A Study of a Supercritical Closed Cycle with Independent Power Turbine

Öz

In this study, thermodynamic analysis of a transcritical closed cycle with independent power turbine was performed. Carbon dioxide (CO2), which stands out with its thermophysical properties, was preferred as the cycle fluid. In addition to the cycle based on the Brayton power cycle, an independent power turbine was added and the cycle parameters were examined. Analysis of the cycle Thermodynamic calculations of the cycle were made using the computer program called Engineering Equation Solver (EES). The effects of turbine inlet temperature and pressure, compressor pressure ratio, compressor efficiency, high and low (independent) pressure turbine efficiency and compressor inlet temperatures on the energy-exergy efficiency and net power of the cycle under different cycle parameters were examined. Additionally, the effects of the low-pressure (independent) turbine in the cycle were evaluated. When the turbine parameters were examined, it was determined that the low-pressure (independent) turbine directly affected the cycle efficiency by 4.12%. In the cycle parameters, maximum energy efficiency was calculated as 20.07%, exergy efficiency was 39.22% and cycle net power was calculated as 306.4 kW. In power cycles, the benefits of using CO2 turbines and the effects of a low-pressure (independent) turbine on the cycle have been evaluated. The gains that can be achieved regarding CO2 turbines are discussed.

Anahtar Kelimeler

• co2
• turbine
• cycle
• analysis

Bağımsız Güç Türbinli Süperkritik Kapalı Bir Çevrimin İncelenmesi

Öz

Bu çalışmada, bağımsız güç türbinli transkritik kapalı çevrimin termodinamik analizi yapılmıştır. Çevrim akışkanı olarak termofiziksel özellikleriyle ön plana çıkan karbondioksit (CO2) akışkanı tercih edilmiştir. Brayton güç çevrim esasına dayalı çevrime ek olarak bağımsız bir güç türbin ilave edilerek çevrim parametreleri incelenmiştir. Çevrimin analizi Engineering Equation Solver (EES) adlı bilgisayar programından faydalanılarak çevrimin termodinamik hesaplamaları yapılmıştır. Farklı çevrim parametrelerinde türbin giriş sıcaklık ve basıncının, kompresör basınç oranı, kompresör verimi, yüksek ve alçak (bağımsız) basınçlı türbin veriminin ve kompresör giriş sıcaklıklarının çevrimin enerji-ekserji verimine ve çevrim net gücüne etkileri incelenmiştir. Bununla birlikte çevrimdeki alçak basınçlı (bağımsız) türbinin çevrim üzerindeki etkileri değerlendirilmiştir. Türbin parametreleri incelendiğinde alçak basınçlı (bağımsız) türbinin çevrim verimine doğrudan %4.12 etki ettiği tespit edilmiştir. Çevrim parametrelerinde maksimum enerji verimi %20.07, ekserji verimi %39.22 ve çevrim net gücü 306.4 kW olarak hesaplanmıştır. Güç çevrimlerinde, CO2 türbinlerinin kullanımının sağladığı faydalar ve alçak basınçlı (bağımsız) türbinin çevrime etkileri değerlendirilmiştir. CO2 türbinleri ile ilgili elde edilebilecek kazanımlar tartışılmıştır.

Anahtar Kelimeler

• co2
• türbin
• çevrim
• analiz

Kaynakça

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