Tgp Chi Khoa Hpc Gido Due Ky Thudt (32/2015) Truing Bgi Hpc SuPhgm Ky Thugt TR HS ChiMinh
NGHIEN c u t ! THIET KE VA LAP DAT HE THONG THI NGHIEM CHO THIET BI NGUTNG TU KENH MICRO
A STUDY ON DESIGN AND EXPERIMENTAL SETUP FOR MICROCHANNEL CONDENSERS
Doan Minh Hiing, Nguyin IVong Hi^u, Dang Th^nh Trung Trudng Dgi hoc Suphgm Ky thudt TP. Ho Chi Minh Ngay tda soan nh$n bai 02/02/2015, ngay phan bi$n danh gia 31/3/2015, ngay chap nhan dang 8/4/2015 TOM TAT
Bai bdo ndy trinh bay idt qud xdy dung he thong thi nghiem phiic v« cho cdc nghien ciiu vi thiit bi ngung tu kenh micro. Ngodi ra bdi bdo con trinh bay ket qud nghien cuu thuc nghiem tren hai mdu thiit bi ngung tu kenh micro vdi liru chdt duac su dung Id nudc cho trudng hap kenh micro dgt thdng dung vd ndm ngang. Cdc kit qud thirc nghiem tir he thong ndy ddng tin cgy, nen he thing thi nghiem ndy co the duac diing de thirc hien cdc thi nghiem truyen nhiet micro,...
Tir khoa.- Thiit ki, Idp ddt, kenh micro, thiet bi ngimg tu, nhiet do.
ABSTRACT
The developing an experimental setup for microchannel condensers was done in this study.
In addition, the paper also showed experimental results on two microchannel condensers with water as the working fluid for the cases of vertical and horizontal microchannels. These experimental results obtained from this system are reliable, so this system can be used for experiments of microchannel heat transfer etc.
Keywords; Design, experimental setup, microchannel, condenser, temperature.
I. G i d l THIEU
Voi su phat tri6n manh me cua khoa hoc va tir tinh. Gflnther ciing cpng su [3] da thiit ky thuat, nhidu san phjm cong nghe eao da ra lap he th6ng kiim tta sir ro ri cua dong ehay doi, dae biet la eae thiit bi, linh kien dien hi trong mgt he th6ng phan ph6i nuoc. Vevelstad CO kich thudc nho din cB nanomet. Cac thiit ciing cong su [4] da nghien ciiu anh huong bi nay yeu ciu co kich thuoe nho nhung voi ciia he th6ng thi nghiem len su suy giam amin.
mat dg dong nhiet Ion. Do do nhu ciu nghien Salas-Cabrera eimg cgng su [5] da lip dat mgt ciru cac thiit bi trao d i i nhiet (TBTDN) cang he thing thi nghiem cho giang day cac vin duge quan tam d i giam kich thuoe tuong ung de dgng luc hge. CJ Viet Nam, tren cae cong nhung cong suit phai Ion moi co thi dap ung b i khoa hge chinh thing, he thing thi nghiem nhu ciu c i p thiit v i ITnh vuc cong nghe cao cho cac thiet bi ngung tu kenh micro chua nay. Vi vay, truyen nhiet miero/nano la mgt dugc noi nao nghien cuu va su dung, trong nhiing ITnh vue moi va duge nhiiu nha Tir nhirng nghien ciiu lien quan tren, cdc khoa hge quan tam trong nhimg nam gin day. tdc gid chua nghien cuu hay cong bo chi tiet Lien quan den cac nghien ciru v i thiit lap ve mQt he thong thi nghiem cho thiet bi ngimg cac thiit hi thi nghiem, Fiorot eiing cpng su ^V kenh micro. Do vay, viec nghien ciiu thiet [1] da nghien ciiu thiit lap mot he thing do k i va c h i tao mgt he thing thi nghiem eho cac luong nhirng hien tugng song lan eho dong thiit bi ngung tu kenh micro d^t cac yeu cau ehay ting trong kenh ho. Manimuthu cung ky thuat va dap img eae nhu cau tren la mgt cgng su [2] da nghien cira thiit lap mgt he thach thiic va cip bach hien nay Nghien cuu thing thi nghiem don gian d i do chit dien moi se phue vu cho phong thi nghiem Truyin nhiet
Tgp Chi Khoa Hge Gido Due Ky Thugt (32/2015) Trudng Dgi Hpc Su Phgm Ky Thugt TPHd ChiMinh
Micro. Phdng thi nghipm nay tai Xudng Nhiet - Dien Ignh dugc trang bj rapt sd thiet bi do, thiet bi thi nghiem cd thi dap ling mpt sd nhu cau nghien ciiu khoa hpc trong ITnh vuc tren cho can bd giang day, hpc vien cao hpc va cac nha khoa hpc trong va ngoai Tnrdng.
