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1

Solar chimney  

International Nuclear Information System (INIS)

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)

2004-06-01

2

Inclined solar chimney for power production  

International Nuclear Information System (INIS)

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.

2011-09-01

3

Inclined solar chimney for power production  

Energy Technology Data Exchange (ETDEWEB)

Highlights: {yields} Solar energy harnessing using inclined face of high mountains as solar chimney. {yields} Solar chimneys with structural stability, ease of construction and lower cost. {yields} Mathematical model developed, using complete (mechanical and thermal) energy balance. {yields} Can harness wind power also, as wind velocities at mountain top add to power output. {yields} 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.

Panse, S.V., E-mail: sudhirpanse@yahoo.com [Institute of Chemical Technology, Matunga, Mumbai 400 019 (India); Jadhav, A.S.; Gudekar, A.S. [Institute of Chemical Technology, Matunga, Mumbai 400 019 (India); Joshi, J.B. [Institute of Chemical Technology, Matunga, Mumbai 400 019 (India); Homi Bhabha National Institute, Trombay, Mumbai 400 094 (India)

2011-09-15

4

Analyzes of solar chimney design  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The aim of this work to study the solar chimney installed in the EPT-lab of the NTNU. The work starts with the development of a CFD model of the solar chimney and comparing with the experimental data, showing a good accuracy of the CFD results. The CFD model is used to compare three types of solar chimneys for different heights and width; obtained that the chimney installed in the EPT-lab gets higher flow rates in the most of the most of the cases. The CFD model shows a uniform temperature an...

Pa?ez Ortega, Eli?as

2011-01-01

5

Analyzes of Solar Chimney Design  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The aim of this work to study the solar chimney installed in the EPT-lab of the NTNU. The work starts with the development of a CFD model of the solar chimney and comparing with the experimental data, showing a good accuracy of the CFD results. The CFD model is used to compare three types of solar chimneys for different heights and width; obtained that the chimney installed in the EPT-lab gets higher flow rates in the most of the most of the cases. The CFD model shows a uniform temperature an...

Paez Ortega, Elias

2011-01-01

6

Solar chimney - overall efficiency, design and performance  

Energy Technology Data Exchange (ETDEWEB)

An analysis is developed for the solar chimney, aimed particularly at deriving overall efficiency and significant performance data. Numerical values are consistent with available information on the 200 m solar chimney at Manzanares, Spain, and projected designs. Overall efficiency is directly related to the height of the chimney and is shown to be about 1% for a height of 1000 m. It is concluded that the solar chimney is essentially a power generator of large scale.

Mullett, L.B.

1987-01-01

7

Parameterization Studies of Solar Chimneys in the Tropics  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 outpu...

Alex Yong Kwang Tan; Nyuk Hien Wong

2013-01-01

8

A simple theoretical model of a solar chimney  

International Nuclear Information System (INIS)

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

2006-12-01

9

A mathematical model of a solar chimney  

Energy Technology Data Exchange (ETDEWEB)

A simple mathematical model of a solar chimney is proposed. The physical model is similar to the Trombe wall. One side of the chimney is provided with a glass cover which with the other three solid walls of the chimney form a channel through which the heated air could rise and flow by natural convection. Openings provided at the bottom and top of the chimney allow room air to enter and leave the channel. Steady state heat transfer equations were set up to determine the boundary temperatures at the surface of the glass cover, the rear solar heat absorbing wall and the air flow in the channel using a thermal resistance network. The equations were solved using a matrix-inversion solution procedure. The thermal performance of the solar chimney as determined from the glass, wall and air temperatures, air mass flow rate and instantaneous heat collection efficiency of the chimney are presented. Satisfactory correlation was obtained with experimental data from other investigators. Further experimental investigation is currently under way. (author)

Ong, K.S. [Monash University, Petaling Jaya (Malaysia)

2003-06-01

10

Parameterization Studies of Solar Chimneys in the Tropics  

Directory of Open Access Journals (Sweden)

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.

Alex Yong Kwang Tan

2013-01-01

11

DESIGN OF A SMALL ? SCALE SOLAR CHIMNEY FOR SUSTAINABLE POWER  

Science.gov (United States)

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....

12

A performance analysis of solar chimney thermal power systems  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 tr...

Al-Dabbas Awwad Mohammed

2011-01-01

13

Solar prototype developments in Spain show great promise. [Solar chimney: combination of solar and wind  

Energy Technology Data Exchange (ETDEWEB)

A successful 200-meter solar chimney surrounded by 225-meter diameter plastic-covered area, and rotor turbines in the chimney base takes advantage of three concepts: greenhouse heating, chimney, and windmill. A joint effort, the chimney is located in Spain, designed by Germans, and funded by both countries. Details of the chimney design are followed by a report on other solar and wind projects in Spain. 6 photographs. (DCK)

Richards, R.

1982-04-01

14

Analytical Analysis of Roof Top Solar Chimney for Power Generation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The solar chimney is a technology, which has been already proved of being capable to generate electrical energy from the sun. On the other hand, the solar chimney has been used on the roof of housing for ventilation purpose. Since the sun is not available during night and cloudy days, there should be another source of input to guarantee continuous operation of the system. Present study is the development of experimental, computational and mathematical models of ?On Roof Solar Chimney...

Sreejaya, K. V.; Al-kayiem, Hussain H.; Syed Ihtsham Ul-Haq Gilani

2011-01-01

15

Solar Chimney Model Parameters to Enhance Cooling PV Panel Performance  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

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

2013-01-01

16

Experimental study and simulation of airflow in solar chimneys  

Energy Technology Data Exchange (ETDEWEB)

With the depletion of traditional energies, new technologies are arising that use renewable energies. The aim of this paper is to present a study of airflow in solar chimneys. Mathematical simulation and experiments were carried out on solar chimneys with different geometries. It was found that the width of the channel and the angle of inclination of the chimney influence the field speed. A case study was then carried out on a solar chimney in Ouargla Province, Algeria, to assess the impact of a chimney's inclination on its performance. The simulation was conducted using a finite volume method in Fluent 6.3.26 computer software. A good match between experimental and simulation results was found. This paper presented a study on airflow in solar chimney and demonstrated that simulations using Fluent and the finite element method were able to provide good results.

Saifi, Nadia; Dokkar, Boubekeur; Negrou, Belkhir; Settou, Noureddine [Laboratory for Bioressources Saharan Preservation and Enhancement, University of Kasdi Merbah (Algeria)], e-mail: saifi.nadia2009@gmail.com

2011-07-01

17

Simulation of a sloped solar chimney power plant in Lanzhou  

International Nuclear Information System (INIS)

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.

2011-06-01

18

Modeling of window-sized solar chimneys for ventilation  

Energy Technology Data Exchange (ETDEWEB)

The mathematical model for predicting airflow velocity in a solar chimney has been developed through predicting temperature of the absorber, air in flow channel and glass cover. Experimental validation of the model has been done using a solar chimney having less than a 1-m-high absorber. Investigations have been carried out with three different combinations of air gap and size of the inlet opening for entry of air in the chimney. Good agreement between observed and calculated results has been obtained. The small size of the analyzed solar chimney has opened possibilities of utilizing windows as solar chimneys since the flow velocity up to 0.24m/s has been experimentally recorded. (author)

Bansal, N.K. [Center for Energy Studies, Indian Institute of Technology, N. Delhi (India); Mathur, Jyotirmay; Mathur, Sanjay; Jain, Meenakshi [Malaviya National Institute of Technology, Jaipur (India)

2005-10-01

19

Performance of a Solar Chimney Under Egyptian Weather Conditions: Numerical Simulation and Experimental Validation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

High solar radiation and ambient temperature, and large desert in Egypt are excellent conditions to install efficiently solar chimney power plants there. Therefore this research aimed to develop a validated mathematical model and governing equations of solar chimney. It is proposed to improve the performance of solar chimney under effects of various parameters, and study of possibility of installing solar chimney in Egypt. The mathematical simulation of the solar chimney has been developed in...

Mostafa, A. A.; Sedrak, M. F.; Abdel Dayem, Adel M.

2011-01-01

20

A Review of solar Chimney Power Generation Technology  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The present paper presents an overview of the main characteristics of a novel kind of solar thermal application called solar chimney power plant. It is a technology of electric power generation using solar energy by employing basic physics that when air is heated it rises. The created updraft can be used to turn a turbine placed at an appropriate position within a tall chimney to generate electricity. The paper discusses the principles and characteristics of such a system, its requirements, i...

2013-01-01

 
 
 
 
21

Ventilation impact of a solar chimney on indoor temperature fluctuation and air change in a school building  

Energy Technology Data Exchange (ETDEWEB)

The aim of this research was to investigate, experimentally, both the feasibility of a solar chimney to reduce heat gain in a house by inducing natural ventilation and the effect of openings (door, window and inlet of solar chimney) on the ventilation rate. The study was conducted using a single-room school house of approximately 25 m{sup 3} volume. The southern wall was composed of three different solar chimney configurations of 2 m{sup 2} each, whereas, the roof southern side included two similar units of 1.5 m{sup 2} each of another solar chimney configuration. Those configurations were built by using common construction materials. Experimental observations indicated that when the solar chimney ventilation system was in use, room temperature was near that of the ambient air, indicating a good ability of the solar chimney to reduce house's heat gain and ensuring thermal comfort. The hourly air change rate varied between 8-15. Opening the window and door is less efficient than using solar chimneys, as temperature difference between room and ambient was higher than that obtained with solar chimneys. (author)

Khedari, J.; Boonsri, B.; Hirunlabh, J. [Energy Technology Division, School of Energy and Materials, King Mongkut' s University of Technology Thonburi, Bangkok (Thailand)

2000-07-01

22

Power generation from wind turbines in a solar chimney  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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/co...

Tudor Foote, Ramesh K. Agarwal

2013-01-01

23

Experimental study for natural ventilation on a solar chimney  

Energy Technology Data Exchange (ETDEWEB)

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)

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

24

Solar Chimney Model Parameters to Enhance Cooling PV Panel Performance  

Directory of Open Access Journals (Sweden)

Full Text Available 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 ambient wind velocity on the photovoltaic panel. Second, analysis air velocities at different points in solar cooling chimney are predicted and the temperature drop also estimated to predicted air velocities in the duct. Finally, from simulation result it was found for chimney height range 0.3 m - 3 m and at 60 oC, the air velocity increase from 0.6 to 1.78 m/s and Pressure difference between inlet and outlet increase from 0.5 to 5.3 KPa, which improve the PV panel voltage 8%.

Mohammed Sh Elden

2013-01-01

25

Analytical Analysis of Roof Top Solar Chimney for Power Generation  

Directory of Open Access Journals (Sweden)

Full Text Available The solar chimney is a technology, which has been already proved of being capable to generate electrical energy from the sun. On the other hand, the solar chimney has been used on the roof of housing for ventilation purpose. Since the sun is not available during night and cloudy days, there should be another source of input to guarantee continuous operation of the system. Present study is the development of experimental, computational and mathematical models of ?On Roof Solar Chimney? for small-scale power generation. The objective of the present study is to review the similar works and to present a mathematical model of a solar chimney operation and analyze the analytical result. The model involves the energy and mass transportation in the system under steady state conditions. Heat transfer equations were set up to determine the boundary temperatures at the surface of the glass cover, the rear solar heat absorbing wall and the air flow in the channel using a thermal resistance network. Results showed the transient behavior of the system during the day. With model area of 15 m2, the highest velocity of 0.17 m sec-1 is predicted at around the mid day time. The mass flow rate increases as the solar radiation increase. The area is a vital parameter in the successful application of the technique. Also enhancement technique to rise up the collector temperature would improve the performance considerably.

K.V. Sreejaya

2011-01-01

26

A performance analysis of solar chimney thermal power systems  

Directory of Open Access Journals (Sweden)

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.

Al-Dabbas Awwad Mohammed

2011-01-01

27

State and recent advances in research and design of solar chimney power plant technology  

Energy Technology Data Exchange (ETDEWEB)

In solar chimney power plants the air under the glass-covered collector is heated by solar radiation, and then released via a central chimney into great atmospheric heights. This mass-stream of warm air drives turbo-generators in the chimney foot producing electricity. The article describes recent progresses in research and development of this technology applicable primarily in arid zones. (orig.)

Backstroem, T.W. von; Kroeger, D.G. [Stellenbosch Univ. (South Africa); Harte, R. [Wuppertal Univ. (Germany); Hoeffer, R. [Bochum Univ. (Germany); Kraetzig, W.B. [Kraetzig und Partners, Bochum (Germany); Niemann, H.J. [Niemann und Partners, Bochum (Germany); Zijl, G.P.A.G. van [Stellenbosch Univ. (South Africa); Technische Univ. Delft (Netherlands)

2008-07-01

28

Performance of a Solar Chimney Under Egyptian Weather Conditions: Numerical Simulation and Experimental Validation  

Directory of Open Access Journals (Sweden)

Full Text Available High solar radiation and ambient temperature, and large desert in Egypt are excellent conditions to install efficiently solar chimney power plants there. Therefore this research aimed to develop a validated mathematical model and governing equations of solar chimney. It is proposed to improve the performance of solar chimney under effects of various parameters, and study of possibility of installing solar chimney in Egypt. The mathematical simulation of the solar chimney has been developed including all its performance parameters, dimensions (of collector, chimney and turbine and the metrological data; which were considered as inputs of the simulation program. A comparison between the mathematical and experimental performance has been investigated to validate the mathematical simulation. The mathematical model has been used to predict the performance of the solar chimney power plant over a year in Egypt. It is used to study of effects of geometrical parameters, and investigate possibility of the optimum geometrical dimensions. It is obtained that there is in fact no optimum physical size for such plants without considering the economical constraints. The chimney height has a significant effect in the chimney performance. Visualizing of annual performance of the solar chimney would seem to be essentially a power generator in Egypt if it installed in a large scale.Key words: Solar chimney; Numerical simulation; Annual performance; Experimental validation; Optimization

A. A. Mostafa

2011-02-01

29

Experimental investigations on solar chimney for room ventilation  

Energy Technology Data Exchange (ETDEWEB)

Experimental investigations on a small size solar chimney show that the rate of ventilation increases with increase of the ratio between height of absorber and gap between glass and absorber. This finding is in agreement with results of the steady-state mathematical model developed for analysis of such systems. Nine different combination of absorber height and air gap have been investigated on the experimental set-up. Highest rate of ventilation induced with the help of solar energy was found to be 5.6 air change per hour in a room of 27m{sup 3}, at solar radiation 700W/m{sup 2} on vertical surface with the stack height-air gap ratio of 2.83 for a 1m high chimney. (author)

Mathur, Jyotirmay; Mathur, Sanjay; Jain, Meenakshi; Anupma, [Malaviya National Institute of Technology, Jaipur 302 017 (India); Bansal, N.K. [Center for Energy Studies, Indian Institute of Technology, New Delhi 110 016 (India)

2006-08-15

30

Chimney engineering manual. Furnaces and flues. Planning - calculation - construction. Handbuch der Schornsteintechnik. Feuerungsanlagen und Abgassysteme. Planung - Berechnung - Ausfuehrung  

Energy Technology Data Exchange (ETDEWEB)

The manual informs about the present state of the art of residential furnaces, chimneys, and flues. Innovative flue gas systems are described in detail. 13 chapters showing various pictures and diagrams deal with the following subjects: historical development of chimney construction; fundamentals of chimney engineering; chimney systems; chimneys and buildings; chimneys and heating systems; air/flue gas/chimney systems (LAS systems - Luft-Abgas-Schornsteinsysteme) for gas-fired heating systems which are independent of room air; high-efficiency boilers - appliances and flues; fireplace installation and flues; detached chimneys; retrofitting of chimneys; cost of chimneys; pollution control; building regulations, standards, guidelines. The fundamental manual is a valuable help in the selection, planning, and construction of modern chimneys. (HWJ) With 179 figs.

Hausladen, G.

1988-01-01

31

An experimental investigation of a solar chimney model with uniform wall heat flux  

Energy Technology Data Exchange (ETDEWEB)

Experiments were carried out using an experimental solar chimney model with uniform heat flux on one chimney wall with a variable chimney gap-to-height ratio between 1:15 and 2:5 and different heat flux and inclination angles. Results showed that a maximum airflow rate was achieved at an inclination angle around 45{sup o} for a 200 mm gap and 1.5 m high chimney, and the airflow rate is about 45% higher than that for a vertical chimney at otherwise identical conditions. It was found that the prediction method available in the literature can substantially overpredict the airflow rate for the chimney geometry investigated in this work, especially for vertical chimneys with large gaps. The main reason for the overprediction of airflow rate was shown due to the underestimation of the pressure losses at the chimney outlet by using loss coefficients obtained for normal forced flows. (author)

Chen, Z.D.; Bandopadhayay, P. [CSIRO Manufacturing and Infrastructure Technology, Highett, Vic. (Australia). Energy and Thermofluids Engineering; Halldorsson, J.; Byrjalsen, C.; Heiselberg, P. [Aalborg Univ. (Denmark). Indoor Environmental Engineering; Li, Y. [Hong Kong Univ. (China). Dept. of Mechanical Engineering

2003-07-01

32

Power generation from wind turbines in a solar chimney  

Energy Technology Data Exchange (ETDEWEB)

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.

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

33

Power generation from wind turbines in a solar chimney  

Directory of Open Access Journals (Sweden)

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 – ? 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.

Tudor Foote, Ramesh K. Agarwal

2013-01-01

34

Solar chimney power generation project - The case for Botswana  

International Nuclear Information System (INIS)

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)

2008-09-01

35

Review on the Enhancement Techniques and Introduction of an Alternate Enhancement Technique of Solar Chimney Power Plant  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Due to the low plant efficiency associated with Solar Chimney Power Plant, there is a need for the plant performance enhancement. This study presents the enhancement techniques of solar chimney power plant. It reviews previous works that had been done in performance enhancement of solar chimney power plants. It also, introduces an alternative approach to enhance the solar chimney performance by hybridizing the solar operation mode and waste heat energy from flue gas. The new idea is to conver...

Aja Ogboo Chikere; Al-kayiem, Hussain H.; Zainal Ambri Abdul Karim

2011-01-01

36

Turbines and generators for floating solar chimney power stations  

Energy Technology Data Exchange (ETDEWEB)

Floating solar air turbine power stations (FSCPS) are typically comprised of 3 components: (1) a large circular solar collector, (2) a tall chimney, and (3) a set of shrouded air turbines geared to appropriate electric generators around the bottom of the solar chimney. The FSCPS is a discrete system capable of converting solar power to electric power. This paper investigated FSCPSs connected to the electric grid using doubly fed induction generators (DFIGs) to control output under various levels of solar irradiance. The study considered rated operation of the FSCPSs as well as operation of the FSCPS with squirrel cage induction generators. The study included an evaluation of the rated power of the FSCPS electronic control unit; an analysis of the annual efficiency of FSCPSs operating with induction generators; and, FSCPSs used to supply constant voltage to hydrogen electrolysis units for autonomous operations. The study showed that efficiencies of the FSCPSs using the DFIG were 97 per cent of the maximum efficiency. It was concluded that the DFIGs were capable of controlling the reactive power output of the FSCPS supplied to the grid. FSCPS efficiencies were higher for hydrogen production by electrolysis. 10 refs., 10 figs.

Papageorgiou, C.D. [School of Electrical and Computer Engineering, Athens (Greece). Electrical Machines Laboratory

2005-07-01

37

33 CFR 165.T01-0176 - Regulated Navigation Area; Lake Champlain Bridge Construction, Crown Point, New York and Chimney...  

Science.gov (United States)

...Construction, Crown Point, New York and Chimney Point, Vermont. 165.T01-0176...Construction, Crown Point, New York and Chimney Point, Vermont. (a) Description...construction zone at Crown Point, New York and Chimney Point, Vermont. The area is bounded by coordinates...

2010-07-01

38

Analysis of some available heat transfer coefficients applicable to solar chimney power plant collectors  

Energy Technology Data Exchange (ETDEWEB)

A solar chimney power plant consists of a translucent collector which heats the air near the ground and guides it into the base of a chimney at its centre. The buoyant air rises in the chimney and electricity is generated through one or more turbines in or near the base of the chimney. Various studies about solar chimney power plant performance have been published. Different calculation approaches with a variety of considerations have been applied to calculate chimney power plant performance. In particular, two comprehensive studies are relevant, namely those of (Bernardes, M.A.d. S., Voss, A., Weinrebe, G., 2003. Thermal and technical analyses of solar chimneys. Solar Energy 75, 511-524; Pretorius, J.P., Kroeger, D.G., 2006b. Solar chimney power plant performance. Transactions of the ASME 128, 302-311). The paper compares the methods used to calculate the heat fluxes in the collector, and their effects on solar chimney performance. Reasons for the discrepancies between the predictions of the two models are given. In general the Pretorius model produces higher heat transfer coefficients and higher heat rate fluxes for both the roof and for the ground surfaces. The two approaches lead to very similar air temperature rises in the collector and thus, similar produced power. (author)

Aurelio dos Santos Bernardes, Marco; Von Backstroem, Theodor W.; Kroeger, Detlev G. [Department of Mechanical Engineering, University of Stellenbosch, Private Bag X1, Western Cape, Matieland 7602 (South Africa)

2009-02-15

39

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 collec...

Miqdam Tariq Chaichan

2011-01-01

40

Review on the Enhancement Techniques and Introduction of an Alternate Enhancement Technique of Solar Chimney Power Plant  

Directory of Open Access Journals (Sweden)

Full Text Available Due to the low plant efficiency associated with Solar Chimney Power Plant, there is a need for the plant performance enhancement. This study presents the enhancement techniques of solar chimney power plant. It reviews previous works that had been done in performance enhancement of solar chimney power plants. It also, introduces an alternative approach to enhance the solar chimney performance by hybridizing the solar operation mode and waste heat energy from flue gas. The new idea is to convert the waste thermal energy in the flue to useful thermal energy in a Solar Chimney Power Plant collector. It is another form of waste heat energy recovery and utilization method.

Hussain H. Al-Kayiem

2011-01-01

 
 
 
 
41

A study of the ventilation performance of a series of connected solar chimneys integrated with building  

Energy Technology Data Exchange (ETDEWEB)

A series of connected solar chimneys consisting of an inclined section on the roof and a vertical section near the south wall was studied in a typical two-floor house. Specifically, the effects of the total length and width of the chimney, the inclined angle of the second floor inlet, the length ratio of the vertical to inclined section, and the chimney inclined angle on the chimney ventilation performance were numerically studied. The results showed that the ventilation was improved with the increase of the total chimney length. The air mass flow rate increased firstly then decreased with the chimney width, indicating that there existed an optimal length to width ratio, which was 12:1. Similarly, the mass flow rate increased firstly then decreased with the inclined angle of the second floor chimney inlet. The optimal inclined angle was found to be 4 from the horizontal. At the fixed total chimney length, the air mass flow rate also varied with the length ratio of the vertical to inclined section, and the maximum mass flow rate can be achieved by choosing the longest vertical length within the restriction of the building code. Finally, with the increase of chimney inclined angle, the velocity distribution inside the chimney was improved and the air flow rate increased. These results may provide the theoretical basis for the practical solar building design. (author)

Wei, Du; Qirong, Yang; Jincui, Zhang [College of Mechanical and Electronic Engineering, Qingdao University, Ningxia Road, No.308, Qingdao 266071 (China)

2011-01-15

42

The impact of the combined chimney outlet size and extended solar wall-roof chimney on airflow patterns using numerical simulation  

Energy Technology Data Exchange (ETDEWEB)

This paper investigates airflow patterns and behavior of combined roof and extended solar wall-roof chimney incorporated into a typical room with an inlet and outlet. Numerical simulations using the Fluid Dynamics software Package, FIDAP, are exploited to describe and analyze the airflow patterns inside the room, and in the extended solar wall-roof chimneys. FIDAP simulation analyses and results of the airflow streamline, velocity vectors, and temperature distributions are presented. Maximum velocity vector, temperatures, and smooth streamlines were found for better performance at separation of 0.25m. At 0.25m separation, in both wall and roof solar chimneys, the maximum chimney outlet flow rate and smooth streamline were found when the wall chimney is 2.00m high, which corresponds to a wall chimney inlet of 1.60m. Results show that the maximum relative speed in the combined chimneys is higher than the solar roof chimney alone. These findings suggest that the exploitation of an extended solar roof-wall chimney could enhance nighttime natural ventilation and the cooling of buildings. The system is limited to cool low-rise buildings in hot-arid regions such as Al-Ain City, UAE, where energy use is enormous.

AboulNaga, M.M.; Alteraifi, A.M.

1999-07-01

43

Experimental study of temperature field in a solar chimney power setup  

International Nuclear Information System (INIS)

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)

2007-08-01

44

Experimental study of temperature field in a solar chimney power setup  

International Nuclear Information System (INIS)

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

2007-08-01

45

Enhancement of natural ventilation in a solar house with a solar chimney and a solid adsorption cooling cavity  

Energy Technology Data Exchange (ETDEWEB)

This paper presents a parametric analytical study on the enhancement of natural ventilation in a solar house induced by a solar chimney and a solid adsorption cooling cavity. Some details on sizing such a system are also provided. Theoretical analyses are carried out to investigate the ventilation in the solar house with solar chimney alone, cooling cavity alone or with combined solar chimney and solar adsorption cooling cavity, without considering the wind effects. It is found that on a typical day, the solar house comprising of a 2.5 m{sup 2} solar chimney, is able to create an airflow rate of more than 150 kg/h for the studied house. In addition, the ventilation rate at night is also increased by about 20% with the solar adsorption cooling cavity. It is expected that the proposed concept is useful to be incorporated with a stand-alone building or with a cluster of buildings for some favorable climates. (author)

Dai, Y.J.; Wang, R.Z. [Shanghai Jiao Tong Univ. (China). Inst. of Refrigeration and Cryogenics; Sumathy, K.; Li, Y.G. [University of Hong Kong (China). Dept. of Mechanical Engineering

2003-01-01

46

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

Energy Technology Data Exchange (ETDEWEB)

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)

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

2009-02-15

47

Numerical Simulation and Comparison of Conventional and Sloped Solar Chimney Power Plants: The Case for Lanzhou  

Science.gov (United States)

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.

Zhang, Yang; Zhao, Liang

2013-01-01

48

Establish feasibility for providing passive cooling with solar updraft and evaporate downdraft chimneys  

Energy Technology Data Exchange (ETDEWEB)

Natural draft towers can be used for cooling and ventilating structures. From an operational perspective, the downdraft evaporatively cooled tower is preferred for a dry climate. Solar chimneys, when used alone, tend to require an excessively large solar collector area when appreciable quantities of air must be moved. When used in combination with a downdraft tower, the roof and attic of buildings may assist the solar chimney and their use becomes more attractive. Both a frame building and a greenhouse were successfully cooled during this program. The economics of the downdraft tower compare favorably with conventional evaporative cooling for some applications.

Cunningham, W.A.; Mignon, G.V.; Thompson, T.L.

1987-01-01

49

Evaluation of operational control strategies applicable to solar chimney power plants  

Energy Technology Data Exchange (ETDEWEB)

Numerical simulations are carried out to study the performance of two schemes of power output control applicable to solar chimney power plants. Either the volume flow or the turbine pressure drop is used as independent control variable. Values found in the literature for the optimum ratio of turbine pressure drop to pressure potential vary between 2/3 and 0.97. It is shown that the optimum ratio is not constant during the whole day and it is dependent of the heat transfer coefficients applied to the collector. This study is a contribution towards understanding solar chimney power plant performance and control and may be useful in the design of solar chimney turbines. (author)

Bernardes, Marco Aurelio dos Santos [Department of Mechanical Engineering, Centro Federal de Educacao Tecnologica de Minas Gerais - CEFET-MG, Av. Amazonas, 7675, Nova Gameleira, 30510-000 Belo Horizonte, MG (Brazil); von Backstroem, Theodor W. [Department of Mechanical Engineering, University of Stellenbosch, Private Bag X1, Matieland 7602 (South Africa)

2010-02-15

50

Establishing feasibility for providing passive cooling with solar updraft and evaporative downdraft chimneys  

Energy Technology Data Exchange (ETDEWEB)

At the present time all experimental towers (chimneys) are completed and operating. This consists of both a solar updraft and a natural-evaporative downdraft tower retrofitted to an existing residence structure and a greenhouse. The residential, experimental, natural-draft cooling system was completed in May, 1985, and five months of summer data on a Hewlet Packard 85 data acquisition computer with a digital voltmeter were acquired. The cooling tower and solar chimney on the experimental greenhouse became operational in September of 1985. A conceptual drawing of both the greenhouse and the residence natural-draft towers is included in the appendix along with the September 85 progress report.

Cunningham, W.A.; Mignon, G.V.

1986-01-01

51

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

International Nuclear Information System (INIS)

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.

2013-01-10

52

Numerical analysis on the performance of solar chimney power plant system  

International Nuclear Information System (INIS)

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.

2011-02-01

53

Numerical analysis on the performance of solar chimney power plant system  

Energy Technology Data Exchange (ETDEWEB)

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/m{sup 2} 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. (author)

Xu, Guoliang; Ming, Tingzhen; Pan, Yuan; Meng, Fanlong; Zhou, Cheng [School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

2011-02-15

54

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

Energy Technology Data Exchange (ETDEWEB)

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)

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

2008-07-01

55

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

Energy Technology Data Exchange (ETDEWEB)

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)

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

56

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

Directory of Open Access Journals (Sweden)

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.

Miqdam Tariq Chaichan

2011-01-01

57

Evaluation of the potential of solar chimneys to drive natural ventilation in non domestic buildings  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The solar chimney allows natural ventilation to be achieved during periods when the wind velocities are low and the difference between internal and external air temperatures is minimal. The correct design of such building components requires that designers have appropriate design tools available to them that are both effective and easy to use. The aim of this project was to evaluate design tools currently available and if appropriate to provide a tool that would allow the ef...

Swainson, M. J.

1997-01-01

58

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

International Nuclear Information System (INIS)

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

2014-02-01

59

Development of the house chimney  

Energy Technology Data Exchange (ETDEWEB)

The article gives an outline of the development of the house chimney. Following a historical survey, the different, now common chimney types are described. Requirements according to the DIN 18160 standard governing the planning and construction of house chimneys are discussed. Furthermore, recent chimney types are described with low susceptibility to moisture precipitation from flue gases.

Dreesen, H.W.

1987-12-01

60

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

International Nuclear Information System (INIS)

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.

2012-11-01

 
 
 
 
61

Simulation of solar chimney power plant with an external heat source  

Science.gov (United States)

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.

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

2013-06-01

62

Simulation of solar chimney power plant with an external heat source  

International Nuclear Information System (INIS)

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.

2013-06-17

63

Chimney manual. Firing and exhaust gas systems: planning, calculation, construction; 3. ed.; Handbuch der Schornsteintechnik. Feuerungsanlagen und Abgassysteme: Planung, Berechnung, Ausfuehrung  

Energy Technology Data Exchange (ETDEWEB)

As more and more modern high-efficiency heat generators with low exhaust gas temperature are installed the early adjustment of heat generator and chimney or exhaust gas system is of increasing importance. This book goes into the following subjects of chimney technology: Development of chimney construction, fuels and combustion, bases of chimney technology, chimney systems (design and field of application), chimney and building, air-exhaust gas chimney systems for the connection to gas heating systems which are independent of room air, high-efficiency burner technology, construction and exhaust gas removal of open chimneys, isolated chimneys, chimney retrofitting, costs, environmental protection, building specifications, standards, regulations. (HW) [Deutsch] Durch den verstaerkten Einbau moderner Waermeerzeuger mit hohen feuerungstechnischen Wirkungsgraden und entsprechend niedrigen Abgastemperaturen kommt einer fruehzeitigen Abstimmung von Waermeerzeuger und Schornstein bzw. Abgasanlage steigende Bedeutung zu. Das vorliegende Buch stellt dabei folgende Themenbereiche der Schornsteintechnik vor: Entwicklung des Schornsteinbaus, Brennstoffe und Verbrennung, Grundlagen der Schornsteintechnik, Schornsteinsysteme (Ausfuehrung und Einsatzbereich), Schornstein und Gebaeude, Schornstein und Heizung, Luft-Abgas-Schornsteinsysteme (LAS) zum Anschluss von raumluftunabhaengigen Gasfeuerstaetten, Brennwerttechnik, Aufstellung und Abgasfuehrung von offenen Kaminfeuern, freistehende Schornsteine, Schornsteinsanierung, Kosten, Umweltschutz, Bauvorschriften, Normen, Richtlinien. (HW)

Hausladen, G.

1994-12-31

64

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

International Nuclear Information System (INIS)

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, ? 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

2009-02-01

65

Study of the natural convection phenomena inside a wall solar chimney with one wall adiabatic and one wall under a heat flux  

Energy Technology Data Exchange (ETDEWEB)

Four wall solar chimneys have been constructed and put at each wall and orientation of a small-scale test room so as to be used for the evaluation and measurement of their thermal behavior and the certification of their efficiency. At this stage, research focuses on the study of the buoyancy-driven flow field and heat transfer inside them. A numerical investigation of the thermo-fluid phenomena that take place inside the wall solar chimneys is performed and the governing elliptic equations are solved in a two-dimensional domain using a control volume method. The flow is turbulent and six different turbulence models have been tested to this study. As the realizable k-{epsilon} model is likely to provide superior performance for flows boundary layers under strong adverse pressure gradients, it has been selected to be used in the simulations. This is also confirmed by comparing with the experimental results. Predicted velocity and temperature profiles are presented for different locations, near the inlet, at different heights and near the outlet of the channel and they are as expected by theory. Important parameters such as average Nusselt number are also compared and calculated at several grid resolutions. The developed model is general and it can be easily customised to describe various solar chimney's conditions, aspect ratios, etc. The results from the application of the model will support the effective set-up of the next configurations of the system. (author)

Bacharoudis, Evangellos; Margaris, Dionysios [University of Patras, Department of Mechanical Engineering and Aeronautics, Division of Energy, Aeronautics and Environment, Patras (Greece); Vrachopoulos, Michalis Gr.; Koukou, Maria K.; Filios, Andronikos E.; Mavrommatis, Stamatis A. [Technological Educational Institution of Chalkida, Mechanical Engineering Department, Environmental Research Laboratory, 344 00 Psachna, Evia (Greece)

2007-09-15

66

Passive-solar construction handbook  

Energy Technology Data Exchange (ETDEWEB)

The case for solar energy, solar energy principles, site planning, orientation and landscaping, solar access, passive solar systems, components, and design, design calculations, construction details, passive solar cooling, interior applications for passive solar design, financial considerations, and marketing and development of passive solar are covered in the Passive Solar Workbook. (LEW)

1981-09-01

67

Performance of solar chimney power plant in Qinghai-Tibet Plateau  

Energy Technology Data Exchange (ETDEWEB)

A solar chimney power plant (SCPP) is proposed to be built in Qinghai-Tibet Plateau where there is abundant solar radiation, high direct solar radiation low atmospheric temperature, large diurnal temperature range, and lots of salt lakes working as heat storage system, which can help to improve the power output of SCPP. The plant is expected to power local railway traffic lines and act as a solar power base to supply power for national development. The performance of the SCPP that will be built in Qinghai-Tibet Plateau is analyzed and power potential estimated by developing a simple mathematical model. It is found that SCPP if built in the plateau can produce twice more power than an SCPP built on the same latitude of other regions. The yearly power potential for SCPP in Qinghai-Tibet Plateau is estimated to be 86.8 million TJ. When 10-20% of the plateau land is used for the SCPP, the yearly power output may reach 8.7 million TJ to 17.4 million TJ, accounting for 10.7-21.3% of China's energy consumption in 2008 which stood at 81.6 million TJ. It is found that the SCPP in the plateau can support local and national development together with other renewable energy resources such as hydroelectric power and wind power. (author)

Zhou, Xinping; Wang, Fang [Department of Mechanics, School of Civil Engineering and Mechanics, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei 430074 (China); Hubei Key Laboratory for Engineering Structural Analysis and Safety Assessment, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei 430074 (China); Fan, Jian [Hubei Key Laboratory for Engineering Structural Analysis and Safety Assessment, Huazhong University of Science and Technology, Luoyu Road 1037, Wuhan, Hubei 430074 (China); Ochieng, Reccab M. [Department of Physics and Materials Science, Maseno University, P.O. Box 333, Maseno (Kenya)

2010-10-15

68

Passive solar construction handbook  

Energy Technology Data Exchange (ETDEWEB)

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)

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

1981-08-01

69

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

International Nuclear Information System (INIS)

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

2008-10-01

70

Chimney cleaner  

Energy Technology Data Exchange (ETDEWEB)

This patent describes a chimney cleaner for cleaning a chimney flue wall, comprising: a plate having a scraping edge; and support means for suspending the plate between a weight and a flexible member. The support means comprises means for permitting the plate to pivot between the weight and the flexible member and for holding the plate generally normally to the chimney flue wall.

Wolf, R.H.; Johnson, B.L.

1987-04-14

71

Establish feasibility for providing passive cooling with solar updraft and evaporative downdraft chimneys. Final report, June 15, 1984--December 31, 1987  

Energy Technology Data Exchange (ETDEWEB)

Natural draft towers can be used for cooling and ventilating structures. From an operational perspective, the downdraft evaporatively cooled tower is preferred for a dry climate. Solar chimneys, when used alone, tend to require an excessively large solar collector area when appreciable quantities of air must be moved. When used in combination with a downdraft tower, the roof and attic of buildings may assist the solar chimney and their use becomes more attractive. Both a frame building and a greenhouse were successfully cooled during this program. The economics of the downdraft tower compare favorably with conventional evaporative cooling for some application.

