Jonathan C. Corbett, N. Goudarzi, Mohammadamin Sheikhshahrokhdehkordi
This research explores utilizing distributed wind turbines in the built environment computationally. The targeted wind turbine design is an unconventional ducted turbine, called Wind Tower technology that its operation and performance metrics have been studied in earlier works in the team. Wind Tower is an established architectural technology that operates by catching wind and directing it into buildings, providing natural ventilation to support HVAC systems, and thus reducing cooling costs in urban environments. Wind power has long struggled to meet expectations in built (urban) environments. By combining wind towers at different cross sections with wind turbines, one might develop a device which provides natural ventilation and produces power in spite of a hostile wind environment. The preliminary results suggest that the maximum potential for a wind tower-turbine combination appears to be 700-1.46 kW under idealized conditions with a 4 m/s site dominant wind speed. This suggests that wind towers might be viable for power harvesting in both remote and grid connected regions. Further analysis suggested that additional turbine performance enhancements are needed to bring the turbine real power production closer to that ideal.
{"title":"Wind Catcher Technology: The Impact of Tower Cross Section and Turbine on Wind Power Harnessing","authors":"Jonathan C. Corbett, N. Goudarzi, Mohammadamin Sheikhshahrokhdehkordi","doi":"10.1115/power2019-1947","DOIUrl":"https://doi.org/10.1115/power2019-1947","url":null,"abstract":"\u0000 This research explores utilizing distributed wind turbines in the built environment computationally. The targeted wind turbine design is an unconventional ducted turbine, called Wind Tower technology that its operation and performance metrics have been studied in earlier works in the team. Wind Tower is an established architectural technology that operates by catching wind and directing it into buildings, providing natural ventilation to support HVAC systems, and thus reducing cooling costs in urban environments. Wind power has long struggled to meet expectations in built (urban) environments. By combining wind towers at different cross sections with wind turbines, one might develop a device which provides natural ventilation and produces power in spite of a hostile wind environment. The preliminary results suggest that the maximum potential for a wind tower-turbine combination appears to be 700-1.46 kW under idealized conditions with a 4 m/s site dominant wind speed. This suggests that wind towers might be viable for power harvesting in both remote and grid connected regions. Further analysis suggested that additional turbine performance enhancements are needed to bring the turbine real power production closer to that ideal.","PeriodicalId":315864,"journal":{"name":"ASME 2019 Power Conference","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127160784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Concentrated Solar Power (CSP) is one of the most promising ways to generate electricity from solar thermal sources. In this situation, large tracking mirrors focus sunlight on a receiver and provide energy input to a heat engine. Inside the receiver the temperature can be well above 1000°C, and molten salts or oils are typically used as heat transfer fluid (HTF). However, since the sun does not shine at night, a remaining concern is how to store thermal energy to avoid the use of fossil fuels to provide baseline electricity demand, especially in the late evenings when electricity demand peaks. In this study, a new method will be investigated to store thermal energy underground using a borehole energy storage system. Numerical simulations are undertaken to assess the suitability and design constraints of such systems using both molten salt as HTF.
