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NAOSITE: Nagasaki University's Ac Title Author(s) 予混合圧縮着火機関における天然ガスおよびメタノールの着火燃焼特性に関する研究鄭, 奭鎬 Citation (2008-03-19)

1 NAOSITE: Nagasaki University's Ac Title Author(s) 予混合圧縮着火機関における天然ガスおよびメタノールの着火燃焼特性に関する研究鄭, 奭鎬 Citation ( ) Issue Date URL Right This document is downloaded

5 C θ θθ

6 R γ ε θ φ

7 ATDC BHP BTDC CA CLD CNG COV DME DPF EGR HCCI H-FID HTR LPG LTR MeOH NDIR NG PCCI PM ROHR SCR TDC After Top Dead Center Brake Horse Power Before Top Dead Center Crank Angle ChemiLuminescence Detector Compressed Natural Gas Coefficient of Variation DiMethyl Ether Diesel Particulate Filter Exhaust Gas Recirculation Homogeneous Charge Compression Ignition Hydrogen-Flame Ionization Detector High Temperature Reaction Liquid Petroleum Gas Low Temperature Reaction Methanol Non-dispersive infrared absorption Natural Gas Pre-mixed Charge Compression Ignition Particulate Matter Rate of Heat Release Selective Catalytic Reduction Top Dead Center

8 SCR(Selective Catalytic Reduction) DPF(Diesel Particulate Filter)

10 Table 1-1 Trend of emission regulations in diesel engine (a) Emission regulations for diesel passenger car (b) Emission regulationsfor diesel truck

11 Figure 1-1 Trend of crude oil price Figure 1-2 Prospect of fuel demand in Europe (source: EUCAR)

12 (Premixed-Charge Compression Ignition Engine) (Homogeneous Charge Compression Ignition Engine) PREDIC(PREmixed lean Diesel Combustion) process

17 2 θκ κ κ,,,

18 θ θ Figure 2-1 Definitions of LTR and HTR, ignition timings of LTR and HTR, and maximum dq/dθ of LTR and HTR Figure 2-2 Heat Release Rate with small LTR

19 Figure 2-3 Definition of CA10, CA50 and CA100 on cumulative ROHR

21 21 21

22 γ

23 100 η 100 Figure 2-4 Schematic diagram of heat balance analysis

24 3 Figure 3-1 LTR scheme for CH 3 OCH 3 oxidation

25 Figure 3-2 Overall reaction scheme for CH 4 oxidation [50]

26 Figure 3-3 LTR scheme for CH 3 OH oxidation [53]

28 Figure 3-4 Change in mole fraction of major species during the HCCI combustion process [57]

30 Figure 3-5 ROHR profiles with 5% addition of different ignition improvers [61]

31 Figure 3-6 Mass fraction of H 2 O 2, CH 2 O and radicals H, OH and HO 2 as a function of crank angle for three additives [61] Figure 3-7 Experimental and calculated species fractions at exhaust as a function of added methanol/dme ratio [53]

33 4 Table 4-1 Engine specifications Specifications Single cylinder 4 cylinders Engine type Cycle Cooling system Bore and Stroke [mm] Displacement volume [cc] Compression ratio Maximum power [kw/rpm] YANMAR NFD170-(E) 4 Water 102 and /2400 ISUZU 4JB1-2 4 Water 93 and /3600

34 Table 4-2 Properties of test fuels Gas oil DME Natural gas Methanol Chemical structure CH 3 OCH 3 CH 4 (88%)+Others CH 3 OH Lower heating value [MJ/kg] Cetane number Ignition point [K] Stoichiometric A/F ratio %wt.carbon %wt.hydrogen %wt.oxygen

35 Figure 4-1 Fuels supply and EGR system in single cylinder engine

36 Figure 4-2 Premixed charge and port injectionsystems of methanol in four cylinder engine

37 Figure 4-3 Schematic diagram of methanol port injection system Figure 4-4 Schematic diagram of control circuit for port injection

38 TESTO 350M/XL()

39 ± ± ± ± ± ±

40 5 θ θ

41 (a) Change in combustion history (b) Change in exhaust emissions and fuel consumption Figure 5-1 Effect of amount of gas oil as ignition source in NG PCCI engine (Pme=0.33[MPa], T IN =120[ C], θ inj =5 BTDC, d N =0.20[mm], ε=18.2)

