The great majority of the research on CO2 capture worldwide is today devoted to the integration of new technologies in power plants, which are responsible for about 80% of the worldwide CO2 emission from large stationary sources. The remaining 20% are emitted from industrial sources, mainly cement...
Thermal modeling of power electronics modules is often used for the prediction of internal temperatures which is essential for safe operation and life time estimations. However, the models provided by manufacturers are normally quite simplified, accounting only partially for the crosscoupling...
It is essential to implement cost-effective operation and maintenance concepts and strategies to achieve a significant reduction of cost of energy from offshore wind farms. A decision support tool (Norwegian offshore wind cost and benefit model – NOWIcob) was developed that simulates the operational...
A baseline control system for the Deepwind floating vertical axis wind turbine (VAWT) concept is analysed with em- phasis on start-up and shut-down schemes. The turbine concept includes a rotating spar with a 2-bladed rotor at the top and a submerged generator at the bottom, anchored to the seabed...
In this work we consider a membrane reactor with catalytic steam methane reforming and/or water gas shift on the feed side, hydrogen separation and direct combustion of hydrogen on the permeate side, where the ultimate goal is an industrial size novel integrated membrane reactor/combustor concept...
High voltage subsea cables are normally sheathed with a metallic water barrier at voltage levels above 36 kV as recommended by the standards (IEC 60840). The main concern with water ingress in power cables is the risk of water tree formation. Water tree growth will reduce the lifetime of power...
A summary of streamer propagation in Exxsol-D140 and Marcol-52 under various experimental conditions is given. The results are compared to those of cyclohexane and mineral transformer oil. Streamer propagation is polarity and liquid dependent. The breakdown and acceleration voltages are also...
The aim of this paper is to improve the basis for the comparison of energy products. The paper will discuss important methodological issues with regard to various energy indicators and it will, by means of a few selected energy indicators, show examples of results for hydropower, wind power and...
During temperature cycling the radial flow of oil, which is caused by differences in thermal expansion between the oil and paper, may lead to cavity formation in mass impregnated HVDC cables. Partial discharge activity in these voids is an important failure mechanism in this type of cable, but...
This paper presents results from laboratory water tree experiments performed on samples of commercially available 6/10 kV XLPE insulated cables. The main purpose of the investigation was to examine possible water tree enhancement, due to mechanical tension of the insulation. During water tree...
Power electronics used for HVDC converters will stress cable insulation with a DC voltage with superimposed transients. The effect these transients have on the performance of the polymeric cable insulation is yet not clear. The main purpose of this work has been to investigate the effect of...
Positive breakdown streamers have been investigated in a short (5 mm) point-plane gap in cyclohexane and n-tridecane with and without the additives N,N-dimethylamine (DMA) with low ionization potential and azobenzene with a not quite as low ionization potential but a very low lowest excitation...
Humidity can enter the insulation system when the outer sheath of a cable becomes damaged. The relative humidity can then increase above a critical value (70 % RH), facilitating initiation and growth of water trees. The purpose of this experimental and numerical work is to determine how fast...
As an alternative to baseline technology a low-temperature syngas separation process has been proposed for pre-combustion CO2 capture from coal-derived syngas for an IGCC plant. Through systematic process synthesis – sequencing of separators and location of compressors and expanders, followed by...