6* NLN-108 Ml/2012
- Moi quan hp giO-a he so trao doi nhiet buong dot 87,7 - 119,2 W/m^K vai tai Ifi hai 3.000^5 000 kg/h, nhiet dp bufing dot 631 ^ 813°C va tfic dfi gio cSp 0,27 -f 0,45 m/s la quan hp t u y i n tinh.
K i t qua tinh toan phu hap vPi giS tn do tai d i l u kiSn van hanh t y a n g i>ng vfi-i t h i l t k l vS so lieu mot II so tac gia da cfing bo. Do vSy co the xem IS tin eay
vS Sp dung vao thyc t l d y p c . ABSTRACT
This paper presents research on calculation of heat transfer coefficient in the rice-husk fired Improvement Fluidized Bed Boiler Furnace - IFBBF. Calculation results were compered with expenmental data. Some main results received are as follows: freeboard heat transfer coefficient is 119.2 W/rr?K, minimum fluidization velocity is 0.2 m/s and fluidization velocity is 0.45 m/s, fluidized bed temperature is 856 °C and freeboard temperature is 813
°C The relations between heat transfer coefficient and unit load, freeboard temperature and bed velocity are analyzed The linear relations could be accepted for the IFBBF design regarding to heat transfer coefficient range 87 7-r119-2W/m^K. unit load 3000^000kg/h, freeboard temperature 631 SI3 °C and bed velocity 0.27^.45m/s.
TAI LIEU THAM KHAO
[1]. P Sathitruangsaka, T. Madhiyanonb, S Soponronnarita (2009) Ricehusk co-finng with coal in a short-combustion- chamberfluidized-bedcombustor (SFBC), Fuel. 88(8), 1394-1402.
[2] M Rozainee, S.P, Ngo, A A Salema K.G Tan, M, Anffin, Z N Zainura (2008) Effect of fluidising vetocity on the combustion of rice husk in a bench-scale fluidised bed combuslor for the produclion of amorphous nee husk ash Bioresource Technology 99(4), 703-71
(3] L Amiesto, A. Bahillo, K Veijonen, A. Cabanillas and J Otero (2002) Combustion behaviour of nee husk in a bubbling fluidised bed.
Bbmass and Bioenergy, 23(3), 171-179
[4] Sheng Huang, Shan Jing, Jinfu Wang, Zhanwen Wang, Yong Jin (2001) Silica while obtained from ncehusk in a fluidized bed Powder Tec/Jno/ogy. 117(3), 232-238 5) F Johnson, B A
[5] Andersson, B Leckner (1987) Heat flow measurements in fluidized bed boilers. Proceedings of a!" International Conference on FBC - Boston, (1), 592-597
[6] W Pnns (1987) Fluidized bed combustion of a single carbon particle. PhD dissertation. University Twente, Enschede (the Netherlands]
[7] Chen Guanyi, Fang Mengxiang, Luo Zhongyang, Yu Chunjiang, Li Xuantian, Ni Mmgjiang, Cen Kefa (1998) The Study on Combustion Charactenstics of Rice Husk Fired Fluidized Bed Boiler Journal of combustion science and technology
[8] T Madhiyanon, P Sathitruangsak and S Soponronnant (2010) Combustion charactenstics of nce-husk in a short-combustion- chamber fluidized-bed combustor (SFBC). Applied Themial Engineering. 30(4), 347-353
[9] Prabir Basu (2006) Combustion and Gasification in Fluidized Beds Taylor & Francis Group, LLC.
