The Experts below are selected from a list of 58869 Experts worldwide ranked by ideXlab platform
Thomas A. Adams - One of the best experts on this subject based on the ideXlab platform.
-
Open Loop and Closed Loop Performance of Solid Oxide Fuel Cell Turbine Hybrid Systems During Fuel Composition Changes
Journal of Engineering for Gas Turbines and Power-transactions of The Asme, 2017Co-Authors: Nor Farida Harun, David Tucker, Thomas A. AdamsAbstract:The dynamic behavior of a solid oxide Fuel cell gas turbine hybrid system (SOFC/GT) from both open and closed loop transients in response to sudden changes in Fuel Composition was experimentally investigated. A pilot-scale (200–700 kW) hybrid facility available at the U.S. Department of Energy, National Energy Technology Laboratory was used to perform the experiments using a combination of numerical models and actual equipment. In the open loop configuration, the turbine speed was driven by the thermal effluent fed into the gas turbine system, where the thermal effluent was determined by the feedforward Fuel cell control system. However, in the closed loop configuration, a load-based speed control system was used to maintain the turbine speed constant at 40,500 rpm by adjusting the load on the turbine, in addition to the implementation of the Fuel cell system control. The open loop transient response showed that the impacts of Fuel Composition changes on key process variables, such as Fuel cell thermal effluent, turbine speed, and cathode feed stream conditions, in the SOFC/GT systems were propagated over the course of the test, except for the cathode inlet temperature. The trajectories of the aforementioned variables are discussed in this paper to better understand the resulting mitigation/propagation behaviors. This will help lead to the development of novel control strategies to mitigate the negative impacts experienced during Fuel Composition transients of SOFC/GT systems.
-
Impact of Fuel Composition transients on SOFC performance in gas turbine hybrid systems
Applied Energy, 2016Co-Authors: Nor Farida Harun, David Tucker, Thomas A. AdamsAbstract:This paper presents a dynamic study of Fuel cell gas turbine (SOFC/GT) hybrid systems, focusing on the response to a drastic transient in anode Fuel Composition for constant turbine speed operations. This work is motivated by the potential of Fuel cells for Fuel flexibility, which could extend the opportunities for sustainability and profitability in energy conversion systems. A combination of hardware and numerical models in a hybrid simulator is used to investigate the transient trajectories of Fuel cell process variables as well as the consequent impacts of Fuel cell thermal effluent on the integrated gas turbine engine. The conversion of thermal energy stored in the Fuel cell stack to chemical energy during the reforming at the beginning of the cell resulted in a 17% increase in thermal effluent from the Fuel cell to the turbine in the first few seconds of the transient. Fuel cell solid temperature gradients increased by 39% at 250s from the initiation of the transient. The distributed dynamic performance of the Fuel cell in terms of the Fuel Composition gradient, thermal, and electrochemical performance across the Fuel cell length was carefully characterized, considering their interactions and their impacts on the total system performance.
