Kinetic models of natural gas combustion in an internal combustion engine

In this study, combustion of methane was simulated using four kinetic models of methane in CHEMKIN 4.1.1 for 0-D closed internal combustion （IC） engine reactor. Two detailed （GRIMECH3.0 ＆ UBC MECH2.0） and two reduced （One step ＆ Four steps） models were examined for various IC engine designs. The detailed models （GRIMECH3.0, ＆ UBC MECH2.0） and 4-step models successfully predicted the combustion while global model was unable to predict any combustion reaction. This study illustrated that the detailed model showed good concordances in the prediction of chamber pressure, temperature and major combustion species profiles. The detailed models also exhibited the capabilities to predict the pollutants formation in an IC engine while the reduced schemes showed failure in the prediction of pollutants emissions. Although, there are discrepancies among the profiles of four considered model, the detailed models （GRIMECH3.0 ＆ UBC MECH2.0） produced the acceptable agreement in the species prediction and formation of pollutants.

An approach for IC engine coolant energy recovery based on low-temperature organic Rankine cycle

To promote the fuel utilization efficiency of IC engine, an approach was proposed for IC engine coolant energy recovery based on low-temperature organic Rankine cycle(ORC). The ORC system uses IC engine coolant as heat source, and it is coupled to the IC engine cooling system. After various kinds of organic working media were compared, R124 was selected as the ORC working medium. According to IC engine operating conditions and coolant energy characteristics, the major parameters of ORC system were preliminary designed. Then, the effects of various parameters on cycle performance and recovery potential of coolant energy were analyzed via cycle process calculation. The results indicate that cycle efficiency is mainly influenced by the working pressure of ORC, while the maximum working pressure is limited by IC engine coolant temperature. At the same working pressure, cycle efficiency is hardly affected by both the mass flow rate and temperature of working medium. When the bottom cycle working pressure arrives at the maximum allowable value of 1.6 MPa, the fuel utilization efficiency of IC engine could be improved by 12.1%.All these demonstrate that this low-temperature ORC is a useful energy-saving technology for IC engine.

Optical Fiber Pyrometer Applied in IC Engine

Based on the theory of thermal radiation,a contact type optical fiber pyrometer applied in IC engine is put forward.It is composed of three parts:a blackbody probe,optical system,electrical process system.The key technology of design is discussed.Experiment is given to prove that the pyrometer has much higher responsive speed,distinguishability and much longer running life than other pyrometers.

DYNAMIC DESIGN OF INTERNAL COMBUSTION ENGINE BLOCK STRUCTURE

Several main steps of internal combustion engine block structure dynamic design,such as model set up,structure dynamic response analysis,optimizing design and vibration and noise control,are discussed for the type of EQ6100 gasoline engine block

Optimization of Transducer Location for Novel Non-Intrusive Methodologies of Diagnosis in Diesel Engines

The health monitoring has been studied to ensure integrity of design of engine structure by detection,quantification,and prediction of damages.Early detection of faults may allow the downtime of maintenance to be rescheduled,thus preventing sudden shutdown of machines.In cylinder pressure developed,vibrations and noise emissions data provide a rich source of information about condition of engines.Monitoring of vibrations and noise emissions are novel non-intrusive methodologies for which positioning of various transducers are important issue.The presented work shows applicability of these diagnosis methodologies adopted in case of diesel engines.The effects of changing various fuel injection parameters was analyzed.Scope of using non-intrusive technique has been analyzed by changing locations of microphone.Novelty of this worklies in exploring signal processing methods for various locations around the engine test set up.Various frequency ranges of contributing noise and vibration sources were identified.Time-Frequency analysis showed the onset of various cyclic.Based on the identification of various frequency bands,it is possible to device suitable filters in order to extract more information.

