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02611 Flexibility analysis of the vessel-piping interface
16 Fuel science and technology (fundamental science, analysis, instrumentation) decrease in the total number of particulates and an increase in the number-averaged diameter of the particulates, as measured by the Electrical Aerosol Size Analyser. The results will be useful in understanding the mechanisms leading to changes in diesel particulates in an exhaust pipe.
04/02610 Feasibility analysis of manufacturing high performance ecological cement in Turkey Arikan, M. Building and Environment, 2004, 39, (9), 1125-1130. The world production of cement has significantly increased in recent years due to the growing demand. This trend in the production increase is one of the most significant factors effecting the technological development in cement industry and updating its manufacturing facilities. Unfortunately, the existing technology for the production of cement clinker has adverse ecological effects, such as consumption of much energy and natural resources and emission of a number of pollutants. The production of blended or high volume mineral additive cement, thus high performance cement, increases the compressive strength of ordinary cement and improves the durability of cementbased materials, permitting the utilization of high volume of inexpensive mineral additives or industrial by-products. Thus, higher strength, better durability, reduction of both pollution and energy consumption at the clinker production stage and decrease in the landfill area required by industrial by-products, all provide ecological advantages for high performance cement. In this study, a feasibility analysis was carried out for Turkish cement manufacturers to demonstrate that it is profitable for the cement manufacturers to invest in high performance cement manufacturing. The effects of various parameters on the investment such as sale price, loan amount, interest rate, expected rate of return, etc. were also studied.
04/02611
Flexibility analysis of the vessel-piping interface
Schwarz, M. M. International Journal of Pressure Vessels and Piping, 2004, 81, (2), 181 189. The connections of a pressure vessel with the interconnecting piping system are the boundaries for the computer model built for the analysis of the vessel. The stiffness and the imposed displacements at these points significantly influence the stresses in the piping as well as forces and moments imposed on the connection to the adjacent pressure equipment. This paper summarizes the results of numerous FEM analyses to establish stiffness coefficients for nozzles in spherical and cylindrical pressure vessels.
04/02612 Forced convection and subcooled flow boiling heat transfer in asymmetrically heated ducts of T-section Abou-Ziyan, H. Z. Energy Conversion and Management, 2004, 45, (7 8), 1043-1065. This paper presents the results of an experimental investigation of heat transfer from the heated bottom side of tee cross-section ducts to an internally flowing fluid. The idea of this work is derived from the cooling of critical areas in the cylinder heads of internal combustion engines. Fully developed single phase forced convection and subcooled flow boiling heat transfer data are reported. Six T-ducts of different width and height aspect ratios are tested with distilled water at velocities of 1, 2 and 3 m/s for bulk temperatures of 60 and 80°C, while the heat flux was varied from about 80 to 700 kW/m 2. The achieved data cover Reynolds numbers in the range of 5.22 x 104 to 2.36 x 105, Prandtl numbers in the range from 2.2 to 3.0, duct width aspect ratio between 2.19 and 3.13 and duct height aspect ratio from 0.69 to 2.0. The results revealed that the increase in either the width or height aspect ratio of the T-ducts enhances the convection heat transfer coefficients and the boiling heat fluxes considerably. The following comparisons are provided for coolant velocity of 2 m/s, bulk temperature of 60°C, wall superheat of 20 K and wall to bulk temperature difference of 20 K. As the width aspect ratio increases by 43%, the convection heat transfer coefficient and the boiling heat flux increase by 27% and 39%, respectively. An increase in the height aspect ratio by 290% enhances the convection heat transfer coefficient and the boiling heat fluxes by 82% and 103%, respectively. When the coolant velocity changes from 1 to 2 m/s, the heat transfer coefficient increases by 60% and the boiling heat flux rises by 62-98% for the various tested ducts. The convection heat transfer coefficient increases by 12% and the boiling heat flux decreases by 31% as the bulk fluid temperature rises from 60 to 80°C. A correlation was developed for Nusselt number as a function of Reynolds number, Prandtl number, viscosity ratio and some aspect ratios of the T-duct.