[10] Simeon N Oka, EJ. Anthony (2004) Fluidized Bed Combustion. Marcel Dekker, Inc Newyork - Basel
111]. Guangxi Vue, Hai Zhang, Changsui Zhao, Zhongyang Luo (2009) Proceedings of the 20" International Conference on Fluidized Bed Combustion Tsinghua University Press, Beijing and Sprmger-Verlag Berlin Heidelberg
[13] Phgm HoSng Lu'ong, Do V3n ThSng (2006), "Nghien cim 1/^ img dung cdng ngh$ ldp sdi vA Idp sdi tuan hoin & Viet nam", B^o cSo liln d« d^ An 10/HO-UTCN 2005-2006 OHBKHN
Phan bien: PGS. I S T r y a n g Duy NghTa
TAN DUNG NHIET THAI TUT DAN NGUNG MAY DIEU HOA KHONG KHI CONG SUAT NHO DUN NUdC NONG
DE TIET KIEM NANG LUONG
B U I N G Q C H U N G , DH Bach khoa- Dfi Quoc gia Tp. Ho Chi Wnh Viec sO dung miy dieu hda khong khi vi miy nwov ndng da tr& nen pho bien trong phan l&n cac hp gia dinh o* cic thinh pho lan cua nudfc ta hien nay. Tuy nhiin cac thiet bj nay dang dwac sir dung mpt each dpc lip dong thdi tiiu ton mpt luv'ng dien nang hang thing ding ke trong cac hp gia dinh. Bai bio niy dua ra mpt hwang tich hgp hai he thong may dieu hda khong khi vi may nied'c ndng noi tren de tiet kiem ning lieg-ng bang each tin dung nhiet thai to- cac dan ngwng miy dieu hda khong khi di dun n u o c ndng. Mgt md hinh thuv nghigm thu hoi nhiet thai tO' dan ngung cua miy dieu hoa khong khi lo^i hai phan rdri (split type air conditioning) su' dung thiit bj trao doi nhigt dang ong xoan da dwo'c hoin thanh. Bang vigc do dac cic thong so hoat dpng cua md hinh da chd'ng minh tinh kha thi cOa mo hinh si> dung thiet bj trao doi nhiet ong xoan cung nhw vigc thu hoi nhiet thai khong anh hwong den hoat dpng binh thwdng cua miy dieu hoa khdng khi.
I. 016^1 THIEU
Nhifit thai tCr t h i l t bi ngyng ty cua hp thong lanh d y a c xem la nguon nhiet thai cP nhiet dp thap Cfi nhieu p h y a n g Sn de thu hoi nhipt thai cua hi thong lanh, tuy nhien ph6 b i l n thyfi-ng IS s y dyng nguon nhiet nSy d l dun nfing n y P c phyc vu sinh hoat hoSc gia nhiet s a bfi cho eSc qua trinh cong nghipp [1].
Boi vPi vipc s y dung mSy d i l u hfia khfing khi hi0n nay, c h y a eP mfit nghiPn cO'u cy t h l v l lupng dipn nang tieu thy hSng thSng trong eSc hp gia dinh cP s y dyng mSy dieu hda. Tuy nhien neu dya vao cSc so lipu thong ki, cong suat difin ti&u thg eho hfi t h i n g dieu hfia trong cac cfing trinh nhy eao I c , vSn phPng, khach san chiem tir 4 5 % d i n 55% tong lyang dien tifeu thu [2]. NgoSi ra mSy nyfi'c nfing cCing d y a c xem IS mfit trong nh&ng t h i l t bj tifeu thti diPn IPn so vPi cSc thiet bi difin gia dung khSe [3]
O i n nay dS co nhieu nghi6n cu-u de giam lypng dipn nang tieu thy cua mSy dieu hfia khfing khi vS mSy n y p c nfing. D l i vPi mSy dieu hfia IS thay doi nhiSt dp cSi dSt ban ngSy, ban dem, thay doi lu'u lypng khfing khi theo phy tai t h y c t l [4] hoSc si>
dung bam nhipt d l t i l t kiem nSng l y a n g [5]. Vi$c su' dyng ong nhiet dao dong de thu hoi nhipt thai t y thilt
bj ngyng tu dang 6ng-vo da d y p c thyc hien bai Ngoe Hung Bui vS cSc cfing s y [6] VPi he thong dieu hPa khfing khi, P Sathiamurthi vS PSS.
Snnivasan [7] dS k i t luSn tinh kha thi vS twin qua kinh t l cua hp thong thu hfii nhiet thai tO mSy dieu hfia khfing khf trung tam cfing suat 16 tons lanh de cung d p nyPc nfing eho sinh hopt cija 600 sinh viPn trong mfit ky tCie xS Trong ITnh v y c dan dung, M M.
