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厌氧折流板反应器-复合人工湿地处理农村生活污水中试研究 总被引:1,自引:0,他引:1
采用厌氧折流板反应器(ABR)为预处理单元,与复合人工湿地形成组合工艺,开展不同条件下组合工艺对农村生活污水的中试处理效能研究。结果表明,在水温为22.1~26.3℃、ABR水力停留时间10~3 h时,组合系统对碳氮磷具有较高的去除潜力,COD、NH4+-N、TN和TP的平均去除率分别达84.6%,59.3%,58.0%和78.1%。对污染物去除途径分析发现,废水中COD的去除主要发生在组合工艺的ABR段,NH4+-N和TN主要在水平潜流和下行垂直流人工湿地被去除,而水平潜流和上行垂直流人工湿地对TP的去除贡献率最高。ABR与复合人工湿地相互结合,优势互补,对农村生活污水具有理想的处理效果。 相似文献
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人工湿地净化富营养化河水试验研究(二)——基质层及流态对氮素污染物净化效果的影响 总被引:2,自引:1,他引:2
通过中试试验研究了基质层及流态对人工湿地净化富营养化河水中氮素污染物的影响情况,结果表明:砾石基质层厚度从80cm增加到120cm对湿地池净化氮素污染物的效果没有明显影响;将上层砾石替换为沸石后,湿地池对NH3-N的净化效果明显提高,说明不同的基质材料对NH4+具有良好的选择性吸附作用,而将上层砾石替换为炉渣后湿地池对氮素污染物的净化效果几乎没有变化;在4种湿地流态中,复合流态(垂直流+潜流)湿地池对TN、NH3-N、NO3-N的去除率均为最高,且与潜流-垂直流相前后次序没有显著相关性;潜流、垂直流湿地池对氮素污染物的去除率介于复合流、表面流之间;表面流最低. 相似文献
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针对村镇生活污水,开展水力负荷对潜流与复合垂直流人工湿地脱氮效果影响的研究,结果表明:两种人工湿地对村镇生活污水均有较好的处理效果;随水力负荷升高,两种人工湿地除碳、脱氮率不同程度降低。潜流人工湿地除碳效果优于复合垂直流人工湿地,复合垂直流人工湿地脱氮效果更佳;水力负荷≤0.25 m3/(m2·d),两种人工湿地对COD去除率均大于90%,复合垂直流人工湿地对NH3-N、TN去除率保持在60%以上,出水水质优于一级A标准。动力学研究表明一级动力学模型能较好拟合两种人工湿地的COD、NH3-N、TN去除规律。 相似文献
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垂直流人工湿地处理农村分散生活污水的应用与工程设计 总被引:1,自引:0,他引:1
概述了农村分散生活污水的特点及处理工艺的选择;结合工程实际情况,介绍了垂直流人工湿地的设计概况,总结了设计特点,并指出垂直流人工湿地系统调试运行的注意事项.运行结果表明,在水力停留时间为40.08h,水力负荷为<0.042m3·m-2·h-1的条件下,系统对农村分散污水中的主要污染物具有较好的去除效果,出水中污染物COD、TN、TP以及NH3-N的平均质量浓度分别小于60、20、1、15 mg·L-1,达到了城镇污水处理厂污染物排放标准(GB 18918-2002)的一级排放标准. 相似文献
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采用垂直流人工湿地系统综合实现了住宅产业化基地的中水回用、湖水循环净化和雨水利用功能。介绍了系统的工艺流程和设计参数,并对系统稳定运行后的水质进行监测分析。结果表明,处理污水的复合垂直流人工湿地系统对COD、BOD5、TP、NH3-N的总去除率分别为86.5%、95.3%、89.7%、87.5%;循环净化湖水的垂直流人工湿地系统对COD、BOD5、TP、NH3-N的总去除率分别为49.1%、53.2%、50%、60.4%。垂直流人工湿地对主要污染物的去除率在50%以上。 相似文献
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流态试验设计及分析方法 总被引:1,自引:0,他引:1
化学反应器在化学工业设备系统中占有极为重要的地位,对其水力特性和混合条件进行研究至关重要;同时停留时间分布(RTD)分析为评估反应器流态提供了一种极为有用的分析工具。文中详细描述了基于示踪-应答技术的流态试验设计方法,包括示踪剂的选取原则、试验的方法及试验的操作要求,为流态试验提供了指导规范。探讨了进行数据处理中的注意事项及为避免误差应采取的措施。通过分析发现采用不同的思想计算平均停留时间分别代表的意义及其关系。由于不同的反应器流态可能得到相同的RTD曲线,因而并不是每一个RTD曲线只对应一个特定的反应器类型或者状态。以RTD理论为基础,确立了各种流态所对应的不同停留时间分布,为比较分析流态试验的曲线提供依据。 相似文献
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Flow behaviors of four kinds of granular particles (i.e. sphere, ellipsoid, hexahedron and binary mixture of sphere and hexahedron) in rectangular hoppers were experimentally studied. The effects of granular shape and hopper structure on flow pattern, discharge fraction, mean particle residence time and tracer concentration distribution were tested based on the visual observation and particle tracer technique. The results show that particle shape affects significantly the flow pattern. The flow patterns of sphere, ellipsoid and binary mixture are all parabolic shape, and the flow pattern shows no significant difference