The continuous demand for oil and gas forces the petroleum industry to develop new and cost-efficient technologies to increase recovery from new fields and enhance extraction from existing fields. Subsea wet gas compression stands out as a promising solution to increase field extraction, utilize remote regions and reduce costs. Today, a few subsea compressor systems are already operating while several new installations are expected within the next years. This creates a need for dynamic simulation tools to ensure proper system design and facilitate production. This paper presents the model setup for the wet gas compressor test facility at the Norwegian University of Science and Technology (NTNU). The test facility is an open loop configuration consisting of a single shrouded centrifugal impeller, a vaneless diffuser and a circular volute. The fluid is a mixture of ambient air and water. The analysis presented here validates the dynamic model behavior against transient experimental test cases, which include step changes in liquid content and driver trip in both wet and dry conditions. Further, the discharge valve performance has been analyzed in both dry and wet gas flow. The test reveals that the dynamic model is able to operate in a stable manner while showing a close correspondence to the transient test cases. Care should be taken in utilizing dry gas valve characteristics in multiphase flows as increased liquid content has a distinct impact on the valve performance.
{"title":"Wet Gas Compressor Model Validation","authors":"Martin Bakken, T. Bjørge, L. Bakken","doi":"10.1115/gt2019-90354","DOIUrl":"https://doi.org/10.1115/gt2019-90354","url":null,"abstract":"\u0000 The continuous demand for oil and gas forces the petroleum industry to develop new and cost-efficient technologies to increase recovery from new fields and enhance extraction from existing fields. Subsea wet gas compression stands out as a promising solution to increase field extraction, utilize remote regions and reduce costs.\u0000 Today, a few subsea compressor systems are already operating while several new installations are expected within the next years. This creates a need for dynamic simulation tools to ensure proper system design and facilitate production. This paper presents the model setup for the wet gas compressor test facility at the Norwegian University of Science and Technology (NTNU). The test facility is an open loop configuration consisting of a single shrouded centrifugal impeller, a vaneless diffuser and a circular volute. The fluid is a mixture of ambient air and water. The analysis presented here validates the dynamic model behavior against transient experimental test cases, which include step changes in liquid content and driver trip in both wet and dry conditions. Further, the discharge valve performance has been analyzed in both dry and wet gas flow.\u0000 The test reveals that the dynamic model is able to operate in a stable manner while showing a close correspondence to the transient test cases. Care should be taken in utilizing dry gas valve characteristics in multiphase flows as increased liquid content has a distinct impact on the valve performance.","PeriodicalId":412490,"journal":{"name":"Volume 9: Oil and Gas Applications; Supercritical CO2 Power Cycles; Wind Energy","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125689425","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}
Supercritical CO2 (sCO2) power cycles find potential application with a variety of heat sources including nuclear, concentrated solar (CSP), coal, natural gas, and waste heat sources, and consequently cover a wide range of scales. Most studies to date have focused on the performance of sCO2 power cycles, while economic analyses have been less prevalent, due in large part to the relative scarcity of reliable cost estimates for sCO2 power cycle components. Further, the accuracy of existing sCO2 techno-economic analyses suffer from a small sample set of vendor-based component costs for any given study. Improved accuracy of sCO2 component cost estimation is desired to enable a shift in focus from plant efficiency to economics as a driver for commercialization of sCO2 technology. This study reports on sCO2 component cost scaling relationships that have been developed collaboratively from an aggregate set of vendor quotes, cost estimates, and published literature. As one of the world’s largest supporters of sCO2 research and development, the Department of Energy (DOE) National Laboratories have access to a considerable pool of vendor component costs that span multiple applications specific to each National Laboratory’s mission, including fossil-fueled sCO2 applications at the National Energy Technology Laboratory (NETL), CSP at the National Renewable Energy Laboratory (NREL), and CSP, nuclear, and distributed energy sources at Sandia National Laboratories (SNL). The resulting cost correlations are relevant to sCO2 components in all these applications, and for scales ranging from 5–750 MWe. This work builds upon prior work at SNL, in which sCO2 component cost models were developed for CSP applications ranging from 1–100 MWe in size. Similar to the earlier SNL efforts, vendor confidentiality has been maintained throughout this collaboration and in the published results. Cost models for each component were correlated from 4–24 individual quotes from multiple vendors, although the individual cost data points are proprietary and not shown. Cost models are reported for radial and axial turbines, integrally-geared and barrel-style centrifugal compressors, high temperature and low temperature recuperators, dry sCO2 coolers, and primary heat exchangers for coal and natural gas fuel sources. These models are applicable to sCO2-specific components used in a variety of sCO2 cycle configurations, and include incremental cost factors for advanced, high temperature materials for relevant components. Non-sCO2-specific costs for motors, gearboxes, and generators have been included to allow cycle designers to explore the cost implications of various turbomachinery configurations. Finally, the uncertainty associated with these component cost models is quantified by using AACE International-style class ratings for vendor estimates, combined with component cost correlation statistics.
