为了改善非道路F292风冷柴油机的NOx和PM排放性能,通过试验研究了不同燃烧室、EGR率和供油提前角的影响,在满足发动机动力性及经济性的情况下,优化匹配这些参数,满足美国环保局非道路第Ⅳ阶段排放标准。试验结果表明,EGR率为5.75%、10°CA BTDC供油提前角、燃烧室口径比为0.4和径深比为2条件下性能达到最优。

In this paper, the effects of combustion chamber geometry, EGR rate and fuel advance angle on emissions from a non-road air-cooled F292 diesel engine are studied in order to reduce NOx and PM, with-out penalty of performance and fuel economy, optimization matching of those parameters for meeting the 1imits of EPA non-road Tier Ⅳ exhaust emission standards. Experimental results show that the perfor-mance is optimal with 10°CA BTDC fuel advance angle, 5.75%EGR ratio, a combustion chamber with 0.4 calibre-diameter ratio and 2 calibre-depth ratio.

介绍了一种发动机各缸一致性补偿参数优选的方法,利用该方法能够完成对高压共轨发动机各缸均匀性判别及补偿。通过在泵试验台单次喷射仪上测试出各喷油器的喷射延迟时间及喷油量,进行控制提前角、控制油量补偿,保证发动机喷射提前角、各缸供油量的均匀性;在发动机台架上测试出各缸的有效功率,进行喷油量补偿,保证发动机各缸有效功率的一致性。应用该方法针对某发动机进行补偿参数优化,经试验验证能够满足发动机性能要求。

A method for compensation parameters optimization to improve the cylinder consistency was introduced and the judgment and compensation for cylinder uniformity was realized with the mentioned method .The injection delay and quantity for each injector were tested on a single injection pump test bench and the injection timing and injection quantity were controlled to keep their uniformity .The effective power for each cylinder was tested on the engine bench and the injection quantity was compensated to keep the consistency of effective power .The compensation parameter of an engine was optimized with the meth-od and verified by the experiment ,which proved that the method could meet the requirements of engine performance .

为满足国Ⅳ排放法规的要求,在某国产二气门国Ⅲ柴油机基础上,改进了增压器及燃烧系统的设计:升级电控系统,设计燃烧室,优化喷油器、增压器,采用冷却废气再循环(EGR)和先进的后处理技术等;并对增压器、燃烧室、供油提前角、轨压、EGR进行排放优化选型及排放标定试验,测量了功率、扭矩、油耗、烟度、气体排放和EGR率、噪声等排放和性能参数,确定了该EGR系统及标定策略。对整机进行了车载故障诊断(OBD)标定。结果表明:这些措施改善了排放和性能;使该柴油机达到了国Ⅳ排放标准,怠速噪声由原来的74 dB降到70 dB。

A two-valve CN-III diesel engine was improved by designs and tests to meet the CN (China)-IV emission regulation. The improved designs involved upgrading the electronic control system, redesigning the combustion chamber, optimizing the injector and the turbocharger, adopting the exhaust gas recirculation (EGR) and the advanced after-treatment technology. The turbocharger, the combustion chamber, the fuel supply advance angle, the rail pressure and EGR were optimized and calibrated. The performance tests, the emission tests and the noise tests were completed. The EGR system and the calibration strategy were conifrmed by measuring and analyzing the parameters ofpower, torque, fuel consumption, smoke, emission, EGR rates, and the idle speed noise. The vehicle was calibrated by OBD (on-board diagnostic). The results show that the diesel engine meets the CN-IV emission regulation, and the idle speed noise decreased from 74 dB to 70 dB by improving emission and performance.