PERFORMANCE ENHANCEMENT OF FUEL CELLS SYSTEMS THROUGH SERIES AND PARALLEL CONNECTIONS OF MULTI STACK ARRAYS

摘要

Fuel cells have been known theoretically for more than a century. Recently conceived high temperature fuel cells, by guaranteeing higher degrees of efficiencies and greater fuel flexibility, have the potential to yield a radical change in the future of distributed electricity market promising high efficient and ultra-clean power generation. In the last years progress has been so relevant that they seem to be on the verge of commercialization.. All plants commissioned seem to consider the parallel flow solution i.e. in which primary fuel flow splits to enter all the stacks that works with nominally equal operational parameters. The present work analysed the possibility of disposing stacks in an array, thus leading to a combination of series and parallel fluid dynamic connection so that one cell anode may have as input the exhaust of another cell anode. The aim is to allow some cells to work with low utilization factors and therefore at greater voltages. Different solutions have been analysed with a tool obtained from the integration of a proprietary code for cells simulation, with Aspen+ flowsheet. Code predictions of cells performances have been validated by experimental campaigns [Lunghi and Burzacca 2002]. The results showed that a noticeable performance increase can be obtained with the proposed configuration without any significant complication in the process. The authors believe that this should be considered as a very interesting research field and strongly encourage participation of the scientific community.