{"title":"Underground CSP Thermal Energy Storage","authors":"Roohany Mahmud, Mustafa Erguvan, D. MacPhee","doi":"10.1115/power2019-1879","DOIUrl":"https://doi.org/10.1115/power2019-1879","url":null,"abstract":"\u0000 Concentrated Solar Power (CSP) is one of the most promising ways to generate electricity from solar thermal sources. In this situation, large tracking mirrors focus sunlight on a receiver and provide energy input to a heat engine. Inside the receiver the temperature can be well above 1000°C, and molten salts or oils are typically used as heat transfer fluid (HTF). However, since the sun does not shine at night, a remaining concern is how to store thermal energy to avoid the use of fossil fuels to provide baseline electricity demand, especially in the late evenings when electricity demand peaks. In this study, a new method will be investigated to store thermal energy underground using a borehole energy storage system. Numerical simulations are undertaken to assess the suitability and design constraints of such systems using both molten salt as HTF.","PeriodicalId":315864,"journal":{"name":"ASME 2019 Power Conference","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126820294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper makes the energy consumption difference analysis of the key parameters variations of a 1000MW Ultra-Supercritical Double Reheat coal-fired power generation system. By applying the constant power variable condition calculation method for the steam turbine thermal system, the energy consumption difference analysis mode is established. The energy consumption difference of the key parameters variations (such as the main steam pressure, the main steam temperature and the exhaust steam pressure) of a 1000MW ultra-supercritical double reheat coal-fired power generation system at THA load, 75%THA load, 50%THA load and 40%THA load are investigated. The effects of the key parameter changes on the gross turbine heat rate and coal consumption rate at different working conditions are analyzed, as well as the corresponding energy consumption variation characteristic curves, and the variation rules of power generation efficiency are explored. In addition, the energy consumption difference variation rules of system at different working conditions are studied when any two key parameters such as the main steam temperature, main steam pressure, and the exhaust pressure change simultaneously. The research results show that within a certain range of variation, when the main steam temperature or the main steam pressure increase, or the exhaust gas pressure decreases, the energy consumption of the overall system drops. And with the reduction of load, the main steam temperature has the greatest influence on the coal consumption. By studying the effects of the simultaneous change of two key parameters on the energy consumption of the overall system, it is found that under the same load, the change of the exhaust gas pressure has the greatest influence on the system energy consumption. This paper will provide the theoretical guidance for the energy-saving diagnosis and operation optimization of ultra-supercritical double reheat coal-fired power generation system.
{"title":"Energy Consumption Difference Analysis of Key Parameters Variations of 1000MW Ultra-Supercritical Double Reheat Coal-Fired Power Generation System","authors":"Duan Liqiang, Sun Jing","doi":"10.1115/power2019-1845","DOIUrl":"https://doi.org/10.1115/power2019-1845","url":null,"abstract":"\u0000 This paper makes the energy consumption difference analysis of the key parameters variations of a 1000MW Ultra-Supercritical Double Reheat coal-fired power generation system. By applying the constant power variable condition calculation method for the steam turbine thermal system, the energy consumption difference analysis mode is established. The energy consumption difference of the key parameters variations (such as the main steam pressure, the main steam temperature and the exhaust steam pressure) of a 1000MW ultra-supercritical double reheat coal-fired power generation system at THA load, 75%THA load, 50%THA load and 40%THA load are investigated. The effects of the key parameter changes on the gross turbine heat rate and coal consumption rate at different working conditions are analyzed, as well as the corresponding energy consumption variation characteristic curves, and the variation rules of power generation efficiency are explored. In addition, the energy consumption difference variation rules of system at different working conditions are studied when any two key parameters such as the main steam temperature, main steam pressure, and the exhaust pressure change simultaneously. The research results show that within a certain range of variation, when the main steam temperature or the main steam pressure increase, or the exhaust gas pressure decreases, the energy consumption of the overall system drops. And with the reduction of load, the main steam temperature has the greatest influence on the coal consumption. By studying the effects of the simultaneous change of two key parameters on the energy consumption of the overall system, it is found that under the same load, the change of the exhaust gas pressure has the greatest influence on the system energy consumption. This paper will provide the theoretical guidance for the energy-saving diagnosis and operation optimization of ultra-supercritical double reheat coal-fired power generation system.","PeriodicalId":315864,"journal":{"name":"ASME 2019 Power Conference","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127737126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The power generation industry has a major role to play in reducing global greenhouse gas emissions, and carbon dioxide (CO2) in particular. There are two ways to reduce CO2 emissions from power generation: improved conversion efficiency of fuel into electrical energy, and switching to lower carbon content fuels. Gas turbine generator sets, whether in open cycle, combined cycle or cogeneration configuration, offer some of the highest efficiencies possible across a wide range of power outputs. With natural gas, the fossil fuel with the lowest carbon content, as the primary fuel, they produce among the lowest CO2 emissions per kWh generated. It is possible though to decarbonize power generation further by using the fuel flexibility of the gas turbine to fully or partially displace natural gas used with hydrogen. As hydrogen is a zero carbon fuel, it offers the opportunity for gas turbines to produce zero carbon electricity. As an energy carrier, hydrogen is an ideal candidate for long-term or seasonal storage of renewable energy, while the gas turbine is an enabler for a zero carbon power generation economy. Hydrogen, while the most abundant element in the Universe, does not exist in its elemental state in nature, and producing hydrogen is an energy-intensive process. This paper looks at the different methods by which hydrogen can be produced, the impact on CO2 emissions from power generation by using pure hydrogen or hydrogen/natural gas blends, and how the economics of power generation using hydrogen compare with today’s state of the art technologies and carbon capture. This paper also addresses the issues surrounding the combustion of hydrogen in gas turbines, historical experience of gas turbines operating on high hydrogen fuels, and examines future developments to optimize combustion emissions.
