bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simple Parametric Model for Quick Assessment of IGCC Performance
Authors: Gülen S. Can , Driscoll Ann V. 
Published: July 2013

Even though almost all components of an Integrated Gasification Combined Cycle (IGCC) power plant are proven and mature technologies, the sheer number of them, the wide variety of competing technologies (e.g., gasifiers, gas clean-up systems, heat recovery options), system integration options (e.g., cryogenic air separation unit and the gas turbine) including the recent addition of carbon capture and sequestration (CCS) with its own technology and integration options render fundamental IGCC performance analysis a monumental task. Almost all published studies utilize highly complex chemical process and power plant heat balance software, including commercially available packages and in-house proprietary codes. This makes an objective assessment of comparable IGCC plant designs, performance (and cost) and other perceived advantage claims (IGCC versus other technologies, too) very difficult if not impossible.
This paper develops a coherent simplified parametric model based on fully physics-based grounds to be used for quick design performance assessment of a large variety of IGCC power plants with and without CCS. Technology parameters are established from complex model runs and supplemented by extensive literature search. The model is tested using published data to establish its confidence interval and is satisfactory to carry conceptual design analysis at a high level to identify promising alternatives, development areas and assess the realism in competing claims.
Available and Future Gas Turbine Power Augmentation Technologies: Techno-Economic Analysis in Selected Climatic Conditions
Authors: Bhargava R. K. , Branchini L. , Melino F. , Peretto A. 
Published: July 2013

There exist a widespread interest in the application of gas turbine power augmentation technologies in both electric power generation and mechanical drive markets attributable to deregulation in the power generation sector, increased electric rates during peak demand period, and need for a proper selection of the gas turbine in a given application. In this study detailed thermo-economic analyses of various power augmentation technologies, implemented on a selected gas turbine, have been performed to identify the best techno-economic solution depending on the selected climatic conditions.
The presented results show that various power augmentation technologies examined have different payback periods. Such a techno-economic analysis is necessary for proper selection of a power augmentation technology.
An Innovative Inlet Air Cooling System for IGCC Power Augmentation: Part II—Thermodynamic Analysis
Authors: Morini Mirko , Pinelli Michele , Spina Pier Ruggero 
Published: July 2013

Integrated Gasification Combined Cycles (IGCCs) are energy systems mainly composed of a gasifier and a combined cycle power plant. Since the gasification process usually requires oxygen as the oxidant, the plant also has an Air Separation Unit (ASU). Moreover, a producer gas cleaner unit is always present between the gasifier and the gas turbine. Since these plants are based on gas-steam combined cycle power plants they suffer from a reduction in performance when ambient temperature increases.
In this paper, an innovative system for power augmentation in IGCC plants is presented. The system is based on gas turbine inlet air cooling by means of liquid nitrogen spray. In fact, nitrogen is a product of the ASU, but is not always exploited. In the proposed plant, the nitrogen is first chilled and liquefied and then it can be used for inlet air cooling or stored for a postponed use.
This system is not characterized by the limits of water evaporative cooling (where the lower temperature is limited by air saturation) and refrigeration cooling (where the effectiveness is limited by pressure drop in the heat exchanger).
A thermodynamic model of the system is built by using a commercial code for the simulation of energy conversion systems. A sensitivity analysis on the main parameters (e.g. ambient air temperature, inlet air temperature difference, etc.) is presented. Finally the model is used to study the capabilities of the system by imposing the real temperature profiles of different sites for a whole year.
Electrical Static Discharge in Turbo Machinery
Authors: Ross David A. 
Published: July 2013

