Improvement of efficiency of a heat exchanger by twisted tubes

This book investigated the effect of twisted tubes on the thermal performance of the shell and tube heat exchanger. The computational fluid dynamics (CFD) with different turbulence models (realizable k-¿ and standard k-¿) was employed to analyze. The results were compared with the published study to verify the present solution. In this book, mass flow rates ranging from 0.5 kg/s to 2 kg/s were considered to investigate thermal performance. The results demonstrated changing the pitch from 180 mm to 135, 90, 67.5, and 45 mm increases the heat transfer coefficient to 7%, 13%, 25%, and 37%, respectively. Comparing the smooth tube with other cases shows that using the twisted tube (P=45 mm) increases the pressure drop by 25% and enhances the heat transfer coefficient by 57%.