Heavy Duty Diesel Engines

Engine downsizing is desired for modern heavy-duty vehicles to enhance fuel economy and reduce emissions. However, the smaller engines usually cannot overcome the parasitic loads during engine start-up. A new clutch system is designed to disconnect the downsized engine from the parasitic losses prior to the idling speed. A multi-scale, multi-physics model is developed to study the clutch system. Multi-body dynamics is used to study the combined translational-rotational motions of the clutch components. A micro-scale contact model is incorporated to represent the frictional characteristics of the sliding surfaces. Although the clutch is designed for dry contact operation, leakage of actuating hydraulic fluid can affect the interfacial frictional characteristics. These are integrated into the multi-body dynamic analysis through tri-bometric studies of partially wetted surfaces using fresh and shear-degraded lubricants. Multi-scale simulations include sensitivity analysis of key operating parameters, such as contact pressure. This multi-physics approach is not hitherto reported in the literature. The study shows the importance of adhesion in dry clutch engagement, enabling full torque capacity. The same is also noted for any leakage of significantly shear-degraded lubricant into the clutch interfaces. However, the ingression of fresh lubricant into the contact is found to reduce the clutch torque capacity.

Numbers of studies has been executed globally in order to seek the alternative way to replace the current fossil-fuel with regards to the rising of fuel-energy demand, running-out of petroleum reserves and to attain the cleaner atmosphere. For that reason, the exploration and studies on Biodiesel Fuel (BDF) has been one of the potential alternative. Thus, a research has been carried out to investigate the effects on performance and exhaust gas emissions of a single cylinder, 4-stroke marine diesel engine with capacity of 638cc using biodiesel blends derived from Crude Palm Oil (CPO) along with neat diesel (DSL) that driven as standard reference. The CPO fuel was blended with DSL in various concentration to produce blended fuels that comprise CPO5, CPO10, CPO15 and CPO20. The CPO biodiesel was chosen in the study due to the availability and readiness of its feedstock sources in Malaysia all over the year. Moreover this research was focusing on marine engine compared to the most today’s research which commonly engaged with automotive engines. The outcomes of this research found that the used of CPO blends fuels promotes to some extent of better performance of marine diesel engine and comparable exhaust gas emissions. The finding from this research also verified that the different levels of blending concentration have its pros and cons on the effects of engine performance and gas emissions. The used of crude palm biodiesel fuels however do good to the marine diesel engines which it can be ran without adjustments in equatorial regions.

This work suggests an interpretation to the quantitatively higher formation of NOx in a compression ignition (CI) engine when fueled with pure biodiesel (B100). A comparative study about the use of rapeseed oil methyl ester (RME) and diesel fuel mixtures on injection timing, in-chamber pressure, heat release rate, and NOx emissions were carried out using a diesel engine equipped with a pump-line-nozzle injection system. Such engines are still widely adopted mainly in agriculture, as the fleet of agricultural machinery is particularly old (often over 20 years) and the use of biofuels can reduce the environmental footprint of the sector. This work aims to supply some general explanations and figures useful to interpret the phenomena occurring within the fuel line and in the combustion process when using biodiesel, as well as in engines with different construction characteristics and fueling systems. Given the contradictory results available in the literature, the so-called “biodiesel NOx effect” cannot be explained solely by the different physical properties of biodiesel (in particular, a higher bulk modulus). Experimental results show that, with the same pump settings, the start of injection with the RME is slightly advanced while the injection pressure values remain almost the same. With the RME, the pressure in the injection line increases faster due to its greater bulk modulus but the pressure rise starts from a lower residual pressure. The start of combustion takes place earlier, the heat release during the premixed phase is steeper, and a higher peak is reached. The NOx emissions with the RME are at least 9% higher when compared to mineral diesel fuel. The greater amount of the RME injected per cycle compensates for its minor lower heating value, and the brake torque at full load is similar to the two analyzed fuels. Finally, a variation of the pump line timing is evaluated in order to assess the effect of the delay and the advance of the injection on the performance of the engine and on the emissions. A viable and simple solution in the variation of the injection strategy is suggested to counterbalance the biodiesel NOx effect.

