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.
| Original language | English |
|---|---|
| Pages (from-to) | 501-512 |
| Number of pages | 12 |
| Journal | Applied Thermal Engineering |
| Volume | 138 |
| DOIs | |
| State | Published - Jun 25 2018 |
Funding
The U.S. Department of Energy (DOE) and the Department of Science and Technology (DST), Government of India (GOI) provided joint funding for this work, which was performed under the U.S.–India Partnership to Advance Clean Energy Research (PACE-R) program’s “U.S.–India Joint Center for Building Energy Research and Development” (CBERD) project. Funding for the research work done by Oak Ridge National Laboratory was provided by the U.S. DOE and the authors wish to thank Dr. Karma Sawyer and Mr. Sven Mumme for their guidance and support. The DST, GOI, administered by Indo-U.S. Science and Technology Forum, supported the India-side research activity. The authors also acknowledge the support from Pluss Advanced Technologies, in providing PCM tiles for the HFMA measurements. Finally, thanks to COMSOL Technical Support for their help in resolving modeling-related issues.
Keywords
- 2D wall model with PCM
- ASTM C1784
- Heat flow meter apparatus
- PCM characterization
- PCM hysteresis modeling