Björn Laumert
Royal Institute of Technology
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Featured researches published by Björn Laumert.
41st AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit. Tucson, AZ. 10 July 2005 - 13 July 2005 | 2005
Lars Winterfeldt; Björn Laumert; Robert Tano; P. James; F. Geneau; G. Hagemann
The Vulcain 2 Nozzle Extension has been reinforced further to the failure of the maiden flight of Ariane 5 ECA. An intensive engineering and testing program was pursued by Volvo Aero Corporation (V ...
Journal of Engineering for Gas Turbines and Power-transactions of The Asme | 2013
Lukas Aichmayer; James Spelling; Björn Laumert; Torsten Fransson
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 ...
Journal of Engineering for Gas Turbines and Power-transactions of The Asme | 2013
Raphaël Sandoz; James Spelling; Björn Laumert; Torsten Fransson
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 ...
Journal of Engineering for Gas Turbines and Power-transactions of The Asme | 2015
Monika Topel; Magnus Genrup; Markus Jöcker; James Spelling; Björn Laumert
Solar steam turbines are subject to high thermal stresses as a result of temperature gradients during transient operation, which occurs more frequently due to the variability of the solar resource. In order to increase the flexibility of the turbines while preserving lifing requirements, several operational modifications for maintaining turbine temperatures during offline periods are proposed and investigated. The modifications were implemented in a dynamic thermal turbine model and the potential improvements were quantified. The modifications studied included: increasing the gland steam pressure injected to the end-seals, increasing the back pressure and increasing the barring speed. These last two take advantage of the ventilation and friction work. The effects of the modifications were studied both individually as well as in different combinations. The temperatures obtained when applying the combined modifications were compared to regular turbine cool-down temperatures and showed significant improvements on the start-up times of the turbine.
Journal of Solar Energy Engineering-transactions of The Asme | 2014
Rafael Guédez; James Spelling; Björn Laumert
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 (TES) 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 (EOHs) is used to further analyze the direct impact of storage integration on the maintenance planning of the turbine units.
Journal of Solar Energy Engineering-transactions of The Asme | 2016
Rafael Guédez; Monika Topel; Inés Conde; Irene Callaba; James Spelling; Zhor Hassar; C.D. Pérez-Segarra; Björn Laumert
The present study analyzes the influence that market conditions have on determining optimum molten salt solar tower plants with storage that maximizes profits (in terms of plant configuration, sizi ...
Journal of Engineering for Gas Turbines and Power-transactions of The Asme | 2013
James Spelling; Björn Laumert; Torsten Fransson
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 st ...
Journal of Engineering for Gas Turbines and Power-transactions of The Asme | 2014
James Spelling; Björn Laumert
The hybridization of combined-cycle power plants with solar energy is an attractive means of reducing carbon dioxide (CO2) emissions from gas-based power generation. However, the construction of th ...
ASME Turbo Expo 2012: Turbine Technical Conference and Exposition, GT 2012; Copenhagen; Denmark; 11 June 2012 through 15 June 2012 | 2012
James Spelling; Björn Laumert; Torsten Fransson
A dynamic simulation model of a hybrid solar gas-turbine power plant has been developed, allowing determination of its thermodynamic and economic performance. In order to examine optimum gas-turbin ...
ASME Turbo Expo 2000: Power for Land, Sea, and Air | 2000
Björn Laumert; Hans Mårtensson; Torsten Fransson
This paper presents the results from three-dimensional (3D) steady and unsteady Navier-Stokes computations, performed on the transonic VKI BRITE EURAM test turbine stage. The work aimed at giving deeper insight in the aerodynamics of the turbine stage. The analysis has been carried out with the nominal stator trailing edge ejection slot geometry and cooling flow ejection. Additionally a simplified rounded stator trailing edge was employed. The results from the unsteady computations were compared with measured pressure perturbation traces at 22 locations around the rotor blade at midspan. Computations with both the ejection slot and the rounded stator trailing edge geometry were in good agreement with the measurements on the pressure side and half chord of the rotor blade’s suction side. Measurements and computations showed less good agreement downstream a weak shock on the suction side of the rotor blade. The measured pressure double peak in the rotor blade leading edge region is only observed in the computations with the ejection slot geometry.Copyright