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Real urban driving conditions challenge exhaust gas aftertreatment systems for diesel passenger cars. One promising approach is the transfer of the selective catalytic reduction to a pre-turbocharger position, resulting in a thermal adjustment of the boundary conditions for the system. The design and functional behaviour of two new pre-turbo concepts are discussed. Challenges arise when the dosing of a urea–water solution and thermal mass are integrated upstream of the turbocharger. The design and results of these new concepts are presented using an integrated methodology. Three-dimensional computational fluid dynamics are used as a tool to fundamentally analyse the flow fields and the preparation process of urea–water-based solution to the reducing agent ammonia. The preparation process includes spray injection, spray interaction phenomena, and mixing of the reducing agent. The prototypically built-up hardware is integrated into an Engine-in-the-Loop test setup. In stationary engine operation, the basic measurement of temperatures and nitrogen oxides allows for the validation of the simulations. Using a simulated vehicle approach, the experimental test setup is capable of being operated in real driving scenarios. An additional 48 V boosting system is integrated and operated in the air pass to analyse and overcome thermal delay. Realistic dynamic load test results and boosted WLTC measurements of a virtual passenger car are presented.

This experimental study investigates the prospective of biogas as fuel in unmodified compression-ignition (CI) diesel engines under biogas-diesel dual-fuel (DF) combustion mode. The premixed air-biogas mixture has been ignited by using diesel as pilot-fuel. The DF mode engine parameters have been investigated with varying the engine load by adjusting the biogas and diesel flow with the individual control mechanism. For the entire tested loads, about 65–69% of diesel mass consumption of the engine has been substituted by biogas under the DF mode. The DF mode consumes lesser friction power than that of the diesel mode. NOx levels have been decreased for the entire loads with biogas fuelled DF mode. The DF mode produced higher CO, HC and CO2 levels to the diesel mode. But, in actual, the $${\text{NO}}_{x} + {\text{HC}}$$ emissions are found within the limit of emission norms, and the amount of CO and CO2 emissions is found much lower when compared to the large volume of CO2 existence in biogas composition. The maximum thermal efficiency of the engine has been observed about 18.66% lower with the biogas-diesel method to diesel way which can be upgraded through advancing the fuel injection timing. This study confirms that it is feasible to use biogas safely being a renewable gaseous fuel in a CI diesel engine with DF mode without operating parameter alterations beyond medium loads. The engine can run for entire loads under DF mode with the achievement of equivalent diesel efficiency, the operating parameters should be adjusted as per the suggestions of this study.

The use of biodiesel blends with petroleum diesel in vehicular engines demands the evaluation of the possible impacts and effects of the gases emitted from their combustion on the environment. Among studies on these questions, biomonitoring using lichens is a viable alternative, given their interactions with the elements dispersed in the atmosphere, as well as its sensitivity and capacity to retain contaminants. In this study, we analyzed the effects of gas emissions from the combustion of biodiesel mixture with petroleum diesel on Cladonia verticillaris thalli. Samples of the lichen (10 g) were exposed to the gases emitted by the exhaust of the generator engine during the combustion process of biodiesel mixtures to petroleum diesel (7% (B7), 10% (B10), 40% (B40), 50% (B50), and 70% (B70)). At 90 days after exposure, samples were analyzed for n-alkane profiles, thallus morphology, photosynthetic pigment contents, and secondary lichen metabolites (protocetraric and fumarprotocetraric acids). Sets B7 and B10 showed better resistance of the lichen to pollutants. Set B40 showed a high stress evidenced by the chain elongation of n-alkanes structure and high chlorophyll production, presenting high morphological damages when compared to the control sets, B7 and B10. The results showed significant reductions of n-alkanes profiles for mixtures with high concentrations of biodiesel (B50 and B70), as well as decreases in the chlorophyll content. These groups showed an increase in the synthesis of secondary metabolites, corroborating the hypothesis that high concentrations of biodiesel in the mixture with petroleum diesel have greater impacts on the lichen. Schematic model for demonstration of using the lichen Cladonia verticillaris as biomonitor of effects from gas emissions from the combustion of biodiesel blends with petroleum diesel by a stationary engine.

Purpose The internal combustion engine operated on gaseous fuels shows great potential in terms of integration of the renewable and traditional sources for an effective solution for clean energy production challenge. Different fuel mixtures that can be used to power the engine are characterized by various combustion properties, which can affect its overall efficiency. The purpose of this paper is to provide reasonable answer, how the operation condition can change due to different fuel, without enormous cost of prototyping processes using physical models a digital model can be seen as promising technique. Design/methodology/approach Presented work discusses the application, and extensive description of two commercial codes Ansys Fluent and Forte for modeling stationary engine fueled by compressed natural gas (CNG) and biogas. To check the model accuracy, all carried out numerical results were compared against experimental data collected at in-house test rig of single cylinder four stroke engine. The impacts of tested gaseous fuel on the engine working conditions and emission levels were investigated. Findings Carried out simulations showed good agreement with experimental data for investigated cases. Application on numerical models give possibility to visualize flame front propagation and pollutant formation for tested fuels. The biogas fuel has shown the impaired early flame phase, which led to longer combustion, lower efficiency, power output, repeatability and in some cases higher HC and carbon monoxide (CO) emissions as a result of combustion during the exhaust stroke. Looking at the CO formation it was observed that it instantly accrue with flame front propagation as a result of methane oxidation, while for NOx formation revers effect was seen. Originality/value The application of new approach for modeling combustion process in stationary engines fueled by CNG and alternative biogas fuel has been discussed. The cons and pros of the Forte code in terms of its application for engine prototaping process has been discussed.

