Search

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

In this work the tracer gas method using nitrous oxide as the tracer gas is implemented on a stationary two-stroke cycle, four-cylinder, fuel-injected large-bore natural gas engine. The engine is manufactured by Cooper-Bessemer, model number GMV-4TF. It is representative of the large bore natural gas stationary engine fleet currently in use by the natural gas industry for natural gas compression and power generation. Trapping efficiency measurements are carried out with the tracer gas method at various engine operating conditions, and used to evaluate the scavenging efficiency and trapped A/F ratio. Scavenging efficiency directly affects engine power and trapped A/F ratio has a dramatic impact on pollutant emissions. Engine operating conditions are altered through variations in boost pressure, speed, back pressure, and intake port restriction.

This paper is related with the use of palm oil and palm biodiesel mixed with diesel in different percentages in a stationary engine. It presented the steps for obtaining biodiesel from palm oil and the characterisation of palm oil and palm biodiesel. It also shows the results for performance and emissions of using palm oil and palm biodiesel in a stationary engine. It was concluded that palm oil can be successfully applied in compression ignition engine blending with diesel up to 20% of palm oil. Palm oil can also be converted in biodiesel and used in compression ignition engines neat or blended with diesel in any proportion. The use of neat palm biodiesel is not recommended in cold weather conditions due to its low pour point. The use of palm oil and palm biodiesel in power generation lead to the concepts of sustainability, by the use of a raw material that contributes to CO2 absorption. [Received: September 23, 2015; Accepted: July 24, 2016]

James Watt, a Scottish inventor and mechanical engineer, was responsible for improvements to the steam engine of Thomas Newcomen, before used to pump water out of mines. Watt developed a reciprocating engine, capable of powering a wheel. Although the Watt engine powered cotton mills and a variety of machinery, it was a large stationary engine.

By making use of the overlapping symmetries between the modal inlet fields and the engine face, it is found that the radar modulation due to a set of rotating blades can be computed using only one solution for any blade position. Frequency domain solutions for the stationary engine face can immediately produce modulation data with a simple postprocessing step. The validity of the modulation scheme is demonstrated with the aid of a simplified engine model possessing a semianalytical mode-matching solution.

Velocity information was collected from an intake port of a single-cylinder piston-ported two-stroke engine by a laser-Doppler velocimetric (LDV) system to better understand and quantify the behavior of intake flow exiting into the cylinder during the scavenging process. Ten measurement locations were chosen along a vertical line through the center of the port exit area. Motored, fired (skipfired), and steady (stationary engine) radial velocity measurements were recorded at engine speeds of 600, 900, and 1200 rpm along with cylinder, intake (two positions), and exhaust pressure data. The ensemble-averaged mean radial velocities during motoring, when plotted versus crank angle, are generally flat over most of the port area and influenced by changes in pressure differential between the intake and exhaust ports. During the initial phase of the port opening, a high-velocity jet exits from the port, causing a peak in the mean radial velocity profile. As the port opening area increases, the reattachment point within the port passage apparently moves toward and beyond the exit plane of the port, resulting in near-zero velocities for the measurement points close to the top of the port. Mean velocities measured after the firing cycles are strongly affected by the expansion waves in the intake system, which induce backflow of cylinder gases at 600 and 900 rpm. At 1200 rpm, velocities for the motoring and firing cycles are very similar since the pressure differential between the intake and exhaust ports during the intake period are similar for the two cases. The root mean square (rms) velocity fluctuations are generally higher in the fired engine over all the measured engine speeds. Properly normalized ensemble-averaged mean velocity profiles along the measured direction are not shaped like a top hat but are very similar for motored, fired, and steady engine conditions, particularly at higher engine speeds. The volumetric flow rate is estimated using LDV results, compared with the actual measured value, and discussed.

With the impending implementation of the Tier 4 emissions standards in the non-road and locomotive sectors, exhaust gas aftertreatment systems will be needed on applications that previously did not require it. Based on the fact that the displacement of these engines is very large, the aftertreatment systems will also be relatively large, heavy and expensive. Additionally, even in these large engine applications, packaging space and systems cost is at a premium. Placing a robust metal aftertreatment system up-stream of the turbo-charger offers an elegant solution to these issues. The higher temperatures and faster temperature rises before the turbine yield faster light-off and better emissions performance. The higher gas density allows the total size of the aftertreatment system in the pre-turbine position to be substantially smaller for a given conversion efficiency, leading to a remarkable packaging and cost benefit of up to 64%. Additionally, by placing the flow-restriction of an aftertreatment system upstream of the turbine, a fuel consumption benefit in the pre-turbine position can be realized as pumping losses of the engine are reduced. The largely steady-state operation of these large engines negates the heat sink effect of the pre-turbine catalytic converters in transient operating conditions. This paper will investigate the benefits of placing an oxidation catalytic converter and partial-flow particulate filter up-stream of the turbo-charger on the fuel consumption of a stationary engine in the 30–35L class by simulation with GT-Power. Different locations for the aftertreatment package as well as optimized sizing for the different locations are investigated to identify the optimum solution for the engine. In addition to the fuel consumption benefits, the cost and weight advantage of the smaller pre-turbine system is emphasized. This view of both the technical and commercial side of the applications, demonstrates a clear advantage for the pre-turbine arrangement of the metal emissions reduction components on large bore engines.Copyright © 2010 by ASME

