Mark Patterson, Nelson Xie, Kyle Beurlot, Timothy J. Jacobs, Daniel B. Olsen
Although pre-combustion chambers, or prechambers, have long been employed for improving large-bore two-stroke natural gas engine ignition and combustion stability, their design predates modern analysis techniques. Employing the latest CFD modeling techniques, this study investigates the importance of temperature and chemistry for ignition of the main chamber, with an emphasis on eliminating unburned methane. The sensitivity of the ignition and complete combustion to main chamber air/fuel mixture homogeneity was also explored. This study compares the effect of purely thermal ignition, purely chemical ignition, and how their interplay can influence the complete combustion of methane in typical mixtures and in homogeneous distributions of fuel in the combustion chamber. The CFD results demonstrated that temperature and chemistry are equally important in the ignition mechanism, and combining the two phenomena is effective at igniting the main chamber. Reduction of residual methane in the main combustion chamber is most effective when chemical intermediates and thermal ignition are combined. A rudimentary analysis of the effect of fuel/air stratification was also conducted, and it demonstrated that a dramatic reduction in methane emissions is observed for homogeneous mixtures. The flow field in the main combustion chamber was shown to create detrimental stratification of the fuel/air mixture, which inhibited complete combustion of the methane in the main chamber. By contrast, in the extreme case of a perfectly homogeneous distribution of both chemical intermediates and fuel in the combustion chamber, it is possible to completely eliminate unburned methane in the main combustion chamber.
{"title":"Analysis of Unburned Methane Emission Mechanisms in Large-Bore Natural Gas Engines with Prechamber Ignition","authors":"Mark Patterson, Nelson Xie, Kyle Beurlot, Timothy J. Jacobs, Daniel B. Olsen","doi":"10.1115/1.4065313","DOIUrl":"https://doi.org/10.1115/1.4065313","url":null,"abstract":"\u0000 Although pre-combustion chambers, or prechambers, have long been employed for improving large-bore two-stroke natural gas engine ignition and combustion stability, their design predates modern analysis techniques. Employing the latest CFD modeling techniques, this study investigates the importance of temperature and chemistry for ignition of the main chamber, with an emphasis on eliminating unburned methane. The sensitivity of the ignition and complete combustion to main chamber air/fuel mixture homogeneity was also explored. This study compares the effect of purely thermal ignition, purely chemical ignition, and how their interplay can influence the complete combustion of methane in typical mixtures and in homogeneous distributions of fuel in the combustion chamber. The CFD results demonstrated that temperature and chemistry are equally important in the ignition mechanism, and combining the two phenomena is effective at igniting the main chamber. Reduction of residual methane in the main combustion chamber is most effective when chemical intermediates and thermal ignition are combined. A rudimentary analysis of the effect of fuel/air stratification was also conducted, and it demonstrated that a dramatic reduction in methane emissions is observed for homogeneous mixtures. The flow field in the main combustion chamber was shown to create detrimental stratification of the fuel/air mixture, which inhibited complete combustion of the methane in the main chamber. By contrast, in the extreme case of a perfectly homogeneous distribution of both chemical intermediates and fuel in the combustion chamber, it is possible to completely eliminate unburned methane in the main combustion chamber.","PeriodicalId":508252,"journal":{"name":"Journal of Engineering for Gas Turbines and Power","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140709706","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 is the first study where a single variable sweep of swirl number (SN) is conducted to assess its impact on lean blowout limits (LBO) in a liquid fueled Lean Direct Injection (LDI) combustor. This study uses a scaled NASA SV-LDI (Swirl Venturi - Lean Direct Injection) hardware and is concerned with the impact of swirl number on the lean blow out limit of a single element LDI system at atmospheric pressure. The SN was varied from 0.31 to 0.66 using continuously variable active SN control system that was developed in-house. It is shown that the minimum operating equivalence ratio is a linearly increasing function of swirl number. While previous literature agrees with the positive slope for this correlation, past work has insisted that the LBO limit is proportional to the swirler vane angle of swirl cup flame holders which is shown to be untrue for LDI systems. By actively varying the swirl number, it is proven that LBO is proportional to SN, and it is well known that SN is not proportional to swirler vane angle. Increased SN reduces LBO margin because the better-mixed, high swirl cases dilute locally rich pockets of fuel air mixture. In addition to a baseline venturi, which was scaled from NASA's geometry, two other venturis were tested. A low pressure loss venturi with a large throat diameter showed poor blow out performance where as a parabolically profiled venturi improved LBO over the baseline for the same swirl number.
