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02375 Trends in development of siliceous products for coke oven batteries in the Chrzanowskie Refractory Plant
13
the high thermal expansion coefficient at this point. This expansion is restricted by the lower thermal expansion coefficient on the opposite side, where there is a tensile stress field. The model indicated that the gunning reduces the brick temperature and the inner stress field.
Space heating and cooling
significantly increase the cooling capacity and COP of the novel refrigerator above that of a conventional absorption unit with little increase in system complexity.
Heat transfer effects on the net work output and efficiency characteristics for an air-standard Otto cycle
98lQ2381
Trends in development of siliceous products for coke oven batteries in the Chrranowskie Refractory Plant
98lo2375
Drozdz, M. Mater. Ogniotwale, 1997, 49, (l), 9-13. (In Polish) Present and future demand for modern siliceous refractory materials, their manufacture and properties and use in constructing coke oven batteries up to the year 2005.
Vitrification of fly ash from thermal power stations 96lO2376 Barbieri, L. et al. Glass Techno/., 1997, 38, (5), 165-170. After mixing with other inorganic wastes such as dolomite slag and glass cullet, samples of fly ash from Spanish thermal power plants were vitrified. The relative viscosity and crystallization behaviour of the glasses obtained were investigated by hot stage microscopy and DTA, from which reheating schedules were chosen for recrystallization. X-ray diffraction analysis showed that diopside (augite) and/or wollastonite could be crystallized from these glasses, giving rise to dendritic and/or acicular microstructures which were observed and analysed by SEM (SEMIEDX). It was shown that the glass ceramics so obtained had improved mechanical properties compared with the untreated glasses.
13
SPACE HEATING COOLING
AND
Comparison of the performances of N&-H20, LiN03 and NH3-NaSCN absorption refrigeration systems
96102377
NH3-
Sun, D.-W. Energy Comers. Mgmt, 1998, 39, (5/6), 357-368. Research in recent years has been devoted to improving the performance of ammonia-water absorption refrigeration systems. In this study, thermodynamic analyses for ammonia-water, ammonia-lithium nitrate and ammonia-sodium thiocyanate cycles are performed. Detailed thermodynamic properties of these binary fluids are expressed in polynomial equations. The performances of these three cycles are compared. Ammonia-lithium nitrate and ammonia-sodium thiocyanate cycles were found to be suitable alternatives to ammonia-water absorption systems. The performance of the ammonia-sodium thiocyanate cycle is slightly better than that of the ammonia-lithium nitrate cycle. 98lO2376 Dynamic thermal behaviour of cooling towers Al-Nimr, M. A. Energy Convers. Mgmt, 1998, 39, (7), 631-636. A simple mathematical model to describe the dynamic thermal behaviour of a counterflow cooling tower is proposed. The model takes considers the effects of both the sensible and latent heat cooling on the tower performance. A simple perturbation technique is used to solve the governing equations of the proposed model in order to get a closed form solution for the temperature variation within the cooling tower. This is subject to the cooling tower having a very large convective heat transfer coefficient between the water droplets and the air. A mathematical criterion is derived, under steady state conditions, to obtain the proper length of the cooling tower which is sufficient to ensure a complete cooling for the hot water stream.
