Anan Agriculture University in 2017 and his host graduation in Canada agriculture New City so uh in this era of the renewable energy and water scarcity this is a very good topic on solar thermal desalination so I welcome Mr President on behalf of parallel Institute of Technology parallel University uh it is up to you now question please carry on thank you parser for the brief introduction about me so I'm directly going to the my presentation so am I audible everyone hello yes yes you are very maturity yeah thank you sir so we all know that uh What uh what is like thermal discipliness and Technologies uh I will give a very much brief into this all thermal destination Technologies so coming to the introduction like we all know that there is only three percentage of fresh water available in the earth like 70 percentage 70 80 percentage is salt water into ocean so for irrigation purpose drinking purpose for everything we need fresh water in fresh water is very scared in the earth also if you if you if you like it is very expensive to convert salt water into uh red fresh water and also now due to global warming the painful is very infrequent so somewhere there will be more rainfall somewhere there will be less rainfall so due to that the fresh water availability is very scared and also due to seawater intrusion integral water the groundwater is getting salty due to the seawater in tourism so we need a source of energy through which we can convert sold so salt based this sea water to convert into fresh water so solar is the one of the best source available renewable source available to us like if we use thermal Technologies for like coal or any petroleum to convert this sea water into fresh water it requires more uh coal and this renew it is in renewable sources which which can be like less which is very Less in dark so solar is a very good source of energy for us so solar deceleration can be in the two two three one is direct solar deceleration you can use the sun heat energy to convert this sea water to fresh water or also we can use some air or any fluid liquid fluid to get the heat from the solar so we will go into that uh what is destination so basically you can say that if so to convert salt water into pure water we need some some amount of energy so uh this energy can be uh get from any renewable or non-renewable sources in 2005 told that 10 000 tons of fear uh 10 000 tons of oil is required per year to convert 1000 meter cube per day pure water so you can see how much oil is required to convert this amount of pure water so uh worldwide nowadays this Solar Technologies uh like renewable Technologies are getting more and more uh popular so compared to hydroelectric energy solar wind and geothermal energy are more used more one percentage more worldwide so in this way you can say that solar this solar distance in plants are very much required and it should be like popular in every country and it should be planned it should be planted in nearby sea areas we can say that uh solar is a free energy and also this solar decision plants doesn't require any moving operation so it is very low low cost so operating cost is very small very low but the main demerit is that it is having very low efficiency so it can be used for small scale production and especially in the Arid areas means where the sunlight is more and we are getting more heat so in this remote read area as an island we can use solar thermal distance and Technologies and also conventional energy such as coal or petroleum is very scared so in this this we can use solar thermal distance and Technologies so coming to the different types so direct solar digital solar deceleration in this you can say we are using the sun energy directly so here here we can see that solar radiation is coming from into this but so directly in the 3050 if it is getting the energy and it is getting evaporated and condenses for this cover and we are we can collect to uh collect the water from here so this is direct solar distance in technology and other way if you can say we can use the solar energy uh collected through some flat flat collectors or any other things like we can use hot air so from that hot air we'll use pre like prepare electricity and that electricity we can use in conventional distance in Plants such as multi effect multiple stage plus and reverse osmosis different types of this is a process in which electricity is required more and this electricity can be produced by the solar energy so this is also called as indirect solar destination technology so coming to direct solar designation means what so this is the a picture in which there is a sea water here in the bottom of the solar decimation tank this is a glass cover so the radiation which is coming to the bottom of the like this uh plant this solar distance in tank the heat energy will be converting this sea water into wet water vapor and compared to the outside temperature inside temperature will be more so the water vapor will contain so the glass this condensed water can be collected at the bottom of this tank and this way we can you get the solar in this way you can get fresh water but you know it is very like low less effective so we will get only 2000 meter per day if it is in the big area so it is saying low operating temperature and low pressure so we will get less efficient so this this was a solar still so a single effect solar cell there was only one side the glass so this uh distilled water is generally portable so what is portable water portable water measure it is a drinking water I mean it is free from salts inorganic and organic components also microbi microbial uh bacterias are also are removed so this will get this fresh water which can be used for drinking purpose and also after the like salty water is getting water weapon the sludge will be formed at the bottom of the tank which can be flushed out through any uh external water water flushing device so it is