Cunningham, W.A.; Mignon, G.V.; Thompson, T.L.

1987-12-31

72

Establish feasibility for providing passive cooling with solar updraft and evaporate downdraft chimneys. Final report, June 15, 1984--December 31, 1987  

Energy Technology Data Exchange (ETDEWEB)

Natural draft towers can be used for cooling and ventilating structures. From an operational perspective, the downdraft evaporatively cooled tower is preferred for a dry climate. Solar chimneys, when used alone, tend to require an excessively large solar collector area when appreciable quantities of air must be moved. When used in combination with a downdraft tower, the roof and attic of buildings may assist the solar chimney and their use becomes more attractive. Both a frame building and a greenhouse were successfully cooled during this program. The economics of the downdraft tower compare favorably with conventional evaporative cooling for some applications.

Cunningham, W.A.; Mignon, G.V.; Thompson, T.L.

1987-12-31

73

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

Energy Technology Data Exchange (ETDEWEB)

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)

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

74

3. international chimney design symposium  

International Nuclear Information System (INIS)

On the 25th and 26th of october 1978, the 3rd International Chimney Design Symposium took place in the Technical University of Munich. About 200 german and 150 foreign experts in chimney design came to participate in the lectures and debates. The deliberations focussed on the scientific aspect and the technical completion of industrial chimneys, considering all the problems which are implied in the planifaction and construction of the foundation, the shaft, and the lining of the chimney. Being one of the main topics, the possibilities of using chimneys in their waste gas eliminating function within the framework of environmental control were discussed thoroughly. Standardization on national and international level was another topic at this conference. Considerable progress has been achieved in the field of security and economy. (orig./RW)

1978-10-26

75

Sandwich Construction Solar Structural Facets  

Energy Technology Data Exchange (ETDEWEB)

Silver/glass mirrors have excellent optical properties but need a method of support in order to be used in concentrating solar thermal systems. In collaboration with the Cummins dish/Stirling development program, they started investigating sandwich construction as a way to integrate silver/glass mirrors into solar optical elements. In sandwich construction, membranes such as sheet metal or plastic are bonded to the front and back of a core (like a sandwich). For solar optical elements, a glass mirror is bonded to one of the membranes. This type of construction has the advantages of a high strength-to-weight ratio, and reasonable material and manufacturing cost. The inherent stiffness of sandwich construction mirror panels also facilitates large panels. This can have cost advantages for both the amount of hardware required as well as reduced installation and alignment costs. In addition, by incorporating the panels into the support structure reductions in the amount of structural support required are potentially possible.

Diver, R. B.; Grossman, J.W.

1998-12-22

76

Testing of three factory-built chimneys  

Energy Technology Data Exchange (ETDEWEB)

Laboratory testing was conducted on 3 factory-built chimneys connected to a factory-built fireplace. One of the chimneys was air-cooled and the others were insulated. The air-cooled chimney had some operating characteristics which were different from the other chimneys: there was an initial increase in outside temperature with height, partly attributed to an increase in the temperature of the cooling air inside the chimney as it travelled up the chimney. This is in contrast to the decrease in outside surface temperature with height for the other 2 chimneys. The overall heat transfer coefficient was estimated for each chimney using a simplified heat loss model. The air-cooled chimney seemed to perform better at high flue mass flow rates. If flue gas temperature is low to begin with, and flue gas flow rates are also low, a significant flue gas temperature drop could occur, which could be a major problem for chimneys connected to wood appliances which can operate at very low burn rates. The higher heat loss rate of the air-cooled chimney produces lower surface temperatures on the flue liner, which could promote increased creosote formation. In systems where spillage is a problem during cool-down, the air-cooled chimney will have a faster reduction in draft during cool-down, and therefore will likely be prone to spillage earlier in the cool-down cycle. With insulated chimneys, highest exterior temperatures occur near the base; for the air-cooled chimney, the highest exterior temperatures will most likely occur ca 3 m above the base, which implies that chimney construction may need to be different for the air-cooled chimney. 9 figs., 2 tabs.

McGugan, C.A.

1989-12-08

77

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

Science.gov (United States)

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 %.

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

2014-05-01

78

Solar array construction  

Energy Technology Data Exchange (ETDEWEB)

An interconnect tab on each cell of a first set of circular solar cells connects that cell in series with an adjacent cell in the set. This set of cells is arranged in alternate columns and rows of an array and a second set of similar cells is arranged in the remaining alternate columns and rows of the array. Three interconnect tabs on each solar cell of the said second set are employed to connect the cells of the second set to one another, in series and to connect the cells of the second set to those of the first set in parallel. Some tabs (making parallel connections) connect the same surface regions of adjacent cells to one another and others (making series connections) connect a surface region of one cell to the opposite surface region of an adjacent cell; however, the tabs are so positioned that the array may be easily assembled by depositing the cells in a certain sequence and in proper orientation.

Crouthamel, Marvin S. (Pennsauken, NJ); Coyle, Peter J. (Oaklyn, NJ)

1982-01-01

79

From large natural draft cooling tower shells to chimneys of solar upwind power plants  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Natural draft cooling towers (NDCTs) presently form the world-largest RC shell structures, solar updraft power plants (SUPPs) will do this in future. The paper starts with explanations of the working principles of NDCTs and SUPPs. In industrialized countries with strong legal emphasis on sustainable power production technologies, NDCTs are widely spread, while SUPPs represent future solar power generation concepts in the world¿s tropical areas, using solar irradiation as power plant fuel. Co...

2009-01-01

80

Why do fiddler crabs build chimneys?  

Science.gov (United States)

Chimneys are mud mounds built by fiddler crabs that encircle the entrance to their burrow. Their function in many species is unknown. In Uca capricornis, crabs of both sexes and all sizes build chimneys, but females do so disproportionately more often. There are no differences in the immediate physical or social environments between crabs with and without a chimney. Chimney owners spend less time feeding and more time underground than non-owners. We show experimentally that burrows with a chimney are less likely to be located by an intruder. It is possible that some crabs construct chimneys around their burrow to conceal the entrance and reduce the risk of losing it to an intruder. PMID:18715845

Slatyer, R A; Fok, E S Y; Hocking, R; Backwell, P R Y

2008-12-23

 
 
 
 
81

Chimney tray hat  

Energy Technology Data Exchange (ETDEWEB)

This patent describes a chimney tray hat apparatus in combination with a tray chimney in a vapor/liquid processing device for de-entraining droplets of liquid entrained in a stream containing vapor and liquid droplets flowing upwardly through the tray chimney. It comprises: a top cover having an upper side and an underside which intercepts entrained liquid flowing upwardly through the tray chimney, a gutter means for collecting and draining the liquid impinging on the underside of the top cover onto a means for supporting the top cover directly above the tray chimney and through the tray chimney into a zone located below the tray chimney.

Bannon, R.P.

1990-06-12

82

Establishing feasibility for providing passive cooling with solar updraft and evaporative downdraft chimneys  

Energy Technology Data Exchange (ETDEWEB)

The solar updraft and a natural evaporative downdraft tower built onto an existing residence structure and a greenhouse were completed and operating. Performance data for the hottest days of June, July, and August, 1985 are included. (MHR)

Cunningham, W.A.; Migon, G.V.

1985-01-01

83

33 CFR 165.T01-0176 - Regulated Navigation Area; Lake Champlain Bridge Construction, Crown Point, New York and Chimney...  

Science.gov (United States)

... Regulated Navigation Area; Lake Champlain Bridge Construction, Crown Point... Regulated Navigation Area; Lake Champlain Bridge Construction, Crown Point... All navigable waters on Lake Champlain 300 yards to the north and...

2010-07-01

84

Análisis de la ventilación inducida en un espacio habitable, mediante un sistema de Chimenea Hidro-Solar / Analisys of Ventilation induced in a Livable Space through a hydro-solar Chimney System  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: Spanish Abstract in spanish El Cuerpo Académico Arquitectura y Tecnología Ambiental de la Universidad Juárez Autónoma de Tabasco, desarrolla la Línea de Investigación Arquitectura y Medio Ambiente, realiza análisis sobre el diseño y la arquitectura bioclimática, teniendo como premisa la sustentabilidad entre usuario, entorno y [...] espacio construido. Este último, en sitios con clima cálido húmedo, presenta incomodidad térmica debido a los altos índices de temperatura y humedad relativa, condición mitigada mediante equipos de aire acondicionado que repercuten en el gasto energético y la economía del usuario. De acuerdo con la arquitectura bioclimática una técnica pasiva para este hecho es la ventilación. La presente investigación es la tercera etapa de una propuesta de ventilación inducida. Consistió en la simulación del sistema denominado Chimenea Hidro-Solar, empleando tubería de cobre y agua como elementos captores de calor. Se planteó el diseño, construcción y evaluación del prototipo. Se construyeron modelos, del espacio proyectado y de referencia, a escala 1:6, observando las dimensiones establecidas por el Reglamento de Construcción para una recámara. El análisis se centró en obtener, valorar y categorizar los datos de magnitud del viento que conllevaron a evaluar el comportamiento del espacio. Los datos validaron el sistema propuesto, proporcionando alternativas de acondicionamiento pasivo al espacio habitable. Abstract in english The academic group called Architecture and Environmental Technology of the Universidad Juárez Autónoma de Tabasco, develops Line Architecture and Environmental Research, producing analyzes on the design and bioclimatic architecture, with the premise of sustainability between user space and built env [...] ironment. The latter, presents thermal discomfort due to the high levels of temperature and relative humidity, condition is mitigated by air conditioners that affect energy expenditure and the economy user. According to the bioclimatic architecture a passive technique for this, is ventilation. This research is the third stage of a proposal on ventilator-induced. It consisted of the simulation system called Hydro-Solar Chimney, using copper tubing and water and heat sensors elements. The steps contemplated the design, construction and evaluation of the prototype. Models were constructed, the projected space and reference, 1:6 scale, noting the dimensions set by the Building Code of the State of Tabasco. The analysis focused on obtaining, evaluating and categorizing the magnitude of the wind data that led to evaluate the behavior within the space. Schematized data validated the proposed system, providing passive conditioning alternative to living space.

H, Pérez Castro; J, Flores; A, López.

85

Viewing instrument for chimney  

Energy Technology Data Exchange (ETDEWEB)

An apparatus is described for visually monitoring the vent of a chimney while the chimney is drawing exhaust gases through a flue entrance that includes: a hollow barrel unit sealed within a horizontal receiving opening passing through a wall of the chimney above the flue entrance, the barrel unit further having an adjusting means for changing the axial length of the unit. The barrel unit can be fitted to the chimney wall. Mounting means removably joins to the outer end of the barrel unit to provide an airtight seal. An elongated quartz rod is contained within the mounting means that passes through the barrel unit into the chimney vent. The rod has an upper light entrance face horizontally disposed at the free end for receiving light from the chimney vent. A reflecting surface immediately below the light entrance face directs entering light axially along the rod and a light exit face perpendicular to the axis of the rod which is located outside the chimney.

Van Patten, F.D.

1987-07-21

86

Enhancement of natural ventilation in buildings using a thermal chimney  

Energy Technology Data Exchange (ETDEWEB)

A new module was developed for and implemented in the EnergyPlus program for the simulation and determination of the energy impact of thermal chimneys. This paper describes the basic concepts, assumptions, and algorithms implemented into the EnergyPlus program to predict the performance of a thermal chimney. Using the new module, the effects of the chimney height, solar absorptance of the absorber wall, solar transmittance of the glass cover and the air gap width are investigated under various conditions. Chimney height, solar absorptance and solar transmittance turned out to have more influence on the ventilation enhancement than the air gap width. The potential energy impacts of a thermal chimney under three different climate conditions are also investigated. It turned out that significant building cooling energy saving can be achieved by properly employing thermal chimneys and that they have more potential for cooling than for heating. In addition, the performance of a thermal chimney was heavily dependent on the climate of the location. (author)

Lee, Kwang Ho [University of California at Berkeley, Berkeley, CA (United States); Strand, Richard K. [University of Illinois at Urbana-Champaign, Champaign, IL (United States)

2009-06-15

87

Chimney liners for wet FGD service  

Energy Technology Data Exchange (ETDEWEB)

In order to meet pollution compliance requirements, many Utilities are adding wet scrubbers to reduce SO{sub 2} emissions. The gas temperatures produced by wet scrubbers also can lead to increased condensation of moisture on interior surfaces of chimney linings and ductwork. This increased condensation can, in turn, increase the risk of corrosion. To protect moist surfaces of chimney liners and ductwork from acid attack, new design and construction methods are required. Materials including high nickel, chrome and titanium alloys are being employed as well as modifications to the widely used acid resistant brick liners which have been conventionally used. This paper explores the experience of chimney manufacturers and builders to address the requirements of operation with wet scrubbers. This includes issues of liner velocities, liquid carryover, the use of new materials and construction techniques.

Sowizal, J. [Industrial Chimney Engineers, Ltd., Hawthorn Woods, IL (United States)

1998-12-31

88

Procedimentos estimativos do potencial de uso de chaminés solares para promover a ventilação natural em edificações de baixa altura / Procedures for estimating the potential use of solar chimneys for natural ventilation enhancement in low-rise buildings  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A ventilação natural é uma das estratégias mais importantes para o condicionamento térmico passivo de ambientes internos de edificações, podendo ocorrer pela ação dos ventos, pelo efeito chaminé ou pela combinação de ambos. Em áreas urbanizadas, a velocidade do vento é sensivelmente reduzida pelos o [...] bstáculos locais, tornando o efeito chaminé uma alternativa de projeto mais viável, pois independe dos ventos. Este artigo tem por objetivo apresentar e discutir procedimentos estimativos do potencial de uso de chaminés solares para edificações de baixa altura, localizadas em regiões de baixa latitude. Desenvolveram-se previsões teóricas, através de um modelo matemático e de simulação computacional. Realizou-se um processo de calibração destes modelos, utilizando como referência os resultados do monitoramento experimental de uma célula de teste. O processo baseou-se na análise comparativa de algumas variáveis selecionadas, considerando-se dados de temperatura superficial, temperatura do ar e vazão volumétrica no interior da chaminé. Os resultados indicaram que os modelos teóricos têm potencial de aplicação na avaliação do desempenho de chaminés solares, especialmente o modelo de simulação, em que foram observadas diferenças inferiores a 20% entre resultados medidos e calculados. Abstract in english Natural ventilation is one of the most important strategies for passive cooling of indoor environments. It can occur by wind forces, by stack effect or by a combination of both strategies. The second choice tends to be more effective in urban areas, where there are obstacles that block or significan [...] tly reduce wind speed. This paper analyses prediction procedures for the potential use of solar chimneys in low-rise buildings at low latitude locations. Theoretical predictions were developed using a mathematical model and computer simulation. A calibration procedure was used, based on results obtained through an experimental set up. The procedure consisted in a comparative analysis of chosen variables, considering data of surface temperature, air temperature and volumetric flow rate inside the chimney channel. The results confirmed the great potential of applicability of the theoretical models in the performance analysis of solar chimneys, especially the simulation model, which presented differences lower than 20% between measured and estimated results.

Neves, Leticia de Oliveira; Roriz, Maurício.

89

Solar building construction. Town planning - construction planning. 2. rev. ed.  

International Nuclear Information System (INIS)

The book discusses the problems of solar energy use under the following aspects: Town planing; Typology of green solar architecture; Typologie of solar architecture; Vegetation in green solar architecture; Planning and simulation; Building materials; Ventilation, illumination; Research projects. (HW)

1994-01-01

90

Establishing feasibility for providing passive cooling with solar updraft and evaporative downdraft chimneys. Progress report, March 1985--September 1985  

Energy Technology Data Exchange (ETDEWEB)

The solar updraft and a natural evaporative downdraft tower built onto an existing residence structure and a greenhouse were completed and operating. Performance data for the hottest days of June, July, and August, 1985 are included. (MHR)

Cunningham, W.A.; Migon, G.V.

1985-12-31

91

Workbook on: passive solar design and energy efficient construction  

Energy Technology Data Exchange (ETDEWEB)

After a discussion of the need for energy education, the MASEC Solar 80 program is described, which is aimed at the commercialization of the design and construction of solar efficient residential buildings. Processes of heat loss and heat gain in buildings are described as background for passive solar design. Then fundamentals of energy efficient construction and of passive solar design are presented. Procedures are given for calculating design heat loads, solar contribution, and auxiliary heating requirement. Means are also described of passive solar cooling. Site selection, analysis and landscaping and interior design for passive solar homes are covered. Financial considerations and passive solar marketing and development are covered. (LEW)

1981-05-01

92

Chimney Open Issues  

Energy Technology Data Exchange (ETDEWEB)

In the process of developing a design for the design report, many side questions or comments arose which were not completely answered or investigated because the work was outside the scope of developing a base design. I have pored over my meeting notes and tried to list all such chimney 'open issues' in this engineering note.

Rucinski, R.; /Fermilab

1993-10-04

93

Fairy Chimneys of Cappadocia and Their Engineering Properties  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Cappadocia region of inner Anatolia has been focus of both historians and geologists due to its underground cities as well as fairy chimneys on the surface. The man-made structures were caved in soft tuffs more than 1500 years ago; thus, many researchers studied the mass properties of rackous materials in the region to evaluate as construction materials. In this study physical and chemical properties of spectacular structures, called fairy chimneys formed due to physicochemical reaction o...

Alper Baba; Abidin Kaya; Necdet Turk

2005-01-01

94

Chimney technique; Schornsteintechnik  

Energy Technology Data Exchange (ETDEWEB)

Modern low temperature plants or calorific value equipments are now standard in building new dwellings. However, an important part of the whole system of the combustion plant, chimney technique, is often ignored. But modern heating systems are dependent on suitable exhaust gas technique. (orig.) [Deutsch] Moderne Niedertemperaturanlagen oder Brennwertgeraete sind beim Wohnungsneubau mittlerweile Standard. Allerdings wird oft ein wesentlicher Teil des Gesamtsystems Feuerungsanlage ausser Acht gelassen: die Schornsteintechnik. Aber gerade die modernen Heizsysteme sind unabdingbar auf die passende Abgasanlagentechnologie angewiesen. (orig.)

Wollenberg, G.

1997-11-01

95

Fairy chimneys in Peru  

CERN Multimedia

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.

Sparavigna, Amelia Carolina

2011-01-01

96

Device for cooling chimney gases  

Energy Technology Data Exchange (ETDEWEB)

The invention relates to a device for cooling chimney-gases in such plants, where water, heated in a heating boiler, is supplied to heat consumers; e.g. radiators. According to the invention, a condenser-heat exchanger is arranged downstream of the heat consumers, a chimney gas cooler is situated in the chimney gas channel from the heating boiler, whereby said condenser-heat exchanger and said chimney gas cooler are parts of a closed cooling system, containing, e.g. Freon gas, together with a refrigerating compressor and a throttle.

Eriksson, L.

1980-10-14

97

Solar Glazing Tips for School Construction  

Science.gov (United States)

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…

Smith, Jonathan

2012-01-01

98

Thermally balanced air flow chimney  

Energy Technology Data Exchange (ETDEWEB)

This patent describes an on demand air cooled three wall chimney system for a building sourcing cooling air from within the building including: a. a starter chimney member having a first inner sheet metal wall forming a first imperforate elongated open ended chamber for the passage of flue gases from a fire source; b. the starter chimney member having a first intermediate sheet metal wall surrounding and generally evenly spaced from the first inner wall and forming therewith a first insulation chamber; c. the starter chimney member having a first outer metal wall surrounding the first intermediate wall forming a first open ended air passage chamber; d. first insulation material substantially filling the first insulation chamber in the starter chimney member; 3. air passage means formed only in the lower portion of the starter chimney member permitting the air within the building to enter the first air passage chamber aajacent the lower end of the starter chimney member for movement only upwardly through the first open ended air passage; f. an upper chimney member having a second inner sheet metal wall in over lapping registration with the first inner sheet metal wall forming a second imperforate elongated open ended chamber for the passage of flue gases from the first imperforate elongated open ended chamber to the atmosphere outside the building.

Townsend, D.M.; Jacklich, J.R.

1986-09-02

99

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

Energy Technology Data Exchange (ETDEWEB)

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. (author)

Zhou, Xinping [School of Civil Engineering and Mechanics, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, Hubei 430074 (China); Yang, Jiakuan; Wang, Jinbo; Xiao, Bo [School of Environmental Science and Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road Wuhan, Hubei 430074 (China)

2009-03-15

100

Design and Construction of a Domestic Passive Solar Food Dryer  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The solar drying system utilizes solar energy to heat up air and to dry any food substance loaded, which is not only beneficial in that it reduces wastage of agricultural produce and helps in preservation of agricultural produce, but it also makes transportation of such dried produce easy and promotes the health and welfare of the people. This paper presents the design and construction of a domestic passive solar food dryer. The dryer is composed of solar collector (air heater) and a solar dr...

Alamu, Oguntola J.; Nwaokocha, Collins N.; Adunola, Olayinka

2010-01-01

 
 
 
 
101

Easy-to-handle chimney designs  

Energy Technology Data Exchange (ETDEWEB)

The manual on 'chimney designs based on the interaction of heating systems and chimneys' is offering solutions to chimney problems occurring during the retrofitting of heating systems. Two examples demonstrate the manual's practical value. Apart from facilitating access to the evaluation of heating system/chimney configurations the manual points out feasable improvements. Among the measures presented are measures relevant to chimneys (thermal insulation of connecting pieces or outer chimney cheeks), measures relevant to the heating system, supplementary air supplies, methods increasing the efficiency of boilers, and the adaptation of chimney cross sections.

Holler, K.F.

1988-02-01

102

Constructing and Characterising Solar Structure Models for Computational Helioseismology  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In local helioseismology, numerical simulations of wave propagation are useful to model the interaction of solar waves with perturbations to a background solar model. However, the solution to the linearised equations of motion include convective modes that can swamp the helioseismic waves that we are interested in. In this article, we construct background solar models that are stable against convection, by modifying the vertical pressure gradient of Model S (Christensen-Dalsgaard et al., 199...

Schunker, H.; Cameron, R.; Gizon, L.; Moradi, H.

2011-01-01

103

Combined chimney cover and damper  

Energy Technology Data Exchange (ETDEWEB)

This device is comprised of an elongated sleeve having a closed end defining the cover and an open end supported within the chimney, support means extending laterally from the sleeve and engageable with the top of the chimney to support and maintain the cover and damper in operative relation to the chimney, at least one aperture in the sleeve between the support means and the closed end of the sleeve, a damper normally resiliently urged upwardly within the sleeve against its closed end to cover the aperture, and means for moving the damper across the aperture to establish communication between the interior of the chimney and the atmosphere. The cover preferably includes a flange spaced horizontally outwardly from and at least partially overlapping the aperture to protect it against wind blown rain and snow.

Lyles, H.H.

1980-01-01

104

Analysis of Self-Supporting Chimney  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Chimneys are tall structures and the major loads acting on these are self weight of the structure, wind load, live load due to lining, earthquake load & temperature loads. In this paper a RC chimneys will be designed considering dead load, wind load and earthquake load. The Bureau of Indian Standards (BIS) design codes procedures will be used for the design of chimney. The present paper discusses the parametric study of RC chimney which is made by obtaining the results from software for diffe...

2013-01-01

105

Chemical processing in geothermal nuclear chimney  

International Nuclear Information System (INIS)

A closed rubble filled nuclear chimney is provided in a subterranean geothermal formation by detonation of a nuclear explosive device therein, with reagent input and product output conduits connecting the chimney cavity with appropriate surface facilities. Such facilities will usually comprise reagent preparation, product recovery and recycle facilities. Processes are then conducted in the nuclear chimney which processes are facilitated by temperature, pressure, catalytic and other conditions existent or which are otherwise provided in the nuclear chimney. (author)

1972-05-08

106

Why do fiddler crabs build chimneys?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Chimneys are mud mounds built by fiddler crabs that encircle the entrance to their burrow. Their function in many species is unknown. In Uca capricornis, crabs of both sexes and all sizes build chimneys, but females do so disproportionately more often. There are no differences in the immediate physical or social environments between crabs with and without a chimney. Chimney owners spend less time feeding and more time underground than non-owners. We show experimentally that burrows with a chi...

Slatyer, R. A.; Fok, E. S. Y.; Hocking, R.; Backwell, P. R. Y.

2008-01-01

107

Fireplace chimney cap and damper combination  

Energy Technology Data Exchange (ETDEWEB)

A chimney cap pivotally mounted at one end to allow secure closure of the cap or opening for operation. The lower end of the chimney is connected to a fireplace which has its own manually operated damper. The chimney cap is operable conjointly with the damper or separately by its own operating apparatus.

Carriveau, T.

1984-11-20

108

You're a What? Chimney Sweep  

Science.gov (United States)

In this article, the author talks about a chimney sweep--also called a "sweep"--which inspects chimneys as well as cleans them. Some inspections are for a specific purpose, such as home appraisal, but most precede cleaning. Chimney cleaning requires a certain level of dexterity, because the job includes a lot of climbing, squatting, kneeling, and…

Green, Kathleen

2010-01-01

109

Design and Construction of a Domestic Passive Solar Food Dryer  

Directory of Open Access Journals (Sweden)

Full Text Available The solar drying system utilizes solar energy to heat up air and to dry any food substance loaded, which is not only beneficial in that it reduces wastage of agricultural produce and helps in preservation of agricultural produce, but it also makes transportation of such dried produce easy and promotes the health and welfare of the people. This paper presents the design and construction of a domestic passive solar food dryer. The dryer is composed of solar collector (air heater and a solar drying chamber containing rack of four cheese cloth (net trays both being integrated together. The air allowed in through air inlet is heated up in the solar collector and channeled through the drying chamber where it is utilized in drying (removing the moisture content from the food substance or agricultural produce loaded. The design was based on the geographical location which is Abeokuta and meteorological data were obtained for proper design specification. Locally available materials were used for the construction, chiefly comprising of wood (gmelina, polyurethane glass, mild steel metal sheet and net cloth for the trays.

Oguntola J. ALAMU

2010-12-01

110

Investigation and Construction of a Thermosyphoning Solar Hot Water System  

Science.gov (United States)

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)

Johnson, Harvey

1978-01-01

111

Design and Construction of a Passive Solar Power Clothing Dryer  

Directory of Open Access Journals (Sweden)

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.

Ali Alahmer

2014-04-01

112

Gas Chimneys -A Key to Risking Prospects  

International Nuclear Information System (INIS)

Gas chimneys can indicate fluid migration pathways between a source rock and the seabed, as well as indicate hydrocarbon charged reservoirs, leaky faults and dry reservoirs. To be able to map gas chimneys in a consistent manner, a method was developed for detecting chimneys in 3D seismic data. The method makes use of multi-attributes, which are fed into a neural network. The networks trained on these attributes to recognize chimneys. The output is a seismic cube which exhibits the shape and spatial distribution of the chimneys. Application of this recently developed method shows consistency in the way chimneys appear above hydrocarbon charged reservoirs, and above dry reservoirs. Alternatively, or in combination with chimneys, mud volcanoes can give similar indications. Examples from the Nigerian Continental Slope, as well as the Norwegian Shelf, the Gulf of Mexico and the Caspian Sea show how the mapping of gas chimneys (and mud volcanoes) can be used to high-grade or down- it. grade prospects. The presence of chimneys in seismic data are in numerous cases observed to coincide with faults, suggesting these faults are acting, or have data between source rocks and reservoirs and between reservoirs and the seabed. Chimneys may also take the shape of widely extended clouds, in which case they do not seem to be related to faults. Different scenarios of chimney appearance can be related to dry or hydrocarbon charged reservoirs

2003-11-16

113

Heating boiler and chimney. Heizkessel und Schornstein  

Energy Technology Data Exchange (ETDEWEB)

The kind of heat generator and particularly its exhaust gas data has a not insignificant impact on the chimney and therefore possibly also on the safe operation of firing systems. In order to avoid problems such as e.g. breakdown due to too low chimney draught or also structural damage due to penetration of dampness in the chimney the heat generator and chimney have to be well-suited to each other. Here apart from building regulations the generally accepted rules of technology have to be complied with. For the planning and dimensioning of chimneys there are particularly DIN 18 160 about 'House chimneys' and DIN 4705 about 'Calulation of chimney dimensions'. (orig.).

Stehmeier, D.

1992-09-01

114

A study of plume rise from multi-tube chimney and types of chimney structure  

Energy Technology Data Exchange (ETDEWEB)

This paper tries to determine the most economical type of reinforced concrete chimney structure based on the same effective height of chimney. Simulation experiments of wind tunnel were performed in the study, which compare multi-tube chimney with single tube chimney based on the same buoyancy flux of plume. According to the comparison of experiment results and the previous studies of plume rise, the paper defines some final plume rise models. Finally, the paper gives the cost-benefit analysis after making cost estimation for different types of chimney structure and recommends the economical and reasonable type of chimney structure in light of the same environmental benefits. 7 tabs.

Liu Yongjiu [Northwest Electric Power Design Institute, Xian (China)

1996-12-31

115

Microbial Diversity of Carbonate Chimneys at the Lost City Hydrothermal Field: Implications for Life-Sustaining Systems in Peridotite Seafloor Environments  

Science.gov (United States)

The Lost City Hydrothermal Field (LCHF) is a novel peridotite-hosted vent environment discovered in Dec. 2000 at 30 N near the Mid-Atlantic Ridge. This field contains multiple large (up to 60 m), carbonate chimneys venting high pH (9-10), moderate temperature (45-75 C) fluids. The LCHF is unusual in that it is located on 1.5 my-old oceanic crust, 15 km from the nearest spreading axis. Hydrothermal flow in this system is believed to be driven by exothermic serpentinization reactions involving iron-bearing minerals in the underlying seafloor. The conditions created by such reactions, which include significant quantities of dissolved methane and hydrogen, create habitats for microbial communities specifically adapted to this unusual vent environment. Ultramafic, reducing hydrothermal environments like the LCHF may be analogous to geologic settings present on the early Earth, which have been suggested to be important for the emergence of life. Additionally, the existence of hydrothermal environments far away from an active spreading center expands the range of potential life-supporting environments elsewhere in the solar system. To study the abundance and diversity of microbial communities inhabiting the environments that characterize the LCHF, carbonate chimney samples were analyzed by microscopic and molecular methods. Cell densities of between 105 and 107 cells/g were observed within various samples collected from the chimneys. Interestingly, 4-11% of the microbial population in direct contact with vent fluids fluoresced with Flavin-420, a key coenzyme involved in methanogenesis. Enrichment culturing from chimney material under aerobic and anaerobic conditions yielded microorganisms in the thermophilic and mesophilic temperature regimes in media designed for methanogenesis, methane-oxidation, and heterotrophy. PCR analysis of chimney material indicated the presence of both Archaea and Eubacteria in the carbonate samples. SSU rDNA clone libraries constructed from the Eubacterial DNA show that diverse microbial communities, including autotrophic microorganisms and animal symbionts, are contained within the vent structures. In concert, these results indicate that abundant and varied microbial communities inhabit different regions of the chimney structure and may be specifically adapted to the reducing, volatile-rich fluids percolating through the chimneys. In addition to expanding the range of known deep-sea ecosystems, the microbial ecology of carbonate structures associated with hydrothermal venting at the LCHF may provide key insights into the microbiology of subsurface environments near this site. Studying the microbial communities within these systems will enable us to better understand geo-microbial processes associated with serpentinite environments and perhaps allow us to expand our search for life elsewhere in the universe.

Schrenk, M. O.; Cimino, P.; Kelley, D. S.; Baross, J. A.

2002-12-01

116

Design, Construction and Testing of Simple Solar Maize Dryer  

Directory of Open Access Journals (Sweden)

Full Text Available This project reports the design, construction and testing of a simple solar maize dryer. It is design in such a way that solar radiation is not incident directly on the maize, but preheated air warmed during its flow through a low pressure thermosphonic solar energy air heater or collector made up of an insulating material (polystyrene of size 100mmx50mmx25.4mm, absorber plate (aluminium sheet painted black of size 100mmx50mm and a cover glass (5mm thickness measuring 100mmx50mm all arranged in this order contributed to the heating. The test results gave temperature above 45OC in the drying chamber, and the moisture content of 50kg of maize reduced to about 12.5% in three days of 9hours each day of drying.

Joshua FOLARANMI

2008-12-01

117

Solar power plant in light-weight construction  

Energy Technology Data Exchange (ETDEWEB)

A solar power plant built as a light-weight construction is introduced. The development had been started in 1972. This power plant is characterized by extremely light rotating parabolic mirrors and a highly transparent cupola under which the mirrors are protected from weather influences, controlled by sensors and directed to the sun. The central point of this new type of power plant are the big foil membrane mirrors. These mirrors concentrate the directly falling sun light on a specially developed linear-Stirling-generator which converts the solar energy directly into electric alternating current. Arranged as modules, the parabolic mirrors can be assembled to solar copula power plant forms. Data of a system with mirrors with 10 m-diameters are presented.

1982-09-01

118

Construction and evaluation of a timber-drying solar kiln  

Energy Technology Data Exchange (ETDEWEB)

A solar timber kiln with the capacity to season 3.24 m{sup 3} of lumber was designed, constructed and used for seasoning commercial sawnwood. The kiln was constructed of a timber frame covered with transparent polythene sheet on the top and black leatherette on the sides. Corrugated, galvanized-iron sheet painted black and tilted at 30{sup o} to the horizontal served as a heat collector. Two fans were fitted for air circulation. The kiln attained a maximum temperature of 24{sup o} above the ambient temperature. The average efficiency of the heat collector was 38.5%. The solar kiln reduced timber drying time by 33.3-57.1% when compared with an air-drying technique. Sawnwoods (25 mm by 300 mm by 360 mm) of Mansonia altissima and Terminalia superba were dried from 46.16 to 15.02% and from 52 to 15.4% moisture content respectively in 12 days. (Author)

Fuwape, I.A.; Fuwape, J.A.

1995-09-01

119

Comparative metagenomics of microbial communities inhabiting deep-sea hydrothermal vent chimneys with contrasting chemistries  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Deep-sea hydrothermal vent chimneys harbor a high diversity of largely unknown microorganisms. Although the phylogenetic diversity of these microorganisms has been described previously, the adaptation and metabolic potential of the microbial communities is only beginning to be revealed. A pyrosequencing approach was used to directly obtain sequences from a fosmid library constructed from a black smoker chimney 4143-1 in the Mothra hydrothermal vent field at the Juan de Fuca Ridge. A total of ...

Xie, Wei; Wang, Fengping; Guo, Lei; Chen, Zeling; Sievert, Stefan M.; Meng, Jun; Huang, Guangrui; Li, Yuxin; Yan, Qingyu; Wu, Shan; Wang, Xin; Chen, Shangwu; He, Guangyuan; Xiao, Xiang; Xu, Anlong

2011-01-01

120

Determination of the nonverticality of high chimneys  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This article deals with practical examples of the applications of modern tachymeters in the determination of the nonverticality of high industrial chimneys, as an alternative to the classic methods. The possibility of a reflectorless measuring mode to determine the point cloud at the chimney's circumference is described. Using these points, we are able to model the chimney as a mathematically correct body using the least squares adjustment method. Subsequently, the unknown nonverticality of t...

Marjetic?, Ales?; Ambroz?ic?, Tomaz?; Kogoj, Dus?an

2011-01-01

 
 
 
 
121

Construction of Solar-Wind-Like Magnetic Fields  

Science.gov (United States)

Fluctuations in the solar wind fields tend to not only have velocities and magnetic fields correlated in the sense consistent with Alfven waves traveling from the Sun, but they also have the magnitude of the magnetic field remarkably constant despite their being broadband. This paper provides, for the first time, a method for constructing fields with nearly constant magnetic field, zero divergence, and with any specified power spectrum for the fluctuations of the components of the field. Every wave vector, k, is associated with two polarizations the relative phases of these can be chosen to minimize the variance of the field magnitude while retaining the\\random character of the fields. The method is applied to a case with one spatial coordinate that demonstrates good agreement with observed time series and power spectra of the magnetic field in the solar wind, as well as with the distribution of the angles of rapid changes (discontinuities), thus showing a deep connection between two seemingly unrelated issues. It is suggested that using this construction will lead to more realistic simulations of solar wind turbulence and of the propagation of energetic particles.

Roberts, Dana Aaron

2012-01-01

122

Salt-gradient solar ponds: design, construction and power production  

Energy Technology Data Exchange (ETDEWEB)

Salt-gradient solar ponds are combined solar energy collectors and thermal storage systems. The ponds are made non-convective by the formation of a density-gradient composed of salt solutions whose concentrations increase with depth. The depth of the various layers of the pond determine the efficiency and thermal storage capacity of the system. The construction of the largest such pond in the US, 2000 m/sup 2/, was completed in 1978 for approximately $35/m/sup 2/. The pond is estimated to produce 1015 GJ/y of low-temperature heat at a cost of $8.95/GJ, when the installation costs are amortized over 15 y. Construction changes are suggested to improve the reliability of the system. Electrical power generation by the use of Rankine cycle turbogenerators connected to solar ponds has been demonstrated in Israel. Feasibility studies are in progress to propose electricity production of up to 2000 MW for projects near the Dead Sea in Israel, and 600 MW in a proposed project at the California Salton Sea.

Wittenberg, L.J.

1980-01-01

123

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

Energy Technology Data Exchange (ETDEWEB)

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.

Stadermann, Gerd (ed.)