-
Open loop and closed loop performance of solid oxide Fuel cell turbine hybrid systems during Fuel Composition changes
Volume 3: Coal Biomass and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration, 2015Co-Authors: Nor Farida Harun, David Tucker, Thomas A. AdamsAbstract:The dynamic behavior of a solid oxide Fuel cell gas turbine hybrid system (SOFC/GT) from both open and closed loop transients in response to sudden changes in Fuel Composition was experimentally investigated. A pilot-scale (200kW – 700kW) hybrid facility available at the U.S. Department of Energy, National Energy Technology Laboratory was used to perform the experiments using a combination of numerical models and actual equipment.In the open loop configuration, the turbine speed was driven by the thermal effluent fed into the gas turbine system, where the thermal effluent was determined by the feedforward Fuel cell control system. However, in the closed loop configuration, a load-based speed control system was used to maintain the turbine speed constant at 40,500rpm by adjusting the load on the turbine, in addition to the implementation of the Fuel cell system control.The open loop transient response showed that the impacts of Fuel Composition changes on key process variables, such as Fuel cell thermal effluent, turbine speed and cathode feed stream conditions in the SOFC/GT systems were propagated over the course of the test, except for the cathode inlet temperature. The trajectories of the aforementioned variables are discussed in this paper to better understand the resulting mitigation/propagation behaviors. This will help lead to the development of novel control strategies to mitigate the negative impacts experienced during Fuel Composition transients of SOFC/GT systems.Copyright © 2015 by ASME
-
Fuel Composition Transients in Fuel Cell Turbine Hybrid for Polygeneration Applications
Journal of Fuel Cell Science and Technology, 2014Co-Authors: Nor Farida Harun, David Tucker, Thomas A. AdamsAbstract:Transient impacts on the performance of solid oxide Fuel cell / gas turbine (SOFC/GT) hybrid systems were investigated using hardware-in-the-loop simulations (HiLS) at a test facility located at the U.S. Department of Energy, National Energy Technology Laboratory. The work focused on applications relevant to polygeneration systems which require significant Fuel flexibility. Specifically, the dynamic response of implementing a sudden change in Fuel Composition from syngas to methane was examined. The maximum range of possible Fuel Composition allowable within the constraints of carbon deposition in the SOFC and stalling/surging of the turbine compressor system was determined.It was demonstrated that the transient response was significantly impact the Fuel cell dynamic performance, which mainly drives the entire transient in SOFC/GT hybrid systems. This resulted in severe limitations on the allowable methane concentrations that could be used in the final Fuel Composition when switching from syngas to methane. Several system performance parameters were analyzed to characterize the transient impact over the course of two hours from the Composition change.Copyright © 2014 by ASME
-
Fuel Composition Transients in Fuel Cell Turbine Hybrid for Polygeneration Applications
ASME 2014 12th International Conference on Fuel Cell Science Engineering and Technology, 2014Co-Authors: Nor Farida Harun, David Tucker, Thomas A. AdamsAbstract:Transient impacts on the performance of solid oxide Fuel cell / gas turbine (SOFC/GT) hybrid systems were investigated using hardware-in-the-loop simulations (HiLS) at a test facility located at the U.S. Department of Energy, National Energy Technology Laboratory. The work focused on applications relevant to polygeneration systems which require significant Fuel flexibility. Specifically, the dynamic response of implementing a sudden change in Fuel Composition from syngas to methane was examined. The maximum range of possible Fuel Composition allowable within the constraints of carbon deposition in the SOFC and stalling/surging of the turbine compressor system was determined. It was demonstrated that the transient response was significantly impact the Fuel cell dynamic performance, which mainly drives the entire transient in SOFC/GT hybrid systems. This resulted in severe limitations on the allowable methane concentrations that could be used in the final Fuel Composition when switching from syngas to methane. Several system performance parameters were analyzed to characterize the transient impact over the course of two hours from the Composition change.
Nor Farida Harun - One of the best experts on this subject based on the ideXlab platform.
-
Open Loop and Closed Loop Performance of Solid Oxide Fuel Cell Turbine Hybrid Systems During Fuel Composition Changes
Journal of Engineering for Gas Turbines and Power-transactions of The Asme, 2017Co-Authors: Nor Farida Harun, David Tucker, Thomas A. AdamsAbstract:The dynamic behavior of a solid oxide Fuel cell gas turbine hybrid system (SOFC/GT) from both open and closed loop transients in response to sudden changes in Fuel Composition was experimentally investigated. A pilot-scale (200–700 kW) hybrid facility available at the U.S. Department of Energy, National Energy Technology Laboratory was used to perform the experiments using a combination of numerical models and actual equipment. In the open loop configuration, the turbine speed was driven by the thermal effluent fed into the gas turbine system, where the thermal effluent was determined by the feedforward Fuel cell control system. However, in the closed loop configuration, a load-based speed control system was used to maintain the turbine speed constant at 40,500 rpm by adjusting the load on the turbine, in addition to the implementation of the Fuel cell system control. The open loop transient response showed that the impacts of Fuel Composition changes on key process variables, such as Fuel cell thermal effluent, turbine speed, and cathode feed stream conditions, in the SOFC/GT systems were propagated over the course of the test, except for the cathode inlet temperature. The trajectories of the aforementioned variables are discussed in this paper to better understand the resulting mitigation/propagation behaviors. This will help lead to the development of novel control strategies to mitigate the negative impacts experienced during Fuel Composition transients of SOFC/GT systems.
