热量表流量计量稳定性的流场动态数值分析  

Numerical analysis of dynamic flow field for the measurement stability of pillar type ultrasonic heat meter

作　　者：官燕玲[1] 江超[1] 肖洋[1,2] 张宇昊[1,3] 

机构地区：[1]长安大学环境科学与工程学院,陕西西安710054 [2]成都基准方中建筑设计有限公司西安分公司,陕西西安710054 [3]信息产业电子第十一设计研究院科技工程股份有限公司西安分院,陕西西安710100

出　　处：《西安建筑科技大学学报（自然科学版）》2015年第4期598-604,共7页Journal of Xi'an University of Architecture & Technology(Natural Science Edition)

基　　金：陕西省科学技术研究发展计划项目(2013K13-02-01);陕西省住房和城乡建设厅科学技术计划项目(2014-04)

摘　　要：对一款DN25的立柱反射体超声波热量表,应用动态数值方法,分析了水流从初场到充分发展的动态过程、流场的非定常性等,在此基础上对热量表流量计量的关键参数即流量修正系数K值的稳定性进行了研究.分析表明,该款热量表因流量的变化再达到一个新的稳定工况所用时间很短;无论流量大小,超声波传播路径的瞬时线平均速度随时间均比较稳定;对应流量的改变,K直会发生变化.在热量表的安装方面,研究表明热量表入口直管长度对K值的稳定性影响较大,出口的直管段长度对其影响不大.The dynamic characteristics of a DN25 travel time ultrasonic heat meter were investigated by means of large-eddy simulation.The focus on the dynamic process from the initial flow field to the fully developed flow field and the unsteady characteristics of the flow field,the reliability of key parameter in flow measurement of heat meter,K-factor,were researched.The results showed that it takes a short period of time to achieve a new steady state after a flow rate variation for this heat meter.The instantaneous mean linear velocities along the ultrasonic transmission routes are stable regardless of the magnitude of the flow rate.There remain uncertainties of K-factor corresponding to the variations of the flow rate.As for the installation of heat meter,research indicated that the influence of upstream straight pice length on the stability of K-factor is remarkable while that of downstream straight nine length is not significant.

关 键 词：超声波热量表 流量计量 流量修正系数 数值分析 

分 类 号：TH7[机械工程—仪器科学与技术]