Search results for "combustion"

Numerical Investigation of a Wood-Chip Downdraft Gasifier

2019

Biomass gasification is regarded as one of the most promising technology in the renewable energy field. The outcome of such operation, i.e. the synfuel, can be exploited in several ways, for example powering engines and turbines, and is considered more flexible than the biomass itself. For this reason, a careful analysis of the gasification performance is of paramount importance for the optimization of the process. One of the techniques that can be used for such a purpose, is the numerical analysis. CFD is indeed a tool that can be of great help in the design and study of the operation of the gasifier, allowing for an accurate prediction of the operating parameters. In this work, a downdraf…

Influence of Biomass Combustion Products on Element Content and Thermal Stability of Latvian Sheep Breed Wool Filter Fibres

2020

Sheep wool is natural, easy obtainable, renewable and biodegradable material with a perspective application as a sorbent in filters for purification of industrial emissions from various environmental pollutants. The element content and thermal stability of Latvian dark-headed sheep wool filter fibres was analysed and described before and after exposure to biomass combustion products. Based on the obtained results, it is concluded that the sheep wool filter fibres can sorb various gaseous combustion products, such as carbon monoxide (CO), carbon dioxide (CO2) and nitrogen oxides (NOx), however, the sorption processes of these gases are irreversible. The obtained results of total reflection X…

Magnetic Field Control of Combustion Dynamics

2016

Abstract Experimental studies and mathematical modelling of the effects of magnetic field on combustion dynamics at thermo-chemical conversion of biomass are carried out with the aim of providing control of the processes developing in the reaction zone of swirling flame. The joint research of the magnetic field effect on the combustion dynamics includes the estimation of this effect on the formation of the swirling flame dynamics, flame temperature and composition, providing analysis of the magnetic field effects on the flame characteristics. The results of experiments have shown that the magnetic field exerts the influence on the flow velocity components by enhancing a swirl motion in the …

Modeling of particle trajectories in an electrostatic precipitator (ESP) for small-scale wood combustion

2009

La combustione HCCI mediante miscele di gas naturale e benzina: una prima esperienza sperimentale

2016

Si presentano in questo articolo i risultati di una sperimentazione volta a valutare la possibilità di effettuare una combustione HCCI (Homogeneous Charge Compression Ignition) stabile mediante l’impiego di miscele di gas naturale (GN) e benzina. La combustione HCCI ha ottime prerogative di basso impatto ambientale, ma la sua realizzazione pone qualche problema di stabilità al variare delle condizioni di carico richieste al motore: lo studio condotto mostra come l’impiego di miscele di GN e benzina, la cui composizione permette di variarne la resistenza all’autoaccensione, consente di ampliare il campo di funzionamento stabile della combustione HCCI. In the last decade the HCCI combustion h…

A New Simple Function for Combustion and Cyclic Variation Modeling in Supercharged Spark Ignition Engines

2022

Research in the field of Internal Combustion (IC) engines focuses on the drastic reduction of both pollutant and greenhouse gas emissions. A promising alternative to gasoline and diesel fuel is represented by the use of gaseous fuels, above all green hydrogen but also Natural Gas (NG). In previous works, the authors investigated the performance, efficiency, and emissions of a supercharged Spark Ignition (SI) engine fueled with mixtures of gasoline and natural gas; a detailed research involving the combustion process of this kind of fuel mixture has been previously performed and a lot of experimental data have been collected. Combustion modeling is a fundamental tool in the design and optimi…

Combustion behavior of black liquors : droplet swelling and influence of liquor composition

2017

The combustion of black liquor (BL) in a recovery boiler is a central process in a kraft pulp mill for recovering the cooking chemicals and for producing heat and power. This work explored the most important combustion behavior of BL, the swelling of in-flight droplets, from the viewpoint of liquor composition. It also studied the combustion behavior of BL droplets obtained from two biorefining subprocesses (carbonation and hot-water pretreatment, HWP) and sulfur-free pulping alternatives (soda-anthraquinone (AQ) and oxygen-alkali pulping). The formation of a plastic state essential for the swelling of BL droplet was found to result from the melting of an array of carbohydrate-derived aliph…

Sustainable Recycling of Insoluble Rust Waste for the Synthesis of Iron-Containing Perovskite-Type Catalysts

2019

Insoluble rust waste from the scraping of rusted iron-containing materials represents a cheap, eco-friendly, and available source of iron. LaFeO3 perovskite-type powders were successfully prepared by solution combustion synthesis using rust waste from an electricity transmission tower manufacturer. Solution combustion synthesis enabled introduction of this insoluble iron precursor directly into the final product, bypassing complex extraction procedures. Catalytic activity in the propylene oxidation of the waste-derived LaFeO3 with stoichiometric Fe/La ratio was almost identical to the commercial iron nitrate-derived LaFeO3 , thus demonstrating the viability of this recycling solution. The a…

Liquid aluminum particle effects on propagation of waves in solid rocket motor internal flow

2007

Aluminum-droplet effects on propagation of acoustic waves in the internal flow of a solid propellant rocket motor are analysed. Changes of the multiphase flow compressibility are calculated by taking into account both the translational and the pulsational motions of the aluminum droplets in consequence of the acoustic waves. Chemical reactions are not included in the analysis to avoid the complications arising from the non-isothermal and non-chemical-uniform combustion of aluminum in the chamber. Some corrections in current metalized propellant rocket instability calculations accounting for the results of the analysis are proposed.

Modeling and Backstepping Control of the Electronic Throttle System

2013

Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2013/871674 Open access Electronic throttle is widely used in modern automotive engines. An electronic throttle system regulates the throttle plate angle by using a DC servo motor to adjust the inlet airflow rate of an internal combustion engine. Its application leads to improvements in vehicle drivability, fuel economy, and emissions. In this paper, by taking into account the dynamical behavior of the electronic throttle, the mechanism model is first built, and then the mechanism model is transformed into the state-space model. Based on the s…