-
Impact of Fuel Composition transients on SOFC performance in gas turbine hybrid systems
Applied Energy, 2016Co-Authors: Nor Farida Harun, David Tucker, Thomas A. AdamsAbstract:This paper presents a dynamic study of Fuel cell gas turbine (SOFC/GT) hybrid systems, focusing on the response to a drastic transient in anode Fuel Composition for constant turbine speed operations. This work is motivated by the potential of Fuel cells for Fuel flexibility, which could extend the opportunities for sustainability and profitability in energy conversion systems. A combination of hardware and numerical models in a hybrid simulator is used to investigate the transient trajectories of Fuel cell process variables as well as the consequent impacts of Fuel cell thermal effluent on the integrated gas turbine engine. The conversion of thermal energy stored in the Fuel cell stack to chemical energy during the reforming at the beginning of the cell resulted in a 17% increase in thermal effluent from the Fuel cell to the turbine in the first few seconds of the transient. Fuel cell solid temperature gradients increased by 39% at 250s from the initiation of the transient. The distributed dynamic performance of the Fuel cell in terms of the Fuel Composition gradient, thermal, and electrochemical performance across the Fuel cell length was carefully characterized, considering their interactions and their impacts on the total system performance.
-
Fuel Composition TRANSIENTS IN SOLID OXIDE Fuel CELL GAS TURBINE HYBRID SYSTEMS FOR POLYGENERATION APPLICATIONS
2015Co-Authors: Nor Farida HarunAbstract:The potential of Solid Oxide Fuel Cell Gas Turbine (SOFC/GT] hybrid systems for Fuel flexibility makes this technology greatly attractive for system hybridization with various Fuel processing units in advanced power generation systems and/or polygeneration plants. Such hybrid technologies open up the possibility and opportunities for improvement of system reliabilities and operabilities. However, SOFC/GT hybrid systems have not yet reached their full potential in term of capitalizing on the synergistic benefits of Fuel cell and gas turbine cycles. Integrating Fuel cells with gas turbine and other components for transient operations increases the risk for exposure to rapid and significant changes in process dynamics and performance, which are primarily associated with Fuel cell thermal management and compressor surge. This can lead to severe Fuel cell failure, shaft overspeed, and gas turbine damage. Sufficient dynamic control architectures should be made to mitigate undesirable dynamic behaviours and/or system constraint violations before this technology can be commercialized. But, adequate understanding about dynamic coupling interactions between system components in the hybrid configuration is essential. Considering this critical need for system identification of SOFC/GT hybrid in Fuel flexible systems, this thesis investigates the dynamic performance of SOFC/GT hybrid technology in response to Fuel Composition changes. Hardware-based simulations, which combined actual equipment of direct-fired recuperated gas turbine system and simulated Fuel cell subsystem, are used to experimentally investigate the impacts of Fuel Composition changes on the SOFC/GT hybrid system, reducing potentially large inaccuracies in the dynamic study. The impacts of Fuel Composition in a closed loop operation using turbine speed control were first studied for the purpose of simplicity. Quantification of safe operating conditions for dynamic operations associated with carbon deposition and compressor stall and surge was done prior to the execution of experimentation. With closed loop tests, the dynamic performance of SOFC/GT hybrid technology due to a transition in gas Composition could be uniquely characterized, eliminating the interactive effects of other process variables and disturbances. However, for an extensive system analysis, open loop tests (without turbine speed control] were also conducted such that potential coupling impacts exhibited by the SOFC/GT hybrid during Fuel transients could be explored. Detailed characterization of SOFC/GT dynamic performance was performed to identify the interrelationship of each Fuel cell variable in response to Fuel Composition dynamics and their contributions to operability of the system. As a result of lowering LHV content in the Fuel feed, which involved a transition from coal-derived syngas to humidified methane Composition in the