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Sample records for constructal solar chimney

  1. Solar chimney

    Solar Chimney is an interesting unconventional method for production of electricity from the sun. It consists of a large greenhouse which purpose is to heat the air and create air flow directing it to the base of the chimney and then through the pressure-staged turbine array. Solar Chimney can be used for pick load operation. Australia plans 200 MW solar plant for the and of 2004, which will be the tallest man made structure in the world with a height of almost 1 km and greenhouse diameter reaching 7.5 km. It is a result of Australia's commitment to find alternative energy solutions in order to reduce the environmental impact of fossil and nuclear technologies for electric power production. (Author)

  2. Inclined solar chimney for power production

    Highlights: → Solar energy harnessing using inclined face of high mountains as solar chimney. → Solar chimneys with structural stability, ease of construction and lower cost. → Mathematical model developed, using complete (mechanical and thermal) energy balance. → Can harness wind power also, as wind velocities at mountain top add to power output. → Air temperature and velocity increase, as air rises in inclined chimney. - Abstract: The present concept of solar chimney is a tall vertical chimney constructed at the center of a large area, which is the collector. This creates questions about stability and economic viability of the chimney and also demands elaborate engineering techniques for constructing a tall chimney. We suggest geometry of 'Inclined Solar Chimney' (ISC), which is constructed along the face of a high rising mountain, on which maximum solar insolation is incident throughout the year. The chimney and the collector get merged here. This makes the structure stable, cost effective and easy for construction. A mathematical model has been developed considering the total energy balance. It predicts the temperature and velocity and kinetic power of the emerging air draft for some chosen values of other parameters. The model also shows the proportion in which absorbed solar energy is divided into different forms, and hence predicts the dependence of kinetic of emerging air draft upon dimensions of the chimney and properties of materials used. Further, it is shown that external winds enhance the kinetic power of the emerging air. Thus ISC can also harness the wind energy, available at the top of the mountain.

  3. Experimental Investigations on Performance and Design Parameters of Solar Chimney

    İbrahim ÜÇGÜL; KOYUN, Arif

    2010-01-01

    In this study, a solar chimney system, which is suitable for climate conditions of Isparta and its surroundings, is designed theoretically. With the aim of studying experimentally as based on that design, a prototype solar chimney has been constructed in the university campus area of Süleyman Demirel University-RACRER (Research and Application Center for Renewable Energy Resources). Additionally, after the experimental studies, the system is modelled theoretically with depending on the design...

  4. A simple theoretical model of a solar chimney

    A simple theoretical model of a solar chimney to predict its performance under varying ambient and geometrical features was proposed. Steady state heat transfer equations were set up using a thermal resistance network and solved using matrix inversion. Surface temperatures of the heat absorbing wall and glass and induced air flow velocity in the chimney are predicted. An experiment model 2 m high x 0.45 m wide with air channel gaps of 0.1, to 0.3 m wide was constructed. Outdoor tests were performed by exposure to both direct and diffuse solar radiation. The effects of air channel gap and solar radiation intensity were investigated. Air velocities between 0.25 to 0.39 ms-1 at radiation intensities up to 650 W m-2 were obtained. No reserve air circulation was observed at the chimney exit. The model was found more suitable for solar chimney with large air gaps

  5. Free-standing inflatable solar chimney: experiment and theory

    Vorobieff, Peter; Mammoli, Andrea; Fathi, Nima; Putkaradze, Vakhtang

    2014-11-01

    Solar chimneys (or solar updraft towers) offer an attractive way to use solar energy for production of baseload power. In a power plant of this type, sunshine heats the air under a wide greenhouse-like roofed collector surrounding the central base of a tall chimney. The heated air drives an updraft flow through the tower, whose energy is harvested with turbines. For a sufficiently large plant of this type, the thermal mass of the heated ground under the collector is sufficient to drive the flow even when the sun is down. The primary challenge in building the solar chimney power plant is the construction of the chimney that generates the updraft, which must be very tall (hundreds of meters for a commercial-sized plant). Here we present a study of an inflatable chimney which is a self-supporting, deformable, free-standing stack of gas-filled tori. The structure is stabilized via a combination of shape, overpressure, and buoyancy. Theoretical considerations suggest that filling the tori with air rather than with a light gas may be advantageous for stability. The chimney shape is optimized for deformation under wind loading. A prototype chimney has demonstrated the viability of the concept, with experimental results in good agreement with theoretical predictions. This research is partially supported by the UNM Research Allocations Comittee (RAC) and UNM Center for Emerging Energy Technologies (CEET).

  6. Experimental Investigations on Performance and Design Parameters of Solar Chimney

    İbrahim ÜÇGÜL

    2010-03-01

    Full Text Available In this study, a solar chimney system, which is suitable for climate conditions of Isparta and its surroundings, is designed theoretically. With the aim of studying experimentally as based on that design, a prototype solar chimney has been constructed in the university campus area of Süleyman Demirel University-RACRER (Research and Application Center for Renewable Energy Resources. Additionally, after the experimental studies, the system is modelled theoretically with depending on the design. Then, this model constituted the basis for developed computer programme and performance parameters of the system are obtained. The obtained findings showed that the solar chimney, which is suitable for climate conditions of Isparta and its surroundings, are sufficient for determining design and performance parameters. The results showed that electricity generation with solar chimney is suitable for areas which have high solar incident and long sunshine duration and similar climate conditions as such as Isparta and its surroundings. When the results are evaluated, it is seen that electricity generation power of solar chimney depends on the region solar data, the chimney height and the size of greenhouse area.

  7. Simulation and optimization of geometric parameters of a solar chimney in Tehran

    Highlights: • A fundamental mathematical of solar chimney model was described. • The performance of solar chimney power plant was analytically simulated. • The results of predictions were compared with the experimental data. • The velocity magnitude can be raised 4–25% in different cases. - Abstract: An analytical and numerical study for geometrical optimizing of a solar chimney prototype at University of Tehran was performed. A fundamental mathematical model that describes the flow was presented, and the performance evaluation of solar chimney was simulated with operational and geometric configurations. The numerical predictions were validated through comparison with the experimental data of the solar chimney pilot which was constructed in height of 2 m and collector radius of 3 m. The results show that, the collector inlet of 6 cm, the chimney height of 3 m, and the chimney diameter of 10 cm were the best alternatives for the constructed solar chimney pilot. It is found that the velocity magnitude can be raised to 4–25% in different cases; also the analysis indicated that the height and diameter of the chimney are the most important physical variables for solar chimney design

  8. Design and measured performance of a solar chimney for natural-circulation solar-energy dryers

    The design and construction of a solar chimney which was undertaken as part of a study on natural-circulation solar-energy dryers is reported. The experimental solar chimney consists of a 5.3m high and 1.64m diameter cylindrical polyethylene-clad vertical chamber, supported structurally by steel framework and draped internally with a selectively-absorbing surface. The performance of the chimney which was monitored extensively with and without the selective surface in place (to study the effectiveness of this design option) is also reported. (author). 14 refs, 7 figs

  9. EXPERIMENTAL ANALYSIS OF A VELOCITY FIELD USING VARIABLE CHIMNEY DIAMETER FOR SOLAR UPDRAFT TOWER

    Neeraj Mehla,

    2011-04-01

    Full Text Available A solar updraft tower consists of an air collector 1.4 m in diameter and 80 cm tall chimney was set upin NIT Hamirpur, Himachal-Pradesh, India. The objective of the study was to investigate the variation of velocity with essential geometricparameter of the system. The solar updraft tower system consists of three essential elements- collector, chimney height and wind turbine. The output power of a system is depended on the input velocity to the wind turbine. Turbine inlet velocity (V is the function of five parameter of the solar updraft tower systems such as collector diameter (Dc, roof glass angle (β, entrance height (h, tower's height (Ht, tower's diameter (D, out of which variable roof angle and the chimney height is analysis. It was found that the solar chimney diameter of 8 cm is having the maximum velocity for the constructed setup, and the ratio of chimney diameter to chimney heightwas found to be 0.1.

  10. Solar Chimney Model Parameters to Enhance Cooling PV Panel Performance

    Mohammed Sh Elden; K. Sopian; Fatah O. Alghoul; Abdelnasser Abouhnik; Ae. Muftah M.

    2013-01-01

    The concept of using the Solar Chimney plays an important role in a wide range of topics to improve cooling system efficiency such as drying process, and single and multi-story buildings ventilation against temperature rising. In this paper, study the effective solar cooling chimney parameter model to enhance the performance of photovoltaic (PV) cooling system. First, a brief description of theoretical performance predictions of the solar cooling chimney also discusses the effect of the ambie...

  11. Simulation of a sloped solar chimney power plant in Lanzhou

    Research highlights: → A sloped solar chimney power plant in Lanzhou, China is investigated. → The configuration sizes are designed separately. → The system has high periodicity and stability but low efficiency. → The sloped solar chimney power system is of high value for Northwest China. -- Abstract: Solar chimney power system is one large-scale utilization style of solar energy, which has drawn high attentions worldwide. Though scholars all over the world have made many researches on the solar chimney power system, reports of sloped solar chimney power system are still few. A sloped solar chimney power plant, which is expected to provide electric power for remote villages in Northwest China, has been designed for Lanzhou City in this paper. The designed plant, in which the height and radius of the chimney are 252.2 m and 14 m respectively, the radius and angle of the solar collector are 607.2 m and 31o respectively, is designed to produce 5 MW electric power on a monthly average all year. The performances, such as the airflow temperature increase, pressure, the airflow speed, system efficiency and solar collector efficiency, of the built sloped solar chimney power plant are simulated and presented. Simulation results show that parameters of the sloped solar chimney power plant are symmetrical and stable; the power plant has better performances in spring and autumn days; the overall efficiency of the power plant is low. Considering the abundant solar radiation, environmental friendliness, easy management and low population density, the sloped solar chimney power system is of high value to Northwest China.

  12. Numerical simulation and exergetic analysis of building ventilation solar chimneys

    Highlights: • Exergetic analysis of a building ventilation solar chimney. • Numerical CFD model developed, validated and employed to study the flow. • Analysis of the solar chimney energy and exergy efficiencies. • Mechanical and thermal exergy distributions have been analysed. • Crucial points in the chimney identified to improve its performance. - Abstract: The solar chimneys used in buildings are passive solar devices which improve natural ventilation. A detailed exergetic analysis has been developed in this work, both for general balance and specific variables. To apply this analysis, a three-dimensional CFD model has been built and validated with bibliographic experimental data. The values of the variables have been examined both inside and at the exit of the solar chimney, resulting in a detailed description of the inner phenomena and parameters influencing the exergetic efficiency. The results of this study offer new tools: a numerical methodology and an exergetic analysis, to improve the design of building ventilation solar chimneys. It also affords a deeper understanding of the thermal and fluid-dynamic behaviour, and suggests some qualitative improvements. However, the numerical data obtained from the case studied, show that solar chimneys as natural ventilation systems offer quite a small efficiency and will remain within the sphere of architectural decisions

  13. Experimental study for natural ventilation on a solar chimney

    Arce, J. [Centro de Investigacion en Energia (CIE-UNAM), Termociencias, Priv. Xochicalco S/N Col. Centro, Temixco, Morelos, CP 62580 (Mexico); Jimenez, M.J.; Guzman, J.D.; Heras, M.R. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Av. Complutense, 22, E-28040 Madrid (Spain); Alvarez, G.; Xaman, J. [Centro Nacional de Investigacion y Desarrollo Tecnologico (CENIDET-DGEST-SEP), Prol. Av. Palmira S/N. Col. Palmira, Cuernavaca, Morelos, CP 62490 (Mexico)

    2009-12-15

    Thermal performance of a solar chimney for natural ventilation was experimentally investigated. The experimental model was implemented on full scale and real meteorological conditions, so that experimental results will be compared with the simulation results. The results show that for a maximum irradiance of 604 W/m{sup 2}, occurring around 13:00 h on September 15th, 2007, a maximum air temperature increment of 7 C was obtained through the solar chimney. Also, a volumetric air flow rate ranging from 50 to 374 m{sup 3}/h was measured on that day. Thus, an average air flow rate of 177 m{sup 3}/h was achieved from 0:00 h to 24:00 h. The experimental solar chimney discharge coefficient, C{sub d}, was 0.52. This coefficient is useful to determine the mass flow rate in the solar chimney design. It was observed that the air flow rate through the solar chimney is influenced by a pressure difference between input and output, caused by thermal gradients and wind velocity, mainly. (author)

  14. Experimental investigations of a chimney-dependent solar crop dryer

    Afriyie, J.K.; Nazha, M.A.A.; Rajakaruna, H. [School of Engineering and Technology, De Montfort University, Queens Building, The Gateway, Leicester LE1 9BH (United Kingdom); Forson, F.K. [Department of Mechanical Engineering, Kwame Nkrumah University of Science and Technology, Kumasi (Ghana)

    2009-01-15

    An experimental investigation into the performance of a solar crop dryer with solar chimney and no air preheating is described. Tests were first performed on the cabinet dryer, using a normal chimney. The trials were repeated with a solar chimney. Still with the solar chimney, further trials were carried out with the roof of the drying chamber inclined further to form a tent dryer. The described tests include no-load tests for airflow rate measurements and drying tests, with cassava as the crop. Air velocities, temperatures, ambient relative humidity and the drop in crop moisture contents at different stages of the drying process are also presented. The effects of the various configurations described above on the drying process are deduced and discussed while comparing the experimental results with one another. In addition, the performance of the dryer in relation to other natural convection dryers is discussed. The results show that the solar chimney can increase the airflow rate of a direct-mode dryer especially when it is well designed with the appropriate angle of drying-chamber roof. However, the increase in flow rate only increases the drying rate when the relative humidity (RH) of the ambient air is below a certain mark (60% for cassava). (author)

  15. DESIGN OF A SMALL – SCALE SOLAR CHIMNEY FOR SUSTAINABLE POWER

    After several months of design and testing it has been determined that a small scale solar chimney can be built using nearly any local materials and simple hand tools without needing superior construction knowledge. The biggest obstacle to over come was the weather conditions....

  16. A performance analysis of solar chimney thermal power systems

    Al-Dabbas Awwad Mohammed

    2011-01-01

    Full Text Available The objective of this study was to evaluate the solar chimney performance theoretically (techno-economic. A mathematical model was developed to estimate the following parameter: Power output, Pressure drop across the turbine, the max chimney height, Airflow temperature, and the overall efficiency of solar chimney. The mathematical model was validated with experimental data from the prototype in Manzanares power. It can be concluded that the differential pressure of collector-chimney transition section in the system, is increase with the increase of solar radiation intensity. The specific system costs are between 2000 Eur/kW and 5000 Eur/kW depending on the system size, system concept and storage size. Hence, a 50 MWe solar thermal power plant will cost 100-250 Eur million. At very good sites, today’s solar thermal power plants can generate electricity in the range of 0.15 Eur/kWh, and series production could soon bring down these costs below 0.10 Eur /kWh.

  17. A NUMERICAL study of solar chimney power plants in Tunisia

    Bahar F, Attig; S, Guellouz M.; M, Sahraoui; S, Kaddeche

    2015-04-01

    A 3D CFD (Computational fluid dynamics) model of a Solar Chimney Power Plant (SCPP) was developed and validated through comparison with the experimental data of the Manzanares plant. Then, it was employed to study the SCPP performance for locations throughout Tunisia.

  18. Solar ventilation: The use of solar chimneys for natural ventilation of buildings

    Macquoy, B.

    2011-01-01

    This paper is written for the TIDO-course AR0532 Smart & Bioclimatic Design Theory. A very old principle is the system of the solar chimney for ventilation, which in recent years has regained interests. This essay will explore the potentials of solar chimneys in a modern application.

  19. Experimental and numerical investigation on an innovative solar chimney

    Highlights: • Intensifiers were applied to increase heat flux. • Numerical and experimental data were compered. • We investigated the rotational pattern of the air inside the SC. • This chimney is equipped with a container, placed exactly beneath the collector. - Abstract: A novel small scale model of solar chimney was investigated experimentally and numerically. Air flow, heat transfer and flow characteristics were numerically calculated and compared with the experimental results in this paper. Two intensifiers were used to intensify the heat flux radiated by the sun all around the solar chimney in the experimental case. An air tank was located downside the system to increase the absorption of the solar radiation reflected by the intensifiers. RNG k–ε model was chosen to simulate the turbulence and the well-known SIMPLE algorithm was used to solve the coupled velocity and pressure equations. Results show that utilization of intensifiers caused an increase in velocity magnitude in the chimney and consequently more power was generated. The maximum velocity of 5.12 m/s was reached which is remarkable, considering the small size of the SC structure

  20. Numerical Study of a Solar Chimney Power Plant

    A. Dhahri

    2014-11-01

    Full Text Available The aim of this study is to present a numerical analysis on the performance of a solar chimney power plant using steady state Navier-Stokes and energy equations in cylindrical coordinate system. The fluid flow inside the chimney is assumed to be turbulent and simulated with the k-ε turbulent model, using the FLUENT software package. Numerical simulations were performed using the Spanish prototype as reference. The computed results are in good agreement with experimental measurements of Manzanares power plant. Besides, a theoretical model was proposed taking into account the kinetic energy difference within the solar collector. The effects of the main geometrical parameters of the collector and the solar radiation intensity on the air mass flow rate and the temperature rise in the collector have been investigated. The fluid and ground temperature distributions were also presented and analyzed.

  1. Annual performance analysis of the solar chimney power plant in Sinkiang, China

    Highlights: • A theoretical model was developed concerning hourly variation of solar radiation. • A limitation on maximum collector radius of an SCPP with a given chimney exists. • Annual performance of a 100 MW SCPP was predicted in hourly interval. • The Hami region is considered suitable for the construction of SCPP. - Abstract: To obtain more accurate prediction of the annual performance of solar chimney power plants (SCPPs), a comprehensive theoretical model is developed by taking into account the hourly variation of solar radiation. The effects of the collector and chimney radii on the power output of the SCPP are analyzed, and the results reveal that a limitation on the maximum collector radius exists for the maximum attainable power output of the SCPP. Then four designs of 100 MW SCPPs with different combinations of collector and chimney radii are proposed and the most cost effective one is chosen from among the four SCPPs. The annual power output of the chosen SCPP in the Hami region is estimated at an interval of 1 h for a whole year. The results indicate that the power generation of SCPP presents obvious seasonal variation. Furthermore, the use of 14% of the unused land in the Hami region for the installation of SCPPs would satisfy the annual power requirement for the whole of the Sinkiang region

  2. Parameterization Studies of Solar Chimneys in the Tropics

    Alex Yong Kwang Tan

    2013-01-01

    Full Text Available The paper examines the effect of the solar chimney’s stack height, depth, width and inlet position on the interior performance (air temperature and speed at 1.20 m height above the ground as well as proposes an optimal tropical solar chimney design. Simulations show that the output air temperature remains constant while the solar chimney’s width is the most significant factor influencing output air speed. The solar chimney’s inlet position has limited influence on the output air speed although regions near the solar chimney’s inlet show an increase in air speed. Furthermore, a regression model is developed based on the solar chimney’s stack height, depth and width to predict the interior air speed. To optimize solar chimney in the tropics, the recommendation is to first maximize its width as the interior’s width, while allowing its stack height to be the building’s height. Lastly, the solar chimney’s depth is determined from the regression model by allocating the required interior air speed.

  3. Power generation from wind turbines in a solar chimney

    Tudor Foote, Ramesh K. Agarwal

    2013-01-01

    Full Text Available Recent studies have shown that shrouded wind turbines can generate greater power compared to bare turbines. A solar chimney generates an upward draft of wind inside a tower and a shroud around the wind turbine. There are numerous empty silos on farms in the U.S. that can be converted to solar chimneys with minor modifications at modest cost. The objective of this study is to determine the potential of these silos/chimneys for generating wind power. The study is conducted through analytical/computational approach by employing the commercial Computational Fluid Dynamics (CFD software. Computations are performed for five different geometric configurations consisting of a turbine, a cylindrical silo, and/or a venturi and/or a diffuser using the dimensions of typical silos and assuming Class 3 wind velocity. The incompressible Navier-Stokes equations with the Boussinesq approximation and a two equation realizable k – ε model are employed in the calculations, and the turbine is modeled as an actuator disk. The power coefficient (Cp and generated power are calculated for the five cases. Consistent with recent literature, it was found that the silos with diffusers increase the Cp beyond Betz’s limit significantly and thus the generated power. It should be noted that Cp is calculated by normalizing it by the turbine area swept by the wind. This study shows the potential of using abandoned silos in the mid-west and other parts of the country for localized wind power generation.

  4. Power generation from wind turbines in a solar chimney

    Foote, Tudor [Graduate Student, Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, Jolley Hall, Campus Box 1185, One Brookings Drive, St. Louis, Missouri, 63130 (United States); Agarwal, Ramesh K. [William Palm Professor, Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, Jolley Hall, Campus Box 1185, One Brookings Drive, St. Louis, Missouri, 63130 (United States)

    2013-07-01

    Recent studies have shown that shrouded wind turbines can generate greater power compared to bare turbines. A solar chimney generates an upward draft of wind inside a tower and a shroud around the wind turbine. There are numerous empty silos on farms in the U.S. that can be converted to solar chimneys with minor modifications at modest cost. The objective of this study is to determine the potential of these silos/chimneys for generating wind power. The study is conducted through analytical/computational approach by employing the commercial Computational Fluid Dynamics (CFD) software. Computations are performed for five different geometric configurations consisting of a turbine, a cylindrical silo, and/or a venturi and/or a diffuser using the dimensions of typical silos and assuming Class 3 wind velocity. The incompressible Navier-Stokes equations with the Boussinesq approximation and a two equation realizable {kappa}-{epsilon} model are employed in the calculations, and the turbine is modeled as an actuator disk. The power coefficient (Cp) and generated power are calculated for the five cases. Consistent with recent literature, it was found that the silos with diffusers increase the Cp beyond Betz’s limit significantly and thus the generated power. It should be noted that Cp is calculated by normalizing it by the turbine area swept by the wind. This study shows the potential of using abandoned silos in the mid-west and other parts of the country for localized wind power generation.

  5. Solar chimney design: Investigating natural ventilation and cooling in offices with the aid of computer simulation

    Angelis, Nikolaos

    Solar chimney design is investigated as a means of improving natural ventilation and passive cooling in office buildings. Existing scientific research and built precedents are generally limited literature review findings on various features of solar chimneys were categorised and used to develop a building simulation strategy. Using UK climatic data, simulations were performed on several computer models in order to investigate solar chimney performance during a single day period and an entire cooling season. Passive cooling with a solar chimney is possible but actual reduction in temperatures in most cases examined could be negligible. Cooling potential is increased on still, warm days, while the prospects for night cooling are further improved. A solar chimney may help reduce considerably the occurrence of resultant temperatures at or above the 25 C and 28 C thresholds. Solar chimney width, height, apertures and integral use of thermal mass are the most significant parameters for cooling. Simulation results showed that a solar chimney can increase significantly natural ventilation rates. Total ventilation rates may be increased by at least 22%. During still days a solar chimney can enhance ventilation rates by 36% or more. Stack ventilation through a solar chimney is typically 20% of cross ventilation during night time this may increase to at least 40-45% and on still days it may reach 100% of typical cross ventilation rates. Solar chimney induced stack ventilation and cross ventilation are interrelated. Resultant air flow patterns may have an important effect on convective heat transfers and thermal comfort. Climate and microclimate conditions should be an integral part of solar chimney design. Key aspects and recommendations regarding solar chimneys, passive cooling and natural ventilation are provided for design guidance and feedback in further research.

  6. Solar chimney power generation project - The case for Botswana

    Import of a huge proportion of electrical energy from the Southern African Power Pool, and the geographical location and population distribution of Botswana stimulated the need to consider renewable energy as an alternative to imported power. The paper describes a systematic experimental study on a mini-solar chimney system. Particular attention is given to measurements of air velocity, temperature and solar radiation. The results for the selected 5 and 6 clear days of October and November, respectively, are presented. These results enable the relationship between average insolation, temperature difference and velocity for selected clear days to be discussed. (author)

  7. Experimental study of temperature field in a solar chimney power setup

    A pilot experimental solar chimney power setup consisted of an air collector 10 m in diameter and an 8 m tall chimney has been built. The temperature distribution in the solar chimney power setup was measured. Temperature difference between the collector outlet and the ambient usually can reach 24.1 deg. C, which generates the driving force of airflow in the setup. This is the greenhouse effect produced in the solar collector. It is found that air temperature inversion appears in the latter chimney after sunrise both on a cool day and on a warm day. Air temperature inversion is formed by the increase of solar radiation from the minimum and clears up some time later when the absorber bed is heated to an enough high temperature to make airflow break through the temperature inversion layer and flow through the chimney outlet

  8. Experimental study of temperature field in a solar chimney power setup

    A pilot experimental solar chimney power setup consisted of an air collector 10 m in diameter and an 8 m tall chimney has been built. The temperature distribution in the solar chimney power setup was measured. Temperature difference between the collector outlet and the ambient usually can reach 24.1 C, which generates the driving force of airflow in the setup. This is the greenhouse effect produced in the solar collector. It is found that air temperature inversion appears in the latter chimney after sunrise both on a cool day and on a warm day. Air temperature inversion is formed by the increase of solar radiation from the minimum and clears up some time later when the absorber bed is heated to an enough high temperature to make airflow break through the temperature inversion layer and flow through the chimney outlet. (author)

  9. Numerical investigation on thermal and fluid dynamic behaviors of solar chimney building systems

    Full text: Buildings as big energy-consuming systems require large amount of energy to operate. Globally, buildings are responsible for approximately 40% of total world annual energy consumption. Sustainable buildings with renewable energy systems are trying to operate independently without consumption of conventional resources. Renewable energy is a significant approach to reduce resource consumption in sustainable building. A solar chimney is essentially divided into two parts, one - the solar air heater (collector) and second - the chimney. Two configurations of solar chimney are usually used: vertical solar chimney with vertical absorber geometry, and roof solar chimney. For vertical solar chimney, vertical glass is used to gain solar heat. Designing a solar chimney includes height, width and depth of cavity, type of glazing, type of absorber, and inclusion of insulation or thermal mass. Besides these system parameters, other factors such as the location, climate, and orientation can also affect its performance. In this paper a numerical investigation on a prototypal solar chimney system integrated in a south facade of a building is presented. The analysis is carried out on a three-dimensional model in air flow and the governing equations are given in terms of k-s turbulence model. Two geometrical configurations are investigated: 1) a channel with vertical parallel walls and 2) a channel with principal walls one vertical and the other inclined. The problem is solved by means of the commercial code Ansys-Fluent and the results are performed for a uniform wall heat flux on the vertical wall is equal to 300 and 600 W/m2. Results are given in terms of wall temperature distributions, air velocity and temperature fields and transversal profiles in order to evaluate the differences between the two base configurations and thermal and fluid dynamic behaviors. Further, the ground effect on thermal performances is examined. key words: mathematical modeling, solar chimney

  10. Cloud Formation in the Plumes of Solar Chimney Power Generation Facilities: A Modeling Study

    Vanreken, T. M.; Nenes, A.

    2006-12-01

    The mounting negative impacts of our dependence on fossil fuels make obvious the need for continued development of alternative power generation technologies. One promising technology is the solar chimney power plant, the concept of which is straightforward and consists of three main components: a solar air collector, the chimney itself, and a power turbine. The solar collector is a large, circular, greenhouse-like structure that gently slopes toward its center; air enters at the outer edge, and as the air parcel warms buoyancy causes it to move upward and toward the center of the collector. When the air has reached the center of the collector, its temperature has increased by an amount ΔT, at which point it enters the chimney. The chimney functions as the main thermal engine in the power plant; the available power for electrical conversion is a function of the maximum potential air velocity through the chimney, which depends primarily on its height and on ΔT. The actual air velocity is determined by the efficiency of the turbine, which is placed between the solar collector and the chimney. A pilot-scale solar chimney power plant has operated in Manzanares, Spain for two decades, and larger facilities have been proposed in China and Australia. As with all new technologies, it is important to consider the potential adverse impacts of solar chimney power generation facilities. This study considers one such impact- the potential for water vapor in solar chimney plumes to affect both the performance of the facility and the local meteorology. Using a cloud parcel model, the progress of a plume up through and out of a solar chimney was simulated for a range of conditions consistent with the proposed Australian facility. As might be expected, in the absence of any water vapor enhancement the plume demonstrated minimal cloud forming potential. However, our results indicate that in cases of moderate water vapor enhancement, cloud formation can occur after the plume exits

  11. Modeling and characteristics analysis of hybrid cooling-tower-solar-chimney system

    Highlights: • A 3-D model for hybrid cooling-tower-solar-chimney system is developed. • The inclusion of heat exchangers into solar chimney boosts the power output. • The huge jump in power output is at the expense of heat dissipation capacity. • The heat exchanger as second heat source has greater impact on system performance. - Abstract: The hybrid cooling-tower-solar-chimney system (HCTSC), combining solar chimney with natural draft dry cooling tower, generates electricity and dissipates waste heat for the coupled geothermal power plant simultaneously. Based on a developed 3-D model, performance comparisons between the HCTSC system, solar chimney and natural draft dry cooling tower were performed in terms of power output of turbine and heat dissipation capacity. Results show that compared to the traditional solar chimney with similar geometric dimensions, HCTSC system can achieve over 20 times increase in the power output of turbine. However, this huge jump in power output is at the expense of heat dissipation capacity, which may lead to the malfunction of the coupled thermal power plant. By increasing the heat transfer area of the heat exchanger, the HCTSC system can manage to recover its heat dissipation capacity

  12. Effect of solar chimney inclination angle on space flow pattern and ventilation rate

    Bassiouny, Ramadan; Korah, Nader S.A. [Department of Mechanical Power Engineering and Energy, Minia University, Minia 61111 (Egypt)

    2009-02-15

    The solar chimney is a simple and practical idea that is applied to enhance space natural ventilation. The chimney could be vertical or inclined. The chimney inclination angle is an important parameter that greatly affects space flow pattern and ventilation rate. In the present study, the effect of chimney inclination angle on air change per hour and indoor flow pattern was numerically and analytically investigated. A numerical simulation using Ansys, a FEM-based code, was used to predict flow pattern. Then the results were compared with published experimental measurements. A FORTRAN program was developed to iteratively solve the mathematical model that was obtained through an overall energy balance on the solar chimney. The analytical results showed that an optimum air flow rate value was achieved when the chimney inclination is between 45 and 70 for latitude of 28.4 . The numerically predicted flow pattern inside the space supports this finding. Moreover, in the present study a correlation to predict the air change per hour was developed. The correlation was tested within a solar intensity greater than or equal to 500 W/m{sup 2}, and chimney width from 0.1 m to 0.35 m for different inclination angles with acceptable values. (author)

  13. Numerical simulation and comparison of conventional and sloped solar chimney power plants: the case for Lanzhou.

    Cao, Fei; Li, Huashan; Zhang, Yang; Zhao, Liang

    2013-01-01

    The solar chimney power plant (SCPP) generates updraft wind through the green house effect. In this paper, the performances of two SCPP styles, that is, the conventional solar chimney power plant (CSCPP) and the sloped solar chimney power plant (SSCPP), are compared through a numerical simulation. A simplified Computational Fluid Dynamics (CFD) model is built to predict the performances of the SCPP. The model is validated through a comparison with the reported results from the Manzanares prototype. The annual performances of the CSCPP and the SSCPP are compared by taking Lanzhou as a case study. Numerical results indicate that the SSCPP holds a higher efficiency and generates smoother power than those of the CSCPP, and the effective pressure in the SSCPP is relevant to both the chimney and the collector heights. PMID:24489515

  14. Feasibility study on optimization of a typical solar chimney power plant

    Najmi, Mohsen; Nazari, Ali; Mansouri, Hossein; Zahedi, Ghazzanfar

    2012-03-01

    The solar chimney which has been built in Kerman (Kerman city-Iran) is a small scale electrical power plant. The chimney of this unit has 60 m height and 3 m diameter. The collector of this unit is 40 m × 40 m square. To reach nominal power of this unit of power plant, parameters which are effective in optimization are studied. In this regard, we deliberate and propose suggestions to maximize usage of solar energy and kinetic energy. The calculation of maximum power is one of the objectives of this study, so the paper present economic analysis for Kerman solar chimney. A home code has been written for this modeling, in MATLAB.

