过热器单管泄漏故障模型及其仿真

Model of superheater single tube leakage fault and its simulation

根据单相介质受热管在泄漏工况下的传热传质机理，将一根过热器单管简化为两个集中参数受热管环节与一个分流环节的串联，给出了过热器单管工质泄漏故障的数学模型。该模型适用于对一类工质微量泄漏影响问题的分析研究。仿真结果表明：１）过热器单管泄漏对泄漏点后的金属管壁温度有较强的影响；２）随着泄漏量的增大，金属管壁的温度也呈升高趋势，且其升高速度与泄漏量的增加成正比，金属管壁温度的变化同时受泄漏点位置和泄漏量的影响，但泄漏量的影响是主要的因素；３）随着泄漏量的增加。

According to the heat and mass transfer mechanism of heated tube with single phase medium under leakage condition, a mathematical model of a single superheater tube with medium leakage is proposed by simplifying the tube as two lumped parameter heated tube sections and a flow dividing section, which can meet the need of analyzing the affection of small medium leakage. Simulation results show that: 1) medium leakage from a single superheater tube has a considerably effect on the temperature of tube behind the leaking point, 2) when the leaking rate increases, the tube temperature goes higher with a speed directly proportional to the leaking increasement. Both the leakage location and the leaking rate affect the tube temperature, and the latter is dominant, and 3) the rising time of tube temperature becomes shorter as the leaking rate increases.