Download or read book Framework for a Robust Predictor of NOx Emissions from Pulverised Coal Combustion written by R. D. C. Smith and published by . This book was released on 1997 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Framework for a Robust Predictor of NOx Emissions from Pulverised Coal Combustion III Existing and Proposed NOx Prediction Methods for PF Plant written by R.D.C. Smith and published by . This book was released on 1997 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Framework for a Robust Predictor of NOx Emissions from Pulverised Coal Combustion II Factors which Contribute to NOx Formation in PF Combustion written by R.D.C. Smith and published by . This book was released on 1997 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Framework for a Robust Predictor of NOx Emissions from Pulverised Coal Combustion written by R. D. C. Smith and published by . This book was released on 1997 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Framework for a Robust Predictor of NOx Emissions from Pulverised Coal Combustion written by R. D. C. Smith and published by . This book was released on 1997 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Predictions of NOx Emissions in Pulverized Coal Combustion written by Niko Hachenberg and published by . This book was released on 2014 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this research work was to develop a transferable mathematically simple model which gives the possibility to make fast and easy predictions regarding the NOx emission behavior of a broad-spectrum of coals within a certain combustion environment. In this context, this thesis is a further step of a common ongoing investigation focused on predicting NOx emissions from self-sustaining, pulverized coal combustion in dry bottom firing systems. A comprehensive literature research focused on already published NOx prediction approaches from scientific publications based on fundamental quantitative relationships or empirical algorithms and statistical relationships was also carried out in this context. This research concentrated on three specific areas which were found to constitute a major gap in the knowledge of NOx formation in industrial full-scale applications: the fuel properties; the dependence of furnace geometry factors; and the specific operating conditions. The developed model shows a strong statistical significance with a coefficient of determination of 0.9876 and a standard error of 28 mg / m3 STPdry at 6 % O2 based on 142 observations coming from 28 utility boilers. Direct comparisons between model history and observations reported by other researchers have also shown very good conformities. For that background, this thesis form a good basis for identifying individual factors which contributes to system related NOx emissions in order to investigate how variations in the process parameters affect the emission level. Perhaps, as contribution to the understanding of NOx formation during coal combustion what is still an imperfectly understood phenomenon, or as basis for possible process optimization which might find application on pulverized coal-fired boilers to make the world a little bit more green.
Download or read book NOx Modelling and Prediction written by Ruksana Moreea-Taha and published by . This book was released on 2000 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NOx in Pulverised Coal Combustion written by Stuart C. Mitchell and published by . This book was released on 1998-01-01 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling and Simulation of SOx and NOx Reduction Processes in Pulverized Coal Furnaces written by and published by Cuvillier Verlag. This book was released on 2003-12-18 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT The current work briefly reviews the formation mechanisms and reduction approaches of the pollutants SOx and NOx in coal combustion and focuses on the simulation of the lower-cost in-furnace measures ƒ{ the dry additive process (DAP) for SOx reduction and the reburning as well as the advanced reburning (hybrid reburning/SNCR) techniques for NOx reduction. In addition, the influence of sulfur compounds on NOx formation is investigated. The major workings include: Simulation of the dry additive desulfurization process (DAP): Different models ƒ{ shrinking core model (SCM), pore model (PM) and grain model (GM) ƒ{ are implemented to describe the gas-particle reaction. Relevant processes such as the sintering of the additive, the self-retention by coal ash, the thermal equilibrium of the sulfation reaction are accounted for and modeled. A comprehensive model for the DAP with calcium based additives is subsequently established and integrated into a combustion CFD (computational fluid dynamics) code AIOLOS, in both Eulerian and Lagrangian schemes. The model is verified with experiments on a test reactor. Mechanism reduction and simulation of reburning/SNCR Processes: A method for reduction of kinetic mechanisms is introduced. A program tool is developed for automatic reduction of detailed reaction mechanisms. Reduced mechanisms for reburning and hybrid reburning/SNCR processes are developed and implemented into the CFD code. CFD-calculations with the reduced mechanisms are performed and compared with experimental measurements to comprehensively evaluate the simulation approach. It is shown that the detailed simulation is capable of modeling the complex reburning and SNCR processes with acceptable computing time and achieves reasonable results in wide parameter ranges. Study of the influence of sulfur compounds on NOx formation: The effect of SO2 on NOx formation is experimentally investigated and analysed with kinetic mechanisms. It is indicated that the presence of SO2 inhabits the NOx formation and reduce the NOx emissions in normal air-rich combustion. Under air-staging conditions, SO2 addition has no obvious influence on the final NOx emissions.
