NGHIEN CU'U-TRAO DOI NGHIEN CU'U MO P H N G A N H HU'DNG QUA DO SAU TREN D[NH PISTON DEN GAG THONG SO VAN HANH G U A D O N G G O XYLANH SLP DUNG NHIEN LIEU GNG SIMULATION STUDY ON EFFECT OF THE HIGH BOWL-IN-PI STON ON OPERATING PARAMETERS IN CONVERTED CNG SINGLE CYLINDER ENGINE ThS Tran Thanh Tam\ KS Giang Trung Hiiu\ ThS Nguyin Minh Thang^ GS,TS Pham Minh Tuan', TS Tran Dang Qudc' 'Vien Co Dpng luc, Trucmg Dai hpc Bach khoa Ha Ngi ^Truong Dai hpc Cong nghiep Ha Npi TOM TAT Bdi bdo ndy trinh bdy nghien cim ve dnh hu&ng cua dp sdu phdn khoet ldm tren dinh piston den cdc thong so van hdnh & dpng ca CNG mpt xylanh chuyen doi Cdc ket qud thu dupe cho thdy rdng, thay doi dp sdu tren dinh piston hieu sudt nhiet cua dpng ca duac cdi thien ddng ke cd toe dp dpng cald n = 2.400 vong/phut Nguyen nhdn de co duac ket qua ndy la dpng hpc cua dong a ben xylanh da duac cdi tdng len tdng dp sdu phdn khoet ldm tren dinh piston Tir khoa: Dp sdu tren piston; Dong hpc cua chdt khi; Thong so van hdnh; Dpng ca mpt xylanh; Dong ca CNG chuyen doi ABSTRACT This article indicates the research on effect of high bowl-in-piston on operating parameter in converted single cylinder CNG engine The obtained results were clearly showed as changing in the high bowl-in-piston, the thermal efficiency were significantly improved regardless of engin speed equal 2400 rpm The main cause to reach these results was due to the gasflowkinetics into cylinder was enhanced when increasing high bowl-in-piston Keywords: High bowl-in-piston, Gas flow kinetics, Operating parameter Single cylinder engine, converted CNG engine •= iSSN 0866 - 7056 TAP CHI CO KHI' VIET NAM, S6 +2 nam 20! ) www.cokhivietnam.vn ^ NGHIEN CU'U-TRAO l GIOI THIEU Chay theo dinh nghia diu tien la "qua trinh xi boa nhanh sinh nhiet va qua tnnh XI hoa cham chi sinh mpt lupng nhiet nho khong dang kk" hoac "qua trinh xi hoa nhanh, d6ng thoi phat anh sang va sinh nhiet, qua trinh xi hoa cham chi tao mot lupng nhipt nho khong dang kk" [1] Vay, qua trinh dot chay nhien lieu a ben xylanh dpng co se tap trung vao qua trinh xi hoa nhanh va ban chS t6i da qua trinh xi boa cham [2] Hai nhan t6 quan trpng sii dung d8 xem xet qua trinh chay a dpng ca dot la tdc dp cua mang lira va kha nang de boc chay cua hon hpp [3] Bk cai thien dupe ch4t lupng qua trinh chay va nang cao hieu su4t nhiet cho dpng co, can phai cai thien su van dpng cua dong moi chat truoc va su6t qua trinh chay [4] Su van dpng cua dong moi chat o ben xylanh dpng co la mpt nhimg thong so rk quan trpng dl ki8m soat cb4t lupng hon hop, qua trinh chay va truyen nhiet Cuong dp van dpng va dac tinh rdi cua dong la hai thong so rat quan trpng d6i voi dong moi chat ben xylanh dpng CO [5] Ban dau cuong dp va dac tinh dong moi chat ben xylanh dpng co dugc tao boi qua trinh nap, nhimg sau dac tinh dong moi chat bl thay doi suot qua trinh nen Cac nhan to chu yeu anh hucmg den cuong dp van dpng va dac tinh roi cua dong ben xylanh dpng co la he thong nap-thai (duong ong va so xuppap), su dich chuyen cua piston va dac biet la hinh dang cua buong chay [6] Mpt nhimg giai phap ky thuat de cai thien dac tinh cua dong xylanh dpng co la sir dung buong chay phu khoet 16m tren dinh piston [7] Voi mpt hinh dang khoet lorn tren dinh piston phii hpp se cai thien dupe dac tinh dpng hpc cua dong ben xylanh dpng CO, nho vay kha nang bat lira va t6c dp chay ciia hon hop duoc cai thien theo chiiu hucmg tich cue ban [81 Tir nhiing phan tich tren co thS