热水供热管网热桥效应及节能措施研究
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摘要
近几年来,城市热力管网发展迅速,尤其是直埋管道敷设技术更是得到了广泛的应用。目前,我国正处于高速发展时期,而能源紧张却制约了经济的发展,因此节能减排已成为我国的长期基本国策。由于供热行业是用能大户,因而也是节能减排的重点对象。
     本文在分析热水集中供热管网国内外节能降耗研究现状的基础上,对热水集中供热管网的热桥效应及热桥效应的影响因素进行了研究。在此研究的基础上得出了适用于热水集中供热管网的热桥隔断措施,并对热桥隔断措施进行了有效性分析,为其实际应用提供了一定的理论基础。
     首先,本文对热水集中供热管网中存在的热桥效应的概念进行了明确,确定了热桥效应在热水集中供热管网不同布置形式中存在的位置。然后对热水集中供热管网热桥效应形成的原因进行了分析,并对影响热桥效应的因素做了初步的分析。分析了热桥效应对于整个热水供热管网系统的输送热损失方面的影响及管网稳定性方面的影响。
     其次,根据工程实例中采集的数据,建立了固定墩热桥效应的物理模型和数学模型,运用CFD技术中的固液耦合传热整场模拟方法,模拟了热水集中供热管网直埋供热管道固定墩处的热桥效应,并对影响固定墩处热桥效应的因素进行了逐个分析模拟。数值模拟结果表明:单个固定墩的散热量巨大,埋深1.5m,供热管道直径为DN800的典型固定墩的散热量为3057W,相比较于具有保温措施的管道来说具有很大的节能潜力;影响固定墩热桥效应的因素中,钢筋混凝土的导热系数和供回水的水温的影响显著,固定墩埋深、土壤表面对流换热系数的影响不显著。对于在建集中供热管网可以通过寻找能有效降低直埋供热管网固定墩处综合导热系数的办法即对固定墩处的管道进行保温,来降低固定墩的散热损失。
     再次,根据工程实例中采集的数据,建立了固定支架热桥效应的物理模型和数学模型,运用CFD技术中的固液耦合传热整场模拟方法,模拟了热水集中供热管网架空供热管道固定墩支架的热桥效应,并对影响固定支架处热桥效应的因素进行了逐个分析模拟。数值模拟结果表明:单个固定支架的散热量巨大,架空高度为3.5m,供热管道直径为DN800的典型固定支架的散热量为1175W,相比较于具有保温措施的管道来说具有很大的节能潜力;影响固定支架热桥效应的因素中,钢筋混凝土的导热系数和供回水的水温的影响显著,管道外表面对流换热系数的影响不显著。对于在建集中供热管网要想有效降低固定支架的散热量还得从有效降低钢筋混凝土的综合导热系数方面入手,寻找切实可行的保温措施。
     最后,对集中供热管网系统中的保温方法进行了总结,在此基础上确定了固定墩、固定支架保温措施及相应的保温材料。在确定保温措施后,利用数值模拟技术对固定墩、固定支架保温措施的隔热有效性和稳定性进行了研究。研究结果表明所选用的保温措施隔热效果明显、稳定性能满足管网稳定、安全运行的要求。并且结合具体的工程实例,分析了固定墩、固定支架散热量在整个管段散热量中所占的比例,研究了增加固定墩、固定支架保温措施后整个管段的散热损失量,即从管网实例分析固定墩、固定支架保温措施的有效性,进而推算出热水集中供热管网进一步节能的潜力,为集中供热管网保温工程提供理论支持,为集中供热管网进一步节能降耗提供理论依据。
In recent years, the rapid development of urban heat pipe network, especially the buried pipe laying technology has been widely used. At present, China is in a rapid development period, the energy crisis has restricted the economic development, and energy conservation has become China's long-term basic national policy. The heating industry is a key target for energy saving.
     This paper analyzes the hot water heating network energy consumption on the present situation of the research at home and abroad. We study the hot water of central heating pipelines thermal bridge effect and the influence factors of thermal bridge effect. On the basis of this study, we have come to cut off measures for centralized hot water heating pipe network of thermal bridges and analysis measures effectiveness to provide a theoretical basis for its practical application.
     Firstly, we determine the thermal bridge effect of hot water central heating pipe network, and given a hot water central heating pipe network the concept of the thermal bridge effect. We find out the effect of thermal bridges in the hot water to focus on the location of the different arrangement of the heating pipe network. And then analyze the reasons for the formation of the thermal bridge effect, and analyze the factors affecting the thermal bridge effect. We analyzed the impact of the thermal bridge effect of the heating pipe network system transmission heat loss and the pipe network stability.
     Secondly, according to data collected in the project example, we have established physical and mathematical models of the thermal bridge effect of the fixed pier. The application of CFD technology in the solid-liquid coupled heat transfer of the entire simulation method to simulate the hot water central heating pipe network buried heating pipe fixed pier at the thermal bridge effect, and to simulate the various factors affecting the fixed pier at the thermal bridge effect. The numerical results show that:great heat dissipation of a single fixed pier, a depth of1.5m, heating pipe diameter of DN800's typical fixed pier of the heat loss of 3057W.The heat dissipation is enormous compared to the pipes with insulation measures. Among the factors affecting the fixed pier thermal bridge effect, the thermal conductivity of the reinforced concrete and the impact of the supply and return water temperature are significant. Central heating pipe network can reduce heat loss of the fixed pie by reducing the thermal conductivity at the fixed pier.