  15. Solar chimney for the natural ventilation of buildings: simulation and mediation; Chimenea solar para la ventilacion natural de edificios: simulacion y mediacion

    Lanceta, D.; Llorente, J.

    2008-07-01

    In this article, the first part of a research project about the modelling of a solar chimney is presented. In this first part, the average ventilation flows measured in an experimental installation have been compared to the results obtained by CFD (Computational Fluid Dynamics) simulations. In order to do so, a solar chimney with a cross-section of 0.78 m x 0.156 m, height 3,6 m, has been constructed. The chimney consists of a glass surface oriented towards the south. The internal (absorber) surface is made of a copper plate, which has been painted black in order to increase the solar absorption. The chimney is connected to a room measuring 5 m x 2.5 m x 2.5 m, from where it extracts air. The comparison of the results obtained by measurements with those obtained by CFD simulations show that computational tools are accurate enough to predict the behaviour of natural buoyancy in this kind of installations. (Author)

  16. Economic analysis of power generation from floating solar chimney power plant

    Solar chimney thermal power technology that has a long life span is a promising large-scale solar power generating technology. This paper performs economic analysis of power generation from floating solar chimney power plant (FSCPP) by analyzing cash flows during the whole service period of a 100 MW plant. Cash flows are influenced by many factors including investment, operation and maintenance cost, life span, payback period, inflation rate, minimum attractive rate of return, non-returnable subsidy rate, interest rate of loans, sale price of electricity, income tax rate and whether additional revenue generated by carbon credits is included or not. Financial incentives and additional revenue generated by carbon credits can accelerate the development of the FSCPP. Sensitivity analysis to examine the effects of the factors on cash flows of a 100 MW FSCPP is performed in detail. The results show that the minimum price for obtaining minimum attractive rate of return (MARR) of 8% reaches 0.83 yuan (kWh)-1 under financial incentives including loans at a low interest rate of 2% and free income tax. Comparisons of economics of the FSCPP and reinforced concrete solar chimney power plant or solar photovoltaic plant are also performed by analyzing their cash flows. It is concluded that FSCPP is in reality more economical than reinforced concrete solar chimney power plant (RCSCPP) or solar photovoltaic plant (SPVP) with the same power capacity. (author)

  17. On the form of the power equation for modeling solar chimney power plant systems

    Fathi, Nima; Vorobieff, Peter

    2015-01-01

    Recently several mathematical models of a solar chimney power plant were derived, studied for a variety of boundary conditions, and compared against CFD calculations. The importance of these analyses is about the accuracy of the derived pressure drop and output power equation for solar chimney power plant systems (SCPPS). We examine the assumptions underlying the derivation and present reasons to believe that some of the derived equations, specifically the power equation in this model, may require a correction to be applicable in more realistic conditions. The analytical resutls are compared against the available experimental data from the Manzanares power plant.

  18. Numerical analysis on the performance of solar chimney power plant system

    Power generating technology based on renewable energy resources will definitely become a new trend of future energy utilization. Numerical simulations on air flow, heat transfer and power output characteristics of a solar chimney power plant model with energy storage layer and turbine similar to the Spanish prototype were carried out in this paper, and mathematical model of flow and heat transfer for the solar chimney power plant system was established. The influences of solar radiation and pressure drop across the turbine on the flow and heat transfer, output power and energy loss of the solar chimney power plant system were analyzed. The numerical simulation results reveal that: when the solar radiation and the turbine efficiency are 600 W/m2 and 80%, respectively, the output power of the system can reach 120 kW. In addition, large mass flow rate of air flowing through the chimney outlet become the main cause of energy loss in the system, and the collector canopy also results in large energy loss.

  19. Computational studies on the effect of geometric parameters on the performance of a solar chimney power plant

    Graphical abstract: This work is aimed at optimizing the geometry of the major components of a solar chimney power plant using ANSYS-CFX. The collector inlet opening, collector height, collector outlet diameter, the chimney throat diameter and the chimney divergence angle were varied for the same chimney height and collector diameter and the performance of the plant was studied in terms of the available power and an optimum configuration was obtained. The temperature and velocity variations in the collector and along the chimney height were also studied. - Highlights: • Geometry of the major components of a solar chimney power plant optimized using CFX. • Collector inlet opening, height, outlet diameter, chimney throat diameter, and the chimney divergence angle were varied. • Temperature and velocity variations and available power were obtained for different configurations. • Optimum values of collector outlet height and diameter and the divergence angle were obtained. - Abstract: A solar chimney power plant (SCPP) is a renewable-energy power plant that transforms solar energy into electricity. The SCPP consists of three essential elements – solar air collector, chimney tower, and wind turbine(s). The present work is aimed at optimizing the geometry of the major components of the SCPP using a computational fluid dynamics (CFD) software ANSYS-CFX to study and improve the flow characteristics inside the SCPP. The overall chimney height and the collector diameter of the SCPP were kept constant at 10 m and 8 m respectively. The collector inlet opening was varied from 0.05 m to 0.2 m. The collector outlet diameter was also varied from 0.6 m to 1 m. These modified collectors were tested with chimneys of different divergence angles (0°–3°) and also different chimney inlet openings of 0.6 m to 1 m. The diameter of the chimney was also varied from 0.25 m to 0.3 m. Based on the CFX computational results, the best configuration was achieved using the chimney

  20. A Cost Effective Desalination Plant Using a Solar Chimney with Recycled Aluminum Can Collector

    Singuru Rajesh

    2016-01-01

    Full Text Available The main objective of the work was to use solar energy for desalination of water. A solar chimney desalination system, which includes the solar chimney, solar collector, evaporation system, and passive condenser, was designed and built. The air enters into collector and gets heated and released at the bottom of chimney. Due to draught effect dry air goes upward. The air is humidified by spraying salt water into the hot air stream using a mistifier at the middle of chimney. Then, the partial vapours contained in the air are condensed to give desalinated water. The performance of the integrated system including power and potable water production was estimated and the results were discussed. With a 3.4 m height setup, experimental test rig was capable of evaporating 3.77 L water daily condensing 2.3 L water. It is compact in nature as it is easy to assemble and dissemble. It can be used for purifying rain water in summer under rain water harvesting. Because of using country wood, recycled Al cans, and GI sheet in fabrication, it is lower in cost.

  1. Analysis and feasibility of implementing solar chimney power plants in the Mediterranean region

    This paper analyzes the feasibility of solar chimney power plants as an environmentally acceptable energy source for small settlements and islands of countries in the Mediterranean region. For the purpose of these analyses, two characteristic geographic locations (Split and Dubrovnik) in Croatia were chosen and simplified model for calculation of produced electric power output is also developed. These locations possess typical characteristics of the Mediterranean climate. The solar characteristics of the chosen geographic locations are shown along with characteristic meteorological data. A solar chimney (SC) power plant with a chimney height of 550 m and a collector roof diameter of 1250 m would produce 2.8-6.2 MW of power. The average annual electric power production of this SC power plant would range between 4.9 and 8.9 GWh/year, but in reality from 5.0 to 6.0 GWh/year in average. An approximate costs analysis, which included a total investment estimate, was performed. The levelized electricity cost was also calculated. It is found that the price of produced electric energy by solar chimney power plant in Mediterranean region is considerably higher compared to the other power sources. (author)

  2. An analytical and numerical study of solar chimney use for room natural ventilation

    Bassiouny, Ramadan; Koura, Nader S.A. [Department of Mechanical Power Engineering and Energy, Minia University, Minia 61111 (Egypt)

    2008-07-01

    The solar chimney concept used for improving room natural ventilation was analytically and numerically studied. The study considered some geometrical parameters such as chimney inlet size and width, which are believed to have a significant effect on space ventilation. The numerical analysis was intended to predict the flow pattern in the room as well as in the chimney. This would help optimizing design parameters. The results were compared with available published experimental and theoretical data. There was an acceptable trend match between the present analytical results and the published data for the room air change per hour, ACH. Further, it was noticed that the chimney width has a more significant effect on ACH compared to the chimney inlet size. The results showed that the absorber average temperature could be correlated to the intensity as: (T{sub w} = 3.51I{sup 0.461}) with an accepted range of approximation error. In addition the average air exit velocity was found to vary with the intensity as ({nu}{sub ex} = 0.013I{sup 0.4}). (author)

  3. Numerical study on mixed buoyancy-wind driving induced flow in a solar chimney for building ventilation

    Zamora, B.; Kaiser, A.S. [Dpto. Ingenieria Termica y de Fluidos, Universidad Politecnica de Cartagena, Doctor Fleming s/n, 30202 Cartagena (Spain)

    2010-09-15

    In a solar chimney, the buoyancy induced flow of air generates ventilation of the building where the chimney is attached. When atmospheric wind blows over the upper part of a solar chimney, a mixed buoyancy-wind driving induced flow appears, and then the thermal behaviour of the chimney changes drastically. Assuming that the chimney is devoid of any protective device at its upper part, numerical results for the pressure difference coefficients, average Nusselt number and the induced mass flow rate are obtained for values of Rayleigh number varying from 10{sup 7} to 10{sup 12} (symmetrically, isothermal heating condition) and 10{sup 11} to 10{sup 15} (symmetrically, uniform heat flux heating condition), with wind speeds from 0 to 10 m/s. A correlation for the non-dimensional mass flow rate is presented, which is valid for the complete range of relevant parameters regarded, with an average deviation about 6%. (author)

  4. Basement Kind Effects on Air Temperature of a Solar Chimney in Baghdad - Iraq Weather

    Miqdam Tariq Chaichan

    2011-01-01

    Full Text Available A solar updraft tower power plant (solar tower is a solar thermal power plant that utilizes a combination of solar air collector and central updraft tube to generate an induced convective flow which drives pressure staged turbines to generate electricity. This paper presents practical results of a prototype of a solar chimney with thermal mass, where the glass surface is replaced by transparence plastic cover. The study focused on chimney's basements kind effect on collected air temperatures. Three basements were used: concrete, black concrete and black pebbles basements. The study was conducted in Baghdad from August to November 2009. The results show that the best chimney efficiency attained was 49.7% for pebbles base. The highest collected air temperature reached was 49ºC when using the black pebbles basement also.also, the maximum basement temperature measured was 59ºC for black pebbles. High increaments in collected air temperatures were achieved in comparison with the ambient air temperatures for the three basement kinds. The highest temperature difference reached was 22ºC with the pebble ground.

  5. Performance analysis of conventional and sloped solar chimney power plants in China

    The solar chimney power plant (SCPP) has been accepted as one of the most promising approaches for future large-scale solar energy applications. This paper reports on a heat transfer model that is used to compare the performance of a conventional solar chimney power plant (CSCPP) and two sloped solar chimney power plants (SSCPPs) with the collector oriented at 30° and 60°, respectively. The power generation from SCPPs at different latitudes in China is also analyzed. Results indicate that the larger solar collector angle leads to improved performance in winter but results in lower performance in summer. It is found that the optimal collector angle to achieve the maximum power in Lanzhou, China, is around 60°. Main factors that influence the performance of SCPPs also include the system height and the air thermophysical characteristics. The ground energy loss, reflected solar radiation, and kinetic loss at the chimney outlet are the main energy losses in SCPPs. The studies also show SSCPPs are more suitable for high latitude regions in Northwest China, but CSCPPs are suggested to be built in southeastern and eastern parts of China with the combination to the local agriculture. - Highlights: ► The optimum collector angle for maximum power generation is 60° in Lanzhou. ► Main parameters influencing performances are the system height and air property. ► Ground loss, reflected loss and outlet kinetic loss are the main energy losses. ► The sloped styles are suitable for Northwest China. ► The conventional styles are suitable for Southeast and East China.

  6. Solar chimney: A sustainable approach for ventilation and building space conditioning

    Lal, S.,

    2013-03-01

    Full Text Available The residential and commercial buildings demand increase with rapidly growing population. It leads to the vertical growth of the buildings and needs proper ventilation and day-lighting. The natural air ventilation system is not significantly works in conventional structure, so fans and air conditioners are mandatory to meet the proper ventilation and space conditioning. Globally building sector consumed largest energy and utmost consumed in heating, ventilation and space conditioning. This load can be reduced by application of solar chimney and integrated approaches in buildings for heating, ventilation and space conditioning. It is a sustainable approach for these applications in buildings. The authors are reviewed the concept, various method of evaluation, modelings and performance of solar chimney variables, applications and integrated approaches.

  7. Design and simulation of a geothermal–solar combined chimney power plant

    Highlights: • A geothermal–solar chimney power plant (GSCPP) is designed and analyzed. • Three different models, viz. full solar model, full geothermal model and geothermal–solar mode are compared. • Power generation under GSM is larger than the sum of FSM and FGM. • GSCPP can effectively solve the continuous operation problem of the SCPP. - Abstract: The solar chimney power plant (SCPP) is dominated by the solar radiation, and therefore its discontinuous operation is an unavoidable problem. In this paper, low temperature geothermal water is introduced into the SCPP for overcoming this problem. Based on a developed transient model, theoretical analyses are carried out to investigate the performance of the geothermal–solar chimney power plant (GSCPP) with main dimensions the same as the Manzanares prototype in Spain. Three operation models, viz. the full solar model, the full geothermal model and the geothermal–solar combined model are compared in typical summer and winter days and throughout the year. It is found that the GSCPP can attractively run in the GSM to deliver power continuously. Due to the ambient-dependant geothermal water outlet temperature, introducing the geothermal water makes greater contribution in winter days than in summer days, in the night than in the daytime. Power generation under GSM is larger than the sum of FSM and FGM. GSM is not the simple superposition of FSM and FGM, but makes better utilization of solar and geothermal energy. In addition, introducing high temperature and mass flow rate geothermal water can doubled and redoubled improve the GSCPP’s power capacity

  8. A scaling investigation of the laminar convective flow in a solar chimney for natural ventilation

    Highlights: • Scaling investigation of a solar chimney for ventilation is carried out. • Three distinct flow regimes are identified depending on the Rayleigh number. • Scaling relations are proposed to describe the transient flow development and are verified by numerical data. -- Abstract: The flow behavior due to natural convection of air (with a Prandtl number less than 1) inside a solar chimney with an imposed heat flux on a vertical absorber wall is investigated by a scaling analysis and a corresponding numerical simulation. Three distinct flow regimes are identified, one with a distinct thermal boundary layer and the other two without a distinct thermal boundary layer, depending on the Rayleigh number. The two regimes without a distinct thermal boundary layer are further classified into low and medium Rayleigh number sub-regimes respectively. These sub-regimes are characterized by conduction dominance in which the thermal boundary layer grows to encompass the entire width of the channel before convection becomes important. Flow development in each of these flow regimes and sub-regimes is characterized through transient scaling, and scaling correlations are developed to describe the temperature, flow velocity and mass flow rate, which characterize the ventilation performance of the solar chimney. The scaling arguments are validated by the corresponding numerical data

  9. Numerical investigation of a plume from a power generating solar chimney in an atmospheric cross flow

    Zhou, Xinping; Yang, Jiakuan; Ochieng, Reccab M.; Li, Xiangmei; Xiao, Bo

    2009-01-01

    A plume in an atmospheric cross flow from a power generating solar chimney is investigated using a three-dimensional numerical simulation model. The simulation model is validated by comparing the data calculated using our model with the numerical simulated results for one-dimensional buoyancy-driven compressible flow in a proposed 1500 m high solar chimney. In this paper, the parametric performances including static pressure, static temperature, density, streamline, and relative humidity field of the flow at the symmetry plane, at the cross plane 2700 m high and at the cross plane 750 m high in the geometry are simulated. It is found that relative humidity of the plume is greatly increased due to the jet of a plume into the surroundings colder than the plume. In addition to a great amount of tiny granules in the plume originating from the ground as effective condensation nuclei of moisture, a condensation would occur, a cloud system and precipitation e.g. rainfall, snow and hail would be formed around the plume when vapor is supersaturated. It is also found that with an increase in chimney height or relative humidity of atmosphere, or a reduction in wind velocity, relative humidity is increased, and increases the probability of precipitation and the potential precipitation areas. Furthermore, the latent heat released from the condensation of supersaturated vapor can aid the plume to keep on rising.

  10. Application of Solar Chimney Concept to Solve Potential Safety Issues of Nuclear Power Plants

    LUHS. In addition to its dual functionality; it provides a complete independent and diverse means of safety functions supporting, a free carbon oxide power production source and allow following the world's trend toward the usage of renewable energy sources. The Solar Chimney Power Plant was suggested to be employed as a supporting system for NPPs to provide emergency power, in case of SBO, and emergency cooling, in case of LUHS. It provides a complete independent and diverse means of safety function supporting. Following the SCPP operation requirements of the availability of high solar irradiation, the UAE region provides a perfect environment for its implementation; furthermore, it can be linked to the under-construction NPPs at Al-Barakah site to deliver alternative emergency power and emergency cooling. Due to the inherent unreliability of the currently utilized EDGs and the AAC power sources, a postulated SBO event could affect the safety of the NPP in general, and for the specific case of the UAE NPPs, a LUHS caused by oil spill accident in the UHS could be experienced, given the massive oil related activates being performed in the Arabian Gulf. Comparing the similarity between Al-Barakah site and the Loviisa NPP in Finland; looking for solution and alternatives for the enhancement of their reactors safety should be considered by the UAE nuclear regulator

  11. Application of Solar Chimney Concept to Solve Potential Safety Issues of Nuclear Power Plants

    Khasawneh, Khalid; PARK, Youn Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    LUHS. In addition to its dual functionality; it provides a complete independent and diverse means of safety functions supporting, a free carbon oxide power production source and allow following the world's trend toward the usage of renewable energy sources. The Solar Chimney Power Plant was suggested to be employed as a supporting system for NPPs to provide emergency power, in case of SBO, and emergency cooling, in case of LUHS. It provides a complete independent and diverse means of safety function supporting. Following the SCPP operation requirements of the availability of high solar irradiation, the UAE region provides a perfect environment for its implementation; furthermore, it can be linked to the under-construction NPPs at Al-Barakah site to deliver alternative emergency power and emergency cooling. Due to the inherent unreliability of the currently utilized EDGs and the AAC power sources, a postulated SBO event could affect the safety of the NPP in general, and for the specific case of the UAE NPPs, a LUHS caused by oil spill accident in the UHS could be experienced, given the massive oil related activates being performed in the Arabian Gulf. Comparing the similarity between Al-Barakah site and the Loviisa NPP in Finland; looking for solution and alternatives for the enhancement of their reactors safety should be considered by the UAE nuclear regulator.

  12. DESIGN NOTE: Ultrasonic velocity meter to evaluate the behaviour of a solar chimney

    Olmos, P.

    2004-07-01

    The addition of solar chimneys represents a substantial improvement in the natural ventilation scheme of a building and is thus an important component of so-called passive cooling, mainly in warm climates. In order to evaluate and/or control its performance, an accurate measurement of the velocity and temperature of the air passing through the duct is needed. Normal commercial equipment, developed for other applications, does not suit this particular scenario very well. An ultrasonic velocity meter has been specially designed, manufactured and tested inside an actual chimney, proving that this approach is a reliable solution to the problem of measuring the ventilation parameters. Here a detailed description of the instrument is given, along with a presentation of its first operational tests.

  13. Simulation of solar chimney power plant with an external heat source

    Solar chimney power plant is a sustainable source of power production. The key parameter to increase the system power output is to increase its size but the plant cannot operate during night hours. This study deals with simulation work to validate results of pilot plant at Manzanares and include the effects of waste heat from a gas turbine power plant in the system. The effects show continuous night operation, a 38.8 percent increase in power at 1000 W/m2 global solar irradiation at daytime and 1.14 percent increase in overall efficiency.

  14. Simulation of solar chimney power plant with an external heat source

    Islamuddin, Azeemuddin; Al-Kayiem, Hussain H.; Gilani, Syed I.

    2013-06-01

    Solar chimney power plant is a sustainable source of power production. The key parameter to increase the system power output is to increase its size but the plant cannot operate during night hours. This study deals with simulation work to validate results of pilot plant at Manzanares and include the effects of waste heat from a gas turbine power plant in the system. The effects show continuous night operation, a 38.8 percent increase in power at 1000 W/m2 global solar irradiation at daytime and 1.14 percent increase in overall efficiency.

  15. Evaluation of the influence of soil thermal inertia on the performance of a solar chimney power plant

    Solar chimney power plants are a technology capable to generate electric energy through a wind turbine using the solar radiation as energy source; nevertheless, one of the objectives pursued since its invention is to achieve energy generation during day and night. Soil under the power plant plays an important role on the energy balance and heat transfer, due to its natural behavior as a heat storage system. The characteristics of the soil influence the ability of the solar chimney power plant to generate power continuously. Present work analyzes the thermodynamic behavior and the power output of a solar chimney power plant over a daily operation cycle taking into account the soil as a heat storage system, through a numerical modeling under non-steady conditions. The influence of the soil thermal inertia and the effects of soil compaction degree on the output power generation are studied. A sizeable increase of 10% in the output power is obtained when the soil compaction increases. -- Highlights: ► Solar chimney power plants are a technology capable to generate renewable energy from solar radiation. ► The ground under the solar chimney can act as a heat storage system. ► The soil thermal inertia plays a relevant role in a scenario where the plant operates continuously. ► A higher compaction of soil causes a relevant increase on total energy generation.

  16. A First Approach to Natural Thermoventilation of Residential Buildings through Ventilation Chimneys Supplied by Solar Ponds

    Ferdinando Salata

    2015-07-01

    Full Text Available The exploitation of natural ventilation is a good solution to improve buildings from an energetic point of view and to fulfill the requirements demanded by the thermohygrometric comfort and the air quality in enclosed spaces. Some past researches demonstrated how some devices, useful to this purpose, follow the principles of solar chimneys and are able to move air masses while exploiting the Archimedes thrust. The natural ventilation must be supplied by a flow moving upward, generated by a heat source performing at temperatures slightly higher than the one present in the environment. To have a minimum energetic effect, the heat can be extracted from solar ponds; solar ponds are able to collect and store solar energy in the geographical regions characterized by sufficient values of solar radiation. Thus it is possible, in summer, to provoke a nocturnal natural ventilation useful for the air change in indoor spaces (in those climatic areas where, during the night, there is a temperature gradient.

  17. Heat transfer by convection, conduction and radiation in solar chimney systems for ventilation of dwellings

    Numerical study by conjugate heat transfer is carried out of solar chimney systems for heating and ventilation of dwellings. Conservation equations are solved by finite difference-control volume numerical method. The governing parameters were: the Rayleigh numbers from 5 x 108 to 1011, the Prandtl number, Pr = 0.7, constant for air, the chimney aspect ratio, A = H/L from 6 to 15, the air channel width l'/L = 0.2 to 0.5, the air entrance port size, h/L = 0.167-0.667, the wall thickness l/L = 0.25-0.4, the conductivity ratio kr from 5 to 50 and the surface emissivity, ε from 0 to 1. The Nusselt number, the dimensionless volume flow rate V. and radiation heat flux ratio qr/qtot are calculated as a function of the governing parameters, and streamlines and isotherms are produced. The results show that the surface radiation modifies the flow and temperature fields, affects the Nusselt number and the volume flow rate, both in a positive way, and improves the ventilation performance of the chimneys

  18. The experimental design of solar heating thermoelectric generator with wind cooling chimney

    Highlights: • We model an experimental design of thermal electrical generator. • Electrical parameters were collected under the solar radiation. • All the calculated values were obtained from collected data. • Generated power and electrical efficiency were changed by thermal gradient. - Abstract: In this paper we present an experimental design of new solar based thermoelectric generator with wind chimney. Presented generator mainly consists of four parts: a heat pipe with solar collector tube for solar heating, a wind chimney for cooling, a thermoelectric (TE) module for electricity generation and measurement devices-sensors. Presented generator based on experimental design. Aim of this experimental design is to show an alternative way for cheap and efficiently renewable energy producing. The most important features of presented generator are uncomplicated structure, efficiently and cheapness. This experimental design can be improved and used for domestic and commercial application. For this reason, main parts of system can be enhanced and system can be improved. To evaluate of presented generator we collected some experimental data on designed system. Then maximum output power, electrical efficiency and Seebeck coefficient are calculated from obtained data. Results of the measurement are displayed in the form of graphs and tables. Our experiment was carried out on 16th and 21th August, in Samsun, on the north coast of Turkey with the exact location 41°14′N 36°26′E with sea level. Collection of the data was performed from 8:30 a.m. to 4 p.m

  19. A parametric study on the feasibility of solar chimney power plants in North Cyprus conditions

    Highlights: • A parametric for solar chimney power plants (SCPPs) feasibility approach is proposed. • We found the annual electricity production of a 30 MW SCPP to be 94.5 GW h. • We compare this production with the same capacity fossil fuel thermal power plant. • We assess the effect of varying some parameters on economic viability of the SCPP. • Capital expenditure plays a critical role in assessing SCPP economic feasibility. - Abstract: The present work investigates the feasibility of installing a solar chimney power plant (SCPP) under North Cyprus (NC) conditions. The method utilized for the simulations of electricity production was compared and verified by the experimental recordings of the prototype in Manzanares, Spain, before carrying out performance predictions for different plant sizes, collector diameters and chimney heights. The annual electricity production of a 30 MW hypothetical SCPP system is estimated to be 94.5 GW h, which can cater for annual electricity needs of over 22,128 residences without any CO2, NOx and SOx emissions. For an installation cost of €145 million, it was estimated that the savings-to-investment ratio (SIR) would be 1.14, indicating a marginal economic feasibility. It is important to find ways of reducing the installation cost in order to strengthen the economic viability of the system. Considering that, at present, fuel oil no. 6 is being used in NC to produce electricity; the SCPP would cause avoidance of 24,840 tonnes of CO2 delivered into the atmosphere annually, if it replaced an equivalently-sized conventional power unit. To identify the most feasible cost option for the installation of the SCPP, a parametric cost analysis is carried out by varying the parameters such as; capital investment costs, carbon dioxide emission trading system price, chimney height, collector diameter and SCPP plant capacity. In all cases, the effect of these parameters on the economic feasibility indicators, such as SIR, net present

  20. Thermal Analyses of Combined Utilization Process of Seawater by Solar Chimney

    WANG Yiping; FANG Zhenlei; ZHU Li

    2009-01-01

    It is promising to simultaneously develop multiple products through the combined utilization of sea-water by solar chimney technology. A small scale experimental system was set up. The collector temperature, the seawater temperature, and the temperature and humidity of the airflow under the collector were measured. Thermal network analysis of the system was carried out. The results show that the airflow is nearly saturated at the entrance of the chimney, and the mean dry-bulb and wet-bulb temperatures of the airflow have increased by 8.4℃ and 9.6℃ respectively. The radiation heat transfer between the collector and the sky is the biggest heat loss in the system, which is up to 29.1% on average of the solar energy. However, the water evaporation heat is about 23.6% on average of the solar energy. To reduce the heat loss and enhance the water evaporation, it is necessary to reduce the emissivity and thermal conductivity of the collector and increase the evaporation areas.

  1. Experimental investigation into heating and airflow in trombe walls and solar chimneys

    Trombe Walls and solar chimneys are examples of passive solar air heating systems. However, the airflow and thermal efficiency characteristics of this type of system are not well understood, and partly for this reason, they are not commonly utilised. This paper reports on an experimental investigation into buoyancy-driven convection in a test rig designed to simulate the operation of a passive solar collector. The test rig comprised a vertical open-ended channel, approximately 1a square, heated from one side. The channel depth could be varied from 20mm to 110mm, and heating inputs varied from 200W to 1000W. Temperatures and airflow rates were measured and recorded, to characterise both steady-state and transient performance. The principal findings are: 1. Time constants (for heating)ranged typically between 30 and 70 minutes. 2. Flow regimes were mainly laminar (Reynolds number varing from ∼500 to ∼4000, depending on heat input and channel depth. 3. The thermal efficiency (as a solar collector and the heat transfer coefficient were functions of heat input, and were not depended on the channel depth. 4. The mass flow rate through the channel increased bath as the heat input increased and as the channel depth increased. The paper presents these findings and discusses their implications in more detail.(Author)

  2. Thermodynamic analysis of a low-temperature waste heat recovery system based on the concept of solar chimney

    Highlights: • A low grade waste heat recovery system based on the concept of solar chimney is proposed. • The effects of three key factors on the system performance are examined. • Thermodynamics analysis is to find a better way to utilize low grade heat source efficiently. - Abstract: The utilization of low-temperature waste heat draws more and more attention due to serious energy crisis nowadays. This paper proposes a low-temperature waste heat recovery system based on the concept of solar chimney. In the system, low-temperature waste heat is used to heat air to produce an air updraft in the chimney tower. The air updraft propels a turbine fixed at the base of the chimney tower to convert waste heat into electricity. The mathematical model of the system is established based on first law and second law of thermodynamics. Hot water is selected as the representative of low-temperature waste heat sources for researching. The heat source temperature, ambient air temperature and area of heat transfer are examined to evaluate their effects on the system performance such as velocity of updraft, mass flow rate of air, power output, conversion efficiency, and exergy efficiency. The velocity of air demonstrates a better stability than the mass flow rate of air and the pressure difference when temperature of heat source, ambient air temperature or area of heat transfer changes

  3. Numerical analysis of flow and heat transfer characteristics in solar chimney power plants with energy storage layer

    Numerical simulations have been performed to analyze the characteristics of heat transfer and air flow in the solar chimney power plant system with an energy storage layer. Different mathematical models for the collector, the chimney and the energy storage layer have been established, and the effect of solar radiation on the heat storage characteristic of the energy storage layer has been analyzed. The numerical simulation results show that: (1) the heat storage ratio of the energy storage layer decreases firstly and then increases with the solar radiation increasing from 200 W/m2 to 800 W/m2; (2) the relative static pressure decreases while the velocity increases significantly inside the system with the increase of solar radiation; (3) the average temperature of the chimney outlet and the energy storage layer may increase significantly with the increase of solar radiation. In addition, the temperature gradient of the storage medium may increase, which results in an increase of energy loss from the bottom of the energy storage layer

  4. A cost-benefit analysis of power generation from commercial reinforced concrete solar chimney power plant

    Highlights: • We develop an economic model different from related models. • We evaluate the initial investment cost of a plant built in northwest China. • We analyze the cost and benefit of a plant built in northwest China. • By the sensitivity analysis, we examine the sensitivity of TNPV to many parameters. - Abstract: This paper develops a model different from existing models to analyze the cost and benefit of a reinforced concrete solar chimney power plant (RCSCPP) built in northwest China. Based on the model and some assumptions for values of parameters, this work calculates total net present value (TNPV) and the minimum electricity price in each phase by dividing the whole service period into four phases. The results show that the minimum electricity price in the first phase is higher than the current market price of electricity, but the minimum prices in the other phases are far less than the current market price. The analysis indicates that huge advantages of the RCSCPP over coal-fired power plants can be embodied in phases 2–4. In addition, the sensitivity analysis performed in this paper discovers TNPV is very sensitive to changes in the solar electricity price and inflation rate, but responds only slightly to changes in carbon credits price, income tax rate and interest rate of loans. Our analysis predicts that RCSCPPs have very good application prospect. To encourage the development of RCSCPPs, the government should provide subsidy by setting higher electricity price in the first phase, then lower electricity price in the other phases

  5. Mathematical modelling and validation of the drying process in a Chimney-Dependent Solar Crop Dryer

    Highlights: ► The simulation code predicts temperatures to within 1.5% of recorded data. ► The ventilation is predicted to within 5% accuracy. ► Effects of heat inertia cause the actual drying path to deviate from the simulated path. ► The two paths converge in the end with a final moisture content prediction to within 10%. ► The simulation code can be used to compare and refine the dryer designs for optimum drying performance. - Abstract: A simulation procedure describing the drying process within a Chimney-Dependent Solar Crop Dryer (CDSCD) has been developed. The simulation follows the authors’ experimental work on the effect of varying drying chamber roof inclination on the ventilation and drying processes, and their work on the development of simulation code to help optimise ventilation in such dryers. The current paper presents the modelling and subsequent validation of the drying process inside the dryer, to come out with a design tool for the CDSCD. The work considers the height of the crop shelf above the drying-chamber base, crop resistance to airflow and the shading on the drying-chamber base and their effects on the drying process. The under-load condition temperatures and velocities are predicted to within a relative difference of 1.5% and 10%, respectively of the observed values. Even though the heat inertia of the physical model causes deviation between the predicted drying path and the observed drying path, the two paths tend to converge at the end of each drying cycle, with a general prediction to within 10% relative difference of the observed crop moisture content. The validation results show that the simulation code can serve as an effective tool for comparing and refining the designs of the CDSCD for optimum drying performance

  6. Examining potential benefits of combining a chimney with a salinity gradient solar pond for production of power in salt affected areas

    Akbarzadeh, Aliakbar; Johnson, Peter; Singh, Randeep [Energy Conservation and Renewable Energy Group, School of Aerospace Mechanical and Manufacturing Engineering, RMIT University, P.O. Box 71, Bundoora 3083, Vic. (Australia)

    2009-08-15

    The concept of combining a salinity gradient solar pond with a chimney to produce power in salt affected areas is examined. Firstly the causes of salinity in salt affected areas of northern Victoria, Australia are discussed. Existing salinity mitigation schemes are introduced and the integration of solar ponds with those schemes is discussed. Later it is shown how a solar pond can be combined with a chimney incorporating an air turbine for the production of power. Following the introduction of this concept the preliminary design is presented for a demonstration power plant incorporating a solar pond of area 6 hectares and depth 3 m with a 200 m tall chimney of 10 m diameter. The performance, including output power and efficiency of the proposed plant operating in northern Victoria is analysed and the results are discussed. The paper also discusses the overall advantages of using a solar pond with a chimney for production of power including the use of the large thermal mass of a solar pond as a practical and efficient method of storing collected solar energy. (author)

  7. Passive solar construction handbook

    Levy, E.; Evans, D.; Gardstein, C.

