Diesel-Ignited Propane Dual Fuel Low Temperature Combustion in a Heavy-Duty Diesel Engine

Abstract

D ep a rtm e n t o f M e cha n ical E n g in e erin g, C enter fo r A d va nce d V e h ic u la r S ystem s, M is s is s ip p i State U nive rsity, M is s is s ip p i State, M S 3 9 7 6 2 e -m a il: krishn a n @ m e .m sstate .e du D iesel-Ignited Propane Dual Fuel Low Tem perature Combustion in a Heavy-Duty Diesel EngineThis paper presents an experimental analysis of diesel-ignited propane dual fuel low tem perature combustion (LTC) based on performance, emissions, and in-cylinder combustion data from a modern, heavy-duty diesel engine. The engine used for these experiments was a 12.9-liter, six-cylinder, direct injection heavy-duty diesel engine with electronic unit diesel injection pumps, a variable geometry turbocharger, and cooled exhaust gas recirculation (EGR). The experiments were performed with gaseous propane (the primary fuel) fumigated upstream of the turbocharger and diesel (the pilot fuel) injected directly into the cylinders. Results are presented for a range of diesel injection timings (SOIs) from 10 deg BTDC to 50 deg BTDC at a brake mean effective pressure (BMEP) of 5 bar and a constant engine speed of 1500 rpm. The effects of SOI, percent energy substitution (PES) o f propane (i.e., replacement of diesel fuel energy with propane), intake boost pressure, and cooled EGR on the dual fuel LTC process were investigated. The approach was to determine the effects of SOI while maximizing the PES of propane. Dual fuel LTC was achieved with very early SOIs (e.g., 50 deg BTDC) coupled with high propane PES (>84%), which yielded near-zero NOx (<0.02 glkW h) and very low smoke emissions (<0.1 FSN). Increasing the propane PES beyond 84% at the SOI of 50 deg BTDC yielded a high COV oflMEP due to retarded combustion phasing (CA50). Intake boost pressures were increased and EGR rates were decreased to minimize the COV, allowing higher propane PES (~93%); however, lower fuel conversion efficiencies (FCE) and higher HC and CO emissions were observed.

The effect of injection parameters and boost pressure on diesel-propane dual fuel low temperature combustion in a single-cylinder research engine

“…Among gaseous primary fuels for dual fuel LTC, methane (or natural gas) has been investigated quite extensively. On the other hand, while conventional diesel-ignited propane dual fuel combustion has been studied by several researchers [38][39][40][41][42][43], very few studies have focused on propane as the primary fuel for dual fuel LTC (e.g., [44,45]). The present effort is an attempt to fill this gap.…”

“…The present effort is an attempt to fill this gap. Building on previous research efforts on dual fuel LTC at Mississippi State University (MSU) [34][35][36][44][45], this paper presents experimental results for diesel-ignited propane dual fuel LTC on a single-cylinder research engine (SCRE). Considering the wellestablished infrastructure for propane production and distribution within the United States, it is attractive as the primary fuel for dual fuel LTC.…”

Experimental Investigation of Acoustic Forcing on the Combustion Effect of Propane - Methane Mixtures

“…Polk et al, in a 6-cylinder diesel engine with dual fuel combustion of low-speed and low-power propane-diesel fuel; investigated their effects on performance, combustion and emission values. In their results, they concluded that as the amount of propane increases, NOX and soot emissions approach zero, and on the other hand, the amount of propane used can be up to 93% by reducing the EGR ratio and increasing the inlet pressure (Polk et al, 2014).…”

Impact of low reactivity fuel type on low load combustion, emissions, and cyclic variations of diesel-ignited dual fuel combustion

“…In dual fuel engines, typically a low reactivity fuel is fumigated into the intake manifold where a high reactivity fuel is directly injected into the combustion chamber. There have been multiple studies performed on different fuel combinations for dual fuel engine operation such as diesel-methane (DM), 1,2 diesel-propane (DP), 3,4 diesel-gasoline (DG), [5][6][7] diesel-natural gas 8,9 diesel-butane (DB), 10 diesel-ethanol, [11][12][13] and biodiesel-CNG (BDCNG). 14 The dual fuel combustion concept is not recent, with one of the earliest studies of an engine operating with the dual fuel strategy performed by Riffkin.…”