Thermodynamic Analysis of Geothermal Energy Sourced Organic Rankine Power Plant

Öz

Geothermal energy from geothermal sources is becoming increasingly popular as a sustainable energy source for electricity generation in our country. Binary geothermal power plants are systems that generate electricity with the help of Organic Rankine Cycle (ORC) using geothermal fluid temperature. Energy and exergy analyses of the cycle and each system component that constitutes the cycle are performed in detail. Engineering Equation Solver (EES) software is used for these analyses. N-pentane is used as the working fluid in the ORC system. As a result of the calculations, the overall energy efficiency of the system is found to be 6% and the exergy efficiency is found to be 45%. Changes in efficiencies according to different operating parameters of the system are presented through graphs. It is determined that the highest exergy loss in the power plant is 6.12 MW (26% of the total exergy loss) in air-cooled condenser 2. Finally, various suggestions and recommendations are made in the study to reduce exergy losses and improve system efficiency.

Anahtar Kelimeler

• Geothermal energy
• Organic rankine cycle
• Energy efficiency
• Exergy analysis.

Jeotermal Enerji Kaynaklı Organik Rankine Güç Santralinin Termodinamik Analizi

Öz

Sürdürülebilir enerji türü olarak jeotermal kaynaklardan elektrik üretimi ülkemizde gittikçe yaygınlaşmaktadır. İkili (binary) jeotermal enerji santrali, jeotermal akışkan ısısından Organik Rankine Çevrimi (ORC) yardımı ile elektrik üreten sistemlerdir. Çevrimin ve çevrimi oluşturan her bir sistem elemanının enerji ve ekserji analizleri ayrıntılı bir şekilde yapılmıştır. Bu analizler için Engineering Equation Solver (EES) yazılımı kullanılmıştır. ORC sisteminde iş akışkanı olarak n-pentan kullanılmıştır. Hesaplamalar sonucunda tüm sistemin enerji verimi %6, ekserji verimi ise %45 olarak bulunmuştur. Sistemin farklı çalışma parametrelerine göre verimlerdeki değişimler grafikler aracılığıyla ortaya konmuştur. Santralde en yüksek ekserji kaybının 6.12 MW (tüm ekserji kaybının %26’sı) ile hava soğutmalı kondenser 2’de olduğu tespit edilmiştir. Çalışmada son olarak ekserji kayıplarının azaltılması ve sistem verimliliğin iyileştirilmesi için çeşitli öneriler ve tavsiyelerde bulunulmuştur.

Anahtar Kelimeler

• jeotermal enerji
• organik rankine çevrimi
• asdasdas
• asdsadas

Kaynakça

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