    1981-08-01

    Many of the basic elements of passive solar design are reviewed. The unique design constraints presented in passive homes are introduced and many of the salient issues influencing design decisions are described briefly. Passive solar construction is described for each passive system type: direct gain, thermal storage wall, attached sunspace, thermal storage roof, and convective loop. For each system type, important design and construction issues are discussed and case studies illustrating designed and built examples of the system type are presented. Construction details are given and construction and thermal performance information is given for the materials used in collector components, storage components, and control components. Included are glazing materials, framing systems, caulking and sealants, concrete masonry, concrete, brick, shading, reflectors, and insulators. The Load Collector Ratio method for estimating passive system performance is appended, and other analysis methods are briefly summarized. (LEW)

  8. Numerical simulation of an innovated building cooling system with combination of solar chimney and water spraying system

    Rabani, Ramin; Faghih, Ahmadreza K.; Rabani, Mehrdad; Rabani, Mehran

    2014-05-01

    In this study, passive cooling of a room using a solar chimney and water spraying system in the room inlet vents is simulated numerically in Yazd, Iran (a hot and arid city with very high solar radiation). The performance of this system has been investigated for the warmest day of the year (5 August) which depends on the variation of some parameters such as water flow rate, solar heat flux, and inlet air temperature. In order to get the best performance of the system for maximum air change and also absorb the highest solar heat flux by the absorber in the warmest time of the day, different directions (West, East, North and South) have been studied and the West direction has been selected as the best direction. The minimum amount of water used in spraying system to set the inside air averaged relative humidity <65 % is obtained using trial and error method. The simulation results show that this proposed system decreases the averaged air temperature in the middle of the room by 9-14 °C and increases the room relative humidity about 28-45 %.

  9. Passive-solar construction handbook

    Levy, E.; Evans, D.; Gardstein, C.

    1981-02-01

    Many of the basic elements of passive solar design are reviewed. Passive solar construction is covered according to system type, each system type discussion including a general discussion of the important design and construction issues which apply to the particular system and case studies illustrating designed and built examples of the system type. The three basic types of passive solar systems discussed are direct gain, thermal storage wall, and attached sunspace. Thermal performance and construction information is presented for typical materials used in passive solar collector components, storage components, and control components. Appended are an overview of analysis methods and a technique for estimating performance. (LEW)

  10. Electricity production with low grade heat in thermal power plants by design improvement of a hybrid dry cooling tower and a solar chimney concept

    Highlights: • A system of a dry cooling tower and a solar chimney are recombined. • The hot flue gas is injected in the hybrid tower to maximize the power output. • Effects of the angle of the tower walls (convergent or divergent) are studied. • Effects of the collector roof slope and base ground slope are studied. • The thermal efficiency of a 250 MW power plant is increased more than 0.5%. - Abstract: In this study, an improved concept design is presented to increase the thermal efficiency of the Rankine cycle of a typical steam power plant by combining a solar chimney and a dry cooling tower. The sources of the wind energy generation, include: the rejected heat from condenser to the air entering dry cooling tower, solar radiation and the airlift pumping effect on the air flow created by the stack hot flue gas which is injected into the hybrid tower as a novel change. This research primarily focuses on the Shahid Rajaee 250 MW steam power plant to determine the velocity of generated flow at the turbine inlet; a numerical finite volume code was employed for a dry cooling tower having a base diameter and a chimney height of 250 and 200 m, respectively. Calculations have been iterated for different angles of chimney walls, slopes of collectors and the base ground to find their effects on the output power. A range of 360 kW to more than 4.4 MW power is captured by the wind turbine by changing the hybrid tower geometrical parameters. Obtained results reveal a maximum of 0.538% increase for the thermal efficiency of the fossil fuel power plant

  11. Hybrid Solar Chimney and Evaporative Cooling System Used in Xinjiang%新疆地区太阳能烟囱复合蒸发冷却通风降温系统

    宣永梅; 马柱柱; 黄翔

    2013-01-01

    提出了太阳能烟囱复合蒸发冷却系统,对复合系统模型进行了理论分析及计算,得出通风量与烟囱高度、宽度及太阳辐射强度之间的关系。结果表明,太阳能烟囱的自然通风量随太阳能辐射强度及烟囱高度的增加而增加;在计算条件下,当宽度取1m 时通风量取得最大值。在此基础上分析得到太阳辐射照度400W/m2、烟囱高度3m、宽度1m 时,太阳能烟囱复合蒸发冷却系统应用于乌鲁木齐建筑时烟囱的理论通风量为0.21kg/s,该通风量基本满足乌鲁木齐夏季通风设计工况下,蒸发冷却降温时所需动力(0.23kg/s),且室内通风换气次数达到10次/h 以上,是一种节能环保的自然通风降温技术。%A hybrid system of solar chimney and evaporative cooling was proposed.The model of this hybrid system was studied by theoritical analysis and calculation.The relationships between air flow rate with chimney height,width and solar radiation were obtained.The calculation results indicated that the air flow rate of solar chimney increases with solar radiation and chimney height.Under design conditions,the air flow rate of solar chimney reaches its maximum value at solar chimney width of 1m. When applied to actual buildings in Urumqi,the obtained air mass flow rate (0.21kg/s)of solar chimney under optimum condi-tions (at chimney height of 3m,width of 1m,solar radiation of 400W/m2 )can approximately meet the ventilation requirements of evaporative cooling (0.23kg/s),and air changes more than 10 times per hour.The proposed hybrid system is an environmental friendly and energy efficient natural ventilation and free cooling technology.

  12. Fairy chimneys in Peru

    Sparavigna, Amelia Carolina

    2011-01-01

    Erosion creates beautiful landscapes. A large part of them is known just by the local population. Google Maps can help in locating the places, study them and start any project for preservation. An interesting example is given by a landscape of fairy chimneys in Peru, near San Pedro de Larcay. It is remarkable the fact that some of them have been adapted as dwelling places.

  13. Entransy dissipation based performance analysis for solar chimney power plant system with vertical collectors%基于火积耗散法的立式集热板太阳能热气流发电系统传热性能分析

    周艳; 刘峰; 王莉; 巢军; 李庆领

    2015-01-01

    On the basis of the principle of entransy dissipation and the principle of minimum thermal resist-ance in heat transfer theory,the expression of entransy dissipation rate of the solar chimney power plant system with vertical collectors was derived and the heat transfer performance of this system was analyzed. The results show that,the structure dimensions of the chimney are the main factors affecting the perform-ance of the solar chimney power plant system with vertical collectors.However,the height and width of the solar chimney are limited by the height and space between the windows of high buildings,thus the thick-ness of the solar chimney is the foremost factor to decrease the entransy dissipation of the solar power plant system.Under conditions with constant chimney height and width,the thermal resistance of entransy dissipation of the solar system reached the minimum when the solar chimney thickness was 0.959 8 m,indi-cating the performance of the system achieved the optimum.%基于火积耗散及火积耗散热阻极值定律推导出立式集热板太阳能热气流发电系统的火积耗散率表达式,并对系统的传热性能进行分析.结果表明:立式集热板太阳能热气流发电系统的烟囱尺寸是影响系统传热性能的主要因素,但是烟囱的高度和宽度受高层建筑的高度及窗户间距的限制,因此烟囱厚度成为系统火积耗散热阻的主要影响因素;在烟囱高度和宽度不变的条件下,厚度取0.9598 m 时系统火积耗散热阻最小,系统性能最优.

  14. 基于火积耗散法的立式集热板太阳能热气流发电系统传热性能分析%Entransy dissipation based performance analysis for solar chimney power plant system with vertical collectors

    周艳; 刘峰; 王莉; 巢军; 李庆领

    2015-01-01

    基于火积耗散及火积耗散热阻极值定律推导出立式集热板太阳能热气流发电系统的火积耗散率表达式,并对系统的传热性能进行分析.结果表明:立式集热板太阳能热气流发电系统的烟囱尺寸是影响系统传热性能的主要因素,但是烟囱的高度和宽度受高层建筑的高度及窗户间距的限制,因此烟囱厚度成为系统火积耗散热阻的主要影响因素;在烟囱高度和宽度不变的条件下,厚度取0.9598 m 时系统火积耗散热阻最小,系统性能最优.%On the basis of the principle of entransy dissipation and the principle of minimum thermal resist-ance in heat transfer theory,the expression of entransy dissipation rate of the solar chimney power plant system with vertical collectors was derived and the heat transfer performance of this system was analyzed. The results show that,the structure dimensions of the chimney are the main factors affecting the perform-ance of the solar chimney power plant system with vertical collectors.However,the height and width of the solar chimney are limited by the height and space between the windows of high buildings,thus the thick-ness of the solar chimney is the foremost factor to decrease the entransy dissipation of the solar power plant system.Under conditions with constant chimney height and width,the thermal resistance of entransy dissipation of the solar system reached the minimum when the solar chimney thickness was 0.959 8 m,indi-cating the performance of the system achieved the optimum.

  15. Dimensioning, construction and commissioning of a coffee beans drying system with use of solar collectors

    A system of low-cost solar drying of coffee beans is dimensioned, built and commissioned by using solar collectors based on recycled aluminum cans. The information is collected from literature about the drying of coffee, types of drying and the various types of solar dryers.The coffee beans drying system is conceptualized and sized based on a solar collector constructed of aluminum cans as solar radiation absorbing material. The grain drying system is then built in coffee benefit CoopeTarrazu to all provided by the company and help materials and labor facilities. A guide to implementation of solar drying technology with general information is tailored to implement, select, build and maintain a solar grain dryer in Central America. The launch of the drying system was made by checking the proper functioning of the system and measurement instruments variables selected to calculate the efficiency of the system. The drying system is tested with a load of 45 kg of coffee bean, using a flow of air through natural convection to operate the system with the exclusive use of renewable energy. The grain is drying from a humidity of 50% (b.n), up to a humidity between 11% and 13% (b.n), which is the range generally used for the safe storage of grain. Facts of solar radiation, temperature, air velocity, relative humidity and grain humidity were taken to determine the behavior of the sized system. The maximum thermal efficiency achieved by the solar collector is determined constructed of 18%, with an air flow of 0.013 kg/s and a solar radiation 1138 W/m2. The average drying efficiency during experimentation was 17.8%, which is among the range of efficiencies for the type of drying equipment. Best thermal efficiencies were obtained from the solar collector built that the commercial solar collector compared. Controlling the flow of air into the equipment is recommended in order to improve the thermal efficiency and drying equipment, using blowers, fans or induced draft chimney

  16. Psychology and photography: chimneys dreaming and chimneys warriors

    Tilde Giani Gallino

    2013-02-01

    Full Text Available The article covers two aspects related to Psychology and Art. The first aspect concerns the similarities found between photography and various Schools of experimental psychology. For instance, the scientists of Psychology of ethological theory, and Non-verbal communication (NVC, observe with particular methodologies the non-verbal messages that animals and humans transmit to their peers through expressions, posture, gestures. The same is done by photographers (those who use the “camera” with a good knowledge of the medium and a “photographic  eye” when they look around, careful to catch an expression, any unusual attitude, or a gesture of friendship. Another School of psychology, the Gestalpsychologie (Gestalt: form, figure, configuration, attributes a decisive value to the perception of space, the foreground and the background, the perspective and vanishing points, the contrast between black and white. All aspects that effectively interest psychologists just as much as photographers. Finally, the second aspect relates to the art of Antony Gaudì and makes some hypothesis about the personality and behavior of the great architect, with regard to the construction of two houses, "Casa Batllo" and "Casa Mila": particularly because of the configuration or Gestalt of the "chimneys" that dominate the two buildings. In this study, cooperate each other psychological analysis and the art of photography. The last enables us to study also the details of the work of Gaudì, as can be seen in the pictures of this essay.

  17. Corrosion at system chimneys made of CrNi-steels

    Pajonk, Gunther [Institute of Materials Testing of Northrhine-Westfalia, D-44285 Dortmund (Germany)

    2004-07-01

    Names like 'chimney' und 'funnel' usually identify flue gas devices made of bricks. Much less known is the fact that chimney elements are still manufactured from alloys. The following article describes the particular demands ruled by legislation on building pro-ducts, just as the consequences resulting from corrosion loads by flue gas condensates. Difficulties caused by manufacturing and construction are primarily discussed. Furthermore a test procedure is introduced that allows to catch and correlate corrosion loads and technical designs systematically to corrosion behaviour and service life of flue gas devices. For the first time a tool for active quality assurance has been given by this test rig allowing to recognize construction errors systematically. This way, manufacturers of system chimneys and flue liners are enabled to optimize their products applications going ahead to the respective requests of the market. (authors)

  18. Novel concept for producing energy integrating a solar collector with a man made mountain hollow

    The concept of the solar chimney thermal power technology was proven with the successful operation of the Manzanares prototype built in the 1980s. However, all previous attempts at producing energy from a commercial solar chimney thermal power plant on a large scale have failed because of bad engineering and safety. A novel concept for producing energy by integrating a solar collector with a mountain hollow is presented and described. Solar energy is collected in the collector and heats the ground, which is used to store heat energy and heat the indoor air. Then, the hot air is forced by the pressure difference between it and the ambient air to move along the tilted segment and up the vertical segment of the 'chimney', driving the turbine generators to generate electricity. The mountain hollow, formed by excavation in a large-elevation mountain, can avoid the safety issues of erecting a gigantic concrete chimney, which is needed for commercial solar chimney thermal power plants. Furthermore, it can also save a great amount of construction materials for constructing a robust chimney structure and reduce the energy cost to a level less than that of a clean coal power plant, providing a good solution to the reclamation and utilization of undeveloped mountains, especially in mountainous countries

  19. Design and Construction of a Passive Solar Power Clothing Dryer

    Ali Alahmer; Mohammed Al-Dabbas

    2014-01-01

    This manuscript presents the design and construction of the energy efficient, time saving, cost effective of passive solar powered clothes dryer. This manuscript begins with a derivation of mathematical model represents of solar dryer followed with an analysis of the elements necessary for successfully designing the various components of a solar dryer. The solar drying performance achieved an average drying rate of 0.35 kg/h and drying time of 3 h in a typical day, even under local low ambien...

  20. Solar Glazing Tips for School Construction

    Smith, Jonathan

    2012-01-01

    Glazing can be optimized to enhance passive solar heating and daylight harvesting by exceeding the prescriptive limits of the energy code. This savings can be garnered without the high cost of external overhangs or expensive glazing products. The majority of savings from solar glazing are attributable to the increase in solar heating and…

  1. Solar thermal systems successful planning and construction

    Peuser, Dr Felix A; Schnauss, Martin

    2013-01-01

    Solar Thermal Systems summarizes the theoretical and practical knowledge gained from over 20 years of research, implementation and operation of thermal solar installations. This work provides answers to a variety of key questions by examining current solar installations, drawing upon past experiences and making proposals for future planning.- how do system components and materials behave under continuous operation?- which components have proven themselves and how are they used properly?- what are the causes of defects and how can they be avoided?- how long is the service life of modern solar i

  2. Toward a Heat Recovery Chimney

    Min Pan

    2011-11-01

    Full Text Available The worldwide population increase and subsequent surge in energy demand leads electricity producers to increase supply in an attempt to generate larger profit margins. However, with Global Climate Change becoming a greater focus in engineering, it is critical for energy to be converted in as environmentally benign a way as possible. There are different sustainable methods to meet the energy demand. However, the focus of this research is in the area of Waste Heat Recovery. The waste heat stored in the exiting condenser cooling water is delivered to the air flow through a water-air cross flow heat exchanger. A converging thermal chimney structure is then applied to increase the velocity of the airflow. The accelerated air can be used to turn on the turbine-generator installed on the top the thermal chimney so that electricity can be generated. This system is effective in generating electricity from otherwise wasted heat.

  3. Experimental study of the resulting flow of plume-thermosiphon interaction: application to chimney problems

    Zinoubi, J.; Maad, R.B.; Belghith, A. [Faculte des Sciences de Tunis, Tunis (Tunisia). Departement de Physique, Laboratoire d' Energetique et des Transferts de Chaleur et de Masse

    2005-03-01

    The quality of the surrounding air depends on the various dismissals of the combustion gases (exhaust cars, smokes of chimneys, ...), their scattering in the environment. Urban development around industrial zones and overexploitation of lands near factories triggered responsible interest in the problem of pollution. In order to decrease the impact of air pollution, several chimneys have been constructed in the different industrial facilities. So the improvement of the industrial chimney range became one of the current research problems. In order to improve the industrial chimney efficiency and to increase the vertical scattering of combustion products, we studied a system that could be integrated to the industrial chimney exit. This system is essentially constituted of an open-ended vertical cylinder of larger diameter. Thermal radiance emitted by smoke heats the internal cylinder wall. The heating of the fluid at the cylinder-inlet is the cause of the thermosiphon effect around the thermal plume. To study the problem in the laboratory we simulated the plume exiting of a chimney by a disk heated uniformly by the Joule effect at constant temperature. Different configurations were studied, while acting, on the source-cylinder spacing and the cylinder height. The study of the average fields permits, in a first stage, to get better information about the mechanism of the resulting flow development, and in a second stage, to determine the spacing of the source-cylinder and cylinder height optima, for which a clean increase of fluid flow rate is obtained. (author)

  4. Investigation and Construction of a Thermosyphoning Solar Hot Water System

    Johnson, Harvey

    1978-01-01

    Describes how a thermosyphoning solar water heater capable of heating 110 kilogram of water to 80 degree Celsius and maintaining this temperature for 24 hours was constructed by four students in the fifth form of Sekolah Date Abdul Razak, Seremban, Malaysia in 1976. (HM)

  5. Do-it-yourself construction guide for solar systems. Projecting and construction of solar systems - a guide. 7. ed.; Solaranlagen Selbstbau. Planung und Bau von Solaranlagen - ein Leitfaden

    Themessl, Armin; Weiss, Werner

    2009-07-01

    Do-it-yourself construction of solar plants is quite common in Austria. The book presents the fundamentals of DIY construction of solar systems, the organization of construction worker groups, the technical trends in DIY systems, and the methodology of construction in a group of co-operative partners.

  6. Piping systems, containment pre-stressing and steel ventilation chimney

    Units 5 and 6 of NPP Kozloduy have been designed initially for seismic levels which are considered too low today. In the frame of an IAEA Coordinated Research Programme, a Swiss team has been commissioned by Natsionalna Elektricheska Kompania, Sofia, to analyse the relevant piping system, the containment prestressing and the steel ventilation chimney and to recommend upgrade measures for adequate seismic capacity where applicable. Seismic input had been specified by and agreed upon earlier by IAEA experts. The necessary investigations have been performed in 1995 and discussed with internationally recognized experts. The main results may be summarized as follows: Upgrades are necessary at different piping sy ports (additional snubbers or viscous dampers). These fixes can be done easily at low cost. The containment prestressing tendons are adequately designed for the specified load combinations. However, unfavourable construction features endanger the reliability. It is therefore strongly recommended to replace the tendons stepwise and to upgrade the existing monitoring system. Finally, the steel ventilation chimney may not withstand a seismic event, however the containment and diesel generator building will not be destroyed at possible impact by the chimney. On the other hand the roof of the main building has to be reinforced partially. It is recommended to continue the project for 1996 and 1997 to implement the upgrade measures mentioned above, to analyse the remaining piping systems and to consolidate all results obtained by different research groups of the IAEA programme with respect to piping systems including components and tanks

  7. Seismic modelling of a masonry chimney

    Pallarés Rubio, Francisco Javier; Ivorra Chorro, Salvador

    2007-01-01

    Different plastic/failure are applied to a masonry structure showing the difficulties to deal with masonry material and the results obtained for a masonry chimney under erathquake loading when two different criteria are used.

  8. Design and Construction of a Passive Solar Power Clothing Dryer

    Ali Alahmer

    2014-04-01

    Full Text Available This manuscript presents the design and construction of the energy efficient, time saving, cost effective of passive solar powered clothes dryer. This manuscript begins with a derivation of mathematical model represents of solar dryer followed with an analysis of the elements necessary for successfully designing the various components of a solar dryer. The solar drying performance achieved an average drying rate of 0.35 kg/h and drying time of 3 h in a typical day, even under local low ambient humidity of around 35% and at moderate outdoor wind speed. Also, the computational fluid dynamic CFD of transient thermal behavior based on Navier-Stokes equations was used to demonstrate the prevailing temperature rises in the solar natural-ventilation system associated with the internal heat flux due to solar radiation and moisture removal. The efficiency of solar dryer was improved using Nano coating technology. The result showed good agreement between the computational solid simulation and the experimental measurements obtained from this system.

  9. Evaluation of corrosion attack of chimney liners

    Blahetová M.; Horák J.; Kubesa P.; Lasek S.; Ochodek T.

    2016-01-01

    The case study of chimney liner corrosion addresses three specific cases of damage of chimney systems from of stainless steels. These systems were used for flue of gas arising from the combustion of brown coal in small automatic boilers, which are used for heating. Detailed analyzes implied that the cause of devastating corrosion of the steel AISI 316 and 304 steel (CSN 17349, 17241) was particularly high content of halides (chlorides and fluorides), which caused a severe pitting corrosion, w...

  10. Design, Construction and Testing of a Parabolic Solar Steam Generator

    Folaranmi, Joshua

    2009-01-01

    This paper reports the design, construction and testing of a parabolic dish solar steam generator. Using concentrating collector, heat from the sun is concentrated on a black absorber located at the focus point of the reflector in which water is heated to a very high temperature to form steam. It also describes the sun tracking system unit by manual tilting of the lever at the base of the parabolic dish to capture solar energy. The whole arrangement is mounted on a hinged frame supported with...

  11. Energy efficient and solar construction. Themes 2008; Energieeffizientes und solares Bauen. Themen 2008

    Stadermann, Gerd (ed.)

    2009-04-15

    Within the annual meeting of the Renewable Energy Research Association (Berlin, Federal Republic of Germany) at 29th to 30th September, 2008, the lectures were held to the following themes: (a) Energy efficient and solar construction - a change of paradigm; (b) Revolution in construction technology; (c) Energetic sanitation of old buildings; (d) Innovative technologies of energy supply; (e) Integrated facility management; (f) Demonstration and practice of new technologies; (g) Market, politics, and sustainability.

  12. Suitability of locally constructed solar dryers for vegetable drying

    Indigenous vegetables and spices are usually common and abundant during the rainy season but unfortunately, almost disappear during the dry season due to inadequate processing because of their high moisture content, poor storage and marketing facilities. A study was therefore conducted to find the possibilities of drying vegetables using locally constructed solar dryers at the Mechanisation section of the University of Education, Mampong Campus. The study was done during the months of March to September, 2004 and six designs of solar panels were used. The panels were constructed using hard wood, binding materials (nails), chicken mesh, nylon net, and black and white polythene sheets. Variations in panels resulted from the type of polythene sheet used (white, black or both), drying platform and shape of the roof. The panels with their interior lined with the black polythene sheet recorded higher temperatures than those with their bases covered with only the chicken mesh and nylon nettings. All the designs recorded higher temperatures than the ambient temperature. The drying of vegetables was observed to be faster in the panels with their drying platforms lined with the black polythene sheet than those with their bases covered with only the chicken mesh and nylon net. Appearance of the vegetables after drying in the solar panels was almost the same as before drying as compared to the open sun drying that got mouldy after drying. Those vegetables that were dried directly on the black polythene sheet however were slightly darker in colour. Solar drying with these locally constructed panels would be a better means of drying vegetables by rural folks. (au)

  13. Design, Construction and Effectiveness Analysis of Hybrid Automatic Solar Tracking System for Amorphous and Crystalline Solar Cells

    Bhupendra Gupta

    2013-01-01

    - This paper concerns the design and construction of a Hybrid solar tracking system. The constructed device was implemented by integrating it with Amorphous & Crystalline Solar Panel, three dimensional freedom mechanism and microcontroller. The amount of power available from a photovoltaic panel is determined by three parameters, the type of solar tracker, materials of solar panel and the intensity of the sunlight. The objective of this paper is to present analysis on the use of two differ...

  14. Constructal method to optimize solar thermochemical reactor design

    Tescari, S.; Mazet, N. [PROMES-CNRS, Rambla de la Thermodynamique, Tecnosud, 66100 Perpignan (France); Neveu, P. [PROMES-CNRS, Rambla de la Thermodynamique, Tecnosud, 66100 Perpignan (France); Universite de Perpignan Via Domitia, 52 Avenue Paul Alduy, 66860 Perpignan (France)

    2010-09-15

    The objective of this study is the geometrical optimization of a thermochemical reactor, which works simultaneously as solar collector and reactor. The heat (concentrated solar radiation) is supplied on a small peripheral surface and has to be dispersed in the entire reactive volume in order to activate the reaction all over the material. A similarity between this study and the point to volume problem analyzed by the constructal approach (Bejan, 2000) is evident. This approach was successfully applied to several domains, for example for the coupled mass and conductive heat transfer (Azoumah et al., 2004). Focusing on solar reactors, this work aims to apply constructal analysis to coupled conductive and radiative heat transfer. As a first step, the chemical reaction is represented by a uniform heat sink inside the material. The objective is to optimize the reactor geometry in order to maximize its efficiency. By using some hypothesis, a simplified solution is found. A parametric study provides the influence of different technical and operating parameters on the maximal efficiency and on the optimal shape. Different reactor designs (filled cylinder, cavity and honeycomb reactors) are compared, in order to determine the most efficient structure according to the operating conditions. Finally, these results are compared with a CFD model in order to validate the assumptions. (author)

  15. Design and construction of a low cost solar simulator

    A solar simulator has been designed and constructed for indoor testing for solar collectors. The simulator consists of 45 halogen lamps. Each lamp has a rated power of a 300 watts. The lamps in ten rows where each row consists of 4 to 5 lamps. The lamps occupied area 6 m2. Dimmers are used to control the amount of lamp intensities. The spacing between the lamps and the collector is about 150 cm. The intensities of the lamps are measured using a pyranometer. The intensity contours or mappings for minimum and maximum average pyranometer readings about 280 to 640 W/m2 are produced, with errors are about of 3.16 % to 4.5 %. (Author)

  16. Design, Construction and Testing of a Parabolic Solar Steam Generator

    Joshua FOLARANMI

    2009-07-01

    Full Text Available This paper reports the design, construction and testing of a parabolic dish solar steam generator. Using concentrating collector, heat from the sun is concentrated on a black absorber located at the focus point of the reflector in which water is heated to a very high temperature to form steam. It also describes the sun tracking system unit by manual tilting of the lever at the base of the parabolic dish to capture solar energy. The whole arrangement is mounted on a hinged frame supported with a slotted lever for tilting the parabolic dish reflector to different angles so that the sun is always directed to the collector at different period of the day. On the average sunny and cloud free days, the test results gave high temperature above 200°C.

  17. Solar building construction - new technologies; Solares Bauen - Neue Technologien fuer Gebaeude

    Luther, J.; Voss, K.; Wittwer, V. [Fraunhofer-Inst. fuer Solare Energiesysteme, Freiburg (Germany). Abt. ``Thermische und Optische Systeme``

    1998-02-01

    There is an increasing demand for integrated building concepts in order to reduce energy consumption. Building design, construction and heating, ventilation and air-conditioning (HVAC) technology are decisive in this respect. Thus, an essentially higher energy efficiency is achieved and solar energy becomes the main energy source. An `active building envelope` assumes the task of controlling the energy flows between inside and outside. This paper reports on new components, system concepts and planning tools for solar building. (orig.) [Deutsch] Fuer zukuenftige Bauten werden in hohem Masse Forderungen nach integrierten Konzepten zur Begrenzung des Energieverbrauchs gestellt. Gestalt, Konstruktion und Klimatechnik sind dabei massgebliche Einflussfaktoren. Hierdurch wird eine wesentlich hoehere Energieeffizienz erzielt und Solarenergie kann die uebrigen Energiequellen zurueckdraengen. Eine `aktive Gebaeudehuelle` uebernimmt die Aufgabe, den Energiefluss zwischen Innen und Aussen zu steuern. Der Beitrag berichtet ueber neue Komponenten, Systemkonzepte und Planungswerkzeuge fuer das Solare Bauen. (orig.)

  18. Evaluation of corrosion attack of chimney liners

    Blahetová M.

