甲醇喷射时刻对甲醇/柴油双直喷发动机性能的影响

doi:10.11949/0438-1157.20241531

摘要/Abstract

摘要：

利用双直喷发动机试验平台开展了甲醇/柴油双直喷发动机运行范围及性能的试验研究。结果表明，甲醇在进气行程中喷射时，甲醇/柴油双直喷发动机的运行范围受两种情况限制：最大压升率超过0.8 MPa·（°）^-1时的粗暴燃烧、指示平均有效压力的循环变动超过5.0%时的不稳定燃烧。当甲醇在压缩行程后期喷射时，发动机运行范围仅受限于粗暴燃烧，最高甲醇替代率可达62.7%，指示热效率高达43.4%。甲醇喷射时刻对甲醇/柴油双直喷发动机燃烧和排放特性均有显著影响。当甲醇喷射时刻为-60°时，爆发压力和最大压升率均达到最高，着火延迟期最短，燃烧持续期最长，同时NO _x 排放最大，但CO、HC和soot排放最低，分别仅为8.5、1.3和0.06 g·（kW·h）^-1。

关键词: 醇, 扩散, 燃料, 污染, 运行范围, 燃烧, 排放

Abstract:

The operating range and performance of a methanol/diesel dual direct injection engine were experimentally studied using a dual direct injection engine test platform. The results demonstrate that when methanol is injected during the intake stroke, the operating range of the methanol/diesel dual direct injection engine is restricted by rough combustion with the maximum pressure rise rate exceeding 0.8 MPa·(°)^-1 and unstable combustion with the coefficient of variation of indicated mean effective pressure exceeding 5.0%. When methanol is injected in the late stage of the compression stroke, the engine's operating range is only limited by rough combustion. Under this condition, the maximum methanol substitution rate can reach 62.7%, and the indicated thermal efficiency can be as high as 43.4%. The timing of methanol injection exerts a profound influence on the combustion and emission characteristics of a methanol/diesel dual direct injection engine. When the methanol injection timing is -60°, both the peak pressure and the maximum pressure rise rate in the cylinder reach their highest values, the ignition delay period is the shortest, the combustion duration is maximized, and the NO _x emissions are at their peak. However, the CO, HC and soot emissions are minimized, amounting to only 8.5, 1.3 and 0.06 g·(kW·h)^-1 respectively.

Key words: alcohol, diffusion, fuel, pollution, operating range, combustion, emissions

中图分类号:

TK 431

段浩, 王文超, 刘栋, 尹晓军, 胡二江, 曾科. 甲醇喷射时刻对甲醇/柴油双直喷发动机性能的影响[J]. 化工学报, 2025, 76(7): 3552-3560.

Hao DUAN, Wenchao WANG, Dong LIU, Xiaojun YIN, Erjiang HU, Ke ZENG. Effects of methanol energy substitution ratio on performance of a methanol/diesel dual direct injection engine[J]. CIESC Journal, 2025, 76(7): 3552-3560.

图/表 8

图1 甲醇/柴油双直喷发动机试验平台

Fig.1 Test platform of methanol/diesel dual-direct injection engine

表1 原柴油机的主要参数

Table 1 Main parameters of original diesel engine

参数	数值或描述
发动机类型	单缸风冷柴油机
排量/L	0.498
缸径/mm	92
行程/mm	75
压缩比	19.0∶1
最大扭矩/(N‧m)	25
转速/(r·min^-1)	2000

图2 不同甲醇喷射时刻下指示热效率随发动机负荷率和甲醇替代率的变化

Fig.2 Indicated thermal efficiency versus methanol substitution ratio at various engine load rate and methanol injection timings

图3 甲醇喷射时刻对燃烧过程的影响

Fig.3 Effect of methanol injection timing on combustion process

图4 甲醇喷射时刻对爆发压力和最大压升率及各自对应曲轴转角的影响

Fig.4 Effect of methanol injection timing explosion pressure, maximum pressure rise rate, and corresponding crankshaft angles

图5 甲醇喷射时刻对缸内平均温度的影响

Fig.5 Effect of methanol injection timing on average temperature in cylinder

图6 甲醇喷射时刻对燃烧特征参数的影响

Fig.6 Effect of methanol injection timing on combustion characteristic parameters

