重型柴油机低温起动及暖机过程的颗粒排放特性

doi:10.12382/bgxb.2023.0625

摘要/Abstract

摘要：

低温环境下重型柴油机起动过程碳烟颗粒排放较高,严重影响起动效率。柴油机的低温起动性能受冷却液和润滑油温度的影响,为揭示低温环境下柴油机起动过程的碳烟颗粒排放变化规律,通过单缸发动机台架试验,对起动和暖机过程不同初始水温油温条件下的缸内压力、碳烟烟度和颗粒物浓度排放进行测量。试验结果表明:发动机低温起动初期碳烟排放最高,随着起动和暖机过程中水温油温升高碳烟排放逐渐降低,聚集态颗粒数浓度降低,核态颗粒数浓度升高,总颗粒数浓度受核态颗粒主导而升高;低温起动时提高初始水温、油温,起动和暖机过程中碳烟排放降低,核态颗粒数浓度、粒径、表面积和质量均降低,聚集态颗粒数浓度降低,大尺寸聚集态颗粒增多使得颗粒表面积和质量升高;低温环境下提高加温锅的加热能力以升高初始水温油温,可降低起动过程的碳烟和颗粒数排放,有助于提高起动效率和减少环境污染。

关键词: 重型柴油机, 低温起动, 暖机, 颗粒排放, 碳烟

Abstract:

The high soot particle emission during the start-up process of heavy diesel engine at low-temperature has a serious effect on the start-up efficiency. The start-up performance of diesel engine at low-temperature is influenced by the coolant and lubricating oil temperature. To reveal the soot particle emission characteristics of diesel engine during start-up process at low temperature, the in-cylinder pressures, and soot and particle emissions at different initial coolant and lubricating oil temperature conditions during start-up and warm-up are measured by single-cylinder engine bench test. The results show that the soot emission of the engine is the highest in the early stage of low-temperature start-up. With the increase of coolant and lubricating oil temperatures during warm-up, the soot emission gradually decreases, the number concentration of aggregated particles is reduced, the number concentration of nucleation mode particles is increased, and the total particle number concentration is dominated by nucleation mode particles. Increasing the initial coolant and lubricating oil temperatures under cold start-up condition reduces the soot emission during the start-up process, the number concentration, particle size, surface area and mass of nucleation mode particles decrease, the number concentration of aggregated particles decreases, and the particle surface area and mass are increased with the increase in large-sized aggregated particles. The soot and particle emissions during the start-up process can be reducedd by increasing the heating capacity of the heating pot at low temperature to increase the initial temperatures of coolant and lubricating oil, which improves the start-up efficiency and reduces environmental pollution.

Key words: diesel engine, low-temperature start-up, warm-up, particle emission, soot

中图分类号:

TK427

曹智焜, 吴晗, 张树纯, 张贵贤, 常江, 李向荣. 重型柴油机低温起动及暖机过程的颗粒排放特性[J]. 兵工学报, 2024, 45(8): 2851-2862.

CAO Zhikun, WU Han, ZHANG Shuchun, ZHANG Guixian, CHANG Jiang, LI Xiangrong. Particle Emission Characteristics of Heavy Diesel Engine During Low-temperature Star-up and Warm-up[J]. Acta Armamentarii, 2024, 45(8): 2851-2862.

图/表 20

图1 单缸机试验台架

Fig.1 Single cylinder diesel engine test system

图2 单缸机试验台架系统示意

Fig.2 Schematic diagram of single cylinder diesel engine test system

表1 单缸柴油机主要参数

Table 1 Single cylinder diesel engine specifications

发动机参数	缸径/ mm	冲程/ mm	排量/ L	连杆长度/ mm	压缩比	涡流比	标定扭矩转速/ (r·min^-1)	最大扭矩转速/ (r·min^-1)	标定功率/ kW
数值	132	145	1.98	262	13.5	0	2500	1800	92

图3 进排气管道主要测点位置

Fig.3 Location of the main measurement points of intake and exhaust pipelines

表2 试验重复性的统计分析

Table 2 Statistical analysis of test repeatability

初始水温、油温/℃	转速/(r·min^-1)				IMEP/MPa				起动初始时刻的烟度/FSN
初始水温、油温/℃	3次试验记录值	平均值	标准差	变异系数/%	3次试验记录值	平均值	标准差	变异系数/%	3次试验记录值	平均值	标准差	变异系数/%
30	500, 500, 500	500.00	0	0	0.055, 0.055, 0.055	0.0550	0	0	1.995, 2.075, 1.899	1.9897	0.0881	4.428
45	500, 500, 500	500.00	0	0	0.055, 0.054, 0.055	0.0547	0.00058	1.060	1.697, 1.723, 1.676	1.6987	0.0235	1.383

图4 发动机暖机过程的缸内压力和瞬时放热率

Fig.4 In-cylinder pressure and heat release rate during engine warm-up

图5 发动机暖机过程的着火时刻

Fig.5 Start of ignition during engine warm-up

图6 燃烧相位

Fig.6 Combustion phase

图7 发动机暖机过程的排气温度、冷却液温度和润滑油温度

Fig.7 Exhaust gas, coolant and oil temperatures during engine warm-up

图8 发动机暖机过程的碳烟排放

Fig.8 Soot emissions during engine warm-up

图9 冷起动和暖机过程的总颗粒数、核态颗粒数和聚集态颗粒数浓度

Fig.9 Total particle, nucleation particle and accumulation particle concentration during cold start-up and warm-up

图10 发动机暖机过程的平均颗粒尺寸分布

Fig.10 Particle size distribution during engine warm-up

图11 不同时间范围的颗粒数量浓度占比

Fig.11 Proportion of particle concentration during engine warm-up

图12 不同冷却液温度的平均颗粒尺寸分布

Fig.12 Particle size distribution at different coolant temperatures

图13 不同冷却液温度的颗粒数量浓度

Fig.13 Particle concentration at different coolant temperatures

图14 不同冷却液温度的中位粒径

Fig.14 Median particle size at different coolant temperatures

图15 不同冷却液温度的颗粒表面积和粒径分布

Fig.15 Surface area of particle and its size distribution at different coolant temperatures

图16 不同冷却液温度的颗粒表面积

Fig.16 Surface area of particle at different coolant temperatures

图17 不同冷却液温度的颗粒质量和粒径分布

Fig.17 Particle mass and particle size distribution distribution at different coolant temperatures

图18 不同冷却液温度的颗粒质量

Fig.18 Particle mass at different coolant temperatures

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