Heat Transfer Performance Potential with a High-Temperature Phase Change Dispersion

Abstract

Phase change dispersions are useful for isothermal cooling applications. As a result of the phase changes that occur in PCDs, they are expected to have greater storage capacities than those of single-phase heat transfer fluids. However, for appropriate heat exchanger dimensions and geometries for use in phase change dispersions, knowledge about the convective heat transfer coefficients of phase change dispersions is necessary. A test unit for measuring the local heat transfer coefficients and Nusselt numbers of PCDs was created. The boundary condition of constant heat flux was chosen for testing, and the experimental heat transfer coefficients and Nusselt numbers for the investigated phase change dispersion were established. Different experimental parameters, such as the electrical wall heat input, Reynolds number, and mass flow rate, were varied during testing, and the results were compared to those of water tests. It was found that, due to the tendency of low-temperature increases in phase change dispersions, the driving temperature difference is greater than that of water. In addition, larger heat storage capacities were obtained for phase change dispersions than for water. Through this experimentation, it was acknowledged that future investigation into the optimised operating conditions must be performed.

Development and Thermophysical Profile of Cetyl Alcohol-in-Water Nanoemulsions for Thermal Management

“…Differential scanning calorimetry (DSC) and T-history analyses showed that the apparent specific heat capacity of the sample doubled that of water at around 323 K [18]. The heat transfer performance of that same emulsion and its potential for advanced temperature management in high voltage electrical devices was experimentally and numerically evaluated in two recent works from the same authors [19,20]. When it comes to fatty alcohols such as 1-hexadecanol (also known as cetyl or palmityl alcohol), these materials have proved effective as core for the preparation of micro- [21][22][23][24][25] or nano-encapsulated [26] PCMs.…”

TES Nanoemulsions: A Review of Thermophysical Properties and Their Impact on System Design

“…In the last 2-3 years, several nanoemulsions fulfilling the above-mentioned TES material requirements have been validated for use in different heat storage applications [47][48][49][50][51][52]. Additionally, several composite or hybrid materials have been studied and proposed as PCMs with improved thermo-physical properties [53][54][55][56].…”