图7 甲醇喷射时刻对排放的影响

Fig.7 Effect of methanol injection timing on emissions

参考文献 35

[1]	Gong C M, Yi L, Zhang Z L, et al. Assessment of ultra-lean burn characteristics for a stratified-charge direct-injection spark-ignition methanol engine under different high compression ratios[J]. Applied Energy, 2020, 261: 114478.
[2]	Ning L, Duan Q M, Kou H L, et al. Parametric study on effects of methanol injection timing and methanol substitution percentage on combustion and emissions of methanol/diesel dual-fuel direct injection engine at full load[J]. Fuel, 2020, 279: 118424.
[3]	Wu Y Y, Wang C, Huang Z X, et al. The combustion and emission characteristics of pure methanol as a substitute fuel for compression ignition engines[J]. International Journal of Green Energy, 2024, 21(14): 3313-3329.
[4]	Liu H F, Cui Y Q, Wen M S, et al. Optical diagnostics and chemical kinetic analysis on partially premixed combustion characteristics fueled with methanol and various cetane improvers[J]. Proceedings of the Combustion Institute, 2024, 40(1/2/3/4): 105214.
[5]	Li Y Z, Yao M F, Liang H P, et al. Energy analysis during cold start and warm up period of a methanol engine hybrid power system under several novel energy conversion strategies[J]. Energy, 2024, 308: 132960.
[6]	Liu X L, Sim J, Raman V, et al. A computational study of methanol combustion engine assisted by glow plug[C]//2024 Stuttgart International Symposium on Automotive and Engine Technology. Wiesbaden: Springer Fachmedien Wiesbaden, 2024: 258-269.
[7]	Huang Z H, Lu H B, Jiang D M, et al. Combustion behaviors of a compression-ignition engine fuelled with diesel/methanol blends under various fuel delivery advance angles[J]. Bioresource Technology, 2004, 95(3): 331-341.
[8]	Hasan A O, Osman A I, Al-Muhtaseb A H, et al. An experimental study of engine characteristics and tailpipe emissions from modern DI diesel engine fuelled with methanol/diesel blends[J]. Fuel Processing Technology, 2021, 220: 106901.
[9]	Sayin C, Ilhan M, Canakci M, et al. Effect of injection timing on the exhaust emissions of a diesel engine using diesel–methanol blends[J]. Renewable Energy, 2009, 34(5): 1261-1269.
[10]	Truong T T, Nguyen X P, Pham V V, et al. Effect of alcohol additives on diesel engine performance: a review[J]. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2021: 1-25.
[11]	Yao C D, Cheung C S, Cheng C H, et al. Effect of diesel/methanol compound combustion on diesel engine combustion and emissions[J]. Energy Conversion and Management, 2008, 49(6): 1696-1704.
[12]	Wei H Y, Yao C D, Pan W, et al. To meet demand of Euro Ⅴ emission legislation urea free for HD diesel engine with DMCC[J]. Fuel, 2017, 207: 33-46.
[13]	姚春德, 王辉, 姚安仁, 等. DMCC技术在高速船用柴油机上的应用研究[J]. 哈尔滨工程大学学报, 2021, 42(1): 112-118.
	Yao C D, Wang H, Yao A R, et al. Performance study of diesel/methanol compound combustion technology applied to high-speed marine engine[J]. Journal of Harbin Engineering University, 2021, 42(1): 112-118.
[14]	姚春德, 王辉, 姚安仁, 等. 柴油多次喷射对船舶DMCC发动机的影响[J]. 天津大学学报 (自然科学与工程技术版), 2020, 53(1): 96-104.
	Yao C D, Wang H, Yao A R, et al. Effect of diesel multiple injection on marine DMCC engines[J]. Journal of Tianjin University (Science and Technology), 2020, 53(1): 96-104.
[15]	Dong Y B, Kaario O, Hassan G, et al. High-pressure direct injection of methanol and pilot diesel: a non-premixed dual-fuel engine concept[J]. Fuel, 2020, 277: 117932.
[16]	Jia Z Q, Denbratt I. Experimental investigation into the combustion characteristics of a methanol-diesel heavy duty engine operated in RCCI mode[J]. Fuel, 2018, 226: 745-753.
[17]	Zhao W B, Li Z L, Huang G, et al. Experimental investigation of direct injection dual fuel of n-butanol and biodiesel on Intelligent Charge Compression Ignition (ICCI) combustion mode[J]. Applied Energy, 2020, 266: 114884.