这是首次对漩涡数（SN）进行单变量扫描，以评估其对液体燃料精益直喷（LDI）燃烧器中贫油喷出极限（LBO）的影响的研究。这项研究使用了按比例缩放的 NASA SV-LDI（漩涡文丘里-精益直接喷射）硬件，关注的是漩涡数对大气压下单元素 LDI 系统精益喷射极限的影响。使用内部开发的连续可变主动 SN 控制系统，SN 在 0.31 至 0.66 之间变化。结果表明，最小工作当量比是漩涡数的线性增加函数。虽然以前的文献同意这种相关性的正斜率，但过去的工作坚持认为 LBO 限制与漩涡杯火焰座的漩涡叶片角度成正比，这对于 LDI 系统来说是不正确的。通过积极改变漩涡数，可以证明 LBO 与 SN 成正比，而众所周知，SN 与漩涡叶片角度并不成正比。增加 SN 会减少 LBO 余量，因为混合更好的高漩涡会稀释局部富余的燃料空气混合物。除了根据 NASA 的几何尺寸缩放的基准文丘里管外，还测试了另外两个文丘里管。一个喉部直径较大的低压损文丘里管显示出较低的吹出性能，而一个抛物面文丘里管在相同漩涡数的情况下比基准文丘里管改善了 LBO。
{"title":"The Effect of Swirl Number On Lean Blow Out Limits of Lean Direct Injection Combustors","authors":"Yogesh Aradhey, Zackary Stroud, Joseph Meadows","doi":"10.1115/1.4065218","DOIUrl":"https://doi.org/10.1115/1.4065218","url":null,"abstract":"\u0000 This is the first study where a single variable sweep of swirl number (SN) is conducted to assess its impact on lean blowout limits (LBO) in a liquid fueled Lean Direct Injection (LDI) combustor. This study uses a scaled NASA SV-LDI (Swirl Venturi - Lean Direct Injection) hardware and is concerned with the impact of swirl number on the lean blow out limit of a single element LDI system at atmospheric pressure. The SN was varied from 0.31 to 0.66 using continuously variable active SN control system that was developed in-house. It is shown that the minimum operating equivalence ratio is a linearly increasing function of swirl number. While previous literature agrees with the positive slope for this correlation, past work has insisted that the LBO limit is proportional to the swirler vane angle of swirl cup flame holders which is shown to be untrue for LDI systems. By actively varying the swirl number, it is proven that LBO is proportional to SN, and it is well known that SN is not proportional to swirler vane angle. Increased SN reduces LBO margin because the better-mixed, high swirl cases dilute locally rich pockets of fuel air mixture. In addition to a baseline venturi, which was scaled from NASA's geometry, two other venturis were tested. A low pressure loss venturi with a large throat diameter showed poor blow out performance where as a parabolically profiled venturi improved LBO over the baseline for the same swirl number.","PeriodicalId":508252,"journal":{"name":"Journal of Engineering for Gas Turbines and Power","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140763902","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 evolution of in-cylinder flow involves small and large-scale structures during the intake and compression strokes, significantly influencing the fuel-air mixing and combustion processes. Extensive research has been conducted to investigate the flow evolution in medium to large-sized engines using laser-based diagnostic methods, computational fluid dynamics (CFD) simulations, and zero-dimensional (0-D) based modeling. However, in the present study, we provide a detailed analysis of the evolution of flow fields in a small-bore spark ignition engine with a displacement volume of 110 cm3. This analysis employs a unique methodology where CFD simulation is performed and validated using measured particle image velocimetry (PIV) data. Subsequently, the validated CFD results are utilized to develop and validate a 0-D-based model as it is computationally more efficient. The validated CFD simulation and 0-D-based model are used to evaluate the quantified strength of the flow fields by calculating the tumble ratio and turbulent kinetic energy (TKE). The streamlines and velocity vectors of the flow fields obtained from CFD simulations are utilized to explain the evolution of these parameters during intake and compression strokes. The study is further extended to analyze the effect of engine speed on the evolution of flow fields. With an increase in engine speed, relatively higher values of tumble ratio and TKE at the end of the compression stroke are observed, which is expected to improve the fuel-air mixing and combustion efficiency.