42 Figure 5-2 Effect of injection amount of gas oil as ignition source on misfire limit in NG PCCI engine (θ inj =5 BTDC, d N =0.20[mm], ε=18.2) Figure 5-3 Change in combustion history due to engine load in NG PCCI engine (T IN =80[ C], G GO =1.47[mg/cycle], θ inj =5 BTDC, d N =0.20[mm], ε=18.2)

43 Pme=0.33[MPa] (b)pme=0.49[mpa] Figure 5-4 Change in combustion history due to intake temperature in NG PCCI engine (G GO =1.47[mg/cycle], θ inj =5 BTDC, d N =0.20 [mm], ε=18.2)

44 Figure 5-5 Change in combustion history due to EGR ratio in NG PCCI engine (Pme=0.33[MPa], T IN =80[ C], G GO =1.47[mg/cycle], θ inj =5 BTDC, d N =0.20 [mm], ε=18.2)

45 Figure 5-6 Effects of EGR and intake temperature on exhaust emissions and fuel consumption in NG PCCI engine (Pme=0.33[MPa], G GO =1.47[mg/cycle], θ inj =5 BTDC, d N =0.20 [mm], ε=18.2) θ

46 Figure 5-7 Relationship between maximum burning rate and oxygen concentration in NG PCCI engine (G GO =1.47[mg/cycle], d N =0.20 [mm], ε=18.2)

47 Figure 5-8 Relationship between ignition delay and mean gas temperature at ignition point in NG PCCI engine (d N =0.20[mm]) θ ±

48 Figure 5-9 Relationship between maximum ROHR and mean gas temperature at maximum ROHR point in NG PCCI engine

49 (a) Port injection (b) Premixed charge Figure 5-10 Change in combustion history due to engine load in MeOH PCCI engine; Comparison between port injection and premixed charge of methanol (T IN-m 100[ C], G GO =7.35[mg/cycle], θ inj =5 BTDC, d N =0.28[mm], ε=16.2)

50 φ Figure 5-11 Effect of methanol charge method on exhaust emissions and fuel consumption in MeOH PCCI engine (T IN-m 100[ C], G GO =7.35[mg/cycle], θ inj =5 BTDC, d N =0.28[mm], ε=16.2)

51 θ ε Figure 5-12 Effect of injection amount of gas oil on misfire limit in MeOH PCCI engine (Premixed charge, θ inj =5 BTDC, ε=16.2)

52 θ ε (a) Change in combustion history (b) Change in exhaust emissions and fuel consumption Figure 5-13 Effect of EGR ratio in MeOH PCCI engine (Pme0.33[MPa], T IN-m 140[ C], G GO =4.90[mg/cycle], θ inj =5 BTDC, d N =0.20 [mm], ε=16.2) θ ε

53 ε ε ε

54 ± ± ± ± ± Figure 5-14 Relationship between ignition delay and in-cylinder mean gas temperature at ignition timing in MeOH PCCI engine

55 Figure 5-15 Relationship between maximum ROHR (dq/dθ) max or 2p and in-cylinder mean gas temperature at maximum ROHR in MeOH PCCI engine

57 (a) Pme=0.33[MPa], θ inj =10[ BTDC] (b) Pme=0.66[MPa], θ inj =TDC Figure 5-16 Improvement in trade-off between NOx and smoke by natural gas charge with EGR (T IN =120[C], d N =0.20[mm], ε=18.2)

58 (a) Pme=0.33[MPa], T IN-m =140[C] (b) Pme=0.66[MPa], T IN-m =100[C] Figure 5-17 Improvement in trade-off between NOx and smoke by premixed charge of methanol with EGR (θ inj =5[ BTDC], d N =0.28[mm], ε=16.2)

59 ± ± ±

60 6

61 (a) Natural gas (b) Methanol Figure 6-1 Change in DME combustion due to natural gas fraction or methanol fraction in single cylinder HCCI engine (Pme=0.13[MPa], T IN =60[ C])

62 Figure 6-2 Effect of natural gasfraction or methanol fraction on exhaust emissions and fuel consumption in single cylinder HCCI engine (Pme=0.13[MPa], T IN =60[ C]) φ φ φ

