Assessment of low viscosity engine oils in terms of fuel consumption and engine wear in heavy duty engines fleet test

As a consequence of the increasingly stringent emissions standards in the world and, on the other hand, the foreseen shortage of fossil fuels, the application of low viscosity engine lubricants (LVO) is considered one of the most cost effective contribution to counteract these challenges. The aim of the test was to verify the potential fuel consumption benefits of using LVO in Heavy Duty Vehicles (HDV) found in literature, mainly obtained in engine bench tests, when they are working on real and “on-road” conditions. Parallel to this study, the performance of low viscosity lubricants regarding to engine wear was assessed, since the use of LVO could imply an increase in engine wear rate. Potential higher wear could result in a life cycle reduction for the internal combustion engines or higher maintenance costs, both nondesired effects. In order to achieve this goal, a sample of 39 urban buses comprising two engine technologies (Diesel and Compressed Natural Gas (CNG)) and four different lubricants were studied over more than 60000 km per vehicle, measuring daily mileage and fuel consumption, and also oil performance was monitored (with 3000 km sampling frequency) using a deep and extensive oil analysis program, specially engine wear was quantified using ICP-OES, in order to detect abnormal engine wear patterns. Results obtained have shown a positive correlation between the use of LVO and fuel consumption reduction in HDV, both for Diesel and CNG. Regarding to oil performance, results indicate that engine wear do not show abnormal patterns due to use of LVO.The authors would like to thank the Spanish Ministerio de Ciencia e Innovación for its funding in this project (Project no. TRA2012-30907), and thank Repsol and EMT de Valencia for their collaboration. Additionally, the authors would like to thank Ruth Calatayud, Lorena Garzón, Leonardo Ramírez and Santiago Ballester for their help in this work

Assessment of low-viscosity oil performance and degradation in a heavy duty engine real-world fleet test

Low viscosity engine oils (LVO) are considered one of the most interesting solutions for improving fuel economy in internal combustion engines (ICE). There are different studies involving LVO and ICE, but currently limited data are available regarding real-world performance of LVO in a real service fleet. Included in a broadest study related with fuel consumption saving effects and performance of LVO in a real service fleet, the aim of this work is to present the results obtained in terms of comparative oil performance. So, on this test, a comparative analysis using 39 buses was performed, based on a deep and extensive oil analysis program to assess those aspects above mentioned. Two engine technologies (Diesel and CNG) were considered and four different lubricants, two of them LVO and other two used as a reference baseline. The test duration comprised two oil drain intervals of 30000 km each one, totalizing more than 2 million of kilometers accumulated. Results have shown that LVO presented an excellent performance along the oil drain interval (ODI), even improving some characteristics of the baseline oils with higher viscosity values. Results have shown that oil degradation is more dependent on engine technology, but in any case presented a penalization in terms of ODI reduction, a key indicator for end-users related with maintenance costs. In the case of CNG engines, higher oil degradation in terms of oil oxidation and nitration was observed.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study was funded by the Spanish Ministerio de Ciencia e Innovacion (Project no. TRA2012-30907).Macian Martinez, V.; Tormos Martínez, BV.; Miró Mezquita, G.; Pérez, T. (2016). Assessment of low-viscosity oil performance and degradation in a heavy duty engine real-world fleet test. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology. 230(6):729-743. doi:10.1177/1350650115619612S729743230

Low viscosity engine oils: Study of wear effects and oil key parameters in a heavy duty engine fleet test

Low viscosity engine oils (LVO) are considered key contributor for improving fuel economy in internal combustion engines (ICE). Attending that the use of LVO could imply a variation in tribological states found in ICE, this work's aim is to test LVO in real fleet, with emphasis on engine wear and oil key performance indicators. This test comprised 39 buses, two engine technologies and four different lubricants. For each sample, the elemental composition of the wear debris by ICP-AES and HTHS viscosity of the oil were measured among other properties. The results showed that, with a correct oil formulation, there is no significant difference when using LVO in terms of engine wear, HTHS viscosity variation and oil consumption. (C) 2015 Elsevier Ltd. All rights reserved.The authors would like to thank the Spanish Ministerio de Ciencia e Innovacion for its funding in this project (Project no. TRA2012-30907), and thank Repsol and EMT de Valencia for their collaboration. Additionally, the authors would like to thank Ruth Calatayud, Lorena Garzon, Leonardo Ramirez and Santiago Ballester for their help in this work.Macian Martinez, V.; Tormos Martínez, BV.; Ruiz Rosales, S.; Miró Mezquita, G. (2016). Low viscosity engine oils: Study of wear effects and oil key parameters in a heavy duty engine fleet test. Tribology International. 94:240-248. doi:10.1016/j.triboint.2015.08.028S2402489

