反渗透专用阻垢剂TJRO101的阻垢性能

反渗透专用阻垢剂的阻垢效果可通过反渗透的动态模拟实验来评价.反渗透装置以“周期性浓缩的全循环模式“运行,使浓水侧的饱和指数逐渐增大,碳酸钙和硫酸垢的结垢趋势逐渐增加,RO的总回收率也逐渐提高.碳酸钙和硫酸垢的沉积使得溶液的组成改变,并以此评价阻垢剂的阻垢效果.对新型反渗透专用阻垢剂TJRO101、传统反渗透阻垢剂SHMP及King Lee的PTP2000的动态模拟实验表明,TJRO101对CaCO3,CaSO4,BaSO4,SrSO4垢有极其优良的阻垢性能,是一种多功能的反渗透专用阻垢剂.     

反渗透阻垢剂的合成、应用及机理研究进展

投加阻垢剂是解决反渗透(Reverse osmosis,RO)膜结垢问题简单有效的方法。综述了RO系统中阻垢剂的合成应用、阻垢特征、机理及存在问题。含磷类阻垢剂因导致水体磷污染已经基本被其它几类阻垢剂替代,绿色环保类阻垢剂在阻垢效果和可降解性方面均比聚合物类好。但任何阻垢剂单独使用都难于满足(RO)系统阻垢的实际需求,阻垢剂的复配可相互弥补单一阻垢剂的缺陷,同时发挥其协同效应,而阻垢剂的特征改性具有更强的针对性和适用性。因此,阻垢剂的复配和改性是其研究的趋势和重点。     

反渗透膜阻垢剂投加量优化及其阻垢性能评价

针对亦庄某再生水厂反渗透系统投加的AntarcticaTM ROSD 9000型号阻垢剂,考察其对RO系统的适用性和最佳投加浓度.模拟了反渗透生产系统,计算回收率75%及实际进水水质下的结垢倾向,结果表明,反渗透浓水侧仅有Langelier饱和指数超过结垢倾向控制指标,CaCO_3结垢倾向明显,有必要适量投加阻垢剂.模拟不同变量条件下的系统安全性,指导实际生产.采用中试装置进行极限碳酸盐硬度试验,证明加药量在2.5～3.0 mg/L时较合适,即系统运行压力无明显变化,RO浓水侧无结垢倾向;加药量在2.0 mg/L不利于系统稳定运行.经实际生产系统验证,投药量在2.5～3.0mg/L时系统运行安全,反渗透清洗频次降低,阻垢剂占系统运行所用生产药剂成本的60%,有效地控制了成本.     

反渗透浓水预处理对气隙式膜蒸馏性能的影响

针对含有Ca2+、Mg2+及SiO32-的反渗透(RO)浓水,提出了化学除硬→絮凝沉淀→离子交换→超滤处理的新型预处理流程.研究了该预处理方法对RO浓水中易结垢离子的去除效果,及其对气隙式膜蒸馏(AGMD)性能的影响.实验结果表明,经过该预处理过程后Ca2+、Mg2+和SiO32-的含量均低于5mg/L.与常规的除硬处理不同,经过该预处理过程后,RO浓水中的难溶盐CaCO3、Mg(OH)2均未达到饱和,进行膜蒸馏浓缩时,不会立即在膜表面沉积.经预处理后,原RO浓水中的主要成分为NaCl,其可在膜蒸馏浓缩得到结晶固体.未经预处理的RO浓水浓缩7倍时,产水通量衰减了40.55%,电导率增大了22.71%,CODCr含量为40~60mg/L;对于预处理后的浓水,该衰减程度减小24.02%,且产水电导率保持相对稳定,COD含量低于10mg/L,产水可以用作工业循环冷却水和工业洗涤水,经活性炭吸附后可用作锅炉用水.预处理后的RO浓水进入AGMD装置浓缩168h,产水通量衰减缓慢,产水电导率一直维持在5μS/cm以下,整个过程中COD均小于10mg/L.     

