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02703 Artificial neural networks for the prediction of the energy consumption of a passive solar building
07 Alternative
energy sources (solar energy)
treatment with lime can lead to corn stower polysaccharide conversions approaching 100%; the success of the saccharification after lime pretreatment depends on the enzyme loading. 00102697 Wastes with caloric content-a potential alternative fuel for manufacture of portland cement clinker Nedelescu, E. Morer. Consrr. (Bucharesr), 1999, 29. (I), 6669. (In Romanian) The results of chemical and energy investigations of the potential of wastes with caloric content, such as electrode waste and scrap tires as alternative fuels for manufacture of portland cement clinker. The characteristics of the wastes and the heavy metal emissions are provided. In addition, the feed points for these wastes in the burning line are described. 00102698 Willow growers in Sweden Rosenqvist, H. Biomms und Bioenergy. 2000, 18, (2), 137-145. The number of willow plantations on Swedish farmland increased considerably between 1991 and 1996. The main driving forces behind this development were: (1) The introduction in 1991 of a new agricultural policy in Sweden which, through deregulation, created lower grain prices and simultaneously introduced compensation for set-aside land as well as subsidies for willow plantations on surplus arable land; (2) higher taxes on fossil fuels; and (3) the existence of a biofuel market in Sweden based on forest fuels. This paper presents a statistical study of willow growers in southern and central-eastern Sweden. Data about willow growers and a stratified random sample of non-willow growers were acquired from the 1995 Farm Register compiled by Statistics Sweden. Willow growers are described according to geographical distribution, willow parcel sizes, farm sizes and farm types. Comparisons are also made with the population of farmers who are not growing willow. A high concentration of willow growers is recorded for central Sweden around Lake Malaren. Willow growers are more often in the age span 50-65 years and as compared to non-willow growers, have larger farms. They are less often focused on animal and milk production and more often on cereal and food crop production, when compared with other farmers. Implications of the Swedish experience for policy making in the fields of energy and agriculture are discussed.
Solar energy
A new high-flux solar furnace for high temperature 00/02699 thermochemical research Haueter, P. er crl. J. Sol. Energy Eng., 1999, I2 I, (I), 77-80. The operation of a new high-flux solar furnace, capable of delivering up to 40 kW at peak concentration ratios exceeding 5000, has commenced at PSI. Its optical design characteristics, main engineering features, and operating performance are described. Primarily, this solar facility will be used for investigating the thermochemical processing of solar fuels at temperatures as high as 2500 K. A study of the U-factor of the window with a high00102700 reflectivity Venetian blind Fang, X. D. S&r Energy, 2000, 68, (2) 207-214. The study focuses on the heat transfer coefficient (U-factor) of a window with a long-wave high-reflectivity Venetian blind (LWHRVB). Two side-byside hot boxes are built in a room for testing the window U-factors. The tested window systems are 100% glass area without frames, which are equivalent to the centre-of-glass of common windows. The slat of Venetian blinds is made of plastic with aluminium film glued on each side and the long-wave reflectivity is 0.93. The two types of window systems tested are the single glazing and the double glazing with the LWHRVB, respectively. The effect of slat slope-angles of Venetian blinds on U-factors is also studied. The empirical equations of the centre-of-glass U-factors are derived from the experimental data. The corrections for effects of window frames and outdoor wind velocity are made thereafter. The corrected empirical. equations can be easily used to estimate the U-factor of the practical window with the LWHRVB. An energy efficient hybrid system of solar powered 00102701 water heater and adsorption ice maker Wang, R. 2. Solar Energy, 2000, 68, (2) 189-195. A new hybrid system of solar powered water heater and adsorption ice maker has been proposed. The working principle of the combined cycles of solar refrigeration and heating is described, theoretical simulation to the thermodynamic processes has been made. Experiments have been performed in a developed prototype hybrid system; it is verified that the hybrid system is capable of heating 60 kg water to about 90°C as well as producing ice at 10 kg per day with a 2 mz solar collector. 00102702 Application of titanium containing amorphous hydrogenated carbon films (a-C: HITi) as optical selective solar absorber coatings Schiiler, A. Solar Energy Morrricrls & Solar Cells, 2000, 60, (3), 295-307.
