کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1282528 | 1497578 | 2011 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Advantages of the direct injection of both diesel and hydrogen in dual fuel H2ICE Advantages of the direct injection of both diesel and hydrogen in dual fuel H2ICE](/preview/png/1282528.png)
The turbocharged Diesel engine is the most efficient engine now in production for transport applications with full load brake engine thermal efficiencies up to 40–45% and reduced penalties in brake engine thermal efficiencies reducing the load. The secrets of the turbocharged Diesel engine performances are the high compression ratio and the lean bulk combustion mostly diffusion controlled in addition to the better use of the exhaust energy. Despite these advantages and the further complications of hydrogen in terms of abnormal combustion phenomena and displacement effect, the most part of the dual fuel Diesel-hydrogen engines has been developed so far injecting hydrogen in the intake manifold or in the intake port, and then injecting the Diesel fuel in the cylinder to ignite there a homogeneous mixture. This paper shows how a latest production common-rail Diesel engine could be modified replacing the Diesel injector by a double injector as those proposed by Westport since more than two decades for CNG first and then for CNG and hydrogen to provide much better performances. A model is first developed and validated versus extensive high quality dynamometer data for the Diesel engine only covering with almost 200 points the load and speed range. This model replaces the multiple injection strategy with a single equivalent injection for the purposes of the brake efficiency results still providing satisfactory accuracy. The model is then used to simulate the dual fuel operation with a pilot Diesel followed by a main hydrogen injection replacing the Diesel fuel with the hydrogen fuel and using the same parameters for start and duration of the equivalent injection at same percentage load and speed. While the top load air-to-fuel ratio of the Diesel is a lean 1.55, the top air-to-fuel ratio of the hydrogen is assumed to be a stoichiometric 1. Within the validity of these assumptions it is shown that the novel engine has better than Diesel fuel conversion efficiencies and higher than Diesel power outputs. These results clearly indicate the development of the direct injection system as the key factor where to focus research and development for this kind of engines.
► Dual fuel h2-Diesel ICE works better with direct injection of both hydrogen and Diesel.
► DI Dual fuel h2-Diesel ICE have same of Diesel top full load efficiency (>40%).
► DI Dual fuel h2-Diesel ICE have same of Diesel part load efficiencies.
► DI Dual fuel h2-Diesel ICE permit increased BMEP vs. the Diesel (35 vs. 22 bar).
Journal: International Journal of Hydrogen Energy - Volume 36, Issue 15, July 2011, Pages 9312–9317