{"title":"Analysis of In-cylinder Flow in a Small-Bore Spark-Ignition Engine Using Computational Fluid Dynamics Simulations and Zero-Dimensional-Based Modeling","authors":"Chandra Kumar Chandrakar, Kartheeswaran A, Varunkumar S, Tnc Anand, Mayank Mittal","doi":"10.1115/1.4065168","DOIUrl":"https://doi.org/10.1115/1.4065168","url":null,"abstract":"\u0000 The evolution of in-cylinder flow involves small and large-scale structures during the intake and compression strokes, significantly influencing the fuel-air mixing and combustion processes. Extensive research has been conducted to investigate the flow evolution in medium to large-sized engines using laser-based diagnostic methods, computational fluid dynamics (CFD) simulations, and zero-dimensional (0-D) based modeling. However, in the present study, we provide a detailed analysis of the evolution of flow fields in a small-bore spark ignition engine with a displacement volume of 110 cm3. This analysis employs a unique methodology where CFD simulation is performed and validated using measured particle image velocimetry (PIV) data. Subsequently, the validated CFD results are utilized to develop and validate a 0-D-based model as it is computationally more efficient. The validated CFD simulation and 0-D-based model are used to evaluate the quantified strength of the flow fields by calculating the tumble ratio and turbulent kinetic energy (TKE). The streamlines and velocity vectors of the flow fields obtained from CFD simulations are utilized to explain the evolution of these parameters during intake and compression strokes. The study is further extended to analyze the effect of engine speed on the evolution of flow fields. With an increase in engine speed, relatively higher values of tumble ratio and TKE at the end of the compression stroke are observed, which is expected to improve the fuel-air mixing and combustion efficiency.","PeriodicalId":508252,"journal":{"name":"Journal of Engineering for Gas Turbines and Power","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140380315","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}
Health parameter estimation is the core of engine Gas Path Analysis (GPA), which is widely adopted for engine safety improvement, as well as for operation and maintenance cost reduction. The major challenge of GPA lies in the contradiction between the high dimensions of parameters under estimation, e.g., health parameters, and the limited measurements obtainable from a small number of sensors. Existent GPA methods for health parameters commonly apply dimension reduction before estimation, leading to information loss and hence inaccurate estimation. To tackle the challenge of limited sensor measurements and to have more system outputs than parameters under estimation, we proposed to augment the output vector of the system model by combining the measurements from multiple adjacent operating points. But the engine model can face the problem of homogenization if using data from adjacent operating points. This can in turn leads to a low identifiability of parameters. We analyze the internal mechanism of such large deviation of the parameter estimation results based on linear models and argue for the need of nonlinear method. Hence, we propose a multi-stage nonlinear parameter estimation method for health parameters, combining biased and unbiased estimation. In our extensive simulations based on 10 output measurements of a JT9D engine, our method can estimate 130% more parameters than the widely-used GPA method, while reducing the maximum estimation error of health parameters from 2.2% to 0.1%.
{"title":"A Multi-Stage Nonlinear Method for Aeroengine Health Parameter Estimation Based on Adjacent Operating Points","authors":"Kai Liu, Quanyong Xu, Jihong Zhu","doi":"10.1115/1.4065191","DOIUrl":"https://doi.org/10.1115/1.4065191","url":null,"abstract":"\u0000 Health parameter estimation is the core of engine Gas Path Analysis (GPA), which is widely adopted for engine safety improvement, as well as for operation and maintenance cost reduction. The major challenge of GPA lies in the contradiction between the high dimensions of parameters under estimation, e.g., health parameters, and the limited measurements obtainable from a small number of sensors. Existent GPA methods for health parameters commonly apply dimension reduction before estimation, leading to information loss and hence inaccurate estimation. To tackle the challenge of limited sensor measurements and to have more system outputs than parameters under estimation, we proposed to augment the output vector of the system model by combining the measurements from multiple adjacent operating points. But the engine model can face the problem of homogenization if using data from adjacent operating points. This can in turn leads to a low identifiability of parameters. We analyze the internal mechanism of such large deviation of the parameter estimation results based on linear models and argue for the need of nonlinear method. Hence, we propose a multi-stage nonlinear parameter estimation method for health parameters, combining biased and unbiased estimation. In our extensive simulations based on 10 output measurements of a JT9D engine, our method can estimate 130% more parameters than the widely-used GPA method, while reducing the maximum estimation error of health parameters from 2.2% to 0.1%.","PeriodicalId":508252,"journal":{"name":"Journal of Engineering for Gas Turbines and Power","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140378148","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}
Bin Bai, Xiang Li, Xingzhong Zeng, Minghui Yao, Niu Yan, Junfeng Man, Zhiqiang Tao
To improve the performance and reduce the vibration of the mistuned blisk, a novel approach combining the hard-coating and multi-packets is presented. Firstly, the dynamical models of the blisk without hard-coating and multi-packets, the hard-coated mistuned blisk without multi-packets, and the hard-coated mistuned blisk with multi-packets, are established based on the lumped parameter model (LPM). Then, the solved results are compared with that of previous literature to validate the feasibility and correctness of the proposed models. Furthermore, the characteristics of the natural frequencies and the vibration responses for the mistuned blisk are investigated by proposed LPMs. Finally, the effect of the hard-coating and multi-packets on the vibration characteristics for the mistuned blisk are discussed. The obtained results manifest that the vibration response of the mistuned blisk can be further suppressed when the hard-coating and the multi-packets are considered simultaneously compared with only the hard-coating or multi-packets considered, which provides useful guidance on the vibration reduction for the mistuned blisk.
