水处理论文污水处理论文纯水制取系统在“电厂化学水处理”教学中的应用摘要：“电厂化学水处理”的课程实践性很强，大部分都是关于设备的原理、结构和运行操作的内容，学生缺乏感性认识很难理解。
本文以纯水制取系统为模型，结合水处理教学设计一些教学环节，能帮助学生快速掌握电厂水处理常见设备的结构与运行，有助于学生弄懂水处理设备运行的详细过程，对水处理的教学起到了积极促进作用。
关键词：电厂化学；水处理；纯水系统；教学设计电厂化学专业是哈尔滨电力职业技术学院（以下简称“我院”）的传统专业，旨在培养适应国家电力行业发展的专业水处理人才，而作为其专业课的“电厂化学水处理”的教学显得尤为重要。
“电厂化学水处理”是电厂化学专业的核心课程之一，由于这门课实践性很强，就净水内容来讲，大部分都是关于设备的原理、结构和运行操作的内容。
由于学生缺乏对现场设备和环境的感性认识，很难去理解和对照。
如何让学生在学习过程中有形象、具体的认识是急需解决的问题。
我院电厂化学专业引进了超纯水制取系统，作为模型模仿火力发电厂水处理的制取过程。
一方面可以对学生进行理论与实践教学，有助于学生弄懂水处理设备运行的详细过程，进行操作和故障处理；另一方面该系统制取的纯水还可供实验室使用，减少了实验室采购蒸馏水的费用。
一、纯水制取系统简介我院电厂化学专业采用的是某公司UPDROMB-500L纯水供水系统，产水量为500 L/h，其主要净水工艺如图1所示。
主要出水指标电阻率≥18MΩ·cm（25℃）；SiO2≤20μg/L，符合锅炉给水要求。
二、纯水制取系统在“电厂化学水处理”教学中的应用1.纯水系统原水水质分析和教学的结合，模拟电厂的原水水质分析本纯水系统采用的处理对象为地下水，利用水质分析实验对地下水的指标进行了化验，模拟电厂的原水水质分析展开，由于实验室正在建设，能开展的常规项目见表1。
具体的取样地点为原水水箱，在系统中增设了5处取样点，进行主要项目的化验。
严格按照GB／T 6903—2005锅炉用水和冷却水分析方法通则和火力发电厂水汽分析方法中的方法进行测定。
2.纯水系统预处理工艺与教学的结合（1）预处理系统的选择和教学的结合。
目前，火力发电厂的补给水预处理工艺主要为：混凝→澄清→ 过滤。
结合纯水制取系统，启发学生思考，我们的预处理为什么这样设定？可以结合火力发电厂化学设计规范中的内容讲解，在系统的选择上，设计问题启发学生结合学过的知识思考。
比如本系统预处理有什么缺欠，针对这个缺欠怎样改进。
结合现有的纯水制取系统中的预处理工艺进行比较教学。
本系统采用的是石英砂过滤和活性炭过滤，根据原水是地下水的特点，含铁锰等金属离子较多，设计中少了除铁过滤器，这个问题让学生自己去发现和总结。
学生学习过了预处理系统的选择要求后，自然很容易发现这个设计问题。
如果不加除铁过滤器，还可以怎样进行呢？有的学生建议，把石英砂过滤器改造成除铁过滤器，即把石英砂滤料更改为锰砂滤料；有的建议在原有的流程上增加除铁过滤器，这样就达到了启发学生的目的，同时也提高了学生分析解决问题的能力。
（2）预处理工艺中主要设备操作及故障处理与教学的结合。
设备的运行和故障处理历来都是水处理教学的重点，以本系统为例，预处理的主要设备有石英砂过滤器和活性炭过滤器，而这两个设备是电厂化学中最重要的两个设备。
结合现有的石英砂过滤器开展以下项目：压力测量；流量测量；石英砂滤料的粒度筛选和装填，根据筛分分析方法选择粒度范围在0.35～3.0mm的石英砂作为过滤材料，让学生自己筛分和装填；运行操作及指标监督。
失效监督：根据出水浊度和进出水压力差两个主要监督指标，结合实验室石英砂过滤器，我们开展了进水出水压力的测量；通过进水和出水的浊度测量，进行数学计算和比较，从而计算出去浊率。
反洗及正洗：在反洗和正洗的教学过程中，让学生自己通过实验摸索最佳反洗水量和时间。
在以上开展的项目中，都要求学生做好数据记录。
经学生实验摸索，让他们亲自确定石英砂过滤器和其运行的最佳条件，教学效果较好。
3.除盐工艺中主要设备操作及故障处理与教学的结合（1）除盐系统的选择要求与教学的结合。
本系统采用的除盐系统为RNa→一级、RO→二级、RO→H/OH；针对地下水硬度大的特点，采用了软化装置，二级反渗透作为预脱盐，抛光混床作为末端处理，本系统的出水可以作为实验室用水。
启发学生去思考为什么选择这样的系统，可以结合火力发电厂化学补给水关于除盐的设计部分进行教学，既有直观的感性认识，又可以让学生尽快掌握火力发电厂除盐设计的一些基本要求和注意事项。
除盐系统另外典型的流程为：H→C→OH→H/OH，可以进行比较教学，引导学生思考两种流程的差异，这样就可以结合纯水系统使学生更好地掌握复杂难以理解的章节《除盐系统组成原则和除盐工艺选择的要求》的内容。
（2）除盐系统主要设备的操作与故障处理与教学的结合。
除盐系统主要设备的操作是“电厂化学水处理”教学的重中之重。
结合本系统中的软化和二级反渗透装置开展以下的教学设计。
RNa交换器的教学设计：1）运行操作与教学的结合。
以往的教学基本都是图示教学，在黑板上画上离子交换器的管路系统进行讲解，只是平面教学，没有感性认识，脱离实践，如果结合设备效果就会更好。
离子交换器运行操作的几个主要步骤依次为运行、反洗、再生、正洗、备用。
针对这几个步骤，让学生熟悉和掌握各个步骤的意义和阀门开启顺序，通过实际操作去摸索运行及反洗、正洗等步骤的最佳水量和条件，培养优化装置的能力，而不是就规程盲目操作。
2）监督与教学的结合。
常规监督项目为进出口压力差，出水Na+、H（硬度）等。
在设定的取样点进行取样，进行化验和监督。
要求学生严格按照火力发电厂水汽分析方法中的方法进行测定，把这些方法复印给学生，培养自我查资料和准备化学药品的能力。
围绕RNa的再生过程开展再生药剂、盐耗、比耗的计算；摸索最佳再生条件，通过学生亲自计算获得不同周期的盐耗，学生就会主动分析原因。
3）故障设计与教学结合。
故障的设计与处理是水处理教学的重点，也是未来工作时解决问题能力的体现。
而设备的结构和原理只是基础知识，据此结合现有设备设计一些故障，培养学生解决问题的能力，为未来工作做铺垫，具体故障如下。
