THAM KHAO - TJM HIEU CONG NGHE SAY CA BANG NANG LlTfTNG MAT TROI Dinh Virong Himg', Nguyen Xudn Trung' I MO DAU Lam kho la mgt phuang phdp bao quan bien doi voi cac loai ca Phoi nang la cdch lam kho dugc sir dung tir xa xua den nay, co uu diem la rdt tien lgi, de dang vd re Tuy nhien, phoi ca thuong bj nhiem bui, cdt, ndm, moc va triing ruoi, bg nen khong dam bao ve sinh thuc phdm, dong thai thai tiet khong thudn lgi se bj mat phdm chdt vd mau chong hu hong Mat khdc, de phoi cdn phai co mat bang rgng Sdy dugc thuc hien bang cac thiet bi say, voi khong nong dugc tao tir cac nguon ndng lugng khac nhau, ddm bao dugc cdc yeu cau ve chdt lugng va ve sinh thuc pham, khong bi mat mat vd hu hong, giam chi phi Iao dgng, giam thoi gian, khong phu thugc vao thixi tiet Tuy vdy, phai ton chi phi cho ddu tu thiet bi say va tieu hao ndng lugng hoa thach Ngay nay, su bat on ve gia ca va su ddn can ki?t ctia nguon ndng lugng hoa thach, sdy nang lugng mat troi dang la gidi phap hdp dan va hieu qud, khong nhung lam giam chi phi sdy, bdo ve moi truang md gop phdn cai thien doi song nong ddn n NGUYEN LY HOAT DONG VA PHAN L O ^ THIET BI SAY NANG LlTONG MAT TRCJI 2.1 Nguyen ly hoat dgng H fOnh I, Scr cdu tao bd ihu nhiei mgt trdi bdng hiiu ung nhd kinh (Nguyin Cong Vdn, 2006) H Biicxamatlrdi; 1,Tim kinh dgy;! Vo cach nhi^t; 3, T^m h^p lliy; Tia v^o c6 birAc sbng ngfln, Tia nhiei co biriic s6ng d^i phat xd tfr tam hdp thii; Tia nlu?t hi phan x? I^i \k ldm hip th^i Tren the gioi da co nhiing nghien ciru phat trien cac thiet bi sdy nang Iugng mat trai noi chung vd say ca nang lugng mat troi noi rieng vai nhiSu thi6t kk khae Tuy nhien, viec ling dung chiing van dang ban chg, a thi truang dl tinh gid ban sdn phdm sdy chenh lech khong dang ke so voi san phdm phoi Trong nhung nam gdn ddy nhu cdu ca sdy cang nhieu, nen viec nghien ciiu sdy ca bdng ndng lugng mat trai cang co yeu cdu cdp thia Sau ddy xin gioi thieu mgt s6 k6t qua nghien ciru vd irng dung mgt s6 thi6t bi sdy casbawngf ndng lugng mat troi Thiet bi sdy nang Iugng mat troi dku co nguyen ly hoat dgng chung la thu ngudn nhiet mat trai bang hieu iing nhd kinh d^ cung cdp cho Iu6ng sdy vd co thk dugc tich trii mot phdn bdng cac loai vdt lieu thu nhiet Kinh CO dac tinh la eho cdc bire xa mat troi CO buoc song nho hon 0,7M.m di qua dl dang, nhung lai ngan cac biic xa thir cdp, phdt tu vat thu c6 nhiet thdp, c6 buac song lan han 0,7^tm Vai mgt hop kin nhu hinh dudi day thi nang lugng tir cdc biic xa dugc tich luy duoi tdm kinh lam nhiet tai tang len, gidng nhu mpt cdi bdy nhiet Nhiet ciia tdm hdp thu bp thu, dat tai trang thai can bang nhiet, co the dat toi khoang 130-^ ISO^C, theo ly thuydt co the dat tdi 180°C (Nguyin Cdng Vdn, 2006) D I tang dien tich thu nhiet, cd the diing tam thu nhiet dang sdng thay vi dang phang ' I S Trudng D^i hpc Nong lam D^i hgc Hok Trudng Trung hgc Giao thong v^n tai Hu4 Luong sdy di tir mdi trudng vao bg thu nhiet, cd th^ ddi luu tu nhien ho$c ddi luu 30 ^f- TAP CHi CONG NGHIEP NONG THON - SO - 2013 T H A M K H A O - T I M HIEU cuong biic, dugc tang nhiet va tiep xiic vdi vat say Vat sdy co the tiep xiic true tiep hoac khdng tiep xiic true tiep vdi dnh sdng mat trcri Ngoai ra, de keo dai thdi gian sdy tat nang cd the cd them bg phdn tieh nhiet, chdt tich nhiet thudng Id nuoc, dau nhiet, muoi ndng chay, kim loai, da cudi, 2.2 Phan loai Janjai vd Bala (2012) chia thiet bi say ndng lugng mat trdi hai loai ca ban la sdy thu dgng va sdy chu ddng Thiet bi sdy thu ddng chi sir dung ndng lugng mat trdi, bao gdm ba loai la say true tiep, sdy gidn tiep va say hdn hgp Thiet bi sdy chii ddng cd sii dung them ngudn ndng lugng khdc de bd sung nhiet cho qua trinh say hoac de van hanh quat thdi ddng sdy Fudholi vd cdng su (2010) cho rdng ve co bdn cd bdn loai thiet bi sdy ndng lugng mdt troi la sdy true liep, sdy gian tiep, sdy hon hgp va sdy lai thiet bi sdy true tiep, bg thu nhiet cung chinh la bd phan sdy, vat say tiep xiic voi anh nang mat trdi Thiet bj say gian tiep cd bg thu nhiet va bg phan say rieng, vat sdy khong tiep xiic vdi anh nang mdt trdi O thiet bi sdy hon hgp, cd bg thu nhiet rieng va bg phan sdy cung chinh la bg thu nhiet thu hai Thiet bi sdy Iai cd su dung them ngudn nhiet ho trg khac Cd Xhk chia nhd hon cdc kieu thiet bj nhu kidu til, ki^u nhd kinh, kieu dng khdi, kieu budng, kieu duong hdm, kieu khoang, Nhu vdy, thiit bi say nang lugng mat trdi gdm hai lo^i co ban la doi luu tu nhien va doi Iuu cuang biic CJ thiet bi say ddi Iuu tu nhien, ludng sdy hoat ddng thu dgng, di tir thap len cao, cd the cd ngudn nhiet khdc hd trg O thiet bi sdy ddi luu cuong biic, luong say dugc cung cdp bdng quat dien va cung cd the co ngudn nhi?t ho trg Thiet bi sdy cd ngudn nhiet ho trg ggi la sdy lai Tat ca cdc loai thiet bi sdy ndng lugng mdt trdi deu cd the tich hgp bd phan tich nhiet, nhien, cho den vi^c luu trii nhiet moi ehi phii hgp vdi thiet bi say quy md nhd III CONG NGHE SAY CA BANG NANG LU'gfNG MAT TROfI Ca bi hu hdng khd nhanh sau danh bdt vi khudn, enzim va cac phan iing hda hgc Qua trinh sdy dugc thyc hien nham ngdn chan hoac giam hoat ddng ciia vi khuan va enzim bdng cdch gidm dm ben ca Ca dugc giam dm xudng dudi 25% de giam hoat ddng ciia vi khudn, xudng duoi 15% ndm mde ngimg phat trien Cd de say co the la ca tuoi, ca hdp (luge) va ca muoi Vdi cd nhd thi de nguyen con, ca ldn thi phi le hode cat lat de sdy Mdt sd kiSu thidt bi say nang lugng mat trdi da duge nghien ciiu vd phdt trien de say cac loai cd khac 3.1 Say doi IUTI tur nhien Thidt bi say ca loai ddi luu tu nhien nhin chung cd cdu tao don gian, chi phi ddu tu vd van hanh thdp, bao tri de dang Nhugc diem id nhiet va tdc say thdp vd khd kiem soat, khdi lugng sdy it Thiet bi phii hgp cho quy md ndng hg, cd cac kieu sau: 3.1.1 Thiet bi sdy kieu leu Doe va cdng su (Janjai and Bala, 2012) thir nghiem mgt Idu say ca d Bangladesh, thiet bi bao gom