Evaluation and optimization of secondary water supply system renovation

Due to pollution in second water supply system (SWSS),nine renovation alternative plans were proposed and com-prehensive evaluations of different plan based on Analytical Hierarchy Process (AHP) were presented in this paper. Comparisons of advantages and disadvantages among the plans of SWSS renovations provided solid foundation for selecting the most appro-priate plan for engineering projects. In addition,a mathematical model of the optimal combination of renovation plans has been set up and software Lingo was used to solve the model. As a case study,the paper analyzed 15 buildings in Tianjin City. After simulation of the SWSS renovation system,an optimal scheme was obtained,the result of which indicates that 10 out of those 15 buildings need be renovated in priority. The renovation plans selected for each building are the ones ranked higher in the com-prehensive analysis. The analysis revealed that the optimal scheme,compared with two other randomly calculated ones,increased the percentage of service population by 19.6% and 13.6% respectively,which significantly improved social and economical benefits.

Review on Optimization of Drinking Water Treatment Process

In the drinking water treatment processes, the optimization of the treatment is an issue of particular concern. In general, the process consists of many units as settling, coagulation, flocculation, sedimentation, filtration and disinfection. The optimization of the process consists of some measures to decrease the managing and monitoring expenses and improve the quality of the produced water. The objective of this study is to provide water treatment operators with methods and practices that enable to attain the most effective use of the facility and in consequence optimize the cubic meter price of the treated water. This paper proposes a review on optimization of drinking water treatment process by analyzing all of the water treatment units and gives some solutions in order to maximize the water treatment performances without compromising the water quality standards. Some practical solutions and methods are performed in the water treatment plant located in the middle of Morocco (Meknes).

A Genetic Fuzzy Analytical Hierarchy Process Based Projection Pursuit Method for Selecting Schemes of Water Transportation Projects

The optimal selection of schemes of water transportation projects is a process of choosing a relatively optimal scheme from a number of schemes of water transportation programming and management projects, which is of importance in both theory and practice in water resource systems engineering. In order to achieve consistency and eliminate the dimensions of fuzzy qualitative and fuzzy quantitative evaluation indexes, to determine the weights of the indexes objectively, and to increase the differences among the comprehensive evaluation index values of water transportation project schemes, a projection pursuit method, named FPRM-PP for short, was developed in this work for selecting the optimal water transportation project scheme based on the fuzzy preference relation matrix. The research results show that FPRM-PP is intuitive and practical, the correction range of the fuzzy rained is both stable and accurate; preference relation matrix A it produces is relatively small, and the result obtherefore FPRM-PP can be widely used in the optimal selection of different multi-factor decision-making schemes.

Optimized Operation of a Solar-Driven Thermoelectric Dehumidification System for Fresh Water Production

The work presents a parametric analysis of the performance of a solar-driven thermoelectric system to dehumidify air and produce fresh water. The system is combined with a solar distiller humidifying ambient air to enhance distillate output to meet the specified fresh water needs for a residential application. The presented system is a totally renewable energy-based system taking advantage of the clean solar energy. A model is developed to simulate the air dehumidification process using TEC （thermoelectrically cooled） channels. An optimization problem for setting system operational parameters is formulated to meet the fresh water requirement of 10 liters per day for a typical residential application in the Lebanese coastal humid climate. Using five TEC channels of length of 1.2 m and area of 0.07 - 0.05 m^2 integrated with 1.2 m^2 solar distiller is capable of meeting the water demand, where the air mass flow rate introduced to each TEC channel is optimally set at 0.0155 kg/s. The optimal electrical current input to the TEC modules from the photovoltaic solar panels varied depending on the month and is set at 2.2 A in June, 2.1 A in July and 2.0 A in August, September and October per each TEC module.

超临界水煤气化耦合SOFC发电系统集成及其能量转化机制

基于超临界水煤气化合成气的富氢特征,提出了一种超临界水煤气化耦合固体氧化物燃料电池(SOFC)及燃气轮机发电系统,气化产物的高温高压显焓由膨胀机回收,化学能由SOFC及燃气轮机先后利用发电,燃气轮机排气及SOFC阴极空气的大部分显热用于预热锅炉给水。在气化温度660℃、气化压力250 bar(1 bar=0.1 MPa)及气化室内煤浆浓度为11.3%(质量)条件下,系统发电效率可以达到54.01%,㶲效率为52.79%。相比于先进的1000 MW超超临界蒸汽朗肯循环燃煤电站,所提新系统可实现年减排CO_(2)39万吨。提出的煤基发电系统,进一步深化了煤炭化学能的梯级利用,实现了各子单元间的高效能级匹配,有助于实现双碳目标。

