KHOA HOC-CdNG NGHg 86 04/2019
Nghien cuu qua trinh nap va nen
cua dong co diesel buong chay thong nhat bang phan mem Ansys-ICE
• ThS. l e VI^T H O N G ; PGS. TS. D 6 VAN DUNG - TrUdng Dai hoc Sd pham Ky thuat TP Ho Chi Minh m ThS. PHAM VAN GIANG; VO KHAC H O A N G - TrUcfng Dqi hpe Bdeh khoa Hd Ndi
m TS. OAO CHI CLTONG - TrUdng Dqi hoe SUpham Ky thudt Hung Yin m PGS. TS. NGU Y i N ANH THI - TrUdng Dgi hpe Qude gia TP. Ho Chi Minh
TOM TAT: Bai bao trinh bay nghien cuu mo phdng qua trinh nap va nen cda dong co diesel RV 165- 2 sd dung buong chay thong nhat Mo hinh so hoa 3D dong khi nap thai va buong chay duoc xay dung bang phan mem Rapid-Form va qua trinh mo phong d toe do 1600 v/ph va 2 2 0 0 v/ph duoc thuc hien bang phan mem Ansys-ICE Ket qua nghien cuu cho thay anh huang cOa toe do dpng CO den phan bo van tdc, nhiet do dong khi nap ben trong xy-lanh dong co trong qua trinh nap va nen Ket qua nay la co sd quan trgng cho qua trinh thiet ke cai tien duong nap va buong chay dong CO RV 165-2
T u KHOA: Dong co diesel, duong nap, buong chay.
ABSTRACT: This paper presents simulation study the intake and compression process of diesel engine RV 165-2 using direct combusion chamber Digitized 3D model of the intake exhaust flow and combusion chamber is built by the Rapid-Form software and simulation process at 1600 rpm and 2H00 rpm of engine speed were carried out using Ansys-iCE software The results showed that the effect of engine speed on velocity and temperature distribution of intake flow inside the engine cylinder In the intake and compression process These results will be an important basis for improving design process the intake manifold and combustion chamber of diesel engien RV 165-2
KEYWORDS: Diesel engine, combustion chamber
intake manifold,
1. BAT VAN O^
Trong nhdng nam gan day, eogldi hda san xuat ndng nghiep eua Viet Nam da va dang phat trien manh, dem lai hieu qua va dap dng ngudn san pham nong nghiep trong nadc va xuat khau. Gdp phan cho sU phat trien nay phai ke den vai trd quan trong cua dpng eo diesel cd nhd 1 xy-lanh cd cong suat t d 6 den 30 ma lae. Chinh vt vay, nhu eau ve so lapng va ehCtng loai dpng eo nay tang manh trong thdi gian qua, vdi mde tang tradng t d 5-^10%,
tuong dng t d 6000-^12000 ddng eo/nam [1]. Trong do, ddng CO do Tong edng ty May dpng lUe va May ndng nghiep Viet Nam (VEAM) ehiem khoang 20%, thi phan cdn lai la khoang 70% dpng cOTrung Quoc va 10% dong eo cua Nhat Ban vaThai Lan [2], Mac du ddng coTrung Quoc ehiem thj phan Idn nhd Ipi the gia thap, nhang tfnh nang kinh te ky thuat thap, phat thai eao, do ben tudi thp thap va phu tijng han che, cdn dpng co Nhat Ban va Thai Lan ed chat lUpng cao nhang gia thanh qua eao. Day chinh la loi the cho VEAM Viet Nam cd the phat trien thj phan trong va ngoai nadc, do vay viee nang cao ehat lapng va giam gia thanh de tang tinh canh tranh la can thiet. De giai quyet van de nay, VEAM Viet Nam da va dang tdng bade dau t a phat trien khoa hpc cdng nghe mdi trong nghien edu eai tien ddng ed nham dua ra thi tradng eae ddng san pham dpng CO diesel 1 xy-lanheotinh nang kinh te ky thuat cao, phat thai giam, dp ben va tuoi tho tang, gia thanh giam de du kha nang canh tranh vdi cac san pham cung loai cua Trung Qude, Nhat Ban va Thai Lan eung nhu hadng tdt xuat khau sang eae nUde trong khu vUc ASEAN trong thdi gian tdi [3]. Dien hinh viec dng dung edng nghe mdi vdl viee trp giup bang may tinh trong nghien edu cai tien qua trinh hinh thanh hdn hop va chay cua dong eo phat ke den eae phan mem chuyen dung nhuKiva, AVL-fire va Ansys-ICE [4-7], Ket qua md phdng bang phan mem se giup cac nha nghien cdu cd the dudoan, quan sat va phan tieh qua trinh hinh thanh hon hop va chay xay ra trong xy- lanh ddng codecd eosdtrong nghien edu eai tien ddng co.
