DESCRIPTION

Technical Description

Fuel cells are energy converters that, unlike heat engines, convert chemical energy directly into electrical energy. Heat is generated as a by-product during this process. 

The main component of ET 292 is a polymer-membrane fuel cell which is operated in combined heat and power generation. 

The system is supplied with high-purity hydrogen from a pressure vessel on the anode side and with oxygen from the ambient air on the cathode side. The fuel cell is operated either current-regulated, voltage-regulated or power-regulated via an integrated electronic load. The setpoint of the electronic load allows a precise adjustment of all operating points and a very accurate recording of characteristics. The technically usable thermal energy is dissipated to the environment via a cooling circuit and can be accounted for via the integrated instrumentation. The water accruing during operation is collected in a water separator. In the fuel cell's dead-end mode the accruing water is disposed of via a fully configurable purge valve for hydrogen. The system is operated via a PC.

Auxiliary energy for pump, fan and control required for operation is provided from the mains. The moisture in the stack can be regulated via the operating temperatures and the supplied air flow, so that no external humidification is required.

All relevant measuring values are recorded to work out the fuel cell's energy balance. The measured values are transmitted directly to a PC via USB. The GUNT data acquisition software is included.

The well-structured instructional material sets out the fundamentals and provides a step-by-step guide through the experiments.

Learning Objectives / Experiments

- conversion of chemical energy into electrical and thermal energy
- function and design of a fuel cell system
- relationships of fuel cell operating parameters
- effects on the electrical performance of fuel cells
- recording and visualisation of all relevant voltage/current characteristics
- calculation of relevant variables