{"title":"Vibration Characteristics Investigation of Hard-Coated Mistuned Blisk With Multi-Packets By Lumped Parameter Model","authors":"Bin Bai, Xiang Li, Xingzhong Zeng, Minghui Yao, Niu Yan, Junfeng Man, Zhiqiang Tao","doi":"10.1115/1.4065141","DOIUrl":"https://doi.org/10.1115/1.4065141","url":null,"abstract":"\u0000 To improve the performance and reduce the vibration of the mistuned blisk, a novel approach combining the hard-coating and multi-packets is presented. Firstly, the dynamical models of the blisk without hard-coating and multi-packets, the hard-coated mistuned blisk without multi-packets, and the hard-coated mistuned blisk with multi-packets, are established based on the lumped parameter model (LPM). Then, the solved results are compared with that of previous literature to validate the feasibility and correctness of the proposed models. Furthermore, the characteristics of the natural frequencies and the vibration responses for the mistuned blisk are investigated by proposed LPMs. Finally, the effect of the hard-coating and multi-packets on the vibration characteristics for the mistuned blisk are discussed. The obtained results manifest that the vibration response of the mistuned blisk can be further suppressed when the hard-coating and the multi-packets are considered simultaneously compared with only the hard-coating or multi-packets considered, which provides useful guidance on the vibration reduction for the mistuned blisk.","PeriodicalId":508252,"journal":{"name":"Journal of Engineering for Gas Turbines and Power","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140223223","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}
Ambikapathy Naganathan, Billy G Holland, C. Demirdogen
Exhaust manifolds in diesel engines undergo continuous thermal cycle loading of varying thermal cycles with different mean, amplitude, and rate of temperature change created by application duty cycles. This makes analysis and testing of the exhaust manifold to meet the thermal mechanical fatigue life expectation of different applications challenging. In this paper a simulation-based product development approach which uses application duty cycles, simulation models of different capabilities including 3D Finite element simulation model, 1-D physis based damage model to develop an abusive thermal cycle engine test for validating exhaust manifold is presented.
