Optimized heat release rate for enhanced thermal efficiency under NOx, noise and peak firing pressure constraints in light-duty Diesel engines

Zaccardi, Jean-Marc; Nicolas, F.; Rudloff, Jordan; Paola, Gaetano De

doi:10.1007/978-3-658-17109-4_13

Cited by 5 publications

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Instead, much simpler and higher heat release rate in delta shape profile is the optimum at both rated and middle speed/middle-load conditions under various practical constraints. 10…”

Section: Resultsmentioning

confidence: 99%

A new concept of actively controlled rate of diesel combustion (ACCORDIC): Part II—simultaneous improvements in brake thermal efficiency and heat loss with modified nozzles

Uchida¹,

Watanabe

2018

International Journal of Engine Research

View full text Add to dashboard Cite

A new diffusion-based combustion concept (named it as Actively Controlled Rate of Diesel Combustion) for the confirmation of brake thermal efficiency optimum heat release rate profile based on multiple fuel injectors has been investigated. The outstanding results are; it is possible to achieve desired heat release rate profile only by the independent control of injection timing and duration of three injectors installed to a cylinder. The optimum brake thermal efficiency was not achieved with the Otto-like cycle but with the Sabathe-like cycle as predicted by a zero-dimensional thermodynamic model. Furthermore, smoke emissions were concurrently reduced with NOx emissions by increasing fuel amount from the side injectors without any deterioration in CO and total hydrocarbon emissions. On the other hand, brake thermal efficiency itself was not so improved than expected, because of lower heat release in the late part of combustion and unexpected less heat loss reduction. To solve these issues, combustion visualization and numerical simulation analysis were carried out. The results suggested that the adjacent sprays with narrower angle from each side injector deteriorated air entrainment and mixture formation, which might also result in the deterioration in wall heat loss in the expansion stroke. To solve both issues simultaneously, modified nozzle to inject against the swirl from the side injectors was utilized and achieved an improvement in both brake thermal efficiency and heat loss. That is the interdependent and reciprocal control of in-cylinder flow and fuel injection will be one of the breakthrough technologies for current trade-offs by the temporal and spatial spray flame optimization. Furthermore, the nozzle having higher flow rate with less number of orifice was utilized for the side injectors. Even though the smoke emissions were not optimized yet, brake thermal efficiency was much improved with higher heat release rate in the late part of combustion.

show abstract

“…Instead, much simpler and higher heat release rate in delta shape profile is the optimum at both rated and middle speed/middle-load conditions under various practical constraints. 10…”

Section: Resultsmentioning

confidence: 99%