This study contrasts two modeling techniques proposed to accurately predict the influence of sintered fibrous metal (a non-woven structure of metallic fibers attached to one another by sintering processes), as a liner substitute, on sound attenuation performance and resulting noise emission for conventional aftermarket dissipative mufflers. Predicted values are compared to sound measurement data from stationary engine exhaust tests of a commercially available single-cylinder 450cc off-road motorcycle. The performance prediction techniques rely on the appropriate application and combination of pre-existing silencer design, engine exhaust and gas flow performance models as an economic alternative to more complex and expensive modeling programs that are typically beyond the reach of most small to medium-sized businesses in the motorcycle aftermarket industry. With respect to test results that showed approximate acoustical parity between mufflers containing the two different liner types, application limitations on the most suitable prediction technique are presented along with suggestions for further model refinement or additional physical testing. Further research is also invited to explore the impact of this liner substitution on muffler backpressure and its consequential impact on realized engine power.Copyright © 2008 by X Sound Technologies LLC

An air-cooled engine with a finned cylinder may have residual heat between the fins. Residual heat decreases heat release from the cylinder when cooling air is not forced over the engine. In order to induce natural convection in the cylinder, cooling ports were drilled in the fins parallel to the cylinder axis to determine if residual heat could be decreased and additional cylinder cooling could be developed. The effects of the fin configurations on air-cooling were investigated to utilize the cooling ports for a stationary engine and a non-moving motorbike engine. The experimental cylinder design permitted variation in the number of fins and fin pitch. Numbers of fins that had various port sizes and port positions were investigated; in addition, the temperature inside of the cylinder and in the space between the fins was measured. Results indicated that heat release from the cylinder was increased by utilizing the fins with ports as compared to the fins without ports. It was also found that fin pitch, number of fins, port size, port position, and number of ports have significant effects on cylinder temperature. These results can be utilized to improve the design of an air-cooled cylinder by utilizing natural convection.

This paper investigates a purely thermal control system for a 6-cylinder HCCI engine. Thermal energy from exhaust gas and from compression is used to condition the charge for the desired engine output. HCCI engine operation is analyzed with a detailed chemical kinetics based engine cycle simulation code. This cycle simulation code is linked to an optimizer that determines the operating conditions that result in maximum brake thermal efficiency, while meeting the restrictions of low NOx , and peak cylinder pressure. The results show the values of the operating conditions that yield optimum efficiency as a function of brake power for a constant engine speed (1800 rpm). It has been determined that a thermally controlled HCCI engine can successfully operate at high efficiency and low emissions over a wide range of conditions from idle to full load. The results show that a 42% brake thermal efficiency can be reached while the NOx emissions are kept under 2 parts per million. The analytical results shown here are expected to guide the ongoing experimental effort of converting a heavy-duty stationary engine to HCCI mode. The experimental work has the goal of meeting the very aggressive efficiency and emissions targets set by the California Energy Commission (CEC) Advanced Reciprocating Internal Combustion Engine (ARICE) Program.Copyright © 2004 by ASME

This paper deals with the possibility of using coconut oil and coconut biodiesel in energy generation. The environmental, energetic and socio-economic aspects are discussed. The steps for obtaining biodiesel from coconut oil are presented as well as the characterisation of coconut oil and coconut biodiesel. Results for performance and emissions of using coconut oil and coconut biodiesel in a stationary engine are also shown. Coconut oil can be successfully applied in compression ignition engine blending with diesel up to 20% of coconut oil. Coconut oil can also be converted in biodiesel and applied in compression ignition engines neat or blended with diesel in any proportion. The possibility of using coconut oil in power generation leads to the concepts of sustainability and cleaner production, by the use of a raw material that contributes to CO2 absorption. [Received: August 16, 2012; Accepted: May 1, 2013]

The characteristics and level of the noise emitted by stationary diesel engines of the type used in power houses are considered. With gas sources adequately silenced the spectrum of the noise of the automotive engine has a pronounced peak in the frequency range 1000–2000 c/s whereas the larger stationary engine shows a peak at a much lower frequency. Most notable among the constructional differences are the exposed flywheel and in many cases panelled crankcase; the significance of these design features is discussed. The authors have attempted to isolate the various noise sources: combustion and mechanical (particularly piston slap). The contributions to the total noise of the individual outer surfaces, such as crankcase frame, flywheel, cylinder head and various covers and panels, are also discussed in detail.