Power cycle and stress analyses for high temperature gas-cooled reactor

The HTSE (High Temperature Steam Electrolysis) was coupled to the reactor and the PCU (Power Conversion Unit) by means of the IHTL (Intermediate Heat Transport Loop). Helium and liquid salt were investigated as working fluids in the IHTL. The purpose of the demonstration is two fold 1) efficient low cost energy generation and 2) hydrogen production. Three configurations of the power conversion unit were demonstrated in this study. A three-shaft design with three turbines and four compressors, a combined cycle with a Brayton top cycle and a Rankine bottoming cycle, and a reheated cycle with three stages of reheat were investigated. In each of these configurations the relative component sizes were estimated for the different working fluids. Parametric studies were carried out on reactor outlet temperature, mass flow, pressure, and turbine cooling. With approximately 50 MW of process heat being transferred to the HTSE facility, hydrogen can be produced at a rate of 96.42 to 113.7 kg/hr. The use of a liquid salt in the IHTL increases the overall cycle efficiency by about 1% by lowering the pumping power required in the loop. Some of the electrical power generated by the PCU must be used to power the electrolysis cell, thus decreasing the net electrical output