绿色阻垢剂在开放式换热器中的抗垢强化传热性能研究

针对一种蒸发式冷凝器系统换热器盘管表面的易结垢现象，采用高精度摄像仪观察法、红外温度摄像仪及热电偶温度测量手段，对绿色阻垢剂（聚天东冬氨酸PASP）抗垢强化传热性能进行了实验研究。结果表明，在管内放热实验中，采用绿色阻垢剂后的管表面温度平均比污垢管表面温度高4～8℃，前者喷淋循环冷却水温度升高基本维持在0．5～0．6℃／min的水平，而污垢管实验中喷淋循环水温升维持在0．3～0．4℃／min的水平。说明在循环水中加入绿色阻垢剂后，污垢热阻大大减少。     

石化企业循环水处理现状及发展趋势

循环水处理技术直接对石化企业的经济效益产生直接影响,严重时会迫使装置停止运行。本文对石化企业循环水处理现状进行了分析,得出循环水处理面临着易腐、结垢、泄漏等情况,今后石化企业循环水处理将会朝循环水浓缩倍数和药剂配给方面研究发展,减轻循环水的对企业的值害。     

阻垢剂阻垢性能及阻垢机理的研究进展

使用阻垢剂是解决工业水处理系统结垢问题最高效实用的方法之一.对比分析了不同类型阻垢剂的阻垢性能,并从螯合增溶、分散吸附、畸变作用和几何匹配等方面阐述了阻垢剂的阻垢机理,可为未来阻垢剂阻垢性能和阻垢机理的发展提供借鉴.     

复合缓蚀阻垢剂对模拟循环冷却水中Q235碳钢的缓蚀与阻垢性能

为寻找性能更优的缓蚀阻垢剂,采用静态失重、静态阻垢、电化学测试、X射线粉末衍射(XRD)、扫描电镜(SEM)等方法,研究了聚环氧琥珀酸(PESA)、羟基乙叉二膦酸(HEDP)及其复合物对模拟循环冷却水中Q235碳钢的缓蚀与阻垢性能。结果表明:复合缓蚀阻垢剂对Q235碳钢的缓蚀率和阻垢率均达到90%以上,其缓蚀、阻垢性能明显优于单组分PESA和HEDP;复合缓蚀阻垢剂是以抑制阴极反应为主的缓蚀剂,能很好地发挥各组分间的协同作用,在碳钢表面形成保护膜,抑制其在循环冷却水中发生腐蚀;复合缓蚀阻垢剂有助于Ca CO3垢样的分散和球霰石晶型的形成,起到较好的阻垢分散作用。     

模拟油田地层水环境中套管钢的结垢规律及防垢剂的选用

集输系统结垢制约了油田开采,注水管线形成的水垢增大了水流阻力和注水能耗,导致管线出现局部腐蚀。模拟油田地层水环境,研究了pH值、温度、盐含量、CO2分压对套管钢结垢规律的影响,并筛选了合适的阻垢剂以有效防止套管钢的破坏、失效。结果表明:套管钢的结垢速率随pH值增大、温度升高、CO2分压增大而增加,随盐含量增加而减小;具有防腐蚀、阻垢双重作用的阻垢剂能更有效地保护套管钢,减缓或避免其发生腐蚀和结垢。     

循环冷却水自动排污自动加药控制系统的设计开发及应用

本文探讨了循环冷却水的电导率与总溶固含量、浓缩倍数之间的关系,并根据它们之间的正比关系,用于控制循环冷却水的浓缩倍数;用电子脉冲水表对排污量或补充水量进行计量,并用于控制缓蚀剂,阻垢剂的投加,以时间为参数控制杀菌灭藻剂的投加,从而实现排污和加工自动化。     