An industrial gas turbine had a reoccurring failure with its accessory gearbox. The gearbox would run for a few days and then begin to show increased vibrations. The vibration level would gradually increase until the turbine alarm and trip signals operated. Studies at the time suggested alignment and accessory coupling issues were the cause. After many realignments and gears being changed the problem persisted. Eventually the gearbox replaced as it was suspected the original had internal alignment issues. This proved to be unsuccessful and the problem continued.
At the time of the unit’s last overhaul it was discovered the generator’s non-drive-end bearings insulation had failed and could not be rectified in time for its return to operation. It was then decided to install a second rotor earthing brush to the non-drive-end of the generator.
The writer reviewed all the historical and current date including a site inspection of the plant. Initial inspection of the gear damage indicated excessive misalignment and gear tooth overload. Finally, examination of the shell bearing liners had indications consistent with Electrical Static Discharge [ESD]. This had been overlooked; interpretation of the marking was due to unusual misalignment and the gear shaft.
Aeroacoustic Optimization for Axial Fans With the Lattice-Boltzmann Method
Authors: Stadler Michael , Schmitz Michael B. , Ragg Peter , Holman David M. , Brionnaud Ruddy 
Published: July 2013

A set of aeroacoustic optimization strategies for axial fans is presented. Their efficiency is demonstrated for small axial fans. Thereby, the generated noise could be reduced significantly while retaining or even improving the aerodynamic performance.
In particular, we discuss the following two optimization strategies in detail: Firstly, we consider the design of winglets using a parametric model for genetic optimization. The resulting winglet geometry helps to control the tip vortex over a large range of operating points, thereby reducing the generated noise. In addition, the power consumption of the fan could be reduced. Various choices of geometrical parameter sets for optimization are evaluated.
Secondly, we discuss the reduction of fan noise via contour optimized turbulators. For axial fans it is desirable to reduce sound emission across a broad operating range, not just for the design point. However, operation in off-design points may be accompanied by flow separation phenomena, which contribute predominantly to noise generation and reduce the aerodynamic performance of the fan. Turbulators can help to minimize these adverse effects. The advantages of various contoured turbulator geometries are discussed for off-design operating points.
The optimization of the above mentioned strategies was driven by aeroacoustic measurements via physical tests as well as numerical analysis based on the Lattice-Boltzmann method. The merits of either method are discussed with respect to the two optimization strategies.
Techno-Economic Analysis of Integrated Gasification Fuel Cell Power Plants Capturing CO2
Authors: Lanzini Andrea , Kreutz Thomas G. , Martelli Emanuele , Santarelli Massimo 
Published: July 2013

This work analyzes the efficiency and economic performance of different configurations of a coal-fed Integrated Gasification Fuel Cell (IGFC) plant with CO2 capture. Our analysis evaluates novel configurations, providing a detailed economic assessment for each case.
The plants studied here are based on a pressurized Solid Oxide Fuel Cell (SOFC) based power cycle integrated with a Shell coal gasifier. The design variations focus on syngas cleaning and pre-processing upstream of the SOFC power island. In particular, we have designed, simulated and optimized three main system configurations; two with a partial methanation process upstream of the SOFC (‘TREMP’ and ‘HICOM’ cases, respectively) and one without (‘DIRECT’ case). Depending on the specific plant layout, carbon capture is accomplished either before or after the SOFC power island, or both.
The best performance, both thermodynamic and economic, was achieved by the HICOM case, whose coal-to-electricity conversion efficiency is 50.6% (lower heating value basis). In addition to outperforming the other IGFC configurations analysed, compared to a conventional IGCC-CCS plant, the ‘HICOM’ case produced over 20% reduction in the levelized-cost-of-electricity (LCOE) delivered by the power plant.
An Integrated Approach for the Multidisciplinary Design of Optimum Rotorcraft Operations
Authors: Goulos Ioannis , Pachidis Vassilios , d’Ippolito Roberto , Stevens Jos , Smith Chrissy 
Published: July 2013

