共查询到20条相似文献,搜索用时 781 毫秒
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以线热源理沦为基础,结合热阻的概念,介绍地源热泵系统垂直U型埋管换热的物理模型,计算了影响系统换热效果的主要参数.将计算结果和实验测试值进行对比,误差在工程允许的范围内.根据该算法能够得出不同埋管形式下的单位井深换热量和所需的埋管间距,可作为工程设计依据. 相似文献
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地源热泵以其环保特性越来越受到空调界的重视。地下埋管换热器是地源热泵研究的重点和难点之一,不同的地质条件会有不同的换热效果。因此,大连理工大学针对大连地区地质为岩石这一特点建立了地源热泵实验系统。由于单管换热特性足研究地源热泵地下埋管特性的基础,所以实验采用电加热器控制单管的进口水温,使其保持恒定,得出了75m埋深地下换热器夏季2小时内单独运行时在不同进口水温和水流量情况下的换热特性。 相似文献
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本文通过TRNSYS搭建水平地埋管系统仿真平台,对水平U型地埋管换热器的换热性能进行研究。在郑州地铁车站实际环境下,分析不同埋深、不同间距等影响因素对水平U型管与土壤间换热性能的影响,研究表明埋设深度和敷设间距对埋管的换热性能有着重要的影响。 相似文献
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概述了总 建筑面积95万m^2的住宅小区小区供暖工程,着重介绍了供热管网和换热站工艺设计。热网高温热水管道和蒸汽管道均采用直埋保温敷设,由于管网布置较合理,管道保温效果较好,整个工程自1994年陆续投入使用至今,供暖系统运行良好。 相似文献
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依托基于热响应实验实现设计预评估、深层地埋管时空转换施工、防拔式地源热泵垂直地埋管管端头、区域式地源热泵分集水器和管群热响应实效测试五大核心技术,本文在上海中冶医院项目中成功实践了地源热泵埋管系统的设计与施工技术,为可行性研究、咨询、设计、材料采购及检验、施工管理、效果验证,直至后期运行维护的所有技术环节提供了全过程一揽子解决方案。 相似文献
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基于有渗流工况下地埋管管群的有限长线热源模型,通过Matlab软件模拟计算了深度为50 m平面处的地下温度场,根据地下温度场的温度分布,分析了布管方式,运行年限,孔隙率对地埋管管群传热效果的影响。研究表明:在物性参数,地埋管布管区域及地埋管总数不变的情况下,将地埋管等间距布置在布管区域内最有利于地源热泵系统的运行。地埋管布管区域冷热量累积效应在初始阶段较为明显,随着运行年限的增加,冷热量累积将在某一时刻达到动态平衡,此后将不随时间的增加而继续累积。对于冬夏季冷热负荷不平衡地区,孔隙率越大的区域越有利于地源热泵系统的运行。 相似文献
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《Automation in Construction》2006,15(1):47-57
The enormity of the problem of deteriorating pipeline infrastructure is widely apparent. Since a complete rebuilding of the piping system is not financially realistic, municipal and utility operators require the ability to monitor the condition of buried pipes. Thus, reliable pipeline assessment and management tools are necessary to develop long term cost effective maintenance, repair, and rehabilitation programs. In this paper a simple, robust and efficient image segmentation algorithm for the automated analysis of scanned underground pipe images is presented. The algorithm consists of image pre-processing followed by a sequence of morphological operations to accurately segment pipe cracks, holes, joints, laterals, and collapsed surfaces, a crucial step in the classification of defects in underground pipes. The proposed approach can be completely automated and has been tested on five hundred scanned images of buried concrete sewer pipes from major cities in North America. 相似文献
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《Geotextiles and Geomembranes》2021,49(5):1117-1128
Buried pipes may transport substances that can be harmful to people and the environment. These structures may be subjected to damages caused by soil movements and external interference, such as surcharges and excavations. Different applications of geosynthetics have demonstrated that they can be used to protect buried pipes and to minimize the consequences of pipe burst. This paper discusses results of large scale laboratory tests on a flexible pipe buried in unreinforced and geosynthetic reinforced soils subjected to surface surcharges. The pipes were buried in a cohesionless soil and different types of reinforcements were tested, with a wide range of tensile stiffness values. The results obtained show that the arrangement of the reinforcement enveloping the pipe reduced significantly pipe displacements and deflections. The efficiency of the reinforcement depended on its type and physical and mechanical properties. The open geogrid tested showed less reinforcement efficiency due to the passage of soil particles through its aperture during the tests. A theoretical solution available for pipes in unreinforced soils was extended to the reinforced situation with good agreement between predictions and measurements and showed that the presence of the reinforcement is equivalent to the pipe being buried in a significantly stiffer unreinforced soil. 相似文献
