Exergy analysis of biodiesel combustion in a direct injection compression ignition (CI) engine using quasi-dimensional multi-zone model

A dual-fuel engine is a compression ignition (CI) engine where the primary gaseous fuel source is premixed with air as it enters the combustion chamber. This homogenous mixture is ignited by a small quantity of diesel, the ‘pilot’, that is injected towards the end of the compression stroke. In the present study, a direct-injection CI engine, was fuelled with three different gaseous fuels: methane, propane, and butane. The engine performance at various gaseous concentrations was recorded at 1500 r/min and quarter, half, and three-quarters relative to full a load of 18.7 kW. In order to investigate the combustion performance, a novel three-zone heat release rate analysis was applied to the data. The resulting heat release rate data are used to aid understanding of the performance characteristics of the engine in dual-fuel mode. Data are presented for the heat release rates, effects of engine load and speed, brake specific energy consumption of the engine, and combustion phasing of the three different primary gaseous fuels. Methane permitted the maximum energy substitution, relative to diesel, and yielded the most significant reductions in CO2. However, propane also had significant reductions in CO2 but had an increased diffusional combustion stage which may lend itself to the modern high-speed direct-injection engine.

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Performance Analysis of a Biodiesel-Fired Engine for Cogeneration

E3S Web of Conferences ◽

10.1051/e3sconf/202131208013 ◽

2021 ◽

Vol 312 ◽

pp. 08013

Author(s):

Luigi Falbo ◽

Ernesto Ramundo

Keyword(s):

Environmental Sustainability ◽

Alternative Fuels ◽

Direct Injection ◽

Pollutant Emissions ◽

Zone Model ◽

Compression Ignition ◽

Compression Ignition Engines ◽

Partial Load ◽

Chp System ◽

Continuous Demand

The continuous demand to reduce both the pollutant emissions and the greenhouse gas (GHG) is increasing the use of alternative fuels as biodiesel in direct-injection compression ignition engines under combined heat and power (CHP) configuration. Although the biodiesel has different thermophysical properties compared to the standard diesel, it can be used in compression ignition engines without significant modifications. However, the pure biodiesel and biodiesel/diesel blends provide different performance and combustion characteristics with respect to the standard diesel engine. In order to estimate the behaviour of a micro-CHP system fuelled with biodiesel, a zero dimensional (0D) numerical model was development. This model is based on a single zone model and predicts the behaviour of a biodiesel/diesel blend-fired engine at full and partial load in terms of electrical efficiency, thermal efficiency and specific fuel consumption. Notwithstanding the biodiesel/diesel blend reveals lower performance in terms of electric and thermal efficiencies, can be used in CHP systems preserving the environmental sustainability avoiding significant modifications in the engine architecture.

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Environment‐friendly fuel Cymbopogon flexuosus : Analysis of fuel properties, performance, and emission parameters of a Direct Injection Compression Ignition research engine

Heat Transfer ◽

10.1002/htj.22194 ◽

2021 ◽

Author(s):

Ramalingam Sathiyamoorthi ◽

Gomathinayagam Sankaranarayanan ◽

Mani Venkatraman ◽

Dinesh Babu Munuswamy ◽

Rajendran Ravisankar

Keyword(s):

Direct Injection ◽

Fuel Properties ◽

Compression Ignition ◽

Environment Friendly ◽

Performance And Emission ◽

Cymbopogon Flexuosus

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Mapping the combustion modes of a dual-fuel compression ignition engine

International Journal of Engine Research ◽

10.1177/14680874211018376 ◽

2021 ◽

pp. 146808742110183

Author(s):

Jonathan Martin ◽

André Boehman

Keyword(s):

Direct Injection ◽

Fuel Combustion ◽

Dual Fuel ◽

Compression Ignition ◽

Compression Ignition Engine ◽

Combustion Modes ◽

Si Engines ◽

Dual Fuel Combustion ◽

Soot Emissions ◽

Ci Engines

Compression-ignition (CI) engines can produce higher thermal efficiency (TE) and thus lower carbon dioxide (CO2) emissions than spark-ignition (SI) engines. Unfortunately, the overall fuel economy of CI engine vehicles is limited by their emissions of nitrogen oxides (NOx) and soot, which must be mitigated with costly, resource- and energy-intensive aftertreatment. NOx and soot could also be mitigated by adding premixed gasoline to complement the conventional, non-premixed direct injection (DI) of diesel fuel in CI engines. Several such “dual-fuel” combustion modes have been introduced in recent years, but these modes are usually studied individually at discrete conditions. This paper introduces a mapping system for dual-fuel CI modes that links together several previously studied modes across a continuous two-dimensional diagram. This system includes the conventional diesel combustion (CDC) and conventional dual-fuel (CDF) modes; the well-explored advanced combustion modes of HCCI, RCCI, PCCI, and PPCI; and a previously discovered but relatively unexplored combustion mode that is herein titled “Piston-split Dual-Fuel Combustion” or PDFC. Tests show that dual-fuel CI engines can simultaneously increase TE and lower NOx and/or soot emissions at high loads through the use of Partial HCCI (PHCCI). At low loads, PHCCI is not possible, but either PDFC or RCCI can be used to further improve NOx and/or soot emissions, albeit at slightly lower TE. These results lead to a “partial dual-fuel” multi-mode strategy of PHCCI at high loads and CDC at low loads, linked together by PDFC. Drive cycle simulations show that this strategy, when tuned to balance NOx and soot reductions, can reduce engine-out CO2 emissions by about 1% while reducing NOx and soot by about 20% each with respect to CDC. This increases emissions of unburnt hydrocarbons (UHC), still in a treatable range (2.0 g/kWh) but five times as high as CDC, requiring changes in aftertreatment strategy.

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