Rahman, Chin Wai Meng vS Adrian Ng [8] da nghien eyu h$ thong thu hoi nhipt thai dun nyPc nfing tO mSy d i l u hfia khfing khi dan dung vPi t h i l t bi trao doi nhipt bSng I n g dfing quSn ben ngoai vo cua binh nyac nfing vS dS k i t luSn r i n g cfi t h l gia nhiet nyPc trong binh t y 30°C den 75°C trong vfing 8 giP may d i l u hfia hoat dfing
Trong nyPc, Nguyin Dinh Vjnh, HS DSng Trung dS nghiPn eyu thiet k l , che tao vS thy nghifim thilt bi bam nhiet dun n y p c nfing s y dung tSe nhan lanh R22 vS dan Ipnh khfing khi trong d i l u kipn khi hSu Viet nam [9], CSc tSc gia da k i t luan thiet h\ bam nhipt dun nyPc nong cfi COP dpt 3,3 den 3,8 trong d i l u kipn mfii tryPng trong nha 22 °C vS dp am 60%, tiet kipm d y a c 65% d i n 70% nSng lyang tieu thu so vPi binh dun nyPc nong bSng diPn.
D^ t i l t kiPm nSng lyang trong viec d i l u hPa khfing khi vS dun nyPc nfing, bSi bSo nSy trinh bSy vipc nghiPn cCru thiet k l c h i tpo mfi hinh thu hoi nhipt thai tCr dSn nfing cua mSy d i l u hfia khfing khi d l dun nyfie nfing phyc vu sinh hopt trong eSc hfi gia dinh. Mfi hinh su" dyng dSn trao doi nhipt doi lyu t y nhien I n g xoln bSng dong dpt bfin trong binh nyfi'c nfing nen de che tgo vS cfi giS thSnh re phCi hap vPi d i l u kien cfing nghfi vS klnh t l cua nyPc ta hipn nay.
II. CAC Y ^ U T 6 ANH HU'DNG D^N VieC THU H 6 | NHieT THAI TLT DAN NGLfNG MAY B\t\J H 6 A KHONG KHi
2.1 Kha nang t h u hdi nhipt thai tLF may d i i u hoa khong khi
Do thj T - S cua sa do nguyPn ly mSy d i l u hPa (hinh 1) d y p c t h l hipn trPn hinh 2. Quan sSt tr&n do thj T - S nhSn thay cfi the thu hoi toSn bp lypng nhipt ngyng ty q^ n l u nhipt dp n y p e nfing s y dung cfi giS tri nhipt dp thap han nhifit dfi ngyng ty eua hp thing Ipnh giai nhifit bSng nyac.
3/7\^y
/ \ \ / \ \ / '^^ Q/" K
1 1 1 1
2
r
S* Sl s
Hinh 2. Dd thl T - S
N l u toSn bfi lypng nhifit thai o- t h i l t bi ngyng tu d y p c thu hoi, la cfi he so thu hoi nhiet thai ly thuylt d y p c tinh nhy sau:
COR, (1)
'•(S)
VPi mSy d l l u hPa khfing khi sCi' dung tSe nhan lanh R22, gia tn COP ly t h u y l t o- cSc nhiet dfi ngyng ty khae nhau d y a c tinh theo cong thyc (1) vS trinh bSy trong bang 2. Qua bang 2 nhpn t h i y giS tn COP cSng cao khi nhiet dfi ngyng ty cSng thap-
Hien nay eSc mSy dieu hfia khfing khi dang dypc s y dung vpi nhieu lopi tSc nhan lanh khSc nhau nhy dypc trinh bSy trong cSe bang 1, 2 vS 3. Dya vSo cSc thflng so trpng thSi cua nh&ng d i l m d§c bipt tr6n chu trinh vd\ cSc loai tSc nhSn lanh nhy R22, R410A, R407C, R134a nh^n thay nhipt dp sau mSy nPn pho biln trong khoang 78°C d i n 82°C d nhiPt dfi ngung ty 50°C. VPi tSc nhSn lanh R22 khi nhi$t dfi ngyng tu thay doi trong khoang 40°C d i n 50°C tht nhifit dfi sau mSy n6n thay doi trong khoang 68°C d i n 82°C. Tuy nhien nhiet dfi cua tSc nhan lanh sau mSy n6n (dilm 2 trfin do thi T-S) cfi t h l cao han [10] do mSy lanh hoat dong vdi chu trinh thyc t l cfi eSc ton that ap suat eua thilt bj ngyng tu, bay hai cCing nhy quS trinh nPn khfing doan nhipt vS khfing thuan nghjch trong mSy n6n nhy d y p c t h l hipn trong hinh 3.