STATE ENGINEERING RESEARCH CENTERS OF THE CAS (Ⅱ)

State Engineering Research Center for Asic Design The National Engineering Research Center for ASIC Design is a national base for ASIC analysis and design.Its current research area includes:IC analysis/design methods,system development and application and commercial IC chip analysis. The center was established on the basis of the Microelectronic Design Center of Institute of Automation of the Chinese Academy of Sciences. As a pool of intelligent and technical resource,many researchers and experts on IC analysis/design and computer software/

渤海和黄海北部工程设计冰厚变化趋势分析

针对渤海和黄海北部沿岸风电、光伏和核电等新兴能源中的工程海冰设计问题,本文研究了重现期冰厚及其在大气候背景下的变化趋势。本文分析72 a冰级时间序列表明渤海和黄海北部总体冰情等级呈明显下降趋势;在此影响下,基于20 a渤海和黄海北部海冰多源观测数据和精细化海冰数值预报资料,研究发现不同重现期冰厚较之前海冰区划值存在不同程度的降低。此外,不同场址设计冰厚受当地海洋环境条件影响较大,单一参考海冰区划值可能存在较大误差。研究表明:针对特定作业地点的工程设计冰厚,需要有针对性地开展精细化评估并考虑大气候背景变化的影响,才能为相关工程海冰参数设计提供更加可靠的依据。

基于融雪效果的导电沥青路面电极优化设计

导电沥青混凝土结构设计过程中,电极的设计与优化是关键工作,决定着导电沥青路面的导电效率,影响路面融冰雪的效果。在前期试验研究的基础上,选择两种最具代表性的电极形式进行影响因素分析及优化方案设计,分别改变电极的间距、长度、材质进行实验,对比导电沥青试件的融雪效果。优化结果显示,选择铜作为电极材料,并综合考虑成本及后期对路面使用性能的影响,推荐最佳电极形式为单束铜电极,且间距为4 cm时沥青路面性价比及升温效果最佳。

不同形状颗粒的阻力系数实验研究

航空发动机高空冰晶粒子的阻力特性会影响冰晶的运动,为了探究不同形状冰晶对阻力系数的影响,采用高速摄像机跟踪拍摄的方法对球形颗粒和非球形颗粒(长圆柱、短圆柱和圆盘)阻力系数进行研究,根据颗粒匀速状态时的速度求得不同颗粒的雷诺数和阻力系数,并利用实验数据拟合获得不同颗粒在工况范围内适用的阻力系数计算关系式,最后利用拟合数据之外的实验数据对关系式进行验证。结果表明:在雷诺数为3961~24144范围内,四种粒子阻力系数的计算值和试验值平均相对误差在5%以内。

基于PSPICE喷油器电磁阀双电源双边驱动电路的设计与优化研究

为了提高喷油器电磁阀的高速驱动性能,建立了精确的电控柴油机电磁阀驱动模块的PSPICE模型,据此仿真分析了驱动方式和续流方式、驱动电压及续流回馈电压对电磁阀开启、关闭响应性影响规律。设计了电磁阀双电源双边驱动钳压续流电路,进行了工作过程的数学分析和参数优化。试验结果表明:该驱动电路提高了各个通道的喷油一致性,小油量(0.5ms喷油脉宽)时各驱动通道的最大偏差率为2.21%,相对标准差为1.41%,同时五次喷油下缸压峰值波动率为0.57%,该驱动电路满足高效清洁燃烧系统对喷油器驱动控制精度和各缸喷油规律一致性的要求。

基于公交IC卡数据的乘客出行分类研究

为得到体现公交乘客出行时空规律的数据,采用基于出行链方法推导出公共汽车乘客的下车站点;建立了描述单个乘客多天出行的完整数据框架;根据乘客参加不同活动所产生的出行时空特征定义了3类出行:通勤类出行、普通类出行和随机类出行,将出行频次与出发时间的标准差作为分类标准对公交乘客出行进行分类。研究表明:39.1%的乘客具有普通类或通勤类出行,生成总客流的76.4%;60.9%的乘客只具有随机类出行,生成总客流的23.6%。通过对乘客出行的分类研究可以更好地掌握乘客公交出行的规律和需求。

基于GPS和IC卡数据的公交出行OD推算方法

主要基于GPS和公交IC卡数据研究推算交通小区公交出行OD的一种方法。将居民公交出行分为闭合型出行链和非连续型公交出行链,通过数据的挖掘融合技术,结合居民公交出行规律推算交通小区的公交OD矩阵,利用站点吸引强度对无明显规律的紊乱出行数据进行修正,提出了基于GPS和公交IC卡数据推算公交出行交通小区OD的方法,并以佛山市中心城区为例验证推算方法的可靠性。研究表明:所得公交出行OD矩阵精度较高。

