Search results for "COMBUSTION"

Power Losses Minimization for Optimal Operating Maps in Power-Split HEVs: A Case Study on the Chevrolet Volt

2021

The power-split architecture is the most promising hybrid electric powertrain. However, a real advantage in energy saving while maintaining high performance can be achieved only by the implementation of a proper energy management strategy. This requires an optimized functional design before and a comprehensive analysis of the powertrain losses after, which could be rather challenging owing to the constructive complexity of the power-split transmission, especially for multi-mode architecture with multiple planetary gearing. This difficulty was overcome by a dimensionless model, already available in the literature, that enables the analysis of any power-split transmission, even in full electr…

Performance and combustion analysis of a supercharged double-fuel spark ignition engine

2019

In order to increase fuel economy and reduce pollutant emissions in the last decades light duty spark ignition (SI) engines have become smaller, supercharged and equipped with direct injection. A suitable alternative to oil derived fuel is represented by gaseous fuels, such as Natural Gas (NG) and Liquefied Petroleum Gas (LPG), whose higher knock resistance and better mixing capabilities substantially improve vehicle fuel economy and pollutant emissions. The simultaneous combustion of gasoline and gaseous fuel (Double-Fuel operation, DF) in a naturally aspirated SI engine has already been investigated in the past also by the same authors, proving remarkable results in terms of engine effici…

Combustion properties of spruce black liquor droplets : Sulfur-free pulping and influence of hot-water pretreatment

2016

Hot-water pretreatment of lignocellulosics prior to sulfur-free alkaline pulping is an interesting approach for recovering value-added carbohydrate- and lignin-derived materials. This paper investigated the chemical composition variations and combustion properties of the black liquors (BLs) from three different cooking processes: two sulfur-free soda-anthraquinone (soda-AQ) and oxygen-alkali (O2-NaOH) cooks and kraft cook, before and after hot-water pretreatment of the spruce sawdust. Relatively less aliphatic acids but more lignin were present in the BLs after hot-water pretreatment as cooking time prolonged. In general, the burning time decreased as follows: soda-AQ BL > O2-NaOH BL ≅ kraf…

Calibration of a knock prediction model for the combustion of a gasoline-natural gas mixture

2009

Gaseous fuels, such as Liquefied Petroleum Gas (LPG) and Natural Gas (NG), thank to their good mixing capabilities, allow complete and cleaner combustion than normal gasoline, resulting in lower pollutant emissions and particulate matter. Moreover natural gas, which is mainly constituted by methane, whose molecule has the highest hydrogen/carbon ratio, leads also to lower ozone depleting emissions. The authors in a previous work (1) experienced the simultaneous combustion of gasoline and natural gas in a bi-fuel S.I. engine, exploiting so the high knock resistance of methane to run the engine with an ‘overall stoichiometric’ mixture (thus lowering fuel consumption and emissions) and better …

Development of combustion dynamics at co-combustion of straw with wood

2018

From wood pellets to wood chips, risks of degradation and emissions from the storage of woody biomass – A short review

2016

Abstract The compounds in stored woody biomass degrade as a result of chemical and/or biological processes during storage. These processes produce gaseous emissions. Recent studies concerning gaseous emissions from wood pellet storages are reviewed herein. The applicability of the results from pellet research to wood chips is discussed. Thorough scientific understanding on the storage phenomena of wood chips is extremely important as the threat of climate change and the need to reduce greenhouse gas emissions have led to an increased need to large scale wood chip storage to ensure supply. Typically the gases produced from stored woody biomasses are carbon monoxide (CO), carbon dioxide (CO 2…

Sustainable Energy Supply Based on Sunflower Seed Husk for Oil mills

2019

The use of biomass, including sunflower husk, for in-situ energy generation has undergone a development in Ukraine last decades. Within this work, four combined heat and power technologies based on oil utilization, husk combustion, gasification, and methanization have been investigated. Their electricity and heat potential has been determined. Criteria for techno-economical assessment of CHP technologies have been suggested. Husk biogas and gasification technologies are not mature. CHP plants based on husk combustion are competitive. Steam turbine generators with a nominal electric capacity higher 1.5 MW may be profitable too.

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

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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…