Thermal Characterization Of Full-Scale PCM Products And Numerical Simulations, Including Hysteresis, To Evaluate Energy Impacts In An Envelope Application (2018)
Abstract: This article presents combined measurements of fatty acid-based organic PCM products and numerical simulations to evaluate the energy benefits of adding a PCM layer to an exterior wall. The thermal storage characteristics of the PCM were
measured using a heat flow meter apparatus (HFMA). The PCM characterization is based on a recent ASTM International standard test method, ASTM C1784. The PCM samples were subjected to step changes in temperature and allowed to stabilize at each temperature. By measuring the heat absorbed or released by the PCM, the temperature-dependent enthalpy functions for melting and freezing were determined.
The simulations were done using a previously-validated two-dimensional (2D) wall model containing a PCM layer and incorporating the HFMA-measured enthalpy functions. The wall model was modified to include the hysteresis phenomenon observed in PCMs, which is reflected in different melting and freezing temperatures of the PCM. Simulations were done with a single enthalpy curve based on the PCM melting tests, both melting and freezing enthalpy curves, and with different degrees of hysteresis between the melting and freezing curves. Significant differences were observed between the thermal performances of the modeled wall with the PCM layer under the different scenarios.
Supported by:
Ministry of New and Renewable Energy Govt. of India, Gujarat Energy Development Agency, U.S. Agency for International Development iNDEXTb (Industrial Extension Bureau) Govt. of Gujarat, Shakti Sustainable Energy Foundation, New Delhi
