Gregory K. Housley

The High-Temperature Electrolysis Integrated Laboratory-Scale Experiment

Abstract The High-Temperature Electrolysis Integrated Laboratory-Scale experiment was designed at the Idaho National Laboratory (INL) and Ceramatec during 2006 and early 2007 and constructed in the spring and summer of 2007. A “half-module,” two stacks of 60 cells each, was tested at Ceramatec for 2040 h in June–September 2006 and a full module, four stacks of 60 cells each, was completed in March 2007. Initial shakedown testing of the INL Integrated Laboratory-Scale (ILS) experimental facility commenced on August 22, 2007. Heatup of the first ILS module started at 4:10 PM on September 24, 2007, and ran for 420 h. The test average H2 production rate was ~1.3 N.m3/h (Normal cubic meters per hour, where Normal conditions are 273 K and 1 atm) (0.116 kg H2/h), with a peak measured H2 production rate of over 2 N.m3/h (0.179 kg H2/h). Significant module performance degradation was observed over the first 250 h, after which no further degradation was noted for the remainder of the test. Once all test objectives had been successfully met, the test was terminated in a controlled fashion.

DESIGN OF A COMPACT HEAT EXCHANGER FOR HEAT RECUPERATION FROM A HIGH TEMPERATURE ELECTROLYSIS SYSTEM

Design details of a compact heat exchanger and supporting hardware for heat recuperation in a high-temperature electrolysis application are presented. The recuperative heat exchanger uses a vacuum-brazed plate-fin design and operates between 300 and 800°C. It includes corrugated inserts for enhancement of heat transfer coefficients and extended heat transfer surface area. Two recuperative heat exchangers are required per each four-stack electrolysis module. The heat exchangers are mated to a base manifold unit that distributes the inlet and outlet flows to and from the four electrolysis stacks. Results of heat exchanger design calculations and assembly details are also presented.