电解铝厂房自然通风的模拟研究

分析了各种厂房形式影响通风的因素,深入研究了各种类型铝电解厂房自然通风规律,找出了影响厂房通风的主要因素为电解槽散热量等工艺特性及操作面高度等建筑特性;在研究电解槽散热量的基础上,利用湍流模型、热辐射模型和浮力模型对电解铝车间的气体流动状态进行了理论分析;针对实际的边界条件,建立了铝电解厂房自然通风CFD模拟计算模型,并使用AirPak软件对普通天窗和弧形天窗形式,在静风、风速为2 m/s和4 m/s条件下的温度场、风速场、空气新鲜度、HF浓度进行了模拟,并对结果进行了分析.     

出口角度对防烟空气幕防烟效果影响的数值模拟

利用火灾动力学模拟软件FDS,以四川消防研究所高层实验塔二层为原型,模拟在不同防烟空气幕出口角度情况下高层建筑前室烟气运动情况,获得在其他条件不变情况下,空气幕运行时的最佳出口角度。试验结果表明:空气幕角度为5°及20°时,模拟试验后期烟气基本突破了空气幕蔓延至前室内,而当出口角度为10°和15°时防烟效果较好,且15°时防烟效果优于10°,故推荐空气幕运行时的最佳出口角度为15°。     

基于蒙特卡罗法的煤巷锚杆支护结构可靠性分析

应用工程结构可靠性理论,建立煤巷锚杆支护结构可靠性模型,针对其结构稳定性的极限状态功能函数高度非线性的特征,采用蒙特卡罗法在Matlab环境下直接产生服从各相应概率分布函数的随机变量数组计算其结构可靠度,编程过程简化,计算速度快,精度高,且不受极限状态方程非线性、随机变量非正态的限制,开辟了煤巷锚杆支护结构可靠度计算的新途径。建立了支护参数与可靠度的关系,指出了提高煤巷锚杆支护结构可靠度的方法和措施,为煤巷锚杆支护参数设计和优化提供了科学依据。     

矿井通风仿真系统双线图的快速自动绘制研究

在深入研究通风网络巷道连接关系的基础上,创造性地提出一种新的效率更高的通风系统双线图的快速自动绘制方法,即"假双线法"。"假双线法"与固定宽度双线法有本质的不同,其本质是将单线巷道的线型用固定宽度双线线型表示,再对交叉点进行消隐处理,无需计算双线坐标来实现双线图的快速自动绘制。该法较好地解决了传统方法的缺陷,具有普遍性,其计算量小,执行效率高,并在双线图的基础上很容易拓展生成通风系统立体图。笔者研究成果,对于研发、改进矿井通风仿真图形系统和解决其他行业类似问题具有一定的参考价值。     

地下储库油气爆炸及抑爆机理与技术研究

针对地下储库受限空间的特点和油气爆炸抑制的需要.在前期所完成的系统油气爆炸试验和理论研究的基础上,采用超细冷气溶胶抑爆新技术,建立地下受限空间油气爆炸及其抑爆模拟试验系统,研制出新型超细冷气溶胶粉体抑爆剂,并对其进行可行性与有效性研究.对地下受限空间油气爆炸抑制的影响因素进行研究,分析了抑爆剂作用机理.结果表明:超细冷气溶胶是一种高效的抑制地下储库油气爆炸的抑爆剂;在相同试验条件下,迎着火焰传播方向喷射抑爆剂的抑爆效果优于垂直火焰传播方向喷射抑爆剂;喷射压力存在临界值,较小较大都不利于油气爆炸抑制,在本文试验条件下.最佳抑爆效果的喷射压力临界值约为0.8 Mpa;抑爆剂用量不能低于临界抑爆浓度,实验得到的抑爆刑临界浓度为0.232 ks/m3;布置方式对抑爆效果具有明显的影响.分散布置比集中布置具有更好的抑爆效果.本文的研究对后续抑爆装置的研制提供了重要的理论参考和关键设计参数.     

