NGHIEN CCfU - TRAD DOI
LTNG DUNG CONG NGHE LAM LANH BAY HQI Sii DUNG
C H A T H O T A M L 6 N G
TRONG DI^U
H O A K H O N GKHf
THE APPLICATION OF EVAPORATIVE COOLING TECHNOLOGY USING LIQLdD DESICCANTS IN AIR CONDITIONING
Nguyen Th^ Bao
Vien Phat triln Nang luong BSn viing ISED
TOM TAT
Bdi bdo trinh bdy ket qud so sdnh giiia so lieu thi nghiem vd chucmg trinh mo phong he thong Idtn lanh bay hai 5W- diuig chdt hut dm long. Sau do chuong trinh mo phong duac su dung dephdn tich kinh te-ky thuat vd ddnh gid khd ndng img dung cong nghe ldm lgnh bay hai sit dung chdt hut dm long trong cdc he thong diiu hoa khong khi trong diiu Uen Viet Nam. Ket qud cho thay, khd ndng img dmg cong nghe nay rdt hieu qud khi sit di^ng cho dieu hda khong khi trong cdc khong gian lan, tdi nhiet dn cao nhu hoi truong, sieu thi, sdn bay, nhd hdng...
Til khoa: Ldm lgnh bay htn, chdt hut dm long, dieu hoa khong khi.
ABSTRACT
The paper presents the comparisons between the results of an experimental study and those of a simulation program for an evaporative cooling system using liquid desiccants. Then the simulation program is used to analyze the feasibility of the evaporative cooling technology using liquid desiccants for air conditioning in Vietnam conditions. The study shows positive results for this application, especially in cases of air-conditioned open spaces with high latent heat loads such as supermarkets, halls, airports, restaurants, etc.
Keywords: Evaporative cooling, liquid desiccants, air conditioning.
1. D^T VAN DE te, tuy nllien cac he thong nay deu sii dung ngu6n nang lugng cao cap la dien.
Theo cac thong ke thi cong suit dien tieu
cho he thdng diSu hoa trong cac cong trinh nhu Cac he th6ng diSu hoa noi tren dgu phii cao 6c van phong, khach san chi&n tu 45-55% lam lanh ca nhiet hien lan nhiet in, ma lugng t6ng lugng dien tieu thii [1]. Mac du hien nay nhiet in thucmg chiSm tiit 20%-60% t6ng nang CO rit nhiju he thong diSu hoa khong khi dugc suit lanh tuy loai cong trinh van phong, nha cai tito nham tiSt kiem nang lugng nhu he hang, sieu thi, dilu kien thai tiit ben ngoai. Vi thing dilu hoa trung tam co luu lupng nuoc, v$y, he thing dilu hoa thong thucmg phai tin luu lugng gio thay doi theo phu tai,...tren co so lugng dien dl khu di lugng nhiet in rit dang hieu chmh nang suit lanh sat voi phu tai thuc kl. Dl khac phuc vin dl tren, mgt trong sl'^
ISSN 0866 - 7056
TAP CHl CO KHI VIET NAM, S6 1+2 nam 2017
NGHIEN CO'U-TRAO06l
cdc giai phap duoc danh gia cao la ket hgp h$
th6ng di6u hok vai chat hiit am Lithium Chlo- ride (va mpt so chat hut am khac CaCl^, Silica gel, Moleccular Sieves,...) de khu di phan nhiet an khong can dung nguon nang luong cao c4p dien ma chi su dung nang luong mat trdi hay nguon nhif t thai the nang thSp sSn co, giiip tiet kiem duoc dien nang tieu th\i dang ke. Tuy theo dieu kien moi trudng ma h$ thOng n ^ co th§ six dung true ti§p nguon nirdc sinh hoat dS lam lanh ma khong can den nude co nhiet dp thip nhu trong he thong lanh trung tam. H$
thong lam lanh bay hoi su dung chat hut am LiCl hay CaCl^ co giai cong suat va nhiet dp gio cap rat rOng, co the rat thap khoaing v£li tram watt, giai cong suat ma may lanh hip thu khong the dap img dugc. Ngoai ra, he th6ng lam lanh bay hoi sir dung hoan toan gio mdi dh cap lanh nen tranh dugc nhilm bin cheo, mgt hi8n tugng lay nhilm tir khong gian dilu h6a nay den khong gian dieu hoa khac.