2009-04-15

124

Nonlinear analysis of a collapsed reinforced concrete chimney  

Digital Repository Infrastructure Vision for European Research (DRIVER)

During the Ismit (Kocaeli) Earthquake of August 17, 1999, a 115 m. High reinforced concrete chimney or heater stack, located at the Tüpras Refinery, collapsed. The falling debris cut 63 pipes, which contributed to interrupted production for more than 14 months. This stack was designed and constructed according to international standards and is representative of similar structures at refineries throughout the world, including those in earthquake-prone regions. It was distinguis...

Gould, Phillip L.; Huang, Wei

2009-01-01

125

Design and construction of a low cost solar simulator  

International Nuclear Information System (INIS)

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)

1999-06-08

126

Analysis of Self-Supporting Chimney  

Directory of Open Access Journals (Sweden)

Full Text Available Chimneys are tall structures and the major loads acting on these are self weight of the structure, wind load, live load due to lining, earthquake load & temperature loads. In this paper a RC chimneys will be designed considering dead load, wind load and earthquake load. The Bureau of Indian Standards (BIS design codes procedures will be used for the design of chimney. The present paper discusses the parametric study of RC chimney which is made by obtaining the results from software for different heights, diameter, earthquake zones, wind zones, type of soils and various load conditions because of changes in the dimensions of chimney, structural analysis such as response to earthquake and wind oscillations have become more critical to influence on the response and design of chimney. Parametric study on chimney from height 150 meters to 250 meters at an interval of 5 meters, for Zone II, Hard soil & Critical Zone of Zone V, Soft soil with wind speed varying from 33 meters/sec to 55 meters/sec with an internal temperature of 100 Degrees. The response of the chimney is studied & recorded in Tables & Graphs. The analysis is carried out using programming software Microsoft Visual Basic 6.0. The results obtained from the above cases are compared. Finally, the maximum values obtained in wind analysis and seismic analyses are then compared for deciding the design value.

Rajkumar

2013-10-01

127

Comparative metagenomics of microbial communities inhabiting deep-sea hydrothermal vent chimneys with contrasting chemistries.  

Science.gov (United States)

Deep-sea hydrothermal vent chimneys harbor a high diversity of largely unknown microorganisms. Although the phylogenetic diversity of these microorganisms has been described previously, the adaptation and metabolic potential of the microbial communities is only beginning to be revealed. A pyrosequencing approach was used to directly obtain sequences from a fosmid library constructed from a black smoker chimney 4143-1 in the Mothra hydrothermal vent field at the Juan de Fuca Ridge. A total of 308,034 reads with an average sequence length of 227 bp were generated. Comparative genomic analyses of metagenomes from a variety of environments by two-way clustering of samples and functional gene categories demonstrated that the 4143-1 metagenome clustered most closely with that from a carbonate chimney from Lost City. Both are highly enriched in genes for mismatch repair and homologous recombination, suggesting that the microbial communities have evolved extensive DNA repair systems to cope with the extreme conditions that have potential deleterious effects on the genomes. As previously reported for the Lost City microbiome, the metagenome of chimney 4143-1 exhibited a high proportion of transposases, implying that horizontal gene transfer may be a common occurrence in the deep-sea vent chimney biosphere. In addition, genes for chemotaxis and flagellar assembly were highly enriched in the chimney metagenomes, reflecting the adaptation of the organisms to the highly dynamic conditions present within the chimney walls. Reconstruction of the metabolic pathways revealed that the microbial community in the wall of chimney 4143-1 was mainly fueled by sulfur oxidation, putatively coupled to nitrate reduction to perform inorganic carbon fixation through the Calvin-Benson-Bassham cycle. On the basis of the genomic organization of the key genes of the carbon fixation and sulfur oxidation pathways contained in the large genomic fragments, both obligate and facultative autotrophs appear to be present and contribute to biomass production. PMID:20927138

Xie, Wei; Wang, Fengping; Guo, Lei; Chen, Zeling; Sievert, Stefan M; Meng, Jun; Huang, Guangrui; Li, Yuxin; Yan, Qingyu; Wu, Shan; Wang, Xin; Chen, Shangwu; He, Guangyuan; Xiao, Xiang; Xu, Anlong

2011-03-01

128

A Construction Methodology of the Large Solar Array System of a Solar Power Satellite  

Science.gov (United States)

A construction methodology of the large solar array system is investigated, assuming the SPS 2000 model of ISAS, the experimental model for the future Solar Power Satellite in Japan. The structure elements such as trusses, beams and solar arrays are transported from the ground 10 times by using a rocket. First, the basic module is assembled and then the subsequent modules are attached towards N-S direction. The construction sequence how to form this basic module has already been examined under the gravity gradient environment. This paper discusses how to extend the flexible solar array sheets over this module. First, the dynamic model when extending an array is developed, by including the moment of inertia and angular momentum change during the extension. Then, the dynamic behaviors during extension are examined. When an extension is made by one array by one, the momentum by extending array and the moment of inertia change induce larger oscillation around all three axes of the basic module. Thus the method to minimize these changes by extending the pair of the arrays simultaneously is studied for reducing the attitude vibration. In conclusion, a method of extending two arrays simultaneously is judged desirable for a practical application.

Shigehara, M.; Ohtaka, A.

1996-02-01

129

Solar concentrator constructed with a circular prism array.  

Science.gov (United States)

We present a novel idea to construct a solar concentrator with a circular prism array. FRED ray tracing software is used to evaluate our proposed structure in which the incident light rays are deflected by total internal reflection and the optical energy is concentrated and collected at the center. The light rays to be collected travel within the disk once they enter the module, saving the space that is reserved for ray propagation in other concentrators. Simulations for both single-wavelength and broadband light are performed. Our device can be used alone or serve as a secondary concentrator when combined with another solar-energy focusing module. For the proposed concentrator, an optical efficiency of 90% (single wavelength, 0.87 microm) is achieved under normal incidence and with antireflection coating, and a high geometric concentration ratio of 93 is reached. When combined with a Fresnel lens, which is used as a primary concentrator, the overall efficiency and concentration ratio can reach 92% (single wavelength, 0.87 microm) and 837, respectively. PMID:20697451

Huang, Jia-hong; Fei, Wun-Ciang; Hsu, Wei-Chi; Tsai, Jui-che

2010-08-10

130

Piping systems, containment pre-stressing and steel ventilation chimney  

International Nuclear Information System (INIS)

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

1996-01-01

131

The decommissioning of the Windscale pile chimneys  

International Nuclear Information System (INIS)

The two pile chimneys on the Windscale site have been part of the landscape since 1957. The piles were originally built to produce weapon - grade plutonium. Subsequent nuclear accidents led to the deposition of radioactive material in the chimneys mainly in the filters near the top of the stacks. The decision to decommission the top sections of both chimneys was taken in 1985/86 mainly because of rising maintenance costs. The work which has been undertaken by British Nuclear Fuels Limited to date associated with decommissioning is described in this article. Future plans to complete the task are also noted. (UK)

1991-01-01

132

Collapse of chimney with impact on reactor building  

International Nuclear Information System (INIS)

The behavior of the chimney for the loads has to be investigated, as a possible collapse onto adjacent safety-relevant structures (reactor building, reactor auxiliary building, fuel-handling building). The loading cases which might cause a collapse are outlined. The mathematical models used to calculate the highly physically and geometrically non-linear behavior are described. The resulting response of the structures subjected to impact is determined and compared to that caused by other external extreme loading conditions. The safe-shutdown earthquake is represented by an artificially generated time history which fits a specified design-response spectrum. For preliminary calculations the response for simple sine wave excitation is determined. The ground acceleration at which collapse first occurs is calculated for different soil parameters and dimensions of the chimney. Overall consideration of the balance of energy and of impulse as well as detailed solutions of the resulting differential equations of motion are performed. These investigations are carried out on models of increasing complexity starting with the idealisation of the chimney as a rigid bar on a rigid, tensionless foundation and leading up to an elastoplastic representation of the structure and of the soil. When impacting onto adjacent buildings, the latter are always considered as being rigid. This allows a load-time relationship to be constructed, which, in a second independent step, is used in the dynamic analysis of the building subjected to impact. Several different failure modes of the chimney are examined. The scope of this paper is to determine the overall response of the structure and of its equipment

1977-08-19

133

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

Directory of Open Access Journals (Sweden)

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

Bhupendra Gupta

2013-10-01

134

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

Energy Technology Data Exchange (ETDEWEB)

This special issue of October 2003 reviews solar architecture, planning, applications, technology, market and knowledge. Subjects: Falkenweg housing development; Q-Cells solar factory; Modehaus Zara building; Haus Westermayr McCready building; Federal Environmental Office building, Dessau; 'Haus im Himmel' building; NRW state representatives building in Berlin; Zero-emission building 'Sunny Woods', Zurich; Hellerau workshop buildings, Dresden; HOCHTIEF PRISMA Haus building, Frankfurt; Solar government buildings, Berlin; SOLARBAU programme; Energy supply concepts based on photovoltaic power supply; Solar cooling; Photovoltaic lamellas; Solar building construction; Solar contracting; Solar building modernisation; Integrated PV systems in Europe; Living in passive buildings; Funding programmes for renewable energy sources and building construction. (orig./AKF)

Rust, A. (comp.)

2003-10-01

135

Seismic modelling of a masonry chimney  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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.

2007-01-01

136

Fire extinguishing attachment for chimney stacks  

Energy Technology Data Exchange (ETDEWEB)

A fire extinguishing attachment including a bracket for mounting on a stove stack and having a tubular guide therethrough. The tubular guide is an elbow tube having an inner end within the stack directed towards the chimney flue and an outer end outside the stack adapted to receive the nozzle of a powder type fire extinguisher. When a chimney fire occurs, the extinguisher is placed over the outer end of the guide end and activated. The powdered material is directed, by the guide, into the stack and up the chimney to the location of the fire thereby extinguishing the fire. The guide and bracket is preferably downstream of the damper in the same section of stack to be close to the chimney, and for unobstructed flow.

Sawtelle, K.

1984-11-13

137

Draft plugging device for a chimney flue  

Energy Technology Data Exchange (ETDEWEB)

A device for plugging a chimney flue when not in use comprises an elongate semi-rigid wand which can be manoeuvered by manual moving of one end so that the opposed end can be inserted into the chimney flue. The opposed end carries an inflatable balloon which can be inflated to grasp the inner surface of the flue by valve arrangement at the lower end.

Penner, P.

1987-12-29

138

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2009-07-01

139

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

2013-03-15

140

Constructal Optimization of Top Contact Metallization of a Photovoltaic Solar Cell  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Aditya Bhakta; Santanu Bandyopadhyay

2005-01-01

 
 
 
 
141

Design of a solar power satellite for construction from lunar materials  

Energy Technology Data Exchange (ETDEWEB)

Solar Power Satellites may be constructed from materials mined on the Moon and transported into free space by means of an electromagnetic catapult called a mass-driver. Both the mass-driver and the chemical processing techniques required to obtain construction materials from lunar soil have been demonstrated in the laboratory. A Solar Power Satellite has been designed for construction from lunar materials. This design requires only 1% of its mass from the Earth.

Maryniak, G.E.; Tillotson, B.

1988-01-01

142

Design, construction and evaluation of solarized airlift tubular photobioreactor  

International Nuclear Information System (INIS)

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.

2013-06-10

143

State of the art chimney for FGD non-reheat service  

Energy Technology Data Exchange (ETDEWEB)

This paper provides an overview of the configuration, materials of construction, auxiliary systems, and design details for a large, multiple (3) flue chimney servicing a wet limestone flue gas desulfurization system (FGDS) at Indianapolis Power and Light Company`s (IPL) Petersburg Station--Units 1 and 2. This project was initiated by IPL in response to the Clean Air Act Amendment of 1990 and is intended to treat the flue gas from two base loaded coal fired units with a combined capacity of approximately 700 MW gross electrical output. The reinforced concrete chimney shell is 80 ft. in diameter and 621 ft. in height with three independent acid resistant brick and mortar (ARBM) liners. A separate liner is dedicated to each units` absorber module with the third liner dedicated to Unit No. 2 bypass mode. The existing Unit 1 and 2 stack serves as the Unit 1 by-pass flue. The scrubbed gas liners are sized for low velocity, non-reheat service to prevent re-entrainment of any liquid carry-over from the liner walls. Both of these liners are equipped with alloy exit chokes to increase gas velocity for better plume dispersion. The absorber outlet ducts, the chimney breeching duct, the breeching section of the liner, and the exit chokes are all equipped with liquid collection devices designed to minimize stack liquid discharge. The paper discusses the unique design features associated with this non-reheat chimney, and the challenges these features presented during the chimney`s design and construction.

O`Donnell, R.J. [Stone and Webster, Boston, MA (United States); Bird, D. [Pullman Power Products Corp., Kansas City, MO (United States); McCord, P. [Indianapolis Power and Light Co., IN (United States)

1997-09-01

144

Chimneys: No fire without smoke; Schornsteinsysteme: Kein Feuer ohne Rauch  

Energy Technology Data Exchange (ETDEWEB)

Modern pellets heating systems and wood heating systems need modern chimney systems of noble steel or ceramics. There is a trend towards universal chimneys for all fuel types and towards operation of heating systems independent of room air. (orig.)

Hilgers, C.

2007-08-27

145

The remote dismantling of the Windscale pile chimneys  

International Nuclear Information System (INIS)

The two Windscale Pile Chimneys are being substantially dismantled to ensure their future structural stability. Radiation dose rates dictate that most of the work at No. 1 Chimney shall be carried out remotely. Lower radiation dose rates at No. 2 Chimney still require the use of some remote equipment to meet the ALARP principle. However this Chimney provides an ideal test facility for techniques which will be developed and transferred to No. 1. (author)

1992-01-01

146

Toy models for the falling chimney  

CERN Document Server

In this paper we review the theory of the ``falling chimney'', which deals with the breaking in mid-air of tall structures, when they fall to the ground. We show that these ruptures can be caused by either shear forces, typically developing near the base, or by the bending of the structure, which is caused primarily by the internal bending moment. In the latter case the breaking is more likely to occur between one third and one half of the height of the chimney. Small scale toy models are used to reproduce the dynamics of the falling chimney. By examining photos taken during the fall of these models we test the adequacy of the outlined theory. This type of experiment, easy to perform and conceptually challenging, can become part of a rotational mechanics lab for undergraduate students.

Varieschi, G U; Varieschi, Gabriele; Kamiya, Kaoru

2003-01-01

147

Chimney safety tests users' manual. Procedures for determining the safety of residential chimneys  

Energy Technology Data Exchange (ETDEWEB)

The manual describes a series of procedures for testing the performance of residential chimney systems. It includes a summary of the safety tests. It discusses the venting system pre-test, venting system test, heat exchanger leakage test, safety inspection, and chimney performance test. The tests provide insulation and sealing contractors, fan installers, and heating tradesmen with a simple way of ensuring that the chimney operating environment resulting from their work will not result in unsafe conditions. The test procedures were extensively field tested and evaluated in a variety of centres across Canada.

1987-01-01

148

Measurement of chimney dimensions and development of special tools for installation of in-chimney bracket in HANARO  

Energy Technology Data Exchange (ETDEWEB)

The in-chimney bracket is a structure which supports the guide tubes of irradiation facilities at the irradiation sites of CT, IR1, IR2, OR4 and/or OR5 in HANARO core to reduce the flow-induced vibration and the dynamic response to seismic load. It horizontally supports the middle part of lthe irradiation facilities for CT/IR sites in addition to the robot arms which had already been installed at the reactor pool liner to support the top of the facilities, and supports the top of the guide tubes for OR sites. For these purposes, the in-chimney bracket was installed in the chimney using four siphoning holes located at 70 cm below the chimney top. It is necessary to measure the dimensions of chimney before the design of in-chimney bracket because there must be manufacturing tolerances and the deformation of the chimney due to the load of the system pipes. To implement this, various special tools had been developed to measure the as-built dimensions of the chimney at the elevation of the siphoning holes, and measured the chimney dimensions and the eccentricity of the chimney center from the reactor core center. Also, a special tool was developed for the installation of the in-chimney bracket by remote operating at the pool top 10 meters apart from the chimney. The installation procedures were established through the enough installation rehearsal using the installation tool and the dummhy chimney which was fabricated to the same dimensions of the real chimney, and the installation interference problems were resolved through the preliminaly installation to the reactor chimney. Finally, the in-chimey bracket was successfully installed at the reactor chimney and is well being used for the irradiation test since the installation on May 16, 2000.

Cho, Yeong Garp; Ryu, J. S.; Lee, J. H.; Lee, Y. S; Lee, B. H

2000-06-01

149

Constructal Optimization of Top Contact Metallization of a Photovoltaic Solar Cell  

Directory of Open Access Journals (Sweden)

Full Text Available 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 losses. Constructal theory explains the geometric form (shape and structure of most volume-to-point systems in nature. In this paper, the applicability of the constructal theory to design top contact metallization for a photovoltaic solar cell has been extended.

Santanu Bandyopadhyay

2005-12-01

150

The W4 chimney/superbubble  

CERN Document Server

A conical void in the Galactic HI within the Perseus arm has been proposed to be a chimney. However, Halpha data suggest that the structure may be closed at higher latitudes and therefore is a superbubble rather than a chimney. Recent observations have extended our view of the HI and the radio continuum emission to higher latitudes, up to 8 degrees;. The new images show the HI structure to be open at the top and a small filament suggests recent breakout. The conical shape of the structure is not easily explained by superbubble models.

Normandeau, M

2000-01-01

151

The W4 chimney/superbubble  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A conical void in the Galactic HI within the Perseus arm has been proposed to be a chimney. However, Halpha data suggest that the structure may be closed at higher latitudes and therefore is a superbubble rather than a chimney. Recent observations have extended our view of the HI and the radio continuum emission to higher latitudes, up to 8 degrees;. The new images show the HI structure to be open at the top and a small filament suggests recent breakout. The conical shape of...

Normandeau, Magdalen

2000-01-01

152

Toy models for the falling chimney  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper we review the theory of the ``falling chimney'', which deals with the breaking in mid-air of tall structures, when they fall to the ground. We show that these ruptures can be caused by either shear forces, typically developing near the base, or by the bending of the structure, which is caused primarily by the internal bending moment. In the latter case the breaking is more likely to occur between one third and one half of the height of the chimney. Small scal...

Varieschi, Gabriele; Kamiya, Kaoru

2002-01-01

153

Aerodynamic tests on chimney cowls. Aerodynamische Untersuchungen an Schornsteinaufsaetzen  

Energy Technology Data Exchange (ETDEWEB)

The function of heating systems can be considerably affected by the wind. In principle, in the horizontal flow to the chimney cowl, localized acceleration occurs that produces a wanted vacuum in the chimney. For this reason, chimneys should always empty into a free wind flow. In the composite of buildings, in large conurbations, this is not always possible for all wind direction, whilst avoiding excess pressures in the chimney. In addition, a virtually uninfluenced effect from the wind force on the chimney cowl is required. Aerodynamically well designed cowls have a choking effect for strong wind and thus regulate the draught. (orig./BWI)

Rawe, R. (Fachhochschule Gelsenkirchen (Germany)); Goeddeke, H. (Inst. fuer Rationellen Energieeinsatz, Boppard (Germany)); Oezcan, A.Y. (Fachhochschule Muenster (Germany)); Postulka, M. (Fachhochschule Muenster (Germany))

1993-05-01

154

Preliminary work for stage 2 decommissioning of B16 pile chimney  

International Nuclear Information System (INIS)

Planning of the second stage of decommissioning of the two pile chimneys at Sellafield started while work was underway on the first stage, which involved removal of the sections above the filters. The second stage requires the removal of all radio-active parts and the dismantling of the filter and diffuser sections, and has to be completed by 1997. The planning involved studying the many possible options and their effects on both radiological and industrial safety. This decommissioning project employs a high proportion of civil engineering and construction techniques, which are then developed to eliminate the hazards from radioactive dusts, and to minimise the effect of radiation on operatives working on the project. Much of this equipment is modified forms of standard construction equipment and includes cutting equipment and remotely operated vehicles. The initial phases of the work involve: provision of a waste packaging and access building; provision of temporary ventilation systems to control the dust generated by the work, cutting of 3 m square access doorway through the 1.5 m thick reinforced concrete wall of the chimney; provision of Remotely Operated Vehicle (ROV) to act as a tool carrier for lining stripping work; removal of the thermal lining from the floor and lower walls of the chimney, and installation of precast concrete walls which separate the pile reactor core from the chimney flue. (author)

1991-03-20

155

Wicking limits for porous deposits with chimneys  

International Nuclear Information System (INIS)

The primary coolant system in light water reactors is subjected to corrosion on surfaces and to the deposition of corrosion products on surfaces. These conditions occur both in-core and out-of-core and inhibit the thermal transfer across the layers. The deposition of such crud layers on reactor fuel element surfaces is a recognized problem that can affect performance and potentially limit the maximum power rating of the fuel. When boiling is present with such crud layers, wick boiling has been postulated to be the dominant mode of heat transfer, at least when it can be assumed that the structure of the deposit includes chimneys, i.e., large pore holes that penetrate deeply into the deposit and almost perpendicularly to the surface on which the deposit has formed. The wick boiling mechanism is explained. In this study, the wicking limit for porous deposits with chimneys is investigated. The major highlights gained from this study include: (1) the dryout heat flux for a heating surface may be caused by the Helmholtz instability due to high-velocity gas jets or by the wicking limit. (2) The dryout heat flux based on the wicking limit decreases very rapidly with decreasing porosity, with decreasing size of particles in the porous layer, and with increasing crud thickness. (3) Physically, it is expected that the chimney population would increase with increasing heat flux. Using a power law relation between heat flux and chimney population density, much lower wicking limits or thinner deposits are predicted

1987-11-15

156

Wicking limits for porous deposits with chimneys  

Energy Technology Data Exchange (ETDEWEB)

The primary coolant system in light water reactors is subjected to corrosion on surfaces and to the deposition of corrosion products on surfaces. These conditions occur both in-core and out-of-core and inhibit the thermal transfer across the layers. The deposition of such crud layers on reactor fuel element surfaces is a recognized problem that can affect performance and potentially limit the maximum power rating of the fuel. When boiling is present with such crud layers, wick boiling has been postulated to be the dominant mode of heat transfer, at least when it can be assumed that the structure of the deposit includes chimneys, i.e., large pore holes that penetrate deeply into the deposit and almost perpendicularly to the surface on which the deposit has formed. The wick boiling mechanism is explained. In this study, the wicking limit for porous deposits with chimneys is investigated. The major highlights gained from this study include: (1) the dryout heat flux for a heating surface may be caused by the Helmholtz instability due to high-velocity gas jets or by the wicking limit. (2) The dryout heat flux based on the wicking limit decreases very rapidly with decreasing porosity, with decreasing size of particles in the porous layer, and with increasing crud thickness. (3) Physically, it is expected that the chimney population would increase with increasing heat flux. Using a power law relation between heat flux and chimney population density, much lower wicking limits or thinner deposits are predicted.

Pan, C.; Jones, B.G.; Machiels, A.J.

1987-01-01

157

Excess of cancer in Swedish chimney sweeps.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The incidence of cancer was investigated among 5266 Swedish chimney sweeps employed for any period between 1918 and 1980. An analysis of the mortality has been reported earlier and showed an increased number of deaths from coronary heart disease, respiratory diseases, and lung, oesophageal, and liver cancer. Excess risks for cancer of the lung and oesophagus were confirmed in this analysis. Among the lung cancers, both squamous cell carcinoma and oatcell/undifferentiated carcinoma were in exc...

Gustavsson, P.; Gustavsson, A.; Hogstedt, C.

1988-01-01

158

Excess mortality among Swedish chimney sweeps.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In a cohort study of 5464 union organised Swedish chimney sweeps employed at any time between 1918 and 1980 mortality was studied from 1951 to 1982 with national statistics used as a reference. Follow up was possible for 98.6% of the individuals: 717 deaths were observed against 540 expected. There was an increased mortality from coronary heart disease, respiratory diseases, and several types of malignant tumours. Lung cancer mortality was significantly increased and positively correlated to ...

Gustavsson, P.; Gustavsson, A.; Hogstedt, C.

1987-01-01

159

On the problem of the 'effective chimney height'  

International Nuclear Information System (INIS)

This article outlines the quantitative attempts at describing pollution levels produced by chimney stacks. Since the early days the notion of an effective chimney height (ECH) has taken hold in assessing the effects of buoyancy on the dispersal of effluents. This essentially engineering concept is quite attractive at first sight and is based on the recognition that the main criterion (as far as air pollution problems are concerned) in designing a chimney is the maximum ground level concentration of effluent.

1967-09-11

160

Distribution of Archaea in a Black Smoker Chimney Structure  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Archaeal community structures in microhabitats in a deep-sea hydrothermal vent chimney structure were evaluated through the combined use of culture-independent molecular analyses and enrichment culture methods. A black smoker chimney was obtained from the PACMANUS site in the Manus Basin near Papua New Guinea, and subsamples were obtained from vertical and horizontal sections. The elemental composition of the chimney was analyzed in different subsamples by scanning electron microscopy and ene...

Takai, Ken; Komatsu, Tetsushi; Inagaki, Fumio; Horikoshi, Koki

2001-01-01

 
 
 
 
161

Fission product distribution in nuclear test cavities/chimneys  

International Nuclear Information System (INIS)

When a nuclear device is exploded, residual radioactive material is distributed throughout the resulting underground cavity and rubble chimney. Refractory materials are more concentrated at the bottom of the cavity and volatile materials are more concentrated in the chimney. The radionuclides deposited in the chimney region are more readily leached by groundwater than those incorporated in the melt glass in the cavity. Studies of expended nuclear test sites may help us anticipate the behavior of radionuclides in a nuclear repository

1993-04-25

162

Chimney grafts in aortic occlusive disease.  

Science.gov (United States)

The aim of this article was to present juxtavisceral aortic occlusive disease with particular reference to a novel therapeutic approach, namely protected stenting by means of so called chimney grafts. The juxta renal aortic occlusion is the last aortoiliac occlusive lesion not to be stented routinely because of the risk for trash and/or need for overstenting of vital aortic side branches. The risk for trash also exists in open repair which makes it particularly challenging in this setting. The patients have advanced atherosclerosis and are poor risks for major surgery. A safe endovascular approach is therefore desirable. These lesions are either predominantly thrombotic or heavily calcified plaques. The thrombotic lesions can be stented under protection of the visceral branches by temporary occlusion balloons. The calcified lesions, on the other hand, require overstenting of the visceral vessels that then need to be preserved by chimney grafts. These endovascular procedures are complex and time consuming but they are associated with less surgical trauma and hence improved morbidity, mortality and recovery. The median term results of chimney grafts are encouraging, although more patients and longer follow-up are still needed. PMID:24796899

Malina, M; Sonesson, B; Bin Jabr, A

2014-04-01

163

Design, construction and experimental study of electric cum solar oven - 2  

Energy Technology Data Exchange (ETDEWEB)

As in most of the developing countries, 35-40% of the population of Costa Rica still use firewood for domestic cooking. Considering the fact that Costa Rica is blessed with good sunshine, high hydroelectric potential and there exists a good electric network, a hybrid solar oven was thought to be useful. The construction and working of one electric cum solar oven (ECSO) has been described. This oven can be used for cooking and baking almost all types of meals at any time during the year employing solar and/or electric energy and consuming the minimum quantity of electric energy when it is required.

Nandwani, S.S.

1989-01-01

164

Solar hot water systems for the southeastern United States: principles and construction of breadbox water heaters  

Energy Technology Data Exchange (ETDEWEB)

The use of solar energy to provide hot water is among the easier solar technologies for homeowners to utilize. In the Southeastern United States, because of the mild climate and abundant sunshine, solar energy can be harnessed to provide a household's hot water needs during the non-freezing weather period mid-April and mid-October. This workbook contains detailed plans for building breadbox solar water heaters that can provide up to 65% of your hot water needs during warm weather. If fuel costs continue to rise, the annual savings obtained from a solar water heater will grow dramatically. The designs in this workbook use readily available materials and the construction costs are low. Although these designs may not be as efficient as some commercially available systems, most of a household's hot water needs can be met with them. The description of the breadbox water heater and other types of solar systems will help you make an informed decision between constructing a solar water heater or purchasing one. This workbook is intended for use in the southeastern United States and the designs may not be suitable for use in colder climates.

None

1983-02-01

165

NUMERICAL ANALYSIS OF HEAT STORAGE OF SOLAR HEAT IN FLOOR CONSTRUCTION  

DEFF Research Database (Denmark)

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 consumption for heating, by using heat storage in the floor construction is calculated using a dynamic simulation model of solar collector, solar tank and heat storage coupled to a building model, using the Danish Design Ref-erence Year as input. The model calculates the performance of the solar heating 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 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 with the highest energy con-sumption. The reduction depends on the solar collector area, distribution of the insulation thickness, heat-ing demand and control strategy, but not on pipe spacing and layer thickness and material. Finally, it is shown that the system can also be used for comfort heating of tiled floors during the summer period.

Weitzmann, Peter; Holck, Ole

2003-01-01

166

Design guide for multi-flue chimneys. PSA (Property Services Agency) Civil Engineering Technical Guide No. 39  

Energy Technology Data Exchange (ETDEWEB)

This Design Guide primarily covers the thermal and structural design of multi-flue chimneys serving conventional boilers and small hospital and laboratory incinerators and having heights less than 50m. Above 50m height, additional effects may come into prominence which are beyond the scope of the Guide. It is not intended to include chimneys serving industrial processes or large refuse incinerators. The Guide is intended to be comprehensive and is directed at civil, mechanical, and electrical and project engineers involved in the procurement of chimneys. It includes descriptions of the stages of a project, outline and detail design (including selection of materials), construction (including quality assurance), operation, and maintenance. Design examples are given for steel and concrete flue linings and support structures.

1987-01-01

167

Solar energy system performance evaluation, design construction, Bigfork, Montana, October 1979-April 1980  

Energy Technology Data Exchange (ETDEWEB)

The Design Construction site is a single-family residence in Bigfork, Montana equipped with an active solar energy system. The solar energy system consists of an array of 792 square feet of Revere, Sun Roof flat-plate, liquid (water drain-down) collectors and a 1400 gallon water storage tank located centrally on the first floor. Heat from the storage tank is transported to a 65 gallon DHW heater equipped with an auxiliary electric heating element. Hot water from the storage tank also passes through an auxiliary electric boiler and then through a four zone baseboard radiator system to provide space heating for the home. There is also a special hydro-heater fireplace built into the side of the storage tank which is used as an auxiliary. The Design Construction solar energy system supplied 35% of the space heating and 27% of the domestic hot water required for this house during the heating season of October 1979 through April 1980. The quantity of collected solar energy that was used was 81% and the collector array efficiency was 28%. (This efficiency is based on the total solar radiation incident on the array.) Solar energy saved 7415 kwh of electricity for the seven-month period. The solar energy system functioned consistently throughout the heating season providing significant amounts of solar energy to the space heating and DHW subsystems. The solar fraction of 35% was somewhat lower than the design goal of 50%. The main reason for this was that the insolation was well below the long-term average for this period (October 1979 through April 1980).

Brauch, M.L.

1980-01-01

168

Solar thermal power plants  

Energy Technology Data Exchange (ETDEWEB)

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)

Schnatbaum, L. [Solar Millennium AG, Erlanger (Germany)

2009-09-15

169

Solar thermal power plants  

International Nuclear Information System (INIS)

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)

2009-09-01

170

Design and construction of a solar-electric vehicle  

Energy Technology Data Exchange (ETDEWEB)

Recent concerns relating to global warming caused by greenhouse gases, coupled with a growing awareness of the limited available resources of fossil fuels, have spurred an interest in alternative energy powered vehicles. This paper describes the analysis, development, and testing of an aerodynamic vehicle powered by photovoltaic cells. The primary components of the vehicle are the composite material body, the aluminum space frame, the wheel hubs and front suspension assembly, the drive train, and the electrical system. The frame was designed using finite element analysis with the components of the frame modeled as beam elements. The body, designed to have a very high strength-to-weight ratio, was of graphite/Kevlar/Nomex sandwich construction. Testing was carried out using the three-point bend test to determine the optimal sandwich cross-sectional configuration. The design of the front suspension, the wheel hubs, and the power transmission are also discussed. The electrical system, based on a monocrystalline photovoltaic cell assembly, and silver-zinc storage cells, is also described. Finally, results of the optimization routine developed are also described.

Bhavnani, S.H. (Auburn Univ., AL (United States). Dept. of Mechanical Engineering)

1994-02-01

171

Distribution of archaea in a black smoker chimney structure.  

Science.gov (United States)

Archaeal community structures in microhabitats in a deep-sea hydrothermal vent chimney structure were evaluated through the combined use of culture-independent molecular analyses and enrichment culture methods. A black smoker chimney was obtained from the PACMANUS site in the Manus Basin near Papua New Guinea, and subsamples were obtained from vertical and horizontal sections. The elemental composition of the chimney was analyzed in different subsamples by scanning electron microscopy and energy-dispersive X-ray spectroscopy, indicating that zinc and sulfur were major components while an increased amount of elemental oxygen in exterior materials represented the presence of oxidized materials on the outer surface of the chimney. Terminal restriction fragment length polymorphism analysis revealed that a shift in archaeal ribotype structure occurred in the chimney structure. Through sequencing of ribosomal DNA (rDNA) clones from archaeal rDNA clone libraries, it was demonstrated that the archaeal communities in the chimney structure consisted for the most part of hyperthermophilic members and extreme halophiles and that the distribution of such extremophiles in different microhabitats of the chimney varied. The results of the culture-dependent analysis supported in part the view that changes in archaeal community structures in these microhabitats are associated with the geochemical and physical dynamics in the black smoker chimney. PMID:11472939

Takai, K; Komatsu, T; Inagaki, F; Horikoshi, K

2001-08-01

172

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

International Nuclear Information System (INIS)

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)

1992-01-01

173

Design manual for HANARO in-chimney bracket  

International Nuclear Information System (INIS)

As a supplementary structure supporting the irradiation facilities, the in-chimney bracket holds guide tubes whose holding position 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. Also, the bracket grips the upper part of the guide tubes when it is applied to hold the instrumented facility loaded in OR sites. The irradiation test will be successfully conducted since this bracket reduces the flow-induced vibration (FIV) and the dynamic response to seismic load. The installation position of the bracket is 60 cm below the top of the chimney, i.e., thermo siphoning hole position. To evaluate the structural integrity on the in-chimney bracket and the related reactor structures, ANSYS finite element analysis model is developed and the dynamic characteristics are analyzed. The seismic response analyses were performed for the in-chimney bracket and the related reactor structures of HANARO under the design earthquake response spectrum loads of OBE and SSE. The analysis results show that 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 much less than 1.0. Therefore any damage on structural integrity is not expected when the in-chimney bracket is installed at the upper part of the reactor chimney. This bracket had been designed and manufactured based on the dimensions of the as-built chimney. In the process of design and preliminary installation, chimney measurement tools, dummy chimney, and installation tools were developed and the installation procedure was prepared and verified through the installation rehearsal

2000-01-01

174

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

Energy Technology Data Exchange (ETDEWEB)

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.

Aldrich, R.

2012-08-01

175

PS10, Construction of a 11MW Solar Thermal Tower Plant in Seville, Spain  

Energy Technology Data Exchange (ETDEWEB)

It is the objective of PS10 project the construction and operation of a concentrating solar thermal plant for electricity production of 11,00 MWe gross power. Based on the technology of tower and heliostats field, this plant will generate 23,00GWh of electricity every year running on a commercial basis. PS10 project will validate investment costs below 3.500/kW in a solar multiple 1.3 scheme. PS10 solar plant has been constructed on the lands of the Casaquemada property, (37.2 Latitude), in Sanlucar la Mayor, 15 km west from the city of Seville in Andalusia, Spain. The project makes use of well proven technologies like glass-metal heliostats, a saturated steam receiver, pressurized water storage system, and saturated steam turbine. The solar field of PS10, consisting on 75.000m2 of reflective surface is spread over 50Has, a relatively large area as low losses for shadows and blocks interactions have been considered in its design. The tower of PS10 reaches an overall height of 120m. Solar multiple for this plant is 1.3, and the storage system capacity allows half hour full load operation for cloudy transients production coverage. Keeping in a side the cosine effect, that is, considering the energy that reachesheliostats, design point efficiency for PS10 raises till 21.2%, achieving annual efficiency of 14,4% in conversion from intercepted solar energy to electricity. The project is promoted by Solucar, a company of Abengoa working on solar energy and has been co-funded by 5th Framework Program of European Commission and by Renewable Energies Program of Andalusia Government. PS10 will come into operation by the end of summer 2006. (Author)

Osuna, R.; Olavarria, R.; Morillo, R.; Sanchez, M.; Cantero, F.; Fernandez-Quero, V.; Robles, P.; Lopez del Cerro, T.; Esteban, A.; Ceron, F.; Talegon, J.; Romero, M.; Tellez, F.; Marcos, M. J.; Martinez, D.; Valverde, A.; Monterreal, R.; Pitz-Paal, R.; Brakmann, G.; Ruiz, V.; Silva, M; Menna, P.