大气中痕量挥发性有机物气相色谱保留时间的预估

为探寻环境中挥发性有机物气相色谱保留行为与结构的关系,应用三维原子场全息作用矢量(3D-HoVAIF),对39个大气中痕量挥发性有机物进行了结构表征.采用逐步回归对变量进行筛选,建立了8变量定量结构色谱保留相关(QSRR)模型,模型的复相关系数为R-1=0.985; 进而将3D-HoVAIF矢量与相对分子质量结合,建立了9变量QSRR模型,模型的复相关系数为R-2 = 0.991; 采用留一法交互检验,结果分别为RCV,1 = 0.970、RCV,2 =0.978,表明模型具有良好的估计能力和稳定性.     

两种生物配体模型(BLM)预测Zn对大型蚤急性毒性的比较

通过天津地区一系列景观水体和配制的模拟溶液,评价应用于大型蚤(Daphnia magna)毒性预测的两种急性Zn-生物配体(BLM)模型(模型A和模型B)的预测能力.采用Visual MINTEQ 2.5.2进行BLM的相关计算和金属形态分析.对一定水化学参数的测定表明,根据Zn对大型蚤的急性毒性数据建立的模型B能够在Zn的生态风险评价中考虑其生物有效性,预测结果准确;以鱼类为对象开发并下调LA50后应用于水蚤毒性预测的模型A的预测值普遍高于实测值.可见,通过调整LA50拓展模型适用性的方法过于简单,还有待进一步研究.     

Leaching behavior of heavy metals and PAHs from MSWI bottom ash in a long-term static immersing experiment

Bottom ash is the main solid residue (in weight) which is produced by municipal solid waste incineration (MSWI) facilities. This material is composed of a mineral matrix and may be used as secondary raw material for construction purpose. However, for this specific application the leaching behavior of the environmentally relevant elements under field conditions is different from the predicted behavior based on results obtained from the standardized leaching test. Therefore, a 70-day simulative experiment has been carried out in this study to investigate the release of major heavy metals (Cu and Pb) and polycyclic aromatic hydrocarbons (PAHs) from several particle fractions of bottom ash under a static leaching condition, where bottom ash was immersed in water at different initial pH values. Results showed that: (1) the leaching behavior of Cu and Pb was much similar with that depicted by the standardized leaching tests, and fit well with the solubility-controlling mechanism; (2) the sorption mechanism on the neoformed phases may control the solubility of Pb, whereas the dissolved organic carbon (DOC) may play an important role in the solubility of Cu; and (3) the leached PAHs were degraded during the later period of leaching process.     

Characterizing effects of uncertainties in MSW composting process through a coupled fuzzy vertex and factorial-analysis approach

A coupled fuzzy vertex and factorial-analysis approach was developed in this study for systematically characterizing effects of uncertainties in a municipal solid waste composting process. A comprehensive composting process model was also embedded into the system framework and used to address substrate decomposition and biomass growth, as well as the interactions between moisture contents, temperatures, and oxygen concentrations. The applicability of the proposed method was verified through a custom-made pilot-scale composting system. Results from fuzzy simulation indicated that the fuzzy vertex method could effectively communicate implicit knowledge into dynamic simulations and thus provide valuable information for enhancing composting process control under uncertainty. The factorial analysis was effective in quantifying the proportion to which the uncertainty of each single or interactive effect of model parameters contributes to the overall uncertainty of the system outcomes. Thus, sensitive parameters that may lead to errors or unreasonable predictions can be determined. The proposed study system could not only be used in characterizing combined effects of uncertainties for composting processes, but was also applicable to many other environmental modelling systems.     

易贡巨型高速滑坡卫星遥感动态监测

多期卫星遥感数据与图像清晰地反映了易贡滑坡的演变及其地貌形态特征,通过专题对比解译与滑坡时程分析,重点监测和评价了滑坡堰塞湖溃决后汹涌水对下游两岸产生的重大生态破坏,结果显示,下游又新增了25个不同规模的浅层滑坡或滑落,新河床两侧新增的大面积滩地覆盖了两则的森林、草地;个别河段出现了移位改道。