Co rit nhiSu ngliien cuu tren thi gidi vk ly thuyet va thirc nghiem cong ngh8 lam lanh bay hoi sit dyng chat hut im long hay ran cho dilu hda khong khi [2]. Mavroudaki va cgng su [3] va HaUiday va cgng su [4] da tiSn hanh hai nghien ciiu dgc lap vh lam lanh bay hoi sir dung chat hiit Sm ket hgp nang lugng mat trdi d nhung thanh ph6 khac nhau t^i chau Au va k§t luan rang, nang lugng dugc ti6t kiem dang kg khi ling dung cong nghe lam lanh nay iing vdi mgi loai thdi tidt khac nhau. Alizadeh va cgng su [5] da thilt kg, t6i uu hoa va chi tao mo hinh bp tai sinh/B6 thu mat trdi (Regenerator/Solar collector) d6i lira cuong biic. Dung dich CaCI dugc su dung la chit htit im va anh hudng cac thong s6 nhu luu lugng khong khi va chit hiit am cung nhu thdi tilt din hoat ddng cua thilt bi tai sinh dugc khao sat. Kit qua khao sat cho thay hoat dpng ciia Bp tai sinh va hi6u suit bp thu mat trdi tang khi luu lugng khong khi tang.
Yadav 16] da mo phong he thdng lam lanh bay hoi sur dung chit hiit im long kit hgp he thing
lanh may nen truyen tiling. Kit qua nghidn cuu chq thiy, Idii thanh phan. tai Sn (latent load) chilm din 90% tdng tai lanh thi he thong nay c6 thi giiip tidt Idem dugc 80% nang lugng so vdi he thong lanh may nen trayen thing. Dai va cpng sir [7] da lam nghien ciiu so sanh giiia he thdng lanh may nen truydn thdng, he thing lanh may nen trayen thdng ket hgp hut am va he thdng lanh may nen trayen thing kit hgp lam lanh bay hoi va chit hiit am. Nghidn ciiu cho thay, hai hd thing sau giiip tang tdi lgnh lin lugt 38,8% va 76% va he sd lam lanh COP cua hai he thdng nay cimg ISn lugt tang 20%
va 35% so vdi he thdng l^nh may nen traydn thong. Mazzei va cdng su [8] da so sdnh chi phi van hanh ciia he thing may lanh nen hoi va he thdng cd sii dung chat hiit am bing chuong trinh md phdng va cho kdt qua chi phi v§n hanh CO the tidt kidm dugc 35%. Trong tmdng hgp chat hiit am dugc tai sinh bing cac nguIn nhiet thai thi tidt kiem chi phi van hanh he thing sit dung hut am cd thd Idn ddn 87% so vdi he thdng lanh may nen hoi. Gin day, Kozubal [9].
Gao va cpng su [10] da kit hop giira thilt bi hut ira va thidt hi lam lanh bay hoi kidu gian tiep trong thi nghiem va so sanh hidu qua vdi he thong may lanh cd may nen hoi va cho tiiiy he thdng nay tilt kiem dugc tu 40-80% nang lugng tidu thu, co thd didu chinh nhidt dp va dd im ciia khdng khi mot each dgc lap do hai thilt bi hiit am vk bay hoi hoat dpng ddc lap nhau.
Tuy nhidn, d Viet Nam lai co kha it cdng trinh nghidn curu vl cdng nghe nay [ 11, 12]. Vi vay, bai bao nay mong muln gdp mot phin vao vide nghidn cuu kha nang ung dung cong nghd lam lanh bay hoi sit dung chat hut im Idng cho didu hda khdng khi tai Vidt Nam.