The effect of biofuel blends on the engine performance and emissions of agricultural machines can be extremely complex to predict even if the properties and the effects of the pure substances in the blends can be sourced from the literature. Indeed, on the one hand, internal combustion engines (ICEs) have a high intrinsic operational complexity; on the other hand, biofuels show antithetic effects on engine performance and present positive or negative interactions that are difficult to determine a priori. This study applies the Response Surface Methodology (RSM), a numerical method typically applied in other disciplines (e.g., industrial engineering) and for other purposes (e.g., setup of production machines), to analyse a large set of experimental data regarding the mechanical and environmental performances of an ICE used to power a farm tractor. The aim is twofold: i) to demonstrate the effectiveness of RSM in quantitatively assessing the effects of biofuels on a complex system like an ICE; ii) to supply easy-to-use correlations for the users to predict the effect of biofuel blends on performance and emissions of tractor engines. The methodology showed good prediction capabilities and yielded interesting outcomes. The effects of biofuel blends and physical fuel parameters were adopted to study the engine performance. Among all possible parameters depending on the fuel mixture, the viscosity of a fuel blend demonstrated a high statistical significance on some system responses directly related to the engine mechanical performances. This parameter can constitute an interesting indirect estimator of the mechanical performances of an engine fuelled with such blend, while it showed poor accuracy in predicting the emissions of the ICE (NO x , CO concentration and opacity of the exhaust gases) due to a higher influence of the chemical composition of the fuel blend on these parameters; rather, the blend composition showed a much higher accuracy in the assessment of the mechanical performance of the ICE.

Measuring the performance of the compression-ignition internal combustion engine of agricultural machines (in particular, the torque delivered instantaneously) is an essential requirement for monitoring: (a) the exploitation of the engine mechanical-energy potential (in terms of generated torque) and (b) its correct operation (in terms of global efficiency, fuel consumption and possible ageing). Due to the many important technical and economic implications, the instant acquisition of the engine torque is therefore a critical point in any operational monitoring system, as well as in predictive maintenance models. Torque measurement is by no means a simple task, especially in old agricultural machines lacking of default data acquisition devices/on-board electronics, and many critical issues arise from the fact that it involves rotating components (shafts), which are often difficult to be accessed. For this reason, an indirect torque measurement methodology, based on a predictive model...

Article describes the most common damages and defects electromagnetic CRIN Bosch Diesel engines injectors. There have been detailed the possibilities reasons developing it. The aspects of effective regeneration theirs have been exhibited and assessed. It has been shown procedure and range during repairing and it has been concerned to Diesel engine commercial vehicle Iveco Daily Unijet 2,8.

This study focuses on the physicochemical fuel characteristics and engine performance-emission features of three prospective alternative transportation fuels: Alexandrian laurel biodiesel (ALBD), jatropha biodiesel (JBD) and GTL fuel at high idling conditions. The blends of GTL fuel (G10, G20), JBD (J10, J20) and ALBD (AL10, AL20) with diesel had been investigated in a multi-cylinder diesel engine at different load-speed conditions. Analysis of the fuel properties showed a linear variation of the major fuel properties with an increase of alternative fuel quantity in the blends. Engine performance test results revealed an average decrease of brake specific fuel consumption (BSFC) (ca. 8.65-12.26%) and brake specific energy consumption (BSEC) (ca. 8.27-11.51%), but a higher brake thermal efficiency (BTE) (ca. 8.56-12.58%) by GTL blends, whereas, the biodiesel blends showed higher BSFC (ca. 5.01-12.18%) and BSEC (ca. 3.41-9.67%) and lower BTE (ca. 3.68-9.93%), respectively, than those of diesel. Referring to the emission analysis, the results revealed that GTL blends showed a slight reduction in NOx (ca. 3.89-6.85%), but a significant reduction in CO (ca. 48.25-51.38%), HC (ca. 44.81-51.43%) and smoke (ca. 15.21-18.78%), respectively, when compared to diesel. The biodiesel blends demonstrated reduced CO (on average ca. 29.12-33.71%), HC (ca. 29.67-35.46%) and smoke (ca. 2.49-6.87%), but increased NOx (on average ca. 2.83-9.81%), respectively, than those of diesel.

