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Designing a power plant with highest efficiency:results from SFB 561

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航空动力学报 2009年第4期24卷 717-728页

作者： dieter bohn Institute of Steam and Gas Turbines RWTH Aachen University

The goal of Collaborative Research Centre(SFB) 561 "thermally highly loaded,porous and cooled multi-layer systems for combined cycle power plants" is to expand the current technological and scientific knowledge on power plants in order to achieve total efficiencies of 65% in a combined cycle power plant in the year ***,the aero-thermomechanical,structural-mechanical,materials' scientific and production fundamentals for the development of steam and gas turbine components that are able to withstand highest thermal loads are being worked out within this *** means for the gas turbine that combustion chamber outlet temperatures of 1520℃ at 1.7MPa are to be *** order to control these high temperatures,it is not only required to develop new materials' solutions,including thermal barrier coatings,but also to apply improved cooling techniques,as for example effusion *** novel cooling concept is to be realised through open-porous *** structures can consist of drilled open-porous multi-layer systems or open-porous metallic *** development of graded multi-layer systems is also extremely important,as the grading will enable the use of coolant in dependence of the *** live steam parameters in the high pressure turbine are expected to be increased up to approximately 700℃ with pressure of *** elevated steam parameters can be encountered with Ni-base alloys,but this is a costly alternative,associated with many manufacturing ***,the SFB proposes cooling the highly loaded turbines instead,as this would necessitate the application of far less Ni-base *** protect the thermally highly loaded casing,a sandwich material consisting of two thin face sheets with a core of a woven wire mesh is used to cover the walls of the steam turbine *** current state of the research shows that by utilising innovative cooling technologies a total efficiency of 65% can be reached without exceeding the m

关键词： gas turbine steam turbine cooling novel materials process calculation

Investigation of the steam-cooled blade in a steam turbine cascade

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航空动力学报 2007年第5期22卷 673-682页

作者： dieter bohn Jing Ren Karsten Kusterer Institute of Steam and Gas Turbines RWTH Aachen UniversityTemplergraben 55 D-52056 Aachen Germany B＆B-AGEMA Gesellschaft far Energietechnische Maschinenund Anlage GmbH Jülicher Strasse 338 52070 Aachen Germany

With the increasing demand for electricity,an efficiency improvement and thereby reduced CO2 emissions of the coal-fired plants are expected in order to reach the goals set in the Kyoto *** can be achieved by a rise of the process ***,live steam pressures and temperatures up to 300 bars and 923 K are planned as the next *** circuit steam cooling of blades and vanes in modern steam turbines is a promising technology in order to establish elevated live steam temperatures in future steam turbine *** this paper,a steam-cooled test vane in a cascade with external hot steam flow is analyzed numerically with the in-house code CHTflow.A parametric analysis aiming to improve the cooling effectiveness is carried out by varying the cooling mass flow *** results from two investigated cases show that the steam cooling technique has a good application potential in the steam *** internal part of the vane is cooled homogeneously in both *** the increased cooling mass flow rate,there is a significant improvement of cooling efficiency at the leading *** results show that the increased cooling mass flow ratio can enhance the cooling effectiveness at the leading *** respect to trailing edge,there is no observable improvement of cooling effectiveness with the increased cooling mass *** implies that due to the limited dimension at the trailing edge,the thermal stress cannot be decreased by increasing the cooling mass flow ***,impingement-cooling configuration at the trailing edge might be a solution to overcome the critical thermal stress *** is also observed that the performance of the cooling effective differs on pressure side and suction *** implicates that the equilibrium of the cooling effectiveness on two sides are influenced by a coupled relationship between cooling mass flow ratio and hole *** future work,optimizing the hole geometry and cooling steam supply conditions might b

关键词：蒸汽轮机层叠蒸汽冷却调查研究翼热转移

Measurements of a 2-Stage Axial Turbine with Shrouded Rotor Cavities

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Journal of Thermal Science 2004年第4期13卷 310-314页

作者： dieter E. bohn Franz KREITMEIER Michael SELL Institute of Steam and Gas Turbines Technical University of Aachen GermanyALSTOM Power CH-5401 Baden SwitzerlandALSTOM Power CH-5401 Baden Switzerland

This paper presents preliminary measurements of a 2-stage axial turbine with shrouded rotor cavities. The research facility and measurement techniques are reported. The flow field at both inlet and outlet was measured using 5-hole probes as well as temperature probes. The measurement results indicate that the inlet flow field is periodical in the tangential direction due to the influence of the first-stator leading-edge. The horse-shoe vortexes cause substantial flow blockage and turbulence near the endwall. Unsteady measurements of the rotor radial tip clearance show that one of the second-rotor blades has a little bigger clearance than the others.