SOFC anode, the system demonstrated a dramatic transient increase in Fuel cell thermal effluent with a time scale of seconds, resulting from the conversion of Fuel cell thermal energy storage into chemical energy. This transient was highly associated with the dynamics of solid and gas temperatures, heat flux, heat generation in the Fuel cell due to perturbations in methane reforming, water-gas shifting, and electrochemical hydrogen oxidation. In turn, the dramatic changes in Fuel cell thermal effluent resulting from the anode Composition changes drove the turbine transients that caused significant cathode airflow fluctuations. This study revealed that the cathode air mass flow change was a major linking event during Fuel Composition changes in the SOFC/GT hybrid system. Both transients in cathode air mass flow and anode Composition significantly affected the hybrid system performance. Due to significant coupling between Fuel Composition transitions and cathode air mass flow changes, thermal management of SOFC/GT hybrid systems might be challenging. Yet, it was suggested that modulating cathode air flow offered promise for effective dynamic control of SOFC/GT hybrid systems with Fuel flexibility.
-
Open loop and closed loop performance of solid oxide Fuel cell turbine hybrid systems during Fuel Composition changes
Volume 3: Coal Biomass and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration, 2015Co-Authors: Nor Farida Harun, David Tucker, Thomas A. AdamsAbstract:The dynamic behavior of a solid oxide Fuel cell gas turbine hybrid system (SOFC/GT) from both open and closed loop transients in response to sudden changes in Fuel Composition was experimentally investigated. A pilot-scale (200kW – 700kW) hybrid facility available at the U.S. Department of Energy, National Energy Technology Laboratory was used to perform the experiments using a combination of numerical models and actual equipment.In the open loop configuration, the turbine speed was driven by the thermal effluent fed into the gas turbine system, where the thermal effluent was determined by the feedforward Fuel cell control system. However, in the closed loop configuration, a load-based speed control system was used to maintain the turbine speed constant at 40,500rpm by adjusting the load on the turbine, in addition to the implementation of the Fuel cell system control.The open loop transient response showed that the impacts of Fuel Composition changes on key process variables, such as Fuel cell thermal effluent, turbine speed and cathode feed stream conditions in the SOFC/GT systems were propagated over the course of the test, except for the cathode inlet temperature. The trajectories of the aforementioned variables are discussed in this paper to better understand the resulting mitigation/propagation behaviors. This will help lead to the development of novel control strategies to mitigate the negative impacts experienced during Fuel Composition transients of SOFC/GT systems.Copyright © 2015 by ASME
-
Fuel Composition Transients in Fuel Cell Turbine Hybrid for Polygeneration Applications
Journal of Fuel Cell Science and Technology, 2014Co-Authors: Nor Farida Harun, David Tucker, Thomas A. AdamsAbstract:Transient impacts on the performance of solid oxide Fuel cell / gas turbine (SOFC/GT) hybrid systems were investigated using hardware-in-the-loop simulations (HiLS) at a test facility located at the U.S. Department of Energy, National Energy Technology Laboratory. The work focused on applications relevant to polygeneration systems which require significant Fuel flexibility. Specifically, the dynamic response of implementing a sudden change in Fuel Composition from syngas to methane was examined. The maximum range of possible Fuel Composition allowable within the constraints of carbon deposition in the SOFC and stalling/surging of the turbine compressor system was determined.It was demonstrated that the transient response was significantly impact the Fuel cell dynamic performance, which mainly drives the entire transient in SOFC/GT hybrid systems. This resulted in severe limitations on the allowable methane concentrations that could be used in the final Fuel Composition when switching from syngas to methane. Several system performance parameters were analyzed to characterize the transient impact over the course of two hours from the Composition change.Copyright © 2014 by ASME
David Tucker - One of the best experts on this subject based on the ideXlab platform.
