基于卡尔曼滤波的空气细颗粒物称重数据处理

针对在细颗粒物采样监测装置中称重部分数据采集易受外部环境的影响,产生测量误差和干扰,导致称重部分的精度达不到要求,进而影响整个监测装置的测量精度和性能.通过经典的卡尔曼滤波算法,对传感器读取的数据进行处理,去除了极端数据,提高了称重部分的检测精度.通过MATLAB编写程序,对称重数据进行处理并图形化显示,满足称重部件精度要求±2 mg的要求,验证了卡尔曼滤波算法在此应用的有效性.该方法可应用于相关领域的数据处理.     

井上下联合处理工艺处理矿井水过程中溶解性有机质变化特征

井上下联合处理工艺处理矿井水过程中,利用三维荧光光谱分析了矿井水中溶解性有机质的组成和变化特征。结果表明：不同处理工艺段对矿井水中DOM去除效果存在较大差异,采空区处理对矿井水中TOC和UV254的去除率分别达到67.453%和65.396%,深度处理可完全去除大分子有机物和芳香族化合物。三维荧光光谱显示,矿井水中表征出3类DOM,酪氨酸类芳香族蛋白质、色氨酸类芳香族蛋白质、溶解性微生物代谢产物。经过采空区处理后,3类有机质荧光强度都有较大降低,下降率分别为50.1%,54.4%和47.2%;深度处理使酪氨酸类有机质荧光峰消失,色氨酸类和溶解性微生物代谢产物荧光强度下降了75%左右。矿井水、采空区出水、常规处理出水中 DOM主要为生物来源;膜过滤出水中残留的DOM主要源于陆生植物和土壤有机质;总体上,矿井水处理过程中来自生物或水生细菌的新近自生源组分比例逐渐增加。     

不同温度下准东煤燃烧颗粒物的生成特性

为研究不同温度下准东煤燃烧颗粒物的生成特性,在实验室沉降炉中开展了准东煤燃烧颗粒物的生成特性的实验。实验温度为900,1 000,1 100,1 300 ℃,实验气氛为模拟空气气氛。燃烧生成的颗粒物被低压撞击器（LPI）收集并获得其粒径分布,其化学成分使用XRF分析。实验结果表明,准东煤在不同温度下的颗粒物生成特性呈现明显的差异。在900 ℃和1 000 ℃时亚微米颗粒物（PM1）的生成量明显高于1 100 ℃和1 300℃时,并且亚微米颗粒的峰值粒径也较1 100 ℃和1 300 ℃大。900~1 100 ℃时超微米颗粒（PM1-10）的生成量相当,而在1 300 ℃时具有显著的上升。对颗粒物的成分分析发现,在较高温度下,煤中灰分对Na蒸气的吸收或反应是PM1生成减少的主要原因。     

燃煤锅炉SCR脱硝过程对颗粒物和痕量元素的影响

选择性催化还原（SCR）技术广泛被应用于燃煤电厂NOx减排,而SCR脱硝技术对颗粒物（PM）的影响尚不清楚。在两台300 MW煤粉锅炉机组SCR反应器的入口和出口进行了颗粒物现场采样,分析了SCR脱硝过程对PM的质量粒径分布和痕量元素含量的影响。研究结果显示,SCR脱硝过程产生NH+4,SO2+4等组分并部分转化为颗粒物,促使0.1 μm以下颗粒物团聚、长大,导致0.3 μm以下颗粒物的峰值粒径由0.1 μm增大到0.3 μm,同时使S含量显著升高,最终导致0.3 μm以下颗粒物浓度升高约30.67%。烟气中部分0.3 μm以上颗粒物在SCR反应器中受惯性碰撞作用而分离,使其浓度降低0.06%~33.11%,但峰值粒径和组成成分不变。SCR反应器入口烟气中的气态痕量元素在脱硝过程中向颗粒物转移,引起PM中痕量元素含量变化。实验条件下,经过SCR反应器后,0.3 μm以下颗粒物中Cd,As,Pb含量分别升高104.15%,12.26%和12.18%,而Cr含量降低23.38%;0.3 μm以上颗粒物中各痕量元素含量均略有升高。     

