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

{"title":"Methane-Hydrogen Blends in Micro Gas Turbines: Comparison of Different Combustor Concepts","authors":"R. Tuccillo, M. C. Cameretti, R. D. Robbio, F. Reale, F. Chiariello","doi":"10.1115/gt2019-90229","DOIUrl":"https://doi.org/10.1115/gt2019-90229","url":null,"abstract":"\u0000 The paper deals with the analysis of the response of two different types of combustors equipping micro gas turbines, when supplied with methane–hydrogen mixtures. Besides the expected reduction in carbon dioxide production, several problems have to be considered concerning the possible increase in nitric oxide formation and flashback phenomena as well.\u0000 The two combustors approach the lean-premixed or RQL concept and the study is carried out with a number of CFD simulations based on detailed kinetic schemes and accurate turbulence models. Some preliminary experimental validations support the numerical modelling of the lean-premixed combustor, so encouraging the authors to proceed with the analysis of increasing hydrogen / methane ratios. The RQL type combustor offers, in addition, the possibility of an effective split of the injection into two different streams, with evident benefits in terms of nitric oxides reduction.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"18 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":"132741334","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":"Detailed Experimental Investigation of the Operational Parameters of a 30 kW Micro Gas Turbine","authors":"Oliver Kislat, J. Zanger, Thomas Krummrein, P. Kutne, M. Aigner","doi":"10.1115/gt2019-90709","DOIUrl":"https://doi.org/10.1115/gt2019-90709","url":null,"abstract":"Numerical studies discussing micro gas turbines (MGTs) as a basis for automotive range extenders can be found in literature. A comprehensive set of experimental measurement data for an MGT of adequate size, however, is currently not available. In this work, a test rig and demonstrator based on a 30 kWel liquid fueled MGT is built up. Its major components’ performance is characterized by measuring temperature and pressure at inlet and outlet, as well as corresponding fuel and air flows and the exhaust gas composition. A compressor bleed air tapping is installed to characterize the turbo components’ off-design behavior. Stationary load points and transient maneuvers are investigated. The presented data provide coherent information on the operational behavior and cycle parameters. This can be used to validate existing numerical investigations. It further provides a foundation to identify the optimization potential of MGT components and will serve as design baseline for subsequent optimization measures to meet the requirements of mobile applications.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"18 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":"120950761","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":"A Numerical Thermohydrodynamic Study of Fixed Pad Oil Lubricated Thrust Bearings","authors":"S. Dousti, P. Allaire, Jianming Cao, Bradley R. Nichols, T. Dimond","doi":"10.1115/gt2019-91596","DOIUrl":"https://doi.org/10.1115/gt2019-91596","url":null,"abstract":"\u0000 Hydrodynamic thrust bearings are vital components of rotating machinery and often undergo high axial loads and temperatures. High loads and the consequent shear heating result in high temperature development and viscosity drop of the lubricant. This phenomenon is captured in the solution of a three dimensional energy equation problem. The inlet flow temperature via a groove mixing model and its interaction with outflow from the previous pad is also included in the analysis. Traditionally, capturing the heat conduction at the lubricant solid interfaces in the energy solution for the fixed pad, lubricant, and rotating disk (runner) have faced significant convergence problems. In this study, an integrated method is proposed to remedy this issue. The effects of various model features on the computed results are investigated.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"38 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":"115969206","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":"Numerical Investigation of the Influence of Flow Deflection at the Upper Hood on Performance of Low Pressure Steam Turbine Exhaust Hoods","authors":"Dickson Munyoki, M. Schatz, D. Vogt","doi":"10.1115/gt2019-90391","DOIUrl":"https://doi.org/10.1115/gt2019-90391","url":null,"abstract":"\u0000 Most of the world’s power is produced by large steam turbines using fossil fuel, nuclear and geothermal energy.\u0000 The LP exhaust hoods of these turbines are known to contribute significantly to the losses within the turbine, hence a minor improvement in their performance, which results in a lower backpressure and thus higher enthalpy drop for the steam turbine, will give a considerable benefit in terms of fuel efficiency.\u0000 Understanding the flow field and the loss mechanisms within the exhaust hood of LP steam turbines is key to developing better optimized exhaust hood systems. A detailed analysis of loss generation within the exhaust hood was done by the authors [1]. It was found that most losses occur at the upper hood and are caused by the swirling flows, which mostly start at the diffuser outlet, especially for the top diffuser inlet sector flows that have a complex path to the condenser. The authors further numerically investigated the influence of hood height variation on performance of an LP turbine exhaust hood [2], which further contributed to the knowledge of the loss mechanisms.\u0000 With the loss mechanisms in exhaust hoods reasonably well understood, flow deflection at the upper hood is investigated in the current paper. The deflection is aimed at minimizing the intensity of the vortices formed thus reducing the exhaust losses. The deflector configurations analyzed are modifications of the walls of the reference configuration’s outer casing. The numerical models of the reference configuration which are based on a scaled axial-radial diffuser test rig operated by ITSM have already been validated by the authors at design and overload operating conditions and three tip jet Mach numbers (0, 0.4 and 1.2)[1].