II. THIET KE HE THONG THI NGHIEM
L He th6ng thi nghif m a. Nguyen ly iam viec cua TBTDN
Hai dugc cap tir Id hoi mini vao bd trao ddi nhiet (Hinh 1) nha nhiet cho nudc giai nhiet ngung Igi thanh Idng hoan toan trudc khi ra khdi bp trao ddi nhiet. Nudc giai nhiet dugc cap bdi bom mini dieu khien dugc luu lugng.
S4 SI Nuoc vao , 1 Hoi vao
Hinh 1: So do nguyen ly ciia TBTDN micro [6]
Cam biin chenh ap dugc sir dung de xac dinh do chenh ap cua thiet bi khi hoi vao thiet bi va nudc ngung ra khdi thiet hi. Bdn cam bien do nhiet dp loai T cd kich thudc dau cam biin la 200pm de do nhiet dp hoi va nudc tir 2 phia vao va ra cua bd trao ddi nhiet, ngoai ra cdn mdt sd cam bien khac dugc bd tri de do nhi?t dp ciia be mat ben ngoai thilt bj va mdi trudng xung quanh.
b. Thilt ke he thdng thi nghifm He thdng thi nghiem dugc thilt k l nhu hinh 2, d day nudc tir binh chiia 4 dugc bom micro 3 bam vao Id hoi mini, rdi dugc dun
sdi nhd dien trd, hoi ra khdi Id hai mini dugc dua vao binh on ap 7 nham dn djnh ap sudt de cdp vao thilt bi ngung tu kenh micro. Tgi day hoi ndng nha nhiet cho nudc giai nhiet, thuc hien qua trinh ngung tu ddng ap trd thanh long hoan toan trudc khi rdi khdi thilt bi ngung tu kenh micro.
Hinh 2: Sa do h? thong thi nghiem cac BTDN kenh micro [6-8]
1. Bp trao ddi nhi6t (thilt bi ngung tu k8nh micro); 2. Lo hoi mini; 3. Bom mini; 4. Binh chiia nudc; 5. Van xa nudc ngung; 6. Van dieu chinh; 7. Binh tach long; 8. Bg thu dii lieu; 9.
Mdy vi tinh.
Nudc giai nhiet dugc bom tir binh chiia day vao thiet bi trao ddi nhiet de nhgn nhiet tir hoi ndng, nhiet dp nudc tang len sau dd dugc day vao binh chiia de lam mat. Trong sudt qua trinh nay, tat ca cac thdng sd ve nhiet dp va dp chenh ap dugc bd luu trft dir lieu ghi nhan va luu tru vao may tinh.
2. Cac thilt bi a. Mini Boiler - Model: EMB-S-9 - Cdng sudt: 9kW - Dien ap: 240V
- Kich thudc: 10 1/2"W x 8 5/8"D x 25"H - Nhiet dp: 90''F . 160"?
- Xudt xir: USA
Tgp Chi Khoa Hpc Gido Due Ky Thugt (32/2015) Trudng Dgi Hpc Su Phgm Ky Thugt TP Hd ChiMinh
Hinh 3: Lo hoi mini
Ld hoi mini cd cdng suat dien trd tdi da dat 9kW (hinh 3), khi he thdng lam viec ta hoan toan cd the dieu chinh dugc cdng suat hoi ra sao cho phii hgp vdi cdng suat cua thiet bi can nghien cim.
b. Can dien tu- - Model: TE214S - Khdi lugng ddi da: 20Ig.
- D p phan giai: 0,0001g.
- S a i s d : ± 0 , 0 0 1 5 g
- Thdi gian ghi nhan dil lieu: 03 giay.
Hinh 4: Can dien tu
Can dien tii nay cd sai sd rat be va dp phan giai cao rat phu hop de xae dinh khdi lugng hoge luu lugng khdi lugng cua luu chat (Hinh 4). Trudc khi do ta phai reset thiet bi de dam bao rang tren man hinh thiet hi hien thi 0,0000 g-
c. Bp thu nhgn vd luu trir dir lieu (MX 100)
- Sd kenh: 20 kenh {nhiet dp va ap suat).
- Tdc dp ghi nhan du lieu: 0,1 giay.