Ener y conservation in high-rise buildings: changes In air con 8 itioning load induced by vertical temperature and humidity profile in Delhi
96102379
Sinha, S. et al. Energy Convers. Mgmt, 1998, 39, (5/6), 437-440. Profiles of temperature and humidity vary between those in the upper atmosphere and those observed by ground level meteorological stations and are used to design HVAC systems for high-rise buildings. There exist correlations among solar energy, atmospheric turbidity and pollutants in urban areas, affecting the temperature and humidity profiles with variation in height. A theoretical model has been developed in this paper and the HVAC load is calculated. The results are compared with the HVAC load calculated from data obtained from the meteorological station, and the comparison showed that the results differ significantly for a hypothetical 200 m high office building. 98102380
Experimental investigation of a combined ejectorabsorption refrigerator
Aphornratanas, S. and Eames, I. W. Inc. J. Energy Res., 1998, 22, (3), 195-207. An experimental study was conducted on a novel heat-operated refrigeration cycle, the ‘combined ejector-absorption refrigeration cycle’. In this cycle, an ejector was placed between a generator and a condenser of a conventional single-effect absorption refrigerator. The high-pressure vapour refrigerant produced in the generator section was used as the motive fluid for the ejector which entrained low-pressure refrigerant vapour from the evaporator and discharged it to the condenser. This was shown to
Chen, L. et al. Energy Cowers. Mgmt, 1998, 39, (7), 643-648. An air-standard Otto cycle is subjected to finite-time thermodynamic analysis. The relationship between net work output and efficiency of the cycle has been derived. The maximum net work output and the corresponding efficiency bound of the cycle with heat transfer considerations are also found and detailed numerical examples are given. The result obtained herein provides a guide to the performance evaluation and improvement for practical Otto engines. 98lO2382
A new three-parameter cubic equation of state of refrigeration engineering calculations
Zhang, H.-L. et al. Int. J. Refrig., 1997, 20, (6). 421-440. The paper proposes a new three-parameter cubic equation of state in which the repulsion pressure term of the semi-empirical van der Waals equation was modified based on the hard-sphere potential and a functional form similar to Redlich-Kwong attraction term is adopted for the attraction term. All three parameters are treated as functions of temperature. In order to examine the applicability of the new equation, it was applied to describe the thermodynamic properties of difluoromethane and pentafluoroethane. The essential thermodynamic properties were found be as accurately represented by the new equation as a conventional far-complicated modified Benedict-Webb-Rubin equation. The new cubic equation was also compared with the Peng-Robinson equation and the CarnahanStarling-De Santis equation.
98lQ2383 Nitrogen production by cryogenic distillation of air Coakley, V. and Mostello, R. A. U.S. US 5,704,229 (Cl. 62-646; F25J3/00), 6 Jan 1998, Appl. 769,025, 18 Dee 1996, 6 pp. A single distillation column is used in the air separation process for nitrogen generation. Part of the compressed, purified and cooled incoming air stream to be separated is expanded and combined with a bottoms waste stream. The combined stream is expanded after partial warming of the combined stream and then utilized to liquefy part of the incoming air and for refrigeration purposes.
Numerical analysis of convection heat transfer in a rectangular packed duct with asymmetric heating
98lO2384
Makkawi, Y. et al. Energy Cowers. Mgmt, 1998, 39, (5/6), 455-463. Based on a two-dimensional model incorporating the effects of Raschig ring packing on the Ergun equation, a numerical analysis was carried out on fully developed, forced convection heat transfer in a rectangular packed duct. The boundary conditions are based on asymmetric heating with only the top wall supplied with a constant heat flux, while the other walls are adiabatic. The numerical predictions are compared with measured temperature profiles and local Nusselt numbers obtained from a large scale packed duct. The prediction represents the experimental data satisfactorily. The volumetric entropy generation of the duct is also evaluated and displayed graphically that shows the distribution of entropy generation due to heat transfer and pressure drop in the duct.
Recent researches in indirect evaporative cooler V: relative thermal performance of buildings coupled to direct and indirect evaporative cooler
98lO2385
Singh, S. P. et al. Int. J. Energy Res., 1997, 21, (15), 1413-1423. To evaluate the relative thermal performance of a building coupled with an indirect or direct evaporative cooler, a mathematical model has been developed. Using periodic analysis for taking into account thermal storage of building envelope, explicit expressions have been obtained for room air temperature and room air humidity. For comparing their performance under different climatic conditions, numerical calculations have been made taking meteorological parameters for a typical day for Delhi (composite climate), Jodhpur (hot-dry climate) and Madras (hot-humid climate). It is found that the indirect evaporative cooler is a more effective and energy efficient system than the air-conditioner; it can hence be commercially used for computer and electronic exchange applications as well as for human comfort in a variety of climatic conditions, whereas direct evaporative cooler has limited use (only in hot-dry and composite climates). 98102386
Thermodynamic property representation for the R32l125 binary system by a new cubic equation of state
Zhang, H.-L. et al. ht. J. Refrig., 1997, 20, (6), 441-451. A new cubic equation of state is used to model the thermodynamic properties of the R-32/125 binary system. The equation was developed and applied to the pure R-32 and R-125 in a previous paper by the present authors. The essential thermodynamic properties such as PVTx properties, vapour-liquid equilibrium, enthalpy, entropy, isobaric specific heat and speed of sound are well represented by the new model simultaneously for the liquid phase, the gas phase, and the two-phase region of the R-32/125 binary system. The developed model is valid for the entire range of compositions and the new model was compared with other reported models in refrigeration cycle calculations.
