Engineering Congress on Alternative Energy Applications November 3 rd –5 th , 2009, KUWAIT 1 EXPERIMENTAL INVESTIGATION ON PEM FUEL CELL PERFORMANCE CHARACTERISTICS Rami S. El-Emam Department of Mechanical Engineering, Mansoura University, Mansoura, Egypt elemam@hotmail.com Ahmed M. Hamed 1 , Mahmoud M. Awad 2 , Mohamed A. Tolba 3 Abstract ― An experimental study on the performance characteristics of proton-exchange-membrane fuel cell (PEMFC) has been carried out. The study has been performed on a single PEMFC unit with an active area of 25 cm 2 using two different cell configurations. The test system has been established to control each of the temperature and the relative humidity of the cathode feeding gas. Supplied reactants flow rates have been controlled during the test. Also, an electrical load bank has been designed to control the load that the fuel cell will experience as will as to measure the voltage and current produced by the fuel cell at different loads. Obtained results show that, operating conditions affect the fuel cell performance significantly. Cell performance is improved as oxidizer relative humidity is increased and its temperature is decreased. The reactants utilization was better with increasing the oxidizer relative humidity; until flooding occurrence. It was observed that the serpentine/ straight open channels cell configuration suited using air more than oxygen. The cell orientation was also investigated and the upward position showed better performance compared to the downward and horizontal position which gave lower performance. Keywords ― fuel cell, humidity, PEMFC. INTRODUCTION Fuel cell is an electrochemical energy conversion device that produces electricity directly from chemical energy, and the by-products are only water and heat. It is seen by many pioneers that fuel cell is the solution to a whole range of environmental challenges, such as global warming and harmful levels of local pollutants. The Proton Exchange Membrane Fuel Cell (PEMFC) is regarded as one of the most promising alternative electric power generation method especially for sub-megawatt scale applications mainly required in most of the developing countries due to its low- temperature operation, relative tolerance for impurities, and high power-density. In recent years, tremendous effort in the research and development of PEMFC has been concentrated on the operation variables to regulate the cell performance [1-7]. Water management is one of the most important PEMFC aspects. Figure 1 shows a scheme of the water transport processes in the PEMFC. The main water transport processes in the membrane are electro-osmotic drag and back diffusion. They affect the water balance in a PEMFC and determine the membrane hydration. Optimum water balance between the anode and cathode is crucial for achieving good cell performance because the water level in a fuel cell strongly affects not only the membrane properties, but also reactant transport and electrode reaction kinetics [5]. Many papers were concerned with understanding the mechanisms of water transport and exploring its effect on cell performance [1,2,5,8-12]. FIGURE 1 WATER MOVEMENTS THROUGH THE PEM ELECTROLYTE ________________________________________________________ 1 Ahmed M. Hamed, Mansoura University, amhamed@mans.edu.eg 2 Mahmoud M. Awad, Mansoura University. 3 Mohamed A. Tolba, Mansoura University.