PE-RT Ⅱ直埋供热管道热膨胀的分析  

Analysis of Thermal Expansion of PE-RT Ⅱ Directly Buried Heating Pipeline

作　　者：苗庆伟[1,2] 王淮 常娅娜 张欢 王冠英[4] MIAO Qingwei;WANG Huai;CHANG Yana;ZHANG Huan;WANG Guanying

机构地区：[1]天津大学环境科学与工程学院,天津300072 [2]中国市政工程华北设计研究总院有限公司科技发展部,天津300381 [3]天津建工集团建筑设计有限公司设计部,天津300384 [4]中国市政工程华北设计研究总院有限公司第六设计研究院,天津300381

出　　处：《煤气与热力》2020年第8期13-17,J0042,共6页Gas & Heat

摘　　要：随着塑料管道技术的进步,PE-RTⅡ预制直埋保温管适用于供水温度≤75℃、压力≤1.0 MPa的城镇集中供热二级管网。分析直埋供热管道主动轴向力随着温度的变化。根据不同温度下PE-RTⅡ管的弹性模量,拟合出弹性模量随管道工作温度而变化的公式。分析表明:工作温度区间为10~75℃时,PE-RTⅡ预制直埋保温管的轴向热应力在工作温度为49.26℃时取得最大值。在实例分析中,城镇集中供热二级管网敷设在非机动车道下,地下水位深度为2 m,管道中心线位于地下水位以上,管道与土壤的最小摩擦系数取0.2,管道设计压力为0.8 MPa。分别计算公称外直径为110~450 mm的PE-RTⅡ管在3种工作温度75℃、49.26℃、40℃时的管道主动轴向力、直管段过渡段最大长度。实例计算结果表明:相同管径下,随着管道工作温度的降低,PE-RTⅡ管的主动轴向力先增加再减小,相应地直管段过渡段最大长度也先增加再减小。在工作温度为49.26℃时,主动轴向力和直管段过渡段最大长度达到最大值。在工作温度为49.26℃时,公称外直径为450 mm的PE-RTⅡ管的主动轴向力增大到最大值21521.92 N,直管段过渡段最大长度增大到最大值4.34 m。单根管长度的PE-RTⅡ预制直埋保温管就可以被锚固。在城镇集中供热二级管网中应用PE-RTⅡ预制直埋保温管时,可以采用无补偿敷设。With the progress of the plastic pipe technology,the PE-RTⅡprefabricated directly buried insulating pipe is suitable for urban centralized heating secondary circuit with water supply temperature≤75℃and pressure≤1.0 MPa.The change of active axial force of directly buried heating pipeline with temperature is analyzed.According to the elastic modulus of PE-RTⅡpipe at different temperatures,the formula for change of the elastic modulus with the working temperature of the pipeline is fitted.The analysis shows that the axial thermal stress of PE-RTⅡprefabricated directly buried insulating pipe takes the maximum value when the working temperature is 49.26℃when the working temperature range is 10 to 75℃.In the example analysis,the urban centralized heating secondary circuit is laid under the non-motor vehicle lane,the depth of groundwater level is 2 m,the centerline of the pipeline is above the groundwater level,the minimum coefficient of friction between the pipeline and soil is 0.2,and the design pressure of the pipeline is 0.8 MPa.The active axial force of the PE-RTⅡpipe with a nominal outer diameter of 110 to 450 mm at three working temperatures of 75℃,49.26℃and 40℃,and the maximum length of the transition section of the straight pipe section are calculated respectively.The calculation results of the example show that under the same pipe diameter,as the working temperature of the pipeline decreases,the active axial force of the PE-RTⅡpipe first increases and then decreases,and the maximum length of the transition section of the straight pipe section also first increases and then decreases.When the working temperature is 49.26℃,the active axial force and the maximum length of the transition section of the straight pipe section reach the maximum.When the working temperature is 49.26℃,the active axial force of the PE-RTⅡpipe with a nominal outer diameter of 450 mm increases to a maximum of 21521.92 N,and the maximum length of the transitional section of the straight pipe section increases

关 键 词：PE-RTⅡ预制直埋保温管 热膨胀 主动轴向力 过渡段长度 

分 类 号：TU995.3[建筑科学—供热、供燃气、通风及空调工程]