04/02613 Graphical method for the determination of water/ gas partition coefficients of volatile organic compounds by a headspace gas chromatography technique Bakierowska, A.-M. and Trzeszczynski, J. Fluid Phase Equilibria, 2003, 213, (1-2), 139-146. Water/gas partition coefficients have been determined for hydrocarbons and chlorinated derivatives of hydrocarbons. In this paper a graphical method based on a static headspace gas chromatography
364 Fuel and Energy Abstracts September 2004
technique is described. This technique relies on the linear dependence of the phase volume ratio in the vial and the ratio of the concentration of the solute in two phases. The partition coefficients were determined at four temperatures ranging from 10 to 25°C. The temperature dependence of the partition coefficients is described by the classical van't Hoff equation.
04/02614 Incorporating different endogenous learning formulations in MERGE Bahn, O. and Kypreos, S. Int. J. Global Energy Issues, 2003, 19, (4), 333-358. This paper presents the implementation of endogenous technological change, following either a one-factor or a two-factor learning curve, in the M E R G E model. A new version of this model, called MERGEETL, has been developed to analyse the dynamics of endogenous technological learning (ETL) in the energy system. This paper describes first the basic formulation of MERGE-ETL, then the solving techniques used for this model, and presents finally some numerical results in the context of policies designed to mitigate a global climate change.
04•02615 Linear equations on thermal degradation products of wood chips in alkaline glycerol Demirba, A. Energy Conversion and Management, 2004, 45, (7 8), 983 994. Wood chips of 0.3 and 2 m m depth from poplar and spruce wood samples, respectively, were degraded by using glycerol as a solvent and alkaline glycerol with and without NazCO3 and NaOH catalysts at different degradation temperatures: 440, 450, 460, 470, 480, 490 and 500 K. By products from the degradation processes of the lignocelluloses include lignin degradation products. Lignin and its degradation products have fuel values. The total degradation degree and cellulose degradation of the wood chips were determined to find the relationship, if any, between the yields of total degradation degree (YTD) and degradation temperature (7). There is a good linear relationship between YTD or the yields of cellulose degradation (YCD) and T(K). For the wood samples, the regression equations from NaOH (10%) catalytic runs for 0.3 m m x 15 m m x 15 m m chip size are: For poplar wood: (a) YTD = 0 . 7 2 5 0 T - 267.507 (render), (b) YCD = 0 . 1 7 3 6 T - 71.707 (render). For spruce wood: (c) Y T D = 0 . 2 6 5 0 T - 105.979 (render), (d) YCD = 0.0707T 27.507 (render). For equations (a), (b), (c) and (d), the square of the correlation coefficient (r e) were 0.9841, 0.9496, 0.9839 and 0.9447, respectively.
04/02616 Local/global analysis of transient heat transfer from building foundations Al-Anzi, A. and Krarti, M. Building and Environment, 2004, 39, (5), 495-504. In this paper, a novel local/global (L-G) analysis technique is developed to solve transient ground-coupled heat transfer problems. The presented (L-G) analysis approach combines analytical and numerical techniques to obtain solutions of building foundation heat transfer problems with significant localized thermal bridges. Even though simplified analytical solutions generally fail to account for thermal bridging in building foundations, they can be very useful when used as global solutions in the proposed (L-G) analysis technique. In this paper, the developed (L-G) analysis is shown to be an efficient and useful tool to evaluate transient heat transfer for slab-on-grade floor foundations. In particular, it is found that a CPU time reduction of about 90% can be achieved without loss of accuracy when the (L-G) analysis technique is compared to finite difference method. The developed (L-G) analysis technique is particularly useful in evaluating the effects of various design parameters of a slab foundation with minimal computational but can be easily extended and applied to various heat transfer problems in building envelope systems.