mgt khung tre hinh khdi tam gidc gdn tren mat ddt, nen va mat phia Bac phii tam polythene den, mdt phia Nam dugc che bdng tdm polythene sudt de hieu qua thu nhiet cao nhdt, nhu d hinh Nhiet tdi da leu cd the dat tdi 48°C so vdi nhiet ben ngoai la 27°C Ca dugc sdy den am cdn thiet ma khdng bi nhiem tning nidi, ca phoi nang cdn ngdy va bi nhilm nang Olokor va cgng su (2009) trinh bay leu say Kainji, dugc cdi tien tir leu say Doe bang each sii dung da cudi son den thay cho tam polythene den trdn mat nen de vira thu nhiet TAP CHi CONG NGHIEP NONG THON - SO - 013 31 THAM KHAO - TIM HIEU vira trii nhiet, cac vi tri nhdn vd thoat deu dugc may vai man de ngan chan su xdm nhap cua cdn tning, khay say dugc treo liu ket cdu may cho thdy nhiet leu cao han so vdi kieu tren 3-5°C Hhtli Leu sdy cd ciia Doe (Janjai and Bala 2012) Mdt nghien ciiu so sdnh khac dugc Ojutiku vd cdng sy (2009) thyc hien vdi viee phoi ndng va say bdng leu sdy bang nang lugng mat trdi Ket qua cho thdy sdn phdm sdy cd chat lugng cao hon ve ve sinh va dinh duong so voi san phdm phoi Nhu vay, so vdi phai, thiet bj sdy kilu liu da nang cao dugc chdt lugng va ve sinh cho san pham cd kho Tuy nhien, nang sudt sdy rdt thdp, ben kem nen it cd kha ndng umg dung hieu qua thuc te 3.1.2 Thiet bf sdy kieu hpp Lawand (Janjai and Bala, 2012) dua mgt thiet hi sdy kieu hop hinh giay nhu d hinh 3, diing dl sdy ca, bao gom mdt tdm sudt (kinh, nhya) phii tren mgt hop each nhiet dugc lam tir vat lieu gid re va dl tim nhu van ep, gach, thep tdm ma kem, be tdng hoac tdm nhdm Vat sdy dugc dat tren ludi thep each day hgp vai cm Lo thdng gid ndm tren ciing va dudi Cling ciia hop Biic xa mat trdi tmyen qua tdm phu sudt vd dugc bl mat den ben hdp thu Khi nhiet ben 32 tang len, khdng nong ddi luu ty nhien di khdi cdc Id thdng gid Khong ben ngoai duge hiit vao qua day vd tao nen ddng khdng ndng ddi Iim qua vdt say Vdi thilt hi nay, nhiet khdng ben vd mdi trudng cd thi chenh lech den khoang 40°C Hinh Thiet bi sdy kieu hop hinh gidy (Janjai and Bala 2012) Mgt cdi tien cua thiet bi sdy hop hinh giay la thiet bi say di ddng (tren banh xe) ed nhilu tdng khay, vdi me sdy quy md nhd va vira, dugc phat triln ij Philippines (Janjai and Bala, 2012) Thiet bi cd hinh dang tuang ty nhung ldn hon va cd nhilu tdng sdy, bao gdm mdt khung go dang hop hinh thang (rgng 1,2 m x dai 2,4 m x cao 1,2 m) voi mdi va la cac tam polyacetate sudt Cd thi nap hoJic da timg khay Khong mdi trudng doi luu ty nhien qua ciia ehdp dieu chinh a phan dudi mat trudc va di ngoai qua Id thoat d phan tren mdt sau Nang sudt say khoang 100 kg Bd phdn tdng nhiet don gian la mdt bg thu phang bang go nap nhua sudt cd tdm thu nhiet bang tdn ma kem son den Ngudn nhiet hd trg la mpt Id ddt sinh khdi de co the sdy vao ban dem Ket cau thilt bi nhu hinh So vdi liu sdy, thilt bi sdy kilu hdp co ndng sudt say cao han, thich hgp vdi sdy tap trung quy mo vira, chenh lech nhiet khdng say va moi trudng