Characteristics of Engine Emissions Using Biodiesel Blends in Low-Temperature Combustion Regimes

Low-temperature combustion(LTC) with multiple injection strategies is a recent trend for NOx and soot reduction in single-cylinder diesel engines. This paper presents a technical study of past research carried out on multiple injections, which are pilot I and pilot II injection before main injection, to decrease engine soot to meet emission legislation while upholding efficiency and decrease or eliminate exhaust after treatment. Previous research indicates that extending ignition lag to enhance the proper premixing, and controlling temperature of combustion to optimal level using Exhaust Gas Recirculation, have been accepted as an important aspect to attain low temperature combustion. In this paper, we first discuss the effect pilot I injection and pilot II injection strategy through varied injection quantity and time range. Thereafter, we briefly review how pilot II injection provides better results compared with the pilot I injection, which is by reason of better premixing, improves the turbulent effect and lowers the emission. Next, we provide a broad overview of the collected works on the effect of injection pressure, temperature and rate of exhaust gas recirculation on engine emissions. We conclude by identifying a few dependencies of engine parameters in low-temperature combustion by multiple injections so as to reduce the engine emissions.

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An Enabling Study of Low Temperature Combustion With Ethanol in a Diesel Engine

Journal of Energy Resources Technology ◽

10.1115/1.4024027 ◽

2013 ◽

Vol 135 (4) ◽

Cited By ~ 29

Author(s):

Tongyang Gao ◽

Prasad Divekar ◽

Usman Asad ◽

Xiaoye Han ◽

Graham T. Reader ◽

...

Keyword(s):

Low Temperature ◽

Direct Injection ◽

Empirical Work ◽

Low Temperature Combustion ◽

Engine Emissions ◽

Engine Efficiency ◽

Temperature Combustion ◽

Charge Cooling ◽

Gas Recirculation ◽

Low Nitrogen

Previous research indicates that the low temperature combustion (LTC) is capable of producing ultra-low nitrogen oxides (NOx) and soot emissions. The LTC in diesel engines can be enabled by the use of heavy exhaust gas recirculation (EGR) at moderate engine loads. However, when operating at higher engine loads, elevated demands of both intake boost and EGR levels to ensure ultra-low emissions make engine controllability a challenging task. In this work, a multifuel combustion strategy is implemented to improve the emission performance and engine controllability at higher engine loads. The port fueling of ethanol is ignited by the direct injection of diesel fuel. The ethanol impacts on the engine emissions, ignition delay, heat-release shaping, and cylinder-charge cooling have been empirically analyzed with the sweeps of different ethanol-to-diesel ratios. Zero-dimensional phenomenological engine cycle simulations have been conducted to supplement the empirical work. The multifuel combustion of ethanol and diesel produces lower emissions of NOx and soot while maintaining the engine efficiency. The experimental setup and study cases are described, and the potential for the application of an ethanol-to-diesel multifuel system at higher loads has been proposed and discussed.

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An Enabling Study of Low Temperature Combustion With Ethanol in a Diesel Engine

ASME 2012 Internal Combustion Engine Division Fall Technical Conference ◽

10.1115/icef2012-92176 ◽

2012 ◽

Cited By ~ 3

Author(s):

Tongyang Gao ◽

Prasad Divekar ◽

Usman Asad ◽

Xiaoye Han ◽

Graham T. Reader ◽

...

Keyword(s):

Low Temperature ◽

Direct Injection ◽

Empirical Work ◽

Fuel Combustion ◽

Low Temperature Combustion ◽

Engine Emissions ◽

Temperature Combustion ◽

Charge Cooling ◽

Set Up ◽

Gas Recirculation

Previous research indicates that the low temperature combustion (LTC) is capable of producing ultra-low nitrogen oxides (NOx) and soot emissions. The LTC in diesel engines can be enabled by the heavy use of exhaust gas recirculation (EGR) at moderate engine loads. However, when operating at higher engine loads, elevated demands of both intake boost and EGR levels to ensure ultra-low emissions make engine controllability a challenging task. In this work, a multi-fuel combustion strategy is implemented to improve the emission performance and engine controllability at higher engine loads. The port fueling of ethanol is ignited by the direct injection of diesel fuel. The ethanol impacts on the engine emissions, ignition delay, heat-release shaping and cylinder-charge cooling have been empirically analyzed with the sweeps of different ethanol-to-diesel ratios. Zero-dimensional phenomenological engine cycle simulations have been conducted to supplement the empirical work. The multi-fuel combustion of ethanol and diesel produces lower emissions of NOx and soot while maintaining the engine efficiency. The experimental set-up and study cases are described and the potential for the application of ethanol-to-diesel multi-fuel system at higher loads has been proposed and discussed.

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