2006-07-01

176

Design, construction and study of a hybrid solar food processor in the climate of Costa Rica  

Energy Technology Data Exchange (ETDEWEB)

During the last 25 years, the author has designed, constructed, studied and promoted solar oven, hybrid solar/electric oven, solar oven cum drier, solar cooker cum water heater and solar still. In different parts of the world, solar cookers have been made, studied, patented, however, their real uses are very limited due to many reasons-unstable climate, economic, cultural, social and single use, etc. In order to overcome part of the problems mainly the last one, author has recently designed one hybrid food processor (multi-purposes device) and studied various technical and practical aspects. It has been used for cooking, heating/pasteurizing water (to inactivate microbes) and distillation of small quantity of water (to remove different minerals) and drying domestic products (fruits, vegetables and condiments/herbs, etc.). For more than three years of use, author has found this to be a useful device, mainly from convenience, fuel saving, economic and also from ecological point of view. This device can be used at any time and for different uses but with the reduced consumption of conventional fuel. (author)

Nandwani, Shyam S. [Laboratorio de Energia Solar, Departamento de Fisica, Universidad Nacional, Heredia 3000 (Costa Rica)

2007-03-15

177

D0 Solenoid Chimney Routing Clearances  

Energy Technology Data Exchange (ETDEWEB)

This engineering note contains information about the measured clearances along the chimney route from the solenoid to the control dewar. This type of information is best conveyed by sketches and a few photos. Twelve photos taken on 2/17/94 are included which gIVe perspective views along the path. The detector was parked in the collision hall on this date. The CF iron was split open to the east and the South EF iron was rolled back. Also the South EndCap Calorimeter was rolled to the south on this day. This allowed personnel access and the photographic opportunity. A full set of raw dimensional sketches are included. These sketches were generated by me using a 25 foot tape measure and a note pad. The sketches are in chronological order with the most recent on top. The first sketch, 5/18/94, describes the 'tightest' location for the upward incline portion of the chimney. The sketches on 2/14/94 thru 2/16/94 are refinements of the early 1992 and 1993 sketches. They pick out quite a bit more detail of specific detector components along the path. The dimensional sketches of 1992 and 1993 gave information in not as much detail and therefore gave a more constrained clearance description. Most of the information of the early sketches was jotted down on the plan view dated 10-29-92. This sketch also had some information lifted from prints which later was superseded by the 1994 sketches. I tried to label components and give views either titled 'Elevation' or 'Plan' which refers to a top view looking down. Also where I could I jotted down direction, ie. South, East etc. Hopefully with a little effort one can decifer it. The curvature of the CC was determined from a three dimensional topographical survey. This survey information is stored in an electronic drawing file 3823.111-ME-317165, 'Solenoid-CC south face 3D shape survey'. The 'z' dimensions for the radial chimney path were picked off this drawing. A curvature was then generated knowing many points by radial and z coordinates. This curve is stored in drawing file 3823.111-ME317164, 'Solenoid-CC south face-chimney contour layout'. All drawings mentioned above are kept in hard copy form in the D-Zero drawing files. The electronic 'master' copy is kept in the XDCS drawing control system, dOms vault. The information contained in this engineering note could be very useful for those who are interested in the clearances and shape of the solenoid chimney path. It could even be of use to future designers and engineers involved with the VLPC project which is planned.

Rucinski, R.; /Fermilab

1994-02-23

178

Design, construction and experimental study of Electric Cum Solar Oven-II  

International Nuclear Information System (INIS)

As in many developing countries, 35-40% of the population of Costa Rica still use firewood for domestic cooking. Considering the fact that Costa Rica is blessed with good sunshine, good hydroelectric potential, and a good electric network, a hybrid solar oven was thought to be useful. In the present paper the construction and working of a new type of Electric Cum Solar Oven (ECSO) has been described. This oven can be used for cooking and baking any type of meal at any time during the year employing solar and/or electric energy but consuming the minimum quantity of electric energy in case it is required. (author). 9 refs, 6 figs, 1 tab

1987-01-01

179

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

Science.gov (United States)

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.

Baranov, V. K.

1984-02-01

180

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

Energy Technology Data Exchange (ETDEWEB)

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)

1979-12-18

 
 
 
 
181

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

Energy Technology Data Exchange (ETDEWEB)

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.)

NONE

2006-11-15

182

Effects of heat and radiation on Gasbuggy chimney gas  

International Nuclear Information System (INIS)

Chemical changes in the gas in the Gasbuggy chimney were observed for about six months following the explosion. Heat and radiation are postulated to cause this change. Samples of gas taken from the chimney at one month were heated and irradiated in the laboratory. Heat produced a decrease in H2 and an increase in CH4 concentration--trends that were observed in the chimney. On the other hand, irradiated samples of this gas showed a dose-related increase in H2 and decrease in CH4. Irradiation also caused about one-third of each gas sample to change into an oil

1976-01-01

183

A new picture of interstellar medium: chimney model  

International Nuclear Information System (INIS)

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

1987-01-01

184

Options for the removal of contaminated concrete from the bore of the Windscale pile chimney - 16083  

International Nuclear Information System (INIS)

A legacy of the 1957 Windscale Pile reactor fire is the penetration of radioactive contamination into the internal surface concrete of the chimney bore. Gamma imaging of Cs- 137 has shown that the contamination is widespread throughout the chimney, and core samples have shown that the contamination has penetrated to depths of around 5-25 mm. The Pile chimney is 100 m tall and has an internal bore diameter of 15 m. It is constructed of a hard concrete comprised of Whinstone aggregate. The baseline decommissioning scheme is to remove approximately 5-25 mm of the surface concrete from the entire bore of the chimney. The technology baseline in 2006 was to remove layers of contaminated concrete by mechanical means using shavers or scabblers. However, risks associated with mechanical technologies that may preclude their use include: the ability of mechanical devices to remove the hard concrete; clogging of the devices due to wet concrete; and deployment of the delivery systems. This paper discusses the options under consideration to reduce the risks associated with the removal of the contaminated concrete through application of alternative techniques. The present baseline technology is high pressure water jetting technique. Demonstrations have shown that this technology can successfully remove concrete without significant reaction forces. However, an inherent problem with this technology is the production of secondary liquid effluent waste, which would need to be treated by an appropriate conditioning process. To address the secondary effluent waste issue, technologies that produce little or no secondary waste have been considered. The technologies that have been considered are laser scabbling, microwave scabbling and nitrogen jet blasting. The paper discusses each technique in turn, highlighting their advantages and disadvantages. The results of an in-active laser scabbling and high pressure liquid nitrogen jetting trial are presented. The paper concludes with a discussion of the merits of each technology in support of the future strategy for concrete removal. (authors)

2009-10-11

185

Rio Blanco: nuclear operations and chimney reentry  

International Nuclear Information System (INIS)

Rio Blanco was the third experiment in the U.S. Atomic Energy Commission's Plowshare Program to develop technology to stimulate gas production from geologic formations not conducive to production by conventional means. The project was sponsored by CER Geonuclear Corporation, with the Lawrence Livermore Laboratory providing the explosives and several technical programs, such as spall measurement. Three nuclear explosives specifically designed for this application were detonated simultaneously in a minimum-diameter emplacement well using many commercially available but established-reliability components. The explosive system performed properly under extreme temperature and pressure conditions. Emplacement and stemming operations were designed with the aim of simplifying both the emplacement and reentry and fully containing the detonation products. An integrated command and control system was used with communication to all three explosives through a single coaxial cable. Reentry and the initial production testing are completed. To date 98 million standard ft3 of chimney gas have been produced. (auth)

1975-01-01

186

Seismic response Analyses of Hanaro in-chimney bracket structures  

International Nuclear Information System (INIS)

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 much less 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

1999-01-01

187

Hullco Construction Company single family dwelling, Prescott, Arizona. Solar project description  

Energy Technology Data Exchange (ETDEWEB)

The Hullco Construction solar energy system is a passive space heating system for a single family residence located in Prescott, Arizona. The south-facing building is a combination greenhouse and direct gain passive system. Incident solar energy enters the building through approximately 400 ft/sup 2/ of double-glazed prefabricated Kalwall panels. Two sliding glass doors between the greenhouse and the house along with a window in the bathroom admit incident solar energy directly into the master bedroom, living room, and bath areas of the house. Collected solar energy not used to satisfy the immediate building space heating demand is stored directly in the massive walls and floors of the building or indirectly in the 670 ft/sup 3/ of two to 6 in. diameter rock storage which is located under the floor or the north half of the building. Summer overheating protection is provided by venting of the greenhouse and by both natural and artificial shading of the greenhouse glazing. Natural shading of the greenhouse is accomplished by the use of an existing tree to the southeast of the structure. Additional greenhouse shading can be provided by a redwood snow fence placed over the glazing. Nighttime venting of the building can be used to cool the energy storage masses, thus cooling the building during the day as energy generated inside the building is absorbed by the walls and floor. Auxiliary energy for space heating can be supplied by either electric radiant heat panels, or by the wood-burning stove.

1980-02-07

188

Report from the ASCE task committee on chimney and stack examination and retrofit. Chimney and stack condition assessment guidelines  

Energy Technology Data Exchange (ETDEWEB)

Industrial and Utility chimneys are typically exposed to severe environmental conditions, and sometimes subjected to changes in operating conditions. Extremes of weather and aggressive industrial atmospheres impose unavoidable stresses and can lead to rapid deterioration. Changes in fuel or the installation of flue gas scrubbers change the flue gas temperature and composition, and can create conditions unanticipated by the chimney designer. The purpose of the ASCE Task Committee for Chimney and Stack Examination and Retrofit was to develop a set of guidelines that would aid owners in understanding the issues involved in maintaining these structures, and at the same time ensure that owners, engineers, and contractors alike have a common frame of reference for the work involved. It is anticipated that, by using these guidelines, requests for chimney inspections or assessments can be answered with qualified responses that address the full scope of work required or expected by the owners.

Hertlein, B.H. [STS Consultants Ltd., Vernon Hills, IL (United States); Bochicchio, V. [ZBD Constructors Inc., Tampa, FL (United States)

1999-11-01

189

Characterisation of construction and catalyst materials for solar thermochemical hydrogen production  

Energy Technology Data Exchange (ETDEWEB)

The decomposition of sulphuric acid into H{sub 2}O, SO{sub 2} and O{sub 2} is a key step to couple concentrated solar radiation or solar high temperature heat into so-called sulphur based thermochemical cycles for the production of H{sub 2} from H{sub 2}O like the Hybrid Sulphur Cycle and the Sulphur-Iodine Cycle. Operational temperatures in excess of 800 C, transient conditions and the presence of highly corrosive species, in particular boiling sulphuric acid and its decomposition products impose high demands on the stability of construction materials and on the required performance and stability of the catalysts for the enhancement of the decomposition reaction. (orig.)

Thomey, D.; Roeb, M.; Oliveira, L. de; Gumpinger, T.; Schmuecker, M.; Sattler, C. [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Koeln (Germany); Karagiannakis, G.; Agrafiotis, C. [Centre for Researcj and Technology Hellas, Thessaloniki (Greece). Aerosol and Particle Technical Lab.; Konstandopoulos, A. [Centre for Researcj and Technology Hellas, Thessaloniki (Greece). Aerosol and Particle Technical Lab.; Thessaloniki Univ. (Greece). Chemical Engineering Dept.

2010-07-01

190

A condensing and photic solar heat exchanger integrating with the residential construction  

Energy Technology Data Exchange (ETDEWEB)

The condensing and photic solar heat exchanger (patent number: ZL200520089160.4) introduced in this article has its particular character on design and work. In addition, taking advantage of proper physical principles to integrate with the residential constructions to make them form an integrative system, the superiority of the heat exchanger will be given a full play. A condensing and photic solar heat exchanger can be used simultaneously by several households in the same dwelling unit in the city. In the countryside, a heat exchanger can satisfy people's requirements of bathing and heating, making use of the facilities such as a methane tank in the courtyard. It can also bring its excellence into play in villas using the underground cement heat preservation trough. And people would also feel comfortable and convenient if they work and live in a workshop, which bring the environment full of humanization because of the heat exchanger. (orig.)

Zhu Wenxiang; Zhang Kaifeng; Wu Limei; Liu Yingchun [Shenyang Inst. of Aeronautical Engineering, LN, Shenyang (China)

2008-07-01

191

Psychology and photography: chimneys dreaming and chimneys warriors Psicologia e fotografia Comignoli sognanti e comignoli guerrieri  

Directory of Open Access Journals (Sweden)

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.L'articolo affronta due aspetti correlati alla Psicologia e all'Arte. Il primo aspetto riguarda le affinità riscontrabili tra  fotografia e varie Scuole di psicologia sperimentale. Ad esempio, gli studiosi della Psicologia della Teoria etologica, e della Comunicazione non verbale (CNV, osservano con particolari metodologie i messaggi non verbali che animali e esseri umani trasmettono ai propri simili attraverso la mimica facciale, la postura, la gestualità. Lo stesso fanno i fotografi (quelli che usano la “camera” con buona sapienza del medium e con “occhio fotografico” quando si guardano attorno, attenti a cogliere una espressione, un atteggiamento inconsueto, un gesto d’amicizia. Un’altra Scuola di psicologia, la Gestalpsychologie o Psicologia della Forma (Gestalt: forma, figura, configurazione,  attribuisce valore determinante alla percezione dello spazio, al primo piano e allo sfondo, alla prospettiva e ai punti di fuga, al contrasto fra bianco e nero. Tutti questi argomenti interessano tanto gli psicologi quanto i fotografi. Il secondo aspetto fa riferimento all'arte di Antony Gaudì e avanza qualche ipotesi circa la personalità e il comportamento del grande architetto, nella costruzione di due case,  "Casa Batllò" e "Casa Milà",  in particolare per le forme o Gestalt dei "comignoli" che dominano i due edifici. In tale studio collaborano fra loro l'analisi psicologica e l'arte fotografica. Quest’ultima consente di studiare anche i singoli dettagli dell’opera di Gaudì.

Tilde Giani Gallino

2013-02-01

192

Microbiological Oxidation Of Sulfide Chimney Promoted By Warm Diffusing Flow In CDE Hydrothermal Field In Eastern Lau Spreading Center  

Science.gov (United States)

A hydrothermal field named as "CDE"(COMRA Discovery Expedition) at 176°11'W, 20° 40'S, about 4 miles south of known ABE hydrothermal field, was discovered by R/V DaYang YiHao in May, 2007. There are amounts of anemones and white microbe mats attached on some pillar sulfide chimneys (from less than one meter to more than 5 meters in height). Some crabs, fishes and microbe mats could be seen in/near chimney groups. Abnormal signatures of turbidity, temperature and CH4 are very strong shown by intensive surveys in deep waters above/near the CDE hydrothermal field by MAPR, CTD and onboard GC analysis of water samplers, respectively. Another prominent characteristics of the chimneys in the CDE is that they are cover with thick oxides/hydroxides crust. It is interesting to notice that there are considerable amounts of Fe oxidant bacteria (FeOB) clones exist in sample of oxide crust according to the phylogenetic analysis by 16S rRNA genes libraries construction. The FeOB clones have higher similarity (>94%) with those known Fe oxidant bacteria such as the genus of Gallionella and Mariprofundus ferrooxydans. In addition, abundant spiral, sheath-like textures known typical sign of FeOB are observed in the samples by Environmental Scanning Electron Microscope (ESEM). Optimum grow temperature of isolations similar to our clones is 20- 35°C. The heat, supporting to colonization of anemones, microbe mats and FeOB with oxides crust, could be supplied by probably neighboring high temperature active venting in the field as there are no visible black or white plumes associated with those video-imaged chimneys during our survey. Another alternative speculation is that those chimneys are warm. After extinction of high temperature venting, diffuse flow with a temperature lower than about 100°C are still active through porous structure in the chimney. The warm chimney provides the ideal habitats of some biologic colonization. In turn, oxidation promoted by FeOB activities makes a result of thick oxides/hydroxides crust.

Zhou, H.; Li, J.; Yang, Q.

2008-12-01

193

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

Energy Technology Data Exchange (ETDEWEB)

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)

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

2010-01-15

194

Solar energy utilization in composting toilets. Final report  

Energy Technology Data Exchange (ETDEWEB)

The goal of the study was to utilize solar energy in lieu of electricity to help alleviate the basic problems with compost toilets. Solar devices were first used to improve the performance of existing facilities and additional systems were designed from inception with solar heating and venting systems. Four independent studies were initiated and executed over the two years of the grant period: the design and construction of a solar pasteurization unit for treatment of 55-gal drum waste collection units; retrofit of an existing Clivus Multrum toilet for direct passive solar heat gain; design and construction of an owner-built flow-through compost toilet with a solar hot air heating system for hill side installation; and design and construction of an integrated bathroom facility that included a solar heated flow-through compost toilet with a solar chimney venting system. In general, the use of high temperature solar devices to enhance the biological process of composting within a privy vault was not successful. The compost toilets in the study demonstrated their vulnerability to shock over loading characteristic of public facilities and therefore demonstrated their unsuitability for such applications. However, their performance under more controlled use rates (at or below design maximum) merits further study.

Kroschel, M.L.

1981-02-01

195

Structural integrity assessment of HANARO in-chimney bracket structures  

Energy Technology Data Exchange (ETDEWEB)

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, the in-chimney bracket was designed. 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. The installation position of the bracket is 60 cm below from the top of the chimney, i.e., thermosiphoning opening position. For evaluating the structural integrity on the 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 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 analysis result shows that the stress values in main points of reactor structures and in-chimney bracket for the seismic loads are also within the SAME Code limits. Therefore any damage on structural integrity is not expected when an in-chimney bracket is installed in the upper part of the reactor chimney. 12 refs., 32 figs., 21 tabs. (Author)

Ryu, Jeong Soo; Lee, J. H.; Cho, Y. G.; Lee, J. H. [Korea Atomic Energy Research Institute, Taejon (Korea)

1999-09-01

196

Dynamic wind interference effects between high chimneys  

International Nuclear Information System (INIS)

In an extensive wind tunnel study vortex-induced cross-wind vibrations of chimneys in a row and in grouped arrangements have been investigated. Most of the model tests have been executed in the subcritical Reynolds number range. In order to indicate the influence of the Reynolds number, some tests have been executed at simulated transcritical Reynolds number range in the large wind tunnel NKl in Dresden. It could be shown, that the exciting forces at stacks in a row and in grouped arrangements are multiple larger in the subcritical range than in the transcritical range and cannot be transferred to full-scale concrete stacks. On the contrary the variation of the Strouhal number versus distance ratio is less influenced by the Reynolds number. It could be verified, that the diameter ratio d2/d1 of the luff-side stack to the lee-side stack is of major importance. A recommendation for the estimation of vortex-induced vibrations of concrete stacks in a row and in grouped arrangements could be developed from the results with simulated transcritical Reynolds number. Strouhal number factors, ?s, and exciting force factors, ?lat, could be evaluated in dependency of the distance ratio a/d1 of the stacks. A proposal for practical application is given in Fig. 10 and 11. It is compared with the proposal for stacks in a row which is given in the German Standard DIN 4133 for steel stacks. (orig.)

2000-01-01

197

Theoretical construction of solar wind temperature anisotropy versus beta inverse correlation  

Science.gov (United States)

In situ measurements from the Wind spacecraft that statistically analyzed the solar wind proton at 1 AU has indicated that the measured temperature anisotropies seem to be regulated by the oblique instabilities (the mirror and oblique firehose). This result is inconsistent with the prediction of linear theory that the ion-cyclotron (for ? ? &l˜ 2) and parallel firehose (for ? ? &l˜ 10) would dominate over the oblique instabilities. Various kinds of physical mechanisms have been suggested to explain this discrepancy between the observations and linear theory. All of the suggestions consider the solar wind as a uniform magnetized plasma. However, the real space environment is replete with the intermediate spatio-temporal scale variations, such as the magnetic field intensity and the density. In this paper we present that the pervasive intermediate-scale temporal variation of the local magnetic field intensity in the real space can lead to the modification of the proton temperature anisotropy versus beta inverse correlation for temperature-anisotropy-driven instabilities. By means of quasilinear theory involving such temporal variation, we construct the simulated solar wind proton data distribution associated with the magnetic fluctuations in (? ? , T?}/T{? ) space. It is shown that the theoretically simulated proton distribution and a general trend of the enhanced fluctuations bounded by the oblique instabilities are consistent with in situ observations. Furthermore, the measured magnetic compressibility can be accounted for by the magnetic spectral signatures of the unstable modes.

Seough, J.; Yoon, P. H.; Kim, K.; Lee, D.

2012-12-01

198

Chimney for enhancing flow of coolant water in natural circulation boiling water reactor  

Science.gov (United States)

A chimney which can be reconfigured or removed during refueling to allow vertical removal of the fuel assemblies. The chimney is designed to be collapsed or dismantled. Collapse or dismantlement of the chimney reduces the volume required for chimney storage during the refueling operation. Alternatively, the chimney has movable parts which allow reconfiguration of its structure. In a first configuration suitable for normal reactor operation, the chimney is radially constricted such that the chimney obstructs vertical removal of the fuel assemblies. In a second configuration suitable for refueling or maintenance of the fuel core, the parts of the chimney which obstruct access to the fuel assemblies are moved radially outward to positions whereat access to the fuel assemblies is not obstructed.

Oosterkamp, Willem Jan (Oosterbeek, NL); Marquino, Wayne (San Jose, CA)

1999-01-05

199

Chimney for enhancing flow of coolant water in natural circulation boiling water reactor  

International Nuclear Information System (INIS)

A chimney which can be reconfigured or removed during refueling to allow vertical removal of the fuel assemblies is disclosed. The chimney is designed to be collapsed or dismantled. Collapse or dismantlement of the chimney reduces the volume required for chimney storage during the refueling operation. Alternatively, the chimney has movable parts which allow reconfiguration of its structure. In a first configuration suitable for normal reactor operation, the chimney is radially constricted such that the chimney obstructs vertical removal of the fuel assemblies. In a second configuration suitable for refueling or maintenance of the fuel core, the parts of the chimney which obstruct access to the fuel assemblies are moved radially outward to positions whereas access to the fuel assemblies is not obstructed. 11 figs

1994-12-01

200

Influence of a tube-building polychaete on hydrothermal chimney mineralization  

Energy Technology Data Exchange (ETDEWEB)

High-temperature chimneys on the Juan de Fuca Ridge are the preferred habitat of the 'sulfide worm' (Paralvinella n. sp.). An investigation of interactions between the biology of the sulfide worm and chimney mineralization has led to a hypothesis linking formation of marcasite-pyrite crusts on chimney surfaces to colonization and tube-building by the worms. Marcasite precipitation beneath worm tubes and worm migration to newly formed areas of chimney together create a moving front of biomineralization that keeps pace with chimney growth. Sulfide oxidation by this organism can potentially produce enough S to form the FeS[sub 2] crusts. The marcasite-pyrite crusts act as a sealing layer within the outer chimney wall, reducing inflow of cold seawater or outflow of hydrothermal fluid. This may enhance temperature increases within the chimney conduit and hasten replacement of the early anhydrite matrix in the chimney wall by higher temperature sulfides.

Juniper, S.K. (Centre Oceangraphique de Rimouski, Quebec (Canada)); Jonasson, I.R. (Geological Survey, Ottawa, Ontario (Canada)); Tunnicliffe, V. (Univ. of Victoria, BC (Canada)); Southward, A.J. (Marine Biological Association, Plymouth (United Kingdom))

1992-10-01

 
 
 
 
201

Chimney for enhancing flow of coolant water in natural circulation boiling water reactor  

Energy Technology Data Exchange (ETDEWEB)

A chimney which can be reconfigured or removed during refueling to allow vertical removal of the fuel assemblies is disclosed. The chimney is designed to be collapsed or dismantled. Collapse or dismantlement of the chimney reduces the volume required for chimney storage during the refueling operation. Alternatively, the chimney has movable parts which allow reconfiguration of its structure. In a first configuration suitable for normal reactor operation, the chimney is radially constricted such that the chimney obstructs vertical removal of the fuel assemblies. In a second configuration suitable for refueling or maintenance of the fuel core, the parts of the chimney which obstruct access to the fuel assemblies are moved radially outward to positions whereas access to the fuel assemblies is not obstructed. 11 figs.

Oosterkamp, W.J.; Marquino, W.

1999-01-05

202

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

Science.gov (United States)

...2010-07-01 false Removal of walls, masonry sections, and chimneys. 1926.854 Section 1926.854 Labor Regulations... § 1926.854 Removal of walls, masonry sections, and chimneys. (a) Masonry walls, or other sections of...

2010-07-01

203

Characteristics of captured ash, chimney solids and trace elements  

International Nuclear Information System (INIS)

Samples of pulverized coal, bulk ash and chimney stack solids were taken from a 500 MW-capacity boiler burning a mixture of East Midlands coal. The surface morphology of size-graded samples was examined in a scanning electron microscope. The analysis of the major components of the respirable particles before and after water and acid etching was carried out by the EDAX technique. Neutron activation and atomic absorption spectrometry were used to determine the concentrations of trace elements. The bulk ash (ie from the electrostatic precipitators) contained 10% by weight of respirable-sized (ie below 5 ?m diameter) particles, but 50% of the chimney stack solids were in this size range. The respirable particles both in bulk and chimney stack samples consisted chiefly of spherical particles of alumino-silicates and iron oxides with a large number of below 0.5 ?m diameter particles attached to them. These attached sub-micron size particles consisted chiefly of sodium and potassium sulphates. The non-attached, sub-micron size particles in the chimney stack solids mostly consisted of calcium sulphate. Different possible modes of distribution of the trace elements in the precipitated ash and chimney stack solids are discussed. (author)

1981-01-01

204

The gas chimney formation during the steam explosion premixing phase  

International Nuclear Information System (INIS)

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)

2001-09-10

205

Chimney retrofitting: Only total system solutions possible. Kamin-Sanierung: Nur noch Gesamtloesungen moeglich  

Energy Technology Data Exchange (ETDEWEB)

Since the new Luftreinhalteverordnung LRV 92 (clean air act) and the new fire protection regulations have come into effect in case of heating system retrofitting also the adaptation of the existing chimney is obligatory in order to avoid damage or malfunctions in the total system, burner, heating boiler and chimney. This article deals with important questions of chimney retrofitting. The necessity to adapt the type and design of the chimney to the heating system is particularly emphasized. (BWI)

Haltiner, E.W.

1994-07-15

206

Ages of barite-sulfide chimneys from the Mariana Trough  

International Nuclear Information System (INIS)

Active and inactive hydrothermal chimneys from the Mariana Trough have young ages ranging from 0.5 to 2.5 years. These estimates are based on disequilibrium between 228Th and 228Ra in barite-rich samples. Mineralogical investigations revealed that the chimneys contain a mixture of barite, galena, sphalerite and chalcopyrite which appear to have formed contemporaneously. Based on radium isotope ratios and Ra/Ba ratios, leaching of freshly exposed basaltic rock must have been the source of the barium found in these deposits. (orig.)

1990-01-01

207

Experimental and theoretical analysis of a NPP chimney  

International Nuclear Information System (INIS)

In the frame of a research project of seismic refraction survey four underground explosions were carried out in April 1987 close to Garigliano NPP, in decommissioning phase since 1978. With the aim to obtain information on soil structure interaction phenomenon, design hypothesis and numerical modeling of structures ENEL and ENEA recorded the four explosions at selected points on the NPP and on the ground. In this report the results of the analyses carried out on accelerograms recorded on the NPP chimney are presented along with optimal values of parameters to be employed in numerical modeling of the chimney, estimated by a simple procedure of system identification

1989-08-14

208

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

Energy Technology Data Exchange (ETDEWEB)

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)

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

209

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

International Nuclear Information System (INIS)

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.

2010-07-01

210

Design, construction, and initial operation of the Los Alamos National Laboratory salt-gradient solar pond  

Energy Technology Data Exchange (ETDEWEB)

A 232 m/sup 2/ solar pond was constructed at Los Alamos National Laboratory for the purpose of studying pond hydrodynamics on a large scale and to complement the flow visualization and one-dimensional pond simulator experiments that are ongoing at the Laboratory. Design methods and construction techniques, some of which are unique to this pond, are described in detail. The pond was excavated from a soft volcanic rock known as tuff; such rock forms a large fraction of the Los Alamos area surface geology. Because tuff has a small thermal conductivity, little insulation was required to reduce perimeter energy losses. In addition, the strength of tuff permitted the pond to be built with vertical side walls; this design eliminated local side wall convection in the gradient zone that is possible with sloping side walls. Instrumentation in the pond consists of traversing and fixed rakes of thermometers and salinity probes, an underwater pyranometer, and a weather station. The traversing rake is a wheeled trolley driven vertically on a rectangular rail. Installed on the trolley are coplanar platinum RTDs, a point conductivity probe, and an induction salinometer. The stationary rake supports 28 thermocouples and 28 sample-fluid withdrawal taps located every 10 cm. About 127 T of sodium chloride has been introduced and is nearly dissolved. A 120-cm-thick salinity gradient was established and the pond is heating. Preliminary results indicate a lower-convective-zone heating rate of 1.2/sup 0/C/day during the pond's first month of operation. Recommendations on pond design, construction, and instrumentation are presented.

Jones, G.F.; Meyer, K.A.; Hedstrom, J.C.; Dreicer, J.S.; Grimmer, D.P.

1983-01-01

211

Evaluation of height chimney effect in a research reactor core  

International Nuclear Information System (INIS)

The STHIRP-1 computer code uses the principles of subchannels approach and has the ability to simulate the thermal and hydraulic phenomena which occur in the core of a water-refrigerated research reactor under a natural convection regime. As the reactor cooling occurs predominantly by natural convection of pool water the driving forces are supplied by the buoyancy of the heated water in the core. A chimney is an unheated extension of the core. The height of the chimney above the upper grid plate depends on the reactor power. At the top of the chimney the water temperature and density are again equal to the bulk water and it can be assumed that the liquid is again motionless. Thermal hydraulic calculations were carried out for the IPR-R1 Triga reactor (CDTN/CNEN) operating at the steady-state power levels of 50, 70 and 100 kW. The height of chimney effect in the reactor core was evaluated from the temperature values calculated at the inlet and outlet of subchannels (author)

2007-10-05

212

External walls made of solar Lego bricks. Sulfurcell head office building: External wall construction according to the dimensions of Sulfurcell solar modules; Solare Legosteinfassade. Die Masse der hauseigenen Module bildeten den Ausgangspunkt fuer die Planung des Sulfurcell-Hauptquartiers  

Energy Technology Data Exchange (ETDEWEB)

The Sulfurcell Solartechnik GmbH constructed a new office building at Berlin-Adlershof. The building's external walls were designed on the basis of the frameless Sulfurcell standard module. The building intends to prove that solar modules are not a luxury item but an efficient and easy-to-handle constructional material. (orig.)

Wagner, Neelke

2009-11-15

213

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

International Nuclear Information System (INIS)

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)

1970-05-01

214

Collapse of chimney with impact on reactor building  

International Nuclear Information System (INIS)

As the chimney does not belong to the higher-safety-class structures of a nuclear power plant, it is normally not designed for such extreme loading conditions as the safe-shutdown earthquake and the aircraft impact. Nevertheless, the behaviour of the chimney for these loads has to be investigated, as a possible collapse onto adjacent safety-relevant structures (reactor building, reactor auxiliary building, fuel-handling building) may significantly influence the design of these structures and of the equipment in them. The loading cases which might cause a collapse are outlined. The mathematical models used to calculate the highly physically and geometrically non-linear behaviour are described. The resulting response of the structures subjected to impact is determined and compared to that caused by other external extreme loading conditions. The safe-shutdown earthquake is represented by an artificially generated time history which fits a specified design-response spectrum. For preliminary calculations the response for simple sine wave excitation is determined. The ground acceleration at which collapse first occurs is calculated for different soil parameters and dimensions of the chimney. As an additional loading case, the direct impact of an aircraft or its freely flying debris on the chimney is investigated approximately. For different locations of impact, the impulse causing collapse is established. Under normal circumstances, debris such as engines can hardly lead to a collapse of the entire chimney. Overall consideration of the balance of energy and of impulse as well as detailed solutions of the resulting differential equations of motion are performed. (Auth.)

1977-08-19

215

The computational optimization of heat exchange efficiency in stack chimneys  

Energy Technology Data Exchange (ETDEWEB)

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 stack chimney heat exchanger is used for heating or cooling applications, what is the expected performance and how do the design parameters relate to this performance'. Simulation models were developed in the BPS tool ESP-r. The most important design parameters and their relative influence on the performance indicators were analysed based on sensitivity analysis (SA). From this analysis general design guidelines were derived ('optimal set of design parameters'). A multi objective optimization of the design parameters was performed on the simulation models, using the responsive surface methods and artificial neural network capabilities of optimization environment ModEContier to speed up the iteration process. In this optimization, 'heat exchange in stack chimneys is optimized annually'. The uncertainty in the optimized results has been analysed using uncertainty analysis (UA). Finally, the appropriateness of deploying a complex, high resolution simulation has been evaluated by studying current modelling resolution selection methodology found in literature.

Van Goch, T.A.J.

2012-02-15

216

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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....

Lindblad, Peter; Lindberg, Pia; Oliveira, Paulo; Stensjo?, Karin; Heidorn, Thorsten

2012-01-01

217

Solar-air power plant. Interim report, January 1, 1980-November 1, 1981  

Energy Technology Data Exchange (ETDEWEB)

The chimney conversion efficiency of transferring solar energy into wind energy for the proposed solar-air power plant has been investigated. The application of a chimney as the air-cooling system for a large-scale photovoltaic concentration power plant to transfer solar energy into electricity has also been studied. Several conclusions in reference to this basic research project and suggestions for further research phases are also summarized in this report.

Chen, I.

1982-01-01

218

A note on chimney formation in ice edge regions  

Science.gov (United States)

This paper investigates a coupled mesoscale ice-ocean system forced by winds and cooling, leading to the phenomenon of 'chimney' formation (i.e., the formation of a rapid deepening of the mixed layer due to a strong surface heat loss) in ice-edge regions. A numerical model, based on Hakkinen's (1987) coupled dynamic-thermodynamic model of an ice-ocean system, was used that included, in addition to wind stirring, the entrainment parameterization. The results are for the most part similar to the results of Hakkinen, indicating the overwhelming relevance of wind mixing, with penetrative convection having additional effects. The model calculations show that the area affected by ice edge upwelling is most prone to entrainment; the convectively induced entrainment is necessary for the production of a chimney.

Hakkinen, Sirpa

1988-01-01

219

Collapse of chimney caused by earthquake or by aircraft impingement with subsequent impact on reactor building  

International Nuclear Information System (INIS)

The behaviour of a typical chimney stack of a nuclear-power plant subjected to earthquake impact loads is examined. The explicit integration procedure using convected coordinates is adopted to perform the transient analyses with large displacement and material nonlinearities of the concrete stack, of the impinging aircraft and of the soil. Thanks to the favourable effects of the parallel separation of the base mat from the soil (lifting-off), the chimney does not collapse for realistic accelerations of the earthquake. Force-time relationships of the aircraft impinging on the chimney are developed. The impact of aircraft debris causes only local damage of the chimney. The direct impingement of an aircraft, however, may lead to partial collapse or total overturning of the chimney. The resulting motion, including the impact of the chimney on the reactor building, is studied. The response of the structure being hit and the equipment located within will in many cases govern their design. (Auth.)

1979-01-01

220

Optimal and hysteretic fluxes in alloy solidification: Variational principles and chimney spacing  

CERN Document Server

We take a numerical approach to analyze the mechanisms controlling the spacing of chimneys -- channels devoid of solid -- in two-dimensional mushy layers formed by solidifying a binary alloy. Chimneys are the principal conduits through which buoyancy effects transport material out of the mushy layer and into the liquid from which it formed. Experiments show a coarsening of chimney spacing and we pursue the hypothesis that this observation is a consequence of a variational principle: the chimney spacing adjusts to optimize material transport and hence maximize the rate of removal of potential energy stored in the mushy layer. The optimal solute flux increases approximately linearly with the mushy layer Rayleigh number. However, for spacings below a critical value the chimneys collapse and solute fluxes cease, revealing a hysteresis between chimney convection and no flow.

Wells, Andrew J; Orszag, Steven A

2010-01-01

 
 
 
 
221

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

International Nuclear Information System (INIS)

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)

1991-01-01

222

GPS FOM Chimney Analysis using Generalized Extreme Value Distribution  

Science.gov (United States)

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.

Ott, Rick; Frisbee, Joe; Saha, Kanan

2004-01-01

223

Optimal and hysteretic fluxes in alloy solidification: Variational principles and chimney spacing  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We take a numerical approach to analyze the mechanisms controlling the spacing of chimneys -- channels devoid of solid -- in two-dimensional mushy layers formed by solidifying a binary alloy. Chimneys are the principal conduits through which buoyancy effects transport material out of the mushy layer and into the liquid from which it formed. Experiments show a coarsening of chimney spacing and we pursue the hypothesis that this observation is a consequence of a variational pr...

Wells, Andrew J.; Wettlaufer, J. S.; Orszag, Steven A.

2010-01-01

224

Modelling and Simulation of Acid Gas Condensation in an Industrial Chimney  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Coal power stations as well as waste incinerators produce humid acid gases which may condense in industrial chimneys. These condensates can cause corrosion of chimney internal cladding which is made of stainless steel, nickel base alloys or non metallic materials. In the aim of polluting emission reduction and material optimal choice, it is necessary to determine and characterize all the phenomena which occur throughout the chimney and more especially condensation and dissolution of acid gase...