    2016-06-01

    Full Text Available The case study of chimney liner corrosion addresses three specific cases of damage of chimney systems from of stainless steels. These systems were used for flue of gas arising from the combustion of brown coal in small automatic boilers, which are used for heating. Detailed analyzes implied that the cause of devastating corrosion of the steel AISI 316 and 304 steel (CSN 17349, 17241 was particularly high content of halides (chlorides and fluorides, which caused a severe pitting corrosion, which led up to the perforation of the liner material. Simultaneous reduction of the thickness of the used sheets was due to by the general corrosion, which was caused by the sulfur in the solid fuel. The condensation then led to acid environment and therefore the corrosion below the dew point of the sulfuric acid has occurred. All is documented by metallographic analysis and microanalysis of the corrosion products.

  19. 太阳能烟囱与露点间接蒸发冷却复合空调节能系统分析%Analysis of an Energy Saving Air Conditioning System Integrated with Solar Chimney and Dew-point Evaporative Cooling

    倪诚明

    2014-01-01

    太阳能烟囱是一种热压作用下的自然通风设备,它利用太阳辐射作为动力,为空气流动提供浮升力,将热能转化为动能。露点间接蒸发冷却技术利用空气的干球温度和不断降低的湿球温度之差进行换热,可以将空气温度冷却到低于环境湿球温度且接近露点温度。本文介绍了太阳能烟囱与露点间接蒸发冷却技术的研究现状,提出一套太阳能烟囱与露点间接蒸发冷却复合的空调节能系统。分析表明,该系统可合理的利用太阳能解决室内通风降温问题,投资和运行费用都很低,节能环保效果显著。%Solar chimney is a kind of natural ventilation application under the action of hot pressing, it using solar radiation as power, providing buoyancy lift for air flow, transfer the thermal energy into kinetic energy.The technol-ogy of dew-point evaporative cooling using the temperature difference of air between dry bulb temperature and low-ing wet bulb temperature to transfer heat.Its able to cool air to temperature below ambient wet bulb temperature and approaching dew-point temperature.This paper review the research status of solar chimney and dew-point evapora-tive cooling.The analysis results showed that the proposed system is a reasonable way to solve the indoor ventilation and cooling problems.its investment and operating cost is lower, and has a remarkable energy saving and environ-ment protection effect.

  20. Design, Construction and Effectiveness Analysis of Hybrid Automatic Solar Tracking System for Amorphous and Crystalline Solar Cells

    Bhupendra Gupta

    2013-10-01

    Full Text Available - This paper concerns the design and construction of a Hybrid solar tracking system. The constructed device was implemented by integrating it with Amorphous & Crystalline Solar Panel, three dimensional freedom mechanism and microcontroller. The amount of power available from a photovoltaic panel is determined by three parameters, the type of solar tracker, materials of solar panel and the intensity of the sunlight. The objective of this paper is to present analysis on the use of two different material of Solar panel like Amorphous & Crystalline in a Solar tracking system at Stationary, Single Axis, Dual Axis & Hybrid Axis solar tracker to have better performance with minimum losses to the surroundings, as this device ensures maximum intensity of sun rays hitting the surface of the panel from sunrise to sunset

  1. Self-construction of a solar water heater; Calentador solar de agua de auto-construccion

    Lentz Herrera, Alvaro E.; Rincon Mejia, Eduardo A. [Universidad Autonoma de la Ciudad de Mexico, Mexico, D.F. (Mexico)

    2009-07-01

    In this work a flat receiver of self construction is shown with relatively low cost and easy manufacture, but with a thermal efficiency superior to 40% for applications at temperatures less than 60 degrees Celsius, that allows satisfying international standards in this respect. The heater has been matter of study in open courses distributed in the Universidad Autonoma de la Ciudad de Mexico (UACM) oriented to that the participants construct their own system, in addition to its installation and tests. The obtained results have been excellent. The massive use of efficient solar receivers of self-construction can truly help to the decreasing of the gas discharges of greenhouse effect. [Spanish] En este trabajo se presenta un captador plano de auto construccion con relativamente bajo costo y facil manufactura, pero con un rendimiento termico superior a 40% para aplicaciones a temperatura menos de 60 grados centigrados que le permite satisfacer estandares internacionales a este respecto. El calentador ha sido materia de estudio en cursos abiertos impartidos en la Universidad Autonoma de la Ciudad de Mexico (UACM) orientados a que los participantes construyan su propio sistema, ademas de su instalacion y pruebas. Los resultados obtenidos han sido excelentes. El uso masivo de captadores solares eficientes de autoconstruccion puede en verdad coadyuvar a la disminucion de las emisiones de gases de efecto invernadero.

  2. Pendulum Dampers for Tall RC Chimney Subjected To Wind

    Dr. B K Raghu Prasad,

    2014-10-01

    Full Text Available Chimneys are a part of industrial growth in any country. Most current chimney design standards require analysis of dynamic analysis of chimney for earthquake and wind induced loads. Because of variation in dimensions of chimney along its height structural analysis such as wind oscillations have become more critical. If ductility is an important consideration in earthquake resistant design, control of deflection become critical in wind induced vibrations. Pendulum dampers are of the devices to control the deflection. In the present work pendulum dampers of different natural frequencies have been tried. The one which has the largest equivalent logarithmic decrement is found to reduce the response significantly. The response is compared with that of chimney with a tip mass. The paper discusses the dynamic analysis of 150m high RCC chimney subjected to wind. Analysis has been carried out for fixed base case.

  3. Hybrid solar-electric oven construction prototype; Construccion de prototipo de horno hibrido solar-electrico

    Hernandez Roman, M. A; Pineda Pinon, J; Arcos Pichardo, A [CICATA, Santiago de Queretaro, Queretaro (Mexico)

    2013-03-15

    The oven construction consists of a solar collector system of cylindrical parabolic type, a heating through electrical resistance and a curing chamber. The warm fluid is air, which is injected into the chamber through forced draft. The temperature required in the system is within a range of 150 to 300 degrees Celsius. [Spanish] La construccion del horno consta de un sistema de captacion solar del tipo cilindrico parabolico, un sistema de calentamiento a traves de resistencias electricas y una camara de curado. El fluido a calentar es aire, el cual es inyectado dentro de la camara a traves de tiro forzado. La temperatura solicitada en el sistema es dentro de un rango de 150 a 300 grados centigrados.

  4. Constructal Optimization of Top Contact Metallization of a Photovoltaic Solar Cell

    Santanu Bandyopadhyay; Aditya Bhakta

    2005-01-01

    A top contact metallization of a photovoltaic solar cell collects the current generated by incident solar radiation. Several power-loss mechanisms are associated with the current flow through the front contact grid. The design of the top metal contact grid is one of the most important areas of efficient photovoltaic solar cell design. In this paper, an approach based on the constructal theory is proposed to design the grid pattern in a photovoltaic solar cell, minimizing total resistive losse...

  5. Solar updraft tower - structural optimisation under dynamic wind action

    Van Eck, S.; Coenders, J.L.; Doomen, R.

    2015-01-01

    A solar updraft tower is a type of power plant which uses solar irradiation to generate electricity. It consists of three elements: a solar air collector, wind turbines and a chimney. The proposed concepts for this chimney schematise it as a 1-km-tall reinforced concrete shell, which are vulnerable

  6. Design, construction and evaluation of solarized airlift tubular photobioreactor

    Bahadur, A.; Zubair, M.; Khan, M. B.

    2013-06-01

    An innovative photobioreactor is developed for growing algae in simulated conditions. The proposed design comprises of a continuous tubular irradiance loop and air induced liquid circulation with gas separation through air lift device. The unique features of air lift system are to ensure the shear free circulation of sensitive algal culture and induce light/dark cycles to the photosynthetic micro-organisms. The design strategy employs to model and construct a 20-liter laboratory scale unit using Boro-silicate glass tubing. The material is selected to ensure maximum photon transmission. All components of the device are designed to have flexibility to be replaced with an alternative design, providing fair chance of modification for future investigators. The principles of fluid mechanics are applied to describe geometrical attributes of the air lift system. Combination of LEDs and Florescent tube lights (Warm white) were used to illuminate the photosynthesis reaction area providing a possibility to control both illumination duration and light intensity. 200 Watt Solar PV system is designed to power up the device which included air pump (100 Watt) and illumination system (100 Watt). Algal strain Chlorella sp was inoculated in photobioreactor which was sparged with air and carbon dioxide. The growth was sustained in the batch mode with daily monitoring of temperature, pH and biomass concentration. The novel photobioreactor recorded a maximum experimental average yield of 0.65 g/l.day (11.3 g/m2.day) as compared to theoretical modeled yield of 0.82 g/l.day (14.26 g/m2.day), suggesting the device can be efficiently and cost-effectively employed in the production of algal biomass for biofuels, concomitantly mitigating CO2.

  7. Design, construction and evaluation of solarized airlift tubular photobioreactor

    An innovative photobioreactor is developed for growing algae in simulated conditions. The proposed design comprises of a continuous tubular irradiance loop and air induced liquid circulation with gas separation through air lift device. The unique features of air lift system are to ensure the shear free circulation of sensitive algal culture and induce light/dark cycles to the photosynthetic micro-organisms. The design strategy employs to model and construct a 20-liter laboratory scale unit using Boro-silicate glass tubing. The material is selected to ensure maximum photon transmission. All components of the device are designed to have flexibility to be replaced with an alternative design, providing fair chance of modification for future investigators. The principles of fluid mechanics are applied to describe geometrical attributes of the air lift system. Combination of LEDs and Florescent tube lights (Warm white) were used to illuminate the photosynthesis reaction area providing a possibility to control both illumination duration and light intensity. 200 Watt Solar PV system is designed to power up the device which included air pump (100 Watt) and illumination system (100 Watt). Algal strain Chlorella sp was inoculated in photobioreactor which was sparged with air and carbon dioxide. The growth was sustained in the batch mode with daily monitoring of temperature, pH and biomass concentration. The novel photobioreactor recorded a maximum experimental average yield of 0.65 g/l.day (11.3 g/m2.day) as compared to theoretical modeled yield of 0.82 g/l.day (14.26 g/m2.day), suggesting the device can be efficiently and cost-effectively employed in the production of algal biomass for biofuels, concomitantly mitigating CO2.

  8. Construction and characterization of spherical Si solar cells combined with SiC electric power inverter

    Oku, Takeo; Matsumoto, Taisuke; Hiramatsu, Kouichi; Yasuda, Masashi; Shimono, Akio; Takeda, Yoshikazu; Murozono, Mikio

    2015-02-01

    Spherical silicon (Si) photovoltaic solar cell systems combined with an electric power inverter using silicon carbide (SiC) field-effect transistor (FET) were constructed and characterized, which were compared with an ordinary Si-based converter. The SiC-FET devices were introduced in the direct current-alternating current (DC-AC) converter, which was connected with the solar panels. The spherical Si solar cells were used as the power sources, and the spherical Si panels are lighter and more flexible compared with the ordinary flat Si solar panels. Conversion efficiencies of the spherical Si solar cells were improved by using the SiC-FET.

  9. Code manual for passive solar design single family residential construction

    None

    1979-08-01

    General information is presented on types of passive solar techniques and a method for estimating passive solar performance. Important codes and standards are described, each description listing the items in the code which could have a potential impact on a passive solar design and analyzing the effect of the code on the use of such techniques. State and local codes and code agencies are summarized. The local summary contains the name of a contact in the enforcement agency to whom specific questions may be addressed. The requirements to file for a building permit are given briefly. (LEW)

  10. A new picture of interstellar medium: chimney model

    Many observational facts which indicate a different picture of the interstellar medium from the McKee-Ostriker's three-phase model are accumulated in this decade. Based upon the sequential star formation model in molecular clouds the gigantic superbubbles are formed by sequential supernova explosions. Such superbubbles stand perpendicular to the disk like chimneys and the hot gas can go up to the halo like smoke in chimneys. About one thousand of chimneys smoke in a galaxy along, the spiral arms. At the interarm region the classical two-phase model is preferable. Here, several observational evidences for this picture are presented, and some implications to the evolution of galaxies are discussed

  11. Solar thermal power plants

    The solar thermal power plant technology, the opportunities it presents and the developments in the market are outlined. The focus is on the technology of parabolic trough power plants, a proven technology for solar power generation on a large scale. In a parabolic trough power plant, trough-shaped mirrors concentrate the solar irradiation onto a pipe in the focal line of the collector. The thermal energy thus generated is used for electricity generation in a steam turbine. Parabolic trough plants can be combined with thermal storage and fossil or biomass fired heat exchangers to generate electricity even when the sun is not shining. Solar Millennium AG in Erlangen has developed the first power plant of this kind in Europe. After two years of construction the plant started operation in Southern Spain in 2008. This one and its sister projects are important steps leading the way for the whole market. The paper also covers the technological challenges, the key components used and the research and development activities concerning this technology. Solar thermal power plants are ideal for covering peak and medium loads in power grids. In hybrid operation they can also cover base-load. The Solar Chimney power plant, another striking technology for the conversion of solar into electric energy, is described briefly. The paper concludes with a look at the future - the import of solar energy from the deserts of North Africa to central Europe. (author)

  12. Seismic response Analyses of Hanaro in-chimney bracket structures

    Lee, Jae Han; Ryu, J.S.; Cho, Y.G.; Lee, H.Y.; Kim, J.B

    1999-05-01

    The in-chimney bracket will be installed in the upper part of chimney, which holds the capsule extension pipes in upper one-third of length. For evaluating the effects on the capsules and related reactor structures, ANSYS finite element analysis model is developed and the dynamic characteristics are analyzed. The seismic response anlayses of in-chimney bracket and related reactor structures of HANARO under the design earthquake response spectrum loads of OBE (0.1 g) and SSE (0.2 g) are performed. The maximum horizontal displacements of the flow tubes are within the minimum half gaps between close flow tubes, it is expected that these displacement will not produce any contact between neighbor flow tubes. The stress values in main points of reactor structures and in-chimney bracket for the seismic loads are also within the ASME Code limits. It is also confirmed that the fatigue usage factor is muchless than 1.0. So, any damage on structural integrity is not expected when an in-chimney bracket is installed to upper part of the reactor chimney. (author). 12 refs., 24 tabs., 37 figs.

  13. Solar Energy Block-Based Residential Construction for Rural Areas in the West of China

    Jizhong Shao

    2016-04-01

    Full Text Available Based on the Great Western Development Strategy and the requirement for sustainable development in the west of China, rural affordable housing, energy conservation, and environmental protection are becoming development standards in the construction field. This paper mainly explores an innovative, sustainable, residential construction method for rural areas in western China, particularly the integration of solar energy technology with modern prefabricated building techniques, formally named solar energy block-based construction. The conscious approach of using volumetric blocks provides superior adaptability and expansibility in integration with a steel structure, thereby reducing the construction time and cost. Allowing a wide variety of configurations and styles in the building layout, this approach can be customized to the end-user’s precise location and climate, making rural residential buildings much more flexible and modern. To take advantage of adequate solar energy resource in western China, the blocks are associated with active and passive solar energy technologies, thereby reducing pollution, mitigating global warming, and enhancing sustainability. Therefore, we concluded that solar energy block-based construction could bring significant benefits to the environment, economy, and society. It could also promote sustainable development in the rural regions of western China.

  14. 75 FR 2133 - Construction and Operation of the Quartzsite Solar Energy Project, La Paz County, AZ (DOE/EIS-0440)

    2010-01-14

    ... Area Power Administration Construction and Operation of the Quartzsite Solar Energy Project, La Paz... used during the construction phase of the Project. The laydown areas, outside of the solar facility... EIS, as defined at 40 CFR 1501.5. The proposed Project would include construction of a new...

  15. Self-Aligning Solar Panel : Construction of a self-aligning platform for solar panels

    Dahlqvist, Mattias; Nilsson-Hedman, Tommy

    2015-01-01

    The purpose of this project is to create a self-aligning platform for solar panels for better utilization of the renewable solar energy source that is available. The difference between present self-aligning solutions and the proposed one is its two repositioning modes to find the optimal position which implies higher efficiency in terms of harnessing the solar energy. The movement is based on two axes rotation. The objective is to compare the final prototype with a stationary support structur...

  16. NUMERICAL ANALYSIS OF HEAT STORAGE OF SOLAR HEAT IN FLOOR CONSTRUCTION

    Weitzmann, Peter; Holck, Ole; Svendsen, Svend

    2003-01-01

    including pipe spacing, storage materials, and distribution of insulation around the thermal storage layer. The energy consump-tion, reduction due to the heat storage and total performance of the solar heating system was calculated. The largest reduction of 100 kWh/m² solar collector occurred in the house......In this paper, heat storage of solar heating in the floor construction of single-family houses is examined. A floor construction with two concrete decks is investigated. The lower is used as heat storage while the upper deck has a floor heating system. The potential for a reduction of the energy...... system room temperature and energy consumption. A single-family house with and without heat recovery unit on the ventilation system of 130 m² with heating demand of approximately 70 kWh/m² and 40 kWh/m² is investigated. A parametrical analysis was performed for the solar collector area, and floor layouts...

  17. Human cultures as niche constructions within the solar system

    Van de Vliert, Evert

    2016-01-01

    This commentary seeks to refine Kashima’s (2016) timely and topical but too-general call for embedding culture within the planetary ecosystem. My starting point is that cultures are to an underestimated extent ongoing niche constructions within the merry-go-round of the Sun’s radiation, the Earth’s

  18. Passive solar systems (solar architecture research and development in Italy). Solare passivo: sottoprogetto energia solare, eolica ed idraulica

    1989-02-01

    This collection of papers on solar achitecture research and development deals with test facilities now available in Italy for performance testing/data acquisition relative to passive solar system components (i.e.Trombe walls) and provides an update on the developments by various consultants of marketable products (solar water heaters, solar chimneys, sunlight dousers, etc).

  19. Experimental investigations of the sodium/air heat exchanger with natural draught chimney for the EFR

    In a first series of experiments in the new large sodium experimental plant ILONA, the post-shutdown heat removal system for the European Fast Breeder Reactor EFR developed by Interatom and working by natural convection was tested. The air-side flow in the heat exchanger and chimney was optimized in extensive model experiments and the results were taken into account in the construction of the Na/air heat exchanger in the ILONA. A considerable increase in output was achieved, compared to the design, based on the flow model experiments for the ILONA heat exchanger. (orig.)

  20. The gas chimney formation during the steam explosion premixing phase

    The crucial part in isothermal premixing experiment simulation is the correct prediction of the gas chimney, which forms when the spheres penetrate into water. The first simulation results with the developed original combined multiphase model showed that the gas chimney starts to close at the wrong place at the top of the chimney and not in the middle, like it was observed in the experiments. To find the physical explanation for this identified weakness of our numerical model a comprehensive parametric analysis (mesh size, initial water-air surface thickness, water density, momentum coupling starting position) has been performed. It was established that the reason for the unphysical gas chimney closing at the top could be the gradual air-water density transition in the experiment model, since there is due to the finite differences description always a transition layer with intermediate phases density over the pure water phase. It was shown that this difference between our numerical model and the experiment can be somewhat compensated if the spheres interfacial drag coefficient at the upmost mesh plane of the unphysical air-water transition layer is artificially risen. On this way a more correct gas chimney formation can be obtained.(author)

  1. Solar Energy Block-Based Residential Construction for Rural Areas in the West of China

    Jizhong Shao; Huixian Chen; Ting Zhu

    2016-01-01

    Based on the Great Western Development Strategy and the requirement for sustainable development in the west of China, rural affordable housing, energy conservation, and environmental protection are becoming development standards in the construction field. This paper mainly explores an innovative, sustainable, residential construction method for rural areas in western China, particularly the integration of solar energy technology with modern prefabricated building techniques, formally named so...

  2. Solar project description. Houston Construction Company single family residence, Eden Prairie, Minnesota March 19, 1982

    The Houston Construction Company solar energy system is designed to provide 62 percent of the space heating and domestic hot water energy requirements for a single-family detached residence containing 1796 square feet. The residence is in Eden Prairie, MN. Energy collection is accomplished by 468 square feet of Solaron flat-plate collectors which face south at an angle of 60 degrees from the horizontal. air is the medium for transfer of solar energy from the collectors to either the conditioned space or storage. Storage is a 314 cubic foot bin containing approximately 24,000 lbs of crushed rock located in a utility room. when solar energy is inadequate to satisfy the requirements of the space heating subsystem, auxiliary thermal energy is supplied from an 80,000 Btu per hour natural gas furnace. Domestic hot water is provided by a 30,000 Btu per hour natural gas water heater if the solar contribution is insufficient.

  3. The construction of a process line for high efficiency silicon solar cells under clean-room conditions

    The aim of this research project was to plan, construct and test a clean-room technology laboratory for the manufacturing of silicon solar cells with 20% efficiency (1.5AM). In addition to the establishment of the laboratory, there existed the case of establishing the material and technological fundamentals of high-efficiency solar cells, testing and optimizing all stages of production as well as constructing test stands for accompanying characterisation work. The following final report describes the construction of the laboratory and characterisation systems, the material elements of high-efficiency solar cells as well as the most important results of solar cell production and optimisation. (orig./BWI)

  4. Design, Engineering, and Construction of Photosynthetic Microbial Cell Factories for Renewable Solar Fuel Production

    Lindblad, Peter; Lindberg, Pia; Stensjoe, Karin (Photochemistry and Molecular Science, Dept. of Chemistry-Aangstroem Laboratory, Uppsala Univ., Uppsala (Sweden)), E-mail: Peter.Lindblad@kemi.uu.se; Oliveira, Paulo (Instituto de Biologia Molecular e Celular, Porto (Portugal)); Heidorn, Thorsten (Bioforsk-Norwegian Inst. for Agricultural and Environmental Research, Aas Oslo, (Norway))

    2012-03-15

    There is an urgent need to develop sustainable solutions to convert solar energy into energy carriers used in the society. In addition to solar cells generating electricity, there are several options to generate solar fuels. This paper outlines and discusses the design and engineering of photosynthetic microbial systems for the generation of renewable solar fuels, with a focus on cyanobacteria. Cyanobacteria are prokaryotic microorganisms with the same type of photosynthesis as higher plants. Native and engineered cyanobacteria have been used by us and others as model systems to examine, demonstrate, and develop photobiological H{sub 2} production. More recently, the production of carbon-containing solar fuels like ethanol, butanol, and isoprene have been demonstrated. We are using a synthetic biology approach to develop efficient photosynthetic microbial cell factories for direct generation of biofuels from solar energy. Present progress and advances in the design, engineering, and construction of such cyanobacterial cells for the generation of a portfolio of solar fuels, e.g., hydrogen, alcohols, and isoprene, are presented and discussed. Possibilities and challenges when introducing and using synthetic biology are highlighted

  5. Construction Status and Early Science with the Daniel K. Inouye Solar Telescope

    McMullin, Joseph P.; Rimmele, Thomas R.; Warner, Mark; Martinez Pillet, Valentin; Craig, Simon; Woeger, Friedrich; Tritschler, Alexandra; Berukoff, Steven J.; Casini, Roberto; Goode, Philip R.; Knoelker, Michael; Kuhn, Jeffrey Richard; Lin, Haosheng; Mathioudakis, Mihalis; Reardon, Kevin P.; Rosner, Robert; Schmidt, Wolfgang

    2016-05-01

    The 4-m Daniel K. Inouye Solar Telescope (DKIST) is in its seventh year of overall development and its fourth year of site construction on the summit of Haleakala, Maui. The Site Facilities (Utility Building and Support & Operations Building) are in place with ongoing construction of the Telescope Mount Assembly within. Off-site the fabrication of the component systems is completing with early integration testing and verification starting.Once complete this facility will provide the highest sensitivity and resolution for study of solar magnetism and the drivers of key processes impacting Earth (solar wind, flares, coronal mass ejections, and variability in solar output). The DKIST will be equipped initially with a battery of first light instruments which cover a spectral range from the UV (380 nm) to the near IR (5000 nm), and capable of providing both imaging and spectro-polarimetric measurements throughout the solar atmosphere (photosphere, chromosphere, and corona); these instruments are being developed by the National Solar Observatory (Visible Broadband Imager), High Altitude Observatory (Visible Spectro-Polarimeter), Kiepenheuer Institute (Visible Tunable Filter) and the University of Hawaii (Cryogenic Near-Infrared Spectro-Polarimeter and the Diffraction-Limited Near-Infrared Spectro-Polarimeter). Further, a United Kingdom consortium led by Queen's University Belfast is driving the development of high speed cameras essential for capturing the highly dynamic processes measured by these instruments. Finally, a state-of-the-art adaptive optics system will support diffraction limited imaging capable of resolving features approximately 20 km in scale on the Sun.We present the overall status of the construction phase along with the current challenges as well as a review of the planned science testing and the transition into early science operations.

  6. Wisdom Way Solar Village: Design, Construction, and Analysis of a Low Energy Community

    Aldrich, R.

    2012-08-01

    This report describes work conducted at the Wisdom Way Solar Village (WWSV), a community of 10 high performance duplexes (20 homes) in Greenfield, MA, constructed by Rural Development, Inc. (RDI). Building America's CARB team monitored temperatures and comfort in several homes during the winter of 2009-2010, and tracked utility bill information from 13 occupied homes. Because of efficient lights, appliances, and conscientious home occupants, the energy generated by the solar electric systems exceeded the electric energy used in most homes.

  7. Solar building construction. Special edition of the journal 'Sonnenenergie'; Solares Bauen. Sonderheft der Sonnenenergie

    NONE

    2006-11-15

    In this edition of ''solar building construction'' designs and completed buildings from Germany and foreign countries are presented, in which passive cooling, an improved daylight use or the utilization of environmental heat were considered. The expected overall energy consumption of the office building Capricorn in Duesseldorf will be approximately 25 percent below the legal requirements due to exemplary thermal insulation, modern air ventilation plants with heat recovery as well as cement core activation. The present edition further provides useful advice for planning and realisation of photovoltaic plants integrated into buildings by showing different plant examples. Additionally award-winning buildings are presented. (orig.)

  8. Design, Construction And Characterization Of A Pyranometer For Measuring Global Solar Radiation

    Due to cost and stringent importation requirement, we have designed and constructed a Pyranometer from locally available materials. The constructed Pyranometer was calibrated against a standard calibrated Eppley pyranometer model PSP17190F3. the two pyranometers were used simultaneously in measuring global solar radiation at Nsukka, Nigeria on latitude 6.8 degree North and longitude 7.35 degree East, located 488m above sea level. The average insolation for each of the two typical clear sky days were 3.221KW per square metre and 3.266KW per square metre. The maximum insolation obtained with the constructed pyranometer was 965.5 W per square metre on 16/1/03. The corresponding insolation obtained with the reference Eppley pyranometre on the same day was 1087.5W per square metre. We are happy to remark that there was not significant difference between the performances of the constructed pyranometer and the standard Eppley pyranometer

  9. Power plants of modular construction with quasi-paraboloidal concentrators of solar energy

    Baranov, V. K.

    1984-02-01

    Solar electric power plants with parabolocylindrical concentrators are not as efficient as those of the tower type and, therefore, another modular construction is considered. The idea is to concentrate solar energy on a small spot and to locate the power plant, which consists of a heat collector and a Stirling, Brayton, or Rankine engine with an electric generator, near that spot. The solar energy concentrator is designed and built to perform like a paraboloidal mirror. The first 13 concepts are based on using plane, spherical, or double curvature facets made of silicate glass with silver backing or polymer film with aluminum coating. The next 4 concepts are based on using aluminized polymer film and forming it by means of air inflation. The last 5 concepts are based on using plane or cylindrical Fresnel mirrors, or a Fresnel lens. These concepts are in various stages of develoment and production.

  10. Natural convection solar crop-dryers of commercial scale in Ghana: design, construction and performance

    Forson, F.K.; Nazha, M.A.A. [De Montfort University, Leicester (United Kingdom). Dept. of Mechanical and Manufacture Engineering; Akuffo, F.O. [UST Kumasi (Ghana). Dept. of Mechanical and Manufacture Engineering

    1996-07-01

    Traditional open sun-drying, the predominant method of food preservation in Ghana, has serious drawbacks leading to significant post-harvest losses (between 20 and 30%). Mechanical dryers can provide high quality products with minimum losses but they require sources of electrical or chemical energy which, in the case of Ghana, are costly or scarce. This makes the development of an effective natural convection solar dryer an attractive alternative. A mixed-mode natural convection solar crop-dryer (a dryer in which the crop is dried by a combination of the direct absorption of solar radiation and by natural convection where air, heated by solar energy, is passed over the crop) has been designed. Two commercial dryers, based on this design and capable of handling between 1,000 and 1,500 kg of various agricultural products (such as cassava, pepper, maize, okra, etc.) have been constructed and partially tested at Agona-Asafo in the central region of Ghana. The results of these preliminary tests indicate that it takes 3-5 days to dry 1,000 kg of pepper from moisture content level of 78% to a safe storage level of 8%. The design, construction details, and the results of the preliminary tests are presented in this paper. (author)

  11. 10-MWe solar-thermal central-receiver pilot plant: collector subsystem foundation construction. Revision No. 1

    1979-12-18

    Bid documents are provided for the construction of the collector subsystem foundation of the Barstow Solar Pilot Plant, including invitation to bid, bid form, representations and certifications, construction contract, and labor standards provisions of the Davis-Bacon Act. Instructions to bidders, general provisions and general conditions are included. Technical specifications are provided for the construction. (LEW)

  12. The computational optimization of heat exchange efficiency in stack chimneys

    Van Goch, T.A.J.

    2012-02-15

    For many industrial processes, the chimney is the final step before hot fumes, with high thermal energy content, are discharged into the atmosphere. Tapping into this energy and utilizing it for heating or cooling applications, could improve sustainability, efficiency and/or reduce operational costs. Alternatively, an unused chimney, like the monumental chimney at the Eindhoven University of Technology, could serve as an 'energy channeler' once more; it can enhance free cooling by exploiting the stack effect. This study aims to identify design parameters that influence annual heat exchange in such stack chimney applications and optimize these parameters for specific scenarios to maximize the performance. Performance is defined by annual heat exchange, system efficiency and costs. The energy required for the water pump as compared to the energy exchanged, defines the system efficiency, which is expressed in an efficiency coefficient (EC). This study is an example of applying building performance simulation (BPS) tools for decision support in the early phase of the design process. In this study, BPS tools are used to provide design guidance, performance evaluation and optimization. A general method for optimization of simulation models will be studied, and applied in two case studies with different applications (heating/cooling), namely; (1) CERES case: 'Eindhoven University of Technology monumental stack chimney equipped with a heat exchanger, rejects heat to load the cold source of the aquifer system on the campus of the university and/or provides free cooling to the CERES building'; and (2) Industrial case: 'Heat exchanger in an industrial stack chimney, which recoups heat for use in e.g. absorption cooling'. The main research question, addressing the concerns of both cases, is expressed as follows: 'what is the optimal set of design parameters so heat exchange in stack chimneys is optimized annually for the cases in which a

  13. The use of a rubble chimney for denitrification of irrigation return waters

    Biological denitrification has been proposed as a means of removing nitrates from waste waters to control eutrophication in receiving waters. A potential use for this method is the treatment of irrigation return waters containing high concentrations of nitrate-nitrogen, since direct discharge of such wastes may cause objectionable algal growth in the receiving waters. For example, the process may be used to treat agricultural waste waters in the San Joaquin Valley in California, where an estimated 580,000 acre-feet/year of return waters, containing 20 mg/l of nitrate-nitrogen, will require disposal by A.D. 2020. Two methods of biological denitrification are presently under study for possible use in the San Joaquin Valley. In one method nitrates are reduced to nitrogen gas by bacterial action in deep ponds; in the other method bacterial denitrification takes place in biological filters. In biological filters, bacteria are grown on columns of submerged stones. A possible alternative to the conventional construction of these filters is the creation of a rubble chimney by a contained nuclear explosion. This paper presents the results of a preliminary investigation of the feasibility of using a rubble chimney as a biological filter for denitrification. (author)

  14. The Inventory Of High Objects Applying Laser Scanning, Focus On The Cataloguing A Reinforced Concrete Industrial Chimney

    Gawałkiewicz, Rafał

    2015-12-01

    There are many surveying methods to measure the inclination of a chimney with the use of classical protractor instruments (Theo 010A/B, T2 Wild), electronic theodolites (TC2002 Wild-Leica), electronic total stations, including mirrorless ones, allowing to define indirectly the course of the construction's axis on the selected observation levels. The methods are the following: indentations, direct projection, double-edged method, polar method with the option of mirrorless measurement. At the moment a very practical and quick measurement technology, significantly eliminating the influence of human errors on the observation results, is laser scanning. The article presents the results of the scanning of 120-metres high reinforced concrete industrial chimney of the Cement Plant "Ożarów", with the application of modern scanning total station VX Spatial Station by Trimble, as an alternative to the methods applied so far. The advantage of scanning is the possibility to obtain a point cloud, which, apart from the information on the course of the chimney axis in the space, provides detail information on the real shape and deformations of the coating of the object's core.

