KHOA HOC CONG NGHE
MO PHDIVG BO THU IVAlVG LUOIMG IVIAT TR01 KIEU PHOI HOP SdlMG CHU V VA P H A I V G TROIMG T H | £ T B !
S A Y C A C O M S U OUIMG IMAIMG LUOIMG MAT TROI
Nguyen Xuin TrungS Dinh Vuong Hung^, Trin Nhu Khuydn^
Nguyin Thanh Hai^ Ngd Qudc Hung^, TVln Nhu Khlnh^
T6MTAT
Bai bao nay trinh b^y k^t qua mo phong va thuc nghiem bo liiu nang lugng m§t trdi ki^u phoi hop song chir V vk pblog trong thiet bi say ca com sd dung nang luong mat trtn. Trong bO thu, ding kh6ng khi di theo hinh chu U qua c ^ phan tbu c6 tam thu nhiet phang va tam thu nhi?t song chir V. Phfc thu pbang viea d6ng vat trd thu nhiet vua la k^nh dan dd ddi chidu dong kbi. G phan thu song chir V, d6ng khi ti^p xiic song song ca mat trgn va mat diroi t ^ thu dd tang kha nang nhan nhiet Vi^c mo phdng duoc thuc bien bang mo binh toan hoc va phin mdm Matlab. Kdt qua m6 phong dtroc so sanh vol ket qui thi nghiem trong mot ngay dau mua he. Nhiet d6 ddng IchSng khi ra khoi b6 thu theo mo phong dat cao nhit M 328,9 K, thuc td dat 327,5 K so voi nhiet d6 m6i trudng la 307,2 K, hieu suat mo phong cua bo thu diit cao nh& 54,4% so voi hieu suat thuc td cao nhat dat 50,8%.
Tit^6a: Mo phdng, bd thu nang Immg mat trdi, phdi hop, song chd V,s^y.
Thidt hi say ca com su dung nang lugng mat trdi dupe thiet ke va che tao tai bd mdn Thidt bi bao quan va Che bien ndng sin - Khoa Co didn-Hoe vien Nong nghidp Vidt Nam. Trong thidt bi say c l com, ^d thu nang lupng mat trdi (bp tfiu nhiet mat trdi hay bd thu) cd chiic nang chuydn biic xa mat trdi thanh nhiet nang de cung d p cho qua trinh sly. Trong b6 thu nang lupng mat trdi, tam thu nhi^t dupe lim bang v | t U&u CO hd so hap thu cao biie xa mat trdi v l cd Idp phu den md vdi t i c nhan say II kh6ng khi.
Hi&n nay, tam thu nhidt dugc su dung phd bien cd dang tam phang. Tam fliu lihidt phing cd mi didm clu tao dan gian, dd thay thd v l bao tri v l siia chira nhimg cd nhugc didm II hieu suit thu nhi&t thap do dien tich hap thu nhiet nhd. Bi: nang cao hidu suit nhiet eua bd thu theo nguydn tac tang didn tich hap thu nhidt, cd nhieu kidu tim thu nhidt khac nhau da dupe nghidn cuu, bao gdm: tam thu nhiet kieu sdng chii V, kidu tam cd canh v l kidu tim ludi can, trong do tam thu nhidt sdng chu VII mot lua chon phu hpp do cd hieu suit nhidt cao ban tam thu nhidt phlng, tim thu cd cinh vl it tdn bao cdng suit eho quat hon so vdi tim thu ludi can (Karim v l Hawlader, 2004) .Tuy nhi^n, tam tiiu nhi^t kidu sdng chu V cd
' Tnrong Cao dang, Giao thong HuS
^Trucmg Dgi hoc Nong Mm- Dai hoc Hu^
^ Hgc vien Nong nghiSp Vigt Nam
nhupc didm 11 phan kenh din ddi hudng chuydn ddng cua ddng khi (khi cin lip ghep nhidu bd thu nhiet vdi nhau) thudng nam ngoai b6 thu nhiet nen chua tan dung tri$t de dien tich hip thu nang lupng mat trdi. Vi vay, vide nghidn euu bg thu nhiet phdi hpp tam phlng v l sdng chii V vdi tim phlng duge lip dat tai kenh dan ddi hudng chuyen ddng cua ddng khi II giai phip tich cue de nang cao hidu suit nhiet cua bd thu nhiet
Bai bao nly trinh biy kdt qua md phdng bd thu nang lupng mat trdi kidu phdi hgp sdng chu V v l phang lam ca so dd thidt ke, che tao bd thu nhiet trong thidt hi say e l com su dung nang lupng mat trdi.