Short-circuit process model in underwater welding using rotating arc sensor

In order to detecting and tracking along the weld seam with rotating arc sensor in underwater welding,the highpressure water environment rotating arc welding hardware platform is established and welding experiments using rotating arc sensor is done. Different radius of rotating arc sensor is used. And the corresponding welding current and voltage is obtained,which is compared with the results of rotating arc sensor short-circuit process simulation model under high-pressure water environment established in this article. The results show that under high-pressure water environment,rotating arc radius should be optimized,otherwise the short-circuit-arcing cycle will transit to a short-circuit-arcing-abruption cycle,making the welding quality poor. At last the critical radius between the short-circuit-arcing cycle and short-circuit-arcing-abruption cycle under high-pressure water environment is obtained.

A Water Line Network Failure Application of Network Design Problems

This study investigated a water supply recovery problem involving municipal water service piping. The problem consisted in recovering full service after network failure, in order to rapidly satisfy all urgent citywide demands. The optimal recovery solution was achieved through the application of so-called network design problems （NDPs）, which are a form of combinatorial optimization problem. However, a conventional NDP is not suitable for addressing urgent situations because （1） it does not utilize the non-failure arcs in the network, and （2） it is solely concerned with stable costs such as flow costs. Therefore, to adapt the technique to such urgent situations, the conventional NDP is here modified to deal with the specified water supply problem. In addition, a numerical illustration using the Sendai water network is presented.

A heuristic design method for batch water-using networks of multiple contaminants with regeneration unit

This work develops a heuristic method for the design of batch water-using networks of multiple contaminants with regeneration unit based on the concepts of concentration potential. A water-using network involving regeneration unit can be formed by adding the regenerated stream(s) into the network involving reuse only. In the design procedure of the network operated in a single batch mode, time is take n as the primary factor a nd con centration potentials as the secondary one. For the networks operated in a repeated mode, the design procedure is similar to that for continuous processes, besides designing the storage tanks with the rules proposed. Continuous regeneration unit is selected in this work. With the proposed method, the network structure corresponding to the minimum freshwater consumption can be obtained. It is shown that the method proposed in this article is simple, effective and has clear engineering meaning.

基于粒子群优化模糊PID控制的水厂加氯系统

水厂加氯过程具有非线性、大时滞等特点,采用传统的PID控制方式难以实现消毒剂精准投加。因此,以某采用次氯酸钠消毒系统的水厂为例,首先通过分析该水厂加氯系统工作原理,结合工程经验和运行数据确定了加氯过程的近似数学模型。然后综合使用粒子群优化算法、模糊控制算法和PID控制算法,设计了一种粒子群优化模糊PID控制器,并利用MATLAB软件搭建了粒子群优化模糊PID控制系统和传统PID控制系统的模型进行仿真验证,结果表明:相较于传统PID控制系统,粒子群优化模糊PID控制系统的超调量减少了89.36%,调节时间减少了46.63%,其抗干扰能力也更强,系统整体控制效果有了较大提升。最后使用基于粒子群优化的模糊PID控制法对水厂加氯控制系统进行改造,试运行后发现,新系统控制效果良好,出厂水游离氯值能够稳定在设定值附近。

葡萄干酿制葡萄酒的工艺优化

目的研究并优化用普通葡萄干酿造葡萄酒的工艺。方法通过单因素和正交试验研究料水比、果胶酶添加量、酵母菌接种量和发酵温度对葡萄酒品质的影响,并优化酿造工艺。结果单因素试验结果表明,料水比、果胶酶的添加量以及发酵温度主要影响葡萄酒的色度,对残糖浓度和酒精度的影响不明显。相比之下,酵母菌接种量对这些特性的改变贡献较小。正交试验表明,发酵温度、酵母菌接种量和料水比对酒精度有显著影响,且果胶酶添加量明显影响感官评分。在最佳的发酵条件下[发酵温度20℃、酵母菌接种量0.50 g/L、果胶酶的添加量25 mg/L、料水比1:6(g/mL)],可以酿造出酒精度约为12.3%vol,感官评分约为90.5分的高品质葡萄酒。结论普通葡萄干酿制葡萄酒可行性较高,不同因素组合选择余地大,葡萄酒品质符合国家标准,酿造工艺具有一定的商业价值。