{"title":"Decarbonizing Power Generation Through the Use of Hydrogen As a Gas Turbine Fuel","authors":"M. Welch","doi":"10.1115/power2019-1821","DOIUrl":"https://doi.org/10.1115/power2019-1821","url":null,"abstract":"\u0000 The power generation industry has a major role to play in reducing global greenhouse gas emissions, and carbon dioxide (CO2) in particular. There are two ways to reduce CO2 emissions from power generation: improved conversion efficiency of fuel into electrical energy, and switching to lower carbon content fuels.\u0000 Gas turbine generator sets, whether in open cycle, combined cycle or cogeneration configuration, offer some of the highest efficiencies possible across a wide range of power outputs. With natural gas, the fossil fuel with the lowest carbon content, as the primary fuel, they produce among the lowest CO2 emissions per kWh generated. It is possible though to decarbonize power generation further by using the fuel flexibility of the gas turbine to fully or partially displace natural gas used with hydrogen. As hydrogen is a zero carbon fuel, it offers the opportunity for gas turbines to produce zero carbon electricity. As an energy carrier, hydrogen is an ideal candidate for long-term or seasonal storage of renewable energy, while the gas turbine is an enabler for a zero carbon power generation economy.\u0000 Hydrogen, while the most abundant element in the Universe, does not exist in its elemental state in nature, and producing hydrogen is an energy-intensive process. This paper looks at the different methods by which hydrogen can be produced, the impact on CO2 emissions from power generation by using pure hydrogen or hydrogen/natural gas blends, and how the economics of power generation using hydrogen compare with today’s state of the art technologies and carbon capture. This paper also addresses the issues surrounding the combustion of hydrogen in gas turbines, historical experience of gas turbines operating on high hydrogen fuels, and examines future developments to optimize combustion emissions.","PeriodicalId":315864,"journal":{"name":"ASME 2019 Power Conference","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116626263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Bojanowski, G. Solbrekken, G. Schnieders, J. Rivers, E. Wilson, L. Foyto
Low-enriched uranium (LEU) fuel element designs for the U.S. high performance research reactors LEU conversion cores have been optimized by each reactor facility to allow the reactors to meet mission, operational, and safety basis requirements using monolithic uranium-molybdenum fuel. As a part of work supporting the Preliminary Safety Analysis Report (PSAR) submitted to the NRC by the University of Missouri Research Reactor (MURR), the impact of thinner 1.12 mm LEU curved fuel plates, compared to the currently used highly-enriched uranium (HEU) curved plate thickness of 1.27 mm, has been assessed for hydro-mechanical performance. Plate deflection can be induced by the hydrodynamic pressure differential caused by differences in the thicknesses of surrounding coolant flow channels. An experimental study was conducted on relevant Materials Test Reactor-type (MTR-type) reactor plate geometries in a water flow test loop to validate computational models simulating flow-induced plate deflection. Three-dimensional fluid-structure interaction (FSI) simulations of the experiments were performed using several commercially available multi-physics simulation codes. Inclusion of as-built geometry of the plates and channels in the simulations was key to achieving good agreement with measured deflections. The validated computational methodology was applied to a model of the prototypic MURR LEU plate. For the nominal flow conditions, a small deflection of the plate on the order of 5 micrometers was predicted. That deflection is significantly less than the allowances in the PSAR for change in coolant channel thickness. The experimental model validation of plate deflection is important since conventional figures of merit for the robustness of MTR-type fuel plates under flow, such as the Miller critical velocity, often show a weak correlation with the prediction of stability. Subsequent to this work, irradiation qualification of the MURR LEU fuel element design has begun and will conclude with a full-size demonstration element test.
