08 Steam raising (boiler operation/design)

technologies have been developed. At the same time, the existing turbine generator equipment, if reasonably maintained, is capable of providing competitive and reliable electrical power production. Different approaches can be taken to provide a new steam generating source for the existing turbine cycle. This paper addresses an alternative solution: conversion of conventional boilers to fluidized bed technology. The Foster Wheeler Energy Corporation (FWEC) has accumulated substantial on-site experi- ence indicating that the fluidized-bed option can provide a significant cost/ benefit advantage.

97103967 Orimulsion-viability as a repowering fuel. Khan, S. Proc. Inl. Tech. Conf. Coal Ml. Fuel Sysr., 1996, 21, 619-628. The technical and economic impacts of an Orimulsion switch at existing fossil-fuelled boiler plants are analysed.

97103966 Prediction of flow, combustion and heat transfer in a three-dimensional, W-shaped boiler furnace Liang, X. H. et al. Proc. Int. Tech. Conf Coal Ml. Fuel Syst., 1997, 22, 669- 679. The study involved conducting numerical simulations of gas-solid flows, heat transfer and gas-solid turbulent combustion for a three-dimensional, W-shaped boiler furnace. The gas-solid flow, distributions of temperature and concentrations, of gas constituents, distributions of the rates of heat release, burnout rates of coal particles, volatiles and CO were predicted.

97103969 Predictions of boiler performance when firing beneficiated coal-based fuels Hargrove, M. Proc. Inl. Tech. Conf. Coal Ml. Fuel S_vst., 1994, 19, 659- 670. Evaluation of the Upper Freeport medium volatile bituminous parent coal and its oil agglomeration was completed. The performance analysis and economic impacts when firing beneficiated coal-based fuels are discussed.

97103970 Predictions of boiler performance when firing flne grind coal fuels Hargrove, M. J. et al. Proc. Inl. Tech. Conf. Coal UN. Fuel Syst., 1996, 21, 377-388. The authors detail the performance evaluation of two utility steam generators designed for either coal or oil-firing. The study units were selected to be representative of a large portion of the current boiler population: a 560 MW coal-designed boiler purchased in 1973; and a 600 MW oil-designed boiler purchased in 1970. Both of these units represent typical design parameters. The results of the performance analysis are summarised and the economic impacts that can be expected when firing this coal ground to different fineness levels in two utility steam generators are discussed.

97103971 Production of coal-water fuel from fine coal for use in a fire-tube boiler Hamilton. B. and Arnold. D. W. Proc. Int. Tech. Conf. Coal Uril. Fuel Syst., 1993, 18, 269-280.~ ’ Slurries from Blue Creek coal in Alabama exhibited high stability and good viscosity for providing good combustion performance..

97103972 10 MW prototype testing of LIDS as part of the Babcock 81 Wilcox low emission boiler system Madden, D. A. and Musiol, W. F. Proc. Int. Tech. Conf. Coal Util. Fuel Sysr., 1996, 21, 415-426. The Limestone Injection with Dry Scrubbing (LIDS) system is currently being developed by Babcock & Wilcox (B&W). Its design objective is to be capable of reducing SO, and particulate emissions significantly below that allowed under the New Source Performance Standards (NSPS) while simultaneously addressing the concerns of solid waste generation and air toxics regulation. The LIDS process is a limestone-based, furriace injection/ dry scrubbing SO2 removal process. The process comprises the cost- effective integration of three commercially proven flue gas cleanup technologies: furnace limestone injection, dry scrubbing, and pulse-jet fabric filtration. Plans are highlighted for 10 MW, LIDS testing to be performed in B&W’s Clean Environment Development Facility to demonstrate the LEBS project SOz removal goal of 98% and particulate emissions goal of less than 0.005 Ib/MBtu under cost-effective operating conditions. Furthermore, air toxics control and solids by-product issues will be addressed. Plans for LIDS in the proof-of-concept demonstration in Phase IV are also provided.

97103973 Flehabllitation project of some coal flred electricity generating units in compliance wlth RENEL’s development strategy Octavian, P. and Cristian, T. Proc. Id. Tech. Conf. Coal Util. Fuel Syst., 1996, 21, 277-286. Retrofitting programmes and further retrofitting needs for utility boilers in Romania are presented.

