Ce/Cu0.5Mn0.5/SBA-15催化剂及其甲苯催化燃烧性能研究

以介孔分子筛SBA-15为载体,采用浸渍法制备了Ce/Cu0.5Mn0.5/SBA-15催化剂,用X-射线衍射（XRD）和程序升温还原（TPR）等现代分析测试手段对催化剂的结构进行了表征,在常压固定床反应器上评价了催化剂的甲苯催化燃烧性能.结果表明,所有催化剂仍然保持SBA-15的介孔结构特征,催化活性组分Cu和Mn分别以CuO和MnO2的物相形式存在,添加适量的催化助剂CeO2后活性组分Cu和Mn以高分散状态存在,从而提高催化活性.当Cu0.5Mn0.5的含量为12%、Ce的含量为3.5%时,催化剂具有最好的活性,甲苯在480℃可完全催化燃烧消除.甲苯浓度较高,空速较大,甲苯转化率下降.     

后驻体喷孔位置对驻涡腔流动冷态数值的影响

为使采用驻涡燃烧的旋转冲压发动机的燃烧组元获得燃烧的稳定性,研究后驻体喷孔位置对驻涡腔流动冷态数值的影响.应用Fluent软件模拟驻涡燃烧室中三维冷态流场的流动特性;湍流模型采用RNG k-ε模型,近壁面处采用标准壁面函数法;设置喷射物质为理想气体;控制方程离散采用基于控制体中心的有限体积方法,选用隐式二阶迎风格式;驻涡燃烧室三维几何模型采用结构化适体网格,网格节点单元数约为600 000;求解方程组采用动量方程和能量方程进行耦合的方法,控制残差<10-4.结果表明:后驻体喷孔位置对驻涡腔的总压损失、喷射质量流率影响较小;随着喷射位置向后驻体外侧偏移,驻涡腔内的流场平均流速有所降低,形成有利于稳定火焰的流动条件.计算预测的变化趋势与实验结果相同,表明可为实际设计提供一种有效的方法.     

基于DCS的煤气燃烧锅炉控制系统的设计

针对煤气燃烧锅炉存在燃烧不稳定、热效率低、自动化程度不高等问题,本文设计了一种基于分布式煤气燃烧锅炉控制系统,对燃烧锅炉现场进行数据采集和远程监控,实现锅炉的液位控制、燃烧控制及监控系统的远程控制.该系统采用MACSV组态软件进行锅炉控制,软件编程层次清楚,现场调试方便,利用其强大的通讯功能可组成各种分布式监控管理系统.     

新型燃烧炉的特点

新的两气回收系统工艺流程和内部筑炉材料都有新的特点，产生巨大的经济效益的同时还产生巨大的社会效益．     

启发式教学在内燃机原理课程教学中的应用

＂内燃机原理＂是热能与动力工程专业的一门专业主干课。本文基于启发式教学的本质与特征,结合＂内燃机原理＂课程特点以及教学组多年来的教学改革与实践经验,分别从教学内容、教学方法以及教学实践等方面提出了提高教学质量的若干思路与方法。指出该课程教学重点是改进教学方式、合理组织教学过程,注重理论与实践相结合,切实提高学生的独立思考与实践能力。     

“燃烧热测定”教学实验的改进

本文介绍了在燃烧热的测定实验中采用双孔带槽模底,单、双股燃烧丝相结合的挂样片法,代替单孔或无孔模底,单股燃烧丝接触样片法,以及压片操作技法。四年的实践表明,这种实验方法大大提高了实验的成功率,缩短了实验操作时间。     

Mercury pollution in the Chongqing part of the Three Gorges Reservoir area and its remediation and prevention

Mercury pollution in the Three Gorges Reservoir area of P. R. China merits special attention. We investigated into the current situation in the Chongqing part of the Reservoir area, identified the pollution sources and proposed some suggestions for the remediation and prevention of mercury pollution in this area. Atmospheric mercury in Chongqing was mainly from coal burning and releases of mercury-containing products such as various types of lights and fever thermometers. Urban drainage in Chongqing and Changshou, and runoffs from the high mercury background area in the lower reaches of the Wujiang River contributed most of the mercury in the water of the Yangtze River. A majority of the blame should be laid on mercury and gold mining in the Wujiang valley. We suggested foresting sloping lands to relieve soil erosion and prevent mercury-bearing soil from running into rivers, educational activities to discourage use of mercury-containing products and improved infrastructure to collect mercury-containing wastes for reducing mercury releases, more facilities for treating wastewater and solid waste to accommodate increased requirements of discharge, and growing selected perennial plants in mercury-contaminated land to absorb the mercury in soil. We also suggested concerted operation of a dedicated water-quality monitoring system, reinforced legislation and an effective administrative mechanism to ensure lasting efforts are invested in curbing mercury releases and restoring mercury contaminated land and water in the Reservoir area.     

Application of neural network in the study of combustion rate of natural gas/diesel dual fuel engine

In order to predict and improve the performance of natural gas/diesel dual fuel engine (DFE), a combustion rate model based on forward neural network was built to study the combustion process of the DFE. The effect of the operating parameters on combustion rate was also studied by means of this model. The study showed that the predicted results were good agreement with the experimental data. It was proved that the developed combustion rate model could be used to successfully predict and optimize the combustion process of dual fuel engine. Project supported by National Lab. for Automotive Engine and Safety, Tsinghua University, China     

超高温多相流燃烧物质红外辐射特性的计算

超高温多相流燃烧研究在快速飞行的航天飞行器应用领域中至关重要。本文依据固体火箭发动机喷焰超音速射流燃烧中产生大量的氧化铝固体颗粒群和多组分气体实际应用为背景,结合粒子浓度的实际特征,建立固体颗粒群粒子浓度分布模型,并根据粒子质量加权平均直径经验公式,计算它们在波长3～5!m范围内的空间红外辐射强度随温度场的分布。同时对燃烧过程中产生的几种多组分接近完全气体,计算其热传导系数,为进一步开展相关红外特性研究和建立用于超高温多相燃烧红外辐射理论模型提供重要依据。     

发动机性能试验数据采集系统及试验的可视化研究

作者开发了基于WINDOWS的发动机性能试验数据采集系统,具有高速、高效、高精度的优点。本系统能同时测量16个参数,同时也提供了一个D／A输出1：2,供进行自动控制使用。用VISUAL C 为工具的编程软件,编制了数据采集、处理、分析,图形绘制、打印软件。引进监督曲线,随时监控试验情况。对柴油机和汽油机分别进行了性能试验,试验结果表明：该系统实现了预期的目的：系统人机界面友好,操作简便,具有良好的通用性和实用价值。