{"title":"Deflections of Plates in Research Reactor Fuel by Disparities in Thicknesses of Flow Channels","authors":"C. Bojanowski, G. Solbrekken, G. Schnieders, J. Rivers, E. Wilson, L. Foyto","doi":"10.1115/power2019-1928","DOIUrl":"https://doi.org/10.1115/power2019-1928","url":null,"abstract":"\u0000 Low-enriched uranium (LEU) fuel element designs for the U.S. high performance research reactors LEU conversion cores have been optimized by each reactor facility to allow the reactors to meet mission, operational, and safety basis requirements using monolithic uranium-molybdenum fuel. As a part of work supporting the Preliminary Safety Analysis Report (PSAR) submitted to the NRC by the University of Missouri Research Reactor (MURR), the impact of thinner 1.12 mm LEU curved fuel plates, compared to the currently used highly-enriched uranium (HEU) curved plate thickness of 1.27 mm, has been assessed for hydro-mechanical performance.\u0000 Plate deflection can be induced by the hydrodynamic pressure differential caused by differences in the thicknesses of surrounding coolant flow channels. An experimental study was conducted on relevant Materials Test Reactor-type (MTR-type) reactor plate geometries in a water flow test loop to validate computational models simulating flow-induced plate deflection. Three-dimensional fluid-structure interaction (FSI) simulations of the experiments were performed using several commercially available multi-physics simulation codes. Inclusion of as-built geometry of the plates and channels in the simulations was key to achieving good agreement with measured deflections.\u0000 The validated computational methodology was applied to a model of the prototypic MURR LEU plate. For the nominal flow conditions, a small deflection of the plate on the order of 5 micrometers was predicted. That deflection is significantly less than the allowances in the PSAR for change in coolant channel thickness.\u0000 The experimental model validation of plate deflection is important since conventional figures of merit for the robustness of MTR-type fuel plates under flow, such as the Miller critical velocity, often show a weak correlation with the prediction of stability. Subsequent to this work, irradiation qualification of the MURR LEU fuel element design has begun and will conclude with a full-size demonstration element test.","PeriodicalId":315864,"journal":{"name":"ASME 2019 Power Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121177061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. Olatunji, S. Akinlabi, N. Madushele, P. Adedeji, S. Fatoba
Africa is so much endowed with a vast amount of renewable resources that can engender economic prosperity and provide adequate capacity to meet up with current and future energy demands. These vast resources made her to be at a vantage position in Renewable Energy (RE) exploration across the globe. One of such RE with enormous potential is biomass, however, the maximum potential has not been realized. This article provides an overview of the biomass resources in some selected African countries. The state-of-the-art in biomass application, availability, energy production in power plant, especially as related to electricity production were discussed. Overall, the authors identify the barrier to biomass energy exploration in these countries and proffer some solution to deal with these challenges.
