Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines最新文献

{"title":"A Biogas Fuelled Micro Gas Turbine: Energetic Performance and Environmental Impact Analysis","authors":"F. Chiariello, F. Reale, R. Calabria, P. Massoli","doi":"10.1115/gt2019-91483","DOIUrl":"https://doi.org/10.1115/gt2019-91483","url":null,"abstract":"\u0000 The use of biogas in micro gas turbines (MGTs) generally requires invasive structural modifications to fuel compression units, control valves and combustor. Costs associated with the modifications significantly reduce the benefits of a rational and sustainable exploitation of energy resources of lower value as the biogas.\u0000 In order to overcome this aspect, in a recent paper the authors proposed a dual fuel approach, identifying a structurally non-invasive and cost-effective technical solution to increase the CO2 concentration in the fuel and to extend the operation domain of the MGT when low calorific value fuels are used. In that study, it has been evaluated, implemented and tested an innovative management strategy of fuel feeding and combustion. Experimental preliminary tests validated the idea of a new supply strategy for exceeding the current limits of biogas exploitation as MGT fuel.\u0000 With this approach the MGT operating domain has been extended, increasing more than twice the CO2 concentration limit than experimentally validated limit available in literature.\u0000 In this study the authors present a more extensive investigation concerning the energetic performance and the environmental impact of a 100 kWe MGT Turbec T100 when fuelled with a mixture of natural gas and carbon dioxide (synthesis biogas) in the dual fuel approach, by varying CO2 concentration in the fuel at part load condition.\u0000 The data acquired by an extensive experimental campaign, in terms of thermodynamic parameters and gaseous exhaust emissions, are presented and compared with the results of numerical simulations.\u0000 A 3D CFD analysis of the combustion process is also presented. Initial and boundary conditions of the numerical approach were obtained from a previous validated 0D thermodynamic matching model.\u0000 The synergistic activity between numerical modeling and experimental work allows to analyze and explain the overall behavior of the micro gas turbine in the dual fuel mode with biogas fuel.\u0000 The study shows that the micro gas turbine can stably operate in a dual fuel mode until the CO2 content rises above 25%.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125730196","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}

{"title":"Design and Manufacturing of a Metal 3D Printed kW Scale Axial Turboexpander","authors":"V. Novotny, Monika Vitvarová, M. Kolovratník, B. B. Stunová, V. Vodicka, J. Spale, P. Zikmund, M. Drasnar, Elizaveta Schastlivtseva","doi":"10.1115/gt2019-91822","DOIUrl":"https://doi.org/10.1115/gt2019-91822","url":null,"abstract":"\u0000 Greater expansion of distributed power and process systems based on thermodynamic cycles with single to hundred kW scale power output is limited mainly there are not available cost-effective expanders.\u0000 Turboexpanders have a perspective of high efficiency and flexibility concerning operating parameters even for the micro applications. However, they suffer from a high manufacturing cost and lead time in the development of traditional technologies (such as casting and machining processes).\u0000 Additive manufacturing provides a possibility to overcome some of the issues. Manufacturing parts with complicated shapes by this technology, combining multiple components into a single part or rapid production by 3D printing for development purposes are among the prospective features with this potential. On the other hand, the 3D printing processes come with certain limitations which need to be overcome.\u0000 This paper shows a design and manufacturing process of a 3 kW axial impulse air turbine working with isenthalpic drop 30 kJ/kg. Several samples to verify printing options and the turbine itself has been manufactured from stainless steel by the DMLS additive manufacturing method. Manufactured are two turbine variations regarding blade size and 3D printer settings while maintaining their specific dimensions. The turboexpanders testing method and rig is outlined. As the surface quality is an issue, several methods of post-processing of 3D printed stator and rotor blading to modify surface quality are suggested. Detailed experimental investigation is however subject of future work.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133607557","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}