{"title":"sCO2 Power Cycle Component Cost Correlations From DOE Data Spanning Multiple Scales and Applications","authors":"N. Weiland, B. Lance, Sandeep R. Pidaparti","doi":"10.1115/gt2019-90493","DOIUrl":"https://doi.org/10.1115/gt2019-90493","url":null,"abstract":"\u0000 Supercritical CO2 (sCO2) power cycles find potential application with a variety of heat sources including nuclear, concentrated solar (CSP), coal, natural gas, and waste heat sources, and consequently cover a wide range of scales. Most studies to date have focused on the performance of sCO2 power cycles, while economic analyses have been less prevalent, due in large part to the relative scarcity of reliable cost estimates for sCO2 power cycle components. Further, the accuracy of existing sCO2 techno-economic analyses suffer from a small sample set of vendor-based component costs for any given study. Improved accuracy of sCO2 component cost estimation is desired to enable a shift in focus from plant efficiency to economics as a driver for commercialization of sCO2 technology.\u0000 This study reports on sCO2 component cost scaling relationships that have been developed collaboratively from an aggregate set of vendor quotes, cost estimates, and published literature. As one of the world’s largest supporters of sCO2 research and development, the Department of Energy (DOE) National Laboratories have access to a considerable pool of vendor component costs that span multiple applications specific to each National Laboratory’s mission, including fossil-fueled sCO2 applications at the National Energy Technology Laboratory (NETL), CSP at the National Renewable Energy Laboratory (NREL), and CSP, nuclear, and distributed energy sources at Sandia National Laboratories (SNL). The resulting cost correlations are relevant to sCO2 components in all these applications, and for scales ranging from 5–750 MWe. This work builds upon prior work at SNL, in which sCO2 component cost models were developed for CSP applications ranging from 1–100 MWe in size.\u0000 Similar to the earlier SNL efforts, vendor confidentiality has been maintained throughout this collaboration and in the published results. Cost models for each component were correlated from 4–24 individual quotes from multiple vendors, although the individual cost data points are proprietary and not shown. Cost models are reported for radial and axial turbines, integrally-geared and barrel-style centrifugal compressors, high temperature and low temperature recuperators, dry sCO2 coolers, and primary heat exchangers for coal and natural gas fuel sources. These models are applicable to sCO2-specific components used in a variety of sCO2 cycle configurations, and include incremental cost factors for advanced, high temperature materials for relevant components. Non-sCO2-specific costs for motors, gearboxes, and generators have been included to allow cycle designers to explore the cost implications of various turbomachinery configurations. Finally, the uncertainty associated with these component cost models is quantified by using AACE International-style class ratings for vendor estimates, combined with component cost correlation statistics.","PeriodicalId":412490,"journal":{"name":"Volume 9: Oil and Gas Applications; Supercritical CO2 Power Cycles; Wind Energy","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129925923","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}
A. Dutta, Adhip Gupta, S. Sathish, Aman Bandooni, Pramod Kumar
The paper presents modeling and Design of Experiments (DOE) analysis for a simple recuperated s-CO2 closed loop Brayton cycle operating at a maximum temperature of 600°C and a compressor inlet temperature of 45°C. The analysis highlights the impact of isentropic efficiencies of the turbine and compressor, decoupled in this case, on other equipment such as recuperator, gas cooler and heater, all of which have a bearing on the overall performance of the s-CO2 Brayton cycle. A MATLAB program coupled with REFPROP is used to perform the thermodynamic analysis of the cycle. A design space exploration with a Design of Experiments (DOE) study is undertaken using I-sight™ (multi-objective optimization software), which is coupled with the MATLAB code. The outcome of the DOE study provides the optimal pressure ratios and high side pressures for maximum cycle efficiency in the design space. By varying pressure ratios along with a floating high side pressure, the analysis reveals that the cycle performance exhibits a peak around a pressure ratio of 2.5, with cycle efficiency being the objective function. A further interesting outcome of the DOE study reveals that the isentropic efficiencies of the compressor and turbine have a strong influence not only on the overall cycle efficiency, but also the optimum pressure ratio as well as the threshold pressures (low as well as high side pressure). An important outcome of this exercise shows that the isentropic efficiency of the turbine has a much greater impact on the overall cycle performance as compared to that of the compressor.