{"title":"Recent Advancement of Biomass in Energy Exploration in Some African Countries","authors":"O. Olatunji, S. Akinlabi, N. Madushele, P. Adedeji, S. Fatoba","doi":"10.1115/power2019-1827","DOIUrl":"https://doi.org/10.1115/power2019-1827","url":null,"abstract":"\u0000 Africa is so much endowed with a vast amount of renewable resources that can engender economic prosperity and provide adequate capacity to meet up with current and future energy demands. These vast resources made her to be at a vantage position in Renewable Energy (RE) exploration across the globe. One of such RE with enormous potential is biomass, however, the maximum potential has not been realized. This article provides an overview of the biomass resources in some selected African countries. The state-of-the-art in biomass application, availability, energy production in power plant, especially as related to electricity production were discussed. Overall, the authors identify the barrier to biomass energy exploration in these countries and proffer some solution to deal with these challenges.","PeriodicalId":315864,"journal":{"name":"ASME 2019 Power Conference","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121301889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The concept of coal-fired power generation aided with solar energy uses stable fossil energy to compensate the instability and intermittently of solar power and reduces the cost of concentrated solar power (CSP) by decreasing the large-scale heat storage and turbine systems of CSP. In this study, trough solar collector system (TSCS) was integrated into the low-pressure heater side of a 660 MW coal-fired power generation system. In the system in which the 6# LP heater is completely replaced by TSCS, the variation value of the steam extraction flowrate of the LP heaters and the turbine output power decrease with the reduction in loads from 100% to 60% THA, and the output power increases by approximately 1 MW under 100% THA. When TSCS completely replaces the 6# LP heater under the load of 75%, the effects of direct normal irradiance (DNI) increase and flow ratio decrease on the main operating parameters of solar-aided coal-fired power plant (SCPP) were studied. Results show that the step increase of DNI decreases the 5# steam extraction flowrate and increases the output power by nearly 3 MW. When the flow ratio decreases by 139.87 kg/s, the output power decreases by around 0.35 MW. The dynamic characteristics of SCPP under different parallel situations with the load of 75% were also studied. As the number of parallel stage increases, the decrement in 5# steam extraction flowrate and the increment in output power decrease. The response time also decreases. Our study aims to provide detailed references for the control system design and optimization of coal-fired power units aided with solar energy.
{"title":"Dynamic Simulation Study on a Coal-Fired Power Plant Aided With Low-Temperature Solar Energy","authors":"Xin Li, Yongliang Zhao, Ming Liu, Junjie Yan","doi":"10.1115/power2019-1857","DOIUrl":"https://doi.org/10.1115/power2019-1857","url":null,"abstract":"\u0000 The concept of coal-fired power generation aided with solar energy uses stable fossil energy to compensate the instability and intermittently of solar power and reduces the cost of concentrated solar power (CSP) by decreasing the large-scale heat storage and turbine systems of CSP. In this study, trough solar collector system (TSCS) was integrated into the low-pressure heater side of a 660 MW coal-fired power generation system. In the system in which the 6# LP heater is completely replaced by TSCS, the variation value of the steam extraction flowrate of the LP heaters and the turbine output power decrease with the reduction in loads from 100% to 60% THA, and the output power increases by approximately 1 MW under 100% THA. When TSCS completely replaces the 6# LP heater under the load of 75%, the effects of direct normal irradiance (DNI) increase and flow ratio decrease on the main operating parameters of solar-aided coal-fired power plant (SCPP) were studied. Results show that the step increase of DNI decreases the 5# steam extraction flowrate and increases the output power by nearly 3 MW. When the flow ratio decreases by 139.87 kg/s, the output power decreases by around 0.35 MW. The dynamic characteristics of SCPP under different parallel situations with the load of 75% were also studied. As the number of parallel stage increases, the decrement in 5# steam extraction flowrate and the increment in output power decrease. The response time also decreases. Our study aims to provide detailed references for the control system design and optimization of coal-fired power units aided with solar energy.","PeriodicalId":315864,"journal":{"name":"ASME 2019 Power Conference","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115910117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