The unique and beneficial characteristics of solid oxide fuel cell (SOFC) technology hold much promise for their eventual widespread adoption in numerous commercial building applications. Nevertheless, cost and durability challenges remain that currently limit SOFC technology penetration in stationary energy applications. Under the U.S. DOE ARPA-E INTEGRATE program, the Colorado School of Mines and its partners are developing a novel hybrid stationary power system comprised of an intermediate temperature (600-degreeC), metal-supported solid oxide fuel cell stack integrated with a high efficiency stationary engine and novel balance-of-point (BOP) equipment.

Measurements of emissions of harmful compounds in the exhaust gas of jet engines are carried out using stationary engine tests. These tests only determine the emission of harmful compounds in the near-airport operations. This creates the need to develop methods and tools that would allow to estimate the emission values of harmful compounds during all operations carried out by the aircraft, including when flying at a given flight level. In order to develop such a method, data from the on-board flight data recorder were associated with the emission factors determined during the LTO test, which is the basic certification test of aircraft engines. The following article presents the methodology necessary to estimate the real emission of harmful compounds during the flight of a Boeing 787-9 Dreamliner, equipped with Rolls-Royce Trent 1000-G engines.

Measurements of emission factors of harmful compounds in the exhaust gases of aircraft engines take place during stationary engine tests. Linking the values of emission factors obtained during such tests with the operational parameters of aircraft engines allows to estimate the emission of harmful compounds during the flight of the aircraft. The problem is to determine the impact of changes in flight altitude on the performance of aircraft engines in terms of emission of harmful compounds in the exhaust. Therefore, it is necessary to correct the developed method for determining emissions during the flight of an aircraft. The following article presents the method of estimating the emissions during the flight of the aircraft, taking into account the impact of changes in flight altitude on engine performance parameters, and thus on the emission values of harmful compounds during the flight. In order to carry out the tests, the flight data of the Boeing 787-9 Dreamliner aircraft were used.

The use of alternative fuels in diesel engines has been the subject of research that seeks new fuels to expand the energy matrix. The aim of this study was to evaluate the performance of the stationary engine with the use of mixtures of biodiesel from soybean and castor bean added to diesel (S500) in two proportions (25% and 40%), evaluating the torque, effective power observed and specific consumption. The five biodiesel mixtures of soybean (S) and castor bean (C) analyzed were: S100C0, S75C25, S50C50, S25C75 and S0C100, which were added to the diesel in proportions B25 and B40, totaling ten treatments, plus the control with diesel S500 (B7). The stationary engine was subjected to the rotations of 3000, 2700, 2400, 2100, 1800 and 1500 rpm. The performance of the engine was similar for all biodiesel mixtures of soybean and castor bean, and commercial diesel (B7). The B40 S100C0 and B40 S75C25 provide better performance in terms of effective power observed and torque at 2700 rpm. The highest effective maximum power (3000 rpm) was obtained with the use of B7 diesel. In the lower rotations, it was possible to identify a similar performance result of the biodiesel mixtures with the B7, in addition to providing better torque and consumption performance compared to the commercial diesel.

In the early stages of development of internal combustion engine (ICE), limitations such as speed, range, and lifespan led to series of researches resulting in the reduction or elimination of these limitations. Combustion in ICE is a rapid and controlled endothermic reaction between air in oxygen and fuel which is accompanied by significant increase in temperature and pressure with the production of heat, flame and carbon particle deposits. This combustion process is a phenomenon that involves turbulence, loss of air-fuel mixture during inflow and outflow into the cylinder. The objection of this study is to perform port flow analysis on ICE to determine flow rate and swirl at different valve lift under stationary engine parts.Methodology employed to analyze and solve the ICE port flow simulation is the use of CFD software that uses the finite volume method of numerical analysis to solve the continuity, Navier-Stokes and energy equations governing the air medium in the internal combustion engine cylinder. The model geometry for the analysis was generated using the Ansys Design Modeller for one cylinder, one suction port and one exhaust port, and two valves. The domain considered is internal combustion engine suction port with 86741 nodes and 263155 elements. Study results revealed that air mass was more concentrated around the valve and inlet port cross-section with swirling motion seen, air stream experienced turbulence as it flowed downwards inside the cylinder, air stream spread was turbulent which will eventually enhance smooth combustion, swirling air stream moves towards the cylinder wall where it experienced tumbling and turbulent which will eventually enhance smooth combustion. From the simulation it was revealed that mass flow rate of inlet air increases with valve lift.

A laboratory study on pollutants (nitrogen oxides and carbon monoxide) removal from the stationary diesel engine exhaust was carried out using electric pulse discharge promoted adsorbent/catalytic technique. The main objective is to explore the exhaust flow rate and engine loading effect on the pollutant removal using plasma hybrid process. Hybrid system consists of plasma cascaded with adsorbent/catalytic reactor which exhibits superior NOx and CO removal efficiency compared to individual processes. Experiments were carried out with different arrangements. More than 93% of NOx reduction by plasma adsorbent hybrid system and about 75% CO reduction by catalyst alone at 400 °C have been achieved. Further, the results of work carried out with different exhaust flow rates, concentration/engine loading conditions are tabulated and discussed.

