NGHIEN cuu-TRAO DCI
Ngay nhan bai: 07/6/2017 Ngay phan bien: 17/6/2017
Tai U@u tham khao:
[1]. Xiujian Yang, Yaoping Li, Rui Qu (2011), Lateral Stability analysis ofthe Tractor-Semitrailer Vehicle in Severe Situations, Electric Information and Control Engineering (ICEICE), 2011 Intemational Conference, USA.
[2]. Nguyln Tien Diing, Vo Van Hudng, Duong Ngpc Khanh, Dam Hoang Phiic (2014); Xe chuyen dung, NXB. Giao due Viet Nam.
[3]. Bui Huynh Long; Chuyen de lai ngn giao thong du&ng bo, cdc chinh sdch gidm thiiu tai ngn giao thong du&ng bo, Trudng Cao d^ng Giao thdng V^n tai III, TP. H6 Chi Minh.
[4]. Michael Blundell and Damian Harty (2004); Multibody Systems Approach to Vehicle Dynamics, Elsevier's Science anh Technology Right Department, Oxford, UK.
[5]. Dieter Ammon (1997); Modellbildung und Systementwicklung in der Fahrzeugtechink, BG Teubner.
[6]. Dieter Schramm, Manti^ed Hiller, Roberto Bardini (2014), Vehicle Dynamic-Modeling and Simulation, Spnnger, USA.
[7]. IS014791 (2000), Road vehicles -Heavy commercial vehiclecombinations and articulated buses - Lateral stability tesi methods, Switzerland.
[8]. NguySn Tien Dung, Vo Van Hudng (2017); Xdy dung mo hinh dgng l\cc hoc nghiin cuu on dfnh hit&ngxe bdn mode khi quay vong. Tap chi Ca khi Viet Nam, s6 03 nam 2017.
[9]. Nguyen Tien Diing, Vo Van Hudng (2017); Nghien ciru ihi nghiem dgng luc hgc dodn xe so mi ra mode khi ddnh ldi hinh sin. Tap chi Giao thong Van tai, s6 thang 06 nam 2017.
[10]. TCVN 4054 (2005); Du&ng 6 lo-Yiu cdu thiel ki. Ha Npi.
ISSN 0866 - 7056
TAP CHi CO KHl VIET NAM, S6 6 nam 2017 www.cokhivietnam.vn
NGHIEN cuu-TRAO D6|
NGHIEN CO'U CHU'NG CAT NU'O'C NGOT BANG N A N G LU'O'NG MAT TROI CO CAP NHIET B 6 SUNG B A N G
COLLECTOR 6 N G NHIET 6 N G CHAN KHONG
S T U D Y O N S O L A R D I S T I L L A T I O N I N T E G R A T E D W I T H E V A C U A T E D T U B E H E A T P I P E C O L L E C T O R I N N A T U R A L M O D E
TS. Nguyen Minh Phu, ThS. Hoang Thi Nam Huong, ThS. Nguyln Thi Minh Trinh Khoa Ca khi, Trudng Dai hpc Bach Khoa, Dai hpc Qudc gia TP. Hd Chi Minh
T O M TAT
Cdc nghien cuu gdn day ve chung cdt nuac ngpt dung ndng luang mat tr&i chu dpng thu&ng tieu tdn ca ndng. Dieu ndy ldm cho he thong tieu ton them ndng lupng cdp cao (thuang Id dien ndng de chay bam hay qugt). Ngodi ra, ldm cho chi phi ddu tucao vd dp tin cdy ciia he thong thdp, phdi thuang xuyen bdo trt. Trong nghien ciru ndy, mpt bp chung cdt nuac ngot ndng luang mat trai logi chu dpng khdng dung bam duac de xudt de gidm chi phi ddu tu, van hdnh vd tdng dp tin cdy cua he thong. Bo thu ndng luang mat trai diing cdc ong nhiet cap nhiet true tiep cho bon nu&c de dgt hieu qud cao nhdt. Ngodi ra, nghien ciru dung tdm day nghieng de gidm the tich nu&c vd tang lucmg hdp thu ndng luang mat trai. Mo hinh hoa vd thuc nghiem duac tien hdnh de xdc dinh cdc thdng sd toi uu cho he thdng nhu gdc nghieng cua collector, gdc nghieng cua idnh, be ddy lap nuac, khodng cdch tir mat nu&c den tdm kinh, be ddy cdch nhiet..
