Study on reliability of high temperature heat exchangers

Compact high temperature heat exchangers are urgently needed in many highly efficient power and propulsion systems. The big thermal stress and creep deformation under high temperature and high pressure conditions are very serious. In this study, our recent contributions on the reliability analysis of CW primary surface recuperators and bayonet tube high temperature heat exchangers are introduced. The reliability of several compact enhanced heat transfer designs including internally finned bayonet tube, internally and externally finned bayonet tube, and cross wavy (CW) primary surface sheet is investigated. The results indicate that for the bayonet tube, the high stress is caused by high temperature, while for the thin CW primary surface sheet, it is caused by big pressure difference. The creep strain of CW primary surface sheet is also influenced by the big pressure difference. The big thermal stress and creep deformation under high temperature and high pressure conditions are observed. And the big thermal stress and deformation areas of these designs have been found so that the corresponding optimized structures and modified measures have been recommended.