This work focuses on the development and application of a generic methodology targeting the design of optimum rotorcraft operations in terms of fuel burn, gaseous emissions and ground noise impact. An integrated tool capable of estimating the performance and emitted noise of any defined rotorcraft configuration within any designated mission has been deployed. A comprehensive and cost-effective optimization strategy has been structured. The methodology has been applied to two generic–baseline missions representative of current rotorcraft operations. Optimally designed operations for fuel burn, gaseous emissions and ground noise impact have been obtained. A comparative evaluation has been waged between the acquired optimum designs. The respective trade-off arising from the incorporation of flight paths optimized for different objectives has been quantified. Pareto front derived models for fuel burn and emitted noise have been structured for each mission. The Pareto models have been subsequently deployed for the design of operations optimized in a multidisciplinary manner.
The results have shown that the proposed methodology is promising with regards to achieving simultaneous reduction in fuel burn, gaseous emissions and ground noise impact for any defined mission. The obtainable reductions are found to be dependent on the designated mission. Finally, the potential to design optimum operations in a multidisciplinary fashion using only a single design criterion is demonstrated.
SGT5-8000H Experimental Test Results and Validation of High Fidelity 3D CFD
Authors: Bigalk Joachim , Biesinger Thomas , Broeker Marc , Buchal Tobias , Nürnberger Dirk , Schmidt Markus 
Published: July 2013

The first Siemens SGT5-8000H had extensively been tested in Simple Cycle in Irsching during 2008 and 2009. About 3000 sensors had been installed for monitoring of the engine operation, the results demonstrated that all performance targets have been exceeded.
Detailed measurements of pressure, temperature and flow were performed in the turbine flow path at various locations in circumferential and radial direction. The experimental test results in the turbine flow path have been used for additional detailed analysis of the fluid dynamics operation by a High Fidelity 3D CFD whole turbine model. This standardized whole turbine CFD process forms an important element in the Siemens design chain. The model was set up with all geometrical details to resolve all relevant flow features such as shrouds, cavities, coating, fillets etc.
This paper summarizes and compares the experimental test results with predicted CFD design values for overall thermodynamic operation and aerodynamics data at turbine outlet.
Besides the results from the Simple Cycle prototype test phase, performance test results are presented from recent measurements during customer acceptance testing in Combined Cycle in 2011. These results show a confirmation of the previously measured overall performance values after complete rebuild and re commissioning of the engine for combined cycle operation.
University of Central Florida Cogeneration Facility: Design and Economic Impact of a Medium Speed Reciprocating Engine Driven Chilled Water System
Authors: Burris Stephen , Oosaki Ryusuke , Shaw L. Todd , Norvell David , Bleeker Brett 
Published: July 2013

The University of Central Florida Cogeneration Facility is a state of the art chilled water CHP system using a natural gas fueled high efficiency 60 Hz medium speed reciprocating engine as the prime mover. The facility features one lean burn 5.5 MW 18KU30GSI (MACH II-SI) spark ignition engine, generator, controls, auxiliaries, multi-effect absorption chiller, secondary cooling, and an advanced emissions control system that includes selective catalytic reduction (SCR) system and oxidation catalyst (OC).
The cogeneration system is located on a constrained site in Orlando, Florida at the second largest university in the United States with a student enrollment of over 56,000. The site is adjacent to a sensitive environmental area to the east, a main thoroughfare to the south, student dormitories to the west, and a lecture hall to the north. The architecture of the new combined heat and power plant was carefully designed to blend with the surrounding campus architecture and sound attenuation methods were employed to minimize noise pollution from the power plant.
The new chilled water system was interconnected to the existing campus chilled water facility, therefore requiring coordination with existing chilled water infrastructure as well as other existing electrical, water, sewer, and storm water utilities on the campus.
This paper describes the plant load profile, design criteria, engine performance, chilled water production heat balance, and emissions requirements. The economic benefit to the University is discussed including both the impact of self generating power and augmentation of the existing chilled water system. In addition, the benefits of using modern 3-dimensional design tools are outlined for a brown-field location such as the subject site.
Aero-Thermal Design and Validation of an Advanced Turbine
Authors: Naik S. , Sommer T. P. , Schnieder M. 
Published: July 2013