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结合内蒙古包头地区的地域特性,基于有限体积法,在实验验证的基础上,数值仿真研究了全年地埋管管群蓄热取热同步模式下的岩土传热特性,分析了蓄热取热同步过程中的蓄热地埋管流体温度、取热地埋管流体温度、岩土结构以及地埋管管群排列方式等因素对岩土温度场的影响规律。研究结果发现:地埋管群全年蓄热取热同步模式可使岩土温度得到快速恢复,进而可缓解岩土热失衡问题;取热流体温度不变的情况下,取热地埋管周围岩土温度随蓄热地埋管流体进口温度的增加而增加;岩土热扩散系数越大,取热地埋管与蓄热地埋管周围岩土温度分布越均匀越不易出现岩土热堆积现象;取热地埋管与蓄热地埋管叉排列时岩土温度分布较顺排列时均匀。 相似文献
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This paper presents the validation of a novel leak detection method for water distribution pipelines, although it could be applied to any buried pressurized fluid flow pipe. The detection method is based on a relative pressure sensor attached non-invasively to the outside of the pipe combined with temperature difference measurements between the pipe wall and the soil. Moreover, this paper proposes an anomaly detection algorithm, originally developed for monitoring website traffic data, which differentiates a ‘leak’ event from ‘normal’ pressure change events. It is compared to two more commonly used methods based on a fixed threshold and a moving average. The validation of the new system in a field trial over a 6-month period showed that all the known leaks were identified with 98.45% accuracy, with the anomaly detection algorithm performing best, making this system a real contender for leak detection in pipes. 相似文献
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地源热泵系统是对地温能进行利用的一种新型技术,其中在地下连续墙或钻孔灌注桩内埋设热交换管称为墙埋管和桩埋管。但是在地下连续墙或灌注桩中埋管是否会对其承载能力造成影响,以及地下连续墙或灌注桩的变形是否会对埋管产生影响分别是结构和暖通两个专业关心的问题。通过地下连续墙和灌注桩埋管前后的截面面积和惯性矩的变化,分析了埋管对其承载能力的影响。根据围护结构的结构特点以及允许位移,分析了围护结构的变形对埋管的影响。同时还研究了在地源热泵运营时,防冻液渗入混凝土可能引起的对围护结构的影响及其避免措施,研究结果表明,围护结构内埋管对其承载能力的影响相当小,围护结构的变形也不会影响热交换管的正常使用。 相似文献
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Sunil K. Sinha Paul W. Fieguth & Maria A. Polak 《Computer-Aided Civil and Infrastructure Engineering》2003,18(2):95-112
Pipeline surface defects such as cracks cause major problems for asset managers, particularly when the pipe is buried under the ground. The manual inspection of surface defects in the underground pipes has a number of drawbacks, including subjectivity, varying standards, and high costs. An automatic inspection system using image processing and artificial intelligence techniques can overcome many of these disadvantages and offer asset managers an opportunity to significantly improve quality and reduce costs. This article presents a system for the application of computer vision techniques to the automatic assessment of the structural condition of underground pipes. The algorithm consists of image preprocessing, a sequence of morphological operations to accurately extract pipe joints and laterals (where smaller pipe is connected to main bigger pipe), and statistical filters for detection of surface cracks in the pipeline network. The proposed approach can be completely automated and has been tested on over 1,000 scanned images of underground pipes from major cities in North America. 相似文献