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Combustion is the most commonly used technology to produce energy from biomass; nevertheless, there are still thermal efficiency problems in current biomass combustion furnaces and a lack of knowledge about the properties of residual biomasses that could be used as fuels. Aiming to contribute to knowledge of the potential of residual biomass for energy generation, this work reports on the implementation of a 2D computational model to study the combustion performance of several solid biomass fuels, and its application in the analysis of Lippia origanoides bagasse combustion. The model uses an Eulerian–Lagrangian approach; in the continuous phase, governing equations are solved, and in the dispersed phase, particles are tracked and the mass, momentum, species and energy transfer between the phases are calculated. The model was validated against experimental data from a combustor fueled by three biomasses: wood pellets, olive stone and almond shell. The results show deviations of less than 13%, with few exceptions, which indicates a good degree of agreement with experimental measurements compared with those reported by other studies on the subject. Furthermore, it was found that the stems of Lippia origanoides bagasse show similar performance to that of other biomass used as solid fuel, while the leaves present lower performance. Minciencias, Ministerio de Educación Nacional, Ministerio de Industria, Comercio y Turismo e ICETEX, Colombia | Ref. RC-FP44842-212-2018

The use of vertical axis wind turbines (VAWT) in Colombia could tackle the energy distribution difficulties as large parts of the territory are not connected to the electrical grid. The present research experimentally determines the wind resource available of a rural place known as Chicamocha’s canyon and selects the airfoil for a VAWT blade through CFD modeling. By using the mean wind speed of the location, the performance of the NACA0018 and DU06W200 airfoils is evaluated in terms of the lift and drag coefficients through a 2D CFD modeling using OpenFOAM and the “Spalart-Allmaras fv3” turbulence model. It is found feasible the use of wind energy at the location where the mean year density power is 485 [W/m2 ], and the DU06W200 airfoil is suggested for constructing the blades of a VAWT, as its aerodynamic efficiency (cl/cd) overcomes by 14% the commonly used NACA0018.

espanolDebido a los graves problemas presentados a causa del amplio uso de biocombustibles de primera generacion, los biocombustibles de segunda generacion se presentan como una posible mejor alternativa para la sustitucion de los combustibles convencionales provenientes del petroleo. En el presente articulo se presenta un estudio del desempeno de motores diesel alimentados con bio-oil hidrotratado proveniente de biomasa lignocelulosica, el cual es un biocombustible de segunda generacion; para esto se desarrollo un modelo termodinamico cero-dimensional de la combustion que predice los parametros de desempeno del motor. Dicho modelo fue validado contra datos experimentales de presion en camara de dos motores diesel alimentados con mezclas diesel/biodiesel y diesel/bio-oil hidrotratado observandose una buena correlacion entre los datos simulados y experimentales, con errores relativos promedio en los valores pico de presion de 0,5 y 1% respectivamente. Los resultados muestran que el bio-oil hidrotratado, al utilizarse en pequenas proporciones, puede convertirse en un sustituto parcial del combustible diesel convencional. EnglishDue to the serious problems encountered because of the extensive use of first-generation biofuels, second generation biofuels are presented as a possible best alternative for replacing conventional fuels from oil. This paper presents a theoretical study of the performance of diesel engines fueled with hydrotreated bio-oil from lignocellulosic biomass, which is a second generation biofuel. For this, a thermodynamic zero-dimensional combustion model simulation was carried out; it predicts the performance parameters of the engine. This model was validated against experimental data of two diesel engines fueled with diesel-biodiesel and diesel/hydrotreated bio-oil blends, and a good correlation between simulated and experimental data was observed, with average relative errors, in pressure peak values, of 0.5 and 1% respectively. The results show that hydrotreated bio-oil in small proportions could become a partial substitute for conventional diesel fuel.

Biomass is an important renewable energy source that has great potential as a substitute for fossil fuels in the short and medium-term, which has led to the development of various methods for its energy conversion, of which combustion is the most widely used. This process has several environmental advantages compared to traditional energy sources, however, there is still a long way to go in terms of process efficiency and emission reduction. In this context, CFD computational models are a powerful tool that allows to study and improve the performance of combustion systems in a safe, fast and economical way, compared to experimental studies. OpenFoam is one of the most important CFD software currently available, however, there are few works that use it to simulate the combustion of solid biomass. In this work an application of the software in modeling of a biomass boiler fueled by grape marc is reported, this model allows predict important parameters like CO, H2O and velocity fields in a 2D domain.

Computational Fluid Dynamics (CFD) modeling is a powerful and cost-effective tool for study and improves the performance of combustion systems. OpenFOAM is a powerful open-source engineering-tool, which has been successfully used in numerous applications. To guide researchers interested in using OpenFOAM for this type of applications, in this document, a general view of solid biomass combustion modeling and a complete review of the topic when OpenFOAM is used are presented. It was found that, although there are relatively few OpenFOAM-based studies on the topic, there is a growing interest in the use of the tool for solid combustion simulation. Those works usually seek to improve thermal efficiency and reduce pollutant emissions in combustion furnaces; by using new biomasses or changing operational parameters. The main articles related to the subject are described and citation analyses are made to identify their relationships and relevance.

Combustion is the most widely used process to generate energy from biomass, however, there are still challenges to overcome in terms of efficiency and lack of knowledge of the properties of potential fuels. In the present work, a kinetic study of the thermal decomposition of Lippia origanoides bagasse from the essential oil distillation process is reported. Thermogravimetric analysis was performed on samples of stems, leaves and their mixture and the respective kinetic parameters were calculated from isoconversional methods of Friedman and Kissinger. The results obtained by the previous methods were evaluated by comparing the theoretical and experimental conversion curves, showing a good correlation between them, except for char combustion stage of leaves and mixture samples. Different characteristic combustion parameters were also evaluated; it was found that the stems samples have better combustion properties than the other two samples and that there is a linear relationship between them and heating rates.

Este trabajo desarrolla un sistema piloto para producción de biodiesel y su futura implementación a nivel regional y nacional. En este estudio, los más importantes parámetros en la producción y calidad del biodiesel fueron determinados preliminarmente y así conocer la relación molar aceite-alcohol y la cantidad de catalizador necesarias. Una vez estos valores fueron obtenidos, la planta piloto fue construida y la producción a una mayor escala y sus pruebas de desempeño en motores fueron efectuadas. Estas pruebas resultaron satisfactorias en lo concerniente a potencia, torque consumo y emisiones contaminantes y concuerdan con resultados que han sido obtenidos en experiencias nacionales e internacionales.

En este trabajo se presenta el sistema de adquisición de datos para señales analógicas DiagmaD-100, que utiliza el bus USB versión 1.1 utilizando un microcontrolador MC68HC908JB8como un dispositivo dedicado a la transmisión de datos a través de un módulo USB embebido. Deesta forma, se tiene un sistema de inserción plug & play que reduce el tiempo de configuración,además implementa una interfaz de usuario que permite visualizar las señales adquiridas en eldominio del tiempo y lafrecuencia y esta orientado a aplicaciones de instrumentación electrónicaen motores de combustión interna alternativos MC1A.

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.