饮用水不同类型消毒剂对分质供水管材溶蚀作用研究

在管道分质供水工程中 ,不同类型消毒剂对管材的溶蚀作用缺乏系统研究。选择三种供水管材、三种消毒剂进行对比试验的结果表明 :对于同一种管材 ,不同类型杀菌剂对浸泡水TOC ,VOCs及口感的影响没有明显差别 ,但对于不同类型管材这些指标存在明显差别。纯净水在管道中产生的这些二次污染 ,虽然不足以引起相关水质指标超标 ,但在一定程度上会影响水的口感。建议在管道分质供水设计中 ,应根据所采用的净水工艺选择合适的管材 ,保证管道分质供水的高品质     

寒冷天气条件下珠海市供水管网爆管分析及应对措施

2008年春节前后,珠海市供水管网连续发生爆管事故,对其进行了统计分析。分析认为珠海市寒冷天气DN75以上的供水管道爆管主要发生在接口(焊缝)和管身锈蚀处;低温、管道材质差、锈蚀、刚性接口、管道地基不均匀下沉等是爆管的主要原因。针对不同情况的爆管列出了相应的抢修方法,并提出预防爆管的措施和建议,为及时处理和预防爆管提供科学依据。     

制丝车间的综合管线布置

针对合肥卷烟厂制丝车间各类综合管线布置时出现的管线布置不合理和交叉管线难以布置的问题 ,提出了将管廊布置技术应用于制丝车间的综合管线布置中。通过在制丝车间内部四周敷设管廊 (综合管道架 ) ,将各专业管线在管廊上综合布置 ,并对有些专业管线的敷设位置进行了整合 ,管廊敷设宽度为 3.8m ,高度为 6 .6m。该技术的使用有效地解决了各专业管线打架的问题 ,管线整体布局更加合理 ,节省了空间 ,且安装和检修方便。     

Finite element calculation of contour integral parameters for cracked P91 pipe weld

Abstract

This paper reports the results of elastic–creep finite element (FE) analyses of a P91 steel pipe weld with two external ‘type IV’ circumferential cracks, subjected to internal pressure and end (system) load using creep properties obtained at 650°C. Numerical contour integral calculations have been performed to obtain both transient and stationary high temperature fracture mechanics parameters. A mesh sensitivity analysis was performed in order to ensure the accuracy of FE analyses in the transient creep stage. The effects of load magnitude, the material mismatch near the crack surfaces and the crack depth on the stationary creep C* contour integrals have been investigated, and corresponding analytical correlations are presented.     

景德镇市城市供水工程管材优化选型探讨

结合江西省景德镇市第四水厂城市供水工程实例,提出了利用现有泵站实现最经济、最大规模供水要求的管材选型的思路——以泵站装机、供水量要求为比选条件的管材选型方法.     

富水地层大口径压力输水隧洞暗挖工法比选

通过对浅埋暗挖法、盾构法和顶管法等几种暗挖工法的比选,认为盾构法工艺先进,能够适应工程地质条件,不需要降水,可更好地控制地面沉降,是能够保证施工安全和工期要求的最优工法.     

Thermoelastic Models of Continua

Axially symmetric thermal stresses in an elastic pipe weakened by two cylindrical cracks are provided. The surfaces of the cracks are assumed to be thermally insulated. The outer surface of the pipe is heated to maintain a constant temperature T _d , and the inner surface of the pipe is cooled to maintain a constant temperature T _b . As a first step, the boundary conditions related to the temperature field are reduced to dual integral equations using the Fourier transform technique. To satisfy the boundary conditions outside the cracks, the temperature difference at the crack surfaces is expanded into a series of functions that diminish to zero outside the cracks. The unknown coefficients in the series are determined by the Schmidt method so as to satisfy the thermal insulation inside the cracks. Next, the boundary conditions related to the stress field are reduced to dual integral equations. To solve the equations, the differences in the displacements at the crack surfaces are again expanded in a series of functions that diminish to zero outside the cracks. The Schmidt method is also used to solve the unknown coefficients in the series so as to satisfy the stress-free conditions inside the cracks. The stress intensity factors are defined and calculated numerically for several configurations of the pipe.     

烟气脱硫装置布置及管道设计特点

随着环境问题在全球范围内的日趋突出,世界各国纷纷加大环境治理力度。目前,我国对炼油厂催化裂化装置的废气排放制定了严格的排放标准,烟气脱硫技术的应用很好的解决了二氧化硫和粉尘的排放问题,作为国内首套成功运行的以氧化镁为吸附剂的烟气脱硫装置,其在装置布置及管道设计方面均有其特点,通过总结为今后类似项目设计提供技术支持和积累。     

GIS技术在供热管网中的应用综述

简述GIS的概念,通过对供热管网现状的分析,结合GIS软件的特点,使GIS运用到供热管网中,实现供热管网管理的标准化、科学化和合理化。     

Comparative study on evaporator heat transfer characteristics of revolving heat pipes filled with R134a, R22 and R410A

Heat pipes are used extensively in various applications including the heating, ventilating and air conditioning (HVAC) systems. The high thermal conductivity of the device, attributed from the two-phase heat transfer processes within the heat pipe, made them superior heat exchanger devices. Heat pipes had been widely used in HVAC applications in energy conservation, dehumidification enhancement, heat dissipation, etc. A number of researches have been conducted to expand the applicability of heat pipes in HVAC in Malaysia, especially in air-to-air heat recovery using stationary heat pipes. However, the potential usage of rotating heat pipe in heat recovery in tropical countries like Malaysia was yet to be explored. Hence, the potential of rotating heat pipe in the HVAC systems used in tropics was explored through a parametric study that incorporates rotational speeds, off-axis displacements and varied refrigerants. The rotating heat pipes charged with R134a, R22 and R410A were tested with varied radial displacement from the rotational axis. The straight and leveled heat pipe with the furthest radial displacement yields the most significant heat transfer, which was attributed to the magnitude of the generated centrifugal force, and effective distribution of liquid in the evaporator.