Impact of Spark Assistance and Multiple Injections on Gasoline PPC Light Load

Along the last years, engine researchers are more and more focusing their efforts on the advanced low temperature combustion (LTC) concepts with the aim of achieving the stringent limits of the current emission legislations. In this regard, several studies based on highly premixed combustion concepts such as HCCI has been confirmed as a promising way to decrease drastically the most relevant CI diesel engine-out emissions, NOx and soot. However, the major HCCI drawbacks are the narrow load range, bounded by either misfiring (low load, low speed) or hardware limitations (higher load, higher speeds) and the combustion control (cycle-to-cylce control and combustion phasing). Although several techniques have been widely investigated in order to overcome these drawbacks, the high chemical reactivity of the diesel fuel remains as the main limitation for the combustion control. The attempts of the researchers to overcome these disadvantages are shifting to the use of fuels with different reactivity. In this sense, gasoline PPC has been able to reduce emissions and improve efficiency simultaneously, but some drawbacks regarding controllability and stability at low load operating conditions still need solution. In this field, previous researches have been demonstrate the multiple injection strategy as an appropriate technique to enhance the combustion stability. However, PPC combustion has been found limited to engine loads higher than 5 bar BMEP when using fuels with octane number greater than 90. In this regard, previous work from the authors showed the capability of the spark plug to provide combustion control in engine loads below this limit even using 98 ON gasoline. The main objective of the present work is to couple the control capability of the spark assistance together with an appropriate mixture distribution by using double injection strategies with the aim of evaluating performance and engine-out emissions at low load PPC range using a high octane number gasoline. For this purpose the optical and metal version of a compression ignition single-cylinder engine, to allow high compression ratio, has been used during the research. A common rail injection system enabling high injection pressures has been utilized to supply the 98 octane number gasoline. An analysis of the in-cylinder pressure signal derived parameters, hydroxyl radical (OH*) and natural luminosity images acquired from the transparent engine as well as a detailed analysis of the air/fuel mixing process by means of a 1-D in-house developed spray model (DICOM) has been conducted. Results from both analysis methods, suggest the spark assistance as a proper technique to improve the spatial and temporal control over the low load gasoline PPC combustion process. A noticeable increase in the cycle to cycle repeatability (5% versus 15.1% CoV IMEP at 2 bar load) as well as a reduction in the knocking level (20.5 versus 33.6 MW/m2 at 7 bar load) is observed. In addition, the combination of the spark assistance with the use of the double injection strategy provides a great improvement in terms of combustion efficiency (93% versus 88% for a single injection strategy) with a benefit around 18% in the IMEPBenajes Calvo, JV.; Tormos Martínez, BV.; García Martínez, A.; Monsalve Serrano, J. (2014). Impact of Spark Assistance and Multiple Injections on Gasoline PPC Light Load. SAE International Journal of Engines. 7(4):1875-1887. doi:10.4271/2014-01-2669S187518877

Monitoring and analysing oil condition to generate maintenance savings: a case study in a CNG engine powered urban transport fleet

The authors from Universitat Politecnica de Valencia wish to thank Spanish Grant TRA2008-06508 from Ministerio de Ciencia e Innovacion - Direccion General de Investigacion for supporting this work. Mr Gomez thanks the UPV for his grant 2011-S2-5003 in the frame of the PAID programme.Tormos Martínez, BV.; Olmeda González, PC.; Gomez Estrada, YA.; Galar, D. (2013). Monitoring and analysing oil condition to generate maintenance savings: a case study in a CNG engine powered urban transport fleet. Insight - Non-Destructive Testing & Condition Monitoring. 55(2):84-87. https://doi.org/10.1784/insi.2012.55.2.84S848755

Potential of low viscosity oils to reduce CO2 emissions and fuel consumption of urban buses fleets

