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Heat transfer characteristics of oscillating heat pipe with water and ethanol as working fluids / Haizhen Xian in Journal of heat transfer, Vol. 132 N° 12 (Décembre 2010) 

Public ISBD [article]  in Journal of heat transfer > Vol. 132 N° 12 (Décembre 2010) . - pp. [121501-1/6] Titre : Heat transfer characteristics of oscillating heat pipe with water and ethanol as working fluids Type de document : texte imprimé Auteurs : Haizhen Xian, Auteur ; YongPing Yang, Auteur Année de publication : 2010 Article en page(s) : pp. [121501-1/6] Note générale : Physique Langues : Anglais (eng) Mots-clés : Oscillating  heat  pipe  Heat  transfer  characteristics  Water  Ethanol Index. décimale : 536 Chaleur. Thermodynamique Résumé : In this paper, experiments were conducted to achieve a better understanding of the oscillating heat pipe (OHP) operating behavior with water and ethanol as working fluid. The experimental results showed that there existed a necessary temperature difference between the evaporator and the condenser section to keep the heat pipe working. The maximum effective conductivity of the water OHP reached up to 259 kW/m K, while that of the ethanol OHP is of 111 kW/m K. Not all the OHPs are operated in the horizontal operation mode. The heat transfer performance of the ethanol OHP was obviously affected by the filling ratio and the inclination angle but the influence law is irregular. The effect of the filling ratio and the inclination angle of the water OHP were smaller than that of the ethanol one. The heat transfer performance of the OHP was improved with increase of operating temperature. The startup characteristics of the OHP depended on the establishment of the integral oscillating process, which was determined by the operating factors. The startup temperature of the ethanol OHP varied from 40°C to 50°C and that of the water, OHP varied from 40°C to 60°C without considering the horizontal operating mode. The water OHP showed a better performance and more stable heat transfer characteristics than the ethanol OHP, which had no obvious advantages of the startup capability as well. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...] [article] Heat transfer characteristics of oscillating heat pipe with water and ethanol as working fluids [texte imprimé] / Haizhen Xian, Auteur ; YongPing Yang, Auteur . - 2010 . - pp. [121501-1/6]. Physique Langues : Anglais (eng) in Journal of heat transfer > Vol. 132 N° 12 (Décembre 2010) . - pp. [121501-1/6] Mots-clés : Oscillating  heat  pipe  Heat  transfer  characteristics  Water  Ethanol Index. décimale : 536 Chaleur. Thermodynamique Résumé : In this paper, experiments were conducted to achieve a better understanding of the oscillating heat pipe (OHP) operating behavior with water and ethanol as working fluid. The experimental results showed that there existed a necessary temperature difference between the evaporator and the condenser section to keep the heat pipe working. The maximum effective conductivity of the water OHP reached up to 259 kW/m K, while that of the ethanol OHP is of 111 kW/m K. Not all the OHPs are operated in the horizontal operation mode. The heat transfer performance of the ethanol OHP was obviously affected by the filling ratio and the inclination angle but the influence law is irregular. The effect of the filling ratio and the inclination angle of the water OHP were smaller than that of the ethanol one. The heat transfer performance of the OHP was improved with increase of operating temperature. The startup characteristics of the OHP depended on the establishment of the integral oscillating process, which was determined by the operating factors. The startup temperature of the ethanol OHP varied from 40°C to 50°C and that of the water, OHP varied from 40°C to 60°C without considering the horizontal operating mode. The water OHP showed a better performance and more stable heat transfer characteristics than the ethanol OHP, which had no obvious advantages of the startup capability as well. DEWEY : 536 ISSN : 0022-1481 En ligne : http://asmedl.aip.org/vsearch/servlet/VerityServlet?KEY=JHTRAO&ONLINE=YES&smode= [...]