Tir Idioa: Chung cdt nu&c ngpt; Ndng luang mat trai; Ong nhiet dng chdn khdng; Thuc nghiem.
ABSTRACT
Recent studies on solar distillation often consume mechanical energy. This causes the system to consume more high-level power (usually electricity to run pumps or fans). In addition it is making high investment costs and low system reliability, regular maintenance. In this study, a novel solar distillation was proposed to reduce the investment, operation and increase reliability ofthe system. Solar collector uses heat pipes in order to heat water directly to achieve the highest efficiency. Moreover, the study uses tilted absorber plate to reduce water volume and increase the amount of solar energy absorbed. Modeling and experimentation were conducted to determine optimum parameters for the system, such as collector angle, angle of inclination, glass thickness, and so on.
Keywords: Distillation, solar energy, evacuated tube heat pipe, experiment. ^
ISSN 0866 - 7056
TAP CHi CO KHi V I £ T NAM, Sd 6 nam 2017 www.cokhivietnam.vn
NGHIEN CO'U - TRAO D6\
1. GIOI THIEU
Qua cac nghien cuu cho thSy, sir dung phuang an chung cdt nudc bSng nang Iupng mat trdi kilu chu ddng cho hieu qua cao han.
Nhilu thdng sd anh hudng din hieu qua chxmg cat nhu b l day Idp nudc trong thiing, vat lieu chl tao, tdc dp gid, biic xa mat trdi, nhiet dp mdi trudng va gdc nghieng. San lugng nudc sach thu dugc dupe xac dinh bdi chenh lech nhi8t dp giua nudc trong thimg va b8 mat trong t4m kinh. Trong chung cdt nudc nggt bi dpng, birc xa mat trdi cung cSp true tiep tdi thung nudc va la ngudn nang Iugng duy nhat lam tang nhiet dp nuoc va do do nudc bdc hai dan din san lugng thdp. Day la mgt nhugc diem chinh cua chung cat nudc nggt bang nang lugng mat trdi Ioai bi ddng, de vugt qua han chl nay, nhieu bp chung cat nudc ngpt Ioai chu ddng da va dang dugc phdt trien. Trong dd, mdt ngudn nhiet nang them dugc cung cap tdi thiing nudc de tang tdc do bay hai va cai thien san lugng. Nhdm nghien cuu diem qua vai cdng trinh tigu bieu dupc cdng bo trong va ngoai nudc: Tiwari va cac cdng su (2007) da nghien cuu so sanh bd chung cat nudc ngpt loai chu dgng vol cac bg thu nang lugng mat trdi khac nhau. Ket qua chi ra rang, bg nang lugng mat trdi Ioai dng chan khdng cd dng nhiet dat san lugng cao nhat (4.24 kg/m^/
ngay). San Iugng nay cao han gap ddi so vdi loai bi dpng (2 kg/m^/ngay). Singh va cac cpng su (2013) da sir dung collector dng chan khong de cap nhiet true ti6p cho bon nudc. Tac dpng cua be day ldp nudc trong bdn din san lugng, hieu suat nang lugng va exergy dugc danh gia.
Ket qua dat dugc ciia nghien cuu cho thay, san lugng 3.8 kg/m^/ngay d b l ddy Idp nudc 30 mm. San Iugng giam khi tang be day lop nudc.
Md phdng sd bd chung cat nudc ngpt bSng nang lugng mat trdi cung dupc quan tam trong nhiing nam gan day. Rahbar va cac cdng su (2015) da md phong CFD bp chung cdt dang
dng. Cac phuang trinh ve he sd truyln nhiet ddi Iuu, san lugng nudc chung cdt da dugc xay dung. Nudc ngung tu nhieu nhdt d phia tren cua kinh phu. Hoang Van Viet va cac cdng su (2015) da nghien ciiu hai bg chung cdt nudc ngpt bang nang lugng mat trdi: Be phdng 02 cdp 01 mai ket hgp dng thiiy tinh chan khdng va dang b l p h ^ g 01 c&p 01 mai ket hgp dng thuy tinh chan khdng va bd ngung tu ngoai.