2. BM TUDIK Vli nWDNG PHAP NGHBII Cliu 2.1. Ddi tupng nghidn cihi
Bp thu nang luong mat trdi kidu phdi hgp sdng chii V vl phang (k^ hieu BT-1,0) duge thiet ke v l chd tao tai bd mdn Thidt bi bao quan v l Chd bidn ndng san, Khoa Co dien, Hpc vien Ndng nghidp Viet Nam.
Bd thu cd dang hmh hop chu: nhit, kich thudc bao ngoii II 3,0 m X 1,0 m X 0,18 m, vd lim bang thep khdng ri diy 1 mm, eJK;h nhidt bang xdp PE - GPP tring nhdm diy 10 mm (hinh 1). Tim tiiu nhiet sdng chii V lam bang nhdm II diy 0,5 mm, son mlu den dupe lip d ben trong bd thu nhidt sao cho khi lam vide ddng khi di d ca tren v l dudi tim tiiu nhiet. Dd ning cao nhiet dp dau ra eda ddng khi, phan thu
NONG NGHIEP VA PHAT TRIEN N 6 N G T H 6 N - KY 2 - THANG 12/2015 43
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KHOA HOC CdNG NGHE
sdng chii V dupe chia lim hai ngan ddi xung vdi nhau qua vich ngSn tao nen hai kenh dan song song, khi dd ddng khi di trong bd thu nhiet phai ddi hudng theo kenh din khi d hai dau bg thu nhiet De tang k h i nang hap thu nhiet tai kenh din khi d hai diu bd thu cd lap tim thu nhiet dang phang. Cua ddng khi vao vl ra cd ban sin cic mat bich dd dd dang ndi ghep cic bg thu nhiet vdi nhau khi can thidt.
Hinh 1. Clu t?io bd thu nang lupng mit ti-di kidu hdn hpp phlng vk sdng chft V I Tam thuphing. 2 Tam thu chd V. 3 Vach ngan. 4. Mat kinh. 5. Vo. Vat lidu cich nhidt
2.2. Phuong phip nghien ohi
- Thidt lap mang nhiet dd mo phdng va tinh toin qua binh tiiiydn nhidt ti-ong bd thu nhiet tirong hi nhu mang dien. Qua hinh huydn nhiet giua cic vat dupe coi nhu qua trinh din dien trong mot mang dien. Tdn thIt nhidt trong qui tiinh trao ddi nhiet d elc didm mit dupe tinh tuong tu nhu tdn that dien gay ra bdi dien txb, dugc goi la "nhiet trd".
- Sii dung phuong phap ma tran de giai he phirong trinh can bang nang lupng vdi cac bude lap cin thiet de dam bao dd chinh xac cho phdp. Diu tien, nhiet dd gil dinh dupe dimg de tinh toin ra nhiet dd mdi.
Nhung gia hi nhiet do mdi dupe so sinh vdi nhiet do gia dinh, ndu chenh lenh hon 0,01''C thi gia dmh lai va tidp tuc tinh toin cho den khi chenh lech nhd hon 0,01"C. Ddn luc dd nhiet do tinh toin dupe coi la nhiet do ti-ung binh cua mdi thinh phin bp thu.
