Spectrum-Splitting Diffractive Optical Element of High Concentration Factor and High Optical Efficiency for Three-Junction Photovoltaics

A spectrum-splitting and beam-concentrating （SSBC） diffractive optical element （DOE） for three-junction pho- tovoltaics （PV） system is designed and fabricated by five-circ/e micro-fabrication. The incident solar light is efficiently split into three sub-spectrum ranges and strongly concentrated on the focal plane, which can be di- rectly utilized by suitable spectrum-matching solar cells. The system concentration factor reaches 12x. Moreover, the designed wavelengths （450nm, 550nm and 65Onto） are spatially distributed on the focal plane, in good agree- ment with the theoretical results. The average optical effic/ency of all the cells over the three designed wavelengths is 60.07%. The SSBC DOE with a high concentration factor and a high optical efficiency provides a cost-effective approach to achieve higher PV conversion efficieneies.

Influence of high concentration Zn^(2+) on floatability of sphalerite in acidic system

The influence of high concentration Zn^(2+) on the floatability of sphalerite in an acidic system was investigated via flotation experiments,zeta potential measurements,contact angle measurements,and X-ray photoelectron spectroscopy.The results indicated that Zn^(2+) was adsorbed on the sphalerite surface and a Zn-hydroxyl complex was formed at a pH of 4 and a Zn^(2+) concentration of 4×10^(-2) mol/L.The zeta potential increased and the contact angle decreased from 84.80°to 36.48°,strongly inhibiting the floatability of sphalerite.When S^(2−) or Cu^(2+) activator was used alone,sphalerite was not activated after Zn^(2+) was adsorbed,and its contact angle did not change significantly.However,by using a combination of S^(2−) and Cu^(2+) activators,its floatability was realized after Zn^(2+) adsorption.This result was attributed to the removal of the Zn-hydroxyl complex on the surface of sphalerite by S^(2-).After this removal,Cu^(2+) was adsorbed on the sphalerite surface to form a Cu_(2)S·S^(0) hydrophobic film.

Application of High-pressure Flat Membranes in Coal Chemical Wastewater Treatment

In the process of using high-pressure flat membranes to treat coal chemical wastewater,the effects of high-pressure flat membranes on the concentration of salt ions and the removal of pollutants were studied under the conditions of different concentrations of influent TDS,COD and silicon dioxide.The results showed that when the concentration of influent TDS was 35 000-55 000 mg/L,the economic benefit of high-pressure flat membrane operation was the best,and the concentration ratio of high-pressure flat membranes was stable,varying from 3.3 to 3.6.As the concentration of influent organic matter ranged from 100 to 1 800 mg/L,the removal rate of organic matter ranged from 60% to 79%.In addition,the retention rate of high-pressure flat membranes to silicon dioxide was more than 90%.

Analysis and Comparison of Doping Level Effects on a Crystalline Silicon PV Cell under Both Moderate Light Concentration and Normal Illumination Modes

The main purpose of this work is to study doping level effects on a silicon PV cell under both moderate light concentration and normal illumination. This study also aims to compare the doping level effects under the both illumination modes. The results show for both illumination modes that diffusion parameters decrease with increasing doping level. These results are in agreement with the studies of the current and the voltage which showed for the two illumination modes that doping level increase leads to a decrease in current density and an increase in voltage. It also emerges for the two illumination modes and for the doping range 1013 cm-3 - 1016 cm-3, a decrease of maximum power and conversion efficiency. The results also show that decrease of diffusion parameters is faster under moderate concentration in comparison with normal illumination. These results predict a greater variation rate of the current, the voltage, the maximum power and the conversion efficiency under moderate concentration compared to normal illumination. Contrary to diffusion parameters study, the results show higher variation rates of parameters under normal illumination. This is explained by the fact that under moderate concentration, carriers density is close to doping level: the cell is then in high injection condition. Consequently, under moderate concentration, carriers density is less sensitive to doping level variations. The study confirms that carriers density variation with the doping level is weak under the moderate concentration compared to normal illumination.