This paper describes the aero-thermal design and validation of an advanced axial flow turbine. This turbine, which has evolved from the existing and proven GT26/GT24 design consists of an optimised annulus flow path using high lift airfoil profiles and improved aerodynamic matching between the turbine stages. A major design feature of the turbine has been to control and reduce the aerodynamic losses, with particular attention being devoted to minimising the secondary, trailing edge and blade tip losses. The advantages of these design changes to the overall turbine efficiency has been verified by extensive controlled experimentation in high-speed cascade test facilities; by the utilisation of 3D multi-row computational fluid dynamics analysis tools, and via engine tests.
In addition to the aerodynamic design modifications of the turbine, the thermal designs of the turbine vanes, blades and heat-shields were also optimised. For the first stage film cooled vane and blade airfoils and platforms, both the film cooling layout and operating characteristics were improved. And for all the internally cooled airfoils, the internal heat transfer design features were additionally optimised, which allowed for more homogenous metal temperature distributions on the airfoil and endwall surfaces. The verification and validation of the thermal designs of the turbine components was confirmed via extensive dedicated testing in high-speed cascades for the film cooling performances, and in scaled perspex models for the internal heat transfer coefficients and local flow distributions.
The complete turbine was further tested and validated in the GT26 Test Power Plant in Birr, Switzerland via a dedicated turbine thermal paint test run and a subsequent performance and mapping testing phase.
Analysis of Direct Carbon Fuel Cell (DCFC) Based Coal Fired Power Cycles With CO2 Capture
Authors: Campanari Stefano , Gazzani Matteo , Romano Matteo C. 
Published: July 2013

This work presents an analysis of the application of Direct Carbon Fuel Cells (DCFC) to large scale, coal fuelled power cycles. DCFCs are a type of high temperature fuel cell featuring the possibility of being fed directly with coal or other heavy fuels, with high tolerance to impurities and contaminants (e.g. sulphur) contained in the fuel.
Different DCFC technologies of this type are developed in laboratories, research centres or new startup companies, although at kW-scale, showing promising results for their possible future application to stationary power generation.
This work investigates the potential application of two DCFC categories, both using a “molten anode medium” which can be (i) a mixture of molten carbonates or (ii) a molten metal (liquid tin) flowing at the anode of a fuel cell belonging to the solid oxide electrolyte family.
Both technologies can be considered particularly interesting for the possible future application to large scale, coal fuelled power cycles with CO2 capture, since they both have the advantage of oxidizing coal without mixing the oxidized products with nitrogen, thus releasing a high CO2 concentration exhaust gas. After a description of the operating principles of the two DCFCs, it is presented a lumped-volume thermodynamic model which reproduces the DCFC behaviour in terms of energy and material balances, calibrated over available literature data. We consider then two plant layouts, using a hundred-MW scale coal feeding, where the DCFC generates electricity and heat recovered by a bottoming steam cycle, while the exhaust gases are sent to a CO2 compression train, after purification in appropriate cleaning processes. Detailed results are presented in terms of energy and material balances of the proposed cycles, showing how the complete system may surpass 65% LHV electrical efficiency with nearly complete (95%+) CO2 capture, making the system very attractive, although evidencing a number of technologically critical issues.
Lessons Learned From the Development of Courses on Gas Turbine Multi-Disciplinary Conceptual Design
Authors: Kyprianidis Konstantinos G. , Grönstedt Tomas , Barbosa João R. 
Published: July 2013

Despite the need for highly qualified experts, multi-disciplinary gas turbine conceptual design has not been a common study topic in traditional post-graduate curriculums. Although many courses on specialised topics in gas turbine technology take place, limited attention is given on connecting these individual topics to the overall engine design process. Teaching conceptual design as part of a post-graduate curriculum, or as an intensive short course, may help to address the industrial need for engineers with early qualifications on the topic i.e., prior to starting their careers in the gas turbine industry.
This paper presents details and lessons learned from: (i) the integration of different elements of conceptual design in an existing traditional MSc course on gas turbine technology through the introduction of group design tasks, and (ii) the development of an intensive course on gas turbine multi-disciplinary conceptual design as a result of an international cooperation between academia and industry.
Within the latter course, the students were grouped in competing teams and were asked to produce their own gas turbine conceptual design proposals within a given set of functional requirements. The main concept behind the development of the new design tasks, and the new intensive course, has been to effectively mimic the dynamics of small conceptual design teams, as often encountered in industry. The results presented are very encouraging, in terms of enhancing student learning and developing engineering skills.
Influenza Viruses: Breaking All the Rules
Authors: Taubenberger Jeffery K. , Morens David M. 
Published: July 2013

