2*KH&CNN - 89*09/2009
guang tap trung bCrc xa mat trdi pliai thiit ke sao ctio khi tia birc xa mat trdi thay doi hu'dng trong ngay thi t h i l t bj (noi niu) van nhan d u a c nhiet bCrc xa.
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-^'~ IDAIUllI _ _ -
Hinh 2. Quy dao trai dat quay quanh mat trd'i Theo dac diem quy dao chuyen dong tuang ddi cua trai dat quanh mat trdi trong mpt nam nhu hinh 2 thi hudng cua tia bCfc xa mat trdi tdi be mat guang dat tai mot vi tri c6 dinh tren mat d i t luon thay doi theo gid trong ngay va tCrng ngay trong nam, tham chi co hudng ngugc nhau trong cac mua. Do vay khi tinh toan thiit ke bo thu dat c6 dinh phai xac dinh thdi gian lam viec chinh cua bo thu trong nam theo mua, vi du nhu" mua ddng hay mua he.
Trong nghien cCru nay se t h i i t k i mot gu'ang tap trung birc xa mat trdi dat tai Da Nang ma hoat dong chu y i u vao miia co nhiiu n i n g , thdi gian nay triing vdi miia Xuan va miia He (tir' 21/3 d i n 22/9) nhu' a hinh 2.
Trong tat ca cac loai gu'ang tap trung thi guang Parabol trdn xoay la t h i i t bi tap trung birc xa mat trdi tdt nhit, vdi d i i u kien hu'dng cua cac tia birc xa tdi phai song song vdi true cua Parabol tron xoay. Do vay trong mpt ngay khi hirdng mat trdi thay doi, thi gu'ang Parabol phai xoay va tam hoi tu cung bi xoay theo, nen neu l i y ca mat Parabol tron xoay lam guang tap trung birc xa thi khong phii hgp vdi viec c i p nhiet cho mpt thiit bi cd dinh. Do vay phai chon mat guang tap trung birc xa sao cho co t h i d i dang quay theo hudng mat trdi va khi gu'ang quay tam hoi tu v i n co dinh. Do dd, guang tap
trung birc xa phai la mpt phan cua mat Parabol tron xoay du'gc cat ra bai hinh tru co tiit dien ngang la dien tich hirng nang cua guang tap trung (hinh 3). Vi vay, gu'ang tap trung birc xa
thu'dng cd hinh dang ellipse.
Trai dat ludn quay xung quanh mot true di qua cyc B i c va cue X Nam, nen gu'ang tap trung birc xa
\ phai xoay quanh mpt true song song vdi true trai d i t theo hu'dng ngupc lal (6ieu nay lam mk tac dung tu quay cua trai dit). T i c do quay cua gu'ang la mot vdng mpt ngay hay noi dung han la nu'a vong trong nua ngay, vi chung ta khong sir dung nang lu'gng mat trdi vao ban dim.
D i i u nay lam cho gu'ang luon hirdng trye t i i p v i phia mat trdi. Tdc do quay khdng doi eua guang dupe d i i u khiin b i n g d i n g h i ca khi.
2.2. T h i i t k i he thdng gu'O'ng tap trung Trong nghien eiru nay se thiit k i mpt module g y a n g tap trung birc xa mat trdi cd kich thu'dc loai vij'a, thuan Igi cho viec van chuyen va l i p dat. Gu'ang dirge t h i i t k i la mpt phan cua mat parabol trdn xoay eo bien dang y = — 4 / CO dien tich hirng n i n g Fhn=5m^. Vdi yeu ciu khoang each tir guang d i n bp sinh hdi Idn (thiit bi nhan birc xa dat xa guang tap trung de
Hinh 3. Gwong tap trung birc xa la mgt phan cua Parabol tron xoay
KH&CNN - 89*09/2009*3
Hinh 4. Cach chgn mat Gwong tap trung birc xa thuan Igi eho viee sif dung va ghep noi cac module vdi nhau) 6' day ta chpn khoang each la 4m. Do vay ta ed chon bien dang mat Parabol cd f = 2000mm hay
y ••
4.2000
khoang each yeu cau ta co cac bien dang cua Parabol khac nhau). Vay guang tap trung birc xa dugc thiit k i vdi bien dang va kich thude nhu hinh 4, cd cdng s u i t trung binh la 3.000W.