Gas engines (fuelled with CNG, LNG or Biogas) for generation of power and heat are, to this date, taking up larger shares of the market with respect to diesel engines. In order to meet the limit imposed by the TA-Luft regulations on stationary engines, lean combustion represents a viable solution for achieving lower emissions as well as efficiency levels comparable with diesel engines. Leaner mixtures however affect the combustion stability as the flame propagation velocity and consequently heat release rate are slowed down. As a strategy to deliver higher ignition energy, an active pre-chamber may be used. This work focuses on assessing the performance of a pre-chamber combustion configuration in a stationary heavy-duty engine for power generation, operating at different loads, air-to-fuel ratios and spark timings. The engine was originally a 6-cylinder compression ignition engine which is here employed as a single cylinder engine and then suitably modified to host the pre-chamber (with its natural gas injection system and spark plug) with a new bowl piston to decrease compression ratio. A 0D model is built to make a thermodynamic analysis to characterize the local conditions in the pre-chamber before spark timing (temperature, pressure and composition), based on a compressible nozzle equation for the mass transfer between the chambers and a simplified Woschni model for the pre-chamber's heat transfer. A mathematical expression was found to describe the relationship between the local conditions and the early stage of the combustion. Experimental results showed the beneficial effect of spark delay and mixture leaning for the reduction of NOx emissions, while CO, unburned hydrocarbons and engine performance see improvement with lower air-to-fuel ratios and spark advance.

This study investigates the influence of biodiesel blends produced from agro-industrial residues of palm oil (Elaeis guineensis), on the performance and emission characteristics of a small diameter single-cylinder diesel engine. The engine tests have been performed at three different loads with a constant speed of 3600 rpm. Experimental results have showed that the blends of biodiesel PB5 and PB10 cause a consumption of 1.12% and 2.45% higher than diesel. The addition of biodiesel from palm oil residues has allowed the reduction of CO, CO2, and HC emissions by 28.6%, 12.6%, and 14.3%. However, biodiesel has caused an increase in NOx emissions and smoke density. The evaluation of the thermal efficiency of the brake has showed a difference of 2.4% and 3.7% for PB5 and PB10 compared to conventional diesel. Similar efficiency compared to diesel and significant reductions in CO, CO2, and HC emissions, show that biodiesel blends produced from palm oil agro-industrial wastes have the potential to replace partially the diesel content in the fuel, thus contributing to the reduction of engine emissions and reducing the environmental pollution caused by this type of waste.

Biodiesel produced from renewable sources is known to reduce carbon footprint compared to fossil diesel and thus, has a more significant potential for compression ignition engine applications. Unlike diesel, biodiesel can be produced from various sources and, thereby, subjected to composition variability. A priori knowledge of engine fuel properties of biodiesel would allow a careful feedstock choice for producing biodiesel for automotive and stationary engine applications. Regression models to predict engine fuel properties of biodiesel from its composition using Chromatographic and Spectroscopic-based approaches are explored in the present study to develop the most suitable method. Regression models are developed using composition and Fourier Transform Infrared spectra of seventy biodiesel samples. The composition of the seventy biodiesel samples measured using gas chromatography is correlated with the properties using multilinear regression. In the Spectroscopic-based approach, the seventy biodiesel samples' mid-infrared spectra are correlated with the properties using partial least square regression. The developed regression models based on Chromatographic and Spectroscopic approaches are validated using 33 external validation biodiesel samples. The results obtained show that the calorific value, cetane number, density, and kinematic viscosity of biodiesel samples are predicted with a mean absolute percentage error of 1.16%, 4%, 0.76%, and 2.6%, respectively, using the Chromatographic approach while it is 3.17%, 4.59%, 0.73%, and 3.66%, respectively with Spectroscopic method. The chromatographic approach, which resulted in better prediction than the Spectroscopic method, also captures biodiesel composition variations on the engine fuel properties.

The aim of this study was to investigate the hydraulic stability of micro injections when using polyoxymethylene dimethyl ether (PODE) as pilot fuel for a dual fuel heavy-duty stationary engine. A two-layered 8-hole solenoid injector with an injection angle of 75° was used for the investigation. The challenge with regard to the investigated type of diesel-ignited gas engines is that the injector has to provide a stable injection for both full-diesel mode and dual fuel mode. The stability of the injection was evaluated using the following values: The injection rate, injection gravimetric quantity, injected amount of energy, standard deviation of the injection quantity, coefficient of variation of the injected quantity, the momentum flux, injection duration and injection delay at various pressures and energizing times with neat base diesel fuel, neat PODE and a 50- vol-% PODE-diesel-blend. PODE was found to have a similar gravimetric total injection rates of all holes compared to base diesel fuel with almost the same standard deviation. At higher injection pressures and longer energizing times, the influence of the fuel on the injection quantity becomes more relevant. The influence of the fuel on the injection delay and injection duration was found to be small. An empiric correlation between the discharge coefficient and the Reynolds number was determined which can be used to calculate the discharge coefficient. In summary, we can conclude that with regard to the hydraulic injection characteristics, PODE could be used as a suitable replacement for diesel as pilot fuel in dual fuel engines.

Pyrolysis has received attention as a potentially low cost thermochemical method that can efficiently utilize lignocellulosic residues. The bioenergy derived can bring many socio-economic benefits, especially to remote areas in developing nations like Zimbabwe. This study explores the potential valorization of pine residues to bioenergy from sawmills located in such remote areas through pyrolysis. Characterization of these residues indicated that they could be a good feedstock for pyrolytic conversion due to the relatively high volatile matter (79.16%), low ash content (0.83%) and high gross calorific value (17.6 MJ/kg). This study focuses on the actual pyrolysis and characterization of the product bio-oil, comparing its properties to conventional fuels. The primary goal is to use the bio-oil in stationary engine applications for power generation in such remote areas, in a country with a 40% electricity access and only 19% of rural areas electrified. The optimum pyrolysis temperature was found at 500°C, while the optimum primary condenser temperature with the best quality oil, was at 110°C. At the condenser temperature of 125°C the bio-oil appeared to have decomposed to a lower viscosity substance, while at 140°C most of the substance volatized. The best quality oil had the highest calorific value (15.780MJ/kg), confirming its quality status. The viscosity of this oil was found to be 10,151mPa.s. Gas chromatography was also carried out on the oil samples and the compounds with the highest mass presence were catalogued. It is concluded that the bio-oil could be used in moderate-slow engines with moderate upgrading, while it needs to be diluted with a solvent then blended with a diesel for use in fast diesel engines. It is also important to establish the particulate composition and flash point of the bio-oil, though these tests were not carried out in this study.

