Sökning: "Marine vessel"

Visar resultat 1 - 5 av 29 avhandlingar innehållade orden Marine vessel.

1. 1. Non-Azeotropic Mixtures as Working Fluids in Heat Pumps: A theoretical and experimental study

   Författare :Marine Högberg; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; HCFC123; HCFC124a; HCFC22; performance comparison; COP; non-azeotropic mixture; capacity; sensitivity analysis; HFC152a; heat pump; CFC114; ethyl chloride; experimental study; HCFC142b; two-stage cycle;

   Sammanfattning : Due to the fact that CFC (Chloro-Fluoro-Carbon) fluids will be forbidden as working fluids in heat pumps for environmental reasons, there is an urgent need for alternatives. As one alternative type of fluid, non-azeotropic mixtures have been suggested. This thesis deals with such mixtures. LÄS MER

3. 2. Waste heat recovery in a cruise vessel

   Författare :Fredrik Ahlgren; Marcus Thern; Aykut Ölcer; Linnéuniversitetet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; whr; orc; ships; waste heat recovery; energy efficiency; cruise ships; Sjöfartsvetenskap; Maritime Science;

   Sammanfattning : In three studies of a cruise ship the author has investigated waste heat recovery (WHR)from exhaust gases using an organic Rankine cycle (ORC), and also mapped the energyand exergy flows within the ship. Data were collected from the ship’s machinerysystem for a total extent of one year, and this data were used for simulations andenergy calculations. LÄS MER

4. 3. Measurements and Prediction of Friction Drag of Rough Surfaces

   Författare :Bercelay Niebles Atencio; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; PIV; RANS; Turbulent Boundary Layers; Flat Plate; Resolved CFD; Hydrodynamics; Roughness Function; Wall Functions; Rotating Disk;

   Sammanfattning : Owing to the increased sea transportation of goods, the environmental impacts of this activity are becoming more and more important, since a ship experiences resistance that directly affects its performance and fuel consumption. The growth of marine organisms (fouling) on ship hulls increases the roughness of the hull surface, which in turn causes a rise in ship resistance with a consequent increase in fuel consumption and greenhouse emissions of up to 40%. LÄS MER

5. 4. Data-driven Ship Performance Models - - Emphasis on Energy Efficiency and Fatigue Safety

   Författare :Xiao Lang; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; semi-empirical; energy efficiency; fatigue assessment; grey-box; full-scale measurements; speed-power relationship; added resistance due to waves; ship performance; machine learning;

   Sammanfattning : Due to digitalization in the maritime industry, a huge amount of ship operation-related data has been collected. The main objective of this thesis is to exploit machine learning/big data analytics to build data-driven ship performance models, focusing on speed-power relationship modeling, and fatigue accumulation assessment during a ship’s operation at sea. LÄS MER

7. 5. Towards Sustainable Shipping: Climate change and other environmental perspectives on carbon-based marine electrofuels and onboard carbon capture

   Författare :Elin Malmgren; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; liquefied natural gas; power-to-X; methanol; power-to-gas; carbon capture and utilization; thematic analysis; Marine renewable energy; onboard carbon capture; marine fuels; LCA; shipping; electrofuels;

   Sammanfattning : The global, local, and regional environment is under pressure from human activity. Shipping is a human activity causing emissions to air, water, and soil, which has direct and indirect effects on the environment. LÄS MER