A novel coal-based hydrogen production system with low CO2 emissions / Gang Xu in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 3 (Mars 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 3 (Mars 2010) . - 09 p. Titre : A novel coal-based hydrogen production system with low CO2 emissions Type de document : texte imprimé Auteurs : Gang Xu, Auteur ; HongGuang Jin, Auteur ; YongPing Yang, Auteur Année de publication : 2010 Article en page(s) : 09 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Adsorption  Air  pollution  control  Carbon  compounds  Coal  Cryogenics  Energy  consumption  Hydrogen  production  Liquefaction  Solidification Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : In this paper, we have proposed a novel coal-based hydrogen production system with low CO2 emission. In this novel system, a pressure swing adsorption H2 production process and a CO2 cryogenic capture process are well integrated to gain comprehensive performance. In particular, through sequential connection between the pressure swing absorption (PSA) H2 production process and the CO2 capture unit, the CO2 concentration of PSA purge gas that enters the CO2 capture unit can reach as high as 70%, which results in as much as 90% of CO2 to be separated from mixed gas as liquid at a temperature of −55°C. This will reduce the quantity and quality of cold energy required for cryogenic separation method, and the solidification of CO2 is avoided. The adoption of cryogenic energy to capture CO2 enables direct production of liquid CO2 at low pressure and thereby saves a lot of compression energy. Besides, partial recycle of the tail gas from CO2 recovery unit to PSA inlet can help enhance the amount of hydrogen product and lower the energy consumption for H2 production. As a result, the energy consumption for the new system's hydrogen production is only 196.8 GJ/tH2 with 94% of CO2 captured, which is 9.2% lower than that of the coal-based hydrogen production system with Selexol CO2 removal process and is only 2.6% more than that of the coal-based hydrogen production system without CO2 recovery. More so, the energy consumption of CO2 recovery is expected to be reduced by 20–60% compared with that of traditional CO2 separation processes. Further analysis on the novel system indicates that synergetic integration of the H2 production process and cryogenic CO2 recovery unit, along with the synthetic utilization of energy, plays a significant role in lowering energy penalty for CO2 separation and liquefaction. The promising results obtained here provide a new approach for CO2 removal with low energy penalty. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000003 [...] [article] A novel coal-based hydrogen production system with low CO2 emissions [texte imprimé] / Gang Xu, Auteur ; HongGuang Jin, Auteur ; YongPing Yang, Auteur . - 2010 . - 09 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 3 (Mars 2010) . - 09 p. Mots-clés : Adsorption  Air  pollution  control  Carbon  compounds  Coal  Cryogenics  Energy  consumption  Hydrogen  production  Liquefaction  Solidification Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : In this paper, we have proposed a novel coal-based hydrogen production system with low CO2 emission. In this novel system, a pressure swing adsorption H2 production process and a CO2 cryogenic capture process are well integrated to gain comprehensive performance. In particular, through sequential connection between the pressure swing absorption (PSA) H2 production process and the CO2 capture unit, the CO2 concentration of PSA purge gas that enters the CO2 capture unit can reach as high as 70%, which results in as much as 90% of CO2 to be separated from mixed gas as liquid at a temperature of −55°C. This will reduce the quantity and quality of cold energy required for cryogenic separation method, and the solidification of CO2 is avoided. The adoption of cryogenic energy to capture CO2 enables direct production of liquid CO2 at low pressure and thereby saves a lot of compression energy. Besides, partial recycle of the tail gas from CO2 recovery unit to PSA inlet can help enhance the amount of hydrogen product and lower the energy consumption for H2 production. As a result, the energy consumption for the new system's hydrogen production is only 196.8 GJ/tH2 with 94% of CO2 captured, which is 9.2% lower than that of the coal-based hydrogen production system with Selexol CO2 removal process and is only 2.6% more than that of the coal-based hydrogen production system without CO2 recovery. More so, the energy consumption of CO2 recovery is expected to be reduced by 20–60% compared with that of traditional CO2 separation processes. Further analysis on the novel system indicates that synergetic integration of the H2 production process and cryogenic CO2 recovery unit, along with the synthetic utilization of energy, plays a significant role in lowering energy penalty for CO2 separation and liquefaction. The promising results obtained here provide a new approach for CO2 removal with low energy penalty. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ000132000003 [...]