-
Fuel Composition effect on cathode airflow control in Fuel cell gas turbine hybrid systems
Journal of Power Sources, 2018Co-Authors: Nana Zhou, Valentina Zaccaria, David TuckerAbstract:Abstract Cathode airflow regulation is considered an effective means for thermal management in solid oxide Fuel cell gas turbine (SOFC-GT) hybrid system. However, performance and controllability are observed to vary significantly with different Fuel Compositions. Because a complete system characterization with any possible Fuel Composition is not feasible, the need arises for robust controllers. The sufficiency of robust control is dictated by the effective change of operating state given the new Composition used. It is possible that controller response could become unstable without a change in the gains from one state to the other. In this paper, cathode airflow transients are analyzed in a SOFC-GT system using syngas as Fuel Composition, comparing with previous work which used humidified hydrogen. Transfer functions are developed to map the relationship between the airflow bypass and several key variables. The impact of Fuel Composition on system control is quantified by evaluating the difference between gains and poles in transfer functions. Significant variations in the gains and the poles, more than 20% in most cases, are found in turbine rotational speed and cathode airflow. The results of this work provide a guideline for the development of future control strategies to face Fuel Composition changes.
-
Open Loop and Closed Loop Performance of Solid Oxide Fuel Cell Turbine Hybrid Systems During Fuel Composition Changes
Journal of Engineering for Gas Turbines and Power-transactions of The Asme, 2017Co-Authors: Nor Farida Harun, David Tucker, Thomas A. AdamsAbstract:The dynamic behavior of a solid oxide Fuel cell gas turbine hybrid system (SOFC/GT) from both open and closed loop transients in response to sudden changes in Fuel Composition was experimentally investigated. A pilot-scale (200–700 kW) hybrid facility available at the U.S. Department of Energy, National Energy Technology Laboratory was used to perform the experiments using a combination of numerical models and actual equipment. In the open loop configuration, the turbine speed was driven by the thermal effluent fed into the gas turbine system, where the thermal effluent was determined by the feedforward Fuel cell control system. However, in the closed loop configuration, a load-based speed control system was used to maintain the turbine speed constant at 40,500 rpm by adjusting the load on the turbine, in addition to the implementation of the Fuel cell system control. The open loop transient response showed that the impacts of Fuel Composition changes on key process variables, such as Fuel cell thermal effluent, turbine speed, and cathode feed stream conditions, in the SOFC/GT systems were propagated over the course of the test, except for the cathode inlet temperature. The trajectories of the aforementioned variables are discussed in this paper to better understand the resulting mitigation/propagation behaviors. This will help lead to the development of novel control strategies to mitigate the negative impacts experienced during Fuel Composition transients of SOFC/GT systems.
-
Impact of Fuel Composition transients on SOFC performance in gas turbine hybrid systems
Applied Energy, 2016Co-Authors: Nor Farida Harun, David Tucker, Thomas A. AdamsAbstract:This paper presents a dynamic study of Fuel cell gas turbine (SOFC/GT) hybrid systems, focusing on the response to a drastic transient in anode Fuel Composition for constant turbine speed operations. This work is motivated by the potential of Fuel cells for Fuel flexibility, which could extend the opportunities for sustainability and profitability in energy conversion systems. A combination of hardware and numerical models in a hybrid simulator is used to investigate the transient trajectories of Fuel cell process variables as well as the consequent impacts of Fuel cell thermal effluent on the integrated gas turbine engine. The conversion of thermal energy stored in the Fuel cell stack to chemical energy during the reforming at the beginning of the cell resulted in a 17% increase in thermal effluent from the Fuel cell to the turbine in the first few seconds of the transient. Fuel cell solid temperature gradients increased by 39% at 250s from the initiation of the transient. The distributed dynamic performance of the Fuel cell in terms of the Fuel Composition gradient, thermal, and electrochemical performance across the Fuel cell length was carefully characterized, considering their interactions and their impacts on the total system performance.