This paper shows the results of a comparative fleet test the main objective of which was to measure the influence of Low Viscosity Oils (LVO) over the fuel consumption and CO2 emissions of urban buses. To perform this test, 39 urban buses, classified into candidate and reference groups depending on the engine oil viscosity, covered a 60,000 km mileage corresponding to two rounds of standard Oil Drain Interval (ODI). In the same way, for 9 buses of the 39 buses, the effect of differential LVO over fuel consumption and their interaction with engine LVO was assessed during the second ODI. Test results confirm that the use of LVO could reduce fuel consumption, hence CO2 emissions. However, special attention should be taken prior to its implementation in a fleet, particularly if the vehicles are powered by engines with high mechanical and thermal stresses during vehicle operation because this could lead to friction loss increase, loss of the potential fuel consumption reduction of LVO and, in the worst scenario, higher rates of engine wear.The authors would like to thank J. Martnez Puerta and L. Navarro of EMT-Valencia for all their support during the test. The authors would also like to thank Santiago Ballester and Juan Manuel Ballester for their help with data acquisition and treatment. Finally, the authors wish to express their gratitude to the Spanish Ministerio de Economia y competitividad Direccion General de Investigacion Cientifica y Tecnica for supporting the FUECOMOIL project (TRA2012-30907).Macian Martinez, V.; Tormos Martínez, BV.; Ruiz Rosales, S.; Ramirez, LA. (2015). Potential of low viscosity oils to reduce CO2 emissions and fuel consumption of urban buses fleets. Transportation Research Part D: Transport and Environment. 39:76-88. https://doi.org/10.1016/j.trd.2015.06.006S76883

Diagnóstico de motores de combustión interna álternativos mediante el análisis de las oscilaciones del bloque

En este artículo se presenta una técnica no intrusiva, pensada para el Mantenimiento Predictivode motores de combustión interna alternativos (MelA), basada en el análisis de las oscilacionesdel bloque suponiendo el motor como un cuerpo rígido soportado por resortes elásticos. Estasconsideraciones permiten la determinación aproximada del par instantáneo del motor, utilizandoúnica y exclusivamente un acelerámetro instalado en un punto del bloque lo más alejado posibledel cigüeñal y registrando la señal temporal de varios ciclos termodinámicos. Las señal asíobtenida puede informar acerca de diferentes tipos de fallos, especialmente aquellos relativos aldiferente comportamiento entre los cilindros. Se utilizó un sencillo modelo físico para estimar el comportamiento del motor bajo diferentescondiciones defuncionamiento. El modelo ha sido validado a través de la realización de diferentesmedidas experimentales tanto en banco de ensayos de motor como en motores en servicio. Asimismose han realizado diferentes ensayos para analizar la influencia de la posición del acelerómetro en el bloque. El objetivo final del estudio es determinar límites de alerta y alarma de ciertos fallos en el motor,como puede ser la inyección o combustión anormal en uno o varios cilindros. Para ello se hacenecesario el análisis tanto en el dominio temporal como en el defrecuencia, diferencia importantecon el resto de técnicas utilizadas para el diagnóstico de maquinaria a través de vibraciones.This article presents a non-intrusive technique, designed for the Predictive Maintenance of alternative internal combustion engines (MCIA), based on the analysis of the oscillations of the block assuming the motor as a rigid body supported by elastic springs.These considerations allow The approximate determination of the instantaneous torque of the motor, using only and exclusively an accelerometer installed at a point of the block as far as possible from the crankshaft and recording the time signal of several thermodynamic cycles The signals thus obtained can inform about different types of failures, Especially those related to the different behavior between the cylinders.A simple physical model was used to estimate the performance of the engine under different operating conditions. The model has been validated through the realization of different experimental measurements both in engine test bench and in engines in service. Different tests have also been carried out to analyze the influence of the accelerometer position on the block.The final objective of the study is to determine alert and alarm limits of certain failures in the engine, such as injection or abnormal combustion in one or several cylinders. For this, it is necessary to analyze both the temporal and the frequency domain, a significant difference with the other techniques used for the diagnosis of machinery through vibrations

Diagnóstico de motores de combustión interna álternativos mediante el análisis de las oscilaciones del bloque

