Abstract
The aim of this study is to oversee the impact of various techniques on thermal performance of heat pipes and to comprehensively cover the progress made so far in improving thermal performance. Thermal performance of heat pipes has been considerably improved by applying very novel techniques proposed by different investigators. Some major techniques have been reviewed and discussed: use of nanofluids, manufacturing different types of grooves and fins, use of different types of wicks, by inner surface treatment, use of self-rewetting fluids, use of embedded heat pipes that is passive cooling mechanism, using various inclination angles in heat pipes, etc. The presented study concludes that there are diverse methods for thermal performance enhancement of heat pipes each having its own impact level and constraints such as optimized parameters, manufacturing constraints, economic feasibility and commercial barriers. Some techniques show reversion in results when exceeded a certain level, e.g., crossing optimum concentration of nanofluid would reduce thermal performance of heat pipes. This review yields enough knowledge to optimize alteration parameters to get maximum augmentation in results and provides strong insight to decide about, which specific technique should be used for a case.