NGHIEN CUfU-TRAO e ! PHAN TICH DONG CHAY QUA BANH CONG TAC TUA BIN FRANCIS V6l ANH HUdNG CUA CHIEU DAI DAY CANH PHU COMPUTATIONAL ANALYSIS OF 2D- FLOW CHARACTERISTICS ON THE EFFECTS OF THE SPLITTERS LENGTH IN FRANCIS TURBINE PERFORMANCE Dinh Minh Hai', D6 Thanh C6ng^ Nguyen TheMich^ Trflofng V i ^ Anh^ ' Viin Thuy dien v i Ning lUpng tai tao, Vien Khoa hpe Thuy lpi Viet Nam ^Bp mon Miy v i TU dpng Thuy khi, Viin C P Dpng Iflc, Trfldng Dai hoc Bich khoa H i NpL TOM TAT Ngdy nay, tua bin Francis dUdc sd dung phd bie'n tgi cdc trgm thuy dien co cot nUdc cao, vi the cho nen bdnh cdng tdc cua logi tua bin ndy dd vd dang la ddi tUdng nghien cdu thiet ke'dUdc quan tdm Bdi bdo ndy trinh bdy ket qud nghien cdu logi bdnh cdng tdc tua bin tdm true co ddy canh phu Diia tren kit qud chgy bdi todn 2D dung phdn mem CFD bien ANSYS Fluent vdi mo hinh k-e Chieu ddi ednh phu ldn lUdt bang 1/3; Vi; 2/3 canh chinh Ket qud cho thdy dgc tinh ndng lUdng cua tua bin phu thugc vdo t^ le chieu canh phu Ket qud cita nghien cdu ndy khdng dinh viec sd dung bdnh cong tdc co ddy canh phu cho Tua bin Francis cgt nUdc cao Id hodn todn khd quan Tfl khoa: Ndng lUdng tdi tgo, thuy dien, tua bin Francis, ddy ednh phu, CFD Nowadays, the Francis turbine is very common usage in the high-head hydroelectric power station Therefore, optimum design of runner for improving turbine's efficiency is an interesting research topic for research works In this study, the model of a Francis turbine runner adding splitter blades was designed for considering the optimization of the turbine efficiency The 2D flow characteristics around the cascade models are visualized and analysis by mean of CFD code - ANSYS Fluent ofRANS and k-e models The splitter length Is is changed to make three cases: Ls = 1/3; 1/2 and 2/3 the length of the main runner blade The effects on the turbine power efficiency by changing the length ratio of the splitter are calculated and analysed From the results of the study, the usage of splitter blade in Francis turbine was clarified hy comparison the head loss and reaction force on the blade and cascade Key^-ords: Renewable energy hydroelectric power, Francis turbine, splitter turbine runner, CFD ^ TAP CHf C O KHf VIET NAM • S6 1+2 (Thing 1+2 nam 2013) NGHIEN CUfU - TRAO Q6\ MO DAU Ve mat ly thuyet thi hiiu suit cua tua bin gao va tam triic la ngang Khi eo cung cot i p dia hinh va lflu lfldng, neu dung tua bin t i m true se IPi hon \i cd cot i p hut nen cd cong suat cao hpn, tua bin tam true dp on thap v i dp ben hon tua bin gio, diiu khien de hPn tua bin gio Tuy nhiin, vdi tua bin t i m true cot nfldc cao, b i n h cong t i c cd chenh lech ve dfldng kinh ldi vio va ldn Them vao do, Idi vao cd dfldng kinh rpng, 161 dudng kinh hep nen chat vao banh cong tie thi de dang nhflng thi khd vi bi chen dong, giam hiiu suat De trinh hiin tflpng chen dong niy, nhdm nghien cflu da d i tinh toin thiet ke banh cong t i e tua bin t i m true gom du 30 einh, sau cat bdt chieu dai eua mpt nfla sd la canh banh eong tie d phia chieu (nhflng li einh bi eat bdt niy dflpc gpi la day einh phu), dung phip biin hinh bao giic trii phang 2D banh cong tac niy rdi dung phan mem Fluent de nghien edu dong chiy v i die tinh ning Iflpng Nam 2011, d hpi thao SEATUC tai Trfldng dai hoc Bach khoa Hi Npi, nhdm tic gia da eong bo ket q u i nghien cflu dong chay qua qua b i n h cong tie tua bin t i m true cd day einh phu bai bao "Nghiin cflu ddng chiy qua binh eong tie tua bin cd day einh phu" [2] Theo ket q u i niy, chiiu dai li einh phu = Vl la cinh ehinh eho ket q u i ve nang lflpng tdt nhat De tim kiim chiiu dai la einh phu tdi flu, nhdm tic gii tiep tue nghiin cflu mo hinh, so sanh die tinh nang Iflpng eua md hinh vdi chieu dii day canh phu lan Iflpt: 1/3; Vi; 2/3 day canh ehinh Cac trfldng hpp khio sit: Ap dung eac thong sd trin eho 03 bii toin vdi Binh cong tie 30 canh; 15 canh ehinh 15 cinh phu: Chieu dii l i canh phu bang 1/3 cinh ehinh (THI) Chieu dii Ii einh phu bang 1/2 einh chinh (TH2) Chieu dai la canh phu bing 2/3 cinh ehinh (TH3) KET QUA VA BINH LUAN Phan bd i p suat (tinh) ^ ^ ^ i THI Do thi phan bo ap suat tren la canh (3 trudng hop) THI ACh4u(J.(i.iilll.