- Su dung phan mdm Maflab de md phdng va so sanh voi ket qua thuc nghiem h-en md hinh thuc.
Nhiet dd vl tdc dp khong khi d mo hinh thuc dupe do bang mIy do cim tay Smartsensor AR836 vl buc xa mat ti-di dupe do bing may do Tenmars TM-206.
Theo ket qua tinh toan sa bg thiet bi say ca com su dung nang lupng mat h-oi, yeu clu: nhiet dp khong khi dua vio budng sly tdi da 11 50°C (313 K), lupng khong khi can thidt cho qui tiinh sly 0,4-0,5 kg/s va thdi gian sly 8-10 gid/me.
3.KErqUAVilTHA0LUAN
3.1. Md hinh hda va md phdng bd thu nhidt - 3.1.1. Mang nhidt
Tu hinh 1 cd the coi bd thu nhiet mat trdi gom nam phan thu ndi tiep nhau, nhidt dd diu ra cua phin nay II dau vao cua phan Ida. Mang nhidt eua cac phin thu phlng va sdng chu V cua mot kenh din khi trong bd thu dupe trinh bay trong hinh 2 v l 3. De mo hinh hda va md phdng, cic gia thidt cin duge dat ra II:
- Nhiet do cua ddng khi thay ddi tuydn tinh theo chieu dii ddng chay;
- Nhiet dd cic be mat ximg quanh ddng khi \i ddng n h i t
- Bd qua tdn that nhidt qua cac mat ben cua bp thu;
- Su chenh lech nhiet dp giua hai bd mat cua tara kinh, tam hip thu II khdng ding ke;
- Tdn that nhiet qua mat diy la do truyen nhiet qua tam cich nhiet va gid, buc xa nhiet cua tam each nhiet II khdng dang kd.
3.1.2. Cic phuong trinh can bdng nang luong a. Phuong trinh cin bang nang lu^/ng cua thi thuphing
- Phuong tiinh can bang nang luong cua tam kinh phu:
Si+h^,a,-Ti)-HhiCrfi-Ti) = UTcri-Tj (i)
Vdi buc xa mat ti-di len tim kmh phii duoe tinh bang: Sj = a^ (2)
- Phuong trinh can bing nSng lupng cua ddng khi d kenh tren:
haCr2-Tfl)=hi(Tfi-TJ-HQj(3) Tfi Ts
Dong]—•
Ta
a) b) Hmh 2. Sa dd tinh toin md phdng (a) vl nuing nhidt
ctia phin thu phSng (b)
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KHOA HOC CdNG HeHE
^hi bj T n — .
Hinh 3. Sa dd tinh toin md phdng (a) v l m^ng nhidt djiaphln Ihu sdng chfi V (b) - Phuong trinh can bang nang lupng ciia tam thu nhi^t phlng:
S2 = h2a2-Tfl)+h^,Cr3-Ti)+UbCr2-T^ (4) Vdi hue xa mat trdi m l tim hap tiiu nhan dupe tinh bing: S2 = T;OC2I (5)
b. Phuong trinh can bang nMng luong cua /ism thu chd V
- Phuong trinh cin bang nang lupng ciia tam thu nhidt sdng chu V:
S2 = haCTs - T ^ + hatTg - Tfj) + h^^O^^ - T3) + h^ia2-T,)(6)
- Phuong trinh can bang nang lupng cua ddng khi d kenh dudi, phin b6 thu sdng chii V:
h a a a - T e ) ^ h ^ a e - T a ) •^Q2(7)
- Phuong trinh can bang nang luong cua mat diy, phin bp thu sdng chu V
h,(Tiz-T0 -Hh^a2-T3) = U ^ a a - T ^ (8) I - Biic X9 mat trdi (W/m^;
hi, hi, hg, hi - Cic he sd huydn nhiet ddi luu, (W/mllO;
hr2i - Hd sd truydn nhiet btrc xa td- tim thu nhiet den tam kinh (W/m^.IO;
hr2j -He sd truydn nhiet biic xa tu tam thu nhiet ddntlmdly(W/m2.K);
Si vl 83 - Biic xa mat trdi do tim kinh hap thu va do tam hap thy hip thu dupe (W/m^;
Ta - Nhiet dp khdng khi mdi trudng (K);
Ti, Tg, T3 - Nhiet dd tiung binh cua bd mat tim k i n h , t ^ hap thu, tim diy (K);
Tfi, TG - Nhidt dd tnmg binh ddng khong khi b kdnh h-dn vl kenh dudi (K);
TS - Nhiet dd blu ti-di, % = 0,0552Tf (K);
Qi, Q2 - Nhidt lugng ma ddng khi d kdnh tren vl dudi nh$n duoc (W/m^;
Ub, Uj - He sd thIt tholt nhidt cua mat day, mat kinh (W/mMg;
tti, 0:2 - Hd sd hap thu cua tim kinh, tim hip thu;
T - Hd sd truyen qua ciia tim kinh.
