Influence of injection of concentrated NOx into diesel engine intake on exhaust gas components and fuel consumption

Abstract

AbstractThe effect of injecting NO (major content of NOx in diesel exhaust gas) into a diesel engine intake, on the reduction of NOx generation at the combustion chamber was investigated. The results demonstrate that 20 to 30% of the injected NO [0.225 to 0.72 slm (slm: standard liter per minute)] is reduced. A discussion of the NOx reduction based on the extended Zeldovich mechanism suggests that the reduction is mainly attributable to the region where the equivalence ratio ranges from 1.1 to 1.5 and that the reaction between NO and hydrocarbon species contributes slightly to the NO reduction. Further experimental data show that the injection of NO slightly improves the specific fuel consumption; for example, a 0.4% reduction is achieved when NO is injected at 0.72 slm for an intake airflow of 285 slm. The experimentally determined change in fuel consumption is highly consistent with the calculations based on the reaction enthalpy of NO reduction and CO oxidation. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 182(3): 39–47, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22341