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02131 Gas reburn on a stoker fired boiler for NOx control
08
Steam raising (boiler operation/design)
99102124 Black liquor gasifier/gas turbine cogeneration Consonni, S. et al. J. Eng. Gas Turbines Power, 1998, 120, (3), 442-449. The purpose of black liquor in most kraft mills today is when it is burned in Tomlinson boilers to produce steam for on-site heat and power and to recover the inorganic chemicals for reuse in the process. Globally, the black liquor generation rate is about 85,000 MWfurl with nearly 50% of this in North America. The majority of presently installed Tomlinson boilers will reach the end of their useful lives during the next 5-20 years. As a replacement for Tomlinson-based cogeneration, black liquor-gasifierlgas turbine cogeneration promises higher electric efficiency, with prospective environmental, safety and capital cost benefits for kraft mills. Several companies are pursuing commercialization of black liquor gasification for gas turbine applications. This paper presents results of detailed performance modelling of gasifierigas turbine cogeneration systems using different black liquor gasifiers and modelled on proposed commercial designs. Boiler heat transfer modeling using CEMS data with 99102125 application to fouling analysis Zibas, S. J. and Idem, S. A. PWR (Am. Sot. Mech. Eng.), 1996, 30, (Proceedings of the International Joint Power Generation Conference, Vol. 2), 655-661. This paper gives a description of a mathematical boiler heat transfer simulation for coal-fired plants. The required model input includes boiler geometry, fuel composition and limited continuous emissions monitoring systems (CEMS) data that are typically available. Radiation heat transfer in the furnace is calculated using curve-fits to the Hottel charts. The model employs empirical heat transfer coefficient correlations to evaluate convection heat transfer to various boiler component surfaces. Fouling/ slagging can be accounted for by including fouling resistance in the calculation of the overall heat transfer coefficient of each component. Model performance predictions are compared to cases available in the literature. 99102126 Boiler tuning with SPO: the critical first step in the NO, compliance strategy of Central 81 South West Company Dharmarajan, N. N. and Patterson, P. D. Proc., Annu. Meet. Air Waste Manage. Assoc., [computer optical disk], 1996, 89, ra105a04/1-ra105a04/9. US utilities must comply with 1990 Clean Air Act Amendments (CAAA), NO, regulations and prepare for the competition of a de-regulated industry. Strategies to provide cost-effective and environmentally compliant fossilfired boiler operations in a competitive environment are being sought after by many US companies. This means they must find ways to deliver services more efficiently, without compromising environmental goals. A logical first step in meeting both challenges is boiler tuning. It offers a least-cost solution and can identity the need for retrofits or re-powering, possibly delaying or avoiding such solutions altogether. A tuning technology developed by Ultramax Corporation and the Electric Power Research Institute (EPRI), based on sequential process optimization (SPO), is being used by a several utilities as a cost-effective, first-pass tool to gain emissions and performance improvements before considering capital expenditures. SPO also enables utilities to meet current compliance needs and use a strategy of continuous improvement to meet future CAAA requirements. Central & South West (C&SW) Services have conducted a case study examination of SPO as a tool in a strategy for NO, compliance and cost reduction. In tailored collaboration with EPRI, C&SW applied SPO to tune a single coal-fired unit as a test case for possible system-wide use. A description of SPO procedures and a comparison with traditional parametric testing methods are included in this case study. 99102127 The DB Riley low emission boiler system (LEBS) proof-of-concept (POC) test facility Beittel, R. et al. hoc. Am. Power Conf., 1998, 60, (l), 179-186. The primary goal of the LEBS programme is to develop the next generation of pulverized coal-fired power systems to meet stringent emissions requirements with high energy conversion efficiency. This paper discusses two potential locations for a proof-of-concept (POC) test facility design. The DB Riley team has been chosen to go forward with Phase IV of the LEBS programme which will include the final design and construction of the POC test facility. The POC test facility plan for the DB Riley Team has been broadened to two potential locations: (1) a greenfield plant at Turns Mine, Elkhart, Illinois and (2) a repowered cogeneration steam plant at the Savannah River Site, Aiken, South Carolina. The Turns Mine location is currently being pursued as the primary site with the Savannah River location being considered as a contingency location. Each POC Facility includes provisions for testing and evaluating two important LEBS technologies: an advanced U-fired low-NO, slagging combustion system and the copper oxide flue gas cleanup (FGC) process. 99102128 Development of and experience with a new eneration of modern coal firing systems in a new high-eff Bciency combined heat and power station Kaess, M. et al. Proc. Am. Power Conf., 1998, 60, (2), 626-630. In the summer of 1997, a highly advanced combined heat and power station which links a steam turbine with a coal-fired main boiler and a gas turbine waste heat system with a total electric output of 381 MW was commissioned. The main boiler is equipped with a new generation pulverized coal firing system which combines ultra-low NOX vortex burners with a tangential firing concept. The firing system, including new pulverized fuel
218
Fuel and Energy Abstracts
May 1999
burners, was developed and tested over the last five years and included extensive computer modelling and pilot scale furnace tests. The firing system combines the advantages of vortex burners and tangential firing systems. The LCS tangentially-fired system leads to very low NO, emissions with high burnout, good ignition in individual burners, intensive, in-furnace flue gas mixing, high corrosion protection, good slagging behaviour, high reliability and low part-load operation even with coal only right down to 15% MCR.
