Simultaneous modular based flowsheeting in chemical processes
Küçük Resim Yok
Tarih
1994
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Ege Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
ÖZET Flowsheeting hesaplamaları, kimyasal proses tasarımı ve simülasyonunda, son yıllarda giderek önem kazanmaktadır. Özellikle bilgisayar teknolojisindeki gelişmeler flowsheeting programlarının kullanım alanlarını genişletmiştir. Proses simülasyonunda başlangıçta sıralı modüler yaklaşım kullanılmaktaydı. Bu yaklaşım özellikle dizayn ve optimizasyon problemlerinin çözümünde birçok kısıtlar getirdiği için günümüzde eşanlı modüler yaklaşım daha cok tercih edilmektedir. Bu çalışmada, bir tek birime yada bütün bir flowsheete ait kütle yada kütle ve enerji hesaplamalarını yapabilen, eşanlı modüler yaklaşıma dayanan flowsheeting paketi Borland C++ dilinin 5.0 versiyonu kullanılarak geliştirilmiştir. Veri bankası 625 organik ve anorganik maddeye ait fiziksel özellikleri içermektedir. Bu veriler kullanılarak termodinamik özellikler farklı foksiyonlarda hesaplanmaktadır. Flowsheet decomposizyonu için Man (197^) tarafından geliştirilen arc-augmentation algoritması programlanmıştır. Kesilen akımların secimi için depth first search algoritması geliştirilmiştir. Prosese ilişkin model denklemlerinin çözümü Newton-Raphson metoduna dayanan denklem çözücüyle yapılmaktadır. Geliştirilen paketle elde edilen tecrübe eşanlı modüler yaklaşımın hesaplama kabiliyetinin yüksek olduğunu göstermiştir. Karşılaşılan en ciddi sorun fiziksel olarak mantıklı bir çözümüm bile bazen yakınsamamasıdır. Bu sorunun bir kısmı debi, sıcaklık, bası ne ve kompozisyon için geliştirilen başlangıç değer atamalarıyla halledilmiştir. 158Geliştirilen paket endüstriyel tesislerin simülasyonunda kullanılabilir. Paketin akademik olarak kullanımının henüz tam olarak değer lend iri 1 memesi ne ragmen, alınan sonuçlar paketin bilgisayar destekli tasarım derslerinde yararlı olabileceğini göstermiştir. U, -îfcEj asa» 1S9
SUMMARY In recent years» process flowsheeting has become an accepted tool for the design and simulation of chemical processes. Advanced computer architectures, especially vector processing and multiprocessing» offer computational power applied to the chemical process flowsheeting problem. Formerly, in the steady-state flowsheet simulation the sequential strategy was generally used. However this approach has several limitations especially when dealing with design and optimization problems. Nowadays simultaneous approaches are becoming more and more preferable in practice. In this study, a flowsheeting program based on the simultaneous modular strategy was developed by using Borland C++ version S.O language. It can perform mass and/or mass- enthalpy balance calculations for a complete flowsheet or for a single unit. The data bank contains physical properties for 6S5 inorganic and organic compounds. The physical and thermophysical properties are calculated using the pure component constants in external functions. For the partitioning of the flowsheet into maximal cyclic nets, the arc-augmentation algorithm proposed by Mah (1974) was modified and programmed. A nonredundant tearing set of stream was determined by depth first search algorithm. The nonlinear unit models were solved by a Newtonian equation solver. Computational experience with the developed package showed that simultaneous modular approach with several convergence methods may considerably increase the computation flexibility. The most serious difficulty is the inability to converge even when a physically acceptable solution 156exists. An important part of this inconvenience was overcomed with a good initialization procedure for flow rates, temperatures, pressures and compositions. The developed flowsheet ing package can be used as a steady state chemical process simulation system in industrial plants. Although the full impact of its use in the academic environments has not yet been fully evaluated, the early indications are that it has been useful and productive in computer aided design courses. 1H7
SUMMARY In recent years» process flowsheeting has become an accepted tool for the design and simulation of chemical processes. Advanced computer architectures, especially vector processing and multiprocessing» offer computational power applied to the chemical process flowsheeting problem. Formerly, in the steady-state flowsheet simulation the sequential strategy was generally used. However this approach has several limitations especially when dealing with design and optimization problems. Nowadays simultaneous approaches are becoming more and more preferable in practice. In this study, a flowsheeting program based on the simultaneous modular strategy was developed by using Borland C++ version S.O language. It can perform mass and/or mass- enthalpy balance calculations for a complete flowsheet or for a single unit. The data bank contains physical properties for 6S5 inorganic and organic compounds. The physical and thermophysical properties are calculated using the pure component constants in external functions. For the partitioning of the flowsheet into maximal cyclic nets, the arc-augmentation algorithm proposed by Mah (1974) was modified and programmed. A nonredundant tearing set of stream was determined by depth first search algorithm. The nonlinear unit models were solved by a Newtonian equation solver. Computational experience with the developed package showed that simultaneous modular approach with several convergence methods may considerably increase the computation flexibility. The most serious difficulty is the inability to converge even when a physically acceptable solution 156exists. An important part of this inconvenience was overcomed with a good initialization procedure for flow rates, temperatures, pressures and compositions. The developed flowsheet ing package can be used as a steady state chemical process simulation system in industrial plants. Although the full impact of its use in the academic environments has not yet been fully evaluated, the early indications are that it has been useful and productive in computer aided design courses. 1H7
Açıklama
Bu tezin, veri tabanı üzerinden yayınlanma izni bulunmamaktadır. Yayınlanma izni olmayan tezlerin basılı kopyalarına Üniversite kütüphaneniz aracılığıyla (TÜBESS üzerinden) erişebilirsiniz.
Anahtar Kelimeler
Kimya Mühendisliği, Chemical Engineering, Bilgisayar programları, Computer programs, Flowsheeting, Flowsheeting
