Thermal fluids with high specific heat capacity through reversible Diels-Alder reactions

Drew Lilley,Peiyuan Yu,Jason Ma,Anubhav Jain,Ravi Prasher

doi:10.1016/j.isci.2021.103540

Drew Lilley, Peiyuan Yu + Show 3 more

Open Access

https://doi.org/10.1016/j.isci.2021.103540

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Abstract

SummaryThermal fluids are used as heat transfer fluids and thermal energy storage media in many energy technologies ranging from solar thermal heating to battery thermal management. The heat capacity of state-of-the-art thermal fluids remains ∼50% of that of water (which suffers from a limited operation range between 0°C and 100°C), and their viscosities are typically more than one order of magnitude higher than that of water. Our results demonstrate that the heat capacity of the proposed thermochemical fluid is significantly higher than that of state-of-the-art thermal fluids over a broad temperature range and is also higher than that of water between 60°C and 90°C. The viscosity of our liquid is only 3 times higher than that of water, and the operating temperature range is between −90°C and 135°C. Furthermore, a model was developed allowing for novel design of thermochemical thermal fluids in the future with even higher heat capacity.

Highlights

90% of the world’s current energy technologies involve thermal processes (Henry et al, 2020)
Thermal fluids are used as heat transfer fluids and thermal energy storage media in many energy technologies ranging from solar thermal heating to battery thermal management
The heat capacity of state-of-the-art thermal fluids remains $50% of that of water, and their viscosities are typically more than one order of magnitude higher than that of water

Summary

Introduction

90% of the world’s current energy technologies involve thermal processes (Henry et al, 2020). Examples include conversion of solar energy to heat (Sharma et al, 2017), conversion of waste heat to electricity (Hung, 2001), thermal storage (Woods et al, 2021), cooling and heating of buildings (Booten et al, 2021), and thermal management of various energy devices such as batteries (Xia et al, 2017), microelectronics, and electrical transformers (Meshkatodd, 2008). A good thermal fluid should possess (1) high specific heat (Cp), (2) low freezing temperature, (3) higher boiling point (depending on the application), (4) higher thermal conductivity (k), and (5) low viscosity. Both the cooling power and thermal storage capacity of thermal fluid are proportional to Cp, whereas thermal and fluid resistance are dependent on thermal conductivity and viscosity, respectively. Microchannel-based heat exchangers have much smaller thermal resistance for a given fluid than larger heat exchangers (Kandlikar et al, 2013)

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