Serwis Infona wykorzystuje pliki cookies (ciasteczka). Są to wartości tekstowe, zapamiętywane przez przeglądarkę na urządzeniu użytkownika. Nasz serwis ma dostęp do tych wartości oraz wykorzystuje je do zapamiętania danych dotyczących użytkownika, takich jak np. ustawienia (typu widok ekranu, wybór języka interfejsu), zapamiętanie zalogowania. Korzystanie z serwisu Infona oznacza zgodę na zapis informacji i ich wykorzystanie dla celów korzytania z serwisu. Więcej informacji można znaleźć w Polityce prywatności oraz Regulaminie serwisu. Zamknięcie tego okienka potwierdza zapoznanie się z informacją o plikach cookies, akceptację polityki prywatności i regulaminu oraz sposobu wykorzystywania plików cookies w serwisie. Możesz zmienić ustawienia obsługi cookies w swojej przeglądarce.
Oxy-H2O combustion is a novel oxy-fuel combustion technology, different from conventional and oxy-CO2 combustion. NO and N2O emissions during devolatilization and char combustion of a single biomass particle in O2/N2 and O2/H2O were investigated in a tube reactor under different temperatures (700°C, 800°C, and 900°C) and oxygen concentrations (21%, 30%, 40%, and 50% by volume). Single biomass pellets...
3D measurements of burning coal particles in the flame are challenging and of great interest. Digital inline holography is applied to perform 3D measurement of coal particle size and 3D position in a laboratory-scale pulverized coal flame. Pulsed laser beam illumination is used to record the coal particle hologram with clear holographic fringes in the presence of high refractive index gradient and...
A dynamic CFD model, which is based on the inertia impaction, the thermophoresis and the direct alkali vapour condensation incorporating the influence of the heat transfer to the tube, has been developed for predicting the ash deposition formation in Zhundong lignite combustion in a pilot-scale furnace. The results show that particle deposition from the inertia impaction and the thermophoresis dictates...
The selective reduction of NO by C3H8 and the sensitivity to H2O and SO2 have been studied over monolithic cordierite-based Fe/Al2O3 catalysts, which were prepared by the sol–gel and impregnation method. The catalysts were investigated by N2 adsorption, X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and in situ diffuse reflectance infrared Fourier...
NOx emission of coke combustion in iron ore sintering was modeled by overall reaction rate equations of NOx formation and reduction. Incorporating into a previous sintering heat treatment model, overall NOx emission can be predicted and the simulated results were well agreed with four sinter pot tests under varying conditions which are similar to actual production. In sintering, NOx emission is significantly...
The particle dispersion mechanisms of rice husk in a fuel-rich/lean burner with an impact-type concentrator were investigated by both digital imaging technique and sampling method. In the experiments, a model burner with a scale ratio of 1/2.708 was studied employing an optical measurement system which consisted of a charge-coupled device (abbreviated as CCD) camera and a laser sheet for illumination...
This paper was addressed to evaluate the sintering behavior of coal ash at different temperatures under oxy-fuel combustion (O2/CO2 combustion) atmosphere. A lignite (Zhundong coal) characterized by high sodium level has been applied as the fuel material. The raw ash was heat treated at four different temperatures: 1350, 1300, 1250, and 1200°C, respectively. In addition, two atmospheres has been applied...
In order to figure out the reasons for high temperature corrosion on side water walls, experimental investigations have been conducted on a 600MWe boiler. Samples collected from the side water walls were analyzed by XRD and SEM–EDS. The results revealed that the deposition of FeS and unoxidized fuel was responsible for the high temperature corrosion. Then the gas particle flow characteristic downstream...
Numerical investigations of the combustion process and NO x emission were conducted for two swirl burners (a prototype swirl burner and an optimised swirl burner) and a 600MWe wall-fired boiler. The predicted results and the measured information from the full-scale boiler were found to be in good agreement. The flow field, particle distribution, temperature pattern, and species concentration...
Steam-separator temperature is an important parameter of ultra-supercritical boilers, where temperature deviations result in an increase in feed-water and a fast decline in steam temperature. Optimizing temperature deviations through manual operating-variables adjustments is difficult because of the complex relationships among influencing factors, as well as unacceptable increases in combustion air...
This paper presents a new on-line coal identification system based on support vector machine (SVM) to achieve on-line coal identification under variable combustion conditions. Four different coals were burnt in a 0.3MW coal combustion furnace with different coal feed rates, total air flow rates and flow rate ratios of primary air and secondary air. The flame monitoring system was installed at the...
Digital image technique was applied to monitor the slagging characteristics of easy to slagging (ES) coal in a pilot scale furnace. Mineral of the ash deposit was analyzed by X-ray diffraction (XRD), chemical composition and microstructure of the ash deposit were analyzed by scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectrometry (EDX), respectively. The ash deposition...
Fuel staging cyclone gasification of wood powder was studied in a cyclone gasifier using air as the gasifying medium. A part of fuel was fed into the upper part of the gasifier, where main part of oxidation reactions took place. Another part of fuel was fed into the lower part of the gasifier. The high temperature flue gas and particles in the upper part of the gasifier were forwarded into the lower...
The objective of this study was to numerically investigate the particle dispersion mechanisms in the gas–solid two-phase jet for a fuel-rich/lean burner by means of coupling the discrete element method (DEM) with the computational fluid dynamics (CFD). The DEM was employed to deal with the particle–particle and the particle–wall interaction in the computation of solid flow; while gas flow was computed...
Support vector regression (SVR) was employed to establish mathematical models for the NO x emissions and carbon burnout of a 300 MW coal-fired utility boiler. Combined with the SVR models, the cellular genetic algorithm for multi-objective optimization (MOCell) was used for multi-objective optimization of the boiler combustion. Meanwhile, the comparison between MOCell and the improved non-dominated...
Numerical simulations were conducted to study the influences of various vortex structures on the dispersion and deposition processes of 1μm to 10μm diameter fly ash particles on the rear side surface of a boiler tube. Turbulent gas flow was simulated with detached eddy simulation (DES) method and vortex structures in the wakes were modeled. Results suggested that the motions of particles in the near...
The objective of this study was to investigate the flow structures and mixing mechanisms of a gas–solid two-phase jet from a burner employed in the utility boiler. Laboratory experiments were conducted in a 0.15m internal diameter test facility. Gas–solid jet flow downstream of the burner exit was measured by a fiber optic probe. Local solid concentration and particle size distribution were obtained...
To predict the particle dispersion in the burner jet is of great importance in industrial application and in the designing of coal burner with good performance. The objective of this study was to numerically investigate the particle dispersion mechanisms in the gas–solid two-phase jet from a fuel rich/lean burner. The detached-eddy-simulation (DES) approach was employed to study the turbulent flow...
Podaj zakres dat dla filtrowania wyświetlonych wyników. Możesz podać datę początkową, końcową lub obie daty. Daty możesz wpisać ręcznie lub wybrać za pomocą kalendarza.