La/FeOOH@PAC对反渗透浓缩液中有机膦酸盐阻垢剂HEDP的吸附性能研究

在反渗透脱盐过程中, 为了避免矿物质结垢广泛使用膦酸盐阻垢剂, 但这会对环境和浓缩液脱硬度产生不利影响, 需要在反渗透浓缩液处理前去除膦酸盐阻垢剂。本工作以活性炭(PAC)为载体, 采用共沉淀法制备了含有氢氧化镧与羟基氧化铁的复合材料(La/FeOOH@PAC), 利用La/Fe的协同作用提高吸附剂的吸附性能。采用不同手段对复合材料的结构和表面性质进行了表征, 并研究了其对模拟反渗透浓缩液中膦酸盐阻垢剂HEDP的吸附行为和性能, 考察了镧铁摩尔比、吸附时间、HEDP浓度和温度对其吸附性能的影响。实验结果表明: 制备的复合材料在298 K、pH=8.0和吸附剂用量为0.4 g/L的条件下, 其吸附等温线符合Langmuir模型, 理论最大吸附量为65.359 mg·g^-1, 吸附动力学可用拟二级动力学方程来描述, 同时吸附过程为自发放热过程。XPS分析表明吸附剂的主要吸附机理为与镧/铁连接的羟基基团和HEDP之间的配体交换作用。     

反渗透系统的性能变化分析及量化评价方法

如何对反渗透系统运行的综合性能进行评价,在实践中往往由于影响的因素多种多样,而且环境条件也发生变化,掌握运用其实并不是容易的．针对具体工程情况,在参考有关文献的基础上,提出了运行指标归一化处理的概念和计算方法．实践证明：这种方法是一反渗透系统进行更加科学管理的手段和量化方法．并还对反渗透系统运行中产水量和脱盐性能的变化进行了分析,列举了可能的各种原因;对影响膜组件的污染因素进行了说明,并提出膜组件污染现象和清洗方法．     

反渗透、纳滤膜及其在水处理中的应用

对反渗透和纳滤膜元件在国内外的发展过程，应用领域和应用现状进行了综述，认为反渗透和纳滤膜应用在全国乃至全世界均处于高速成长期，具有广泛的应用前景．但同时指出应及时总结目前的应用情况，开发潜在的应用领域，加强技术的国产化，确保该技术的良性高速发展．     

Optimization by random search with jumps

We give a random optimization (RO) algorithm to optimize a real‐valued function of n real variables. During the optimization process, interpolation points are examined to follow valleys, and jumps to new starting points are executed to avoid numerous iterations in local minima. Convergence with probability one to the global minimum of a function is proved. The proposed RO method is a simple, derivative‐free and computationally moderate algorithm, with excellent performance compared to other RO methods. Seven functions, which are commonly used to test the performance of optimization methods, are used to evaluate the performance of the RO algorithm given here. Copyright © 2004 John Wiley & Sons, Ltd.     

Experimental evaluation of velocity and power estimation forultrasound blood flow imaging, by means of a two-dimensionalautocorrelation approach

This paper evaluates experimentally the performance of a novel axial velocity estimator, the 2D autocorrelator, and its Doppler power estimation counterpart, the 2D zero-lag autocorrelator, in the context of ultrasound color flow mapping. The evaluation also encompasses the well-established 1D autocorrelation technique for velocity estimation and its corresponding power estimator (1D zero-lag autocorrelator), to allow performance comparisons under identical conditions. Clutter-suppressed in vitro data sets from a steady-flow system are used to document the effect of the range gate and ensemble length, noise level and angle of insonation on the precision of the velocity estimates. The same data sets are used to examine issues related to the estimation of the Doppler signal's power. The first-order statistics of power estimates from regions corresponding to flow and noise are determined experimentally and the ability of power-based thresholding to separate flow signals from noise is characterized by means of ROC analysis. In summary, the results of the in vitro evaluation show that the proposed 2D-autocorrelation form of processing is consistently better than the corresponding 1D-autocorrelation techniques, in terms of both velocity and power estimation. Therefore, given their relatively modest implementation requirements, the 2D-autocorrelation algorithms for velocity and power estimation appear to represent a superior, yet realistic, alternative to conventional Doppler processing for color flow mapping     

Chaotic Whale Optimized Fractional Order PID Controller Design for Desalination Process