  15. Formation of Chimneys in Mushy Layers: Experiment and Simulation

    Anderson, Anthony M; Worster, Grae

    2011-01-01

    In this fluid dyanmics video, we show experimental images and simulations of chimney formation in mushy layers. A directional solidification apparatus was used to freeze 25 wt % aqueous ammonium chloride solutions at controlled rates in a narrow Hele-Shaw cell (1mm gap). The convective motion is imaged with schlieren. We demonstrate the ability to numerically simulate mushy layer growth for direct comparison with experiments.

  16. GPS FOM Chimney Analysis using Generalized Extreme Value Distribution

    Ott, Rick; Frisbee, Joe; Saha, Kanan

    2004-01-01

    Many a time an objective of a statistical analysis is to estimate a limit value like 3-sigma 95% confidence upper limit from a data sample. The generalized Extreme Value Distribution method can be profitably employed in many situations for such an estimate. . .. It is well known that according to the Central Limit theorem the mean value of a large data set is normally distributed irrespective of the distribution of the data from which the mean value is derived. In a somewhat similar fashion it is observed that many times the extreme value of a data set has a distribution that can be formulated with a Generalized Distribution. In space shuttle entry with 3-string GPS navigation the Figure Of Merit (FOM) value gives a measure of GPS navigated state accuracy. A GPS navigated state with FOM of 6 or higher is deemed unacceptable and is said to form a FOM 6 or higher chimney. A FOM chimney is a period of time during which the FOM value stays higher than 5. A longer period of FOM of value 6 or higher causes navigated state to accumulate more error for a lack of state update. For an acceptable landing it is imperative that the state error remains low and hence at low altitude during entry GPS data of FOM greater than 5 must not last more than 138 seconds. I To test the GPS performAnce many entry test cases were simulated at the Avionics Development Laboratory. Only high value FoM chimneys are consequential. The extreme value statistical technique is applied to analyze high value FOM chimneys. The Maximum likelihood method is used to determine parameters that characterize the GEV distribution, and then the limit value statistics are estimated.

  17. D0 - Chimney Lead Quench Detection, Beta Solenoid

    The voltage drop across the superconducting chimney lead is sensed to detect a quench. The return sense lead is mounted outside the chimney. The return sense lead and the superconducting chimney wire form a loop with area A ∼ 1.7 m2 (information from R. Ru. cinski). Changing flux through area A will induce a voltage in the sense loop and could cause false quench detection. Assume that the field through A changes 1 kGauss (0.1 Wb/m2) in 10-3 sec. The induced voltage is then: e = d0/dt = dBA/dt and e = 0.1 x 1.7/10-3 = 170 V. This is probably a very pessimistic estimate, but it shows that we have to watch out. Changes of 100 Gauss in 100 msec (CDF experience?) are probably more likely and cause: e = 0.01 x 1.7/10-2 ∼ 1.7 V noise. This noise is still too high because trip levels are planned to sit at ∼50 mV? It is practically impossible to predict what the real noise values would be, but I expect them to be in the order of 1 to 10 V. This is more than we can handle and I would expect nuisance trips.

  18. Guide for a building energy label. Promoting bio-climatic and solar construction and renovation

    NONE

    2004-07-01

    Technically speaking, building experts have the knowledge to deal with thermal inertia of buildings, solar gains, insulation, efficient ventilation, and daylighting... to get low energy buildings that provide comfort for the users. Buildings should always be designed according to the specificities of the local climate, according to a ''solar and bio-climatic construction'' approach. It is not always possible to fully apply these principles, particularly in urban areas with high density. However, this is unacceptable to keep building with such errors as insufficient insulation and direct electrical heating, single glazing, thermal bridges, low efficiency heating systems. This guide aims at encouraging the building experts to take into account the energy efficiency. Implementing a building energy label will allow general public to be aware of this issue and then, and will then lead to develop better practices. (author)

  19. Seismic decoupling of an explosion centered in a granite chimney rubble -- scaled experiment results. Final report

    Keller, C. [Science & Engineering Associates, Inc., Santa Fe, NM (United States); Miller, S.; Florence, A.; Fogle, M.; Kilb, D.

    1991-12-01

    This report describes the small scale evaluation of the feasibility of significant decoupling by siting an explosion in granite rubble. The chimney characteristics scaled to laboratory dimensions were those of the PILE DRIVER event. The scaled charges were of 1 KT and 8KT in the PILE DRIVER chimney. The measure of the effect was the velocity field history in the granite outside the chimney volume with the chimney rubble and with no rubble. A number of chimney sizes and shapes were studied. The explosion process was modeled via two-din=mensional, finite-difference methods used for prediction of velocity histories at the Nevada Test Site. The result was that both the spectral shape and the magnitude of the transmitted shock wave were drastically altered. The chimney geometry was as important as the rubble characteristics.

  20. Construction and Testing of Lightweight and Low-Cost Pneumatically Inflated Solar Concentrators

    F. M. I. De Los Santos-García; Y. Nahmad-Molinari; J. Nieto-Navarro; Alanís-Ruiz, C.; Felipe Patiño-Jiménez

    2016-01-01

    Design, construction, and evaluation of a cylindrical-trough solar concentrator with 1.3 m aperture, 2.15 m length, and 0.54 m focal length, with heat-pipe or vacuum tube receiver and one axis tracking system, are presented. Design performance was tested under ASHRAE standard 93-1986 (RA 91). The concentrator system is lightweight and inexpensive since it was made of polymeric membranes and was pneumatically inflated to acquire its cylindrical shape achieving good optical quality. Further imp...

  1. Antecedent and progress of the project on the treatment of chimney gases with electrons in Mexico

    After the realization of the chimney gases treatment seminar with electrons, organized jointly among the National Institute of Nuclear Research (ININ) and the International Atomic Energy Agency (IAEA), in August of 1990 and following one of the received recommendations, it was elaborated an economic technical feasibility study of this process in Mexico, using technical data of a thermoelectric power station of Federal Commission of Electricity, where is being consumed fuel oil. This study is good to know some technical parameters of a plant of this process, proposed to settle in Mexico, so as some economic estimates of installation and operation costs of this plant; also, it is traced about the construction of a demonstration plant of the process, with capacity of 20,000 m3N/h, using the same data of the thermoelectric power station considered previously, as the first step in the scaling of this process toward industrial level. (Author)

  2. Improvement of the Vertical Dispersion of Pollutants Resulting From Chimneys by Thermosiphon Effect

    A. O.M. Mahmoud; J. Zinoubi; R.B. Maad; A. Belghith

    2006-01-01

    The dispersion of pollutants, resulting from industrial chimneys, in the surrounding atmosphere made the interest in realizing emitting conditions appears. It also encourages the vertical dispersion of these pollutants. At a given wind velocity, the height of this dispersion is essentially a function of the thermal power and the flow rate at the chimney exit. To improve these qualities, we propose a system that could be integrated to the industrial chimney exit. An open-ended vertical cylinde...

  3. Simplifying the construction of dye-sensitized solar cells to increase their accessibility for community education

    Appleyard, Steve [Department of Environment and Conservation, PO Box K822, Perth, WA 6842 (Australia)

    2010-01-15

    Simple dye-sensitized solar cells were developed using blackboard chalk as a substrate for mixed ZnO and SnO{sub 2} films that were sensitized with Mercurochrome (Merbromine) dye. Graphite pencil 'leads' were used as counter electrodes for the cells and the electrolyte consisted of an aqueous solution of iodine and potassium iodide that was gelled with a disinfectant containing quaternary ammonium compounds and cyanoacrylate adhesive (Superglue {sup registered}). The open circuit potential of constructed cells was typically 0.50-0.64 V and the short circuit current varied between 0.5 and 2.0 mA cm{sup -2}. The cells were developed as an educational resource that could be simply and safely constructed in a home or school environment with readily accessible materials. (author)

  4. Natural convection enhancement in an asymmetrically heated channel-chimney system

    In this paper, a numerical study is performed in order to analyze the effect of adding a chimney to a vertical open channel. The channel is heated asymmetrically at uniform heat flux while the chimney is symmetric and wider than the channel. The thermal and dynamic aspects of the channel-chimney system (T chimney) are studied by varying the width and the height of the chimney while the aspect ratio of the channel is kept fixed. The main objective of this work is to determine the optimal geometric parameters of the chimney: the expansion ratio B (chimney width normalized by the channel width) and the extension ratio Er (chimney height normalized by the channel height), that maximize the mass flow rate (G) and the average Nusselt number (Nua). More than four hundred numerical simulations have been carried out at modified Rayleigh numbers ranging from 102 to 5x104 (laminar regime). The computations allowed the identification of three types of system responses. The flow structure and the pressure field were also analyzed to elucidate why the increase of the chimney width can improve or deteriorate the mass flow rate and the heat transfer. Finally, appropriate correlations have been proposed for determining the optimal configurations and the corresponding enhancement of the mass flow rate and the heat transfer coefficient. (authors)

  5. Design, construction and characterization of a rural solar furnace; Diseno, construccion y caracterizacion de un horno solar rural

    Hernandez Luna, Gabriela

    2001-06-15

    This thesis presents the design, construction and characterization of a solar furnace, box type, for its use in rural communities in the inter-tropical zone. The work presented in this thesis departs from the opto-geometric design of a solar furnace, box type, proposed by an enthusiastic group of young students from the Centro de Investigacion de Energia (CIE) of the Universidad Nacional Autonoma de Mexico (UNAM). The contents of this thesis includes the systematization of the work previously made by these authors: the design and the optimization of geometry, the experimental evaluation of the same, as well as a theoretical model of the thermal behavior of the solar furnace based on a global balance of energy that assumes thermal states in cuasi-equilibrium of the internal components of the furnace. In this thesis a theoretical model of the solar concentration of energy by the reflectors of the furnace based on the model of Peres and Karsson (1993) is developed. The predictions of this model are satisfactorily compared with the experimental results of Jaramillo et al. (1999). Counting on the opto-geometric design of the furnace, the design is completed selecting the materials to be used in the different parts of the same, as well as defining constructive details. The material selected for the inner and outer boxes and the reflectors is stainless steel mirror finishing. Mineral wool is used As insulating mineral. The upper part of the furnace is protected by a glass that allows the entrance of the solar energy and diminishes the energy convective and radiation losses. For the thermal evaluation of the furnace an experimental methodology, based on the international procedures standardized for tests of furnaces and solar stoves is followed. Three tests for each one of the following operation conditions were performed: without load, with oil and with water. The maximum temperature registered in the inside air of the furnace, for the first condition was of 150

  6. Design, construction and evaluation of a system of forced solar water heating.

    Hernández, E.; Bautista, G. A.; Ortiz, I. L.

    2016-07-01

    The main purpose of this project was to design, construct and evaluate a system of forced solar water heating for domestic consumption, at the Universidad Pontificia Bolivariana-Bucaramanga, Colombia; using solar energy. This is a totally system independent of the electrical grid and an important characteristic is the heating water doesn't mix with the consumption water. The system receives the solar radiation through a flat-plate collector, which it transmits the heat to the water that it flow with impulse from the centrifugal pump of 12VDC, the water circulates toward helical serpentine it is inside of the tank of the storage whose capacity is 100 liters of water. The temperature of the tank is regulated with a controller in such a way that de-energized the pump when it gets the temperature required. The performance thermal or efficiency of the system was evaluated like a relationship between the delivered energy to the water in storage tank and the incident energy in the flat-plate collector.

  7. Renewable energy and wild life conservation: design and construction of a solar incubator

    Evans, John Martin; Schiller, Silvia de; Garreta, Fabian [Universidad de Buenos Aires, Centro de Investigacion Habitat y Energia, Buenos Aires (Argentina)

    1998-09-01

    This paper presents the design, construction and results of a solar powered incubator and pools for rearing yacare, a specie of the crocodile family, found in northern Argentina. The design was developed by the Research Centre Habitat and Energy, Faculty of Architecture, Design and Urbanism, Buenos Aires University in the framework of a Cooperation Agreement with the Argentine Wild Life Foundation. The installation, located in a Wild Life Refuge in a remote sub-tropical area of the Chaco Province in the north-east region of Argentina, consists of an incubation chamber for hatching the yacare with strict temperature conditions, pools for rearing the young during a year, heated by solar energy, an auxiliary wood-fired water heater and PV system to power the pumps control system and other minimal requirements such as lighting. The concepts, system development and integration, construction process and measured performance are presented together with the first results of this project which integrates low impact renewable energy systems to support the conservation of an endangered specie. (Author)

  8. Growth history of hydrothermal chimneys at EPR 9―10°N: A structural and mineralogical study

    PENG; Xiaotong; ZHOU; Huaiyang

    2005-01-01

    Based on structural and mineralogical characteristics of four hydrothermal chimney samples collected by submersible Alvin, growth history and formation environment of hydrothermal chimney at EPR 9―10°N are established. It is shown that there occur two types of hydrothermal chimney with different deposition environments at EPR 9―10°N according to differences in their shape, structure and mineral assemblage: type I chimney forms in an environment with high temperature, low pH and strong reducing hydrothermal focus flow and type II chimney forms in a relatively low temperature, high pH and rich Zn hydrothermal environment. Growth of type I chimney begins with the formation of anhydrite. Subsequently deposition of Cu-Fe-Zn sulphide in various directions of chimneys decides the final structure of this type of chimney. According to observation and analysis of mineral assemblages, the formation process of type I chimney could be divided into three stages from early, middle to late. Changes of temperature and major chemical reaction type in the process of hydrothermal chimney formation are also deduced. Different from type I chimney, quenching crystalline of pyrite and/or crystalline of sphalerite provide the growth foundation of type II chimney in the early stage of chimney formation.

  9. Methane seepage in the Shenhu area of the northern South China Sea: constraints from carbonate chimneys

    Guan, Hongxiang; Zhang, Mei; Mao, Shengyi; Wu, Nengyou; Lu, Hongfeng; Chen, Duofu

    2016-02-01

    Two authigenic carbonate chimneys were recovered from the Shenhu area in the northern South China Sea at approximately 400 m water depth. The chimneys' mineralogy, isotopic composition, and lipid biomarkers were studied to examine the biogeochemical process that induced the formation of the chimneys. The two chimneys are composed mostly of dolomite, whereas the internal conduits and semi-consolidated surrounding sediments are dominated by aragonite and calcite. The specific biomarker patterns (distribution of lipids and their depleted δ13C values) indicate the low occurrence of methanotrophic archaea ANME-1 responsible for the chimneys' formation via anaerobic oxidation of methane. A significant input of bacteria/planktonic algae and cyanobacteria to the carbon pool during the precipitation of the carbonate chimneys is suggested by the high contributions of short-chain n-alkanes (69% of total hydrocarbons) and long-chain n-alcohols (on average 56% of total alcohols). The oxygen isotopic compositions of the carbonate mixtures vary from 3.1‰ to 4.4‰ in the dolomite-rich chimneys, and from 2.1‰ to 2.5‰ in the internal conduits, which indicates that they were precipitated from seawater-derived pore waters during a long period covering the last glacial and interglacial cycles. In addition, the mixture of methane and bottom seawater dissolved inorganic carbon could be the carbon sources of the carbonate chimneys.

  10. Methane seepage in the Shenhu area of the northern South China Sea: constraints from carbonate chimneys

    Guan, Hongxiang; Zhang, Mei; Mao, Shengyi; Wu, Nengyou; Lu, Hongfeng; Chen, Duofu

    2016-06-01

    Two authigenic carbonate chimneys were recovered from the Shenhu area in the northern South China Sea at approximately 400 m water depth. The chimneys' mineralogy, isotopic composition, and lipid biomarkers were studied to examine the biogeochemical process that induced the formation of the chimneys. The two chimneys are composed mostly of dolomite, whereas the internal conduits and semi-consolidated surrounding sediments are dominated by aragonite and calcite. The specific biomarker patterns (distribution of lipids and their depleted δ13C values) indicate the low occurrence of methanotrophic archaea ANME-1 responsible for the chimneys' formation via anaerobic oxidation of methane. A significant input of bacteria/planktonic algae and cyanobacteria to the carbon pool during the precipitation of the carbonate chimneys is suggested by the high contributions of short-chain n-alkanes (69% of total hydrocarbons) and long-chain n-alcohols (on average 56% of total alcohols). The oxygen isotopic compositions of the carbonate mixtures vary from 3.1‰ to 4.4‰ in the dolomite-rich chimneys, and from 2.1‰ to 2.5‰ in the internal conduits, which indicates that they were precipitated from seawater-derived pore waters during a long period covering the last glacial and interglacial cycles. In addition, the mixture of methane and bottom seawater dissolved inorganic carbon could be the carbon sources of the carbonate chimneys.

  11. 29 CFR 1926.854 - Removal of walls, masonry sections, and chimneys.

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Removal of walls, masonry sections, and chimneys. 1926.854....854 Removal of walls, masonry sections, and chimneys. (a) Masonry walls, or other sections of masonry... steel framing may be left in place during the demolition of masonry. Where this is done, all steel...

  12. Thermal management of a symmetrically heated channel-chimney system

    Andreozzi, A. [Universita degli Studi di Napoli Federico II, Dipt. di Energetica, Termofluidodinamica applicata e Condizionamenti ambientali, Napoli (Italy); Buonomo, B.; Manca, O. [Seconda Universita degli Studi di Napoli, Dipt. di Ingegneria Aerospaziale e Meccanica, (CE) (Italy)

    2009-03-15

    A parametric analysis of natural convection in air, in a channel-chimney system, symmetrically heated at uniform heat flux, obtained by means of a numerical simulation, is carried out. The analyzed regime is two-dimensional, laminar and steady-state. Results are presented in terms of wall temperature profiles in order to show the more thermally convenient configurations which correspond to the channel-chimney system with the lowest maximum wall temperature. For the considered Rayleigh number, the difference between the highest and the lowest maximum wall temperatures increases with increasing the channel aspect ratio. The optimal expansion ratio values depend strongly on the Rayleigh number and extension ratio values and slightly on the channel aspect ratio. Correlations for dimensionless mass flow rate, maximum wall temperature and average Nusselt number, in terms of Rayleigh number and dimensionless geometric parameters are presented in the ranges: 5{<=}Ra{sup *}{<=}2.0 x 10{sup 4}, 1.5{<=}L/L{sub h}{<=}4.0 and 1.0{<=}B/b{<=}4.0. (authors)

  13. Thermal management of a symmetrically heated channel-chimney system

    A parametric analysis of natural convection in air, in a channel-chimney system, symmetrically heated at uniform heat flux, obtained by means of a numerical simulation, is carried out. The analyzed regime is two-dimensional, laminar and steady-state. Results are presented in terms of wall temperature profiles in order to show the more thermally convenient configurations which correspond to the channel-chimney system with the lowest maximum wall temperature. For the considered Rayleigh number, the difference between the highest and the lowest maximum wall temperatures increases with increasing the channel aspect ratio. The optimal expansion ratio values depend strongly on the Rayleigh number and extension ratio values and slightly on the channel aspect ratio. Correlations for dimensionless mass flow rate, maximum wall temperature and average Nusselt number, in terms of Rayleigh number and dimensionless geometric parameters are presented in the ranges: 5≤Ra*≤2.0 x 104, 1.5≤L/Lh≤4.0 and 1.0≤B/b≤4.0. (authors)

  14. Drying and jerking with solar energy. Construction and operation of solar driers. 2. ed.; Trocknen and Doerren mit der Sonne. Bau und Betrieb von Solartrocknern

    Lorenz-Ladener, Claudia (ed.)

    2011-07-01

    Drying is an age-old method of conservation. The book presents solar driers for the home garden or balcony. They are robust, long-lived and can be made in DIY construction. Only simple tools are required, and the cost is low. The book also contains basic information on drying and practical hints. (orig./AKB)

  15. Design, construction and performance testing of a solar dryer for agroindustrial by-products

    Montero, I.; Miranda, T.; Rojas, S.; Celma, A.R. [University of Extremadura, Department of Chemical and Energetics Engineering, Industrial Engineering School, Av. Elvas s/n, 06071 Badajoz (Spain); Blanco, J. [PSA (CIEMAT), Department of Solar Chemistry, Ctra. Sens, P.O. Box 22, 04200 Tabernas (Almera) (Spain)

    2010-07-15

    Spain generates a big amount of agroindustrial by-products of high moisture that produce a high environmental impact. This fact motivates the aim of this paper, in which a solar dryer prototype is designed, constructed, and performance tested for the analysis of the drying kinetics of these by-products and their possible power valuation. The characteristics of the prototype are presented, together with the variations of the properties of temperature, relative humidity, air mass flow, and efficiency for indirect, mixed, passive, active, and hybrid operation modes. The most efficient operation mode will be the forced-hybrid one, followed by the passive and active modes. The analysis of the drying kinetics of the olive pomace shows the better performance of the hybrid and mixed modes, obtaining reductions of the drying time of a 50% in both cases. (author)

  16. Construction of a 100 kW solar thermal-electric experimental plant

    Boy-Marcotte, J. L.; Dancette, M.; Bliaux, J.; Bacconnet, E.; Malherbe, J.

    1985-08-01

    A focusing collector thermal-electric power plant has been erected in Corsica (France). This plant consists of a field of 1176 sq m fixed mirror concentrators, producing heat at 250 C, a stratification thermal energy storage of about 1250 kWh, two power conversion units of 45 kWe each, with a supersonic turbine expanding a heavy organic working fluid, and two cooling towers of 200 kW each. This full-scale prototype has been built mainly to demonstrate the capability of the distributed collector solar plant concept, in the power range from 50 kWe to 1000 kWe, and the temperature range from 150 to 300 C. This paper describes the conceptual design and the performance of the plant and discusses problems that were met during construction.

  17. Tree cavity use by Chimney Swifts: implications for forestry and population recovery

    Carolyn Zanchetta

    2014-12-01

    Full Text Available The Chimney Swift (Chaetura pelagica is an aerial insectivore and a cavity-nesting/roosting specialist designated as threatened in several jurisdictions. As the occurrence of suitable chimneys declines, Chimney Swifts may increasingly nest and roost in tree cavities. It is therefore important to identify characteristics of suitable nest or roost trees and assess their frequency of occurrence. We reviewed 59 historic and modern records of trees used by Chimney Swifts to understand characteristics of suitable nest or roost trees. Chimney Swifts used at least 13 different deciduous and coniferous tree species. All of the trees were greater than 0.5 m diameter at breast height (DBH and were described as hollow or having cavities. Nest or roost tree height was 12.7 ± 7.0 m (mean ± SD; range: 3.6-28.0 m; n = 25 and DBH was 1.0 m ± 0.5 m (range 0.5-2.1 m; n = 21. According to our description of used trees, the number of suitably hollow Chimney Swift nest or roost trees may be two to three times higher, although still rare, in most unlogged compared to logged hardwood forests. Whether the current total supply of suitable nest or roost trees is sufficient to carry the anticipated increase in use by Chimney Swifts as chimney habitat is modified or deteriorates is unknown. Monitoring the frequency of use of tree cavities by nesting and roosting Chimney Swifts over time, and more robustly quantifying the availability of suitable tree cavities in different forest types for nesting and roosting Chimney Swifts, particularly in unlogged versus logged forests, are fruitful areas for future research.

  18. Full scale monitoring of the twin chimneys of the rovinari power plant

    Bayati I.

    2015-01-01

    Full Text Available The presented paper deals with the structural identification and monitoring of two twin chimneys in very close arrangement. Due to twin arrangement, important interference effects are expected to modify the chimney response to wind action, causing vortex shedding and state-dependent excitation associated to the oscillatory motion of the leeward chimney, in and out of the windward chimney wake. The complexity of the physics of this problem is increased by the dependency of the aerodynamics of circular cylinders on Reynolds number; however, there is a weakness of literature about cylinders behaviour at critical and super-critical range of Reynolds number, due to experimental limitations. Also the International Committee on Industrial Chimneys (CICIND does not provide, at present, any specific technical guideline about twin chimneys whose interaxis distance is less or equal two times the diameter, as in this case. For this reason a Tuned Mass Damper (TMD has been installed in order to increase the damping of the chimney, as merely suggested. This work aims at assessing the effectiveness of the installed TMD and characterizing the tower dynamic behaviour itself due to the wind excitation, as well as providing full scale measurements for twin cylinders configuration at high Reynolds numbers.

  19. ChEVAS: Combining Suprarenal EVAS with Chimney Technique

    Torella, Francesco, E-mail: f.torella@liverpool.ac.uk [Royal Liverpool University Hospital, Liverpool Vascular & Endovascular Service (United Kingdom); Chan, Tze Y., E-mail: tze.chan@rlbuht.nhs.uk; Shaikh, Usman, E-mail: usman.shaikh@rlbuht.nhs.uk [Royal Liverpool University Hospital, Department of Radiology (United Kingdom); England, Andrew, E-mail: a.england@salford.ac.uk [University of Salford, Department of Radiography (United Kingdom); Fisher, Robert K., E-mail: robert.fisher@rlbuht.nhs.uk [Royal Liverpool University Hospital, Liverpool Vascular & Endovascular Service (United Kingdom); McWilliams, Richard G., E-mail: richard.mcwilliams@rlbuht.nhs.uk [Royal Liverpool University Hospital, Department of Radiology (United Kingdom)

    2015-10-15

    Endovascular sealing with the Nellix{sup ®} endoprosthesis (EVAS) is a new technique to treat infrarenal abdominal aortic aneurysms. We describe the use of endovascular sealing in conjunction with chimney stents for the renal arteries (chEVAS) in two patients, one with a refractory type Ia endoleak and an expanding aneurysm, and one with a large juxtarenal aneurysm unsuitable for fenestrated endovascular repair (EVAR). Both aneurysms were successfully excluded. Our report confirms the utility of chEVAS in challenging cases, where suprarenal seal is necessary. We suggest that, due to lack of knowledge on its durability, chEVAS should only been considered when more conventional treatment modalities (open repair and fenestrated EVAR) are deemed difficult or unfeasible.

  20. ChEVAS: Combining Suprarenal EVAS with Chimney Technique

    Endovascular sealing with the Nellix® endoprosthesis (EVAS) is a new technique to treat infrarenal abdominal aortic aneurysms. We describe the use of endovascular sealing in conjunction with chimney stents for the renal arteries (chEVAS) in two patients, one with a refractory type Ia endoleak and an expanding aneurysm, and one with a large juxtarenal aneurysm unsuitable for fenestrated endovascular repair (EVAR). Both aneurysms were successfully excluded. Our report confirms the utility of chEVAS in challenging cases, where suprarenal seal is necessary. We suggest that, due to lack of knowledge on its durability, chEVAS should only been considered when more conventional treatment modalities (open repair and fenestrated EVAR) are deemed difficult or unfeasible

  1. A laboratory and theoretical study of the growth of ``black smoker'' chimneys

    Turner, J. S.; Campbell, I. H.

    1987-03-01

    Observational evidence suggests that black smoker chimneys are formed by the precipitation of anhydrite from seawater producing a solid framework which is replaced successively by iron, zinc and copper sulfides. We have demonstrated the feasibility of this process using a laboratory model in which KNO 3 is first crystallized from a warm, nearly saturated solution round an inflowing plume of cold K 2CO 3. The chimney grows in length at a nearly constant rate and, at the same time, it thickens as heat conduction causes further crystallization. The dynamic replacement process has been modelled separately, with CuSO 4 passed through a previously formed chimney of KNO 3 and flowing out through the porous walls when the flow rate, and hence the pressure difference, is increased. The formation of chimneys at a line or slit source has also been investigated in the laboratory. It has been shown that, in this case, the slit is quickly blocked off by crystallization over most of its length and that the growth is concentrated at just a few points to form a small number of nearly axisymmetric chimneys. A theory has been developed which predicts both the diameter of the outlet vent and the sign of the pressure difference between the inside and the outside of an axisymmetric chimney of constant internal diameter for a specified flow rate and density difference. It suggests that changes in flow rate or in the internal diameter of the chimney can cause fluid to flow in or out through the porous wall, leading to changes in the position of mineral stability fields within the evolving chimney. The theory has been extended to describe the pressure distribution in tapering interior conduits and it leads to the conclusion that the direction of flow through a porous chimney can reverse along its length.

  2. Finite Element Analysis and Linear Regression of Maximum Temperature for Inner Wall of Chimney Foundation

    2005-01-01

    The uniform design method was adopted and the twenty-four groups of different geometric and physical parameters were chosen. The finite element model was built. Comparisons between the simulation results and the test results prove that the simulation results are correct. The distribution of the temperature field of the chimney foundation was analyzed. The multivariate linear regression of the hightest tomperature was performed on the inner wall of the chimney foundation by the numerical calculated results. The fitting property of the highest temperature with six influence factors was obtained. A simple method for the calculation of the temperature field of the chimney foundation was provided.

  3. Solar ventilation and tempering

    Adámek, Karel; Pavlů, Miloš; Bandouch, Milan

    2014-08-01

    The paper presents basic information about solar panels, designed, realized and used for solar ventilation of rooms. Used method of numerical flow simulation gives good overview about warming and flowing of the air in several kinds of realized panels (window, facade, chimney). Yearlong measurements give a good base for calculations of economic return of invested capital. The operation of the system in transient period (spring, autumn) prolongs the period without classical heating of the room or building, in winter the classical heating is supported. In the summer period the system, furnished with chimney, can exhaust inner warm air together with necessary cooling of the system by gravity circulation, only. System needs not any invoiced energy source; it is supplied entirely by solar energy. Large building systems are supported by classical electric fan respectively.

  4. Dynamic characteristic and seismic response analyses for installation of in-chimney bracket structures in HANARO

    The in-chimney bracket structures will be installed on the upper part of chimney, which holds the capsule extension pipes in upper one-third of length. For evaluating the seismic effects on the capsules and related reactor structures by installation of the in-chimney bracket, an ANSYS analysis model is developed, and the dynamic characteristics are analyzed. The seismic response analyses of in-chimney bracket and related reactor structures of HANARO under the design earthquake response spectrum loads of SSE(0.2g) are performed. The several candidated designs of the capsule extension pipes and support spring stiffness to meet the displacement limit of the flow tubes in core region are proposed

  5. Analytical study of the closure flow inside the ETRR-2 core chimney

    The present work is carried out in order to study the closure flow inside the core chimney of the Egypt second research reactor (ETRR-2). Based on the finite difference technique, a two dimensional model is developed to simulate the coolant flow inside the chimney. The model is verified by FEHT finite element program. Then a study of different closure flow values inside the chimney was made using the developed model where a flow map is plotted showing the stagnation depth for each closure flow. The flow map shows that for a closure flow greater than 0.16 m3/h, no active water ascends from the core to the pool through the chimney. The model results are analyzed and discussed. (orig.)

