长大区间隧道抽出式串联通风机排烟能力实验研究

为实现有效通风以降低隧道火灾带来的损失和伤亡,依托青岛市地铁8号线大洋站至青岛北站区间隧道,建立线性比尺为1∶15的隧道通风排烟模型实验系统,针对通风机串联单抽,围绕3种通风机频率匹配组合,测定单机的变频频率值、电功消耗、排烟道与行车道的断面平均风速以及右侧行车道静压。研究结果表明：在相同功率消耗下,不同频率匹配的串联通风机排烟效果存在差异;针对此差异,利用气体挡烟墙性能及其计算欧拉数值比较发现,风井近端的通风机频率较大时,下游对污染气流的抵抗力更强,拥有更好的排烟效果。研究结果可为隧道火灾提供更有效率的防灾救灾数据支持,并从欧拉数方面为研究隧道临界风速提供新角度。     

环境风作用下弧形立面机场航站楼自然排烟效果的数值模拟研究

机场航站楼公共区域多采用自然排烟方式,而环境风和排烟窗控制模式会影响排烟效果,尤其在弧形立面航站楼中影响效果显著。以某弧形立面航站楼为研究对象,选取候机指廊弧形区域的自然排烟窗分3段控制启闭,进而确定6种控制模式,采用 FDS火灾动力学模拟软件研究了不同模式下的排烟效果,获得了环境风和发烟量对危险到达时间的影响规律, 提出了排烟窗控制模式流程。结果表明:对于弧形立面航站楼而言,排烟窗分段控制模式下的排烟效果优于不分段控制模式,可以有效降低环境风对自然排烟的影响。当环境风速超过10 m/s时,须关闭迎风向排烟窗,避免烟气倒灌。在法向环境风作用的不利条件下,当发烟量在0. 05~0. 20之间时,危险到达时间的最大值tmax与发烟量x满足一次函数关系式:tmax=-3018x+1030.5。     

上海市能耗与GDP大气污染的协整关系研究

采用计量经济学中的协整理论考察上海市能源消费量与经济增长、废气排放量、二氧化硫排放量之间的关系。结果显示,上海市能源消费只与经济增长、废气排放量之间存在长期协整关系,并建立了相应的长期均衡方程及误差修正模型。另外,对1978～2003年的能源消费与经济增长之间进行Granger因果关系检验,提出实现上海市经济-能源-环境和谐发展的措施。     

铁矿石对脱除烧结废气中NOx的催化效应

向混合料中加添加剂能够在烧结过程中脱除烧结废气中的NO。实验研究了铁矿石对NO脱除反应的催化效应。在900℃下,分别以5种不同铁矿石作为填料层,用2种标准气体和压缩空气配制的混合气体模拟烧结废气。试验结果表明,铁矿石种类对铁矿石的催化能力有重要影响。D型铁矿的催化能力最强而且不会发生弱化,NO转化率接近100%;其它几种铁矿石的催化能力较差,随着反应时间的延长有明显的弱化现象,但很快即基本趋于稳定状态,NO转化率达到了60%~70%。     

街道峡谷内汽车排放污染物浓度分布的观测与数值模拟

在上海某典型街道峡谷内按一定的空间布点,在一定时段内同时对各布点进行采样并做一氧化碳浓度分析,同时记录车辆种类、车流量、气象条件等,分析街道峡谷内污染物浓度的分布.运用风向频率加权(WDFW)方法,结合大气流动和污染物扩散的CFD模型进行数值模拟计算.结果表明,数值模拟结果和现场观测结果较吻合,建筑物低的一侧污染物浓度远高于建筑物高的一侧污染物浓度,两侧的污染物浓度随着高度的增加而降低.     