-
Open loop and closed loop performance of solid oxide Fuel cell turbine hybrid systems during Fuel Composition changes
Volume 3: Coal Biomass and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration, 2015Co-Authors: Nor Farida Harun, David Tucker, Thomas A. AdamsAbstract:The dynamic behavior of a solid oxide Fuel cell gas turbine hybrid system (SOFC/GT) from both open and closed loop transients in response to sudden changes in Fuel Composition was experimentally investigated. A pilot-scale (200kW – 700kW) hybrid facility available at the U.S. Department of Energy, National Energy Technology Laboratory was used to perform the experiments using a combination of numerical models and actual equipment.In the open loop configuration, the turbine speed was driven by the thermal effluent fed into the gas turbine system, where the thermal effluent was determined by the feedforward Fuel cell control system. However, in the closed loop configuration, a load-based speed control system was used to maintain the turbine speed constant at 40,500rpm by adjusting the load on the turbine, in addition to the implementation of the Fuel cell system control.The open loop transient response showed that the impacts of Fuel Composition changes on key process variables, such as Fuel cell thermal effluent, turbine speed and cathode feed stream conditions in the SOFC/GT systems were propagated over the course of the test, except for the cathode inlet temperature. The trajectories of the aforementioned variables are discussed in this paper to better understand the resulting mitigation/propagation behaviors. This will help lead to the development of novel control strategies to mitigate the negative impacts experienced during Fuel Composition transients of SOFC/GT systems.Copyright © 2015 by ASME
-
Fuel Composition Transients in Fuel Cell Turbine Hybrid for Polygeneration Applications
Journal of Fuel Cell Science and Technology, 2014Co-Authors: Nor Farida Harun, David Tucker, Thomas A. AdamsAbstract:Transient impacts on the performance of solid oxide Fuel cell / gas turbine (SOFC/GT) hybrid systems were investigated using hardware-in-the-loop simulations (HiLS) at a test facility located at the U.S. Department of Energy, National Energy Technology Laboratory. The work focused on applications relevant to polygeneration systems which require significant Fuel flexibility. Specifically, the dynamic response of implementing a sudden change in Fuel Composition from syngas to methane was examined. The maximum range of possible Fuel Composition allowable within the constraints of carbon deposition in the SOFC and stalling/surging of the turbine compressor system was determined.It was demonstrated that the transient response was significantly impact the Fuel cell dynamic performance, which mainly drives the entire transient in SOFC/GT hybrid systems. This resulted in severe limitations on the allowable methane concentrations that could be used in the final Fuel Composition when switching from syngas to methane. Several system performance parameters were analyzed to characterize the transient impact over the course of two hours from the Composition change.Copyright © 2014 by ASME
Thomas Schmitt - One of the best experts on this subject based on the ideXlab platform.
-
Gas Turbine Gas Fuel Composition Performance Correction Using Wobbe Index
Journal of Engineering for Gas Turbines and Power-transactions of The Asme, 2011Co-Authors: Mike J. Gross, Thomas SchmittAbstract:Gas turbine thermal performance is dependent on many external conditions, including Fuel gas Composition. Measured performance must be corrected to specified reference conditions prior to comparison against performance specifications. A performance correction for Fuel Composition is thus required. One current method of correction commonly used is to characterize Fuel Composition effects as a function of heating value and hydrogen to carbon ratio. This method has been used in the past within a limited range of Fuel Composition variation around the expected Composition, yielding relatively small correction factors on the order of ±0.1%. With industry trends suggesting continued exposure of gas turbines to a broader range of Fuels such as liquefied natural gas and synthesized low BTU Fuel, the corresponding performance effects will be much larger. As a result, a more comprehensive correction methodology is required to encompass a broader range of Fuel constituents encountered. Analytical studies have been completed with the aid of thermodynamic models to identify the extent to which the Wobbe index can be used to correlate the response of gas turbine performance parameters to Fuel gas Composition. Results suggest that improved performance test accuracy can be achieved by using the Wobbe index compared with the aforementioned conventional Fuel characteristics. This proposed method remains compliant with intent of internationally accepted test codes such as ASME PTC-22, ASME PTC-46, and ISO 2314.