ABSTRACTInfluenza A viruses (IAV) are significant pathogens able to repeatedly switch hosts to infect multiple avian and mammalian species, including humans. The unpredictability of IAV evolution and interspecies movement creates continual public health challenges, such as the emergence of the 2009 pandemic H1N1 virus from swine, as well as pandemic threats from the ongoing H5N1 and the recent H7N9 epizootics. In the last decade there has been increased concern about the “dual use” nature of microbiology, and a set of guidelines covering “dual use research of concern” includes seven categories of potentially problematic scientific experiments. In this Perspective, we consider how in nature IAV continually undergo “dual use experiments” as a matter of evolution and selection, and we conclude that studying these properties of IAV is critical for mitigating and preventing future epidemics and pandemics.
6: Seismicity, crustal structure, and intraplate tectonics of the interior of the western Cordillera
Authors: Smith Robert B. 
Published: July 2013

Seismicity, fault-plane solutions, and Cenozoic geology are used to infer contemporary west to northwest extension and components of lateral slip between subplates of the western North American plate. Seismicity of the western interior of the Cordillera is characterized by earthquakes that occur in broad zones, up to 150 km wide, in the Nevada and the Intermountain seismic zones. Epicenters are scattered and when accurately located many do not coincide with mapped faults. Focal depths are shallow and seldom exceed 20 km. Secondary seismicity occurs around the margins of the Colorado Plateau, in central Idaho, and in eastern Oregon and Washington. The contemporary strain pattern of the Western United States, as interpreted from fault-plane solutions, suggests that three intraplate lithospheric blocks—the Sierra Nevada, the Great Basin-High Lava Plains, and the Northern Rocky Mountains-Columbia Plateau are moving west to northwest as “slivers” between the obliquely converging Pacific and North American plates. Intraplate extension within the Great Basin is primarily accommodated by north-south normal faulting in north-central Nevada and along the Wasatch Front, but significant components of strike-slip faulting occur along active seismic zones in southwestern Nevada and along the northern Intermountain seismic belt in Montana.
A thin crust, ~25 km, characterizes the east margin of the Great Basin, with average Pn-velocities of ~7.5 km /s. A crustal low-velocity layer, at 5 to 15 km depth, coincides with the eastern margin of the Great Basin. A thin crust, with an apparent Pn-velocity of ~7.7 km /s, occurs on the northwest margin of the Great Basin and beneath parts of the Oregon-High Lava Plains. The central part of the Great Basin has a thicker crust, ~30 km, and higher Pn-velocities, 7.7 to 7.9 km /s. The Colorado Plateau and the Rocky Mountains have thicker crusts, 40 to 50 km, and Pn-velocities of ~7.8 km/s.
An upper-mantle diapir or an upwelling thermal mechanism, facilitated by stress relaxation above the now-truncated Farallon subducting plate, is postulated to have uplifted, extended, and heated the crust of the Great Basin beginning at ~20 m.y. Late Cenozoic centers of volcanism appear to have progressed outward from a northern Great Basin thermal center in two divergent directions—northwesterly along a combined extensional-strike-slip zone of deformation in the High Lava Plains of southeastern Oregon and northeasterly along an extensional zone marked by the Snake River Plain. Lithospheric heating is thought to have produced a broad uplift of the Great Basin with concomitant crustal thinning and diminishing of upper-mantle Pn-velocities. The thermal mechanisms are hypothesized to have produced laterally divergent mantle flow to form symmetric zones of crustal thinning and low Pn-velocities that presently mark the east and west margins of the Great Basin.