Performance and power smoothing of innovative closed-circuit oscillating water column wave energy converter
University College Cork
Due to the urgency to limit global warming to 1.5◦C, it is necessity to find alternatives to fossil fuel energy to empower human activities. Among the alternative resources of energy, wave energy has a large potential as it could potentially represent 10% of the world electricity demand. Significant progress in this field is however still needed to produce affordable electrical energy. Oscillating-Water-Column (OWC) devices are among the most promising types of wave energy converters because of their relative simplicity. The present work investigates the possibility of improving the performance of this well-established concept by introducing a variation in the working principle. The resulting new Tupperwave concept is equipped with non-return valves and air pressure accumulators to create a smooth unidirectional air flow, harnessed efficiently by a unidirectional turbine. In this thesis, the Tupperwave concept is investigated physically and numerically on a floating structure. In order to assess the relevance of the Tupperwave device against the conventional OWC, wave-to-wire numerical models for both devices are developed, using different thermodynamic approaches and considering the use of the current state-of-the-art turbines for each device. The different power conversion processes of the wave-to-wire models are validated through physical experiments. The wave-to-wire models are then used to identify the benefits of pneumatic power smoothing by the Tupperwave device and assess its electrical power performance. The results demonstrate the potential of the new Tupperwave concept to outperform the conventional OWC concept in terms of electrical power production and quality.
Wave energy , Non-return valves , Air turbine , Non-isentropic , Oscillating water column , Wave-to-wire model
Benreguig, P. 2019. Performance and power smoothing of innovative closed-circuit oscillating water column wave energy converter. PhD Thesis, University College Cork.