{"title":"Simple Recuperated s-CO2 Cycle Revisited: Optimization of Operating Parameters for Maximum Cycle Efficiency","authors":"A. Dutta, Adhip Gupta, S. Sathish, Aman Bandooni, Pramod Kumar","doi":"10.1115/gt2019-90315","DOIUrl":"https://doi.org/10.1115/gt2019-90315","url":null,"abstract":"\u0000 The paper presents modeling and Design of Experiments (DOE) analysis for a simple recuperated s-CO2 closed loop Brayton cycle operating at a maximum temperature of 600°C and a compressor inlet temperature of 45°C. The analysis highlights the impact of isentropic efficiencies of the turbine and compressor, decoupled in this case, on other equipment such as recuperator, gas cooler and heater, all of which have a bearing on the overall performance of the s-CO2 Brayton cycle. A MATLAB program coupled with REFPROP is used to perform the thermodynamic analysis of the cycle. A design space exploration with a Design of Experiments (DOE) study is undertaken using I-sight™ (multi-objective optimization software), which is coupled with the MATLAB code. The outcome of the DOE study provides the optimal pressure ratios and high side pressures for maximum cycle efficiency in the design space. By varying pressure ratios along with a floating high side pressure, the analysis reveals that the cycle performance exhibits a peak around a pressure ratio of 2.5, with cycle efficiency being the objective function. A further interesting outcome of the DOE study reveals that the isentropic efficiencies of the compressor and turbine have a strong influence not only on the overall cycle efficiency, but also the optimum pressure ratio as well as the threshold pressures (low as well as high side pressure). An important outcome of this exercise shows that the isentropic efficiency of the turbine has a much greater impact on the overall cycle performance as compared to that of the compressor.","PeriodicalId":412490,"journal":{"name":"Volume 9: Oil and Gas Applications; Supercritical CO2 Power Cycles; Wind Energy","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132209840","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}
James P. Anderson, Alejandro Camou, E. Petersen, M. Harris, D. Cusano
A rugged, mid-infrared (IR) CO laser absorption diagnostic has been developed to monitor the amount of CO produced by a high-pressure CH4-O2 combustor test rig operating at supercritical CO2 conditions (30 MPa and 1150°C). The laser system operates at the fundamental absorption band, ν″ = 0, R(12), of CO near 4.5 μm. The mid-IR diagnostic was constructed from a tunable quantum cascade laser (QCL), an absorption cell with two window ports for monitoring CO exhaust concentration, and two IR photodetectors. Temperature and pressure sensors were mounted near the absorption cell to monitor exhaust flow conditions, and the operational wavelength of the laser was determined by a calibration process using a known mixture of CO and N2. Environmental conditions at the remote outdoor test facility posed significant difficulties in the data acquisition process for the IR diagnostic. Fluctuating environmental temperatures proved to be problematic when operating cryogenic photodetectors and stabilizing a QCL designed to operate with an internal temperature of −15°C. Improvements to the IR system included elimination of problematic stagnation regions via a new absorption cell design and an increase in the CO detection limit. During steady state conditions, the mid-IR diagnostic measured the CO concentration to within ± 80.6 ppm. The IR diagnostic was shown to have superior CO detection response time and the ability to resolve features not detected by other CO detector counterparts.
