共查询到19条相似文献，搜索用时 171 毫秒
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采用对比分析方法,推得各种管径的给水管材与相应公称直径的镀锌钢管单位长度水头损失的比值K,通过对各种规格管材K值的分析,从节能角度提出选用给水管材的合理化建议. 相似文献
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铝塑复合管作为一种新型的给水管材正得到广泛应用.针对铝塑复合管作为给水管材的特性,讨论其在实际工程中选用与施工的要点. 相似文献
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水压图和水力工况的计算与分析是建筑环境与设备工程专业教学中的的重点和难点.1983年哈尔滨工业大学设计、开发了热水网路水力工况教学实验台,2001年开发了热水网路水力工况教学软件,并用于实验课中.理论与实验的对照有助于学生更好地理解热水网路水压图和水力工况的基本原理,方便学生更快地掌握水力工况的分析方法.由此,激发了学生将理论与实践相结合、专业课与专业基础课相结合、专业课与技术课相结合的兴趣,有利于提高学生的综合素质. 相似文献
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对市场上的塑料给水管材进行了技术指标比较后,采用了先进的PB管,并对用水定额当量进行优化,取得良好的运行效果. 相似文献
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铝塑复合管在给水管道中的应用与施工 总被引：1，自引：0，他引：1
李淑艳 《石家庄铁路职业技术学院学报》2006,5(Z1):21-23
铝塑复合管是一种新型的给水管材.介绍铝塑复合管的特性、安装和施工中应注意的问题. 相似文献
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在中专《给水工程》、《排水工程》、《建筑给水排水》等教材的管道材料一节,以金属管材和水泥管材为主要内容。这些管材在上世纪70年代至90年代得到了广泛应用,在市政行业中起到了主导作用。我国经济建设快速发展和城市化进程进一步加快,对市政基础设施提出了更高的要求。这些传统的管材在材料性能及施工方面的弊端日益显露出来,新型管材的开发和应用已成为必然趋势。现就目前我国已经使用的几种塑料管材作一些介绍。硬质聚氯乙烯管聚氯乙烯管材是很早就已开发出来的产品,但由于PVC对环境和健康的危害,一直没有得到推广。最新研究表明,废… 相似文献
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以某电厂工业水管网为例,运用EPANET软件进行水力计算,通过对管段内流速的控制,精确控制管径以及节点压力,达到管网优化设计的效果,软件操作简便,计算快速准确,满足工程设计的要求。 相似文献
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近些年来,建筑给排水的最大热点是新型管材的广泛应用.传统的镀锌钢管和普通排水铸铁管由于易锈蚀、自重大、运输施工不便等原因被取而代之.现在就常用给水管材的一些物理性能、价格、工程造价、使用范围等方面作一简要论述. 相似文献
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Simulation investigation on fluid characteristics of the water hydraulic jet pipe servo valve (WHJPSV) is conducted through a commercial computational fluid dynamics (CFD) software package FLUENT. In particular, the factors to fluid characteristics of WHJPSV are addressed, which include diameter combination of jet pipe and receiver pipe, jet pipe nozzle clearance, angle between two jet receiver pipes and deflection angle of the jet pipe. It is concluded from the results that: (i) Structural parameters have ... 相似文献
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Hua ZHU Bo ZHUAN Jin-jun TAN Rong-hua HONG 《浙江大学学报(A卷英文版)》2008,9(3):410-415
This paper focuses on the heat transfer performance of semi-open heat pipe which is a new type of heat pipe. After analyzing its condensation heat transfer mechanisms theoretically, several semi-open heat pipes in different length ratios and upper hole diameters are studied experimentally and compared with the same dimensions closed heat pipes. Experimental results show that the heat transfer performance of semi-open heat pipe becomes better by increasing heat transfer rate. At the first transitional point, the heat transfer performance of semi-open heat pipe approaches the level of the closed heat pipe. It is suitable to choose upper small hole about 1 mm in diameter and length ratio larger than 0.6 for the semi-open heat pipe. 相似文献
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供水管网中的节点流量具有不确定性,为了研究节点流量不确定性对供水管网漏损定位能力的影响,建立供水管网节点流量分布在不同条件下的需求分布水力模型。一种是供水管网中各节点平均分配流入量的均匀模型,另一种是在供水管网各节点按需分配流入量的分配模型,比较两种需求分布模型的漏损定位性能。利用加权最小二乘算法完成供水管网水力模型的漏损定位,加权最小二乘算法具有模型精度高和计算效率高的优点,该方法通过计算供水管网中监测值与水力模型模拟值的差异,判断是否发生漏损,并能准确定位漏损节点。最后通过实例证明供水管网节点流量的不确定性对供水管网漏损定位性能有突出影响。 相似文献