{"title":"Simulation Based Thermal Fatigue Validation Test Development for Exhaust Manifold","authors":"Ambikapathy Naganathan, Billy G Holland, C. Demirdogen","doi":"10.1115/1.4065112","DOIUrl":"https://doi.org/10.1115/1.4065112","url":null,"abstract":"\u0000 Exhaust manifolds in diesel engines undergo continuous thermal cycle loading of varying thermal cycles with different mean, amplitude, and rate of temperature change created by application duty cycles. This makes analysis and testing of the exhaust manifold to meet the thermal mechanical fatigue life expectation of different applications challenging. In this paper a simulation-based product development approach which uses application duty cycles, simulation models of different capabilities including 3D Finite element simulation model, 1-D physis based damage model to develop an abusive thermal cycle engine test for validating exhaust manifold is presented.","PeriodicalId":508252,"journal":{"name":"Journal of Engineering for Gas Turbines and Power","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140229315","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}
Zhijia Yang, Byron Mason, Brian Wooyeol Bae, Fabrizio Bonatesta, E. Winward, Richard Burke, Ed Chappell
Piston surface temperature is an important factor in reducing harmful emissions in modern Gasoline Direct Injection engines. In transient operation, the piston surface temperature can change rapidly, increasing the risk of fuel puddling. The prediction of the piston surface temperature provides the means to significantly improve multiple-pulse fuel injection strategies by avoiding fuel puddling. It can also be used to intelligently control the Piston Cooling Jet (PCJ) which are common on modern engines. Considerable research has been undertaken to identify generalized engine heat transfer correlations and to predict piston and cylinder wall surface temperatures during operation. Most of these correlations require in-cylinder combustion pressure as an input, as well as the identification of numerous model parameters, these render such an approach impractical. In this study, the authors have developed a thermodynamic model of piston surface temperature based on the Global Energy Balance (GEB) methodology, which includes the effect of PCJ activation. The advantages are the simple structure, no requirement for in-cylinder pressure data, and only limited experimental tests are needed for model parameter identification. Moreover, the proposed model works well during engine transient operation, with maximum average error of 6.68% during rapid transients. A detailed identification procedure is given. This, and the model performance, have been demonstrated using experimental piston crown surface temperature data from a prototype 1-liter 3-cylinder turbocharged GDI engine, operated in both engine steady-state and transient conditions with an oil jet used for piston cooling turned both on and off.
{"title":"Estimation of Piston Surface Temperature During Engine Transient Operation for Emissions Reduction","authors":"Zhijia Yang, Byron Mason, Brian Wooyeol Bae, Fabrizio Bonatesta, E. Winward, Richard Burke, Ed Chappell","doi":"10.1115/1.4065061","DOIUrl":"https://doi.org/10.1115/1.4065061","url":null,"abstract":"\u0000 Piston surface temperature is an important factor in reducing harmful emissions in modern Gasoline Direct Injection engines. In transient operation, the piston surface temperature can change rapidly, increasing the risk of fuel puddling. The prediction of the piston surface temperature provides the means to significantly improve multiple-pulse fuel injection strategies by avoiding fuel puddling. It can also be used to intelligently control the Piston Cooling Jet (PCJ) which are common on modern engines. Considerable research has been undertaken to identify generalized engine heat transfer correlations and to predict piston and cylinder wall surface temperatures during operation. Most of these correlations require in-cylinder combustion pressure as an input, as well as the identification of numerous model parameters, these render such an approach impractical. In this study, the authors have developed a thermodynamic model of piston surface temperature based on the Global Energy Balance (GEB) methodology, which includes the effect of PCJ activation. The advantages are the simple structure, no requirement for in-cylinder pressure data, and only limited experimental tests are needed for model parameter identification. Moreover, the proposed model works well during engine transient operation, with maximum average error of 6.68% during rapid transients. A detailed identification procedure is given. This, and the model performance, have been demonstrated using experimental piston crown surface temperature data from a prototype 1-liter 3-cylinder turbocharged GDI engine, operated in both engine steady-state and transient conditions with an oil jet used for piston cooling turned both on and off.","PeriodicalId":508252,"journal":{"name":"Journal of Engineering for Gas Turbines and Power","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140245698","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}
With the planned future reliance on variable renewable energy, the ability to store energy for prolonged time periods will be required to reduce the disruption of market fluctuations. This paper presents a method to analyze a hybrid liquid-oxygen (LOx) storage / direct-fired sCO2 power cycle and optimize the economic performance over a diverse range of scenarios. The system utilizes a modified version of the NET Power process to produce energy when energy demand exceeds the supply while displacing much of the cost of the ASU energy requirements through cryogenic storage of oxygen. The model uses marginal cost of energy data to determine the optimal times to charge and discharge the system over a given scenario. The model then applies ramp rates and other time-dependent factors to generate an economic model for the system without storage considerations. The size of the storage system is then applied to create a realistic model of the plant operation. From the real plant operation model, the amount of energy charged and discharged, the CAPEX of each system, energy costs and revenue and other parameters can be calculated. The economic parameters are then combined to calculate the net present value (NPV) of the system for the given scenario. The model was then run through the SMPSO genetic algorithm in Python for a variety of geographic regions and large-scale scenarios (high solar penetration) to maximize the NPV based on multiple parameters for each subsystem. The LOx storage requirements will also be discussed.
