基于转矩模型的柴油机功率在线测试方法研究  

Online Measurement Method of Diesel Engine Power Based on Torque Model

作　　者：唐琦军 常宏博 蒋蘋[1] 罗锋[2] 郑帅帅 TANG Qijun;CHANG Hongbo;JIANG Pin;LUO Feng;ZHENG Shuaishuai(College of Mechanical and Electrical Engineering,Hunan Agricultural University,Changsha 410128,China;Guangxi Yuchai Machinery Co.,Ltd.,Yulin 537000,China)

机构地区：[1]湖南农业大学机电工程学院,长沙410128 [2]广西玉柴机器股份有限公司,玉林537000

出　　处：《农业机械学报》2020年第S02期571-578,共8页Transactions of the Chinese Society for Agricultural Machinery

基　　金：湖南省自然科学基金青年基金项目(2019JJ50276);湖南省教育厅优秀青年项目(17B122)。

摘　　要：针对拖拉机耕作过程柴油机输出功率不易精准测量的问题,基于柴油机燃油控制策略的转矩模型,对雷沃拖拉机在理论速度为5.7 km/h和8.9 km/h的耕地过程的柴油机功率进行了在线测量。将在线测量的指示功率与燃烧分析仪测量的指示功率进行了对比,结果表明:在拖拉机耕作速度较稳定的一段区间内,在线测量的指示功率平均值误差为2.99%,但瞬时值严重失真;分析发现喷油量和喷油时刻的变化是引起功率测量偏差较大的主要原因。为了提高柴油机输出功率在线测量的精准度,利用GTPower模型得到了该柴油机12个典型工况的空燃比和喷油时刻与转矩的定量关系,并提出利用喷油量修正系数和喷油时刻修正系数对在线测量方法进行修正。优化后方法的测试结果表明:拖拉机稳定运行阶段柴油机功率平均值误差为0.88%,瞬时值误差明显改善。The output power of diesel engine is one of its important performances.For the individual components of an engine,the accurate output power can be measured through the dynamometer.However,it is not easy to accurately measure the output power of the diesel engine during tractor ploughing.Based on the torque model of the diesel fuel control strategy,the output power of the diesel engine was measured online during the Lovol tractor ploughing process with the theoretical speed of 5.7 km/h and 8.9 km/h.The indicated power of the torque model was compared with that of the combustion analyzer.The test results showed that when the tractor's ploughing speed was relatively stable,the error of the average value of the indicated power was 2.99%,but the instantaneous value became distorted seriously.It was found that the changes in the fuel injection amount and the injection timing are the main reasons for the large deviation in power measurement.To improve the accuracy of the online measurement for diesel engine output power,the quantitative relationships between the fuel injection quantity,fuel injection time and torque under 12 typical working conditions were obtained by using the GTPower model.Then,the correction coefficients of fuel injection quantity and fuel injection time were used to optimize the original measurement method.The optimized results showed that under the stable operation,the average measurement error of diesel engine output power is 0.88%,and the instantaneous value’s error was reduced significantly.It can be learned that optimizing the fuel injection strategy of the diesel engine is an important way to improve the performance of the diesel engine during tractor ploughing.

关 键 词：柴油机 功率测量 转矩模型 试验 

分 类 号：TK427[动力工程及工程热物理—动力机械及工程]