Development of an ethanol E100 combustion engine.
Introduction Dresser Rand has developed two stationary Guascor ? engines with powers of 450 and 680 KW that are able to work with ethanol E100 fuel at 1800 rpm. Both ethanol engines are based upon the SFGLD natural gas family, with the following main modifications: All engine components needed for the natural gas carburation system have been removed from the engine. An ethanol multipoint low pressure injection system was developed, whereby the ethanol spray is indirectly injected into the combustion chamber towards the intake ports of head cylinder. Different turbochargers, piston bowls, spark plugs and ignition systems were tested to optimize efficiency and ethanol combustion. A new engine control system was developed. Used equipment Two Guascor gas engines were reconfigured for the ethanol tests: SFGLD240: 8 L; displacement 24 dm3 ; 452 kW; SFGLD480: 12 V; displacement 36 dm3 ; 680 kW; Other characteristics: bore 152 mm, stroke 165 mm, 1800 rpm, 12,6 bar bmep . Results and discussion Some results and specific considerations obtained in both 8L and 12V ethanol engines are as follows: Engine start up from cold temperatures. Below 10°C, the engine cranking is difficult because the ethanol does not evaporate correctly. The ethanol goes into the combustion chamber in liquid phase, wetting the spark plugs, and does not allow the ignition system to start the combustion process. Different spark plugs and ignition systems have been tested to find the correct solution. Combustion peculiarities. The ethanol engine combustion has a higher COVimep than the equivalent gas engines. The ethanol engines can not run as lean as gas engines, causing the misfire point to be reached at higher emissions of NOx than gas engines. Different ignition configurations, piston bowls and variables have been tested to improve the engine behavior against misfire. Tests were performed to define the best injection configuration, in relation to injection pressure, injection pattern, injection configuration (using 1 or 2 injectors per cylinder) and injection timing. For example, two injectors/cylinders have efficiencies 1 point higher than one injector/cylinder. The exhaust temperatures and lambda values measured in different cylinders are similar, so there is no deviation of ethanol injection quantities from one cylinder to another. Efficiency and emissions. It has been tested how efficiency and emissions change when the engine runs at different conditions. The following variables have been considered: ambient, water, ethanol temperatures, injection pressures, injection patterns, water percentages mixed on ethanol, exhaust back pressures, and intake pressure losses. For example, if the water temperature is increased by 10°C, the emissions will increased by 200 ppm. NOx. Control system definition. A new engine control system and algorithms were developed, that can work with grid parallel mode or island mode. Based on the previous indicated tests, the control system was developed to give a correct automatic feedback against any condition change. Oil life. Before combustion, liquid ethanol is injected into the combustion chamber and a percentage of incorrectly evaporated ethanol goes through piston rings. Oil is therefore contaminated by the ethanol and acidity reduces the oil life. If no action is taken to solve this problem, the oil viscosity can be reduced by as much as 25% during only 10 hours of running. It was analyzed how to improve oil life. Conclusion After successful development, the two Guascor engines running with ethanol E100 reached the efficiency and electrical power of the original natural gas engine. The development covered performances tests, and also an endurance test of 4000 hours of continuous operation using the 8L engine in a potential client’s facility. Engine inspections were performed during the endurance test, confirmed that there was not accelerate damage of the internal components. Maintenance schedules of ethanol engines are similar to the original gas engines.
Jon Fernandez de Landa Magarin
Dresser-Rand,Spain
国际会议
上海
英文
1-14
2013-05-13（万方平台首次上网日期，不代表论文的发表时间）