李壮壮,姚安仁,陈超,姚春德,王辉,刘明宽,窦站成,张德福.DMDF模式下冷却水温度对发动机燃烧与排放特性的试验研究[J].环境科学学报,2019,39(4):1113-1122
DMDF模式下冷却水温度对发动机燃烧与排放特性的试验研究
- Experimental study of cooling water temperature on combustion and emission characteristics of engine in DMDF mode
- 基金项目：国家自然科学基金重点项目（No.51336005）；天津科委自然科学基金项目（No.15JCYBJC21300）
- 李壮壮
- 天津大学, 内燃机燃烧学国家重点实验室, 天津 300072
- 姚安仁
- 天津大学, 内燃机燃烧学国家重点实验室, 天津 300072
- 陈超
- 天津大学, 内燃机燃烧学国家重点实验室, 天津 300072
- 姚春德
- 天津大学, 内燃机燃烧学国家重点实验室, 天津 300072
- 王辉
- 天津大学, 内燃机燃烧学国家重点实验室, 天津 300072
- 刘明宽
- 天津大学, 内燃机燃烧学国家重点实验室, 天津 300072
- 窦站成
- 天津大学, 内燃机燃烧学国家重点实验室, 天津 300072
- 张德福
- 天津理工大学, 海运学院, 天津 300384
- 摘要：在一台增压中冷的电控单体泵柴油机上采用柴油/甲醇二元燃料燃烧（Diesel/Methanol Duel Fuel，DMDF）模式，在重型柴油机常用的A50工况下，通过改变冷却水温度，对各替代率工况下的燃烧特性、排放特性及经济性进行了初步实验探索.实验结果表明，在各替代率工况下，提高冷却水温度，可导致滞燃期缩短，燃烧始点前移，预混燃烧与扩散燃烧占比出现转变，总放热量变化不大.上止点附近缸压有所降低，最高燃烧压力出现小幅度增大.燃烧持续期在替代率为40%左右时变化趋势不同，CA50在替代率为30%、冷却水温度为90℃时最接近上止点.双燃料模式下，随冷却水温度升高，NOx与CO排放变化并不明显，甲醛与甲醇排放不断降低，且降低幅度不断增大，当量比油耗有所降低.
- Abstract：By modifying a turbocharged intercooled electronic unit pump diesel engine, a low-pressure methanol injection device was installed in the diesel intake manifold to inject methanol to make it running in Diesel/Methanol dual fuel (DMDF) mode. The experiment was conducted at A50 working condition among Euro Steady State Test Cycle (ESC) 13 modes, and the cooling water outlet temperature values of the engine were set as 60, 70, 80 and 90℃ in turn, respectively, conducted under pure diesel mode and different methanol substitution percent (MSP) conditions. The experimental results showed that in the DMDF engine, increased the temperature of the cooling water under each MSP test, the combustion start point was lightly advanced, the proportion of premixed combustion decreased while the proportion of diffusion combustion increased. At the same time, the highest combustion pressure favored the higher cooling water temperature. In addition, increased the cooling water temperature would shorten the ignition delay period. The trend of combustion duration was varied around 40% MSP. Meanwhile, under the DMDF mode the CA50 was close to the top dead center (TDC) in general, and was more closer to TDC when the MSP is 30%, the cooling water temperature is 90℃, makeing the combustion heat release more concentrated. For exhaust emissions, there was only a slight increase of NOx and CO2 but HCHO and CH3OH emissions were significantly reduced in DMDF mode. In such mode, to increase cooling water temperature at the same MSP, the equivalent ratio fuel consumption was decreased, which helped to improve fuel economy.