Hmh 5: Bg thu nhan va luu tru dii lieu Trong nhieu trudng hgp neu eac nghien cihi can sd lugng kenh nhieu hon, van cd the ghep noi them nhieu bd Analog Input kem theo va nhu vgy sd lugng kenh de lap cam bien ap suat va nhiet do khdng cdn bj ban che. Su hien thi kit qua do dugc the hien d hinh 5.
d. Cdm biin chenh l^ch dp suat - Dien ap dau ra: 1 to 5 V - Dp chenh ap: 0-1 bar - Dp chinh xac: ±0,025% FS - Nhiet do hogt ddng: -20 . 8a°C
Hinh 6: Cam bien chenh 16ch ap suat Cam bien nay cd dp chinh xac cao sii dung rdt phii hgp d l xac djnh dp chenh ap cua luu chat giua dau vao va dau ra cua thiet bi trao ddi nhiet kenh raicro. Tin hieu dau ra 0-5V dugc lip vao bd thu nhan dii lieu MX 100 va luu trii dii lieu vao raay tinh.
e. Cam bien nhiet dp
Cam biin dugc su dung la logi T cd kich thudc rdt nhd vdi dudng kinh day va ddu cam biin khoang 200 pm. Vdi kich thudc nay, cac cam biin d l dang bo tri tgi cac dau vao va dau ra cua thilt bi frao ddi nhiet ma khdng gSy anh hudng Idn din ddng ehay cua luu chat.
3 . Mot s6 thilt bi khac
Thilt bi an toan diing trong he thdng dilu khiin cua id hoi mini gdm: _ ,
- Van an toan tu dpng dugc lap cd dinh tren
Tgp Chi Khoa Hpc Gido Due Ky Thugt (32/2015) Trudng Dgi Hge Su Pligm Ky Thugt TP Ho ChiMinh
dudng hoi ra: van an toan nay lam viec khi ap suat hoi qua cao ma ro le ap suat chua hoge khdng tac ddng.
- Ro le ap suat dugc su dung de bao ve tir dpng eho Id hai: niu ap suat cua hoi cao han gia trj cai dgt thi ro le tac ddng ngat ngudn dien cdp cho dien trd gia nhiet cua Id hoi.
- R a le nhiet dp dugc sii dung de dam bao an toan trong trudng hgp thieu nudc cap vao Id hoi, liic nay phan dien trd se gia nhiet cho phan hoi bao hda lam dp qua nhiet ciia hoi tang: n i u nhiet dp hoi qua nhiet han gia tri cai dat thi ra le nhiet ciing tac dpng lam ngat ngudn dien cap cho dien trd gia nhiet cua Id hoi.
Lugng hoi va cac thdng sd vat ly (nhiet do vd dp sudt) dugc dieu khien dn djnh de cap vao bp trao ddi nhiet nhd van giam ap (xd ra moi trudng) dugc dieu chinh bang tay.
Muc nudc trong 16 hai dugc duy tri nhd bom mini cap nudc, bom nay dugc dieu chinh cap nudc diing bang lugng nudc trong 16 hai da hoa hoi.
1. Nghi§n cmi thuc nghiem qua trinh ngung ty cua thiet bj trao ddi nhiet kenh
Bdng 1: Mo ta hinh hge ciia hai thiet bi Uac doi nhiet dimg trong thi nghiem [6]
STT
Tl T2
Kich thudc substrate (mm) L 46 46
W 26,5 26,5
T 1,2 1
Kich thuoe cac kenh micro (jim) Phia hoi W 500 500
D_
300 300
Phia nuac W^
500 500
D, 300 180
Hinh 8: Mo ta kich thudc cua cac mau thi nghiem [6-8]
Trong nghien ciiu nay tac gia da nghien Cliu sir anh hudng ciia chieu ddng ehay len dac tinh truyin nhiet ciia cac bd trao ddi nhiet kenh micro cho 2 thiet bi ngung tu mau Tl va T2 (hinh 8. hdng I). Kit qua dugc thi hien tren bang 2.
Bang 2: Ket qua cdng sv^t thiet bi
Hinh 7: He thdng thi nghiem da hoan thien va dua vao van hanh thii nghiem.
III. KET QUA THirC HIEN He thdng thi nghiem nay da dugc dua vao su dung, cac ket qua thi nghiem cung da dugc cdng bd tren mdt sd tap chi va hdi nghi khoa hoc cd phan bien (nhu Hinh 7). Sau day la mot sd kit qua minh chimg tir ling dung ciia he thdng nay.