\u0000 Deflector configurations investigated are found to re-direct the flow at the upper hood and minimize the intensity of the swirling flows hence leading to improvement in performance of LP steam turbine exhaust hoods. The best performing deflector configuration is found to give a considerable improvement in performance of 20% at design load and 40% at overload both at tip jet Mach number of 0.4 (corresponding to shrouded last stage blades). At design load and tip jet Mach number of 1.2 (corresponding to unshrouded last stage blades), the improvement is found to be moderate. About 7% performance increase is observed.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"64 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":"126405787","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":"Effect of Blade Secular Change on Unsteady Flows in Middle Pressure First-Stage Steam Turbines","authors":"A. Uemura, Hironori Miyazawa, Takashi Furusawa, S. Yamamoto, K. Yonezawa, S. Umezawa","doi":"10.1115/gt2019-90644","DOIUrl":"https://doi.org/10.1115/gt2019-90644","url":null,"abstract":"\u0000 This paper presents the effect of blade secular changes in stator and rotor blade passages on unsteady flows through the first-stage in a middle pressure steam turbine. The scales from the boilers may collide with the stator and rotor blade surfaces, and the blades could become gradually thinned or adhered over time because of the collision. The secular-changed blades influence the performance of steam turbines and may further induce unexpected accidents. Therefore, the maintenance, repair, and overhaul (MRO) of steam turbines is essential. The optimization of MRO scheduling is quite crucial for electric power companies. We simulated unsteady steam flows through an actual middle pressure steam turbine working at a coal-fired power plant while setting manufactured and secular-changed blades. The shape of the secular-changed blades was measured from actual blades during overhaul. The numerical method developed at Tohoku University was employed for the simulation. The difference in the results between the manufactured and secular-changed blades is shown, and the effect of secular changes on unsteady flows is investigated. In addition, the possibility of utilizing the results in the MRO of real turbines is highlighted.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"161 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114048655","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":"Validation of Lifetime Models for Recuperator Foils Through Long-Term Laboratory and Engine Testing","authors":"S. Dryepondt, B. Pint","doi":"10.1115/gt2019-90927","DOIUrl":"https://doi.org/10.1115/gt2019-90927","url":null,"abstract":"\u0000 For the next-generation of turbine-based combined heat & power (CHP) systems, materials development can enable lower costs and higher efficiency, particularly for alloy foils used in the recuperator. To quantify the potential benefits, lifetime models are being developed for current chromia-forming alloys such as 625, 120, 310 and 709 (also called 2025Nb) as well as new alumina-forming austenitic (AFA) steels, which are much more oxidation resistant in exhaust gas. A combination of long-term laboratory (up to 30 kh) and field exposure data (up to 100 kh) are being used to develop and validate the model for operation at 650°–800°C.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"80 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":"114717404","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":"Steam Turbine Hot Standby: Electrical Pre-Heating Solution","authors":"Y. Kostenko, D. Veltmann, S. Hecker","doi":"10.1115/gt2019-90464","DOIUrl":"https://doi.org/10.1115/gt2019-90464","url":null,"abstract":"\u0000 Growing renewable energy generation share causes more irregular and more flexible operational regimes of conventional power plants than in the past. It leads to long periods without dispatch for several days or even weeks. As a consequence, the required pre-heating of the steam turbine leads to an extended power plant start-up time [1].\u0000 The current steam turbine Hot Standby Mode (HSM) contributes to a more flexible steam turbine operation and is a part of the Flex-Power Services™ portfolio [2].\u0000 HSM prevents the turbine components from cooling via heat supply using an electrical Trace Heating System (THS) after shutdowns [3]. The aim of the HSM is to enable faster start-up time after moderate standstills. HSM functionality can be extended to include the pre-heating option after longer standstills.\u0000 This paper investigates pre-heating of the steam turbine with an electrical THS. At the beginning, it covers general aspects of flexible fossil power plant operation and point out the advantages of HSM. Afterwards the technology of the trace heating system and its application on steam turbines will be explained. In the next step the transient pre-heating process is analyzed and optimized using FEA, CFD and analytic calculations including validation considerations. Therefor a heat transfer correlation for flexible transient operation of the HSM was developed. A typical large steam turbine with an output of up to 300MW was investigated. Finally the results are summarized and an outlook is given.\u0000 The results of heat transfer and conduction between and within turbine components are used to enable fast start-ups after long standstills or even outages with the benefit of minimal energy consumption. The solution is available for new apparatus as well as for the modernization of existing installations.