Invasive and encroaching (IE) species have posed a threat to biodiversity in ecosystems, rangeland productivity, groundwater generation, the environment and economy in savannah ecosystems like Botswana and Namibia. While de-bushing of large diameter stocks have yielded huge economic returns for countries like Namibia through a lucrative charcoal and fuelwood or chips, smaller diameter ones have little economic value, especially the shrubs that encroach space in cities and towns. The goal of this study is to explore possible means of deriving economic value from the encroachers, which are currently disadvantaging Botswana through reduced rangeland productivity and de-bushing costs. Pyrolysis has received attention as a potentially low cost thermochemical method that can efficiently utilize such lignocellulosic residues. The primary goal is to use the bio-oil in stationary engine applications for power generation, especially in remote areas of sparsely populated Botswana, where it has been deemed uneconomic to connect them to the national grid. Characterization of encroacher bush indicated it could be a good feedstock for pyrolytic conversion due to the relatively high volatile matter (76.51 %), moderately low ash content (3.90%) and high gross calorific value (17.3 MJ/kg). The A. tortilis was then pyrolyzed under varying overall and condenser temperatures to establish the optimum operating parameters. The obtained bio-oil was characterized, comparing its properties to conventional fuels. The optimum pyrolysis temperature was found at 550°C, while the optimum primary condenser temperature, with the best quality oil (36.809MJ/kg), was at 125°C. The viscosity of this oil was estimated to be 24.024 mPa.s using the other characterized samples. Gas chromatography was also carried out on the oil samples and the compounds with the highest mass presence were catalogued. It is concluded that the bio-oil could be used in moderate-slow engines with moderate upgrading, while it needs to be diluted with a solvent then blended with a diesel for use in fast diesel engines. It is also important to establish the particulate composition and flash point of the bio-oil, though these tests were not carried out in this study.

The effect of injection strategies of diesel on combustion, performance and emissions of a single cylinder, light duty, common rail, and methanol-diesel dual fuel engine were investigated. Methanol was port injected and experiments were carried out at a speed of 1500 rpm, brake mean effective pressure of 4.3 bar (75% rated load) and methanol to diesel energy share of about 50%. The directly injected diesel was first introduced as a single pulse, then as two pulses – Pilot and main injection and finally as three pulses – pilot, main and post injection. Single pulse injection of diesel resulted in delayed combustion which lowered the combustion stability and brake thermal efficiency. With the pilot main injection strategy combustion rate, peak combustion temperature and combustion stability were enhanced due to increased charge reactivity. Further, hydrocarbon and carbon monoxide emissions were reduced due to the complete combustion of methanol. The pilot with main and post injection strategy could reduce the rate of pressure rise, Nitric oxide levels and average in-cylinder temperature as compared to the pilot main injection mode. Through proper selection of the quantity and timing of the post injected diesel (1.25 mg/cycle and 5°crank angle after top dead center) which is employed along with pilot and main injections, a significant reduction in Hydrocarbon, Carbon mono-oxide, Nitric oxide and Soot emissions with good combustion stability and low ringing index could be achieved in the dual fuel mode.

Effect of addition of anti-oxidants into the algae biodiesel blend with modification of its fuel injection timing was investigated for the emission control of a compression ignition (CI) engine. It was planned to control the NOx emission of the engine fuelled with algae biodiesel blend by equally concentrating on the smoke control and brake thermal efficiency (BTE). Hence NOx, smoke and BTE were the responses for the present investigation. Experiment test matrix were designed with two different anti-oxidants (Pyrogallol (PY) and Butylated hydroxytoluene (BHT)) and fuel injection timing as the factors by choosing three levels in each factor. A single cylinder stationary engine was tested with the designed test matrix as per the Taguchi Orthogonal array. Experiments results were analysed by calculating multi response signal to noise (MRSN) ratio for the loss functions of the selected responses and also by analysing the variance of obtained MRSN ratio. From the results it was observed that when fuelled with algae biodiesel blend, BHT plays a most significant role followed by injection timing for the reduction of engine NOx emission with equal importance to the smoke control and BTE. It was also observed that the influence of pyrogallol was less when compared with other factors for the NOx control of the CI engine fuelled with algae biodiesel blend.

In the present work an attempt was made to determine the most influencing factor through numerical optimization and also to develop a statistical model for the NOx and smoke control of a DI CI engine with less compromise on engine performance. Seven numeric factors (retarded injection timing, injection pressure, percentage of exhaust gas recirculation, percentage of biodiesel, Butanol, Proponol and Pentanol) and one categorical factor (piston geometry) were selected as the factors for the investigation. Experiments were designed through Taguchi orthogonal array and a single cylinder stationary engine was chosen for conducting the experiments. Results of the experiments were fed into the input for the statistical analysis. NOx, smoke and brake specific fuel consumption (BSFC) were chosen as the responses for the present work. Analysis of variance (ANOVA) and Half Normal plot methods were performed to investigate the factor effects on the chosen responses. A coded regression equation was also developed to predict the responses. From the analysis, it was observed that piston geometry and percentage of biodiesel in the blend have major effect when compared with the other factors tested in this work. Numerical optimization and Fit statistical results were compared with experimental results and toroidal piston geometry at 20 percentage of biodiesel in the blend were found as the best combination of factor levels for this work.