{"title":"Carbon Monoxide Emission Measurements From a Supercritical CO2 Combustor Rig Using a Mid-Infrared Laser Absorption Diagnostic","authors":"James P. Anderson, Alejandro Camou, E. Petersen, M. Harris, D. Cusano","doi":"10.1115/gt2019-91779","DOIUrl":"https://doi.org/10.1115/gt2019-91779","url":null,"abstract":"\u0000 A rugged, mid-infrared (IR) CO laser absorption diagnostic has been developed to monitor the amount of CO produced by a high-pressure CH4-O2 combustor test rig operating at supercritical CO2 conditions (30 MPa and 1150°C). The laser system operates at the fundamental absorption band, ν″ = 0, R(12), of CO near 4.5 μm. The mid-IR diagnostic was constructed from a tunable quantum cascade laser (QCL), an absorption cell with two window ports for monitoring CO exhaust concentration, and two IR photodetectors. Temperature and pressure sensors were mounted near the absorption cell to monitor exhaust flow conditions, and the operational wavelength of the laser was determined by a calibration process using a known mixture of CO and N2. Environmental conditions at the remote outdoor test facility posed significant difficulties in the data acquisition process for the IR diagnostic. Fluctuating environmental temperatures proved to be problematic when operating cryogenic photodetectors and stabilizing a QCL designed to operate with an internal temperature of −15°C. Improvements to the IR system included elimination of problematic stagnation regions via a new absorption cell design and an increase in the CO detection limit. During steady state conditions, the mid-IR diagnostic measured the CO concentration to within ± 80.6 ppm. The IR diagnostic was shown to have superior CO detection response time and the ability to resolve features not detected by other CO detector counterparts.","PeriodicalId":412490,"journal":{"name":"Volume 9: Oil and Gas Applications; Supercritical CO2 Power Cycles; Wind Energy","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131765372","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}
Ching-jen Tang, Aaron Mcclung, D. Hofer, Megan Huang
Four different control methods for ramping down the power output from a Supercritical Carbon Dioxide (sCO2) simple cycle were studied to support the development of 10 MWe Pilot Plant Test Facility, funded by the US Department of Energy. These detailed transient models are written using NPSS (Numerical Propulsion System Simulation). The main components of the NPSS models include a compressor, turbine, High-Temperature Recuperative heat exchanger (HTR), cooler, heater, pipes, and valves. In the transient models, the thermal mass and CO2 fluid volume for each main component are based on representative data or proven design practices for the corresponding component. The steady-state performance of each main component has been validated with representative data while the transient performance of the HTR has been validated with published experimental data. The models have been used to study the methods to ramp down the power output. The methods include extracting the CO2 from the inventory, reducing the opening of turbine inlet throttle valve, and increasing the temperature of the cooling water entering the cooler. These methods, along with a hybrid method of combining the first two methods, were evaluated for the rate of turndown in the power output, operability of the compressor, and cycle efficiency. The preliminary results suggest that inventory extraction is the most efficient but has a slow turndown rate while turbine throttle control is less efficient but results in a faster turndown rate. In addition, the inventory extraction reduces the margin of the compressor choke line but the turbine throttle control increases the margin of the choke line.
