For the verification of a finite element based calculation procedure for the strength and fatigue design of aluminum brazed Plate Fin Heat Exchangers (PFHE) an extensive experimental investigation program was planned and executed.
In the first step high temperature loadings as single events were applied to the PFHEs to recognize, whether damage (a leak) can be produced by a severe single loading. After various tests on different geometries the investigations were enlarged to thermal cycling tests on small PFHEs until leaks were detected.
The tests were executed with three blocks in parallel to cover a statistical influence and the tests were repeated with three new blocks under identical conditions. All six blocks gave nearly the same number of load cycles until first detection of leaks. In addition three blocks of the same geometry were loaded with lower thermal stress, giving higher load cycle numbers until a leak occurred.
The experimentally determined cycle numbers were compared to calculated cycle numbers out of the finite element modeling and showed very good agreement. Those tests and comparisons are a strong basis for fatigue and lifetime considerations on large scale PFHEs in the process industry.
Experimental investigation on the fatigue design of anchor channels
