WorldWideScience

Sample records for underground heat distribution

  1. Underground storage of heat

    International Nuclear Information System (INIS)

    Despois, J.; Nougarede, F.

    1976-01-01

    The interest laying in heat storage is envisaged taking account of the new energy context, with a view to optimizing the use of production means of heat sources hardly modulated according to the demand. In such a way, a natural medium, without any constructions cost but only an access cost is to be used. So, porous and permeable rocky strata allowing the use of a pressurized water flow as a transfer fluid are well convenient. With such a choice high temperatures (200 deg C) may be obtained, that are suitable for long transmissions. A mathematical model intended for solving the conservation equations in the case of heat storage inside a confined water layer is discussed. An approach of the operating conditions of storage may involve either a line-up arrangement (with the hot drilling at the center, the cold drillings being aligned on both sides) or a radial arrangement (with cold drillings at the peripheral edge encircling the hot drilling at the center of the layer). The three principal problems encountered are: starting drilling, and the circuit insulation and control [fr

  2. Heat transfer in underground heating experiments in granite, Stipa, Sweden

    International Nuclear Information System (INIS)

    Chan, T.; Javandel, I.; Witherspoon, P.A.

    1980-04-01

    Electrical heater experiments have been conducted underground in granite at Stripa, Sweden, to investigate the effects of heating associated with nuclear waste storage. Temperature data from these experiments are compared with closed-form and finite-element solutions. Good agreement is found between measured temperatures and both types of models, but especially for a nonlinear finite-element heat conduction model incorporating convective boundary conditions, measured nonuniform initial rock temperature distribution, and temperature-dependent thermal conductivity. In situ thermal properties, determined by least-squares regression, are very close to laboratory values. A limited amount of sensitivity analysis is undertaken

  3. Magneto-Inductive Underground Communications in a District Heating System

    DEFF Research Database (Denmark)

    Meybodi, Soroush Afkhami; Nielsen, Jens Frederik Dalsgaard; Bendtsen, Jan Dimon

    2011-01-01

    Feasibility of underground data communications is investigated by employing magnetic induction as the key technology at physical layer. Realizing an underground wireless sensor network for a district heating plant motivates this research problem. The main contribution of the paper is to find the ...

  4. VT VEC Primary Overhead and Underground Distribution Lines

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) Vermont Electric Cooperative, Inc. (VEC) Primary Overhead and Underground Distribution Lines. VEC’s Distribution lines were drawn from pole to...

  5. Assessment of professional risk caused by heating microclimate in the process of un-derground mining

    Directory of Open Access Journals (Sweden)

    М. Л. Рудаков

    2017-06-01

    Full Text Available The paper reviews the possibility to apply probit-function to assess professional risks of underground mining under conditions of heating microclimate. Operations under conditions of heating microclimate, whose parameters exceed threshold criteria, can lead to dehydration, fainting and heat stroke for mine workers. Basing on the results of medico-biological research on the effects of microclimate on human body, the authors have assessed probabilistic nature of excessive heat accumulation depending on heat stress index.Using Shapiro-Wilk statistics, an assessment has been carried out in order to test correspondence of experimental data on heat accumulation in the human body to the normal law of distribution for different values of heat stress index, measured in the process of underground mining operations under conditions of heating microclimate.The paper justifies construction of a probit-model to assess professional risks caused by overheating for various types of underground mining operations, depending on their intensity.Modeling results have been verified by way of comparison with a currently used deterministic model of body overheating. Taking into account satisfactory convergence of results, the authors suggest using probit-model to assess professional risks of overheating, as this model allows to obtain a continuous dependency between professional risk and heat stress index, which in its own turn facilitates a more justified approach to the selection of measures to upgrade working conditions of personnel.

  6. Heat exhaustion in a deep underground metalliferous mine.

    Science.gov (United States)

    Donoghue, A M; Sinclair, M J; Bates, G P

    2000-03-01

    To examine the incidence, clinical state, personal risk factors, haematology, and biochemistry of heat exhaustion occurring at a deep underground metalliferous mine. To describe the underground thermal conditions associated with the occurrence of heat exhaustion. A 1 year prospective case series of acute heat exhaustion was undertaken. A history was obtained with a structured questionnaire. Pulse rate, blood pressure, tympanic temperature, and specific gravity of urine were measured before treatment. Venous blood was analysed for haematological and biochemical variables, during the acute presentation and after recovery. Body mass index (BMI) and maximum O2 consumption (VO2 max) were measured after recovery. Psychrometric wet bulb temperature, dry bulb temperature, and air velocity were measured at the underground sites where heat exhaustion had occurred. Air cooling power and psychrometric wet bulb globe temperature were derived from these data. 106 Cases were studied. The incidence of heat exhaustion during the year was 43.0 cases/million man-hours. In February it was 147 cases/million man-hours. The incidence rate ratio for mines operating below 1200 m compared with those operating above 1200 m was 3.17. Mean estimated fluid intake was 0.64 l/h (SD 0.29, range 0.08-1.50). The following data were increased in acute presentation compared with recovery (p value, % of acute cases above the normal clinical range): neutrophils (p air velocity was 0.54 m/s (SD 0.57, range 0.00-4.00). Mean air cooling power was 148 W/m2 (SD 49, range 33-290) Mean psychrometric wet bulb globe temperature was 31.5 degrees C (SD 2.0, range 25.2-35.3). Few cases (air velocity > 1.56 m/s, air cooling power > 248 W/m2, or psychrometric wet bulb globe temperature air cooling power > 250 W/m2 at all underground work sites.

  7. Heat transfer analysis of underground U-type heat exchanger of ground source heat pump system.

    Science.gov (United States)

    Pei, Guihong; Zhang, Liyin

    2016-01-01

    Ground source heat pumps is a building energy conservation technique. The underground buried pipe heat exchanging system of a ground source heat pump (GSHP) is the basis for the normal operation of an entire heat pump system. Computational-fluid-dynamics (CFD) numerical simulation software, ANSYS-FLUENT17.0 have been performed the calculations under the working conditions of a continuous and intermittent operation over 7 days on a GSHP with a single-well, single-U and double-U heat exchanger and the impact of single-U and double-U buried heat pipes on the surrounding rock-soil temperature field and the impact of intermittent operation and continuous operation on the outlet water temperature. The influence on the rock-soil temperature is approximately 13 % higher for the double-U heat exchanger than that of the single-U heat exchanger. The extracted energy of the intermittent operation is 36.44 kw·h higher than that of the continuous mode, although the running time is lower than that of continuous mode, over the course of 7 days. The thermal interference loss and quantity of heat exchanged for unit well depths at steady-state condition of 2.5 De, 3 De, 4 De, 4.5 De, 5 De, 5.5 De and 6 De of sidetube spacing are detailed in this work. The simulation results of seven working conditions are compared. It is recommended that the side-tube spacing of double-U underground pipes shall be greater than or equal to five times of outer diameter (borehole diameter: 180 mm).

  8. Heating and cooling energy demand in underground buildings : potential for saving in various climates and functions

    NARCIS (Netherlands)

    van Dronkelaar, C.; Costola, D.; Mangkuto, R.A.; Hensen, J.L.M.

    2014-01-01

    Underground buildings are pointed out as alternatives to conventional aboveground buildings for reducing total energy requirements, while alleviating land use and location problems. This paper investigates the potential in reducing the heating and cooling energy demand of underground buildings

  9. Discrete Wavelet Transform for Fault Locations in Underground Distribution System

    Science.gov (United States)

    Apisit, C.; Ngaopitakkul, A.