随着未来对可再生能源可变性的依赖，需要具备长时间储能的能力，以减少市场波动带来的干扰。本文介绍了一种分析混合液氧（LOx）存储/直燃二氧化碳发电循环的方法，以及在各种情况下优化经济效益的方法。该系统利用改进版的 NET Power 流程，在能源供不应求时生产能源，同时通过低温储存氧气取代 ASU 能源需求的大部分成本。该模型使用边际能源成本数据来确定在特定情况下系统的最佳充放电时间。然后，该模型应用斜率和其他随时间变化的因素，生成一个不考虑储存因素的系统经济模型。然后再应用储能系统的大小来创建一个真实的电厂运行模型。通过真实的电站运行模型，可以计算出充放电能量、每个系统的资本支出、能源成本和收入以及其他参数。然后将这些经济参数结合起来，计算出给定情景下系统的净现值 (NPV)。然后通过 Python 中的 SMPSO 遗传算法对各种地理区域和大规模场景（高太阳能渗透率）运行该模型，以根据每个子系统的多个参数最大化净现值。此外，还将讨论 LOx 存储要求。
{"title":"Oxygen Storage Incorporated Into Net Power And The Allam-Fetvedt Oxy-Fuel Sco2 Power Cycle - Technoeconomic Analysis","authors":"J. J. Moore, Owen Pryor, Ian Cormier, J. Fetvedt","doi":"10.1115/1.4065048","DOIUrl":"https://doi.org/10.1115/1.4065048","url":null,"abstract":"\u0000 With the planned future reliance on variable renewable energy, the ability to store energy for prolonged time periods will be required to reduce the disruption of market fluctuations. This paper presents a method to analyze a hybrid liquid-oxygen (LOx) storage / direct-fired sCO2 power cycle and optimize the economic performance over a diverse range of scenarios. The system utilizes a modified version of the NET Power process to produce energy when energy demand exceeds the supply while displacing much of the cost of the ASU energy requirements through cryogenic storage of oxygen. The model uses marginal cost of energy data to determine the optimal times to charge and discharge the system over a given scenario. The model then applies ramp rates and other time-dependent factors to generate an economic model for the system without storage considerations. The size of the storage system is then applied to create a realistic model of the plant operation. From the real plant operation model, the amount of energy charged and discharged, the CAPEX of each system, energy costs and revenue and other parameters can be calculated. The economic parameters are then combined to calculate the net present value (NPV) of the system for the given scenario. The model was then run through the SMPSO genetic algorithm in Python for a variety of geographic regions and large-scale scenarios (high solar penetration) to maximize the NPV based on multiple parameters for each subsystem. The LOx storage requirements will also be discussed.","PeriodicalId":508252,"journal":{"name":"Journal of Engineering for Gas Turbines and Power","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140250394","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}
Zhewen Xu, Xin Lin, Min Chen, Hailong Tang, Jiyuan Zhang
The Adaptive Cycle Engine (ACE) has multiple coupled components on the same spool and complex bypass system, which makes it have more complex inter-component coupling relation and hard to coordinate in the flow path design. In this study, the coupling relation of the ACE components and the component reference conditions are analyzed and determined, a multi-component collaborative optimization design method is proposed to enable the quantitative evaluation of flow path design solutions. In this method, two optimization strategies are presented based on the different priorities of the inter-component size coupling parameters, the inter-component aerodynamic coupling parameter and the component performance in the optimization problem. ACE flow path solutions for various feasible design speed combinations are generated automatically considering the component performance and inter-component coupling relation. According to an ACE flow path design case study, the design physical rotational speeds of low-pressure spool (NL,d) and high-pressure spool (NH,d) should be 7000 to 7600 r/min and 10000 to 15000 r/min, respectively. At NH,d=12000 r/min and NL,d=7200 r/min, the high-pressure compression components and the fan components could be designed with the lowest aerodynamic load, respectively. NH,d is the key factor affecting the axial length of ACE. This method can be applied to other gas power plant designs.
