| 1. |
- Aichmayer, Lukas, et al.
(författare)
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Micro Gas-Turbine Design for Small-Scale Hybrid Solar Power Plants
- 2013
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Ingår i: Proceedings of the ASME Turbo Expo 2013. San Antonio, USA. June 3-7. - : ASME. - 9780791855188
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Konferensbidrag (refereegranskat)abstract
- Hybrid solar micro gas-turbines are a promising technology for supplying controllable low-carbon electricity in off-grid regions. A thermoeconomic model of three different hybrid micro gas-turbine power plant layouts has been developed, allowing their environmental and economic performance to be analyzed. In terms of receiver design, it was shown that the pressure drop is a key criterion. However, for recuperated layouts the combined pressure drop of the recuperator and receiver is more important. The internally-fired recuperated micro gas-turbine was shown to be the most promising solution of the three configurations evaluated, in terms of both electricity costs and carbon emissions. Compared to competing diesel generators, the electricity costs from hybrid solar units are between 10% and 43% lower, while specific CO2 emissions are reduced by 20 – 35%.
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| 2. |
- Besem, F., et al.
(författare)
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Student perceptions on the new teaching methods for engineers : The influence of podcasting on education
- 2013
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Ingår i: Proceedings of the ASME Turbo Expo. - 9780791855188
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Konferensbidrag (refereegranskat)abstract
- This paper presents the perceptions of engineering students who followed podcasted courses during their higher education. Podcasting is widely used in remote education, but it also benefits on-campus students because it supports flexible and personalized teaching. The first three generations of students from an international Master's degree program participated in a survey to give their impressions about the use of podcasting in their program. This preliminary survey targeted three aspects of podcasting: the format, the effect on learning experience, and the effect on student isolation. Results showed a majority of students considered recorded lectures a very helpful tool to support traditional on-campus lectures. The students appreciated the opportunity to pause and re-watch the videos to learn at their own pace. However, few students would consider a purely remote education; they felt less engaged in their education because of the lack of direct contact with teachers and peers. This highlights the importance of the social networking that happens on-site. In conclusion, the main advantage of podcasting is to compensate for the lack of individually adapted teaching in higher education. However, it will not completely replace traditional lectures without the development of both new tools to facilitate the professor-student interactions, and of teaching techniques to keep students engaged in their studies.
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| 3. |
- Eriksson, Robert, et al.
(författare)
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Cyclic Hot Corrosion of Thermal Barrier Coatings and Overlay Coatings
- 2013
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Ingår i: Proceedings of ASME Turbo Expo 2013: Turbine Technical Conference and Exposition, GT2013. - : The American Society of Mechanical Engineers (ASME). - 9780791855188 ; , s. 1-8
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Konferensbidrag (refereegranskat)abstract
- The influence, and interdependence, of water vapor and Na2SO4–50 mol% NaCl on the oxidation of a NiCoCrAlY coating and a thermal barrier coating (TBC) were studied at 750 °C. Water vapor was found to have a negligible effect on oxide composition, but influenced the oxide morphology on the NiCoCrAlY coating. Na2SO4–50 mol% NaCl deposits on the coatings influencedoxide composition, most notably by the promotion of a Y rich phase. The effect of Na2SO4–50 mol% NaCl deposits was also evident for the TBC coated specimen, where the formed metal/ceramic interface oxide was affected by salt reaching the interface by penetration of the zirconia TBC.
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| 4. |
- Guédez, Rafael, et al.
