Documents disponibles écrits par cet auteur

A comparison of different generalised modelling approaches for a scroll refrigerant compressor / C. K. Lee in International journal of refrigeration, Vol. 36 N° 4 (Juin 2013) 

Public ISBD [article]  in International journal of refrigeration > Vol. 36 N° 4 (Juin 2013) . - pp. 1369–1375 Titre : A comparison of different generalised modelling approaches for a scroll refrigerant compressor Titre original : Comparaison des différentes approches générales à la modélisation du compresseur à spirale frigorifique Type de document : texte imprimé Auteurs : C. K. Lee, Auteur ; H. N. Lam, Auteur Année de publication : 2013 Article en page(s) : pp. 1369–1375 Note générale : Refrigeration Langues : Anglais (eng) Mots-clés : Vapour-compression  cycle;  Refrigerant;  Polytropic  process;  Isentropic  efficiency;  Polytropic  efficiency;  Polytropic  coefficient Résumé : A comparison was made between the errors for the simulated and test performance of a scroll compressor based on three generalised modelling approaches. Four types of refrigerants, namely R22, R134a, R407C and R410A, were analysed, each using a number of compressors which cover the low to medium capacity range. It was found that the use of the constant-polytropic-coefficient approach (CPC) yielded much higher errors in the simulated isentropic efficiencies than those based on the constant-polytropic-efficiency approach (CPE) and the Mallen–Saville approach (MS). The CPE was the best among the three approaches considered, although it was computationally the least efficient. The average errors in the simulated isentropic efficiencies ranged from 8.3 to 10.1% for the four types of refrigerants considered while the corresponding errors in the simulated refrigerant mass flow rates and compressor power inputs varied from 1.1 to 1.8% and 7.7 to 10%. Meanwhile, the simplest CPC should be dismissed on account of the large resultant error and the yielding of incorrect trends in the simulated isentropic efficiencies. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700713000170 [article] A comparison of different generalised modelling approaches for a scroll refrigerant compressor = Comparaison des différentes approches générales à la modélisation du compresseur à spirale frigorifique [texte imprimé] / C. K. Lee, Auteur ; H. N. Lam, Auteur . - 2013 . - pp. 1369–1375. Refrigeration Langues : Anglais (eng) in International journal of refrigeration > Vol. 36 N° 4 (Juin 2013) . - pp. 1369–1375 Mots-clés : Vapour-compression  cycle;  Refrigerant;  Polytropic  process;  Isentropic  efficiency;  Polytropic  efficiency;  Polytropic  coefficient Résumé : A comparison was made between the errors for the simulated and test performance of a scroll compressor based on three generalised modelling approaches. Four types of refrigerants, namely R22, R134a, R407C and R410A, were analysed, each using a number of compressors which cover the low to medium capacity range. It was found that the use of the constant-polytropic-coefficient approach (CPC) yielded much higher errors in the simulated isentropic efficiencies than those based on the constant-polytropic-efficiency approach (CPE) and the Mallen–Saville approach (MS). The CPE was the best among the three approaches considered, although it was computationally the least efficient. The average errors in the simulated isentropic efficiencies ranged from 8.3 to 10.1% for the four types of refrigerants considered while the corresponding errors in the simulated refrigerant mass flow rates and compressor power inputs varied from 1.1 to 1.8% and 7.7 to 10%. Meanwhile, the simplest CPC should be dismissed on account of the large resultant error and the yielding of incorrect trends in the simulated isentropic efficiencies. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700713000170

Simplified explicit calculation algorithms for determining the performance of refrigerant coils in vapour-compression systems / C. K. Lee in International journal of refrigeration, Vol. 38 (Février 2014) 

Public ISBD [article]  in International journal of refrigeration > Vol. 38 (Février 2014) . - pp. 178–188 Titre : Simplified explicit calculation algorithms for determining the performance of refrigerant coils in vapour-compression systems Titre original : Algorithmes explicites simplifiés de calcul pour la détermination de la performance de serpentins frigorifiques dans des systèmes à compression de vapeur Type de document : texte imprimé Auteurs : C. K. Lee, Auteur ; H. N. Lam, Auteur Année de publication : 2014 Article en page(s) : pp. 178–188 Note générale : Refrigeration Langues : Anglais (eng) Mots-clés : Refrigerant  coil;  Vapour-compression  cycle;  Overall  heat  transfer  value;  Heat  transfer  coefficient;  Temperature  effectiveness Résumé : Simplified explicit calculation algorithms were proposed for determining the performance of the condenser, evaporator and air cooler in a vapour-compression system based on a zone-model approach. It was assumed that the fluid temperature changes in the sub-cooled and superheated portions were small and that the wet portion of an air cooler only occurred in the entire saturated portion if it was not fully-dry. With R134a employed as the refrigerant, the simulated coil capacity based on the present modelling approach were compared with those based on a multi-node numerical approach at different refrigerant mass flow rates. It was found that the errors in the simulated specific enthalpy change of the refrigerant across the coil did not exceed 3.6% in all cases. In particular, the errors incurred by employing the present modelling approach in simulating the capacity and compressor power input of a sample water-cooled chiller at different condenser and evaporator fluid entering temperatures were less than 2.7% and 3.1% respectively. This showed that the present approach could be a good choice for improving the computation efficiency of a vapour-compression system significantly while the accuracy of the simulation could still be maintained at an acceptable level. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700713002326 [article] Simplified explicit calculation algorithms for determining the performance of refrigerant coils in vapour-compression systems = Algorithmes explicites simplifiés de calcul pour la détermination de la performance de serpentins frigorifiques dans des systèmes à compression de vapeur [texte imprimé] / C. K. Lee, Auteur ; H. N. Lam, Auteur . - 2014 . - pp. 178–188. Refrigeration Langues : Anglais (eng) in International journal of refrigeration > Vol. 38 (Février 2014) . - pp. 178–188 Mots-clés : Refrigerant  coil;  Vapour-compression  cycle;  Overall  heat  transfer  value;  Heat  transfer  coefficient;  Temperature  effectiveness Résumé : Simplified explicit calculation algorithms were proposed for determining the performance of the condenser, evaporator and air cooler in a vapour-compression system based on a zone-model approach. It was assumed that the fluid temperature changes in the sub-cooled and superheated portions were small and that the wet portion of an air cooler only occurred in the entire saturated portion if it was not fully-dry. With R134a employed as the refrigerant, the simulated coil capacity based on the present modelling approach were compared with those based on a multi-node numerical approach at different refrigerant mass flow rates. It was found that the errors in the simulated specific enthalpy change of the refrigerant across the coil did not exceed 3.6% in all cases. In particular, the errors incurred by employing the present modelling approach in simulating the capacity and compressor power input of a sample water-cooled chiller at different condenser and evaporator fluid entering temperatures were less than 2.7% and 3.1% respectively. This showed that the present approach could be a good choice for improving the computation efficiency of a vapour-compression system significantly while the accuracy of the simulation could still be maintained at an acceptable level. En ligne : http://www.sciencedirect.com/science/article/pii/S0140700713002326