Documents disponibles écrits par cet auteur

Development of one-dimensional model for initial design and evaluation of oil-free Co2 turbo-compressor / Bartosz, Kus in International journal of refrigeration, Vol. 36 N° 8 (Décembre 2013) 

Public ISBD [article]  in International journal of refrigeration > Vol. 36 N° 8 (Décembre 2013) . - pp. 2079-2090 Titre : Development of one-dimensional model for initial design and evaluation of oil-free Co2 turbo-compressor Titre original : Développement d'un modèle unidimensionnel pour la conception initiale et l'évaluation d'un turbo-compresseur sans huile au CO2 Type de document : texte imprimé Auteurs : Bartosz, Kus, Auteur ; Petter Nekså, Auteur Année de publication : 2014 Article en page(s) : pp. 2079-2090 Note générale : Refrigeration Langues : Anglais (eng) Mots-clés : Radial  turbo-compressor;  carbon  dioxide;  compression;  oil-free  compressors;  oil-free  refrigeration Résumé : A 1-dimenional tool for preliminary design and performance prediction of oil-free CO2 compressor is presented. The model describes high speed centrifugal compressor in a hermetic configuration supported on foil gas bearings. To give possibly comprehensive overview of the technology, a wide range of loss mechanisms is considered. The model predicts aerodynamic performance of the compressor as well as losses related to the windage of rotor and bearings and due to the internal cooling. Numerical investigation of different compressor stages was used to validate aerodynamic predictions of the 1D model. Maximal prediction discrepancy amounted 2% for efficiency and 5% for pressure ratio. The prediction of the total compressor efficiency was compared with test data from a 50 kW compressor published Sandia Laboratories. The predicted peak compressor efficiencies are between 66 and 67.5% while experimentally measured values are within 65–70% region. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700713001217 [article] Development of one-dimensional model for initial design and evaluation of oil-free Co2 turbo-compressor = Développement d'un modèle unidimensionnel pour la conception initiale et l'évaluation d'un turbo-compresseur sans huile au CO2 [texte imprimé] / Bartosz, Kus, Auteur ; Petter Nekså, Auteur . - 2014 . - pp. 2079-2090. Refrigeration Langues : Anglais (eng) in International journal of refrigeration > Vol. 36 N° 8 (Décembre 2013) . - pp. 2079-2090 Mots-clés : Radial  turbo-compressor;  carbon  dioxide;  compression;  oil-free  compressors;  oil-free  refrigeration Résumé : A 1-dimenional tool for preliminary design and performance prediction of oil-free CO2 compressor is presented. The model describes high speed centrifugal compressor in a hermetic configuration supported on foil gas bearings. To give possibly comprehensive overview of the technology, a wide range of loss mechanisms is considered. The model predicts aerodynamic performance of the compressor as well as losses related to the windage of rotor and bearings and due to the internal cooling. Numerical investigation of different compressor stages was used to validate aerodynamic predictions of the 1D model. Maximal prediction discrepancy amounted 2% for efficiency and 5% for pressure ratio. The prediction of the total compressor efficiency was compared with test data from a 50 kW compressor published Sandia Laboratories. The predicted peak compressor efficiencies are between 66 and 67.5% while experimentally measured values are within 65–70% region. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700713001217

Novel partial admission radial compressor for CO2 applications / Bartosz, Kus in International journal of refrigeration, Vol. 36 N° 8 (Décembre 2013) 

Public ISBD [article]  in International journal of refrigeration > Vol. 36 N° 8 (Décembre 2013) . - pp. 2065–2078 Titre : Novel partial admission radial compressor for CO2 applications Titre original : Nouveau compresseur radial à admission radiale pour applications au dioxyde de carbone Type de document : texte imprimé Auteurs : Bartosz, Kus, Auteur ; Petter Nekså, Auteur Année de publication : 2014 Article en page(s) : pp. 2065–2078 Note générale : Refrigeration Langues : Anglais (eng) Mots-clés : Novel  partial  admission  compressor;  oil-free  compressors;  oil-free  refrigeration;  CO2  turbo-compressor Résumé : A novel partial admission turbo compressor concept is proposed as an alternative to a conventional radial oil-free CO2 compressor. The concept aims at the improvement of the overall performance through the reduction of the non-stage windage and cooling losses enabled by compression at significantly reduced shaft speeds. Transient CFD analysis gives fairly optimistic prediction of more than 80% of base stage efficiency at around 1.4 total pressure ratio. The study shows potential for efficiency improvement by optimization of the shape and number of blades. The conceptual compressor may be an interesting alternative for commercial CO2 applications operating at close to critical pressures, provided that the deceleration of the gas in the diffuser is efficient. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700713001801 [article] Novel partial admission radial compressor for CO2 applications = Nouveau compresseur radial à admission radiale pour applications au dioxyde de carbone [texte imprimé] / Bartosz, Kus, Auteur ; Petter Nekså, Auteur . - 2014 . - pp. 2065–2078. Refrigeration Langues : Anglais (eng) in International journal of refrigeration > Vol. 36 N° 8 (Décembre 2013) . - pp. 2065–2078 Mots-clés : Novel  partial  admission  compressor;  oil-free  compressors;  oil-free  refrigeration;  CO2  turbo-compressor Résumé : A novel partial admission turbo compressor concept is proposed as an alternative to a conventional radial oil-free CO2 compressor. The concept aims at the improvement of the overall performance through the reduction of the non-stage windage and cooling losses enabled by compression at significantly reduced shaft speeds. Transient CFD analysis gives fairly optimistic prediction of more than 80% of base stage efficiency at around 1.4 total pressure ratio. The study shows potential for efficiency improvement by optimization of the shape and number of blades. The conceptual compressor may be an interesting alternative for commercial CO2 applications operating at close to critical pressures, provided that the deceleration of the gas in the diffuser is efficient. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700713001801