Fuel and Energy Abstracts
May 1998
215
the high thermal expansion coefficient at this point. This expansion is restricted by the lower thermal expansion coefficient on the opposite side, where there is a tensile stress field. The model indicated that the gunning reduces the brick temperature and the inner stress field.
Space heating and cooling
significantly increase the cooling capacity and COP of the novel refrigerator above that of a conventional absorption unit with little increase in system complexity.
Heat transfer effects on the net work output and efficiency characteristics for an air-standard Otto cycle
98lQ2381
Trends in development of siliceous products for coke oven batteries in the Chrranowskie Refractory Plant
98lo2375
Drozdz, M. Mater. Ogniotwale, 1997, 49, (l), 9-13. (In Polish) Present and future demand for modern siliceous refractory materials, their manufacture and properties and use in constructing coke oven batteries up to the year 2005.
Vitrification of fly ash from thermal power stations 96lO2376 Barbieri, L. et al. Glass Techno/., 1997, 38, (5), 165-170. After mixing with other inorganic wastes such as dolomite slag and glass cullet, samples of fly ash from Spanish thermal power plants were vitrified. The relative viscosity and crystallization behaviour of the glasses obtained were investigated by hot stage microscopy and DTA, from which reheating schedules were chosen for recrystallization. X-ray diffraction analysis showed that diopside (augite) and/or wollastonite could be crystallized from these glasses, giving rise to dendritic and/or acicular microstructures which were observed and analysed by SEM (SEMIEDX). It was shown that the glass ceramics so obtained had improved mechanical properties compared with the untreated glasses.
13
SPACE HEATING COOLING
AND
Comparison of the performances of N&-H20, LiN03 and NH3-NaSCN absorption refrigeration systems
96102377
NH3-
Sun, D.-W. Energy Comers. Mgmt, 1998, 39, (5/6), 357-368. Research in recent years has been devoted to improving the performance of ammonia-water absorption refrigeration systems. In this study, thermodynamic analyses for ammonia-water, ammonia-lithium nitrate and ammonia-sodium thiocyanate cycles are performed. Detailed thermodynamic properties of these binary fluids are expressed in polynomial equations. The performances of these three cycles are compared. Ammonia-lithium nitrate and ammonia-sodium thiocyanate cycles were found to be suitable alternatives to ammonia-water absorption systems. The performance of the ammonia-sodium thiocyanate cycle is slightly better than that of the ammonia-lithium nitrate cycle. 98lO2376 Dynamic thermal behaviour of cooling towers Al-Nimr, M. A. Energy Convers. Mgmt, 1998, 39, (7), 631-636. A simple mathematical model to describe the dynamic thermal behaviour of a counterflow cooling tower is proposed. The model takes considers the effects of both the sensible and latent heat cooling on the tower performance. A simple perturbation technique is used to solve the governing equations of the proposed model in order to get a closed form solution for the temperature variation within the cooling tower. This is subject to the cooling tower having a very large convective heat transfer coefficient between the water droplets and the air. A mathematical criterion is derived, under steady state conditions, to obtain the proper length of the cooling tower which is sufficient to ensure a complete cooling for the hot water stream.
