Characteristics of Water Absorption and the Loss of Dust-Sticking Agent

The development of NCZ-1 dust-sticking agent was first intreduced in china. The speed of water absorption of dust-stick-ing agent was measured and studied on mining site and in laboratory, and then the law of water absorption of dust-sticking agent was analyzed. In addition, the mathematical model of the loss rate of dust-sticking agent was established by the application of fluid mechanics theory, and the method of determining the sprinkle parameters of dust-sticking agent was obtained. Through practical verifi-cation, it is found that the error of this mathematical model is less than 10%. So it can be used in the field.

聚变灰尘实验装置STARDUST失真空事故的数值模拟

建立了聚变灰尘实验装置STARDUST相应的数值计算模型,用数值模拟对失真空事故(LOVA)实验物理过程进行了重现。模拟计算了该实验装置在不同位置处的破口产生LOVA后的速度场发展过程。给出腔室内关键位置速度变化曲线,并与实验所测量到的相应点的速度变化曲线进行了比较。结果表明应用计算流体力学所进行的数值模拟计算达到了对实验重现的目的,其中RNG k-ε湍流模型能够对发生失真空事故下的气体流动状态进行较好的模拟,而且可以较好地预测失真空事故的风险。

Characterization of Band Sawing Dusts Generated in Cutting of Multi-crystalline Silicon Ingots

Physical-chemical characteristics of the band sawing dusts regarding to recovery of pure silicon from them were investigated.The experimental results show 50vol%-60vol% amorphous phases exist in the dusts,which is mostly amorphous silica.The as-received saw dusts are found to form hard agglomerates of larger than 50 microns in diameter.The iron-based inclusions collected by magnets are found to match well with the band saw material in XRD patterns.Weight loss in heating was observed by thermal gravity tests,up to 900 ℃,presumably due to reaction of the amorphous silica with carbon contaminant in the dusts.The saw dusts were variously treated to examine their physical-chemical responses,and the results were also presented.

Effects of dust,soiling,aging,and weather conditions on photovoltaic system performances in a Saharan environment—Case study in Algeria

Solar photovoltaic(PV)power represents one of the most promising future sources of energy in the world.Considered the cleanest form of energy,extensive research is being undertaken to widen its use.Notably,mega projects are being considered for installation in the Middle East and North Africa(MENA)region because of its high solar potential,with hopes of eventually feeding Europe from the PV electricity generated in this region and transported through high voltage direct current(DC)lines.However,current implementation of PV systems has shown that their reliability and efficiency depend upon surrounding environmental factors,such as the ambient temperature,wind,and rainfall,as well as soiling,pollution,and aging.The aim of this study was to investigate,through experimental tests,the effects of such factors on the power output of a grid connected PV station.The results showed that the output power and efficiency are deeply affected by various environmental factors,which are weather dependent.These findings may help us develop appropriate solutions to overcome these drawbacks.

Corrosion inhibition of a hygroscopic inorganic dust-depressor

Metallic corrosion is a serious problem in the application of a hygroscopic inorganic dust-depressor. The basic characteristics of a hygroscopic inorganic dust-depressor and its corrosivity, corrosion mechanism, as well as the principle of corrosion inhibition were analyzed. The static mass-loss test was carried out to investigate the corrosion behavior and the effect of the dust-depressor. The static corrosion rates of steel specimens were measured in six different corrosion inhibitor solutions of the dust-depressor, and the suitable corrosion inhibitors for the dust-depressor to reduce the corrosivity were found out.

旋风滤布除尘器的除尘性能研究

为了解决传统旋风除尘器对颗粒捕集效率差、袋式除尘器使用寿命短等问题,将传统旋风除尘与滤布除尘有效结合,形成一种优势互补的一体式旋风滤布除尘装置。采用数值模拟和试验相结合的方法,探究在不同出口压力的条件下,旋风滤布除尘器的除尘效率及压力损失情况。利用Fluent软件对旋风滤布除尘器的除尘性能进行模拟,模拟采用雷诺应力模型(Reynolds Stress Model, RSM)和多相流模型(Discrete Phase Model, DPM)。通过搭建试验平台,测试除尘装置的除尘性能,验证数值模拟的可靠性与正确性。结果表明:旋风滤布除尘器的除尘效率相对于旋风除尘有明显的提高,旋风滤布除尘器的除尘效率与出口负压呈正相关,旋风滤布除尘总效率随出口负压的增加而逐渐增加,且旋风滤布除尘器除尘效率的最小值都高于旋风除尘部分除尘效率的最大值;旋风滤布除尘器的压力损失随出口负压的增加而线性增大,压力损失增大使得除尘器损耗的功率也增多,且压力损失的上升速度快于除尘效率的提升速度;在旋风滤布除尘器中,负压增大后,旋风除尘捕获大粒径颗粒,逃逸到滤布部分的颗粒粒径都较小,降低了滤布被大颗粒划破的风险,提高了滤袋的使用寿命。

