Load Variation Effects on Combustion Regimes in A Hydrogen-Diesel Dual Fuel Engine

AbstractThis work presents an experimental study about the impacts of the use of hydrogen as a partial substitution in a direct injection diesel engine. Hydrogen gas was fumigated into the intake manifold of a single cylinder diesel engine to mix with fresh air before entering the combustion chamber of the engine at constant speed with load variation. The homogeneous charges of air-hydrogen mixture were then ignited in the chamber by the main diesel injected. The added hydrogen amounts generated the hydrogen-to-diesel ratios. These affect combustion pressure, heat release rate, and combustion variation in the three regimes investigated, i.e. ignition delay, premixed combustion phase, and mixing-controlled combustion phase as well as the heat release in each combustion phase due to the different hydrogen-to-diesel ratios. The obtained results have shown the reductions in diesel and total fuel consumptions, including exhaust gas emissions when adding hydrogen. These lead the thermal efficiencies to be higher when adding hydrogen. The benefits of this research will be appropriately used in the improvement and development of hydrogen-diesel dual fuel engine and its fuel strategy management in the near future

Reformed Exhaust Gas Recirculation Products of Rapeseed-based Biodiesel: A Chemical Equilibrium Simulation

AbstractThis paper simulates the products from an exhaust gas fuel reforming of rapeseed methyl ester (RME) in comparison with ultra-low sulphur diesel (ULSD). Both types of fuel were also correspondingly used as reformer fuels. In all cases, the reactor inlet temperature was kept constant at 300°C which represents exhaust gas temperature at low load engine condition and is comparable to the actual average exhaust gas temperature. The gas hourly space velocity (GHSV) was set-up at 30,000 h-1 and 45,000 h-1 whereas the latter is a half of typical value for automotive three-way catalytic converters. Different fuel flow rates between 25 and 55 ml×h-1 were tested. The reforming products and temperatures were calculated using an equilibrium model. The results have shown that different engine and reforming fuels affect the produced reformed gasses. Reforming of RME produced less hydrogen compared to the ULSD reforming. The results from simulation were compared with those from experiment at the same condition. At the higher GHSV, an offset between the measured experimental results and the predicted results from the equilibrium model has been found for all conditions tested. For the lower GHSV, the equilibrium model enables a good prediction in reforming yields of hydrogen

Design and Development of Electronic Fuel Injection Control System Program for Single Cylinder Diesel Engine

This research aimed to evaluate mainly on engine-out emission of a single cylinder diesel engine on two conditions of fuel injection system: mechanically and electronically controlled fuel injection system. The research engine was modified to have changeable fuel injection system. The in-house built PECU was capable of producing 3 consecutive injection pulses. Fuel pressure was adjusted between 500 bar to 1100 bar. Engine with electronically controlled fuel injection system produced less NOx than original engine approximately 50%. However, as the result of higher injection pressure HC and CO were increased due to fuel impingement on combustion chamber

The Investigation of CNG Dual-Biodiesel fuel Approach to Address the Performance - Emission Assisted Multipurpose Diesel Engine

AbstractDiesel engines can operate on a variety of the different fuels such as diesel fuel derived from crude oil, natural gas and biodiesel. Nowadays, the price of compress natural gas (CNG) and biodiesel is cheaper than diesel fuel since it is a potential advantage to use a combined CNG and biodiesel for multipurpose diesel engine. The aims of this work were to investigate the efficiency and emission from the multipurpose diesel engine. In the experiments, the fuel used in a combustion chamber was diesel, biodiesel derived from waste cooking oil (B100) and combined B100 and CNG. Effect of the various ratios of CNG (10, 20 and 30%), engine load (25, 50 and 75%) and exhaust gas recirculation (EGR: 0, 10 and 20%) were also investigated. Based on these experiments, the brake thermal efficiency decreased with an increase in CNG ratio. However, the brake thermal efficiency increased with an increase in the engine load. When the CNG ratio in a combustion chamber increased, the hydrocarbon concentration and Smoke number (SN) increased whereas the nitrogen oxide decreased. In term of exhaust gas recirculation (EGR), the use of EGR was not significant effect to brake thermal efficiency for various fuels. However, the increasing of EGR and CNG ratio led to an increase in hydrocarbon, carbon monoxide and Bosch smoke number. It should be noted that the nitrogen oxide decreased with an increase in EGR and CNG ratio

Nano-particle Characteristic Emitted from Gasoline Direct Injection Engine Equipped with Non-Thermal Plasma Device

