Technical Feasibility Study of Energy Generation from the Tide in Southern Coasts of Iran Using Helical Turbines

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1 J. Al. Envion. Biol. Sci., 5(1)39-48, , TextRoad Publication ISSN: Jounal of Alied Envionental and Biological Sciences Technical Feasibility Study of Enegy Geneation fo the Tide in Southen Coasts of Ian Using Helical Tubines M. Biglai, M. S. aliou, H. Rahany * Deatent of Mechanical Engineeing, Senan Univesity, Senan, Ian Received: Setebe 7, 2014 Acceted: Novebe 12, 2014 ABSTRACT Available, clean and eliable tidal enegy exists in a vast aea. It can also be esented to any cities and societies living nea the coast. It can be used as a clean enegy fo coastal aeas of the wold, including islands and southen coasts of Ian. Futheoe, it s alied in envionental issues to egeneate the coastal coals. Kinetic enegy of the tide is conveted to electicity by vaious tubines. In this ae diffeent ethods of enegy exloitation fo tidal cuents and also the tides of southen coast of Ian ae investigated and coaed with each othe. Besides, we study the oduction of helical tubine which has seveal advantages and also investigate the esults and technical feasibility study fo constuction of the enegy exloitation station in south of the county. As final esults deonstated, constuction of the station fo electicity geneation in Pesian Gulf is necessay. KEYWORDS: Renewable enegy; helical tubine; Ian s southen coasts; enegy convesion INTRODUCTION Renewable enegies (like wind, ive flow, etc.) ae altenatively oduced by sola owe afte convesion and ae usually known as clean fuels. These enegies ae egeneated by the sun. Renewable enegies ae liited, a chaacteistic which akes the diffeent fo stoed enegies deived fo fossils. The tidal enegy which is widely accetable as an enegy souce is a new way of using clean enegy develoent stategies. Develoed counties in Asia, south and Cental Aeica, Euoe, Pacific and Atlantic oceans can benefit the advantages of tidal enegy. Econoizing in costs of equients and establishent installation is educed to 50% coaed with sola and diesel stations. In southen coasts of Ian such as Chabaha coast, since the aea is a gulf, we have a desied aount of tidal cuents and in laces like Tis ot, Ab-shiinkon and Kenaak ot which ae located inside Chabaha bay, we can geneate electicity fo tidal cuents and thei kinetic enegy using helical tubines [1]. Histoy of taditional enegy exloitation fo the tide goes back to 1580 in Geany whee they steeed big wate wheels by daing in tide s height diffeence. Reseaches about enegy exloitation fo tidal cuents in a wold in which oe than 70% of counties own coastal boundaies, ae elatively ae and a few scientists have studied this subject [2]. Twenty fou 10MW tubines have been installed in ive Rance in Fance since 1966 which geneate 240MW electicity. The aveage height of tide is 8.5 in this location. The ive s aea is alost Aoxiate cuent is 2 billion 3 and axiu edicted enegy of that is 7734 billion Kilowatt hou e yea fo which just 6% is exloited in actice. The oduced enegy is and Kilowatt hou e day in nea and sing, esectively. Sing to nea atio is 18:1. The aveage of both situations is 500 billion Kilowatt hou e yea. Electicity geneating via this ethod is cheae than oil, coal o even nuclea enegy. The tidal cuent in Passaaquoddy in downe at of the Bay of Fundy in New Bunswick, Canada is also one of the iotant laces fo enegy exloitation fo the tide. The aveage tide height in this lace is 5.5. Tidal cuent is alost about 21 billion 3 e cycle. Aoxiate aea of this bay is about and aound 3.5% of estiated axiu enegy is exloited. Its design finally has been obtained afte having been studied by a coittee between 1956 and 1961 [3]. Moeove, in Ian, a few studies about velocity and tidal cuent have been done in univesities. ahdat Tobati caied out a study unde the title of studying and investigating the velocity ofile of tidal cuents in stait of Hooz in winte of 1999 in which she investigated the velocity and tidal cuent flux and also the chaacteistics of the tide in diffeent laces like ive ouths and fiths. Anothe study about tidal cuents unde the title of studying the tide and tidal cuents in outh of ives ond and dalki has been esented by Gholai in Bousheh Povince in winte of 2006 in this univesity. Also, in at of this study, investigation and easons of the tidal cuents have been ointed out. Besides, in sing of 2006, Ali Mohaadi, a student of this univesity, has investigated the height of the tide with sto suge in Chabaha. Coesonding autho: H. Rahany, Deatent of Mechanical Engineeing, Senan Univesity, Senan, Ian 39