http://pubs.rsc.org/en/content/articlehtml/2015/ra/c4ra16239k

Measuring the performance of the compression-ignition internal combustion engine of agricultural machines (in particular, the torque delivered instantaneously) is an essential requirement for monitoring: (a) the exploitation of the engine mechanical-energy potential (in terms of generated torque) and (b) its correct operation (in terms of global efficiency, fuel consumption and possible ageing). Due to the many important technical and economic implications, the instant acquisition of the engine torque is therefore a critical point in any operational monitoring system, as well as in predictive maintenance models. Torque measurement is by no means a simple task, especially in old agricultural machines lacking of default data acquisition devices/on-board electronics, and many critical issues arise from the fact that it involves rotating components (shafts), which are often difficult to be accessed. For this reason, an indirect torque measurement methodology, based on a predictive model relying on the exhaust gas temperature, is preferable. An accurate measurement of temperature data is of primary importance to precisely calculate the torque, which means performing an accurate thermocouple choice, placement, and data elaboration. This is made even more challenging by the fact that the temperature of the exhaust gas is often in a transient state due to variable engine regime necessary for machine operation. The study presented here illustrates some considerations about the trend and the equation of the experimental measurements of the exhaust gas temperature, considering three different positions for the thermocouples on the exhaust line, and proposes an optimal technical solution in terms of sensitivity and promptness of response.

A truly universal system to optimize consumptions, monitor operation and predict maintenance interventions for internal combustion engines must be independent of onboard systems, if present. One of the least invasive methods of detecting engine performance involves the measurement of the exhaust gas temperature (EGT), which can be related to the instant torque through thermodynamic relations. The practical implementation of such a system requires great care since its torque-predictive capabilities are strongly influenced by the position chosen for the temperature-detection point(s) along the exhaust line, specific for each engine, the type of installation for the thermocouples, and the thermal characteristics of the interposed materials. After performing some preliminary tests at the dynamometric brake on a compression-ignition engine for agricultural purposes equipped with three thermocouples at different points in the exhaust duct, a novel procedure was developed to: (1) tune a CFD-FVM-model of the exhaust pipe and determine many unknown thermodynamic parameters concerning the engine (including the real EGT at the exhaust valve outlet in some engine operative conditions), (2) use the CFD-FVM results to considerably increase the predictive capability of an indirect torque-detection strategy based on the EGT. The joint use of the CFD-FVM software, Response Surface Method, and specific optimization algorithms was fundamental to these aims and granted the experimenters a full mastery of systems’ non-linearity and a maximum relative error on the torque estimations of 2.9%.

La resultante de filtrar correctamente "La elección puede parecer compleja o simple, sin embargo debemos comprender que el único propósito de un filtro de partículas es entregar un código ISO 4406 acorde a la tolerancia de los componentes o equipos según lo establecido por el fabricante original (OEM)" Una propuesta seria: ISO 16889:99 El fabricante de un filtro debe poder dimensionar y recomendar un elemento que cumpla con una meta ISO 4406; ratificable, medible y comprobable. Para el efecto el primer paso son las credenciales del filtro y la certificación ISO 16889:99 es la herramienta fundamental para comparar varias opciones. Factor Beta o Eficiencia Beta Se acostumbra preguntar a cuantas micras filtra un filtro. Mucho cuidado! Un filtro tiene una eficiencia certificada para cada micronaje (ISO 16889). Adicional, no es de interés mayor lo que un filtro retiene sino lo que deja pasar, siendo siempre importante considerar la condición ISO del fluido para determinar la eficiencia beta mínima requerida para el cumplimiento de la ISO 4406. Flujo Un filtro debe ser certificado al flujo real de trabajo. Muchos fabricantes realizan sus certificaciones a flujos menores de las recomendaciones de uso y esto genera que el filtro pierda eficiencia en condiciones reales. Mayor flujo=Menor eficiencia Menor flujo=Mayor eficiencia Solicite el ISO 16889:99 completo La vida útil del filtro El DHC (dirt holding capacity) es la referencia de la vida úil de un filtro y esta se define por la capacidad de retención en gramos y el costo por gramo. El tipo de polvo de la prueba debe ser acorde a la eficiencia del filtro y las condiciones reales de trabajo; por esto el más recomendado es el MTD (medium test dust). Búsquelo en el ISO 16889:99 Delta P El diferencial de presión de un filtro y su curva de saturación es parte fundamental del óptimo desempeño de su elección de filtración, ya que las pruebas ISO 16889:99 nos confirman si los datos obtenidos del Beta, Flujo, DHC van acorde a la restricción que los sistemas toleran o trabajan. Exigir la curva de saturación Monitoreo ISO 4406 Después de haber optado por la mejor opción de filtración; se recomienda mantener un monitoreo constante del ISO 4406 para verificar que se cumplan las expectativas del sistema de filtración elegido y las metas de limpieza ISO. Accesorios que garanticen las continua filtración son parte importante de una práctica controlada. Conocer más sobre técnicas de monitoreo ISO 4406