Serris, Eric; Cournil, Michel; Je?ro?me, Peultier

2009-01-01

225

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

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

2006-01-01

226

SiO chimneys and supershells in M82  

CERN Multimedia

In this Letter we present the first images of the emission of SiO and H13CO+ in the nucleus of the starburst galaxy M82. Contrary to other molecular species that mainly trace the distribution of the star-forming molecular gas within the disk, the SiO emission extends noticeably out of the galaxy plane. The bulk of the SiO emission is restricted to two major features. The first feature, referred to as the SiO supershell, is an open shell of 150 pc diameter, located 120 pc west from the galaxy center. The SiO supershell represents the inner front of a molecular shell expanding at 40 km/s, produced by mass ejection around a supercluster of young stars containing supernova remnant SNR 41.95+57.5. The second feature is a vertical filament, referred to as the SiO chimney, emanating from the disk at 200 pc east from the galaxy center. The SiO chimney reaches a 500 pc vertical height, and it is associated with the most prominent chimney identified in radio continuum maps. The kinematics, morphology, and fractional ab...

García-Burillo, S; Fuente, A; Neri, R

2001-01-01

227

D0 - Chimney Lead Quench Detection, Beta Solenoid  

International Nuclear Information System (INIS)

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.

1993-01-01

228

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

International Nuclear Information System (INIS)

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

1985-06-10

229

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

Energy Technology Data Exchange (ETDEWEB)

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.

Dick, R.D.; Blacic, J.D.; Pettitt, D.R.

1985-01-01

230

Chimney damage in the greater Seattle area from the Nisqually earthquake of 28 February 2001  

Science.gov (United States)

Unreinforced brick chimneys in the greater Seattle area were damaged repeatedly in the Benioff zone earthquakes of 1949, 1965, and 2001. A survey of visible chimney damage after the 28 February 2001 Nisqually earthquake evaluated approximately 60,000 chimneys through block-by-block coverage of about 50 km2, identifying a total of 1556 damaged chimneys. Chimney damage was strongly clustered in certain areas, in particular in the neighborhood of West Seattle where prior damage was also noted and evaluated after the 1965 earthquake. Our results showed that damage produced by the 2001 earthquake did not obviously correspond to distance from the earthquake epicenter, soft soils, topography, or slope orientation. Chimney damage correlates well to instrumented strong-motion measurements and compiled resident-reported ground-shaking intensities, but it offers much finer spatial resolution than these other data sources. In general, most areas of greatest chimney damage coincide with best estimated locations of strands of the Seattle fault zone. The edge of that zone also coincides with areas where chimney damage dropped abruptly over only one or two blocks' distance. The association between shaking intensity and fault-zone structure suggests that abrupt changes in the depth to bedrock, edge effects at the margin of the Seattle basin, or localized trapping of seismic waves in the Seattle fault zone may be significant contributory factors in the distribution of chimney damage.

Booth, D. B.; Wells, R. E.; Givler, R. W.

2004-01-01

231

Estimated effective chimney heights based on rawinsone observations at selected sites in the United States  

International Nuclear Information System (INIS)

The plume rise equations of Briggs (1975) for variable vertical profiles of temperature and wind speed are described and applied for hypothetical short and very tall chimneys at five National Weather Service rawinsonde stations across the United States. Annual average effective chimney heights are presented and from other available data additional information on plume behavior is deduced. For example, based on the 0515 CST soundings at Nashville, 61% of the effective plume heights for 50 m chimneys were in a temperature inversion, but only 21% of the plumes for 400 m chimneys were so constrained. Ordinarily, such plumes would be in a fanning configuration. Most of the plumes from tall chimneys (60%) were above an inversion, practically isolated from the ground. Overall, 98% of the short-chimney plumes were reached by the afternoon mixing height, but only 85% of the tall-chimney plumes were reached. Such information supports the obvious presumption that the effluent from tall chimneys remains airborne longer than that from short chimneys, is transported over greater distances, and has more opportunity to undergo chemical transformations before reaching the ground

1978-01-01

232

Leakage-flow-induced vibrations of a chimney structure suspended in a liquid flow  

Energy Technology Data Exchange (ETDEWEB)

Results are presented of flow-induced vibration tests conducted to assess the vibration characteristics of a chimney structure suspended in a liquid flow. The test article is a full-scale model of a flow chimney used in a nuclear reactor as a part of reactor upper internals. All pertinent prototype conditions achievable were simulated in a laboratory environment. The test results show that the chimney experiences an unstable, motion-limited vibration which has a distinct lock-in phenomenon with respect to the flowrate. This unstable vibration is associated with the leakage-flow-modulated excitation through the small clearances between the chimney and its supports.

Chung, H.

1984-06-01

233

Analysis Study of Solar Tower Power Plant & Its Configuration Effects on Its Performance in Iraq (Baghdad City  

Directory of Open Access Journals (Sweden)

Full Text Available A solar chimney power plant model, consisting of a solar collector to produce a hot air when the incident solar radiation hit it, a solar chimney and a wind turbine with generator was investigated in this study. The mathematical model as a tool was used to study and analyze the performance of the power plant for electrical production in Baghdad city of Iraq as a result a mathematical equation was obtained for the hot air outlet temperature from the collector as a function of collector’s area and solar radiation. The Manzanares model was used in this study and the results obtained from the proposed model of solar tower, having the height 195 m, diameter of 10 m, and the solar collector diameter of 244 m were compared with the results obtained when the solar tower configuration is changed. The results indicate that the significant impact to improve the output power is by increasing the collector’s diameter from 244 m to 300 m. It is also found that output power is effectively dependent on the chimney’s height, it yields moderate increasing in power output when the height is increased from 195 m to 300 m, and the chimney’s diameter has a lower impact on solar tower output power in comparison with the other configuration of solar tower when it increases from 10 m to 20 m.

Mohammed H. Ali

2013-03-01

234

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

Science.gov (United States)

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.

Gomez, Rafael; Segura, Jose L.

2007-01-01

235

Hullco Construction, Prescott, Arizona: solar energy system performance evaluation, October 1979-May 1980  

Energy Technology Data Exchange (ETDEWEB)

A single-family passive solar residence located in Prescott, Arizona was designed to supply 97% of the heating load. Included in the system is an attached greenhouse, a Trombe wall, rock bin, direct gain floor slab, and secondary storage in the building mass. The actual solar contribution was 91% in this colder than average season. (MHR)

Miller, P.C.; Pollock, E.

1980-01-01

236

Design of chimney of the Sandreuth district heating power station at EWAG-Energie und Wasserversorgung AG, Nuernberg, from the point of view of enhancing theoretical and architectonic knowledge  

Energy Technology Data Exchange (ETDEWEB)

The chimney of the 109 MW disrict heating power station is located in the centre of Nuremberg in the vicinity of well-maintained industrial installations built at the turn of the century. The paper deals comprehensively with the interactive influence of architecture and maintenance of clean air in design and construction.

Kolar, J.; Kahn, R.

1981-09-01

237

Solar power satellite. System definition study. Part 1, Volume 3: Construction, transportation and cost analyses  

Energy Technology Data Exchange (ETDEWEB)

Concepts developed for both LEO and GEO construction of photovoltaic and thermal engine satellites are analyzed. Topics discussed include: satellite construction; crew scheduling; crew jobs and organizations; operator productivity rating; constructability rating; transportation systems for cargo launch, refueling operations, personnel transport, and orbit transfer; collision analysis, cost analysis, and radiation evironment and effects.

1977-08-08

238

Solar power satellite. System definition study. Part 1, volume 3: Construction, transportation and cost analyses  

Science.gov (United States)

Concepts developed for both LEO and GEO construction of photovoltaic and thermal engine satellites are analyzed. Topics discussed include: satellite construction; crew scheduling; crew jobs and organizations; operator productivity rating; constructability rating; transportation systems for cargo launch, refueling operations, personnel transport, and orbit transfer; collision analysis, cost analysis, and radiation evironment and effects.

1977-01-01

239

SOLERAS - Solar Energy Water Desalination Project: Boeing Engineering and Construction. System Design Final Report.  

Science.gov (United States)

The system design for a future commercial solar energy brackish water desalination plant is described. Key features of the plant are discussed along with its configuration selection rationale, design objectives, operation, and performance. The water treat...

1986-01-01

240

Experimental investigation and construction of PV solar tracker control system using image processing  

Directory of Open Access Journals (Sweden)

Full Text Available The sun tracking system of a solar panel based on computer image processing of a shadow is investigated. This is done by using a camera to obtain the picture of a shadow on a screen by solar panel displacements. This system is independent respect to geographical location of the solar panel and periodical alignments such as daily or monthly regulations. The collected energy was measured and compared with that on a fixed surface tilted at towards the South. The results indicate that the measured collected solar energy on the moving surface was significantly larger (up to 46.77% compared with the fixed surface. The tracking system developed in this study provides easy installation, simple mechanism and less maintenance. Furthermore, the operation of the system is independent respect to the initial configuration and the start time situation.

morteza taki

2011-11-01

 
 
 
 
241

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

International Nuclear Information System (INIS)

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

1993-01-01

242

Construction and testing of a transportable solar adsorption refrigerator; Construction et test d'un refrigerateur solaire a adsorption transportable  

Energy Technology Data Exchange (ETDEWEB)

The report describes the development of an autonomous solar adsorption refrigerator characterized by its compactness and transportability. The refrigerator utilizes water as the working fluid and silicagel as the adsorbent and operates discontinuously over the day/night cycle. For a cooling volume of about 100 liters a collector-adsorber surface of 1 m{sup 2} is required and the total mass of the system amounts to about 150 kg. In order to keep its mass as low as possible the apparatus has been built with light weight materials. The cold-storage room has been insulated with a high-performance insulation material, thus minimizing thermal losses without excessively reducing the cooled volume. A new automatic valve system has been developed making superfluous any manual manipulation during normal operation. The dimensioning of the cooling system allows to cool the equivalent of 2.5 to 3.7 kg of water by 30 K daily in a climate of the Sahelien type. The cooling energy is stored in the form of ice in the evaporator and allows to bridge a period of three overcast-sky days. The construction of the solar refrigerator was made in cooperation with small regional enterprises and workshops. The cooperation with a non governmental organization allowed to test the system from May to September 2002 in a Subsaharian region of Africa where an equivalent model had been built using locally available materials. Likewise, a market study has been made in Burkina Faso in order to analyze the potential of solar adsorption refrigerators in this region. The result of the study suggests that the opening of a production workshop for such refrigerators in Burkina Faso is promising.

Mayor, J.; Dind, P.

2002-07-01

243

The double two-chimney technique for complete renovisceral revascularization in a suprarenal aneurysm.  

Science.gov (United States)

Suprarenal pathologies can be treated with immediately available devices with the chimney technique, which offers a bail-out in patients not eligible for a branched or fenestrated stent graft. We present an adjusted chimney technique for total renal and visceral revascularization in a patient with a suprarenal aneurysm. Although short-term results look promising, longer follow-up is anticipated. PMID:23402874

Tolenaar, Jip L; Zandvoort, Herman J A; Hazenberg, Constatijn E V B; Moll, Frans L; van Herwaarden, Joost A

2013-08-01

244

Experiments of chimney flows for the validation of the behaviour of passive autocatalytic recombiners  

International Nuclear Information System (INIS)

For the validation of the computational code REKO-DIREKT simulating the operational behaviour of passive autocatalytic recombiners in severe accidents, experiments on chimney flows were performed in cooperation between RWTH Aachen and Forschungszentrum Juelich. This compact describes the experimental setup and shows the correlation between the H2 concentration, the catalyst temperature and the inlet velocity at various recombiner chimney heights. (orig.)

2013-10-01

245

Ant mound as an optimal shape in constructal design: Solar irradiation and circadian brood/fungi-warming sorties.  

Science.gov (United States)

Sizes, shapes, ambient and in-dome temperature, incoming solar radiation and illumination are measured on a Formica rufa anthill in a mixed forest of the Volga-Kama National Reserve in Russia. These data are used in a conceptual model of insolation of a right conical surface by direct-beam, descending atmospheric and ascending ground-reflected radiation. Unlike a standard calculation of the energy flux intercepted by a solar panel, the anthill is a 3-D structure and double-integration of the cosine of the angle between the solar beams and normal to the surface is carried out for a "cozy trapezium", where the insects expose themselves and the brood to "morning" sunbathing pulses (Jones and Oldroyd, 2007). Several constructal design problems are formulated with the criteria involving either a pure solar energy gained by the dome or this energy, as a mathematical criterion, penalized by additive terms of mechanical energy (potential and friction) lost by the ants in their diurnal forays from a "heartland" of the nest to the sun-basking zone on the surface. The unique and global optima are analytically found, with the optimal tilt angle of the cone explicitly expressed through the zenith angle of the Sun and meteorological constants for the isotropic sky model. PMID:24681404

Kasimova, R G; Tishin, D; Obnosov, Yu V; Dlussky, G M; Baksht, F B; Kacimov, A R

2014-08-21

246

Atmospheric concentrations of polycyclic aromatic hydrocarbons during chimney sweeping.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Air sampled from the breathing zone of chimney sweeps during "dirty work" and soot samples were analysed for polycyclic aromatic hydrocarbons (PAH). A total of 20 PAH were quantified by gas chromatography-mass spectrometry in 115 air samples and 18 soot samples. These included benzo(b)fluoranthene, benzo(a)pyrene (BaP), chrysene, dibenz(a,h)anthracene, and indeno (1,2,3-cd)pyrene, all of which are animal carcinogens. The summed atmospheric concentration of these compounds depended on the type...

Knecht, U.; Bolm-audorff, U.; Woitowitz, H. J.

1989-01-01

247

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

Directory of Open Access Journals (Sweden)

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.

R. D. García

2014-04-01

248

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

Science.gov (United States)

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.

García, R. D.; Cuevas, E.; García, O. E.; Cachorro, V. E.; Pallé, P.; Bustos, J. J.; Romero-Campos, P. M.; de Frutos, A. M.

2014-04-01

249

Influence of the Chimney Dimensions on the Heat Transfer of a Vertical Cylinder in a Duct  

Energy Technology Data Exchange (ETDEWEB)

A thermally insulated chimney attached to a vertical heated section induces an increase in the natural convection flow in the heated vertical cylinder and leads to a higher heat transfer rate. The flows in the chimney are originally driven by the natural convection. However its behavior is similar to the forced convective flows as the heated vertical cylinder is located in a duct or chimney and then the mass flow rate at every elevation should be the same. Heat transfer in the chimney depends on the dimensionless geometrical parameters (Fig. 1), such as the extension ratio (the total length of chimney system, L{sub t}, over the heated section length, L{sub h}), the expansion ratio (the diameter of chimney, D{sub t}, over the diameter of heated vertical cylinder, D{sub h}), the aspect ratio of cylinder (the length of cylinder, L{sub h}, over the diameter of cylinder, D{sub h}), and the location of cylinder in a duct (the top or bottom of chimney). Although some works have been done on the heat transfer in the chimney, arrangements detailed experimental investigations on the determination of the optimal location of the heated cylinder in the chimney are rare. And previous studies have been performed for extension ratio 1.0-5.0. This work investigated the influence on the chimney dimensions (entrance and exit length, and diameter) on the heat transfer of a vertical cylinder in a duct. The measured mass transfer rates for the natural convection of vertical cylinder in a duct were presented for Prandlt number 2,094, Rayleigh number 4.55x10{sup 9}, 5.79x10{sup 10}, and 1.69x10{sup 11}. Experiments were performed using a copper sulfate electroplating system to simulate heat transfer based upon the analogy concept

Lim, Chul Kyu; Chung, Bum Jin [Jeju National University, Jeju (Korea, Republic of)

2011-10-15

250

Solar Euromed: A New Player to Developed, Engineer and Construct 1000 MW CSP Power Plants in the Mediterranean Area  

Energy Technology Data Exchange (ETDEWEB)

Solar Euromed, a new company registered under the law of France, has been incorporated in 2006 in order to participate the GMI for CSP technology by Developing, Engineering and Constructing 1000 MW parabolic through power plants in the next decade all over the Mediterranean countries. It incorporates a team of highly qualified engineers and technicians, all experienced in the field of combined and cogeneration cycle design, project engineering, management and construction, thermal, electrical and I and C, mechanical and civil engineering applications. The targeted countries are Morocco, Algeria, Tunisia, Libya, Jordan, United Arab Emirates, Saudi Arabia and France. In this later country, the company expects to build a commercial testing facility sizing 20 MWe in the Pyrenean in order to contribute the global R and D initiative and the corresponding cost reduction objective. (Author)

Benmarraze, M. M.

2006-07-01

251

Thermal management of a symmetrically heated channel-chimney system  

International Nuclear Information System (INIS)

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)

2009-03-01

252

Treating the paravisceral aorta with parallel endografts (chimneys and snorkels).  

Science.gov (United States)

While excellent results can be achieved with the open repair of juxtarenal and suprarenal aortic aneurysms in good-risk patients, the outcomes in high-risk patients are less favorable. The use of standard infrarenal endografts to treat these patients has been limited due to the absence of a suitable proximal landing zone. Using infrarenal endografts outside the instructions for use has been shown to lead to poorer outcomes with a higher incidence of type I endoleaks and graft migration. Fenestrated and branched endografts are viable options, but until recently have not been commercially available within the United States. In addition, they require meticulous preoperative planning and 4 to 6 weeks to manufacture. This makes them unsuitable for use in the urgent setting. Others have looked at the use of parallel covered stents placed alongside the main endograft body, the "chimney" or "snorkel" graft technique, to allow for continued perfusion to visceral/renal vessels. This technique allows for proximal placement of the landing zone of the main body, while maintaining blood flow to critical branches. The purpose of this article is to review the current literature on chimney grafts, their efficacy, and associated morbidity and mortality. PMID:23206566

Shuja, Fahad; Kwolek, Christopher J

2012-12-01

253

Construction and trial of a solar oven. Bau und Erprobung eines Sonnenofens  

Energy Technology Data Exchange (ETDEWEB)

Two solar ovens were built for examining the utilisability of sun irradiation in central Europe, which has only a moderate annual yield compared with other regions of the Earth. In testing practical applications it proved possible to cook meals and bake cakes. The work also deals with the weak points of the models developed. (orig./DG)

Schaefer, T.; Beuck, I.

1994-05-01

254

More and more solar panels in construction projects; Steeds meer zonnepanelen in bouwprojecten  

Energy Technology Data Exchange (ETDEWEB)

The application of photovoltaic energy in the built environment is increasingly common in the Netherlands. An important question is how solar panels can be fit architecturally and technically into the design. Although that question can not yet be completely answered, much practical knowledge is now available.

NONE

1999-02-01

255

CFD simulation of a solar tower  

Energy Technology Data Exchange (ETDEWEB)

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.

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

2011-07-01

256

Designing, Construction and Analysis of Speed Control System of the Fan with PV Feeding Source in an Air Solar Collector  

Directory of Open Access Journals (Sweden)

Full Text Available Solar energy is one of the renewable energy sources which can be received more by designing more accurate systems. In this article a flat solar collector with the area of 2×1m2 and thickness of 0.5mm, made of steel iron in the form of venetian blinds (in order to increase exposure to air has been used. The surface of absorber plate was black and for insulation of the body of the collector glass wool has been used with 5 cm thickness. One of the essential problems of air solar collectors is that the temperature of the exiting air temperature from the collector is variable during the day and their efficiency is low in the last hours of the day and also when the weather suddenly gets cloudy .In this study, to keep constant the exiting air from the collector consistent in the desired limits, a control system is designed and constructed by applying photovoltaic cells, a microcontroller (AVR and temperature sensors (LM35. Three temperature sensors were installed in the exit of the collector .The experiment results showed that by automatic change of the fan's speed in the designed system, the exiting temperature of the collector was obtained in the desired limits which is an outstanding advantage for various applications.

Amir Hematian

2011-12-01

257

Formation of a series of chimney-ladder compounds in the Ru-Re-Si system  

International Nuclear Information System (INIS)

Rhenium-alloyed ruthenium sesquisilicide alloys have been prepared over the wide composition range Ru1-?Re ?Si1.5, 0 ? ? ? 0.85. The phase relationships of these alloys have been investigated using X-ray powder diffraction, scanning electron microscopy and transmission electron microscopy. Alloys with ? ? 0.03 are multi-phase, composed of a series of (Ru,Re)Si y chimney-ladder phases with compositions of Ru1-xRe xSi1.5386+0.1783x (0.14 ? x ? 0.76) and B20-type monosilicide (Ru,Re)Si as a secondary phase. These chimney-ladder structures are considered to form to stabilize the high-temperature Ru2Si3 chimney-ladder phase through the substitution of Ru with Re. The solubility limit of Re in a series of chimney-ladder phases is as large as 76% Re (x = 0.76) and the Si/(Ru + Re) ratio of the chimney-ladder phases increases with increasing Re content. The observed deviation of the chimney-ladder structure from the idealized composition and the possibility of adjusting the semiconducting properties of these chimney-ladder structures are discussed in terms of the valence electron concentration per metal atom

2006-06-01

258

CFD simulation of turbulent mixing of two opposing flow inside the model of a chimney  

International Nuclear Information System (INIS)

Numerical simulation was carried out to study the turbulent mixing behaviour of two opposing flow inside the model of a chimney structure. Open pool type research reactors often use this type of chimney structure to prevent mixing of core outlet water directly into the pool in order to keep the radioactivity level at the pool top to a lower limit. The chimney design facilitates guiding of the radioactive water from the reactor core towards the side outlet nozzles and simultaneously allows sucking of water from the reactor pool through the chimney top. The present work aims at studying the turbulent mixing behaviour of water coolant inside a 1/6th scaled down model of chimney structure. The Reynolds number considered in the simulation is 2.9 x 106 which corresponds to an upward core flow of 25 kg/s. The core bypass flow which is sucked in the downward direction is varied form 0 to 10%. The effects of flow ratio between the upward flow and downward flow on the mixing behaviour are analysed by means of commercial software. Turbulence is modelled by using the Reynolds averaged Navier Stokes (RANS) equation. The results indicate that increase in bypass flow causes the stagnation depth (the depth at which upward flow velocity becomes zero with respect to the top opening edge of the chimney) to increase. It is observed that if sufficient bypass flow is provided, no water from the core will be able to reach the reactor pool through the chimney top. (author)

2011-03-01

259

Measurements of chimney top temperatures at a 2000 MW oil-fired power station  

Energy Technology Data Exchange (ETDEWEB)

Low surface temperatures within the flue gas systems of oil-fired boilers promote the deposition of acid and carbon. Subsequent re-entrainment of this agglomerated acidic carbon gives rise to acid smut emission. Temperature measurements at the top of a 2000 MW power station chimney have identified two processes which cool the inside surface of the chimney. The first of these is caused by heat radiation to the atmosphere through the open chimney outlet. Measured temperature depressions are in agreement with previous predictions. The second process caused cooling of the inner surface on the windward side of the chimney at high wind speeds. It is demonstrated that the likely mechanism of this wind-induced cooling is a distortion of flue gas flow causing a reduction in the convective heat transfer coefficient between flue gas and surface. The magnitude of the cooling is such that acid deposits can accumulate at the chimney top under normal operating conditions, thus causing the top of the chimney to be a major source of acid smut emission. The cooling could be countered by supplying heat to the top of the chimney.

Aldham, O.; Billingsley, J.

1982-09-01

260

Feasibility of utilising solar-induced ventilation in Malaysia  

International Nuclear Information System (INIS)

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

2006-12-01

 
 
 
 
261

Effects of chimney on thermo-hydraulic and core instability of boiling natural circulation loop  

International Nuclear Information System (INIS)

Thermo-hydraulic instabilities of a boiling natural circulation loop with a chimney under high pressure were investigated using linear stability analysis. The effect of nuclear coupling was also considered. Instability could occur when exit quality was relatively low. When instability occurred, void was generated near channel exit, and void wave propagated in the chimney. In high power condition, though flow could be very stable, the decay ratio of higher mode could be larger than that of lower mode. The sensitivity of decay ratio to the thermal power, inlet subcooling, void reactivity feedback coefficient and so on could be very small when there was a long chimney. (author)

2003-04-20

262

Concentration levels of solutes in porous deposits with chimneys under wick boiling conditions  

International Nuclear Information System (INIS)

Concentration levels of infinitely soluble solutes in porous deposits with chimneys, for which wick boiling appears to be the major mode of heat transfer, has been investigated by a two-dimensional model. Wick boiling promotes the development of high concentration levels of solutes within porous deposits, especially in the region near the intersection of the heating surface and the chimney wall. The maximum concentration factor increases with decreasing porosity; with increasing chimney population; with increasing system pressure in the range of system pressures of interest to LWRs, and approximately exponentially with both increasing heat flux and crud thickness

1985-01-01

263

Talc Chimneys on the Mid Cayman Rise Spreading Centre  

Science.gov (United States)

The Von Damm Vent Field, located at a depth of 2300 metres on the Mid-Cayman Rise Spreading Centre, features an 80 metre, steep sided, conical mound. Hosted in ultramafic/mafic intrusives it is one of the few known off-axis vent sites, and is located on the Mount Dent Oceanic Core Complex. There are two main fluid orifices, which vent shimmering fluid, located at the top of the main mound with contrasting morphologies. The highest temperature fluid at 230oC is emanating from a wide-based spire approximately 3 metres high, with a wide 1-metre diameter hole on the western side of the spire, venting fluids at around 125oC. The chimneys are composed of talc (75%), silica (15%) and sufides (10%), with chalcopyrite representing the most common sulfide phase, despite the relatively low T and colourless plumes. In the chimneys, talc occurs as botryoidal and colloform masses indicating primary precipitation into pore space and is intergrown with silica in a very fine grained groundmass. Sulfides occur disseminated in both talc and silica, with minor pyrite and sphalerite present as well as the chalcopyrite. To our knowledge no other sea floor hydrothermal vent sites feature the concentrations of talc observed at Von Damm, which likely represents a third, new type of hydrothermal system after conventional black smoker systems and lower temperature, serpentinisation driven carbonate occurrences. During hydrothermal circulation of seawater at seafloor spreading centres magnesium is sequestered into clays and chlorite in the upper oceanic crust resulting in complete removal of Mg and absence of Mg in the emanating vent fluid. However, the presence of Mg-bearing silicates in mound and chimney material is not uncommon, but not in the volumes reported here, with the magnesium thought to originate from seawater, pore water, or sediments. Experimental studies confirm that on reaction with mafic and in particular pyroxene dominated lithologies, Mg is preferentially removed from the hydrothermal fluid, whereas during reaction with dunite, Mg remains in the fluid (Allen and Seyfried 2003). It is possible that, even with the removal of Mg in the upper levels of the oceanic crust on its down flowing limb, interaction with an olivine-rich dunite pod may recharge the fluid with magnesium. The location of the Von Damm vent field on an oceanic core complex could change our understanding of the distribution of venting along ultra-slow spreading ridges, as detachment faults penetrating into thin oceanic crust act as pathways for hydrothermal fluids driven out from depth that have been heated by magma chambers closer to the volcanic ridge or by gabbroic intrusions into the ultramafic host.

Hodgkinson, M.; Murton, B. J.; Roberts, S.

2012-12-01

264

The design, construction, and initial operation of a closed-cycle, salt-gradient solar pond  

Energy Technology Data Exchange (ETDEWEB)

In operation of a closed-cycle salt-gradient solar pond (CCSGSP) system, fresh or low salinity water is supplied at the surface of the solar pond (SP) as make-up for evaporation losses as well as for surface washing. In the present investigation the surface water is flushed to an evaporation pond (EP) and concentrated for reinjection at the bottom of the SP. A 20 m[sup 2] SP incorporating an EP for concentrating brine, has been established. Theoretical modelling of the CCSGSP is presented. Results from the initial operation of the SP show that wind action and convective mixing caused some erosion of the gradient layer thereby increasing the surface layer thickness. Salt flux to the surface was found to be approximately 19 kg/m[sup 2] per year. Sodium hypochlorite solution proved successful as shock treatment during severe algal bloom. The result of acidification w as less promising in maintaining pond clarity. Occasional addition of alum helped in settling some of the suspended particulates in the pond.

Alagao, F.B.; Akbarzadeh, A.; Johnson, P.W. (Royal Melbourne Institute of Technology, Victoria (Australia))

1994-10-01

265

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

Energy Technology Data Exchange (ETDEWEB)

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.

Long, R.C.

1996-12-31

266

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

International Nuclear Information System (INIS)

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

1999-05-01

267

The Chimney Effect on Natural Circulation in The Coolant Channel of TRIGA 2000 Reactor  

International Nuclear Information System (INIS)

To accomplish the safety evaluation of the TRIGA 2000 reactor, a theoretical and an experimental analysis have been carried out. In the present study, the effect of chimney on the thermal hydraulics parameter will be presented. In the theoretical analysis, the STAT computer code has been used to determine the temperature and velocity of coolant in the reactor core. Meanwhile, in the experiments, a special probe to measure the bulk temperature of the coolant at different position in the coolant channel has been inserted to central thimble (CT). The theoretical results obtained indicated that the coolant temperatures which considering the chimney effect are approximately (15 - 30) % lower than ones of the core without chimney. Meanwhile, the experimental study showed that, for various of reactor powers, the coolant temperatures which considering the chimney effect are approximately (35 - 40) % higher than the theoretical calculation for the highest position of the coolant channel (x/L = 0.87). (author)

2006-02-01

268

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

Energy Technology Data Exchange (ETDEWEB)

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.)

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

2006-12-15

269

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

International Nuclear Information System (INIS)

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

2007-03-01

270

Concentration levels of solutes in porous deposits with chimneys under wick boiling conditions  

International Nuclear Information System (INIS)

Concentration levels of highly-soluble impurities and additives in porous deposits with chimneys, when wick boiling is the major mode of heat transfer, have been investigated by a two-dimensional model. Wick boiling promotes the development of high concentration levels of solutes within porous deposits, especially in the region near the intersection of the heating surface and the chimney wall. The maximum concentration factor increases with decreasing porosity; increasing chimney population density; increasing system pressure in the range of interest to LWRs; and approximately exponentially with heat flux and crud thickness. The two-dimensional solute concentration distribution in porous deposits is consistent with limited experimental observations of higher concentration at the chimney wall. (orig.)

1987-02-01

271

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

International Nuclear Information System (INIS)

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.)

2006-12-01

272

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

2007-01-01

273

Investigating Microbial Habitats in Hydrothermal Chimneys using Ti-Thermocouple Arrays: Microbial Diversity  

Science.gov (United States)

In order to examine the changes that occur in the microbial community composition as a deep-sea hydrothermal vent chimney develops, we deployed Ti-thermocouple arrays over high temperature vents at two active sites of the Guaymas Basin Southern Trough. Chimney material that precipitated around the arrays was recovered after 4 and 72 days. Chimney material that precipitated prior to deployment of the arrays was also recovered at one of the sites (Busted Shroom). Culture-independent analysis based on the small subunit rRNA sequence (cloning and DGGE) was used to determine the microbial diversity associated with subsamples of each chimney. The original Busted Shroom chimney (BSO) was dominated by members of the Crenarchaeota Marine Group I, a group of cosmopolitan marine Archaea, ? -Proteobacteria, and ? -Proteobacteria, two divisions of Bacteria that are common to deep-sea vents. The 4 days old Busted Shroom chimney (BSD1) was dominated by members of the Methanocaldococcaceae, hyperthermophilic methanogens, and the 72 days old chimney (BSD2) by members of the Methanosarcinaceae, mesophilic and thermophilic methanogens. At the second site, Toadstool, the 72 days old chimney material that had precipitated around the array (TS) revealed the dominance of sequences from uncultured marine Archaea, the DHVE group I and II, and from the ? -Proteobacteria. Additionally, sequences belonging to the Methanocaldococcaceae and Desulfurococcaceae were recovered next to thermocouples that were at temperatures of 109° C (at Busted Shroom) and 116° C (at Toadstool), respectively. These temperatures are higher than the upper limit for growth of cultured representatives from each family.

Pagé, A.; Tivey, M. K.; Stakes, D. S.; Bradley, A. M.; Seewald, J. S.; Wheat, C. G.; Reysenbach, A.

2004-12-01

274

Structural Analysis of a Masonry Chimney – In-Situ Assessment Tools  

Digital Repository Infrastructure Vision for European Research (DRIVER)

At the end of the XIX and the beginning of the XX century there was a considerable industrial development in Portugal, characterized by the flourishing of several industrial plants. Brick masonry chimneys represent some of the most interesting examples of the industrial architectural heritage. The paper shows the case study of a chimney from a former ceramic factory near Porto city and that now is part of a cultural and leisure public park. With the main goal of evaluating the ...

Valter Lopes; João Paulo Miranda Guedes; Esmeralda Paupério; António Arêde; Aníbal Costa

2008-01-01

275

Numerical Analysis of a Masonry Chimney Supported by In-Situ Assessment Tools  

Digital Repository Infrastructure Vision for European Research (DRIVER)

At the end of the XIX and the beginning of the XX century there was a considerable industrial development in Portugal, characterized by the flourishing of several industrial plants. Brick masonry chimneys represent some of the most interesting examples of the industrial architectural heritage. The paper shows the case study of a chimney from a former ceramic factory near Porto city and that now is part of a cultural and leisure public park. With the main goal of evaluating the ...

Valter Lopes; João Paulo Miranda Guedes; Esmeralda Paupério; António Arêde; Aníbal Costa

2008-01-01

276

Dismantling of the exhaust gas chimney of the Rossendorf isotope production facility  

International Nuclear Information System (INIS)

Since 1958 in the Rossendorf research center isotope production has been performed. in 2000 the facility was shut-down. The exhaust air was released by a chimney with 50 m height. Following the complete dismantling of the isotope production facility the chimney is the last component to be dismantled. The authors describe the radiological and technical problems to be solved. Based on the measuring program the decontamination procedure and the dismantling procedures were planned and performed.

2009-01-01

277

Technical report for quality requirements establishment of in-chimney bracket  

International Nuclear Information System (INIS)

This technical report provides the methods on how to sustain the items of experimental materials, nuclear fuel on examination, ect. This report applies to the quality assurance(QA) programmes of the design, fabrication in-chimney bracket.The organization having overall responsibility for the nuclear power item design, preservation, fabrication shall be described in this report in each stage of chimney bracket fabrication project

2000-01-01

278

Technical report for quality requirements establishment of in-chimney bracket  

Energy Technology Data Exchange (ETDEWEB)

This technical report provides the methods on how to sustain the items of experimental materials, nuclear fuel on examination, ect. This report applies to the quality assurance(QA) programmes of the design, fabrication in-chimney bracket.The organization having overall responsibility for the nuclear power item design, preservation, fabrication shall be described in this report in each stage of chimney bracket fabrication project.

Kim, Kwan Hyun

2000-06-01

279

Turbulent mixing inside the chimney model of a pool type research reactor  

International Nuclear Information System (INIS)

Open pool type research reactors often use a chimney structure to prevent mixing of core outlet water directly into the pool in order to keep the radioactivity level at the pool top to a lower limit. This chimney structure facilitates guiding of the radioactive water from the reactor core towards the side outlet nozzles and simultaneously sucking water from the reactor pool through the chimney top. The present work aims at studying the turbulent mixing behaviour of water coolant inside a 1/6th scaled down model of chimney structure. The range of dimensionless numbers considered in the simulation are 1.44 x 106 6 and 0.002 < Ri < 0.008. The effects of flow ratio between upward flow and downward flow and their temperature difference on the mixing behaviour are analysed by means of commercial software. Turbulence is modelled by using the Reynolds averaged Navier Stokes (RANS) equation. The results indicate that the increase in downward (core bypass) flow, increases stagnation depth and try to keep the radio-activity well within the chimney region. On the contrary, the temperature difference between the hot upward fluid and cold downward fluid tries to reduce the stagnation depth. It is observed that if sufficient bypass flow is provided, no water from the core will reach the reactor pool through the chimney top opening. (author)

2011-10-24

280

Mechanical vibrations caused by wind - chimneys and ventilating pipes. Tuulen aiheuttamat mekaaniset vaeraehtelyt - savu- ja tuuletuspiiput  

Energy Technology Data Exchange (ETDEWEB)

The mechanical vibrations of power transmission lines caused by wind have been much studied. This paper applies the results of these studies to the mechanical vibrations of homogeneous vertical and round structures having the same diameter from one end to the other in cases where the lower end of the vibrating structure is rigidly fastened to its base. This report will show that metallic structures having low loss factors - for example, steel-structured chimneys as such - vibrate nearly always at their highest possible amplitude. Concrete chimneys, whose internal damping is from 10 to 20 times the damping of steel chimneys, vibrate at insignificant amplitudes. Generally speaking, vertical chimneys vibrate either at maximum amplitudes or - with sufficient damping - at insignificant amplitudes. The best damping method of the mechanical vibrations of chimneys is a spiral known as Scruton, which effectively prevents the wind energy from giving vibration energy to a structure susceptible to vibration. The locatin of mechanical vibration dampers into a chimney generates e.g. difficult location problems.

Lampio, E.

1987-01-01

 
 
 
 
281

Determination of chimney height, if the chimney height cannot be determined with the nomogram in the technical directive for air pollution control  

Energy Technology Data Exchange (ETDEWEB)

For the case that determining the chimney height leads into the broken or open area of the Q/S-lines of the nomogram in the technical directive for air pollution control the Landesanstalt fuer Immissionsschutz in Essen proposes the following procedure, which is based on calculations with a diffusion model: From the ends of the solid Q/S-lines the user draws vertical lines to the abscissa. The intersection with the corresponding vertical line marks the chimney height for the broken or open area of the Q/S-lines of the nomogram.

Giebel, J.