said that to produce maximum 9 liter per meter Square uh area per day of water including heat losses it requires maximum 250 watts per meter Square solar radiation for 24 over 24 hours so it is very much and less effective because we require 250 watt per meter squared for 24 hours and also Garcia rodrigue studied this single effect solar still and they stated that 30 to 40 percentage efficiency is it is gained 30 to 40 percent education so which is very low so it is having low thermal efficiency also low productivity so it is set that to 1 kg of like water uh 30 degree celsius it requires 2.4 into 10 raised to 6 Joule of energy so this much amount of energy to get from Sun we required more efficient techniques of solar desalination and also Sun moving at all in 2020 experimented that if we keep some nanoparticle coating at the bottom of the uh steel the evaporation will get increased so they studied This Ti titanium dioxide per nanoparticles coating and this is good good at around 57.60 percentage of efficiency was there in summer and 36.69 percentage of uh efficiency was there in the winter so they got the increase of the efficiency through the nanoparticles coating which which is either way also in like expensive thing so now coming to indirect solar designation Technologies so in this we are not getting we are not using direct solar heat but we are storing the heat energy and we are using it to produce electricity or any other uh heat Source medium uh for the solar designation so solar pond so it is generally constructed the seller pond in which they are having three layers the bottom layer is having salt so salt concentration will be more in this area Less in this area and this will be a relatively fresh water zone so whenever the solar radiation is coming here it will get hit inside the small concentrated water and this heat cannot be get lost due to the more concentration of salt so the water heat it will be trapped here in the bottom layer and that will throw some heat exchanger or any tube water you can use this hot water uh at the bottom for solar destination or any electricity uh we can use that heat to produce electricity so generally lower layer is getting 70 to 85 percentage degree celsius during the day time in summer and winter that can be different according to the temperature so uh this the solar point is used for getting heat from the bottom of the layer but it is saying only 10 to 15 percentage efficiency if we are using Small Ponds if you are using large ones the efficiency will increase according to the size of pond so this is a more convenient Source there are no moving parts so the way we don't need any mechanical thing it is a simple thing uh also it is inexpensive so you can also optimize the solar salinity gradient solar Bond so solar Bond also named this salinity gradient solar point so there is a difference between salinity between two layers so it is called salinity gradient solar Pawn we can use some optimization technique to increase the operation so uh they have used in NaCl and na2so for mixture uh to optimize uh solar pond efficiency the asari at all studied this in 2020 and they found that the control amount of na2so4 improves the thermal and salinity stability so different amount of energy so4 and NaCl were studied and they found that some control amount of a network so far will improve the thermal stability now also improve the storage capacity of heat at the bottom layer so high percentage one or two and network sf4 requires less time to stabilized and also reduces the density radiation so it causes the rapid destruction of upper layer so it was found that 0.75
percentage of Android 2so4 was perfect and Optimum for maximum extraction of it from the solar pond and they to prevent algae they spreaded a HCL spray and a high high percentage of no2so4 so the the algae won't be covering the surface area so in this way sorry I told studied this solar point and he gave the uh how we can optimize the solar bond energy and how we can use it now coming to the another indirect Solon distance and Technology let's collect so what is this so in this this is a box in which there are absorber pipes which are having selective Coatings and these pipes we are transferring some heat transfer fluid this this heat transfer fluid can be either water or air anything we can use and this we are covering this pipes into the we are coding this place to selective Coatings which reduces the heat loss and also increases the radiation absorption so you can you select black color pipes so it will increase the radiation absorption so it was not much efficient so the floodplat collectors were not found any useful for distance Technologies because using this heat hot water hot air it was not getting much efficiency compared to the directional audition technology so what they did they did this they did if they used FPC for additional energy source so if we are using some major energy energy source uh like electricity or something if if you are getting less then we can use this FPC for additional energy source to complete the whole Solar dissonance implant so in Mexico uh this this deceleration facility uh derives energy from flatbread collectors and parabolic drugs are also like uh type of parabolic glass reflectors which concentrates the energy at the center of the uh any material which can get heated and you can use that heat Source from that so in this way FPC is used then coming to evacuated tube collector so we have also shown that on the top of our route we are having solar water heater so in that there are different types of tubes and indeed these tubes they are having two glasses it's in between two glasses they are hang vacuum so why we are getting we are having that vacuum to decrease the losses due to uh infrared radiation so in same way we are using this evacuated tubes which is having two tubes and in between two tubes there is a vacuum to reduce heat loss and