Nhy vpy he so thu hoi nhiet thai thye t l cP t h l d y p c tinh tren ca so* lypng nhifit n y a c nfing trong binh nhSn d y a c vS dien nSng tieu thy cua mSy dieu hPa cu the theo cfing thCfc nhy sau;
co/;,=f:S^l (2)
S^ng" 1. Thdng so cua cic diem tr^ng thii trin do thi T- S sir dyng tSc nhSn lanh R22
Hinh 1. Scr d& nguy§n ly cua mAy dieu hda khdng khi
R22
trangthii 1 1' 2 2' 3 i
trc]
0 10 81.64
50 50 0
Plbarl i [kjykg]
4 983 ' 704 28 4 983 7 U 6 2 19.395 T-lJ.SOaS , 19.395 r 716 78
19 395 T 562.75 4,983 562,75
s [kJ/kG K]
1 7479 1 77d3 1.7743 1 5 8 3 2 1 2065 1 2297
8 * NLN-108'11/2012
Sang 2, Nhiet do sau may nen, ap suit ngung tu va hi so COP nhiet thai cua R22 (9/ cac gia tn nhiet dq ngung tg
khac nhau J'C]
40
rci
81.64 74.82 67 92
s p s j a t n e v n E t w Ibir) I 19.395 17.265 15 315
COP 5,1372S 5 75633 6,0553:
2.2 Tac nhan lanh va cac thong s o hoat dong Bang 3: Nhi^t dg sau may nen cua mpt sd tac nhan l^nh
thdng dicing a nhi$t dp ngung tu 5(fC Tacnhanlanh
H22
R407C R410A
Mii^td^c u may ntn o-nbi^f d$ ngu-ng l y SO'C 81.G4
63 51 79 73
Hfi s6 tmyIn nhiPt tCr hai tSc nhSn lanh quS nhipt a d i l m 2 d i n trang thSi hai bao hpa o" d i l m 2' dypc tinh theo quS trinh t m y I n nhipt 1 pha gii>a dfing hai trong fing vS nyfi'c dfii lyu t y nhiPn bPn ngoSi fing nhu sau
a = wj d
Trong dfi; A^K =0,021 R e " ' P r " " ' (4) Hp sfi t r u y i n nhi#t khi ngyng cua hai tac nhSn lanh bao hoa a diem 2' d i n trang thSi long bao hoa a d i l m 3 d y p c tinh theo quS trinh ngyng hai trong trong ong va n y P c doi l y u t y nhi§n bfin ngoSitng.
Theo [11] hfi so tea nhi0t khi ngyng tu cua hai t^c nhSn lanh trong ong d y a c tinh theo cfing thue nhu sau
^o,.sf^^|^(..^c.(,. -O
(5)III. MO HiNH THU'C NGHIEM SCF DUNG DAN TRAO D O I NHIET 6 N G X O A N O O I LUOJ TU" NHIEN
3.1 T h i l t k l mo h i n h
Mo hinh bao gom 1 phfing a gia dinh co dien tich 12 m^. PhPng d y a c trang b| 1 bfi may d i l u hoa nhiet dp loai 2 phan rpi s y dung tSe nhan lanh R22. Mpt van by-pass d y p c trang bj de cfi the hoat dfing mfi hinh 6' 2 c h i dfi cfi thu hoi nhiet thai vS khfing cfi thu hoi nhiet thai (hinh 4)
Theo [2] tinh d y p c cfing s u i t cua mSy d i l u hfia la 9000 BTU/h Gia s y phfing cfi 3 ngyPi a, mfii ngypi s y dung 30 lit n y a c nfing cfi nhiet dfi 45''C trong mfit ngSy, xSc dmh l y p n g nyPe nPng can cung d p IS 90 lit
Thiing n y p c nfing co dung tich 90 lit d y p c lam bSng inox 304 c h y a dan trao doi nhl^t ong x o l n b i n g I n g dong cfi d y a n g kinh ngoSi 10 mm, De giam ton thSt nhiet cua nyfi-c nfing ra mfii trypng, binh d y a c boc eSch nhiet bSng vat lieu thermaflex cfi b l dSy 20 mm. NgoSi ra de tang hifiu qua trao doi nhiet, t h i l t bj trao doi nhi^t ong xoan cfi ngfi vSo cua tSc nhan lanh o' phia tren vS ngo ra a phia dyPi nhy d y a c minh hpa trong hinh 5.
