衡水电厂3B给水泵汽轮机转速摆动原因分析

给水泵小汽轮机的转速摆动是给水系统中常见的问题,引起的原因有测量不准、PID参数整定不当、伺服系统故障等多个方面。介绍了衡水电厂3B给水泵汽轮小机转速摆动故障的分析解决过程,分析了EH油质对电液伺服系统的重要性,提出了相关检修维护注意事项。     

Chemical Behaviour of Calcium in Stabilized Oil Ash Reef Blocks After Five Years in the Ocean

Abstract

Reef blocks made from stabilized oil ash were taken from the sea after five years in the ocean to examine the chemical behaviour of calcium. Experiments included (1) determination of the calcium leaching rate and a comparison with the rate for unexposed blocks to test the validity of a diffusion model for predicting long term (5 years) leaching rates, (2) determination of the effect of biological cover (shell) on the leaching rate, (3) determination of the leaching rate of the core of exposed reef blocks, (4) determination of the calcium content in ‘ring areas’ - regions of discoloration observed in sectioned exposed reef blocks, and (5) determination of the leachable fraction of the total calcium in exposed reef blocks. Results showed the presence of a pronounced calcium discontinuity zone located 3–7 cm from the outside surface of the reef blocks. Cumulated calcium release rates ranged from 2.81–3.14 μmol cm^?2 day^?1 for original unexposed reef blocks and the core of exposed (in the ocean for five years) blocks, respectively, to 0.47–0.50 μmol cm^?2 day^?1 for outside (facing sea water) surfaces of exposed reef blocks. Tank leaching studies also showed that the presence or absence of hard biological cover (shells) had little or no effect on the calcium release rate. the diffusion model normally used in modelling the chemical behaviour of calcium cannot be used to predict the long term (five years) leaching of calcium. the core of the exposed blocks released calcium at a rate similar to new, unexposed reef block material. Overall, it appears that the calcium discontinuity zone is probably responsible for restricting the release of calcium and hence the failure of the diffusion model.     

Analysing household decision-making on oil palm cultivation in Thailand

This paper analyses the dynamics of land use via the perspectives, motivations and behaviours of local landowners looking at land-use change (through the landowner’s eyes) in the way that the landowners would prefer to do and not to do in various situations. The dynamics are explored in the context of an oil-palm-based biodiesel development in Thailand where the advent of oil palm (OP) has caused the loss of paddy areas. A sequential mixed-method strategy, including 10 in-depth interviews and 180 responses to a questionnaire survey, indicates that the likelihood of a landowner switching traditional land for OP cultivation is affected by a number of factors including age and education of the head of household, number of household farming labourers, amount and source of income, land size and land right. Moreover, the results indicate that success of switching land to OP cultivation was determined by factors influencing willingness and capacity to change. Willingness-related factors are relevant to outcome expectation and social networks and connections while capacity-related factors are relevant to finance, labour, capital, land rights and transportation.     

加强农药的环境管理刻不容缓

介绍和分析了农药对我国生态环境污染与危害的现状。指出造成我国农药环境污染严重的重要原因是缺乏必要的环境监督管理 ,研究制定出符合我国国情的农药污染控制政策与措施已经刻不容缓     

供电企业面向作业危险辨识方法研究

在对供电企业生产特点分析的基础上,以作业项目为研究对象,通过事故逆推法、调查问卷法和访谈法等多种方法确定供电企业危险检查表,共计19类118项;并建立了适用于一线员工使用的危险检查表与工作危害分析(JHA)危险场景描述相结合的危险辨识方法;该方法在太原供电分公司6大专业146个作业项目及1084个工作场景进行应用,实用结果表明:通过员工层控制可达到危险消除或控制的效果。     

废弃酸碱精制实现变压器油清洁生产

利用糠醛精制代替酸碱精制实现变压器油清洁生产，每年减少废渣排放5454t，减少加工损失5454t，取得了良好的环保效益和经济效益。     

城市污水处理厂污泥直接热化学液化处理技术

污泥直接热化学液化技术是国外８０年代开始发展的一项污泥处理兼资源回收技术。它可使污泥中有机质的４０％以上转化为燃料油（热值≥３３ＭＪ／ｋｇ）,相应的有机碳转化率达到９０％左右。整个过程为一能量净输出过程。本文对其发展源流、研究现状和发展前景进行了综述和讨论。     

荧光灯管芯柱玻璃中金属铅的机械化学硫化

以硫化钠为硫化剂,机械化学硫化荧光灯管芯柱玻璃中金属铅,实现金属铅向硫化铅快速转化.通过单因素实验,考察了不同机械化学硫化条件,即球磨时间、球磨转速和球料比对硫化率的影响,并通过XRD、SEM和粒度对硫化产物进行表征.结果表明,硫化率随球磨时间和球磨转速的增大而增大,随球料比的增大先增大后减小,当球磨转速为750r/min、球磨时间为120min、球料比为50：1g/g时,荧光灯管芯柱玻璃中金属铅的硫化率可达96.18%.XRD结果表明,荧光灯管芯柱玻璃中金属铅的机械化学硫化产物为PbS、SEM和粒度结果表明,荧光灯管芯柱玻璃的粒径随球磨转速和球磨时间的增加而减小.     

油田储油罐非甲烷总挥发实验及仿真模拟

针对油田单井拉油罐非密封生产带来的油气泄漏问题,建立小型原油储油罐挥发损耗实验模拟平台,通过气相色谱法探究各因素对其损耗的影响,利用Fluent仿真软件模拟储油罐的泄漏扩散。结果表明:储液温度和有无风环境对储油罐非甲烷总烃(NMHC)挥发影响较大,储液高度和环境温度对其影响较小;仿真模拟无风环境下,储油罐泄漏口短时间内存在油气积聚现象;有风环境下,当风速为1 m/s,油气积聚不明显;随风速增大,扩散浓度场面积不断增大,油品损耗量增大,在风速为5 m/s的环境下,扩散300 s时的浓度场面积相比扩散200 s时较小,但泄漏口处的油气积聚面积增大。     

城市高温灾害及其预防

本文通过实例阐述了大城市高温灾害的主要成因是热岛效应；分析了高温对工业生产、人民生活的影响和危害，进而提出了城市高温灾害的预防措施和对策。