Theoretical and experimental investigations on diffusion gap evaporators for the regeneration of electrolyte in alkaline fuel cells
Abstract
Four different technical concepts of electrolyte regenerators for the use in alkaline fuel cell systems were evaluated and the test results of an experimental diffusion gap evaporator block and evaporators with several porous hydrophobic membranes were presented. As a result of theoretical investigations, two models for transport processes in diffusion gap evaporators and in evaporators with hydrophobic membranes have been developed and successfully verified by experiments. They may be used for calculating the performance of electrolyte regenerators. Furthermore they contribute to understanding of functioning of such regenerators and allow to make specific improvements. The experimental diffusion gap evaporator block performed satisfactorily but there are still some problems in manufacture. The evaporator with hydrophobic membranes has found to be the most promising type of electrolyte regenerator. Its feasibility has successfully been demonstrated, but no appropriate membrane for technical use has been found until now.