Do vay, nhdm nghien cdu se trinh bay eae ket qua nghien cdu qua trinh van ddng dong moi chat ben trong xy-lanh trong qua trinh nap va nen eua dpng eo diesel RV165-2 do VEAM san xuat bang phan mem Ansys-ICE. Ket qua nghien cau se la cosd quan trong de daa ra cac hadng cai tien ket eau dadng nap thai va buong chay dinh pit-tdng nham cat thien qua trinh hinh thanh hon hop va chay eua dpng CO RV165-2, eung nha gop phan tang bade nang eao hteu suat va giam phat thai dpng CP RV165-2 de canh tranh ve ky thuat doi vdi cac ddng eO cung loai cua Nhat Ban va That Lan.
2. MO HiNH H 6 A VA MO P H 6 N G 2.1. Xay difng mo hinh
Tren co sd ket cau nap may, ban ve 2D ehi tiet nap
101
KHOA HOC - CONG N G H l _
may va pit-tdng, nhdm nghien cdu da sd dung phaong phap thiet ke ngape de sd hda dadng nap, dadngtheii va buong ehay ddng co RV165-2 b^ng may quet 3D va phan mem xd ly RapldForm [8]. Md hinh sau khi xd ly xong co ket quci nha t h ^ hien tren Hinh 2.1.
a) - Quit 3D nap may; b) - Mo hinh dim may diem nap may;
c) - M6 hinh dam may diem dudng ngp thii; d) - Mo hinh dudng n$p thai dupc so hoa: e) - Md hinh dudng n^p thai va buong chay sau khi
sdhoa xong
Hinh 2.1: Qua trinh mo hinh dudng nap thii va buong ehiy Vdi mo hinh dadng nap th^i va budng ehay dpng co RV165-2 sau khi ddOe so hda xong nhuthe hien tren Hinh 2.1 e, se daoc daa sang phan mem Ansys-ICE de thiet lap eae be mat eho md hinh va thae hien chia ladi cCing nha khai bao thong tin va dieu kien bien eho md hinh, nha the hien tren Hin/j 2.2.
a) • Md hinh sau khi phin tich va thiet lip cac be m$t, b)-Mdhinh sau khi chia ludi Hinh 2.2: Md hinh dudng nap thii va buong chay dupe xdly
trin Ansys-ICE
2.2. Ccrsdiy thuyet
Tinh toan md phdng qua trinh lau dpng cua ddng moi chat ben trong dadng nap va xy-lanh ddng ca trong qua trinh nap va nen vdi cac thdng s6 khi ddng hpc thay doi phde tap va bai toan e^ng trd nen phdc tap hon kht dape tinh toan d cac che dp tdc dd dpng co diesel khac nhau. D l giSi quyet b^i toan nay ma van dSm bSo dp tin cay, trong Ansys-ICE sd dung ly thuyet eua CFD de mo ta trao doi nang laong va dpng laong cua ddng moi chcit, gom cac phaong trinh nha sau [9]:
Phaong trinh lien tuc:
Phaong trinh dpng lapng:
—(pv) + V(pvv) = -Vp + p.7 Phaong trinh nang Iddng;
(1)
iH-4
+v p U + ^ V =-v(pv)+p9+p.(/i;) (3) Trong i^d; f-Thdi gian; r- Khoi lapng rieng; v-Tde ctp ddng; p - Ap suat ddng; q - Nhiet laong chuyen hda rieng;e - Npi nang; f~ Ndi ldc; S^ - Khoi laong dape them vao pha lien tuc t d pha khuech tan thd hai va cac ngudn do ngadi dtjng djnh nghTa.
2.3. Dieu kien bien
Trong nghien cdu nay, dpng co RV165-2 daoc li/a chpn lam doi taong nghien cdu, cac thdng so ky thuat dapc the hien trong Bdng 2.1.
