A parametric analysis of a deep sea radioisotopic thermoelectric generator employing a heat pipe.

Abstract

A parametric design analysis was performed using a heat pipe in an existing deep sea Radioisotopic Thermoelectric Generator (SNAP-21). Heat is transferred from an annular fuel pellet to an annular thermoelectric generator through a connecting heat pipe. The fuel pellet is fully shielded so that the thermoelectric generator is easily removable. Overall efficiency and the weight of major components were determined for varying fuel radii of from 1.3 inches to 1.7 inches and for varying insulation thicknesses of from 1.0 inch to 2.0 inch. The analysis indicates that there is a particular fuel radius (at constant insulation thickness) at which minimum weight is reached, while the maximum overall efficiency (at the beginning of life) of 5.4% and a total weight of 570 lbs. These design results, when compared to the existing SNAP-21 design gives an increase in overall efficiency of at least 7%, and a reduction in total weight of 12%.