Sökning: "stationary energy systems"

Visar resultat 16 - 20 av 62 avhandlingar innehållade orden stationary energy systems.

1. 16. Modelling and Numerical Analysis of the Centrifugal Compressor and its Operation in the Pressurised SOFC GT Process

   Författare :Andre Hildebrandt; Kraftverksteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; applied thermodynamics; Thermal engineering; radial compressor; Gas Turbine; Termisk teknik; Solid Oxide Fuel Cell; termodynamik;

   Sammanfattning : Small-scale power plants based on the SOFC-GT (Solid Oxide Fuel Cell-Gas Turbine) system are foreseen for future application such as APU units in flight transportation systems or stationary power production. Although these new systems offer high load flexibility and potentially high efficiency, there are several constraints referring to thermal/mechanical stress of the fuel cell as well as to a potential risk of aerodynamic instability of the GT compressor due to the different physical behavior of the SOFC and the GT. LÄS MER

3. 17. Wireless Sensor Network and Radio Wave Propagation in Harsh Environments

   Författare :Mathias Grudén; Anders Rydberg; Erik Björnemo; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wireless Sensor Network; WISENET; Wave Propagation; Radio Communication; Harsh Environmnents; Engineering Science with specialization in Microwave Technology; Teknisk fysik med inriktning mot mikrovågsteknik;

   Sammanfattning : This licentiate thesis cover two important subjects regarding the application of wireless sensor networks (WSNs). Both subjects are related to propagation mechanisms. The first subject is what the radio channel looks like and how it behaves. LÄS MER

4. 18. Spatial Resource Allocation in Massive MIMO Communications : From Cellular to Cell-Free

   Författare :Trinh Van Chien; Emil Björnson; Erik G. Larsson; David Gesbert; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : Massive MIMO (multiple-input multiple-output) is considered as an heir of the multi-user MIMO technology and it has gained lots of attention from both academia and industry since the last decade. By equipping base stations (BSs) with hundreds of antennas in a compact array or a distributed manner, this new technology can provide very large multiplexing gains by serving many users on the same time-frequency resources and thereby bring significant improvements in spectral efficiency (SE) and energy efficiency (EE) over the current wireless networks. LÄS MER

5. 19. Optical Design for Stationary Solar Concentrators

   Författare :Johan Nilsson; Avdelningen för Energi och byggnadsdesign; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; photovoltaic cells; parabolic reflectors; optical efficiency; Solar concentrators; photovoltaic-thermal systems; non-imaging optics; optical properties; building integrated photovoltaics; non uniform irradiance distribution; structured reflectors; solar cell modelling; ray tracing;

   Sammanfattning : Solar electricity is one of the most promising technologies for our future electricity supply. By using concentrators, it is possible to reduce the cost of generating photovoltaic electricity. This thesis discusses how to design stationary low concentrating systems for photovoltaic or PV/Thermal applications. LÄS MER

7. 20. Electromechanical Interactions in Shuttle Systems and Carbon Nanotube Relays

   Författare :Tomas Nord; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Coulomb blockade; carbon nanotubes; memory device; nanorelay; single electron tunneling; van der Waals forces; NEMS; shuttle transport; mesoscopic; nanoelectromechanical systems;

   Sammanfattning : In this thesis we theoretically investigate two kinds of nanoscale systems where there is a strong electromechanical coupling, i.e. an intricate relation between the Coulomb forces that can appear in these systems and the displacements of parts of the systems that they cause. LÄS MER