A novel method to overcome the shortcomings of turbocharging a single cylinder diesel engine

Single-cylinder diesel engines are generally not turbocharged because of highly pulsating exhaust gas flow, resulting in increased speed fluctuations and reduced turbine performance. In the present work, a novel and simple method is proposed wherein an exhaust plenum is placed before the turbine to reduce the flow fluctuations. A production light-duty naturally aspirated (NA) diesel engine modified into the turbocharged version was incorporated with an exhaust plenum. Steady-state experiments were performed with the base naturally aspirated engine, the turbocharged version without an exhaust plenum (conventional pulse turbocharging), and the turbocharged version with the exhaust plenum. The present work attempts to establish the limitations of conventional pulse turbocharging in a single-cylinder diesel engine unavailable in the existing literature. Though the conventional pulse turbocharged version could deliver a boost pressure of about 2 bar (absolute), a brake power reduction of 40% and the associated drop in brake mean effective pressure was observed compared to the base NA engine due to high exhaust back pressures. The pumping work was four times higher in conventional pulse turbocharging than the NA engine, thus reducing the performance. After validating the simulation models, a one-dimensional simulation tool was used to evaluate the effect of incorporating exhaust plenum before the turbine. Simulated results predicted the brake power output within a 3% error for the NA and plenum turbocharging configurations. An optimal plenum volume was arrived at using the validated simulation model. Subsequent experiments on the turbocharged engine with the plenum in place showed a significant improvement in the engine performance and reduced exhaust emissions compared to the NA version. Brake power output was enhanced by 25%, which indicated improved thermal efficiency of 2%. Compared to the NA version, the soot, carbon monoxide (CO) and unburned hydrocarbon HC emissions were reduced by 93%, 88%, and 53%, respectively. However, an increase in oxides of nitrogen (NOx) emissions was seen, which can be controlled with suitable mitigation methods taking advantage of the significantly lower soot levels. Thus, the proposed method of placing an exhaust plenum before the turbine makes turbocharging viable on single-cylinder diesel engines with performance improvement and emission reduction when suitable NOx mitigation measures are adopted.

The Effect of Compression Ratio on Performance of Generator Set Fuelled with Raw Biogas

In order to utilize a raw biogas as a fuel of generator set (gen-set), it is important to figure out optimum operating parameter of the gen-set, i.e. compression ratio. The present work aims to investigate the effect of compression ratio on performance of 3 kW gen-set fuelled with raw biogas and to obtain optimum compression ratio for operation of the gen-set on raw biogas. The gen-set used in the present work is bi-fuel engine, i.e. fuelled with gasoline or LPG. The performance of the engine fuelled with raw biogas in terms of brake power, brake torque, brake specific fuel consumption, and thermal efficiency is evaluated at compression ratio of 7.5, 8.5, 9.5, and 10.5. The work is carried out under electrical load of 240, 420, and 600 Watt. The result indicates that compression ratio affects the rotational speed, brake power, brake torque, brake specific fuel consumption, and thermal efficiency of the gen-set. Optimum compression ratio for the gen-set fuelled with raw biogas is 9.5. At the optimum compression ratio, maximum brake power, brake torque, and thermal efficiency of are 450.37 W, 1.66 Nm, and 46.93%, respectively. Minimum brake specific fuel is 0.59 kg/kWh at the optimum compression ratio.

Plasma-Ozone Treatment of Air Supply on Performance and Emissions of Diesel Engine

In improving performance and reducing exhaust emissions in combustion engines, the addition of ozone to the air supplied in the combustion chamber was studied. In this research, ozone can be produced using plasma technology (plasma-ozone) which is a simple and eco-friendly technology. Plasma-ozone was generated using the Dielectric Barrier Discharge (DBD) method. Air is passed in plasma-ozone reactors at different voltages with an ozone variation of 3 mg, 12 mg, 15 mg and 18 mg is obtained. Ozone concentration was detected using an Ozone meter O3 Air Quality Detector and OPA-100 was used to determine exhaust emissions. The result showed that the addition of ozone to the air supply has no significant effect on brake power but is able to increase specific fuel consumption, increase cylinder pressure, shorten combustion processes, and reduce heat release values. The addition of ozone decreases the opacity of exhaust emissions in TV-1 diesel engines become more eco-friendly.

