供热直埋输送干线循环次数统计方法的研究

Research on Statistical Methods of Cycle Index of Heating Directly-buried Transportation Trunk

针对《城镇供热直埋热水管道技术规程》中疲劳分析缺乏供热管道循环次数的问题,对某市大型热电厂和大型区域锅炉房的供水温度连续测试了5个采暖期,按照t分布函数计算出每天、每周和每月的最大循环温差,以及样本方差的估计值。利用泊尔姆格林-米纳(Palmgren-Miner)公式计算出等效温差循环次数,小温差的等效温差循环次数叠加上计算年限内启停和事故大温差次数可以得到输送干线寿命期内的循环次数。这种方法用于各供热城市的输送干线、输配干线、用户支线等,就可得出不同城市、各种应用级别管道的实际循环次数,为每个城市的不同级别管道采用不同的疲劳极限值进行疲劳分析奠定了基础,具有重要的理论意义和工程应用价值。

Currently there is a lack of theoretical and empirical research about transportation trunk＇s equivalent temperature difference cycle index, specific to technical specification for direct- ly buried hot-water heating pipeline in city. The thermal power plants and heat source factories＇ operation temperature, of five heating cycles were collected, and the daily, monthly and yearly temperature difference, was calculated with t-distribution function. Furthermore, the equivalent temperature difference cycle index was calculated with Palmgren-Minerformula equation. The main transmission life cycles can be obtained by adding the index of equivalent temperature differ- ence cycles with start-stop and accident temperature difference cycle index in calculation period. The real cycle index of different cities and all kinds of application level pipes can be acquired by means of our theory. Therefore, the research project has great theoretical significance and engi- neering application value and provides the basis for the directly buried heating pipe fittings fatigue analysis and member＇s local fatigue analysis in technical specification for directly buried hot-water heating pipeline in city.