软水装置不能再生；出现硬水——（模拟电厂软化器实际）；系统用盐过多——（模拟电厂软化器再生盐箱结晶问题）；排水管流出树脂——（模拟电厂软化器配水装置的问题）；盐罐中水过量——（模拟电厂软化器再生液浓度的选择）；出水出现盐水——（模拟电厂软化器运行初期出水不合格）；不能吸盐——（模拟电厂软化器再生喷射器故障）。
以上只是故障中常见的几项，据此分析故障出现的原因，讨论如何解决这些故障，让学生主动分析。
二级RO的教学设计：1）回收率、SDI、脱盐率、ZD、游离氯等常规指标的测定。
反渗透系统的进水指标是十分严格的，而这些指标的教学只是一带而过，如果结合具体的设备，对其中每个进水指标实际测定，可以让学生体验更深。
以SDI值为例，给出资料，让学生自己组建测定装置的微型过滤器，如何选择滤膜及尺寸，通水时间及如何接满500mL水，可以让学生更深刻地理解SDI值测定过程。
2）RO安装及膜组件的选择。
RO相对来说比较抽象，如何让学生更快地理解和掌握，关键在于感性认识，即实践教学。
在纯水系统安装时，我们让学生现场观看，并留有膜组件样品，让学生认识膜组件的外观。
本系统用的是什么样结构的膜组件，结合实物有立体的认识感受更深。
本系统采用的是陶氏化学膜组件，结合膜组件实物，讲解材料和型号的意义。
RO中“级”和“段”的理解很关键，我们从安装时结合膜组件的组合，现场演示水流方向，让学生自己去总结“级”和“段”的意义。
对于为什么前面的段中膜组件数目多而后面的少，这样设计有何优点等问题就相对简化，容易被学生掌握。
3）RO启动过程与教学结合。
结合纯水系统进行反渗透系统的启动教学。
开展的项目有：保安过滤器的滤芯更换（模拟电厂保安过滤器的反洗及更换滤芯）；启动顺序的阀门开启顺序（模拟电厂 RO启动顺序及高压泵操作）；低压冲洗（模拟电厂 RO低压冲洗过程）；不同回收率的调整（模拟RO系统的最佳运行状态调试过程）。
在实际工作中，需要注意的就是高压泵启动之后，如何调节其后的压力控制阀。
应该是缓慢加大，结合RO系统可以让学生亲自操作，从而加深对这一操作过程的印象。
4）运行维护与教学结合。
RO系统的维护和加药等问题对反渗透系统的安全运行起着重要的作用，通过学生对取样点指标的实际测定进行判断是否加药。
4.系统图的绘制根据火力发电厂化学系统图的规定，要求学生根据现场的实物画出具体的补给水流程图，锻炼其手工绘图的能力。
三、结束语以上是纯水制取系统在“电厂化学水处理”教学中应用的几点尝试，其目的是为了提高水处理教学的直观性和易懂性，目前取得的效果较好，但教学的设计较为繁琐同时设备的投资过大，仍在摸索中。
建议在有条件的情况下，可以制作一些除盐制水装置的教学模型，模拟火力发电厂化学补给水系统多种离子交换器的运行和操作，对占传统地位的离子交换器的教学具有极大的帮助。
Water treatment papers sewage treatment papersPure water making system in "power plant chemical water treatment" teaching applicationAbstract: the "power plant chemical water treatment" coursepractice-needed, mostly about equipment the principle, structure and operation content, students lack the perceptual knowledge is hard to understand. Based on pure water making system, integrating with treatment for model design teaching some teaching links, can help students grasp the plant water treatment common equipment, the structure and operation will help students understand water treatment equipment operation, the detailed process of water treatment teaching played a positive role in promoting.Keywords: power plant chemical; Water treatment; Pure water system; Teaching designPower plant chemical specialty is Harbin power professional technology institute (hereinafter referred to as "our"), the traditional professional training to adapt to the national electric power industry to develop professional water treatment talents, and as its professional class "power plant chemical water treatment" teaching is particularly important."Power plant chemical water treatment" is the core of plant chemical professional course of, because this course practice-needed, water purification content speaking, mostly about equipment the principle, structure and operation of content. 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