Experimental Validation of Power Output and Efficiency for an Oscillating Water Column (OWC)

Yıl 2024, , 54 - 72, 30.06.2024

Şafak Nur Ertürk Bozkurtoğlu

https://doi.org/10.54926/gdt.1405048

Öz

With the global energy demand escalating and concerns over the environmental impact of fossil fuels, there's a pressing need for cleaner, sustainable alternatives. This study highlights the potential contribution of wave energy to the power needs of coastal structures in the context of renewable energy. The research evaluates the power output and efficiency for an Oscillating Water Column (OWC) system that can be integrated into coastal structures to meet part of their power needs. Findings from both theoretical calculations and a 1:10 scale model experiment are presented. The mechanical power output and efficiency of the system for a full-scale prototype were calculated for deep water conditions with a wave height of 3m. The water surface oscillation inside the chamber is assumed to reflect the oscillation occurring outside the chamber. The maximum average mechanical power output for the full-scale prototype, corresponding to a wavelength of 22.5 m, was determined to be 64.8 kW, achieving a mechanical efficiency of 64.4%.
The overall efficiency of the system is calculated as 55% by assuming the generator efficiency to be 85%, resulting in an average power output of approximately 55 kW. A 1:10 scale model of the OWC system with a Wells turbine was constructed and tested in a tank for deep water conditions. Froude similarity and Keulegan-Carpenter similarity were used, ensuring a seamless transition from the model to the prototype. The OWC model was subjected to controlled heaving motion with a period of T=1.2 s. The power generated by the OWC model illuminated four integrated 3.4V LEDs on the Wells turbine, which were used to measure the power output produced. The power output of the model was measured to be a minimum of 0.12 W for a rotational speed of 107 rpm, which corresponds to a power output of 12 kW for the scaled-up prototype. This system has the potential for further enhancement by incorporating multiple OWCs into coastal structures exposed to wave action. Such development could facilitate meeting the power requirements of coastal structures, thereby contributing to the promotion of both renewable energy generation and a sustainable environment. Future research will focus on optimizing OWC chamber sizes for specific sites and refining the model to better capture water surface oscillation dynamics.
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Anahtar Kelimeler

Renewable Energy, Wave Energy, Oscillating Water Column, Sustainability

Teşekkür

The author acknowledges resources and support from Ata Nutku Ship Model Testing Laboratory at ITU Faculty of Naval Architecture and Ocean Engineering

Salınımlı Su Kolonu (OWC) için Güç Çıkışı ve Verimin Deneysel Olarak Doğrulanması

Öz

Küresel enerji talebinin artması ve fosil yakıtların çevresel etkilerine ilişkin endişeler nedeniyle daha temiz, sürdürülebilir alternatiflere acil ihtiyaç duyulmaktadır. Bu çalışma, yenilenebilir enerji bağlamında dalga enerjisinin kıyı yapılarının güç ihtiyaçlarına potansiyel katkısını vurgulamaktadır. Araştırma, kıyı yapılarına entegre edilebilecek, böyle bu yapıların güç ihtiyacının bir kısmını karşılayabilecek bir Salınımlı Su Kolonu (OWC) sistemi için güç çıkışı ve verimliliği değerlendirmektedir. Hem teorik hesaplamalardan hem de 1:10 ölçekli bir model deneyinden elde edilen bulgular sunulmuştur. Tam bir prototip için sistemin çıkış gücü ve verimliliği, 3 m dalga yüksekliğine sahip derin su koşulları için hesaplanmıştır. Hazne içindeki su yüzeyi salınımının hazne dışında meydana gelen salınımı yansıttığı varsayılmıştır. Tam ölçekli prototip için 22,5 m dalga boyuna karşılık gelen maksimum ortalama mekanik güç çıkışı 64,8 kW olarak belirlenmiş ve %64,4'lük bir mekanik verim elde edilmiştir. Wells türbinli OWC sisteminin 1:10 ölçekli bir modeli oluşturulmuş ve derin su koşulları için bir tankta test edilmiştir. Froude benzerliği ve Keulegan-Carpenter benzerliği kullanılarak modelden prototipe sorunsuz bir geçiş sağlanmıştır. OWC modeli, T=1.2 s periyotla kontrollü dalıp-çıkma hareketine tabi tutulmuştur. OWC modeli tarafından üretilen güç, Wells türbini üzerindeki entegre dört adet 3.4V LED'i aydınlatmış ve bu da üretilen güç çıkışını ölçmek için kullanılmıştır. Modelin güç çıkışı 107 rpm dönüş hızı için minimum 0,12 W olarak ölçülmüştür ve bu da ölçeklendirilmiş prototip için 12 kW'lık bir güç çıkışına karşılık gelmektedir. Bu sistem, dalga etkisine maruz kalan kıyı yapılarına birden fazla OWC'nin dahil edilmesiyle daha fazla geliştirilme potansiyeline sahiptir. Bu tür bir gelişme, kıyı yapılarının güç gereksinimlerinin karşılanmasını kolaylaştırabilir ve böylece hem yenilenebilir enerji üretiminin hem de sürdürülebilir bir çevrenin teşvik edilmesine katkıda bulunabilir. Gelecekteki araştırmalar, belirli sahalar için OWC hazne boyutlarını optimize etme ve su yüzeyi salınım dinamiklerini daha iyi yakalayacak şekilde modeli iyileştirmeye odaklanacaktır.

Anahtar Kelimeler

Yenilenebilir Enerji, Dalga Enerjisi, Salınımlı Su Kolonu, Sürdürülebilirlik

Kaynakça

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