    2010-10-01

    In this paper, a technique for detecting faults in underground distribution system is presented. Discrete Wavelet Transform (DWT) based on traveling wave is employed in order to detect the high frequency components and to identify fault locations in the underground distribution system. The first peak time obtained from the faulty bus is employed for calculating the distance of fault from sending end. The validity of the proposed technique is tested with various fault inception angles, fault locations and faulty phases. The result is found that the proposed technique provides satisfactory result and will be very useful in the development of power systems protection scheme.

  10. Occupational heat strain in a hot underground metal mine.

    Science.gov (United States)

    Lutz, Eric A; Reed, Rustin J; Turner, Dylan; Littau, Sally R

    2014-04-01

    In a hot underground metal mine, this study evaluated the relationship between job task, physical body type, work shift, and heat strain. Thirty-one miners were evaluated during 98 shifts while performing deep shaft-sinking tasks. Continuous core body temperature, heart rate, pre- and postshift urine specific gravity (USG), and body mass index were measured. Cutting and welding tasks were associated with significantly (P < 0.05) increased core body temperature, maximum heart rate, and increased postshift urine specific gravity. Miners in the obese level II and III body mass index categories, as well as those working night shift, had lower core body temperatures (P < 0.05). This study confirms that job task, body type, and shift are risk factors for heat strain.

  11. Habitat features and distribution of Salamandra salamandra in underground springs

    Directory of Open Access Journals (Sweden)

    Raoul Manenti

    2009-12-01

    Full Text Available Subterranean habitats are among the less known terrestrial habitats, but can reveal an unexpected biodiversity, and can play an underestimated role for amphibians. The fire salamander Salamandra salamandra is sometimes found in underground environments, but the factors affecting its distribution in subterranean spaces remain substantially unexplored. We repeatedly surveyed some hypogeous springs, such as draining galleries and “bottini” in NW Italy, in order to evaluate the relationship between environmental features and distribution of S. salamandra in these underground springs. We performed visual encounter surveys to assess the occurrence of larvae, juveniles or adults in springs. We also recorded four habitat variables: easy of access, isolation, macrobenthos richness and forest cover of the surrounding landscape. We used generalized linear models to evaluate the relationships between habitat features and occurrence of larvae. We observed larvae of S. salamandra in 13 out of 22 springs; their presence was associated to springs with high easy of access and with relatively rich macrobenthos communities. In underground springs, larval development apparently required longer time than in nearby epigeous streams. Nevertheless, S. salamandra can attain metamorphosis in this environment. The occurrence of S. salamandra in underground environments was not accidental, but repeated in the time and interesting from an ecological point of view, confirming the high plasticity of the species.

  12. UNDERGROUND

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1993-11-15

    Full text: Cossetted deep underground, sheltered from cosmic ray noise, has always been a favourite haunt of neutrino physicists. Already in the 1930s, significant limits were obtained by taking a geiger counter down in Holborn 'tube' station, one of the deepest in London's underground system. Since then, neutrino physicists have popped up in many unlikely places - gold mines, salt mines, and road tunnels deep under mountain chains. Two such locations - the 1MB (Irvine/ Michigan/Brookhaven) detector 600 metres below ground in an Ohio salt mine, and the Kamiokande apparatus 1000m underground 300 km west of Tokyo - picked up neutrinos on 23 February 1987 from the famous 1987A supernova. Purpose-built underground laboratories have made life easier, notably the Italian Gran Sasso Laboratory near Rome, 1.4 kilometres below the surface, and the Russian Baksan Neutrino Observatory under Mount Andyrchi in the Caucasus range. Gran Sasso houses ICARUS (April, page 15), Gallex, Borexino, Macro and the LVD Large Volume Detector, while Baksan is the home of the SAGE gallium-based solar neutrino experiment. Elsewhere, important ongoing underground neutrino experiments include Soudan II in the US (April, page 16), the Canadian Sudbury Neutrino Observatory with its heavy water target (January 1990, page 23), and Superkamiokande in Japan (May 1991, page 8)

  13. UNDERGROUND

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Full text: Cossetted deep underground, sheltered from cosmic ray noise, has always been a favourite haunt of neutrino physicists. Already in the 1930s, significant limits were obtained by taking a geiger counter down in Holborn 'tube' station, one of the deepest in London's underground system. Since then, neutrino physicists have popped up in many unlikely places - gold mines, salt mines, and road tunnels deep under mountain chains. Two such locations - the 1MB (Irvine/ Michigan/Brookhaven) detector 600 metres below ground in an Ohio salt mine, and the Kamiokande apparatus 1000m underground 300 km west of Tokyo - picked up neutrinos on 23 February 1987 from the famous 1987A supernova. Purpose-built underground laboratories have made life easier, notably the Italian Gran Sasso Laboratory near Rome, 1.4 kilometres below the surface, and the Russian Baksan Neutrino Observatory under Mount Andyrchi in the Caucasus range. Gran Sasso houses ICARUS (April, page 15), Gallex, Borexino, Macro and the LVD Large Volume Detector, while Baksan is the home of the SAGE gallium-based solar neutrino experiment. Elsewhere, important ongoing underground neutrino experiments include Soudan II in the US (April, page 16), the Canadian Sudbury Neutrino Observatory with its heavy water target (January 1990, page 23), and Superkamiokande in Japan (May 1991, page 8)

  14. Ground surface temperature and continental heat gain: uncertainties from underground

    International Nuclear Information System (INIS)

    Beltrami, Hugo; Matharoo, Gurpreet S; Smerdon, Jason E

    2015-01-01

    Temperature changes at the Earth's surface propagate and are recorded underground as perturbations to the equilibrium thermal regime associated with the heat flow from the Earth's interior. Borehole climatology is concerned with the analysis and interpretation of these downward propagating subsurface temperature anomalies in terms of surface climate. Proper determination of the steady-state geothermal regime is therefore crucial because it is the reference against which climate-induced subsurface temperature anomalies are estimated. Here, we examine the effects of data noise on the determination of the steady-state geothermal regime of the subsurface and the subsequent impact on estimates of ground surface temperature (GST) history and heat gain. We carry out a series of Monte Carlo experiments using 1000 Gaussian noise realizations and depth sections of 100 and 200 m as for steady-state estimates depth intervals, as well as a range of data sampling intervals from 10 m to 0.02 m. Results indicate that typical uncertainties for 50 year averages are on the order of ±0.02 K for the most recent 100 year period. These uncertainties grow with decreasing sampling intervals, reaching about ±0.1 K for a 10 m sampling interval under identical conditions and target period. Uncertainties increase for progressively older periods, reaching ±0.3 K at 500 years before present for a 10 m sampling interval. The uncertainties in reconstructed GST histories for the Northern Hemisphere for the most recent 50 year period can reach a maximum of ±0.5 K in some areas. We suggest that continuous logging should be the preferred approach when measuring geothermal data for climate reconstructions, and that for those using the International Heat Flow Commission database for borehole climatology, the steady-state thermal conditions should be estimated from boreholes as deep as possible and using a large fitting depth range (∼100 m). (letter)

  15. Dynamic underground stripping: steam and electric heating for in situ decontamination of soils and groundwater

    Science.gov (United States)

    Daily, William D.; Ramirez, Abelardo L.; Newmark, Robin L.; Udell, Kent; Buetnner, Harley M.; Aines, Roger D.