cung cao hon hdn, dg TAP CHi CONG NGHIEP NONG THON - SO - 2013 THAM KHAO - TIM HIEU ben cao han Viec ldp them bd phdn tang nhiet va ngudn nhiet ho trg rat thuan lgi cho nang yeu va cho viec say vao ban dem ty nhien phii hgp vdi quy md nhd tai vimg ven bien Sri Lanka, gdm hai loai la co djnh va di ddng Thiet bi say cd dinh, nhu d hinh 6, la mgt khung gd, phu tdm polythene sudt co kich thuoc dai 7,7 m x rgng 4,7 m x cao 3,9 (tinh den ndc), lap dat cd dinh tren nen xi radng vdi tuong gach cao 0,8 m Tudng gach dugc son den de tang cudng thu nhiet, gia say dat ngang vdi tudng Cac tdm thu nhiet bdng tdm kim loai dang lugn sdng son den dugc lap dudi phdn mai, hgp vdi eac bSn tao thdnh budng Hinh Thiit bi sdy co nhieu ldng khay vdi ngudn nhiil say Khdng ddi luu ty nhi6n qua hai dng hd trg (Janjai and Bala 2012) thoat hinh tru trdn cd ldp qud cdu hiit nhiet, ben ngoai dng dugc son den de tang kha nang ddi 3.1.3 Thiet bi sdy icieu nha kinh luu Thiet bi cd nang sudt 100 kg/me Thilt Mdt thiet bi say ca ndng lugng mat trdi bi sdy di ddng la mgt khung kim loai, xep lai kieu nha kinh dugc Mukherjee va cgng su dugc, phii tdm polythene sudt, dat tren (Janjai and Bala, 2012) thiet ke va xay dung tai nen be tdng Kich thudc thiet bj la dai 3,8 m x Vien Cdng ngh| An Do (IIT), Kharagpur, An rgng 3,2 m x cao 2,0 m, ben ddt bdn gia sly Do Kich thudc ciia thiet bi sdy la dai 5,0 m x bang gd cd bay tdng khay cdng ludi nhya Nang rdng 3,0 m x cao 2,05 m, nhu d hinh Thilt bi suat la 50 kg/me sdy dugc thu nghiem tai mgt cdng cd ven bien Ket qud cho thdy nhiet ben chenh lech tir 18-24°C so vdi mdi trudng, 56 kg ca cac loai dugc sdy kho vdng 2-3 de ldm gidm am tir khoang 75% xudng khoang 15% Thiet bi say duge ket luan la phu hgp vdi quy md gia dinh o vanh dai ven bien Htnh Thiet hj sdy cd kieu nhd kinh lai Kharagpur, An Dg (Janjai and Bala, 2012) Td chirc Practical Action (2006) da xdy dyng cdc thiet bi sdy ca kieu nha kinh doi luu Hinh Thiel bi sdy cd kieu nhd kinh c6 dfnh (a) vd di dpng (b) lai Sri Lanka (Practical Action, 2006) TAP CHi CONG NGHIEP NONG THON - SO - 2013 33 THAM KHAO - TIM HIEU Nhu vdy, cd the thdy thiet bi say kieu nhd kinh ddi luu tu nhien cd uu diem la khdi lugng say Ion so vdi sdy leu va say hop, tir 50 - 300 kg/me Tuy vay, tdc sdy thdp han d sdy hop va tuong ty sdy leu Cac thiet bi loai chu yeu de dam bao ve sinh cho san pham say, nhung d cac thi trudng dl tinh san phdm sdy se cd gia thdnh khdng khdc voi san phdm phoi Do dd, viec ling dung se gap khd khan 3.1.4 Thiet bi sdy kieu budng Chavan va cdng su (2008) nghien ciru qua trinh sdy ca bac ma (Rastrilliger kangurta) bdng thiet bj sdy lai ddi luu ty nhien cua Vien Cdng nghe Chdu A (AIT), nhu d hinh Thilt bi cd budng sdy duge xdy dyng bang gach va vu'a, mdt Id ddt sinh khdi dugc thiet ke ddc biet de d ben ngoai voi bg phdn trao ddi nhiet kieu dng dat ben va phia dudi budng sdy, mdt bp thu phang Idp kinh sudt dl thu ndng lugng mdt trdi Mpt