San lugng nudc chung cat cho phuang an Ala 10.75 kg/m^/ngay, phuang an B la 9.68 kg/ml Vo Kiln Qudc va cac cgng su (2016) nghien ciJni he thdng chung cat nudc nggt bang nang lupng mat trdi diing cdng nghe phun tach am.
Kit qua nghien cim chiing td tdn tai mpt ty le luu Iugng tdi uu giira nudc phun va khdng khi de he sd nang sudt la ldn nhat.
Trong nghien ciiu nay, mgt bd chung cat nudc nggt nang lugng mat trdi loai chii dgng khdng dung bam dugc de xudt de giam chi phi ddu tu, van hanh va tang dp tin cay cua he thdng. Bd thu nang lugng mat trdi dung cac dng nhiet cap nhiet true tilp cho bdn nudc de dat hipu qua cao nhdt, cac nghien ciiu ly thuyet va thuc nghidm dugc tien hanh va so sanh.
2. M 6 HINH TOAN
Hinh 1. Mo hinh chung cdl nu&c ngpt bdng ndng luang mat tr&i cd cdp nhiet bo xung
Cac md hinh toan dl tinh todn bg chung cat trong hinh 7 gom cd:
ISSN 0866 - 7056
TAP CHi CO KHi V I £ T NAM, Sd 6 nam 2017 www.cokhivietnam.vn
NGHIEN c u u - T R A O D 6 I
- Tinh cudng do biic xa ddn cac mat nghieng tii cudng dp biic xa ddn mat ngang;
- Tinh trao ddi nhiet trong bdn nudc;
- Tinh nhiet lugng hiiu ich tir collector ong nhidt;
Dli lieu thdi tilt (biic xa, nhiet dp, tdc dg gid) dimg de tinh todn cac md hinh toan tren dugc trich hi phan mem TRNSYS 16 [7] lay d dia dilm TP. Hd Chi Mmh.
2.1. Birc xa m^t troi din mat nghidng [lOj Thanh phdn tia true xa xuyen qua bdu trdi cd dp trong sang tieu chuan den be mat
U = 1353 3600 1 * 0 . 0 3 3 cos 350 — C O S ( e , ) %
Thanh phan tia khueeh tan xuyen qua bau trdi cd dp trong sang tieu chuan den be mat ngang:
ma 1*0033 mm OSlBiJ (0.271 - 02939 n )
Tdng biic xa xuyen qua bau trdi cd dp trong sang tieu chuan den be mat ngang:
Biic xa khueeh tan dugc tinh nhu sau:
Neu 0.48< - < l . l t h i :
1,11 •>- 0 . 0 3 9 6 •
Trong dd, I la biic xa den be mat ngang.
Thanh phan true xa:
Thanh phan true xa den be mat nghieng:
Ir.b Rb lb
Trong do:
c o s U - P l casji ) ci>s(a) * S i n n - p ) - s i i i ( 5 1 cos{() C05(i ) cos[a) * aii(t) sin(J )
Vdi p la goc nghieng cua be mat.
Thanh phan khulch tan den mat nghieng:
Nlu 1.1 < :
ltd = Id- 1 M l b * l d ) - p 1 Trong dd, p la he sd phan xa ciia mat dat. Lay p = 0.7.
