Electrohydrodynamically Controlled Phase Change Heat Transfer and Thermal Storage Systems

电力电子、电池技术和能量收集系统的功率密度和瞬态热负荷的快速增长需要创新的热管理解决方案，这些解决方案不仅要增强热传递，还要提供对系统的主动控制。电流体动力学（EHD）是一种新的基于物理的机制，可以调节热性能以实现精确的温度控制和提高储热率。在两相液-气系统中研究了EHD效应，主要是为了增强其传热潜力，但利用EHD来主动控制系统状态的研究有限。此外，固液相变材料（PCMs）是有吸引力的热能储存解决方案，因为与传统的水箱储能相比，它们具有更高的能量密度。PCM面临的挑战是其热导率非常低，限制了充放电速率。应用EHD来提高或控制充电速率以及优化PCM电池设计是可以推进这一创新解决方案采用的两个领域。该项目将研究不同的工艺参数，如电压、流体流速、热流密度和材料性能对这些先进传热系统性能的影响。这项研究计划的长期目标是开发新的热交换器设计和增强的储热解决方案，以建立EHD作为增强和智能控制的机制。该研究将产生两相流和EHD增强的PCM传热模型和相关性，以及用于工业设计目的的有用技术转移工具。EHD控制热管理解决方案的发现驱动研究可用于许多不同的工程应用，包括废热的能量收集、储热系统、电力电子和电池热管理。该研究的新颖之处在于，从使用泵和阀门的传统热管理方法到集成EHD电极的新型热交换器的范式转变。这些先进的热交换器通过调节电压和频率来实现主动控制，从而降低了功率要求，同时增强了控制关键系统温度的可控性。我们的成功将帮助加拿大成为EHD热系统的世界领导者，这项技术将成为先进能量收集和热管理策略的催化剂，从而将传热率提高到8倍。这项新技术的开发将通过改善能源系统技术，同时减少碳排放，为加拿大的可持续创新组合做出重大贡献。

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.