埋地聚乙烯管冬季施工技术的探讨

聚乙烯低温下容易变脆,易折的缺点,使得冬季施工中较难达到质量要求,这是一个值得探讨的课题。     

管缝锚杆支护技术在井巷施工中的应用

通过对管缝锚杆支护的技术原理、特点和相应理论的介绍,结合羊角尾萤石矿基建工程的实际应用情况,证明管缝锚杆支护具有工艺流程简单、无需锚固剂、成本低廉、维护量小的优势,在井巷施工过程中发挥着超前控顶、防止冒顶片帮事故的重要作用,对现代化高效率、本质安全型矿山建设具有积极意义。     

埋地聚乙烯管寒冷地区施工技术的探讨

聚乙烯管在低温下易脆、易折的缺点 ,使得聚乙烯管在寒冷地区冬季施工中必须采取相应的技术保护措施。     

大口径预应力钢筒混凝土管当量粗糙度取值探究

为了探究大口径预应力钢筒混凝土管（PCCP管）当量粗糙度取值问题,以新疆三个泉倒虹吸管（DN2 800 mm）及天津新地河泵站PCCP试验管（DN1 600 mm）为例,通过库尔干诺夫式判别大口径PCCP管水流流态,选用齐恩公式、哈兰德公式计算PCCP管9个典型当量粗糙度对应的多组流量工况下的管道水头损失值,并将计算结果与实测资料做了对比分析。结果表明,新疆三个泉倒虹吸PCCP管当量粗糙度取值范围为0.03~0.07 mm;天津新地河泵站PCCP试验管当量粗糙度取值范围为0.05~0.07 mm;建议大口径PCCP管当量粗糙度取0.10 mm。研究成果为下一步研究奠定了基础。     

尼尔基左岸灌溉管闸门井滑框倒模设计与施工

阐述了滑框倒模模板施工工艺在尼尔基左岸灌溉管闸门井工程中的应用,提出了合理的模板设计方案,并通过对该方案施工全过程的介绍,得出该工艺施工质量好、耗材少、速度快、经济效益高,具有工程实际应用价值。     

后滨沉积地质条件下小型定向钻机铺管施工技术——以厦门环岛路工程为例

结合具体工程,从地质条件、施工前准备、工作坑开挖、导向孔施工、孔径扩大、拉管就位及泥浆配制等方面,阐述厦门环岛路应用小型定向钻机施工技术铺设中400眦n污水管施工过程.     

干料打结工频炉衬的材料与施工

一、概述现代大型铸造车间为满足铸件生产质量的要求和适应大批量生产的需要,已较普遍采用冲天炉—工频炉的双重熔炼工艺。应用工频炉可以贮存铁水、均衡生产、均匀不同炉次的冲天炉铁水成份、提高浇注铁水的温度,特别是在连续生产的浇注线和薄壁体的生产中,更显其良好的作用。     

凝汽器胀管加工胀管率计算公式与胀管率值的控制

电厂中凝汽器冷凝管胀口产生泄漏问题的直接原因是欠胀,胀管率确定的准确与否直接关系到其胀管质量。将最常用的胀管率公式推荐出来,以便加工中直接选用,同时从实践和理论上分析了这些公式的适用范围,并且详细论述了在应用中如何保证胀管质量。     

内衬管对U型辐射管表面温度分布的影响

通过FLUENT软件,对U型辐射管内的燃烧与传热过程进行了三维数值模拟。研究了内衬管相对位置对辐射管表面温度分布以及烟气中污染物含量的影响。结果表明:当内衬管相对燃烧室距离40～60 mm时,管内燃烧与传热情况较好;烟气中NO的含量与内衬管位置无明显关系。     

Solarisation of a seed drier in Mauritius

Drying agricultural food crops is very energy intensive. In Mauritius, much precious foreign exchange is imported annually for the sole purpose of drying crops in conventional industrial driers. The aim of this project is to investigate the technological and economic feasability of utilising solar energy to dry food crops. It is proposed to design, construct and test a solar system to be integrated to a conventional drier: the roof top, made of corrugated iron sheets, of the building housing the batch drier has been converted into a solar preheater.A mathematical model has been made. After its validation by comparison with experimental measures, it is possible to optimize the design of the solar roof.     

Unveiling the solar resource potential for photovoltaic applications in Mauritius

Mauritius is considered to have high solar resource potential but it has not yet been fully quantified and exploited due to the lack of valid solar energy data. This paper unveils the solar potential of Mauritius. Ground-based measurements were performed at intervals of 30 s in order to obtain accurate global horizontal irradiance data which can depict all changes in solar power. The latter is used to evaluate average monthly global horizontal irradiance, maximum irradiance, monthly average insolation and monthly sky clearness index. A solar geometry model was used to define the average monthly, seasonal and yearly maximum elevations and extraterrestrial radiation. Measurement data were compared to Meteonorm and NASA SSE 3-hourly averaged solar data. Comparison shows that average irradiance values are in good agreement, whereas insolation and sky clearness values obtained from external sources are inferior to high quality measurement data. The results, presented in this paper, complement solar data of Meteonorm and NASA SSE and secondly, provides PV and solar engineers as well as scientists with highly valuable information on the solar resource of Mauritius that can be used during planning and design of PV systems as well as for conducting further research in Mauritius and surrounding regions.     