2. MO HINH THI NGHIfiM 2.1. Thilt bi thi nghiem
M6 hinh tiii nghidm nghien ciiu qua trinh
ISSN 0866 - 7056
TAP CHI CO KHl V I £ T NAM, Sd 1+2 nam 2017
www.cokhivietnam.vn
NGHIEN CU'U - TRAO DOI
hut im bing chit hiit im Idng LiCl dd ling dung ttong he tiidng didu hda khdng khi. So dd md hinh tiii nghidm nhu hinh 1 va 2.
Ngudn nhidt dd gia nhidt dung dich Idn nhidt dd hoan nguydn la nude nong. 6 day, dl thuan tidn cho vide thi nghidm thi nude dugc dun ndng bang dien trd. Cdng suit cua didn ttd 9 kW, gdm 3 didn ttd vdi cdng suit mdi didn trd 3 kW.
Do ttong thi nghidm nhiet do dung dich dam dac trudc khi vao thap tach im ta ydu ciu khoang (20-^35)^C, do do nude lam mat dung dich CO thd la nude smh ho^t hoac nude lanh tii may I ^ l^nh nude (may lanh water chiller).
Nen mo hinh gdm co mot may lanh water chiller dd lam lanh dung dich khi qui trinh yen can nhiet dp thap va mgt thap giai nhidt nude lam mat dung dich khi nhidt do dung dich ydu cau khong qua thip.
Hinh 1. Sado nguyen ly he thdng ihi nghiem:
1) 131^ giai ahifl niroe;
2) Thip tich am, 3)Hi6p hoan ngiiyen:
4) May lgnh Water Chiller:
i) Binh chia dung rijch LiCI/CaCI^ dgm Sac:
6) Binh chua dung dtch LiCI/CaCl, loang:
7} Bifn tr&gia nki^l:
S. 9) Van 3 nga. JO. Bam nti&c ldm mdi, 11.12} Bam nuac lanh
13) Bum tiung dich LiCUCaCl^ loang len thip hodn ngi^en:
14) Bam dimg djch UCl/CaClj dam dqc len Ihip idch dm MN May nin.
BN: Binh n^mg lii:
\m. Van nil luu BBH- Binh bay hm
Hinh 2. He thdng thuc nghiim vd thiet bi ^ao ddi nhiet.
3.©ANHGIAD0TINCAYCUACHiraNG TRINH M 6 PHONG
Dd phan tich kinh te-ky thu$t va danh gia kha nang img dung cdng ngjbid lam lanh bay hoi sit dung chat hut am long ttong cac he thdng didu hda khdng khi, mot chuong trinh md phdng da dugc vidt [9,10]. Hmh 3, thd hien giao dien cua chudng trinh md phdng:
Hinh 3. Giao diin cua chirang trinh md phong hi thong ldm lgnh bay hai.
v a nham danh gia dp tin cay cua chuong trinh md phdng dua vao sir so sanh giua kdt qua cua chuong trinh md phdng vdi md hinh ttii nghidm nhu da dl cap d phin 1 bdn tren ddi vdi cac tiidng sl trang tiidi nhu nhidt dp, dp im tuong ddi, nhidt dp dung dich hiit im ciia thap thap hut am am va thdp tai sinh. Dudi day la cac kit qua so sanh giira sl lieu tiii nghidm va chuong trinh md phdng.
