THE USE OF HYDROGEN AS A FUEL FOR COMPRESSION IGNITION ENGINES Thesis by Jorge M.G. Antunes In Partial Fulfilment of the Requirements for the Degree of Doctor of Philosophy Date of Submission September 2010 ii Keywords: diesel engine, compression ignition, hydrogen, injection, simulation, pulsed injection, emissions, HCCI, Miller cycle, Abstract The objective of this research was to investigate the applicability of hydrogen as a fuel for compression ignition engines. The research indicates that hydrogen is a suitable fuel for “compression ignition” (CI) engines, “fumigated diesel” (FD), “homogeneous charge compression ignition” (HCCI) and “direct injection of hydrogen” (DIH2). Peculiarities of the various modes of operation with hydrogen were investigated using a high speed commercial direct injection diesel engine, Deutz 1FL 511 with a compression ratio of 17:1, as well as a simulation model to assist with on the understanding of certain phenomena that were impossible to reproduce due to the engine and transducers physical limitations. Instrumentation with high-speed data acquisition was designed and installed to measure crankshaft speed and position, airflow rate, inlet air pressure and temperature, fuel consumption, brake power, cylinder combustion pressure, and exhaust gas temperature. The design, construction and characterization of a pulse controlled hydrogen injection system for HCCI and DIH2 was carried out and discussed. In this research, special attention was paid to characterize and identify the operating parameters that control the hydrogen combustion in a CI engine. High rates of engine cylinder pressure rise were found when using hydrogen and some form of control solution is required. Simulation and engine tests were carried out to characterize and identify new design approaches to control such high rates of pressure rise, culminating in the proposal of a pulsed injection methodology, and also the use of the Miller cycle to mitigate the observed high rates of pressure rise. A number of possible iii innovative solutions and measures, making the hydrogen engine operation reliable and safe are also presented. iv Acknowledgments This research work was carried out at the TecnoVeritas - Services of Engineering and Systems Technology Ltd. laboratory, without which it would not be possible. Profound thanks are due to my family for their unconditional support, and love given throughout my student life, most in particular during the present research work, for bearing my bad mood when research work looked like being impossible, and the discouragement was beating hard. During the development of this research at the School of Marine Science and Technology, I received a valuable help, advice and financial support from my friend and supervisor Professor A. P. Roskilly. I wish to thank, Mr. João Reis, for the Saturdays and nights spent with me around the engine and Dr Yao Dong Wang for his patience and support. Thank you GOD! There is more to come! I will be counting on you! To: Margarida, Joana, Anucha, Gabi, Mia e Jaime. v vi List of papers Antunes J. and Roskilly A., (2004). “The use of H2 on compression ignition engines”, 3rd European Congress on economics and management of energy in industry, Lisbon. Antunes J. and Roskilly A., (2006). “Opportunities & advantages of the use of hydrogen on board ships – new concepts”, X International Naval Engineering Conference, Lisbon. Antunes J. and Roskilly A. R.Mikalsen, (2008). “An investigation of hydrogen-fuelled HCCI engine performance and operation”, Published by the International Journal of Hydrogen Energy. Antunes J. and Roskilly A. R.Mikalsen, (2008). “An experimental study of a direct injection compression ignition hydrogen engine”, Published by International Journal of Hydrogen Energy. Antunes J. and Roskilly A. R.Mikalsen, (2009). “The hydrogen-fuelled HCCI engine performance and operation”, Paper presented at the Conference HYPOTHESIS VIII Hydrogen Power Theoretical and Engineering Solutions - International Symposium April 2009. Antunes J. and Roskilly A. R.Mikalsen (2009) “Conversion of large-bore diesel engines for heavy fuel oil and natural gas dual fuel operation”. Paper submitted in 2009, waiting for publication by CIMAC. vii viii Contents Abstract ............................................................................................................................. iii Acknowledgements .................................................................................................. v List of papers ............................................................................................................... vii List of figures ............................................................................................................... xv List of tables ............................................................................................................... xxv Nomenclature ............................................................................................................xxvii 1 Introduction .................................................................................................................1 1.1 Alternative power generating systems ................................................................................2 1.1.1 Stationary power generation ...............................................................................2 1.1.2 Propulsion systems .............................................................................................3 1.2 Internal combustion engines ............................................................................................... 4 1.2.1 The use of hydrogen in CI engines .....................................................................4 1.3 Contribution to existing research ........................................................................................6 2 Hydrogen engine research review .............................................................9 2.1 Hydrogen utilisation as an engine fuel ................................................................................9 2.2 Spark ignition hydrogen engine operation ........................................................................11 2.3 Improvement of CI engines performance: bi-fuel experience ........................................... 12 2.3.1 Early work on bi-fuel CI engine operation ......................................................... 13 2.3.2 Bi-fuel operation with hydrogen induction ......................................................... 14 2.4 Compression ignition hydrogen engines ...........................................................................17 2.4.1 The DIH2 engine ................................................................................................18 2.4.2 DIH2 engine specific problems .......................................................................... 27 2.4.3 The HCCI hydrogen engine .............................................................................. 27 2.4.4 HCCI hydrogen engine specific problems .........................................................29 2.5 Fundamental hydrogen engine specific properties ...........................................................30 ix 2.5.1 Comparison of hydrogen versus methane combustion ..................................... 31 2.5.2 Heat transfer in hydrogen fuelled engines ........................................................34 2.5.3 Exhaust heat losses in hydrogen fuelled engines ............................................. 37 2.6 Hydrogen engine safety .................................................................................................... 39 2.7 Conclusions ....................................................................................................................... 40 3 Engine performance analysis through experimentation ......... 43 3.1 Engine experimental setup ...............................................................................................43 3.1.1 Compression ignition engine ............................................................................. 43 3.1.2 Air supply system modifications ........................................................................47 3.1.3 Fuel system .......................................................................................................47 3.1.4 Exhaust gas system ..........................................................................................48 3.1.5 Test rig instrumentation and data acquisition system .......................................49 3.1.6 Data acquisition system hardware ....................................................................50 3.1.7 Data acquisition system software ......................................................................53 3.1.8 Engine speed and crank angle measurement ..................................................57 3.1.9 Cylinder pressure transducer ............................................................................58 3.1.10 Air mass flow transducer and measurement ................................................... 58 3.1.11 Hydrogen mass flow measurement .................................................................59 3.1.12 Lambda oxygen transducer and measurement ..............................................59 3.2 Hydrogen fuel injection systems .......................................................................................59 3.2.1 Material considerations when using hydrogen ..................................................59 3.2.2 Hydrogen HCCI