大型集中式光伏电站效率测试及提效对策研究

随着光伏电站的投产运行,光伏发电量的大小直接影响电站效益,如何科学的对光伏电站效率进行测试、分析与评价,提高电站发电效率,显得尤为重要。通过调研200 MW集中式光伏电站运行情况,研究光伏电站系统能效测试技术,制定电站测试项目、测试要求、抽样原则,开展光伏电站现场测试,并对电站系统效率、组件串联失配率、组串并联失配率、逆变器转换效率、组件衰减率、洁净度对光伏板功率影响度、倾角与辐照度测试结果进行分析,从减少弃光率、组件清洗、组件倾角调整以及运维管理水平等方面,提出针对性的提效对策,在提高电站系统效率的同时,进一步提升电站效益。

矩形矿井巷道内UWB路径损耗研究

为了探究UWB无线信号在煤矿巷道内的传输特性,结合电磁波信号的传输以及反射定律原理,分析了矩形矿井巷道中可能出现的不规则传输路径其过程中存在的粉尘浓度、空气湿度、四壁不同程度的粗糙面以及煤壁倾斜程度等因素引起的信号损耗。构建了不同条件下的损耗模型,并运用MATLAB软件对巷道内信号的损耗进行了仿真分析。仿真结果表明:粉尘浓度和空气湿度都会对电磁波造成衰减,增加粉尘浓度加速信号的损耗,其信号的衰减要远大于空气湿度引起的损耗;粗糙和倾斜加速了信号的衰减,但是粗糙和反射引起的损耗远远低于倾斜引起的损耗,倾斜损耗起主导作用。

烟叶打叶后大片率调控关键技术研究

为解决当前烟叶打叶后大片率过高的问题,提出了对打叶后烟片采用振筛机大片叶筛选、图像监控打辊机可控再打叶的技术处理方案。设计实现了烟片分选再处理装置,并通过实验研究了不同控制参数对再打叶后烟叶的影响。结果表明:(1)提高振筛机筛孔孔径有助于大片叶分离;(2)再处理打辊机框栏开口尺寸与形状相比提高转速对再打叶效果的影响更为显著,使用圆形50.8 mm框栏开口的打辊机可实现再打叶后大片率低于30%、中片率高于45%、含末率低于0.3%的水平;(3)提高打辊机转动频率和增加再处理大片叶分料比例有助于降低大片率,但均会导致中片率降低和烟末增加。实验表明打辊机转动频率和分料比例分别控制在40 Hz和50%左右时表现较好。

基于K-means算法和积灰损耗系数的西北地区光伏电站清洗策略建模分析

针对当前西北地区光伏场站缺乏科学合理的清洗策略来清除组件表面积灰的问题,提出基于K-means算法和积灰损耗系数的光伏电站清洗策略模型。利用K-means算法对场站提供的日志发电数据进行聚类得到晴天数据样本,利用该样本数据拟合发电能力损耗曲线求解积灰损耗系数,联立清洗成本建立清洗策略模型。文章利用西北地区某光伏场站的发电数据对模型进行了验证,分析结果表明模型准确性较高,也为西北地区光伏电站清洗策略的研究提供了新思路。

Change in Grain-Size Composition of Lignite under Cyclic Freezing-Thawing and Wetting-Drying

The paper presents the change in grain-size composition of lignite under cyclic freezing-thawing (FTC) and wetting-drying (WDC). The article shows that in the spring and autumn periods the lignites can be subjected to repeated freezing-thawing and wetting-drying, which determines the possibility of changing their grain-size composition and structure. Experimental studies in laboratory conditions on the influence of cyclic freezing-thawing (FTC) and wetting-drying (WDC) on the quality indicators of lignites have been carried out, their granulometric (fractional) composition has been studied. Freezing-thawing cycle conditions are as follows (FTC): minimum exposure temperature: -20°C;maximum: +5°C;relative humidity: 30%;number of processing cycles: 3. Wetting-drying cycles are as follows (WDC): drying temperatures are +20, +40, +60, +80°C, drying time 90 minutes, the coals are further subjected to rain (soaking) for a period of water saturation to humidity of 30% - 40% and dry again. The number of wetting-drying cycles is 3 times. The tests have revealed the destructive effects of FTC and WDC on the samples of lower metamorphic grade coal, and the cycles of wet-dry lead to the much higher yield of fine sizes (-6+0;-13+0 mm) than the cycles of freeze-thaw. Furthermore, it is found that the increase in the yield of fines depends on the heating temperature: coal disintegration proceeds more intensively at a higher temperature of drying.