    1995-01-01

    A dynamic underground stripping process removes localized underground volatile organic compounds from heterogeneous soils and rock in a relatively short time. This method uses steam injection and electrical resistance heating to heat the contaminated underground area to increase the vapor pressure of the contaminants, thus speeding the process of contaminant removal and making the removal more complete. The injected steam passes through the more permeable sediments, distilling the organic contaminants, which are pumped to the surface. Large electrical currents are also applied to the contaminated area, which heat the impermeable subsurface layers that the steam has not penetrated. The condensed and vaporized contaminants are withdrawn by liquid pumping and vacuum extraction. The steam injection and electrical heating steps are repeated as necessary. Geophysical imaging methods can be used to map the boundary between the hot, dry, contamination-free underground zone and the cool, damp surrounding areas to help monitor the dynamic stripping process.

  16. Soil temperature distribution around a U-tube heat exchanger in a multi-function ground source heat pump system

    International Nuclear Information System (INIS)

    Li Shuhong; Yang Weihua; Zhang Xiaosong

    2009-01-01

    The imbalance of heat extracted from the earth by the underground heat exchangers in winter and ejected into it in summer is expected to affect the long term performance of conventional ground source heat pump (GSHP) in territories with a cold winter and a warm summer such as the middle and downstream areas of the Yangtze River in China. This paper presents a new multi-function ground source heat pump (MFGSHP) system which supplies hot water as well as space cooling/heating to mitigate the soil imbalance of the extracted and ejected heat by a ground source heat pump system. The heat transfer characteristic is studied and the soil temperature around the underground heat exchangers are simulated under a typical climatic condition of the Yangtze River. A three-dimensional model was constructed with the commercial computational fluid dynamics software FLUENT based on the inner heat source theory. Temperature distribution and variation trend of a tube cluster of the underground heat exchanger are simulated for the long term performance. The results show that the soil temperature around the underground tube keeps increasing due to the surplus heat ejected into the earth in summer, which deteriorates the system performance and may lead to the eventual system deterioration. The simulation shows that MFGSHP can effectively alleviate the temperature rise by balancing the heat ejected to/extracted from underground by the conventional ground source heat pump system. The new system also improves the energy efficiency.

  17. Assessment of professional risk caused by heating microclimate in the process of un-derground mining

    OpenAIRE

    М. Л. Рудаков; И. С. Степанов

    2017-01-01

    The paper reviews the possibility to apply probit-function to assess professional risks of underground mining under conditions of heating microclimate. Operations under conditions of heating microclimate, whose parameters exceed threshold criteria, can lead to dehydration, fainting and heat stroke for mine workers. Basing on the results of medico-biological research on the effects of microclimate on human body, the authors have assessed probabilistic nature of excessive heat accumulation depe...

  18. Survey on depth distribution of underground structures for consideration of human intrusion into TRU waste repository

    International Nuclear Information System (INIS)

    Sakamoto, Yoshiaki; Senoo, Muneaki; Sugimoto, Junichiro; Ohishi, Kiyotaka; Okishio, Masanori; Shimizu, Haruo.

    1996-01-01

    Depth distributions of some kinds of underground structure in Japan have been investigated to get an information about suitable depth of underground repository for TRU waste that is arising from reprocessing and MOX fuel fabrication plants. The underground structures investigated in this work were foundation pile of multistoried building, that of elevated expressway, that of JR shinkansen railway, tunnel of subway and wells. The major depth distribution of the underground structures except for the wells was in range from 30 to 50m, and their maximum depth was less than 100m. On the other hand, the 99% of wells was less than 300m in depth. Maximum depth of the other underground structures has been also investigated for a survey of the utilization of underground by artificial structures in Japan. (author)

  19. Heat pipe cooling system for underground, radioactive waste storage tanks

    International Nuclear Information System (INIS)

    Cooper, K.C.; Prenger, F.C.

    1980-02-01

    An array of 37 heat pipes inserted through the central hole at the top of a radioactive waste storage tank will remove 100,000 Btu/h with a heat sink of 70 0 F atmospheric air. Heat transfer inside the tank to the heat pipe is by natural convection. Heat rejection to outside air utilizes a blower to force air past the heat pipe condenser. The heat pipe evaporator section is axially finned, and is constructed of stainless steel. The working fluid is ammonia. The finned pipes are individually shrouded and extend 35 ft down into the tank air space. The hot tank air enters the shroud at the top of the tank and flows downward as it is cooled, with the resulting increased density furnishing the pressure difference for circulation. The cooled air discharges at the center of the tank above the sludge surface, flows radially outward, and picks up heat from the radioactive sludge. At the tank wall the heated air rises and then flows inward to comple the cycle

  20. Investigation on thermal environment improvement by waste heat recovery in the underground station in Qingdao metro

    Science.gov (United States)

    Liu, Jianwei; Liu, Jiaquan; Wang, Fengyin; Wang, Cuiping

    2018-03-01

    The thermal environment parameters, like the temperature and air velocity, are measured to investigate the heat comfort status of metro staff working area in winter in Qingdao. The temperature is affected obviously by the piston wind from the train and waiting hall in the lower Hall, and the temperature is not satisfied with the least heat comfort temperature of 16 °C. At the same time, the heat produced by the electrical and control equipments is brought by the cooling air to atmosphere for the equipment safety. Utilizing the water-circulating heat pump, it is feasible to transfer the emission heat to the staff working area to improve the thermal environment. Analyzed the feasibility from the technique and economy when using the heat pump, the water-circulating heat pump could be the best way to realize the waste heat recovery and to help the heat comfort of staff working area in winter in the underground metro station in north China.

  1. Detection of underground water distribution piping system and leakages using ground penetrating radar (GPR)

    Science.gov (United States)

    Amran, Tengku Sarah Tengku; Ismail, Mohamad Pauzi; Ahmad, Mohamad Ridzuan; Amin, Mohamad Syafiq Mohd; Sani, Suhairy; Masenwat, Noor Azreen; Ismail, Mohd Azmi; Hamid, Shu-Hazri Abdul

    2017-01-01

    A water pipe is any pipe or tubes designed to transport and deliver water or treated drinking with appropriate quality, quantity and pressure to consumers. The varieties include large diameter main pipes, which supply entire towns, smaller branch lines that supply a street or group of buildings or small diameter pipes located within individual buildings. This distribution system (underground) is used to describe collectively the facilities used to supply water from its source to the point of usage. Therefore, a leaking in the underground water distribution piping system increases the likelihood of safe water leaving the source or treatment facility becoming contaminated before reaching the consumer. Most importantly, leaking can result in wastage of water which is precious natural resources. Furthermore, they create substantial damage to the transportation system and structure within urban and suburban environments. This paper presents a study on the possibility of using ground penetrating radar (GPR) with frequency of 1GHz to detect pipes and leakages in underground water distribution piping system. Series of laboratory experiment was designed to investigate the capability and efficiency of GPR in detecting underground pipes (metal and PVC) and water leakages. The data was divided into two parts: 1. detecting/locating underground water pipe, 2. detecting leakage of underground water pipe. Despite its simplicity, the attained data is proved to generate a satisfactory result indicating GPR is capable and efficient, in which it is able to detect the underground pipe and presence of leak of the underground pipe.