{"title":"High Power Steam Turbine Lifetime Increase by Means of Front End Seal Arrangement and Start-Up Heating Conditions Improvement","authors":"L. Moroz, R. Kochurov, J. Bakhmutska, V. Goloshchapov","doi":"10.1115/gt2019-90437","DOIUrl":"https://doi.org/10.1115/gt2019-90437","url":null,"abstract":"\u0000 Use of high power steam turbines in maneuver regimes by power plants became a widely-distributed practice in chase of short-term economic benefits. At the same time, these actions resulted in much higher levels of lifetime consumption for turbines which are not designed for high numbers of start-ups.\u0000 The purpose of the present study is to improve operational flexibility for 325 MW steam turbine through design modifications.\u0000 For the accurate simulation of rotor thermo-structural state and lifetime, an improved methodology was developed. The approach allows engineers to account for the steam film condensation process and the steam flow physics for regions with the anticipated high-stress levels at front-end seal zone, and the influence of the inter-casing space steam film condensation on the flow parameters in the front-end seals chambers.\u0000 Based on the simulation results for the 325 MW supercritical steam turbine HP rotor, the design changes of the front-end seal arrangement and heating conditions modification during the pre-warming phase are proposed. The results show that the proposed changes make it possible to provide a more uniform heating and lower thermo-stress level for the high-pressure cylinder rotor at the front-end seal region during the pre-warming phase, which results in an increased allowable number of turbine start-ups.\u0000 The influence of heating conditions on thermo-stresses and low cycle fatigue lifetime for the baseline and modified designs as well as modeling details for transient thermo-structural analysis have been discussed.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"129 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132504853","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}

{"title":"Unsteady Aerodynamics on Multi-Passage LP Last Stage Induced by Flow Separation Under Low Load Flow","authors":"Jing Zhang, Danmei Xie, Fan Wu, Haifen Du, Wei Chen","doi":"10.1115/gt2019-90661","DOIUrl":"https://doi.org/10.1115/gt2019-90661","url":null,"abstract":"\u0000 With the rapid development of renewable energy generation, the requirement for operational flexibility of power plants has increased. This has led to steam turbine operating frequently at low load flow conditions.\u0000 This paper focuses on the investigation of unsteady aerodynamic excitation in the last stage of LP under low load flow, which was conducted by assuming one single passage, to provide detailed flow information for optimization design. We present a numerical investigation of unsteady pressure forces on Multi-passage LP last blade rows caused by flow separation under low load flow. The flow field of the turbine was calculated by transient 3D computational fluid dynamic (ANSYS CFX16.0).\u0000 The results indicate the vortex strength induced by high incidence angle under low load flow having the characteristic of spatial non-uniformity and time non-uniformity. We found that the unsteady pressure forces on the rotor are significantly influenced by the separation vortex and have different phase pressure fluctuation between neighboring two rotor blades. The variation in the forces indicates that the neighboring rotor blades experience a load imbalance at every time step which may results in oscillation in the last long moving blades. In particular, the tip vortex plays a crucial part in unsteady aerodynamics.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116607882","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}

{"title":"Thermo-Structural Analysis of Steam Turbine in Pre-Warming Operation With Hot Air","authors":"P. Łuczyński, Dennis Toebben, Lukas Pehle, M. Wirsum, W. Mohr, K. Helbig","doi":"10.1115/gt2019-90580","DOIUrl":"https://doi.org/10.1115/gt2019-90580","url":null,"abstract":"\u0000 In pursuit of flexibility improvements and extension of lifetime, a concept to pre-warm steam turbines using hot air was developed. In order to further optimize the pre-warming operation, an extensive numerical investigation is conducted to determine the time-dependent temperature and stress fields.\u0000 In this work, the transient thermal and structural analyses of an IP 19-stage steam turbine in pre-warming operation with hot air are presented. Based on the previous investigations, a hybrid (HFEM - numerical FEM and analytical) approach especially developed for this purpose is applied to efficiently calculate the solid body temperatures of a steam turbine in pre-defined pre-warming scenarios. The HFEM model utilizes the Nusselt number correlations to describe the heat transfer between the hot air and the turbine components in the flow channel. These correlations were developed based on unsteady CHT-simulations of multistage turbine models. In addition, most of the thermal energy in turbine pre-warming operation is transferred through vanes and blades. Therefore, the HFEM approach considers the thermal contact resistance (TCR) on the surfaces between vanes/casing and blades/rotor. After the calibration of the HFEM model with experimental data based on measurements of the natural cooling curve, the pre-warming processes for different pre-warming scenarios are simulated. Subsequently, the obtained temperature fields are imported to an FEM model in order to conduct a structural analysis, which, among other variables, includes the values and locations of highest stresses and displacements.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129676115","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}