A Simulation of Four Stroke Marine Diesel Engines to Predict Internal Cylinder Characteristics

This paper introduces a simulation of four-stroke marine diesel engines. The submodel of a particular cylinder was carried out, based on the first law of thermodynamics, programmed by Matlab/Simulink program, which describes the relations among internal characteristics, including cylinder performance parameters, heat release, heat loss, and pressure. The heat release is based on the Wiebe function and the heat loss is based on the Woschni function to build submodels. From the result of the model, the indicated pressure of a single cylinder was taken, the brake power of the engine could be estimated through this pressure. The object of the simulation is a new engine, hence the technical documents and test records provided by the manufacturer are sufficient. The model got the input parameters from this and the key outputs of the model (for example the brake power, peak combustion pressure, specific fuel consumption) were compared with the test records to adjust and make it more accurate. These gaps were not over 5%, therefore, this model can be used to predict key complicated internal cylinder characteristics, for example, the pressure, temperature, and thermal efficiency of engines.

A Review of Comparative Study on The Effect of Hydroxyl Gas in Internal Combustion Engine (ICE) On Engine Performance and Exhaust Emission

This introductory study comes up with an innovative idea of using Hydroxyl gas as a fuel performance enhancer to reduce the natural sources and the overuse of fossil fuel resulting in increased pollution levels. Many researchers have used HHO gas to analyze gasoline and diesel in internal combustion engines. The main challenges of using HHO gas in engines have been identified as system complexity, safety, cost, and electrolysis efficiency. This article focuses on different performance reports and the emission characteristics of a compression ignition engine. As opposed to general diesel, this study found that using HHO gas improved brake power and torque. In all cases, an increase in braking thermal efficiency can be observed. This was due to the presence of hydrogen in HHO gas with higher calorific value than fossil fuels. At the same time, the fuel consumption unit of the engine was reduced, and the combined impact of hydrogen and oxygen helped to achieve complete combustion and improved the combustion capacity of the fuel when HHO gas was injected. The addition of HHO gas also improved the Brake Power (BP), Brake Torque (BT), Brake Specific Fuel Consumption (BSFC), and thermal efficiency while simultaneously reducing CO and HC formation. The rise in CO2 emissions represented the completion of combustion. Therefore, the usage of HHO gas in the Compression Ignition (CI) engine improved the engine performance and exhaust emissions.

Performance characteristics of diesel engine using blends of Jatropha biodiesel

Jatropha is a tropical herb and can be matured in a diverse soil with low to high rainfall. It provides a chunk of the fuel supply in the transportation and energy sectors. Jatropha biodiesel implies a diesel equivalent and consist of methyl esters. It is produced through the transesterification process which is a chemical reaction of jatropha oil with an alcohol in the presence of a catalyst. In the present work, the physical and chemical attributes of jatropha biodiesel were determined. Various blended samples of jatropha biodiesel with mineral diesel were used to run diesel engine to see the variation of the brake power, brake specific fuel consumption and brake thermal efficiency of engine with percentage increase of jatropha biodiesel in the mixture. It was observed that these properties remain unchanged for 5% and 10% blend of jatropha biodiesel to mineral diesel and hence its use is quite feasible without any change in engine design. This provides an edge to the countries having surplus lands in low rain areas to generate 10% of their energy resources for power generation and transport through the cultivation and growth of jatropha plants.

Analysis of Operational Effi ciency of the Proposed Propulsion Systems for Selected Large RoPax Vessel

This paper presents the characteristics of ferry shipping with particular emphasis on large RoPax vessels operating in the Baltic Sea. A critical review of main propulsion system used on large RoPax ferries has been done. Optimal propeller parameters and required brake power have been estimated on the basis of total resistance of bare hull and appendages approximated according to Holtrop-Mennen method. Main engines and generating sets have been selected for minimized fuel consumption approximated with quadratic regression. Operational parameters and costs of analysed large RoPax main propulsion systems have been compared.

