Electrohydrodynamically Controlled Phase Change Heat Transfer and Thermal Storage Systems

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The rapidly increasing power density and transient thermal loads of power electronics, battery technologies and energy harvesting systems require innovative thermal management solutions that not only enhance heat transfer but provide active control of the system. A novel physics based mechanism that can modulate the thermal performance for precise temperature control and enhance thermal storage rates is based on electrohydrodynamics (EHD). The EHD effect has been studied in two-phase liquid-vapor systems primarily for its heat transfer enhancement potential but there has been limited research into using EHD to actively control the state of the system. Further, solid-liquid phase-change materials (PCMs) are attractive solutions for thermal energy storage as they have a higher energy density compared to traditional energy storage in water tanks. The challenge with PCM is their thermal conductivity is very low, limiting the rate of charging and discharging. Applying EHD to enhance or control charging rates along with optimizing the PCM cell design are two areas that can advance adoption of this innovative solution. This program will study the effects of different process parameters such as voltage, fluid flow rates, heat fluxes and material properties on the performance of these advanced heat transfer systems. The long-term objective of this proposed research program is to develop expertise in new heat exchanger design and enhanced thermal storage solutions that establish EHD as the mechanism of enhancement and intelligent control. The research will generate two-phase flow and EHD enhanced PCM heat transfer models and correlations, as well as useful technology transfer tools for industrial design purposes. The discovery driven research into EHD controlled thermal management solutions developed can be used in numerous different engineering applications including energy harvesting of waste heat, thermal storage systems and power electronics and battery thermal management. The novelty of the proposed research is the paradigm shift from the traditional approach to thermal management using pumps and valves to novel heat exchangers with integrated EHD electrodes. With these advanced heat exchangers active control is achieved by modulating the voltage and frequency which reduces power requirements while simultaneously enhancing controllability to manage critical system temperatures. Our success will help position Canada as a world leader in EHD thermal systems and this technology will act as a catalyst for advanced energy harvesting and thermal management strategies, leading to enhancement in heat transfer rates as high as eight-fold. The development of this novel technology will significantly contribute to a sustainable innovation portfolio in Canada by improving energy system technologies while simultaneously reducing carbon emissions.