{"title":"Transient Modeling of 10 MW Supercritical CO2 Brayton Power Cycles Using Numerical Propulsion System Simulation (NPSS)","authors":"Ching-jen Tang, Aaron Mcclung, D. Hofer, Megan Huang","doi":"10.1115/gt2019-91443","DOIUrl":"https://doi.org/10.1115/gt2019-91443","url":null,"abstract":"\u0000 Four different control methods for ramping down the power output from a Supercritical Carbon Dioxide (sCO2) simple cycle were studied to support the development of 10 MWe Pilot Plant Test Facility, funded by the US Department of Energy. These detailed transient models are written using NPSS (Numerical Propulsion System Simulation). The main components of the NPSS models include a compressor, turbine, High-Temperature Recuperative heat exchanger (HTR), cooler, heater, pipes, and valves. In the transient models, the thermal mass and CO2 fluid volume for each main component are based on representative data or proven design practices for the corresponding component. The steady-state performance of each main component has been validated with representative data while the transient performance of the HTR has been validated with published experimental data. The models have been used to study the methods to ramp down the power output. The methods include extracting the CO2 from the inventory, reducing the opening of turbine inlet throttle valve, and increasing the temperature of the cooling water entering the cooler. These methods, along with a hybrid method of combining the first two methods, were evaluated for the rate of turndown in the power output, operability of the compressor, and cycle efficiency. The preliminary results suggest that inventory extraction is the most efficient but has a slow turndown rate while turbine throttle control is less efficient but results in a faster turndown rate. In addition, the inventory extraction reduces the margin of the compressor choke line but the turbine throttle control increases the margin of the choke line.","PeriodicalId":412490,"journal":{"name":"Volume 9: Oil and Gas Applications; Supercritical CO2 Power Cycles; Wind Energy","volume":"114 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133777730","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}
Deepak Thirumurthy, B. Ruggiero, Gautam Chhibber, Jaskirat Singh
The RT61 is a three-stage industrial power turbine which couples with the SGT-A35 aeroderivative gas generator (formerly named Industrial RB211). It was designed for improved efficiency and modular construction for ease in maintainability. The aeroderivative SGT-A35 (GT61) product serves both oil & gas and power generation market with a fleet size of greater than 90 units. In recent years, there has been increased emphasis on clean energy, only complemented by the regulatory changes and market conditions. The power generation and oil & gas customers (upstream, midstream, and downstream) are continuously looking for opportunities to decrease their greenhouse gas emissions and reduce fuel consumption by improving the gas turbine cycle efficiency. The SGT-A35 (GT61) power turbine has > 93% isentropic efficiency and industry standard overhaul schedule of 100,000 hours. However the potential for further cycle efficiency improvements and reduction in emissions exist by optimizing the power turbine capacity to a specific load range. This served as the main motivation for this technical work. This paper discusses the engineering efforts taken in implementing the above stated improvement and further optimizing the product for reduced emissions. The improvements are discussed on the product level and on the TransCanada Pipelines fleet level. A new power turbine variant was developed on a demanding timeline driven by the customer project. A detailed development project was undertaken to establish the new operating point, aerodynamic design, and the new geometry. It was optimized to the customer project-specific load range. During the manufacturing phase, novel rapid prototyping methods were used to achieve desired lead times. Flow path change was limited to the first stage vane to minimize the introduction of new risks and uncertainties.
{"title":"Optimized SGT-A35 (GT61) for Improved Emissions and Enhanced Efficiency Across the Load Range","authors":"Deepak Thirumurthy, B. Ruggiero, Gautam Chhibber, Jaskirat Singh","doi":"10.1115/gt2019-90610","DOIUrl":"https://doi.org/10.1115/gt2019-90610","url":null,"abstract":"\u0000 The RT61 is a three-stage industrial power turbine which couples with the SGT-A35 aeroderivative gas generator (formerly named Industrial RB211). It was designed for improved efficiency and modular construction for ease in maintainability. The aeroderivative SGT-A35 (GT61) product serves both oil & gas and power generation market with a fleet size of greater than 90 units.\u0000 In recent years, there has been increased emphasis on clean energy, only complemented by the regulatory changes and market conditions. The power generation and oil & gas customers (upstream, midstream, and downstream) are continuously looking for opportunities to decrease their greenhouse gas emissions and reduce fuel consumption by improving the gas turbine cycle efficiency.\u0000 The SGT-A35 (GT61) power turbine has > 93% isentropic efficiency and industry standard overhaul schedule of 100,000 hours. However the potential for further cycle efficiency improvements and reduction in emissions exist by optimizing the power turbine capacity to a specific load range. This served as the main motivation for this technical work.