Simulation of bed-to-wall heat transfer in circulating fluidized beds

Bu çalışmada, sirkülasyonlu akışkan yataklı yakıcılarda yataktan duvara ısı geçişinin nümerik simülasyonu yapılmıştır. Simülasyonda, daha önceden geliştirilmiş olan ve hidrodinamik ve yanmayı aynı anda tahmin edebilen ve tanecik yaklaşımını kullanan iki boyutlu sirkülasyonlu akışkan yatak modelinden yararlanılmıştır. Çalışma, aynı zamanda, literatürde yayınlanmış çalışmalarla da doğrulanmıştır. Simülasyon tahminlerinin deneysel verilerle karşılaştırılması; işletme hızı, tane çapı ve yatak yığın yoğunluğu gibi farklı işletme şartları için modelin esnekliğini göstermiştir. Ayrıca, simülasyon sonuçlarının; yatak yığın yoğunluğunun bir fonksiyonu olan ısı geçiş katsayısı için farklı sıcaklık değerlerinde deneysel verilerle göstermiş olduğu uyum, simülasyonun aynı zamanda hem soğuk, hem de sıcak akışkan yataklar için de geçerli olduğunun bir göstergesidir.

Sirkülasyonlu akışkan yataklarda yataktan duvara ısı geçişinin simulasyonu

In this study, the numerical simulation of bed-to-wall heat transfer in CFBs is presented which based on previously developed 2D CFB model which uses the particle-based approach and integrates and simultaneously predicts the hydrodynamics, combustion aspects. The study is also validated with published data. The comparisons of the model predictions and experimental data indicate that the model is flexible enough to operate under different operational conditions concerning superficial velocity, particle diameter and suspension density values. Additionally, the simulation matches the measured data quite faithfully for heat transfer coefficient as a function of the suspension density at different temperature values which is also an indicator that that the simulation is valid for both cold and hot CFB units.

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