大流量高扬程雨水泵站设计

泵站作为雨水系统重要组成部分,水泵选型及泵站设计合理与否直接关系到该雨水系统的排水安全。结合具体工程实例,着重探讨了泵站规模确定及大流量高扬程雨水泵站主要设备水泵选型,并介绍了该泵站工艺流程、泵站各工艺构筑物设计功能及设计参数,通过实际运行反馈认为在泵站设计中水泵数量、水泵具体选型、前池及进水流道的设计等对泵站至关重要,直接影响到泵站能否正常、高效运行。泵站压力出水管选用新型管材PCCP,具有施工快捷,防腐性能好等特点,可为实际类似工程提供参考。     

徐州市骆马湖水源地取水泵站水泵选型设计

以徐州市骆马湖水源地取水泵站工程为例,着重介绍水泵机组选型设计。工程通过更换叶轮大小、设置变频调速等方式满足不同工况的要求。详细介绍了设计过程,为以后类似大型取水工程水泵选型提供了借鉴。     

景电灌区取水泵站优化设计方法研究

对景电灌区二期总干一泵站的运行工况计算分析,发现水源最枯水位与最大提水量存在季节差异时,理想工况比实际工况浪费19.09%的提水能力,按现有方法所选水泵超出实际需要,造成水泵机组投资和电能浪费,增大折旧费用和管理运行费用。鉴于此,打破取水泵站传统设计方法,在水源水位和提水量变化时,提出以景电灌区春灌、夏灌所需提水量和提水扬程为控制依据的优化设计方法,为景电灌区取水泵站的节能降耗技术研究提供了参考。     

提水泵站变频调速下多泵运行台数的合理选择

提水泵站是供水系统中最为重要的环节之一,它能否经济运行一直是人们关注的焦点.以由4台离心式水泵组成的某提水泵站为例,首先确定水泵在工频和变频调速下单泵或多泵并联运行合成的特性曲线拟合方法;其次导出适应水源水位变化的开式系统泵的转速、流量、扬程、效率和能耗的计算公式;再通过算例确定多种变工况下水泵的合理运行台数;其结论纠正了人们对在任何工况下水泵运行台数越少越好的习惯认识,也为多泵供水系统的优化运行提供了参考.     

胶东国际机场下穿隧道雨水泵站设计探讨

在胶东国际机场下穿隧道工程雨水泵站的设计中,结合短历时暴雨强度和长历时雨量水文资料,分析确定泵站工艺的主要设计参数,包括泵站设计规模、水泵选型、集水池容积、出水管等。通过提高下游排水管道设计标准与隧道设计标准一致的方式保障隧道出水管排水通畅,可为类似工程提供参考。     

襄阳市庞二雨水泵站工艺设计过程讨论

论述了襄阳市庞二雨水泵站项目实施的必要性,从泵站选址、水泵选型、水泵扬程、雨水量设计标准等方面,阐述了雨水泵站的设计要点,并提出了泵站的防倒流措施,有助于解决该区域的排水问题。     

合理选择多泵运行台数，优化多泵站运行

作为新时期供水系统中最为重要的环节之一,提水泵站的经济运行一直是当前相关领域的研究热点,本文将以4台离心式水泵组成的某提水泵站为例,在工频和变频调速下,结合多泵或单泵并联运行合成曲线拟合方法,并根据此得出沿程、流量、能耗等的计算公式,针对多种变工况下的水泵合理运行台数进行计算,以期能达到优化多泵站运行的目的。     

西江引水工程泵站的设计

介绍了西江引水工程泵站级数、取水泵站及配水泵站的设计情况,对二级和三级泵站加压方案中管道运行压力、经济性及系统控制复杂性进行了分析。泵站级数采用二级,设置取水泵站和配水泵站。从取水头部、前池、水泵配置、水泵调速方案及进、出水管等几个方面介绍了取水泵站的设计要点。从配水泵站加压方式、调节池、水泵配置及进、出水管等几个方面介绍了配水泵站的设计要点。     

提高水泵效率的几项措施

目前 ,用于农田排灌的中小型泵站的水泵效率偏低 ,一般仅为 4 0 %左右。为提高水泵效率 ,经实践证明可采用以下几项措施 :1　合理选型根据水量、水压合理选择水泵型号 ,使水泵的实际工况点处在高效区。同时 ,管路设计、阀门选型也要合理以减小输水阻力。2　设计和安装水泵自动灌水装置吸上式水泵往往需设吸水底阀、止回阀 ,这使得吸水阻力增大 ,并且底阀损坏或密封不严会降低水泵效率。笔者在某一加压泵站的每台水泵的吸水管上设计安装了一个自动灌水装置 ,该装置既能使水泵自动灌水 ,又取消了吸水管段的底阀、滤网和止回阀等 ,减小了吸水阻…     

无锡太湖新城大溪港排涝泵站结构型式选择

结合无锡太湖新城大溪港排涝泵站选型,介绍了城市低扬程大流量泵站的设计思路,详细分析了常用立式轴流机组、新型竖井贯流机组泵站的结构型式,并进行了经济技术比较。竖井贯流泵装置作为一种新的低扬程水泵装置形式,与立式机组相比,具有装置效率较高、设备安装检修方便、土建结构简单、工程投资省等优点,可在低扬程及特低扬程大流量城市排涝泵站推广使用。     

