Gas properties as a limit to gas turbine performance

Although increasing the turbine inlet temperature has traditionally proved the surest way to increase cycle efficiency, recent work suggests that the performance of future gas turbines may be limited by increased cooling flows and losses. Another limiting scenario concerns the effect on cycle performance of real gas properties at high temperatures. Cycle calculations of uncooled gas turbines show that when gas properties are modelled accurately, the variation of cycle efficiency with turbine inlet temperature at constant pressure ratio exhibits a maximum at temperatures well below the stoichiometric limit. Furthermore, the temperature at the maximum decreases with increasing compressor and turbine polytropic efficiency. This behaviour is examined in the context of a two-component model of the working fluid. The dominant influences come from the change of composition of the combustion products with varying air/fuel ratio (particularly the contribution from the water vapour) together with the temperature variation of the specific heat capacity of air. There are implications for future industrial development programmes, particularly in the context of advanced mixed gas-steam cycles.

Industrial practice in technology planning - Implications for a useful tool catalogue for technology management

A survey on technology planning and its implications for a useful tool catalogue for technology management was conducted. The survey provided a picture of technology planning, across a broad range of company size, manufacturing type and sector. It was concluded from the findings that technology planning is an important business activity across industry sectors and company types, driven increasing competition, market requirements and regulation technology change. The process technology roadmapping was used to support technology strategy and planning and could be useful way of structuring both the use of tools in a company and a tool catalogue.

Advanced DC link capacitor technology application for a stiff voltage-source inverter

Problem of DC link size in a stiff voltage-source inverter for electric drive is described in the paper. Advantages of advanced film capacitor technology over conventional one for DC link application are reviewed. Conventional DC link capacitor selection methods are questioned in view of advanced capacitor technology utilization in stiff voltage-source inverter. For capacitor selection maximum ripple rms current point is shown. DC link ripple current spectrum analysis under modern PWM techniques is presented. Some capacitor selection recommendations are given. The analysis has been aided greatly by computer modeling in PSpice. ©2005 IEEE.

Advanced thermal processing of semiconductor materials in the msec-range

This paper reviews the advances that flash lamp annealing brings to the processing of the most frequently used semiconductor materials, namely silicon and silicon carbide, thus enabling the fabrication of novel microelectronic structures and materials. The paper describes how such developments can translate into important practical applications leading to a wide range of technological benefits. Opportunities in ultra-shallow junction formation, heteroepitaxial growth of thin films of cubic silicon carbide on silicon, and crystallization of amorphous silicon films, along with the technical reasons for using flash lamp annealing are discussed in the context of state-of-the-art materials processing. © 2005 IEEE.

Developing a framework for mapping industrial emergence

The industrial landscape is becoming increasingly complex and dynamic, with innovative technologies stimulating the emergence of new industries and business models. This paper presents a preliminary framework for mapping industrial emergence, based on roadmapping principles, in order to understand the nature and characteristics of such phenomena. The focus at this stage is on historical examples of industrial emergence, with the preliminary framework based on observations from 20 'quick scan' maps, one of which is used to illustrate the framework. The learning from these historical cases, combined with further industrial consultation and literature review, will be used to develop practical methods for strategy and policy application. The paper concludes by summarising key learning points and further work needed to achieve these outcomes. © 2009 PICMET.

Roadmapping in industrial companies: Experiences

From its origins in the US electronics sector in the 1970s, technology roadmapping has been adapted (and adopted) widely, for many different innovation, strategy and policy applications. Communication is commonly cited as one of the key benefi ts of roadmapping, particularly in terms of the process that brings different organizational perspectives together, with the roadmap providing a common visual 'language'. There is signifi cant demand for methods that are agile, in the sense of being rapid, flexible and effective to apply, focused on strategic decisions and actions. 'Fast-start' roadmapping workshop techniques enable key stakeholders to address strategic issues efficiently using the visual structure of roadmaps to capture, discuss, prioritize, explore and communicate. This paper presents the learning from a set of five diverse applications of the fast-start approach in the Basque Country, which demonstrate the agility of the technique.

Application of scalar dissipation rate modelling to industrial burners in partially premixed regimes

The objective of this paper is to test various available turbulent burning velocity models on an experimental version of Siemens small scale combustor using the commercial CFD code. Failure of burning velocity model with different expressions for turbulent burning velocity is observed with an unphysical flame flashback into the swirler. Eddy Dissipation Model/Finite Rate Chemistry is found to over-predict mean temperature and species concentrations. Solving for reaction progress equation with its variance using scalar dissipation rate modelling produced reasonably good agreement with the available experimental data. Two different turbulence models Shear Stress Transport (SST) and Scale Adaptive Simulation (SAS) SST are tested and results from transient SST simulations are observed to be predicting well. SAS-SST is found to under-predict with temperature and species distribution.