GA与分层优化结合的掺水集油工艺参数优化

为降低进入特高含水阶段油田的掺水集油能耗,对掺水集油工艺参数进行优化。以掺水温度、掺水量、掺水压力为外层决策变量,加热炉和掺水泵运行方案为内层决策变量,以掺水集油工艺综合能耗最低为目标函数,建立掺水集油工艺参数优化模型。提出了一种遗传算法(Genetic Algorithm,GA)与分层优化结合的求解策略,将掺水温度作为染色体上的基因,先优化个体对应加热炉和掺水泵运行方案,得到个体对应的最小集油能耗,再通过种群的不断迭代进化,得到掺水集油工艺的最优参数。研究结果表明,与优化前相比,掺水温度降低8.3℃,掺水量减少131.6 m^(3)/d,掺水压力降低0.15 MPa,集输吨液综合能耗降低13.64%,优化效果良好。研究成果可为进入特高含水阶段油田降低掺水集油能耗提供借鉴。

基于激光选区熔化技术的金属悬垂圆孔结构无支撑成形工艺优化与质量研究

基于激光选区熔化(SLM)技术制造的随形冷却模具,凭借其优异的冷却性能,能够显著提高加工效率,有效降低生产成本,成为未来注塑成型模具的重要发展方向,但目前在使用SLM技术成形随形冷却模具内部的圆形流道方面仍存在诸多挑战。在SLM成形时,随形冷却模具内部圆形流道的结构主要表现为悬垂圆孔结构,若直接使用传统工艺策略成形悬垂圆孔结构易出现翘曲、粘粉等缺陷,同时由于随形冷却模具内部流道复杂的特点,其内部流道无法通过添加支撑辅助成形。采用在模具外侧添加支撑结构的方法,可调整模具成形角度,增强悬垂圆孔结构自支撑性,但会增加额外成形时间与成形材料,导致生产成本增高。优化悬垂圆孔结构无支撑成形工艺,实现在不添加支撑结构的前提下满足随形冷却模具对流道成形质量要求,能够有效降低随形冷却模具生产成本并获得高质量成型件。本文对金属悬垂圆孔结构成形工艺策略进行优化,以316L不锈钢悬垂圆孔结构为对象,分析了工艺策略、孔径对悬垂圆孔成形质量的影响。采用一种基于加工层角度自适应的下表面工艺区域划分策略,研究该工艺区策略对于无支撑金属悬垂圆孔成形的适用性,并使用该工艺制造冷却模具样件,对成件的成形质量进行分析。结果表明采用基于加工层角度自适应的下表面工艺区域划分策略可明显抑制成形过程中的翘曲行为。使用该工艺策略成形的随形水冷模具样件无明显质量缺陷,内部流道的表面质量与成形精度满足使用要求。

数字图像处理在结构优化结果提取中的应用

结构优化结果的提取和应用主要考虑如何有效地将优化结果转化为可用的CAD模型,实现CAE和CAD之间的数据共享和模型转换。基于数字图像原理提取轮廓范围及像素点坐标,根据相邻点坐标计算离散曲率,并根据曲率值对构件的边缘形状进行分类,得到拓扑优化结果。该方法提高了拓扑优化结果的精度和可用性及提取的效率,减少了人为因素的干扰,提取的模型更符合实际,有助于更好地理解和分析拓扑优化结果,对拓扑优化后处理的结果提取轮廓重构及成果应用有一定参考作用。

芦笋下脚料多糖提取工艺优化

以新鲜芦笋修整后产生的老根茎部分下脚料为主要研究对象,采用水浴浸提-超声波辅助法提取芦笋下脚料多糖,设计单因素试验,分别研究液料比、超声时间、超声功率、浸提温度、浸提时间、醇沉浓度对芦笋下脚料中多糖提取率的影响。根据单因素试验结果,设计响应面试验,优化芦笋下脚料多糖的提取工艺。结果表明,芦笋下脚料多糖的最佳提取工艺为液料比32∶1(mL/g)、超声时间27 min、超声功率300 W、浸提温度87℃、浸提时间104 min、醇沉浓度95%,该提取条件下,多糖提取率为(6.26±0.06)%。