  2. Deep underground reactor (passive heat removal of LWR with hard neutron energy spectrum)

    Energy Technology Data Exchange (ETDEWEB)

    Hiroshi, Takahashi [Brookhaven National Lab., Upton, NY (United States)

    2001-07-01

    To run a high conversion reactor with Pu-Th fueled tight fueled assembly which has a long burn-up of a fuel, the reactor should be sited deep underground. By putting the reactor deep underground heat can be removed passively not only during a steady-state run and also in an emergency case of loss of coolant and loss of on-site power; hence the safety of the reactor can be much improved. Also, the evacuation area around the reactor can be minimized, and the reactor placed near the consumer area. This approach reduces the cost of generating electricity by eliminating the container building and shortening transmission lines. (author)

  3. Deep underground reactor (passive heat removal of LWR with hard neutron energy spectrum)

    International Nuclear Information System (INIS)

    Hiroshi, Takahashi

    2001-01-01

    To run a high conversion reactor with Pu-Th fueled tight fueled assembly which has a long burn-up of a fuel, the reactor should be sited deep underground. By putting the reactor deep underground heat can be removed passively not only during a steady-state run and also in an emergency case of loss of coolant and loss of on-site power; hence the safety of the reactor can be much improved. Also, the evacuation area around the reactor can be minimized, and the reactor placed near the consumer area. This approach reduces the cost of generating electricity by eliminating the container building and shortening transmission lines. (author)

  4. Ziar nad Hronom will be heated by an underground heat plant

    International Nuclear Information System (INIS)

    Stiegel, J.

    1999-01-01

    The World Bank and the European Bank for Reconstruction and Development are concerned in co-participation in funding a project for utilising geothermal ground water in heating premises in Ziar nad Hronom. The project implementations costs will be running at U.S.$18 million, of which the two bank institutions would provide for a non-specified part in the form of credit. In heating residential houses, production and commercial infrastructure of Ziar nad Hronom, 72 thousand tonnes of coal are consumed annually to generate 810 TJ heat. By implementing the new project there will be over 100 TJ savings, with a new more efficient distribution hot water network and 39 reconstructed heat exchange station making for effective consumption of heat. The current heat plant will only serve as an auxiliary source under extremely chilly weather conditions with an expected coal consumption of at most 9 thousand tonnes. In addition to cost implications, the geothermal water heating will make a significant contribution through environmental impact. Ecologists calculated that by shutting down the solid fuel burning heat plant the air burden will be reduced by 59 thousand tonnes of carbon dioxide, 290 tonnes of sulfur dioxide, 48 tonnes of nitrogen oxide, 230 tonnes of dust and nearly 12 tonnes of ash. The implementer of the project scheduled to complete in 2001 is a subsidiary of the joint-stock company Zavod SNP - Geothermal, Ltd, Ziar nad Hronom. Aimed at geothermal water sampling in the depth of some 2,500 meters, a trial drill at Ziarska kotlina - site Varticka will last roughly till April 9 1999. The drilling set of Nafta Gbely erected on December 21, 1998 is technically capable of reaching the depth 2,800 meter, just in case that the geothermal water level is lower than the expected 2,500 m. In all In all Nafta Gbely staffs will carry out two production and two reinjection drills. (author)

  5. Current status of ground source heat pumps and underground thermal energy storage in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Sanner, B. [Justus Liebig University, Giessen (Germany). Institute of Applied Geosciences; Karytsas, C.; Mendrinos, D. [Center for Renewable Energy Sources, Pikermi (Greece); Rybach, L. [Geowatt AG, Zurich (Switzerland)

    2003-12-01

    Geothermal Heat Pumps, or Ground Coupled Heat Pumps (GCHP), are systems combining a heat pump with a ground heat exchanger (closed loop systems), or fed by ground water from a well (open loop systems). They use the earth as a heat source when operating in heating mode, with a fluid (usually water or a water-antifreeze mixture) as the medium that transfers the heat from the earth to the evaporator of the heat pump, thus utilising geothermal energy. In cooling mode, they use the earth as a heat sink. With Borehole Heat Exchangers (BHE), geothermal heat pumps can offer both heating and cooling at virtually any location, with great flexibility to meet any demands. More than 20 years of R and D focusing on BUE in Europe has resulted in a well-established concept of sustainability for this technology, as well as sound design and installation criteria. Recent developments are the Thermal Response Test, which allows in-situ-determination of ground thermal properties for design purposes, and thermally enhanced grouting materials to reduce borehole thermal resistance. For cooling purposes, but also for the storage of solar or waste heat, the concept of underground thermal energy storage (UTES) could prove successful. Systems can be either open (aquifer storage) or can use BHE (borehole storage). Whereas cold storage is already established on the market, heat storage, and, in particular, high temperature heat storage (> 50{sup o}C) is still in the demonstration phase. Despite the fact that geothermal heat pumps have been in use for over 50 years now (the first were in the USA), market penetration of this technology is still in its infancy, with fossil fuels dominating the space heating market and air-to-air heat pumps that of space cooling. In Germany, Switzerland, Austria, Sweden, Denmark, Norway, France and the USA, large numbers of geothermal heat pumps are already operational, and installation guidelines, quality control and contractor certification are now major issues

  6. Challenges in Selecting an Appropriate Heat Stress Index to Protect Workers in Hot and Humid Underground Mines

    Directory of Open Access Journals (Sweden)

    Pedram Roghanchi

    2018-03-01

    Full Text Available Background: A detailed evaluation of the underground mine climate requires extensive measurements to be performed coupled to climatic modeling work. This can be labor-intensive and time-consuming, and consequently impractical for daily work comfort assessments. Therefore, a simple indicator like a heat stress index is needed to enable a quick, valid, and acceptable evaluation of underground climatic conditions on a regular basis. This can be explained by the unending quest to develop a “universal index,” which has led to the proliferation of many proposed heat stress indices. Methods: The aim of this research study is to discuss the challenges in identifying and selecting an appropriate heat stress index for thermal planning and management purposes in underground mines. A method is proposed coupled to a defined strategy for selecting and recommending heat stress indices to be used in underground metal mines in the United States and worldwide based on a thermal comfort model. Results: The performance of current heat stress indices used in underground mines varies based on the climatic conditions and the level of activities. Therefore, carefully selecting or establishing an appropriate heat stress index is of paramount importance to ensure the safety, health, and increasing productivity of the underground workers. Conclusion: This method presents an important tool to assess and select the most appropriate index for certain climatic conditions to protect the underground workers from heat-related illnesses. Although complex, the method presents results that are easy to interpret and understand than any of the currently available evaluation methods. Keywords: climatic conditions, heat stress index, thermal comfort, underground mining

  7. The destabilizing influence of heat flow on the geological environment during underground nuclear explosions

    International Nuclear Information System (INIS)

    Politikov, M.I.; Kamberov, I.M.; Krivchenko, V.F.; Lukashenko, S.N.; Solodukhin, V.P.

    2001-01-01

    The study has determined the fact that the processes of gas-radioactive ectoplasm intrusion from nuclear cavities in the geological environment bring the significant contribution in bosom destabilizing besides the mechanical rock destruction as affected by underground nuclear explosions. Not only heat field forming that reduces the rock resistance and increases its porosity is related to it, but also the forming, on the way, of man-caused contamination aureoles of the geological environment, including the underground water bearing horizon. Unfortunately, this problem is hardly studied, mainly for the lack of reliable apparatus and methods. Judging by the results of information search, the best way to solve the problem is not yet known. (author)

  8. An underground nuclear power station using self-regulating heat-pipe controlled reactors

    Science.gov (United States)

    Hampel, V.E.

    1988-05-17

    A nuclear reactor for generating electricity is disposed underground at the bottom of a vertical hole that can be drilled using conventional drilling technology. The primary coolant of the reactor core is the working fluid in a plurality of thermodynamically coupled heat pipes emplaced in the hole between the heat source at the bottom of the hole and heat exchange means near the surface of the earth. Additionally, the primary coolant (consisting of the working fluid in the heat pipes in the reactor core) moderates neutrons and regulates their reactivity, thus keeping the power of the reactor substantially constant. At the end of its useful life, the reactor core may be abandoned in place. Isolation from the atmosphere in case of accident or for abandonment is provided by the operation of explosive closures and mechanical valves emplaced along the hole. This invention combines technology developed and tested for small, highly efficient, space-based nuclear electric power plants with the technology of fast- acting closure mechanisms developed and used for underground testing of nuclear weapons. This invention provides a nuclear power installation which is safe from the worst conceivable reactor accident, namely, the explosion of a nuclear weapon near the ground surface of a nuclear power reactor. 5 figs.