3.1.3 Cdc he sd truydn nhidt - Tai mit Ti, vdi phan thu phlng
Hd sd truyen nhiet ddi luu do gid tren be mat tim kinh dupe tmh theo cdng thiic McAdams (1954), vdi VII v^n tdc gid:
h^ = 5,7 + 3,8v (9)
Hd sd truyen nhiet biic x^ giira tim kinh va blu trdi quy vd nhiet dd mdi trudng ed thd vidt II (Karim etal., 2013):
h „ = O E , ( T , - . T , ) ( T , ^ - . T ; ^ ) f c ^ ( 1 0 ) Khi cae he sd truydn nhiet h^ vl h,^ da cd, he sd tdn thIt nhiet mat tren tam kinh dupe tinh la:
UT = h,-Hh^(ll)
He so truyen nhiet biic x^ giiia tara kinh phii vl tim hap thu diroe tinh bang:
He so truyen nhiet ddi luu giiia ddng khi vl tam kinh phu dupe xac dinh bing phuong trinh do Hollands vIShewen (199i):
h , = N u , , ^ ( 1 3 )
Trong dd, dudng kinh thuy luc cua ddng khi Dh dugc tinh nhu sau:
D , = - 5 ^ (14) ' H+W
H - Khoang each tir tam kinh d^n tam thu nhi^t ph4ng (m).
Sd Nusselt duoc iroc tinh theo Kays va Crawford (1980):
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 12/2015 45
KHOA HOC CdNG N G H £
Nui2 = 0,0158Re''-*' (15)
Trong dd. Re II sd Reynolds vl dupe tinh theo cdng thiic:
Re = 2 p v , ^ ( 1 6 )
p - Trgng lugng rieng cua khdng khi (kg/m^;
|i - Dd nhdt ddng luc cua khong khi (kg/m.s).
Ddi vdi nhiet do (T) ciia ddng khdng khi nam trong khoang 280 -e- 470 K, elc mdi tirong quan thue nghiem sau diy cd thd dupe su dung tinh toan (Weast 1970):
p 3,9147 0,016082T + 2,9013.10^^
1,9407.10«T^(17)
k= (0,0015215+ 0,097459T-3,3322.ia^.l0^(18)
\i = (1,6157 + 0,06523T- 3,0297.10-^^.10^ (19) - Tai nilt Ti, vdi phan thu sdng chii V He so truydn nhidt giiia tim kinh vl ddng khi d kenh tren dugc xic dinh theo phuong trinh (13).
Nhung vdi tam hip thu sdng chii V dien tich thu nhiet Idn ban b tam phlng nen hd sd truyen nhiet hidugc tinh nhu sau, vdi Oil gdc chii V (Karim et al., 2013):
Ndu 2800
-hi
n -1UJJ
(20)
Trong do, duong Idnh thuy lire ciia dong Idii D^
dupe tinh theo cong thiic:
= H + -H. (21)
He - Khoang each tir dinh song chir V den mat kinh (m).
