Hydrogen Concentration Sensor Selection for the Renewable Energy Vehicle
Hydrogen Concentration Sensor Selection for the Renewable Energy Vehicle
School of Mechanical Engineering, The University of Western Australia ABSTRACT: This paper discusses the selection of a hydrogen concentration sensor for the use in the University of Western Australia’s Renewable Energy Vehicle (REV). Prior to selecting a sensor, it is important to consider the available sensing methods and the specific properties of the measurand, hydrogen. The selection process leading up to the purchase of two different hydrogen sensors from Neodym Technologies, is documented and finally the method of sensor calibration is outlined.
1
INTRODUCTION
The University of Western Australia’s Renewable Energy Vehicle (REV) project aims to show the viability of using renewable energy as a means of transport. The vehicle will resemble the cars of today, but will be solely powered by a hybrid of hydrogen fuel and solar energy. The proposed car’s completion date is late 2005, allowing it to be driven around Australia in 2006. The REV requires numerous amounts of measured physical quantities for both data logging and controlling the car’s systems. For each measured physical quantity, a sensor is required to convert this quantity into an electrical signal. Safety is always first priority, and for this reason hydrogen leak safety sensors were given the highest priority on the list of required sensors.
2
HYDROGEN CONCENTRATION MEASUREMENT
Hydrogen gas is extremely flammable having an EL1 of 4.1–74.8 % by volume in air. The minimum energy of hydrogen gas ignition in air at atmospheric pressure is about 0.02 mJ and it has been shown that escaped hydrogen is very easily ignited [1], the ignition temperature in air is 520–580 ◦ C. In high concentrations, hydrogen may exclude an adequate supply of oxygen to the lungs, causing asphyxiation. Hydrogen gas is colourless, odourless and insipid, so the victim may be unaware of its presence. It is therefore, crucial that any hydrogen
School of Mechanical Engineering, The University of Western Australia ABSTRACT: This paper discusses the selection of a hydrogen concentration sensor for the use in the University of Western Australia’s Renewable Energy Vehicle (REV). Prior to selecting a sensor, it is important to consider the available sensing methods and the specific properties of the measurand, hydrogen. The selection process leading up to the purchase of two different hydrogen sensors from Neodym Technologies, is documented and finally the method of sensor calibration is outlined.
1
INTRODUCTION
The University of Western Australia’s Renewable Energy Vehicle (REV) project aims to show the viability of using renewable energy as a means of transport. The vehicle will resemble the cars of today, but will be solely powered by a hybrid of hydrogen fuel and solar energy. The proposed car’s completion date is late 2005, allowing it to be driven around Australia in 2006. The REV requires numerous amounts of measured physical quantities for both data logging and controlling the car’s systems. For each measured physical quantity, a sensor is required to convert this quantity into an electrical signal. Safety is always first priority, and for this reason hydrogen leak safety sensors were given the highest priority on the list of required sensors.
2
HYDROGEN CONCENTRATION MEASUREMENT
Hydrogen gas is extremely flammable having an EL1 of 4.1–74.8 % by volume in air. The minimum energy of hydrogen gas ignition in air at atmospheric pressure is about 0.02 mJ and it has been shown that escaped hydrogen is very easily ignited [1], the ignition temperature in air is 520–580 ◦ C. In high concentrations, hydrogen may exclude an adequate supply of oxygen to the lungs, causing asphyxiation. Hydrogen gas is colourless, odourless and insipid, so the victim may be unaware of its presence. It is therefore, crucial that any hydrogen
References: [1] Safety standard for hydrogen and hydrogen systems. Washington DC. [Online]. Available: //www.hq.nasa.gov/office/codeq/doctree/871916.pdf http: [2] A. P. Jardine. (2000) Hydrogen sensors for hydrogen fuel cell applications. [Online]. Available: http://www.powerpulse.net/powerpulse/archive/aa 111300a1.stm [3] P. Riiedi, P. Heim, A. Mortua, E. Franzi, H. Oguey, and X. Arreguit, “Interface circuit for metal-oxide gas sensor,” 2001. [4] A. D. Brailsford, M. Yussouff, and E. M. Logothetis, “Theory of metal oxide gas sensors for measuring combustibles,” 1997. [5] L. Makadmini and M. Horn, “Self-calibrating electrochemical gassensor,” 1997. [6] J. Vetelino, J. Andle, and R. Falconer, “Theory, design and operation of surface generated acoustic wave sensors,” 1994. [7] B. Drafts. (2000, Oct.) Acoustic wave technology sensors. [Online]. Available: http://www.sensorsmag. com/articles/1000/68/main.shtml [8] V.I.Anisimkin, “Russia-italy researches on surface acoustic wave gas sensors,” 1996. [9] W. Jakubik and M. Urba´czyk, “Hydrogen detection in surface acoustic wave gas sensor based on n interaction speed,” 2004. [10] (2005) Neodym technologies inc. Vancouver, Canada. [Online]. Available: http://www.neodymsystems.com [11] “Miniknowz datasheet,” MiniKnowz Datasheet 100.pdf, 2005. [Online]. Available: neodymsystems.com/download/MiniKnowz Datasheet 100.pdf [12] B. McDonald, private communication, Neodym Technologies Inc., 2005. [13] “Panterra-TCOND Product Brief,” Panterra-TCOND Brief 100.pdf, 2005. [Online]. Available: http: //www.neodymsystems.com/download/Panterra-TCOND Brief 100.pdf http://www.