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The paper describes an experimental study concerning the feasibility of using bio-oil obtained from flash pyrolysis of wood for fuelling diesel power plants. The research is based on various tests aimed at verifying relevant operative characteristics of the fuel: spray analyses, engine tests, thermogravimetric analyses (TGA), single-drop reactor tests and corrosion tests. The spray analyses show that the achievement of a satisfactory atomisation with flash-pyrolysis oil is problematic. The engine experimentation shows that flash-pyrolysis oil needs to be modified or mixed (e.g. with alcohol) to make self ignition possible. Besides, unacceptable build-up of carbonaceous deposits, injection system clamping and engine seizure occur. Very large char generation is the main finding of the tests in the TGA apparatus and in the single-drop atmospheric reactor (“drop-tube”). The corrosion tests demonstrate that steel undergoes fast erosion by contact of flash-pyrolysis oil.

The study and the evolution of a simple air-assisted injection system for two-cycle, S.I. engines is described. In the first stage of the research the validity of the system was investigated. During this time the system underwent several improvements and modifications. Later, the research was carried on with the following aims: a) to distinguish the spray characteristics by means of a high speed photographic technique; b) to investigate the dependence of such characteristics on some parameters of the injection system, and their influence on engine performance, with special regard to fuel economy and exhaust emissions. Finally, the case of fuel vaporisation at the outlet of the electroinjector was investigated. In fact, vaporisation and ideal atomisation are similar under some aspects and the knowledge of b.s.f.c. and HC emission in the limit case of perfect atomisation would give a precise idea of the improvements obtainable through betterments in spray characteristics.

The study and the evolution of a simple air-assisted injection system for two-cycle, S.I. engines is described. In the first stage of the research the validity of the system was investigated. During this time the system underwent several improvements and modifications. Later, the research was carried on with the following aims: a) to distinguish the spray characteristics by means of a high speed photographic technique; b) to investigate the dependence of such characteristics on some parameters of the injection system, and their influence on engine performance, with special regard to fuel economy and exhaust emissions. Finally, the case of fuel vaporisation at the outlet of the electroinjector was investigated. In fact, vaporisation and ideal atomisation are similar under some aspects and the knowledge of b.s.f.c. and HC emission in the limit case of perfect atomisation would give a precise idea of the improvements obtainable through betterments in spray characteristics.