Gia tri sd Nusselt phtr thu6c v^o dong khi trong kenh dan. truoc tien cin tinh sd Reynolds dd xac dinh sd Nusselt. Sd Reynolds dupe tinh theo cdng thirc (Hollands vaShewen, 1991):
Re = p V , 5 t (22) 11
Nfa Re< 2800 thi Nu = 2.821+0,126 R e - i (23) L.
Re Nu,, = 1,9.10' R e ' " + 2 2 5 - i (24) H .
L , Ndu 10<< Re <
10* thi
10=
Nu,; = 0,0302Re°'*+ 0 , 2 4 2 R e " —5- (25) - Tai mit Tn, voi ca hai phan thu
Hd sd truyen nhidt ddi liru giira ddng khi voi tam hap thu gia dinh la bling voi he sd truyen nhidt ddi luu giiia tam kinh va ddng khi h2= hj. Lupng nhidt ma ddng khi nhgn dupe a phan thu phSng va chir V la;
(T„-T.) Q, =2mC,.^
v 4 Q , =2mC WL,
(T,i-T.)
WL, (26)
W- chidu rdng kdnh din khi ciia bd thu, m;
Lf chieu dai ciia phan thu phang, m hj- chidu d^ cua phan thu chii V, m.
- Tai nut T2,vdi p h ^ thu phang Hd sd tdn that nhiet d tam day:
U j = X 1
— + — . ( 2 7 )
Nhidt dd diu ra cua phan thu:
T.=T.+2.^(28)
m C p
- Tjii mit Tj, vdi phan thu sdng chu V Hd sd truyen nhiet buc xa giira tim hip Ihu va mat diy hr23 dupe tinh nhu cdng thiie (12), he so truydn nhidt ddi luu hg giiia tim hap thu vl ddng klii dupe tinh nhu cong thiic (20).
- T?d mit T{2, vdi phin thu sdng chii V He sd truydn nhiet ddi lim giiia ddng khi vl tim diy dupe gia dinh II bang he sd truydn nhiet ddi luu gida tam hap thu v l ddng khi h^ = hj. Lugng nhidt m^
ddng khi d kenh dudi nhan duoc U:
Q,=2mC ^'^^^^'^^^29) - Tai mit Tj, vdi phan thu sdng chii V
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Hd sd tdn thft nhi$t b t&n day U^ dupe tinh nhu cdng thirc (27). Nhidt dd diu ra cua phin thu sdng chii V dupe xac dinh theo cdng thiic:
T. = T , + (Q, + Q,)WL.
(30)
- Hidu suat ciia bp thu nhidt dirpc tinh theo cdng thiic chung cho ca phan thu phang vd chir V:
m C ^ ( ^ - T ^ (31) 2IWL
W, Lr Chidu dii va chieu rdng cua bp thu, m.