Bang 2.1. Thdng sdkif thu$t eda ddng caRV16S-2 TT
1 2 3 A 5 6
'
Cac thong s5 Loai dong co The ti'ch lam viec Oi/dng kinh x hanh trinh piston T)f so nen
Tdc do dinh m u t Cong suat dinh miJc M6-men cLfcdai
GMtri Diesel, 4 ky, khong tang ip 839 cm^
105mm X 97mm 16 2200 v/ph 14ml/2200v/ph 57Nm/1600v/ph Pha phdi khi eua dpng co RV165-2 dupz khai bao cho mo hinh thdng qua file d d lieu ValveUft dupc xay dang tren co sd quan he gtda gdc quay true khuj'u v^ dp nang xu-pap nha the hien tren Hinh 2.3.
Crank Angle (deg) Hinh 2.3: Pha phdi khi cda ddng coRV165-2 102
KHOA HOC-CONG NGHE-
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Bing 2.2. Dieu kien bien cho mo hinh
Cic thdng set cho mo hinh Nhi§t do khong khi nap 05 tang nhiet do kht nap mdi Nhietdo khi nap tnJdc xu-pap nap Nhl&t do cuoi qua trinh ngp Nhiet do cudi quS trinh nen Ap suat khdng khi nap Ap suat cuoi qua trinh nap Ap suit cudi qua trinh nen H§ so du liJOng khong khi
ThAngstf Kyhiftu
T„
DT
L
T T, P„
P, P, 1
GUtri 302 20 302 3344 1032 0.1 0.085
4.72 1.55
" •
K K K K K MPa MPa MPa
Cac thdng so dieu kien bien nhap cho md hinh ddng cd RVl 65-2 trong Ansys-ICE dddc the hien trong Bdng 2.2.
Khi chay md phdng d che dp toe dd 1600 v/ph va 2200 v/ph thi dng vdi moi bade tinh, ladi dapc xae lap lai theo dung quy luat dpng hpe eua piston va xu-pap vdi dp tang gde quay true khuyu 0.5'TK. Ket qu5 tinh toan md phdng savan ddng eua ddng khi nap tren dadng nap, trong xi-lanh dpng eo dapc phan tich bdt edng eu ICE- Setup nha the hien trong phan sau.
3. KiT QUA VA THAO LUAN
3.1. Phan bo van toe dong moi chat ben trong durdng nap v^ xy-lanh b che do nap va nen
Phan bd van toe ddng mdi chat ben trong dadng nap va xy-lanh dpng eO tai tiet dien mat c^t di qua dadng tam xu-pap nap va thSi trong qua trinh nap va nen taong dng cac vi tri gdc quay true khuyu cda qua trinh nap la 700'TK, O'TK, 45'TK, 90°TK, 135°TK va 180°TK va qua trinh nen la 225°TK, 270'TK, 315'TK va BdO'TK 6 che dp tdc dp 1600 v/ph va 2200 v/ph dUPe the hien tren Hinh 3.1^3.4.
Dien bien qua trinh nap the hien tren Hinh 3.1 vd 3.2 eho thay, dng vdi cac vj tri gde quay true cp^^ < 45^K thi van toe ddng khi nap chaa cao va phan bd kha deu, cdn khi q),^ > 45°TK van toe ddng khi nap tang eao va xuat hien d mot pham vi hep. Hien tuang nay ed the giat thich la do ban dau qua trinh thai van tiep dien nen toe dp lau ddng cda ddng khi nap khdng cao.
liU S3
Hinh 3.1: Phan bo van tdc trong xy-lanh &qua trinh nap tai che dp n= 1600 v/ph
Khi ket thuc qua trinh thai xu-pap th^i ddng, qua trinh nap thac sa bat dau, khi do van tdc lau ddng qua de xu-pap tang cao va phan bo khdng deu va cd xu hadng hoi lech ve phia dadi xu-pap nap. Khi cp^^^ tiep tuc tang, thi van tdc khdng qua cao va cd xu hadng phan bo
deu trong toan bd the tieh buong chay va dat gia tri cgc dai khoang 130 m/s tai dng vdi cp,^ = QOTK, con tai ip,^ = 135'TKthi van tdc phan bo kha deu va dat gia tri trung binh khoang 35 m/s. Cdn khi so sanh d hai che dp toe dp 1600 v/ph va 2200 v/ph tai cp,^ = ISO'TK, cho thay dien bien thay ddi van toe moi chat trong qua trinh nap eua ea hai la kha taong dong, tuy nhien van tdc cae dai ddng mdt chat dng vdi tde dp 2200 v/ph dat khoang 50 m/s, Idn hon kha nhieu so vdi che dd 1600 v/ph.