bd phdn kilm soat nhiet tu dgng kieu co - nhiet dam bao tri nhiet buIng sdy khodng 55-60''C Khi sdy, khdng ben ngoai doi luu tu nhien qua bg thu nhiet, vdo budng sdy vd di ngodi Vao ban dem hode troi ndng ylu Id ddt sinh khdi dugc sii dung Kit qua eho thdy thdi gian sdy cd la 24 gid, phoi la 44 gid tir dg dm 74% xudng 17% Cdc phan tich sinh hda, vi sinh vdt vd cdm quan cho thdy san phdm sdy dat chdt lugng cao hon dang ke so vdi sdn phdm phoi, dac biet la lugng vi khudn va ndm mdc -^ Hinh Thiil bl sdy lai kiiu buong cda AIT (Kumar and Bhatlacharya 2005) Tdm lai, cd the cho rang ea sdy true tilp ddi luu ty nhien bdng ndng lugng mat trdi cd chdt lugng tuong ty san pham phoi, sdy gian tiep vdi ngudn nhiet hd trg cd chdt lugng cao hon dang ke Viec tiep xiic tryc tiep voi anh nang mdt trdi cd the gdy anh hudng tieu cue den su thay ddi sinh hda ben cd, ddng thoi, tdc say thdp cung cd the gdp phan tieu cyc dang ke 3.2 Say doi luu cu'dng hire Sy han che ve tdc vd nang sudt sdy cua cac thiet bi sdy ddi Iim tu nhien dan din ddi hdi phai cd su nghien ciiu phat triln cac thilt bi sdy doi luu cudng biic Ddng khong doi luu cudng hire bdng quat dien, ngudn di$n cung cdp cd the la dien ludi, dien mat trdi hoac tir may phat dien Ddng thoi, cdn cd bd phan dilu khiln de tri nhiet gidi ban cho phep Cac loai thiet bi sdy ddi Iuu cuang biic cd thd dugc ling dung eho quy md tieu cdng nghiep vdi san pham say cd chdt lugng Thiet bi sdy ea bang nang lugng mat trdi ddi luu cudng bire bao gdm cac loai sau; 3.2.1 Thiet bi sdy kieu nhd kinh Thiet bi bao gdm mdt cdu tnic dang khung cao 1,98 m - 2,73 m dat tren san be tdng son den 3,27 m^, toan bd duge phii tdm nhya chdng tia tli ngoai sudt day 1,5 mm vdi he so truyin qua 70% Cd hai quat 80W dugc lip phia tren cira de doi luu cuong biic ddng say Trong vdng gio, 65 kg ca nhd dugc sdy khd vdi nhiet sdy 51°C Cdu tao thilt bi nhu d hinh Hinh Sa cdu tgo thiit bi sdy ddi luu cudng buc kieu nhd kinh (Janjai and Bala 2012) BO phan thu nhifl m ^ troi, BQ phjln trao ddi nhi^i; Bdn diiira mr6c nong d^ irCt n h i ^ , Hai qu?t hut; S BO ph^in cdm iing chSnh isch TAP CHI CONG NGHIEP NONG THON - • 2013 THAM KHAO - TIM HIEU 3.2.2 Thiel bi sdy kieu dudrng hdm Thiet bi say nang lugng mat trai kieu dudtig ham Muhlbauer vd cdng sy (Janjai and.Bala, 2012) nghien ciiu phat trien tai Dai hpc Hohenheim, Diic, tir thdp nien tam muoi cjia the ky XX va da dugc iing dung cdng d 35 qudc gia cho san xudt quy md nhd, san phdm say la cac loai trai cay, rau, gia vi, cd, thit Thiet bi cd cau tao nhu hinh 9, budng sdy va bp thu nhiet cd dang nhu mot dudng hdm dugc phii bang tdm nhua sudt, mat ddy son den, phia dudi each nhiet bang tdm sgi thiiy tinh, vdt sdy dugc ddt tren mat ludi nhya buong say De thoat nuoc tdt trdi mua, phan mai eiia dudng ham dugc lap cd djnh va nghieng ve hai ben theo chieu dgc Hai quat hiit, dugc cdp dien bang mpt md dun pin mat trdi 40W, ddi luu cuong biic ludng sdy Todn