Fossil fuel emissions derived from crude oil have a significant impact on the environment, climate change, air pollution, and others. Under these circumstances, there is a great interest in alternative energy resources, especially those that are able to reduce the emission of atmospheric pollutants. The aim of this study is to evaluate the burning emissions of the following binary mixture and biofuels: commercial diesel (diesel with 5% of biodiesel, B5), pure soy biodiesel (B100), additivated biodiesel (B100 adt) stored at 40 °C for 1, 2, and 3 weeks, and additivated ethanol (Ethanol adt). The burning emissions were evaluated by the levels of benzene, toluene, ethylbenzene, and xylenes (BTEX) and total particulate matter (TPM). The quality of the biofuels was given by oxidative stability during storage. The combustion products were originated from a diesel cycle stationary engine, operating in 1800 rpm and 0% load. For a greater reliability in the results, some figures of merit were evaluated for the determination of BTEX by gas chromatography and flame ionization detection (GC-FID) and the particulate matter was determined by gravimetric analysis. Results show that operating time of the engine influences combustion efficiency. During the initial 15 min, cold engine start, there was increasing in BTEX and TPM emissions, when comparing B100 and B5. Regarding to the storage period of 1–2 weeks, B100, B100 adt, and B5 showed reduction of approximately 36%, 16%, and 4% for TPM, respectively. Evaluating each component of BTEX, the benzene emissions were greater for biofuels, which is in agreement with previous studies. As observed for TPM, the storage time of 1–2 weeks was beneficial for the mitigation of aromatic emissions. A reduction about 60% percent was measured for benzene and ethylbenzene. However, these emissions can also be influenced by the engine operating conditions (load and speed), engine type, and characteristics of biofuels. Additivated ethanol also presented low emissions for these pollutants as well as the lowest percentage of emissions of TPM. It is noteworthy that Ethanol adt present the lowest percentage of benzene emission.

Cooling tower is a type of heat exchanger used to dissipate the unwanted heat from a medium into the atmosphere. A well-designed cooling tower provides prolong contact time for water with air and breaks down the water to have large surface area to promote the heat transfer rate. In the present work, an induced draft cooling tower is fabricated and used with a stationary IC Engine to minimize the overall usage of water. The performance of the tower with two different bed materials (Jute carpet & Polystyrene balls) with and without wire mesh at three different water flow rates viz., 12, 18 and 30 lpm are studied. The cooling tower parameters such as range, approach, efficiency, effectiveness, heat loss, windage losses, and evaporative losses are calculated from the experimental data. At higher flow rates, jute carpets with wire mesh provided optimal results for the parameters while at low flow rates polystyrene balls are found to provide better results. The experimental results showed that the efficiency of the cooling tower increased by 67% as the flow rate increased from 12 lpm to 30 lpm with jute carpet and wire mesh, whereas the efficiency decreases as the flow rate increases with polystyrene as the bed material. Also, the similar trend is observed for the effectiveness of cooling tower.

The possibilities of the vibration accelerations signals parameters application for the assessment of thermodynamic processes in the turbojet engine of the F-16 airplane given in its real work conditions have been presented in the paper. The aim is early detection of negative changes in the mixture formation and combustion processes taking place at the aircraft turbojet engine to maintain the high overall efficiency and safety of aviation tasks. Diagnostics of combustion and injection processes have been conducted for stationary engine investigations in the way to obtain quantity measures (dimensional and non-dimensional) and characteristics for these phenomena in the process value domain. The quality of the fuel injection and combustion, expressed in engine operation parameters of the best sensitivity, has been linked to the particular vibration impulse and energy representations, giving the important functional relations for building a diagnostic system for turbojet F-16 airplane engines for real operating conditions. The results show the proposed method assures early and accurate diagnostics for engine dynamic characteristics, making possible diagnostic system application. The diagnostic system design for combustion and injection processes monitoring and malfunctions detections has been proposed.

This study explore the application of Taguchi design and Response surface methodology for optimizing the NOx and smoke emission of a diesel engine with minimum penalty in brake specific fuel consumption (BSFC). A single cylinder 4.4 kW Direct Injection stationary engine was used for the investigation. Eight parameters (percentage of Biodiesel, percentage of Butanol, percentage of propanol, percentage of pentanol, Piston Geometry, Retarded injection Timing, Injection pressure. Percentage EGR) which have significant effects on engine emissions and performance were selected as factors and NOx, smoke and BSFC were selected as variables for the present investigation. Three levels were chosen in each factor and tests were conducted with different levels of the chosen factors by selecting suitable orthogonal array. ANOVA was employed to obtain the most influencing factor for the chosen variables. Taguchi design was employed for screening the significant factors and optimal custom design under Response Surface Methodology (RSM) was used for optimizing the level of the factors. A predictive correlation was developed for the chosen engine variables as a function of tested factors through regression analysis.

