某空冷器管束失效分析

Failure Analysis of Tube Bundle of an Air Cooler

某翅片式空冷器管束在投入使用前进行气密性试验时发生泄漏。通过宏观检验、力学性能测试、金相分析、扫描电镜、能谱分析及数值计算等方法,研究了该空冷器管束鼓胀开裂的原因。结果表明:该翅片式空冷器基管中存在残留水,在低温下水结成冰造成较大体积膨胀,对基管产生径向冰胀力,从而导致基管发生鼓胀并萌生裂纹,最终在气密性试验时发生开裂。

A number of base tube bulging leakage happened during gas tightness test before the finned air cooler tube bundle was put into use in a gas station.Through macroscopic inspection,mechanical properties testing,metallurgical analysis,scanning electron microscopy,energy spectrum analysis and numerical calculations,etc.,the crack causes were studied.Results show that residual water in the base tube of the finned air cooler forms ice at low temperature and has a large volume expansion,which produces radial ice expansion force on the base tube,resulting in the base tube bulging and cracks initiation,and eventually crack during the air tightness test.