also we are having the inside tube will be having safety coating to increase the types of something this tube is also called as Diva tubes so this tubes due to vacuum and selective coating materials it is more sophisticated more expensive but uh due to less losses of due to infrared radiation uh we are getting more temperature so around 200 degree Celsius temperature we can attain through the evacuated tube collector and it is it is saying very high high efficiency and compared to the cost it is around 200 per meter Square to 550 dollar per meter Square so this it is a high temperature this illness and plant distillation plants also we can say which can be used to for for solar deceleration and also the cost is Optimum which can be used at the plants which is on medium scale plants uh now coming to the high scale processor hang in the more area which we can use multi-stage plus process in 2017 studied the whole process uh in this there are several Chambers in the it is in the more area you can use this multi-stage process so there will be several Chambers and pre-treated cell and water will be used from the after before so here you can see the process so here there will be different in end States so different stages of flash process will build so uh high temp in the first process high temperature and high pressure we'll treat the pre-treated saline water so due to the high temperature and high pressure uh it will the boiling boiling point of water will get reduced and it will directly get into the first stage so first stage water will be spread the brain though what due to this hot water vapor will get above and will condense from this pipe so it will be collected here and again it will go to the second one in this way different stages the pre-treated cell and water will be passed and at the end of the end so we can calculate the number of stages according to the our volume of flow and at the end stage we will get the fresh water as a product and also a sludge or a brain you can collect it from the bottom so building water is in the fresh chamber the pressure is suddenly reduced so due to that the water vapor will directly the water will directly get it to water weapon and it will get condensed above and again it will go to the second chamber so a different type of stem different chambers will be continuously going so in this way we are using this multi-stage process so explain if you are getting my screen yes okay so so when was I remote sir like like when I was like next slide next slide this was completed yes yeah this one this has gone gone Okay so this multi as we studied multi-state split process uh look at the next play can you please minimize the presentation yeah yeah this slide yes no no next yes 14th number 14. 14 yeah okay so uh same this multi effect this lesson is working with same principle and uh multi-stage relative operator we studied in the previous slide so in this what we are having we are having different chambers in this each chamber we are con creating vacuum conditions so what will happen due to vacuum conditions the heat to operation temperature will get reduced and the operation will be very fast so as you can see in photo here in every chamber we are using vacuum and the sea water will be fit from the top the steam will be come from this boiler and the water vapor will the water vapor of first chamber will be used is a heat source for the second word second chamber so the efficiency of the plant will also increase will use the pump to test for all the brine water from each in the into the heat chamber so this through this this relation process we are getting we are using the heat source of previous chamber so it's required very less amount of heat energy and also it is very efficient so and also the fresh water will be connected from each chamber so it is it is working on the same Principle as the previous one but here we are using vacuum condition and uh it is more efficient than uh multiple flesh Chambers so if we are having if you if we need more efficient we will increase the multiple number of Chamber but what happens if we use number of multiple Chambers we need to create vacuum in each chamber and it will require height uh leg operating cost so we have to consider some optimum number of Chambers for rectangle flow of water to be converted into fresh water so more number of Chamber higher number of performance performance ratio multi multi-effect dissemination so fire engine into 2003 estimated uh production course that uh to produce 500 meter cube per day it requires 3.2 dollar per meter cube and if we require more number uh more water then the cost is getting reduced so see from 500 to 5000 the cost is reduced from 3.22 so higher higher
the chamber it will reduce the number of uh with the cost of per meter cube of water to produce the water to produce the dollar like num what is uh water it will get reduced so we can also modify the plants so we study direct and indirect solar destination plants in this we can modify each and every uh plant to increase the efficiency so so we augment the operative performance you can use several techniques so here the first one we studied the single effect solar still here we are seeing double effects velocity so two two set glass we are keeping and at the both side we are collecting the fresh water and the in this way we can increase the Basin still performance so again uh what we can do is in single effect still if we are keeping two glass and in between two glasses we are continuously flowing the cooling water deficiency will be great increase why because there is a higher temperature difference between Basin and the cover so evaporating evaporation rate will directly get increase so uh any cooling water or saline water we can use to like flow from that Gap so it will increase the increase maximize the temperature difference between water inside and the water flowing from the top so the condenser will also