PROPANE DRIVEN HOT GAS EJECTOR FOR ANODE OFF GAS RECYCLING IN A SOFC-SYSTEM

摘要

A compact propane driven SOFC-system with recycling of hot AOG is developed at CUTEC Institute with partners from Zentrum fur BrennstoffzellenTechnik GmbH (ZBT, Duisburg), Institute of Energy and Process Systems Engineering (InES, TU Braunschweig) and Institute of Electrical Power Engineering (IEE, TU Clausthal). The system extends the commercially available integrated stack module (ISM) of Staxera GmbH (Dresden, Germany) by the required fuel processing unit and auxiliary components. The expected electrical power output for a propane flow of 1.0 l_N/mm is 950 W_e (gross). Thus, electrical system efficiency will be 61 % (based on propane LHV). CUTEC developed a tailor-made hot gas ejector for anode offgas recycling that uses pressurised propane from standard gas bottles as propellant gas. Propane leaves the ejector nozzle at high velocity and hereby mixes with AOG. A Laval nozzle accelerates the propane stream to supersonic speed and enables a recycle ratio sufficient for soot-free reformer operation. As the ejector has no moving parts it is expected to work robust, even at the high operating temperatures of about 600°C. The system concept, design options for thermal integration and high compactness and experimental results for the component development will be discussed. Ejector performance data will be presented.