' l ^ f ti
Hinh 3.2: Phan bo van toe trong xy-lanh dqua trinh nap
e
tai che dp n = 2200 v/ph
Phan bo van tdc trong qua trinh nen the hien tren Hinh 3.3 vd 3.4 eho thay, van toe mdi chat trong xy-lanh thay doi va phan bo kha taong dong trong ca hai che dp toe dd 1600 v/ph va 2200 v/ph, trong dd d dau qua trinh nen dng vdi (p^^ - 225°TK tai vung phia tren dinh pt't-tdng cd van tde thap nhat khoang 3.7 m/s va 5 m/s tUong dng tde dp dpng eo la 1600 v/ph va 2200 v/ph. Hien tapng nay cd the giai thich la do thdi diem dd qua trinh nen bSt dau thae hien khi xu-pap nap ddng hoan toan va tde do pit-tong tang dan. Chinh vi vay, van toe tai viing nay cung nha eae vung lan can dapc tang dan trong qua trinh nen.
Tai thdi diem <p,^ - SISTK, van toe ddng mdi chat cua tradng hpp 1600 v/ph ed sa phan vung rd ret hon so vdi tradng hdp 2200 v/ph, cd mpt so vung sat thanh xy-lanh phia xu-pap thai ed van tde dat tdi 25.9 m/s.
Hinh 3.3: Phin bo van toe trong xy-lanh dqui trinh nen tai ehe ddn = 1600 v/ph
Tai thdi diem euoi qua trinh nen dng vdi (p^^ = 360 "TK 103
KHOA HOC - CONG NGHE .
van tdc ddng mdi chat phan bo deu hon, tuy nhien phan ehinh gida ed van toe nhd hon cac phan cdn lat va hi&n taong nay cang the hien rd dng vdi tdc dd 1600 v/ph. Ket qua nay cd the da doan kha nang hda trdn va hinh thanh hon hop d toe dp 1600 v/ph tot hon so vdi 2200 v/ph, bdi nhd sa phan bo khdng deu cua van toe ddng mdt chat d thdi diem euoi nen va bat dau thdi diem phun nhien lieu.
Day cung la eef sd de ed the dUa ra cac hadng eai tien ket cau budng chay dinh pit-tdng de c^i thien qua trinh hinh thanh hon hop d dai tdc do eao.
nhiet dp dp trong xy-lanh d dau qua trinh nap duac deu hon, eung nhacSi thien trang thai nhiet cua dinh pit-tdng.
I 'I m9»
nic
• • r ^ i 0'
Hinh 3.5: Phan bo nhiet dd trong xy-lanh dqua trinh nap tai ehedd n = 1600 v/ph
V: l:i
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1
Hinh 3.4: Phan bo van tdc trong xy-lanh & qui trinh nen tai ehedd n = 2200 v/ph
3.2. Phan bo nhiet do ben trong dudng nap va xy-lanh cf che do nap va nen
Hinh 3.5 vd 3.6 the hien phan bd nhiet do mdt ehat ben trong dadng nap va xy-lanh dpng co tai tiet dien mat e^t di qua dadng tam xu-pap nap va that trong qua trinh nap dng vdi cac vj tri gdc quy true khuyu la 700'TK, O^TK, 45*'TK, gOTK, 135''TK va ISOTK d che dp 1600 v/ph va 2200 v/ph. Ket qua eho thay, phan bd nhiet dp mdi chat tat cae thdi diem eua qua trinh nap trong cli hai che dd tde do la kha taong ddng nhau. Thdi diem dau qua trinh nap, nhiet dp mdi chat kha cao va toe dp dpng eo cang cao thi nhiet dp eang Idn va dat khoang hon 550-600 K. Hien tapng nay cd the giai thieh la do anh hadng bdi trang thai nhiet dp eao cua budng chay cudi qua trinh gian nd, ngoai ra khi tdc dp dpng co tang thi anh hadng nay eung tang theo.