超疏水表面的防/除冰研究与应用

为了避免表面覆冰对日常生产生活造成的巨大影响,解决传统防/除冰技术存在效率低、能耗大、高污染等问题,本文梳理了基于超疏水特性实现表面防/除冰的研究进展。介绍了固体表面浸润性理论及常见的超疏水表面的制备方法,对超疏水表面的被动防冰和主动除冰方法进行了综述和讨论,归纳了基于超疏水表面的防/除冰策略在航空、船舶、电力等领域的具体应用。总结和剖析了超疏水防/除冰表面在实际应用中存在的问题和面临的挑战,对未来的发展方向进行了展望。

TEMIC系列射频卡及其应用

介绍了TEMIC公司射频卡系列的特点、工作原理和使用方法,并就实际的使用经验,对软硬件的一些问题做了简要的叙述。

基于分布式中间件ICE的应用架构研究

在分布式系统中,分布式平台之间的差异增加了开发的复杂性。基于一种轻量级的分布式中间件ICE,提出了在分布式异构环境中的一般架构模型。该模型可以降低模块之间的耦合度,解决服务器负载过大的问题。将该模型应用到网络安全管理系统中,解决了网络安全管理系统中平台差异问题和服务器负载均衡问题。

特高压直流在线融冰技术及其工程应用

雅湖直流线路跨越数个易发覆冰灾害的区域,易出现线路覆冰现象,影响直流输电稳定性。为解决上述问题,本文研究设计特高压直流融冰功能。首先,分析融冰主接线隔离开关的配置情况,避免运维人员人工搭线的操作过程;其次,设计融冰隔离开关的顺控及联锁逻辑,保障运维人员安全、快速地进行运行方式的转换;再次,阐述融冰的基本控制策略及在线融冰技术,保证常规运行转入融冰运行时,功率输送不中断;最后,介绍融冰配置的特殊功能,降低融冰运行异常对系统的影响。通过实时数字仿真试验验证了在线融冰技术的有效性,并一次性成功通过了现场解锁、功率升降、闭锁试验。融冰功能的研究设计提高了雅湖直流线路在冰雪灾害天气下的输电可靠性。

基于IC卡和RBF神经网络的短时公交客流量预测

在公交客流量特性分析基础上,通过IC卡获取了实时公交客流量数据;结合GPS数据,利用OD反推法分析了实时客流分布;进而建立了基于IC卡和RBF神经网络的短时公交客流量预测模型并介绍了具体预测过程。对重庆市841公交线路进行了实例分析,得到上下车客流真实值与预测值的平均绝对相对误差均小于1.5%,实例计算结果表明该模型能获取实时客流数据,预测精度高,具有一定的实际应用价值。

内循环厌氧反应器(IC)的应用与发展

从工程实践的角度对IC反应器的应用与研究现状进行了介绍,并对IC反应器在工程应用中暴露出来的问题进行了详细分析,最后指出了IC反应器的研究发展趋势,表明IC反应器具有产业化的发展前景。

基于IC卡信息的居民公交出行动态特性

通过对公交IC卡数据库中大量数据的筛选和处理,分析了不同公交乘客群体的性别、年龄构成,绘制了工作日、双休日及节假日公交客流的时间分布曲线,重点研究了客流高峰时段的居民公交出行特性。提出了基于公交IC卡信息的若干指标,定量分析了公交客流量在一天营运时间内的变动,在一个月中以星期为周期的律动以及一年中各月客流量的波动等动态特性,揭示了城市居民公交出行的基本规律,可为城市公交政策的制定、公交系统规划和运营管理提供可靠的理论依据和实用参数。

氢氧内燃机增氧定容燃烧特性研究

航天器携带推进剂有限,氢氧内燃机适宜采用纯氢纯氧+富氢燃烧方式,但目前内燃机纯氢纯氧燃烧缺乏地面试验验证。为此开展氢氧内燃机增氧定容燃烧试验,采用内燃机定容燃烧逐步增氧的技术路线,获得增氧乃至纯氧条件下氢氧内燃机的层流燃烧特性,实现氢氧内燃机高性能高可靠工作。试验结果表明:随着氧气浓度的增大,层流燃烧速度随当量比成倍增加,变化的幅度会逐渐减小;高氧气浓度条件下,层流燃烧速度维持在很高的水平,且随当量比的变化很小。