En este artículo se presenta una técnica no intrusiva, pensada para el Mantenimiento Predictivode motores de combustión interna alternativos (MelA), basada en el análisis de las oscilacionesdel bloque suponiendo el motor como un cuerpo rígido soportado por resortes elásticos. Estasconsideraciones permiten la determinación aproximada del par instantáneo del motor, utilizandoúnica y exclusivamente un acelerámetro instalado en un punto del bloque lo más alejado posibledel cigüeñal y registrando la señal temporal de varios ciclos termodinámicos. Las señal asíobtenida puede informar acerca de diferentes tipos de fallos, especialmente aquellos relativos aldiferente comportamiento entre los cilindros. Se utilizó un sencillo modelo físico para estimar el comportamiento del motor bajo diferentescondiciones defuncionamiento. El modelo ha sido validado a través de la realización de diferentesmedidas experimentales tanto en banco de ensayos de motor como en motores en servicio. Asimismose han realizado diferentes ensayos para analizar la influencia de la posición del acelerómetro en el bloque. El objetivo final del estudio es determinar límites de alerta y alarma de ciertos fallos en el motor,como puede ser la inyección o combustión anormal en uno o varios cilindros. Para ello se hacenecesario el análisis tanto en el dominio temporal como en el defrecuencia, diferencia importantecon el resto de técnicas utilizadas para el diagnóstico de maquinaria a través de vibraciones.This article presents a non-intrusive technique, designed for the Predictive Maintenance of alternative internal combustion engines (MCIA), based on the analysis of the oscillations of the block assuming the motor as a rigid body supported by elastic springs.These considerations allow The approximate determination of the instantaneous torque of the motor, using only and exclusively an accelerometer installed at a point of the block as far as possible from the crankshaft and recording the time signal of several thermodynamic cycles The signals thus obtained can inform about different types of failures, Especially those related to the different behavior between the cylinders.A simple physical model was used to estimate the performance of the engine under different operating conditions. The model has been validated through the realization of different experimental measurements both in engine test bench and in engines in service. Different tests have also been carried out to analyze the influence of the accelerometer position on the block.The final objective of the study is to determine alert and alarm limits of certain failures in the engine, such as injection or abnormal combustion in one or several cylinders. For this, it is necessary to analyze both the temporal and the frequency domain, a significant difference with the other techniques used for the diagnosis of machinery through vibrations

Assessment of the effect of low viscosity oils usage on a light duty diesel engine fuel consumption in stationary and transient conditions

Regarding the global warming due CO2 emissions, the crude oil depletion and its corresponding rising prices, OEMs are exploring different solutions to increase the internal combustion engine efficiency, among which, the use of Low Viscosity Oils (LVO) represents one attractive cost-effective way to accomplish this goal. Reported in terms of fuel consumption, the effect of LVO are round 2%, depending on the test conditions, especially if the test has taken place in laboratory or "on road" conditions. This study presents the fuel consumption benefits of a commercial 5W20, compared against higher SAE grade oils, on a light duty diesel engine, when it is running under motored test, stationary fired test and the New European Driving Cycle (NEDC).The authors wish to express their gratitude to the Spanish Ministerio de Economia y competitividad Direccion General de Investigacion Cientifica y Tecnica for supporting the FUECOMOIL project (TRA2012-30907).Macian Martinez, V.; Tormos Martínez, BV.; Bermúdez, V.; Ramírez Roa, LA. (2014). Assessment of the effect of low viscosity oils usage on a light duty diesel engine fuel consumption in stationary and transient conditions. Tribology International. 79:132-139. https://doi.org/10.1016/j.triboint.2014.06.003S1321397

A review of degradation process on compressed natural gas and diesel engines lubrican oils

[EN] In this study, a representative sample of urban buses, powered with CNG and diesel engine technologies and working on urban duty operation, have been studied in order to evaluate engine oil evolution of degradation. Main parameters evaluated have been related with oil degradation: oxidation, nitration, viscosity, Antioxidant additives depletion, antiwear, TAN, TBN and RUL Number. Results obtained have shown higher degradation rates for oils used on CNG engines than diesel engine. CNG engines studied showed a high thermal and mechanical stress, and lower oil sump volume. Experience with FT-IR technique on degradation study allowed to defi ne optimal spectral ranges to quantify the changes of oxidation, nitration and fuel dilution problem in MCIA[ES] En este estudio, una muestra representativa de autobuses de servicio urbano, con motorizaciones GNC y diesel, han sido estudiados con el fin de evaluar la evolución de la degradación de sus aceites. Los principales parámetros evaluados en relación con la degradación del aceite son: oxidación, nitración, viscosidad, agotamiento de los aditivos antioxidantes amínicos, antidesgaste, TAN, TBN y el número RUL. Los resultados obtenidos evidencian mayores tasas de degradación de los aceites usados en los motores GNC frente a los motores diesel. Los motores de GNC estudiados presentan una mayor exigencia a sus aceites al contar con mayores solicitaciones térmicas, mecánicas, y menor volumen del cárter de aceite. La experiencia adquirida con la aplicación de la técnica de FTIR para el estudio de la degradación, ha permitido definir rangos espectrales óptimos para cuantificar los cambios de oxidación, nitración y presencia de combustible en MCIA.Los autores quieren mostrar su agradecimiento al apoyo recibido desde el Ministerio de Ciencia e Innovación - Dirección General de Investigación: TRA2008-06508 (GLAUTO).Macian Martinez, V.; Tormos Martínez, BV.; Gomez Estrada, YA.; Bermúdez, V. (2013). Revisión del proceso de la degradación en los aceites lubricantes en motores de gas natural comprimido y diesel. DYNA: Ingeniería e Industria. 88(1):49-58. https://doi.org/10.6036/5077S495888