300
Fuel and Energy Abstracts
September
2000
A combined PVDiPECVD process for the vacuum deposition of titanium containing, amorphous hydrogenated carbon films is described. Elemental compositions of the deposited films have been determined by in situ core level photoelectron spectroscopy (XPS). The long-term stability of the plasma process has been demonstrated. Target poisening has not been observed. Optical selective surfaces have been fabricated by the deposition of a-C: H/Ti multilayers onto aluminium substrates. Even though layer thicknesses and stoichtometries have not yet been optimized, the experimental results are promising. Accelerated aging tests of these coatings have demonstrated their ageing stabiltty: the service lifetime is predicted to amount to more than 25 years. Raman spectroscopy has been used to monitor changes in the structure of the aged coatings. Degradation mechanisms are being discussed. 00/02703 Artificial neural networks for the prediction of the energy consumption of a passive solar building Kalogirou, S. A. and Bojic, M. Energy, 2000, 25, (5) 479491. Artificial neural networks (ANNs) have been used for the prediction of the energy consumption of a passive solar building. The building structure conststs of one room with an inclined roof. Two cases were investigated, an all insulated building and a building with one wall made completely of masonry and the other walls made partially of masonry and thermal insulation. The investigation was performed for two seasons: winter, for which the building with the masonry-only wall is facing south and summer, for which the building with the masonry-only wall is facing north. The building’s thermal behaviour was evaluated by using a dynamic thermal building model constructed on the basis of finite volumes and time marching. The energy consumption of the building depends on whether all walls have insulation, on the thickness of the masonry and insulation and on the season. Simulated data for a number of cases were used to train an artificial neural network (ANN) in order to generate a mapping between the above easily measurable inputs and the desired output, i.e. the building energy consumption in kWh. The simulated buildings had walls varying from 15 cm to 60 cm in thickness. The objective of this work is to produce another simulation program, using ANNs, to model the thermal behaviour of the building. A multilayer recurrent architecture using the standard back-propagation learning algorithm has been applied. The results obtained for the training set are such that they yield a coefficient of multiple determination (RI value) equal to 0.9985. The network was used subsequently for predictions of the energy consumption for cases other than the ones used for training. The coefficient of multiple determination obtained in this case was equal to 0.9991, which is very satisfactory. The ANN model proved to be much faster than the dynamic simulation programs. 00/02704 Bringing the sun to market Vale, B. A. and Vale, R. J. D. Solar Progress, 1999, 20, (4), 14. The paper compares and contrasts three examples of housing projects, which make use of solar design in an attempt to build, zero emissions housing. All three houses are in the United Kingdom, the Autonomous House, the Hockerton Housing Project and the Fiskerton Houses. The authors of this paper designed the three projects. All are attempts to make houses, which are more sustainable, in that they use no non-renewable energy in their day-to-day operation. Two of the examples, one urban and one rural, go further in their quest for sustainability in that they are designed to provide their own energy, water and sewage services on-site resources. The three projects show how radical ideas about performance can be tried out in one-off houses and refined to the point where they can be applied at no additional cost to conventional affordable homes. 00102705 Coal gasification by CO1 gas bubbling in molten salt for solar/fossil energy hybridization Matsunami, J. S&r Energy, 2000, 68, (3) 257-261. Coal gasification with CO1 (the Boudouard reaction: C + CO2 = 2C0. f&H” = 169.2 kJ/mol at 1I50 K), which can be applied to a solar thermochemical process to convert concentrated solar heat into chemical energy, was conducted in the molten salt medium (eutectic mixture of Na2COs and K>COs, weight ratio = l/l) to provide thermal storage. When CO2 gas was bubbled through the molten salt, higher reaction rates were observed compared to the case without CO* gas bubbling (CO* gas was streamed over the surface of the molten salt). Thus the coke formed by coal pyrolysis was well suspended in the molten salt by CO2 gas bubbling. When the CO2 flow rate was increased from I5 to 60 bmol/s, the CO evolution rate was increased (15-26 pmol/s). However, CO2 conversion efficiency was decreased (50-22%). Based on the maximum CO evolution rate (26 pmol/s), solar thermal energy from a solar farm (300 x 300 m2) could be converted to chemical energy at a rate of 50 000 kJ/s by the coal (23 ton as C) gasification process studied here. This assumes 50% solar heat to chemical energy conversion efficiency which can be generally obtained by the actual solar experiments. 00/02706 Compact linear fresnel reflector solar thermal powerplants Mills, D. R. Solrrr Energy, 2000, 68, (3), 263-283. This paper evaluates Compact Linear Fresnel Reflector (CLFR) concepts suitable for large-scale solar thermal electricity generation plants. In the CLFR, it is assumed that there will be many parallel linear receivers elevated on tower structures that are close enough for individual mirror rows to have the option of directing reflected solar radiation to two
