Heat pipes in thermal management of electrical machines-A review

Thermal management of PEMD has become one of the key enabling factors in delivering future high-specific output solutions for low-/zero-emission electrified propulsion. This extended review paper evaluates HP technology in application to EMs with focus on opportunities and challenges associated with successful deployment of such heat transfer/removal approaches. Although, the use of HPs in EMs has been explored by numerous authors over decades of research, continuous developments in the materials and manufacturing techniques have opened new design avenues, with high-rate heat transfer, low-added-weight, high-level of integration and reliability being some of the benefits of HP-enabled cooling solutions. In this paper, underpinning fundamentals of the HPs' construction and operation are discussed, with emphasis on the new/emerging solutions allowing for a more measured integration of HP-based or assisted thermal management systems in EMs. Several examples of employing HPs in commercial and research applications are provided from the most recent available literature together with the authors forecasts of the possible future technology advancement.