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Development and analysis of a natural gas reliquefaction plant for small gas carriers / P. Nekså in Journal of natural gas science and engineering, Vol. 2 N° 2-3 (Juillet 2010) 

Public ISBD [article]  in Journal of natural gas science and engineering > Vol. 2 N° 2-3 (Juillet 2010) . - pp. 143–149 Titre : Development and analysis of a natural gas reliquefaction plant for small gas carriers Type de document : texte imprimé Auteurs : P. Nekså, Auteur ; E. Brendeng, Auteur ; M. Drescher, Auteur Année de publication : 2012 Article en page(s) : pp. 143–149 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : LNG  Process  development  Reliquefaction  Gas  carriers  Small  scale  Exergy  analysis Résumé : A small-scale reliquefaction plant for natural gas boil-off gas from gas tankers has been developed, analysed and experimentally tested in laboratory and in full-scale. The reliquefaction plant is installed onboard a 10 000 m3 gas carrier intended for transport of LNG between export and receiving terminals, initially in Scandinavia and in the Baltic Sea. Typical production capacity of a full-scale plant is 20 tonnes of LNG per day. Standard refrigeration components, easily available as off the shelf products, are used in the system design. Copper brazed plate heat exchangers are among the key components. The combination of using a lubricant injected screw compressor and a mixed component refrigerant contributes to achieve relatively high energy efficiency. The gas carrier is also designed to carry other gases such as ethylene, LPG and VCM, and is therefore equipped with a newly developed ordinary cascade refrigeration plant. When the vessel is in LNG service the capacity of the cascade plant is used for precooling of LNG boil-off as well as for precooling of the mixed component refrigerant. A theoretical analysis of the plant shows a specific power consumption of 0.49 kWh/kg LNG, corresponding to an exergy efficiency of 34%. The specific suction volume is 1.8 m3/kg LNG with the current mixed refrigerant composition. The loss analysis shows several possible improvement possibilities. Successful full-scale tests have been performed, verifying the liquefaction capacity and operation of the plant. ISSN : 1875-5100 En ligne : http://www.sciencedirect.com/science/article/pii/S1875510010000326 [article] Development and analysis of a natural gas reliquefaction plant for small gas carriers [texte imprimé] / P. Nekså, Auteur ; E. Brendeng, Auteur ; M. Drescher, Auteur . - 2012 . - pp. 143–149. Génie Chimique Langues : Anglais (eng) in Journal of natural gas science and engineering > Vol. 2 N° 2-3 (Juillet 2010) . - pp. 143–149 Mots-clés : LNG  Process  development  Reliquefaction  Gas  carriers  Small  scale  Exergy  analysis Résumé : A small-scale reliquefaction plant for natural gas boil-off gas from gas tankers has been developed, analysed and experimentally tested in laboratory and in full-scale. The reliquefaction plant is installed onboard a 10 000 m3 gas carrier intended for transport of LNG between export and receiving terminals, initially in Scandinavia and in the Baltic Sea. Typical production capacity of a full-scale plant is 20 tonnes of LNG per day. Standard refrigeration components, easily available as off the shelf products, are used in the system design. Copper brazed plate heat exchangers are among the key components. The combination of using a lubricant injected screw compressor and a mixed component refrigerant contributes to achieve relatively high energy efficiency. The gas carrier is also designed to carry other gases such as ethylene, LPG and VCM, and is therefore equipped with a newly developed ordinary cascade refrigeration plant. When the vessel is in LNG service the capacity of the cascade plant is used for precooling of LNG boil-off as well as for precooling of the mixed component refrigerant. A theoretical analysis of the plant shows a specific power consumption of 0.49 kWh/kg LNG, corresponding to an exergy efficiency of 34%. The specific suction volume is 1.8 m3/kg LNG with the current mixed refrigerant composition. The loss analysis shows several possible improvement possibilities. Successful full-scale tests have been performed, verifying the liquefaction capacity and operation of the plant. ISSN : 1875-5100 En ligne : http://www.sciencedirect.com/science/article/pii/S1875510010000326

Use of sophisticated heat exchanger simulation models for investigation of possible design and operational pitfalls in LNG processes / G. Skaugen in Journal of natural gas science and engineering, Vol. 2 N° 5 (Novembre 2010) 

Public ISBD [article]  in Journal of natural gas science and engineering > Vol. 2 N° 5 (Novembre 2010) . - pp. 235–243 Titre : Use of sophisticated heat exchanger simulation models for investigation of possible design and operational pitfalls in LNG processes Type de document : texte imprimé Auteurs : G. Skaugen, Auteur ; G.A. Gjøvåg, Auteur ; P. Nekså, Auteur Année de publication : 2012 Article en page(s) : pp. 235–243 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : LNG  Process  optimization  Heat  exchanger  design  Static  instability  Ledinegg  instability Résumé : The simulation rating programs S-FIN for PFHE and S-PLATE for PHE have been developed at SINTEF Energy Research. These tools can be incorporated in process simulation environments like PRO/II and Aspen HYSYS®, and thus be used as an integrated part when doing process energy simulation and optimization. Static flow instabilities that can occur in heat exchangers used in cryogenic services are discussed. Examples on how to perform, and how to interpret, a Ledinegg instability analysis, are shown using the developed programs. With the well-known single mixed refrigerant process as a case study, a thermally valid plate-fin heat exchanger was designed that was subjected to Ledinegg instability. Remedies to avoid this and the effect on the process energy consumption are discussed. For the selected case, the compressor power increased by 14% going from an unstable to a stable design/operation. The examples show that detailed heat exchanger simulations should be performed as a part of process optimization. ISSN : 1875-5100 En ligne : http://www.sciencedirect.com/science/article/pii/S1875510010000752 [article] Use of sophisticated heat exchanger simulation models for investigation of possible design and operational pitfalls in LNG processes [texte imprimé] / G. Skaugen, Auteur ; G.A. Gjøvåg, Auteur ; P. Nekså, Auteur . - 2012 . - pp. 235–243. Génie Chimique Langues : Anglais (eng) in Journal of natural gas science and engineering > Vol. 2 N° 5 (Novembre 2010) . - pp. 235–243 Mots-clés : LNG  Process  optimization  Heat  exchanger  design  Static  instability  Ledinegg  instability Résumé : The simulation rating programs S-FIN for PFHE and S-PLATE for PHE have been developed at SINTEF Energy Research. These tools can be incorporated in process simulation environments like PRO/II and Aspen HYSYS®, and thus be used as an integrated part when doing process energy simulation and optimization. Static flow instabilities that can occur in heat exchangers used in cryogenic services are discussed. Examples on how to perform, and how to interpret, a Ledinegg instability analysis, are shown using the developed programs. With the well-known single mixed refrigerant process as a case study, a thermally valid plate-fin heat exchanger was designed that was subjected to Ledinegg instability. Remedies to avoid this and the effect on the process energy consumption are discussed. For the selected case, the compressor power increased by 14% going from an unstable to a stable design/operation. The examples show that detailed heat exchanger simulations should be performed as a part of process optimization. ISSN : 1875-5100 En ligne : http://www.sciencedirect.com/science/article/pii/S1875510010000752