     Thirdly, according to data collected in the project example, we have established physical and mathematical models of the thermal bridge effect of the fixation. The application of CFD technology in the solid-liquid coupled heat transfer of the entire simulation method to simulate the thermal bridge effect of the mounting bracket on overhead hot water central heating pipe network.The numerical results show that:great heat dissipation of a single fixation, a height of3.5m, heating pipe diameter of DN800's typical fixation of the heat loss of1175W. The heat dissipation is enormous compared to the pipes with insulation measures. Among the factors affecting the fixed pier thermal bridge effect, the thermal conductivity of the reinforced concrete and the impact of the supply and return water temperature are significant. Central heating pipe network can reduce heat loss of the fixation by reducing the thermal conductivity at the fixation.
     Finally, we summed up the insulation in the central heating pipe network system. We determined the fixed pier and mounting bracket insulation measures and the corresponding thermal insulation material. We simulated a fixed pier, mounting bracket insulation measures insulation effectiveness and stability. The results show that the insulation measures have good thermal insulation and stability. We use a specific project examples, and analysis of the proportion of the fixed pier and mounting bracket amount of heat loss in the entire tube of heat loss. Hot water central heating pipe network energy saving potential from the instance of the pipe network, and provide theoretical support for the central heating pipe network insulation works, to provide a theoretical basis for the central heating pipe network to further energy saving.
引文
[1]温小波.浅析直埋供热管道散热损失[J].山西建筑,2010,36(15):187-188.
    [2]李世武.管网系统热经济决策理论与方法的研究[D].西北工业大学博十学位论文2002:1-v31.
    [3]王莹君.直埋敷设供热管网中井室固定墩的受力分析[J].沈阳建筑工程学院学报.1998,14(1):20-22.
    [4]清华大学建筑节能研究中心.中国建筑节能年度发展研究报告2008[M].北京:中国建筑工业出版社,2008:8-70
    [5]徐宝平,孙树林.供热管道直埋敷设技术的探讨[J].煤气与热力.1999,2.
    [6]张运翻.直埋蒸汽管道设计[J].管道技术与设备.2007,5:3-5,8.
    [7]王峰.直埋管道设计与计算方法[D].西安建筑科技大学硕十学位论文.2004,5.
    [8]隋书波,张伟.供热管道直圳敷设方式探讨[J].山东电力技术.1999,2.
    [9]王飞、张建伟.直埋供热管道工程设计[M].中国建筑工业出版社,2007.
    [10]徐宝平,孙树林.直埋热水供热管道敷设方式比较[J].煤气与热力.2006,26(11):50-52.
    [11]董重成,那威等.供热管网保温厚度的计算分析[J].暖通空调.2005,35(2):7-10.
    [12]Cai Mingqing, Liu Xuelai, Li Yongan. A Numerical Simulation on Temperature Fileds of Buried Heating Pipe'S Fixed Anchorage And Its Surrounding Soil. Asia-Pacific Power and Energy Engineering Conference [C]. Wuhan, China,2011,03.
    [13]Zhiye Zhao, On the calculation of boundary stresses in boundary element,Engineering Analysis with Boundary Elements 16(1995)317-322.
    [14]L.C.Wrobel and C.A.Brebbia, Boundary Element in Thermal Problems,in Numerical Methods in Heat Transfer [M], Edited by R.WLewis,1981.
    [15]A.R.Jawoshi, Boundary Elements for Heat Conduction in Composite Media[J],APPI.Math.Modelling.Vol.5,Feb.1981.
    [16]WheelerJ.A. Simulation of heat transfer from a Warm Pipeline Buried in Permafrost [J], AICHE 74 the National Meetings, New Orleans, La.1973.
    [17]ThomtonD.E. Steady-state and quasi-static thermal results for bare insulted pipes in permafrost[J],CAN,CEQTEH,J,Vol13,1976.
    [18]RosalindAAMiehaelJO.Models for heat transfer from a buried pipe.SPE Journal,1997(2).
    [19]Sweby P K. High resolution schemes using flux limiters for hyper bolic conservation laws[J].SIAMJNumAnal,1984,21:995-101.
    [20]Steger J L, Warming R F. Flux vector splitting of the inviscid gasdynamic equations with application to finite difference methods [J].JCompPhys,1981,(40):263-293.
    [21]Hirsch Ch. Numerical Computation of Internal and External Flows[M].New York:John Wiley and Sons,1988.
    [22]Turkel E. Preconditioning method for solving the incompressible and low speed compressible equations [J].J Comp Phys,1988,(72):277-298.