Ket qua thi nhidm vdi khdng khi vao tiiap vdi cac tiidng sl t - 34''C, <|) = 70%. Dung dich dam dac vao thdp tach im vdi luu lugng 4Ut/phut (luu lugng dung dich vao hai thap nhu nhau), nlng do = 40%, nhidt do dung dich'^
ISSN 0866 - 7056
TAP CHl CO KHi V\%1 NAM, Sd \+2 nam 2017
NGHIEN CO'U-TRAOeOl
= 27''C va nhi^t do dung dich hoan nguydn dung dich =75°^. Thay ddi tdc dp khdng khi vao (tdc dd khdng khi vao hai thap la nhu nhau) vd do cdc thdng sd ddu ra img vdi timg toe do tucmg iing. Ket q u i thi nghidm dugc thd hidn ttong bang sau:
STT 1 2 3 4 5
T6C d$ khdng khi (m/s)
1.0 1.5 2.0 2.5 3.0
LiCl Thip tich im
tldtCC) (|)kk(%) tJ-Q 31
31.8 32.5 33 33
37 36 36 35 34
29.5 30.7 31.2 32.5 33.1
Thap hoin nguySn tj-Q *kk(%) t „ e c )
48 47.2 46.6 46 46
70 71 72 74 75
58.5 55.4 54.6 54.1 53
B$ giim kmia (g/kgkk)
13.22 12.15 11.89 11.69 10.08 Chay chuong trinh mo phong vdi cdc
thdng sd nhu ttdn va so sdnh k i t qua bua chuong trinh vol cac sd lieu thi nghidm va dugc the hidn dudi dang dd thi nhu dudi day:
3.1. T h a p t^eh i m
Sai Ifch nhidt do, dp i m tuong d l i va nhidt do dung dich ttong thap tdch i m giira thi nghidm va chuong trinh mo phong till hidn lin lugt ttdn cdc Hinh 4, 5 & 6. Bien dang cua hai d l thi tuong d l i giong nhau, dp sai lech l i n lugt khodng 7%, 11 % & 10% tuong iing.
1 Sai V n
I 1 :;
"
^~.J1.
1 —'-^
L.«ch NMf 1 D« Kliai« Kbi _ - — ' •
.-—— ——"
[ . « b 7 D | (B^A)
'.? ' " ''* ' " • ' " *
»*.. » . M . „ «
Hinh 4. Su sai l$ch nhiet dg trong thdp tdch dm giQa thi nghiem vd chucmg trinh md phdng.
Sai L4di 0 4 Xm TtAAig Dtfl
•i "
Hinh 5. Su sai l$ch dd am tuang ddi trong thdp tdch dm giiia thi nghi$m vd chuong trinh md phdng.
Hinh d. Su sai lech nhiet do dung djch trong thdp tdch dm giua thi nghidm vd chuong trinh md phong.
Hinh 7. Ste sai lich nhiet do trong thdp idi sinh giiia thi nghiem vd chuong trinh md phdng.
3.2. T h a p t^i sinh
Tuong tu, sai lech nhiet do, dd i m tuong doi va nhidt do dung dich ttong thap tai smh giira thi nghiem va chuong ttinh md phong the hidn l i n lugt ttdn cdc hinh 7, 8 & 9. Bidn dang cua hai dd thi tuong d l i gidng nhau, dd sai lech lin lugt khodng 10%, 2 3 % & 4 % tuong img.
ISSN 0866 - 7056
TAP CHI C O KHf VIET NAM, S l 1+2 nam 2017 www.cokhivietnam.vn
NGHIEN CLfU-TRAODOI
Sa
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i "
" IB
1 ^ — i m " * * "
. • * - ' " " •
1 L^ch DQ Am TdUtas D«l
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- ^-_^__-, • - -•: - , .
m m
( 9 170 f l
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n
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TS 1
ifinfi 8. Su sai lich do dm tuang doi trong thdp tdi sinh giiia thi nghiim vd chuorng trinh md phdng.
Hinh 9. Su sgi lech nhiet do dung dich trong thdp tdi sinh giOa thi nghiem vd chuong trinh md phong.
Qua ket qua tinh todn bing phin mim md phong vd thi nghiem sai sl trung binh la ddi vdi nhidt do khdng khi la 11 %, dO im tuong ddi Id 23%, nhidt dd dung dich la 11%.
Cac sai sd nay bao gdm sai sd cdc thilt hi do, sai sd do bd tri cac thilt bi do chua tiiich hgp, sai so do he thong chua that hoan chinh, v.v.
- Tu kdt qua md phdng ta nhan thiy, niiiet do cua dung dich va ciia khdng khi thi cao hon so vdi thi nghidm va ngugc lai dp im tuong ddi thi thdp hon. Didu nay do sai sl cua cac thidt bj va vi tri lap thiet hi do nhidt do.
Con dp am tuong ddi tin khi nhiet do cao thi do am tuong dli giam.
- Bien dang cua cua do thi ciia chuong trinh md phong thay ddi thay quy luat nhu md hinh thi nghiem.