  6. Analytical study of the closure flow inside the ETRR-2 core chimney

    The present work is carried out in order to study the closure flow inside the core chimney of the Egypt second research reactor (ETRR-2). Based on the finite difference technique, a two dimensional model is developed to simulate the coolant flow inside the chimney. The model is verified by FEHT finite element program. Then a study of different closure flow values inside the chimney was made using the developed model where a flow maps is plotted showing the stagnation depth for each closure flow. The flow maps shows that for a closure flow greater than 0.16 m3/h, no radioactive water ascends from the core to the pool through the chimney. The model results are analyzed and discussed

  7. Analytical study of the closure flow inside the ETRR-2 core chimney

    El-Din El-Morshdy, S. [Atomic Energy Authority, Cairo (Egypt). Reactors Dept.

    2006-12-15

    The present work is carried out in order to study the closure flow inside the core chimney of the Egypt second research reactor (ETRR-2). Based on the finite difference technique, a two dimensional model is developed to simulate the coolant flow inside the chimney. The model is verified by FEHT finite element program. Then a study of different closure flow values inside the chimney was made using the developed model where a flow map is plotted showing the stagnation depth for each closure flow. The flow map shows that for a closure flow greater than 0.16 m{sup 3}/h, no active water ascends from the core to the pool through the chimney. The model results are analyzed and discussed. (orig.)

  8. Analytical study of the closure flow inside the ETRR-2 core chimney

    El-Morshdy, Salah El-Din [Reactors Department, Atomic Energy Authority, Cairo (Egypt)]. E-mail: selmorshedy@etrr2-aea.org.eg

    2007-03-15

    The present work is carried out in order to study the closure flow inside the core chimney of the Egypt second research reactor (ETRR-2). Based on the finite difference technique, a two dimensional model is developed to simulate the coolant flow inside the chimney. The model is verified by FEHT finite element program. Then a study of different closure flow values inside the chimney was made using the developed model where a flow maps is plotted showing the stagnation depth for each closure flow. The flow maps shows that for a closure flow greater than 0.16 m{sup 3}/h, no radioactive water ascends from the core to the pool through the chimney. The model results are analyzed and discussed.

  9. Modelling and simulation of condensation phenomena of acid gases in an industrial chimney

    Serris, Eric; Cournil, Michel; Peultier, Jérôme

    2007-01-01

    Coal power stations as well as waste incinerators produce humid acid gases which condensate in industrial chimneys. These condensates may cause corrosion of the internal cladding made of stainless steels, nickel base alloys or non metallic materials. In the aim of polluting emission reduction and material optimal choice, it is necessary to determine all the phenomena which occur throughout the chimney such as condensation and dissolution of acid gases (in this particular case, sulphur dioxide...

  10. Fish assemblages in Tanzanian mangrove creek systems influenced by solar salt farm constructions

    Mwandya, Augustine W.; Gullström, Martin; Öhman, Marcus C.; Andersson, Mathias H.; Mgaya, Yunus D.

    2009-04-01

    Deforestation of mangrove forests is common occurrence worldwide. We examined fish assemblage composition in three mangrove creek systems in Tanzania (East Africa), including two creeks where the upper parts were partly clear-cut of mangrove forest due to the construction of solar salt farms, and one creek with undisturbed mangrove forest. Fish were caught monthly for one year using a seine net (each haul covering 170 m 2) within three locations in each creek, i.e. at the upper, intermediate and lower reaches. Density, biomass and species number of fish were lower in the upper deforested sites compared to the mangrove-fringed sites at the intermediate and lower parts in the two creeks affected by deforestation, whereas there were no differences among the three sites in the undisturbed mangrove creek system. In addition, multivariate analyses showed that the structure of fish assemblages varied between forested and clear-cut sites within the two disturbed creeks, but not within the undisturbed creek. Across the season, we found no significant differences except for a tendency of a minor increase in fish densities during the rainy season. At least 75% of the fishes were juveniles and of commercial interest for coastal fisheries and/or aquaculture. Mugil cephalus, Gerres oyena and Chanos chanos were the most abundant species in the forested sites. The dominant species in the clear-cut areas were M. cephalus and Elops machnata, which were both found in relatively low abundances compared to the undisturbed areas. The conversion of mangrove forests into solar salt farms not only altered fish assemblage composition, but also water and sediment conditions. In comparison with undisturbed areas, the clear-cut sites showed higher salinity, water temperature as well as organic matter and chlorophyll a in the sediments. Our results suggest that mangrove habitat loss and changes in environmental conditions caused by salt farm developments will decrease fish densities, biomass

  11. Effect of cold inflow on chimney height of natural draft cooling towers

    Highlights: ► Natural convection data were obtained from an air-cooled heat exchanger model. ► The extent of cold inflow was quantified to relate to the decrease in effective chimney height. ► Installation of wire mesh screen on chimney outlet blocked off cold inflow to improve the chimney efficiency. ► Evidence of existence of effective plume-chimney for when cold inflow was blocked off warrants further work. - Abstract: Temperature and pressure drop data obtained from an air-cooled heat exchanger model with cross-sectional flow areas of 0.56 m2, 1.00 m2 and 2.25 m2 operating under natural convection are presented that indicate significant cold inflow, resulting in the reduction of effective chimney height. Cold inflows encountered in actual applications where the Froude number is typically 0.2, may not be as severe as described in this paper, which was of the order of 10−6–10−4. Additional tests on smaller scale models appeared to favor the explanation that the occurrence of cold inflow in the air-cooled heat exchanger model was primarily due to the relative ease in either drawing cold air from inlet or from outlet, and to a lesser extent the Froude number of the chimney or the critical velocity estimated by formula. A CFD study will bring much understanding of the phenomenon for the different situations.

  12. SolarBau: MONITOR, a forum for information exchange on energy efficiency and solar energy use in non-domestic building construction; SolarBau: MONITOR - Ein Forum fuer Erfahrungen und Ergebnisse ueber Energieeffizienz und Solarenergienutzung im Nichtwohnungsbau

    Voss, K. [Fraunhofer-Institut fuer Solare Energiesysteme (ISE), Freiburg im Breisgau (Germany). Gruppe Solares Bauen; Loehnert, G. [Architekturbuero solidar, Berlin (Germany); Wagner, A. [Karlsruhe Univ. (T.H.) (Germany). Fakultaet fuer Architektur

    1999-03-01

    Within it's program 'Optimized Solar Construction', the German Ministry of Economics and Technology supports large non-housing construction demonstration projects. Meaningfully combining energy saving measures with utilization of renewable energies within an integral planning process, the objective is to achieve primary energy needs below 100 kWh/m{sup 2}a for heating, ventilation, in-door climate control and lighting combined. Data/results of the demonstration projects are assembled, analyzed and published (via print media and Internet) in an accompanying project named SolarBau:MONITOR, serving also as a forum for the exchange of ideas for the different planning teams. The Solar Bau:MONITOR concept and the demonstration project under construction are presented. (orig.) [German] Mit dem Foerderprogramm 'Solaroptimiertes Bauen' foerdert das Bundesministerium fuer Wirtschaft und Technologie (BMWi) Demonstrationsprojekte aus dem Bereich grosser Nichtwohnungs-Neubauten. Durch eine sinnvolle Kombination aus Massnahmen zur Energieeinsparung und der Nutzung erneuerbarer Energien im Rahmen eines integralen Planungsprozesses ist als wesentliches Ziel gefordert, dass die Primaerenergiekennzahl fuer Heizung, Lueftung, Klima und Licht in Summe unter 100 kWh/m{sup 2}a liegt. SolarBau:MONITOR ist das dazugehoerige Begleitprojekt. Es stellt Fakten und Analysen zu den Einzelprojekten auf einer gemeinsamen Informationsplattform via Internet und Printmedien zusammen und bietet ein Forum fuer die Planungsteams der Projekte. Der Beitrag stellt das Konzept von SolarBau:MONITOR und die bereits begonnenen Demonstrationsprojekte vor. (orig.)

  13. Photovoltaic solar panel and procedure to construction it; Fotovoltaisch zonnepaneel en werkwijze voor het vervaardigen daarvan

    Verhoef, L.A.; Michiels, P.P.

    1995-07-03

    The panel surface of a photovoltaic (PV) solar panel consists of active areas where incoming solar radiation results in an electric current from the solar panel, and inactive areas, where no or hardly any electric current is generated. The title invention aims at improving those panels such that solar radiation that comes in on inactive areas is intercepted to use it for the production of electricity and thus increase the peak capacity. This is realized by means of positioned directional tools, which direct at least a part of the solar radiation that comes in on the inactive areas to the solar panel active surface. The directional tools can be reflectors, diffractors, scattering tools or a combination of such tools. 9 figs., 2 tabs.

  14. MPPT algorithm test on a photovoltaic emulating system constructed by a DC power supply and an indoor solar panel

    Highlights: • A novel PV emulator is constructed by using conventional solar panels with a DC power supply. • The proposed PV emulator is cost-effectiveness, relatively easy implementation. • The proposed PV emulator avoids the bandwidth problem associated with electronics PV emulators. • Indoor testing of MPPT algorithms and power converters avoids the dependency on solar irradiation. • The PV emulating system has been used for testing a P and O MPPT algorithm and a boost dc converter. - Abstract: In this paper a novel photovoltaic (PV) emulating scheme for testing maximum power point tracking (MPPT) algorithms and PV inverters has been proposed. It is constructed by the parallel connection of conventional solar panels with a DC power supply operating in current source mode. The advantages of the proposed scheme are cost-effectiveness, relatively easy implementation and indoor testing of MPPT algorithms and power converters avoiding weather and time of day dependency on solar irradiation levels. Furthermore, the proposed PV emulator avoids the bandwidth problem associated with the dc converter based PV emulating systems. Detailed circuit connection, parameters, electrical characteristics and mathematical model of the PV emulator are presented and discussed. Proposed PV emulating system has been used to test a boost DC/DC converter controlled by Perturb and Observe (P and O) MPPT algorithm. Test results confirmed the effectiveness of the proposed PV emulation system and all achieved results correspond well to the original designed values

  15. Use of chemical explosives for emergency solar flare shelter construction and other excavations on the Martian surface

    The necessity to shelter people on the Martian surface from solar flare particles at short notice and the need for long-term habitats with thick cosmic ray shielding suggests that explosives could be used effectively for excavation of such structures. Modern insensitive high explosives are safe, efficient, and reliable for rock breakage and excavation. Extensive Earth-bound experience leads us to propose several strategies for explosively-constructed shelters based on tunneling, cratering, and rock casting techniques

  16. Innovative Second-Generation Wavelets Construction With Recurrent Neural Networks for Solar Radiation Forecasting

    Capizzi, Giacomo; Napoli, Christian; Bonanno, Francesco

    2013-01-01

    Solar radiation prediction is an important challenge for the electrical engineer because it is used to estimate the power developed by commercial photovoltaic modules. This paper deals with the problem of solar radiation prediction based on observed meteorological data. A 2-day forecast is obtained by using novel wavelet recurrent neural networks (WRNNs). In fact, these WRNNS are used to exploit the correlation between solar radiation and timescale-related variations of wind speed, humidity, ...

  17. Development of the lined masonry chimney oil appliance

    Krajewski, R.; Strasser, J. [Brookhaven National Lab., Upton, NY (United States)

    1996-07-01

    This paper describes the development of the lined masonry chimney venting tables form the output of the Oil Heat Analysis Program 9OHVAP. These new tables are different from the prior format, offered in the Proceedings of the 1995 Oil Heat Technology Conference and Workshop, paper No. 95-4. Issues expressed by representatives of the oil heat industry at last years conference during the Venting Technology Workshop resulted in subsequent discussions. A full day meeting was held, co-sponsored by BNL and the Oilheat Manufacturers Association (OMA), to address revision of the format of the venting tables prior to submission to the National Fire Protection Association (NFPA) Standard 31 Technical Committee. The resulting tables and text were submitted to NFPA during the first week of October, 1995. Since then minor changes were made reflecting the addition of data obtained by including intermediate firing rates (0.4, 0.65, and 0.85 gph) not included in the original tables which were developed in increments of 0.25 gph. The new tables address the specific question; {open_quotes}If remediation is required, what is the recommendation for the sizing of a metal liner and the appropriate firing rate range to be used with that liner?{close_quotes}

  18. Effects of industrial chimney gases on the Nif Mountain vegetation

    Cireli, B.

    1975-01-01

    This investigation has been carried out on vegetation in order to find out changes in the morphology, anatomy and ultrastructure of cells brought about by the chimney gases from the surrounding factories. Different dicots and monocots have been used as experimental material. Results obtained are summarized as follows: (A) In all the experimental plants affected by the pollutants, an inhibition of the elongation has been observed. (B) Anatomical studies revealed that the epidermis, palisade and spongy parenchymatic tissues and cells of pollutant-affected plants appeared to be different from those of control plants. (C) Along with the anatomical changes, ultrastructural modifications have also been observed between pollutant-affected and control plants. (D) In order to investigate the causes of loss of green color in pollutant-affected plants, spectrophotometric pigmentation determinations have been carried out. The results have indicated such a decrease in pigment contents of pollutant-affected plants. (E) Calcium, magnesium and sulphate contents of control and pollutant-affected plants have been determined with an atomic absorption spectrophotometer. Pollutant-affected plants appeared to contain less calcium and magnesium and more sulphate than control plants. (F) Comparative oil analyses of fruits of pollutant-affected and control Olea plants have been carried out. (G) It has been concluded that air pollutants, affecting the various metabolic activities of the cells, cause modifications in the cell ultrastructure and cell anatomy and consequently give rise to typical morphological changes manifested in the form of growth inhibition.

  19. Beautiful heat: a master chimney sweep talks about burning issues

    Hederich, M.P.

    2001-07-01

    Fire has played a major role in mankind's life from the beginning. Used for heating and cooking, its various uses have evolved to include controlled explosions shortly after the development of gunpowder, and the generation of electricity made other uses possible. The author, a certified solid fuel technician and chimney sweep, as well as a licensed technician for natural gas and propane, has written this book to enable the reader to enjoy safe and dependable wood fires year round by taking the necessary steps. The first recommendation made is against the homeowner installing himself/herself any solid fuel system. It is a job better left to the professionals, considering the substantial product and regulation knowledge and experience required. Specific information related to solid fuel burning technology is included in this book, to be used as a guide. Part 1 of the book deals with the fuel, touching on issues such as energy and the environment, wood combustion and air pollution, buying firewood, wood ashes, cleaning your heating system and others. Part 2 is devoted to the heating system. It introduces topics ranging from the systems advisor to the location and installation of the system, the principles of space heating, high efficiency wood burning, inspections, to name just a few. 22 refs., tabs., figs.

  20. CFD simulation of a solar tower

    Koten, Hasan; Yukselenturk, Yalcyn; Yilmaz, Mustafa [Marmara University Mechanical Engineering Department (Turkey)], E-mail: hasan.koten@marmara.edu.tr

    2011-07-01

    With the depletion of fossil fuels and the rising concerns about their impacts on the environment, the use of alternative energy sources has become necessary. Among the alternatives, solar energy, with its unlimited resources and its low impact on the environment, is the most promising. The aim of this paper is to present a numerical model of a regular solar tower. A CFD analysis of the solar tower was performed with a commercial CFD code and velocity fields, temperature measurements and flow characteristics were determined and compared to experimental results available in the literature. It was found that the numerical model is capable of assessing the buoyant air flow in chimneys. In addition results showed that increasing the solar chimney height, solar collector area, or solar irradiance increases power generation capacity while ambient temperature does not significantly affect this capacity. This study provided a numerical model which is proficient in modeling solar towers.

  1. Construction of 3-dimensional ZnO-nanoflower structures for high quantum and photocurrent efficiency in dye sensitized solar cell

    Graphical abstract: - Highlights: • The structural and optical characterizations of ZnO nanoflowers were carried out on ITO by hydrothermal method. • Dye sensitized solar cell based ZnO nanoflowers were constructed on substrate. • The surface morphology effect on quantum efficiency and solar conversion efficiency were investigated. - Abstract: 3-dimensional ZnO nanoflower were obtained on FTO (F:SnO2) substrate by hydrothermal method in order to produce high efficiency dye sensitized solar cells (DSSCs). We showed that nanoflowers structures have nanoscale branches that stretch to fill gaps on the substrate and these branches of nano-leaves provide both a larger surface area and a direct pathway for electron transport along the channels. It was found that the solar conversion efficiency and quantum efficiency (QE) or incident photon to current conversion efficiencies (IPCE) is highly dependent on nanoflower surface due to high electron injection process. The highest solar conversion efficiency of 5.119 and QE of 60% was obtained using ZnO nanoflowers/N719 dye/I−/I−3 electrolyte. In this study, three dimensional (3D)-nanoflower and one dimensional (1D)-nanowires ZnO nanostructures were also compared against each other in respect to solar conversion efficiency and QE measurements. In the case of the 1D-ZnO nanowire conversion efficiency (η) of 2.222% and IPCE 47% were obtained under an illumination of 100 mW/cm2. It was confirmed that the performance of the 3D-nanoflowers was better than about 50% that of the 1D-nanowire dye-sensitized solar cells

  2. Plastic Solar Cells: A Multidisciplinary Field to Construct Chemical Concepts from Current Research

    Gomez, Rafael; Segura, Jose L.

    2007-01-01

    Examples of plastic solar-cell technology to illustrate core concepts in chemistry are presented. The principles of operations of a plastic solar cell could be used to introduce key concepts, which are fundamentally important to understand photosynthesis and the basic process that govern most novel optoelectronic devices.

  3. Improved solar models constructed with a formulation of convection for stellar structure and evolution calculations without the mixing-length theory approximations

    Lydon, Thomas J.; Fox, Peter A.; Sofia, Sabatino

    1993-01-01

    We have updated a previous attempt to incorporate within a solar model a treatment of convection based upon numerical simulations of convection rather than mixing-length theory (MLT). We have modified our formulation of convection for a better treatment of the kinetic energy flux. Our solar model has been updated to include a complete range of OPAL opacities, the Debye-Hueckel correction to the equation of state, helium diffusion due to gravitational settling, and atmospheres by Kurucz. We construct a series of models using both MLT and our revised formulation of convection and the compared results to measurements of the solar radius, the solar luminosity, and the depth of the solar convection zone as inferred from helioseismology. We find X(solar) = 0.702 +/- 0.005, Y(solar) = 0.278 +/- 0.005, and Z(solar) = 0.0193 +/- 0.0005.

  4. Solar building construction. Special edition of the journal 'Sonnenenergie'; Solares Bauen. Sonderheft der Sonnenenergie

    NONE

    2005-10-01

    This special issues of SOLARES BAUEN presents examples of solar architecture to illustrate the many options for combining aesthetically pleasing architecture with sustainable power supply. An initiative of the Deutsche Energie-Agentur dena shows that a structural change in power supply in existing buildings is urgently required. Germany is a densely built country, so innovative new buildings can never solve the existing energy problems. Up to 80 percent of the energy demand of existing buildings may be covered by renewables after modernisation. In order to mobilise this enormous potential, the dena initiative comprised the testing of innovative technical standards from which economically acceptable recommendations can be derived for the future. The high potential for savings can be utilized only if measures like thermal insulation, controlled ventilation, modern windows, high-efficiency boilers and renewable energy sources are combined. (orig.)

  5. Metagenome reveals potential microbial degradation of hydrocarbon coupled with sulfate reduction in an oil-immersed chimney from Guaymas Basin

    Ying eHe

    2013-06-01

    Full Text Available Deep-sea hydrothermal vent chimneys contain a high diversity of microorganisms, yet the metabolic activity and the ecological functions of the microbial communities remain largely unexplored. In this study, a metagenomic approach was applied to characterize the metabolic potential in a Guaymas hydrothermal vent chimney and to conduct comparative genomic analysis among a variety of environments with sequenced metagenomes. Complete clustering of functional gene categories with a comparative metagenomic approach showed that this Guaymas chimney metagenome was clustered most closely with a chimney metagenome from Juan de Fuca. All chimney samples were enriched with genes involved in recombination and repair, chemotaxis and flagellar assembly, highlighting their roles in coping with the fluctuating extreme deep-sea environments. A high proportion of transposases was observed in all the metagenomes from deep-sea chimneys, supporting the previous hypothesis that horizontal gene transfer may be common in the deep-sea vent chimney biosphere. In the Guaymas chimney metagenome, thermophilic sulfate reducing microorganisms including bacteria and archaea were found predominant, and genes coding for the degradation of refractory organic compounds such as cellulose, lipid, pullullan, as well as a few hydrocarbons including toluene, ethylbenzene and o-xylene were identified. Therefore, this oil-immersed chimney supported a thermophilic microbial community capable of oxidizing a range of hydrocarbons that served as electron donors for sulphate reduction under anaerobic conditions.

  6. Feasibility of utilising solar-induced ventilation in Malaysia

    The feasibility of applying solar-induced ventilation in a typical Malaysian house measuring 3 m high x wide x 5 m deep was considered based on experimental results obtained from a laboratory-scale model. A wall-type solar chimney was considered. The design of the solar chimney incorporated providing a glass panel alongside a vertical wall of a building. Openings at the top and bottom of the wall allowed fresh air to be introduced into the building. Simulations obtained from a simple theoretical model showed that the solar chimney was able to induce air flow rates of between 640 to 1040 m3 h-1 with a 0.3 m air gap. These ventilation rates are found to be in compliance with codes specified by ASHRAE and the Uniform Building By-laws. Full scale studies would need to be conducted in order to evaluate its effectiveness especially the flow pattern in the room

  7. Design, construction and test run of a two-tonne capacity solar rice dryer with rice-husk-fired auxiliary heater

    The design and construction details of a two-tonne per batch capacity natural-circulation solar rice dryer and the highlights of the design of its rice-husk-fired auxiliary heating system which is still under construction are presented. The dryer measures approximately 17.7m long by 9.8m wide by 6m high. Preliminary results of a test run on the solar dryer section only is reported. (author). 5 refs, 3 figs

  8. Construction and simulation of a solar dryer for drying pineapples in Ghana

    Bogojevic, Ivana

    2012-01-01

    Drying of agricultural products using solar energy is a method for preservation that has been used for centuries all over the world. This method has been effective especially in tropical and subtropical climates, due to the great availability to solar energy. The village Edumafa in Ghana has great cultivation of pineapples but has no post harvest process. A post harvest process as drying of pineapples can increase cultivation and introduce a new product to be sold at the market. This thesis i...

  9. Numerical simulation of turbulent flow mixing inside a square chimney structure of a research reactor

    Sengupta, S.; Bhatnagar, A. [Bhabha Atomic Research Centre, Mumbai (India). Research Reactor Design and Projects Div.; Vijayan, P.K. [Bhabha Atomic Research Centre, Mumbai (India). Reactor Engineering Div.; Singh, R.K. [Bhabha Atomic Research Centre, Mumbai (India). Reactor Safety Div.; Raina, V.K. [Bhabha Atomic Research Centre, Mumbai (India). Reactor Group

    2013-11-15

    Numerical simulation was performed to study the turbulent mixing behavior of two opposing flows inside a square chimney structure of a research reactor. The chimney design facilitates drawing pool water in the downward direction and thereby suppresses the upward flow of radioactive water jet to limit the radiation field at the reactor pool top. Analyses were carried out considering a mass flow rate of 750 kg/s for the upward flowing hot water from the core, which corresponds to Reynolds number of 3 x 10{sup 6}. Mass flow ratios of the downward flow and the upward flow were 0.0, 0.05, 0.1 and 0.15. The effects of mass flow ratio, chimney height on the velocity and temperature distribution inside three-dimensional chimney structure was evaluated using CFD code PHOENICS. The effect of temperature difference between the opposing flows on velocity was also analysed. It is observed that increase in downward flow causes the jet height to decrease due to the opposing momentum of downward flow against the upward jet. The effects of chimney height and temperature difference on the jet height are found to be marginal because of dominating inertial force over buoyancy force for the study. (orig.)

  10. Vibration test for HANARO in-chimney bracket and instrumented fuel assembly

    The vibration characteristics and structural integrity of the instrumented fuel assembly and in-chimney bracket structures, which is recently installed in HANARO reactor chimney, are investigated. For this purpose, four acceleration data on the guide tube of the instrumented fuel assembly and in-chimney bracket structures subjected to fluid induced vibration are measured and analyzed. In time domain analysis, maximum amplitudes and RMS values of accelerations and displacements are obtained from the measured vibration signal. The frequency components of the vibration data are analyzed by using the frequency domain analysis. These analysis results show that the levels of the measured vibrations are within the allowable limit, and the low frequency component near 10 Hz is dominant in the vibration signal. For the evaluation of the structural integrity on the in-chimney bracket and related structures, the static analysis for ANSYS finite element model is carried out. The maximum displacements of the measured vibration signals are used as the load inputs. These analysis results show that the maximum stresses and within the allowable stresses of the ASME code, and the maximum displacement at the top of the flow tube is within the displacement limit. Therefore any damage on the structural integrity is not expected when the irradiation test is performed using the in-chimney bracket

  11. Simulation, construction and testing of a two-cylinder solar Stirling engine powered by a flat-plate solar collector without regenerator

    Tavakolpour, Ali Reza; Zomorodian, Ali [Department of Mechanics of Farm Machinery Engineering, Shiraz University, Shiraz (Iran); Akbar Golneshan, Ali [Department of Mechanical Engineering, Shiraz University, Shiraz (Iran)

    2008-01-15

    In this research, a gamma-type, low-temperature differential (LTD) solar Stirling engine with two cylinders was modeled, constructed and primarily tested. A flat-plate solar collector was employed as an in-built heat source, thus the system design was based on a temperature difference of 80{sup o}C. The principles of thermodynamics as well as Schmidt theory were adapted to use for modeling the engine. To simulate the system some computer programs were written to analyze the models and the optimized parameters of the engine design were determined. The optimized compression ratio was computed to be 12.5 for solar application according to the mean collector temperature of 100{sup o}C and sink temperature of 20{sup o}C. The corresponding theoretical efficiency of the engine for the mentioned designed parameters was calculated to be 0.012 for zero regenerator efficiency. Proposed engine dimensions are as follows: power piston stroke 0.044 m, power piston diameter 0.13 m, displacer stroke 0.055 m and the displacer diameter 0.41 m. Finally, the engine was tested. The results indicated that at mean collector temperature of 110{sup o}C and sink temperature of 25{sup o}C, the engine produced a maximum brake power of 0.27 W at 14 rpm. The mean engine speed was about 30 rpm at solar radiation intensity of 900 W/m{sup 2} and without load. The indicated power was computed to be 1.2 W at 30 rpm. (author)

  12. Design and Construction of a Solar Observatory in a Liberal Arts Environment: Austin College’s Gnomon and Meridian Line

    Baker, David; Salisbury, D.

    2014-01-01

    Austin College’s indoor solar observatory is one of the most distinctive features in its new IDEA Center science building. Patterned after 16th and 17th century solar observatories in European cathedrals, the IDEA Center solar facility will be used extensively for public events, introductory astronomy courses, and reproductions of important historical scientific measurements. A circular aperture, or gnomon hole, on the roof with diameter 32 mm allows a beam of sunlight to trace a path across the atrium floor 15.37 meters below. At local solar noon, the Sun’s image falls directly on a brass meridian line. Special markers for solstices and equinoxes highlight western, eastern, and indigenous cultural contributions to astronomy: Macedonian symbol of the Sun marks summer solstice, Chinese Sun symbol showcases the equinoxes, and the Mayan symbol of the Sun celebrates winter solstice. The location directly beneath the gnomon hole is marked by the universal scientific symbol of the Sun. Direct solar measurements and mathematical models were used in design and implementation of the meridian line. During IDEA Center building construction in Fall 2012, undergraduate students measured the Sun’s position at various times. The finished floor was set in February 2013, well before a full year’s worth of measurements could be recorded. A mathematical model including the effects of aperture size and atmospheric refraction was needed to predict the size and location of the Sun on the meridian line throughout the year. Confirmation of the meridian line occurred on Summer Solstice 2013 when the Sun’s image precisely hit the Macedonian marker at the correct time.

  13. Structural Integrity Evaluation of an New In-Chimney Bracket Structures for HANARO

    In HANARO are there provided three hexagonal irradiation holes (CT, IR1 and IR2) in the central region of the core while four circular irradiation holes (OR3 ∼ OR6) in the outer core. There exist two types of irradiation facilities: uninstrumented or instrumented. The uninstrumented irradiation facility is little influenced by the coolant flow. But the dynamic behavior by the flow-induced vibration (FIV) and seismic loads is expected to largely occur in case of the instrumented test facility due to the long guide tube to protect the instrumentation cables. To suppress this dynamic behavior of the facility, the in-chimney bracket was designed. As a supplementary supporting structure for irradiation facility, this bracket will hold guide tubes whose holding position of the instrumented facility in CT or IR is the middle part of the instrumented facility between the hole spider and the robot arm already provided in the reactor pool liner. On the while, the bracket will grip the upper part of the guide tube when it is applied to hold the instrumented facility loaded in OR sites. Therefore it is believed that the irradiation test can be successfully conducted since this bracket can reduce the FIV and dynamic response to seismic load as well. In new in-chimney bracket, IR1 is reserved for IPS(In-Pile Section) so only CT/IR2 guide tubes are supported by CT/IR clamp units and the shape of In-chimney bracket is redesigned. For evaluating the structural integrity on the new in-chimney bracket and related reactor structures, ANSYS finite element analysis model is developed and the dynamic characteristics are analyzed. The seismic response analyses of new in-chimney bracket and related reactor structures of HANARO under the design earthquake response spectrum loads of OBE(0.1g) and SSE(0.2g) are performed. The response shows that the stress values for main points on the reactor structures and the new in-chimney bracket for seismic loads are within the ASME Code limits. It is

  14. Studies of the thermohydraulics of the Irradiation Research Facility (IRF) chimney using computational fluid dynamics

    AECL is developing a concept for a new Irradiation Research Facility (IRF) that will be used to support ongoing development of CANDU technology and advanced materials research after the NRU reactor shuts down. As part of the IRF Pre-Project Engineering Program, computational fluid dynamics (CFD) analyses of the flow patterns and heat transfer within four reactor components - the inlet plenum, reflector tank, chimney, and the pool - were done to support the design. This paper describes the results of the CFD analyses of the IRF chimney. (author)

  15. Structural Integrity Evaluation of an New In-Chimney Bracket Structures for HANARO

    Ryu, Jeong Soo; Cho, Yeong Garp; Lee, Jung Hee; Jung, Hoan Sung; Seo, Choon Gyo; Shin, Jin Won

    2007-12-15

    In HANARO are there provided three hexagonal irradiation holes (CT, IR1 and IR2) in the central region of the core while four circular irradiation holes (OR3 {approx} OR6) in the outer core. There exist two types of irradiation facilities: uninstrumented or instrumented. The uninstrumented irradiation facility is little influenced by the coolant flow. But the dynamic behavior by the flow-induced vibration (FIV) and seismic loads is expected to largely occur in case of the instrumented test facility due to the long guide tube to protect the instrumentation cables. To suppress this dynamic behavior of the facility, the in-chimney bracket was designed. As a supplementary supporting structure for irradiation facility, this bracket will hold guide tubes whose holding position of the instrumented facility in CT or IR is the middle part of the instrumented facility between the hole spider and the robot arm already provided in the reactor pool liner. On the while, the bracket will grip the upper part of the guide tube when it is applied to hold the instrumented facility loaded in OR sites. Therefore it is believed that the irradiation test can be successfully conducted since this bracket can reduce the FIV and dynamic response to seismic load as well. In new in-chimney bracket, IR1 is reserved for IPS(In-Pile Section) so only CT/IR2 guide tubes are supported by CT/IR clamp units and the shape of In-chimney bracket is redesigned. For evaluating the structural integrity on the new in-chimney bracket and related reactor structures, ANSYS finite element analysis model is developed and the dynamic characteristics are analyzed. The seismic response analyses of new in-chimney bracket and related reactor structures of HANARO under the design earthquake response spectrum loads of OBE(0.1g) and SSE(0.2g) are performed. The response shows that the stress values for main points on the reactor structures and the new in-chimney bracket for seismic loads are within the ASME Code limits

  16. Survey of new forms of organization and financing constructions in the Dutch solar electricity market

    In the title project the focus is on organizations and projects in the Dutch market for solar electricity, characterized by: minimal dependence on subsidies (state aid), the removal of high initial investments by users (financing), and structures that can easily be extended or replicated (scale)

  17. Innovative second-generation wavelets construction with recurrent neural networks for solar radiation forecasting.

    Capizzi, Giacomo; Napoli, Christian; Bonanno, Francesco

    2012-11-01

    Solar radiation prediction is an important challenge for the electrical engineer because it is used to estimate the power developed by commercial photovoltaic modules. This paper deals with the problem of solar radiation prediction based on observed meteorological data. A 2-day forecast is obtained by using novel wavelet recurrent neural networks (WRNNs). In fact, these WRNNS are used to exploit the correlation between solar radiation and timescale-related variations of wind speed, humidity, and temperature. The input to the selected WRNN is provided by timescale-related bands of wavelet coefficients obtained from meteorological time series. The experimental setup available at the University of Catania, Italy, provided this information. The novelty of this approach is that the proposed WRNN performs the prediction in the wavelet domain and, in addition, also performs the inverse wavelet transform, giving the predicted signal as output. The obtained simulation results show a very low root-mean-square error compared to the results of the solar radiation prediction approaches obtained by hybrid neural networks reported in the recent literature. PMID:24808074

  18. Constructing a One-solar-mass Evolutionary Sequence Using Asteroseismic Data from Kepler

    Silva Aguirre, V.; Chaplin, W.J.; Ballot, J.;

    2011-01-01

    Asteroseismology of solar-type stars has entered a new era of large surveys with the success of the NASA Kepler mission, which is providing exquisite data on oscillations of stars across the Hertzsprung-Russell diagram. From the time-series photometry, the two seismic parameters that can be most...