99102129 Evaluation of retrofitted post-combustion NO, control technology on a wet-bottom coal-fired utility boiler Huhmann, A. L. et al. Proc., Annu. Meet. Air Waste Manage. Assoc., 1996, 89, rp13907, 1-16. The effectiveness of post-combustion NO, control technologies on a wetbottomed, coal-fired utility boiler has been evaluated by Public Service Electric and Gas (PSE&G). The technologies under study were conventional urea-based SNCR, horizontal in-duct and air heater SCR and a combination of SNCR and SCR designated as SNCRiSCR Hybrid. While SNCR and, to a limited extent, SCR have been used on coal-fired boilers, these processes had not been demonstrated on a unit with the same configuration as the wet-bottom, split furnace design, continuous slagging, 321 MW pulverized coal electric utility boilers operated at PSE&G’s Mercer Generating Station. In 1993, PSE&G conducted a three-month demonstration of urea based SNCR on one half of Mercer Unit 2. Building on these results, in 1994, PSE&G installed a plate-type catalyst in the horizontal ductwork between the economizer outlet and air heater inlet of Unit 2. Immediately following this in-duct SCR evaluation, on SNCRSCR hybrid demonstration was performed. To meet the near term 31 May, 1995 NO, Pact Compliance date imposed by the state of New Jersey, a commercial SNCR system was installed on both Mercer Units numbers 1 and 2. This paper summarizes the results of the demonstration programs and comparisons to baseline NO,. Of particular interest was the relationship of each technology to operation of the unit. The ability to maintain low NO, emissions while varying loads and fuels, as well as determining ammonia slip and pressure drop was also demonstrated. Additionally, the success of commercial SNCR systems in controlling NO, emissions with respect to reliability and longer term performance results is discussed.
Experience with low NO, technology for competi99102130 tive coal fired generation Allen, D. M. and King, J. L. Proc. Am. Power Conf., 1998,60, (1) 527-532. This paper reviews low-nitrogen oxide burners for coal-fired boilers and nitrogen oxide abatement by reburning. 99102131 Gas reburn on a stoker fired boiler for NO, control Jordan, T. D. et al. Eng. Papermakers: Form. Bonds Better Papermaking, 1997, 1, 255-265. A 220 MW coal fired stoker cogeneration power plant that uses selective non-catalytic reduction (SNCR) for NO, control is discussed. The SNCR was required as an air permit condition as specified by the Virginia Department of Environmental Quality (VDEQ). The SNCR system, operating under certain boiler load swings, has created severe operational and maintenance problems with the steam generators, particulate collection equipment and flue gas desulfurization equipment. This paper documents the results of the test programme that has been implemented to use natural gas reburn and flue gas recirculation as an alternate method of NO, control at the Richmond facility. The test programme was carried out using one of the eight stoker fired steam generators at the facility and consisted of recirculating flue gas from the steam generator outlet and mixing it with natural gas prior to reinjecting it into the furnace.
99102132 Gas reburning for high efficiency NO, control. Boiler durability assessment Folsom, B. A. et al. Proc., Annu. Meet. Air Waste Manage. Assoc., 1996, 89, rp13904/1-rp13904/15. The results of extensive gas reburning (GR) durability tests on three full scale coal fired utility boiler installations are presented and they confirm that GR has no adverse affects. GR is a NO, control technology for boiler/ furnace applications which can meet Clean Air Act Title I and Title IV requirements. Natural gas is injected above the burner zone to produce a slightly fuel rich zone where NO, may be reduced by 60-70%. Overfire air injection completes the gas combustion. The furnace walls in the reburning zone are exposed to reducing conditions and this suggests the potential for increased tube wastage. Three comprehensive GR field evaluations have been completed on US utility boilers to confirm the emission reduction and to evaluate boiler impacts including tube wastage. The three units were operated over a range of conditions to determine optimum settings. The boiler operators then operated the units with GR during long term tests. NO, emissions were reduced up to 76%. A comprehensive programme of boiler durability assessments was conducted during the long term tests. The data were analysed statistically accounting for the accuracy of the instrumentation. The results of the tests confirmed that GR had no adverse impacts on boiler durability.