tb4y riing, tien hanh "Nghien cuu mo phong anh huong cua dp sau tren dinh piston d^n cac thong sd van hanh a dpng co xylanh su dung nhien lieu CNG" la clin thilt De c6 duoc cac ket qua nghien cuu, phucmg phap nghien cuu se duoc ti6n hanh theo hai buoc: (1) Thu nghiem tren dpng ca Diesel mot xylanh vai nhien lieu CNG duac cdp tren duong 6ng nap (2) Tir nhimg s6 lieu thu dupe tir thuc nghiem, tien hanh mo phong va hieu chuan dpng ca bang phin mSm AVL Boost [91 D O N G CO MO PHONG Dpng ca Diesel mpt xylanh co ducmg kinh xylanh D ^ 103, hanh trinh piston 8=115, ty s6 nen cua dpng ca giam xuong e = 10, nhien lieu CNG cip tren duong nap ciia dong ca bang mot voi phun rihien lieu XAY DITNG VA DIEU KHIEN M HINH 3.1 Xay dung dfing cff mo phong Tren co sa cac thong so ket cau dpng co mot xylanh, mo hinh duac xay dung boi phan mgm AVL-Boost nhu hinh va cac phan tir bang Bang Cdc phdn tif ciia md hinh: Ky hieu Ten phan tir So lireng SB Dieu kien bien CL LOG C Xylanh R Can dong PL Binh on ap MP Diem Doan ong noi ISSN 0866 - 7056 sa TAP CHi CO KHI VIET NAM, S6 +2 nam 2019 www.cokhivietnam.vn NGHIEN c u u - T R A O 0 t6c dp dpng ca khoang n ^ (1000 ^ 2400) vong/phut, buae thay doi An ^ 200 + GOC danh lira sam (BTDC) dugc hieu chinh d^ dat M6-men lan nhat vai buoc thay dOilaAIT-l + Giii CO dinh cac gia tri nhu: G^,= 0,58 (g/s) hoac Me de xem xet anh huang cua Hb den dac tinh lara viec cua dpng ca > X /fin/; Mo hinh dpng co tren AVL-Boost 9,4 3.2 Hieu chuan md hinh NblcnUjniCNG -ã-H = V| tn bv^m ga-1001ô E = 10&).= ^B^^IIJS Z Tien hanh hieu chuan mo hinh bang each nhap cac so lieu thuc nghiem tai moi toe dp dpng ca, sau dieu chinh tren mo hinh mo phong Sai so ket qua giira mo men thuc nghiem va mo phong xap xi la 5%, vai sai so mo hinh mo phong duoc chap nhan de tien hanh nghien cmi = « i ^ ^ ^ ^^ - S 4,6 1000 120O 1403 1600 18C0 2000 2200 2400 2600 T6C d$ d$Dg cv, Q (v5Dg/phiit) Hinh Su thay ddi cua cong sudt theo tdc ddng ca PHAN TICH KET QUA 4.1 Anh huffng cua sau dinh piston d€n thong so van hanh lOCO 1200 lAOJ 1500 1800 20CD 2200 Toe (1$ H^Dg cir, D {i ADg/phiiO 2400 2600 Hinh Su thay ddi cua md men theo toe dp dong ca 3.3 Dieu khien dong cff mo phong + Buom gio duoc mo hoan toan (WOT) doi vai cac dinh piston co sau Hb thay doi tir H^-(0;10;17,5va25) + Lambda dupe giii o ? = thay doi Hinh 2, the hien su thay doi cua Me theo n voi bon gia tri H^^ khac nhau, xu huang thay doi cua M^ la giong tang n Tai moi n, M^ ciia H^^ ^ 10, 17,5 va 25 deu Ian ban so voi H|^ = 0, gia tri M^ ldn nhat H^^ > dSu tap trung tai 2000 vong/phiit Trong khoang n - (1000 - 2400) vong/phiit Me cua H^ - 17,5 luon luon Ion han so vai cac gia trj khac Dac biet la M^ tai n ^ 2400 vong/phut bang vai gia tri M^^^ tai n - 1400 vong/phut cua H^^ - Su thay doi la he so nap (q^) duac cai thien H^ tren dinh piston thay doi D^ lam ro ban anh hucmg cua H,^ den cac thong s6 van hanh cin xem xet su thay ddi N^ thay doi n "^ ISSN 0866 - 7056 TAP CHf C O KHf VIET NAM, S6 1+2 nam 2019 www.cokhivietnam.vn NGHIEN CU'U-TRAO D C I Cac kit qua tren hinh cho thay H^ khong chi anh huong d^n M^ ma anh huong dSn N^ Voi H^ khac nhau, N^ c6 xu huong thay d6i nhu n tang N^ duac tang den N^^^ va sau giam a cac n Ion ban, N^^^ cua H^^ =^ xuit hien tai n = 1800 vong/phiit nhung vai H^ > thi N^^^^ tap trung tai n - 2200 vong/phiit Su dich ciiuy§n ciia N^^^^ tru'ong hap chil ygu la riit ngan duac thai gian chay ciia hon bop 1000 1200 1400 1600 1800 2000 2200 Toe dp dgng c