Biodiesel run engines are gaining popularity since the last few years as a viable alternative to conventional petro-diesel based engines. In biodiesel exhaust the content of volatile organic compounds, oil mist, and mass of particulate matter is considerably lower. However, the concentration of oxides of nitrogen (NOx) is relatively higher. In this paper the biodiesel exhaust from a stationary engine is treated under controlled laboratory conditions for removal of NOx using dielectric barrier discharge plasma in cascade with adsorbents prepared from abundantly available industrial waste byproducts like red mud and copper slag. Results were compared with gamma-alumina, a commercial adsorbent. Two different dielectric barrier discharge (DBD) reactors were tested for their effectiveness under Repetitive pulses /AC energization. NOx removal as high as 80% was achieved with pulse energized reactors when cascaded with red mud as adsorbent.

The main objective of the present work was to reduce the higher NOx emission of a stationary engine fueled with diesel with less increase in smoke density and compare the results with that of crude rice bran oil methyl ester (CRBME). Design of experiments method was employed to design the experiments and Taguchi’s L9 orthogonal array was used to conduct the engine tests. Experiment results were analyzed by calculating multi response signal-to-noise ratio (MRSN) and the optimum combination level of factors for the chosen objective was obtained simultaneously using Taguchi’s parametric design. Variance of the MRSN ratio was analyzed through analysis of variance method and the most influencing factor for the chosen objective was obtained for diesel and compared with CRBME. Confirmation experiment was conducted for the obtained optimum combination level of factors and the results were compared with normal operating conditions.

The article contains a thermodynamic analysis of a new combustion system that allows the combustion of stratified gas mixtures with mean air excess coefficient in the range 1.4-1.8. Spark ignition was used in the pre-chamber that has been mounted in the engine cylinder head and contained a rich mixture out of which a turbulent flow of ignited mixture is ejected. It allows spark-jet ignition and the turbulent combustion of the lean mixture in the main combustion chamber. This resulted in a two-stage combustion system for lean mixtures. The experimental study has been conducted using a single-cylinder test engine with a geometric compression ratio e = 15.5 adapted for natural gas supply. The tests were performed at engine speed n = 2000 rpm under stationary engine load when the engine operating parameters and toxic compounds emissions have been recorded. Analysis of the results allowed to conclude that the evaluated combustion system offers large flexibility in the initiation of charge ignition through an appropriate control of the fuel quantities supplied into the pre-chamber and into the main combustion chamber. The research concluded with determining the charge ignition criterion for a suitably divided total fuel dose fed to the cylinder.

A combined catalyst system of Ag/Al 2 O 3 and Fe-BEA was tested in a light-duty engine-bench for H 2 -assisted NH 3 -SCR. Ag/Al 2 O 3 was used to provide a high low-temperature activity, while Fe-BEA can provide a high activity at higher temperatures without the need to co-feed H 2 . The catalysts were combined in a sequential dual-brick layout and compared to Ag/Al 2 O 3 and Fe-BEA only. The aim of the study was to investigate the performance of the catalysts in real life exhaust in contrast to synthetic gas. The catalysts were both tested during stationary and transient conditions. Transient testing was carried out with the New European Driving Cycle (NEDC). Laboratory tests were performed to complement the results from engine tests. Ag/Al 2 O 3 showed a lower NO x conversion in stationary engine tests than expected. This was investigated further in a laboratory test set-up and was attributed to deactivation by soot and/or Ag oxidation, low H 2 levels and low specific catalyst loading. NO 2 increased the catalytic activity at below 250 and above 300 °C. For the combined systems, it was preferred to have Fe-BEA in an upstream position of Ag/Al 2 O 3 compared to the opposite. The high engine out NO 2 /NO x ratio, giving fast-SCR over the Fe-BEA, was believed to be the reason. At low temperature, the activity over the combined systems was higher than that for the individual catalysts showing that there were synergy effects of combining Ag/Al 2 O 3 and Fe-BEA. This was also seen in the transient tests. However, the overall cycle NO x conversion was low due to very demanding conditions with a lot of the NO x being emitted at below 150 °C. The order of performance based on an overall conversion during the NEDC was dual-brick with Ag/Al 2 O 3 upstream = Ag/Al 2 O 3 only > dual-brick Fe-BEA upstream > Fe-BEA only. The Ag/Al 2 O 3 containing layouts showed a noticeable NO x conversion from the start of the cycle, i.e. before any NH 2 or H 2 was dosed. We believe that the NO x conversion seen came from NO x storage on the Ag/Al 2 O 3 .

This paper presents a feedforward control algorithm for the EGR and VGT systems of passenger car diesel engines. The air-to-fuel ratio and boost pressure are selected as control indicators and the positions of EGR valve and VGT vane are used as control inputs of the EGR and VGT controller. In order to compensate the non-linearity and coupled dynamics of the EGR and VGT systems, we have proposed a non-linear model-based feedforward control algorithm which is obtained from static model inversion approach. It is observed that the average modeling errors of the feedforward algorithm is about 2% using stationary engine experiment data of 225 operating conditions. Using a feedback controller including proportional-integral, the modeling error is compensated. Furthermore, it is validated that the proposed feedforward algorithm generates physically acceptable trajectories of the actuator and successfully tracks the desired values through engine experiments.

In this paper, a multi-objective particle swarm optimization (MOPSO) algorithm and a nondominated sorting genetic algorithm II (NSGA-II) are used to optimize the operating parameters of a 1.6 L, spark ignition (SI) gasoline engine. The aim of this optimization is to reduce engine emissions in terms of carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx), which are the causes of diverse environmental problems such as air pollution and global warming. Stationary engine tests were performed for data generation, covering 60 operating conditions. Artificial neural networks (ANNs) were used to predict exhaust emissions, whose inputs were from six engine operating parameters, and the outputs were three resulting exhaust emissions. The outputs of ANNs were used to evaluate objective functions within the optimization algorithms: NSGA-II and MOPSO. Then a decision-making process was conducted, using a fuzzy method to select a Pareto solution with which the best emission reductions can be achieved. The NSGA-II algorithm achieved reductions of at least 9.84%, 82.44%, and 13.78% for CO, HC, and NOx, respectively. With a MOPSO algorithm the reached reductions were at least 13.68%, 83.80%, and 7.67% for CO, HC, and NOx, respectively.