increase and we can get more uh more fresh water but now this cooling so the cost is also high in this so we have to make this Arrangement and also we have to flow continuously flow continuously plump the fresh water so it will also increase the cost but will get fresh water and efficiency will also increase so here this manjunath in 2016 study then stated that this lesson output is interest 3.32 times compared to the non-modified person and also the this single steel efficiency is increased seven percentage so we can say that it increases the output capacity and also efficiency of the steel then instead of the water flowing you can use some pump or any additional condenser to condense the water at the top of the shedded area so but at 2002 founded that by adding passive condenser in the Shaded region of this is glass it is called a standard region so if we are using some additional condenser uh by single slope still the efficiency will increase 45 percentage but also we are using some fan on electricity again the same thing the operating cost will be high so also another modification is like in the sea water if we black dye is mixed with that black Dyke uh act as a absorption thing so more heat will be absorbed from the Sun so the temperature the more water will be evaporated so injecting blood die in the sea water it is the distillation little by 11 to 16 percentage so it is the in the efficiency or the its National increases the cost will also increase because the black dye the high like the cost of black Devolution increase the how much percentage of black dye to uh the absorbed in the water how much percentage we have to study everything so in This way everything you can use then also weak steel so what is weak like a week is uh the what we call in Gujarati we call pothra so that if we uh this if we spread over here the uh evaporation of the water will increase so weak still we are using a weak material to spread over the tilted uh this plate and the absorption absorption will also heat up the Sun Also increase we have to make some Optimum angle for the better better angle so that we can get more absorption of heat and uh each and every time from here the float floating it will allow the water only small amount of water to come over this thing so let's less water at a time so more uh quickly it will get heated and more uh uh with high temperature so more evaporation will be there so Tanaka in 1981 stated that superiority of tilted weak productivity increased from 20 to 50 percentage so uh we can use any weak material to increase the productivity so compared to the amazing steel or single effect based in previous or non-modified this efficiency will be far better in simple week still if we are using some complex weak still it will get more uh more efficiency but the cost will also high but simple with still it is having it is lightweight low cost and it is having a significant output so a number of the hybrid structure of weight localization materials increases the heater operation so what is this hshlm so it is different type of material see here we are seeing uh carbon electric graphite Flex carbon ferment uh combination of both so this one was a graph graphite Flex this one is carbon phone carbon forms so these two materials we can use to increase the uh it is a week to increase the evaporating or high absorption and also a hydrophilic capillary force due to this the material ability to to capillar with the water it will the temperature of evaporating temperature will decrease and also less amount of water we are keeping over the weeks so the efficiency will directly increase so here see the productivity of graphite the exploited graphite Flex using useless weak increases 34 percentage productivity by using carbon foam it is a 28.6 and by using combination of both graphite flux and carbon form uh the productivity increased 51.8 percentage and also the effect of efficiency of solar Steel in a combination of both entries 37.6 percentage so in this way different type of weeks we can use to increase the productivity of solar Steel now another aspect is a Greenhouse we are now Greenhouse is getting more popular so what if we use the greenhouse and solar steel both as a combination so here we can see the photo at the top we are having the single evaporator and this is the greenhouse so water is pumped at the top of the the soil still the water will get evaporated and the fresh water we are collecting here and this fresh water we can use to irrigate the plants in the uh Greenhouse so what is benefit of it so uh the inside temperature will get like minimized due to the solar cell at the top the inside temperature will be Optimum so transpiration will get reduced and also uh it is used in small small scale systems only because at the top we can't use a heavy system so 25 meter cube per day or less only we can use and also in the remote area so the trans wavelength transmitted in the greenhouse is photosynthesis wavelength from 380 to 710 nanometer so the temperature of water at the top won't be much and the efficiency won't be uh is space compared to the other types but the temperature inside the greenhouse will be lowered and the climate inside the crop will be better so we won't require any event lesson requirement ventilation thing uh requirements and also water consumption of the plant will reduce because the transportation is reduced so in this way this solar system can be very useful uh the heat inside the greenhouse can be used at the night time also to evaporate the water under top so Davis and pattern in 2005 stated that the amount of freshwater produced exists the evaporation requirement of the crop so in the daytime uh the water will be the transparated water will be left and also your pressure will be less due to the solar steel at the top so what they told that amount of fresh water produced from the solar steel it is more than the Evo transpiration of the plant