2 Biglai et al.,2015 A study by the title of edicting the velocity of tidal cuents in stait of Hooz has been done by Fallahi in sue of 2006 in Tabiat Modaes Univesity. In this study, the autho has investigated seveal tyes of aine flows and elations about the tide and tidal cuents. Futheoe, the velocity of these cuents in diffeent deths has been studied as well; howeve, none of the have had actical esults at the end [9]. The tidal enegy is distibuted in the whole wold, in laces like ive Rance in Fance and Bay of Fundy in Canada. Southen coasts of Ian ae also one of the laces having consideable tidal enegy. One tye of tidal cuents is the one able to geneate electicity without a da. The second tye is used when an enoous tide haens, a ocess in which the tidal enegy can be hanessed by constucting a da in the outh of the fith. This is done by aking a height diffeence which leads to tubine otation as a esult of obtained high seed. These tubines, called high-seed tubines, have two tyes of vetical and hoizontal axis. One disadvantage of daing on the outh of the fith is the envionent destuction. Coutational elations in tidal enegy Maxiu tidal enegy is obtained as follow [4]: E whee E is enegy in KWh/y, H is the tide s scoe in and Q is the aount of tide s cuent in Watt (j/s). When we have a tide, the axiu enegy is: E 2HQ E whee is in HQ H PotentialE negy s 2h 0 ghd z 2sgh 2 S: aea of the lace, g: gavitational acceleation, : wate density The aveage otential enegy is calculated as follow: the above elation is obtained bette fo seidiunal tide than othe tides. 2 2sgh MeanPowe (5) TidalPeiod Tyes of tubines and thei efficiency Hoizontal-axis and vetical-axis tubines ae the ost geneal tyes of tubines which have diffeent efficiencies with egad to thei function and design. The efficiency of hoizontal-axis tubines is 16 to 20% while that of odinay vetical-axis and helical vetical-axis tubines ae 23.5 and 35% esectively. (1) (2) (3) (4) Figue 1: Coaing the efficiency of tubines [6] As it is seen in figue 2, if the cuent velocity is doubled in a helical tubine, its owe inceases about 5 to 7 ties. 40

3 Powe (watts) J. Al. Envion. Biol. Sci., 5(1)39-48, Fee Flow (Ft/sec) Figue 2: The elation between cuent velocity and foce [5] Figue 3 deonstates the costs fo hanessing seveal tyes of enewable and non-enewable enegies SOAR WIND HYDRO NUCEAR COA OI GAS TIDA Red: high estiate Blue: low estiate Figue 3: Coaing the consution cost and obtained foce in dollas/kw [5] Taking the above gah into consideation, the clean enegy of the tide has the lowest cost coaed to othe enegies [1]. Tidal cuents in southen coasts of Ian Southen coasts of Ian ae one of locations with high caability of tide existence. Because of this and on the basis of studies caied out in this ae, these coasts ae caable fo installing the stations to geneate electicity fo tidal cuents. In this at, we study the tyes of the tide and its height which is the esult of hoizontal tidal cuents in thee aeas, east, cente and west of southen coasts of Ian. The ost easten coastal city of this county is Chabaha in Sistan-and-Balouchestan ovince and the ost westen one in Pesian Gulf is Khoashah in Khuzeztan ovince. Banda-Abbas in Hoozgan ovince is also in the beginning of Pesian Gulf and alost in the iddle of the coastal line in south of Ian. In fact, Chabaha is located in nothen coast of Oan sea with geogahic coodinate of 25 17N,60 37E It usually has shallow coasts on which the wate coes in and goes out consideably afte the tidal cuents. Chabaha owns two Bays, Kenaak and Abshiinkon in which the tide s height is about 50c oe coaed with Chabaha whee the head ean of the tide is about 2. The extea of the flood tide and ebb tide ae about 3.15 and 20c, esectively. The tide is seidiunal in Chabaha which eans 2 ebb tides and 2 flood tides in 24 hous. The ost tide height occus between 10 a.. and 6.. Figue 4 shows the tide details fo August 10 th to 18 th in 2014 in Chabaha. 41

4 Biglai et al.,2015 Figue 4: Tides details fo August 10 th to 18 th in 2014 in Chabaha bay The tide s details fo August 10 th to 13 th in Chabaha bay is deonstated in table 1, as well [6]. Table 1: The tide s details fo August 10 th to 11 th in Chabaha bay 42

5 J. Al. Envion. Biol. Sci., 5(1)39-48, 2015 Afte studying the tides in Chabaha, we study it in Banda-Abbas located between a coastal line in south of Ian and noth of stait of Hooz. Banda-Abbas with geogahic coodinate of N,56 17E, the head ean of 3.5, flood tide exteu of 4 and ebb tide exteu of 50c has seidiunal tides. Figue 5 esents daily tide details in Banda-Abbas fo August 8 th to 16 th in Figue 5: daily tide details in Banda-Abbas fo August 8 th to 16 th in The tide s details in August 8 th and 9 th in 2014 in Banda-Abbas can also be seen in table 2 [6]. Table 2: The tide s details in August 8 th and 9 th in 2014 in Banda-Abbas 43