04•02617 Transient modeling of combined catalytic combustion/CH4 steam reforming Robbins, F. A. et al. Catalysis Today, 2003, 83, (1 4), 141-156. This paper presents an investigation into the complex interactions between catalytic combustion and CH4 steam reforming in a co-flow heat exchanger where the surface combustion drives the endothermic steam reforming on opposite sides of separating plates in alternating channel flows. To this end, a simplified transient model was established to assess the stability of a system combining H2 or CH4 combustion over a supported Pd catalyst and CH4 steam reforming over a supported Rh catalyst. The model uses previously reported detailed surface chemistry mechanisms, and results compared favourably with experiments using a flat-plate reactor with simultaneous H2 combustion over a "y-A1203-supported Pd catalyst and CH4 steam reforming over a "y-A1203-supported Rh catalyst. Results indicate that stable reactor operation is achievable at relatively low inlet temperatures (400°C) with H2 combustion. Model results for a reactor with CH4 combustion indicated that stable reactor operation with reforming fuel
04/02610 Feasibility analysis of manufacturing high performance ecological cement in Turkey Arikan, M. Building and Environment, 2004, 39, (9), 1125-1130. The world production of cement has significantly increased in recent years due to the growing demand. This trend in the production increase is one of the most significant factors effecting the technological development in cement industry and updating its manufacturing facilities. Unfortunately, the existing technology for the production of cement clinker has adverse ecological effects, such as consumption of much energy and natural resources and emission of a number of pollutants. The production of blended or high volume mineral additive cement, thus high performance cement, increases the compressive strength of ordinary cement and improves the durability of cementbased materials, permitting the utilization of high volume of inexpensive mineral additives or industrial by-products. Thus, higher strength, better durability, reduction of both pollution and energy consumption at the clinker production stage and decrease in the landfill area required by industrial by-products, all provide ecological advantages for high performance cement. In this study, a feasibility analysis was carried out for Turkish cement manufacturers to demonstrate that it is profitable for the cement manufacturers to invest in high performance cement manufacturing. The effects of various parameters on the investment such as sale price, loan amount, interest rate, expected rate of return, etc. were also studied.
04/02611
Flexibility analysis of the vessel-piping interface
Schwarz, M. M. International Journal of Pressure Vessels and Piping, 2004, 81, (2), 181 189. The connections of a pressure vessel with the interconnecting piping system are the boundaries for the computer model built for the analysis of the vessel. The stiffness and the imposed displacements at these points significantly influence the stresses in the piping as well as forces and moments imposed on the connection to the adjacent pressure equipment. This paper summarizes the results of numerous FEM analyses to establish stiffness coefficients for nozzles in spherical and cylindrical pressure vessels.
04/02612 Forced convection and subcooled flow boiling heat transfer in asymmetrically heated ducts of T-section Abou-Ziyan, H. Z. Energy Conversion and Management, 2004, 45, (7 8), 1043-1065. This paper presents the results of an experimental investigation of heat transfer from the heated bottom side of tee cross-section ducts to an internally flowing fluid. The idea of this work is derived from the cooling of critical areas in the cylinder heads of internal combustion engines. Fully developed single phase forced convection and subcooled flow boiling heat transfer data are reported. Six T-ducts of different width and height aspect ratios are tested with distilled water at velocities of 1, 2 and 3 m/s for bulk temperatures of 60 and 80°C, while the heat flux was varied from about 80 to 700 kW/m 2. The achieved data cover Reynolds numbers in the range of 5.22 x 104 to 2.36 x 105, Prandtl numbers in the range from 2.2 to 3.0, duct width aspect ratio between 2.19 and 3.13 and duct height aspect ratio from 0.69 to 2.0. The results revealed that the increase in either the width or height aspect ratio of the T-ducts enhances the convection heat transfer coefficients and the boiling heat fluxes considerably. The following comparisons are provided for coolant velocity of 2 m/s, bulk temperature of 60°C, wall superheat of 20 K and wall to bulk temperature difference of 20 K. As the width aspect ratio increases by 43%, the convection heat transfer coefficient and the boiling heat flux increase by 27% and 39%, respectively. An increase in the height aspect ratio by 290% enhances the convection heat transfer coefficient and the boiling heat fluxes by 82% and 103%, respectively. When the coolant velocity changes from 1 to 2 m/s, the heat transfer coefficient increases by 60% and the boiling heat flux rises by 62-98% for the various tested ducts. The convection heat transfer coefficient increases by 12% and the boiling heat flux decreases by 31% as the bulk fluid temperature rises from 60 to 80°C. A correlation was developed for Nusselt number as a function of Reynolds number, Prandtl number, viscosity ratio and some aspect ratios of the T-duct.
04/02613 Graphical method for the determination of water/ gas partition coefficients of volatile organic compounds by a headspace gas chromatography technique Bakierowska, A.-M. and Trzeszczynski, J. Fluid Phase Equilibria, 2003, 213, (1-2), 139-146. Water/gas partition coefficients have been determined for hydrocarbons and chlorinated derivatives of hydrocarbons. In this paper a graphical method based on a static headspace gas chromatography
364 Fuel and Energy Abstracts September 2004
technique is described. This technique relies on the linear dependence of the phase volume ratio in the vial and the ratio of the concentration of the solute in two phases. The partition coefficients were determined at four temperatures ranging from 10 to 25°C. The temperature dependence of the partition coefficients is described by the classical van't Hoff equation.