    [23]cai Mingqing, Liu Xuelai, Li Yongan. A Numerical Simulation on Temperature Fileds of Buried Heating Pipe'S Fixed Anchorage And Its Surrounding Soil. Asia-Pacific Power and Energy Engineering Conference [C].Wuhan,China,2011,03.
    [24]樊洪明、史守峡、何钟怡.地下直埋管道的温度场分析[J].哈尔滨工业大学学报,1999,32(5):60-65.
    [25]莫理京、马家滋.直埋蒸汽管道保温层外表面温度的探讨[J].煤气与热力,2000(05):178-180、183.
    [26]庞丽萍、王浚.热介质直埋管道周围温度场进行了仿真研究[J].系统仿真学报,2004,16(3):485-487、491.
    [27]吴挺,赵军,张春雷,齐春华.水平埋管周围土壤温度场数值模拟研究[J].华北电力大学学报,2004,31(6):68-71.
    [28]吴国忠、陈超.埋地管道传热数值模拟网格划分方法[J].大庆石油学院学报.2005,29(2):82-84.
    [29]郑平,马贵阳,龚智力,顾锦彤.埋地管道周围温度场数值模拟的研究现状及趋势[J].管道与技术设备,2006,2:5-7、10.
    [30]郭孝峰,夏再忠,吴静怡,王如竹.埋地管道温度特性数值模拟与相似性实验研究[J].太阳能学报,2010,31(6):727-730.
    [31]于雅泽、李晓恭.直埋热水供热管道有限元模型的建立[J].2009,29(1):8-9.
    [32]莫理京、马家滋.直埋蒸汽管道保温层外表面温度的探讨[J].煤气与热力,2000(05):178-180、183.
    [33]温小波.浅析直埋供热管道散热损失[J].山西建筑,2010,36(15):187-188.
    [34]程艳.直埋管道温度场计算与分析[D].大连理工大学硕士学位论文,2004,6.
    [35]王莹君.直埋敷设供热管网中井室固定墩的受力分析[J].沈阳建筑工程学院学报.1998,1.
    [36]王希杰.直埋热力管道板肋型固定支墩的优化设计[J].区域供热,2001,4:12-14.
    [37]马鸣、付杰.直埋管道固定墩的结构探讨[J].大连民族学院学报.2005,7(5):79-81.
    [38]王世伟、郭丰.浅谈城市热力网直埋管道固定支墩结构设计[J].2007,1.
    [39]孙大明、周海珠等.建筑热桥研究现状与展望[J].建筑科学,2010(02):128-132.
    [40]于福军.计算流体流体动力学分析—CFD软件原理与应用[M].北京:清华大学出版社,2004:2-122.
    [41]李进良.精通FLUENT 6.3流场分析[M].北京:化学工业出版社,2009.9.
    [42]韩占忠.流体工程仿真计算实例与应用[M].北京:北京理工大学出版社,2008
    [43]王富耻ANSYS10.0有限元分析理论与工程应用[M].北京:电子工业出版社,2006.4.
    [44]王琴,程宝义等.三维非稳态耦合传热问题的数值方法研究[J].中国知网,1994-2011:682-686.
    [45]陶文铨.数值传热学(第二版)[M].西安交通大学出版社,2003.
    [46]郑平,马贵阳等.埋地管道周围温度场数值模拟的研究现状及趋势[J].管道与技术设备,2006,2:5-7、10.
    [47]郭孝峰,夏再忠等.埋地管道温度特性数值模拟与相似性实验研究[J].太阳能学报,2010,31(6):727-730.
    [48]高亚南,李永安.管道中含有固体内热源的导热及对流换热耦合问题的研究[J].山东制冷空调,2010,275-277,281.
    [49]李艳杰,邹平华.十壤热导率对直埋蒸汽管道保温层厚度的影响[J].煤气与热力,2006,26(3):56-58.
    [50]杨锦东.钢筋混凝土结构的温度场分析[J].广东建材,2004,7:29-31.
    [51]孙志坚,孙玮.国内绝热保温材料现状及发展趋势[J].实用节能技术,2001,4:26-28.
    [52]张战峰.管道保温的发展[J].能源与环境,2006,4:73-75.
    [53]刘晓燕,余’学江等.集中供热管网保温存在的问题及解决方案[J].科学技术与工程,2010,10(18):4544-4547.
    [54]干松涛,穆树方等.直埋蒸汽管道保温结构的研究与探讨[J].区域供热,2001,1:25-31.
    [55]李磊,王运阁.蒸汽管道保温材料性能的测定[J].煤气与热力,2003,23(7):410-412.
    [56]刘平,孙奇.加气混凝土复合夹芯保温砌块物理力学性能研究[J].混凝土,2010,5:108-110.
    [57]高强.供热直埋管道固定墩受力分析[D].太原理工大学硕十学位论文,2011,5.
    [58]袁宏.固定支架在热力管道工程中的受力分析[J].区域供热,2002,4:31-33.
    [59]赵丽萍.浅谈固定支架在热力管道中的重要性[J].山西建筑,2007,33(21):201-202.
    [60]刘敏.供热管道固定支墩的设计[J].煤气与热力,2004,24(2):91-93.

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