Steam raising (boiler operation/design)
99102124 Black liquor gasifier/gas turbine cogeneration Consonni, S. et al. J. Eng. Gas Turbines Power, 1998, 120, (3), 442-449. The purpose of black liquor in most kraft mills today is when it is burned in Tomlinson boilers to produce steam for on-site heat and power and to recover the inorganic chemicals for reuse in the process. Globally, the black liquor generation rate is about 85,000 MWfurl with nearly 50% of this in North America. The majority of presently installed Tomlinson boilers will reach the end of their useful lives during the next 5-20 years. As a replacement for Tomlinson-based cogeneration, black liquor-gasifierlgas turbine cogeneration promises higher electric efficiency, with prospective environmental, safety and capital cost benefits for kraft mills. Several companies are pursuing commercialization of black liquor gasification for gas turbine applications. This paper presents results of detailed performance modelling of gasifierigas turbine cogeneration systems using different black liquor gasifiers and modelled on proposed commercial designs. Boiler heat transfer modeling using CEMS data with 99102125 application to fouling analysis Zibas, S. J. and Idem, S. A. PWR (Am. Sot. Mech. Eng.), 1996, 30, (Proceedings of the International Joint Power Generation Conference, Vol. 2), 655-661. This paper gives a description of a mathematical boiler heat transfer simulation for coal-fired plants. The required model input includes boiler geometry, fuel composition and limited continuous emissions monitoring systems (CEMS) data that are typically available. Radiation heat transfer in the furnace is calculated using curve-fits to the Hottel charts. The model employs empirical heat transfer coefficient correlations to evaluate convection heat transfer to various boiler component surfaces. Fouling/ slagging can be accounted for by including fouling resistance in the calculation of the overall heat transfer coefficient of each component. Model performance predictions are compared to cases available in the literature. 99102126 Boiler tuning with SPO: the critical first step in the NO, compliance strategy of Central 81 South West Company Dharmarajan, N. N. and Patterson, P. D. Proc., Annu. Meet. Air Waste Manage. Assoc., [computer optical disk], 1996, 89, ra105a04/1-ra105a04/9. US utilities must comply with 1990 Clean Air Act Amendments (CAAA), NO, regulations and prepare for the competition of a de-regulated industry. Strategies to provide cost-effective and environmentally compliant fossilfired boiler operations in a competitive environment are being sought after by many US companies. This means they must find ways to deliver services more efficiently, without compromising environmental goals. A logical first step in meeting both challenges is boiler tuning. It offers a least-cost solution and can identity the need for retrofits or re-powering, possibly delaying or avoiding such solutions altogether. A tuning technology developed by Ultramax Corporation and the Electric Power Research Institute (EPRI), based on sequential process optimization (SPO), is being used by a several utilities as a cost-effective, first-pass tool to gain emissions and performance improvements before considering capital expenditures. SPO also enables utilities to meet current compliance needs and use a strategy of continuous improvement to meet future CAAA requirements. Central & South West (C&SW) Services have conducted a case study examination of SPO as a tool in a strategy for NO, compliance and cost reduction. In tailored collaboration with EPRI, C&SW applied SPO to tune a single coal-fired unit as a test case for possible system-wide use. A description of SPO procedures and a comparison with traditional parametric testing methods are included in this case study. 99102127 The DB Riley low emission boiler system (LEBS) proof-of-concept (POC) test facility Beittel, R. et al. hoc. Am. Power Conf., 1998, 60, (l), 179-186. The primary goal of the LEBS programme is to develop the next generation of pulverized coal-fired power systems to meet stringent emissions requirements with high energy conversion efficiency. This paper discusses two potential locations for a proof-of-concept (POC) test facility design. The DB Riley team has been chosen to go forward with Phase IV of the LEBS programme which will include the final design and construction of the POC test facility. The POC test facility plan for the DB Riley Team has been broadened to two potential locations: (1) a greenfield plant at Turns Mine, Elkhart, Illinois and (2) a repowered cogeneration steam plant at the Savannah River Site, Aiken, South Carolina. The Turns Mine location is currently being pursued as the primary site with the Savannah River location being considered as a contingency location. Each POC Facility includes provisions for testing and evaluating two important LEBS technologies: an advanced U-fired low-NO, slagging combustion system and the copper oxide flue gas cleanup (FGC) process. 99102128 Development of and experience with a new eneration of modern coal firing systems in a new high-eff Bciency combined heat and power station Kaess, M. et al. Proc. Am. Power Conf., 1998, 60, (2), 626-630. In the summer of 1997, a highly advanced combined heat and power station which links a steam turbine with a coal-fired main boiler and a gas turbine waste heat system with a total electric output of 381 MW was commissioned. The main boiler is equipped with a new generation pulverized coal firing system which combines ultra-low NOX vortex burners with a tangential firing concept. The firing system, including new pulverized fuel
218
Fuel and Energy Abstracts
May 1999
burners, was developed and tested over the last five years and included extensive computer modelling and pilot scale furnace tests. The firing system combines the advantages of vortex burners and tangential firing systems. The LCS tangentially-fired system leads to very low NO, emissions with high burnout, good ignition in individual burners, intensive, in-furnace flue gas mixing, high corrosion protection, good slagging behaviour, high reliability and low part-load operation even with coal only right down to 15% MCR.