{"title":"Comprehensive Flow Path Design Method for the Adaptive Cycle Engine Considering the Coupling Relation of Multiple Components","authors":"Zhewen Xu, Xin Lin, Min Chen, Hailong Tang, Jiyuan Zhang","doi":"10.1115/1.4065049","DOIUrl":"https://doi.org/10.1115/1.4065049","url":null,"abstract":"\u0000 The Adaptive Cycle Engine (ACE) has multiple coupled components on the same spool and complex bypass system, which makes it have more complex inter-component coupling relation and hard to coordinate in the flow path design. In this study, the coupling relation of the ACE components and the component reference conditions are analyzed and determined, a multi-component collaborative optimization design method is proposed to enable the quantitative evaluation of flow path design solutions. In this method, two optimization strategies are presented based on the different priorities of the inter-component size coupling parameters, the inter-component aerodynamic coupling parameter and the component performance in the optimization problem. ACE flow path solutions for various feasible design speed combinations are generated automatically considering the component performance and inter-component coupling relation. According to an ACE flow path design case study, the design physical rotational speeds of low-pressure spool (NL,d) and high-pressure spool (NH,d) should be 7000 to 7600 r/min and 10000 to 15000 r/min, respectively. At NH,d=12000 r/min and NL,d=7200 r/min, the high-pressure compression components and the fan components could be designed with the lowest aerodynamic load, respectively. NH,d is the key factor affecting the axial length of ACE. This method can be applied to other gas power plant designs.","PeriodicalId":508252,"journal":{"name":"Journal of Engineering for Gas Turbines and Power","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140250675","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}
Aerodynamic instability plays an important role in compressor design and may cause performance degradation and fatigue damage. In this paper, an experimental study on the evolution of aerodynamic instability is carried out on a compressor that combines the performance benefits of an axial stage and centrifugal stage. The spatiotemporal characteristics of unsteady wall pressure were obtained using fast-responding pressure transducers over a range of operating conditions. The results show that the axial stage works on the positive slope of the performance characteristic curve from choke to stall at low-speed operating conditions, and mainly features rotating instability. Rotating stall is also observed in the impeller (IMP) and diffuser passages. At medium-speed operating conditions, the centrifugal stage suffers a high-frequency mild surge, alternating with rotating stall. With the increase in back pressure, the mild surge diminishes, and rotating stall persists. This behavior is similar to a two-regime-surge, which has been reported for centrifugal compressors. At high-speed operating conditions, the compressor directly reaches surge without other instabilities. Further analysis of the spatial pattern of the rotating stall revealed the existence of a high-pressure region near the volute tongue, resulting in obvious pressure distortion along the circumferential direction at the volute inlet. This induced the amplitude difference of stall cells in corresponding diffuser passages. The disturbance caused by stall cells propagates upstream through the blade passage, and the largest pressure disturbance induced by the stall cell propagation appears in a circumferential position 45 deg downstream of the volute tongue at the impeller inlet and the axial stage inlet.
{"title":"Experimental Investigation on the Aerodynamic Instability Process of a High-Speed Axial-Centrifugal Compressor","authors":"Jiaan Li, Baotong Wang, Xuedong Zheng, Zhiheng Wang, Xinqian Zheng","doi":"10.1115/1.4064624","DOIUrl":"https://doi.org/10.1115/1.4064624","url":null,"abstract":"\u0000 Aerodynamic instability plays an important role in compressor design and may cause performance degradation and fatigue damage. In this paper, an experimental study on the evolution of aerodynamic instability is carried out on a compressor that combines the performance benefits of an axial stage and centrifugal stage. The spatiotemporal characteristics of unsteady wall pressure were obtained using fast-responding pressure transducers over a range of operating conditions. The results show that the axial stage works on the positive slope of the performance characteristic curve from choke to stall at low-speed operating conditions, and mainly features rotating instability. Rotating stall is also observed in the impeller (IMP) and diffuser passages. At medium-speed operating conditions, the centrifugal stage suffers a high-frequency mild surge, alternating with rotating stall. With the increase in back pressure, the mild surge diminishes, and rotating stall persists. This behavior is similar to a two-regime-surge, which has been reported for centrifugal compressors. At high-speed operating conditions, the compressor directly reaches surge without other instabilities. Further analysis of the spatial pattern of the rotating stall revealed the existence of a high-pressure region near the volute tongue, resulting in obvious pressure distortion along the circumferential direction at the volute inlet. This induced the amplitude difference of stall cells in corresponding diffuser passages. The disturbance caused by stall cells propagates upstream through the blade passage, and the largest pressure disturbance induced by the stall cell propagation appears in a circumferential position 45 deg downstream of the volute tongue at the impeller inlet and the axial stage inlet.","PeriodicalId":508252,"journal":{"name":"Journal of Engineering for Gas Turbines and Power","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140253700","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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