High intensity colorless distributed combustion has been a promising combustion technique as it enables much reduced pollutant emissions such as NO and CO, as well as more thermal uniformity, flame stability and combustion efficiency. The main requirement for achieving distributed conditions is to provide controlled entrainment of reactive hot product gases into the fresh mixture prior to ignition. In this way, the oxygen concentration is reduced, which results in lower reaction rates, promoting longer mixing times and volumetric distribution of the reaction zones. Though distributed combustion has been extensively studied for various heat loads and intensities, fuels, geometries, there is limited information related to fuel flexibility. Therefore, it is of interest to investigate hydrogen enriched gaseous fuels for greater understanding of low calorific high flame speed fuels in a distributed combustion system. Three various hydrogen content gaseous fuel (40–60% by volume) were investigated in a swirl-stabilized burner for this study, through the use of either N2 or CO2 as the diluent in order to achieve distributed conditions. The OH* chemiluminescence flame signatures were obtained in the flame front and emissions were measured from the combustor exit. The results showed that both the hydrogen concentration and diluent type considerably impacted the oxygen concentration at which transition to CDC occurred. Distributed conditions were achieved at oxygen concentrations of 10–12% with entrained N2 and 13–15% with entrained CO2 for various gaseous fuels consumed. It was determined that the transition to CDC occurred at a lower oxygen concentration for high hydrogen content fuels due to the higher flame speed of hydrogen. The flame images demonstrated that the flashback propensity of the gaseous fuels were eliminated and enhanced flame stability was achieved under the favorable CDC conditions. For NO pollutant emission, ultra-low NO level was achieved under CDC (less than 1 ppm) while CO pollutant emission decreased gradually with condition approaching distributed conditions, and then increased slightly due to the lower flammability limit and dissociation of CO2.
{"title":"Hydrogen Enrichment Effects in Gaseous Fuels on Distributed Combustion","authors":"Serhat Karyeyen, Joseph S. Feser, A. Gupta","doi":"10.1115/power2019-1893","DOIUrl":"https://doi.org/10.1115/power2019-1893","url":null,"abstract":"\u0000 High intensity colorless distributed combustion has been a promising combustion technique as it enables much reduced pollutant emissions such as NO and CO, as well as more thermal uniformity, flame stability and combustion efficiency. The main requirement for achieving distributed conditions is to provide controlled entrainment of reactive hot product gases into the fresh mixture prior to ignition. In this way, the oxygen concentration is reduced, which results in lower reaction rates, promoting longer mixing times and volumetric distribution of the reaction zones. Though distributed combustion has been extensively studied for various heat loads and intensities, fuels, geometries, there is limited information related to fuel flexibility. Therefore, it is of interest to investigate hydrogen enriched gaseous fuels for greater understanding of low calorific high flame speed fuels in a distributed combustion system. Three various hydrogen content gaseous fuel (40–60% by volume) were investigated in a swirl-stabilized burner for this study, through the use of either N2 or CO2 as the diluent in order to achieve distributed conditions. The OH* chemiluminescence flame signatures were obtained in the flame front and emissions were measured from the combustor exit. The results showed that both the hydrogen concentration and diluent type considerably impacted the oxygen concentration at which transition to CDC occurred. Distributed conditions were achieved at oxygen concentrations of 10–12% with entrained N2 and 13–15% with entrained CO2 for various gaseous fuels consumed. It was determined that the transition to CDC occurred at a lower oxygen concentration for high hydrogen content fuels due to the higher flame speed of hydrogen. The flame images demonstrated that the flashback propensity of the gaseous fuels were eliminated and enhanced flame stability was achieved under the favorable CDC conditions. For NO pollutant emission, ultra-low NO level was achieved under CDC (less than 1 ppm) while CO pollutant emission decreased gradually with condition approaching distributed conditions, and then increased slightly due to the lower flammability limit and dissociation of CO2.","PeriodicalId":315864,"journal":{"name":"ASME 2019 Power Conference","volume":"240 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126811568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The article presents an investigation of CH (C-X) planar laser induced fluorescence imaging (PLIF) of highly turbulent methane-air flames inside a windowed combustor. Flame dynamics and flame growth and evolution of methane-air flames stabilized over a backward facing step at high Reynolds Number (Re) (Re = 15000 and Re = 30000) with an equivalence ratio of 0.7 are discussed. It was observed that the flame evolution was faster at Re = 30000 than that of Re = 15000. The rate of initiation or formation of wrinkles, detachment of the wrinkles and burnout of the burned gases from the flame core increased with the increase in Re. The qualitative flame imaging shows that the width of the flame profile increases as the flame progress towards downstream and the flame becomes thinner as the turbulence level increases. An experimental methodology was developed to optimize the system for excitation, detection of the CH C-X band and post-processing the PLIF images.