基于电解水处理的荞麦富集酚酸发芽工艺优化

为研究电解水理化指标及发芽培育条件对荞麦芽中酚酸总量的影响,以‘晋荞6号’为原料,选取电解水pH值、电解水有效氯浓度、发芽温度、发芽时间为单因素,酚酸总量为响应值,在单因素试验的基础上,采用响应面分析法对荞麦发芽条件进行优化。结果表明:使用pH5.90、有效氯浓度19.50 mg/L的电解水处理荞麦种子,并在26℃条件下培养,发芽6.5 d采收,测得荞麦芽中酚酸总量为15.06 mg/g,较自来水对照组提高了74.10%。在检测到的11种酚酸中,绿原酸为含量最高的酚酸(9.03 mg/g),电解水处理组荞麦芽中香草酸、水杨酸、丁香酸、绿原酸含量均显著高于自来水对照组(P<0.05),对羟基苯甲酸和咖啡酸含量显著低于自来水对照组(P<0.05),其余主要酚酸含量与自来水对照组均无显著性差异(P>0.05)。

有缆式第四代智能分层注水技术优化及现场应用

青海油田注水开发油藏类型多,非均值性强,开发矛盾突出,在精细注水实施过程中测调工作量和测试力量不足,由于井况条件产生的测试遇阻问题也未能有效解决。为此油田引进第四代分层注水工艺,不需要投捞测试仪器,解决了仪器遇阻、遇卡的问题,优化电缆密封方式、研制电缆直穿式封隔器和远程通信及控制技术,实现了对注水层段在实时在线调控,为油田开发提供了技术支撑,为后续工艺升级提供了基础。有缆式智能分注技术在青海油田实施45口井,最大分注级数为5封5配,最大下深2033.5 m,施工层段密封率达到100%,单井调配时间相比桥式偏心提高了6倍,测试成功率达到100%。

水导激光加工CFRP质量和效率实验研究

为实现碳纤维增强复合材料的高质高效切割,采用水导激光加工技术对CFRP进行微槽加工,通过正交实验法、单因素实验法研究了激光功率、扫描速度和扫描路径重叠率对热影响区宽度和材料去除率的影响规律,并以此为目标进行了优化。结果表明:激光功率、扫描路径重叠率对热影响区宽度和材料去除率的影响显著;当激光功率35 W、扫描速度4 mm/s和扫描路径重叠率40%时,热影响区宽度为184.484μm,材料去除率为0.068 mm ^(3)/s,能获得较小的热影响区宽度和较高的加工效率。

马蹄脆片微波真空干燥工艺优化及其水分变化

以马蹄为原料,采用微波真空干燥技术干燥马蹄脆片,考察微波功率、干燥温度、真空度、切片厚度对马蹄脆片色差值、总糖含量、脆度的影响,以响应面试验优化干燥工艺,采用低场核磁共振技术研究马蹄脆片干燥过程水分变化情况。结果表明,微波真空干燥马蹄脆片的最佳工艺为微波功率2.0 kW、干燥温度71℃、真空度-95 kPa、切片厚度3.1 mm,所得产品色差值、总糖含量、脆度分别为3.42、50.51 mg/100 g、464.96 g,产品色泽白亮,酥脆可口,马蹄风味浓厚。低场核磁共振检测结果表明:马蹄片内部主要存在3种状态水,分别是自由水、不易流动水及结合水,其中自由水占比较高、结合水和不易流动水的比例相对较低,在最佳工艺下到达干燥终点时自由水完全除去,只剩少量的不易流动水以及结合水。

XC水厂硝酸盐去除应急工程实例

QX市XC水厂的水源水出现季节性硝酸盐含量超标,为保障当地居民的饮用水安全,降低了水体中的硝酸盐含量,水厂采用“硝酸盐选择性离子交换复合深度处理+再生废水安全处置及回用系统”的工艺改造方案,出水硝酸盐质量浓度保持在3 mg/L以下。该系统对水体中氨氮、有机物和浑浊度有一定的去除,对溶解性总固体(TDS)、pH等水质指标基本没有影响,处理出水完全满足我国现行生活饮用水卫生标准的所有要求。改造工程每吨水的处理成本约为0.4元,兼具高效性与经济性,可为同类型水厂的改造提供借鉴。

S油田注水站站场改造和工艺优化整合效果研究

随着油田的进一步开发,注水系统水、聚驱注水站的界限将逐步被打破,单座注水站运行负荷率低,深度水和普通水注水站合建效益越发明显。通过对结合产能工程已完成改造的南十和新南十注水站进行效果评价,提出在满足改造对所辖注水管网的压力损耗影响较小的前提下,对S油田两站之间距离近、建成时间长、设备腐蚀和老化严重的8座注水站的站场采取改造和工艺优化整合措施,改造及优化后,整体核减站场4座、优化岗位用工40人,达到减员增效、降低注水单耗的目的。该项研究对其他采油厂完成注水站站场改造和工艺优化整合工作具有重要的借鉴意义。