Nhifit dfi cua nyPc trong binh d y a c do b i n g 03 cam b i l n gSn a 3 vj tri b6n d y P i (each dSy binh 100 mm), ben tren (cSch dfnh binh 100 mm) vS gi&a binh nhy hinh ve 5. NgoSi ra eae thong sP nhiet dfi mfii tryfi'ng, nhiet do tae nhSn lanh vSo va ra bp trao doi nhifit, ap s u i t ngyng ty va ap suat bay hai, cyfi'ng dp dong dien vS di#n ap cung d y a c do dfing thPi trong quS trinh thi nghiem
3.2 Tinh dien tich hi mat t r u y i n nhiet cua t h i l t bj thu hfii nhiet thai dang fing xoSn trong mo hinh
QuS trinh t r u y i n nhi^t tii' tSc nhan lanh trong thiet bj trao doi nhi$t den nyPc nong trong bon tich try bao gom 2 phan. t r u y i n nhipt 1 pha giya nyPc vS hai tSc nhSn lanh ti> trang thSi qua nhifit d i n hai bSo hda khfi va quS trinh ngyng ty eua hai bao hfia khfi d i n trang thSi long bSo hfia
Vai mSy d i l u hoa khong khi eP eong suSt 9000 Btu/h, thay cac gia tri so eua tSc nhSn lanh R22 trong bfl trao doi nhigt dfii l y u t y nhifin dang fing xoln b i n g dPng co dyPng kinh ngoSi 10 mm dSt ben trong binh n y a c nong cfi nhi^t do trung binh 40*'C vao cSe eflng t h y c (3), (4) vS (5) ta eP d y p c k i t qua tong chieu dai I n g truyen nhi^t IS 10,7 m IV. K^T QUA VA THAO LUAN
Cac so lieu thye nghipm d y p c ghi nhan dong thd'i theo thpi gian tai nhieu thPi diem khSe nhau trong ngay de the hien eho hoat donp eiia 1 mSy d i l u hfia trong thye t l vS d y p c the hien bSng eSc do thj nhy hinh 6
S y thay doi nhiet dfi eua nyPe nfing trong binh theo thai gian d y a c t h l hi6n trPn hinh 6. Nhiet do nyfi'c thay doi t y 32°C d i n 53''C trong thai gian 1 gia 50 phut. Luc d i u nhi^t dfi cua nyPe tang nhanh do nyPe trong binh co nhiet dp thap nen toan bfi lypng nhiet l y p n g thai cua mSy dieu hfia dyac nu'Pc hap thy va he t h i n g cP the xem nhy d y p c giai nhi6t bSng n y a c . Khi nhiet dp n y P c tSng, nhi^t dp ngung tu vS ap suat ngyng tu se tSng theo. Khi Sp suit ngyng tu tang d i n giS tri bSng giS trj cua hp thong giai nhi&t b i n g khong khi thl nhi0t lypng nyfi'c trong binh nhan d y p c b i t dau giam ISm cho nhifit dp cua n y a c trong binh tang chSm lai vS khi nhi#t dfl nufi'c cao han nhipt dp ngyng ty thl nyPc chT cfin nhan d y a c phSn nhiet l y p n g quS nhipt cua tSe nhan lanh (ty diem 2 d i n d i l m 2' tren do thi T - S), gia tri nhiet dfi Ifi-n nhat cua nyfi'c trong binh phu thufic vSo nhifit dp eua tSe nhSn lanh sau mSy nen (diem 2 tren do thl T - S) vS loai t h i l t bi trao doi nhi$t s y dung Ngocii ra d y a vSo hinh 6 nhan thay can mpt thai gian hoat dpng eua mSy dieu hfia khoang 40 phut d l gia nhi^t cho nyPc t y nhifit dp moi tryPng 32°C den nhiet dg cfi the s y dung cho sinh hopt IS 45°C
Hinh 7 trinh bSy s y thay doi nhi^t dp cua tac nhan lanh dl vSo va ra khoi bO trao doi nhipt t y a n g yng vd\
nhiet dp eua nyPe nPng trong binh tieh tri> Khi h§
thong^ b i t dau hopt dpng, do nyPc trong binh co nhi^t dfl thap nen toSn bfi nhipt lypng thai ra a t h i l t bi
Hinh 3. D6 thi T-S cua chu trinh lanh thyc
Hinh 4. Sodd nguyen ly cua md hinh thuc nghiem
Hinh 7. Su thay doi nhi^t do cua tac nhan l$nh di vao vA ra khoi bo trao doi nhi$t
ngyng tu d i u d y a c nyPe hSp thy Khi nhifit do nyPc trong binh tich try tang dSn, nhipt dp cua tSc nhSn lanh dl ra eung tang theo, cfi nghTa IE ' "ong nhiet thu hfii giam.