关键词： axial turbine shrouded rotor measurement.

Parameter Survey of Thermally Highly Loaded,Porous and Cooled Multi-Layer Systems for Turbine Blades

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Journal of Thermal Science 2007年第2期16卷 181-185页

作者： Peng Shan dieter bohn Jing Ren N.Surken Department of Jet Propulsion Beijing University of Aeronautics & AstronauticsBeijing 100083China Institute of Steam and Gas Turbines RWTH Aachen52056 AachenGermany

This study is an advanced investigation for the cooling of high temperature turbine vanes and blades. The efficient heat exchanging near the surface of a blade may be achieved by forcing a cooling air flow emitting out of a thin layer of the porous metal which is pasted on the structural high strength metal. The contents include the consideration on the computational model of heat transfer through a layer of porous material, the concrete modeling and the analysis of the model, the numerical survey of key parameters for both the two-layer porous materials and the heat transfer fluid flow passing through the model channels. The results revealed that the constructed system is reasonable. Proposed an evaluation formula for the porous material heat transfer efficiency.

关键词： heat transfer thermally highly loaded porous multi-layer

Investigation on heat transfer enhancement and pressure loss of double swirl chambers cooling

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Propulsion and Power Research 2013年第3期2卷 177-187页

作者： Gang Lin Karsten Kusterer dieter bohn Takao Sugimoto Ryozo Tanaka Masahide Kazari B&B-AGEMA GmbH Juelicher Str.338Aachen 52070Germany RWTH Aachen University Templergraben 55Aachen 52056Germany Kawasaki Heavy Industries LTD.Gas Turbine&Machinery CompanyAkashi 673-8666Japan Kawasaki Heavy Industries LTD.Technical InstituteAkashi 673-8666Japan

By merging two standard swirl chambers,an alternative cooling configuration named double swirl chambers(DSC)has been *** the DSC cooling configuration,the main physical phenomena of the swirl flow in swirl chamber and the advantages of swirl flow in heat transfer augmentation are ***,three new physical phenomena can be found in DSC cooling configuration,which result in a further improvement of the heat transfer:(1)impingement effect has been observed,(2)internal heat exchange has been enhanced between fluids in two swirls,and(3)“∞”shape swirl has been generated because of cross effect between two chambers,which improves the mixing of the *** of all these improvements,the DSC cooling configuration leads to a higher globally-averaged thermal performance parameter(Nu/Nu_(∞)/(f/f0)^(1/3))than standard swirl *** particular,at the inlet region,the augmentation of the heat transfer is nearly 7.5 times larger than the fully developed non-swirl turbulent flow and the circumferentially averaged Nusselt number coefficient is 41%larger than the standard swirl *** the present work,a further investigation on the DSC cooling configuration has been focused on the influence of geometry parameters *** ratio of chambers and aspect ratio of inlet duct on the cooling *** results show a very large influence of these geometry parameters in heat transfer enhancement and pressure drop *** with the basic configuration of DSC cooling,the improved configuration with 20%to 23%merging ratio shows the highest globally-averaged themal performance *** the same cross section area in tangential inlet ducts,the DSC cooling channel with larger aspect ratio shows larger heat transfer enhancement and at the same time reduced pressure drop ratio,which results in a better globally-averaged themal performance parameter.

关键词： Gas turbine Internal cooling Double swirl chambers Thermal performance Heat transfer enhancement

Conjugate calculation of a film-cooled blade for improvement of the leading edge cooling configuration

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Propulsion and Power Research 2013年第1期2卷 1-9页

作者： Norbert Moritz Karsten Kusterer dieter bohn Takao Sugimoto Ryozo Tanaka Tomoki Taniguchi B&B-AGEMA GmbH Juelicher Str.338Aachen 52070Germany RWTH Aachen Aachen 52056Germany Kawvasaki Heavy Industries LTD.Gas Turbine&Machinery CompanyAkashi 673-8666Japan

Great efforts are still put into the design process of advanced film-cooling *** particular,the vanes and blades of turbine front stages have to be cooled extensively for a safe *** conjugate calculation technique is used for the three dimensional thermal load prediction of a fim-cooled test blade of a modern gas ***,it becomes possible to take into account the interaction of internal flows,external flow,and heat transfer without the prescription of heat transfer *** focus of the investigation is laid on the leading edge part of the *** numerical model consists of all internal flow passages and cooling hole rows at the leading ***,the radial gap flow is also part of the *** comparison with thermal pyrometer measurements shows that with respect to regions with high thermal load a qualitatively and quantitatively good agreement of the conjugate results and the measurements can be *** particular,the region in the vicinity of the mid-span section is exposed to a higher thermal load,which requires further improvement of the cooling *** the achieved results demonstrate that the conjugate calculation technique is applicable for reasonable prediction of three-dimensional thermal load of complex cooling configurations for blades.

