Keywords
IEM-M (KL0-mecanica), Motor de seis tiempos, árbol de levas, inyección de agua, adaptación motor., Six-Cycle engine, crankshaft, water injection, engine conversion.
Six-cycle engine conversion
Abstract
Los motores de gasolina de cuatro tiempos son extremadamente ineficientes a la hora de utilizar toda la energía térmica liberada durante la combustión. Tradicionalmente, el exceso de energía térmica dentro del cilindro del motor simplemente se transfiere al entorno exterior para evitar el sobrecalentamiento. Se estima que el 62% de la energía contenida en el combustible se pierde en forma de calor.
El objetivo de este proyecto es solucionar este problema adaptando un motor de gasolina de cuatro tiempos existente a un prototipo que aproveche la energía desprendida de la combustión para obtener un aumento de eficiencia. Después de considerar diversas soluciones, la ruta elegida ha sido modificar el motor para ejecutar el ciclo de un motor tipo “Crower”, un ciclo de seis tiempos que inyecta agua en el cilindro después de que se agoten los productos de la combustión. Gracias a la gran expansión del agua cuando se cambia el estado del líquido a vapor, el exceso de calor producido convertirá el agua en vapor, y la expansión de este vapor proporciona al motor un golpe de potencia adicional. Se necesita un sistema de inyección directa y una válvula de escape adicional para introducir y evacuar el agua y el vapor. El prototipo se divide en cuatro subsistemas principales: el sistema de inyección de agua, el árbol de levas, el piñón de distribución y motor base. El nuevo árbol de levas es necesario para accionar las válvulas en los momentos apropiados para el ciclo modificado, y el piñón de distribución debe modificarse para girar la leva a una velocidad que le permita controlar tres revoluciones del cigüeñal sobre las dos habituales. Este proyecto describe en detalle el proceso para diseñar y fabricar un motor de estas características.
Four-stroke gasoline engines are extremely inefficient at utilizing all of the thermal energy released during combustion. Traditionally, excess thermal energy within the cylinder of the engine is simply transferred to the outside environment in order to prevent overheating. It is estimated that 62% of the energy contained in fuel is lost in the form of heat. The project will address this shortcoming by modifying an existing four-stroke gasoline engine into a prototype that demonstrates a means of recovering and using otherwise wasted heat. After analyzing many approaches, the chosen route has been to modify the engine to run the Crower cycle, a six-stroke cycle which injects water into the cylinder after the combustion products are exhausted. Thanks to the great expansion of water when changing state from liquid to steam, the excess heat produced will convert the water into steam, and the expansion of this steam provides the engine with an additional power stroke. A direct injector and additional exhaust valve are necessary to introduce and evacuate the water and steam. Our prototype is broken down into four major subsystems: water injection, camshaft, timing gear and base engine. The custom camshaft is needed in order to actuate the valves at the appropriate times for the modified cycle, and the timing gear must be modified to turn the cam at a speed that allows it to control three revolutions of the crankshaft over the usual two. This project describes in detail the process that has been followed to design and manufacture an engine of these characteristics.
Four-stroke gasoline engines are extremely inefficient at utilizing all of the thermal energy released during combustion. Traditionally, excess thermal energy within the cylinder of the engine is simply transferred to the outside environment in order to prevent overheating. It is estimated that 62% of the energy contained in fuel is lost in the form of heat. The project will address this shortcoming by modifying an existing four-stroke gasoline engine into a prototype that demonstrates a means of recovering and using otherwise wasted heat. After analyzing many approaches, the chosen route has been to modify the engine to run the Crower cycle, a six-stroke cycle which injects water into the cylinder after the combustion products are exhausted. Thanks to the great expansion of water when changing state from liquid to steam, the excess heat produced will convert the water into steam, and the expansion of this steam provides the engine with an additional power stroke. A direct injector and additional exhaust valve are necessary to introduce and evacuate the water and steam. Our prototype is broken down into four major subsystems: water injection, camshaft, timing gear and base engine. The custom camshaft is needed in order to actuate the valves at the appropriate times for the modified cycle, and the timing gear must be modified to turn the cam at a speed that allows it to control three revolutions of the crankshaft over the usual two. This project describes in detail the process that has been followed to design and manufacture an engine of these characteristics.
Información detallada
Materias, derechos, colecciones e identificadores