Qua kdt qua so sanh giiia chuong trmh vd mo hinh thi nghiem nhan thiy, chuong trinh md phdng cho ra cdc kdt qud tuong dli xac thuc td va CO thd dng dung dl md phdng cac thidt hiit am vd tai sinh hay ca he thing lam dieu hda khdng khi cd su dyng chit hut im.
Trdn hdt, chuong trinh md phdng nay hoan toan cd thd diing dd phan tich kinh td - ky thuat va ddnh gia kha n ^ g iing dyng cdng nghe lam lanh bay hoi sit dung chit hiit im long trong cdc he tiidng didu hda khdng khi.
4. TfNH TOAN KINH TE - KY THUAT Trong phan nay, chung ta se xem xet didu kien dd dp dyng ttong tiiyc tl va tinh toan kinh te-ky thu$t cho so do lira chgn ttong cdc khia canh sau:
- Phan tich he thdng cho cimg mdt phy tai lanh tdng nhung vdi cdc trudng hgp phdn tai nhiet in va nhidt hidn khac nhau dl ta dd ddnh gia xem hd thdng nen su dung d ddu va ttong tradng hgp nao.
- Phan tich he thdng vdi phu nhiet thay ddi dd danh gia hieu qua giiia vide sur dyng mdy nen hoi dd Idm lanh va lam lanh bay hoi gidn tidp.
- Phan tich cdc chi phi dau tu, chi phi vdn hanh cho tradng hgp su dung may lanh nen hoi va phuong an lua chpn dd xem xet, danh gia tmh kinh te ddi vdi hai phuong an nay.
4.1. Kha nang ihig dung trong thuc te De xem xet kha nang dng dyng he thing ttong thyc td ta xet tradng hgp cu thd sau: He thing phuc vu cho khdng gian didu hda co phu tai lanh la 100 kW vdi ty Id giua tdi nhidt hidn vd tai nhiet an ttong khdng gian didu hoa thay ddi va lugng gio mdi cip vao khoang 10% so®^
ISSN 0866 - 7056
TAP CHi CO KHI VI$T NAM, Sl 1+2 nam 2017
NGHIEN ClJU-TRAO DCI
vdi lucmg gio lam lanh. Cac thong so diu vao 14:
- JChang khi troi: t| = 34°C, dp to 70%.
- Khong gian diSu hoa: t^ = 25°C, do to 55%.
- Nhi$t dp dung djch tach to 27°C va 40%, Imi luong dung dich so vdi luu lupng khoi luong khong khi hut to khoang 0.8 -1.2.
- L t o lanh khong khi bSng gian bay hoi true tiep DX.
-Nhiet dp nuoc l t o mat v^o - ra: 24''C-31''C.
- Nhiet dp nuoc nong vao ra: 77°C - 70°C.
Dung chuong trinh mo phong neu tr6n dS xac djnh cac thong s6 cin thiSt vi ta co kSt qua nhu b ^ g sau:
Bdng 2. Luu luang cdc dong luu chat theo phdn bo logi tdi lgnh.
Tai lanh (kW) Tai nblft In
80 70 60 50 40
T i l nhift bifn 20 30 40 50 60
Lull lir^ng cac dong liru chat (m^/h) Kh6ngkhl
24661 21544 18462 15379 12297
Dung dich (l/p) 400 350 300 250 200
Nirdc lam mat 30.14 26.37 22.61 18.84 15.07
Nude ndng 30.76
27.1 23.1 19.28 15.45 Bdng 3. Nang lugng tieu hao cua hi thdng theo suphdn bd logi tdi lgnh.
Tai lanh (kW) Tai nhiet
^n 80 70 60 50 40
Tai nhiet liien
20 30
•40 50 60
Tiiu hao difn (kW) Bom
nude 2.52 2.21 1.89 1.58 1.26
Bom dung dieh
2.52 2.21 1.90 1.58 1.27
Quat gid 4.8 4.2 3.6 3.0 2.4
May l^nh DX 32.1 29.4 26.7 24.2 21.4
Lam lanh gian dep
9.1 8.0 6.9 5.8 4.6
Tieu Ti§u hao thu nhiet d i | n ndng 41.9
38.0 34.1 30.6 26.2
244.9 215.6 195.1 171.4 149.9
III
1337 130.2 125.9 121.1 117.3 Tu ket qua ndu ttong cdc bang sl lieu vd
dd till tten ta thiy, nlu ttong cimg mdt dilu kidn tdng tdi nhu nhau thi khi khdng gian dilu hoa co tai nhidt hidn cao thi tidu hao nang lugng nhidt giam khdng ddng kl, do do khdng tilt kidm dugc chi phi van hanh nhidu so vdi cac phuong phdp dilu hda khdng khi traydn thing.
