Presentation
Collecting energy from a planetary entropic Stirling engine
Asian Conference on Sustainability, Energy, and the Environment 2013
(2013)
Abstract
We extend previous work [1,2] on entrochemical systems, energetically closed systems which spontaneously creates internal thermal gradients. Like electrical batteries, these thermal batteries use differing chemical potentials to generate work, and thermal work is extracted from their environment. This paper introduces a 'spontaneous' methodology for recharging the system. We utilize a solar chimney to generate airflow over a draw solution, evaporating water and reconcentrating the solution. The reconcentrated solution is used to restore the original internal concentration gradient which enables the entrochemical system. We examine a device comprising three major parts: a reaction chamber, a distiller, and a solar chimney. We measure the output of our thermal battery at 129.3 ± 11.9 W/m2 using KCl as an enabling salt and 235.3 ± 15.3 W/m2 using NaCl as an enabling salt. We measure internal recharge rates of 55.6 ± 6.9 W/m2 when using a KCl / NaCl salt pair and 116.4 ± 18.0 W/m2 when using a NaCl / CaCl2 salt pair. We utilize a 6.096 m tall solar chimney with a 0.74 m2 solar collector. This solar chimney enables airflow of 37.05 m3/day. We measure a maximal evaporative performance of 1.213 L/day/m2. This corresponds to an effective energy utilization of 75.49 W/m2 (50.5% of maximum, given the airflow). Extrapolation using the model of Schlaich et. al. to model a 35 degree Celsius thermal lift and a 200 m tall chimney indicates an effective energy utilization of 405.49 W/m2. We discuss how this energy can enable water distillation. The process naturally stores entropic potential removing daily solar irradiance limitations and enabling on-demand energy. Waste products are humidified air, which may enable precipitation, and salt crystals.
Disciplines
Publication Date
June, 2013
Location
Osaka, Japan
Citation Information
S. Kazadi, A. Schwartz, J. Huang, R. Goy, et al.. "Collecting energy from a planetary entropic Stirling engine" Asian Conference on Sustainability, Energy, and the Environment 2013 (2013) Available at: http://works.bepress.com/sanza-kazadi/11/