التفاصيل البيبلوغرافية
| العنوان: |
临界温度下循环喷油量对柴油机冷起动和排放特性的影响. (Chinese) |
| Alternate Title: |
Effects of circulation injection quantity on the cold start and emission performance of diesel engines at the critical temperature. (English) |
| المؤلفون: |
雷基林, 李道硕, 王东方, 杨朗建, 陈俊霖, 刘康, 宋国富, 孙亮, 陈丽琼 |
| المصدر: |
Transactions of the Chinese Society of Agricultural Engineering; May2024, Vol. 40 Issue 10, p247-254, 8p |
| Abstract (English): |
This study aims to investigate the impact of circulation injection quantity on the cold start and emission performance of small agricultural diesel engines. The optimal quantity of circulation injection was also determined at critical temperatures. The study focuses on an inline twin-bar high-pressure common rail diesel engine. Using the environment simulation cabin whole engine test platform, several pre-tests were conducted. The results showed that the diesel engine started successfully without opening the preheating device at an altitude of 2 000 m and a critical temperature of -5 ℃. Three types of injections were used in this case. Specifically, the injection time of pre-injection 2, pre-injection 1 and main injection was -22, -14.4 and - 7.7 °CA ATDC (crank angle after top dead center), respectively, and the injection duration of pre-injection 2 was 2.5 °CA, and the circulation injection quantity was fixed at 2.5 mg. The pre-injection 1 injection duration was 3 °CA, and the pre-injection amount was fixed at 3 mg. The circulation injection quantity was varied in the main injection volume, with the values of 8, 15, 17, 20, 25, 30, 34, and 40 mg. The target speed was set as 1 050 r/min. The cold start time and emissions of HC, CO, and NOx were measured at various circulation injection quantities during the test. The results indicate that the cold start time of the diesel engine increased or even resulted in the start failure with the larger or smaller amount of circulation fuel injection. As the circulation injection quantity increased, the cold start time initially decreased and then increased again. The shortest start time was 266 s at the 20 mg of circulation injection quantity. The longest start time was 365 s at the 15 mg of circulation injection quantity, with a difference of nearly 100 s. Additionally, the lowest peaks of HC and CO emissions were also observed as 12 984 and 3 008 mg/L, respectively, at 20 mg. The variation in the circulation injection quantity also resulted in an increase in the peak of HC and CO emissions. Furthermore, the peak value of CO emission increased significantly with the larger circulation injection quantity, where the peak value appeared earlier. The circulation injection quantity had a greater effect on the NOx emission peak. The lowest peak of NOx emission was 368 mg/L at the circulation injection quantity of 30 mg. Therefore, there was a significant impact of circulation injection quantity on the cold start and emission performance of diesel engines. The optimal quantity of circulation injection was also beneficial to reducing the start time and emissions for higher generating efficiency and a friendly environment. Furthermore, 20 mg was the optimal circulation injection quantity for the cold start in this small diesel engine at an altitude of 2 000 m and an ambient temperature of -5 ℃. These findings can also provide experimental data to optimize the cold start and emissions of engines. The circulation injection quantity with after-treatment devices can further reduce the cold start emissions. [ABSTRACT FROM AUTHOR] |
| Abstract (Chinese): |
为探明循环喷油量对小型农用柴油机冷起动特性和排放性能的影响规律，同时寻求其临界温度下的最佳循环喷 油量，该研究以一款直列双缸高压共轨柴油发动机为研究对象，利用环境模拟舱整机试验平台，通过多次预试验测得海 拔 2000 m 下，该机不开启预热装置能够成功起动的临界温度为-5 ℃。在此工况下，采用 3 次喷射方式，通过改变主喷 油量研究循环喷油量对该机冷起动特性和排放性能的影响。结果表明：较大或较小的循环喷油量均会导致柴油机冷起动 时间增加，甚至起动失败；随着循环喷油量增大，冷起动时间先减小后增加，循环喷油量为 20 mg 时冷起动时间最短， 且 HC、CO 排放峰值均最低，分别为 12 984 和 3 008 mg/L；增大或减少循环喷油量均会导致 HC 和 CO 排放峰值增加。 循环喷油量较大时，CO 排放峰值显著增加，并且峰值出现时刻提前。改变循环喷油量对 NOx 排放峰值有较大影响，循 环喷油量为 30 mg 时 NOx 排放峰值最小，为 368 mg/L。综合考虑，海拔高度 2 000 m，环境温度-5 ℃ 工况下该柴油机 起动的最佳循环喷油量为 20 mg。研究结果可为柴油机冷起动特性和排放优化提供支撑。 [ABSTRACT FROM AUTHOR] |
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| قاعدة البيانات: |
Complementary Index |
