Thesis INVESTIGACIÓN EXPERIMENTAL DE LAS EMISIONES Y DESEMPEÑO DE UN MOTOR DE COMBUSTIÓN INTERNA DIÉSEL ENRIQUECIDO CON HIDRÓGENO
Date
2018
Authors
CASTRO SORUCO, NICOLÁS RENÉ
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Abstract
El presente trabajo estudia las emisiones y desempeño de un motor diésel sobrealimentado de 2.0 litros con sistema de inyección directa, en el que se sustituye parcialmente el combustible convencional por hidrógeno, adicionándolo a través de la admisión de aire. Se caracteriza la línea base de operación en cuanto a emisiones y desempeño utilizando sólo diésel a cuatro velocidades de giro (2000, 2400, 2800 y 3000 RPM) y tres niveles de carga (30%, 60% y 100%). A partir de la eficiencia y estabilidad de operación observada a 2400 RPM, se elige esta velocidad para desarrollar las pruebas con adición de H2.El consumo específico de combustible diésel disminuyó con la adición de H2 en todos los casos exceptuando la inyección de una pequeña cantidad de hidrógeno a baja carga (10% de reemplazo). El menor consumo específico (136 [g/kWh]) se midió a 60% de carga y máximo nivel de reemplazo (60%). La eficiencia térmica del motor disminuyó conforme aumentaba la adición de hidrógeno, esta disminución fue mayor en la operación a 30% de carga, mientras que a plena carga este parámetro se vio menos afectado, reduciéndose sólo 5% con el máximo nivel de reemplazo (40%) para esta carga. En el caso de 30% de carga se alcanzó 80% de reemplazo. Los parámetros de operación del motor se mantuvieron dentro de los rangos medidos durante la operación normal (sólo diésel). Se detectó la ocurrencia de “knock” para los máximos niveles de reemplazo a media y plena carga.El incremento de la concentración de hidrógeno sobre los límites de flamabilidad permitió la ocurrencia de retroceso de llama, impidiendo alcanzar mayores niveles de reemplazo.Las emisiones de CO2 se redujeron en todos los casos, mientras que las de NO aumentaron, se mantuvieron y disminuyeron en los casos de plena, media y baja carga.
The present research study emissions and performance of a diesel direct injection supercharged engine with diesel substitution by means of hydrogen air intake injection. Four different velocities (2000, 2400, 2800, and 3000 RPM) are studied at three loads (30%, 60%, 100%) with diesel fueling. 2400 RPM is chosen for hydrogen addition due to good efficiency and stability operation.Specific fuel consumption of diesel was reduced with hydrogen addition in all cases, excepting the injection of a small amount of hydrogen (10% substitution of diesel by hydrogen) at 30% load. The smallest specific fuel consumption (136 [g/kWh]) was obtained at 60% load and higher substitution rate (60%). Brake thermal efficiency diminished with increase of hydrogen addition, at 30% load the loss of efficiency was worse than at full load, in which case just a 5% reduction was observed with maximum substitution rate (40%) for this load operation. In the 30% load case the highest substitution rate was 80%. Engine operation parameters were in normal diesel operation range. Knock onset was detected at highest substitution levels in 60% and 100% load operation.Increase in molar fraction of hydrogen in air intake stream over flammability limit caused backfire and stopping of the enginemaking impossible a further rise in substitution rate at 60% and full load operation.CO2 emissions were reduced in all the cases while NO behaviour was different for each load, at full load emissions were increased, 60% load were no difference with hydrogen addition and for 30% load emissions were slightly reduced.
The present research study emissions and performance of a diesel direct injection supercharged engine with diesel substitution by means of hydrogen air intake injection. Four different velocities (2000, 2400, 2800, and 3000 RPM) are studied at three loads (30%, 60%, 100%) with diesel fueling. 2400 RPM is chosen for hydrogen addition due to good efficiency and stability operation.Specific fuel consumption of diesel was reduced with hydrogen addition in all cases, excepting the injection of a small amount of hydrogen (10% substitution of diesel by hydrogen) at 30% load. The smallest specific fuel consumption (136 [g/kWh]) was obtained at 60% load and higher substitution rate (60%). Brake thermal efficiency diminished with increase of hydrogen addition, at 30% load the loss of efficiency was worse than at full load, in which case just a 5% reduction was observed with maximum substitution rate (40%) for this load operation. In the 30% load case the highest substitution rate was 80%. Engine operation parameters were in normal diesel operation range. Knock onset was detected at highest substitution levels in 60% and 100% load operation.Increase in molar fraction of hydrogen in air intake stream over flammability limit caused backfire and stopping of the enginemaking impossible a further rise in substitution rate at 60% and full load operation.CO2 emissions were reduced in all the cases while NO behaviour was different for each load, at full load emissions were increased, 60% load were no difference with hydrogen addition and for 30% load emissions were slightly reduced.
Description
Catalogado desde la version PDF de la tesis.
Keywords
COMBUSTIBLES ALTERNATIVOS , INYECCION DE HIDROGENO , MOTOR DUAL HIDROGENO-DIESEL