A field evaluation of a liquid petroleum gas engine on a harvesting platform

This paper reports a field evaluation of a liquid petroleum gas (L.P.G.) powered engine on a harvesting platform. A self-propelled harvesting platform, equipped with a small Otto engine was chosen to study mechanical solutions to adapt the chosen machine to L.P.G. fuelling and to compare pollutant emissions using petrol and L.P.G. Field test using petrol and L.P.G. were carried out during pears harvesting. Work capacity of the machine, man-power efficiency, fuel consumption and several basic components of exhausted gases mixture (O2, CO, CO2, HC) were measured and evaluated. Field tests were compared with bench tests made on the same engine. The results confirm that L.P.G. fuelling on agricultural machines needs technical and mechanical solutions simpler than the actually adopted on the civil motor-vehicles. These solutions have to be mainly ensure correct regulation and control of L.P.G. delivery and a correct placement of the L.P.G. feeding cylinder, in order to workers safety and simple management during the field operations. Moreover, the field tests point out that the work capacity of the studied machine is the same for both petrol and L.P.G. fuelling, while consumption and engine pollutant emissions are quite lower for L.P.G. fuelling.