The Analysis of Fuel Consumption and Exhaust Emissions From Forklifts Fueled by Diesel Fuel and Liquefied Petroleum Gas (LPG) Obtained Under Real Driving Conditions

Abstract

The paper presents an analysis of gaseous exhaust emissions and fuel consumption obtained from two forklifts based on the measurements performed under actual driving conditions. The first of the investigated objects was fitted with a diesel engine and the second with a spark ignition engine fueled with LPG. In order to carry out the research, the authors developed a proprietary methodology because the VDI 2198 test procedure (developed by VDI - Association of German Engineers) for the determination of forklift energy consumption, did not fully reflect the actual conditions of operation of these vehicles. The VDI procedure only determines the energy consumption according to predetermined sequences (collecting load, load transport, load-dropping) performed only in indoor areas. The authors developed a test route composed of similar sequences i.e. collecting load, load transport, load-dropping and driving without a load. The measurements were carried out in a warehouse and outdoors, which better reflected the actual forklift driving conditions. During the trials, the exhaust emissions were measured (Semtech - Portable Emission Measurement System) along with the driving parameters such as speed, acceleration and distance covered. Based on the obtained parameters, on-road exhaust emissions and fuel consumption were obtained. The obtained data allowed a comparison of the measurement conditions and the type of fuel used for the forklifts. Both tested vehicles were loaded with identical type of load of the same weight.