1982-02-01

282

The boiling flow instability of a natural circulation BWR with a chimney at low pressure start-up  

International Nuclear Information System (INIS)

The boiling flow instability of a natural circulation BWR with a long chimney was investigated experimentally. The flow could become unstable when the chimney length was increased and the chimney inlet subcooling was close to zero. Instability could occur in both a relatively large subcooling and small heating region, where the effect of gravity induced flashing was significant, and in a relatively small subcooling and large heating region, where the effect of gravity induced flashing was significant if the pressure was low. (author)

1992-01-01

283

Solar thermal utilization--an overview  

International Nuclear Information System (INIS)

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)

2007-11-01

284

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

Directory of Open Access Journals (Sweden)

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.

YingHe

2013-06-01

285

Diffusion of Solar Energy Technologies in the New-Construction Market: A Survey of New Solar-Home and Conventional-Home Buyers.  

Science.gov (United States)

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 characteri...

D. Rains D. Dunipace C. K. Woo

1981-01-01

286

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

Science.gov (United States)

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 DE-AC04-94AL85000.

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

2013-12-01

287

SOLAR POWER PLANTS  

Directory of Open Access Journals (Sweden)

Full Text Available The electrical energy import-export balance of Hungary is negative. The renewable energy sources will not solve the power supply of the country but there are cases when these systems offer an optimal solution for energy supply of special establishments. This paper presents the possibilities of power production using solar energy. The efficiency of power production using different systems is analysed taking into consideration the Hungarian climate and design parameters. Different solutions of power plant conception are presented comparing the efficiency of power production process. Beside the well known photovoltaic systems, the solar trough, the solar dish/engine system, the solar power tower, the solar chimney, the solar lake is presented.

KALMÁR Ferenc

2009-06-01

288

Lower Eocene carbonate cemented chimneys (Varna, NE Bulgaria): Formation mechanisms and the (a)biological mediation of chimney growth?  

Science.gov (United States)

In the area of Pobiti Kamani (Varna, northeast Bulgaria), massive carbonate cemented columns ("chimneys", up to 1.5 m diameter and 8 m high) and horizontal interbeds (? 1.5 m thickness) occur in dispersed outcrops over an area of 70 km 2 within loose Lower Eocene sands. Field observations and petrographical and stable isotope geochemical characterisation of four studied locations reveal a relationship between these structures and processes of ancient hydrocarbon seepage. Column and interbed structures both consist of similar well-sorted silt- to sand-sized nummulitic host sediments, predominantly cemented by early diagenetic, low-magnesium calcite. Filamentous textures, about 10 ?m in diameter and 80-650 ?m long, are only locally detected within interparticle calcite cement of columns. Column samples from two sites reveal a similar, linear and inverse covariant trend of ?13C- ?18O values, which was interpreted as a mixing trend between two end member fluid/precipitation conditions, i.e. (1) a methane- and/or higher hydrocarbon-derived carbon member characterised by ?13C values as low as - 43‰ and marine controlled precipitation conditions with ?18O of - 1 ± 0.5‰ V-PDB and (2) a member with less contribution of methane which was mixed most likely with less depleted carbon sources explaining ?13C values ranging up to - 8‰ V-PDB. The corresponding, depleted ?18O values, with many samples clustering around - 8‰ V-PDB, are interpreted in terms of precipitation at elevated temperatures. This suggests the venting system was not a true "cold" seep, sensu stricto. Furthermore, column cross-transects often document an internal pattern consisting of (concentric) zones with distinct isotopic signatures, which vary between the two end members. The mixing and internal pattern of column isotopic data, together with petrographical observations, are qualitatively interpreted as evidence of alternating precipitation conditions, controlled by varying seepage rates of a single fluid source at depth, during build-up of individual chimney pipes near the sediment surface. Based on several field observations, migration of the hydrocarbon-charged fluids in Lower Eocene times was possibly channelled along NE oriented faults. Isotopic signatures of calcite cemented horizontal interbeds, with depleted ?18O ratios as low as - 8.88‰ V-PDB and variable ?13C (- 1‰ to - 16‰, mainly around - 5‰ to - 7‰) suggest that ascending fluids contributed to their cementation or resetted the calcite cement isotopic signature, predominantly during periods of active seepage of warmer fluids. Only few petrographical (and preliminary lipid-biomarker) evidence has been found, pointing to the presence or possibly former activity of microbiota, involved in carbon cycling and calcite precipitation, typical of cold seep settings. This may result from diagenetic alteration of organic components. However, considering the processes of chimney formation, a cementation process, governed by the inorganic oxidation of hydrocarbons in which interstitial oxygen is rapidly consumed without bacterial mediation, is considered.

De Boever, E.; Swennen, R.; Dimitrov, L.

2006-03-01

289

Development of the lined masonry chimney oil appliance  

Energy Technology Data Exchange (ETDEWEB)

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}

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

1996-07-01

290

Silica chimneys formed by low-temperature brine spring discharge.  

Science.gov (United States)

Vertical pipes comprised of loose silica and lined by chert nodules have been observed in the abandoned Mafeking Quarry in central Manitoba, Canada. Discovery of microfossils within these features of the same age as the carbonate host rock indicates that they are a dissolution/replacement structure rather than infill of karst features by younger sediments. These features occur on the low thermal maturity edge of the intercratonic Williston Basin, are not associated with any known tectonic or hydrothermal activity, and show no sign of localized discharge of high-temperature fluids. Modern low-temperature brine springs with silica-filled discharge channels occur nearby, which suggests the silica chimneys are relic spring channels. Geochemical models have shown that dissolution/replacement reactions would be expected due to mixing of brine spring water with shallow groundwater in the region. Results indicate that silica pipe features in the rock record cannot be assumed to be indicative of hydrothermal activity. At the same time, results increase the astrobiological significance of low-temperature siliceous deposits. PMID:20041746

Grasby, S E; Bezys, R; Beauchamp, B

2009-12-01

291

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

Energy Technology Data Exchange (ETDEWEB)

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)

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

1981-02-01

292

Vibration test report for in-chimney bracket and instrumented fuel assembly  

International Nuclear Information System (INIS)

The vibration levels of in-chimney bracket structure which is installed in reactor chimney and instrumented fuel assembly(Type-B Bundle) are investigated under the steady state normal operating condition of the reactor. For this purpose, 4 acceleration data on the guide tube of the instrumented fuel assembly and in-chimney bracket structures subjected to fluid induced vibration are measured. For the analysis of the vibration data, vibration analysis program which can perform basic time and frequency domain analysis, is prepared, and its reliability is verified by comparing the analysis results with those of commercial analysis program(I-DEAS). In time domain analysis, maximum amplitudes, and RMS values of accelerations and displacements from the measured vibration signal, are obtained. 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 level, 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 including the instrumented fuel assembly, the static analysis for ANSYS finite element model is carried out. These analysis results show that the maximum stresses are within the allowable stresses of the ASME code, and the maximum displacement of 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

2000-01-01

293

Dolo?itev nevertikalnosti visokih dimnikov ; Determination of the nonverticality of high chimneys  

Directory of Open Access Journals (Sweden)

Full Text Available V ?lanku je obravnavan prakti?en primer uporabe aplikacij sodobnega tahimetra pri dolo?evanju nevertikalnosti visokih industrijskih dimnikov kot alternativa klasi?nemu na?inu dolo?itve. Opisana je možnost merjenja to?k brez uporabe reflektorja, s ?imer na obodu dimnika dolo?imo množico to?k. Na njihovi podlagi lahko modeliramo dimnik kot pravilno matemati?no telo v prostoru z uporabo izravnave po metodi najmanjših kvadratov. Nevertikalnost dimnika nato dolo?imo kot odmik glavne osi modeliranega telesa od navpi?nice ; This article deals with practical examples of the applications of modern tachymeters in the determination of the nonverticality of high industrial chimneys, as an alternative to the classic methods. The possibility of a reflectorless measuring mode to determine the point cloud at the chimney’s circumference is described. Using these points, we are able to model the chimney as a mathematically correct body using the least squares adjustment method. Subsequently, the unknown nonverticality of the chimney is determined as the deviation of the primary axis of the modelled body from the vertical.

Dušan Kogoj

2011-01-01

294

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

International Nuclear Information System (INIS)

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 106. 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.)

2013-11-01

295

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

Energy Technology Data Exchange (ETDEWEB)

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.)

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

296

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

International Nuclear Information System (INIS)

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

2000-10-01

297

The chimney-graft technique for preserving supra-aortic branches: a review  

Science.gov (United States)

Evolution in the endovascular era has influenced the management of aortic arch pathologies. “Chimney” or “snorkel” graft technique has been used as an alternative in high risk patients unfit for open repair. We reviewed the published literature on the chimney graft technique for preservation of the supra-aortic branches in order to provide an extensive insight of its feasibility and efficacy and investigate its outcomes. 18 reports were identified, with a total of 124 patients and 136 chimney. Primary technical success was achieved in 123/124 patients (99.2%). The perioperative mortality rate was 4.8% and the stroke rate was 4%, while events of spinal cord ischemia were rare. The overall endoleak rate was 18.5%; 13 patients (10.5%) developed a type I endoleak and 10 (8%) patients a type II endoleak. During a median follow-up period of 11.4 months (range, 0.87-20.1 months) all implanted chimney grafts remained patent. From this, we conclude that endovascular aortic arch repair with chimney grafts is associated with a lower mortality rate compared to totally open or hybrid reconstruction. However, the stroke rate remains noteworthy, and requires longterm data to elucidate.

Mylonas, Spyridon N.; Dalainas, Ilias; Sfyroeras, George S.; Markatis, Fotis; Kotsis, Thomas; Kakisis, John; Liapis, Christos D.

2013-01-01

298

Experimental study of fluidization of 1G-Geldart D-type particles in a rotating fluidized bed with a rotating chimney  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The new, concept of rotating chimney for rotating fluidized beds is experimentally investigated using a step-response technique. The chimney rotates in the same sense as the rotating particle bed, but not necessarily at the same rotational speed. In particular, chimney rotational speeds such that the particles at contact with the chimney obtain a rotational speed higher than the average particle bed rotational speed are possible. The increase of the centrifugal force in the vicinity of the ch...

Wilde, Juray; Broqueville, Axel

2008-01-01

299

Hydrologic processes and radionuclide distribution in a cavity and chimney produced by the Cannikin nuclear explosion, Amchitka Island, Alaska  

International Nuclear Information System (INIS)

An analysis of hydraulic, chemical, and radiochemical data obtained in the vicinity of the site of a nuclear explosion (code-named Cannikin, 1971), on Amchitka Island, Alaska, was undertaken to describe the hydrologic processes associated with the saturation of subsurface void space produced by the explosion. Immediately after detonation of the explosive, a subsurface cavity was created surrounding the explosion point. This cavity soon was partly filled by collapse of overburden, producing void volume in a rubble chimney extending to land surface and forming a surface-collapse sink. Surface and groundwater immediately began filling the chimney but was excluded for a time from the cavity by the presence of steam. When the steam condensed, the accumulated water in the chimney flowed into the cavity region, picking up and depositing radioactive materials along its path. Refilling of the chimney voids then resumed and was nearly complete about 260 days after the explosion. The hydraulic properties of identified aquifers intersecting the chimney were used with estimates of surface-water inflow, chimney dimensions, and the measured water-level rise in the chimney to estimate the distribution of explosion-created porosity in the chimney, which ranged from about 10 percent near the bottom to 4 percent near the top. Chemical and radiochemical analyses of water from the cavity resulted in identification of three aqueous phases: groundwater, surface water, and condensed steam. Although most water samples represented mixtures of these phases, they contained radioactivity representative of all radioactivity produced by the explosion

1978-01-01

300

Combining interventions: improved chimney stoves, kitchen sinks and solar disinfection of drinking water and kitchen clothes to improve home hygiene in rural Peru L’association d’interventions - améliorer les cuisinières à bois, mettre en place des éviers, désinfecter l’eau domestique et le linge de cuisine par le solaire – permet d’améliorer l’hygiène dans les foyers ruraux du Pérou Intervenciones combinadas: mejorar las cocinas a leña, instalar fregaderos y desinfectar el agua para beber y los paños de cocina con energía solar para mejorar la higiene en hogares rurales en Perú  

Directory of Open Access Journals (Sweden)

Full Text Available Home based interventions are advocated in rural areas against a variety of diseases. The combination of different interventions might have synergistic effects in terms of health improvement and cost effectiveness. However, it is crucial to ensure cultural acceptance. The aim of the study was to develop an effective and culturally accepted home-based intervention package to reduce diarrhoea and lower respiratory illnesses in children. In two rural Peruvian communities we evaluated the performance and acceptance of cooking devices, household water treatments (HWT and home- hygiene interventions, with qualitative and quantitative methods. New ventilated stove designs reduced wood consumption by 16%. The majority of participants selected solar water disinfection as HWT in a blind tasting. In-depth interviews on hygiene improvement further revealed a high demand for kitchen sinks. After one year of installation the improved chimney stoves and kitchen sinks were all in use.  The intervention package was successfully adapted to local customs, kitchen-, home- and hygiene management. High user satisfaction was primarily driven by convenience gains due to the technical improvements and only secondarily by perceived health benefits.Les interventions à domicile sont recommandées dans les zones rurales pour éviter diverses maladies. L’association de différentes interventions entraîne une synergie en termes d’amélioration de la santé et de rapport coût-efficacité. Il est cependant crucial d’obtenir l’adhésion de la population. Le but de l’étude était d'élaborer un programme d’interventions à domicile, efficaces et acceptées par la population, visant à réduire la diarrhée et les affections des voies respiratoires basses chez l’enfant. Nous avons évalué, dans deux communautés rurales du Pérou, l’efficacité et l’acceptation d’appareils de cuisson, des traitements de l’eau domestique (HWT et d’interventions d’hygiène à domicile à l’aide de méthodes qualitatives et quantitatives. De nouvelles cuisinières avec ventilation ont permis de réduire la consommation de bois de 16 %. La majorité des participants ont choisi la désinfection solaire de l’eau comme moyen de HWT lors d’un essai à l’aveugle. Des entretiens approfondis sur l’amélioration de l’hygiène ont en outre révélé une forte demande d’éviers. Un an après leur installation, les nouvelles cuisinières et les éviers sont tous utilisés. Le programme d’interventions a été adapté avec succès aux coutumes locales, à la gestion de la cuisine, du foyer et de l’hygiène. Le haut degré de satisfaction des utilisateurs résulte en premier lieu des bénéfices obtenus en termes de commodité dus aux améliorations techniques, et, en second lieu, des bénéfices obtenus en termes de santé.Las intervenciones en los hogares en áreas rurales se recomiendan para luchar contra una variedad de enfermedades. Combinar distintas intervenciones puede tener efectos de sinergia en cuanto a mejorar la salud y la rentabilidad. Sin embargo, es indispensable lograr la aceptación cultural. El objeto de este estudio fue desarrollar un paquete de intervención en el hogar eficaz y culturalmente aceptado para reducir la diarrea y las enfermedades de las vías respiratorias inferiores en niños. En dos comunidades rurales en Perú, se evaluó el rendimiento y la aceptación de dispositivos de cocina, tratamientos de agua doméstica (HWT e intervenciones de higiene del hogar, con métodos cualitativos y cuantitativos. El nuevo diseño de las cocinas reduce el consumo de madera en un 16 %. La mayoría de los participantes eligió la desinfección solar del agua como método de HWT en una cata ciega. Las entrevistas detalladas acerca de las mejoras de la higiene también revelaron una alta demanda de fregaderos. Un año después de ser instaladas, las cocinas mejoradas y los fregaderos estaban todos en uso. El paquete de intervención fue adaptado con éxito a las costumbres locales y de gestión de la cocin

Ana I. Gil

2012-05-01

 
 
 
 
301

Validation experiments of the chimney model for the operational simulation of hydrogen recombiners  

International Nuclear Information System (INIS)

The calculation program REKO-DIREKT allows the simulation of the operational behavior of a hydrogen recombiner during accidents with hydrogen release. The interest is focused on the interaction between the catalyst insertion and the chimney that influences the natural ventilation and thus the throughput through the recombiner significantly. For validation experiments were performed with a small-scale recombiner model in the test facility REKO-4. The results show the correlation between the hydrogen concentration at the recombiner entrance, the temperature on catalyst sheets and the entrance velocity using different chimney heights. The entrance velocity increases with the heights of the installed chimney that influences the natural ventilation significantly. The results allow the generation of a wide data base for validation of the computer code REKO-DIREKT.

2013-05-14

302

Influence of the Exit Length and Geometry of the Chimney on the Heat Transfer  

International Nuclear Information System (INIS)

A chimney is frequently used to enhance the natural convection heat transfer in many practical applications such as the natural draft device, heat exchangers and passive safety system. It provides effective and stable means of the heat removal as thermally insulated chimney induces an increase in the natural convective flow in the heated vertical cylinder and leads to a higher heat transfer rate. The natural convection heat transfer inside a duct becomes very complex due to the interactions between the flows along the heated wall and unheated surface of the chimney. This work investigated the influence on the exit length and the geometry of a duct on the heat transfer of a vertical cylinder in the duct. Two different types of duct geometries (circular and square) were used. Heights of the duct and the heights of the cylinder inside the duct were varied. Experiments were performed using a copper sulfate electroplating system to simulate heat transfer based upon the analogy concept

2012-05-01

303

New energy from an old chimney; Nieuwe energie uit een oude schoorsteen  

Energy Technology Data Exchange (ETDEWEB)

A new purpose has been found for the unused monumental stack chimney at the Eindhoven University of Technology. The idea is to use the chimney to provide free cooling. Using advanced simulation and analysis methods, the feasibility of the concept was studied. The results show that it is indeed possible to use the chimney effectively to provide free cooling to the neighbouring Ceres (Central Energy and Control Station) building [Dutch] De ongebruikte monumentale schoorsteen van de Universiteit Eindhoven is nieuw leven ingeblazen door hem in te zetten voor vrije koeling. Een studie naar de haalbaarheid hiervan is uitgevoerd met behulp vangeavanceerde simulatie en analysetechnieken. Het is gebleken dat de schoorsteen inderdaad effectief kan worden ingezet voor het leveren van koeling aan het naastgelegen Ceres (Centraal Energie en Regelstation) gebouw.

Van Goch, T.A.J. [BAM Techniek, Benningbroek (Netherlands)

2013-07-15

304

Influence of diameter and cross section of a chimney on the heat transfer: simplified balance equation approach  

International Nuclear Information System (INIS)

The need for the implementation of the passive safety characteristics for the NGNP (Next Generation Nuclear Plant) has grown. A chimney can be used as an important heat sink of a nuclear system because it provides effective and stable means of heat removal. Within a chimney, a buoyant head is established as the air is heated, expands, rises, and exits the stack with cold air drawn in at the chimney inlet. And the convective heat transfer and friction pressure drop processes inside the chimney depend on the velocity profile at the wall. The objective of the present work is to investigate the influence on the varied diameter and different cross sectional shape of a chimney on the heat transfer using simplified balance equation approach

2012-10-01

305

Influence of diameter and cross section of a chimney on the heat transfer: simplified balance equation approach  

Energy Technology Data Exchange (ETDEWEB)

The need for the implementation of the passive safety characteristics for the NGNP (Next Generation Nuclear Plant) has grown. A chimney can be used as an important heat sink of a nuclear system because it provides effective and stable means of heat removal. Within a chimney, a buoyant head is established as the air is heated, expands, rises, and exits the stack with cold air drawn in at the chimney inlet. And the convective heat transfer and friction pressure drop processes inside the chimney depend on the velocity profile at the wall. The objective of the present work is to investigate the influence on the varied diameter and different cross sectional shape of a chimney on the heat transfer using simplified balance equation approach.

Lim, Chul Kyu; Chung, Bum Jin [Jeju National Univ., Jeju (Korea, Republic of)

2012-10-15

306

Quantifying metabolic rates in submarine hydrothermal vent chimneys: A reaction transport model  

Science.gov (United States)

The fluids emanating from active submarine hydrothermal vent chimneys provide a window into subseafloor processes and, through mixing with seawater, are responsible for steep thermal and compositional gradients that provide the energetic basis for diverse biological communities. Although several models have been developed to better understand the dynamic interplay of seawater, hydrothermal fluid, minerals and microorganisms inside chimney walls, none provide a fully integrated approach to quantifying the biogeochemistry of these hydrothermal systems. In an effort to remedy this, a fully coupled biogeochemical reaction transport model of a hydrothermal vent chimney has been developed that explicitly quantifies the rate of microbial catalysis while taking into account geochemical processes such as fluid flow, solute transport and oxidation-reduction reactions associated with fluid mixing as a function of temperature. Methanogenesis, hydrogen oxidation by oxygen and sulfate, sulfide oxidation by oxygen and methane oxidation by oxygen and sulfate are the metabolisms included in the reaction network. Model results indicate that microbial catalysis is fastest in the hottest habitable portion of the vent chimney except for methane oxidation by oxygen, which peaks near the seawater-side of the chimney at 20 nmol /cm^3 yr. The dominant metabolisms in the chimney are hydrogen oxidation by sulfate and oxygen and sulfide oxidation at peak rates 3200 , 300 and 900 nmol /cm^3 yr, respectively. The maximum rate of hydrogenotrophic methanogensis is just under 0.07 nmol /cm^3 yr, the slowest of the metabolisms considered. Due to thermodynamic inhibition, there is no anaerobic oxidation of methane by sulfate (AOM). The model developed here provides a quantitative approach to understanding the rates of biogeochemical transformations in hydrothermal systems and can be used to better understand the role of microbial activity in the deep subsurface.

LaRowe, D.; Dale, A.; Aguilera, D.; Amend, J. P.; Regnier, P.

2012-12-01

307

Modeling microbial reaction rates in a submarine hydrothermal vent chimney wall  

Science.gov (United States)

The fluids emanating from active submarine hydrothermal vent chimneys provide a window into subseafloor processes and, through mixing with seawater, are responsible for steep thermal and compositional gradients that provide the energetic basis for diverse biological communities. Although several models have been developed to better understand the dynamic interplay of seawater, hydrothermal fluid, minerals and microorganisms inside chimney walls, none provide a fully integrated approach to quantifying the biogeochemistry of these hydrothermal systems. In an effort to remedy this, a fully coupled biogeochemical reaction-transport model of a hydrothermal vent chimney has been developed that explicitly quantifies the rates of microbial catalysis while taking into account geochemical processes such as fluid flow, solute transport and oxidation-reduction reactions associated with fluid mixing as a function of temperature. The metabolisms included in the reaction network are methanogenesis, aerobic oxidation of hydrogen, sulfide and methane and sulfate reduction by hydrogen and methane. Model results indicate that microbial catalysis is generally fastest in the hottest habitable portion of the vent chimney (77-102 °C), and methane and sulfide oxidation peak near the seawater-side of the chimney. The fastest metabolisms are aerobic oxidation of H2 and sulfide and reduction of sulfate by H2 with maximum rates of 140, 900 and 800 pmol cm-3 d-1, respectively. The maximum rate of hydrogenotrophic methanogenesis is just under 0.03 pmol cm-3 d-1, the slowest of the metabolisms considered. Due to thermodynamic inhibition, there is no anaerobic oxidation of methane by sulfate (AOM). These simulations are consistent with vent chimney metabolic activity inferred from phylogenetic data reported in the literature. The model developed here provides a quantitative approach to describing the rates of biogeochemical transformations in hydrothermal systems and can be used to constrain the role of microbial activity in the deep subsurface.

LaRowe, Douglas E.; Dale, Andrew W.; Aguilera, David R.; L'Heureux, Ivan; Amend, Jan P.; Regnier, Pierre

2014-01-01

308

Repeated fluid expulsion through sub-seabed chimneys offshore Norway in response to glacial cycles  

Science.gov (United States)

Focused fluid flow through sub-seabed sediments is a common phenomenon on continental margins worldwide. However, the governing controls and timing of this fluid release have been difficult to understand, in particular, for fluid flow features buried beneath sub-surface sediments. A link between fluid flow activity, ensuing pockmark formation and the last glacial maximum has been hypothesized on the formerly glaciated Norwegian margin. New high-resolution P-Cable 3D seismic data from the Nyegga area on the mid-Norwegian margin reveal at least two more periods of fluid expulsion from sub-seabed sediments. The 3D seismic data show depositional patterns within chimney features, expressed as truncations of seismic horizons against the flanks of the chimneys. The truncations are interpreted, by analogy with present day observations, as evidence for buried carbonate mounds and/or sediment wash-out during formation of pockmarks in the past. The truncations are, hence, an indicator and a chronological marker for fluid expulsion in the past. The classification of chimneys results in three major groups: (1) chimneys that have been formed and consecutively reactivated one or two times during the last 200 kyr and that have a fluid flow expression at the present seafloor; (2) chimneys that are approx. 125-160 ka BP old without any associated fluid-flow expression at the present day seafloor; (3) chimneys with no stratigraphical evidence for reactivation formed after the last glacial maximum (18-25 ka BP). The observations suggest that each activity period was likely related to the last stages of maximum glaciations in the region. The emplacement of thick sequences of glacigenic debris flow deposits during these maximum stages most likely caused rapid increase in overpressure and subsequently the formation of focused fluid flow features piercing through sediments of the Naust formation at Nyegga.

Plaza-Faverola, Andreia; Bünz, Stefan; Mienert, Jürgen

2011-05-01

309

Scenarios for solar thermal energy applications in Brazil  

International Nuclear Information System (INIS)

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.

2012-09-01

310

Repair of type I endoleak by chimney technique after endovascular abdominal aortic aneurysm repair.  

Science.gov (United States)

Endovascular aneurysm repair is a minimally invasive, durable and effective alternative to open surgery for treatment of abdominal aortic aneurysms (AAA). However, in patients who do not have an adequate sealing zone, open surgical repair is required, which may increase mortality and morbidity. An alternative treatment in patients with challenging anatomy is the so-called "chimney graft" technique. Here, we describe a case using the chimney graft technique for treatment of juxtarenal type I endoleak followed by a previous conventional stent graft insertion to the AAA with good results. PMID:24851230

Kim, Na Hee; Kim, Woo Chul; Jeon, Yong Sun; Cho, Soon Gu; Hong, Kee Chun

2014-05-01

311

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

Energy Technology Data Exchange (ETDEWEB)

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. It is also confirmed that the fatigue usage factor is much less than 1.0. Therefore any damage on structural integrity is not expected when a new in-chimney bracket is installed in the upper part of the reactor chimney.

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

2007-12-15

312

On the observabilities of the chimney model of the interstellar medium  

International Nuclear Information System (INIS)

The Monte Carlo simulation is employed to study the distribution of superbubbles and supernova remnants according to the chimney model of the interstellar medium, taking into account the global spiral pattern in the Galaxy. The observabilities of superbubbles and hot gas within them by H I 21-cm and diffuse X-ray emission are examined, showing expected observational characteristics of H I supershells and an X-ray ridge. The structure of interstellar medium with many superbubbles concentrated in spiral arms, the so-called chimney model, does offer a possible explanation to the various observed structures of the interstellar medium. 20 refs

1990-01-01

313

Investigation into coolant vapor-phase distribution through chimney of heat-only reactor model  

International Nuclear Information System (INIS)

A chimney model of the vessel-type boiling reactor for heat-only nuclear plant was used to investigate vapour phase distribution in two-phase coolant flow. Investigations were carried out on by the electroprobing method by means of conductometric transducers. Results of investigations on the reactor model with natural coolant circulation agree well with experimental data obtained at the VK-50 facility. The data describe specific features of vapour phase motion through the reactor chimney and can be used in calculating models

1987-01-01

314

Bailout chimney technique for graft detachment in a mycotic infrarenal aneurysm.  

Science.gov (United States)

Mycotic aortic aneurysm is a not-so-rare condition and its modalities of treatment are still debated. Graft detachment represents a catastrophic complication after open repair of an abdominal aortic aneurysm. The dehiscence of a graft may have several causes, such as infection, fatigue of materials, and progression of the disease. In recent years, the use of the chimney technique has increased the applicability of endovascular aortic repair for challenging neck anatomies in the abdominal aorta. We report a case involving the use of the bailout chimney technique for graft detachment in a previously treated mycotic infrarenal aortic aneurysm. PMID:23809933

Troisi, Nicola; Peretti, Elisa; Esposito, Giovanni; Beretta, Alessandra; Barzaghi, Maria Elena; Setti, Marco; Pitì, Antonino

2013-07-01

315

Dose reduction during remote dismantling of pile chimneys at BNFL Sellafield  

International Nuclear Information System (INIS)

A remote handling machine (RHM) and a radio controlled excavator will be deployed to dismantle parts of the Windscale pile reactor chimneys. The potential radiation dose uptake associated with decommissioning parts of pile 1 chimney makes remote controlled equipment an essential part of the dose control strategy. During the project planning phase, the major areas of examination leading to the chosen engineering methodologies have been (1)dose rate variation and source distribution; (2) phasing of major source removal; (3) minimization of work in high dose rate areas; (4) development of remote/semiremote technology; (5) waste handling and packaging requirements; and (6) analysis of shielding options

1990-11-11

316

I.S. code provisions for seismic design of tall chimneys  

International Nuclear Information System (INIS)

The provisions of IS : 1893-1984 for earthquake analysis and design of tall chimneys have been reviewed. It is seen that the design seismic force specified by the Indian code is very much on the lower side. Ten chimneys with height ranging from 107.5 m to 336.2 m have been analysed by the finite element method and the results compared with those from expressions recommended in the code. It is seen that for the given design spectrum the code overestimates base shear by 45-70%, and therefore the corresponding expression in the code needs to be revised. (author). 6 refs., 2 tabs

1990-01-01

317

Natural convection in a vertical heated tube attached to a thermally insulated chimney of a different diameter  

Energy Technology Data Exchange (ETDEWEB)

Natural convection is often a convenient and inexpensive mode of heat transfer. It is commonly employed in the cooling of electronic equipment and many other applications. Since the initial work by Bodoia and Osterle (1962) on finite difference solutions of natural convection between vertical isothermal plates, many other researchers have studied natural convection in vertical channels. Specifically Davis and Perona (1971) studied natural convection in vertical heated tubes. A thermally insulated chimney attached to a vertical heated channel induces an increase in the natural convection in the channel and leads to a higher heat transfer rate. This is the well-known chimney effect discussed in the paper by Haaland and Sparrow (1983). If the chimney diameter is larger than the heated tube diameter, the friction loss in the chimney region decreases with increasing chimney diameter. This induces an increase in the mass flow rate and leads to a higher heat transfer rate than the case for a chimney of the same diameter. However, from a geometric consideration it is evident that the chimney effect diminishes in the limiting case of an extremely large chimney diameter compared with its height. Therefore, there exists an optimum diameter where the heat transfer is maximum. To investigate the chimney effect computations are carried out for a Rayleigh number of 12.5, based on the heated tube radius, and for a Prandtl number of 0.7. The numerical results are based on a control volume finite difference method. The average Nusselt number results are compared with the numerical results obtained for a chimney attached to a tube of the same diameter.

Asako, Y.; Nakamura, H. (Tokyo Metropolitan Univ. (Japan)); Faghri, M. (Univ. of Rhode Island, Kingston (USA))

1990-08-01

318

Process for minimising exhaust gas temperatures of chimneys and to improve the draught. Verfahren zur Minimierung von Abgastemperaturen in Schornsteinanlagen und zur Verbesserung der Zugverhaeltnisse  

Energy Technology Data Exchange (ETDEWEB)

The invention concerns a process for controlling exhaust gas temperatures in chimneys and smoke stacks. For this purpose a suction and acceleration section is fitted in the chimney, consisting of a circular duct, for sucking the stack gas in and a previous acceleration nozzle, through which the stack gas is returned to the chimney. A fan connected to the exhaust gas circular duct takes the stack gas through a heat exchanger, where is cooled. A measuring system optimises heat recovery. The draught of the chimney is improved by the simultaneous acceleration of the exhaust gas in the centre of the chimney.

Rode, W.

1982-11-25

319

Conception, construction, and test of a second-generation solar reactor; Konzeption, Bau und Test eines Solar-Photoreaktors der zweiten Generation  

Energy Technology Data Exchange (ETDEWEB)

The chief idea underlying the second-generation of solar photoreactors is to enhance the space-time yield of the photoreaction so as to produce chemicals at a larger scale (E-Caprolactam production). The requisite photon quality is achieved through a greater concentration of the sunlight (>10-2 - 10-4). In this project a solar reactor was built and tested for use in the high flux density solar furnace of DLR. (orig./MM) [Deutsch] In der zweiten Generation solarer Photoreaktoren steht das Ziel im Vordergrund, die Raum-Zeit-Ausbeute der Photoreaktion zu steigern, um Chemikalien in groesserem Massstab zu produzieren (E-Caprolactam-Produktion). Die erforderliche Photonenqualitaet wird durch eine hoehere Konzentrierung des Sonnenlichts (>10{sup 2}-10{sup 4}) erreicht. In diesem Projekt wurde ein Solarreaktor fuer den Einsatz im Hochflussdichte-Sonnenofen der DLR gebaut und getestet. (orig./MM)

Riffelmann, K.J.; Funken, K.H. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V., Koeln (Germany). Hauptabteilung Energietechnik

1997-12-31

320

SEBASOL, organized construction of solar installations by house owners under professional guidance; SEBASOL, la construction organisee et encadree professionnellement d`installations solaires par leurs proprietaires  

Energy Technology Data Exchange (ETDEWEB)

Within the framework of ENERGY 2000, owners in whole Switzerland will be able to build themselves their own solar systems for domestic hot water and, optionally space heating, with a high quality standard. In Austria, such a procedure is very common and successful since nearly ten years. We first examined in detail the Austrian experience and adapted techniques and organization to Swiss conditions. At the present time, we are setting up the necessary infrastructure (national centre, regional centres) for the assistance of the selfbuilders. In the present paper the SEBASOL concept is presented and the time schedule for its introduction is given. (author) 5 figs., 4 refs.

Suter, J.M.; Keusch, P.; Kissling, R.; Meier-Istvan, W. [SEBASOL Suisse, Aarau (Switzerland)

1993-12-31

 
 
 
 
321

Which Tropical Continental 'Chimney' Dominates the Global Electrical Circuit, and Why?  

Science.gov (United States)

Global measures of lightning activity, including classical thunder day observations, optical measurements with the Optical Transient Detector and Lightning Imaging Sensor in space and Schumann Resonance observations are all consistent in showing a predominance of Africa among the three tropical "chimneys". Given the common assumption that thunderstorms are the "batteries" of the global circuit and the Wilson conduction current measurements over thunderstorms (Blakeslee et al, 1989), one expects Africa to dominate the DC global circuit. Yet the classical `Carnegie Curve' and numerous diurnal records of ionospheric potential (Markson) clearly show South America as the dominant chimney. This paradox has resolution in an often overlooked aspect of C.T.R. Wilson (1920) giving special attention to "shower clouds" as contributors to the DC global circuit in addition to thunderstorms. Observations from the NASA TRMM (Tropical Rainfall Measuring Mission) satellite support a greater number of shower clouds in South American than Africa. Further climatological thermodynamic comparisons for surface stations in the Amazon and Congo River basins are examined to understand chimney ranking in lightning and in conduction current. Evidence will be presented that the hotter and dryer characteristics of the most continental chimney (Africa) can account for its factor of two predominance in lightning activity.

Williams, E. R.; Satori, G.

2003-12-01

322

ESTIMATED EFFECTIVE CHIMNEY HEIGHTS BASED ON RAWINSONDE OBSERVATIONS AT SELECTED SITES IN THE UNITED STATES  

Science.gov (United States)

The plume rise equations of Briggs (1975) for variable vertical profiles of temperature and wind speed are described and applied for hypothetical small and very large chimneys at five NWS rawinsonde stations across the United States. From other available data additional informati...

323

Hydrology of underground nuclear tests: The effect of collapse-chimney formation.  

Science.gov (United States)

Underground nuclear tests in the saturated zone produce a variety of hydrologic effects, the most lasting of which are changes in permeability. In particular, the formation of a collapse chimney above the test forms a permeable conduit that can allow vert...

T. H. Brikowski

1991-01-01

324

Nonlinear mushy-layer convection with chimneys: stability and optimal solute fluxes  

CERN Multimedia

We model buoyancy-driven convection with chimneys -- channels of zero solid fraction -- in a mushy layer formed during directional solidification of a binary alloy in two-dimensions. A large suite of numerical simulations is combined with scaling analysis in order to study the parametric dependence of the flow. Stability boundaries are calculated for states of finite-amplitude convection with chimneys, which for a narrow domain can be interpreted in terms of a modified Rayleigh number criterion based on the domain width and mushy-layer permeability. For solidification in a wide domain with multiple chimneys, it has previously been hypothesised that the chimney spacing will adjust to optimise the rate of removal of potential energy from the system. For a wide variety of initial liquid concentration conditions, we consider the detailed flow structure in this optimal state and derive scaling laws for how the flow evolves as the strength of convection increases. For moderate mushy-layer Rayleigh numbers these flo...

Wells, Andrew J; Orszag, Steven A

2012-01-01

325

Multiple periscope and chimney grafts to treat ruptured thoracoabdominal and pararenal aortic aneurysms  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The periscope and chimney graft technique provides a simpler, less invasive way to maintain blood flow to the renovisceral arteries during urgent endovascular aortic repairs. The very low 30-day mortality rate and the stability of the repairs in the midterm are encouraging. This technique has the potential to profoundly influence the treatment of acute aortic pathologies.

Pecoraro, F.; Pfammatter, T.; Mayer, D.; Frauenfelder, T.; Papadimitriou, D.; Hechelhammer, L.; Veith, F. J.; Lachat, M.; Rancic, Z.

