Comprehensive analysis of the combustion of low carbon fuels (hydrogen, methane and coke oven gas) in a spark ignition engine through CFD modeling

Abstract

The use of low carbon fuels (LCFs) in internal combustion engines is a promising alternative to reduce pollution while achieving high performance through the conversion of the high energy content of the fuels into mechanical energy. However, optimizing the engine design requires deep knowledge of the complex phenomena involved in combustion that depend on the operating conditions and the fuel employed. In this work, computational fluid dynamics (CFD) simulation tools have been used to get insight into the performance of a Volkswagen Polo 1.4L port-fuel injection spark ignition engine that has been fueled with three different LCFs, coke oven gas (COG), a gaseous by-product of coke manufacture, H 2 and CH 4 . The comparison is made in terms of power, pressure, temperature, heat release, flame growth speed, emissions and volumetric efficiency. Simulations in Ansys® Forte® were validated with experiments at the same operating conditions with optimal spark advance, wide open throttle, a wide range of engine speed (2000-5000 rpm) and air-fuel ratio (λ) between 1 and 2. A sensitivity analysis of spark timing has been added to assess its impact on combustion variables. COG, with intermediate flame growth speed, produced the greatest power values but with lower pressure and temperature values at λ = 1.5, reducing the emissions of NO and the wall heat transfer. The useful energy released with COG was up to 16.5% and 5.1% higher than CH 4 and H 2 , respectively. At richer and leaner mixtures (λ = 1 and λ = 2), similar performances were obtained compared to CH 4 and H 2 , combining advantages of both pure fuels and widening the λ operation range without abnormal combustion. Therefore, suitable management of the operating conditions maximizes the conversion of the waste stream fuel energy into useful energy while limiting emissions.

Hydrogen Recovery from Coke Oven Gas. Comparative Analysis of Technical Alternatives

“…Moreover, a computational fluid dynamics (CFD) simulation showed that intermediate spark advance values of COG reduced the combustion pressure and temperature within the cylinder, decreasing NOx emissions and the wall heat transfer. In this way, COG generated the highest power values compared to CH 4 and H 2 at lean air-to-fuel mixtures …”

“…In this way, COG generated the highest power values compared to CH 4 and H 2 at lean air-to-fuel mixtures. 180 Garcı ́a et al 181 analyzed the environmental impact of the energy recovery of waste streams in steel production by means of the life cycle analysis tool. Coke oven gas and Linz-Donawitz converter gas were evaluated as supplementary fuels to natural gas in different scenarios that were defined according to the energy contribution of natural gas and off-gases.…”

Use of Hydrogen as Fuel: A Trend of the 21st Century

“…Hydrogen has several characteristics that make it a promising fuel, such as the large amount of energy released when combusted, i.e., a high calorific value [6,26] (Table 1).…”

“…Calorific value of different fuels under standard conditions of temperature and pressure. Adapted from Zhao et al [6] and Ortiz-Imedio et al [26].…”

Analysis of thermal barrier coated pistons in the COMSOL and the effects of their use with water + ethanol doped biodiesel

“…In recent years academic studies in internal combustion engines, artificial intelligence estimate [10,11], optimization [12,13] and computer-assisted design and analysis environments [14,15] is also supported. The researchers aim to perform analyzes without entering the laboratory environment with calculations based on this type of mathematical modelling.…”