Integration Of Direct Methanol Fuel Cell Testing System And Experimental Study

Fuel cell is an electrochemical device that converts chemical energy of fuel and oxygen to electric power. Fuel cell is considered to be a main substitute for fossil energy resources because of its advantages such as high energy density, high efficiency conversion and low noise. An exclusive set of equipment for performance test is needed in study of fuel cell, because characteristics of fuel cell are very different from most conventional batteries. In this paper, the function requirements and composition principle of DMFC testing system have been investigated and a DMFC performance test platform was integrated.Both the anode reactant (methanol solution) feed subsystem and cathode reactant (air) supply subsystem are improved designed and fabricated according to the reactant supply requirements of DMFC. A peristaltic pump is added into the fuel feed system to expand the flow rate range. The accuracy and speed of temperature control are increased by improving the heating block. The gas supply system can be divided into two parts: an adaptive PID control strategy is applied in the oxygen or air supply part using proportional flow valve as the actuator; several manual flow valves are used in the hydrogen supply part to ensure the security.According to the performance test requirements of DMFC, a power testing instrument and a performance monitoring system for individual cells in a series fuel cell stack are designed and implemented. By using the power testing instrument, the voltage and current about special point of the circuit can be real-time measured and then the output power and efficiency can be calculated. In performance monitoring system for individual cells, several analog multiplexers are used to choice the relevant individual cell and the voltage and current of each cell are measured to avoid damage of either the individual cell or the whole stack. In Microsoft Visual C++ 6.0, a software interface was programmed to display and store the measured data which were used to plot polarization curves.After all the above mentioned subsystems were debugged, all the instruments including commercial electronic load and electrochemical workstation were distributed in the cabinet to be an integral instrument. And subsequently, joint debug was carried out. Experimental results have shown that this system for DMFC can be used to measure the performance of fuel cell stack, and what's more, it has a good extensibility.