97103974 Reliability improvement and life extension of mixed fuel-fired steel plant boilers Somasundaram, M. and Chattopadhyay, D. Proc. Am. Power Conf.. 1997, 59, (2), 618-623. The paper outlines the structural and operational problems of the steam boiler in an integrated steel mill. The boilers were fired with mixed fuels including coal, blast furnace gas and coke oven gas with start up oil burners. The boilers were experiencing frequent forced outages due to boiler pressure parts failure, capacity limitations of ID fans due to excessive air ingress into the system and combustion problems. Steel production at the plant was also affected by reduced steam production. This report details the various problems faced, the inspection/analysis carried out to identify the causes, the remedial/improvement measures implemented. with success, to improve the system reliability, and the actions taken to extend the life of the boiler.

97103975 Research and development on stabilizing pulver- ized coal combustion technology by counter-offsetting primary air and coal streams for T-fired boilers Zhao, Z. and Zhang, M. Ranshao Kexue Yu Jishu, 1997. 3. (I). 88-96. (In Chinese) The paper presents and then analyses the design concept for stabilizing pulverized coal combustion technology by counter-offsetting primary air and coal streams for T-fired boilers. Based on the numerical modelling of three-dimensional turbulence flow in furnace, burner retrofitting for unit three at Jiaozuo power plant were optimized. Computational results and post-retrofitted field tests confirmed that the stabilizing combustion technology in this way could significantly increase the residence time of coal particles in the early stages of combustion. Therefore improved ignition conditions are achieved and the remaining swirl at the furnace outlet could be effectively alleviated to reduce flue gas imbalance. In addition, the tangential trajectory of coal particles could be changed to reduce the slagging and high temperature corrosion potential along furnace water walls near burner zones.

97103976 Researches on the aerodynamic characteristics of CWS tangentially arranged burners in utility boilers Liu, J. et al. Proc. Inr. Tech. Conf. Coal Util. Fuel Syst., 1994, 19. 505-516. A study of aerodynamic characteristics of the burners for coal water slurry in two cold model facilities is reported.

97103977 Retrofit of lignite based 420 T/H boiler Pavnotescu, 0. and Totolo, C. Proc. Int. Tech. Conf. Coal Util, Fuel Syst., 1997, 22, 659-668. The paper discusses emission level evaluation, conversion of power generation unit from lignite-fired one to hard-coal fired one, current lignite-fired boiler performance, and retrofitting options, in relation to improvement of power and heat supply in Romania.

97103976 Retrofits and its effects on burner, i.e. boiler performance Salewski, G. and Mars, F. Proc. Int. Tech. Conf Coal Util. Fuel Syst., 1996, 21,439-449. Several models are introduced of pulverized coal rotary classifiers designed by Loesche for utility boilers. They can be used to replace existing less efficient classifiers.

97103979 Retrofitting oil-fired boilers to fire coal-water slurry: an economic evaluation Addy, S. N. and Considine, T. J. Proc. Int. Tech. Conf. Coal Util. Fuel Syst., 1994, 19, 341-352. Congress has directed the United States Department of Defense (DOD) to decrease its dependence on foreign oil and increase its use of domestic coal. The use of micronized coal-water slurry fuels (MCWSFs) is one of the alternatives under consideration. This retrofitting has associated costs and problems. An economic evaluation of retrofitting oil-designed boilers to fire MCWSF is presented. The evaluation addresses commercial and govern- mental concerns. It also includes a stochastic risk analysis using Monte Carlo simulation. The variables that most strongly influence the economic feasibility of retrofitting to fire MCWSF are the differential fuel cost (DFC), the expected life of the boiler plant, its size, total capital requirement (TCR), boiler derated capacity (BDC), and the discount rate. DFC is the major driving force, requiring at least $l.SO/MMBtu for commercial viability. Given the current trend in oil prices, there seems little incentive for commercial retrofitting, however, DOD can take advantage of a lower discount rate.

97103960 System designs to convert a package boiler to fire coal-based fuels Morrison, D. K. et al. Proc. Im. Tech. Conf. Coal Util. Fuel Sysr., 1994, 19, 5 l-62. An existing heavy fuel oil and natural gas-fired water tube boiler is being engineered to fire either micronized coal-water slurry fuel (MCWSF) or dry, micronized coal (DMC). This project is being carried out by the Energy and Environmental Research Corporation (EEF) and the Pennsylvania State University. Retrofit options currently being evaluated are the direct firing of MCWSF and DMC, and coal pre-combustion technologies. The status of the evaluations and designs of the MCWSF and DMC direct firing technologies is presented.

334 Fuel and Energy Abstracts September 1997