-
Gas Turbine Gas Fuel Composition Performance Correction Using Wobbe Index
ASME 2010 Power Conference, 2010Co-Authors: Mike J. Gross, Thomas SchmittAbstract:Gas turbine thermal performance is dependent on many external conditions, including Fuel gas Composition. Variations in Composition cause changes in output and heat consumption during operation. Measured performance must be corrected to specified reference conditions prior to comparison against performance specifications. The Fuel Composition is one such condition for which performance corrections are required. The methodology of Fuel Composition corrections can take various forms. One current method of correction commonly used is to characterize Fuel Composition effects as a function of heating value and hydrogen-to-carbon ratio. This method has been used in the past within a limited range of Fuel Composition variation around the expected Composition, yielding relatively small correction factors on the order of +/− 0.1%. Industry trends suggest that gas turbines will continue to be exposed to broader ranges of gas constituents, and the corresponding performance effects will be much larger. For example, liquefied natural gas, synthesized low BTU Fuel, and bio Fuels are becoming more common, with associated performance effects of +/− 0.5% or greater. As a result of these trends, performance test results will bear a greater dependency on Fuel Composition corrections. Hence, a more comprehensive correction methodology is required to encompass a broader range of Fuel constituents encountered. Combustion system behavior, specifically emissions and flame stability, is also influenced by variations in Fuel gas Composition. The power generation industry uses Wobbe Index as an indicator of Fuel Composition. Wobbe Index relates the heating value of the Fuel to its density. High variations in Wobbe Index can cause operability issues including combustion dynamics and increased emissions. A new method for performance corrections using Wobbe Index as the correlating Fuel parameter has been considered. Analytical studies have been completed with the aid of thermodynamic models to identify the extent to which the Wobbe Index can be used to correlate the response of the gas turbine performance parameters to Fuel gas Composition. Results of the study presented in this paper suggest that improved performance test accuracy can be achieved by using Wobbe Index as a performance correction parameter, instead of the aforementioned conventional Fuel characteristics. Furthermore, a relationship between this method’s accuracy and CO2 content of Fuel is established such that an additional correction yields results with even better accuracy. This proposed method remains compliant with intent of internationally accepted test codes such as ASME PTC-22, ASME PTC-46, and ISO 2314.Copyright © 2010 by ASME
Raul Payri - One of the best experts on this subject based on the ideXlab platform.
-
Boundary condition and Fuel Composition effects on injection processes of high-pressure sprays at the microscopic level
International Journal of Multiphase Flow, 2016Co-Authors: Julien Manin, Lyle M Pickett, Michele Bardi, Raul PayriAbstract:Detailed imaging of n-dodecane and ethanol sprays injected in a constant-flow, high-pressure, high-temperature optically accessible chamber was performed. High-speed, diffused back-illuminated long-distance microscopy was used to resolve the spray structure in the near-nozzle field. The effect of injection and ambient pressures, as well as Fuel temperature and Composition have been studied through measurements of the spray penetration rates, hydraulic delays and spreading angles. Additional information such as transient flow velocities have been extracted from the measurements and compared to a control-volume spray model. The analysis demonstrated the influence of outlet flow on spray development with lower penetration velocities and wider spreading angles during the transients (start and end of injection) than during the quasi-steady period of the injection. The effect of Fuel Composition on penetration was limited, while spreading angle measurements showed wider sprays for ethanol. In contrast, varying Fuel temperature led to varying penetration velocities, while spreading angle remained constant during the quasi-steady period of the injection. Fuel temperature affected injector performance, with shorter delays as Fuel temperature was increased. The comparisons between predicted and measured penetration rates showed differences suggesting that the transient behavior of the spreading angle of the sprays modified spray development significantly in the near-field. The reasonable agreement between predicted and measured flow velocity at and after the end of injection suggested that the complete mixing assumptions made by the model were valid in the near nozzle region during this period, when injected flow velocities are reduced.
