This page has only limited features, please log in for full access.
Power generation units based on the bio-syngas system face two main challenges due to (i) the possible temporary shortage of primary sources and (ii) the engine power derating associated with the use of low-energy density fuels in combustion engines. In both cases, an external input fuel is provided. Hence, complementing syngas with traditional fuels, like natural gas, becomes a necessity. In this work, an experimental methodology is proposed, aiming at the quantification of the impact of the use of both natural gas and syngas in spark ignition (SI) engines on performance and emissions. The main research questions focus on investigating brake thermal efficiency (BTE), power derating, and pollutant emission (NOx, CO, THC, CO2) formation, offering quantitative findings that present the basis for engine optimization procedures. Experimental measurements were performed on a Toyota 4Y-E engine (a 4-cylinders, 4-stroke spark ignition engine) at partial load (10 kW) under different syngas energy shares (SES) and at four different spark ignition timings (10°, 25°, 35° and 45° BTDC). Results reveal that the impact of the different fuel mixtures on BTE is negligible if compared to the influence of spark advance variation on BTE. On the other hand, power derating has proven to be a limiting factor and becomes more prominent with increasing SES. An increasing SES also resulted in an increase of CO and CO2 emissions, while NOx and THC emissions decreased with increasing SES.
Carlo Caligiuri; Urban Žvar Baškovič; Massimiliano Renzi; Tine Seljak; Samuel Rodman Oprešnik; Marco Baratieri; Tomaž Katrašnik. Complementing Syngas with Natural Gas in Spark Ignition Engines for Power Production: Effects on Emissions and Combustion. Energies 2021, 14, 3688 .
AMA StyleCarlo Caligiuri, Urban Žvar Baškovič, Massimiliano Renzi, Tine Seljak, Samuel Rodman Oprešnik, Marco Baratieri, Tomaž Katrašnik. Complementing Syngas with Natural Gas in Spark Ignition Engines for Power Production: Effects on Emissions and Combustion. Energies. 2021; 14 (12):3688.
Chicago/Turabian StyleCarlo Caligiuri; Urban Žvar Baškovič; Massimiliano Renzi; Tine Seljak; Samuel Rodman Oprešnik; Marco Baratieri; Tomaž Katrašnik. 2021. "Complementing Syngas with Natural Gas in Spark Ignition Engines for Power Production: Effects on Emissions and Combustion." Energies 14, no. 12: 3688.
To achieve a near zero emission footprint of combustion in power generation, introduction of fuels with low global warming potential, namely low-carbon or carbon neutral fuels and simultaneous reduction of harmful emissions through implementation of advanced combustion concepts is necessary. The study addresses this challenge experimentally by proposing a new approach which combines the benefits of highly oxygenated waste derived fuels, here represented by glycerol, and an introduction of external exhaust gasses recirculation (EGR) aimed for further reduction of NOx emissions. Thus, the recognized role of the high oxygen content in glycerol can positively influence the well-known penalties of EGR, which are commonly perceivable through elevated CO and soot emissions. The measurements were performed with an experimental gas turbine equipped with an exhaust heat regeneration system and feedback loop for 8% and 13% EGR content in compressor intake air. The proposed system layout represents a technically viable and cost-efficient approach for upgrading existent gas turbine setups with a goal to improve their emission footprint. Results confirm that with 8% and 13% EGR rate, NOx, CO and soot can be reduced simultaneously, thus improving the CO- NOx and soot- NOx trade off approximately 2-fold for each species. Additionally, underlying phenomena responsible for observed improvements while increasing EGR rate are identified as an increased soot reactivity, a competing effect of EGR related dilution and an increased primary air temperature together with spray related parameters linked to low stoichiometric ratio of glycerol.
Žiga Rosec; Tomaž Katrašnik; Urban Žvar Baškovič; Tine Seljak. Exhaust gas recirculation with highly oxygenated fuels in gas turbines. Fuel 2020, 278, 118285 .
AMA StyleŽiga Rosec, Tomaž Katrašnik, Urban Žvar Baškovič, Tine Seljak. Exhaust gas recirculation with highly oxygenated fuels in gas turbines. Fuel. 2020; 278 ():118285.
Chicago/Turabian StyleŽiga Rosec; Tomaž Katrašnik; Urban Žvar Baškovič; Tine Seljak. 2020. "Exhaust gas recirculation with highly oxygenated fuels in gas turbines." Fuel 278, no. : 118285.
An innovative computationally efficient method for the simultaneous determination of top dead centre (TDC) offset and pressure offset is presented. It is based on characteristic deviations of the rate of heat release (ROHR) that are specific for both offsets in compression phase and expansion phase after the end of combustion. These characteristic deviations of the ROHR are derived from first principles and they were also confirmed through manual shifts of the pressure trace. The ROHR is calculated based on the first law of thermodynamics using an in-cylinder pressure trace, engine geometrical parameters and operating point specific parameters. The method can be applied in off-line analyses using an averaged pressure trace or in on-line analyses using a single pressure trace. In both application areas the method simultaneously determines the TDC position and the pressure offset within a single processing of the pressure trace, whereas a second refinement step can be performed for obtaining more accurate results as correction factors are determined more accurately using nearly converged input data. Innovative analytic basis of the method allows for significant reduction of the computational times compared to the existing methods for the simultaneous determination of TDC offset and pressure offset in fired conditions. The method was validated on a heavy-duty and a light-duty diesel engine.
Urban Žvar Baškovič; Rok Vihar; Igor Mele; Tomaž Katrašnik. A New Method for Simultaneous Determination of the TDC Offset and the Pressure Offset in Fired Cylinders of an Internal Combustion Engine. Energies 2017, 10, 143 .
AMA StyleUrban Žvar Baškovič, Rok Vihar, Igor Mele, Tomaž Katrašnik. A New Method for Simultaneous Determination of the TDC Offset and the Pressure Offset in Fired Cylinders of an Internal Combustion Engine. Energies. 2017; 10 (1):143.
Chicago/Turabian StyleUrban Žvar Baškovič; Rok Vihar; Igor Mele; Tomaž Katrašnik. 2017. "A New Method for Simultaneous Determination of the TDC Offset and the Pressure Offset in Fired Cylinders of an Internal Combustion Engine." Energies 10, no. 1: 143.