Enhancing the Energy Efficiency of a Proton Exchange Membrane Fuel Cell with a Dead-Ended Anode Using a Buffer Tank

Enhancing energy efficiency is essential for proton exchange membrane fuel cells (PEMFCs) operating in a dead-ended anode (DEA) mode. This study proposes the integration of a buffer tank, positioned between the mass flow meter and the fuel cell, to reduce hydrogen loss during purge events. The buffer tank stores hydrogen when the purge valve is closed and releases it when the valve opens, thereby stabilizing anode pressure, minimizing hydrogen waste, and improving overall system efficiency. The effectiveness of the buffer tank is experimentally evaluated under varying load currents, hydrogen supply pressures, purge intervals, and purge durations. The objective is to determine the optimal purge duration that maximizes energy efficiency, both with and without the buffer tank. The results show that the buffer tank consistently improves energy efficiency. Under optimal conditions (0.1 bar, 8 A, 0.1 s purge duration, and 20 s purge interval), efficiency increases by 3.3%. Under non-optimal conditions (0.1 bar, 1 A, 0.1 s purge duration, and 20 s interval), the improvement reaches 71.9%, demonstrating the buffer tank’s effectiveness in stabilizing performance across a wide range of operating conditions.