{"title":"Development and Verification Tests of Titanium 50-Inch and 60-Inch Last Stage Blades for Steam Turbines","authors":"Shigeki Senoo, T. Kudo, H. Fukushima, K. Segawa, K. Sakakibara","doi":"10.1115/gt2019-90003","DOIUrl":"https://doi.org/10.1115/gt2019-90003","url":null,"abstract":"\u0000 Increasing the annulus area of the last stage in steam turbines provides an effective way of increasing power output and improving the efficiency by reducing the amount of lost kinetic energy. The 50-inch and 60-inch last stage blades, which provide some of the world’s largest exhaust annulus areas, have been developed for 3600 rpm and 3000 rpm units respectively. The blades are designed to suppress the increase in losses caused by the supersonic inflow, and to ensure reliability. This paper describes the verification of the aerodynamic performance through four-stage model steam turbine tests. In addition, the unsteady flow phenomena caused by shock wave interactions near the tip between the last stage stator and rotor are clarified by unsteady flow measurements and calculations.\u0000 The characteristic of total-to-static efficiencies and flow distributions measured with pneumatic five-hole probes are obtained as designed. Static pressure recovery is also confirmed by static pressure measurement on the exhaust hood walls and three-dimensional turbulent flow analysis.\u0000 Regarding the unsteady stator-rotor interactions, the flow fluctuations such as static pressures and flow angles become relatively larger, when the travelling bow shock waves emanating from upstream of the rotor leading edge impinge near the stator trailing edge, because the axial distance between the emanating and impinging position of the shock wave is smaller. The static pressure on the suction surface of the rotor blade becomes locally large when it comes to the same circumferential portion as the stator trailing edge. However, the mass flow rate and loss variations caused by the unsteadiness are small, because the inlet relative Mach number is as small as 1.25, so that the strength of the shock wave is small.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"507 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133500522","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}

{"title":"Innovative Mechanical Integrity Approaches for Steam Turbines: Industrial Needs","authors":"Henning Almstedt, Zeynep Yiğit-Rohde, Jürgen Havemann, T. Thiemann, M. Stadler","doi":"10.1115/gt2019-91633","DOIUrl":"https://doi.org/10.1115/gt2019-91633","url":null,"abstract":"\u0000 The increased installation of renewable energy resources results in a requirement for higher steam turbine cycling capabilities. In addition, there is a strong demand to save our environment by improved efficiency, as well as acceptable life-cycle costs whilst keeping a high level of reliability and availability. Optimization using state of the art deterministic methods for dimensioning of components is the traditional way addressing such challenges. The use of more advanced methods like fracture mechanics, assisted by probabilistic design are innovative alternatives that have been pushed significantly in recent years.\u0000 However, to fully exploit the latest developments of advanced engineering methods, acceptance criteria are essential. Due to the lack of specific steam-turbine standards for several calculation tasks, today acceptance criteria are often based on OEM internal standards and are part of the specific OEM know-how.\u0000 New methods require the definition or modification of existing acceptance criteria. In case of lack of acceptance criteria one option is to refer to available standards for industries dealing with comparable components, materials and loading conditions. An example is the adaption of acceptance criteria from pressure-vessel codes for high-pressure steam turbine components. The obvious advantage is the ease of use, but the drawback might be an unnecessary conservatism in the design. Another option is the development of acceptance criteria for advanced methods.\u0000 The main intent of the paper is to contribute to the discussion of acceptance criteria for the application of advanced design methods for steam turbine components. A selected steam-turbine example is discussed, acceptance criteria are compared with available standards and the need for the development of component specific criteria are highlighted.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"159 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126725218","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}