Exergy and energy analysis of the Spirulina microalgae blends in a direct injection engine at variable engine loads

This paper explores the exergy analysis of the diesel engine with the selected Spirulina Microalgae biooil (SMBO) biodiesel. The adaptability of the biofuels as an efficient replacement to the fossil fuel has to be tested and proved. To estimate the overall efficiency of the engine with the biofuel blends, it is essential to find out the energy conversion capability of the engine. Different fuel blends were taken as B0 (100% diesel), B10 (10% SMBO+90% diesel), B20 (20% SMBO+80% diesel) and B30 (30% SMBOO+70% diesel). All experimental tests were conducted in a naturally aspirated DI engine. The brake power (BP), heat release rate (HRR), exergy destruction, ideal efficiency, actual efficiency, exergy rate and energy rate of the fuel as well as exhaust were measured for all fuel blends. All tests were conducted at different rpm from 0 to 3000 rpm with 500 rpm interval and also at different loads such as 0%, 25%, 50%, 75% and 100% load. The loss of exergy of fuel and thermal was on the rise and noticed in B0, B10, B20 and B30 while the HRR and loss of exergy rate were found in exhaust as more decreasing one in B10, B20 and B30 fuel blends than B0 (pure diesel).

Hydrogen Addition to Natural Gas in Cogeneration Engines: Optimization of Performances Through Numerical Modeling

A numerical study of the energy conversion process occurring in a lean-charge cogenerative engine, designed to be powered by natural gas, is here conducted to analyze its performances when fueled with mixtures of natural gas and several percentages of hydrogen. The suitability of these blends to ensure engine operations is proven through a zero–one-dimensional engine schematization, where an original combustion model is employed to account for the different laminar propagation speeds deriving from the hydrogen addition. Guidelines for engine recalibration are traced thanks to the achieved numerical results. Increasing hydrogen fractions in the blend speeds up the combustion propagation, achieving the highest brake power when a 20% of hydrogen fraction is considered. Further increase of this last would reduce the volumetric efficiency by virtue of the lower mixture density. The formation of the NOx pollutants also grows exponentially with the hydrogen fraction. Oppositely, the efficiency related to the exploitation of the exhaust gases’ enthalpy reduces with the hydrogen fraction as shorter combustion durations lead to lower temperatures at the exhaust. If the operative conditions are shifted towards leaner air-to-fuel ratios, the in-cylinder flame propagation speed decreases because of the lower amount of fuel trapped in the mixture, reducing the conversion efficiencies and the emitted nitrogen oxides at the exhaust. The link between brake power and spark timing is also highlighted: a maximum is reached at an ignition timing of 21° before top dead center for hydrogen fractions between 10 and 20%. However, the exhaust gases’ temperature also diminishes for retarded spark timings. Lastly, an optimization algorithm is implemented to individuate the optimal condition in which the engine is characterized by the highest power production with the minimum fuel consumption and related environmental impact. As a main result, hydrogen addition up to 15% in volume to natural gas in real cogeneration systems is proven as a viable route only if engine operations are shifted towards leaner air-to-fuel ratios, to avoid rapid pressure rise and excessive production of pollutant emissions.

A Study on Performance and Emission Characteristics of Diesel Engine Using Ricinus Communis (Castor Oil) Ethyl Esters

Countries globally are focusing on alternative fuels to reduce the environmental pollution. An example is biodiesel fuel, which is leading the way to other technologies. In this research, the methyl esters of castor oil were prepared using a two-step transesterification process. The respective properties of the castor oil (Ricinus Communis) biodiesel were estimated using ASTM standards. The effect of performance and emission on diesel engines was noted for four various engine loads (25, 50, 75, and 100%), with two different blends (B5 and B20) and at two different engine speeds (1500 and 2000 rpm). The study determined that B5 and B20 samples at 1500 rpm engine speed obtained the same power, but diesel fuel generated greater control. The power increased at 2000 rpm for B5 samples, but B20 samples, as well as diesel, were almost the same values. In the 40–80% range, load and load values were entirely parallel for each load observed from the engine performance of the brake power in all samples.