Assessment of High Concentrated Photovoltaic/Thermal Collector in Hot Climate

This work investigates the performance of combined hybrid high concentrated photovoltaic/thermal collector (HCPV/T) in Kuwait harsh climate. The proposed system consists of triple junction solar cells (InGaP/InGaAs/Ge) attached to heat source to discharge thermal energy to cooling media. Published HCPV/T models do not consider the effect of shunt resistance which greatly affects the system performance. So, a single diode model employing five parameters including the effect of shunt resistance is adapted to analyze the proposed system. To analyze the thermal performance of the proposed system, a two-dimensional thermal model based on the technique of finite difference is introduced to determine the efficiency of the hybrid HCPV/T system. The present developed subroutines are integrated with other involved codes in TRNSYS software to calculate HCPV/T system efficiency. Electrical and thermal as well as the whole system efficiency at different weather circumstances are evaluated and assessed. The effect of different weather conditions, cell temperature, concentration ratio and the temperatures of the coolant fluid on system performance are studied. Current results indicate that the model of single diode is a reliable one rather than using the two-diode complex model. Compared to measurements provided by high concentrated PV manufacturer, the current results revealed a total root mean square error of approximately 1.94%. Present predictions show that PV cell temperature has logarithmic increase with the rise in concentration ratio but with low values till concentration ratio of 400 suns after that the rise is faster at higher concentration values up to 1500 suns. Results also revealed that hybrid HCPV/T system works effectively specially in severe hot climate where thermal efficiency increases with high surrounding temperature for higher values of concentration ratio. In addition, an increase of approximately 15% in thermal efficiency and 10% in total efficiency can be achieved by utilizing active cooling device in HCPV/T system.

豆浆固形物含量及浆液深度对腐竹生产及品质的影响

目的:确定腐竹高效优质生产适宜的豆浆固形物含量和浆液深度。方法:探究豆浆固形物含量和浆液深度对腐竹得率、成膜速率、营养成分、机械性能、蒸煮损失率和复水比等的影响。结果:当豆浆固形物含量为6%,豆浆浆液深度为6 cm时,腐竹得率(34.68%)和营养物质含量最高,其蛋白质含量为51.05%,脂肪含量为23.42%,且抗拉强度和复水性较好,分别为3.74 MPa和3.80 g/g。结论:综合考虑腐竹得率、成膜速率和食用品质等指标,建议采用豆浆固形物含量6%,豆浆浆液深度6 cm进行腐竹的高效优质生产。

低品位铋多金属精矿加压碱浸分离钼、钨、硫和铋

针对传统铋精矿冶炼原料适应性差、不适于低品位铋精矿、有价金属综合回收率低、火法冶炼产生低浓度SO_(2)治理难、成本高等问题,以柿竹园低品位铋多金属精矿为原料,提出加压氧化碱浸分离钼、钨、硫和铋的新工艺,研究了碱用量、时间、温度、总压及液固比等因素对钼、钨、硫、铋浸出率的影响。在优化工艺条件下,钼、钨、硫的浸出率分别达99.73%、90.81%和97.69%,铋不浸出在渣中富集,实现了低品位铋多金属精矿中钼、钨、硫与铋的高效分离。

袁家村微细粒难选磁赤混合铁矿石提铁降硅试验研究

袁家村铁矿选矿厂原生产工艺流程获得的铁精矿TFe品位仅65%左右、SiO_(2)含量达4%~5%,难以满足市场对高品质铁精矿的需求。为此,在详细分析生产流程中混合磁选精矿性质的基础上,采用卧式搅拌磨机细磨—弱磁选+强磁选—反浮选工艺流程开展了提铁降硅试验研究。对TFe品位42.44%、SiO_(2)含量35.42%的混合磁选精矿,在磨矿细度为-0.045 mm占97%情况下,全流程试验获得了产率53.87%、TFe品位67.87%、SiO_(2)含量1.96%、TFe回收率86.15%的高品质铁精矿;磨矿细度为-0.045 mm占94%情况下,适当增大捕收剂RA用量,可获得产率54.76%、TFe品位67.14%、SiO_(2)含量2.09%、TFe回收率86.63%的高品质铁精矿。研究结果可作为选矿厂提铁降硅工艺流程优化决策依据,对类似性质难选铁矿石的高效开发利用具有参考价值。

云南某贫细硫化铜矿石选矿工艺优化研究

云南某低品位细粒嵌布的铜矿石铜、硫品位分别为0.161%和9.704%,有价铜矿物嵌布粒度细,铜硫分离富集难度较大。为实现该硫化铜矿石资源的高效开发利用,在选厂原选矿流程及原矿工艺矿物学研究基础上,进行了系统的磨浮试验。结果表明:矿石采用磨矿—1粗2扫铜硫混合浮选—混浮粗精矿再磨—1粗3精2扫铜硫分离浮选闭路流程处理,可获得铜品位14.69%、铜回收率63.15%的铜精矿,硫品位29.16%、硫回收率75.10%的硫精矿,试验铜精矿品位较现场提高近3个百分点,铜回收率提高15个百分点以上,显著优于现场生产指标,达到了理想的综合回收铜硫效果。研究结果可作为工艺流程优化的依据。