2011-01-01

326

Diagnostics of a 177 m high RC- chimney using wind excited vibration.  

Czech Academy of Sciences Publication Activity Database

. Eindhoven : UT Eindhoven, 2001 - (Wisse, J.; Kleinman, K.), s. 271-276 ISBN 90-6814-121-X.[European and African conference on Wind Engineering /3./. Eindhoven (NL), 02.07.2001-06.07.2001]Grant CEP: GA ?R GV103/96/K034Klí?ová slova: vibration, cracks, chimney.Kód oboru RIV: JM - Inženýrské stavitelství

Pirner, Miroš; Fischer, Ond?ej

327

CLIMATIC DATA ON ESTIMATED EFFECTIVE CHIMNEY HEIGHTS IN THE UNITED STATES  

Science.gov (United States)

Plume rise calculations are based on the equations of Briggs (1975) for use with variable vertical profiles of temperature and wind speed. Results are presented for small and large chimneys, based on five years of twice-daily rawinsondes throughout the contiguous United States. I...

328

Effect of chimneys on indoor air concentrations of PM10 and benzo(a)pyrene in Xuan Wei, China  

Energy Technology Data Exchange (ETDEWEB)

This paper reports the effect of chimneys in reducing indoor air pollution in a lung cancer epidemic area of rural China. Household indoor air pollution concentrations were measured during unvented burning (chimneys blocked) and vented burning (chimneys open) of bituminous coal in Xuan Wei, China. Concentrations of particulate matter with an aerodynamic diameter of 10 {mu} m or less (PM10) and of benzo(a)pyrene (BaP) were measured in 43 homes during normal activities. The use of chimneys led to significant decreases in indoor air concentrations of particulate matter with an aerodynamic diameter of 10 mu m or less (PM10) by 66% and of benzo(a)pyrene (BaP) by 84%. The average BaP content of PM10 also decreased by 55% with the installation of a chimney. The reduction of indoor pollution levels by the installation of a chimney supports the epidemiology findings on the health benefits of stove improvement. However, even in the presence of a chimney, the indoor air concentrations for both PM10 and BaP still exceeded the indoor air quality standards of China. Movement up the energy ladder to cleaner liquid or gaseous fuels is probably the only sustainable indoor air pollution control measure.

Tian, L.W.; Lan, Q.; Yang, D.; He, X.Z.; Yu, I.T.S.; Hammond, S.K. [Chinese University of Hong Kong, Hong Kong (China). School for Public Health

2009-07-15

329

Solar power plants. Annual meeting of ForschungsVerbund Sonnenenergie; Solare Kraftwerke. Jahrestagung des ForschungsVerbunds Sonnenenergie  

Energy Technology Data Exchange (ETDEWEB)

Subjects: Solar thermal power plants - technology and perspectives; Solar thermal power plants - potential and implementation; Industrial-scale PV systems; Wind power systems (Offshore systems, integration in power supply networks, solar chimneys); Solar hydrogen - innovative power generation technology. In the poster session, a combined cycle solar power station in Egypt was presented. [German] Das Dokument befasst sich mit den folgenden Themen: Solarthermische Kraftwerke - Technologie und Perspektiven; solarthermische Kraftwerke - Potenziale und Umsetzung; photovoltaische Grossanlagen; Windenergie Kraftwerke (Offshore-Windenergietechnik und Integration in die Energieversorgung; Aufwindkraftwerke); Solarer Wasserstoff - innovative Technik zur Erzeugung. Und in der Poster-session Bericht ueber ein GuD-Solarkraftwerk in Aegypten. (AKF)

Stadermann, G. (ed.)

2002-07-01

330

A study of the various baffles used in the Marcoule chimneys and the search for a new model (1961)  

International Nuclear Information System (INIS)

The baffle placed at the top of a chimney determines the shape of the smoke pall for low exit-velocities. The G. 1 type baffle was studied taking into account the characteristics of its collar: totally hollow - partially hollow - solid; on a ribbed chimney or on a plain chimney. The Pu type baffle was also tested. The search for a new type of baffle was limited to variants of the blade - type baffle: - a porous envelope device; - a cone - shaped device and - a deflector of the cupel type. Only the blade-type baffle was rejected, efficient solutions are proposed using the other types or their combinations. (authors)

1961-01-01

331

Study on the long-term diffusion factor for the chimneys of Biblis reactors A, B, C. Report 5  

International Nuclear Information System (INIS)

The largest long-term diffusion factors are anticipated on the leeward side of the cooling towers and within a distance of x -7 s/m3, in the distance range of 700 to 800 m from the chimney. Since neither measurements for shorter distances from the chimney near wind tunnel surveys for the maximum ground concentrations in critical spots are available, greater values for LTDF are anticipated in ranges closer to the chimney. Further model surveys have been suggested in order to clarify the actual situation. (orig./DG)

1980-03-01

332

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

Directory of Open Access Journals (Sweden)

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.

Delfran Batista dos Santos

2012-08-01

333

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  

International Nuclear Information System (INIS)

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)

2002-02-01

334

Passive-solar retrofit concepts  

Science.gov (United States)

Four retrofit passive solar designs for single family dwellings are presented. The first design, for a house in Minnesota, involves insulating wall cavities and the attic with blown cellulose, reduction of infiltration, and installation of insulating shades on all windows. The second, for a house in Michigan, combines weatherization, a sunspace with clerestory, and a thermosiphoning collector. The third, for a house in Missouri, involves the addition of a large sunspace with a passive solar hot water preheater for a hot tub. The fourth, for a house in Indiana, combines intensive weatherization with a two story sunspace and thermal chimney addition. All designs are thoroughly illustrated.

1981-09-01

335

Chimney retrofitting: In case of danger - new, well-conceived interior; Schornsteinsanierung: Bei Gefahr - neues Innenleben mit System  

Energy Technology Data Exchange (ETDEWEB)

When installing a new boiler it is absolutely necessary to calculate the cross-section of the chimney. It may be that the exhaust gases are reduced and cooled to such an extent that their ascending force becomes insufficient for leaving the chimney. In this case excessive sooting can corrode the chimney walls from inside through the action of sulphuric-acid-containing condensation water. Here chimney inserts are a possible remedy. These retrofitting systems are available in various materials. (orig.) [Deutsch] Mit der Umstellung auf einen neuen Heizkessel muss auf jeden Fall auch eine Nachberechnung des Schornsteinquerschnittes verbunden sein. Reicht naemlich der Auftrieb durch deutlich kuehlere und reduzierte Abgase nicht mehr aus, droht eine Versottung: schwefelsaures Schwitzwasser zernagt die Schachtwaende. Abhilfe schaffen Rohreinsaetze, die als Sanierungssysteme in unterschiedlichen Materialien angeboten werden. (orig.)

Anon.

1996-12-31

336

Alternativas de construcción utilizando materiales de bajo costo para la evaluación térmica de cocinas solares tipo caja / Construction alternatives using low-cost materials for the thermal test of box-type solar cookers  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: Spanish Abstract in spanish Se presenta la evaluación y resultados térmicos de cocinas tipo cajas, realizadas con el objeto de comparar diversos factores constructivos de las mismas utilizando un protocolo de prueba conocido como RICSA (Red Interamericana de Cocción Solar de Alimentos). Para ellos se dispuso de cuatro cocinas [...] en donde se combinaron dos materiales de placa y dos materiales que sirven como aislante. Se sometieron a radiación solar directa calentando la placa colectora y luego al calentamiento utilizando agua como líquido de prueba. Se procedió a medir las perdidas térmicas y la eficiencia térmica. Parámetros adicionales como el tiempo en que alcanza la temperatura de cocción efectiva y el tiempo en que la mantiene sin intervención del operador también fueron medidos. De aquí, el análisis de la información proporcionó un buen rendimiento comparable entre cocinas con placa de hierro y los dos aislantes probados por sobre las cocinas de placa de aluminio; además, por la relación precio-rendimiento, se recomienda su construcción utilizando materiales que tienen alto rendimiento y bajo precio. Abstract in english This document presents the evaluation of a different set of solar ovens in terms of their thermal performance by the RICSA protocol. For this purpose, four solar ovens were constructed differentiated mainly by the type of isolation and plates. All were exposed to direct solar radiation. First, only [...] the collector plate was heated to measure thermal losses and efficiency and second, a determined amount of water was introduced to measure the thermal power of the solar oven. Additional parameters like the time in which it reaches the temperature of effective boiling point and the time in which it maintains functioning without intervention of the operator also were measured. The analysis provide empirical evidence regarding adequate levels of thermal performance of solar ovens constructed using iron on one hand, and aluminum on the other. It is recommended to extend the use of this type of equipments given the priceeffi ciency obtained in the experiments.

Mealla Sánchez, Luis Enrique; Bonaveri Arangoa, Pablo Daniel.

337

Microbial lipid remnants within sulfide chimneys reveal organic matter transport in seafloor hydrothermal systems  

Science.gov (United States)

Several investigations have detected enigmatic evidence for microbial life in high-temperature (>150°C) interiors of hydrothermal vent ';chimney' structures - habitats much hotter than the known temperature limit of life. It is unclear whether these findings reflect fluid ingress after collection, cross-contamination with exterior microbial biomass, or genuine natural phenomena. While the abundant microbial biomass on the exteriors of vent edifices has been more commonly characterized, the origin of biomolecules inside these structures is poorly understood. In this study, we used a novel ';clean' sampling approach to investigate these interior regions in both a moderate temperature ';diffuser' and an inactive ';smoker' chimney structure from the Manus Basin, and use microbial DNA- and detailed lipid-based characterization to elucidate provenances. Mineralogical analysis using scanning-electron- and reflected-light-microscopy suggests vent fluid temperatures of up to ~200°C for the diffuser and >200°C during previous venting of the inactive chimney. No DNA could be amplified from any interior samples and cell membrane intact polar lipids were only recovered from the outer surfaces of the structures, precluding the possibility of active microbial communities in interior regions of either. Free fatty acids from bacteria, however, were abundant in the inactive chimney, including the previously high temperature interior, suggesting possible microbial colonization of the interior or inward transport of biomass during waning of fluid flow. Free fatty acids were not detected in the interior of the active diffuser chimney, consistent with uninhabitable temperatures for microbes and outward fluid flow. In contrast to fatty acids, archaeal core diether and tetraether lipid remnants with distinctive provenances were present in interior and exterior samples from both structures. Principal component analysis (PCA) of these mixtures reveals gradients in their distribution, with presumed hyperthermophilic archaeal lipid remnants more prevalent in interior and more mesophilic lipids in outer regions of the inactive chimney. Diffuser interior samples, however, are highly unusual, in that they contain presumed mesophilic archaeal core lipids, despite uninhabitable temperatures. Thermal degradation of an in situ microbial community (e.g. due to transient fluid flow variability) is a possible explanation, but the nature of these lipids suggests they may instead reflect transport and pyrolysis of microbial material from lower temperature mixing zones within the crustal aquifer. Not only does this study broaden our understanding of lipid biomolecule distribution in the interiors of sulfide edifices, it provides an initial evaluation of possible sources and implications for carbon cycling in seafloor hydrothermal systems.

Reeves, E.; Goldenstein, N. I.; Yoshinaga, M. Y.; Pjevac, P.; Bach, W.; Hinrichs, K.

2013-12-01

338

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

Science.gov (United States)

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??m 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??m 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, a condition that may have led to the onset of an autotrophic metabolism through the reduction of carbon dioxide. PMID:22111762

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

2011-12-01

339

Designing, Construction and Analysis of Speed Control System of the Fan with PV Feeding Source in an Air Solar Collector  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Solar energy is one of the renewable energy sources which can be received more by designing more accurate systems. In this article a flat solar collector with the area of 2×1m2 and thickness of 0.5mm, made of steel iron in the form of venetian blinds (in order to increase exposure to air) has been used. The surface of absorber plate was black and for insulation of the body of the collector glass wool has been used with 5 cm thickness. One of the essential prob...

2011-01-01

340

Isolation and physiological characterization of two novel, piezophilic, thermophilic chemolithoautotrophs from a deep-sea hydrothermal vent chimney  

Digital Repository Infrastructure Vision for European Research (DRIVER)

P>Two novel, thermophilic piezophiles, capable of chemolithoautotrophic growth, are successfully cultivated and isolated from a black smoker chimney at the TAG field (Mid Atlantic Ridge: MAR) by using a piezophilic cultivation technique. Both strains (strains 106 and 108) represent dominant cultivated populations of the microbial communities in the chimney surface habitat. Strain 106 represents typically thin, long spiral cells under the piezophilic growth condition but short bent cells under...

Takai, Ken; Miyazaki, Masayuki; Hirayama, Hisako; Nakagawa, Satoshi; Querellou, Joel; Godfroy, Anne

2009-01-01

 
 
 
 
341

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 met...

He, Ying; Xiao, Xiang; Wang, Fengping

2013-01-01

342

CT angiography at 24 months demonstrates durability of EVAR with the use of chimney grafts for pararenal aortic pathologies  

Digital Repository Infrastructure Vision for European Research (DRIVER)

PURPOSE: To present the 24-month radiological follow-up data for patients with pararenal aortic pathologies treated with chimney and periscope grafts during endovascular repair. METHODS: Between January 2008 and December 2011, 124 high-risk patients with complex pararenal aortic pathologies were treated using the chimney technique at 2 European vascular and cardiovascular centers with advanced experience of the described technique. In particular, 50 patients were treated at Site 1 and 74 a...

Donas, Konstantinos P.; Pecoraro, Felice; Bisdas, Theodosios; Lachat, Mario; Torsello, Giovanni; Rancic, Zoran; Austermann, Martin; Mayer, Dieter; Pfammatter, Thomas; Puchner, Stefan

2013-01-01

343

Mortality and incidence of cancer in a cohort of Swedish chimney sweeps: an extended follow up study.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Despite 200 years of efforts to regulate safety in this occupation, chimney sweeps have increased mortality from cancer, ischaemic heart disease, and respiratory disease. Mortality and incidence of cancer were examined in a cohort of 5542 Swedish chimney sweeps employed through their national trade union at any time between 1918 and 1980. Previous studies of this cohort found increased risks of ischaemic heart disease, respiratory disease, accidental deaths, and various neoplasms. By increasi...

1993-01-01

344

Thermo-mechanical solar power plants. Proceedings of the 2. international workshop on the design, construction and operation of solar central receiver projects, Varese, Italy, 4-8 June 1984  

Energy Technology Data Exchange (ETDEWEB)

This workshop, supported by all operators of solar central receiver power plants, was organized by the Commission of the European Communities. The proceedings provide a comprehensive overview of the technology of central receivers and heliostats. Although solar power plants of the central receiver type employ very simple and classical components, as system they are of tremendous complexity. Six large experimental plants are built so far to meet this difficulty and to gain experience in this field. Technical aspects as well as economic outlook are discussed, in particular for the smaller plants. The larger plants still have the drawback that the required design and construction costs for one single plant are so high that it is difficult to find sources to finance the project. Separate abstracts are made for each contribution of the workshop. (A.V.)

Gretz, J.; Strub, A.S.; Skinrood, A. (eds.)

1985-01-01

345

Archaea and bacteria with surprising microdiversity show shifts in dominance over 1,000-year time scales in hydrothermal chimneys.  

Science.gov (United States)

The Lost City Hydrothermal Field, an ultramafic-hosted system located 15 km west of the Mid-Atlantic Ridge, has experienced at least 30,000 years of hydrothermal activity. Previous studies have shown that its carbonate chimneys form by mixing of approximately 90 degrees C, pH 9-11 hydrothermal fluids and cold seawater. Flow of methane and hydrogen-rich hydrothermal fluids in the porous interior chimney walls supports archaeal biofilm communities dominated by a single phylotype of Methanosarcinales. In this study, we have extensively sampled the carbonate-hosted archaeal and bacterial communities by obtaining sequences of >200,000 amplicons of the 16S rRNA V6 region and correlated the results with isotopic ((230)Th) ages of the chimneys over a 1,200-year period. Rare sequences in young chimneys were commonly more abundant in older chimneys, indicating that members of the rare biosphere can become dominant members of the ecosystem when environmental conditions change. These results suggest that a long history of selection over many cycles of chimney growth has resulted in numerous closely related species at Lost City, each of which is preadapted to a particular set of reoccurring environmental conditions. Because of the unique characteristics of the Lost City Hydrothermal Field, these data offer an unprecedented opportunity to study the dynamics of a microbial ecosystem's rare biosphere over a thousand-year time scale. PMID:20080654

Brazelton, William J; Ludwig, Kristin A; Sogin, Mitchell L; Andreishcheva, Ekaterina N; Kelley, Deborah S; Shen, Chuan-Chou; Edwards, R Lawrence; Baross, John A

2010-01-26

346

Distribution of trace elements including tellurium, gallium, indium, and select REE in sulfide chimneys from Brothers submarine volcano, Kermadec arc  

Science.gov (United States)

Brothers volcano is a dacitic volcano located along the Kermadec arc, New Zealand, and hosts the NW Caldera hydrothermal vent field perched on part of the steep caldera walls. The field strikes for ~600 m between depths of 1550 and 1700 m and includes numerous, active, high-temperature (max 302°C) chimneys and even more dead, sulfide-rich spires. Chimney samples collected from Brothers show distinct mineralogical zonation reflecting gradients in oxidation state, temperature, and pH from the inner walls in contact with hydrothermal fluids through to the outer walls in contact with seawater. Minerals deposited from hotter fluids (e.g., chalcopyrite) are located in the interior of the chimneys and are surrounded by an external zone of minerals deposited by cooler fluids (e.g., sulfates, sphalerite). Four chimneys types are identified at Brothers volcano based on the relative proportions of chalcopyrite and sulfate layers, and the presence or absence of anhydrite. Two are Cu-rich, i.e., chalcopyrite-rich and chalcopyrite-bornite-rich chimneys, and two are Zn-rich, i.e., sphalerite-rich and sphalerite-chalcopyrite-rich. Barite and anhydrite are common to both Cu-rich chimney types whereas Zn-rich chimneys contain barite only. The main mineral phases in all the chimneys are anhydrite, barite, chalcopyrite, pyrite/marcasite, and sphalerite. Trace minerals include galena, covellite, tennantite, realgar, chalcocite, bornite, hematite, goethite, Pb-As sulfosalts, and Bi- or Au-tellurides. The vast majority of tellurides are <5 ?m in size, although columnar crystals up to 80 ?m long have been observed. The tellurides commonly form in bands, cluster in patches, or occur along internal grain boundaries within chalcopyrite. They also are found at the contact between chalcopyrite and pyrite grains. In sulfate layers adjacent to the chalcopyrite zones tellurides can occur as inclusions in anhydrite, barite or pyrite and/or occupy void space within the chimney. One Cu-rich chimney also contained native Te in a similar distribution as the tellurides. Whole rock geochemical analysis has determined the maximum concentration of trace elements and REE such as In (53.1 ppm), Ga (1870), Y (26), La (21.2), Ce (21), Sm (2.8), Gd (4), and Yb (3) in Brothers chimneys. To better understand the mineral associations and zonation of these and other trace elements within the chimney walls, we have undertaken element mapping on the four different chimneys types with both X-Ray fluorescence microscopy using synchrotron radiation and with Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS). For example, in a chalcopyrite-rich chimney visibly laminated chalcopyrite in the interior contains bands of Co, Mo, Ag, Te, Au, and Bi, whereas In, La, Ce, Ga, and Y are concentrated in other mineral phases towards the exterior. Element mapping allows us to better understand the physico-chemical gradients within chimney walls, as well as metal sources and transportation, and depositional processes.

Berkenbosch, H. A.; de Ronde, C. E.; McNeill, A.; Goemann, K.; Gemmell, J. B.

2011-12-01

347

Double-diffusive layers adjacent to cold chimney flows during transient mushy-layer growth  

Science.gov (United States)

We examine the cooling effect of chimney flows in the liquid region during transient upward growth of a mushy layer in solidifying aqueous ammonium chloride. Through drainage channels in a mushy layer, cold, relatively fresh fluid is carried into the warm, salt-stratified liquid region. Double-diffusive cells form due to the cooling effect of the chimney flows and evolve into a series of downwelling horizontal layers. Using shadowgraph methods and dyed fluids we demonstrate the vigorous flow circulations and compositional mixing within each layer. Vertical concentration and temperature profiles reveal the double-diffusive staircase structure across the layers. The downward velocity of the layers decreases as they approach to the mush-liquid interface, which is interpreted by a filling-box model representing the momentum and compositional transport of turbulent continuous plumes in a confined region. The present experiment provides insight to evaluate the solute fluxes from growing mushy layers.

Zhong, Jin-Qiang; Xue, Qiwei; Wettlaufer, John

2013-03-01

348

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

Directory of Open Access Journals (Sweden)

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.

Sébastien Rioux

2010-12-01

349

Cancer and non-cancer mortality of chimney sweeps in Copenhagen  

Energy Technology Data Exchange (ETDEWEB)

This is a cohort study of the mortality among chimney sweeps in Copenhagen, Denmark, during 1958-77. Nearly all the chimney sweeps started in the trade around the age of 15, and so this age gives the time of first exposure to the environmental conditions of the trade. The analysis applies a continuous time model with stratification by cause of death (cancer, non-cancer), time and age, where cumulative mortality rates are derived from current mortality tables. For each stratum of interest the observed/expected mortality ratio (O/E ratio) is calculated and a test performed, based on the normal distribution. The main result is a significantly higher cancer mortality for the 40-69 year age class compared with the population at large (O/E ratio . 3.9).

Hansen, E.S.; Olsen, J.H.; Tilt, B.

1982-12-01

350

The influence of certain astronomical and constructive parameters on the concentration of solar radiation with plane heliostats fields  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper, we present the influence of some astronomical and constructive parameters on the HFT working. The astronomical parameters are : (1) hour and (2) day. The constructive parameters are : (3, 4) the east-west and north-south distances between heliostats, (5) the mirror size, (6) the tower height, (7) the distance between the tower and the heliostats field. The HFT working is analysed from three points of view : (i) the mirrors orientation, (ii) the heliostats optical performances a...

1985-01-01

351

Radioactive air emissions notice of construction for the decontamination and closure of the 183-H Solar Evaporation Basins  

International Nuclear Information System (INIS)

A Notice of Construction (NOC) is required by the Washington State Department of Health (DOH), pursuant to Washington Administrative Code (WAC) Chapter 246-247-060, for any proposed construction or modification of an existing registered or unregistered emissions unit. The following document is the NOC application to be submitted to the DOH for the establishment of a new environmental analytical laboratory at the 100-N Area on the Hanford Site. The environmental analytical laboratory will contain a radioactive air emissions unit

1995-01-01

352

Wind-induced vibration of a brace on a 530 foot high chimney  

Energy Technology Data Exchange (ETDEWEB)

A double-angle diagonal brace was used to support an exterior trolley beam on the Unit 3 chimney at Fayette Power Project (FPP). The brace was located approximately 460 feet above grade. Shortly after installation, severe wind-induced vibration of the brace was observed. The member developed cracks that led to failure of the brace. This paper describes the assessment of the phenomenon and presents the innovative repair details that were evaluated. Also, guidelines are presented to avoid this phenomenon.

Hubalik, T.M. [Sargent and Lundy Engineers, Chicago, IL (United States)

1997-09-01

353

Incidence and Diversity of Microorganisms within the Walls of an Active Deep-Sea Sulfide Chimney  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A large, intact sulfide chimney, designated Finn, was recovered from the Mothra Vent Field on the Juan de Fuca Ridge in 1998. Finn was venting 302°C fluids on the seafloor and contained complex mineralogical zones surrounding a large open central conduit. Examination of microorganisms within these zones, followed by community analysis with oligonucleotide probes, showed that there were variations in the abundance and diversity of eubacteria and archaea from the exterior to the interior of th...

Schrenk, Matthew O.; Kelley, Deborah S.; Delaney, John R.; Baross, John A.

2003-01-01

354

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 i...

Hashemi, H.; Tax, D. M. J.; Duin, R. P. W.; Javaherian, A.; Groot, P.

2008-01-01

355

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 temp...

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

2010-01-01

356

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 i...

Hashemi, H.; Tax, D. M. J.; Duin, R. P. W.; Javaherian, A.; Groot, P.

2008-01-01

357

Methane related authigenic carbonates, chimneys and crusts from the Gulf of Cadiz  

Science.gov (United States)

During the TTR 11 and TTR 12 cruises (2001 and 2002), the area south and southwest of the Guadalquivir Diapiric Ridge was intensely surveyed with seismics, side scan sonar (MAK), underwater TV and sampling. This area is characterized by a very strong backscatter on the available side scan sonar images and a very irregular seafloor, with morphological and sedimentological features evidencing fluid escape structures (mud diapirs and mud volcanoes); and sedimentary structures associated with the outflow of the Mediterranean water (MOW). Based on the data and samples collected during the TTR11 and TTR12 cruises, complemented with data from the ANASTYA 2000 and 2001 cruises, it seems that this area corresponds to a large field of carbonate chimneys and crusts. Dredge profiles on the Iberico dome and west of this structure, on the main channel of the MOW, yielded a large amount of carbonate slabs and chimneys. These consist essentially of intrapelbiomicrite. Petrographic and XRD shows that their mineralogical composition consists mainly of dolomite, high magnesium calcite, quartz, feldspar and clays. Bioclasts of plantonic foraminifera (globigerinoids), ostracods and peletts are observed. Iron and manganese oxides are present and the cement is essentially biomicrite. In different samples from the same chimney a variation on the dolomite/calcite ratio is observed from the interior to the external part of the chimney. Values of dolomite show a variation from 47% in the interior to 17 % in the exterior. As regards Si02 (19-16%), Al2O3 (4-3%) and Fe2O3 (5-7%), the variations observed are not significant. Stable isotopic analysis of Carbon shown low d13C values (down to -46.88 per mil vs. PDB) and d18O up to + 4.90 per mil vs.

Magalhães, V.; Vasconcelos, C.; Gaspar, L.; Monteiro, H.; Pinheiro, L.; Ivanov, M.; Díaz-del-Río, V.; Somoza, L.

2003-04-01

358

Arrangement for reducing discharge of heat from a chimney. Foerfarande och anordning foer att minska utstroemningen av vaerme fraan en skorsten  

Energy Technology Data Exchange (ETDEWEB)

In order to reduce the discharge of heat from a chimney, insulating material is pressed into the chimney outlet. Inside the muff there is an U-shaped socket inserted which is open to the interior of the chimney. The outer end of the socket ends on a lower level than the highest point of the inner radius of the U-shaped socket. The socket is sealed with water and heat resistant glue at the muff joint. (L.F.).

Oestbo, N.

1986-10-13

359

Numerical Investigation of the Heat Transfer of a Vertical Cylinder in a Chimney  

International Nuclear Information System (INIS)

The chimney is frequently used to enhance the natural convection heat transfer in many practical applications such as the natural draft device, heat exchangers and passive safety system. It provides effective and stable means of heat removal. The natural convection heat transfer inside a duct becomes very complex due to the interactions between the flows along the heated wall and unheated surface of the chimney and also due to the pressure loss along the chimney and the down-flow from the exit. Thus the heat transfer will be affected by the exit length. The present work investigated the heat transfer and the flow behavior of a hot cylinder located at the inlet of a duct, varying the exit length using FLUENT 6.2. The height of the vertical cylinder was 0.069m and the diameter was 0.054m, which corresponded to RaH 5.55x1010. The diameter of the duct was 0.06m and the height was varied from 0.069m to 2m

2011-10-01

360

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1995-04-01

 
 
 
 
361

Modeling Collapse Chimney and Spall Zone Settlement as a Source of Post-Shot Subsidence Detected by Synthetic Aperture Radar Interferometry  

Energy Technology Data Exchange (ETDEWEB)

Ground surface subsidence resulting from the March 1992 JUNCTION underground nuclear test at the Nevada Test Site (NTS) imaged by satellite synthetic aperture radar interferometry (InSAR) wholly occurred during a period of several months after the shot (Vincent et al., 1999) and after the main cavity collapse event. A significant portion of the subsidence associated with the small (less than 20 kt) GALENA and DIVIDER tests probably also occurred after the shots, although the deformation detected in these cases contains additional contributions from coseismic processes, since the radar scenes used to construct the deformation interferogram bracketed these two later events, The dimensions of the seas of subsidence resulting from all three events are too large to be solely accounted for by processes confined to the damage zone in the vicinity of the shot point or the collapse chimney. Rather, the subsidence closely corresponds to the span dimensions predicted by Patton's (1990) empirical relationship between spall radius and yield. This suggests that gravitational settlement of damaged rock within the spall zone is an important source of post-shot subsidence, in addition to settlement of the rubble within the collapse chimney. These observations illustrate the potential power of InSAR as a tool for Comprehensive Nuclear-Test-Ban Treaty (CTBT) monitoring and on-site inspection in that the relatively broad ({approx} 100 m to 1 km) subsidence signatures resulting from small shots detonated at normal depths of burial (or even significantly overburied) are readily detectable within large geographical areas (100 km x 100 km) under favorable observing conditions. Furthermore, the present results demonstrate the flexibility of the technique in that the two routinely gathered satellite radar images used to construct the interferogram need not necessarily capture the event itself, but can cover a time period up to several months following the shot.

Foxwall, W.

2000-07-24

362

Barite chimneys from two hydrothermal sites along the slow-spreading Arctic Ridge system: Initial isotope and mineralogical results  

Science.gov (United States)

Two hydrothermal sites along the slow-spreading Arctic Ridge systems, the Jan Mayen vent fields (JMVFs) and the recently discovered Loki’s Castle hydrothermal field (LCHF) contains numerous barite chimneys partially covered by microbial mats. The JMVFs are located at 71°N on the south-western Mohns Ridge, approximately 50 km north of the Jan Mayen fracture zone. The LCHF is located at 73.5°N on an axial volcanic ridge where the Mohns Ridge transitions into the Knipovich Ridge and consists of two venting areas. Active hydrothermal venting at both sites is confirmed by elevated hydrogen sulphide concentrations and discharge of high-temperature fluids, reaching 270°C in the JMVFs and 317°C in the LCHF. Barite chimneys from the JMVFs are composed of barite, silica and abundant pyrite-dominated sulphide minerals that display a conspicuous concentric morphology. Raman spectroscopic analysis of the central regions of these concentric sulphide minerals points to the existence of mackinawite (FeS). Furthermore, the existence of greigite (Fe3S4) surrounding the mackinawite is suggested. This observation confirms the general conclusion of earlier experimental studies that these phases act as the metastable precursors of pyrite. In contrast, the barite chimneys of the LCHF consist mainly of pure barite with lesser amounts of sulphide minerals. The difference in the mineralogical composition between the two sites is also expressed in its sulphur isotopic composition. ?34Ssulphate values of the barite chimneys from the JMVFs are lower than ?34S of seawater sulphate (?34S = +21‰) and ?34Ssulphide values point to a magmatic sulphur source (?34S = 0‰). This implies that the JMHFs barite chimneys have been formed by a mixture of seawater and hydrothermal fluids, similar to the origin of black smokers. In contrast to the JMVFs, the ?34Ssulphate values from the LCHF barite chimneys are higher than ?34S values for seawater sulphate, but show remarkable differences between the surface of the chimneys and the interior. The highest ?34Ssulphate values have been found in the chimney interior, reaching ?34Ssulphate values up to +34.9‰. These high ?34Ssulphate values can be explained by various processes, including biogenic or thermogenic sulphate-reduction. The presence of twisted microstructures within the chimneys (reveiled by SEM) strongly suggests that biologic processes could have caused the observed sulphur isotope fractionation. Further mineralogical and isotope studies will provide more detailed insights on the formation of barite chimneys found in these hydrothermal sites along the slow-spreading Arctic ridge system.

Eickmann, B.; van Zuilen, M. A.; Thorseth, I. H.; Pedersen, R.

2010-12-01

363

Conserving gallons and kilowatts. Challenges of today's solar power plants. An EPC (Engineering, Procurement and Construction) perspective  

Energy Technology Data Exchange (ETDEWEB)

With the increasing restrictions on CO2 emissions, the utilization of solar power is emerging as an effective way to increase the renewable portfolio for utility power. For example in California, the utilities' current renewable portfolios must increase from 20% to 33% by 2020. This drive has made renewable power considerably more desirable. However, fresh water availability and optimal solar irradiation are generally two mutually exclusive local characteristics that make locating and designing these plants challenging. Not only is fresh water scarce at the desert locations where these solar plants are generally located, but options for disposal of wastewater can be very limited as well. These factors have pushed the design of these plants to develop a fine balance between conserving and reusing water to the greatest extent practical and reducing parasitic electrical loads. This paper addresses the challenges associated with developing solar power plant designs that optimize house electrical load while minimizing water footprint. Through the implementation of operational water management techniques and optimized water treatment processes, water usage can be reduced to manageable levels. Utilizing systems that recover and recycle wastewater, the system can be further optimized to reduce the overall water footprint. Case studies are presented for multiple sites detailing the individual optimization required based on the water quality provided. Lessons learned during plant siting and permitting are provided to shed light on the current issues associated with wastewater disposal in these areas and utilization of evaporation ponds. In addition, various design philosophies are discussed to guide the reader through the difficulties of determining the right mix of initial capital cost, optimized water usage, minimized operating cost and minimized parasitic electrical load. (orig.)

Shoemaker, Jeanette [Ivanpah Solar Electric Generating Facility, CA (United States); Bechtel Power Corp., Frederick, MD (United States); Huth, Christopher; Sinha, Kumar [Bechtel Power Corp., Frederick, MD (United States)

2013-03-15

364

Stable isotope studies of vent fluids and chimney minerals, southern Juan de Fuca Ridge: Sodium metasomatism and seawater sulfate reduction  

Energy Technology Data Exchange (ETDEWEB)

Sulfur isotope values (delta/sup 34/S) or H/sub 2/S in vent fluids from the southern Juan de Fuca Ridge hydrothermal sites range from 4.0 to 7.4% and are variably /sup 34/S-enriched with respect to coexisting inner wall chimney sulfides. Chimney sulfides range from 1.6 to 5.7%. The chimneys consist of Fe-sphalerite zoned to inner zinc sulfide and chalcopyrite ( +- isocubanite)-pyrrhotite lining channels. Sulfide from inner walls of type A chimneys have the lightest delta/sup 34/S values. Type B chimneys (porous, unzoned, low-Fe-sphalerite) have the isotopically heaviest chimney sulfides and occur at vent sites distal to the along-axis shallow point of the ridge crest, hence distal to the magma chamber. These variations are largely ascribed to sulfate reduction by ferrous iron in the hydrothermal fluid in chimneys of substrate mounds, probably due to transitory entrainment of ambient sulfate-bearing seawater. The delta/sup 18/O values of end-member hydrothermal fluids range from 0.6 to 0.8%, significantly lower than the delta/sup 18/O values at 21 /sup 0/N vent fluids. The deltaD values of the fluid samples range from -2.5 to 0.5%. Isotopic differences from the 21 /sup 0/N fluids may be due to slightly higher water/rock ratios, approximately 1.0, in the southern Juan de Fuca Ridge hydrothermal system. Admixture of a small amount of residual brine from an earlier phase separation even may have contributed water with low deltaD values.

Shanks W.C. III; Seyfried W.E. Jr.

1987-10-10

365

ZnO nanosheet arrays constructed on weaved titanium wire for CdS-sensitized solar cells  

Science.gov (United States)

Ordered ZnO nanosheet arrays were grown on weaved titanium wires by a low-temperature hydrothermal method. CdS nanoparticles were deposited onto the ZnO nanosheet arrays using the successive ionic layer adsorption and reaction method to make a photoanode. Nanoparticle-sensitized solar cells were assembled using these CdS/ZnO nanostructured photoanodes, and their photovoltaic performance was studied systematically. The best light-to-electricity conversion efficiency was obtained to be 2.17% under 100 mW/cm2 illumination, and a remarkable short-circuit photocurrent density of approximately 20.1 mA/cm2 was recorded, which could attribute to the relatively direct pathways for transportation of electrons provided by ZnO nanosheet arrays as well as the direct contact between ZnO and weaved titanium wires. These results indicate that CdS/ZnO nanostructures on weaved titanium wires would open a novel possibility for applications of low-cost solar cells.

Wu, Cuncun; Wei, Lin; Li, Yitan; Liu, Chang; Jiao, Jun; Chen, Yanxue; Mei, Liangmo

2014-03-01

366

Chimney reconstruction systems. New heating systems and old chimneys do not harmonize. Schornstein-Sanierungssysteme. Neue Heizungen und alte Schornsteine vertragen sich nicht  

Energy Technology Data Exchange (ETDEWEB)

New burner systems with lower exhaust gas temperatures resulted in increased reconstruction of chimneys within the last years. The traditional materials for reconstruction such as leight weight concrete shells or flexible special steel pipes proved to be insufficient. Nowadays rigid special steel pipes with and without heat insulating shell as well as fire-clay pipes, which are applied with acid-resisting cement and backfilled with insulating layer. Recusist special glass is regarded as a relatively new, efficient reconstructional material. In addition to their corrosion resistance, Recusist is gas- and condensate tight resistant to temperature change, favorable with regard to flow, non-porous (and thus, easily to clean) as well as not harmful to the environment. (orig.).

Wollenberg, H.D.

