Thermal modeling and efficiency of a dual-stage sodium heat engine

Journal Article · Mon Sep 17 00:00:00 EDT 2018 · Applied Thermal Engineering

DOI:https://doi.org/10.1016/j.applthermaleng.2018.09.071· OSTI ID:1608461

Limia, Alexander ^[1]; Kottke, Peter ^[1]; Fedorov, Andrei G.  ^[1]; Yee, Shannon K.  ^[1]

---

1. Georgia Inst. of Technology, Atlanta, GA (United States)

In this paper, a thermal design of an axisymmetric dual-stage sodium thermal electrochemical converter (Na-TEC) is presented, where a reduced-order finite-element model is used in conjunction with a Na-TEC thermodynamic model to determine the total parasitic heat loss of this dual-stage design. A number of simplifications are applied in the reduced-order model to decrease the computational time while maintaining acceptable accuracy. These include the use of effective thermal conductivities to account for complex corrugated geometries and apparent surface emissivities to accommodate the effect of radiation shields. Furthermore, a simplified analytical model is developed to account for conduction bypass through the Na-TEC liquid-return path. An iterative procedure between the finite-element and thermodynamic models is described in detail, and the thermal performance of the design proposed herein is analyzed. According to this analysis, a maximum efficiency of 29% and a maximum power output of 125 W can be achieved.

• Research Organization: Georgia Institute of Technology, Atlanta, GA (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office; National Science Foundation (NSF)
• Grant/Contract Number: EE0007110; DGE-1650044
• OSTI ID: 1608461
• Journal Information: Applied Thermal Engineering, Vol. 145, Issue C; ISSN 1359-4311
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
30 DIRECT ENERGY CONVERSION
42 ENGINEERING
thermally regenerative electrochemical system (TRES)
alkali-metal thermal electric converter (AMTEC)
beta"-alumina solid-electrolyte (BASE)
thermo- electro-chemical conversion