63 (a) Natural gas (b) Methanol Figure 6-3 Change in combustion history due to engine load in single cylinder HCCI engine (T IN =60 [ C])

64 Figure 6-4 Comparison of exhaust emissions and fuel consumption between single cylinder HCCI engine and diesel engine (T IN =60[ C])

65 Figure 6-5 Change in maximum ROHR of LTR due to cetane number in single cylinder HCCI engine

66 Figure 6-6 Relationship between ignition temperatures of LTR and HTR, and cetane number in single cylinder HCCI engine

67 ± ± Figure 6-7 Relationship between maximum ROHR of HTR and in-cylinder mean gastemperature at maximum ROHR of HTR in single cylinder HCCI engine

68 φ φ (a) Stable running condition (b) Unstable running condition (Pme=0.33[MPa], φ DME =0.062, (Pme=0.38[MPa], φdme=0.058, COV imep =1.55) COV imep =9.34) Figure 6-8 Variations of engine speed and maximum in-cylinder pressure during 350 cycles in multi-cylinder DME/NG HCCI engine (T IN =40 [ C])

69 φ ± ± Figure 6-9 Change in COV imep due to φ DME and intake temperature in multi-cylinder DME/NG HCCI engine

70 φ φ φ φ φ Figure 6-10 Cylinder-to-cylinder variations of liner temperature at top ring position under stable and unstable running conditions in multi-cylinder DME/NG HCCI engine (T IN =40[ C])

71 φ φ Figure 6-11 Comparison of cylinder-to-cylinder variations of exhaust gas temperature between stable condition with φ DME =0.062 and unstable condition with φ DME =0.058 in multi-cylinder DME/NG HCCI engine (T IN =40[ C])

72 Figure 6-12 Cylinder-to-cylinder variations of exhaust gas temperature due to amount of DME in multi-cylinder DME/NG HCCI engine (Pme=0.25 [MPa])

73 φ φ Figure 6-13 Change in combustion history due to engine load in single cylinder HCCI engine (X EGR =0.5, T IN =60[ C])

74 Figure 6-14 Effect of EGR ratio on exhaust emissions and fuel consumption in single cylinder HCCI engine (T IN =60[ C])

75 (a) X EGR =0.0 (b) X EGR =0.2 (c) X EGR =0.4 Figure 6-15 Change in combustion history due to engine load in multi-cylinder HCCI engine (T IN =60[ C])

76 Figure 6-16 Effect of EGR ratio on exhaust emissions and fuel consumption in multi cylinder HCCI engine (T IN =60[ C])

77 η loss-cool η loss-exh η loss-cool η loss-exh (a) Single cylinder (b) Multi cylinder Figure 6-17 Effect of EGR ratio on heat balance in DME/NG HCCI engine (T IN =60[ C])

78 Figure 6-18 Correlation between thermal efficiency increment and EGR ratio in DME/NG HCCI engines (T IN =60[ C])

79 Figure 6-19 Correlation between THC decrement and EGR ratio in DME/NG HCCI engine (T IN =60[ C])

80 (a) Single cylinder (Pme=0.26[MPa]) (b) Multi cylinder (Pme=0.33[MPa]) Figure 6-20 Change in cumulative heat release due to EGR in DME/NG HCCI engines (T IN =60[ C])

81 Figure 6-21 Correlation between thermal efficiency and combustion efficiency increments due to EGR in DME/NG HCCI engines (T IN =60[ C])

82 Figure 6-22 Running load range in relation between CA50 and Pme (Single cylinder DME/NG HCCI engine, T IN =60 [ C])

83 Figure 6-23 Running load range in relation between CA50 and Pme (Multi cylinder DME/NG HCCI engine, T IN =60 [ C])

84 ± ±

86 7

88 ± ± ± ± ±

Journal of the Combustion Society of Japan Vol.51 No.155 (2009) FEATURE Clarification of Engine Combustion and the Evolution デ

51 155 2009 23-30 Journal of the Combustion Society of Japan Vol.51 No.155 (2009) 23-30 FEATURE Clarification of Engine Combustion and the Evolution ディーゼルエンジン燃焼の課題と今後 Diesel Combustion Challenge and Future