bd thiet bi dugc ddt tren mdt khung dd kim loai va cd kieh thuoc dai 20 m, rdng m Cd the ndi ddy la loai thiet bi sdy nang lugng mat trdi ddi luu cuang biic dugc sii dung phd bien cho sdy ca Hiith Cdu tgo thiet bj sdy Hohenheim (Janjai and Bala 2012) W va cd the sdy khd tdi da 150 kg cd mdt me Nhiet khdng tai bg thu nhiet dao dpng tir 35,1°C din 52,2°C qua trinh say Cd dugc udp mudi vd xep chdng Ien khoang 16 gid, sau dd nia sach rdi xep thdnh ldp mdng de say, dp dm ban dau la 67 % Qua trinh sdy cho thdy nhiet khdng ben tang dgc theo chieu dai bp thu nhiet va gan nhu khdng ddi sudt chieu ddi budng say, vdy, dm ca sau say khdng cd su chenh lech theo chieu ddi thiet bi sdy Sau ngdy vdi thdi gian say hang tir gid den 16 gid, ca say dat dp dm 16,78 % so vdi 32,84 % d ca phai Viee phdn tich sinh hda cho thay ca say cd chat lugng va ve sinh thuc phdm cao han cd phoi Reza vd cdng sy (2009) nghien ciiu tdi uu hda qua trinh sdy ca bang thiet bi sdy Hohenheim vdi nhieu loai ca d Trung Hoa vd vinh Bengal, Do dm cac mau ca dat 16% sau 36 va 32 gid sdy vdi nhiet sdy tuong iing la 45 50°C va 50 -55°C San phdm sdy khoang nhiet 45 - 50°C dugc danh gia Id tdt ve mdu sac, huong vi va ket cdu Thiet bi sdy kieu dudng ham vdi cac md dun pin mat trdi da chiing td nhieu uu diem va cd khd nang iing dung cao cho say ca Tuy vdy, hoan toan phu thugc vdo ndng lugng mat trdi nen se gap khd khan cdn sdy lien tuc vao ban dem va trdi ndng yeu 3.2.3 Thiet bi sdy kieu budng Serafica va del Mundo (2003) thiet ke vd danh gia hieu qud mdt thiet bi say cd bang nang lugng mat trdi doi luu cudng biic kieu budng, cd ngudn nhiet sinh khdi vdi bg thu nhiet dang hop kim loai nhu d hinh 10 Day la thilt bi sdy Iai vdi nang sudt 20-70 kg/me I Khong vao; Quat hut; Mo dun pin m^t Iriii, BO thu nlii?t M9t ban: Diu ciia bO thu nhi^l: Thanh d» bang g5; Mai Iir6i nhva Khung phu i4m nhira su6t 10 Khung dd 11 Thanh cuOn 12 D&a ctia thidt b | say Bala va Mondol {2001) da tien hdnh nghien Cliu thyc nghi?m say cd dii bac bang thiet bj sdy Hohenheim, tai Bangladesh Thiel bi cd bdn quat hiit cdp dien tir hai md dun pin mat troi 40 fip thu nhiqt Buong sdy Lo dot sinh Ichoi Hinfi 10 Cac bo phan cua thiet bi say lai kieu buong (Serafica and del Mundo 2003) TAP CHi CONG NGHIEP NONG THON - SO - 2013 35 T H A M KHAO - T I M HIEU Thiet bi gdm bdn phdn chinh la bd thu nhiet hop kim loai, Id dot smh khdi, bd phan trao ddi nhiet va budng sdy Bg thu nhiet hinh hop chii nhdt, dai 2,44 m x rgng 1,27 m x cao 0,10 m, dugc lam tir thep ma kem day 0,91 mm, son den Mat dudi bd thu nhiet la mdt tdm nhdm day 0,81 mm, due Id dudng kinh 1,6 mm va cheo hang 14,5 mm, khdng ben ngoai di vao theo cac lo Budng say dai 1,83 m va rdng 0,8 m dugc Jam bang thep tam ma kem day 0,91 mm, cd sau khay sdy dat lam ba tdng vdi tdng di?n tieh la 4,4 m Khdng dugc hiit vao bg thu nhiet, di qua vd bd trao ddi nhiet va vao budng say nhd mdt quat hiit 12 V chay bang pin mdt trdi, mdt