顶空-气相色谱法(氮磷检测器)测定固定污染源废气中三甲胺

建立了顶空-气相色谱法测定固定污染源废气中三甲胺的分析方法。弱酸性吸收液采集固定污染源废气中的三甲胺,碱液中和后顶空进样气相色谱仪氮磷检测器分析。并对平衡温度、平衡时间、盐析效应、氨水和氢氧化钠条件实验进行优化,在最佳实验条件下,三甲胺的方法检出限为0. 46μg/m~3(以采集20 L空气样品计),加标回收率为97%～107%,相对标准偏差在9. 26%以下。利用该方法对垃圾焚烧发电厂厂界空气及鱼粉厂有组织废气中三甲胺进行检测分析,该方法能够满足国家标准及上海地方标准中三甲胺排放限值的要求。     

烹饪油烟污染与处理技术探讨

为了降低油烟对环境的污染,分析了油烟中的主要污染物成分及油烟对人体健康的几种危害。讨论了五种油烟净化技术:惯性分离法、过滤分离法、液体洗涤法、静电沉积法、复合技术。分析了液体洗涤油烟净化技术的原理、水循环利用时对洗涤废液进行的油水分离,提出了采用流场分析喷淋,以了解其流场的特性。结果表明,采用液体洗涤法去除油烟效率高,安全可靠。     

Impacts of converting from leaded to unleaded gasoline on ambient lead concentrations in Jakarta metropolitan area

Total suspended particulate mater （TSP） concentrations were monitored for one year from July 2000 and for one year from April 2003 in Jakarta City. Thirteen elemental TSP components, aluminum （Al）, sodium （Na）, iron （Fe）, lead （Pb）, potassium （K）, zinc （Zn）, titanium （Ti）, manganese （Mn）, bromine （Br）, copper （Cu）, chromium （Cr）, nickel （Ni）, and vanadium （V） were analyzed by a sequential X-ray fluorescence spectrometer. Al, Na, Fe, K, and Pb were major components at most of the sampling locations in 2000. However, only Pb in 2003 dramatically decreased to one tenth. The phase-out of leaded gasoline began on July 1, 2001 in Jakarta City and lead content in gasoline decreased to one tenth, too. The decrease in Pb concentration was a result of the phase-out of leaded gasoline, as lead emissions mainly are exhaust gas from vehicles.     

A numerical study on the effects of EGR and spark timing to combustion characteristics and NOx emission of a GDI engine

EGR is one of the most significant strategies for reducing especially nitrogen oxides (NO_x) emissions from internal combustion engines. The thermal efficiency of spark ignition engines is lower than compression ignition engines because of its lower compression ratio. If the compression ratio is increased to obtain higher thermal efficiency, there may be a knocking tendency in spark ignition engines. EGR can be used in order to reduce NO_x emissions and avoid knocking phenomena at higher compression ratios. In-cylinder temperature at the end of combustion is decreased and heat capacity of fresh charge is increased when EGR applied. Besides EGR, spark timing is another significant parameter for reducing exhaust emissions such as nitrogen oxides, and unburned hydrocarbon (UHC). In this study the effects of EGR and spark timing on spark ignition engine were investigated numerically. KIVA codes were used in order to model combustion process. The combustion process has been modeled for a single cylinder, four stroke and gasoline direct injection (GDI) spark ignition engine. The results showed that in-cylinder pressure and heat release rate decrease as EGR ratio increase. In-cylinder pressure increases with the advancing of spark timing. Advancing spark timing increases the heat release rate and in-cylinder temperature. The simulation results also showed that EGR reduced exhaust gas temperature and NO_x emissions.     

An experimental apparatus for testing biodiesels based on a CFR engine—setup and validation with different methyl ester blends

A cooperative fuel research (CFR) engine was modified and instrumented in order to control operating conditions and to measure engine parameters and in-cylinder pressure diagrams. Aiming at the comparison of different alternative fuels, an experimental procedure was defined, including cetane number (CN) evaluation and the definition of engine operating quantities in different working points, for fixed levels of compression ratio (CR) and injection advance. An investigation was made considering several blends of methyl-esters of rapeseed oil (RME) and of a mix of vegetable oils (VOME) with conventional diesel oil. The defined experimental procedure was applied to assess CN, engine brake thermal efficiency (bte) and exhaust emissions. Results show that the biodiesel content has a positive influence on soot emissions, with strong reduction, while thermal efficiency and NO_X emissions are negatively affected, which can be justified taking into account fuel properties and changes in combustion process. As observed outcomes are generally in line with those presented in literature, the facility proved to be a suitable tool for basic investigations on alternative fuels to be used in specific applications.