  9. Underground nuclear power station using self-regulating heat-pipe controlled reactors

    Science.gov (United States)

    Hampel, Viktor E.

    1989-01-01

    A nuclear reactor for generating electricity is disposed underground at the bottom of a vertical hole that can be drilled using conventional drilling technology. The primary coolant of the reactor core is the working fluid in a plurality of thermodynamically coupled heat pipes emplaced in the hole between the heat source at the bottom of the hole and heat exchange means near the surface of the earth. Additionally, the primary coolant (consisting of the working flud in the heat pipes in the reactor core) moderates neutrons and regulates their reactivity, thus keeping the power of the reactor substantially constant. At the end of its useful life, the reactor core may be abandoned in place. Isolation from the atmosphere in case of accident or for abandonment is provided by the operation of explosive closures and mechanical valves emplaced along the hole. This invention combines technology developed and tested for small, highly efficient, space-based nuclear electric power plants with the technology of fast-acting closure mechanisms developed and used for underground testing of nuclear weapons. This invention provides a nuclear power installation which is safe from the worst conceivable reactor accident, namely, the explosion of a nuclear weapon near the ground surface of a nuclear power reactor.

  10. Underground nuclear power station using self-regulating heat-pipe controlled reactors

    International Nuclear Information System (INIS)

    Hampel, V.E.

    1989-01-01

    The author presents a nuclear reactor for generating electricity disposed underground at the bottom of a vertical hole that can be drilled using conventional drilling technology. The primary coolant of the reactor core is the working fluid in a plurality of thermodynamically coupled heat pipes emplaced in the hole between the heat source at the bottom of the hole and heat exchange means near the surface of the earth. Additionally, the primary coolant (consisting of the working fluid in the heat pipes in the reactor core) moderates neutrons and regulates their reactivity, thus keeping the power of the reactor substantially constant. At the end of its useful life, the reactor core may be abandoned in place. Isolation from the atmosphere in case of accident or for abandonment is provided by the operation of explosive closures and mechanical valves emplaced along the hole. This invention combines technology developed and tested for small, highly efficient, space-based nuclear electric power plants with the technology of fast-acting closure mechanisms developed and used for underground testing of nuclear weapons. This invention provides a nuclear power installation which is safe from the worst conceivable reactor accident, namely, the explosion of a nuclear weapon near the ground surface of a nuclear power reactor

  11. Distribution of phthalate esters in underground water from power ...

    African Journals Online (AJOL)

    This study investigates the distribution of phthalateacid esters (PAEs) in groundwater from some power stations in Delta State. Groundwater samples were collected from eight power transmission and distribution stations. Concentrations (μg/L) of six phthalate acid esters compounds in the groundwater ranged from ...

  12. Underground Water Distribution System, Fort Belvoir, Virginia. Leak Detection Survey

    National Research Council Canada - National Science Library

    1995-01-01

    .... The survey was conducted by myself, Donald Muir, Operations Coordinator, and required 12.25 working days. This was not a survey of the entire water distribution system but instead a survey of water mains 8 inch and larger...

  13. Probability distribution of pitting corrosion depth and rate in underground pipelines: A Monte Carlo study

    International Nuclear Information System (INIS)

    Caleyo, F.; Velazquez, J.C.; Valor, A.; Hallen, J.M.

    2009-01-01

    The probability distributions of external-corrosion pit depth and pit growth rate were investigated in underground pipelines using Monte Carlo simulations. The study combines a predictive pit growth model developed by the authors with the observed distributions of the model variables in a range of soils. Depending on the pipeline age, any of the three maximal extreme value distributions, i.e. Weibull, Frechet or Gumbel, can arise as the best fit to the pitting depth and rate data. The Frechet distribution best fits the corrosion data for long exposure periods. This can be explained by considering the long-term stabilization of the diffusion-controlled pit growth. The findings of the study provide reliability analysts with accurate information regarding the stochastic characteristics of the pitting damage in underground pipelines.

  14. Probability distribution of pitting corrosion depth and rate in underground pipelines: A Monte Carlo study

    Energy Technology Data Exchange (ETDEWEB)

    Caleyo, F. [Departamento de Ingenieria Metalurgica, ESIQIE, IPN, UPALM Edif. 7, Zacatenco, 07738 Mexico, D.F. (Mexico)], E-mail: fcaleyo@gmail.com; Velazquez, J.C. [Departamento de Ingenieria Metalurgica, ESIQIE, IPN, UPALM Edif. 7, Zacatenco, 07738 Mexico, D.F. (Mexico); Valor, A. [Facultad de Fisica, Universidad de La Habana, San Lazaro y L, Vedado, 10400, La Habana (Cuba); Hallen, J.M. [Departamento de Ingenieria Metalurgica, ESIQIE, IPN, UPALM Edif. 7, Zacatenco, 07738 Mexico, D.F. (Mexico)

    2009-09-15

    The probability distributions of external-corrosion pit depth and pit growth rate were investigated in underground pipelines using Monte Carlo simulations. The study combines a predictive pit growth model developed by the authors with the observed distributions of the model variables in a range of soils. Depending on the pipeline age, any of the three maximal extreme value distributions, i.e. Weibull, Frechet or Gumbel, can arise as the best fit to the pitting depth and rate data. The Frechet distribution best fits the corrosion data for long exposure periods. This can be explained by considering the long-term stabilization of the diffusion-controlled pit growth. The findings of the study provide reliability analysts with accurate information regarding the stochastic characteristics of the pitting damage in underground pipelines.

  15. Auxiliary Heat Exchanger Flow Distribution Test

    International Nuclear Information System (INIS)

    Kaufman, J.S.; Bressler, M.M.

    1983-01-01

    The Auxiliary Heat Exchanger Flow Distribution Test was the first part of a test program to develop a water-cooled (tube-side), compact heat exchanger for removing heat from the circulating gas in a high-temperature gas-cooled reactor (HTGR). Measurements of velocity and pressure were made with various shell side inlet and outlet configurations. A flow configuration was developed which provides acceptable velocity distribution throughout the heat exchanger without adding excessive pressure drop

  16. Underground seasonal storage of industrial waste heat; Saisonale Speicherung industrieller Abwaerme im Untergrund

    Energy Technology Data Exchange (ETDEWEB)

    Reuss, M.; Mueller, J. [Bayerische Landesanstalt fuer Landtechnik, TU Muenchen-Weihenstephan, Freising (Germany)