quat hiit khdc dugc lap tren Id thodt tren ddu budng sdy Bp trao ddi nhiet ciia 16 ddt dat phia dudi budng sdy Id ddt sinh khdi sir dung dam gd va vd dira Nhu vdy, mdi ngudn nang lupng cd the dugc sii dung ddc lap hoEic ket hgp vdi Ket qua thi nghiem cho th^y vdi 20 kg ca da qua so ch^ cd dm 75.5 %, can 2,5 de sdy xudng dg dm 18,1 % Khodng 30 % am mat di la bdng nang lugng mdt trdi, phdn cdn lai ngudn nhiet sinh khdi d thiet bi nay, ngudn nhiet chinh la tir Id dot sinh khdi, nang lugng mat trdi chi ddng vai trd ho trg va gdp phdn giam chi phi ndng Iugng Bg thu nhiet khdng kinh cd hieu suat thu nhi?t thdp han nhung cung cd gia thdp han bd thu nhiet bdng hieu iing nha kinh (Serafica and del Mundo, 2003) 3.3 Thiet bi say ea bang nang Iwong mat trdi ff Vift Nam O Viet Nam, den da cd mdt sd thilt bi sdy bang ndng lugng mat trdi cho cae loai ndng san vd hai sdn dugc nghien ciiu phdt triln Ndm 1996, Vien Co dien Ndng nghiep va chl biln ndng san phat trien thilt bi sdy SD-25 cho cac loai rau, cu, trai cay va ca vdi nang sudt 18 kg/me (Janjai and Bala, 2012) Thilt bi bao gdm hai phdn chinh la budng sdy ldp ndi vdi dng khdng ndng vd bd thu Bd thu dugc phu kinh day 1-2 mm, dien tich 2,4 m^ Budng sdy 36 cd the tich 1,00 m , lam bang kim loai va dugc each nhiet Thiet bi cd the ddi luu tu nhien ho|ic ddi luu cudng biic bdng mgt quat 40W Nhiet khdng say dat 35-50°C so vdi nhiet dp 20-35°C ciia mdi trudng Thiet bi say cd thi lam bdng vat lieu sdn cd va re tien, phii hgp vdi vimg xa, hdi ddo Ndm 2000, Vien da nghien cvru thilt kl vd lap dat thiet bi sdy hai sdn bang nang lugng mat trdi nang sudt tdn/me tai huyen dao Cd Td, tinh Quang Ninh Ddy la thilt bj sdy ddi luu cudng biic kieu budng vdi bg thu nhiet 50 m^ Thiet bi say cdn cd may phat O3, bd phdn diSu khiln ty ddng Iam viec cua quat dao, quat hiit vd he thdng dng hdi luu mdt phdn thai Sdn phdm sau say cd chdt lugng tdt hon phoi ndng vd sdy bang than ciii V KET LUAN Nhin chung, thiet bi sdy ca nang lugng mat trdi la chgn lya hieu qua nham muc dich: - Ndng cao chat lugng san pham so vdi phoi ndng; - Tiet kiem chi phi nang lugng so vdi say bang ndng lugng hda thach Cdc thiet bi cd cau tao don gian, re tien thi hieu sudt va nang suat thdp, tudi thg thdp, nhung chdt lugng sdn phdm tdt hon phoi nang Cac thiet bi cd hieu suat vd ndng sudt cao thi che t^o dat tien hon, tudi thg cao hon, chdt lugng sdn pham tdt hon Thiet bi say kieu leu, kieu hop chi thich hgp vdi quy md gia dinh Thiet bi say ddi ltru cudng biie kieu nha kinh, kieu dudng ham va say lai kieu budng cd the phii hgp vdi quy mo thuang mai Vdi thiet bi sdy lai kieu budng, de tang quy mo say can cd ngudn didn ludi de v ^ hanh quat va ddm bao ngudn nhiet mat trdi bdng each tang dien tieh ciing nhu hieu sudt bp thu nhiet Mat khac, thilt bi sdy lai cd khd ndng hoat dgng lien tuc nen se nit ngdn thdi gian thu hdi vdn cung nhu giam gia san pham say • TAP CHi CONG NGHlf P NONG THON - SO - 2013