\u0000 This paper discusses the engineering efforts taken in implementing the above stated improvement and further optimizing the product for reduced emissions. The improvements are discussed on the product level and on the TransCanada Pipelines fleet level.\u0000 A new power turbine variant was developed on a demanding timeline driven by the customer project. A detailed development project was undertaken to establish the new operating point, aerodynamic design, and the new geometry. It was optimized to the customer project-specific load range. During the manufacturing phase, novel rapid prototyping methods were used to achieve desired lead times. Flow path change was limited to the first stage vane to minimize the introduction of new risks and uncertainties.","PeriodicalId":412490,"journal":{"name":"Volume 9: Oil and Gas Applications; Supercritical CO2 Power Cycles; Wind Energy","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123513947","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}
A. Bianchini, F. Balduzzi, Leopold Haack, S. Bigalli, B. Müller, G. Ferrara
The increasing interest in deep-water floating applications and in wind turbine installations in turbulent flows, is putting vertical-axis wind turbines back again in research agendas. However, due to the lack of activities in past years, the accuracy and robustness of available design tools is much lower than the corresponding ones for horizontal-axis rotors. Moving from this background, the study presents the development of a hybrid simulation model able to simulate H-type Darrieus turbines with low computational effort and an accuracy higher than that of conventional low-fidelity models. It is based on the coupling of unsteady RANS CFD with the Actuator Line theory to replace the airfoils. The present tool has been implemented within the commercial solver ANSYS® FLUENT® and it is then of practical interest for a large number of potential users. With respect to other examples in the literature, the present approach includes some new findings in the correct manipulation of airfoil polars that notably increased its accuracy. The validation of the model is assessed by means of two different study cases featuring a simplified 1-blade rotor and a real 3-blade turbine, for which both detailed CFD simulations and experiments were available. The model was able to produce accurate results — both in terms of aggregate power production and of flow field description — for turbines with a medium-low chord-to-radius ratio and the tipspeed ratios typical of turbine operation.
{"title":"Development and Validation of a Hybrid Simulation Model for Darrieus Vertical-Axis Wind Turbines","authors":"A. Bianchini, F. Balduzzi, Leopold Haack, S. Bigalli, B. Müller, G. Ferrara","doi":"10.1115/gt2019-91218","DOIUrl":"https://doi.org/10.1115/gt2019-91218","url":null,"abstract":"\u0000 The increasing interest in deep-water floating applications and in wind turbine installations in turbulent flows, is putting vertical-axis wind turbines back again in research agendas. However, due to the lack of activities in past years, the accuracy and robustness of available design tools is much lower than the corresponding ones for horizontal-axis rotors.\u0000 Moving from this background, the study presents the development of a hybrid simulation model able to simulate H-type Darrieus turbines with low computational effort and an accuracy higher than that of conventional low-fidelity models. It is based on the coupling of unsteady RANS CFD with the Actuator Line theory to replace the airfoils. The present tool has been implemented within the commercial solver ANSYS® FLUENT® and it is then of practical interest for a large number of potential users. With respect to other examples in the literature, the present approach includes some new findings in the correct manipulation of airfoil polars that notably increased its accuracy. The validation of the model is assessed by means of two different study cases featuring a simplified 1-blade rotor and a real 3-blade turbine, for which both detailed CFD simulations and experiments were available. The model was able to produce accurate results — both in terms of aggregate power production and of flow field description — for turbines with a medium-low chord-to-radius ratio and the tipspeed ratios typical of turbine operation.","PeriodicalId":412490,"journal":{"name":"Volume 9: Oil and Gas Applications; Supercritical CO2 Power Cycles; Wind Energy","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124611466","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}
L. Manservigi, M. Venturini, G. Ceschini, G. Bechini, E. Losi
Sensor fault detection is a crucial aspect for raw data cleaning in gas turbine industry. To this purpose, a comprehensive approach for Improved Detection, Classification and Integrated Diagnostics of Gas Turbine Sensors (named I-DCIDS) was developed by the authors to detect and classify several classes of fault. For single-sensors or redundant/correlated sensors, the I-DCIDS methodology can identify seven classes of fault, i.e. Out of Range, Stuck Signal, Dithering, Standard Deviation, Trend Coherence, Spike and Bias. Since the considered faults are detected by means of a methodology which relies on basic mathematical laws and user-defined parameters, sensitivity analyses are carried out in this paper on I-DCIDS parameters to derive some rules of thumbs about their optimal setting. The sensitivity analyses are carried out on four heterogeneous and challenging datasets with redundant sensors installed on Siemens gas turbines.