04/02614 Incorporating different endogenous learning formulations in MERGE Bahn, O. and Kypreos, S. Int. J. Global Energy Issues, 2003, 19, (4), 333-358. This paper presents the implementation of endogenous technological change, following either a one-factor or a two-factor learning curve, in the M E R G E model. A new version of this model, called MERGEETL, has been developed to analyse the dynamics of endogenous technological learning (ETL) in the energy system. This paper describes first the basic formulation of MERGE-ETL, then the solving techniques used for this model, and presents finally some numerical results in the context of policies designed to mitigate a global climate change.
04•02615 Linear equations on thermal degradation products of wood chips in alkaline glycerol Demirba, A. Energy Conversion and Management, 2004, 45, (7 8), 983 994. Wood chips of 0.3 and 2 m m depth from poplar and spruce wood samples, respectively, were degraded by using glycerol as a solvent and alkaline glycerol with and without NazCO3 and NaOH catalysts at different degradation temperatures: 440, 450, 460, 470, 480, 490 and 500 K. By products from the degradation processes of the lignocelluloses include lignin degradation products. Lignin and its degradation products have fuel values. The total degradation degree and cellulose degradation of the wood chips were determined to find the relationship, if any, between the yields of total degradation degree (YTD) and degradation temperature (7). There is a good linear relationship between YTD or the yields of cellulose degradation (YCD) and T(K). For the wood samples, the regression equations from NaOH (10%) catalytic runs for 0.3 m m x 15 m m x 15 m m chip size are: For poplar wood: (a) YTD = 0 . 7 2 5 0 T - 267.507 (render), (b) YCD = 0 . 1 7 3 6 T - 71.707 (render). For spruce wood: (c) Y T D = 0 . 2 6 5 0 T - 105.979 (render), (d) YCD = 0.0707T 27.507 (render). For equations (a), (b), (c) and (d), the square of the correlation coefficient (r e) were 0.9841, 0.9496, 0.9839 and 0.9447, respectively.
04/02616 Local/global analysis of transient heat transfer from building foundations Al-Anzi, A. and Krarti, M. Building and Environment, 2004, 39, (5), 495-504. In this paper, a novel local/global (L-G) analysis technique is developed to solve transient ground-coupled heat transfer problems. The presented (L-G) analysis approach combines analytical and numerical techniques to obtain solutions of building foundation heat transfer problems with significant localized thermal bridges. Even though simplified analytical solutions generally fail to account for thermal bridging in building foundations, they can be very useful when used as global solutions in the proposed (L-G) analysis technique. In this paper, the developed (L-G) analysis is shown to be an efficient and useful tool to evaluate transient heat transfer for slab-on-grade floor foundations. In particular, it is found that a CPU time reduction of about 90% can be achieved without loss of accuracy when the (L-G) analysis technique is compared to finite difference method. The developed (L-G) analysis technique is particularly useful in evaluating the effects of various design parameters of a slab foundation with minimal computational but can be easily extended and applied to various heat transfer problems in building envelope systems.
04•02617 Transient modeling of combined catalytic combustion/CH4 steam reforming Robbins, F. A. et al. Catalysis Today, 2003, 83, (1 4), 141-156. This paper presents an investigation into the complex interactions between catalytic combustion and CH4 steam reforming in a co-flow heat exchanger where the surface combustion drives the endothermic steam reforming on opposite sides of separating plates in alternating channel flows. To this end, a simplified transient model was established to assess the stability of a system combining H2 or CH4 combustion over a supported Pd catalyst and CH4 steam reforming over a supported Rh catalyst. The model uses previously reported detailed surface chemistry mechanisms, and results compared favourably with experiments using a flat-plate reactor with simultaneous H2 combustion over a "y-A1203-supported Pd catalyst and CH4 steam reforming over a "y-A1203-supported Rh catalyst. Results indicate that stable reactor operation is achievable at relatively low inlet temperatures (400°C) with H2 combustion. Model results for a reactor with CH4 combustion indicated that stable reactor operation with reforming fuel