HYHP · salt HYdrate Heat Pipes; a breakthrough in thermal energy transfer methods

salt HYdrate Heat Pipes; a breakthrough in thermal energy transfer methods

Heat pipes (HPs) are highly efficient passive devices employed for heat transfer between different regions. Due to their high thermal conductivity, HPs are capable of transferring heat through their evaporator and condenser sections without a significant temperature gradient. Recent advances in HP technology have demonstrated promising results across various applications, particularly in compact systems requiring high heat flux, such as aerospace and automotive industries, electronic device cooling (e.g., computers and mobile phones), fuel production, HVAC systems, and renewable energy technologies. Although current HPs provide acceptable levels of thermal efficiency, further improvements could significantly enhance their applicability, rendering them more effective in the fields above and beyond. This project evaluates a new generation of HPs through interdisciplinary research involving thermochemical salt hydrates (SHs). To achieve this objective, various categories of SHs were systematically investigated, with particular attention to their thermochemical and thermophysical properties. A comprehensive review of SHs used in renewable energy technologies across a range of temperature levels was conducted, addressing critical challenges such as toxicity, corrosiveness, and cost. Based on this review, the most promising SHs were identified in terms of chemical energy density and cost-effectiveness at different operating temperatures. Subsequently, the study outlined key challenges, highlighted existing research gaps, and proposed potential directions for future investigations. Among the candidate salts, the one exhibiting the greatest potential (MgSO4.7H2O) for HP applications based on criteria such as low operational temperature, high energy density, availability, and cyclic stability was selected for detailed experimental and computational fluid dynamics (CFD) analyses. Both powdered and aqueous forms of the salt hydrate are examined as working fluids. The results of parametric studies—including variations in concentration, filling ratio, and operational parameters—will be presented. In light of these efforts to overcome challenges, an additional salt (CaCl.6H2O) was assessed to further enhance system performance. Also, some competitive candidates for working fluids in HP were introduced. Furthermore, a geometric optimization through numerical simulations using COMSOL software will be employed to achieve optimal design and operational efficiency.

Data: CORDIS, © European Union