Khi tai nhidt in cao ta thiy luu lugng dung dich LiCI vd luu lugng khdng khi cin thiet cho khdng gian dieu hda ddu nhd hon do cdng suit di^n tieu thu se giam ddng kl, chi phi diu tu tiiiet bi bom quat ban diu cung thip hon. Mat khdc, do lugng muli LiCl tieu hao nhd dan den chi phi dau tu ban diu ciing dugc
ISSN 0866 - 7056
TAP CHI CO KHl VIET NAM. Sd 1+2 nam 2017 www.cokhivietnam.vn
NGHIEN CO'U- I RAO OOl
gidm xudng. Nhu \ky, khi khdng gian ma tdi nhidt hidn cao hon tai nhidt in thi sd dung so dd lua chgn se khdng mang lai hieu qua kinh tl cao.
Tdm IEU, khi Ididng gian ma tai nhidt hidn cao hon tai nhidt in thi vide sii dyng so dd lya chpn se khdng khd thi va khdng mang hi hidu qua kinh te cao. So dd hd tiling da lua chgn se phu hgp va mang tmh kmh td cao hon khi sii dung ttong cac khdng gian didu hoa co nhidt in cao hon nhidt hidn. Didu nay ciing cd nghia la he thing se co thd canh tranh dugc cdc he thing didu hoa khdng khi traydn thdng ddi vdi cdc khdng gian cin luu lugng gid tuoi Ion, noi tdp tnmg ddng ngudi nhu r^p hat, nha ga, san bay, sieu thi, trudng hgc.v.v.
4.2. Tinh toan kinh td ky thuat Trong muc nay chung ta se danh gia tinh kinh tl cho hai phuong
Phuong £Hi 1: Sii dung he thing DHKK ldm lanh bay hoi vd tdch im bing dung dich LiCl nhu da lua chgn d ttdn.
Phuong an 2: Sd dyng may lanh nen hoi cho DHKK.
Hai phuong dn tten du kien diu tu cho he thing DHKK cd cdng suit lanh la 20RT, ti Id nhiet hien vd nhidt an nhu nhau gid mdi cap vao 11%, van hanh 20 gid/ngay, 7 ngay/
tuin, tdc Id 7.300 gid/nam.
4.2,1. Chiphldau tttthietbivdchiphiv^n hdnh Bdng 4. Chi phi ddu tu vd van hdnh cdc phuang dn
dieu hoa khdng khi:
H^ng muc
Chi phi diu tu(USD) Chi phi van
hanh (USD/nam)
May lanh nen htfi gidi nhift mro'c 14.130 15.746
May lanh nen hoi giSi
nhi@t gi6 10.374 19.245
Lam lanh bay hoi-t^ch
am bang chit hut i m
14.558 15.252
Bang 4, trinh bay chi phi dau tu va van hanh 3 phuong dn DHKK: May lanh ndn hoi giai nhidt nude, may lanh nen hoi gidi nhidt gid vd Idm Ipih bay hoi-tach im bing chit hut am. Cac tinh toan diu tu thilt bi dua ttdn dua vdo bdo gia thidt bi, vat tu ciia cac haig Trane, Wescor, Gnmdfoss, Pentax, gid LiCI co ttdn tin tradng va tham khao va chi phi lap d^t thilt bi cua Cdng ty Tu v&i Thilt kl MEI. Chi ttoh phin tinh toan cac chi phi nay CO thd tim thiy ttong [11].