Biodiesel derived from waste cooking oil (WCO) is gaining increased attention as an alternative fuel due to lower particulate emissions and other beneficial factors such as low cost and utilization of waste oil. However, very little information is available on toxicity of airborne particulate matter (PM) emitted from biodiesel combustion. In this study, PM emitted from WCO-derived biodiesel (B100) was analyzed for its toxic potential together with ultra low sulphur diesel (ULSD) as a reference fuel and their blend (B50). Human lung epithelial carcinoma cells (A549) were used for this comparative toxicity study. Results indicate that cytotoxicity and oxidative stress were higher for B100 relative to ULSD. Furthermore, caspase 3/7 activity indicates that cell death induced by B100 was due to either caspase independent apoptotic process or other programmed cell death pathways. The toxicity was also evaluated for different engine load conditions. It was observed that at lower loads there was no significant difference in the toxicological response of B100 and ULSD. However, with increase in the engine load, B100 and B50 showed significantly higher toxicity and oxidative stress compared to ULSD.

When high-quality power management in spark-ignition engines to the modes of partial loads and idling go significantly deteriorating performance fuel economy as a result of significant after-burning fuel. In the work considered disabling cycles as an exercise to improve the stationary engine 11GD100M on modes of partial loads and idling. It is shown that disabling cycles can significantly improve the performance of the engine under load characteristic. The algorithm disabling cycles step regulation of engine power with a degree (1/20) Ne n .

The silencer or muffler is used to reduce the engine exhaust noise and also to reduce the exhaust flue gas temperature. To achieve this, a proper design of silencer is very important. The aim of this study is to find the effect of radial jets at the upstream of muffler on temperature and acoustic pressure. The radial jets were introduced at different reservoir pressure at the downstream of muffler. The simulation study has been carried out to determine the temperature and pressure distribution inside the silencer with and without radial jets and experiments were carried out to validate the result. It is observed that around 10 dB reduction in OASPL with interaction of jets in cross flow. These jets also reduces the exhaust gas temperature by 80 0C for engine speed 4000 rpm with jets at 2 bar reservoir pressure. Thus, this study concludes that the technique is effective to reduce the temperature of exhaust and noise. This technique can be applied easily to all vehicle mufflers where air at higher pressure is readily available as well as stationary engine mufflers using high pressure from small compressor.

This paper deals with the possibility of using beef tallow and beef tallow biodiesel in energy generation. The environmental, energetic and social–economic aspects are discussed. The steps for obtaining biodiesel from beef tallow are presented as well as the characterization of beef tallow and beef tallow biodiesel. Results for performance and emissions of using beef tallow and beef tallow biodiesel in a stationary engine are also shown. Beef tallow can be successfully applied in compression ignition engine blending with diesel up to 15% of beef tallow. Beef tallow can also be converted in biodiesel and applied in compression ignition engines neat or blended with diesel in any proportion. In the case of neat beef tallow biodiesel, it is not recommended to be used in cold weather conditions, due to its relatively low pour point. The possibility of using beef tallow in power generation, leads to the concepts of sustainability and cleaner production, by the use of a material usually discarded in butcheries.

Problem statement: The increasing awareness of the environmental haza rds and the alarming levels of air pollution have led to more r estrictive regulations on engines emission control in recent years. Approach: The dwindling resources and rising cost of crude o il had resulted in an intensified search for alternate fuels. In the pres ent study biodiesel (palm oil methyl ester) blends with diesel was investigated in a direct injection stati onary diesel engine. The stationary engine test bed used consists of a single-cylinder four stroke dies el engine, eddy current dynamometer with computer control data acquisition system and exhaust emissio ns analyzer. Results: Engine tests were conducted at constant speed using neat diesel fuel and variou s proportions of biodiesel blends. The exhaust emissions such as CO, HC and NOx were measured using exhaust gas analyzer. Performance characteristics like brake thermal efficiency and s pecific fuel consumption were recorded. The differences in the measured emissions and performance of the biodiesel-diesel fuel blends from the baseline operation of the engine, i.e., when workin g with neat diesel fuel were determined and compared. Conclusion: It is concluded that the lower blends of biodiesel increased the brake thermal efficiency and reduced the fuel consumption. Biodie sel blends produces lower engine emissions than diesel. From the result, it has been established th at 20-40% of palm oil biodiesel can be use as a substitute for diesel without any engine modificati ons.

Stationary diesel engines, especially diesel generators, are increasingly being used in both developing countries and developed countries because of increased power demand. Emissions from such engines can have adverse effects on the environment and public health. In this study, particulate emissions from a domestic stationary diesel generator running on ultra-low-sulfur diesel (ULSD) and biodiesel derived from waste cooking oil were characterized for different load conditions. Results indicated a reduction in particulate matter (PM) mass and number emissions while switching diesel to biodiesel. With increase in engine load, it was observed that particle mass increased, although total particle counts decreased for all the fuels. The reduction in total number concentration at higher loads was, however, dependent on percentage of biodiesel in the diesel-biodiesel blend. For pure biodiesel (B100), the reduction in PM emissions for full load compared to idle mode was around 9%, whereas for ULSD the reduction was 26%. A large fraction of ultrafine particles (UFPs) was found in the emissions from biodiesel compared to ULSD. Nearly 90% of total particle concentration in biodiesel emissions comprised ultrafine particles. Particle peak diameter shifted from a smaller to a lower diameter with increase in biodiesel percentage in the fuel mixture.