3.1.4. Ap dung thuat toin ma tran - Vdi phin thu nhiet phlng
Bien ddi hai ve eac phuong trinh (1) vl (4), dat 7
= 2mCp/Wl^ rdi thay vao (26) va (3), ta dupe he phuong trinh sau:
fOi, + h^i + UT)TI - hiTa - hr2iT2 = Si + U-rT, hiTi ~ (hi + ha + Y)Tfl + h^Ta = - fTfl (32) - h^iTi - haTfi + (ha + h^i + U^) T^ = S2 + U^T, - Vdi phan thu nhidt sdng chu V
Tuong tu tren va tir phuong trinh (6)va (8) bidn ddi hai ve trli cd hd phuong trinh sau:
(hi + h,2i + U-r) Ti - hiTfl - h^iT^ = Si + UTT, h i T i - ( h i + ha + T)Tfl + haT2 = - f r ,
h^Ti-h3Ta+(h2+h3+h^+h^)T2-h3T2- b^T3=S^ (33) haTg - (ha -H h4 + Y)TE + h^Tj = - fTf,
.- h^% - hiTe + (h^3 -H h, + Ub)T3 = UbT, Hai he phuong tiinh tren dupe gili theo phuong phip ma tran bang md phong Matlab, gil tn cac nhiet dp trung binh duge xac dinh bang phdp chia ma tran:
[T] = [A]-^[B] (34)
3.2. Kdt qui md phdng v l thi nghiem 3.2.1. Bidu kidn thdi tidt thi nghidm vi cac thdng sd che tao bo thu nhidt
Gil tn elc thdng sd che taobo thu nhiet mat trdi dupe trinh biy trong bing 1. Thi nghiem dupe tidn hinh de xle dinh nhiet do ra cua ddng khi vl hieu suit bd thu trong ngly 02/5/2014 tai huyen Gio Linh, tinh Quang Tri.
Bang 1. Cdc gid h i thdng sd su dung thidt kd, chd tao bd thu nhiet m^t trdi Thdng sd
Chidu rdng ciia phan thu Chieu dai cua phan thu phang Chidu daiciiaphan thu sdng chir V Chieu cao sdng chir V Luu lirpng khdng khi Nhifet dd khdng khi mdi trudng Dd din nhidt ciia vSt li6u each nhiet Hd sd phdt xa ciia tim kinh Hd sd phdt xa ciia tiim hip thu He sd phat xa ctia tam day He sd hap thu cila tam kinh He sd hip thu cua tim hap thu Hd sd truydn qua ctia tdm^dnh Tdc dd gid
Tdc dd ddrig khi trong bd thu
KyhiSu W
u
L,H j
M T.
k,
S l 82 Es a,
<h
T V V,
Don vi tinh m m m m kg/s
K W/mK
m/s m/s
Gi4tri 0,5 0,25 2,5 0,13 0,25 300 0,032 0,94 0.95 0,03 0,06 0,95 0,84 1,0 1,0 Nhidt dd khdng khi mdi trudng v4 biic xa mat *™™g ™ " ' ™ « "^ ^'•^ ' ^ ™* t^" ^"^^ "8*y ^°
trdi ten bd thu nang lupng mat trdi theo thdi gian ^"''^- "^ n*'* ''*'='' » * '* ^00,2 K va 126 W/m^ cao trong ngay trdn hinh 4. Nhiet dd khdng khi mdi nhat liic 13 gid la 307,2 K v4 812 W/m^.
NONG NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 12/2015
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Hinh 5. Nhiet dd vio, nhidt dd ra md phdng vl nhiet dd ra tii^c td ciia bo Ihu
Qua dd thi, cd the thiy ring nhiet dp dau ra cua bd thu bi anh hudng chii yeu tu cudng d6 buc xa mat ti-di, nhiet dp mdi trudng cd anh hudng thap. Hinh 6 vl 7 tiinh biy md phdng su tiiay ddi nhiet dp cua ddng khi theo chidu dii mot bd thu d thdi diem buc xa mat ti-di thip nhit liic 7 gid (126 W/m^ va cao nhit liic 13 gid (812 W/m^. Dd thi md phdng su thay ddi nhiet do ddng khi theo chieu dii cua bg thu la
tuyen tinh. Dudng gap khuc nhd II tai vi tri cac phan thu phang, noi ddng khi ddi chieu, nhiet dp ddn^khi tang len khi di qua phan thu phang 0,1-0,15 K
Vdi thdi gian say 8-10 gid/me, thdi didm bit diu say khoang 7-8 gid sing cd nhiet dd dau ra cua bS tiiu dat 303,2-312,5 K II khi thap, khdng dip iing dugc ydu clu cdng nghe sly. Trudng hpp can tang luu lupng khdng khi, dd tang khdi lupng say thi nhi&t dd diu ra se cdn giim thip hon.