{"title":"Flame Imaging of Highly Turbulent Premixed Methane-Air Combustion Using Planar Laser Induced Fluorescence (PLIF) of CH (C-X)","authors":"M. Hossain, Nawshad Arslan Islam, A. Choudhuri","doi":"10.1115/power2019-1894","DOIUrl":"https://doi.org/10.1115/power2019-1894","url":null,"abstract":"\u0000 The article presents an investigation of CH (C-X) planar laser induced fluorescence imaging (PLIF) of highly turbulent methane-air flames inside a windowed combustor. Flame dynamics and flame growth and evolution of methane-air flames stabilized over a backward facing step at high Reynolds Number (Re) (Re = 15000 and Re = 30000) with an equivalence ratio of 0.7 are discussed. It was observed that the flame evolution was faster at Re = 30000 than that of Re = 15000. The rate of initiation or formation of wrinkles, detachment of the wrinkles and burnout of the burned gases from the flame core increased with the increase in Re. The qualitative flame imaging shows that the width of the flame profile increases as the flame progress towards downstream and the flame becomes thinner as the turbulence level increases. An experimental methodology was developed to optimize the system for excitation, detection of the CH C-X band and post-processing the PLIF images.","PeriodicalId":315864,"journal":{"name":"ASME 2019 Power Conference","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131062026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Traditional carbon capture technology has been shown to effectively capture emissions, but at a cost of reducing power plant output. Molten carbonate fuel cell technology (MCFC) has the potential to be able to concentrate plant carbon emissions into a gas stream that is suitable for storage while boosting total plant power output. When considering this type of technology, the original purpose and function of the power plant must be considered. In particular, gas turbines (GT) based natural gas combined cycle (NGCC), which are capable of dynamic load following operation, are likely to need to maintain operational flexibility. This work explores the retrofit of an existing GT with MCFC technology for carbon capture when the plant is operated at part load. Physical models for major plant components are built and used to select optimal operating set points such that operating cost is minimized. Special attention is given to ensuring feasible operation across all engine components. The results show MCFC operational parameters that minimize change in fuel cell operating conditions when the gas turbine is operated at part load.
{"title":"Using Molten Carbonate Fuel Cell Systems for CO2 With a Natural Gas Combined Cycle Operating at Part Load","authors":"Robert Flores, J. Brouwer","doi":"10.1115/power2019-1944","DOIUrl":"https://doi.org/10.1115/power2019-1944","url":null,"abstract":"\u0000 Traditional carbon capture technology has been shown to effectively capture emissions, but at a cost of reducing power plant output. Molten carbonate fuel cell technology (MCFC) has the potential to be able to concentrate plant carbon emissions into a gas stream that is suitable for storage while boosting total plant power output. When considering this type of technology, the original purpose and function of the power plant must be considered. In particular, gas turbines (GT) based natural gas combined cycle (NGCC), which are capable of dynamic load following operation, are likely to need to maintain operational flexibility. This work explores the retrofit of an existing GT with MCFC technology for carbon capture when the plant is operated at part load. Physical models for major plant components are built and used to select optimal operating set points such that operating cost is minimized. Special attention is given to ensuring feasible operation across all engine components. The results show MCFC operational parameters that minimize change in fuel cell operating conditions when the gas turbine is operated at part load.","PeriodicalId":315864,"journal":{"name":"ASME 2019 Power Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131031766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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