    1998-12-31

    The thermal efficiency of subject systems, especially at higher temperatures is influenced by heat and humidity transport underground. Thermal conductivity and specific thermal capacity depend on the humidity content of the soil. A simulation model was developed that describes the coupled heat and humidity transport in the temperature range up to 90 C. This model will be validated in laboratory and field tests and then be used for designing and analysing underground stores. Pilot plants for the storage of industrial waste heat were designed and planned on the basis of this simulation. In both cases these are cogeneration plants whose waste heat was to be used for space heating and as process energy. Both plants have a very high demand of electric energy which is mostly supplied by the cogeneration plant. The waste heat is put into the store during the summer. In the winter heat is supplied by both the store and the cogeneration plant. In both cases the store has a volume of approx. 15,000 cubic metres with 140 and 210 pits located in a depth of 30 and 40 metres. The plants are used to carry out extensive measurements for the validation of simulation models. (orig.) [Deutsch] Die thermische Leistungsfaehigkeit solcher Systeme wird insbesondere im hoeheren Temperaturbereich durch den Waerme- und Feuchtetransport im Untergrund beeinflusst. Sowohl die Waermeleitfaehigkeit als auch die spezifische Waermekapazitaet sind vom Feuchtegehalt des Bodens abhaengig. Es wurde ein Simulationsmodell entwickelt, das den gekoppelten Waerme- und Feuchtetransport im Temperaturbereich bis 90 C beschreibt. Dieses Modell wird an Labor- und Feldexperimenten validiert und dient dann zur Auslegung und Analyse von Erdwaermesonden-Speichern. Basierend auf diesen theoretischen Grundlagenarbeiten wurden Pilotanlagen zur saisonalen Speicherung industrieller Abwaerme ausgelegt und geplant. In beiden Faellen handelt es sich um Kraft/Waermekopplungsanlagen, deren Abwaerme zur Gebaeudeheizung und

  17. Study on the overcurrent character analysis and its protective system of underground LV distribution networks

    Energy Technology Data Exchange (ETDEWEB)

    Song, J.; Shi, Z.; Yang, Y.; Shi, W.; Wei, H.; Zhai, S.; Xie, H. [Taiyuan University of Technology, Taiyuan (China)

    2001-02-01

    The overcurrent fault characteristics in underground LV cable distribution networks is analysed and the fundamental principle of overcurrent protective system is described in this paper. The emphasis is paid to the determination of the characteristic curves of phase-sensitive symmetrical short-circuit protection, the design of negative-sequence current filter and the definition of the mathematical model of overload. Besides, the hardware block diagram and the software flowchart of the protective system, which is controlled by a single chip microcomputer, is also introduced in the paper. The protective system was tested before being applied to the underground LV distribution networks. The results obtained are in conformity with the design specification. It has been verified that the protective distance is extended and the protective sensitivity is improved with the protective system. The field experience has shown that the protective system is stable and reliable, and will be of great application value in the mining industry. 7 refs., 5 figs., 2 tabs.

  18. Regional waste treatment facilities with underground monolith disposal for all low-heat-generating nuclear wastes

    International Nuclear Information System (INIS)

    Forsberg, C.W.

    1982-01-01

    An alternative system for treatment and disposal of all ''low-heat-generating'' nuclear wastes from all sources is proposed. The system, Regional Waste Treatment Facilities with Underground Monolith Disposal (RWTF/UMD), integrates waste treatment and disposal operations into single facilities at regional sites. Untreated and/or pretreated wastes are transported from generation sites such as reactors, hospitals, and industries to regional facilities in bulk containers. Liquid wastes are also transported in bulk after being gelled for transport. The untreated and pretreated wastes are processed by incineration, crushing, and other processes at the RWTF. The processed wastes are mixed with cement. The wet concrete mixture is poured into large low-cost, manmade caverns or deep trenches. Monolith dimensions are from 15 to 25 m wide, and 20 to 60 m high and as long as required. This alternative waste system may provide higher safety margins in waste disposal at lower costs

  19. Heat storage in underground caverns - measurements and simulations; Speicherung von Waerme in Grubenraeumen - Messung und Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Schaberg, A; Krause, H; Poetke, W [TU Bergakademie Freiberg (Germany). Inst. fuer Waermetechnik und Technische Thermodynamik

    1997-12-01

    Among the different discussed underground concepts for longterm storing of solar or waste heat old waterfilled mines can be an interesting solution. To examine the temperature behaviour of this storage type a testing store is built in a mine belonging to the Freiberg University of Mining and Technology in Saxonia. In a longterm project temperatures are measured inside the water volume and in the adjacent rock. The temperature behaviour depends on the operating conditions. Inside the water volume temperature stratification can be observed. During loading and standstill heat is transported into the rock surrounding. A certain part of this amount of heat can be discharged again. For designing and optimizing this storage type a numerical modell is developed. The modell is validated with experimental data from the testing plant. (orig.) [Deutsch] Unter den verschiedenen, in der Diskussion stehenden Untegrund-Waermespeichern fuer Solarwaerme oder Abwaerme bieten sich auch geflutete Gruben als Waermespeicher an. Zur Untersuchung des Temperaturverhaltens dieses Speichertyps ist im Saechsischen Lehr- und Besucherbergwerk der TU Bergakademie Freiberg ein Versuchsspeicher errichtet worden. In einem Langzeitversuch wird das Temperaturfeld im Wasser und im angrenzenden Gestein aufgezeichnet. Das Temperaturverhalten ist von den Betriebsgroessen abhaengig. Im Grubenwasser stellt sich eine stabile Temperaturschichtung ein. Waehrend der Beladung und der Stillstandszeiten wird Waerme in die Gesteinsumgebung transportiert. Ein Teil dieser Waermemenge kann wider entspeichert werden. Zur Auslegung und Optimierung von Gruben-Waermespeichern ist ein numerisches Modell entwickelt worden. Das Modell ist anhand der Messergebnisse des Versuchsspeichers validiert worden. (orig.)

  20. Quality frontier of electricity distribution: Supply security, best practices, and underground cabling in Finland

    International Nuclear Information System (INIS)

    Saastamoinen, Antti; Kuosmanen, Timo

    2016-01-01

    Electricity distribution is a prime example of local monopoly. In most countries, the costs of electricity distribution operators are regulated by the government. However, the cost regulation may create adverse incentives to compromise the quality of service. To avoid this, cost regulation is often amended with quality incentives. This study applies theory and methods of productivity analysis to model the frontier of service quality. A semi-nonparametric estimation method is developed, which does not assume any particular functional form for the quality frontier, but can accommodate stochastic noise and heteroscedasticity. The empirical part of our paper examines how underground cabling and location affect the interruption costs. As expected, higher proportion of underground cabling decreases the level of interruption costs. The effects of cabling and location on the variance of performance are also considered. Especially the location is found to be a significant source of heteroscedasticity in the interruption costs. Finally, the proposed quality frontier benchmark is compared to the current practice of Finnish regulation system. The proposed quality frontier is found to provide more meaningful and stable basis for setting quality targets than the average practice benchmarks currently in use. - Highlights: • Cost regulation may create adverse incentives to lower the service quality. • We model the frontier of service quality using a semi-nonparametric approach. • Our nonparametric frontier accounts for stochastic noise and heteroscedasticity. • We estimate how underground cabling and location affect interruption costs. • We compare our quality frontier with the current quality regulation in Finland.

  1. Prediction accident triangle in maintenance of underground mine facilities using Poisson distribution analysis

    Science.gov (United States)

    Khuluqi, M. H.; Prapdito, R. R.; Sambodo, F. P.

    2018-04-01

    In Indonesia, mining is categorized as a hazardous industry. In recent years, a dramatic increase of mining equipment and technological complexities had resulted in higher maintenance expectations that accompanied by the changes in the working conditions, especially on safety. Ensuring safety during the process of conducting maintenance works in underground mine is important as an integral part of accident prevention programs. Accident triangle has provided a support to safety practitioner to draw a road map in preventing accidents. Poisson distribution is appropriate for the analysis of accidents at a specific site in a given time period. Based on the analysis of accident statistics in the underground mine maintenance of PT. Freeport Indonesia from 2011 through 2016, it is found that 12 minor accidents for 1 major accident and 66 equipment damages for 1 major accident as a new value of accident triangle. The result can be used for the future need for improving the accident prevention programs.

