PEFC System Reactant Gas Supply Management and Anode Purging Strategy: An Experimental Approach

In this report, a 5 kW PEFC system running on dry hydrogen with an appropriately sized Balance of Plant (BoP) was used to conduct experimental studies and analyses of gas supply subsystems. The improper rating and use of BoP components has been found to increase parasitic loads, which consequently has a direct effect on the polymer electrolyte fuel cell (PEFC) system efficiency. Therefore, the minimisation of parasitic loads while maintaining desired performance is crucial. Nevertheless, little has been found in the literature regarding experimental work on large stacks and BoP, with the majority of papers concentrating on modelling. A particular interest of our study was the anode side of the fuel cell. Additionally the rationale behind the use of hydrogen anode recirculation was scrutinised, and a novel anode purging strategy was developed and implemented. Through experimental modelling, the use of cathode air blower was minimised since it was found to be the biggest contributor to the parasitic loads.

A Supramolecular Heat-Pump: an Electrochemical Cooling System Utilizing the Enthalpy Change of a Host–Guest Interaction

Redox-stimulated host–guest chemistry was applied for the electrochemical Peltier effect, which is a heat transportation phenomenon observed in redox-active electrolytes. The refrigeration capability was enhanced up to 70%. By the addition of alpha-Cyclodextrin (α-CD) into I−/I3− aqueous solution, the amount of heat transported from the cathode side to the anode side was observed. The enhancement of the heat transportation was derived from the elimination heat of I3− from α-CD associated with the shift of host–guest equilibrium caused by the exhausting of I3− by the reduction. This is the first report that utilized the stimuli-responsive supramolecular interaction for heat transportation.

Bilateral Measurements in Electrical Circuits with Gas-discharge Devices

If the electrical circuit is unbranched, then usually the current that flows through the circuit is measured only at one point of such a series circuit. Therefore, in gas-discharge devices, when powered by a current that contains a variable component, it is necessary to simultaneously measure current both from the anode side and from the cathode side. Dynamic processes will be very different from the average for the period of change in the discharge current. The experimental results of such measurements and a comparison with current measurements at one point in a series circuit with a gas-discharge device are present, for example, not only a change in the dynamic resistance of the discharge, but also a dynamic change in the electrical capacitance of the discharge.