ACERC
Abstracts - 1993 |
ACERC
Abstracts - 1993 |
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Thrust Area 6: Model Evaluation Data and Process Strategies |
Germane, G.J.; Eatough,
C.N. and Cannon, J.N.
Chapter 2, Fundamentals of Coal Combustion: For Clean and Efficient Use,
(L.D. Smoot, ed.), Elsevier Science Publishers, The Netherlands, 1993. Funded
by ACERC.
This chapter documents the measurement methods and multidimensional data for evaluation of combustion models. Data are reported for several scales from laboratory to full-scale furnaces. The design of advanced combustion systems and processes for gas, liquid and solid fossil fuels can be greatly enhanced by the utilization of verified predictive and interpretive combustion models. Development of an accurate three-dimensional model applicable to non-reacting and reacting flow systems, and specifically coal combustion and entrained flow gasification, is a primary research initiative of ACERC, and is also being pursued in several other countries. Once the code, with appropriate submodels, has been completed, it is necessary to make comparisons of code predictions to data from turbulent flames in reactors that embody various aspects of turbulent combustion of coal, oil, gas or slurry fuels. Consequently, data from a range of different-sized facilities are necessary in order to adequately demonstrate the adequacy of the code predictions, and to establish the degree of precision that the code can give in making predictions for industrial furnaces. Such detailed data gives new insights into combustion processes and strategies. The detailed measurements possible in the laboratory-scale facilities complement the coarser or sparser measurements of three-dimensional flow patterns and flame heat transfer characteristics obtained in industrial and utility furnaces.
Germane, G.J.
Energy & Fuels, 7, (6):906-909, 1993. Funded by ACERC.
The mission of ACERC is to conduct advanced experimental and theoretical combustion engineering research and produce useful products that have the promise of improving the technical competitiveness of U.S. industry. The strategic plane of this Thrust Area includes developing advanced instrumentation for combustion measurements and obtaining detailed combustion data to properly evaluate the predictive and interpretive computational models being developed in ACERC. A cylindrical, down-fired reactor (CPR) has been built which allows detailed control of wall temperature, inlet air velocities, and swirl, fuel type, inlet conditions, and complete radial and axial optical and intrusive probe access to the flame. Researchers in the Thrust Area have been involved in obtaining appropriate validation data using advanced instruments such as CARS in natural gas and coal flames in the CPR, where the near field is accessible and inlet conditions are well-characterized, and in full-scale industrial coal-fired boilers where far-field data obtained with advanced particle in situ counting and sizing instrumentation and radiometers provide valuable information concerning the heat-transfer and combustion products composition essential to model evaluation. Comparison of ACERC comprehensive codes with other coal-quantified models, such as CQIM, is also a research initiative in Thrust Area 6.
Monson, C.R. and Germane,
G.J.
Energy & Fuels, 7 (6):928-936, 1993. Funded by US Department of Energy,
Morgantown Energy Technology Center and ACERC.
A number of processes, including coal gasification, combined cycles and heat engines, are being used or developed that combust coal at elevated pressures. While practical research is being conducted on the use of coal in these applications, little is known about the basic nature of high-pressure coal combustion. The few studies that have examined the effect of pressure on these reactions during the past 25 years have been limited by experimental apparatus (shock tubes) and have produced conflicting results. A need clearly exists for well-characterized facilities that can be used for high-pressure coal combustion research. This paper describes the design and characterization of an elevated pressure drop-tube facility. This unique facility consists of a high-pressure drop-tube reactor, a tar/char/gas separation and collection system, an optical pyrometer and support equipment. The electrically heated, computer controlled reactor was shown to provide the following capabilities: pressure from 1 to 5 atm, wall and gas temperatures from 1000 to 1700 K, controllable temperature profile along the reaction tube length, particle residence times from 30 to 1000 ms, variable gas compositions of inert and oxidizing gases, and optical access ports for in situ diagnostics. Characterization of the reactor over the range of design operating conditions verified the suitability of the reactor for coal combustion experiments. Results from a series of char oxidation tests are also presented, demonstrating the wide range of possible experimental conditions; these oxidation experiments spanned a broader range of conditions than other known work.
Sanderson, D.K. and Germane,
G.J.
Energy & Fuels, 7 (6):910-918, 1993. (Also presented at the Advanced
Combustion Engineering Research Center Seventh-Year Conference, Park City,
UT, March 1993.) Funded by ACERC.
This paper presents a comprehensive set of in situ gas species concentration measurements of O2, CO2, CO, NOx, SOx, HCN, and NH3 and particle composition measurements of ash, carbon, hydrogen, and nitrogen taken in a 0.3 MWe pulverized coal flame in a controlled profile reactor with well-defined and controlled wall temperature and inlet flow characteristics. An evaluation of the effects of varying coal mass mean particle size, equivalence ratio, and secondary air swirl number on the measured data is shown through a graphical analysis of the data. Mass and carbon balances were calculated to ensure closure and overall accuracy of the data set. A series of seven combustion tests were conducted using Utah Blind Canyon high volatile bituminous coal. A water quenched probe was used to collect gas and solid samples from an average of 27 distinct locations in the reactor. Coal mass mean particle size, equivalence ratio, and secondary air swirl number were varied one at a time throughout the tests. Two tests were repeated twice to demonstrate the accuracy of reactor test conditions through repeatability of the data. A graphical analysis of the data shows that the repeatability of test conditions was very good except for the sensitivity of a centrally located recirculation zone to reactor settings. Carbon and mass balances were obtained for all test using the data presented in this paper and other temperature and particle data collected concurrently by other researchers.
Martin, C.N.
A Sensitivity Analysis
of the Coal Quality Impart Model with Comparisons to CQEA and PCGC-3, M.S./BYU,
August 1993. Advisor: Cannon
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