Hinh 4. Nhidt dd Uidng khi mdi trudng vl biic xa mat trdi Idn bd thu ngly 02/5/2014 3.2.2. Ket qua md phdng vi thi nghiem Nhiet do khdng khi mdi trudng trong ngly do dupe 300,2-307,2 K, buc xa mat ti^di 126-812 W/m^
nliiet dp khong khi ra khdi bp thu theo mo phdng dat 303,5 - 328,9 K, kdt qua tiii nghiem dat 303,2-327,5 K (binh 5). Chenh Idch giira nhiet do vio va ra khdi bd thu tdi da theo ket qua thi nghidm la 20,3 K, hieu suit bd tiiu dat tdi da theo thuc te 50,8% vl 54,4% theo md phdng. Nhu vay, kdt qui md phdng gan vdi kdt qua thi nghiem.
304 303.5 303 302.5 302
1 Nhl^ta5(l=126W;m',Ta=3017K)| /"
Hinh 6. Md phdng s^r thay ddi nhidt dp ra cua ddng khi theo chidu dii cua bd Ihu nhiet d 1=126
W/m2vlT, = 301.7 K
Hinh 7. M6 phdng su thay ddi nhiet dO ra ciia ddng khi theo chidu dii ciia bd thu nhidt d I=812W/m^ vl
T, = 307,2 K
Sd khic phuc didu nly, gili phap ed thd tiiuc hien la ghep ndi tiep cic bd thu, nhidt do ddng khdng khi se tang len theo chidu dli cua bd thu. Tren hinh 8 vl 9 mo phdng su thay ddi nhiet dd cua ddng khi theo chidu dli 4 bd thu ghep ndi tidp d thdi diem biic xa mat trdi thip nhit liic 7 gid (126 W/m^ vl cao nhit luc 13 gid (812 W/m^. Hinh dang cua dd thi 48
KHOA HOC CdNG N G H l
cho thiy sd lupng 4 bd thu ghep ndi tiep II phii hpp.
sd bp thu cang nhidu thi kha nang tang nhidt ciia ddng khi cang giam. ndu nhieu ban se khdng kinh td vi se lim tang trd luc cho qu9t Trong trudng hpp d n tang luu luong ddng khi say cd the ghep song song cac cum 4 bd Ihu vdi nhau.
Ifinh 8. Md phdng SI; thay d6i nhiet dd ctia ddng khi theo chidu dli 4 bo Ihu ^ d p ndi t i ^ a 1=126 W/m^
vAT.-301,7 K
6 8 10 12 14 16 18 20 22 24 aii^daib$thu{m)
Hinh 9. Md phdng sijtlht^ ddi nhiet dd cua ddng khi theo chidu dli 4 bO thu ghdp ndi tidp d 1=812 W/m^
v l T.-307,2 K
Tbfri gian trong ng^ (aw)
I£nh 10. Md phdng nhidt do diu ra ciia bdn bO tfau
^ d p ndi tidp
Hinh 10 trinh biy md phdng sy thay ddi nhidt dd ra cila ddng khi vdi 4 bp thu ghep ndi tiep trong
ngly. Nhiet dp dau ra liic 8 gid 11324,1 K, eao nhat i l 350,4 K luc 13 gid, luc 16 gid II 323,8 K. Vdi nhidt dp nly dim bio yeu clu cdng nghd say el com neu thdi gian say trong ngly 8 gid, bat diu 8-16 gid. Dd dam bao luu lupng khong khi eho qui tiinh sly 0,5kg/s can lip ghep song song 2 cijm thu nhidt, mdi cum cd 4 bd thu nang lugng mat trdi lap ndi tidp. Khi nhiet dd ddng Idu cao hon nhiet dp yen clu can phai hda trpn them vdi khdng khi mdi trudng. Vi vay trong thidt hi say can phai cd bd hda trdn khi dd xu ly nhidt dd khdng khi thich hpp trude khi dua vio budng sly.