There has been an increasing concern about the emissions of airborne particulate matter (PM) from diesel engines because of their close association with adverse health and environmental impacts. Among the alternative fuels being considered, biodiesel made by the transesterification of waste cooking oil has received wide attention in recent years because of its low cost and the added advantage of reducing waste oil disposal. This study was conducted to make a comparative evaluation of the particulate-bound elements emitted from ultra low sulphur diesel (ULSD) and waste cooking oil-derived biodiesel (B100) and a blend of both the fuels (B50). It was observed that the PM mass concentrations were reduced by about 36% when B100 was used. Crustal elements such as Mg, K and Al were found to be in higher concentrations compared to other elements emitted from both B100 and ULSD. Zn, Cr, Cu, Fe, Ni, Mg, Ba, K were found to be higher in the biodiesel exhaust while Co, Pb, Mn, Cd, Sr, and As were found to be higher in the ULSD exhaust. To evaluate the potential health risk due to inhalation of PM emitted from diesel engines running on ULSD and B100, health risk estimates based on exposure and dose–response assessments of particulate-bound elements were calculated assuming exposure for 24 h. The findings indicate that the exposure to PM of the B100 exhaust is relatively more hazardous and may pose adverse health effects compared to ULSD.

A supply system of dual biogas/gasoline is proposed for a smallspark ignited internal combustion (SIIC) engine. This work comprehendsthe design, manufacturing and testing of the fuel supply system, includ-ing the devices to maintain the constant engine speed at all loads. Forthe development of the carburetor—mixing device, the authors have em-ployed a mathematical model to optimise its geometry, with the aim ofreducing the pressure losses and maintaining an adequate fuel/air ratio.Moreover, this work shows the experimental results carried out at Insti-tute of Internal Combustion Engines—at Universidad Nacional de Ing-eniería (UNI) in Peru, using a 6 kW, one cylinder, stationary engine. Withrespect to original gasoline engine, with the biogas fired engine, the teamwas able to achieve a drastic reduction in toxic emissions.

Many short-run studies point to the potential for direct fueling of compression ignition engines with plant oil fuels. There is a much smaller body of work that examines the potential for these fuels in long-run tests that illuminate engine endurance and longevity issues. Generally, longevity studies involving direct fueling of engines with straight plant oils have shown significant impact to the life of the engine, though test results vary widely depending on the oil, engine type, test conditions, and measurement approach. This study utilizes a previously designed modification kit [1] to investigate the longevity implications of directly fueling straight plant oil in an indirect injection (IDI) listeroid type, slow speed stationary engine common in agro-processing applications in developing countries. Specifically this study focuses on the lubrication oil by developing a model to characterize the engine wear and estimate lube oil change frequency. The model is extended to an analysis of the piston rings. Cylinder liner wear, emissions, engine performance, and a visual investigation of several critical engine components are also studied. The 500 hour test with waste vegetable oil fuel resulted in several important findings. The engine break-in period was identified as taking between 200 and 300 h. Emissions analysis supported the break-in definition as smoke opacity and carbon monoxide values fell from 9% and 600 ppm (respectively) during the first few hundred hours, to 5% and 400 ppm in the final 200 h. Lubrication oil viscosity was found to be the limiting degradation factor in the lube oil, requiring oil to be changed every 110 h. Piston ring mass loss was found to correlate very closely with chromium buildup in the lubrication oil and the mathematical model that was developed was used to estimate that piston ring inspection and replacement should occur after 1000 h. Cylinder ovalisation was found to be most sever at top dead center (TDC) at 53 microns of averaged increased diameter.

The identification of the nonlinear dynamic behavior of combustion engines on test benches is described. A method, that is based on the combination of statistical stationary engine measurement (Design of Experiments - DoE) and dynamic identification techniques for nonlinear multi-input systems is shown. The dynamics are excited by several amplitude-modulated pseudorandom-binary-signals (APRBS), which act on the engine simultaneously, in order to allow a short measurement time period. To show the applicability of the described identification and modelling methods several models for a common-rail diesel engine with exhaust gas recirculation and variable geometry turbocharger (VGT) are shown, with five input variables and the outputs nitrogen-oxide emissions, opacity, air-fuel ratio (Lambda) and exhaust gas temperature.

In the present investigation an attempt was made to test the feasibility of crude rice bran oil methyl ester (CRBME) which is derived from high free fatty acid (FFA) crude rice bran oil (CRBO) by a two-step transesterification process as a fuel for a heavy-duty automotive compression ignition (CI), i.e. diesel engine in blended form. While running with CRBME blend significant reductions in CO, UBHC and particulate emission were observed with a marginal increase in NOx emission than that of diesel. Brake thermal efficiency of the engine reduced marginally for CRBME blend when compared with diesel. In addition to technical feasibility, the economic feasibility of CRBME blend as a CI engine fuel was also analyzed by comparing its hourly fuel cost with CRBO blend and diesel. It was found that the hourly fuel cost of CRBME blend is higher than CRBO blend and diesel. Calculations have shown that the hourly fuel cost of CRBME blend when used in a stationary engine increases by 50% while that in an automotive engine increases by 45% when compared to diesel. Experimental results show that as a fuel for a heavy-duty diesel engine CRBME blend shows better emission characteristics than diesel with a marginal increase in NOx emission. Hence efforts can be taken to utilize it effectively.