Computational study of entropy generation minimisation in continuous stirred tank reactor

Abstract

Entropy generation minimisation (EGM) for optimising stirred tank reactor (CSTR) is performed by considering two cases: constant wall temperature and heat flux thermal boundary conditions. Entropy generation is computed from the temperature and velocity gradients which are predicted using CFD simulation. The selected parameters for EGM are inlet Reynolds number, impeller rotation, impeller clearance and impeller blade width. The optimum inlet Reynolds number increases with the wall temperature and heat flux. The effect of impeller rotation is also found on entropy generation. The optimum impeller clearance varies with the wall temperature and is invariant with the wall heat flux. The optimum impeller blade width depends on the magnitude of the wall temperature and heat flux. Bejan number is also determined, and it shows that the entropy generation is mostly dominated by heat transfer over the fluid friction irreversibility in the present study.