  19. Linkages between mineralogy, fluid chemistry, and microbial communities within hydrothermal chimneys from the Endeavour Segment, Juan de Fuca Ridge

    Lin, T. J.; Ver Eecke, H. C.; Breves, E. A.; Dyar, M. D.; Jamieson, J. W.; Hannington, M. D.; Dahle, H.; Bishop, J. L.; Lane, M. D.; Butterfield, D. A.; Kelley, D. S.; Lilley, M. D.; Baross, J. A.; Holden, J. F.

    2016-02-01

    Rock and fluid samples were collected from three hydrothermal chimneys at the Endeavour Segment, Juan de Fuca Ridge to evaluate linkages among mineralogy, fluid chemistry, and microbial community composition within the chimneys. Mössbauer, midinfrared thermal emission, and visible-near infrared spectroscopies were utilized for the first time to characterize vent mineralogy, in addition to thin-section petrography, X-ray diffraction, and elemental analyses. A 282°C venting chimney from the Bastille edifice was composed primarily of sulfide minerals such as chalcopyrite, marcasite, and sphalerite. In contrast, samples from a 300°C venting chimney from the Dante edifice and a 321°C venting chimney from the Hot Harold edifice contained a high abundance of the sulfate mineral anhydrite. Geochemical modeling of mixed vent fluids suggested the oxic-anoxic transition zone was above 100°C at all three vents, and that the thermodynamic energy available for autotrophic microbial redox reactions favored aerobic sulfide and methane oxidation. As predicted, microbes within the Dante and Hot Harold chimneys were most closely related to mesophilic and thermophilic aerobes of the Betaproteobacteria and Gammaproteobacteria and sulfide-oxidizing autotrophic Epsilonproteobacteria. However, most of the microbes within the Bastille chimney were most closely related to mesophilic and thermophilic anaerobes of the Deltaproteobacteria, especially sulfate reducers, and anaerobic hyperthermophilic archaea. The predominance of anaerobes in the Bastille chimney indicated that other environmental factors promote anoxic conditions. Possibilities include the maturity or fluid flow characteristics of the chimney, abiotic Fe2+ and S2- oxidation in the vent fluids, or O2 depletion by aerobic respiration on the chimney outer wall.

  20. Solar thermal utilization--an overview

    Solar energy is an ideal renewable energy source and its thermal utilization is one of its most important applications. We review the status of solar thermal utilization, including: (1) developed technologies which are already widely used all over the world, such as solar assisted water heaters, solar cookers, solar heated buildings and so on; (2) advanced technologies which are still in the development or laboratory stage and could have more innovative applications, including thermal power generation, refrigeration, hydrogen production, desalination, and chimneys; (3) major problems which need to be resolved for advanced utilizaiton of solar thermal energy. (authors)

  1. Experimental Investigation of Two Modified Energy-Saving Constructions of Solar Greenhouses

    Ermuratskii, V; Oleschuk, V.; Blaabjerg, Frede

    2015-01-01

    The paper presents outcomes of experimental evaluation of operation of two structures of sustainable greenhouse systems. Thermal performance of greenhouse with on-ground heat accumulator and movable internal heat reflectors, and of greenhouse with under-ground accumulator and movable heat (roof-b......-based) reflectors, has been analyzed. Metering of solar irradiation, and temperature and humidity inside greenhouses, has been executed for different seasons and regimes. Conclusions regarding basic peculiarities of operation of two topologies of greenhouses have been formulated....

  2. Translucent load-bearing GFRP envelopes for daylighting and solar cell integration in building construction

    Pascual Agullo, Carlos

    2014-01-01

    This project investigates the light transmittance of load-bearing glass fiber-reinforced polymer (GFRP) laminates with a view to two architectural applications: the daylighting of buildings through load-bearing translucent GFRP envelopes and encapsulation of solar cells into the GFRP building skins of sandwich structures. The total and diffuse visible light transmittances of the laminates were experimentally investigated using a spectrophotometer coupled to an integrating sphere. The refracti...

  3. Construction of a Quadratic Model for Predicted and Measured Global Solar Radiation in Chile

    Ercan YILMAZ; Beatriz CANCINO; Edmundo LOPEZ

    2007-01-01

    @@ Global solar radiation data for sites in Chile are analysed and presented in a form suitable for their use in engineering. A new model for monthly average data is developed to predict monthly average global radiation with acceptable accuracy by using actinographic data due to scarcing of pyranometer data. Use of the new quadratic model is proposed because of its relatively wider spectrum of values for (A)ngstrom coefficients a0, a1,and a2.

  4. Influence of Chimney Flow Pattern on Natural Convection Heat Transfer of Open Channel Finned Plates

    Hong, Seung-Hyun; Chung, Bum-Jin [Kyung Hee University, Yongin (Korea, Republic of)

    2015-05-15

    The enhancement of the efficiency and effectiveness of the passive cooling system, have long been the topic of those studies. In this study, we investigated the heat transfer enhancement of finned plates, especially the chimney effect appeared in finned plates. The fin not only enlarges the heat transfer area but also draws fresh fluid from the open side of the channel composed of the base plate and fins, which further enhances the cooling capability of finned plate – a chimney flow pattern. This study aims at investigating the influence of the chimney flow pattern on the natural convection heat transfer of the finned plate. To analyze the phenomenological study, both experimental and numerical analyses were performed. Numerical analysis was performed for the natural convection heat transfer of a finned plate in an open channel. In order to investigate the influence of the chimney flow pattern the heat transfer, several fin height were simulated and compared. The temperature profiles varied drastically depending on the values of the Prandtl number. As the Prandtl number increases, the thermal boundary layer reduces.

  5. Influence of Chimney Flow Pattern on Natural Convection Heat Transfer of Open Channel Finned Plates

    The enhancement of the efficiency and effectiveness of the passive cooling system, have long been the topic of those studies. In this study, we investigated the heat transfer enhancement of finned plates, especially the chimney effect appeared in finned plates. The fin not only enlarges the heat transfer area but also draws fresh fluid from the open side of the channel composed of the base plate and fins, which further enhances the cooling capability of finned plate – a chimney flow pattern. This study aims at investigating the influence of the chimney flow pattern on the natural convection heat transfer of the finned plate. To analyze the phenomenological study, both experimental and numerical analyses were performed. Numerical analysis was performed for the natural convection heat transfer of a finned plate in an open channel. In order to investigate the influence of the chimney flow pattern the heat transfer, several fin height were simulated and compared. The temperature profiles varied drastically depending on the values of the Prandtl number. As the Prandtl number increases, the thermal boundary layer reduces

  6. Upward-migrating methane induced seismic chimney formation in the Nordland Group, Southern Viking Graben

    Kempka, Thomas; Unger, Victoria; Kühn, Michael

    2016-04-01

    The Nordland Group in the Southern Viking Graben hosts seismic chimneys, represented by anomalies in seismic data and determined by residual methane accumulations. These seismic chimneys are generally interpreted as focused fluid flow structures, and thus pose the risk of potential fluid leakage in geological subsurface utilization. The aim of the present study was to assess two popular scientific hypotheses on seismic chimney formation in the Nordland Group. The first one assumes excess pore pressure to result from buoyancy effects caused by upward-migrating methane and the development of a gas column with a thickness of several hundred meters, whereas the second one considers the load of the Fennoscandian ice sheet to be responsible for occurrence of hydraulic fracturing. In this context, we applied coupled hydromechanical simulations to determine the mechanism inducing the formation of these potential leakage pathways. Our simulation results demonstrate that hydraulic fracturing in the Nordland Group already occurs before the maximum methane column heights develop below. Consequently, the load of the Fennoscandian ice sheet is not initiating seismic chimneys formation.

  7. 78 FR 72060 - Chimney Rock National Monument Management Plan; San Juan National Forest; Colorado

    2013-12-02

    .... Forest Service (USFS) planning regulations (36 CFR part 219) as allowed by the transition provision of the 2012 forest planning regulations. The 1982 planning regulations are available at http://www.fs.fed...; ] DEPARTMENT OF AGRICULTURE Forest Service Chimney Rock National Monument Management Plan; San Juan...

  8. Geochemical processes and fluxes at a methane gas chimney on the Hikurangi Margin (New Zealand)

    Dale, A.; Haffert, L.; Hütten, E.; Crutchley, G.; Greinert, J.; de Haas, H.; de Stigter, H.; Bialas, J.

    2012-04-01

    The initial results presented in this study focus on the pore water geochemistry of Takahe methane seep located at 1050 m water depth on the Hikurangi Margin. The main objectives are to characterize and quantify the geochemical processes occurring in the upper meters of sediment. Parasound images of the study site showed a well-defined seismic blanking zone of around 230 m in diameter that is likely generated by trapped methane gas. At the northern edge of this seismic gas chimney bubble release has been observed by using hydroacoustic methods (singlebeam and multibeam echosounders). At the seafloor the more northern part of the chimney area showed white Beggiatoa bacterial mats and in places dark sediment patches due to geochemically reduced environments. No other "seep specific" fauna as tube worms or clams as well as no massive chemoherm carbonate where found in the area. This points towards a rather young seepage history. Geochemical data measured in 8 gravity cores across the gas chimney support this notion and gas hydrate layers several cm thick were observed in several cores. Sulphate and total alkalinity concentrations varied little from seawater values in the upper 50 to 100 cm towards the southerly end of the seismic gas chimney area; a feature attributed to irrigation by escaping methane gas bubbles. At these stations, the pore fluids were highly enriched in biogenic methane. However, the dissolved methane was mostly consumed anaerobically by sulphate, resulting in steep gradients of sulphate, methane, total alkalinity and hydrogen sulphide. Geochemical gradients at reference site immediately outside the chimney area were essentially vertical, indicating very little upwards transport and dissolution of methane. The geochemical data are applied to a numerical reaction-transport model to quantify the total upward flux of methane at each station and, ultimately, for the entire gas chimney. Temperature measurements of thermistor probes attached to the barrel

  9. Experimental and numerical characterization of wind-induced pressure coefficients on nuclear buildings and chimney exhausts

    Ricciardi, Laurent, E-mail: laurent.ricciardi@irsn.fr; Gélain, Thomas; Soares, Sandrine

    2015-10-15

    Highlights: • Experiments on scale models of nuclear buildings and chimney exhausts were performed. • Pressure coefficient fields on buildings are shown for various wind directions. • Evolution of pressure coefficient vs U/W ratio is given for various chimney exhausts. • RANS simulations using SST k–ω turbulence model were performed on most studied cases. • A good agreement is overall observed, with Root Mean Square Deviation lower than 0.15. - Abstract: Wind creates pressure effects on different surfaces of buildings according to their exposure to the wind, in particular at external communications. In nuclear facilities, these effects can change contamination transfers inside the building and can even lead to contamination release into the environment, especially in damaged (ventilation stopped) or accidental situations. The diversity of geometries of facilities requires the use of a validated code for predicting pressure coefficients, which characterize the wind effect on the building walls and the interaction between the wind and chimney exhaust. The first aim of a research program launched by the French Institut de Radioprotection et de Sûreté Nucléaire (IRSN), was therefore to acquire experimental data of the mean pressure coefficients for different geometries of buildings and chimneys through wind tunnel tests and then to validate a CFD code (ANSYS CFX) from these experimental results. The simulations were performed using a steady RANS approach and a two-equation SST k–ω turbulence model. After a mesh sensitivity study for one configuration of building and chimney, a comparison was carried out between the numerical and experimental values for other studied configurations. This comparison was generally satisfactory, averaged over all measurement points, with values of Root Mean Square Deviations lower than 0.15 for most cases.

  10. Origin of a native sulfur chimney in the Kueishantao hydrothermal field, offshore northeast Taiwan

    ZENG; ZhiGang; LIU; ChangHua; CHEN; ChenTung; A; YIN; XueBo; CHEN; DaiGeng; WANG; XiaoYuan; WANG; XiaoMei; ZHANG; GuoLiang

    2007-01-01

    Analyses of rare earth and trace element concentrations of native sulfur samples from the Kueishantao hydrothermal field were performed at the Seafloor Hydrothermal Activity Laboratory of the Key Laboratory of Marine Geology and Environment,Institute of Oceanology,Chinese Academy of Sciences.Using an Elan DRC II ICP-MS,and combining the sulfur isotopic compositions of native sulfur samples,we studied the sources and formation of a native sulfur chimney.The results show,when comparing them with native sulfur from crater lakes and other volcanic areas,that the native sulfur content of this chimney is very high (99.96%),the rare earth element (REE) and trace element constituents of the chimney are very low (ΣREE<21×10-9),and the chondrite-normalized REE patterns of the native sulfur samples are similar to those of the Kueishantao andesite,implying that the interaction of subseafloor fluid-andesite at the Kueishantao hydrothermal field was of short duration.The sulfur isotopic compositions of the native sulfur samples reveal that the sulfur of the chimney,from H2S and SO2,originated by magmatic degassing and that the REEs and trace elements are mostly from the Kueishantao andesite and partly from seawater.Combining these results with an analysis of the thermodynamics,it is clear that from the relatively low temperature (<116℃),the oxygenated and acidic environment is favorable for formation of this native sulfur chimney in the Kueishantao hydrothermal field.

  11. Experimental and numerical characterization of wind-induced pressure coefficients on nuclear buildings and chimney exhausts

    Highlights: • Experiments on scale models of nuclear buildings and chimney exhausts were performed. • Pressure coefficient fields on buildings are shown for various wind directions. • Evolution of pressure coefficient vs U/W ratio is given for various chimney exhausts. • RANS simulations using SST k–ω turbulence model were performed on most studied cases. • A good agreement is overall observed, with Root Mean Square Deviation lower than 0.15. - Abstract: Wind creates pressure effects on different surfaces of buildings according to their exposure to the wind, in particular at external communications. In nuclear facilities, these effects can change contamination transfers inside the building and can even lead to contamination release into the environment, especially in damaged (ventilation stopped) or accidental situations. The diversity of geometries of facilities requires the use of a validated code for predicting pressure coefficients, which characterize the wind effect on the building walls and the interaction between the wind and chimney exhaust. The first aim of a research program launched by the French Institut de Radioprotection et de Sûreté Nucléaire (IRSN), was therefore to acquire experimental data of the mean pressure coefficients for different geometries of buildings and chimneys through wind tunnel tests and then to validate a CFD code (ANSYS CFX) from these experimental results. The simulations were performed using a steady RANS approach and a two-equation SST k–ω turbulence model. After a mesh sensitivity study for one configuration of building and chimney, a comparison was carried out between the numerical and experimental values for other studied configurations. This comparison was generally satisfactory, averaged over all measurement points, with values of Root Mean Square Deviations lower than 0.15 for most cases

  12. The design, construction, and monitoring of photovoltaic power system and solar thermal system on the Georgia Institute of Technology Aquatic Center. Volume 1

    Long, R.C.

    1996-12-31

    This is a report on the feasibility study, design, and construction of a PV and solar thermal system for the Georgia Tech Aquatic Center. The topics of the report include a discussion of site selection and system selection, funding, design alternatives, PV module selection, final design, and project costs. Included are appendices describing the solar thermal system, the SAC entrance canopy PV mockup, and the PV feasibility study.

  13. Optical and structural characterization od titanium dioxide films used for construction of dye-sensitized solar cells

    The dye-sensitized solar cells are the most serious concept that could replace the silicon solar cells. These are low-cost photovoltaic, and represent a technology which could seriously decrease the cost of the electrical energy they produce. The dye-sensitized solar cells are composed of several layers of materials that belong to the group of inorganic semiconductors. For the efficiency improvement of these cells, there are two basic concepts of research regarding the construction materials. On one side, investigation of new materials that will, as a result of their physical and electrochemical characteristics, increase the cell efficiency, and on the other side, use of materials that will contribute to the long term stability of the cell in atmospheric conditions. As a part of this Master thesis, compact and meso porous Ti(>2 films for dye- sensitized solar cells have been prepared. The compact Ti02 films were deposited with the technique of spray pyrolysis, and the preparation of the meso porous films was made with a blade casting technique. The optical and structural analysis and characterization of the films was done with optical spectroscopy in the visible and ultraviolet spectral region (UV- Vis), Raman spectroscopy and atomic force microscopy (AFM). The crystal structure of the films, surface uniformity, thickness and grain size dependence on the deposition parameters was investigated, this led to calculation of the optical constants for the compact films, as well as the determination of the electron transitions and the determination of the bang gap energy. Also regarding the structure and porosity of the meso porous films, characterization of the quality of the film depending on the chemical composition of the paste used for deposition was made. As a result of the preformed investigations, through defining the structural and optical parameters of quality compact and meso porous TiC>2 films for dye-sensitized solar cells, the optimal parameters for film

  14. Novel Barite Chimneys at the Loki's Castle Vent Field Shed Light on Key Factors Shaping Microbial Communities and Functions in Hydrothermal Systems

    Steen, Ida H.; Dahle, Håkon; Stokke, Runar; Roalkvam, Irene; Daae, Frida-Lise; Rapp, Hans Tore; Pedersen, Rolf B.; Thorseth, Ingunn H.

    2016-01-01

    In order to fully understand the cycling of elements in hydrothermal systems it is critical to understand intra-field variations in geochemical and microbiological processes in both focused, high-temperature and diffuse, low-temperature areas. To reveal important causes and effects of this variation, we performed an extensive chemical and microbiological characterization of a low-temperature venting area in the Loki's Castle Vent Field (LCVF). This area, located at the flank of the large sulfide mound, is characterized by numerous chimney-like barite (BaSO4) structures (≤ 1 m high) covered with white cotton-like microbial mats. Results from geochemical analyses, microscopy (FISH, SEM), 16S rRNA gene amplicon-sequencing and metatranscriptomics were compared to results from previous analyses of biofilms growing on black smoker chimneys at LCVF. Based on our results, we constructed a conceptual model involving the geochemistry and microbiology in the LCVF. The model suggests that CH4 and H2S are important electron donors for microorganisms in both high-temperature and low-temperature areas, whereas the utilization of H2 seems restricted to high-temperature areas. This further implies that sub-seafloor processes can affect energy-landscapes, elemental cycling, and the metabolic activity of primary producers on the seafloor. In the cotton-like microbial mats on top of the active barite chimneys, a unique network of single cells of Epsilonproteobacteria interconnected by threads of extracellular polymeric substances (EPS) was seen, differing significantly from the long filamentous Sulfurovum filaments observed in biofilms on the black smokers. This network also induced nucleation of barite crystals and is suggested to play an essential role in the formation of the microbial mats and the chimneys. Furthermore, it illustrates variations in how different genera of Epsilonproteobacteria colonize and position cells in different vent fluid mixing zones within a vent field

  15. High Efficiency Quantum Well Waveguide Solar Cells and Methods for Constructing the Same

    Welser, Roger E. (Inventor); Sood, Ashok K. (Inventor)

    2014-01-01

    Photon absorption, and thus current generation, is hindered in conventional thin-film solar cell designs, including quantum well structures, by the limited path length of incident light passing vertically through the device. Optical scattering into lateral waveguide structures provides a physical mechanism to increase photocurrent generation through in-plane light trapping. However, the insertion of wells of high refractive index material with lower energy gap into the device structure often results in lower voltage operation, and hence lower photovoltaic power conversion efficiency. The voltage output of an InGaAs quantum well waveguide photovoltaic device can be increased by employing a III-V material structure with an extended wide band gap emitter heterojunction. Analysis of the light IV characteristics reveals that non-radiative recombination components of the underlying dark diode current have been reduced, exposing the limiting radiative recombination component and providing a pathway for realizing solar-electric conversion efficiency of 30% or more in single junction cells.

  16. Concentrated solar power on demand demonstration: Construction and operation of a 25 kW prototype

    Gil, Antoni; Codd, Daniel S.; Zhou, Lei; Trumper, David; Calvet, Nicolas; Slocum, Alexander H.

    2016-05-01

    Currently, the majority of concentrated solar power (CSP) plants built worldwide integrate thermal energy storage (TES) systems which enable dispatchable output and higher global plant efficiencies. TES systems are typically based on two tank molten salt technology which involves inherent drawbacks such as parasitic pumping losses and electric tracing of pipes, risk of solidification and high capital costs. The concept presented in this paper is based on a single tank where the concentrated sunlight is directly focused on the molten salt. Hot and cold volumes of salt (at 565 °C and 280 °C, respectively) are axially separated by an insulated divider plate which helps maintain the thermal gradient. The concept, based on existing technologies, seeks to avoid the listed drawbacks as well as reducing the final cost of the TES system. In order to demonstrate its feasibility, Masdar Institute (MI) and Massachusetts Institute of Technology are developing a 25 kW prototype to be tested in the Masdar Solar Platform beam down facility.

  17. A Contemporary Analysis of the O'Neill-Glaser Model for Space-Based Solar Power and Habitat Construction

    Curreri, Peter A.; Detweiler, Michael K.

    2011-01-01

    In 1975 Gerard O Neill published in the journal Science a model for the construction of solar power satellites. He found that the solar power satellites suggested by Peter Glaser would be too massive to launch economically from Earth, but could be financially viable if the workforce was permanently located in free space habitats and if lunar and asteroid materials were used for construction. All new worldwide electrical generating capacity could be then achieved by solar power satellites. The project would financially break even in about 20 years after which it would generate substantial income selling power below fossil fuel prices. Two NASA / Stanford University led studies at Ames Research center during the summers of 1974 and 1976 found the concept technically sound and developed a detailed financial parametric model. Although the project was not undertaken when suggested in the 1970s, several contemporary issues make pursuing the O Neill -- Glaser concept more compelling today. First, our analysis suggests that if in the first ten years of construction that small habitats (compared to the large vista habitats envisioned by O Neill) supporting approximately 300 people were utilized, development costs of the program and the time for financial break even could be substantially improved. Second, the contemporary consensus is developing that carbon free energy is required to mitigate global climate change. It is estimated that 300 GW of new carbon free energy would be necessary per year to stabilize global atmospheric carbon. This is about 4 times greater energy demand than was considered by the O Neill Glaser model. Our analysis suggests that after the initial investments in lunar mining and space manufacturing and transportation, that the profit margin for producing space solar power is very high (even when selling power below fossil fuel prices). We have investigated the financial scaling of ground launched versus space derived space solar power satellites. We

  18. Geochemistry and mineralogy of a silica chimney from an inactive seafloor hydrothermal field (East Pacific Rise, 18°S)

    Dekov, V.M.; Lalonde, S.V.; Kamenov, G.D.; Bayon, G.; Shanks, W. C.; Fortin, D.; Fouquet, Y.; Moscati, R.J.

    2015-01-01

    An inactive vent field comprised of dead chimneys was discovered on the ultrafast East Pacific Rise (EPR) at 18 degrees S during the research campaign NAUDUR with the R/V Le Nadir in December 1993. One of these chimneys was sampled, studied and found to be largely composed of silica-mineralized bacterial-like filaments. The filaments are inferred to be the result of microbial activity leading to silica (+/- Fe-oxyhydroxide) precipitation. The chimney grew from the most external layer (precipi...

  19. Design, construction, and testing of the Colorado State University Solar House I heating and cooling system. United States special format report

    Loef, G.O.G.; Ward, D.S.

    1976-06-01

    The primary objective of the project is the design, construction, testing, and evaluation of a practical system for utilizing solar energy to drive heating, cooling, and domestic hot water subsystems, supplemented as necessary with auxiliary fuel. System design was accomplished during the first five months (September 1973 to January 1974) and construction completed during the following five month period (February to June 1974). This report details the evaluation of the system's performance during the period 1 September 1974 through 31 August 1975. Efforts are now underway to modify and improve the performance of the solar system, and conduct a comparative evaluation of the original design and the modified system. (WDM)

  20. A study on thermo-hydraulic instability of boiling natural circulation loop with a chimney. 4. An analytical consideration of the stability and thermo-hydraulic characteristics in the chimney in high pressure

    Thermo-hydraulic instabilities of a boiling natural circulation loop with a chimney under high pressure were investigated using linear stability analysis. Drift-flux model was used for two-phase flow model. The instability regions as well as the thermo-hydraulic characteristics in the chimney such as wavy feature were examined, which were compared with the characteristics in low pressure. Instability could occur when exit quality was relatively low, which was the same manner as the characteristics in low pressure. In high-pressure, void was generated near channel exit, and void wave propagated in the chimney. In low pressure, steam was generated only near the chimney exit due to gravity induced flashing, and single-phase enthalpy wave, that is, temperature wave propagated in single-phase flow region. Though flow could be very stable in the high pressure and high power condition, the decay ratio of higher mode could be larger than that of lower mode. (author)

  1. Iron-sulfide-bearing chimneys as potential catalytic energy traps at life's emergence.

    Mielke, Randall E; Robinson, Kirtland J; White, Lauren M; McGlynn, Shawn E; McEachern, Kavan; Bhartia, Rohit; Kanik, Isik; Russell, Michael J

    2011-12-01

    The concept that life emerged where alkaline hydrogen-bearing submarine hot springs exhaled into the most ancient acidulous ocean was used as a working hypothesis to investigate the nature of precipitate membranes. Alkaline solutions at 25-70°C and pH between 8 and 12, bearing HS(-)±silicate, were injected slowly into visi-jars containing ferrous chloride to partially simulate the early ocean on this or any other wet and icy, geologically active rocky world. Dependent on pH and sulfide content, fine tubular chimneys and geodal bubbles were generated with semipermeable walls 4-100 μm thick that comprised radial platelets of nanometric mackinawite [FeS]±ferrous hydroxide [∼Fe(OH)(2)], accompanied by silica and, at the higher temperature, greigite [Fe(3)S(4)]. Within the chimney walls, these platelets define a myriad of micropores. The interior walls of the chimneys host iron sulfide framboids, while, in cases where the alkaline solution has a pH>11 or relatively low sulfide content, their exteriors exhibit radial flanges with a spacing of ∼4 μm that comprise microdendrites of ferrous hydroxide. We speculate that this pattern results from outward and inward radial flow through the chimney walls. The outer Fe(OH)(2) flanges perhaps precipitate where the highly alkaline flow meets the ambient ferrous iron-bearing fluid, while the intervening troughs signal where the acidulous iron-bearing solutions could gain access to the sulfidic and alkaline interior of the chimneys, thereby leading to the precipitation of the framboids. Addition of soluble pentameric peptides enhances membrane durability and accentuates the crenulations on the chimney exteriors. These dynamic patterns may have implications for acid-base catalysis and the natural proton motive force acting through the matrix of the porous inorganic membrane. Thus, within such membranes, steep redox and pH gradients would bear across the nanometric platelets and separate the two counter-flowing solutions

  2. Design construction and analysis of solar ridge concentrator photovoltaic (PV) system to improve battery charging performance.

    Narasimman, Kalaiselvan; Selvarasan, Iniyan

    2016-05-01

    A ridge concentrator photovoltaic system for a 10W multi-crystalline solar panel was designed with the concentration ratios of 1X and 2X. The ray tracing model of ridge concentrator photovoltaic system was carried out using Trace-Pro simulation. The optimum tilt angle for the concentrator PV system throughout the year was computed. The electrical parameters of the 3 panels were analyzed. The effect of temperature on the electrical performance of the panel was also studied. The reduction of voltage due to increasing panel temperature was managed by MPES type Charge controller. Glass reflector with reflectivity 0.95 was chosen as the ridge wall for the concentrator system. The maximum power outputs for the 1X and 2X panel reached were 9W and 10.5W with glass reflector. The percentage of power improvement for 1X and 2X concentrations were 22.3% and 45.8% respectively. The 2X concentrated panel connected battery takes lower time to charge compared with normal panel connected battery. PMID:26852396

  3. Scenarios for solar thermal energy applications in Brazil

    The Solar and Wind Energy Resource Assessment (SWERA) database is used to prepare and discuss scenarios for solar thermal applications in Brazil. The paper discusses low temperature applications (small and large scale water heating) and solar power plants for electricity production (concentrated solar power plants and solar chimney plants) in Brazil. The results demonstrate the feasibility of large-scale application of solar energy for water heating and electricity generation in Brazil. Payback periods for water heating systems are typically below 4 years if they were used to replace residential electric showerheads in low-income families. Large-scale water heating systems also present high feasibility and many commercial companies are adopting this technology to reduce operational costs. The best sites to set up CSP plants are in the Brazilian semi-arid region where the annual energy achieves 2.2 MW h/m2 and averages of daily solar irradiation are larger than 5.0 kW h/m2/day. The western area of Brazilian Northeastern region meets all technical requirements to exploit solar thermal energy for electricity generation based on solar chimney technology. Highlights: ► Scenarios for solar thermal applications are presented. ► Payback is typically below 4 years for small scale water heating systems. ► Large-scale water heating systems also present high feasibility. ► The Brazilian semi-arid region is the best sites for CSP and chimney tower plants.

