Kevin Krist

Structure, microstructure and transport properties of mixed ionic-electronic conductors based on bismuth oxide Part I. Bi-Y-Cu-O system

Abstract An ionic-electronic mixed conductor consisting of a stabilized fcc Bi1.5Y0.5O3 ionic conductive matrix phase, and a tetragonal Bi2Cu2+1−nCu1+nO4−0.5n electronic conductive second phase has been developed. The ionic transference numbe r and conductivity of the composite material depend critically on the amount of the bismuth copper oxide second phase and its morphology.

Prediction and Measurement of Pitting Damage Functions for Condensing Heat Exchangers

Abstract Pitting corrosion is a form of localized attack resulting in rapid penetration into a metal substrate. It is one of the most destructive and insidious forms of corrosion that occurs in ind...

GRI research on thermophotovoltaics

Thermophotovoltaic (TPV) systems have potential applicability to residential and commercial gas furnaces that generate their own electric power. Two key requirements are high‐temperature, wavelength‐selective emitters that are durable and reliable, and low‐cost, PV cells designed for TPV. GRI‐supported research at the Tecogen Division of Thermo Power Corporation is progressing toward the development of a supported, continuous‐fiber structure that operates effectively at temperatures of 1400 °C–1800 °C and emits radiation selectively at wavelengths near the band‐gap of silicon PV cells. These structures also have potential in gas lighting and radiant burner applications. Tecogen has estimated the ultimate costs of its TPV system to be between

A radiation-based approach to planar solid oxide fuel cell modules

0.30 and

Electrochemical conversion of CO2 and CH4 to C2 hydrocarbons in a single cell

1.50 per watt. The costs depend strongly on the radiant intensity produced by the selective emitter and the cost and efficiency of the PV cells. Significant efficiency improvements and more evaluation are needed for using TPV in on‐site cogeneration.

Composite mixed ionic-electronic conductors for oxygen separation and electrocatalysis

This article describes the initial analysis underlying the design of a core module consisting of a 1 to 3 kW solid oxide fuel cell (SOFC) stack and a radiant air preheater (RAP) module. The design and testing of three SOFC stack/RAP modules was part of a California Energy Commission-sponsored project with the Gas Technology Institute. The objective of the design was to improve the thermal management of an SOFC system through radiant heat transfer from the stack walls to adjacent air preheater panels. The testing of this and subsequent modules has suggested that use of the radiation-based approach significantly improved the management of stack-generated heat.