Search results for " Combustion"
showing 10 items of 106 documents
NO formation tendency characterization for solid fuels in fluidized beds
2013
Abstract Usually the standard fuel analysis is not enough to allow for accurate NO emission predictions in large scale fluidized bed combustion. This paper presents NO formation tendency characterization results from novel laboratory measurements in a small-scale fluidized bed combustor. With the special two-stage oxidation method it is possible to eliminate the observed problems of unstable test conditions during rapid pyrolysis of high-volatile fuels in batch combustion. Experimental results of the conversion of fuel nitrogen to NO are presented for wide range of fuels, ranging from coal-type fuels to peat, biomasses and wastes. A NO formation tendency database is formed based on the resu…
Heat Recovery Systems for Agricultural Vehicles: Utilization Ways and Their Efficiency
2018
The focus of today&rsquo
A regenerative braking system for internal combustion engine vehicles using supercapacitors as energy storage elements - Part 2: Simulation results
2020
Abstract In this two-part work, an electric kinetic energy recovery system (e-KERS) for internal combustion engine vehicle (ICEV) is presented and its performance evaluated through numerical simulations. The KERS proposed is based on the use of a supercapacitor as energy storage, interfaced to a brushless machine through a properly designed power converter. In Part 1, the system is described and analysed, and the mathematical model used for the simulations is presented. For each component of the KERS, the real efficiency and the power or energy limitations are adequately considered. In Part 2, the energetic and economic advantages attainable by the proposed KERS are evaluated using MATLAB S…
A regenerative braking system for internal combustion engine vehicles using supercapacitors as energy storage elements - Part 1: System analysis and …
2020
Abstract In this two-part work, an electric kinetic energy recovery system (e-KERS) for internal combustion engine vehicle (ICEV) is presented, and its performance evaluated through numerical simulations. The KERS proposed is based on the use of a supercapacitor as energy storage, interfaced to a brushless machine through a properly designed power converter. In part 1, the system is described and analysed, and the mathematical model used for the simulations is presented. For each component of the KERS, the real efficiency, and the power or energy limitations are adequately considered. In part 2, the energetic and economic advantages attainable by the proposed KERS are evaluated using MATLAB…
A COMPARISON BETWEEN COMBUSTION PHASE INDICATORS FOR OPTIMAL SPARK TIMING
2008
The closed-loop control of internal combustion engine spark timing may be accomplished by means of a combustion phase indicator, i.e., a parameter, derived from in-cylinder pressure analysis, whose variation is mainly referable to combustion phase shift and assumes a fixed reference value under optimal spark timing operation. The aim of the present work is a comparison between different combustion phase indicators, focusing on the performance attainable by a feedback spark timing control, which uses the indicator as pilot variable. An extensive experimental investigation has been carried out, verifying the relationship between indicators’ optimal values and the main engine running parameter…
Influence of Elevated Pressure on the Torrefaction of Wood
2016
The use of pressurized reactors in industrial processes can improve efficiency and economics. Torrefaction is a partial pyrolysis of lignocellulosic biomass designed to result in a solid product with improved fuel properties for utilization in combustion and gasification. In this work, the influence of elevated pressure on the torrefaction of wood has been investigated. Wood samples were torrefied using a pressurized thermogravimetric reactor (PTGR) with pressures of 0.1 to 2.1 MPa. The results indicate that reactor pressure, particle size of feedstock, and wood species are all factors in torrefaction yield improvements. Torrefaction at 2.1 MPa pressure improved the higher heating value (ca…
Rapid Compression Machine. 2013.
2013
A rapid compression machine is a type of ideal internal combustion reactor which is well suited for gas phase kinetics studies and physical processes of combustion. These studies consist in recording the evolution of the reactivity and of the composition of the reacting mixtures as a function of temperature, pressure, residence time and the composition of the compressed mixture. Pressure measurement is used to analyse the evolution of the combustion process, but more recent studies couple pressure measurement with optical diagnostics in order to assess the homogeneity of the combustion process. Speciation based on rapid sampling of the intermediates formed, during the oxidation of the fuel,…
Thermal Engine and Climate Change Challenge
2021
Thermal engines have dominated sectors of economy, and particularly transportation. Their current development and state of the art are the results of XXth century priorities related to economy and environment. In the future, thermal engines will face the challenge of emerging technologies in the frame of sustainable mobility and development. After an analysis of functioning principles and perspectives of development, particularly of combustion engines, thermal engines are compared to other realistic scenarios for transports applications in well-to-wheel and life cycle analysis.
Distribution of biomass and site location of combustion and gasification power plants in western Sicily
2012
The substitution of conventional fossil fuels with biomass for energy production results both in the reduction of greenhouse gases emissions and in the replacement of non-renewable energy sources. The use of biomass for energy production responds to the growing pressure of government policies towards the achievement of better environmental sustainability of power generation processes. This is particularly true for the agricultural areas of Sicily, where the realization of new economic dynamics can lead to development of a local economic system. However, at present, generating energy from biomass is rather expensive due to both technological limits related to low conversion efficiencies, and…
Calibration of a knock prediction model for the combustion of gasoline-LPG mixtures in spark ignition engines
2015
Gaseous fuels, such as liquefied petroleum gas (LPG) and natural gas (NG), thanks to their good mixing capabilities, allow complete and cleaner combustion than gasoline in spark ignition (SI) engines, resulting in lower pollutant emissions and particulate matter. In a previous work the authors showed that the simultaneous combustion of gasoline and LPG improves an SI engine efficiency with respect to pure gasoline operation with any significant power loss. The addition of LPG to the gasoline-air mixture produces an increase in knock resistance that allows running the engine at full load with overall stoichiometric mixture and better spark advance. In order to predict both performance and ef…