Search results for "Combustion"
showing 10 items of 232 documents
Atmospheric aging of small-scale wood combustion emissions (model MECHA 1.0) – is it possible to distinguish causal effects from non-causal ass…
2020
Abstract. Primary emissions of wood combustion are complex mixtures of hundreds or even over a thousand compounds, which pass through a series of chemical reactions and physical transformation processes in the atmosphere (aging). This aging process depends on atmospheric conditions, such as concentration of atmospheric oxidizing agents (OH radical, ozone and nitrate radicals), humidity and solar radiation, and is known to strongly affect the characteristics of atmospheric aerosols. However, there are only few models that are able to represent the aging of emissions during its lifetime in the atmosphere. In this work, we implemented a model (Model for aging of Emissions in environmental CHAm…
Black and brown carbon over central Amazonia: long-term aerosol measurements at the ATTO site
2018
The Amazon rainforest is a sensitive ecosystem experiencing the combined pressures of progressing deforestation and climate change. Its atmospheric conditions oscillate between biogenic and biomass burning (BB) dominated states. The Amazon further represents one of the few remaining continental places where the atmosphere approaches pristine conditions during occasional wet season episodes. The Amazon Tall Tower Observatory (ATTO) has been established in central Amazonia to investigate the complex interactions between the rainforest ecosystem and the atmosphere. Physical and chemical aerosol properties have been analyzed continuously since 2012. This paper provides an in-depth analysis of t…
Ship emissions measurement in the Arctic by plume intercepts of the Canadian Coast Guard icebreaker <i>Amundsen</i> from …
2016
Abstract. Decreasing sea ice and increasing marine navigability in northern latitudes have changed Arctic ship traffic patterns in recent years and are predicted to increase annual ship traffic in the Arctic in the future. Development of effective regulations to manage environmental impacts of shipping requires an understanding of ship emissions and atmospheric processing in the Arctic environment. As part of the summer 2014 NETCARE (Network on Climate and Aerosols) campaign, the plume dispersion and gas and particle emission factors of effluents originating from the Canadian Coast Guard icebreaker Amundsen operating near Resolute Bay, NU, Canada, were investigated. The Amundsen burned dist…
Application of aerosol optical properties to estimate aerosol type from ground-based remote sensing observation at urban area of northeastern China
2015
Abstract Aerosol optical properties were derived from ground-based sunphotometer observations between 2009-2013 at three urban sites of Shenyang, Anshan, Fushun in northeastern China. The annual means for extinction aerosol optical depths (EAOD) at 500 nm were 0.57±0.38, 0.52±0.35, and 0.41±0.31 at Shenyang, Anshan, Fushun, respectively. The corresponding annual means for the extinction Angstrom exponents (EAE) computed for the wavelengths of 440 and 870 nm were 0.86±0.32, 0.86±0.34 and 0.91±0.35, respectively, indicating that urban area of Northeast China were affected by both coarse and fine particles. Hygroscopic growth in summer and incursions of dust aerosols in spring were evidently r…
Corrosion Resistance of Alloys in IGCC Environment
2001
IGCC recovery boiler materials are subject to severe corrosion in environments composed of a gas mixture (CO-H 2 -H 2 O-CO 2 -H 2 S) and vanadium-containing fly-ash resulting from the combustion of oil residues. This paper presents a study of the corrosion behaviour of two Fe-Ni-Cr austenitic alloys in a typical IGCC environment at 400°C. The alloy composition influences the vanadium incorporated in the corrosion scales during the test, which affects the scale growth process. The valence state (determined by micro-XANES) and the amount of the incorporated vanadium is modified by a subsequent air flow at 400°C.
DETERMINATION OF TDC IN INTERNAL COMBUSTION ENGINES BY A NEWLY DEVELOPED THERMODYNAMIC APPROACH
2010
Abstract In-cylinder pressure analysis is nowadays an indispensable tool in internal combustion engine research & development. It allows the measure of some important performance related parameters, such as indicated mean effective pressure (IMEP), mean friction pressure, indicated fuel consumption, heat release rate, mass fraction burned, etc. Moreover, future automotive engine will probably be equipped with in-cylinder pressure sensors for continuous combustion monitoring and control, in order to fulfil the more and more strict emission limits. For these reasons, in-cylinder pressure analysis must be carried out with maximum accuracy, in order to minimize the effects of its characteristic…
Sizing of ICE and Lithium-ion battery for series hybrid vehicle over life cycle with battery aging
2013
This paper presents a method to evaluate the volume and weight of the internal combustion engine (ICE) and lithium-ion battery for a series hybrid vehicle that allows to minimize the mean consumption over system life. Individual driving cycles of the car over a total distance of 100 000 km are simulated. The ICE and battery dimensions are approximated; the fuel consumption is evaluated using a general approach. Lithium-ion battery is described including capacity fading and the energy split between ICE and battery system is evaluated using an heuristic approach. Results show a decrease of mean fuel consumption down to 5.1 L/100km.
Gasification of pelletized renewable fuel for clean energy production
2011
Abstract The main aim of the study was to develop and investigate a small-scale experimental gasification technique for the effective thermal decomposition of pelletized renewable fuels (wood sawdust, wheat straw). The technical solution of the biomass gasifier for gasification of renewable fuels presents a downdraft gasifier with controllable additional heat energy supply to the biomass using the radial propane flame injection into the bottom part of the biomass layer. From the kinetic study of the mass conversion rate of pelletized biomass and variations of the composition of produced gas it is concluded that the process of biomass gasification is strongly influenced by the amount of addi…
Towards controlling PCDD/F production in a multi-fuel fired BFB boiler using two sulfur addition strategies. Part II: Thermodynamic analysis
2014
Abstract A staged equilibrium process model was developed for a bubbling fluidized bed boiler firing SRF, bark and sludge. The model was used to study the influence of sulfur addition strategies (S-pellet additive and peat co-firing) on the behavior of copper, bromine, and alkalis. Aerosol samples collected from the backpass of the boiler were used to validate the chemistry predicted by the model. The model revealed that Cu existed as Cu 2 S (s3) in the reducing zone, and CuCl (g) (for all test cases) and CuO (s) (during peat co-firing) in the oxidation zones. CuBr 3(g) was also present after the introduction of tertiary air. However the model failed to predict the formation of CuSO 4 , an …
CARS spectroscopy of CH4 for implication of temperature measurements in supercritical LOX/CH4 combustion
2007
International audience; Experimental and theoretical investigations of coherent anti-Stokes Raman spectroscopy of CH4 have been carried out. Experimental spectra were measured in a heated high-pressure test cell and compared with numerical simulations. Good agreement was obtained for the temperature and the pressure dependence of CARS spectra in the ranges 300-1100 K and 0.1-5.0 MPa. The observed dependencies provide useful guidance for CARS thermometry, allowing quantitative measurements of temperature in high-pressure combustors. Application of multiplex CH4 CARS thermometry for single-shot measurements in a LOX/CH4 combustion at high pressure was demonstrated at supercritical conditions …