1 st Ocean Energy colloquium Ocean Thermal Energy

1 st Ocean Energy colloquium Ocean Thermal Energy Conversion June 2015 Challenge the future 1

Agenda of today 12: 45 Ocean Energy Platform at TU Delft - B. J. Kleute 12: 50 OTEC research & developments - Dr. ir. C. A. Infante Ferreira 13: 10 OTEC thesis - Vilborg Guðjónsdóttir 13. 20 Discussion Challenge the future 2

Context • Oceans cover 70% of the Earth’s surface and are a vast renewable energy resource • Oceans are still relatively unexplored • TU Delft is renowned in Water and Offshore Energy research (2 nd position globally in Offshore Wind) • TU Delft can build on an extensive network of knowledge partners and industry in the Water and Offshore field Challenge the future 3

Ocean Energy Tidal / current Wave Aquatic biomass Thermal gradient Salinity gradient Challenge the future 4

Ocean Energy platform TU Delft aims to play a major role in ocean energy research, education, development, knowledge transfer, and international cooperation and to help solve the key challenges of Ocean Energy: • Ocean energy resource analysis • Energy conversion optimization • Offshore engineering • System integration Challenge the future 5

Ocean Energy platform The Ocean Energy platform will work on: • Cluster expertise and connect researchers with an interest in Ocean Energy at the TU Delft faculties • Attract funds and start of research projects (e. g. Ph. D’s) in Ocean Energy; • Initiation of laboratory prototype projects; • Ocean energy education resources, e. g. teaching materials, books, and videos. Challenge the future 6

Ocean Energy platform http: //oceanenergy. tudelft. nl/ Challenge the future 7

Ocean Thermal Energy Conversion activities at Process and Energy Carlos Infante Ferreira Challenge the future 8

Analysis of External Influences on an OTEC cycle Vilborg Guðjónsdóttir Challenge the future 9

The Project • What are the effects of temperature fluctuations on the OTEC cycle? • • Based on previous optimization of the OTEC cycle Model created Experiments performed to validate the model Three working fluid researched • Ammonia water • R 32 – R 134 a Challenge the future 10

The model • Steady state off design model • Implemented in MATLAB • Thermodynamic properties from the REFPROP database • Experiments performed with pure ammonia to validate the model Challenge the future 11

The Thermodynamic cycle Challenge the future 12

The OTEC Demo Challenge the future 13

Validation Challenge the future 14

Results Challenge the future 15

Results Challenge the future 16

Conclusions • Decrease in power and efficiency is proportional to the decrease in temperature difference • Warm and cold seawater temperature fluctuations have similar effects • Each degree difference has high impact • Mass flow of the working fluid can be varied to improve the performance slightly Challenge the future 17

Recommendations • Combine the off design model with optimizing model • Perform more experiments with more sensors • Confirm pressure drop correlations • Confirm heat transfer correlations for ammonia water Challenge the future 18

1 st Ocean Energy colloquium Questions ? June 2015 Challenge the future 19

Next lunch lecture: Monday, 28 September Peter Scheijgrond – Ocean Energy roadmap Challenge the future 20