Electrohydrodynamically Controlled Phase Change Heat Transfer and Thermal Storage Systems

电力电子、电池技术和能量采集系统的功率密度和瞬时热负荷迅速增加，需要创新的热管理解决方案，不仅能增强热传递，还能对系统进行主动控制。基于电流体动力学(EHD)，提出了一种新的物理机制，可以调节热性能以实现精确的温度控制和提高储热速率。EHD效应在气液两相系统中的研究主要是由于其强化换热的潜力，但利用EHD来主动控制系统状态的研究还很有限。此外，固-液相变材料(PCM)与传统的水箱储能相比，具有更高的能量密度，是一种有吸引力的热能储存解决方案。相变材料面临的挑战是它们的导热系数非常低，限制了充放电的速度。应用EHD来提高或控制充电率以及优化PCM电池设计是推动采用这一创新解决方案的两个领域。该项目将研究不同的工艺参数，如电压、流体流量、热通量和材料特性对这些先进热传递系统性能的影响。这项拟议研究计划的长期目标是开发新的热交换器设计和增强型蓄热解决方案方面的专业知识，以确立EHD作为增强型和智能控制的机制。这项研究将产生两相流和EHD增强的相变材料的传热模型和关联式，以及用于工业设计的有用的技术转移工具。开发的EHD受控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，包括余热能量收集、热存储系统、电力电子和电池热管理。这项研究的创新之处在于，从使用泵和阀门的传统热管理方法转变为集成EHD电极的新型热交换器。有了这些先进的热交换器，通过调节电压和频率实现了主动控制，从而降低了功率需求，同时提高了管理关键系统温度的可控性。我们的成功将有助于将加拿大定位为EHD热系统的世界领先者，这项技术将成为先进的能量收集和热管理策略的催化剂，使热传输率提高高达8倍。这项新技术的开发将通过改进能源系统技术，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.