energy sources (solar energy)
treatment with lime can lead to corn stower polysaccharide conversions approaching 100%; the success of the saccharification after lime pretreatment depends on the enzyme loading. 00102697 Wastes with caloric content-a potential alternative fuel for manufacture of portland cement clinker Nedelescu, E. Morer. Consrr. (Bucharesr), 1999, 29. (I), 6669. (In Romanian) The results of chemical and energy investigations of the potential of wastes with caloric content, such as electrode waste and scrap tires as alternative fuels for manufacture of portland cement clinker. The characteristics of the wastes and the heavy metal emissions are provided. In addition, the feed points for these wastes in the burning line are described. 00102698 Willow growers in Sweden Rosenqvist, H. Biomms und Bioenergy. 2000, 18, (2), 137-145. The number of willow plantations on Swedish farmland increased considerably between 1991 and 1996. The main driving forces behind this development were: (1) The introduction in 1991 of a new agricultural policy in Sweden which, through deregulation, created lower grain prices and simultaneously introduced compensation for set-aside land as well as subsidies for willow plantations on surplus arable land; (2) higher taxes on fossil fuels; and (3) the existence of a biofuel market in Sweden based on forest fuels. This paper presents a statistical study of willow growers in southern and central-eastern Sweden. Data about willow growers and a stratified random sample of non-willow growers were acquired from the 1995 Farm Register compiled by Statistics Sweden. Willow growers are described according to geographical distribution, willow parcel sizes, farm sizes and farm types. Comparisons are also made with the population of farmers who are not growing willow. A high concentration of willow growers is recorded for central Sweden around Lake Malaren. Willow growers are more often in the age span 50-65 years and as compared to non-willow growers, have larger farms. They are less often focused on animal and milk production and more often on cereal and food crop production, when compared with other farmers. Implications of the Swedish experience for policy making in the fields of energy and agriculture are discussed.
Solar energy
A new high-flux solar furnace for high temperature 00/02699 thermochemical research Haueter, P. er crl. J. Sol. Energy Eng., 1999, I2 I, (I), 77-80. The operation of a new high-flux solar furnace, capable of delivering up to 40 kW at peak concentration ratios exceeding 5000, has commenced at PSI. Its optical design characteristics, main engineering features, and operating performance are described. Primarily, this solar facility will be used for investigating the thermochemical processing of solar fuels at temperatures as high as 2500 K. A study of the U-factor of the window with a high00102700 reflectivity Venetian blind Fang, X. D. S&r Energy, 2000, 68, (2) 207-214. The study focuses on the heat transfer coefficient (U-factor) of a window with a long-wave high-reflectivity Venetian blind (LWHRVB). Two side-byside hot boxes are built in a room for testing the window U-factors. The tested window systems are 100% glass area without frames, which are equivalent to the centre-of-glass of common windows. The slat of Venetian blinds is made of plastic with aluminium film glued on each side and the long-wave reflectivity is 0.93. The two types of window systems tested are the single glazing and the double glazing with the LWHRVB, respectively. The effect of slat slope-angles of Venetian blinds on U-factors is also studied. The empirical equations of the centre-of-glass U-factors are derived from the experimental data. The corrections for effects of window frames and outdoor wind velocity are made thereafter. The corrected empirical. equations can be easily used to estimate the U-factor of the practical window with the LWHRVB. An energy efficient hybrid system of solar powered 00102701 water heater and adsorption ice maker Wang, R. 2. Solar Energy, 2000, 68, (2) 189-195. A new hybrid system of solar powered water heater and adsorption ice maker has been proposed. The working principle of the combined cycles of solar refrigeration and heating is described, theoretical simulation to the thermodynamic processes has been made. Experiments have been performed in a developed prototype hybrid system; it is verified that the hybrid system is capable of heating 60 kg water to about 90°C as well as producing ice at 10 kg per day with a 2 mz solar collector. 00102702 Application of titanium containing amorphous hydrogenated carbon films (a-C: HITi) as optical selective solar absorber coatings Schiiler, A. Solar Energy Morrricrls & Solar Cells, 2000, 60, (3), 295-307.