The impact of non-thermal plasma (NTP) on particulate matter (PM) removal, nitrogen oxide (NOx) reduction, and hydrocarbon species in exhaust gases from gasoline direct injection (GDI) engines using gasoline E20 fuel and a mean effective pressure (IMEP) of 6 bar. The experiments were conducted with an exhaust gas flow rate of 20 L/min, applying high voltage in the range of 0 to 10 kV (2 kV per step) at a frequency of 500 Hz. The results show that NTP reduces PM concentrations, particularly in the nucleation mode (10 nm particles). Maximum PM removal of approximately 83% However, with experimental results, compared to 0 kV, the production of particulate matter Aitken mode increased up to 19 times for a voltage increase of 10 kV, and NOx removal has been at a maximum of about 9.5%, with an energy density of 5 J/L at 10 kV. The effects of NTP on hydrocarbon species such as ethylene, propylene, acetylene, 1.3 butadiene, methane, and ethane have been slightly affected by increased high voltages

Effect of Injection Timing on the Engine Performance and Exhaust Emissions of a Dual-Fuel Compression Ignition Engine

AbstractThe investigation of available alternative fuel to meet high efficiency and more stringent emission controls for compression ignition engine is very challenge. Di-Methyl Ether (DME) is a very interesting fuel of choice in the evolution of alternative fuel due to the physical and chemical properties that matches with conventional diesel fuel. DME combustion also emits overall low emissions especially, particulate matter (PM). The aims of this study was to demonstrate and evaluate the feasibility of the engine performance improvement with lower fuel consumption by optimising the injection timing. The experimentation was conducted on different injection timing (e.g. 15.5°, 13.5° and 17.5° BTDC (before top dead center)). The retard injection timing (13.5° CAD) at high engine load with EGR addition was able to improve engine performances and reduced the level of NOX emissions however this can be  effect on higher black smoke. Therefore, the optimisation of injection timing for dual fuel (DME additions together with diesel engine) engine is required for different operating conditions

Activity for Diesel Particulate Matter Oxidation of Silver Supported on Al2O3, TiO2, ZnO, and CeO2: The Effect of Oxygen Concentration

Particulate matter (PM) is a problem for human health the major producer of PM are diesel engines. The diesel particulate filters (DPFs) are used for the limitation of the PM. The DPF operation consists of two sequential functions: PM filtering and regeneration. One of the main contributing factors affecting the regeneration of DPF is the oxygen concentration in the exhaust gas. This study investigates the impact of different oxygen concentrations (99.99%, 10%, and 5%) on (PM) oxidation when using silver catalysts supported on CeO2, ZnO, TiO2, and Al2O3. The synthesized catalysts were characterized using XRD, SEM, SEMEDX, and H2-TPR techniques, and the PM oxidation activity was evaluated using TGA. The results demonstrated that different oxygen concentrations had little effect on light VOCs oxidation compared to no catalyst or the same catalyst. However, heavy VOCs and soot combustion, which require a higher oxygen concentration, significantly reduce combustion performance when the oxygen concentration decreases

The Influence of Direct Non-Thermal Plasma Treatment on Soot Characteristics under Low Exhaust Gas Temperature

This study aimed to assess the effectiveness of nonthermal plasma (NTP) technology utilizing a dielectric barrier discharge (DBD) reactor, both with and without exhaust gas recirculation (EGR), in reducing soot particles and their impact on nitrogen oxides (NOx). The experiment involved maintaining a constant flue gas flow rate of 10 l/min, employing high voltage values of 0, 6, and 10 kV, fixed frequency of 500 Hz and setting the various IMEP of 5, 6, and 7 bar and the engine speed at 2,000 rpm. The findings demonstrated that NTP was successful in removing NOx by approximately 16.84% and 17.01%, achieving particle matter (PM) removal efficiencies of around 60.79% and 81.13%, and effectively reducing activation energy by approximately 18.34% and 31.5% (with and without EGR, respectively) at a high voltage of 10 kV. These results highlight the potential of NTP technology in mitigating emissions and reducing the environmental impact associated with diesel engines

Numerical modeling of combustion of low-calorific-producer-gas from Mangium wood within a late mixing porous burner (LMPB)

This article presents a numerical study of combustion of low-calorific-producer-gas from Mangium wood within a late mixing porous burner (LMPB). The LMPB consists of four main components, i.e., the fuel preheating porous (FP), the porous combustor (PC), the air jacket, and the mixing chamber. Interestingly, this LMPB was able to highly preheated and it still maintained high safety in operation. A single-step global reaction, steady state approach and a one-dimensional model were considered. The necessary information for burner characteristics, i.e., temperature profile, flame location and maximum temperature were also presented. The results indicated that stable combustion of a low-calorific-producer-gas within LMPB was possible achieved. Increasing equivalence ratio resulted in increasing in the flame temperature. Meanwhile, increasing the firing rate caused slightly decrease in flame temperature. The flame moved to downstream zone of the PC when the firing rate increased. Finally, it was found that the equivalence ratio did not affect the flame location