>m) Hinh Phdn bo dp suat tinh tren BCT (A) canh ddi; (B) canh ngdn TAP CHl CO KHi VIET NAM V S6 1+2 (Thang 1+2 nam 2013) | NGHIEN CUfU-TRAO OOl Qua hinh cho thay: T H I : Ap suat phin bo deu trin mat Iflng v i bung einh, khdng ed sfl dot bien ve gia tri Vdi canh dai ap suat phia bung ldn hPn phia Iflng dam b i o sU ehinh lich i p tao momen quay cho tflng l i canh Trin toan bp be mat einh khong sinh i p suit b i o hoa, chinh lich i p suat bung v i Iflng tang dan theo chieu dai Tuy nhien tdi chieu dai 560mm khe hd gifla lUng v i bung hep, van tdc dong chiy tang eao nen ap suat tai day nho va cd xu hfldng dio chiiu, i n h hfldng tdi viee truyen ning Iflpng eua ddng nfldc chiy qua banh eong tac Vdi canh ngan i p suat dao chieu Iflng bung tfl dflpc 1/2 chiiu dii Ii einh Diiu niy, eung gay ton that ning Iflpng ldn vdi la canh ngln tai chiiu dai phia sau TH2: Ap suit phan bo diu trin mat Iflng v i bung cinh, khong cd sU dot bien ve gia tri Vdi canh dai ap suat phia bung ldn hon phia lUng d i m b i o sU chenh lech ap tao momen quay cho tflng la einh Trin toin bp b i mat einh khong sinh ap suit bao hoa, chinh lech ap suat bung v i Iflng ting dan theo chieu dii Tuy nhien tdi chieu dai 580mm khe hd gifla Iflng v i bung hep, van toe dong ehay tang cao nen ap suat tai day nhd v i ed xu d i o chiiu lim anh hfldng tdi viic truyin nang Iflpng cua ddng nfldc ehay qua b i n h eong tic Chieu dii einh chiu anh hfldng d i o chieu i p suat n i y nhd hfln trfldng hpp Vdi einh ngan i p suat d i o chiiu Iflng bung tfl dflpc 1/3 chieu dai la cinh Dieu gay ton thit nang lflpng ldn vdi l i einh ngan tai chieu dii phia sau Trfldng hpp neu tren la phan bo ap suat tinh tren mat einh De xie dinh anh hfldng einh ngan tdi hiiu suat tua bin can bai toan nghien cflu nhieu cac thong so khic nfla TH3: Ap suat p h i n bo deu tren mat Iflng va bung einh, khong cd sfl dot bien ve gii tri Vdi cinh dai ap suat phia bung ldn hon phia lUng dam bao sfl chinh lech ap tao momen quay eho tflng li einh, tren t o i n bp be mat canh khong sinh ap suat bao boa, chenh lech i p suit bung vi lUng tang dan theo chieu dai, nhien tdi chieu dai 580mm khe hd gifla lUng va bung hep, van toe dong chiy ting cao n i n ap suat tai diy nhd va co xu hudng dao chieu, i n h hfldng tdi viee truyen ning Iflpng eua dong nfldc chay qua binh cdng tic Tuy nhien, chiiu dai canh ehiu i n h hfldng dao chieu i p suat niy nho hpn trfldng hpp V6i canh ngin ap suit dao chieu Iflng ldn i p suat bung giy mat ning lflpng, i n h hUdng ldn tdi hiiu suat cua banh eong tic Phan bo van toe '-.'^r.^- X^*st KET LUAN Ngay nhan bai: 15/12/2012 Ngay phan bien: 15/01/2013 Ngirdi phan bien: PGS, TS Vu Ngoc Pi, Trudng Dai hoc Ky thuat Cong nghiep, Dai hoc Thai Nguyen Nhdm tac gia da xem xet nghien curu thiit k i binh cdng tie tua bin tam true vdi goc vao va nam ngoai dai ap dung ly thuyet tu truac den T i i lieu tham khao: [ ] Vo Sy Huynh, Nguyin Thi Xuan Thu 'Tua bm nu&c", NXB Khoa hoc Ky thuat, Ha Npi, 2004 [2], Dinh Minh Hai, Do Thanh Cong, Truong Viet Anh, Nguyen The Mich, ".^ 2D numerical study of flow characteristics in francis turbine runner with splitter blades''^ Seatuc Symposium Hanoi University of Science and Technology 2011 [3] Yi-hua Hou, Xue-yi Qi, Ren-nian Li, Jmg Zhang, ''''Numerical Simulation of 3-D Flow in Low Specific Speed Francis Runner with Splitter Blades" 2008 International Symposium on Information Science and Engieering [4] Shinji Yumoto, Takashi Kaito, Yasuo Takeuchi, Kiyohito Tani and Katsumasa Shimmei '''The Development of Runner With Splitter Blades" 2008 International Symposium on Information Science and Engineering [5] Wiliam Djaja Tjokroaminata "^ Design Study Of Radial Inflow Turbines With With Splitter Blades in Three Dimensional Flow" University of Maryland, College Park 1990 ^ J TAP CHf CO KHf VIET NAM • S6 1+2 (Thing 1+2 nam 2013) ... eong bo ket q u i nghien cflu dong chay qua qua b i n h cong tie tua bin t i m true cd day einh phu bai bao "Nghiin cflu ddng chiy qua binh eong tie tua bin cd day einh phu" [2] Theo ket q u i... cd cong suat cao hpn, tua bin tam true dp on thap v i dp ben hon tua bin gio, diiu khien de hPn tua bin gio Tuy nhiin, vdi tua bin t i m true cot nfldc cao, b i n h cong t i c cd chenh lech ve... hiiu suit cua tua bin gao va tam triic la ngang Khi eo cung cot i p dia hinh va lflu lfldng, neu dung tua bin t i m true se IPi hon \i cd cot i p hut nen cd cong suat cao hpn, tua bin tam true