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This paper explores the feasibility of using Syngas with low methane number as fuel for commercial turbocharged internal combustion engines. The effect of methane number (MN), compression ratio (CR), and intake pressure on auto-ignition tendency in spark ignition internal combustion engines was determined. A nondimensional model of the engine was performed by using kinetics mechanisms of 98 chemical species in order to simulate the combustion of the gaseous fuels produced from different thermochemical processes. An error function, which combines the Livengood–Wu with ignition delay time correlation, to estimate the knock occurrence crank angle (KOCA) was proposed. The results showed that the KOCA decreases significantly as the MN increases. Results also showed that Syngas obtained from coal gasification is not a suitable fuel for engines because auto-ignition takes place near the beginning of the combustion phase, but it could be used in internal combustion engines with reactivity controlled compression ignition (RCCI) technology. For the case of high compression ratio and a high inlet pressure at the engine's manifold, fuels with high MN are suitable for the operating conditions proposed.

This study investigates the current situation of electricity generation from non-conventional renewable energy sources (NCRES) in Colombia. In general, it was shown that Colombia has potential in renewable sources such as solar, wind, and biomass. However, barriers such as lack of human capital, policies focused on conventional technologies and high investment costs have impeded their growth. Although the development of these sources has been encouraged through Law 1715 of 2014, more policies and developments are needed to promote this type of NCRES. The use of thermoelectric devices (TED) can become a potential NCRES alternative, while the political and technological conditions improve in Colombia. Around the world, TEDs have allowed the recovery of waste heat in a variety of industrial applications and the automotive sector. They are allowing in the latter, not only the generation of electric power, but also the reduction in engine emissions. Besides, its characteristics have allowed it to be used for the generation of electric power, both in developed and developing countries. In this document, an example presentation is developed that demonstrates the applications of the TED in the cases above to demonstrate the potential that the TED can have in almost any place that has a heat source.

How to cite: Duarte, J., et al., Thermodynamic Analysis of SelfIgnition in Spark-Ignited Engines Operated with Alternative Gaseous Fuels, TECCIENCIA, Vol. 11 No. 20,[57][58][59][60][61][62][63][64][65] AbstractCurrently, detailed studies exist on the self-ignition phenomenon in liquid fuels and even for natural gas. However, studies for syngas are quite limited and existing ones are mainly focused on combustion kinetics and do not study self-ignition prior to the ignition point. This paper presents the development of a thermodynamic analysis to study the self-ignition phenomenon in gaseous alternative fuels during the compression stroke in spark-ignited internal combustion engines. Analysis takes into account the fuel composition, relevant process parameters, and variation due to pressure and temperature intake changes. The approach is focused on equilibrium thermodynamics, which easily allows estimating engine operating conditions. These results permit studying adequate compression ratios to obtain good efficiencies, as those achieved by using natural gas, but in heat engine applications to generate power with low-methane-number syngas fuels. Keywords: Self-ignition, Gaseous Fuels, Combustion, Internal Combustion Engines ResumenEn la actualidad, existen estudios detallados del fenómeno de la auto-detonación en combustibles líquidos e inclusive para el gas natural. Sin embargo, los estudios para gas de síntesis son muy limitados y los existentes se centran principalmente en la cinética de la combustión y no se ha estudiado el autoencendido antes del punto de ignición. En este trabajo se presenta el desarrollo de un análisis termodinámico para estudiar el fenómeno de auto-ignición en combustibles gaseosos alternativos durante la carrera de compresión, cuando son utilizados en motores de encendido provocado. El análisis tiene en cuenta la composición del combustible, los parámetros relevantes del proceso y la influencia debido a los cambios de presión y temperatura en la admisión. El enfoque se centra de la termodinámica de equilibrio, lo que permite una estimación práctica de la condición de funcionamiento del motor. Estos resultados permiten estudiar las relaciones de compresión adecuadas con el fin de obtener eficiencias similares a las obtenidas utilizando gas natural, pero en aplicaciones de motores térmicos para la generación de energía eléctrica utilizando gas de síntesis de metano bajo número como combustible

The injection systems have had a strong evolution in recent years, going from lowpressure system of a mechanical drive to complex high-pressure electronic systems. The electronics applied to this type of systems has allowed handling sequential injections and increasing the injection pressure. In the present work a review of the evolution of the injection systems in the last 20 years is made and how techniques have been developed to model the hydrodynamic behavior of the injectors in Diesel internal combustion engines. With this review, the trends for the modeling of the injection process are visualized, which has an important impact on the thermodynamic modeling and the prediction of the indicator parameters in Diesel internal combustion engines. This review allows to visualize the future development of this type of systems and the implications they have on the performance of internal combustion engines and the thermodynamic modeling of them. The optimization in the operation of diesel engines is possible by improving the operation of injection systems, which has led to more powerful engines but smaller.