(365d) Discovery of Electronics Cooling Fluids

Modern miniaturization trends have enabled the development of power intensive electronic devices and resulted in a dramatic increase in electronics cooling requirements that traditional cooling approaches are unable to supply. Efforts to identify working fluids for electronics equipment could enhance cooling performance and meet environmental and safety requirements. Among all cooling approaches, two-phase cooling systems can achieve high heat flux as they rely on phase change of the liquid. Micro-channel heat sinks have become one of the most promising two-phase cooling systems as they allow the combined action of heat conduction, latent heat absorption, and forced convection, leading to sufficient heat dissipation while maintaining a safe device temperature. However, heat transfer performance of micro-channel heat sinks has been plagued by the poor heat transfer characteristics of available cooling fluids. In this work, we aim to identify an efficient replacement of the common industrial cooling liquid HFE-7200.

We build on molecular design methodology [1] that addresses the challenge of large combinatorial search spaces in computer-aided molecular design through decomposition. The approach decomposes the complex CAMD problems into three subproblems: composition design, structure generation, and extended design. This three-phase approach has been implemented in the software AMODEO, which is an ideal tool to solve the coolant design problem. We looked closely into the physical and chemical property constraints that new fluids should satisfy. We used group contribution methods as the major property estimation tool along with additional accurate property models. The resulting candidate molecules were ranked by a heat transfer per unit pressure drop metric, developed specifically for the micro-channel heat sinks regime. Five organic families with the least environmental impact were identified, including hydrofluoroethers (HFEs), hydrofluoroolefins (HFOs), fluorinated esters, ethers, and aliphatics. Most candidate molecules are novel compounds, suggesting promising directions for developing safe, biodegradable, low ozone depleting, and low global warming potential coolants.

[1] A. Samudra and N. V. Sahinidis., Optimization-based framework for computer-aided molecular design., AIChE Journal, 59:3686–3701, 2013