This book presents select proceedings of the International Conference on Energy Conversion and Thermo-fluid Systems (i-CONECTS 2021). It covers the latest trends in the areas of energy conversion and thermofluid systems. The topics covered include enhanced heat transfer, multi-phase flows, power generation technologies, fluid-structure interaction, alternative fuels, micro- and-nano-scale heat and mass transfer, energy, emissions control technologies, etc. The book will be a valuable reference for the researchers and professionals interested in the energy conversion technologies and allied fields.