Decentralized scheme for leaks’ location in a branched pipeline

This article presents a novel scheme for the detection and isolation of single leaks in a pipeline with a branch junction by measuring only the flow rate and pressure at the ends of the line. For the solution of this realistic issue, which commonly occurs in pipeline networks, the position of the branch junction and its flow rate are supposed to be known. The idea consists of deriving a model considering the branch junction as a known point in the pipeline such that the leak position is characterized by two possible orientations with respect to the branch (upstream and downstream of it). Thus, this model allows proposing a diagnosis scheme which includes a static selector and two identifiers designed by using a continuous extended Kalman filter with only one deviation parameter to be estimated. This framework reduces the identification task to one parameter which is associated with the deviation from a prescribed positive base position located between one of the pipeline ends and the branch. Simulation and experimental results with data of a hydraulic pilot pipeline of 200 [m] show the promise of the novel scheme.     

炼厂含硫污水处理优化思路探讨

分析了炼厂含硫污水处理存在的问题,提出了含硫污水处理优化运行的思路和方法,并对企业下一步优化工作提出建议。     

Applied tracer tests in fractured rock: Can we predict natural gradient solute transport more accurately than fracture and matrix parameters?

Applied tracer tests provide a means to estimate aquifer parameters in fractured rock. The traditional approach to analysing these tests has been using a single fracture model to find the parameter values that generate the best fit to the measured breakthrough curve. In many cases, the ultimate aim is to predict solute transport under the natural gradient. Usually, no confidence limits are placed on parameter values and the impact of parameter errors on predictions of solute transport is not discussed. The assumption inherent in this approach is that the parameters determined under forced conditions will enable prediction of solute transport under the natural gradient. This paper considers the parameter and prediction uncertainty that might arise from analysis of breakthrough curves obtained from forced gradient applied tracer tests. By adding noise to an exact solution for transport in a single fracture in a porous matrix we create multiple realisations of an initial breakthrough curve. A least squares fitting routine is used to obtain a fit to each realisation, yielding a range of parameter values rather than a single set of absolute values. The suite of parameters is then used to make predictions of solute transport under lower hydraulic gradients and the uncertainty of estimated parameters and subsequent predictions of solute transport is compared. The results of this study show that predictions of breakthrough curve characteristics (first inflection point time, peak arrival time and peak concentration) for groundwater flow speeds with orders of magnitude smaller than that at which a test is conducted can sometimes be determined even more accurately than the fracture and matrix parameters.     

涡流检波器建模研究及参数识别

笔者分析了涡流检波器的工作原理 :综合考虑了检波器磁路系统中 ,外壳、磁靴等部件的电磁感应对固定线圈感应电流的影响 ;建立了七参数的动力学模型。理论分析表明 :涡流检波器的外壳系统的附加耦合效应 ,影响了检波器的频率特性。在上述分析和研究的基础上 ,设计了检波器参数识别实验系统 ;验证了七参数动力学模型的合理性 ;研究的结论为检波器结构设计中改善和控制其特性参数、提高其工作安全可靠性等 ,提供了理论依据。     

试论高压水射流清洗系统的合理匹配

随着高压水射流清洗的应用领域日益广泛， 高压水射流清洗系统的合理匹配已成为急待解决的问题。因为只有高压水射流清洗系统的合理匹配，才能充分发挥高压水射流的高效、高质量清洗及节能、污染小的特点。笔者利用系统分析的方法，从实际应用角度出发，结合理论与实验，从高压泵技术指标的选择、清洗设备的选择及参数简析、清洗压力的选择等几个方面，分析了合理匹配高压水射流清洗系统主要参数的一般方法和原则，并将其应用于铁路罐车的高压水射流清洗系统的匹配。实际应用结果表明，这种方法是行之有效的     

胺萃取法处理含氰废水工艺的研究

对黄金选冶过程中排放的含氰废水用N₂₃₅作萃取剂从含氰废水中萃取铜、锌进行了研究,探讨了预处理有机相、温度条件、相比、平衡pH、相接触时间和萃取级数等因素对萃取的影响。试验结果表明,在选定的条件下,铜的萃取率达99%以上,从负载有机相中反萃铜,反萃率可达99%。同时还可以回收氰化物,根据试验结果,提出了处理含氰废水的工艺流程      

Chemical plant innovative safety investments decision-support methodology

Introduction

This article examines the extent to which investing in safety during the creation of a new chemical installation proves profitable.

Method

The authors propose a management supporting cost-benefit model that identifies and evaluates investments in safety within a chemical company. This innovative model differentiates between serious accidents and less serious accidents, thus providing an authentic image of prevention-related costs and benefits. In classic cost-benefit analyses, which do not make such differentiations, only a rudimentary image of potential profitability resulting from investments in safety is obtained.

Results

The resulting management conclusions that can be drawn from such classical analyses are of a very limited nature. The proposed model, however, is applied to a real case study and the proposed investments in safety at an appointed chemical installation are weighed against the estimated hypothetical benefits resulting from the preventive measures to be installed at the installation.

Conclusion

In the case-study carried out in question, it would appear that the proposed prevention investments are justified.

Impact on industry

Such an economic exercise may be very important to chemical corporations trying to (further) improve their safety investments.     

有机污染土壤通风去污技术优化设计

有机污染土壤通风去污技术（SVE）是一种经济,安全的场内治理技术,SVE优化设计包括建立污染土壤通风去污模型和抽排去污流场模型,并以此为基础算工程费用,用一虚拟工况对提出的模型及计算公式进行了验证。     

钢铁厂废酸对印染前处理废水的混凝沉淀实验

棉纺织印染前处理废水水质成分复杂,污染物含量极高,是印染厂污水处理难以达标的重要原因。实验针对常州某印染厂棉纺织印染前处理车间废水水质特性,选取钢铁厂废酸作为混凝剂对棉纺织印染前处理废水进行了混凝试验研究。得出废酸的最佳投加量为30mL/L;混凝最佳搅拌方式为：以300rpm速度快速搅拌2min,以40rpm搅拌10min;助凝剂阳离子型聚丙烯酰胺（CPAM）以投加4mg/L为宜;最佳沉淀时间为20min。     

利用遗传算法进行软件可靠性增长模型参数估计

为解决利用传统数值方法估计软件可靠性增长模型参数值时存在的问题 ,笔者讨论了利用遗传算法进行求解的相关策略 ;提出了一种新的编码方式及变异算子 ;通过涉及多个模型的实验 ;采用实际数据 ,对所提出算法的效果与传统数值方法进行了对比。实验与对比分析结果显示 :该算法针对这些模型表现出了良好的普适性。