with the change of wedge angle. The flowing zone becomes more sharp-angled with the increasing outlet size. The flow pattern of hexahedron is featured with straight lines. The discharge rates are in increasing order from hexahedron, sphere, binary mixture to ellipsoid. The discharge rate also increases with the wedge angle and outlet size. The mean particle residence time becomes shorter when the outlet size increases. The difference of mean particle residence time between the maximum and minimum values decreases as the wedge angle increases. The residence time of hexahedron is the shortest. The tracer concentration distribution of hexahedron at any height is more uniform than that of binary mixture. The tracer concentration of sphere in the middle is lower than that near the wall, and the contrary tendency is found for ellipsoid particles. 相似文献
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研究了去离子水在3种规格矩形微槽内竖直向上流动沸腾的流阻特性,着重考察了出口干度、质量流速、进口过冷度和微槽尺寸对沸腾流动压降的影响.试验结果表明,两相摩擦压降随出口干度增大而增大,在相同出口干度下,入口质量流速越大摩擦压降越大,摩擦压降与入口过冷度无关;随着微槽道尺寸减小,摩擦压降增大. 相似文献
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1 INTRODUCTION Gas-liquid two-phase cross flow and heat transfer exists in oil production and chemical facilities. With the rapid development of the technology of modern industry, the gas-liquid two-phase flow across a rod and heat transfer characteristics are studied more ex- tensively, and its thorough understanding is of great importance to the design and operation of processing equipment. Flow pattern and its transition are important in the study of multiphase flow. Because of the com… 相似文献
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采用CFD数值模拟方法研究热风循环隧道烘箱的内部温度及流场分布,提出了6种结构优化方案,考察了不同方案下的气流分布特性。结果表明,烘箱出口面局部温差在1 K以内,温度分布较均匀;气流速度分布是影响烘干品质的主要因素,原始结构下出口气流分布极不均匀,出口面角落位置出现局部高速区,最大速度达3.48 m/s,平均速度为0.94 m/s,相对均方根值为0.73;相比原始结构,6种改进方案中,弯头三隔板结构出口面的相对均方根值最低,最大速度降低51.4%,最佳风速区域占比提升至75.17%,整流效果最明显;弯头内设置三块隔板后,风罩内再设置隔板对气流均匀性的改进作用不大。 相似文献
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The present work has attempted to identify the flow patterns during liquid-liquid two phase flow through a vertical pipe. Dyed kerosene and water have been selected as the test fluids. The measurements have been made for phase velocities varying from 0.05 to 1.5 m/s for both the liquids. The conductivity probe technique has been adopted and three different probe designs have been used to identify the patterns under different flow conditions. A parallel wire type probe traversing the entire cross-section along a diametral plane has indicated the existence of bubbly flow at low phase flow rates and dispersed bubbly flow at high velocities of water. Apart from the visual appearance of the signals, different statistical analysis namely the probability density function and wavelet analysis have been performed for