浅析高速公路工程招投标中的最低评标价法

结合目前高速公路施工项目招投标活动的实际情况,阐述了最低评标价法的概念,归纳了其优点及存在问题,对完善最低评标价法提出几点策略,以期促进招标投标市场更加规范有序。     

Place-Making in Megaprojects in Melbourne

This article analyses state-led place-making practices in Melbourne. The two levels of government that influence planning in Melbourne make much of the city as ‘culturally vibrant’ and ‘creative’, and have incorporated creative city-inspired place-making principles into many layers of the planning system. An examination of the development of two mixed-use megaprojects in central Melbourne reveals however that ideals of culturally engaging public places, and indeed of creative landscapes for middle-class consumption, wither in the face of more basic imperatives for economic development. In these case studies the ‘creative city’, no matter how the idea is interpreted, has little traction either as a set of inclusive place-making principles or as a gentrification strategy. The article concludes that the creative city-inspired place-making objectives in the planning system at both state and local levels are ambiguous in their overall intents and completely unsupported by statutory controls. Such place-making objectives as are realised are the compromised results of the interplay of uncoordinated decisions, delivered at the pleasure of the developer.     

Pathogens in septage in Vietnam

Septage is widely acknowledged as a major source of infectious pathogens while disposal of septage, and the operation and maintenance of septic tanks, is not regulated in many developing countries. Twenty untreated septage and septage sludge samples were taken from Can Tho City, Vietnam to examine their pathogen content, and indicator micro-organisms. Escherichia coli and Enterococcus spp. were detected in all samples, regardless of sludge storage time. Phages were detected in 80% of samples. Salmonella spp. were detected in 70% of the untreated septage and 60% of septage sludge samples. Concentrations of phages and bacteria tested in septage sludge after many years of tank storage were much higher than the expected levels. Helminth ova were present in 95% of untreated septage samples with an average of 450 ova l^− 1, and were detected in all septage sludge samples with an average of 16,000 ova l^− 1. Twelve varieties of helminth ova were identified. More helminth ova varieties in higher concentrations were found in septage than those reported from stool samples. The varieties' frequency ranged from 10% to 50% and Ascaris lumbricoides predominated. Results show that pathogens and indicator micro-organisms, especially helminth ova, accumulate in sludge. Thus helminth ova should be considered when septage sludge is treated and used for agriculture. Proper health protection measures must be applied for people handling septage.     

在市场中实践在实践中学习在学习中进步--工程公司市场化进程的回顾与展望

近两年来，工程公司在提高市场竞争意识、推动市场化进程中做了大量工作，其中坚持走出去的方针是我们自我加压、推行加快市场化步伐的一个重要战略步骤。     

新时期广东城市化的新特点

新时期广东城市化出现以下特点:知识源导向、城市由单体向群体化发展、产业集群推动、政府主导自上而下的集约化发展、城镇化向城市化转变、由重“数量”发展向重“质量”发展的转变。     

2005年北京办公物业市场七大趋势

趋势一:CBD区域写字楼集中放量从各区域规划方案上看,CBD区域多数项目在03～04年处于项目的报批手续及拆阶段,预计2005年正式推向市场,因此2005年CBD区域将成为北京市场供应集中的域,区域即将供应的项目有北京财富中心(二期)、金地国际花园、万达广场、SOHO尚都、万通中心、世纪财富中心、怡禾国际中心、光华国际等。除去未知项目,2005CBD写字楼办公面积的供应量为60万平方米左右。中关村区域经过一段时间的集中供后开始逐步放缓,2005年供应的体量相对较大的项目有中关村金融中心、新中关。金街区域可能开盘的项目只有2个:英蓝国际中…     

Developments in immersed tunnelling in Holland

Holland has 22 immersed tunnels (14 road, 5 rail and 3 utilities tunnels). Another three are under construction, and more are foreseen. The tunnels are of the concrete type, i.e., constructed without a steel shell. The paper describes developments in technology and in design philosophy since the first immersed tunnel was completed 52 years ago. These developments include, amongst others: the introduction of the Gina rubber gasket between elements; the division of elements into sections divided by flexible joints; the application (if possible) of longer elements (up to 268 m); the use of precast sections for tunnels that have a small cross-section; the omission of the watertight lining (made possible by cooling the concrete of the walls during the first days after pouring); various foundation methods (e.g., sand flow instead of sand jet system; piled foundations when necessary); the use of the excavation for the open ramps (or the part of the tunnel built on land) as a casting basin for the elements; the changed approach to casting basins now that well pumping is usually forbidden; and the transport of the elements across shallow locations and across the sea. It is emphasized that the current state of immersed tunnel technology is the result of a continuous international exchange of ideas and experiences.     

在加拿大经历严冬

正在加拿大旅居一段时间,感触极深的是这里冬季的严寒与冰雪。冷到什么程度?我所待的萨斯克彻温省,只要有寒流"光顾",白天户外零下三四十摄氏度就是"常温"。2014年2月份一次强寒流来袭,加上风寒指数,当地最低温度竟降至-80℃!记得去年圣诞节聚会,将汽车停在户外不过四五个小时,车轮竟生生冻在了地面上!加拿大的冷,不单纯体现在