Döner rejeneratörlerde geçici rejim ısı aktarımının sayısal analizi

Bu çalışmada, paralel ve karşıt akışlı rejeneratörlerin ısıl analizi incelenmiştir. Rejeneratör diferansiyel denklemleri Termodinamiğin Birinci kanunu kullanılarak ve akış yönündeki ısı iletimi dikkate alınarak çıkarılmıştır. Rejeneratördeki akışkan ve duvar sıcaklıklarını hesaplamaya yarayan diferansiyel denklemler sonlu farklar yöntemiyle çözülerek rejeneratördeki sıcaklık dağılımları bulunmuştur. Bu sıcaklık dağılımlarından da rejeneratör etkinlik değerleri hesaplanmıştır. Sonuç olarak transfer birimi sayısı Ntu ve ısıl kapasite oranı Cr* değerlerinin orantılı bir şekilde artırılması rejeneratör etkinliğini arttırmaktadır.

Numerical analysis of transient conjugate heat transfer in rotary regenerators

In this study, the thermal analysis of parallel and counter-flow regenerators are investigated. Regenerator differential equations are written by using the first law of thermodynamics. In the regenerator differential equations, conductive heat transfer in flow direction is taken into consideration. Two differential equations are used for calculation of fluid and wall temperature from finite difference methods in the regenerator. This effectiveness of regenerator is computed from the temperature distributions. As an outcome, the proportional increase in Ntu and the Cr* results in increasing of the regenerators' effectiveness.

PDF

___

1.F.E. Romie, Transient response of rotary regenerators, Journal of Heat Transfer, Transactions of ASME, Vol. 110, pp.836-840, 1988.
2.T. Skiepko, The effect of matrix longitudinal heat conduction on the temperature fields in the rotary heat exchanger, Int. Journal of Heat Mass Transfer, Vol.31, No. 11, pp.2227-2238, 1988.
3.R. Scaricabarozzi, Simple particular solutions and speed calculation of regenerator, Heat Recovery Systems and CHP, Vol.9, No.5, pp.421 -432, 1989.
4.A.J. Willmott and R.C. Duggan, Refined closed methods for the contra-flow thermal regenerator problem, Int. Journal of Heat Mass Transfer, Vol. 23, pp.655-662, 1980.
5.I.L. Maclaine-Cross, Effect of interstitial fluid heat capacity on regenerator performance, Journal of Heat Transfer, Transactions of ASME, Vol.102, pp.572-574, 1980.
6.C.H. Li, A numerical finite difference method for performance evaluation of a periodic-flow heat exchanger. Journal of Heat Transfer, Transactions of ASME, Vol.105, pp.611-617, 1983.
7.P.J. Banks, The representation of regenerator fluid carryover by bypass flows, Journal of Heat Transfer, Transactions of ASME, Vol.106, pp.210-220, 1984.
8.F.E. Romie, Transient response of the counter flow heat exchanger, Journal of Heat Transfer,Transactions of ASME, Vol. 106, pp. 620-626, 1984.
9.P.J. Banks, Prediction of heat and mass regenerator performance using nonlinear analogy method: Part 1- Basic, Journal of Heat Transfer, Transactions of ASME. Vol.107, pp.222-229,1985.
10.P.J. Banks, Prediction of heat and mass regenerator performance using nonlinear analogy method: Part 2- Comparison of methods, Journal of Heat Transfer, Transactions of ASME,Vol.107, pp.230-238, 1985.
11.Z. Wozniak, Dynamics of transient states of the counter flow heat regenerator. Numerical Heat Transfer, Vol.8, pp.751-760, 1985.
12. B.S. Baclic, The application of the Galerkin method to the solution of the symmetric and balanced counter flow regenerator problem, Journal of Heat Transfer, Transactions of ASME, Vol.107, pp.214-221, 1985.
13.F.E. Romie, Transient response of the parallel-flow heat exchanger, Journal of Heat Transfer,Transactions of ASME, Vol. 107, pp.727-730, 1985.
14.F. Demiralp, Döner tip rejeneratörlerin etkinliğinin sonlu farklar yöntemiyle hesaplanması.Yüksek Lisans Tezi, Fırat Üniversitesi Fen Bilimleri Enstitüsü, 86s, 2002.