关键词： Gas turbine Rotor blade Film-cooling Conjugate heat transfer Conjugate calculation Pyrometer measurement

涡轮级轮缘封严内非定常流场的准三维LDV测量

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航空动力学报 2004年第4期19卷 455-458页

作者：马宏伟 dieter E bohn Achim Decker Bernd Rudzinski 北京航空航天大学能源与动力工程学院北京100083 Institute of Steam and Gas Turbine Aachen University

研究涡轮级封严内流动和主流的相互作用、相互影响,进一步认识盘腔内燃气入侵等非定常现象,急需流场实验数据验证。针对轮缘封严内空间狭窄、光路安排困难等问题,本文发展了一种用于测量涡轮级轮缘封严内非定常流场的准三维LDV技术,即... 详细信息

研究涡轮级封严内流动和主流的相互作用、相互影响,进一步认识盘腔内燃气入侵等非定常现象,急需流场实验数据验证。针对轮缘封严内空间狭窄、光路安排困难等问题,本文发展了一种用于测量涡轮级轮缘封严内非定常流场的准三维LDV技术,即测量分两步,首先在机匣上安置二维测速系统用符合方式测出径向、切向速度及湍流度,再在轮毂内安置一维探头重复测量,从两次测量数据中计算出轴向速度;该技术借助锁相采样等技术能测出不同动静叶相对位置情况下封严及盘腔内的周期性非定常流场细节,本文给出了部分典型的动态流场测量结果。

关键词：航空、航天推进系统涡轮轮缘封严非定常流场准三维LDV测量

Emerging Directions in Electroanalysis

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Journal of Analysis and Testing 2019年第2期3卷 123-124页

作者： Paul W.bohn University of Notre Dame Notre DameUSA

With roots reaching back to the eighteenth century and pros-pects as new as the development of advanced energy storage technologies,electrochemistry is at once both old and *** a history of development as long as this,electrochem-istry’s obituary has been written multiple ***-less,this fascinating science focused on understanding and manipulating electron transfer reactions continues to spawn new areas of application and fascinating fundamental *** is why it is such a pleasure to create and introduce this excellent collection of articles for the Jour-nal of Analysis and *** of contributions that literally circle the globe-from Asia,Europe,and North America-these papers serve as a guide to some of the most recent and exciting new developments in electrochemistry,generally,and electroanalysis specifically.

关键词： analysis circle continue

Estimating the carbon fluxes of forests with an individual-based forest model

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Forest Ecosystems 2017年第2期4卷 133-142页

作者： Edna Rodig Andreas Huth Friedrich bohn Corinna Rebmann Matthias Cuntz UFZ-Helmholtz Centre for Environmental Research Permoserstr.1504318 LeipzigGermany University of Osnabruck BarbarastraSe 1249076 OsnabruckGermany German Centre for Integrative Biodiversity Research(iDiv)HaHe-Jena-leipzig Deutscher Platz 5e04103 LeipzigGermany INRA-Universite de Lorraine UMRU37 Ecologie et Ecophysiologie Foresti^res54280 ChampenouxFrance

Background： Capturing the response of forest ecosystems to inter-annual climate variability is a great *** this study, we tested the capability of an individual-based forest gap model to display carbon fluxes at yearly and daily time *** forest model was applied to a spruce forest to simulate the gross primary production（GPP）, respiration and net ecosystem exchange（NEE）.We analyzed how the variability in climate affected simulated carbon fluxes at the scale of the forest ***： Six years were simulated at a daily time scale and compared to the observed eddy covariance（EC） *** general, the seasonal cycle of the individual carbon fluxes was correctly described by the forest ***, the estimated GPP differed from the observed data on the days of extreme climatic *** new parameterizations were developed： one resulting from a numerical calibration, and the other resulting from a filtering *** suggest new parameter values and even a new function for the temperature limitation of ***： The forest model reproduced the observed carbon fluxes of a forest ecosystem quite *** the three parameterizations, the calibrated model version performed ***, the filtering approach showed that calibrated parameter values do not necessarily correctly display the individual functional *** concept of simulating forest dynamics at the individual base is a valuable tool for simulating the NEE, GPP and respiration of forest ecosystems.

关键词： Forest model Temperate forest Carbon fluxes Eddy covariance FORMIND