4.KETLUMI
Md hinh h)ln hpc vl chuong trinh tinh toin md phdng da xac dinh dupe mdi quan he giiia nhiet do ddng khi vl chidu dli bd thu nhiet. Kdt qua tinh toan md phdng II ca sd khoa hpc dd khIo sit elc tham sd Inh hudng den hieu suit thu nhiet, tii dd cd thd lua chpn dupe elc thong sd eo ban cfiia bd thu nang luong mat trdi nham dinh hudng cho vide thiet kd, che tao.
Dd dam bao yeu clu cdng nghe say cl com vdd cudng dp biic xa thip cin lip ndi tidp 4 bd thu nang lupng mat trdi, de dam bao luu lugng khdng khi can thiet eho qui trinh say cin lap ghep song song 2 cum thu nhidt, mdi cum cd 4 bd thu nang luong mat trdi lip ndi tiep.
TAI UEU THAM KtUO
1. HoUands K G. T and Shewen E. C. (1991).
Optimization of flow passage geometry for air- handling plate type soiar collectors. Journal of Solar Energy Engineering, 103(4): 323-330.
2. Karim M. A. and Hawlader M. N. A. (2004).
Development of solar air collectors for drying applications. Energy Conversion and Management, 45(3): 32^344.
3. Karim M. A., Perez E. and Amin Z. M.
(2013). Mathematical modelling of counter flow v- grove solar air collector. Renewable Energy, 67:192- 201.
4. Kays W. M. and Crawford M. E. (1980).
Convective heat and mass transfer. McGraw-Hill, 2"^
edn. New York.
5. McAdams W. H. (1954). HeatTransimission.
McGraw - Hill, 3"* edn. New York.
6. Weast R. C. (1970). Handbook of Tables for applied engineering science. CRC Press, Boca Raton.
N O N G NGHIEP VA PHAT TRIEN NONG THON - KY 2 - THANG 12/2015 49
KHOA HOC CONG NGHE
'^'•^ •^ I- SOME RESULTS OF RESEARCH OF SOLAR DRYER FOR ANCHOVIES Ngiqren Xuan Thing, Dinh Vuong Hung, TVan Nhu KhiQnEn,
•61^ 9£> NguymThanh Hai, Ngo Quoc Hung,Tten Nhu Khanh Y£2 fhh Summary ThM^ail^Freports the result of the simulation and the expenment of flat and V groove mixed-mode solar air coiledi^tor the dried appUcations of anchovies by the solar air. In this collector, the air current flows the U- s h a ^ f ^ a ^ f t e part of the flat and V groove absorber. Tbe flat absorber both plays the role of collecting the heat aijd.^e derivation to haul the air current. In the wedge-shaped wave collecting part, the air current toiiehe^iwtii the parallel both the fece side and the under side of the absorber to increase tiie capapility of g^t&Sgbtfl^ h e a t The simulation is carried out by the mathematics and Matlab software. The resuk of smiulation is compared with the result of expenment in an early summer day. The temperature of the air current is out the collector with the simulahon of getting highest is 328.9 K, getting in reality is 327.5 K comtailed with the environment temperature js 307.2 K, the simulative efQciency of the collector gets higlBSS^s54.496 compared with the real efficiency is 50.8%.
Ke^WSftlk' Simulation, solar collector, mixed mode, V groove, drying.
jii'j it-
N g ^ ^ l ^ bi^n: GS. TSKH. Ph^m V i n Lang N g l y i i O i l n b l i : 2 6 / 0 1 / 2 0 1 5
N g l y thdng qua p h i n bidn: 2 6 / 0 2 / 2 0 1 5 N g l y diiydt dSng: 5 / 3 / 2 0 1 5
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