a better appraisal of the flow situation. The information in the PDFs have been quantified by means of the statistical moments. The existence of the core-annular flow at high kerosene and low water velocities has been confirmed from measurements using a different probe design. The intermediate region between the bubbly and annular flow patterns is characterized by a random distribution of the two liquids with continually changing interface between them. This has been named as the churn turbulent flow pattern. The information thus obtained has been represented in the form of a flow pattern map. 相似文献
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声发射(AE)作为一种无损检测手段,用于气液两相流的测量具有非侵入式、测量不破坏被测管道及流场分布,信号强、灵敏度高等优点。利用声发射技术在河北大学垂直管气液两相流管道上进行了大量实验,运用现代信息数据处理方法对气液两相流垂直管道流型特征参数进行了提取。分析结果表明利用声发射手段提取出的流型特征参数可以反映出典型流型下的动力学特征。垂直管道中,泡状流、弹状流、环状流以及过渡状态下的乳沫状流在时域和频域信号中有着明显区别,小波能量和小波包分解后的信息熵的值也存在较大的差异性,从另一角度验证了在不同流型下两相流体在管道内部不同的运动状态,利用模式识别的思想,对垂直管4种典型流型进行了流型识别,取得了较好的效果,研究结果表明声发射技术可以作为一种技术手段用于气液两相流流动的检测。 相似文献
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An experimental investigation was conducted to study the holdup distribution of oil and water two‐phase flow in two parallel tubes with unequal tube diameter. Tests were performed using white oil (of viscosity 52 mPa s and density 860 kg/m3) and tap water as liquid phases at room temperature and atmospheric outlet pressure. Measurements were taken of water flow rates from 0.5 to 12.5 m3/h and input oil volume fractions from 3 to 94 %. Results showed that there were different flow pattern maps between the run and bypass tubes when oil‐water two‐phase flow is found in the parallel tubes. At low input fluid flow rates, a large deviation could be found on the average oil holdup between the bypass and the run tubes. However, with increased input oil fraction at constant water flow rate, the holdup at the bypass tube became close to that at the run tube. Furthermore, experimental data showed that there was no significant variation in flow pattern and holdup between the run and main tubes. In order to calculate the holdup in the form of segregated flow, the drift flux model has been used here. 相似文献
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针对传统温度控制策略在水冷型质子交换膜燃料电池(proton exchange membrane fuel cell,PEMFC)工作中水泵和散热器风扇存在的强耦合性,并为了提高电堆的工作性能和寿命,提出一种流量跟随电流的温度控制策略,根据电堆电流变化调节冷却水流量来控制电堆冷却水进出口温差,通过PID控制器调节散热风扇控制电堆入口温度。在水冷PEMFC热管理平台上对传统控制策略、流量跟随控制策略做了实验对比。结果表明,流量跟随电流控制策略使冷却水出口温度最大超调量减少64.3%,冷却水出入口温差最大偏差减少46.7%,调整时间平均缩短73 s,达到了较高的控制精度和响应速度,削弱了水泵和散热风扇的强耦合作用,流量跟随电流控制策略能够满足PEMFC系统对温度控制的要求。 相似文献
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基于气化炉大型冷模实验的研究结果和煤气化过程的特点,分析了气流床水煤浆气化炉内各个区域的流动与化学反应特征,建立了水煤浆气化过程中残碳量的计算模型,考察了煤的挥发分、煤颗粒平均直径以及气化炉平均停留时间对残碳量的影响。计算结果表明,平均停留时间增加,残碳量减小;在相同的平均停留时间和颗粒平均直径下,煤中挥发分增加,出气化炉残碳量减小;在相同的平均停留时间和挥发分含量下,煤浆中煤颗粒平均直径减小,出气化炉残碳量减小。 相似文献