汽轮机高中压转子弯曲原因及防范措施

湛江电力有限公司4号汽轮机通流改造后首次大修时发现高中压转子弯曲,最大弯曲度为0.10 mm,弯曲点位于高中压缸中间汽封靠中压缸侧,轴向距离转子中低压联轴器3 660 mm。在对汽轮机缸体、转子轴径、动静叶片、围带、转子轴承和汽封等进行全面检查的基础上,对通流改造后首次启动至首次揭缸大修停运期间的16次启、停数据进行了详细的对比分析,分析认为:转子弯曲是在运行中造成的,而快冷投运、轴封温度突变并未对转子弯曲造成影响,应该是异物碰磨导致的。返厂更换螺栓、修复隔板静叶片和清理异物后,机组重新启动,转子轴承振幅达标,机组各项运行参数稳定。同时,提出优化轴封供气,严格执行机组启、停过程操作等措施确保机组正常运行。     

Effect of particle size on flow and mixing in a bladed granular mixer

A number of studies have modeled flow and mixing of granular materials using the discrete element method (DEM). In an attempt to reduce computational costs, many of these DEM studies model particles larger than the actual particle size without investigating the implications of this assumption. Using DEM, the influence of the modeled particle size on flow and mixing in a bladed granular mixer is studied. The predicted flow microdynamics, including mixing rates, are strongly dependent on the particle diameter. The effect of particle size on macroscopic advective flow also is significant, particularly for dilute flow regions. These results suggest that the influence of particle size needs to be taken into consideration when using larger particles in DEM mixing simulations. To guide scale‐up efforts, particle‐size‐based scaling relationships for several key flow measurements are presented. © 2014 American Institute of Chemical Engineers AIChE J, 61: 46–57, 2015     

Modeling segregation of bidisperse granular materials using physical control parameters in the quasi‐2D bounded heap

Quantitatively predicting segregation of size‐disperse granular materials is of potential value in many industrial applications. We consider granular segregation of size‐bidisperse particles in quasi‐2D bounded heaps, a canonical granular flow, using an advection‐diffusion transport equation with an additional term to account for particle segregation. The equation is characterized by two dimensionless parameters that are functions of control parameters (flow rate, system size, and particle sizes) and kinematic parameters (flowing layer depth, diffusion coefficient, and percolation length scale). As the kinematic parameters are usually difficult to measure in practice, their dependence on the control parameters is determined directly from discrete element method simulations. Using these relationships, it is possible to determine which values of the control parameters result in a mixed or segregated heap. The approach used here is broadly applicable to a wide range of other flow geometries and particle systems. © 2015 American Institute of Chemical Engineers AIChE J, 61: 1524–1534, 2015     

Thermochemical Conversion of Sewage Sludge by TGA-FTIR Analysis: Influence of Mineral Matter Added

Thermal treatments, such as combustion, gasification, and pyrolysis, have been proven to be a convenient alternative to conventional sludge disposal technologies. Today, process development implies scaling up and so improving the reactor's design. In continuously operated reactors, fresh sewage sludge is in contact with solid residues (reacted material rich in mineral matter and char). Mineral matter has been reported to catalyze the thermo-chemical reactions involved but few works focus on this aspect. In this work, sewage sludge residues were added to fresh sewage sludge. Non-isothermal thermo-gravimetric analysis (TGA) coupled with infrared spectrometry (FTIR) showed that added residues reduce the characteristic reaction temperatures during char combustion and gasification (air, air-N₂, and CO₂ atmospheres). However, any considerable influence of residues was observed during pyrolysis experiments (N₂ atmosphere). The analysis of gas produced during those experiments revealed further details about the solid decomposition, showing considerable differences between different atmospheres.     

有机无机复混肥中有机质检测的因素影响

根据GB 18877-2009,采用重铬酸钾容量法检测有机-无机复混肥料中的有机质,讨论在检测过程中,样品称样量、氧化剂加入量及水浴加热时间等因素对有机质检测结果的影响。实验表明,水浴加热时间的影响最为明显。