  2. The lateral distribution of muons in showers at 40 mwe underground

    International Nuclear Information System (INIS)

    Bergamasco, L.; Castagnoli, C.; Dardo, M.; D'Ettorre Piazzoli, B.; Mannocchi, G.; Picchi, P.; Visentin, R.; Sitte, K.; Freiburg Univ.

    1975-01-01

    The multiplicity distribution of muon showers at 40 mwe underground was studied with a 4 m 2 spark chamber telescope. The observed frequencies deviate systematically from those calculated with the 'standard' lateral distributions of Vernov or of Greisen. Agreement can be attained if an enhancement of the muon component at small shower sizes is assumed, in accordance with the assumptions of a two-component theory of cosmic ray origin. It is improved by introducing an age dependence of the lateral structure function. (orig.) [de

  3. Advice on Sustainable Use of the Underground for Heat and Cold Storage; Advies Duurzaam Gebruik van de Bodem voor WKO

    Energy Technology Data Exchange (ETDEWEB)

    Oomes, J.

    2009-09-15

    Insights and ideas are given and discussed with regard to sustainable use of soil and underground for heat and cold storage. Also attention is paid to the marginal conditions for the application of heat and cold storage [Dutch] Inzichten en ideeen worden gegeven en besproken over duurzaam gebruik van de bodem voor warmte- koudeopslag (WKO). Daarnaast worden ook de randvoorwaarden van WKO in kaart gebracht.

  4. A heating experiment in the argillites in the Meuse/Haute-Marne underground research laboratory

    International Nuclear Information System (INIS)

    Wileveau, Yannick; Su, Kun; Ghoreychi, Mehdi

    2007-01-01

    A heating experiment named TER is being conducted with the objectives to identify the thermal properties, as well as to enhance the knowledge on THM processes in the Callovo-Oxfordian clay at the Meuse/Haute Marne Underground Research Laboratory (France). The in situ experiment has being switched on from early 2006. The heater, 3 m length, is designed to inject the power in the undisturbed zone at 6 m from the gallery wall. A heater packer is inflated in a metallic tubing. During the experiment, numerous sensors are emplaced in the surrounding rock and are experienced to monitor the evolution in temperature, pore-water pressure and deformation. The models and numerical codes applied should be validated by comparing the modeling results with the measurements. In parallel, some lab testing have been achieved in order to compare the results given with two different scales (cm up to meter scale). In this paper, we present a general description of the TER experiment with installation of the heater equipment and the surrounding instrumentation. Details of the in situ measurements of temperature, pore-pressure and strain evolutions are given for the several heating and cooling phases. The thermal conductivity and some predominant parameters in THM processes (as linear thermal expansion coefficient and permeability) will be discussed. (authors)

  5. Radon Progeny In Underground Phosphate Mines and Their Activity Distributions In Human Lung

    International Nuclear Information System (INIS)

    Abd El-Hady, M.; Mohammed, A.; El-Hussein, A.; Ali, A.E.; Ahmed, A.A.

    2001-01-01

    In addition to workers in uranium mines, the staff of other underground mines, such as worker in underground phosphate mines, Can be exposed to 222 Rn and its progeny. In this study the individual radon progeny concentrations were measured in three Egyptian underground phosphate mines to estimate the occupational exposure to the workers in those sites. Active techniques are employed to fulfill the objective of measuring individual radon progeny concentrations (C RaA , C RaB and C RaC ). The mean reported values of radon progeny concentrations exceed the action levels recommended by ICRP 65 (1993). Based on the physical properties of attached radon progeny aerosol and physiological parameters for heavy work activity which recommended by ICRP 66 (1994). the deposition fraction for each airway generation was calculated. From the measured individual radon progeny concentrations in these mines and the calculated values of deposition fractions, the surface activity distribution per generation were calculated in human respiratory system (BB and regions). The maximum values of these activities were found in the upper bronchial airway generations. According to the obtained results, some of the corrective actions were recommended in this study

  6. Numerical Investigation of the Thermal Regime of Underground Channel Heat Pipelines Under Flooding Conditions with the Use of a Conductive-Convective Heat Transfer Model

    Science.gov (United States)

    Polovnikov, V. Yu.

    2018-05-01

    This paper presents the results of numerical analysis of thermal regimes and heat losses of underground channel heating systems under flooding conditions with the use of a convective-conductive heat transfer model with the example of the configuration of the heat pipeline widely used in the Russian Federation — a nonpassage ferroconcrete channel (crawlway) and pipelines insulated with mineral wool and a protective covering layer. It has been shown that convective motion of water in the channel cavity of the heat pipeline under flooding conditions has no marked effect on the intensification of heat losses. It has been established that for the case under consideration, heat losses of the heat pipeline under flooding conditions increase from 0.75 to 52.39% due to the sharp increase in the effective thermal characteristics of the covering layer and the heat insulator caused by their moistening.

  7. A New Contribution in Reducing Electric Field Distribution Within/Around Medium Voltage Underground Cable Terminations

    Directory of Open Access Journals (Sweden)

    S. S. Desouky

    2017-10-01

    Full Text Available Ιn medium voltage cables, the stress control layers play an important part in controlling the electric field distribution around the medium voltage underground cable terminations. Underground cable accessories, used in medium voltage cable systems, need a stress control tube in order to maintain and control the insulation level which is designed for long life times. The term “electrical stress control” refers to the cable termination analysis of optimizing the electrical stress in the area of insulation shield cutback to reduce the electrical field concentration at this point in order to reduce breakdown in the cable insulation. This paper presents the effect of some materials of different relative permittivities and geometrical regulation with the curved shape stress relief cones on the electric field distribution of cable termination. The optimization was done by comparing the results of eight materials used. Also, the effect of the change in the thickness of the stress control tube is presented. The modeling design is very important for engineers to find the optimal solution of terminator design of medium voltage cables. This paper also describes the evolution of stress control systems and their benefits. A developed program using Finite Element Method (FEM has calculated a numerical study to the stress control layering electric field distribution.

  8. Electron distribution function in laser heated plasmas

    International Nuclear Information System (INIS)

    Fourkal, E.; Bychenkov, V. Yu.; Rozmus, W.; Sydora, R.; Kirkby, C.; Capjack, C. E.; Glenzer, S. H.; Baldis, H. A.

    2001-01-01

    A new electron distribution function has been found in laser heated homogeneous plasmas by an analytical solution to the kinetic equation and by particle simulations. The basic kinetic model describes inverse bremsstrahlung absorption and electron--electron collisions. The non-Maxwellian distribution function is comprised of a super-Gaussian bulk of slow electrons and a Maxwellian tail of energetic particles. The tails are heated due to electron--electron collisions and energy redistribution between superthermal particles and light absorbing slow electrons from the bulk of the distribution function. A practical fit is proposed to the new electron distribution function. Changes to the linear Landau damping of electron plasma waves are discussed. The first evidence for the existence of non-Maxwellian distribution functions has been found in the interpretation, which includes the new distribution function, of the Thomson scattering spectra in gold plasmas [Glenzer , Phys. Rev. Lett. 82, 97 (1999)

  9. Underground measurements of aerosol in radon and thoron progeny activity distributions

    International Nuclear Information System (INIS)

    Khan, A.; Bandi, F.; Phillips, C.R.; Duport, P.