[18]	Huang G, Li Z L, Zhao W B, et al. Effects of fuel injection strategies on combustion and emissions of intelligent charge compression ignition (ICCI) mode fueled with methanol and biodiesel[J]. Fuel, 2020, 274: 117851.
[19]	Li Z L, Zhang Y Y, Huang G, et al. Control of intake boundary conditions for enabling clean combustion in variable engine conditions under intelligent charge compression ignition (ICCI) mode[J]. Applied Energy, 2020, 274: 115297.
[20]	Zhang Y Y, Mi S J, Zhao W B, et al. Experimental study on the application of bioethanol in dual-fuel intelligent charge compression ignition (ICCI) engine[J]. Fuel, 2021, 303: 121181.
[21]	蔡开源, 王志, 刘奕, 等. 氨柴双燃料高压缩比发动机柴油喷射策略优化[J]. 汽车安全与节能学报, 2023, 14(6): 783-789.
	Cai K Y, Wang Z, Liu Y, et al. Optimization of diesel injection strategy for ammonia-diesel dual-fuel engines with high compression ratio[J]. Journal of Automotive Safety and Energy, 2023, 14(6): 783-789.
[22]	张鼎成, 张光德, 陈书郅. 喷油策略对甲醇/PODE _n 双燃料压燃燃烧特性的影响[J]. 汽车安全与节能学报, 2023, 14(4): 513-520.
	Zhang D C, Zhang G D, Chen S Z. Effects of fuel injection strategy on combustion characteristics of methanol/PODE _n dual-fuel compression ignition mode[J]. Journal of Automotive Safety and Energy, 2023, 14(4): 513-520.
[23]	Wen M S, Wang C, Zhang Z, et al. Effects of operating parameters on start performance of compression ignition engine by using high-pressure direct-injection pure methanol fuel[J]. Applied Thermal Engineering, 2024, 249: 123352.
[24]	Zhao W B, Zhang Y Y, Huang G, et al. Experimental study of butanol/biodiesel dual-fuel combustion in intelligent charge compression ignition (ICCI) mode: a systematic analysis at low load[J]. Fuel, 2021, 287: 119523.
[25]	Li B, Xiao G, Zhang H, et al. Experimental study of independent two-stage in-cylinder heat release using jet controlled compression ignition[J]. Fuel, 2021, 289: 119925.
[26]	Wu T Y, Yao A R, Yao C D, et al. Effect of diesel late-injection on combustion and emissions characteristics of diesel/methanol dual fuel engine[J]. Fuel, 2018, 233: 317-327.
[27]	Tang Q J, Jiang P, Peng C W, et al. Comparison and analysis of the effects of spark timing and lambda on a high-speed spark ignition engine fuelled with n-butanol/gasoline blends[J]. Fuel, 2021, 287: 119505.
[28]	Yin X J, Sun N N, Sun T, et al. Experimental investigation the effects of spark discharge characteristics on the heavy-duty spark ignition natural gas engine at low load condition[J]. Energy, 2022, 239: 122244.
[29]	Yin X J, Xu L L, Duan H, et al. In-depth comparison of methanol port and direct injection strategies in a methanol/diesel dual fuel engine[J]. Fuel Processing Technology, 2023, 241: 107607.
[30]	Wang Q G, Wei L J, Pan W, et al. Investigation of operating range in a methanol fumigated diesel engine[J]. Fuel, 2015, 140: 164-170.
[31]	Wang Y, Wang H, Meng X Y, et al. Combustion characteristics of high pressure direct-injected methanol ignited by diesel in a constant volume combustion chamber[J]. Fuel, 2019, 254: 115598.
[32]	Saccullo M, Nygren A, Benham T, et al. Alcohol flexible HD single cylinder diesel engine tests with separate dual high pressure direct fuel injection[J]. Fuel, 2021, 294: 120478.
[33]	Xu L L, Bai X S, Li C L, et al. Emission characteristics and engine performance of gasoline DICI engine in the transition from HCCI to PPC[J]. Fuel, 2019, 254: 115619.
[34]	Li Z L, Liu G B, Cui X F, et al. Effects of the variation in diesel fuel components on the particulate matter and unregulated gaseous emissions from a common rail diesel engine[J]. Fuel, 2018, 232: 279-289.
[35]	Tree D R, Svensson K I. Soot processes in compression ignition engines[J]. Progress in Energy and Combustion Science, 2007, 33(3): 272-309.