(författare)
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Reducing the Number of Turbine Starts in Concentrating Solar Power Plants through the Integration of Thermal Energy Storage
- 2013
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Ingår i: Proceedings of the ASME TurboExpo 2013. - 9780791855188
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Konferensbidrag (refereegranskat)abstract
- The operation of steam turbine units in solar thermal power plants is very different than in conventional base-load plants. Due to the variability of the solar resource, much higher frequencies of plant start-ups are encountered. This study provides an insight to the influence of thermal energy storage integration on the typical cycling operation of solar thermal power plants. It is demonstrated that the integration of storage leads to significant reductions in the annual number of turbine starts and is thus beneficial to the turbine lifetime. At the same time, the effects of storage integration on the electricity costs are analyzed to ensure that the designs remain economically competitive. Large storage capacities, can allow the plant to be shifted from a daily starting regime to one where less than 20 plant starts occur annually. Additionally, the concept of equivalent operating hours is used to further analyze the direct impact of storage integration on the maintenance planning of the turbine units.
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| 5. |
- Larsson, Emil, 1981-, et al.
(författare)
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Fault Tolerant Supervision of an Industrial Gas Turbine
- 2013
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Ingår i: Proceedings of ASME Turbo Expo. - 9780791855188
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Konferensbidrag (refereegranskat)abstract
- Supervision of the performance of an industrial gas turbine is important since it gives valuable information of the process health and makes efficient determination of compressor wash intervals possible. Slowly varying sensor faults can easily be misinterpreted as performance degradations and result in an unnecessary compressor wash. Here, a diagnostic algorithm is carefully combined with non-linear state observers to achieve fault tolerant performance estimation. The proposed approach is evaluated in an experimental case study with six months of measurement data from a gas turbine site. The investigation shows that faults in all gas path instrumentation sensors are detectable and isolable. A key result of the case study is the ability to detect and isolate a slowly varying sensor fault in the discharge temperature sensor after the compressor. The fault is detected and isolated before the wash condition of the compressor is triggered, resulting in fault tolerant estimation of compressor health parameters.charge temperature sensor after the compressor. The fault is detected and isolated before the wash condition of the compressor is triggered, resulting in fault tolerant estimation of compressor health parameters.
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| 6. |
- Sandoz, Raphael, et al.
(författare)
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Air-Based Bottoming-Cycles for Water-Free Hybrid Solar Gas-Turbine Power Plants
- 2013
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Ingår i: Proceedings of the ASME TurboExpo 2013. - 9780791855188
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Konferensbidrag (refereegranskat)abstract
- A thermoeconomic model of a novel hybrid solar gas- turbine power plant with an air-based bottoming cycle has been developed, allowing its thermodynamic, economic, and environmental performance to be analyzed. Multi-objective optimization has been performed to identify the trade-off between two conflicting objectives: minimum capital cost and minimum specific CO2 emissions. In-depth thermoeconomic analysis reveals that the additional bottoming cycle significantly reduces both the levelized cost of electricity and the environmental impact of the power plant (in terms of CO2 emissions and water consumption) when compared to a simple gas-turbine power plant without bottoming cycle. Overall, the novel concept appears to be a promising solution for sustainable power generation, especially in water-scarce areas.
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| 7. |
- Spelling, James, 1987-, et al.
(författare)
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A Comparative Thermoeconomic Study of Hybrid Solar Gas-Turbine Power Plants
- 2013
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Ingår i: Proceedings of the ASME Turbo Expo. - 9780791855188
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Konferensbidrag (refereegranskat)abstract
- The construction of the first generation of commercial hybrid solar gas-turbine power plants will present the designer with a large number of choices. To assist decision making, a thermoeconomic study has been performed for three different power plant configurations, namely simple- and combined- cycles as well as simple-cycle with the addition of thermal energy storage. Multi-objective optimization has been used to identify Pareto-optimal designs and highlight the trade-offs between minimizing investment costs and minimizing specific CO2 emissions. The solar hybrid combined-cycle plant provides a 60% reduction in electricity cost compared to parabolic trough power plants at annual solar shares up to 20%. The storage integrated designs can achieve much higher solar shares and provide a 7 – 13% reduction in electricity costs at annual solar shares up to 90%. At the same time, the water consumption of the solar gas-turbine systems is significantly lower than conventional steam-cycle based solar power plants.
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