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SUN Lin zhi SUN Ping WANG Cun min QIN Xin jie 《上海大学学报(英文版)》1999,3(4):308-312
１ Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｍｉｌｌｉｍｅｔｅｒｓｉｚｅｍｉｃｒｏｍａｃｈｉｎｅｓｂａｓｅｄｏｎｍｏｄｅｒｎｐｒｅｃｉｓｉｏｎｍａｃｈｉｎｉｎｇｈａｖｅｐｏｔｅｎｔｉａｌａｐｐｌｉｃａｔｉｏｎｉｎｉｎｄｕｓｔｒｙ．Ｓｏｍｅｎａｒｒｏｗｓｐａｃｅｓｏｒｓｍａｌｌａｒｅａｓｎｅｅｄｔｈｅｓｅｍｉｃｒｏｍａｃｈｉｎｅｓｔｏｉｎｓｐｅｃｔａｎｄｒｅｐａｉｒｄｅｆｅｃｔｓ．Ｒｅｓｅａｒｃｈｅｒｓｈａｖｅｗｏｒｋｅｄｏｎｆａｂｒｉｃａｔｉｏｎｏｆｖａｒｉｅｄｖｅｈｉｃｌｅｓｗｉｔｈｗｈｅｅｌｓ,ｍｏｂ… 相似文献
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A trapped air pocket can cause a partial air lock in the top of a hump pipe zone. It increases the resistance and decreases the hydraulic cross section, as well as the capacity of the water supply pipeline. A hydraulic model experiment is conducted to observe the deflection and movement of the trapped air pocket in the hump pipe zone. For various pipe flow velocities and air volumes, the head losses and the equilibrium slope angles are measured. The extra head losses are also obtained by reference to the original flow without the trapped air pocket. Accordingly, the equivalent sphere model is proposed to simplify the drag coefficients and estimate the critical slope angles. To predict the possibility and reduce the risk of a hump air lock, an empirical criterion is established using dimensional analysis and experimental fitting. Results show that the extra head losses increase with the increase of the flow velocity and air volume. Meanwhile, the central angle changes significantly with the flow velocity but only slightly with the air volume. An air lock in a hump zone can be prevented and removed by increasing the pipe flow velocity or decreasing the maximum slope of the pipe. 相似文献
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It is required to develop micro-machine for inspection and maintenance of defects inside small pipe withdiameter smaller than one inch. Considering the advantages of electromagnetic actuators with simple mechanism,high response, convenience to control and fabricate, we tried to develop a new micro-robot in small pipe based on in-teraction principle of electromagnetic attraction and spring force. This paper describes its structure and design. Thedimension of the prototype is diameter of 15 mm, length of 30 mm and weight of 25 g. It can climb in small pipe ofdiameter of 20 mm with a speed of 6～8 mm/s in horizontal or in vertical situation. 相似文献
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In water distribution systems, water leakage from cracked water pipes is a major concern for water providers. Generally, the relationship between the leakage rate and the water pressure can be modeled by a power function developed from the orifice equation. This paper presents an approximate solution for the computation of the steady-state leakage rate through a longitudinal line crack of a water distribution pipe considering the surrounding soil properties. The derived solution agrees well with results of numerical simulations. Compared with the traditional models, the new solution allows assessment of all the parameters that related with leakage including the pressure head inside the pipe, hydraulic conductivity, crack size and its position, and pipe size and its depth. 相似文献