Development of a novel wavelength agile laser sensor for solid oxide fuel cell diagnostics

Completed

Hydrogen and Fuel Cells(Fuel Cells)

Basic and strategic applied research

ENGINEERING AND TECHNOLOGY (Chemical Engineering)

Not Cross-cutting

Dr JF Hult
Chemical Engineering
University of Cambridge

Standard

EPSRC

31 October 2005

30 October 2008

36 months

£232,864

Tools; technologies & methods

East of England

Engineering -- Materials, Mechanical and Medical Eng

Dr JF Hult, Chemical Engineering, University of Cambridge

Project Contact, Rolls-Royce Fuel Cell Systems Ltd

Most of the world's energy production is currently based on combustion of fossil fuels, and will continue to do so for the foreseeable future. This widespread use of combustion has led to problems with global warming and pollution of our environment, and thus urgently calls for improved technology. Fuel cell technology is considered as one of the strongest candidates for future energy production, as fuel cells are more efficient and have lower CO2 and pollutant emissions than competingtechnologies. However, large-scale fuel cell systems are still in the development stage, and need further improvements to achieve widespread commercial application. To develop and optimise fuel cells, but also e.g. internal combustion engines, engineers and researchers need to have a detailed understanding of the complex chemical and physical processes taking place inside these devices. This proposed research addresses this need by developing the tools necessary to experimentally study these processes. Laser based sensors will be developed which are capable of on-line measurements of composition and temperature of the burning or reacting gases in fuel cells and engines.One of the requirements for such sensors is that they must be rapid enough to resolve the fast processes taking place in these systems. It is furthermore advantageous if the wavelength of the laser source can be scanned over a vide range, to allow the measurement of several different chemical species with the same laser. I propose to develop a novel wavelength agile laser sensor, fulfilling both these requirements. This sensor will utilize recent developments in fibre and laser technology, to allow wavelength scanning over more than 100 nm, at rates up to 10 MHz. Such a sensor would allow simultaneous measurements of H2O, CO2, CO and CH4 concentrations as well as gas temperatures in real-time, using a single laser source. The laser source of this sensor will be a fibre laser, which emits extremely short pulses (less than one trillionth of a second) at a high repetition rate (up to 100 million times/second). The spectral width of these short pulses is first widened with the help of crystal fibres, through a process called supercontinuum generation. A rapid wavelength sweep is then achieved by dispersing these short pulses using a high dispersion fibre. This light is sent through the test object, e.g. a fuel cell gas channel, and from the resulting absorption which is recorded using a photodiode andan oscilloscope, the gas composition and temperature can be calculated.The laser sensor development will take place at the Department of Chemical Engineering, University of Cambridge. Once developed the sensors will then be used for on-line measurements in industrial fuel cell systems and in engines. The aims of these measurements are to study the complex reactions taking place in these devices, and to directly aid in the practical development and optimisation of these systems. The work on fuelcells will beperformed in close collaboration with Rolls-Royce Fuel Cell Systems Ltd. who are currently developing high temperature solid oxide fuel cell (SOFC) systems for large scale power applications. Through this collaboration I will get access to state-of-the-art large-scale fuel cell test facilities. The laser sensor will be used to monitor fuel and product gas compositions in real time under running conditions, at several different positions in the system. The results of these measurements will then feed directly into the Rolls-Royce SOFC development program.The proposed research will directly benefit engineers and researchers in the fuel cell and combustion fields, by providing the tools needed to characterize the reacting gas mixtures inside fuel cells or engines. The research will thus aid in the development of cleaner and more efficient technology for energy production, which will eventually benefit us all

01/01/07