4.2.2. Ddnh gid hieu qud kinh ti
Qua tinh todn sd Hdu tten, ta chi xet loai may didu hda gidi nhiet gid vi so he thdng didu hda sit dyng chit hut dm thi kinh td hon so vdi nude. Ta thiy, chi pHi diu tu cua he thing DHKK dung lanh bay hoi vd tdch im bang dung dich H^O-LiCI la 12.465 USD cao hon mdt it so vdi mdy lanh giai nhiet gid.
Chi phi van hanh ciia he thing DHKK may lanh nen hoi so vdi dimg lam lanh bay hoi va tdch im bang dung dich H^G-LiCl tiii cao hon 16.576 USD/nam.
Chdnh lech tiidi gian thu hdi von la; 4.184 USD/3.992 =1.04 nam.
Tmh todn tuong ty cho cac tradng hgp tai lanh khdc nhau c6 bang quan he giiia thdi gian thu hdi vin chdnh lech giua 2 phuong dn va tai lanh nhu sau: ^
ISSN 0866 - 7056
TAP CHi CO KHI Vl£T NAM, Sd 1+2 nam 2017
NGHieNCCrU-TRAODdl
Bang 5-. Thai gian thu hoi vdn chenh lich phu thudc vdo tdi lgnh (Phuang dn mdy diiu hog gidi nhiet gid):
Tai lanh (RT) 20 30 45 60
Ch^nh Ifch chi plii d4u tuPAl-PA2 (USD) 4.183,92 6.275,88 8.284,16 8786,23
ChSnh Ifch chi phi v$n hanh PA1-PA2
(USD) 3.992,32 6.287,91 9.881,01 14.37,.38
ThM gian thu hoi von chenh Ifch (nam)
1,05 1,00 0,84 0,61 Bang 6. Thdi gian thu hdi vdn chenh lech phu thugc vdo
tdi lgnh (Phuong dn mdy diiu hog gidi nhiet nude):
Tai lanh (RT) 20 30 45 60
ChSnh ifch chi pM &ku tipPAl-PA2 (USD) 427,96 641,94 847,36 898,72
Ch^nh Ifch ehi pill v3n hanh PA1-PA2
(USD) 630,16 992,50 1.559,64 2.268,57
ThM gian thu hhi von chenh Ifch (nam)
0,68 0,65 0,54 0,40 Qua sd lieu da trinh bdy d tten thay, he thdng se thu hdi vdn chenh lech so vdi phuong aa may lanh nen hoi nhanh hon nhidu khi sit dyng cho cdc khdng gimi CO tai lanh Idn. Dac bidt, ttong tradng hgp cd nguon nhidt thdi ddp iing dugc ydu cdu cung cip nhiet cho vide tdo tao dung dich thi ta thiy hidu qud kinh tl cao hon nhilu, do ta khdng tin hoac tin rit it cho chi phi nhiet cua hd thing.
5. KE;T LUAN
Qua vide phan tich, danh gia lua chpn phuong an va thih toan kinh tl - ky thuat ndu tten, ta thiy vide ling dyng cdng nghe lam lanh bay hoi vd tach dm bdng chit hiit im cho he thing DHKK ttong dilu Viet Nam la hodn toan mang lai hidu qua cao khi su dung cho cdc khdng gian Idn, tai nhiet in cao nhu hdi tradng, sieu thi, san bay, nhd hang, vii tradng.v.v.
Mac du chi phi dau tu cao hon so vdi phuong an
sii dung may lanh nen hoi nhung bu lai, he thing lua chpn lai tidu tin rit it didn nang va su dung cdc ngudn nang lugng re tidn hoac cd sdn do do khd Tiang thu hdi vdn rit nhanh. Mat khdc, hd thong didu hda khdng khi lam l?inh bay hci - tach im bang chit hut dm se han chd mdt phin hay toan bd vide sic dung cdc tdc nhdn I^nh HCFC.
Tom lai, DHKK su dung Idm lanh bay hoi va tdch am bang chat hdt dm da dap ling dugc van dd sit dung hidu qua nang lugng, bdo vd mdi tradng do nhiing uu diem la:
- Tidu hao it nang lugng didn, sir dyng true tidp nhidt nang do do cd thd tan dyng dugc cac ngudn nhidt thai hay nang lugng mat ttdi,
- Khdhg su dyng tae nhan lanh HCFC ldm pha buy tang Ozone gay d nhidm mdi tradng.