高剪切调浆预处理对煤泥浮选动力学的影响研究

为明确高剪切调浆预处理对煤泥浮选动力学的影响,基于对煤样的可浮性和粒度组成分析,通过改变调浆转速和调浆时间,以浮选精煤产率、灰分和浮选速率常数等作为试验指标进行了实验室单元浮选试验。结果表明:高剪切调浆可有效提高浮选速度并缩短浮选时间;适度的调浆转速和调浆时间可同步提高浮选精煤的产率和浮选过程的选择性;对于可浮性较好的细粒煤需要的调浆时间较短,对于可浮性较差的细粒煤则需适度延长调浆时间;相较于经典一级浮选动力学模型,KELSALL分速动力学模型更符合细粒煤可浮性分布的非均一性特点。研究结果对提高现有煤泥浮选工艺效果具有一定帮助。

基于聚光光伏电池系统热管式换热器的数值研究

针对在高倍聚光下光伏电池效率受表面温度的影响,文章对聚光光伏电池系统中耦合翅片热管散热器进行了数值模拟研究。在水冷、风冷情况下,研究了热管散热器的翅片数量、分布、流体流量对电池效率、温度表面均匀性的影响,并将研究结果与普通散热器进行比较。结果表明:水冷型热管散热器的电池表面温差较低,均匀性和电池效率较高;在流量为0.64 m/s,翅片间距为1.5 mm,翅片厚度为0.4 mm的工况下,电池的综合性能最优,表面温度为314 K,温差小于1 K,均匀性良好,电效率为31.25%,热效率为66.03%。

旋流微泡浮选柱处理难浮煤泥的研究现状

旋流微泡浮选柱气泡尺寸小、泡沫二次富集作用强,在微细煤泥浮选时比传统浮选设备具有更好的分选效果。但对于其他难浮煤泥,如固体浓度高、粒度组成宽的浮选入料,尤其是很多配煤入选的选煤厂出现煤质波动时,旋流微泡浮选柱的浮选效果并不理想,这些问题限制了旋流微泡浮选柱的应用。因此,综述了旋流微泡浮选柱结构改进方面的研究进展,分析了不同结构的旋流微泡浮选柱针对三种难浮煤泥(微细煤泥、高浓度煤泥和宽粒级煤泥)的分选效果,并针对不同难浮煤泥提出了结构优化措施,以指导旋流微泡浮选柱有效分选多变的浮选入料。

某高硫难选铜钼矿浮选工艺优化及工业应用研究

某铜钼矿原矿铜品位0.45%,钼品位0.015%,硫品位2.47%,含金0.12 g/t,是典型的斑岩型铜钼矿。因长期暴露而氧化率逐渐升高,导致目的矿物可浮性变差。原有药剂制度及工艺条件对其适应性较差,生产指标不理想。针对该难选矿石开展了实验室工艺优化试验研究,制定了"铜钼快速浮选-铜硫混合浮选再分离"的工艺流程,工业试验结果相比优化前铜回收率提高了0.60个百分点,钼回收率提高了5.33个百分点。

基于外源排查和工程改造的污水系统提质增效实践

分流制污水管网的外水侵入是造成管网高水位运行、污水浓度低的主要原因之一。针对某污水系统A、B污水厂进水水质浓度降低、污水处理总量波动较大的现象,坚持系统治水,在全面摸查管网的基础上,通过物料平衡法、水量平衡法初步判断进入系统的山水、河涌水、湖水、雨水的外水量和区域,再进行外水点实际踏勘、监测、验证,对外水进行溯源,精准定量、定位。结合4类水特点和基础条件,通过一系列工程实施有力地减少外水入侵,提高了污水厂进水水质浓度。上述研究成果为后续推进污水系统提质增效、营造健康的城市排水保障系统探索出一条实施路径。

基于TiO_(2)的近红外大数值孔径、高聚焦效率、高透射率会聚透镜

利用相位调控原理设计了一种基于TiO_(2)材料的具有非周期同心圆环形高折射率差亚波长光栅结构的会聚透镜,可实现大数值孔径、高聚焦效率、高透射率、低损耗特性,同时具有体积小、易集成的优点。采用时域有限差分法对提出的透镜结构进行仿真和分析,工作波长为850 nm时,该透镜透射率为90.5%,焦距约为10.4μm,焦斑的半高全宽为0.61μm。通过对仿真得到的数据进行分析,可得数值孔径为0.92,聚焦效率高达91.07%,损耗为0.41 dB,平衡了高数值孔径与高聚焦效率之间的矛盾,可在小器件直径下接近衍射极限实现点会聚效果。