The main aim of this work is to design a suitable Fractional Order Proportionl Integral Derivative (FOPID) controller with Chaotic Whale Optimization Algorithm (CWOA) for a RO desalination system. Continuous research on Reverse Osmosis (RO) desalination plants is a promising technique for satisfaction with sustainable and efficient RO plants. This work implements CWOA based FOPID for the simulation of reverse osmosis (RO) desalination process for both servo and regulatory problems. Mathematical modeling is a vital constituent of designing advanced and developed engineering processes, which helps to gain a deep study of processes to predict the performance, more efficiently. Numerous approaches have been employed for mathematical models based on mass and heat transfer and concentration of permeable flow rate. Incorporation of FOPID controllers is broadly used to improve the dynamic response of the system, at the same time, to reduce undershoot or overshoot, steady state error and hence improve the response. The performances of the FOPID controller with optimization is compared in terms of measures such as Integral Time Absolute Error (ITAE) and Integral Square Error (ISE). Simulation results with FOPID on desalination process achieved rise time of 0.0311 s, settling time of 0.0489 s and 0.7358% overshoot, better than the existing techniques available in the literatures.     

Safety system consideration of a supercritical-water cooled fast reactor with simplified PSA

The probabilistic safety of the supercritical-water cooled fast reactor (SCFR) is evaluated with the simplified probabilistic safety assessment (PSA) methodology. SCFR has a once-through direct cycle where all feedwater flows through the core to the turbine at supercritical pressure. There are no recirculation loops in the once-through direct cycle system, which is the most important difference from the current light water reactor (LWR). The main objective of the present study is to assess the effect of this difference on the safety in the stage of conceptual design study. A safety system configuration similar to the advanced boiling water reactor (ABWR) is employed. At loss of flow events, no natural recirculation occurs. Thus, emergency core flow should be quickly supplied before the completion of the feedwater pump coastdown at a loss of flow accident. The motor-driven high pressure coolant injection (MD-HPCI) system cannot be used for the quick core cooling due to the delay of the emergency diesel generator (D/G) start-up. Accordingly, an MD-HPCI system in an ABWR is substituted by a turbine-driven (TD-) HPCI system for the SCFR. The calculated core damage frequency (CDF) is a little higher than that of the Japanese ABWR and a little lower than that of the Japanese BWR when Japanese data are employed for initiating event frequencies. Four alternatives to the safety system configurations are also examined as a sensitivity analysis. This shows that the balance of the safety systems designed here is adequate. Consequently, though the SCFR has a once-through coolant system, the CDF is not high due to the diversity of feedwater systems as the direct cycle characteristics.     

A systematic approach to analysing errors of commission from diagnosis failure in accident progression

The accident scenarios of a nuclear power plant are composed of an initiating event (IE), additional events/failures and human inappropriate actions, the combinations of which lead to irreversible consequences. In such a dynamic situation, operators should diagnose the occurring events/failures (including an initiating event and additional events) and assess the related situations utilising the available resources such as operating procedures or human–machine systems to control and maintain the plant in a stable condition. The misdiagnosis or diagnosis failure of the occurring events could cause critical human inappropriate actions that aggravate the plant condition, which is termed as errors of commission (EOCs). This paper presents a methodology for analysing the potential for diagnosis failure of the initiating and additional events and the consequent EOC events, based on the operating procedures, in the accident scenarios of nuclear power plants. The method to be presented categorizes the diagnostic situations in the accident scenarios into three cases according to the structure of the emergency operating procedures (EOPs) and the time of the occurring events: (1) the diagnosis of an initiating event, (2) the diagnosis of both an initiating event and an additional event when an additional event occurs prior to the performance of the diagnosis procedure, and (3) the diagnosis of an additional event when an additional events occurs after the performance of the diagnosis procedure. The application of the method is illustrated through three case example scenarios: (1) the power-operated relief valve (PORV) or the pressurizer safety valve (PSV) LOCA, (2) the loss of all feedwater (LOAF) event (loss of main feedwater*loss of auxiliary feedwater), (3) the sequence of<the station blackout (SBO)*loss of turbine-driven (or diesel-driven) auxiliary feedwater*PSV stuck-open*recovery of AC power>.     

基于层次结构的给排水工程CAD自动成图

为实现建筑工程中给排水系统图的计算机辅助设计自动成图，分析了给排水系统图的成图规律，确定了数学模型，用层次结构组织成图数据；采用面向对象的方法，构造给排水元件对象库；进而编制CAD成图软件，正确地描述了给排水专业系统图的成图规律。