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"18 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":"128871375","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":"Investigation of Mixed Micro-Compressor Casing Treatment Using Non-Matching Mesh Interface","authors":"Purvic Patel, Gecheng Zha","doi":"10.1115/gt2019-90977","DOIUrl":"https://doi.org/10.1115/gt2019-90977","url":null,"abstract":"\u0000 In this paper, a non conservative interpolation boundary condition, for the non-matching mesh blocks, was developed and validated for the micro compressor casing treatment. The conservative variables were interpolated in the halo layers of non-matching mesh interface using Finite Element Method (FEM) type linear interpolation shape functions, instead of using overset grids. Using this new boundary condition, the effect of casing treatment on stall margin and compressor performance is investigated for a mixed flow type micro-compressor. The computed compressor performance map for the casing treatment case is compared with the experimental results and shows good agreement except in the region close to stall. With the application of the casing treatment, improvement in the stall margin is observed without the loss of efficiency over the operating range.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"958 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":"123307842","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":"Power-Density vs Efficiency Trade-Off for a Recuperated Inside-Out Ceramic Turbine (ICT)","authors":"B. Picard, A. L.-Blais, M. Picard, David Rancourt","doi":"10.1115/gt2019-91017","DOIUrl":"https://doi.org/10.1115/gt2019-91017","url":null,"abstract":"\u0000 Recuperated cycles can significantly increase the efficiency of small gas turbines that are today operating with low pressure ratios and uncooled or lightly cooled turbine blades. However, for mass-driven applications such as aeroengines, the efficiency benefit is typically outweighed by the increased weight associated with the heat exchanger (HX). Increase in specific power could overcome this penalty by reducing the mass flow through the system and therefore its weight and size. To do so, the Turbine Inlet Temperature (TIT) must be increased by ∼250 K over state-of-the-art small gas turbines. The Inside-out Ceramic Turbine (ICT) propose a new path to increase TIT of small turbines, where blade cooling schemes are impractical and costly. This new architecture increases the achievable TIT by using ceramic blades loaded in compression under centrifugal loads supported by an air-cooled rotating composite rim. This paper provides a system-level evaluation of the power-density to efficiency trade-off for the sub-megawatt class turbines using the ICT configuration. The numerical simulation includes 3 submodels to provide cycle efficiency and mass estimates for various cycle and HX design: (1) a station-based thermodynamic model; (2) a 1D-FEM HX model for a straight counterflow recuperator; and (3) a system-level mass model of the recuperated engine configured for a turboprop or turboshaft. At a TIT of 1550 K, the optimal ICT configuration provides a power density of 3 kW/kg and 40% thermal efficiency, which is 4 times lighter than recuperated turbines at 1300 K for the same efficiency level. Further increase in TIT to 1800 K would reach current state-of-the-art turboprop power densities (up to 5 kW/kg) while still achieving over 40% thermal efficiency or — for applications where power density can be traded for efficiency — up to 50% thermal efficiency while maintaining low pressure ratios and associated simplicity.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"35 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":"122041136","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 Flow Analysis of a Radial Outflow Turbo-Expander","authors":"Xuesong Wang, Jinju Sun, Changjiang Huo, Guilong Huo, Peng Song","doi":"10.1115/gt2019-90346","DOIUrl":"https://doi.org/10.1115/gt2019-90346","url":null,"abstract":"\u0000 Radial-outflow turbo-expanders have emerged in the recent years to suit some special applications where complex multi-phase and multi-component flows (like liquid-rich gases and solid particle-laden gases) need to be expanded. This paper presents a systematic study on the design and flow behavior of a single stage radial-outflow turbo-expander, which is to be used in organic Rankine power system to covert the low-temperature heat into shaft power. A mean-line code coupled with the optimization algorithm is developed and used to carry out the one-dimensional preliminary design, where 7 non-dimensional parameters are used as design variables (nozzle velocity coefficient, rotor velocity coefficient, reaction, rotor inlet and outlet flow angles, velocity ratio, and rotor diameter ratio). In comparison with the original design, significant design performance gains are achieved with the matched combination of design parameters. Geometric shape design is further performed for the expander. In consideration of the flow features in nozzle and rotor blade passages being nearly two-dimensional, blade shape design of both rows is conducted on the basis of the airfoils used for conventional axial flow turbines, where a conformal mapping method is used to convert the axial profile into the polar coordinate frame and it is then represented by 11 parameters of mean cylindrical diameter, radial and tangential chord, leading and trailing edge radius, blade inlet and outlet angles, blade inlet wedge angle, number of blades, unguided turning, and throat size. Flow and overall performance are simulated and predicted for the designed expander, where the output shaft power and overall isentropic efficiency is respectively predicted as 87.86 kW and 81.60% at design condition.","PeriodicalId":105494,"journal":{"name":"Volume 8: Microturbines, Turbochargers, and Small Turbomachines; Steam Turbines","volume":"90 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":"130644029","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}