Download or read book ASME 70 WA APC 3 written by C. R. McCann and published by . This book was released on 1970 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NOx Emissions from Coal Combustion written by Lesley L. Sloss and published by . This book was released on 1991 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Towards Robust Nitrogen Chemistry Model Development written by Antoine Durocher and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "An urgent transition of the energy sector to low-carbon sources has become necessary to mitigate the adverse impacts of the anthropogenic emissions of greenhouse gases (GHG). Chemical fuels consumed in combustion systems are expected to remain an important part of the energy landscape with their high energy and power densities. Whether it be hydrogen, ammonia, biofuels, or even metals, the combustion of any sustainable fuel in air will still emit nitrogen oxides (NOx). The detrimental consequences of NOx on both the human health and the environment have led to increasingly stringent regulations and a significant decrease in emissions from the energy sector. A better understanding of the NOx formation mechanisms is now needed to develop predictive models to help identify promising industrial designs and further reduce pollutant emissions. This work first implements an uncertainty quantification framework to evaluate the impact of inherent uncertainties present in thermochemical models on NOx concentration. The propagation of parametric uncertainty through flame simulations shows that emissions predictions can vary by up to 600% from the nominal solutions, highlighting the need for a comprehensive approach through inference to use independent experimental datasets targeting different formation pathways. In an effort to decouple the different production pathways, a series of experiments is designed with hydrogen as a fuel. Going back to the simplest fuel constrains the parametric set describing the combustion process and reduces the potential of model description errors. Velocity, temperature, and NO concentration measurements are performed in premixed, stagnation flames of hydrogen diluted with argon and helium at atmospheric and supra-atmospheric pressures. Axial velocity profiles, obtained with particle tracking velocimetry (PTV), provide a measure of the reactivity of the fuel-mixtures to assess the accuracy of the hydrogen-oxidation system. Temperature and NO concentration profiles are obtained from multi-line thermometry and NO laser-induced fluorescence (LIF), respectively, which achieves a detection of sub-ppm concentration levels in flames. Significant variability is observed between the predictions of different thermochemical mechanisms and measurements for both flame speed and NO concentration. Although recent models better capture the emissions formation, when using the same hydrogen-oxidation mechanism, the respective nitrogen chemistries exhibit large discrepancies. Inaccuracies in the oxidation chemistry can mask an inaccurate description of the nitrogen chemistry if models are adjusted, or optimized, to specific targets. Consequently, there is a need for improved oxidation mechanisms, as well, to enable the development of predictive thermochemical models. These measurements, and future NO investigations, used within the uncertainty quantification framework will enable an accurate and robust model development of the nitrogen chemistry to predict emissions with higher fidelity"--
Download or read book Methods for Predicting NOx Emission in Coal Combustion and Unburned Carbon in Fly Ash written by Toshihiko Nakata and published by . This book was released on 1988 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NOx Formation During Pulverised Coal Combustion written by Ir. Riman Sipahutar and published by . This book was released on 1992 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reduction of NOx Emissions from Pulverized Coal Furnaces written by Kenneth Leroy Nielsen and published by . This book was released on 1973 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A study of fuel NOx formation in pulverized coal combustion written by M. Sato and published by . This book was released on 1986 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling the Nox Emissions in a Low Nox Burner While Fired with Pulverized Coal and Dairy Biomass Blends written by Hari Krishna Uggini and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: New regulations like the Clean Air Interstate Rule (CAIR) will pose greater challenges for Coal fired power plants with regards to pollution reduction. These new regulations plan to impose stricter limits on NOx reduction. The current regulations by themselves already require cleanup technology; newer regulations will require development of new and economical technologies. Using a blend of traditional fuels and biomass is a promising technology to reduce NOX emissions. Experiments conducted previously at the Coal and Biomass energy lab at Texas A & M reported that dairy biomass can be an effective Reburn fuel with NOX reduction of up to 95 percent; however little work has been done to model such a process with Feedlot Biomass as a blend with the main burner fuel. The present work concerns with development of a zero dimensional for a low NOX burner (LNB) model in order to predict NOx emissions while firing a blend of Coal and dairy biomass. Two models were developed. Model I assumes that the main burner fuel is completely oxidized to CO, CO2,H20 and fuel bound nitrogen is released as HCN, NH3, N2; these partially burnt product mixes with tertiary air, undergoes chemical reactions specified by kinetics and burns to complete combustion. Model II assumes that the main burner solid fuel along with primary and secondary air mixes gradually with recirculated gases, burn partially and the products from the main burner include partially burnt solid particles and fuel bound nitrogen partially converted to N2, HCN and NH3. These products mix gradually with tertiary air, undergo further oxidation-reduction reactions in order to complete the combustion. The results are based on model I. Results from the model were compared with experimental findings to validate it. Results from the model recommend the following conditions for optimal reduction of NOx: Equivalence Ratio should be above 0.95; mixing time should be below 100ms. Based on Model I, results indicate that increasing percentage of dairy biomass in the blend increases the NOx formation due to the assumption that fuel N compounds (HCN, NH3) do not undergo oxidation in the main burner zone. Thus it is suggested that model II must be adopted in the future work.
