Search for dissertations about: "energy level engineering"

Showing result 1 - 5 of 885 swedish dissertations containing the words energy level engineering.

  2. 1. Distributed thermal response tests : New insights on U-pipe and Coaxial heat exchangers in groundwater-filled boreholes

    Author : José Acuña; Björn Palm; Jeffrey Spitler; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Borehole heat exchangers; Distributed Thermal Response Test; Ground Source Heat Pumps; Coaxial; U-pipe; Multi-pipe; Pipe-in-pipe; Multi-chamber; Groundwater; Thermosyphon; SRA - Energy; SRA - Energi;

    Abstract : U-pipe Borehole Heat Exchangers (BHE) are widely used today in ground source heating and cooling systems in spite of their less than optimal performance. This thesis provides a better understanding on the function of U-pipe BHEs and Investigates alternative methods to reduce the temperature difference between the circulating fluid and the borehole wall, including one thermosyphon and three different types of coaxial BHEs. READ MORE

  4. 2. Prediction horizon requirement  in control and extreme load analyses for survivability : Advancements to improve the performance of wave energy technologies

    Author : Zahra Shahroozi; Jens Engström; Malin Göteman; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; control; optimal velocity; non-causality; maximum power output; extreme waves; wave tank experiment; end-stop compression; wave breaking slamming; PTO damping; return level; return period; peak-over-threshold;

    Abstract : The main objective of wave energy converters (WECs) is to ensure reliable electricity production at a competitive cost. Two challenges to achieving this are ensuring an efficient energy conversion and offshore survivability. READ MORE

  5. 3. Modular Battery Systems for Electric Vehicles based on Multilevel Inverter Topologies - Opportunities and Challenges

    Author : Anton Kersten; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dynamic reconfiguration; Energy storage; Energy efficiency; Drive cycle efficiency; Power MOSFET; vehicles; H-bridge; Multilevel systems; Electromagnetic compatibility; Modular battery systems; Battery system performance; Modular multilevel converters; Conduction losses; Electric vehicles; Batteries; Dual battery pack; Cascaded converters; DC-AC power converters; BMS; Common mode noise; Battery modeling; vehicle electrification;

    Abstract : Modular battery systems based on multilevel inverter (MLI) topologies can possibly overcome some shortcomings of two-level inverters when used for vehicle propulsion. The results presented in this thesis aim to point out the advantages and disadvantages, as well as the technical challenges, of modular vehicle battery systems based on MLIs in comparison to a conventional, two-level IGBT inverter drivetrain. READ MORE

  6. 4. On the Design Considerations for Thermal Energy Storage with Phase Change Materials: Material Characterization and Modelling

    Author : Pepe Tan; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Phase Change Materials; Simulation; T-History; Thermal Energy Storage;

    Abstract : Integrating thermal energy storage (TES) technologies to a process enables storing and releasing thermal energy on demand. Depending on the implementation, this may lead to economic and ecological improvements, e.g. by shifting the peak demand to off-peak hours or by increasing the share of utilized renewable energy. READ MORE

  7. 5. Multi-Disciplinary Conceptual Design of Future Jet Engine Systems

    Author : Konstantinos G. Kyprianidis; Stephen O. T. Ogaji; Riti Singh; Herbert Saravanmuttoo; UK Cranfield University; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Gas Turbine; Intercooled; Recuperated; Turbofan; Future; Simulation; Performance; Aircraft; Emissions; Multi-disciplinary; Jet Engine; Energy- and Environmental Engineering; energi- och miljöteknik;

    Abstract : This thesis describes various aspects of the development of a multi-disciplinary aero engine conceptual design tool, TERA2020 (Techno-economic, Environmental and Risk Assessment for 2020), based on an explicit algorithm that considers: engine performance, engine aerodynamic and mechanical design, aircraft design and performance, emissions prediction and environmental impact, engine and airframe noise, and production, maintenance and direct operating costs.As part of this research effort, a newly-derived semi-empirical NOx correlation for modern rich-burn single-annular combustors is proposed. READ MORE