99102129 Evaluation of retrofitted post-combustion NO, control technology on a wet-bottom coal-fired utility boiler Huhmann, A. L. et al. Proc., Annu. Meet. Air Waste Manage. Assoc., 1996, 89, rp13907, 1-16. The effectiveness of post-combustion NO, control technologies on a wetbottomed, coal-fired utility boiler has been evaluated by Public Service Electric and Gas (PSE&G). The technologies under study were conventional urea-based SNCR, horizontal in-duct and air heater SCR and a combination of SNCR and SCR designated as SNCRiSCR Hybrid. While SNCR and, to a limited extent, SCR have been used on coal-fired boilers, these processes had not been demonstrated on a unit with the same configuration as the wet-bottom, split furnace design, continuous slagging, 321 MW pulverized coal electric utility boilers operated at PSE&G’s Mercer Generating Station. In 1993, PSE&G conducted a three-month demonstration of urea based SNCR on one half of Mercer Unit 2. Building on these results, in 1994, PSE&G installed a plate-type catalyst in the horizontal ductwork between the economizer outlet and air heater inlet of Unit 2. Immediately following this in-duct SCR evaluation, on SNCRSCR hybrid demonstration was performed. To meet the near term 31 May, 1995 NO, Pact Compliance date imposed by the state of New Jersey, a commercial SNCR system was installed on both Mercer Units numbers 1 and 2. This paper summarizes the results of the demonstration programs and comparisons to baseline NO,. Of particular interest was the relationship of each technology to operation of the unit. The ability to maintain low NO, emissions while varying loads and fuels, as well as determining ammonia slip and pressure drop was also demonstrated. Additionally, the success of commercial SNCR systems in controlling NO, emissions with respect to reliability and longer term performance results is discussed.
Experience with low NO, technology for competi99102130 tive coal fired generation Allen, D. M. and King, J. L. Proc. Am. Power Conf., 1998,60, (1) 527-532. This paper reviews low-nitrogen oxide burners for coal-fired boilers and nitrogen oxide abatement by reburning. 99102131 Gas reburn on a stoker fired boiler for NO, control Jordan, T. D. et al. Eng. Papermakers: Form. Bonds Better Papermaking, 1997, 1, 255-265. A 220 MW coal fired stoker cogeneration power plant that uses selective non-catalytic reduction (SNCR) for NO, control is discussed. The SNCR was required as an air permit condition as specified by the Virginia Department of Environmental Quality (VDEQ). The SNCR system, operating under certain boiler load swings, has created severe operational and maintenance problems with the steam generators, particulate collection equipment and flue gas desulfurization equipment. This paper documents the results of the test programme that has been implemented to use natural gas reburn and flue gas recirculation as an alternate method of NO, control at the Richmond facility. The test programme was carried out using one of the eight stoker fired steam generators at the facility and consisted of recirculating flue gas from the steam generator outlet and mixing it with natural gas prior to reinjecting it into the furnace.
99102132 Gas reburning for high efficiency NO, control. Boiler durability assessment Folsom, B. A. et al. Proc., Annu. Meet. Air Waste Manage. Assoc., 1996, 89, rp13904/1-rp13904/15. The results of extensive gas reburning (GR) durability tests on three full scale coal fired utility boiler installations are presented and they confirm that GR has no adverse affects. GR is a NO, control technology for boiler/ furnace applications which can meet Clean Air Act Title I and Title IV requirements. Natural gas is injected above the burner zone to produce a slightly fuel rich zone where NO, may be reduced by 60-70%. Overfire air injection completes the gas combustion. The furnace walls in the reburning zone are exposed to reducing conditions and this suggests the potential for increased tube wastage. Three comprehensive GR field evaluations have been completed on US utility boilers to confirm the emission reduction and to evaluate boiler impacts including tube wastage. The three units were operated over a range of conditions to determine optimum settings. The boiler operators then operated the units with GR during long term tests. NO, emissions were reduced up to 76%. A comprehensive programme of boiler durability assessments was conducted during the long term tests. The data were analysed statistically accounting for the accuracy of the instrumentation. The results of the tests confirmed that GR had no adverse impacts on boiler durability.