Cristian Nutu

Aspects of the animal fat use at the diesel engine fuelling

The general objective of the research is analyzes of the preheated gas oil-animal fat blends use at the experimental diesel engine, type CFR- IT9-3M, adequate instrumentation. The engine was fuelled firstly with diesel fuel then with different diesel fuel-animal fats blends (5%, 10%, 15% animal fats content in mixture with diesel fuel). The main animal fat advantages - cetane number and calorific value close to diesel fuel, higher oxygen content it recommend a good alternative fuel for diesel engines. But, the high viscosity and poor vaporization characteristics of animal fats need prior their heating. The results of experimental investigations show the animal fats effects on auto ignition delay, on the combustion parameters and on the pollutants emissions level. Thus, at the animal fats content increase in mixture with diesel fuel, for same engine adjustments, were obtained the follow results: auto ignition delay increases with ~20%; maximum gas pressure decreases with 10%; gas temperature decreases with 8%; indicate efficiency decreases with 10%; NOx emissions level decreases with 30%; CO emission level increases with 28%; HC emissions level increases with 58%; CO2 emission level decreases with 3.5% and smoke emissions decreases with 65%. Was established the animal fats effects on the fuel auto ignition and combustion. Animal fats can be considered a good alternative fuel for diesel engine, assuring the replace of the fossil fuels and resolving the major problem of animal wastes.

Aspects of Experimental Research on Hydrogen Fuelled Automotive Diesel Engine

The use of hydrogen at the diesel engines for improvement energetic and ecologic their performance is the main objective of the paper. The research work has been carried out on truck diesel engine at the 55 % load and 1400 rpm. The engine was fuelled firstly with diesel fuel, then with diesel fuel and hydrogen at different rates between 11–40 L/min. The minimum brake specific energetic consumption decreases with ~9 % and NOx emission decreases with 5.5 % due to combustion improvement at the hydrogen use. The engine energetic and ecologic performances are improved.

Study of the Diesel Engine Cycle Variability at LPG Fuelling

Efficiency improves and pollutant emissions decrease of the automotive diesel engine can be assured by Liquid Petroleum Gas fuelling. Paper target is the study of cycle variability at LPG fuelling, which shows new, important, considerable implication and effects of LPG use at diesel engine, completing the general experimental investigation of engine running at fuelling with alternative fuel for a clean environmental. The K9K EURO 4 diesel engine was mounted on the test bed, equipped with instrumentation and fuelled with LPG by diesel gas method. The investigated engine operating regimes were 55 % and 70 % load at speed of 2000 rpm, at fuelling with diesel fuel and LPG at different substitute ratios. The increase of LPG cycle dose leads to the increase of cycle maximum pressure and maximum pressure cycle dispersion, thus the dispersion of successive running cycle’s increases. This fact may become a limitation criterion for the LPG substitute ratio value.

Effect ofHydrogen Use on Diesel Engine Performance

Necessity of pollutant emissions decreasing, a great interest aspect discussed at 2015 Paris Climate Conference, highlights the necessity of alternative fuels use at diesel engines. Hydrogen is considered a future fuel for the automotive industry due to its properties which define it as the cleanest fuel and due to the production unlimited sources. The use of hydrogen as fuel for diesel engines has a higher degree of complexity because of some hydrogen particularities which lead to specific issues of the hydrogen use at diesel engine: tendency of uncontrolled ignition with inlet backfire, in-cylinder combustion with higher heat release rates and with high NOx level, storage difficulties. Because hydrogen storing on vehicle board implies important difficulties in terms of safety and automotive range, the partial substitution of diesel fuel by hydrogen injected into the inlet manifold represents the most efficient method. The paper presents the results of the experimental researches carried on a truck diesel engine fuelled with diesel fuel and hydrogen, in-cylinder phenomenas study showing the influence of some parameters on combustion, engine performance and pollutant emissions. The paper novelty is defined by the hydrogen fuelling method applied to diesel engine and the efficient control of the engine running.

Experimental investigations of the hydrogen addition effects on diesel engine performance

In the global content regarding the impact on the environmental of the gases emissions resulted from the fossil fuels combustion, an interest aspect discussed on the 21st Session of the Conference of the Parties from the 2015 Paris Climate Conference and the gradual diminution of the worldwide oil reserves contribute to the necessity of searching of alternative energy from durable and renewable resources. At the use of hydrogen as addition in air to diesel engine, the level of CO, HC and smoke from the exhaust gases will decrease due to the improvement of the combustion process. At low and medium partial loads and low hydrogen energetic ratios used the NOX emission level can decrease comparative to classic diesel engine. The hydrogen use as fuel for diesel engine leads to the improving of the energetic and emissions performance of the engine due to combustion improvement and reduction of carbon content. The paper presents, in a comparative way, results of the experimental researches carried on a truck compression ignition engine fuelled with diesel fuel and with hydrogen diesel fuel and hydrogen as addition in air at different engine operation regimes. The results obtained during experimental investigations show better energetic and pollution performance of the engine fuelled with hydrogen as addition in air comparative to classic engine. The influences of hydrogen addition on engine operation are shown.