Influence of Fuel Composition, Engine Power and Operation Mode on Exhaust Gas Particulate Size Distribution and Gaseous Emissions From a Gas Turbine Engine

Abstract

The impact of fuel composition, engine power (idle and full power) and operation mode (cold and hot idle) on the gaseous emissions, particle number and mass concentrations and size distributions from an aircraft auxiliary power unit (APU) was investigated. A re-commissioned Artouste MK113 APU engine was used. The engine was run at three operational modes: i.e. approximately 6 minutes at idle (cold idle) after stabilized from start, 6 minutes at full power and then returning to idle again (hot idle) for 6 minutes. All operating parameters of the engine were monitored and recorded. The engine exhaust particle measurements and gaseous emissions were taken at three operating modes. Five alternative fuels/blending components were tested and compared to neat conventional JetA1 fuel either in pure or blended forms. These fuels varied in their compositions in terms of H/C ratio, density and other properties. A Scanning Mobility Particle Sizer (SMPS) with a Nano-Differential Mobility Analyzer (NDMA) was used to determine the number and mass concentration and size distribution of engine exhaust in the size range from 5 nm to 160 nm. The influence of fuel elemental ratio (H/C), engine power and cold/hot operation on particle number and mass size distribution was investigated. The results show that there was a good correlation between fuels H/C ratio and particle concentrations, particle size and distributions characteristics. The engine at hot idle produced ∼20% less particles compare to the results at cold idle. The alternative fuel blends produced less particles than JetA1 fuel. The testing fuels produced similar levels of NOx, slight reductions in CO and remarkable reductions in UHC compared to JetA1.

Particulate Emissions and Size Distributions of Biofuel in Micro Gas Turbine Engine

“…These observations were similar to those reported by Li and Tan [20,21] which could be as a result of substantial formation of nucleation mode particles. There was a slight increase in total particle concentration in Jet A1, B10 and B20 and a significant decrease in total particle concentration in B30 and B50.…”

“…Jet A1 was noticed to have the least particle size with its peak at 44.5 nm diameters at idle position, 61.5 nm diameters at 70% and 68.5 nm diameter at full power. [18,19,20,21]. Although there was a slight decrease in the size distribution with B70, which is 119 nm at full power, 113 nm at 70% power and 120 nm at idle position.…”

About the emissions of alternative jet fuels

“…Only a slight reduction of CO emissions were noticed by Wilson et al [67] in testing the SWAFEA-fuels, mostly Jet A-1 blends of FAE and HEFA.…”

Investigations on Combustion and Emissions Characteristics of Aromatic Fuel Blends in a Distributed Combustor

“…Although they are an essential part of fuel systems, they are also the primary source of PM emissions . It is reported in the literature that not all aromatics generates the same amount of PM emissions. , Hence, a comprehensive analysis and proper selection of the right composition of aromatic would lead to both low PM emissions and better seal compatibility. The American Society for Testing and Materials (ASTM) has reviewed a modified fuel specification with up to 50% blending in conventional fuels .…”