浅析燃油液位传感器抗腐蚀电路对燃油指示的影响与正确读数

为提高燃油油位传感器的使用寿命,及时清洁硫化腐蚀,景程在油位传感器上增加抗腐蚀电路。本文就抗腐蚀电路对燃油指示的影响和如何正确读取燃油读数进行相应分析。     

PFI汽油机空燃比控制仿真及试验研究

基于发动机台架试验,建立并标定了进气道燃油喷射单缸汽油机一维仿真模型,探索了空燃比控制的新方法。依据经典控制理论,通过所建空燃比PID控制器与参数整定,实现了稳态空燃比控制。基于x-τ油膜模型,提出了其代数控制X-Y油膜方程,分析了进气道燃油传输过程对空燃比控制的影响;通过燃油阶跃扰动法,对X,Y参数进行识别,获得了X,Y参数MAP图,构建了离散化燃油动态补偿器,实现了空燃比在瞬态工况下的前馈控制。     

Fully coupled BEM-FEM analysis for ship hydroelasticity in waves

This paper considers the problem of ship hydroelasticity, which is an important technical issue in the design of ultra-large vessels. For the analysis of fluid-structure interaction problems, a partitioned method is applied. The fluid domain surrounding a flexible body is solved using a B-spline Rankine panel method, and the structural domain is handled with a three-dimensional finite element method. The two distinct methods are fully coupled in the time domain by using an implicit iterative scheme. The numerical results of natural frequency and the motion responses of simple and segmented barges are computed to validate the present method through comparisons with experimental and numerical results. This study extends to the application to two real ships, 6500 TEU and 10,000 TEU containerships, for more validation and also observation on the practicality of the present method. Based on this study, it is found that the present method provides reliable solutions to linear ship hydroelasticity problems.     

基于高频注入的永磁同步电机参数辨识策略

永磁同步电机高性能控制依赖电机参数和磁极初始位置的准确性,辨识磁极初始位置可以保证无位置传感器矢量控制启动过程的平稳性。传统的参数辨识方法辨识过程较为复杂或者精度不高,本文提出了一种易于实现的高频注入控制算法,通过注入高频电压,提取高频电流,就可以直接快速辨识出永磁同步电机电感,再通过注入两个脉冲电压矢量,就可以辨识磁极初始位置。这种方式辨识精度高,快速性好,工程实现方便,而且不需要转动电机,具有广泛的实用性。     

船舶使用850 cSt重油的设计研究

针对近年来船东在新造船中提出使用越来越高粘度重油的要求,文章突破ISO 8217质量标准及厂家指导手册中对燃油最高粘度700 cSt的限制,以某3500TEU支线集装箱船使用850cSt重油为案例,从设计的角度分析了船舶使用850cSt重油的合理性,从机器设备、系统、控制等方面提供了解决高粘度燃油问题的理论依据,并提出了较为合理的解决方案。这些方案的实施,为船舶使用越来越低廉的燃油,进一步降低船舶营运中的燃油费用提供了可能,具有良好的市场应用前景。     

Real-world gaseous and particle emissions of a Bi-fuel gasoline/CNG Euro 6 passenger car

The objective of the present study is the assessment of the environmental impact of a bivalent (bi-fuel) vehicle, running either on gasoline or compressed natural gas (CNG). To that aim, a Euro 6 passenger car was tested under various real-world driving conditions. In order to cover the full range of conventional powertrains currently in the market, the tests were also repeated on a Euro 6 diesel passenger car. Both cars were driven in two routes, the first complying with the regulation limits and the second going beyond them. Carbon monoxide (CO), nitrogen oxides (NO_x) and particle number (PN) emissions were recorded using a Portable Emissions Measurement System (PEMS). Apart from the aggregated emission levels, in g/km, the exact emission location along the route was also assessed. Natural gas proved beneficial for CO and PN emissions, the level of which always remained below the respective legislation limits. On the other hand, under the dynamic driving conditions with gasoline, the relevant limits were exceeded. Cold start, occurring at the beginning of the urban part, and motorway driving were identified as major contributors to total emissions, especially in gasoline mode. However, the application of natural gas was associated with a penalty in NO_x emissions, which were significantly increased as compared to gasoline. Local peaks within the urban part were identified in CNG mode. In any case, the diesel vehicle was by far the highest NO_x emitter.     

Serving vs. settling: What drives the establishment of low-cost carriers’ foreign bases?

This paper uses a probit model on a cross-sectional dataset of 202 airports and 29 airlines to assess the drivers for the establishment of foreign bases by European low-cost carriers (LCCs). We find that managerial, organizational, and environmental factors impact on foreign base establishment. In particular, there is evidence that the presence of a growth-oriented firm leader and the strategic importance of an airport for an airline significantly increase the probability of the presence of bases, while national unit labor costs, the volatility of flight operations and the membership of an LCC in an airline group significantly decrease this probability.     

燃料电池车辆开发的可行性

介绍燃料电池车辆的开发现状,对不同燃料作了比较,叙述了初步试验结果.     

基于事故树分析法的船舶LNG燃料加注火灾防控研究

文章采用事故树分析法,对船舶LNG燃料加注时可能引起火灾的事件进行了分析,提出了相应对策,为LNG动力船舶燃料加注的安全管理提供了参考。