TBTDN
Tl T2
g/s
0,123 0,0481
m g/s
3,159 3,159
Cong suat nhiet (W) Nguge
chieu 194,63 111,52
Ciing chieu 184,32 107,197 la luu lugng hoi ngung (g/s)
: la luu lugng nudc giai nhiet (g/s)
Tgp Chi Khoa Hpc Gido Due Ky Thuat (32/2015) Trudng Dm Hge Su Phgm Ky Thugt TP HS Chi Minh
Trong qua trinh thuc nghiem ca hai md hinh cd cimg dieu kien lam viec: hoi cd nhiet dp 101°C va nudc lam mat cd nhiet dp va luu lugng khdi lugng tuong ling la 32°C va 3,159 g/s. Ca hai md hinh nay dugc thi nghiem khi cimg vi tri nam ngang. No dugc khao sat cho thay rang lugng nhiet thu dugc tir so dd nguge chieu ludn cao hon gia tri thu dugc tir so dd cung chieu: Gia tri thu dugc tir so dd nguge chilu gdp 1,04 din 1,05 idn so vdi gia tri thu dugc tir so dd cung chieu. Ket qua nay ciing ddng thuan vdi ket qua thu dugc trong truyen nhiet mdt pha (single phase); tuy nhien, nd chi ra rdng su anh hudng ciia chieu dong ehay trong d6ng hai pha khdng nhieu bang anh hudng trong ddng mdt pha [6].
Trong nghien cim nay tac gia da su dung hai md hinh diimg va nam ngang de danh gia hieu qua trao ddi nhiet cua hai thiet bi tren (bang 1).
Kit qua thu dugc tu nghien ciiu nay the hien rang hoi ngung tu qua thiet hi giam khi giam dudng kinh quy udc cua kenh, nhu the hien d hinh 10. Vdi bd trao ddi nhiet cd dudng kinh quy udc cua kenh 375 pm, san lugng hoi qua thiet bi nay dugc ngung tu d 0,123 g/s;
vdi bp trao ddi nhiet cd dudng kinh quy udc cua kenh 265 pm, san lugng hoi qua thiet bi nay dugc ngung tu d 0,0481 g/s.
• Water lein)aaiure diflaHKC
Inlet water temperature, °C
Hinh 9: Anh huong nhiet do dau vao ciia nudc lam mat trong BTDN Tl [6]
Ngoai ra, tac gia cdn danh gia su anh cua nhiet dp nudc giai nhiet den nhiet dp dau ra cua ca phia hoi va nudc cho bd trao ddi nhiet T l . Ket qua cho thay rang khi nhiet dp nudc dau vao lam mat tang, nhiet dp dau ra cua nudc lam mat tang; tuy nhien, dp chenh nhiet dp giua dau vao va dau ra nay tang cham.
Nhu mdt ket qua, dp chenh nhiet dp cua phia hoi giam hay nhiet dp dau ra phia hoi tang nhanh. Dieu nay cd y nghia ring hieu qua truyen nhi8t ngung tu trong cac thilt bi ngung tu kenh micro nay giam khi tang nhiet dp dau vao cua nudc giai nhiet, nhu thi hien d hinh 9.
2. Nghien cmi anh hudng kich thirdc kenh den qua trinh ngung tu cua bg trao doi nhiet kenh micro.
Hydraulic diameter, mm
Hinh 10: Moi quan he giiia hoi ngung tu va dudng kinh quy udc cua kenh micro [7].
Ddng thdi vdi ket qua hinh 11 the hien mdt quy luat trong thiet bi nay dd la khi luu lupng khdi lugng cua nudc lam mat giam thi hoi ngung ty giam tuy nhien giam khdng dang ke.
Them vao dd, vdi nhirng sd lieu thuc hien tren bp trao ddi nhiet T l , kit qua thuc nghiem thi hien rdng mdt lugng nhiet 269,21W thu dugc d trgng thai hoi cd nhiet dp va san lugng hoi ddu vao tuong ling la 101°C va 0,1299g/s va cho nudc giai nhiet cd nhiet dp va luu lugng khdi lugng tuong ling la 33°C va 3,1136g/s.
So sanh giiia kit qua thu dugc ttong nghien Cliu nay vdi cac kit qua thu dugc trong [7], nd da thi hien ring lugng nhiet trong qua trinh ngung tu cao hon so vdi nhiet lugng trong qua trinh ttiiyin nhiet mdt phase khi diing ciing mdt bp trao ddi nhiet TL
Tgp Chi Khoa Hpc Gido Due Ky Thugt (32/2015) Tnrdng Dgi Hge Su Phgm Ky Thugt TP. Hd Chi Minh
Mass fbw rale of water, g/s
Hinh 11: Mdi quan he giira hoi ngung tu va luu lugng khoi lugng cua nudc [7].