- Cung cap hodn todn khdng khi tuoi sach cho khdng gian didu hda.
- Kdt can thidt bi don gian va hodn toan cdldia nang chd tao ttong nude.
Tuy nhidn, he thdng DHKK lam lanh bay hoi va tdch dm b ^ g chit hdt am long cung co nhihig nhugc didm la:
- Thidt hi cdng kdnh do do cin khdng gian Idn dd dat thidt bi.
- Chi phi dau tu cao hon so vdi may lanh cd may nen hoi.
- Muc dich su dung bi han chi do chi dat dugc hieu qud sit dung cao vdi khdng gian Idn, c6 ty le nhiet in eao.
ISSN 0866 - 7056
TAP CHl CO KHi VIET NAM, Sl 1+2 nam 2017 www.cokhivietnam.vn
NGHIEN c u u - T R A O OOl
- Cdc thiet bi phai cd tinh chdng an mdn
-Nhidt can kha Idn, neu khdng cd ngudn nhiet thai hay ngudn nang lugng mat ttdi thi he thdng nay khdng cd Igi so vdi he thdng may nen hoi. •
Ngay nhan bai: 15/11/2016 Ngay phan bien; 25/12/2016
Tai lieu tham khao:
[1], Nguyen The Bao (2015); Bdo todn vd qudn ly ndng lugng trong cong nghiep vd trong cac tda nhd. NXB. Khoa hgc va Ky thudt.
[2], Daou K., Wang R.Z. and Xia Z.Z (2006);
Desiccant cooling air conditioning: a review. Renewable and Sustainable Reviews (10) 55-77.
[3]. Mavroudaki P., Beggs C.B. Sleigh P.A, HaUiday S.P (2002) - The potential for solar powered single-stage desiccant cooling in Southern Europe. Applied Thermal Engineering (22) 1129-1140.
[4]. HaUiday S.P, Beggs C.B. Sleigh P.A (2002) - The use of solar desiccant cooling in UK: a feasibility study. Applied Themial Engineering (22) 1327 - 1338.
[5]. Ahzadeh S., Saman W.Y. (2002) An experimental study of a forced flow
solar collector/ regenerator using liquid desiccant. Solar Energy 73 (5): 3 4 5 - 3 6 2 . [6]. Yadav YK. (1995) - Vapour-compression
and liquid-desiccant hybrid solar space- conditioning system for energy conservation.
Renewable Energy (7) 719 - 723.
[7]. Dai Y.J., Wang R.Z, Zang H.F., Yu J.D.
(2001) - Use of desiccant cooling to improve the performance of vapour compression air conditioning. Apphed Thermal Engineering (21)1185-1205.
[81. Mazzei P., Michiello P., Pahna D. (2002) - Desiccant HVAC systems for commercial buildings. Apphed Thennal Engineering (22) 545 - 560.
[9]. Kozubal, E. (2013) - Desiccant enhanced evaporative air cooling. Energy Conversion and Management (65) 208-220 [10]. Gao W. Z. et al. (2014) - Experimental
investigation on integrated liquid desiccant
— indirect evaporative air cooling system utilizing the Maisotesenko-cycle. Applied Thermal Engineering (71) 1-9.
[11]. Nguyen Thi Bao (2008); Nghien cuu ung dung cdng nghe ldm lgnh bay hai nu&c diing chdt hut dm dgng long trong mot sd hi thdng dieu hda Ididng khi. Be tai nghien cuu khoa hoc, Sd Khoa hoc & Cdng nghe TP. H i Chi Minh.
[12]. NguySn Thi Bdo & Lam Thanh Hung (2010); Sa dd md phdng he thdng ldm lgnh bay hai co su dgng chdt hit dm Lifiiium Choloride trong diiu hda khdng khi nhdm tiit Mem ndng lugng; Tap chi Nang lugng Nhiet, s l 92 (3) 1-5.
ISSN 0866 - 7056
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