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Abstract. This paper presents an experimental research on the fuel control system which is installed on the diesel engine Cummins to assess the technical characteristics and emissions, when the engine is using dual fuel liquid LPG-Diesel with different ratios of LPG. The experimental results show that the engine running dual fuel LPG -Diesel reached 96 % maximum moment. Average torque and average power were reduced, but not significantly compared to the case of the engine using 100 % diesel. The percentage of the alternative LPG fuel could be reached by 60 %. For engine using dual fuel, the concentration of CO 2 and particle concentration are decreased.Keywords: dual engine, diesel, LPG, exhaust emission. IntroductionThe dual compression ignition (CI) engine (LPG gas and diesel) is operated simultaneously on diesel and LPG. This engine has some specific features against the diesel engine, e.g., the engine can only be started on diesel and can only be converted to dual operation after short-term engine warm-up. In dual operation, the dual engine control system must regulate the gaseous fuel dose and the injected diesel dose, so that the combustion course of the homogeneous LPG-air mixture has a sufficient reserve against detonation burning (so-called "knocking"). The risk of "knocking" increases with the increasing richness of the LPG and air mixture and decreases, when the temperature of the intake mixture to the engine is reduced. Injection of liquid LPG into the pipeline behind the charge air cooler (coupled with cooling the mixture) allows for increased LPG share in dual engine operation. With a greater reduction in the fuel injected, an additional risk of dual engines is overheating of the injection nozzles: the dual-engine control system must therefore ensure reliability of operation also from this point of view.

This paper presents the results and the procedure for measuring the efficiency of a single-speed reduction gearbox developed for an autonomous electric utility vehicle. The resulting efficiency of the gearbox was investigated on three different driving cycles, which were selected because their speed profiles most closely matched the expected use of the autonomous vehicle. The required torque for each cycle was obtained from simulations of the vehicle’s driving behaviour including its predicted mass and dimensional parameters after a given driving cycle. The results of this research represent the achieved efficiency and average power loss of the gearbox on each driving cycle. The resulting gearbox efficiency was around 50 % in the predominant areas of driving cycles.

The current standard methods of determining the mechanical losses of the ICE by motoring do not correspond to the low pressures in the cylinders of real engine operation. The new tried and tested method of determining passive resistances by motoring ICE with high working pressures in the cylinders is based on blowing doses of compressed air into the cylinders around BDC with special self-acting valves. When motoring with the new method, the same course of pressures in the cylinders and the same load on the crank mechanism, including the piston group, is achieved during combustion. The measurement proved the problem-free functionality of the self-acting valves, and the conducted experiments provided data on the dependence of mechanical and heat losses in the ICE on the working pressures in the cylinder.

This paper presents an experimental analysis of the overall efficiency of the gearbox for an electric vehicle with a Dual Motor Drive System (DMDS) propulsion system. The efficiency was measured in the powertrain testbed where the gearbox was placed between two dynamometers. The main aim of the experiment was to get relevant values of an overall efficiency as a function of input speed and torque. All these measured values of the gearbox efficiency are included in graphs and efficiency maps. Tests were run with two different amounts of oil charge. The experiment confirmed the expected high values of the overall mechanical gearbox efficiency. The results can be used further for advanced simulations and other electric vehicle experiments.