Documents disponibles écrits par cet auteur

An experimental and numerical investigation on the thermal-hydraulic performance of double notched plate / Zhang, Lei in Journal of heat transfer, Vol 134 N° 9 (Septembre 2012) 

Public ISBD [article]  in Journal of heat transfer > Vol 134 N° 9 (Septembre 2012) . - 07 p. Titre : An experimental and numerical investigation on the thermal-hydraulic performance of double notched plate Type de document : texte imprimé Auteurs : Zhang, Lei, Auteur ; Defu Che, Auteur Année de publication : 2012 Article en page(s) : 07 p. Note générale : heat transfer Langues : Anglais (eng) Mots-clés : rotary  air  preheater;  double  notched  plate;  single-blow  technique;  numerical  simulation;  heat  transfer;  friction  factor Index. décimale : 536 Chaleur. Thermodynamique Résumé : The double notched (DN) plate is commonly used in rotary air preheaters, but relevant investigations are rare. Thus, thermal-hydraulic performances of the DN plate are investigated in this paper. A single-blow, transient technique is refined and then used to measure the overall mean heat transfer coefficients and friction factors. A validated numerical method is also utilized to provide local information. The measured results show that the performance of the DN plate approaches that of the double undulated (DU) plate and lies between that of the cross corrugated (CC) plate and the parallel plate. No swirling flow pattern is identified in the predicted velocity fields. Basically, two types of flow are observed: wavy channel flow and pipe flow. High or low Nusselt numbers, Nu, are obtained at the luff or lee side of undulations and notches, respectively. Nu values increase and Nu distributions become more homogenous with increasing Reynolds numbers, Re. A recommendation is made that the DN plate be operated under moderate Re to achieve homogenous and enhanced heat transfer, given the allowable pressure drop. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JHTRAO000134000009 [...] [article] An experimental and numerical investigation on the thermal-hydraulic performance of double notched plate [texte imprimé] / Zhang, Lei, Auteur ; Defu Che, Auteur . - 2012 . - 07 p. heat transfer Langues : Anglais (eng) in Journal of heat transfer > Vol 134 N° 9 (Septembre 2012) . - 07 p. Mots-clés : rotary  air  preheater;  double  notched  plate;  single-blow  technique;  numerical  simulation;  heat  transfer;  friction  factor Index. décimale : 536 Chaleur. Thermodynamique Résumé : The double notched (DN) plate is commonly used in rotary air preheaters, but relevant investigations are rare. Thus, thermal-hydraulic performances of the DN plate are investigated in this paper. A single-blow, transient technique is refined and then used to measure the overall mean heat transfer coefficients and friction factors. A validated numerical method is also utilized to provide local information. The measured results show that the performance of the DN plate approaches that of the double undulated (DU) plate and lies between that of the cross corrugated (CC) plate and the parallel plate. No swirling flow pattern is identified in the predicted velocity fields. Basically, two types of flow are observed: wavy channel flow and pipe flow. High or low Nusselt numbers, Nu, are obtained at the luff or lee side of undulations and notches, respectively. Nu values increase and Nu distributions become more homogenous with increasing Reynolds numbers, Re. A recommendation is made that the DN plate be operated under moderate Re to achieve homogenous and enhanced heat transfer, given the allowable pressure drop. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JHTRAO000134000009 [...]

Chemical, electrochemical and spectral characterization of water leachates from biomass / Lei Deng in Industrial & engineering chemistry research, Vol. 51 N° 48 (Décembre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 48 (Décembre 2012) . - pp. 15710–15719 Titre : Chemical, electrochemical and spectral characterization of water leachates from biomass Type de document : texte imprimé Auteurs : Lei Deng, Auteur ; Defu Che, Auteur Année de publication : 2013 Article en page(s) : pp. 15710–15719 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Electrochemical  Leachates  Biomass Résumé : To develop pretreatment strategies for better industrial utilization of biomass materials, six types of biomass were washed with deionized water at 303, 333, and 363 K, and the leachate was characterized by chemical, electrochemical, and spectral analysis. The results show that K+ is the most abundant cation in the leachates. An increase in the washing temperature leads to an increase in the cation concentration mainly because of the increment of K+. The chemical oxygen demand (COD) and the charge difference between inorganic cations and anions for leachate suggest that, in addition to inorganic ions, a few organic compounds and organic anions are released from biomass during washing. Fourier transform infrared (FTIR) spectra of the dry leachate samples reveal that carbohydrates and carboxylates are the major components of the organic compounds and organic salts, respectively. Except for the leachate of rice straw, the charge difference and COD increase with increasing washing temperature because of the increment of carboxylates for all of the other leachates. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301468b [article] Chemical, electrochemical and spectral characterization of water leachates from biomass [texte imprimé] / Lei Deng, Auteur ; Defu Che, Auteur . - 2013 . - pp. 15710–15719. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 48 (Décembre 2012) . - pp. 15710–15719 Mots-clés : Electrochemical  Leachates  Biomass Résumé : To develop pretreatment strategies for better industrial utilization of biomass materials, six types of biomass were washed with deionized water at 303, 333, and 363 K, and the leachate was characterized by chemical, electrochemical, and spectral analysis. The results show that K+ is the most abundant cation in the leachates. An increase in the washing temperature leads to an increase in the cation concentration mainly because of the increment of K+. The chemical oxygen demand (COD) and the charge difference between inorganic cations and anions for leachate suggest that, in addition to inorganic ions, a few organic compounds and organic anions are released from biomass during washing. Fourier transform infrared (FTIR) spectra of the dry leachate samples reveal that carbohydrates and carboxylates are the major components of the organic compounds and organic salts, respectively. Except for the leachate of rice straw, the charge difference and COD increase with increasing washing temperature because of the increment of carboxylates for all of the other leachates. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301468b