Tdng biic xa den be mat nghieng dugc tinh nhu sau:
It iT.b -^ iT.d 2.2. B^n nudc 11-4]
Toe dp bay hai ciia nudc dugc cho bdi:
g^=h^.(T^-T,,)
San phdm thu dugc hang gid:
Sdn phdm thu dugc hang gid dugc tinh
theo phuang trinh dudi day: ^
ISSN 0866 - 7 0 5 6
TAP CHi CO KHi VIET NAM, Sd 6 nam 2017 www.cokhivietnam.vn
NGHIEN c u u - T R A O D 6 |
_A^(r„-rg,)x3600
" Z
Sdn phdm thu dupe hang ngay:
(12)
Tdng san phdm hdng ngay thu dupc dua vao phuang trinh sau:
24
Hieu suat nhiet:
- Kilu thu ddng:
'"""" 2](r(i)s^4>'3600)
-Kieu chu dpng:
2.3. Collector 6ng nhiSt
Nang luang hiru ich tren tu Collector ong nhiet duac tinh nhu sau:
Q„^A,F,[{aTlf-U,^(T^-T^)]
Trong do:
Chuang trinh tinh toan bd chung cdt nudc ngpt cap nhiet bd xung bang collector dng nhiet dng chan khdng dupe vilt dung ngdn ngii Matlab. Cac gia hi thdi tilt va kich thudc bp thu dugc nhap vdo, ban ddu gia sii nhiet dp kinh, nhigt dp nudc vd nhiet dp tdm day hdp
thu, sau do tinh lai va lap den khi hdi tu.
3. KET QUA VA THAO L U ^
Hinh 2, trinh bay anh hudng cua goc nghieng collector lugng nudc sach thu dugc.
Goc nghieng tdi uu trong dieu kien Thdnh phi Hd Chi Minh la 20°.
....
..L.l,i--i:i:i:i4.L!-.
. : . : . 1 ! . 1 : : : ! 1 ! :
Hinh 2 Luang nu&c sgch thu duac hdng ndm theo goc nghiing collector Hinh 3, the hien lupng nudc sach thu dugc hang thang cho ca hai trudng hgp, chii dgng va bi ddng. Loai chu dgng cd san lugng thu dupe cao han nhieu lan so vdi loai chii dpng. Cac thang d quy 1, cho san lugng cao nhat vi nhung thang nay khdng mua, nang tdt, trdi quang may.
Hinh 3. Lupng nu&c sgch thu duac cdc ngdy trong thdng
ISSN 0866 - 7056
TAP CHi CO KHi VIET NAM, Sd 6 nam 2017 www.cokhivietnam.vn
NGHIEN CLfU-TRAODC^I Mdt md hmh kich thudc b l mat bdc
hoi 500x500mra dupc thilt k l va chl tao. Md hinh dimg de do dat thuc nghiem cac thdng sd nham so sanh vdi ket qua phan tich ly thuylt d phan tren. Bdn nudc dugc cdp nhiet them bdi 6 collector dng nhiet 6ng chan khong. Hinh 4 trinh bay md hinh thi nghiem dugc chl tao.
r^}ymMJtJj.^i^^
Hinh 4. Mo hinh thuc li Thi nghiem voi md hinh tren cho thay hai nudc ngung tu rat nhieu, thanh cac hat to d phan dinh ciia budng kinh, tuy nhien van khdng du do nghieng de chay xudng ranh ngung tu. Hinh 5, bieu dien md hinh sau khi lam lai budng kinh mdi, gdc nghieng nhieu han (30"), de nudc ngimg de chay vao mang.
5 ••
Hinh 6. Kel qud mo phdng vdo thdng 5
Hinh 5. Tdng gdc nghiing tdm kinh ngung
2SI5 27/5 28'5 S9I5 Nfliy
Hinh 7 Kit qud thuc nghiim cdc ngdy trong thdng 5
Hinh 6, cho thay tdng lupng nudc sach la 1.108 lit. Ket qua kha trung khdp vdi do dac thuc te d hinh 7. U"ng vdi dien tich 0.5x0.5m thi lugng nudc thu dugc trong 1 ngdy la khoang I lit, vi thl ling vdi dien tich 1x1 thi cd thd thu dugc 1 ngay cd 4 lit, cd the du nudc sach cho 2 ngudi udng. Dieu nay khd hiiu ich khi cd the cdp dugc 1 lugng nudc tuang ddi nhieu dii udng cho 1 ngudi (2 lit/ngay). Tu cac ket qua md phdng va do dac thuc nghiem, ta thay sai lech khdng dang ke. Do do, md hinh todn vd chuang trinh md phdng bang MATLAB la tin cay, cd the sir dung trong cac nghien ciru khac
va tinh toan thiet ke. ' ^ ISSN 0866 - 7056
TAP CHi CO KHi V I £ T NAM, So 6 nam 2017 www.cokhivietnam.vn
NGHIEN CUU - TRAO D 6 I
4. KET LU^N
Trong nghien cuu nay, mdt bp chung cat nudc ngpt bang nang lugng mat trdi cd cap nhiet bd xung bdng collector mat tidi dng nhiet dng chan khdng dugc nghien cim Iy thuyet vd thuc nghiem. So sanh giii hai each tiep can dat dupc ket qua kha gdn nhau. Ket qud chi ra rang, lugng nudc sach thu dugc trong ngdy dat hem 4 lit ling vdi 1 m^ be mat thung nudc. Ket qua nay phii hgp vdi cac cdng bd qudc te, tuy nhien bp chung cat trong nghien cuu nay dan gian han, Ididng su dung ca nang do dd dp tin cay cao han. Ket qua thuc nghiem chimg td gdc nghieng cua kinh ngung 20° ldm nudc khd chay xudng. Do dd, chiing tdi d l xuat tang gdc nghieng Ien 30°.
