Toward high efficiency radioisotope thermophotovoltaic system by spectral control

This thesis describes the design, modeling, and measurement results of a radioisotope thermophotovoltaic system (RTPV) using a two-dimensional photonic crystal emitter and low bandgap thermophotovoltaic (TPV) cell to realize spectral control. The RTPV generator aims to use the decay heat released by plutonium-238 fuel to heat up the emitter to incandescence and convert the infrared radiation to electricity in the TPV cell. With spectral control, high energy photons above the cell bandgap ([lambda] < 2.25 [mu]m for InGaAsSb cell) are emitted to produce more electrical power while low energy photons ([lambda] > 2.25 [mu]m) in far infrared are suppressed to reduce waste heat. We validated a system simulation using the measurements of a prototype system powered by an electrical heater equivalent to one plutonium fuel pellet. The thermal insulation design used multilayer insulation, which was found to be both efficient and chemically compatible with the photonic crystal emitter. We compared the system performance using a photonic crystal emitter to the one using a polished flat tantalum emitter and found that spectral control with the photonic crystal was four times more efficient. Based on the simulation, we further extended the design and performance estimates to real life RTPV generators optimized for both space and terrestrial applications. With the experimentally tested InGaAsSb TPV cell, the system efficiency can potentially reach above 8% with a specific power of 7.5 W/kg. With more advanced InGaAs monolithic-integrated-modules, the system efficiency can reach around 20% with a specific power above 17 W//kg.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2017

Author dc:creator

• Wang, Xiawa

Advisor dc:contributor.advisor

• Peter H. Fisher.

• Electrical Engineering and Computer Science.

Statement dc:rights

• MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/113984

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/113984