Bang 3 cho thay rang lugng nhiet thu dugc tii vi tri nam ngang khdng khac gi so vdi cac gia tri thu dugc ciia bd trao ddi nhiet dat d vi tri thang diing.
Bdng 3: Cac gia tri thuc nghiem d vi tri diing va nam ngang [7]
Cac ket qua trong bang 4 cho bd trao ddi nhiet T2 dat dugc cac gia trj tren d dieu kien hoi cd nhiet dp va luu lugng vao tuong ling la 101 °C va 0,0481 g/s va nudc giai nhiet cd nhiet dp va luu lugng vao tuong img la 31,9°C va 3,1904g/s. Tu cac gia tri trong bang 4, nd dugc the hien rang lugng nhiet thu dugc tir bd trao ddi nhiet T1 cao hon gia tri thu dugc tir bp h-ao ddi nhiet T2 [2]. Lugng nhiet 187,6 W thu dugc tii T l d dieu kien hoi cd nhiet dp va luu lugng vao tuong ling la 101°C va 0,0758g/s va nudc giai nhiet cd nhiet dp va luu lugng vao tuong img la 32°C va 3,2004g/s.
Tir nhiing ket qua thi nghiem tren, he thdng thi nghiem nay dang tin cay va hoan toan cd kha nang dap ling cho cac dinh hudng nghien Cliu khac trong tuong lai.
IV. KET LUAN
He thdng thi nghiem da dugc thiet ke va lap dgt thanh cdng, san sang phue vu cho cac nhu cdu thi nghiem tuong tu nhu nhfing ket qua da nghien ciiu d tren.
Cac ket qua thye nghiem tir h& thdng nay dang tin cay, nen he thdng thi nghiem nay cd thi dugc dimg d l thuc hien cac thi nghiem truyen nhiet micro,...
Ngoai ra, he thdng nay cdn cd the phue vu cho su danh gia hieu qua cac thiet bi trao ddi nhiet khac nhau cho ca trudng hpp luu chat khdng chuyen pha hoae chuyen pha tir trang thai hai ngung tu thanh trang thai long va nguge Igi.
TAI LIEU THAM KHAO
[1] G.H. Fiorot, G.F. Maciel, E.F. Cunha, and C. Kitano, Experimental setup for measuring roll waves on laminar open channelfiows, Flow Measurement and Instrumentation, Vol.
41, 2015, pp. 149-157
[2] P. Manimuthu, N. Praveen Shanker, K. Saravana Kumar, and C. Venkateswaran, A simple experimental setup for magneto-dielectric measurements, Physica B: Condensed Matter, Vol. 448, 2014, pp. 354-355
[3] M. Gunther, D. Steffelbauer, M. Neumayer, and D. Fuchs-Hanusch, Experimental Setup to Examine Leakage Outflow in a Sealed Water Distribution Network, Procedia Engineering, VoL 89, 2014, pp. 311-317
[4] Solrun Johanne Vevelstad, Andreas Grimstvedt, Hanna Knuutila, Eirik Falck da Silva, and Hallvard F. Svendsen, Influence of experimental setup on amine degradation, International Journal of Greenhouse Gas Control, Vol. 28, 2014,pp. 156-167
Vitri Dung Nam ngang
Cong suit nhiet Q (W) MluTl
187,3 187,6
M§uT2 107,4 107,2
Tgp Chi Khoa Hpc Gido Due Ky Thugt (32/2015) b 9 Truong Dgi Hoc Su Phgm Ky Thugt TR Hd ChiMinh
[5] Salas-Cabrera, R.; Mayo-Maidonado, J.C. ; Gonzalez-Hernandez, J.G. ; Salas- Cabrera, E.N. ; Garcia-Santiago, F A . ; Martinez-Bemal, J.E. ; Castillo-Gutierrez, R., An experimental setup for teaching dynamic systems, Electrical Communications and Computers (CONIELECOMP), 2011 21st International Conference on, Feb. 28 201 l-March 2 2011, pp. 239-243
[6] Thanhtrung Dang and Minhhung Doan - An Experimental Investigation on Condensation Heat Transfer of MicroChannel Heat Exchangers, International Journal of Computational Engineering Research, Vol. 3, Issue 12, pp. 25-31(EI)
[7] Thanhtrung Dang, Minhhung Doan, Ngoctan Tran, and Jyh-tong Teng - Efi^ect of Configuration on Efficiency of Condensation Heat Transfer in Microchannels - An Experimental Shidy, ISEPD 2014.