高浓度快速浮选技术在铅锌硫化矿浮选中的研究与应用

采取高浓度快速浮选技术,解决了在不改变选矿工艺的情况下原矿处理量增大对生产指标的影响。技术改造后,铅、锌金属回收率分别提高了1.75%和1.61%,伴生银回收率提高了8.60%,药剂成本下降了1.36元/t,降低了选矿生产用水量,年创造经济效益约511.80万元,保护了生态环境。

含泥金矿石高效选别流程研究与生产实践

某金矿选矿厂处理蚀变岩型低硫化物含碲金矿石,该矿石原生矿泥含量高达15%,且矿泥中金有富集现象,采用常规三段破碎+洗矿+两段闭路磨矿+充气式浮选机单一浮选的工艺流程进行选别,存在流程复杂、劳动生产率低、生产组织不顺畅、浮选作业波动较大、尾矿中细粒级金属流失较多、回收率偏低等问题。扩产技改时,采用粗碎+半自磨+球磨的SAB流程取代原碎磨流程,采用浮选柱粗精选、浮选机扫选的柱-机顺序浮选流程取代原单一浮选机浮选流程,后创造性的将柱-机顺序浮选流程改进为浮选柱粗精选、浮选机精扫选的柱-机双精选流程,并对调浆设备进行高效化改造,解决了原工艺流程存在的诸多弊端。劳动生产率提高了25%,吨矿成本降低了20%,金回收率提高了2.44个百分点,年创效益1568.1万元,经济效益和社会效益显著。该高效选别流程的成功实践,对同类型矿石的高效回收具备较强的借鉴意义。

云南某白钨矿加温浮选尾矿再回收试验研究

云南某白钨矿采用常温粗选、加温精选的浮选工艺,目前该白钨矿加温精选尾矿WO3品位达到0.27%,因此对该加温浮选尾矿进行浮选回收钨金属试验研究具有经济意义。由于该加温浮选尾矿矿浆浓度偏低为10.20%,且在加温浮选作业过程经水玻璃高温、长时间搅拌,白钨矿受到强烈抑制,再浮选回收率低,精矿品位难以得到提升。经过探索试验研究,将加温浮选尾矿矿浆浓度预先浓缩到40%,添加500 g/t水玻璃、400 g/t氧化石蜡皂进行粗选,可获得粗精矿WO3品位为1.741%,回收率为73.09%的粗选指标。选出的粗精矿经添加高效组合抑制剂(水玻璃15000 g/t+高效抑制剂BTF 15000 g/t)进行常温一粗三精的开路精选试验,可获得精矿WO3品位为11.65%、回收率为43.86%的精选指标。最终闭路试验流程为:加温浮选尾矿经过一次粗选二次扫选得到粗精矿后,经一次粗精选三次精选,可获得钨精矿WO3品位为10.52%、回收率为51.79%的选矿指标。

某高硫含砷低品位金精矿选矿工艺研究

为提高某高硫含砷低品位难处理金精矿选别指标,分别采用尼尔森离心重选和高效旋流器分级工艺进行金精矿分选试验研究。试验结果表明:在保障金精矿冶炼净返系数等级的基础上,采用试验条件为重力倍数60G、反冲洗水量4 L/min、给矿速度400 g/min的尼尔森离心重选工艺,可获得金品位为30.97 g/t,金回收率为19.97%的重选精矿;采用试验条件为矿浆浓度20%、沉砂口直径22 mm的高效旋流器分级工艺,可获得金品位为26.02 g/t,金回收率为12.50%的溢流。尼尔森离心重选、高效旋流器分级工艺可使最终精矿产品的金回收率分别提高1.6%~1.9%和0.7%~1.0%。考虑到尼尔森离心重选工艺成熟工艺少、后期投资高,故推荐高效旋流器分级工艺进行该金精矿分选试验,以提高该金精矿利用价值。

生猪屠宰废水处理工程实例

某大型生猪屠宰企业生产废水具有浓度变化大、有机污染物浓度高、悬浮物多等特点,呈红褐色并有明显腥臭味,采用气浮-水解酸化-两级AO-高密度沉淀为主的组合处理工艺,当进水COD、BOD5、SS、氨氮、总磷、总氮质量浓度分别为1844、767、864、54.4、4.52、87.6 mg/L时,出水质量浓度分别为46、21.7、12、3.74、1.75、8.74 mg/L,均符合企业内控要求和GB 13457—1992《肉类加工工业水污染物排放标准》中三级排放标准,达标后的出水进入产业集聚区污水处理厂处理。该处理工艺运行稳定可靠,抗冲击能力强,处理效果好,便于自动化运行操作和维护管理。