inside the the greenhouse so so if we are using this fresh water as irrigation then also we are having some amount of water left with us for the other purpose so this is a very uh modern concept is solar steel Greenhouse combination uh multiple effect basins so we studied that solar still of single effect so what we can do is we can have three or five layers of single effect solar steel to evaporate the different amount of water so two or more compartments you can uh get over the gate over the each still so multiple effects solar dissonance and systems are more productive than single system due to reduced latent heat so to transfer from water liquid water wave liquid water to water vapor less energy is required so multiple effects so Basin still is more efficient than more productive than single effects still and also the increased efficiency surpluses and increased capital and operating costs so we require more heat to increase the because there are different types different compartments so each and every compartment required the heat to evaporate so in this complexity is a complexities are also more cost is also more but efficiency is around 25 or more we can get compared to the single effects system uh Scholars are in 2001 experimented that which desenation with six six stages so here we saw the photo of three stages the same way uh for six stages he studied uh for this lesson and next he founded production rate reached 25 liter per meter Square per day uh for a value of around 4.8 kilowatt hour per meter Square per day of solar radiation so we can get a much amount of water uh from the multiple effect Basin still compared to singles effects so in this way you can modify it so there is a small case study uh at the first we we have seen that use of nanoparticle and the the bottom to increase absorption so that are casterly a small case study I have taken um in the case study was uh at the research center of physics in the Andhra Pradesh India during January 2018 to February February 2019 uh with global radiation around 1100 watt per meter Square so what they did uh they used uh titanium dioxide nanoparticles and mixed with cro2 and O3 coating for the Bayesian area to achieve more absorptivity and titanium isoperoxide was used for titanium source so this this mixture was used in the coating for Basin area that the bottom of the area they used this nanoparticles matter to increase the absorptivity of uh this sun uh so it's a good result for so without uh quoting and with quoting in the summer and winter season in solar radiation uh and the time for the day so the blue one so we can see in the uh area which which liquid Coating in the winter season and summer season it got high and without uh coating this winter and summer is good low this one uh temperature attained the temperature in 18 volt In Summer with uh with the coating and in Winter which coating got high in the same way uh efficiency of the plant uh same way it was increased in with coating and it's summer and winter season so anyway we can see that the coating material or modification rinsing is the Basin still increases the efficiency of the plant and also the production rate so here we can see that production rate was 6.1 kg
per meter Square per hour in the daytime in the summer with Coating in comparately it got reduced in the the coming one and also at the night time also due to the heat stored nighttime also they got around 4. like 1.792 kg per meter Square per hour output so this is a very much the night time in the summer so this type of coating materials on anything we can use to increase the absorptivity at the bottom so the conclusion of the case study was that advantage of Nano layer coated is the ability to raise the temperature of basin by 60.1 and 70 degree in the winter and summer is isn't respectively so here we can see around 70 degree Celsius in the summer and 60 degree Celsius in the winter was achieved due to this Nano layer coated uh bottom and also Daily yield a daily yield was in with 6.1 kg per meter Square per hour per day and 4.1 kg per meter kg meter Square per hour per day in the summer and winter respectively summer we got 6 kg and in Winter we got 4.1 kg so this is very much a high efficient uh system we are using nanoparticles but again the cost will also high but different studies are going on so with less operating costs we are getting more productivity and also those efficiency of system in summer which coating was 57.16 compared to the non-coating
27.72 percentage so see how much efficiency it got in increased and also in winter season uh it's coating it was 36.69 percentage and compared to non-coated 24.03 so
here we can see the differences in summer due to high heat the efficiency increased 30 percentage and here we got only around 10 percentage or 12 percentage increase in winter so in this if we use this modifications in the digital different conventional plant we can increase the productivity in the main aspect of and these plants are to get uh more and more output and with the less amount of operating and maintenance costs so the a solar deceleration is a very good good type of technique nowadays use with the use of solar energy to get the fresh water which we can use in irrigation or drinking purposes but nowadays it is in the development and research consideration so in the future we will get some good distillation Technologies at the like see the seashore or any ocean we can use this type of service and Technologies we which can be very beneficial in our future uh so thank you sir this was all about solar distance and Technologies and uh any questions if you if you have any questions hello sir hello hi so guys you have any question then you can write in the chat box of the Facebook so I can convey to presence okay thank you prasang for delivering such a good webinar one of this topic thank you very much thank you sir thank you okay okay thank you sir thank you
2022-10-03