{"title":"Validation of an Advanced Diagnostic Methodology for the Identification and Classification of Gas Turbine Sensor Faults by Means of Field Data","authors":"L. Manservigi, M. Venturini, G. Ceschini, G. Bechini, E. Losi","doi":"10.1115/gt2019-90056","DOIUrl":"https://doi.org/10.1115/gt2019-90056","url":null,"abstract":"\u0000 Sensor fault detection is a crucial aspect for raw data cleaning in gas turbine industry. To this purpose, a comprehensive approach for Improved Detection, Classification and Integrated Diagnostics of Gas Turbine Sensors (named I-DCIDS) was developed by the authors to detect and classify several classes of fault. For single-sensors or redundant/correlated sensors, the I-DCIDS methodology can identify seven classes of fault, i.e. Out of Range, Stuck Signal, Dithering, Standard Deviation, Trend Coherence, Spike and Bias.\u0000 Since the considered faults are detected by means of a methodology which relies on basic mathematical laws and user-defined parameters, sensitivity analyses are carried out in this paper on I-DCIDS parameters to derive some rules of thumbs about their optimal setting. The sensitivity analyses are carried out on four heterogeneous and challenging datasets with redundant sensors installed on Siemens gas turbines.","PeriodicalId":412490,"journal":{"name":"Volume 9: Oil and Gas Applications; Supercritical CO2 Power Cycles; Wind Energy","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126448877","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}
J. Marion, M. Kutin, Aaron Mcclung, J. Mortzheim, Robin W. Ames
A team led by Gas Technology Institute (GTI), Southwest Research Institute® (SwRI®) and General Electric Global Research (GE-GR), along with the University of Wisconsin and Natural Resources Canada (NRCan), is actively executing a project called “STEP” [Supercritical Transformational Electric Power project], to design, construct, commission, and operate an integrated and reconfigurable 10 MWe sCO2 [supercritical CO2] Pilot Plant Test Facility located at SwRI’s San Antonio, Texas campus. The $119 million project is funded $84 million by the US DOE’s National Energy Technology Laboratory (NETL Award Number DE-FE0028979) and $35 million cost share by the team, component suppliers and others interested in sCO2 technology. This project is a significant step toward sCO2 cycle based power generation commercialization and will inform the performance, operability, and scale-up to commercial facilities. Supercritical CO2 (sCO2) power cycles are Brayton cycles that utilize supercritical CO2 working fluid to convert heat into power. They offer the potential for higher system efficiencies than other energy conversion technologies such as steam Rankine or organic Rankine cycles, especially when operating at elevated temperatures. sCO2 power cycles are being considered for a wide range of applications including fossil-fired systems, waste heat recovery, concentrated solar power, and nuclear. The pilot plant design, procurement, fabrication, and construction are ongoing at the time of this publication. By the end of this 6-year project, the operability of the sCO2 power cycle will be demonstrated and documented starting with facility commissioning as a simple closed recuperated cycle configuration initially operating at a 500°C (932°F) turbine inlet temperature and progressing to a recompression closed Brayton cycle technology (RCBC) configuration operating at 715°C (1319 °F).
