北方某市水源更换过程中管网黄水产生机制的探讨

针对北方某市在水源更换过程中管网出现局部黄水的现象,从新旧水源水质特征对比、管网的管材构成、管道内壁腐蚀层结构特征等方面探讨了产生黄水的内在原因,并对水源更换过程中防控黄水应采取的措施提出了建议。     

李渔园论的创新意识

李渔不仅是一位戏曲家和戏曲理论家,同时,他也是一位造园家和造园理论家。他所著的《闲情偶寄》虽然不是系统论述造园的专著,但它却是研究中国园林艺术理论必读的著作。该文对李渔《闲情偶寄》中有关园林的论述以及他的创新意识进行了探讨。     

某喷漆机库改造项目电气防爆设计介绍

结合工程实例,介绍飞机喷漆工艺,依据国内外标准关于爆炸危险区域划分的原则,适当划分喷漆机库爆炸危险区域,并采取相应的防范措施。     

重力式风力发电机基础沉降观测技术研究及应用

通过在风机塔筒内悬挂发光源,发光源的正下方固定标盘,在标盘中的刻度显示基础的倾斜率,实现了无需计算,可直接判断风机基础的倾斜率是否超出规范要求,提高了观测的精确性,在第一时间消除了因风机基础不均匀沉降而产生的隐患。     

某酒店的暖通空调系统设计

通过介绍某酒店工程暖通空调设计中冷热源方案,空气处理方式的选择,采用过渡季节全新风运行和全热回收系统,从而有效地节约了能源,降低了空调系统的运行费用。     

华南某开发区污水处理技术方案

对华南某高新技术产业开发区工业废水、生活污水和生活垃圾的污染问题进行了研究,通过现场勘查,分析了开发区污水的来源,并针对污染源提出了处理方法及应急处理措施,为相关工程的处理工作提供了技术参考。     

浅析潍坊市中心市区城市供水水源地水质情况

针对潍坊市两处主要水源地水质情况进行了连续3年19项指标的监测分析研究,并对其中的感官性状和一般化学指标、有机综合指标、毒理指标、生物指标等关键指标进行了重点分析,根据年均值、最大值、最小值的变化情况,对潍坊市水源水质污染的发展趋势做出了合理总结和评估.结果表明,一些重要的毒理指标正呈现逐渐下滑的趋势,波动幅度也逐渐减小;但从藻类指标来看,两处水源均为高藻水源且近年来显示为不同程度的上升.该结果可应用于潍坊市中心城区饮用水水源水质的风险预控,有助于潍坊市中心城区水源水质的风险管理.     

黄浦江水源及净水过程中水质的生物急性毒性分析

应用发光细菌法对黄浦江闵行段及闵行二水厂各处理单元出水的生物急性毒性进行了测定与评价。结果表明：黄浦江闵行段水体的生物急性毒性与沿途污染物的排放、汇入和水文特征有关,水厂取水口处的毒性最低。在净水过程中,水质的生物急性毒性变化受投加氧化剂和消毒剂的影响较大,投加KMnO4及加氯加氨均可使生物急性毒性升高;当余氯浓度降低后,其毒性会显著降低。絮凝沉淀、砂滤单元可使生物急性毒性降低。     

固定化包埋硝化菌处理微污染源水的研究

采用固定化包埋颗粒,借助气升式内循环好氧流化床反应器,对人工模拟低氨氮、低有机物的微污染源水进行处理。分别研究了DO和碳氮比对氨氮和有机物去除率的影响。研究表明,在T=24℃,HRT=60min,pH=7．1～7．3的条件下,当C：N=1：1、DO为3～8mg／L时,系统对氨氮的去除率〉90％,对COD的去除率保持在50％～60％;当DO=8mg／L、C：N＝2：1时,对氨氮的去除率最高达93．56％,对COD的去除率为50％～60％;当C：N=3：1时,对氨氮的去除率〉90％,对COD的去除率在40％左右。在微污染源水的处理过程中,固定化包埋硝化菌有较强的适应能力和较高的处理效率。     

CFD boundary conditions for contaminant dispersion,heat transfer and airflow simulations around human occupants in indoor environments

Indoor computational fluid dynamics (CFD) simulations can predict contaminant dispersion around human occupants and provide valuable information in resolving indoor air quality or homeland security problems. The accuracy of CFD simulations strongly depends on the appropriate setting of boundary conditions and numerical simulation parameters. The present study explores influence of the following three key boundary condition settings on the simulation accuracy: (1) contaminant source area size, (2) convective/radiative heat fluxes, and (3) shape/size of human simulators. For each of the boundary conditions, numerical simulations were validated with experimental data obtained in two different environmental chambers. In CFD simulations, a small release area of a contaminant point source causes locally high concentration gradients that require a very fine local grid system. This fine grid system can slow down the simulations substantially. The convergence speed of calculation is greatly increased by the source area enlargement. This method will not influence the simulation accuracy of passive point source within well-predicted airflow field. However, for active point source located within complicated airflow filed, such an enlargement should be carried out cautiously because simulation inaccuracy might be introduced. For setting thermal boundary conditions, convection to radiation heat flux ratio is critical for accurate CFD computations of temperature profiles around human simulators. The recommended convection to radiation (C:R) ratio is 30:70 for human simulators. Finally, simplified human simulators can provide accurate temperature profiles within the whole domain of interest. However, velocity and contaminant concentration simulations require further work in establishing the influence of simplifications on the simulation accuracy in the vicinity of the human simulator.