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Large Heat Capacity (large + heat_capacity)
Selected AbstractsTransient response of closed-loop MHD experimental facilityELECTRICAL ENGINEERING IN JAPAN, Issue 1 2007Hidemasa Takana Abstract Transient responses of a closed-loop MHD experimental facility from nonpower generation to power generation have been investigated by means of time-dependent quasi-one-dimensional numerical simulations. For the long-time continuous power generation experiment, the time required to obtain the steady state for the power generation is estimated to be approximately 20 hours. By increasing the electrical input power to the heater as an exponential function of time, the temperature increment of ceramics can be moderated. When the duration of the experiment is around 10 minutes, argon gas temperature at the exit of the heater hardly changes because of the large heat capacity of structure materials. It is found that the fluid disturbances are induced at the instant of the power generation and they propagate as they repeatedly reflect at the sudden change of duct shape. Since all of the induced disturbances attenuate approximately 0.4 second after the power generation, the time scale that the disturbances exist in the facility is estimated to be 1 second at most. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 158(1): 46,52, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20237 [source] Adhesion and detachment characteristics of a TBAB hydrate solid on a heat transfer surface (Effect of concentration of TBAB solutions)HEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 6 2009Tadafumi Daitoku Abstract In air-conditioning systems, it is desirable that the liquid,solid phase change temperature of a cool energy storage material be approximately 10°C, with respect to improving the coefficient of performance (COP). Moreover, a thermal storage material that forms slurry can realize a large heat capacity of the working fluids. A solid that adheres to the heat transfer surface forms a thermal resistance layer and significantly reduces the rate of cold storage; therefore, it is important to avoid the adhesion of a thick solid layer on the surface so as to realize efficient energy storage. Considering a harvest type cooling unit, the force required for removal of the solid phase from the heat transfer surface was investigated. Tetra-n-butylammonium bromide (TBAB) clathrate hydrate was used as a cold storage material and the effect of the TBAB solution concentration on the scraping force required to detach the adhered TBAB hydrate solid from the heat transfer surface was experimentally examined. The TBAB hydrate solids were broadly categorized into two types, and the scraping force required for removal of these two types of TBAB hydrate solid was different. The scraping force required for removal of the solid increased due to the effect of increasing the concentration of the TBAB solution. © 2009 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20254 [source] An effect of scraper shapes on detachment of solid adhered to cooling surface for formation of clathrate hydrate slurryHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 8 2007Tadafumi Daitoku Abstract In air-conditioning systems, it is desirable that the liquid, solid phase change temperature of a cool energy storage material is approximately 10°C from the perspective of improving the coefficient of performance (COP). Moreover, a thermal storage material that forms slurry can realize large heat capacity of working fluids. Since the solid that adheres to the heat transfer surface forms a thermal resistance layer and remarkably reduces the rate of cold storage, it is important to avoid the adhesion of a thick solid layer on the surface so as to realize efficient energy storage. Considering a harvest type cooling unit, the force required for removing the solid phase from the heat transfer surface was studied. Tetra-n-butylammonium bromide (TBAB) clathrate hydrate was used as a cold storage material. The effect of the scraper shapes on the scraping force for detachment of the adhered solid of TBAB hydrate to the heat transfer surface was examined experimentally. The TBAB hydrate solids were categorized broadly into two kinds of solids. The scraping force of the TBAB hydrate solid on the heat transfer surface was different for the two kinds of the TBAB hydrate solids. And the scraping force of the TBAB hydrate solid formed after scraping was improved by the modifying the scraper shape. © 2007 Wiley Periodicals, Inc. Heat Trans Asian Res, 36(8): 489, 500, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20179 [source] Adhesion of thermoplastic elastomer on surface treated aluminum by injection moldingPOLYMER ENGINEERING & SCIENCE, Issue 8 2007P.A. Fabrin Hybrid composites were prepared using insert injection molding without preheating. Thermoplastic elastomer (TPE) was overmolded on etched aluminum sheets having porous surface to provide large contact area between insert and TPE. The resulting bond strength was studied using a 180° peel test. The effect of aluminum microstructure and various processing steps of the surface treatment procedures on adhesion were studied. Maximum peel strength obtained was 9.33 N/cm using P2 treatment with alkaline-acid pretreatment. Lowest peel strength of 1.68 N/cm was achieved by alkaline,acid treatment. Increasing insert thickness lowers the peel strength since large heat capacity of thicker insert cools the melt and limits penetration of the melt to insert microcavities. At certain insert thickness microcavities are impregnated by the melt and no additional effect can be obtained by decreasing the insert thickness. POLYM. ENG. SCI., 47:1187,1191, 2007. © 2007 Society of Plastics Engineers [source] | ||||||||||