Khi cpj^ > 45'TK, nhiet dd trong xy-lanh cd xu hadng giam va phan bo kha deu mac du vung sat dinh pit-tdng nhiet dd van eao hon cac vijng cdn lai khi gde quay true khuyu tang. Hien tupng nay cd the giai thich la do khi nap mdi ed nhiet dp thap dupe nap vao xy-lanh nen da lam nhiet dp mdi chat giam va vung sat dinh pit-tdng bi anh hadng nhieu bdi trang thai nhiet cua pit-tdng nen cao hon cac vung cdn lai. Tuy nhien tai thdi diem tp^^^ - 45°TK, che dp 1600 v/ph cd nhiet do phan bo khdng deu bang che dp 2200 v/ph, hien taong nay cd the giai thieh la do anh hadng bdi van toe ddng khi nap lijc ban dau. Ket qua nay la CO sd de cat tien ket eau dudng nap sao eho phan bd
104
Hinh 3.6: Phin tio nhiit dd trong xy-lanh a qua trinh nap tai che dp n = 2200 v/ph
Phan bd nhiet do mdi chat trong qua trinh nen dupe the hien tren Hinh 3.7 vd 3.8, ket quci cho thay phan bd nhiet dp trong xy-lanh eua ea hat che dp tdc dp la kha deu va giong nhau va cung cd xu hadng tang nhiet dd khi (p^
tang. Tai thdi diem b^tdau qua trinh nen (p^i^ - 225°TK thi vung buong ehay dinh pit-tdng va chinh gida xy-lanh cd nhiet do dat khoang 335-345 K, eao hon eae viJng cdn lai. Cudi qua trinh nen, nhiet dd mdi chat dat khoang 845-^875 K. Vdi ket qua nayedthedubaoday la dieu kien thuan loi eho qua trinh chay cua diesel.
If i C ^
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Hinh 3.7: Phan bd nhiet dp trong xy-lanh 6 qua trinh nin tai ehedd n = 1600 v/ph
KHOA H O C - C 6 N G NGHE
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Engineering Science and Technology, vol.12, no.4, 1048-1066.
[7]. Alessandra Nigro, Angelo Algieri, Carmine De Bartolo, Sergio Bova, Fluid dynamic investigation of innovative intake strategies for multivalve internal combustion engines. International Journal of IVleehanical Science 2017; 123:297-310.
[8]. Le Viet Hung, Pham Van Giang, Khong Vu Quang, Tran Thi Thu Haong, Nguyen Anh Thi (2018), Nghien cdu so hda md hinh 3D dudng ngp, thdi vd bUdng chay Idm ca sd nghien cdu md phdng ddng ca diesel. Tap ehi GTVT, sd thangl1,ISSN2354-0818.
[9]. K.David Huang, Khong Vu Quang, Kuo-Tung Tseng, Study ofthe effect of contraction of cross-sectional area on flow energy merger in hybrid pneumatic power system. Applied Energy 2009; 86:2171-2182.
Hinh 3.8: Phan bd nhiit do trong xy-lanh & qui trinh nin tai ehedd n = 2200 v/ph
4. K^T L U A N
Tren eo sd k^t quct dat daoe va phan tieh d tren ed the daa ra mpt so ket luan sau:
-Da md phdng thanh eong qua trinh nap va nen eua dpng CO diesel RVl 65-2 tren phan mem Ansys-ICE;
-Van tdc va nhiet do moi chat trong xy-lanh phan bd taong doi deu d ea hai ehe dp tde do 1600 v/ph va 2200 v/ph.Trong dd, van toe cac dai ddng mdt chat dng vdt tde dp 2200 v/ph dat khocing 50 m/s, Idn hOn nhieu so vdi 1600 v/ph, cdn nhiet dd mdi chat cudi qua trinh nen dat khoang 845-875 K;
- Ket quS nghien edu tren la co sd de cai tien bien dang dadng nap va ket eau buong chay tren dinh pit-tdng de eai thien qua trinh nap va nang cao ehat laong qua trinh hda trpn va chay.
Ngay nhan bai: 16/02/2019 Ngay chap nhan dang: 01/4/2019 Ngilolphan bien: TS.DinhXuanThanh
TS. Nguyen Van Thjnh
Tai lieu tham khSo
[1]. Vu Xuan Thiep, Khong Vu Quang, Le Van Binh {W20M),AStudy ofIntakeManifoldlmprovementof Diesel Engine by Using CFD, The 3rd International Conference on Sustainable Energy, ISBN 978-604-73-1990-9.
[2]. Le Van Binh, Nghiin cdu qud trinh vdn dpng cua dong khi trong duPng nap cda dpng ca diesel 1 xy-lanh bang phdn mem CFD, Luan van Thac sy, Tradng Dai hpc Bach khpa, khda 201 OB.
[3]. Http-//veam.com.vn/?act=content&pid= 1&cid= 122.
[4]. S.Bari, Idris Saad, CFD modelling of the effect of guide vane swirl and tumble device to generate better in-cylinder air flow in a Cl engine fuelled by blodlesel, Computers & Fluids 2013; 84:262-269.
[5]. I.V.Kurchatkin, A.A. Gorshkalev, EV.BIagin, Methods ofthe working processes modelling of an internal combustion engine by an ANSYS IC Engine module.
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