Thermal impact of the products pipeline on the crude oil pipeline laid in one ditch – The effect of pipeline interval

Numerical simulations are carried out to study the thermal impact of the cold products pipeline on the hot crude oil pipeline of the steady state. The pipelines studied are those used in the West Pipelines in China. The physical properties of North Xinjiang crude oil and those of 90# gasoline were used in this study. The effect of pipeline interval on the thermal impact is studied in details at various conditions.     

Forecasting of peak electricity demand in Mauritius using the non-homogeneous Gompertz diffusion process

In this study, the non-homogeneous Gompertz diffusion process (NHGDP) is used to model the monthly peak electricity demand in Mauritius in order to predict the future values on the basis of a Genetic Algorithm (GA) approach. Our model is developed based a key economic indicator which is the gross domestic product (GDP) and the weather factors such as temperature, hours of sunshine and humidity. Genetic Algorithm then searches for the best coefficients by minimizing the root mean square error. Monthly data from January 2005 to December 2008 are considered to test the model. Finally, the Artificial Neural Network (ANN) is used to forecast each independent variable for the year 2009 and the NHGDP model is validated for that year. Our results show that the model provides an accurate and reliable prediction for the monthly peak electricity demand in Mauritius.     

Extended sugarcane biomass utilisation for exportable electricity production in Mauritius

The availability and exportable electricity-production potential of bagasse and sugarcane residues are estimated for various technologies which determine steam production and utilisation at cogenerating sugar factories. Almost 565 kg of fibrous sugarcane biomass (expressed as kilogrammes of bagasse at 50% moisture) are potentially available for exportable electricity production for every tonne of cane milled. A “bagasse proper only” strategy would utilise 28% of the fibrous cane biomass and can potentially produce between 60 to 180 kW h of electricity per tonne of millable cane. Use of cane tops and leaves as a bagasse extender would utilise another 32% of the sugarcane biomass and the electricity output could range between 146 and 401 kW h/t of millable cane. The extreme case where 100% of the fibrous sugar cane biomass is utilised has the potential of producing up to 678 kW h/t of millable cane.     

北干二级站集水井施工

利用液压反铲,在流沙地基上快速开挖集水池基础,并及时浇筑防渗体混凝土获得成功,阻挡了流砂大量向基坑内涌进,确保了集水池的顺利施工。     

P-wave检测PCCP管断丝原理的三维数值仿真

预应力钢筒混凝土管道在服役期间会由于钢丝断裂而引发爆管,影响管道的使用寿命。P-wave是检测大口径PCCP管断丝的重要方法,采用三维电磁场有限元方法,仿真P-wave检测E型PCCP管道。对于有阴极保护钢带的E型管道,根据检测信号幅值和相位的变化规律可以确定非钢带处断丝的数量和轴向位置,结合PCCP的受力特征,判定断丝的环向位置。同时通过敏感性分析,探究了P-wave的检测原理,P-wave借助屏蔽盘隔绝直接耦合分量,使得激励场垂直穿过管壁,在钢丝内激发出涡流效应,从而实现近场检测;发生断丝时钢丝断口附近电流密度下降,导致感应磁场分布发生变化,检测信号的幅值和相位也随之变化。该研究为大口径PCCP管断丝检测实际应用提供了理论依据。     

Strategies for augmenting sugarcane biomass availability for power production in Mauritius

Field biomass productivity has a direct bearing on the electricity production potential of sugarcane bio-energy systems. Inclusion of cane tops and leaves (CT and L) and trash in the fuel chain can potentially boost the field biomass productivity. The results of field assessments carried out in Mauritius indicate that fresh CT and L occur at the rate of 31.3% of that of fresh cane with a moisture content of 69%. Cane trash, with a moisture content of 19.3%, represents 10.2% of fresh cane weight. On a bagasse equivalent basis, the inclusion of CT and L in the fuel chain has the potential to increase bagasse production by a factor of 1.62. The inclusion of trash in the fuel chain can potentially boost bagasse production by a factor of 3.25.     

三个泉倒虹吸预应力钢筒混凝土管沿程水头损失计算分析

针对三个泉倒虹吸过流量富余的问题,基于工程特点及其水力设计方法,借鉴大口径钢管和预应力钢筒混凝土管(PCCP管)当量粗糙度的取值,根据雷诺数与相对粗糙度,结合莫迪图判别分析了大流量工况下倒虹吸管道水流流态,在此基础上,利用齐恩公式、海曾—威廉公式、谢才公式分别计算了三个泉倒虹吸水头损失值,并与实测资料进行对比分析。结果表明,随着管径增大,管壁光滑程度增加,使得PCCP管内水流处于紊流过渡区而非阻力平方区,因此不应选用谢才公式,而这正是导致三个泉倒虹吸过流能力与设计标准不符的主要原因。此外,发现齐恩公式、海曾—威廉公式适用于大口径有压PCCP管沿程水头损失计算。