{"title":"The STEP 10 MWe sCO2 Pilot Plant Demonstration","authors":"J. Marion, M. Kutin, Aaron Mcclung, J. Mortzheim, Robin W. Ames","doi":"10.1115/gt2019-91917","DOIUrl":"https://doi.org/10.1115/gt2019-91917","url":null,"abstract":"\u0000 A team led by Gas Technology Institute (GTI), Southwest Research Institute® (SwRI®) and General Electric Global Research (GE-GR), along with the University of Wisconsin and Natural Resources Canada (NRCan), is actively executing a project called “STEP” [Supercritical Transformational Electric Power project], to design, construct, commission, and operate an integrated and reconfigurable 10 MWe sCO2 [supercritical CO2] Pilot Plant Test Facility located at SwRI’s San Antonio, Texas campus. The $119 million project is funded $84 million by the US DOE’s National Energy Technology Laboratory (NETL Award Number DE-FE0028979) and $35 million cost share by the team, component suppliers and others interested in sCO2 technology. This project is a significant step toward sCO2 cycle based power generation commercialization and will inform the performance, operability, and scale-up to commercial facilities.\u0000 Supercritical CO2 (sCO2) power cycles are Brayton cycles that utilize supercritical CO2 working fluid to convert heat into power. They offer the potential for higher system efficiencies than other energy conversion technologies such as steam Rankine or organic Rankine cycles, especially when operating at elevated temperatures. sCO2 power cycles are being considered for a wide range of applications including fossil-fired systems, waste heat recovery, concentrated solar power, and nuclear.\u0000 The pilot plant design, procurement, fabrication, and construction are ongoing at the time of this publication. By the end of this 6-year project, the operability of the sCO2 power cycle will be demonstrated and documented starting with facility commissioning as a simple closed recuperated cycle configuration initially operating at a 500°C (932°F) turbine inlet temperature and progressing to a recompression closed Brayton cycle technology (RCBC) configuration operating at 715°C (1319 °F).","PeriodicalId":412490,"journal":{"name":"Volume 9: Oil and Gas Applications; Supercritical CO2 Power Cycles; Wind Energy","volume":"105 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124731967","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}
Gas foil thrust bearings have been utilized in high speed lightweight machines for many decades. These bearings are environment-friendly and capable of withstanding extreme conditions. However, there are also some challenges for foil thrust bearings at high speed conditions, such as insufficient heat dissipation and thermal management. The heat generated by viscous shearing continues to raise the temperature inside the gas film and may cause failures. Among all the methods to enhance heat dissipation, a promising passive thermal management method is modifying the top foil’s trailing edge shape. This modification will enhance the air mixing in between the bearing pads. The aim of this study is to identify the optimal design of the top foil trailing edge shape and provide a guideline for future bearing design. A 3-D computational fluid dynamics (CFD) model for a thrust foil bearing was created using ANSYS-CFX software. The trailing edge of the top foil was modified to a chevron shape. A sensitivity study was conducted to investigate the connection between the top foil trailing edge shape and the thermal conditions in the gas film. The maximum temperature inside the air gas film is selected as the output. The design of experiments (DOE) technique was used to generate the sampling points. A surrogate model was generated based on the output data by using the neural network method. The surrogate model was used together with a genetic multi-objective algorithm to minimize the maximal temperature inside the gas film and maximize the load carrying capacity. The optimal design was then compared with the baseline model. Results suggest the optimized trailing edge shape is capable of reducing the temperature inside the gas film. This optimal design approach can be used for improvements of chevron foil thrust bearing design.
{"title":"Surrogate Model Based Optimization for Chevron Foil Thrust Bearing","authors":"A. Untăroiu, Gen Fu","doi":"10.1115/gt2019-90228","DOIUrl":"https://doi.org/10.1115/gt2019-90228","url":null,"abstract":"\u0000 Gas foil thrust bearings have been utilized in high speed lightweight machines for many decades. These bearings are environment-friendly and capable of withstanding extreme conditions. However, there are also some challenges for foil thrust bearings at high speed conditions, such as insufficient heat dissipation and thermal management. The heat generated by viscous shearing continues to raise the temperature inside the gas film and may cause failures. Among all the methods to enhance heat dissipation, a promising passive thermal management method is modifying the top foil’s trailing edge shape. This modification will enhance the air mixing in between the bearing pads.\u0000 The aim of this study is to identify the optimal design of the top foil trailing edge shape and provide a guideline for future bearing design. A 3-D computational fluid dynamics (CFD) model for a thrust foil bearing was created using ANSYS-CFX software. The trailing edge of the top foil was modified to a chevron shape. A sensitivity study was conducted to investigate the connection between the top foil trailing edge shape and the thermal conditions in the gas film. The maximum temperature inside the air gas film is selected as the output. The design of experiments (DOE) technique was used to generate the sampling points. A surrogate model was generated based on the output data by using the neural network method. The surrogate model was used together with a genetic multi-objective algorithm to minimize the maximal temperature inside the gas film and maximize the load carrying capacity. The optimal design was then compared with the baseline model. Results suggest the optimized trailing edge shape is capable of reducing the temperature inside the gas film. This optimal design approach can be used for improvements of chevron foil thrust bearing design.","PeriodicalId":412490,"journal":{"name":"Volume 9: Oil and Gas Applications; Supercritical CO2 Power Cycles; Wind Energy","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123113807","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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