Nghien ciiu dugc tai tip bdi Trudng Dai hpc Bach khoa, Dai hpc Quoc gia TP. H6 Chi Minh trong khudn khd De tai ma sd T-CK- 2016-102.*:*
Ngay nhan bai: 05/6/2017 Ngdy phan bien: 17/6/2017
Tai lieu tham Idiao:
[1]. Tiwari, G.N., et al. Comparative thermal performance evaluation of an active solar distillation system. Intemational Joumal of Energy Research, 2007. 31(15): p. 1465- 1482.
[2]. Tiwari, G.N., V. Dimri, and A. Chel, Paramettic study of an active and passive solar distillation system: Energy and exergy analysis. Desaluiation, 2009. 242(1-3): p.
1-18.
[3]. Sampathkumar, K., et dl., Active solar distillation—A detailed review. Renewable
and Sustainable Energy Reviews, 2010.
14(6): p. 1503-1526.
[4]. Singh, H.N. and G.N. Tiwari, Monthly perfonnance of passive and active solar stills for different Indian climatic conditions.
Desalination, 2004. 168: p. 145-150.
[5]. Nader Rahbar, Javad Abolfazli Esfahani, Ehsan Fotouhi-Bafghi, Estimation of convective heat transfer coefficient and water-productivity in a tubular solar still - CFD simulation and theoretical analysis, Solar Energy, Volume 113, March 2015, Pages 313-323.
[6]. Ragh Vendra Singh, Shiv Kumar, M.M.
Hasan, M. Emran Khan, G.N. Tiwari, Perfonnance of a solar still integrated with evacuated tube collector in natural mode, Desalination, Volume 318, 3 June 2013, Pages 25-33.
[7]. Solar Laboratory of Energy (USA):
Manuals of TRNSYS ver.l6, Umversity of Wisconsin-Madison, USA, 1994.
[8]. Vo Kien Quoc, Le Chi Hi$p, Nguyen Van Tuyen, Nguyen Thi Minh Trinh; Nghien cwu dnh hu&ng cua nhiet dp nu&c phun vd chink lech nhiit dp toi thiiu din he so ndng sudt cda hi thong khir muoi bdng phuang phdp phun tdch dm. Tap chi Phat trien Khoa hpc va Cong nghe, Dai hpc Qudc gia TP. H6 Chi Minh, K3,34-42 (2016) -ISBN/ISSN: 1859- 0128.
[9]. Hoang Van Vilt, Le Xuan Phong, Nguyen Thanh Diing, Trdn Xuan An, Nguyln Thl Bao; Ly thuyet tinh todn vd thifc nghm thiet bi chung cdt nu&c su dung ndng luang mat tr&i dgng Single basin kit hpp dng thuy tinh chdn khong. Tap chi Co khi Vi^t Nam, sd 6 nam 2015.
[10]. John A. Duffie and Wiliam A. Beckman, Solar engineering of thermal process, 2nd Ed, Wiley
ISSN 0866 - 7056
TAP CHI CO KHi VlfiT NAM, Sd 6 nam 2017 www.cokhivietnam,vn