Hinh 8 trinh bSy s y thay doi eua Sp suat ngyng tu theo nhifit dfi cua nyfi'c nfing trong binh tich trij Khi nhiet dp nyPc trong binh tich try tSng thi Sp s u i t ngyng ty tang Tuy nhien khi nhiet dfi nyPc nfing trong binh lan han 45''C thl Sp suat khfing tSng vS giU I n dmh a giS trj gan b i n g vo'i gia tri ap s u i t cOa he thfing khi khfing thu hoi nhiet thai. D i l u nay IS do bfi trao doi nhipt I n g x o l n d y p c ISp noi tiep vd'i dSn ngyng giai nhipt b i n g khfing khi cua mSy d i l u hfia.
Do dfi khi nyfi'c trong binh tSng thi ap suat ngyng ty tang theo, khi ap s u i t nSy tSng d i n giS tn Sp s u i t cua he thong giai nhiet b i n g khfing khi thi tScnhSn lanh khfing ngyng ty trong t h i l t bi thu hoi mS b i t dSu ngyng ty trong dSn ngyng giai nhifit b i n g khfing khi cua mSy dieu hfia. Ap s u i t ngyng ty I n dmh khi toSn bfi nhiet lyang ngyng ty ( d i l m 2' d i n 3 tren do thj T- S) d y a c thai ra o' dSn ngyng cua may d i l u hfia. Do Sp s u i t ngyng tu cua t h i l t bi ngyng tu giai nhipt bSng khfing khi phu thufic nhifit dp mfii tryfi'ng va phu tai trong phong, nen khi cSc thfing so nSy thay doi ISm cho Sp s u i t ngyng tu dao dflng the hipn bSng eSc giS tri Sp s u i t giam vS tSng lai nhy d y p c t h l hien tren hinh 8.
Hinh 6. Sy thay d6i nhi^t dd cia nuac ndng trong binh tich tru theo thdi gian
Nhifl a5 tnjng binh cua nirtc troni) Binh llcft Irir fC\
Hinh 8 Sy thay doi ip suit ngung tii theo nhiet dp cOa nu&c ndng tmng binh tich Iru
10* NLN-108'11/2012
Hinh 9 Sy thay doi cudng dd ddng di$n cua md hinh trong trud'ng hop cd thu hdi nhiet thai va khong thu hoi nhiet thai Hinh 9 trinh bSy s y thay doi c y p n g dp dfing dien eua mfi hinh trong tryang hap cfi thu hfli nhiet thai vS khflng thu hfli nhiet thai. Khi hfi thflng hoat dflng o- c h i dfi khfing thu hoi nhiet thai (van by-pass tren mfl hinh ma), cyfi'ng dp dfing dien on dinh quanh giS tn dinh mi>c vS chi dao dflng theo nhiet dp mfli tryang, dien ap vS phy tai. Khi he thong hoat dflng a che dfl thu hoi nhiet thai, cyPng dp dfing dien co gia tn nho han giS trj djnh miFC khi nhiet dO nyPc nfing trong binh thu hoi cfin thSp Khi nhiet dfi nyPc tang d i n thi cyPng dfl dfing dien tang, nhyng v i n khfing v y a t quS giS tn hoat dflng cua he thfing trong traang hap khfing thu hoi nhiet thai Dieu nSy cfi nghTa vPi he t h i n g cfi thu hfli nhiet thai, cfi the t i l t kiem mot phan difin nSng khi nhiet dfi n y p c trong binh tich trij cfi giS tri nho han 40°C.