Mat guang dugc e h i tao bing eae la nhdm (co do phan xa cao) gan tren khung ed bien dang nhu da thiit k i . (hinh 5).
2.3. T h i i t k i ddng hd co' kh gu'O'ng tap trung
H# t h i n g d i i u chinh gyang duge thiit k i sao cho cd the t y dpng quay he gu'ang theo hudng mat trdi vdi chu ky hoat dpng la 12 gid, ngoai ra he t h i n g hoat dgng khong c i n phai ed cac nguon nang lu'gng nhu" dien hoac khi nen. Do vay trong nghien ciru nay chung tdi thiit k i he t h i n g dieu ch?nh gyang theo kieu dong ho ca khi, nang lygng hoat dgng ciia d i n g h i d day la the nang cua qua nang hoac nang lugng dy try eua day cot
(hinh 6). He t h i n g d i i u chinh nay phai cd nang lugng du d i quay dirge he t h i n g guang V2 vdng trong thdi gian 12 gid.
He t h i n g guang tap trung birc xa cd the dinh vj theo phyang mat trdi da d y g c thiit ke, che tao va thu' nghiem thanh cdng tai khoa Cdng nghe Nhiet Dien lanh, trydng Oai hgc Bach khoa Da Nang de c i p nhiet cho he t h i n g n i u an va thiit bj san x u i t hai n y d c (hinh 7).
3. K^T LUAN
Trong m i y nam g i n day da ed n h i i u de tai va d y an nghien eiru t r i i n khai irng dung cac loai b i p n i u diing nang lygng mat trdi a Viet Nam r i t hieu qua, qua do cho t h i y nhu c i u va y thirc cua ngirdi dan ve viec sir dung nguon nang lu'gng mat trdi d i phuc vu ddi song hang- ngay la r i t cao. Tuy nhien vdi dae d i i m eua cac loai b i p trirdc day khi n i u , ngu'di dan phai ra dirng d ngoai trdi n i n g , nen r i t v i t va va bat tien. Vdi loai he t h i n g girang tap trung bire xa da nghien eiru, eho phep ngudi nau ed the thye hien d trong nha, each xa va each biet vdi nai dat guang tap trung, nen r i t thuan Igi.
U'u diem vugt trdi eua Guang tap trung birc xa la thiit k i e h i tao vdi nguyen vat lieu re t i i n , d i i u k h i l n san ed tai dja phuang nen gia thanh t h i p ed the
(tuy vao
Hinh 5. Kich thwoc mat Gwong tap trung birc xa
•f'KH&CVV • 89=^(39 2009
Hinh 6. Vi tri lam viec cua CuKmg tap trung birc xa tai Da ning vao miia he
trien <,hai irng dung rgng rai. Ngoai ra khi k i t n i i cae module vol nhau ta co the tao ra tie t h i n g nang kfgng Ion de c i p nhiet cho cac muc dich cdng nghiep nhir cac loai t>ip nau tap fte, hay thay the eho cae loai Id hoi dfit nhien lieu hda thach n h i m gop phan t i ^ kiem nang liforrg va bao ve mdi trudng.
ABSTRACT
In til is a aide, we are introduoed atx}ut the results of research on nrnmr solar concentration to foltow the sun ftsr supplying thermal energy in civl and industry.
TAI U E U THAM KHAO 1. TS. Hoang Du^ortg Hung (2007), Nang luang Mat trcri ly thuyet va Cing dung. Nha x u i t ban Khoa Hpc KTthuaL
2. John A. DufBe. WOliam A_ BedonaiL 1991. Solar Engineering of Therm^
Processes. A Wiley - Intersdencs Publication.
3. Published by Technology for LSe, Finland. 1995. Manual For Solar Box cookers.
4. Trang web:
\'.vtv/.Sca"e-Brj6cke.orq
Hinh 7. Nguyen ly hoat dpng cua dbng ho ca khi Phan bien: PGS. TS Truomg Duy Nghia
Hinh 8. He thong gwong tap trung birc xa cb cbng suit trung tiinh 3.000 W