1991-02-01

367

Adaptation with the burner; Modernisation of heating plants hand in hand with chimney retrofitting. [Chimney retrofitting]. Mit dem Brenner auf einem Nenner; Heizungsmodernisierung Hand in Hand mit der Schornsteinsanierung  

Energy Technology Data Exchange (ETDEWEB)

The conversion from solid fuels to oil or gas and the introduction of new heating technologies result in noticeable reductions of the exhaust temperature and mass flow. Therefore the chimney has to be retrofitted as the developing condensate causes damage to the chimney. For this purpose internal pipes of corrosion-resistant material have to be used e.g. of stainless steel, ceramics, fire clay or special glass. Which material should be used mainly depends on the corrosion load to be expected. In case of above-average loads the use of internal pipes of special glass is recommended. (BWI)

Wollenberg, H.D.

1992-11-01

368

Design and realization of an apparatus for the continuous control of 41Ar release at the LENA chimney  

International Nuclear Information System (INIS)

We describe the realization of an apparatus for the continuous measurement of 41Ar released from LENA chimney. The apparatus is sensitive enough to determine activity concentrations as low as 102 Bq m-3. The detector is a 3' x 3' crystal NaI(Tl) scintillator with a 6 % energy resolution placed on the lateral surface of the superior part of the chimney. The pulses produced in the detector by the gamma-rays are amplified and conted by a 1024 channel analyzer. The total efficiency has been determined using a Monte Carlo program. The intrinsic efficiency of the detector has been calculated for a gamma-rays source uniformly distributed on its base surface; the geometric efficiency has been then calculated using a source uniformly distributed in the final cylindrical section of the chimney. The Monte Carlo program has been tested by comparing the intrinsic efficiency calculated for a point source versus energy with data reported in the literature. (orig.)

1984-08-21

369

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

Directory of Open Access Journals (Sweden)

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%.

A. O.M. Mahmoud

2006-01-01

370

Trace element distribution, with a focus on gold, in copper-rich and zinc-rich sulfide chimneys from Brothers submarine volcano, Kermadec arc  

Science.gov (United States)

Brothers volcano is a dacitic volcano located along the Kermadec arc, New Zealand, and hosts the NW Caldera hydrothermal vent field perched on part of the steep caldera walls. The field strikes for ~600 m between depths of 1550 and 1700 m and includes numerous, active, high-temperature (max 302°C) chimneys and even more dead, sulfide-rich spires. Chimney samples collected from Brothers show distinct mineralogical zonation reflecting gradients in oxidation state, temperature, and pH from the inner walls in contact with hydrothermal fluids through to the outer walls in contact with seawater. Minerals deposited from hotter fluids (e.g., chalcopyrite) are located in the interior of the chimneys and are surrounded by an external zone of minerals deposited by cooler fluids (e.g., sulfates, sphalerite). Four chimneys types are identified at Brothers volcano based on the relative proportions of chalcopyrite and sulfate layers, and the presence or absence of anhydrite. Two are Cu-rich, i.e., chalcopyrite-rich and chalcopyrite-bornite-rich chimneys, and two are Zn-rich, i.e., sphalerite-rich and sphalerite-chalcopyrite-rich. Barite and anhydrite are common to both Cu-rich chimney types whereas Zn-rich chimneys contain barite only. The main mineral phases in all the chimneys are anhydrite, barite, chalcopyrite, pyrite/marcasite, and sphalerite. Trace minerals include galena, covellite, tennantite, realgar, chalcocite, bornite, hematite, goethite, Pb-As sulfosalts, and Bi- or Au-tellurides. The vast majority of tellurides are specular hematite and Bi- or Au-tellurides associated with chalcopyrite are consistent with magmatic contributions to the NW Caldera vent site. These tellurides are the first gold-bearing phase to be identified in these chimneys, and the Bi-Au association suggests that gold-enrichment up to 91 ppm is due to scavenging by liquid bismuth. To better understand the mineral associations and zonation of these and other trace elements within the chimney walls, we have undertaken element mapping on the four different chimneys types with both X-Ray fluorescence microscopy using synchrotron radiation and with Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS). For example, in a chalcopyrite-rich chimney, visibly laminated chalcopyrite in the interior contains bands with a magmatic suite of elements including Co, Mo, Ag, Te, Au, and Bi. In comparison in a sphalerite-chalcopyrite-rich chimney, Au is again associated with minor Cu, although not with Bi and Te indicating alternative methods of gold transport and deposition are dominant. Element mapping allows us to better understand the physico-chemical gradients within chimney walls, as well as metal sources and transportation, and depositional processes.

Berkenbosch, H. A.; de Ronde, C. E.; McNeill, A.; Goemann, K.; Gemmell, J. B.

2012-12-01

371

Eggebek, of all places. Germany's biggest solar farm is under construction near the Danish border because inhabitants were against wind power; Ausgerechnet Eggebek. Hoch im Norden entsteht Deutschlands groesster Solarpark - weil Anwohner keine Windkraft wollten  

Energy Technology Data Exchange (ETDEWEB)

When a NATO airport near the Danish border was abandoned, investors, regional planners and the wind power industry wanted to construct a wind farm. However, inhabitants of the nearby community of Eggebek were against these plans. After a long and heated controversy, which has its aftermath even today, it was decided to construct Germany's biggest solar farm in windy Schleswig-Holstein.

Krause, Matthias B.

2011-07-15

372

Endovascular Aortic Aneurysm Repair with Chimney and Snorkel Grafts: Indications, Techniques and Results  

Energy Technology Data Exchange (ETDEWEB)

The chimney technique in endovascular aortic aneurysm repair (Ch-EVAR) involves placement of a stent or stent-graft parallel to the main aortic stent-graft to extend the proximal or distal sealing zone while maintaining side branch patency. Ch-EVAR can facilitate endovascular repair of juxtarenal and aortic arch pathology using available standard aortic stent-grafts, therefore, eliminating the manufacturing delays required for customised fenestrated and branched stent-grafts. Several case series have demonstrated the feasibility of Ch-EVAR both in acute and elective cases with good early results. This review discusses indications, technique, and the current available clinical data on Ch-EVAR.

Patel, Rakesh P., E-mail: rpatel9@nhs.net [Northwick Park Hospital, Department of Vascular Radiology (United Kingdom); Katsargyris, Athanasios, E-mail: kthanassos@yahoo.com; Verhoeven, Eric L. G., E-mail: Eric.Verhoeven@klinikum-nuernberg.de [Klinikum Nuernberg, Department of Vascular and Endovascular Surgery (Germany); Adam, Donald J., E-mail: donald.adam@tiscali.co.uk [Heartlands Hospital, Department of Vascular Surgery (United Kingdom); Hardman, John A., E-mail: johnhardman@doctors.org.uk [Royal United Hospital Bath, Department of Vascular Radiology (United Kingdom)

2013-12-15

373

Endovascular Aortic Aneurysm Repair with Chimney and Snorkel Grafts: Indications, Techniques and Results  

International Nuclear Information System (INIS)

The chimney technique in endovascular aortic aneurysm repair (Ch-EVAR) involves placement of a stent or stent-graft parallel to the main aortic stent-graft to extend the proximal or distal sealing zone while maintaining side branch patency. Ch-EVAR can facilitate endovascular repair of juxtarenal and aortic arch pathology using available standard aortic stent-grafts, therefore, eliminating the manufacturing delays required for customised fenestrated and branched stent-grafts. Several case series have demonstrated the feasibility of Ch-EVAR both in acute and elective cases with good early results. This review discusses indications, technique, and the current available clinical data on Ch-EVAR

2013-12-01

374

Endovascular aortic aneurysm repair with chimney and snorkel grafts: indications, techniques and results.  

Science.gov (United States)

The chimney technique in endovascular aortic aneurysm repair (Ch-EVAR) involves placement of a stent or stent-graft parallel to the main aortic stent-graft to extend the proximal or distal sealing zone while maintaining side branch patency. Ch-EVAR can facilitate endovascular repair of juxtarenal and aortic arch pathology using available standard aortic stent-grafts, therefore, eliminating the manufacturing delays required for customised fenestrated and branched stent-grafts. Several case series have demonstrated the feasibility of Ch-EVAR both in acute and elective cases with good early results. This review discusses indications, technique, and the current available clinical data on Ch-EVAR. PMID:23674274

Patel, Rakesh P; Katsargyris, Athanasios; Verhoeven, Eric L G; Adam, Donald J; Hardman, John A

2013-12-01

375

Evidence for chimney breakout in the Galactic supershell GSH 242-03+37  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present new high resolution neutral hydrogen (H I) images of the Galactic supershell GSH 242-03+37. These data were obtained with the Parkes Radiotelescope as part of the Galactic All-Sky Survey (GASS). GSH 242-03+37 is one of the largest and most energetic H I supershells in the Galaxy with a radius of $565 \\pm 65$ pc and an expansion energy of 3x10^{53} ergs. Our images reveal a complicated shell with multiple chimney structures on both sides of the Galactic plane. Thes...

Mcclure-griffiths, N. M.; Ford, A.; Pisano, D. J.; Gibson, B. K.; Staveley-smith, L.; Calabretta, M. R.; Dedes, L.; Kalberla, P. M. W.

2005-01-01

376

Chimney technique for aortic dissection involving an aberrant right subclavian artery.  

Science.gov (United States)

We report a case involving a ruptured acute type B aortic dissection originating from an aberrant right subclavian artery (ARSA). A thoracic stent-graft was deployed in the distal arch close to the origin of the ARSA; the entry site at the origin of the ARSA was embolized with metallic coils. Perfusion of the left subclavian artery was preserved without a surgical bypass by using a chimney graft. This procedure is a feasible and less invasive treatment for high-risk sternotomy patients and is an effective strategy for acute aortic dissections involving an ARSA. PMID:24384181

Samura, Makoto; Zempo, Nobuya; Ikeda, Yoshitaka; Kaneda, Yoshikazu; Suzuki, Kazuhiro; Tsuboi, Hidetoshi; Hamano, Kimikazu

2014-01-01

377

Constructing 3D branched nanowire coated macroporous metal oxide electrodes with homogeneous or heterogeneous compositions for efficient solar cells.  

Science.gov (United States)

Light-harvesting and charge collection have attracted increasing attention in the domain of photovoltaic cells, and can be facilitated dramatically by appropriate design of a photonic nanostructure. However, the applicability of current light-harvesting photoanode materials with single component and/or morphology (such as, particles, spheres, wires, sheets) is still limited by drawbacks such as insufficient electron-hole separation and/or light-trapping. Herein, we introduce a universal method to prepare hierarchical assembly of macroporous material-nanowire coated homogenous or heterogeneous metal oxide composite electrodes (TiO2 -TiO2 , SnO2 -TiO2 , and Zn2 SnO4 -TiO2 ; homogenous refers to a material in which the nanowire and the macroporous material have the same composition, i.e. both are TiO2 . Heterogeneous refers to a material in which the nanowires and the macroporous material have different compositions). The dye-sensitized solar cell based on a TiO2 -macroporous material-TiO2 -nanowire homogenous composition electrode shows an impressive conversion efficiency of 9.51?%, which is much higher than that of pure macroporous material-based photoelectrodes to date. PMID:24677777

Wu, Wu-Qiang; Xu, Yang-Fan; Rao, Hua-Shang; Feng, Hao-Lin; Su, Cheng-Yong; Kuang, Dai-Bin

2014-05-01

378

A study on thermo-hydraulic instability of boiling natural circulation loop with a chimney. A consideration of the effect of axial higher mode  

International Nuclear Information System (INIS)

Thermo-hydraulic instabilities of a boiling natural circulation loop with a chimney under low and high pressure were investigated using linear stability analysis. The effect of nuclear coupling was also considered. Both in low- and high-pressure conditions, instability could occur when exit quality was relatively low. In low-pressure condition, flashing only near the exit of the chimney could induce instability, and enthalpy wave of single-phase flow was generated in the chimney. In high-pressure condition, void was generated near channel exit, and void wave propagated in the chimney. In the high pressure and high power condition, though flow could by very stable, the decay ratio of higher mode could be larger than that of lower mode. The sensitivity on decay ratio to the thermal power, inlet subcooling, void reactivity feedback coefficient and so on could be very low when there was a long chimney. (author)

2000-10-01

379

An experimental and theoretical approach to determining linkages between geochemical variability and microbial biodiversity in seafloor hydrothermal chimneys.  

Science.gov (United States)

New experimental results of fluid-mineral reactions at hydrothermal conditions relevant to life demonstrate that key redox reactions involving iron, sulfur, and hydrogen remain at disequilibrium at 100 °C, even in a heterogeneous system and thus are energetically favorable for microbial metabolism. Predictions from geochemical models utilizing the experimental results and specific to two contrasting case studies from the East Pacific Rise were statistically characterized and correlated to the energetics of redox reactions available for intra-chimney microbial populations. In general, predictions of available energy for autotrophic metabolism are largely similar between the mature and the nascent chimneys, although important differences still exist. Metabolic processes predicted by energetics exhibit the same trends observed in the field data for the mature chimney, but overestimate the diversity observed in the nascent chimney. Several combinations of redox reaction pairs are predicted to support mixed consortia, while some combinations appear to favor more versatile microbes capable of utilizing several reactions under rapidly changing environmental conditions within chimney walls. In addition, conditions favorable to elemental sulfur reduction and methanogenesis exhibit a negative control on the diversity of microbial populations within these chimney walls, whereas H?S oxidation, elemental sulfur oxidation and the knallgas reaction are positively correlated with both abundance and diversity of micro-organisms. Coupling field observations of both microbial diversity and geochemical heterogeneity with lab-based experimental and theoretical modeling can facilitate translation of the observed genetic diversity into physiological diversity, thus enhancing understanding of linked phenomena of microbially induced biogeochemical transformations in complex heterogeneous systems. PMID:20726900

Houghton, J L; Seyfried, W E

2010-12-01

380

Evidence for chimney breakout in the Galactic supershell GSH 242-03+37  

CERN Multimedia

We present new high resolution neutral hydrogen (H I) images of the Galactic supershell GSH 242-03+37. These data were obtained with the Parkes Radiotelescope as part of the Galactic All-Sky Survey (GASS). GSH 242-03+37 is one of the largest and most energetic H I supershells in the Galaxy with a radius of $565 \\pm 65$ pc and an expansion energy of 3x10^{53} ergs. Our images reveal a complicated shell with multiple chimney structures on both sides of the Galactic plane. These chimneys appear capped by narrow filaments about 1.6 kpc above and below the Galactic mid-plane, confirming structures predicted in simulations of expanding supershells. The structure of GSH 242-03+37 is extremely similar to the only other Galactic supershell known to have blown out of both sides of the plane, GSH 277+00+36. We compare the GASS H I data with X-ray and H-alpha, finding no strong correlations.

McClure-Griffiths, N M; Pisano, D J; Gibson, B K; Staveley-Smith, L; Calabretta, M R; Dedes, L; Kalberla, P M W

2006-01-01

 
 
 
 
381

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

Directory of Open Access Journals (Sweden)

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.

H. Hashemi

2008-11-01

382

The versatile in situ gene expression of an Epsilonproteobacteria-dominated biofilm from a hydrothermal chimney.  

Science.gov (United States)

The Epsilonproteobacteria, including members of the genus Sulfurovum, are regarded as important primary producers in hydrothermal systems. However, their in situ gene expression in this habitat has so far not been investigated. We report a metatranscriptomic analysis of a Sulfurovum-dominated biofilm from one of the chimneys at the Loki's Castle hydrothermal system, located at the Arctic Mid Ocean Ridge. Transcripts involved in hydrogen oxidation, oxidation of sulfur species, aerobic respiration and denitrification were abundant and mostly assigned to Sulfurovum, indicating that members of this genus utilize multiple chemical energy sources simultaneously for primary production. Sulfurovum also seemed to have a diverse expression of transposases, potentially involved in horizontal gene transfer. Other transcripts were involved in CO? fixation by the reverse TCA cycle, the CRISPR-Cas system, heavy metal resistance, and sensing and responding to changing environmental conditions. Through pyrosequencing of PCR amplified 16S rRNA genes, the Sulfurovum-dominated biofilm was compared with another biofilm from the same chimney, revealing a large shift in the community structure of Epsilonproteobacteria-dominated biofilms over a few metres. PMID:23584970

Dahle, Håkon; Roalkvam, Irene; Thorseth, Ingunn H; Pedersen, Rolf B; Steen, Ida H

2013-04-01

383

Microbial Sulfur Cycle in Two Hydrothermal Chimneys on the Southwest Indian Ridge  

Science.gov (United States)

ABSTRACT Sulfur is an important element in sustaining microbial communities present in hydrothermal vents. Sulfur oxidation has been extensively studied due to its importance in chemosynthetic pathways in hydrothermal fields; however, less is known about sulfate reduction. Here, the metagenomes of hydrothermal chimneys located on the ultraslow-spreading Southwest Indian Ridge (SWIR) were pyrosequenced to elucidate the associated microbial sulfur cycle. A taxonomic summary of known genes revealed a few dominant bacteria that participated in the microbial sulfur cycle, particularly sulfate-reducing Deltaproteobacteria. The metagenomes studied contained highly abundant genes related to sulfur oxidation and reduction. Several carbon metabolic pathways, in particular the Calvin-Benson-Bassham pathway and the reductive tricarboxylic acid cycles for CO2 fixation, were identified in sulfur-oxidizing autotrophic bacteria. In contrast, highly abundant genes related to the oxidation of short-chain alkanes were grouped with sulfate-reducing bacteria, suggesting an important role for short-chain alkanes in the sulfur cycle. Furthermore, sulfur-oxidizing bacteria were associated with enrichment for genes involved in the denitrification pathway, while sulfate-reducing bacteria displayed enrichment for genes responsible for hydrogen utilization. In conclusion, this study provides insights regarding major microbial metabolic activities that are driven by the sulfur cycle in low-temperature hydrothermal chimneys present on an ultraslow midocean ridge.

Cao, Huiluo; Wang, Yong; Lee, On On; Zeng, Xiang; Shao, Zongze; Qian, Pei-Yuan

2014-01-01

384

Metal sources of black smoker chimneys, Endeavour Segment, Juan de Fuca Ridge: Pb isotope constraints  

International Nuclear Information System (INIS)

Hydrothermal chimney sulfides, vent cap chimney samples, Fe-oxide and basalts from sediment-starving Juan de Fuca Ridge, in the Endeavour segment, exhibit a range of Pb isotope ratios (206Pb/204Pb = 18.658-18.769; 207Pb/204Pb = 15.457-15.566; 208Pb/204Pb = 37.810-38.276). The data array is not parallel to the northern hemisphere mantle reservoirs indicating a possible sediment component within the sulfides. By assuming that the potential end-member sediment component has a 207Pb/204Pb (15.70) similar to Middle Valley sediment, it is suggested the potential end-member sediment component may have 206Pb/204Pb = 18.90; 208Pb/204Pb = 38.82. Basalt-derived Pb for the Endeavour segment hydrothermal system involves about 50/50 leaching of E-MORB and T2-MORB. Detailed observations show the Mothra field derives more Pb from T2-MORB than the Main Endeavour field does. According to the binary mixing model, the results show little Pb (4+, CH4 and Br/Cl ratios in hydrothermal fluids are consistent with a sediment component within the segment. Reconciling the Pb isotope data with the chemistry data of hydrothermal fluids, it is suggested that the sediment component may be located in a lower temperature recharge zone where Pb could not be mobilized from the sediment.

2009-10-01

385

Continuous enrichment cultures: insights into prokaryotic diversity and metabolic interactions in deep-sea vent chimneys.  

Science.gov (United States)

The prokaryotic diversity of culturable thermophilic communities of deep-sea hydrothermal chimneys was analysed using a continuous enrichment culture performed in a gas-lift bioreactor, and compared to classical batch enrichment cultures in vials. Cultures were conducted at 60 degrees C and pH 6.5 using a complex medium containing carbohydrates, peptides and sulphur, and inoculated with a sample of a hydrothermal black chimney collected at the Rainbow field, Mid-Atlantic Ridge, at 2,275 m depth. To assess the relevance of both culture methods, bacterial and archaeal diversity was studied using cloning and sequencing, DGGE, and whole-cell hybridisation of 16S rRNA genes. Sequences of heterotrophic microorganisms belonging to the genera Marinitoga, Thermosipho, Caminicella (Bacteria) and Thermococcus (Archaea) were obtained from both batch and continuous enrichment cultures while sequences of the autotrophic bacterial genera Deferribacter and Thermodesulfatator were only detected in the continuous bioreactor culture. It is presumed that over time constant metabolite exchanges will have occurred in the continuous enrichment culture enabling the development of a more diverse prokaryotic community. In particular, CO(2) and H(2) produced by the heterotrophic population would support the growth of autotrophic populations. Therefore, continuous enrichment culture is a useful technique to grow over time environmentally representative microbial communities and obtain insights into prokaryotic species interactions that play a crucial role in deep hydrothermal environments. PMID:17576518

Postec, Anne; Lesongeur, Françoise; Pignet, Patricia; Ollivier, Bernard; Querellou, Joël; Godfroy, Anne

2007-11-01

386

Formation of carbonate chimneys in the Mediterranean Sea linked to deep-water oxygen depletion  

Science.gov (United States)

Marine sediments at ocean margins vent substantial amounts of methane. Microbial oxidation of the methane released can trigger the precipitation of carbonate within sediments and support a broad diversity of seafloor ecosystems. The factors controlling microbial activity and carbonate precipitation associated with the seepage of submarine fluid over geological time remain poorly constrained. Here, we characterize the petrology and geochemistry of rocks sampled from metre-size build-ups of methane-derived carbonate chimneys located at the Amon mud volcano on the Nile deep-sea fan. We find that these carbonates comprise porous structures composed of aggregated spherules of aragonite, and closely resemble microbial carbonate reefs forming at present in the anoxic bottom waters of the Black Sea. Using U-series dating, we show that the Amon carbonate build-ups formed between 12 and 7 thousand years ago, contemporaneous with the deposition of organic-rich sediments in the eastern Mediterranean, the so-called sapropel layer S1. We propose that the onset of deep-water suboxic or anoxic conditions associated with sapropel formation resulted in the development of intense anaerobic microbial activity at the sea floor, and thus the formation of carbonate chimneys.

Bayon, Germain; Dupré, Stéphanie; Ponzevera, Emmanuel; Etoubleau, Joël; Chéron, Sandrine; Pierre, Catherine; Mascle, Jean; Boetius, Antje; de Lange, Gert J.

2013-09-01

387

Metal sources of black smoker chimneys, Endeavour Segment Juan de Fuca Ridge: Pb isotope constraints  

Science.gov (United States)

The hydrothermal chimney sulfides and vent cap chimney samples from the Endeavour Segment, Juan de Fuca Ridge, a sediment-starving mid-ocean ridge, display Pb isotope compositions that are indistinguishable from the local basalt, indicating the primary Pb source of sulfides and hydrothermal fluids in Endeavour Segment is basalt. Mean while the relative large Pb isotope composition variation range when compared with other sediment-starving ridges and the anomaly Pb-Pb plot, indicating a sediment component contribution. Results of binary mixing models suggest that the sediment sources contribution is no more than 1%. Combining the Pb isotope data with the chemistry data of hydrothermal fluid within the Endeavour Segment, we suggested the sediment component may locate in the recharge zone, rather than high temperature reaction zone. In addition, the sediment component should have a lower 206Pb/204Pb inferred from the "BF" line which through the densest cluster of Pb isotope data. The lower 206Pb/204Pb sediment component may have a common provenance with that of Middle Valley, providing a new insight on the evolution of the north end of the Juan de Fuca ridge.

Yao, H.-Q.; Zhou, H.-Y.; Peng, X.-T.; Wu, Z.-J.; Li, J.-T.; Bao, S.-X.

2009-04-01

388

Solar Racing  

Science.gov (United States)

In this 'Energy Education for the 21st Century' design challenge, students construct and evaluate a solar-powered model car. Students utilize the design process and undergo review by their peers to select an optimal gear ratio and components for their car. As a culminating activity, students compete in a Solar Sprint race modeled after the National Renewable Energy Laboratory's Junior Solar Sprint competition.

Teachers, Pbs

389

Repair of a complex post-EVAR type III endoleak using a chimney aortouniiliac stent graft and femorofemoral crossover bypass  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Post-EVAR type III endoleaks present a particular challenge as they carry a significant risk of rupture. We present a case of an 81-year-old gentleman, 10 years post-EVAR, with complex type III endoleak with component separation that was successfully treated with a combination of left renal artery chimney, aortouniiliac stent grafting and femorofemoral crossover bypass.

Ch Ng, Jack Kian; Taneja, Manish; Chua, Benjamin Soo Yeng

2013-01-01

390

Diversity and abundance of ammonia-oxidizing archaea in hydrothermal vent chimneys of the juan de fuca ridge.  

Science.gov (United States)

The abundance and diversity of archaeal ammonia monooxygenase subunit A (amoA) genes from hydrothermal vent chimneys at the Juan de Fuca Ridge were investigated. The majority of the retrieved archaeal amoA sequences exhibited identities of less than 95% to those in the GenBank database. Novel ammonia-oxidizing archaea may exist in the hydrothermal vent environments. PMID:19395559

Wang, Shufang; Xiao, Xiang; Jiang, Lijing; Peng, Xiaotong; Zhou, Huaiyang; Meng, Jun; Wang, Fengping

2009-06-01

391

Biosignatures in chimney structures and sediment from the Loki's Castle low-temperature hydrothermal vent field at the Arctic Mid-Ocean Ridge.  

Science.gov (United States)

We investigated microbial life preserved in a hydrothermally inactive silica–barite chimney in comparison with an active barite chimney and sediment from the Loki's Castle low-temperature venting area at the Arctic Mid-Ocean Ridge (AMOR) using lipid biomarkers. Carbon and sulfur isotopes were used to constrain possible metabolic pathways. Multiple sulfur (d?34S, ?33S) isotopes on barite over a cross section of the extinct chimney range between 21.1 and 22.5 % in ?34S, and between 0.020 and 0.034 % in ?33S, indicating direct precipitation from seawater. Biomarker distributions within two discrete zones of this silica–barite chimney indicate a considerable difference in abundance and diversity of microorganisms from the chimney exterior to the interior. Lipids in the active and inactive chimney barite and sediment were dominated by a range of 13C-depleted unsaturated and branched fatty acids with ?13C values between -39.7 and -26.7 %, indicating the presence of sulfur-oxidizing and sulfate-reducing bacteria. The majority of lipids (99.5 %) in the extinct chimney interior that experienced high temperatures were of archaeal origin. Unusual glycerol monoalkyl glycerol tetraethers (GMGT) with 0–4 rings were the dominant compounds suggesting the presence of mainly (hyper-) thermophilic archaea. Isoprenoid hydrocarbons with ?13C values as low as -46 % also indicated the presence of methanogens and possibly methanotrophs. PMID:24659146

Jaeschke, Andrea; Eickmann, Benjamin; Lang, Susan Q; Bernasconi, Stefano M; Strauss, Harald; Früh-Green, Gretchen L

2014-05-01

392

U-Th systematics and 230Th ages of carbonate chimneys at the Lost City Hydrothermal Field  

Science.gov (United States)

The Lost City Hydrothermal Field (LCHF) is a serpentinite-hosted vent field located 15 km west of the spreading axis of the Mid-Atlantic Ridge. In this study, uranium-thorium (U-Th) geochronological techniques have been used to examine the U-Th systematics of hydrothermal fluids and the 230Th ages of hydrothermally-precipitated carbonate chimneys at the LCHF. Fluid sample analyses indicate that endmember fluids likely contain only 0.0073 ng/g U or less compared to 3.28 ± 0.03 ng/g of U in ambient seawater. For fluid samples containing only 2-21% ambient seawater (1.1-11 mmol/kg Mg), Th concentration is 0.11-0.13 pg/g and surrounding seawater concentrations average 0.133 ± 0.016 pg/g. The 230Th/ 232Th atomic ratios of the vent fluids range from 1 (±10) × 10 -6 to 11 (±5) × 10 -6, are less than those of seawater, and indicate that the vent fluids may contribute a minor amount of non-radiogenic 230Th to the LCHF carbonate chimney deposits. Chimney 238U concentrations range from 1 to 10 ?g/g and the average chimney corrected initial ? 234U is 147.2 ± 0.8, which is not significantly different from the ambient seawater value of 146.5 ± 0.6. Carbonate 232Th concentrations range broadly from 0.0038 ± 0.0003 to 125 ± 16 ng/g and 230Th/ 232Th atomic ratios vary from near seawater values of 43 (±8) × 10 -6 up to 530 (±25) × 10 -3. Chimney ages, corrected for initial 230Th, range from 17 ± 6 yrs to 120 ± 13 kyrs. The youngest chimneys are at the intersection of two active, steeply-dipping normal faults that cut the Atlantis Massif; the oldest chimneys are located in the southwest portion of the field. Vent deposits on a steep, fault-bounded wall on the east side of the field are all LCHF is the most long-lived hydrothermal system known to date. It is likely that seismic activity and active faulting within the Atlantis Massif and the Atlantis Fracture Zone, coupled with volumetric expansion of the underlying serpentinized host rocks play major roles in sustaining hydrothermal activity at this site. The longevity of venting at the LCHF may have implications for ecological succession of microorganisms within serpentinite-hosted vent environments.

Ludwig, Kristin A.; Shen, Chuan-Chou; Kelley, Deborah S.; Cheng, Hai; Edwards, R. Lawrence

2011-04-01

393

A study on thermo-hydraulic instability of boiling natural circulation loop with a chimney. 2. Experimental approach to clarify the flow instability in detail  

International Nuclear Information System (INIS)

Experiments are conducted to investigate two-phase flow instabilities in a boiling natural circulation loop with a chimney induced by flashing in the chimney at lower pressure. The type of instability that occurred in the experiments is suggested to be density wave oscillations induced by flashing in the chimney. The differences from other instabilities such as geysering, flow pattern transition instability, and natural circulation oscillations are discussed on the basis of the dynamic characteristics, the oscillation period, and the transient flow resume. (author)

1995-11-01

394

A study on thermo-hydraulic instability of boiling natural circulation loop with a chimney. 2. Experimental approach to clarify the flow instability in detail  

Energy Technology Data Exchange (ETDEWEB)

Experiments are conducted to investigate two-phase flow instabilities in a boiling natural circulation loop with a chimney induced by flashing in the chimney at lower pressure. The type of instability that occurred in the experiments is suggested to be density wave oscillations induced by flashing in the chimney. The differences from other instabilities such as geysering, flow pattern transition instability, and natural circulation oscillations are discussed on the basis of the dynamic characteristics, the oscillation period, and the transient flow resume. (author).

Furuya, Masahiro; Inada, Fumio; Yasuo, Akira [Central Research Inst. of Electric Power Industry, Komae, Tokyo (Japan). Komae Research Lab.

1995-11-01

395

Thermal Safety of the Current Buses inthe Chimney of the D0 Solenoid  

Energy Technology Data Exchange (ETDEWEB)

The thermal and electrical behaviour of the current buses in the chimney of the D0 solenoid during upset conditions is modeled to guide the selection of trip levels for magnet protection circuits which discharge the magnet if abnormal conditions are detected. The current buses in the chimney are designed to operate safely without likelihood of loss of superconductivity as long as normal cooling conditions are maintained. Helium liquid level probes, helium flow instrumentation, and thermometry all are provided to certify that proper cooling conditions exist in the subcooler and chimney at all times. Rising temperatures in any portion of the system, excessive voltage drops on the vapor cooled leads, or decreasing liquid level in the subcooler or flow rate in the system, will each cause the fast discharge system to be triggered. Postulated failures of the helium flow system, somehow undetected by any and all of the aforementioned instrumentation, can in principal eventually lead to loss of superconductivity in the buses. Quenching in one bus will rapidly lead to quenching in the other. Potential taps on the buses and magnet coil halves connected to voltage-detection bridges external to the system provide at least dually redundant signals which will unambiguously trigger the magnet rapid discharge system. The conservative design of the bus system ensures that it will not be damaged during such incidents, however improbable they may be. The transition leads in the subcooler are equally conservatively designed, and would not be damaged if they were operated in a fully non-superconducting state for several minutes. The loss of liquid helium in the sub cooler required to cause this condition would imply that helium flow from the magnet had stopped, which in turn would imply that flow to the magnet had also stopped. The lack of flow into the sub cooler would result in insufficient flow to the vapor cooled leads. Any or all of these conditions would be detected, as would easily detected spurious voltages on the potential tap system, before damage to the transition leads occurred.

Smith, R.P.; /Fermilab

1998-01-20

396

Thermal Safety of the Current Buses in the Chimney of the D0 Solenoid  

International Nuclear Information System (INIS)

The thermal and electrical behaviour of the current buses in the chimney of the D0 solenoid during upset conditions is modeled to guide the selection of trip levels for magnet protection circuits which discharge the magnet if abnormal conditions are detected. The current buses in the chimney are designed to operate safely without likelihood of loss of superconductivity as long as normal cooling conditions are maintained. Helium liquid level probes, helium flow instrumentation, and thermometry all are provided to certify that proper cooling conditions exist in the subcooler and chimney at all times. Rising temperatures in any portion of the system, excessive voltage drops on the vapor cooled leads, or decreasing liquid level in the subcooler or flow rate in the system, will each cause the fast discharge system to be triggered. Postulated failures of the helium flow system, somehow undetected by any and all of the aforementioned instrumentation, can in principal eventually lead to loss of superconductivity in the buses. Quenching in one bus will rapidly lead to quenching in the other. Potential taps on the buses and magnet coil halves connected to voltage-detection bridges external to the system provide at least dually redundant signals which will unambiguously trigger the magnet rapid discharge system. The conservative design of the bus system ensures that it will not be damaged during such incidents, however improbable they may be. The transition leads in the subcooler are equally conservatively designed, and would not be damaged if they were operated in a fully non-superconducting state for several minutes. The loss of liquid helium in the sub cooler required to cause this condition would imply that helium flow from the magnet had stopped, which in turn would imply that flow to the magnet had also stopped. The lack of flow into the sub cooler would result in insufficient flow to the vapor cooled leads. Any or all of these conditions would be detected, as would easily detected spurious voltages on the potential tap system, before damage to the transition leads occurred.

1998-01-01

397

Construction of RC tower-like structures of complicated geometry by use of the slipform construction process; Slipform koho ni yoru fukuzatsuna keijo wo shita RC tojo kozobutsu no seko  

Energy Technology Data Exchange (ETDEWEB)

In big cities, such as Tokyo, the policy is that wastes, such as refuse, generated locally be disposed of within the locality, and this leads to the construction of an increasing number of incineration plants. There is an increase, again, in the demand for the construction of thermoelectric power plants, this ensuing from a recently conducted review of energy related problems. Chimneys belonging to such facilities are all designed to be symbolic and artistic in configuration to respect the surrounding scenery. In this report, the construction of super-tall chimneys at the middle of big cities is described. A technique named `slipform construction process` introduced here is a method in which a formwork is elevated by a jack and concrete is continuously poured while the formwork is being slided up. This method is advantageous over others in that it shortens the term of work, dispenses with the need of refilling the formwork, results in high-quality products, assures safety in the execution of the work, and others. The cost related merit depends on the scale of the construction work undertaken. Outlined in this report is the slipform construction process as applied to the recent construction of a chimney (208.5m high) for a waste incineration plant in Toshima District, Tokyo. 14 figs., 5 tabs.

Ito, M.; Nozaki, T.; Igarashi, K. [Obayashi Corp., Tokyo (Japan)

1998-05-25

398

Contaminant transport during atmospheric pumping of a nuclear chimney: Progress report  

International Nuclear Information System (INIS)

Cyclical variations in barometric pressure cause an oscillatory up-and-down motion of gases within the chimney produced by an underground nuclear test. Analytical and experimental modeling of this atmospheric pumping mechanism has been undertaken to better understand and to quantify the associated rates of cavity gas migration toward the earth's surface and the probable rate of release to the atmosphere. Three different types of models are being investigated: (1) homogeneous porous medium; (2) fractured medium with impermeable matrix blocks; and (3) double-porosity media consisting of fracture networks among porous matrix blocks. A primary purpose is to understand how the oscillatory character of the atmospheric pumping process might significantly enhance the contaminant transport in any or all of the three classes of media. This preliminary report describes some of the analytical, numerical, and experimental work which have been completed

1986-01-01

399

Characteristics of bubbly flow in chimney model of lead-bismuth-cooled fast reactor  

International Nuclear Information System (INIS)

The characteristics of Pb-Bi-Ar two-phase flow were investigated in a rectangular vessel (400mm in width, 1500mm in height, 50mm in depth) simulating the chimney in the fast reactor. Ar was injected through the nozzles of 4mm into Pb-Bi, and the superficial Ar velocity was 0.01-0.03m/s at atmospheric pressure. The horizontal distributions of the flow structure, such as bubble velocity and chord length and void fraction were measured by seven double sensor electro conductivity probes. The PDF histograms of the bubble velocity and chord length were obtained. It was estimated that the existing drag coefficient to bubble in water is larger than in Pb-Bi by comparing the experimental results with the analytical results. (author)

2006-06-02

400

D0 Solenoid Upgrade Project: Chimney LN2 Radiation Shield Attachment Area Calculation  

Energy Technology Data Exchange (ETDEWEB)

A short calculation was done to check the attachment method of the radiation shield to it's LN2 cooling tubes. The case considered was only for the obround chimney section. The proposed attachment method was to use 1/8-inch plug welds spaced every 5-inch along the length of the shield. The calculations were done conservatively for 6-inch spacing between plug welds. The criteria used was that the LN2 shield warmest temperature be less than 2 K above the temperature of the LN2 fluid. Using a very conservative heat transfer model. the calculations predict that the warmest temperature on the radiation shield will be < 1.4 K warmer than the LN2 fluid temperature.

Rucinski, R.; /Fermilab

1993-05-26