6 Biglai et al.,2015 The final lace whose tide is studied is the end oint of Ian s southen coast and Pesian Gulf. Although the fathest city of this aea is Khoashah, since thee is a Bay called Khow-e-Mousa in this aea in which the tidal cuents in bay estuay ae oe effective, we study the tides in Khow-e-Mousa. This city is a tiangula at in the fathest end of Noth West of Pesian Gulf. Its geogahic coodinate is 29 36N,49 35E and deth is which eaches 73 in soe laces. Figue 6 indicates daily tide details fo August 10 th to 18 th in 2014 in Khow-e-Mousa. Figue 6: daily tide details fo August 10 th to 18 th in 2014 in Khow-e-Mousa The tide head ean in Khow-e-Mousa is about 3.5 the extee of flood and ebb tide ae 4.18 and 50c, esectively and the tide is seidiunal hee. The tide details in August 8 th and 9 th in 2014 in Khow-e-Mousa is shown in table 3, too [6]. Table 3: The tide details in August 8 th and 9 th in 2014 in Khow-e-Mousa 44

7 J. Al. Envion. Biol. Sci., 5(1)39-48, 2015 Accoding to studies and eseaches and the tye of obseved tides in thee oints of coastal line in south of Ian, it s concluded that the tidal cuents seed inside Pesian Gulf, esecially in fathest oint, is about 1.5 ties oe than easten ats. Designing and anufactuing the device and function of helical tubine The device odeled and ade in the esent study has vaious angles of otation in tubine s blade, as it is deonstated in figue 7. The blades and the axes ae ade fo aluinu to esist wate and usting, and the ots ae ade of bass. Figue 7: diffeent designs of helical blade of Tubine a) Blades with flat width and little sial b) Blades with flat width and uch sial c) Blades with hoogenous cuved width and little sial d) Blades with heteogeneous cuved width and uch sial We ade the laboatoy odel, consideing the size of the eal device with 2.2 diaetes and scale of 1:8 fo the height of wate canal. So we have the following sizes fo laboatoy odel: Height of eal tubine: 2.5/8=0.312 height of laboatoy tubine Diaete of eal tubine: 2.2/8=0.275 diaete of laboatoy tubine Blade width of eal tubine: 0.3/8=0.03 blade width of laboatoy tubine In tubines used in this study, blades have vaious otation angles. The otation angle fo eal tubine (downe late to ue late) is 50 degees. As a esult, in the designed tubines in this eseach we use the 50-degee blade fo the fist stage of exeient with otation. Othe tyes of blades ae designed and ade with egad to the esults of exeients. In the second tye of tubine-designing, the otation angle of blades is 110 degees. The helical fo of blades is one advantage of these tubines, causing the otation of tubine in one diection, which eans the diection of tubine otation is constant because of blades being helical and if the cuent hits the tubine in any diection, it has no effect on the diection of tubine otation. Afte designing vaious blades, they ae laced in a fixed stuctue which is the ain ile of tubine. The ain stuctue is not only sile but also designed in a way that diffeent tyes of blades ae changeable and can elace each othe. Figue 8: Diffeent designed and ade tyes of helical tubine Pactical function of device in laboatoy and wate canal The ain chaacteistic of steady cuent in canals is shown by diensionless Reynolds nube. Reynolds nube coaes the stength of inetia with viscosity and deteines the esistance against the cuent. 45

8 Biglai et al.,2015 ud Re (6) In equation 6, u is velocity; D is deth and is kinetic viscosity coefficient that is olecula viscosity to density atio. If the cuent is unde Re 2000, it is steady and the cuent 5 oe than Re 10 is coletely tubulent [1]. Now if we suose the aveage wate velocity in canal is 1/s and the canal s deth is 1 and egading that 6 2 w / s We will have Re So this wate cuent in canal is coletely tubulent. Moeove, to odel the velocity of wate in a laboatoy canal coaed with the eal velocity, we use the following equations and the laboatoy cuent velocity is given by [7]: (7) 0.5 ( ) ( inea atio of geoetic diensions between the ceated odel and the ain one ) 0.5 (8) (9) : Diensions of the ain design odel diension : inea atio of velocity between the ceated odel and the ain one : velocity of the ain design : odel velocity Fo exale, if the velocity in Chabaha Bay is 0.7/s and the odel scale is 1:8, using the above equation, the laboatoy velocity will be obtained 0.24 /s. ( ) ( ) if ( ) 0.24 / s / s The aveage of axiu velocities in Chabaha ot is aound 0.07 /s, so the odeled seed of 0.24/s is uch low to otate the tubine. This is why we cay out seveal exeients in canals with diffeent blades. Afte 46