  4. Assessing the influence of physical, geochemical and biological factors on anaerobic microbial primary productivity within hydrothermal vent chimneys.

    Olins, H C; Rogers, D R; Frank, K L; Vidoudez, C; Girguis, P R

    2013-05-01

    Chemosynthetic primary production supports hydrothermal vent ecosystems, but the extent of that productivity and its governing factors have not been well constrained. To better understand anaerobic primary production within massive vent deposits, we conducted a series of incubations at 4, 25, 50 and 90 °C using aggregates recovered from hydrothermal vent structures. We documented in situ geochemistry, measured autochthonous organic carbon stable isotope ratios and assessed microbial community composition and functional gene abundances in three hydrothermal vent chimney structures from Middle Valley on the Juan de Fuca Ridge. Carbon fixation rates were greatest at lower temperatures and were comparable among chimneys. Stable isotope ratios of autochthonous organic carbon were consistent with the Calvin-Benson-Bassham cycle being the predominant mode of carbon fixation for all three chimneys. Chimneys exhibited marked differences in vent fluid geochemistry and microbial community composition, with structures being differentially dominated by gamma (γ) or epsilon (ε) proteobacteria. Similarly, qPCR analyses of functional genes representing different carbon fixation pathways showed striking differences in gene abundance among chimney structures. Carbon fixation rates showed no obvious correlation with observed in situ vent fluid geochemistry, community composition or functional gene abundance. Together, these data reveal that (i) net anaerobic carbon fixation rates among these chimneys are elevated at lower temperatures, (ii) clear differences in community composition and gene abundance exist among chimney structures, and (iii) tremendous spatial heterogeneity within these environments likely confounds efforts to relate the observed rates to in situ microbial and geochemical factors. We also posit that microbes typically thought to be mesophiles are likely active and growing at cooler temperatures, and that their activity at these temperatures comprises the

  5. Active reduction of the dominant clear tone component of the noise pollution from power plant chimneys

    An investigation of a system for active reduction of an irritating dominant clear tone emitted as a part of the noise pollution from a power plant chimney is described. Experiments were carried out on a scale model with diameters 3-4 times less than the actual chimney. Reduction of 25-30 decibels was achieved in relation to the clear tone in the frequency range in connection with which it could be expected that the noise-muffling system would work. The system was also seen to be able to follow the expected variation in the noise signals and to be stable during a longer period of time. The theories on which the experiment was based, the experimental setup and measurement methods and results are presented. (AB)

  6. Scientific and Cost Effective Monitoring: The Case of an Aerial Insectivore, the Chimney Swift

    Sébastien Rioux

    2010-12-01

    Full Text Available The increased pace of species listing worldwide, coupled with the scarcity of conservation funding, promote the use of targeted monitoring. We applied the recommendations of Nichols and Williams (Trends in Ecology and Evolution 2006 24:668-673 to optimize the Québec Chimney Swift Monitoring Program, an ongoing volunteer-based monitoring initiative launched in 1998. Past objectives of the program were to fill knowledge gaps about occupancy patterns at roosts sites, determine spatial and temporal distribution of Chimney Swifts (Chaetura pelagica across the province, locate active nest sites, and monitor temporal fluctuations of the population. By applying an adaptive management framework, we modified the current monitoring scheme into a more focused initiative testing newly developed hypotheses about the state of the system. This new approach yielded significant scientific gains as well as annual savings of 19.6%. It may prove pertinent to current and future swift monitoring initiatives and to other aerial insectivore species.

  7. Barometric pressure transient testing applications at the Nevada Test Site. Nuclear chimney analysis. Final report

    Hanson, J.M.

    1985-12-01

    Investigations of barometric pressure testing of NTS nuclear chimneys were reviewed. This review includes the models used in the interpretation, methods of analysis, and results. Analytic and semi-analytic models were presented and applied to both historical data and new data taken for this current project. An interpretation technique based on non-linear least squares methods was used to analyze this data in terms of historic and more recent chimney models. Finally, a detailed discussion of radioactive gas transport due to surface barometric pressure fluctuations was presented. This mechanism of transport, referred to as ''barometric pumping,'' is presented in terms of conditions likely to be encountered at the NTS. The report concludes with a discussion of the current understanding of gas flow properties in the alluvial and volcanic areas of the NTS, and suggestions for future efforts directed toward increasing this understanding are presented.

  8. Barometric pressure transient testing applications at the Nevada Test Site. Nuclear chimney analysis. Final report

    Investigations of barometric pressure testing of NTS nuclear chimneys were reviewed. This review includes the models used in the interpretation, methods of analysis, and results. Analytic and semi-analytic models were presented and applied to both historical data and new data taken for this current project. An interpretation technique based on non-linear least squares methods was used to analyze this data in terms of historic and more recent chimney models. Finally, a detailed discussion of radioactive gas transport due to surface barometric pressure fluctuations was presented. This mechanism of transport, referred to as ''barometric pumping,'' is presented in terms of conditions likely to be encountered at the NTS. The report concludes with a discussion of the current understanding of gas flow properties in the alluvial and volcanic areas of the NTS, and suggestions for future efforts directed toward increasing this understanding are presented

  9. An Assessment of Water Demand and Availability to meet Construction and Operational Needs for Large Utility-Scale Solar Projects in the Southwestern United States

    Klise, G. T.; Tidwell, V. C.; Macknick, J.; Reno, M. D.; Moreland, B. D.; Zemlick, K. M.

    2013-12-01

    In the Southwestern United States, there are many large utility-scale solar photovoltaic (PV) and concentrating solar power (CSP) facilities currently in operation, with even more under construction and planned for future development. These are locations with high solar insolation and access to large metropolitan areas and existing grid infrastructure. The Bureau of Land Management, under a reasonably foreseeable development scenario, projects a total of almost 32 GW of installed utility-scale solar project capacity in the Southwest by 2030. To determine the potential impacts to water resources and the potential limitations water resources may have on development, we utilized methods outlined by the Bureau of Land Management (BLM) to determine potential water use in designated solar energy zones (SEZs) for construction and operations & maintenance (O&M), which is then evaluated according to water availability in six Southwestern states. Our results indicate that PV facilities overall use less water, however water for construction is high compared to lifetime operational water needs. There is a transition underway from wet cooled to dry cooled CSP facilities and larger PV facilities due to water use concerns, though some water is still necessary for construction, operations, and maintenance. Overall, ten watersheds, 9 in California, and one in New Mexico were identified as being of particular concern because of limited water availability. Understanding the location of potentially available water sources can help the solar industry determine locations that minimize impacts to existing water resources, and help understand potential costs when utilizing non-potable water sources or purchasing existing appropriated water. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract

  10. Diffusion of solar energy technologies in the new-construction market: a survey of new solar-home and onventional-home buyers

    Rains, D.; Dunipace, D.; Woo, C.K.

    1981-02-01

    Comsumer motivations for choosing a solar energy equipped new home when the non-solar or conventional model was also available were investigated. The approach was to test the relative importance of demographic, dwelling unit, and heating system characteristics in household decisions to purchase a home equipped with solar energy devices. Two statistical models were developed: one to examine the relationship between the types of home buyers (as an identifiable market segment) and the decision to purchase a solar home, and the other to compare the energy use of solar vs. conventional homes selected in the sample. (MHR)

  11. Uranium prospecting in alkaline mountain chimneys of Serra Negra and Salitre - Minas Gerais, Brasil

    The occurence of radioactive minerals such as apatite and pyrochlore, in the alkaline chimneys of Serra Negra and Salitre (Minas Gerais, Brazil), is discussed. Also mentioned are other minerals of interest associated with the alkaline magma such as columbite, fluorite, monazite, zircon, baddeleyite, etc, which in favourable conditions may occur in deposits of great economical value, and which may present high contents of rare earths, thorium and uranium

  12. Scientific and Cost Effective Monitoring: The Case of an Aerial Insectivore, the Chimney Swift

    Sébastien Rioux; Savard, Jean-Pierre L.; François Shaffer

    2010-01-01

    The increased pace of species listing worldwide, coupled with the scarcity of conservation funding, promote the use of targeted monitoring. We applied the recommendations of Nichols and Williams (Trends in Ecology and Evolution 2006 24:668-673) to optimize the Québec Chimney Swift Monitoring Program, an ongoing volunteer-based monitoring initiative launched in 1998. Past objectives of the program were to fill knowledge gaps about occupancy patterns at roosts sites, determine spatial and tempo...

  13. Lung function in woodsmoke-exposed Guatemalan children following a chimney stove intervention.

    Heinzerling, AP; Guarnieri, MJ; Mann, JK; Diaz, JV; Thompson, LM; Diaz, A.; Bruce, NG; Smith, KR; Balmes, JR

    2016-01-01

    Household air pollution (HAP) from solid fuel combustion is a major contributor to the global burden of disease, with considerable impact from respiratory infections in children. The impact of HAP on lung function is unknown.The Childhood Exposure to Respirable Particulate Matter (CRECER) prospective cohort study followed Guatemalan children who participated in the Randomised Exposure Study of Pollution Indoors and Respiratory Effects (RESPIRE) trial of a chimney stove intervention to determi...

  14. Framework for the Energetic Assessment of South and South-East Asia Fixed Chimney Bull’s Trench Kiln

    Brun Niccolò Le

    2016-01-01

    Full Text Available One of the major sources of fuel consumption and greenhouse gas emission in South and South-East Asia is brick manufacturing. One of the most commonly implemented technologies for brick manufacturing in this region is the fixed chimney Bull’s trench kiln (FCBTK. This type of technology largely depends on manual labour and is very inefficient when compared to more modern technologies. Because the adoption of more advanced technologies is hindered by the socio-economical background, the much needed innovations in the brick sector are necessarily related to improving/modifying the FCBTK already operational. However, few scientific studies have been conducted on FCBTK probably due to the basic level of technological development. Such studies are however important to systematically and methodologically assess the challenges and solutions in FCBTK. In this study we develop a thermo-energetic model to evaluate the importance of the parameters pertained to FCBTK construction and operation. The prospective of this study is to build an initial thermo-energetic framework that will serve as a basis to investigate possible energetic improvements.

  15. The application of masonry chimney venting tables for oil-fired appliances

    Krajewski, R.F.; Strasser, J. [Brookhaven National Lab., Upton, NY (United States)

    1995-04-01

    This paper presents an overview of the results of work in developing a set of rational guidelines for the venting of modern oil-fired appliances. The activities included the continued development and completion of the Oil-Heat Vent Analysis Program (OHVAP), Version 1.0 and the interpretation of nearly 2,000 runs in preparing recommendations for presentation in table form. These results are presented in the form of venting tables for the installation of chimney vent systems for mid- and high-efficiency oil-fired heating appliances using masonry chimneys. A brief description of OHVAP is given as well as a discussion of what the program does. Recommendations based on the results of OHVAP are presented in the form of five tables spanning oil-fired appliance Steady state Efficiencies (Eff{sub ss}) of 80% to 88%. The assumptions used in the calculations and examples of the computed results are presented as well as a discussion of the rationale for masonry chimney system treatment. Working examples are given with suggested diagnostic approaches for application of the table recommendations.

  16. Continuous In Situ Measurements of Near Bottom Chemistry and Sediment-Water Fluxes with the Chimney Sampler Array (CSA)

    Martens, C. S.; Mendlovitz, H. P.; White, B. L.; Hoer, D.; Sleeper, K.; Chanton, J.; Wilson, R.; Lapham, L.

    2011-12-01

    The Chimney Sampler Array (CSA) was designed to measure in situ chemical and physical parameters within the benthic boundary layer plus methane and oxygen sediment-water chemical fluxes at upper slope sites in the northern Gulf of Mexico. The CSA can monitor temporal changes plus help to evaluate oceanographic and sub-seafloor processes that can influence the formation and stability of gas hydrates in underlying sediments. The CSA consists of vertical cylinders (chimneys) equipped with internal chemical sensors and with laboratory flume-calibrated washout rates. Chimney washout rates multiplied by chimney mean versus ambient concentrations allow calculation of net O2 and methane sediment-water fluxes. The CSA is emplaced on the seafloor by a ROVARD lander using a ROV for chimney deployments. The CSA presently includes two 30 cm diameter by 90 cm length cylinders that seal against the sediment with lead pellet beanbags; within each chimney cylinder are optode, conductivity and methane sensors. The CSA's data logger platform also includes pressure and turbidity sensors external to the chimneys along with an acoustic Doppler current meter to measure temporal variation in ambient current velocity and direction. The CSA was deployed aboard a ROVARD lander on 9/13/2010 in the northern Gulf of Mexico (Lat. 28 51.28440, Long. 088 29.39421) on biogeochemically active sediments within Block MC-118. A ROV was utilized for chimney deployment away from the ROVARD lander. The CSA monitored temporal changes in water column physical parameters, obtained near-bottom chemical data to compare with pore fluid and sediment core measurements and measured temporal variability in oxygen and methane sediment-water fluxes at two closely spaced stations at MC-118. A continuous, three-week data set was obtained that revealed daily cycles in chemical parameters and episodic flux events. Lower than ambient chimney dissolved O2 concentrations controlled by temporal variability in washout rates

  17. Biogeochemistry of Hydrothermal Chimney Environments: Continuous-Flow Experiments at in situ Temperature and Pressure

    Houghton, J.; Seyfried, W.; Reysenbach, A.; Banta, A.; von Damm, K.

    2002-12-01

    Recent interest in the existence of a subsurface microbial biosphere at hydrothermal vents has resulted in a plethora of new questions that might best be answered using interdisciplinary techniques that combine geochemistry, microbial ecology, and molecular biology. Ideally, such studies will quantitatively address issues concerning what organisms exist in the subsurface, what metabolisms are sustained in the hydrothermal environment, and what effects these active organisms might have on the nearby fluid and rock. We present a new experimental approach to studying these questions that enables monitoring of an active hydrothermal community of microbes in the presence of chimney material at in situ temperature and pressure. This apparatus is designed as a continuous-flow reactor from which fluid samples can be extracted during the course of the experiment to measure chemistry and biomass, and at the termination of an experiment solids can be extracted for analysis of mineralogical changes and microbial identification. Results of a series of experiments conducted using hydrothermal chimney material (solids and microbial community) collected from 21° N and 9° N East Pacific Rise are presented. At 70° C, a seawater-based fluid with additional NO3-, CO2(aq), and H2(aq) was reacted with chimney material from L vent, 9° N EPR. The fluid lost significant NO3-, PO43-, and gained SO42- even after accounting for the contribution from anhydrite dissolution. No significant sulfide or iron was observed in the fluid. Analysis of the DNA extracted from the solids at the termination of the experiment using partial 16S-rRNA sequence data revealed that the dominant bacteria were S-oxidizing tube worm endosymbionts, a S/NO3- reducing member of the Deferribacter genus, and a H2-oxidizing/NO3- reducing strain of Aquifex. Mineral analysis from before and after the experiment indicates the loss of pyrrhotite (FeS) and anhydrite (CaSO4), and the gain of an Fe-oxide phase tentatively

  18. Diffusion of solar energy technologies in the new-construction market: A survey of new solar-home and conventional-home buyers

    Rains, D.; Dunipace, D.; Woo, C. K.

    1981-02-01

    Consumer motivations for choosing a solar energy equipped home when the nonsolar or conventional model was available were investigated. The approach was to test the relative importance of demographic, dwelling unit, and heating system characteristics in household decisions to purchase a home equipped with solar energy devices. Two statistical models were developed: one to examine the relationship between the types of home buyers (as an identifiable market segment) and the decision to purchase a solar home; and the other to compare the energy use of solar vs. conventional homes selected in the sample.

  19. Microbial Primary Productivity in Hydrothermal Vent Chimneys at Middle Valley, Juan de Fuca Ridge

    Olins, H. C.; Rogers, D.; Frank, K. L.; Girguis, P. R.; Vidoudez, C.

    2012-12-01

    Chemosynthetic primary productivity supports hydrothermal vent ecosystems, but the extent of that productivity has not been well measured. To examine the role that environmental temperature plays in controlling carbon fixation rates, and to assess the degree to which microbial community composition, in situ geochemistry, and mineralogy influence carbon fixation, we conducted a series of shipboard incubations across a range of temperatures (4, 25, 50 and 90°C) and at environmentally relevant geochemical conditions using material recovered from three hydrothermal vent chimneys in the Middle Valley hydrothermal vent field (Juan de Fuca Ridge). Net rates of carbon fixation (CFX) were greatest at lower temperatures, and were similar among structures. Rates did not correlate with the mineralogy or the geochemical composition of the high temperature fluids at each chimney. No obvious patterns of association were observed between carbon fixation rates and microbial community composition. Abundance of selected functional genes related to different carbon fixation pathway exhibited striking differences among the three study sites, but did not correlate with rates. Natural carbon isotope ratios implicate the Calvin Benson Bassham Cycle as the dominant mechanism of primary production in these systems, despite the abundance of genes related to other pathways (and presumably some degree of activity). Together these data reveal that primary productivity by endolithic communities does not exhibit much variation among these chimneys, and further reveal that microbial activity cannot easily be related to mineralogical and geochemical assessments that are made at a coarser scale. Indeed, the relationships between carbon fixation rates and community composition/functional gene abundance were also likely obfuscated by differences in scale at which these measurements were made. Regardless, these data reveal the degree to which endolithic, anaerobic carbon fixation contributes to

  20. Improvement of the Vertical Dispersion of Pollutants Resulting From Chimneys by Thermosiphon Effect

    A. O.M. Mahmoud

    2006-01-01

    Full Text Available The dispersion of pollutants, resulting from industrial chimneys, in the surrounding atmosphere made the interest in realizing emitting conditions appears. It also encourages the vertical dispersion of these pollutants. At a given wind velocity, the height of this dispersion is essentially a function of the thermal power and the flow rate at the chimney exit. To improve these qualities, we propose a system that could be integrated to the industrial chimney exit. An open-ended vertical cylinder of larger diameter essentially constitutes this system. In order to determine the characteristics of the resulting flow, we simulated the problem in the laboratory while studying the evolution of a free thermal plume generated by a disk heated uniformly by the Joule effect at a constant temperature. The thermal plume expands in a quiet environment of isotherm temperature. To study the thermosiphon effect, we surrounded the plume source by a vertical cylinder opened at the extremities. Thermal radiation emitted by the hot disk heats the cylinder wall. The pressure drop due to the acceleration of the flow at the cylinder inlet causes the appearance of thermosiphon effect around the thermal plume. The analysis of the average fields of velocity and temperature shows that the thermosiphon effect entails a good homogenization of the flow at the system exit. Furthermore, the comparison of the results obtained at the exit of the two studied systems shows a relative increase of the flow rate and the thermal power absorbed by the air of the order of 50% under the thermosiphon effect. This result is expressed by a gain in the plume rise of the order of 40%.

  1. Retrieval columns of SO2 in industrial chimneys using DOAS passive in traverse

    Galicia Mejía, Rubén; de la Rosa Vázquez, José Manuel; Sosa Iglesias, Gustavo

    2011-10-01

    The optical Differential Optical Absorption Spectroscopy (DOAS) is a technique to measure pollutant emissions like SO2, from point sources and total fluxes in the atmosphere. Passive DOAS systems use sunlight like source. Measurements with such systems can be made in situ and in real time. The goal of this work is to report the implementation of hardware and software of a portable system to evaluate the pollutants emitted in the atmosphere by industrial chimneys. We show SO2 measurements obtained around PEMEX refinerys in Tula Hidalgo that enables the identification of their pollution degree with the knowledge of speed wind.

  2. Early Results of Chimney Technique for Type B Aortic Dissections Extending to the Aortic Arch

    Huang, Chen [Affiliated Hospital of Nantong University, Department of General Surgery (China); Tang, Hanfei; Qiao, Tong; Liu, Changjian; Zhou, Min, E-mail: 813477618@qq.com [The Affiliated Hospital of Nanjing University Medical School, Department of Vascular Surgery, Nanjing Drum Tower Hospital (China)

    2016-01-15

    ObjectiveTo summarize our early experience gained from the chimney technique for type B aortic dissection (TBAD) extending to the aortic arch and to evaluate the aortic remodeling in the follow-up period.MethodsFrom September 2011 to July 2014, 27 consecutive TBAD patients without adequate proximal landing zones were retrograde analyzed. Chimney stent-grafts were deployed parallel to the main endografts to reserve flow to branch vessels while extending the landing zones. In the follow-up period, aortic remodeling was observed with computed tomography angiography.ResultsThe technical success rate was 100 %, and endografts were deployed in zone 0 (n = 3, 11.1 %), zone 1 (n = 18, 66.7 %), and zone 2 (n = 6, 22.2 %). Immediately, proximal endoleaks were detected in 5 patients (18.5 %). During a mean follow-up period of 17.6 months, computed tomography angiography showed all the aortic stent-grafts and chimney grafts to be patent. Favorable remodeling was observed at the level of maximum descending aorta and left subclavian artery with expansion of true lumen (from 18.4 ± 4.8 to 25 ± 0.86 mm, p < 0.001 and 27.1 ± 0.62 to 28.5 ± 0.37 mm, p < 0.001) and depressurization of false lumen (from 23.7 ± 2.7 to 8.7 ± 3.8 mm, p < 0.001, from 5.3 ± 1.2 to 2.1 ± 2.1 mm, p < 0.001). While at the level of maximum abdominal aorta, suboptimal remodeling of the total aorta (from 24.1 ± 0.4 to 23.6 ± 1.5 mm, p = 0.06) and true lumen (from 13.8 ± 0.6 to 14.5 ± 0.4 mm, p = 0.08) was observed.ConclusionBased on our limited experience, the chimney technique with thoracic endovascular repair is demonstrated to be promising for TBAD extending to the arch with favorable aortic remodeling.

  3. Vallitalea pronyensis sp nova, isolated from a marine alkaline hydrothermal chimney

    Ben Aissa, F.; Postec, A.; Erauso, G.; Payri, Claude; Pelletier, Bernard; Hamdi, M.; Ollivier, Bernard; Fardeau, Marie-Laure

    2014-01-01

    A novel thermotolerant, anaerobic, Gram-stain-positive, spore-forming bacterium was isolated from a hydrothermal chimney in Prony Bay, New Caledonia. This strain, designated FatNl3(T), grew at 15-55 degrees C (optimum 30 degrees C) and at pH 5.8-8.9 (optimum 7.7). It was slightly halophilic, requiring at least 0.5% NaCl for growth (optimum 2.5-3.0 %), and was able to grow at up to 6% NaCl. Sulfate, thiosulfate, elemental sulfur, sulfite, nitrate and nitrite were not used as terminal electron ...

  4. Early Results of Chimney Technique for Type B Aortic Dissections Extending to the Aortic Arch

    ObjectiveTo summarize our early experience gained from the chimney technique for type B aortic dissection (TBAD) extending to the aortic arch and to evaluate the aortic remodeling in the follow-up period.MethodsFrom September 2011 to July 2014, 27 consecutive TBAD patients without adequate proximal landing zones were retrograde analyzed. Chimney stent-grafts were deployed parallel to the main endografts to reserve flow to branch vessels while extending the landing zones. In the follow-up period, aortic remodeling was observed with computed tomography angiography.ResultsThe technical success rate was 100 %, and endografts were deployed in zone 0 (n = 3, 11.1 %), zone 1 (n = 18, 66.7 %), and zone 2 (n = 6, 22.2 %). Immediately, proximal endoleaks were detected in 5 patients (18.5 %). During a mean follow-up period of 17.6 months, computed tomography angiography showed all the aortic stent-grafts and chimney grafts to be patent. Favorable remodeling was observed at the level of maximum descending aorta and left subclavian artery with expansion of true lumen (from 18.4 ± 4.8 to 25 ± 0.86 mm, p < 0.001 and 27.1 ± 0.62 to 28.5 ± 0.37 mm, p < 0.001) and depressurization of false lumen (from 23.7 ± 2.7 to 8.7 ± 3.8 mm, p < 0.001, from 5.3 ± 1.2 to 2.1 ± 2.1 mm, p < 0.001). While at the level of maximum abdominal aorta, suboptimal remodeling of the total aorta (from 24.1 ± 0.4 to 23.6 ± 1.5 mm, p = 0.06) and true lumen (from 13.8 ± 0.6 to 14.5 ± 0.4 mm, p = 0.08) was observed.ConclusionBased on our limited experience, the chimney technique with thoracic endovascular repair is demonstrated to be promising for TBAD extending to the arch with favorable aortic remodeling

  5. A novel large filamentous deltaproteobacterium on hydrothermally inactive sulfide chimneys of the Southern Mariana Trough

    Kato, Shingo; Yamagishi, Akihiko

    2016-04-01

    Unusual large filamentous bacteria (LFB) have been found on the deep seafloor environments. They play a significant role in geochemical cycling in the dark environments. However, our knowledge of the spatial distribution and phylogenetic diversity of the LFB on the deep seafloor are still limited due to the inaccessibility to these environments. Here, we report the discovery of a novel LFB on a hydrothermally inactive sulfide chimney in a deep-sea hydrothermal field of the Southern Mariana Trough. Light and electron microscopic observation showed that the width and total length of the LFB were >8 μm and >100 μm, respectively, of which morphology was similar to that of other known LFB such as "cable bacteria" of the Desulfobulbaceae. Analyses of a 16S rRNA gene clone library and fluorescence in situ hybridization revealed that this LFB belongs to the Desulfobulbaceae. The 16S rRNA gene of the LFB showed 94% similarity to those of the reported cable bacteria and cultured deltaproteobacterial species, suggesting that the LFB is a novel cable bacterium of the Desulfobulbaceae. The novel LFB potentially play a role in sulfur cycling on sulfide chimneys at the hydrothermally ceasing or even ceased deep-sea hydrothermal fields.

  6. Gas chimney detection based on improving the performance of combined multilayer perceptron and support vector classifier

    H. Hashemi

    2008-11-01

    Full Text Available Seismic object detection is a relatively new field in which 3-D bodies are visualized and spatial relationships between objects of different origins are studied in order to extract geologic information. In this paper, we propose a method for finding an optimal classifier with the help of a statistical feature ranking technique and combining different classifiers. The method, which has general applicability, is demonstrated here on a gas chimney detection problem. First, we evaluate a set of input seismic attributes extracted at locations labeled by a human expert using regularized discriminant analysis (RDA. In order to find the RDA score for each seismic attribute, forward and backward search strategies are used. Subsequently, two non-linear classifiers: multilayer perceptron (MLP and support vector classifier (SVC are run on the ranked seismic attributes. Finally, to capitalize on the intrinsic differences between both classifiers, the MLP and SVC results are combined using logical rules of maximum, minimum and mean. The proposed method optimizes the ranked feature space size and yields the lowest classification error in the final combined result. We will show that the logical minimum reveals gas chimneys that exhibit both the softness of MLP and the resolution of SVC classifiers.

  7. Performance of digester decant system with biological filter followed by constructed wetland and solar reactor in the treatment of domestic sewage

    Delfran Batista dos Santos

    2012-08-01

    Full Text Available This study aimed to analyze the performance of digester decant system with biological filter followed by constructed wetland and solar reactor in the treatment of domestic sewage from Milagres rural community in Apodi-RN. The treatment system was monitored for the period of October and November 2010, 48 days after planting Pennisetum purpureum Schumach. Samples of domestic sewage were collected at different stages of treatment, in four replications on time, to determine physicochemical and microbiological characteristics about the system performance. The results indicated significant removal of turbidity, biochemical oxygen demand, chemical oxygen demand, total solids, suspended solids, phosphorus and oil and grease using the set digester decant with biological filter, followed by constructed wetland and solar reactor; the association of average solar radiation of 28.73 MJ m-2 d-1, effluent depth of 0.10 m on reactor and time of sun exposure of 12 hours provided removal of fecal coliform up to 99.99% of domestic sewage in Apodi, RN, the treated effluent met microbiological standard of the Brazilian guidelines for agricultural use with restrictions.

  8. The Guaymas Basin Hiking Guide to Hydrothermal Mounds, Chimneys, and Microbial Mats: Complex Seafloor Expressions of Subsurface Hydrothermal Circulation

    Teske, Andreas; de Beer, Dirk; McKay, Luke J.; Margaret K. Tivey; Biddle, Jennifer F.; Hoer, Daniel; Lloyd, Karen G.; Lever, Mark A.; Røy, Hans; Albert, Daniel B.; Mendlovitz, Howard P.; MacGregor, Barbara J.

    2016-01-01

    The hydrothermal mats, mounds, and chimneys of the southern Guaymas Basin are the surface expression of complex subsurface hydrothermal circulation patterns. In this overview, we document the most frequently visited features of this hydrothermal area with photographs, temperature measurements, and selected geochemical data; many of these distinct habitats await characterization of their microbial communities and activities. Microprofiler deployments on microbial mats and hydrothermal sediment...

  9. General Strategy to Construct Hierarchical TiO2 Nanorod Arrays coupling with Plasmonic Resonance for Dye-sensitized Solar Cells

    Graphical abstract: The general strategy reported here will offer a facile approach to improve the electron transfer process via the construction of HTNRs, and to further enhance the light harvesting of dye molecules by introduction of SPR effects. Display Omitted -- Abstract: We demonstrate a general strategy to construct hierarchical TiO2 nanorod arrays (HTNRs) coupling with plasmon resonant metallic nanoparticles for dye-sensitized solar cells (DSCs). The electron transfer and interfacial recombination process have been optimized via the construction of photoanodes. Moreover, localized electric fields produced by the introduction of Au nanoparticles could excite dye molecules more effectively than the incident far-field light, resulting in further enhancement of light adsorption and photocurrent generation of DSCs. The synergistic effect of surface plasmon resonance (SPR) and constructed HTNRs has been investigated by optical spectroscopy, J-V, IPCE, EIS and OCVD measurements. An evidently improvement in energy conversion efficiency of the devices beyond 25% has been achieved via the cooperation of constructed HTNRs and SPR effects in DSCs

  10. Re-construction of global solar radiation time series from 1933 to 2013 at the Izaña Atmospheric Observatory

    R. D. García

    2014-04-01

    Full Text Available This paper presents the re-construction of the 80 year time series of daily global shortwave downward radiation (SDR at the subtropical high-mountain Izaña Atmospheric Observatory (IZO, Spain. For this purpose, we combine SDR estimates from sunshine duration (SD data using the Ångström–Prescott method over the 1933/1991 period, and SDR observations directly performed by pyranometers between 1992 and 2013. Since SDR measurements have been used as a reference, a strict quality control has been applied, when it was not possible data have been re-calibrated by using the LibRadtran model. By comparing to high quality SDR measurements, the precision and consistency over time of SDR estimations from SD data have successfully been documented. We obtain a overall root mean square error (RMSE of 9.2% and an agreement between the variances of SDR estimations and SDR measurements within 92% (correlation coefficient of 0.96. Nonetheless, this agreement significantly increases when the SDR estimation is done considering different daily fractions of clear sky (FCS. In that case, RMSE is reduced by half, up to about 4.5%, when considering percentages of FCS > 40% (90% of days in the testing period. Furthermore, we prove that the SDR estimations can monitor the SDR anomalies in consistency with SDR measurements and, then, can be suitable for re-constructing solar radiation time series. The re-constructed IZO global SDR time series between 1933 and 2013 confirms discontinuities and periods of increases/decreases of solar radiation at Earth's surface observed at a global scale, such as the early brightening, dimming and brightening. This fact supports the consistency of the IZO SDR time series presented in this work, which may be a reference for solar radiation studies in the subtropical North Atlantic region.