{"title":"Improvement of Steam Turbine Blade Foil With Biomimetic Design and its Influence on Aerodynamic Performance","authors":"Fan Wu, Danmei Xie, Jing Zhang, Hengliang Zhang, Chun Wang","doi":"10.1115/gt2019-91128","DOIUrl":"https://doi.org/10.1115/gt2019-91128","url":null,"abstract":"\u0000 To improve the steam turbines’ efficiency, researchers have put their efforts on blade foil design. Aiming at improve the aerodynamic performance of steam turbine at low load, this paper will study the effect of blade foil with bionics design on steam turbine aerodynamic performance, based on humpback whale’s fin. This paper mainly discusses a bionic foil design used on steam turbine. There are three main control parameters for each tubercle structure — amplitude, wavelength, and thickness. Taking the axial torque as the decisive consideration data and combining the vorticity diagram to analyze the flow, and on this basis, the influence of the vortex pair on the flow of the turbine blade is studied. The greater the torque, the stronger the function, so the steam turbines’ efficiency is higher.\u0000 The flow condition of the optimized blade shape is improved compared to the original blade shape because it fits the blade more closely and the separated flow vortex is suppressed.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129621149","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}

{"title":"Methodology to Optimize and Predict the Measurement Point Distribution for Compressor Mapping on the Hot-Gas Test Bench","authors":"H. Mai, A. Kaufmann, M. Vogt","doi":"10.1115/gt2019-91422","DOIUrl":"https://doi.org/10.1115/gt2019-91422","url":null,"abstract":"\u0000 Current and future legal requirements for internal combustion engines (ICE) are increasing the complexity of modern charging systems. Test system manufacturers are facing high demands in terms of hardware specifications and methods for turbocharger testing on a hot-gas test bench. Innovative test systems and methodologies help to improve the quality of the turbocharger and engine matching process and significantly optimize the operating strategy in engine process simulation, especially in the early development and design phase.\u0000 The compressor and turbine characteristic maps are the most important sources of information in order to quantify the performance of the turbocharger. This is achieved in practice by thermodynamically evaluating turbochargers on the hot-gas test bench under test conditions that are as close as possible to real engine operation conditions. Turbocharger compressor mapping relies on the measurement of pressure and temperature upstream and downstream of the compressor at designated operating points. For use in the turbocharger matching process, mostly equidistant points on the operation line between surge and choke are required. Comparison to Computational Fluid Dynamics (CFD) requires a higher density of measurement points, especially in the vicinity of maximum compressor efficiency to analyze different geometries. The requirement to measure different point distributions at fixed rotational speed is the logical consequence.\u0000 The primary objective of this paper is to develop and evaluate a methodology that allows different operating point distributions of compressor speed lines for the compressor mapping on the hot-gas test bench. The secondary objective deals with the prediction of the measurement points with respect to pressure ratio and volume flow rate at a fixed rotational speed. This facilitates the pre-selection of settings on the hot-gas test bench.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125286382","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}

{"title":"Flow-Driven Design Optimization of Centrifugal Compressor Volutes for Turbochargers","authors":"Andrea Tanganelli, G. Andreini, M. Rossini, F. Balduzzi, A. Bianchini, G. Ferrara","doi":"10.1115/gt2019-90867","DOIUrl":"https://doi.org/10.1115/gt2019-90867","url":null,"abstract":"\u0000 The design of the volute (in terms of area distribution and shape of the cross section) has a relevant impact on the efficiency and the operating range of a centrifugal compressor. This latter aspect is even more relevant in turbochargers, where the compressor has to cover a functioning range much wider than that of industrial applications. In addition, beyond conventional aerodynamic requirements, the design of the cross section shape is driven often in these applications also by space constraints imposed by the vehicle layout, leading to a variety of volute layouts. In a previous study, some of the authors highlighted the prospects of using the entropy generation rate to evaluate the losses within a volute, since this parameter allows an exact localization of irreversibilities. Starting from these results, the present study shows the suitability of this parameter as an indicator for the fine design optimization of the volute shape. A methodology is presented, which, based on the CFD computed contours of both the entropy generation rate and the total pressure, is able to drive the fine optimization of the volute cross-section at different azimuthal positions in order to maximize its efficiency. Multiple volute shapes are analysed in the paper and the effect of the operating conditions is accounted for by investigating different mass flow rates. The proposed approach indeed lead to a maximization of the volute efficiency with only a few trials and it could indeed provide room for future automatized fine optimization strategies.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"161 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122623607","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}