酒钢复配除尘灰直接还原-磁选试验研究

除尘灰的处理一直是冶金领域的难点问题。为实现除尘灰的资源化利用,减少除尘灰中有害元素对周边生态环境的影响,对酒钢6种除尘灰复配设计,验证火法工艺处理除尘灰的可行性及有害元素脱除效率,并根据直接还原实验结果确定合适的窑渣磁选实验配料。实验结果表明,按照质量百分比复配,高炉布袋灰∶炼钢二次除尘灰∶堆存高炉布袋灰∶混合除尘灰∶高炉重力除尘灰∶炼钢OG泥=28.50∶7.50∶15.50∶6.50∶28.50∶13.50,配碳量30%,焙烧温度1100℃,焙烧时间60 min,焙烧后烧损率为36.62%,锌、钾、钠的脱除率分别为67.86%、75.56%、72.41%,铁品位为30.77%,焙烧物料经过细磨磁选后,得到的铁精粉铁品位为80.84%,铁回收率高达81.44%。多种除尘灰复配后直接还原-磁选回收金属铁的试验及机理分析,有望为除尘灰的处理开拓新途径。

GMC-96B钢轨打磨车新型集尘装置设计研究

钢轨打磨车在作业过程中会产生大量的磨削粉尘,因此需要配备一套集尘装置收集磨削粉尘,以减少扬尘和残留粉尘对周边环境的污染。根据GMC-96B型钢轨打磨车集尘装置的实际使用情况,针对性提出一种适用于该打磨车的新型集尘装置,并对关键子系统进行详细的技术设计及分析计算。计算结果表明,新型集尘装置相比原有集尘装置具有明显的性能提升。

吸湿型路面抑尘剂配方研制及工业试验

针对露天采场路面扬尘特点及机理,研制出一种吸湿型路面抑尘剂.基于正交试验,以失水率为评价指标,对抑尘剂各组分进行优化,并在实验室条件下对最优配方进行吸湿性、抗风吹等性能测试.结果表明,实验室研制的配方在25 d内最低含水率达到8.18%,具有很好的防风抑尘性能.将该抑尘剂配方进行工业试验,结果表明,该抑尘剂的有效抑尘时间为10 d,与传统洒水方法相比,抑尘费用降低了30.71%,节水效率达到94.67%.

煤炭铁路运输专用扬尘覆盖剂应用性试验研究

为了解决煤炭铁路运输过程中的扬尘污染问题,节约煤炭资源,研制了新型煤炭铁路运输专用扬尘覆盖剂。通过对大秦铁路沿线运煤列车煤覆盖剂前后的扬尘量和煤炭损失率进行对比,证明了扬尘覆盖剂可以大大降低煤炭铁路运输过程中的损失。

露天矿采场路面抑尘剂研制及性能表征

基于露天采场路面扬尘特点及机理的分析,确定抑尘剂组分。通过吸湿剂、凝并剂、表面活性剂单体选择试验,初步确定单体及浓度范围。基于正交试验,以失水率为评价指标,确定了最优配方,并对其自然环境下的吸湿放湿性、抗风吹等性能进行了测试。结果表明,研究出的抑尘剂具有较好的吸湿、保水性能,干燥条件下,表面强度高,固结性能好,具有较好的防尘抑尘性能,且材料来源广泛、制备简单、成本低,具有较好的应用前景。

烟草甲虫为害损失调查

采用实验室和贮烟仓库投虫的方法控制烟草甲虫的不同为害程度,研究了片烟虫害损失的测定方法,同时根据片烟虫害损失的测定方法对国内部分卷烟企业的虫害损失情况进行了调研。结果表明:片烟质量损失率和尸屑率呈极显著正相关,通过尸屑率可估算出片烟质量损失率;46个片烟样品的直接虫害损失率约为0.716%,按有虫片烟占30%的比例推算,所调查卷烟企业的虫害直接损失率约为0.215%。

文丘里洗涤器压力损失试验研究

使用空气 -水系统 ,试验研究文丘里洗涤器操作参数 (液气比、喉管气速 )及喉管长度对其压力损失的影响。结果表明 ,喉管气速对压力损失的影响比液气比的大 ,压力损失随液气比增加呈线性增加 ,而随喉管气速的变化基本为平方关系。在此基础上 。

基于状态监测的电池板积灰清洗周期确定与费用评估

光伏电池板(电池板)积灰可降低透光率、引起热斑效应、腐蚀玻璃表面,实时监测积灰状态,及时清洗积灰将为光伏电站带来显著的经济效益。提出一种电池板积灰状态发电效率监测方法,构建电功率损失率随积灰时间变化的渐近型预测模型,并建立电池板积灰费用评估数学模型,以年累计电量损失费与清洗维护费之和最小化来确定最佳清洗周期。实例分析表明:蒙东地区50MW光伏电站积灰43天时电功率损失率达到15.32%,最佳清洗周期为20.3天,与当前现场固定清洗周期90天比较,将积灰经济损失由18.96万元·MW^-1×a^-1降至12.85万元·MW^-1×a^-1,占发电收益比例由15.3%降到10.4%;装机容量和年累计清洗时间对最佳清洗周期无显著影响,但并网电价越低、单位面积清洗费用越高时,最佳清洗周期越长。

青浦县榻榻米生产企业粉尘危害调查及经济损失探讨

生产榻榻米的工人长期接触高浓度粉尘 ,对其身体的损害极大 ,并可能产生矽肺 ,本文拟对青浦区榻榻米生产企业的经济损失做一探讨。 [方法 ]本文运用现时寿命表法对榻榻米生产企业的监督监测的资料进行分析。 [结果 ]榻榻米生产企业的经济效益随着时间的推移会出现负增长。[结论 ]地方政府应当本着对人民身体健康负责的态度 ,本着可持续发展的战略眼光 ,阻止榻榻米之类的高危害作业进入我国。