Ener y conservation in high-rise buildings: changes In air con 8 itioning load induced by vertical temperature and humidity profile in Delhi
96102379
Sinha, S. et al. Energy Convers. Mgmt, 1998, 39, (5/6), 437-440. Profiles of temperature and humidity vary between those in the upper atmosphere and those observed by ground level meteorological stations and are used to design HVAC systems for high-rise buildings. There exist correlations among solar energy, atmospheric turbidity and pollutants in urban areas, affecting the temperature and humidity profiles with variation in height. A theoretical model has been developed in this paper and the HVAC load is calculated. The results are compared with the HVAC load calculated from data obtained from the meteorological station, and the comparison showed that the results differ significantly for a hypothetical 200 m high office building. 98102380
Experimental investigation of a combined ejectorabsorption refrigerator
Aphornratanas, S. and Eames, I. W. Inc. J. Energy Res., 1998, 22, (3), 195-207. An experimental study was conducted on a novel heat-operated refrigeration cycle, the ‘combined ejector-absorption refrigeration cycle’. In this cycle, an ejector was placed between a generator and a condenser of a conventional single-effect absorption refrigerator. The high-pressure vapour refrigerant produced in the generator section was used as the motive fluid for the ejector which entrained low-pressure refrigerant vapour from the evaporator and discharged it to the condenser. This was shown to
Chen, L. et al. Energy Cowers. Mgmt, 1998, 39, (7), 643-648. An air-standard Otto cycle is subjected to finite-time thermodynamic analysis. The relationship between net work output and efficiency of the cycle has been derived. The maximum net work output and the corresponding efficiency bound of the cycle with heat transfer considerations are also found and detailed numerical examples are given. The result obtained herein provides a guide to the performance evaluation and improvement for practical Otto engines. 98lO2382
A new three-parameter cubic equation of state of refrigeration engineering calculations
Zhang, H.-L. et al. Int. J. Refrig., 1997, 20, (6). 421-440. The paper proposes a new three-parameter cubic equation of state in which the repulsion pressure term of the semi-empirical van der Waals equation was modified based on the hard-sphere potential and a functional form similar to Redlich-Kwong attraction term is adopted for the attraction term. All three parameters are treated as functions of temperature. In order to examine the applicability of the new equation, it was applied to describe the thermodynamic properties of difluoromethane and pentafluoroethane. The essential thermodynamic properties were found be as accurately represented by the new equation as a conventional far-complicated modified Benedict-Webb-Rubin equation. The new cubic equation was also compared with the Peng-Robinson equation and the CarnahanStarling-De Santis equation.
98lQ2383 Nitrogen production by cryogenic distillation of air Coakley, V. and Mostello, R. A. U.S. US 5,704,229 (Cl. 62-646; F25J3/00), 6 Jan 1998, Appl. 769,025, 18 Dee 1996, 6 pp. A single distillation column is used in the air separation process for nitrogen generation. Part of the compressed, purified and cooled incoming air stream to be separated is expanded and combined with a bottoms waste stream. The combined stream is expanded after partial warming of the combined stream and then utilized to liquefy part of the incoming air and for refrigeration purposes.
Numerical analysis of convection heat transfer in a rectangular packed duct with asymmetric heating
98lO2384
Makkawi, Y. et al. Energy Cowers. Mgmt, 1998, 39, (5/6), 455-463. Based on a two-dimensional model incorporating the effects of Raschig ring packing on the Ergun equation, a numerical analysis was carried out on fully developed, forced convection heat transfer in a rectangular packed duct. The boundary conditions are based on asymmetric heating with only the top wall supplied with a constant heat flux, while the other walls are adiabatic. The numerical predictions are compared with measured temperature profiles and local Nusselt numbers obtained from a large scale packed duct. The prediction represents the experimental data satisfactorily. The volumetric entropy generation of the duct is also evaluated and displayed graphically that shows the distribution of entropy generation due to heat transfer and pressure drop in the duct.
Recent researches in indirect evaporative cooler V: relative thermal performance of buildings coupled to direct and indirect evaporative cooler
98lO2385
Singh, S. P. et al. Int. J. Energy Res., 1997, 21, (15), 1413-1423. To evaluate the relative thermal performance of a building coupled with an indirect or direct evaporative cooler, a mathematical model has been developed. Using periodic analysis for taking into account thermal storage of building envelope, explicit expressions have been obtained for room air temperature and room air humidity. For comparing their performance under different climatic conditions, numerical calculations have been made taking meteorological parameters for a typical day for Delhi (composite climate), Jodhpur (hot-dry climate) and Madras (hot-humid climate). It is found that the indirect evaporative cooler is a more effective and energy efficient system than the air-conditioner; it can hence be commercially used for computer and electronic exchange applications as well as for human comfort in a variety of climatic conditions, whereas direct evaporative cooler has limited use (only in hot-dry and composite climates). 98102386
Thermodynamic property representation for the R32l125 binary system by a new cubic equation of state
Zhang, H.-L. et al. ht. J. Refrig., 1997, 20, (6), 441-451. A new cubic equation of state is used to model the thermodynamic properties of the R-32/125 binary system. The equation was developed and applied to the pure R-32 and R-125 in a previous paper by the present authors. The essential thermodynamic properties such as PVTx properties, vapour-liquid equilibrium, enthalpy, entropy, isobaric specific heat and speed of sound are well represented by the new model simultaneously for the liquid phase, the gas phase, and the two-phase region of the R-32/125 binary system. The developed model is valid for the entire range of compositions and the new model was compared with other reported models in refrigeration cycle calculations.
Fuel and Energy Abstracts
May 1998
215