^ Hinh 10 trinh b S y s y thay doi cua he sfi COP thu hoi nhiet thai thyc t l theo nhiet dfl eua nyPc nong trong binh tich _tr& Qua hinh 10 nhSn thay hp sfi COP thyc t l b i t dSu giam khi nhiet dp n y a c cao han 40°C Khi nhiet dfi n y p c nfing cSng eao thi gia trj COP thyc t l cSng giam. So sSnh giS tri eua hfi so COP thyc t l vo'i giS tri eua he so COP ly t h u y l t trong bang 2 nhan thay khi nhipt do n y P c nflng trong binh cfi g^ia tn nho han 40°C thi l y p n g nhiet thai thac t l thu hoi d y a c khodng 50% d i n 60% so vPi ly thuylt
Nhl^l 0^ ntr<>c ndng irong binh I °C|
Hinh 10 Su thay doi cOa he so COP thu hoi nhiet thai thuc te theo nhiet do nuac ndng trong binh tich Irij-
Khi nhiet dp nyPe nong trong binh tang d i n 45 °C thi chi cPn thu hoi d y p c khoang 2 5 % vS l y p n g nhifit thu hfli se giam d i n khi nhiPt dfi nyfi'c trong binh cSng tSng. Dieu nSy cfi nghTa la hP thong ehi hoat dfing hipu qua khi nhiet dfi n y p c nPng can s y dung cfi giS tri nho han 40*'C
V. K^T LUAN
Lypng nhifit thai co the thu hfii t y 1 mSy d i l u hfia khfing khi phu thupc rat nhieu y l u to ve dieu ki^n hoat dflng nhy nhiet dfl ngyng ty, nhiet do tSc nhSn lanh sau mSy nen, nhiet dfl vS l y p n g nyPc n^ng si>
dung. Ngoai ra con cfi nhyng yeu t l lien quan den t h i l t bi n h y tSc nhSn lanh, loai thiet b| trao doi nhiet
He so COP thu hoi nhiet thai thyc t l phu thufic vao nhipt dfi n y a c nong trong binh thu hoi, nhiet do n y p e nfing s i i dyng cSng cao thi giS tri COP cSng giam va he thfing chi hoat dfing hipu qua khi nhiet dp n y p c nong c i n s y dung co giS tn nho han 40°C.
Viee tan dung nhiet thai khfing anh hyang den hoat dfing binh t h y p n g cua mSy dieu hPa khfing khf NgoSi ra khi he thong co thu hoi se t i l t kiem mpt phan dien nang tieu thu khi nhifit do n y P c trong binh tich tru' nho han 40°C.
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[3] S6 tay huwig d i n thong tin san phlim may nu'dc n6ng nSng Impng m^t titi. Tmng tam tfit ki^m nang luwng Tp. HCM, 2009
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_ [5] N g u y i n Mgnh HCing - Bern Nhi#t Vdi Chu'ong Trmh Tiet Kiem Nang Lu'p'ng Va H i r i n g Nghifin Ci>u Moi - T^p Chl Khoa Hoc Va C6ng Nghe Nhi§t So 86 IhSng 3/2009
[6] Ngoc - Hung Bui, Ju - W o n Kim, In - Seung Jang, Jeiing - Kil Kang, And Jong - Soo Kim "Sludy On Performance Evaluation Of Oscillating Heat Pipe Heat Exchanger for Low Temperature Waste Heat Recovery" International Joumal Of A i r - Conditioning And Refrigeration
[7] P Sathiamurthi va PSS. Srinivasan - Design and Development of Waste Heat Recovery System for air conditioning Unit - European Journal of Scientific Research ISSN 1450-216X Vol 54 No 1 (2011), pp 102-110
[8] M M Rahman, Chin Wai Meng va Adrian Ng - Ar Conditioning and Water Heating-An Environmental Friendly and Cost Effective Way of Waste Heat Recovery - AEESEAP Joumal of Engineering Education 2007, Vol. 3 1 , No, 2.
[9] NguySn Dinh Vmh, HS 0 3 n g Trung - Thi^t Ke C h l Tgo VS Thtf Nghidm B o m Nhiet S u n Nu-oc Nong Si> Dgng Dan Lgnh Khong Khi - Tap Chi Khoa Hgc VS Cflng Nghfe Nhifit S6 68 thang 3/2006
[101 Roy J Dossat - Pnnciptes of Refrigeration - Prentice Hall, INC [11] Yunus A Cengel - Heat Transfer. A Practical Approach - McGrawHill, 1998 •
PhSn bi6n: GS.TS. Le Chi Hipp