基于公交工况的VNT柴油机性能开发和整车匹配优化研究

发布时间：2018-03-17 08:38

本文选题：城市公交车　切入点：动力性　出处：《湖南大学》2016年硕士论文　论文类型：学位论文

【摘要】：城市公交车是城市公共交通系统的重要组成部分,与城市居民的生活息息相关。然而随着城市规模与人口的迅速增长,公交车的数量越来越多,消耗量了大量能源,污染了环境。因此,为提高公交车的动力性和经济性以及减少排放,本文做了如下工作:(1)选择典型的公交车辆和使用区域,通过对发动机和整车运行工况数据进行采集和分析,提炼了公交车的运行工况特点,并为后续增压器匹配、发动机性能开发以及整车仿真计算作技术条件和边界输入。(2)建立了VNT增压器发动机性能开发试验系统,研究了VNT开度在不同发动机转速和负荷工况下对油耗率、增压压力、进气流量、排气烟度和温度等主要性能的影响,并对比VNT增压器发动机和原旁通阀增压器发动机的基本性能。结果表明,在中低速工况下,发动机动力性、经济性均有大幅改善,更适合公交工况。(3)将VNT增压器应用到公交车上进行道路试验验证,采集整车和发动机工况数据,通过对比数据的分布差别规律,对整车动力性、经济性影响进行评估。结果表明,起步加速动力性方面,VNT增压车辆改善幅度为13~15%,等速油耗改善幅度为4~7%,实际营运油耗改善幅度约为6%。(4)利用AVL-CRUISE软件建立了9m公交客车的整车仿真计算模型,并通过前文的整车动力性、经济性测试数据,对模型进行了修正和校核。基于建立的模型,进行了基于VNT增压器发动机性能基础上的多种传动系统速比配置对比计算,结果表明原车配置(5档直接档变速箱+4.875主减速比)能够兼顾动力性和经济性,但是使用5档直接档变速箱+4.67主减速比在满足动力性的前提下,综合油耗还可以降低1.84%,并且与旁通阀增压器整车状态相比,综合油耗可以改善约6~7%;(5)针对6J VNT增压发动机配套11.5m公交车进行了动力性、经济性仿真分析评估,并与典型11.5m公交车型配置的6G平台发动机的计算结果对比分析,结果表明,采用6J平台系列发动机+VNT增压器技术+优化主减速比的方案可以达到匹配11.5~12m公交车的要求,且在动力性和经济性方面优于原6G发动机配置。
[Abstract]:Urban bus is an important part of urban public transportation system, which is closely related to the life of urban residents. However, with the rapid growth of urban scale and population, the number of buses is increasing, and a large amount of energy is consumed. Therefore, in order to improve the power and economy of buses and reduce emissions, this paper has done the following work: 1) selecting typical public transport vehicles and using areas, collecting and analyzing the operating conditions data of engines and whole vehicles. The operating condition characteristics of the bus are refined, and the VNT turbocharger engine performance development test system is established for the subsequent turbocharger matching, engine performance development and vehicle simulation calculation as well as the boundary input. The effects of VNT opening on the main performance of engine, such as fuel consumption rate, pressurized pressure, inlet air flow rate, exhaust smoke and temperature, were studied under different engine speed and load conditions. The basic performances of the VNT turbocharger engine and the original bypass valve turbocharger engine are compared. The results show that the engine power and economy are greatly improved under the medium and low speed working conditions. The VNT supercharger is applied to the bus for road test and verification. The data of the whole vehicle and the engine are collected, and the power performance of the whole vehicle is compared by comparing the distribution of the data. Economic impact assessment. Results show that, In terms of starting acceleration power, the improvement range of VNT turbocharged vehicles is 13 / 15, the improvement range of isokinetic fuel consumption is 4 / 7, and the actual operating fuel consumption improvement range is about 6. 4) using AVL-CRUISE software, the vehicle simulation calculation model of 9m bus is established. Based on the above data, the model is revised and checked. Based on the established model, the speed-ratio configuration of various transmission systems based on the performance of VNT turbocharger engine is calculated and compared. The results show that the main deceleration ratio (4.875) of the original vehicle can give consideration to both power and economy, but the 4.67 main deceleration ratio of the five gear direct gear box can satisfy the power performance. The comprehensive fuel consumption can also be reduced by 1.84, and compared with the whole vehicle condition of the bypass valve supercharger, the comprehensive fuel consumption can be improved by about 6 / 7 / 5) the power performance of the 6J VNT turbocharged engine matching 11.5m bus is evaluated, and the economic simulation analysis and evaluation are carried out. The calculation results of 6G platform engine with typical 11.5m bus configuration are compared and analyzed. The results show that the scheme of using 6J platform series engine VNT supercharger technology to optimize the main deceleration ratio can meet the requirement of matching 11.5m 12m bus. And it is superior to the original 6 G engine configuration in power performance and economy.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U464.172

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