300
Fuel and Energy Abstracts
September
2000
A combined PVDiPECVD process for the vacuum deposition of titanium containing, amorphous hydrogenated carbon films is described. Elemental compositions of the deposited films have been determined by in situ core level photoelectron spectroscopy (XPS). The long-term stability of the plasma process has been demonstrated. Target poisening has not been observed. Optical selective surfaces have been fabricated by the deposition of a-C: H/Ti multilayers onto aluminium substrates. Even though layer thicknesses and stoichtometries have not yet been optimized, the experimental results are promising. Accelerated aging tests of these coatings have demonstrated their ageing stabiltty: the service lifetime is predicted to amount to more than 25 years. Raman spectroscopy has been used to monitor changes in the structure of the aged coatings. Degradation mechanisms are being discussed. 00/02703 Artificial neural networks for the prediction of the energy consumption of a passive solar building Kalogirou, S. A. and Bojic, M. Energy, 2000, 25, (5) 479491. Artificial neural networks (ANNs) have been used for the prediction of the energy consumption of a passive solar building. The building structure conststs of one room with an inclined roof. Two cases were investigated, an all insulated building and a building with one wall made completely of masonry and the other walls made partially of masonry and thermal insulation. The investigation was performed for two seasons: winter, for which the building with the masonry-only wall is facing south and summer, for which the building with the masonry-only wall is facing north. The building’s thermal behaviour was evaluated by using a dynamic thermal building model constructed on the basis of finite volumes and time marching. The energy consumption of the building depends on whether all walls have insulation, on the thickness of the masonry and insulation and on the season. Simulated data for a number of cases were used to train an artificial neural network (ANN) in order to generate a mapping between the above easily measurable inputs and the desired output, i.e. the building energy consumption in kWh. The simulated buildings had walls varying from 15 cm to 60 cm in thickness. The objective of this work is to produce another simulation program, using ANNs, to model the thermal behaviour of the building. A multilayer recurrent architecture using the standard back-propagation learning algorithm has been applied. The results obtained for the training set are such that they yield a coefficient of multiple determination (RI value) equal to 0.9985. The network was used subsequently for predictions of the energy consumption for cases other than the ones used for training. The coefficient of multiple determination obtained in this case was equal to 0.9991, which is very satisfactory. The ANN model proved to be much faster than the dynamic simulation programs. 00/02704 Bringing the sun to market Vale, B. A. and Vale, R. J. D. Solar Progress, 1999, 20, (4), 14. The paper compares and contrasts three examples of housing projects, which make use of solar design in an attempt to build, zero emissions housing. All three houses are in the United Kingdom, the Autonomous House, the Hockerton Housing Project and the Fiskerton Houses. The authors of this paper designed the three projects. All are attempts to make houses, which are more sustainable, in that they use no non-renewable energy in their day-to-day operation. Two of the examples, one urban and one rural, go further in their quest for sustainability in that they are designed to provide their own energy, water and sewage services on-site resources. The three projects show how radical ideas about performance can be tried out in one-off houses and refined to the point where they can be applied at no additional cost to conventional affordable homes. 00102705 Coal gasification by CO1 gas bubbling in molten salt for solar/fossil energy hybridization Matsunami, J. S&r Energy, 2000, 68, (3) 257-261. Coal gasification with CO1 (the Boudouard reaction: C + CO2 = 2C0. f&H” = 169.2 kJ/mol at 1I50 K), which can be applied to a solar thermochemical process to convert concentrated solar heat into chemical energy, was conducted in the molten salt medium (eutectic mixture of Na2COs and K>COs, weight ratio = l/l) to provide thermal storage. When CO2 gas was bubbled through the molten salt, higher reaction rates were observed compared to the case without CO* gas bubbling (CO* gas was streamed over the surface of the molten salt). Thus the coke formed by coal pyrolysis was well suspended in the molten salt by CO2 gas bubbling. When the CO2 flow rate was increased from I5 to 60 bmol/s, the CO evolution rate was increased (15-26 pmol/s). However, CO2 conversion efficiency was decreased (50-22%). Based on the maximum CO evolution rate (26 pmol/s), solar thermal energy from a solar farm (300 x 300 m2) could be converted to chemical energy at a rate of 50 000 kJ/s by the coal (23 ton as C) gasification process studied here. This assumes 50% solar heat to chemical energy conversion efficiency which can be generally obtained by the actual solar experiments. 00/02706 Compact linear fresnel reflector solar thermal powerplants Mills, D. R. Solrrr Energy, 2000, 68, (3), 263-283. This paper evaluates Compact Linear Fresnel Reflector (CLFR) concepts suitable for large-scale solar thermal electricity generation plants. In the CLFR, it is assumed that there will be many parallel linear receivers elevated on tower structures that are close enough for individual mirror rows to have the option of directing reflected solar radiation to two