9 J. Al. Envion. Biol. Sci., 5(1)39-48, 2015 exeienting vaious seeds and tyes of blade otation, we ut the tubine with 110 degees otation angle in a wate canal with 0.07/s seed. This tubine stated otating with 18 when the wate velocity was 0.07 /s, inceasing to 22 when we boosted the wate seed to 1 /s. The inteesting oint is not only the nube of tubine otation but also its owe enhanced so consideably that the tubines could ove the Mege electicitygeneato device and electicity was geneated. Rotating the tubine by Mege, the aount of educed to 16 which indeed caused twenty 1-watt las to tun on. Technical feasibility study of the design in Chabaha bay We can haness the enoous owe of the tide in Chabaha, to soe extent. Of couse, egading the low seed of tidal cuents with axiu aveage of 0.6 /s in Chabaha bay outh, the exectation of a colete and consideable hanessing can t be et in actice. Howeve, if we suose it s ossible to install the ceated laboatoy tubines vetically and nea each othe in Chabaha bay outh, the geneated enegy out of such a collection can be calculated as follow: In aveage and taking the exeiental esults to consideation, if the electicity outut of each tubine is about 15 Watt, ceated tubines (with laboatoy diensions) in this study should be used to obtain 15 0 KW electicity (the aveage aount of consued electicity in a anufactuing factoy); in a way that if two tubines ae ut in each ete deth of sea, in 12.5 deth, 21 tubines will be ut, and suosing the width of each tubine 0.5, 240 of bay outh sace will be taken. In othe wods, thee will be 480 coluns of tubines each having 21 tubines. As a esult, the effective aea in font of the tubines will be We conside the elations of inut and outut owe and the efficiency: 3 0.5A (10) P w P t 0.5 A 3 (11) Pt (12) Pw Whee Pt is owe in Kilowatt, is tubine efficiency (axiu efficiency fo 3 blade helical tubine has obtained 35%), is wate density, A is the effective fontal aea in 2, is the tidal cuent velocity in /s, and w is the owe of assing wate fee flow fo tansactional aea of A. The efficiency of the ceated tubine in this study (if installed in Chabaha bay) is calculated as follow: A s kg Pt W o outut 30% Indeed, accoding to the infoation we have gained fo othe southen oints of the county, thee ae uch oe suitable laces than Chabaha bay whee we can do the exeients entioned hee and benefit oe fo ceated tubines. One of these laces is Kho-e-Mousa. The tidal cuent velocity in Kho-e-Mousa is about 1.5 ties oe than that in Chabaha Bay. Conclusion 1. Coaing diffeent ethods of enegy exloitation fo tidal cuents indicated that using helical tubines is one of the effective solutions in electicity geneation. In this eseach, it has been shown actically that the designed helical tubines fo southen coasts of Ian have oe efficiency coaed with the foeign siila ones in a way that the efficiency of helical tubine ade in this study, when being tested in wate canal and installed in Chabaha Bay with the edicted diensions, is aound 33% and 30%, esectively. While the axiu efficiencies fo wate tubines in the wold have been easued just 24%. 47

10 Biglai et al., Hanessing the enegy by helical tubines is so high since it otates just in one diection unchangeably egadless to the cuent diection. 3. Using a tidal enegy fo electicity geneation in sall scale aeas which ae fa fo the cente and enegy geneation is econoic fo owe stations. 4. To otect the envionent and develo the touis industy using the tidal enegy, we can both ake the coal hills atificially and eai the endangeed hills. 5. Accoding to the iotant issue of new and enewable enegies and thei geneation, investing on constucting enegy geneating owe stations and studying its feasibility in Pesian Gulf sees essential. 6. The axiu oduction costs of 1 kilowatt hou enegy using the tide enegy is aound 1000 dollas which is lowe than that fo othe enegies like oil and gas. REFERENCES [1] ai K. and Rahani H.2012, Distibution Tidal Wave Enegy and its Alications in Coasts of Ian Jounal of Basic and Alied Scientific Reseach, [2] Pontes M.T. and Falcao A Ocean enegy convesion. Institueto nacional de engenhaia e tecnologia industial, isboa, Potugal. [3] Egbet G. D.and Ray R. D. JUNE 2000 Significant dissiation of tidal enegy in the dee ocean infeed fo satellite altiete data Macillan Jounal of td [4]Søensen and Bent,2000. Renewable Enegy Second Edition. San Diego: Acadeic Pess, 911. ISBN , [5] Andeson S. May 2006 The Tide-Enegy Poject Nea the Mouth of the Aazon Tidal Enegy Jounal [6] [7] Thoas J. G Global Coal Reef Alliance Cabidge, MA 02139, USA [8] Golov M.July 2004 Hanessing owe fo ocean cuents and tides Sea Technology Jounal [9] ahid CH. 1998, Waves Theoy Shekat-e-Tahghighat-e-Ab va Keshavazi Publishe. 48