    1990-01-01

    Aerosol and activity distributions of 218 Polonium, 214 Lead, 214 Bismuth, and 212 Lead were determined in two different underground mining environments by means of an optimized time-delay counting scheme and diffusion batteries. In one environment, diesel equipment was operating; and in the other, electrically powered equipment. The two environments differed significantly in total aerosol concentration. In the diesel environment, in particular, aerosol concentrations were unsteady, and fluctuated with vehicular traffic and mining activities. As measured by radon progeny disequilibrium, the age of the air ranged from about 25 to 60 minutes. Thoron working levels were of the same order as radon working levels. In this paper, comparisons are made between the aerosol and activity size distributions in both the diesel and electric mine

  10. Spatial and temporal distribution of mosquitoes in underground storm drain systems in Orange County, California.

    Science.gov (United States)

    Su, Tianyun; Webb, James P; Meyer, Richard P; Mulla, Mir S

    2003-06-01

    Underground storm drain systems in urban areas of Orange County include thousands of miles of gutters and underground pipelines, plus hundreds of thousands of catch basins and manhole chambers, all of which drain runoff water from residential, business and commercial establishments as well as highways and streets. These systems serve as major developmental and resting sites for anthropophilic and zoophilic mosquitoes. Investigations on spatial and temporal distribution of mosquitoes in these systems were conducted during November 1999 to October 2001. Immature mosquitoes were sampled by dipper or dipping net and adult mosquitoes by non-attractive CDC traps in manhole chambers, catch basins and a large drain. Culex quinquefasciatus Say prevailed at all 15 structures of the study in 4 cities of Orange County as the predominant species (> 99.9%). Larvae and pupae were present from April to October, peaking from May to September. The population density of adults was the lowest in February with 2 peaks of abundance occurring from May to July and from September to October. Manhole chambers and catch basins harbored more mosquitoes than did the large drain. Minimum and maximum temperatures during a 24 h sampling period was an important factor influencing adult mosquito activity and catches; more mosquitoes were caught in traps when it was warmer, especially when the minimum temperatures were higher. The proportion of females to males in general increased during winter and early spring an ddeclined during summer. The proportion of gravid females to empty females was higher during the winter than in summer. Other dipteran taxa such as psychodid moth flies and chironomid midges exhibited somewhat similar seasonal patterns as did mosquito populations. Average water temperature was relatively stable throughout the year, and water quality in underground drain systems was characterized by low dissolved oxygen, coupled with above normal electrical conductivity and salinity levels

  11. Temperature distributions of a conductively heated filament

    International Nuclear Information System (INIS)

    Tamura, Koji; Ohba, Hironori; Shibata, Takemasa

    1999-07-01

    Temperature distributions of a heated filament were measured. A W-Re(5%) filament (0.25 mm in diameter, 24.7 mm in length) was conductively heated by currents between 5A and 7A with a DC power supply, and the surface of the filament was imaged with a charge coupled device (CCD) camera through a monochromatic filter. The spectral radiation intensity at the filament center region was almost uniform. Since the temperature distribution was also uniform and the energy loss by thermal conduction was negligible, temperature in this region was determined from the energy balance between applied power and radiation loss. Temperature distribution of the filament was determined based on the Planck's law of radiation from the spectral radiation intensity ratio of the filament surface using obtained temperature as a reference. It was found that temperature distribution of a filament was easily measured by this method. (author)

  12. Identifying (subsurface) anthropogenic heat sources that influence temperature in the drinking water distribution system

    Science.gov (United States)

    Agudelo-Vera, Claudia M.; Blokker, Mirjam; de Kater, Henk; Lafort, Rob

    2017-09-01

    The water temperature in the drinking water distribution system and at customers' taps approaches the surrounding soil temperature at a depth of 1 m. Water temperature is an important determinant of water quality. In the Netherlands drinking water is distributed without additional residual disinfectant and the temperature of drinking water at customers' taps is not allowed to exceed 25 °C. In recent decades, the urban (sub)surface has been getting more occupied by various types of infrastructures, and some of these can be heat sources. Only recently have the anthropogenic sources and their influence on the underground been studied on coarse spatial scales. Little is known about the urban shallow underground heat profile on small spatial scales, of the order of 10 m × 10 m. Routine water quality samples at the tap in urban areas have shown up locations - so-called hotspots - in the city, with relatively high soil temperatures - up to 7 °C warmer - compared to the soil temperatures in the surrounding rural areas. Yet the sources and the locations of these hotspots have not been identified. It is expected that with climate change during a warm summer the soil temperature in the hotspots can be above 25 °C. The objective of this paper is to find a method to identify heat sources and urban characteristics that locally influence the soil temperature. The proposed method combines mapping of urban anthropogenic heat sources, retrospective modelling of the soil temperature, analysis of water temperature measurements at the tap, and extensive soil temperature measurements. This approach provided insight into the typical range of the variation of the urban soil temperature, and it is a first step to identifying areas with potential underground heat stress towards thermal underground management in cities.

  13. Heat transfer and temperature distribution in fuel

    International Nuclear Information System (INIS)

    Katanic-Popovic, J.; Stevanovic, M.

    1966-01-01

    This paper describes methods and procedures for determining the integral, mean and effective heat conductivity and temperature distribution in fuel, with the experimental solutions for measuring these parameters. A procedure for measuring the integral conductivity by measuring the power generated in the fuel is given [sr

  14. EXPERIMENTAL CALIBRATION OF UNDERGROUND HEAT TRANSFER MODELS UNDER A WINERY BUILDING IN A RURAL AREA

    Directory of Open Access Journals (Sweden)

    Francesco Tinti

    2017-01-01

    Full Text Available Ground temperature and hydrogeological conditions are key parameters for many engineering applications, such as the design of building basements and underground spaces and the assessment of shallow geothermal energy potential. Especially in urban areas, in the very shallow depths, it is diffi cult to fi nd natural undisturbed underground thermal conditions because of anthropic interventions. The assessment of underground behaviour in disturbed conditions will become more and more relevant because of increasing awareness to energy effi ciency and renewable energy topics. The purpose of this paper is to show a three-dimensional representation - based on models calibrated on experimental data - of the underground thermal behaviour aff ected by a building in a rural area in Italy. Temperature varies in space and time and it depends on ground, climate and building characteristics, and all these parameters are taken into account by the seasonal periodic modelling implemented. The results obtained in a context of low urbanization indirectly suggest the importance of these eff ects in dense urban areas; taking greater account of these aspects could lead to improvements in the design of underground spaces and geo-exchanger fi elds for geothermal energy exploitation.

  15. Transient variation of aerosol size distribution in an underground subway station.

    Science.gov (United States)

    Kwon, Soon-Bark; Namgung, Hyeong-Gyu; Jeong, Wootae; Park, Duckshin; Eom, Jin Ki

    2016-06-01

    As the number of people using rapid transit systems (subways) continues to rise in major cities worldwide, increasing attention has been given to the indoor air quality of underground stations. This study intended to observe the change of PM distribution by size in an underground station with PSDs installed located near the main road in downtown Seoul, as well as to examine causes for the changes. The results indicate that the PM suspended in the tunnel flowed into the platform area even in a subway station where the effect of train-induced wind is blocked by installed PSDs, as this flow occurred when the PSDs were opened. The results also indicate that coarse mode particles generated by mechanical friction in the tunnel, such as that between wheels and rail, also flowed into the platform area. The PM either settled or was re-suspended according to size and whether the ventilation in the platform area was in operation or if the platform floor had been washed. The ventilation system was more effective in removing PM of smaller sizes (fine particles) while the wash-out performed after train operations had stopped reduced the suspension of coarse mode particles the next morning. Despite installation of the completely sealed PSDs, inflow of coarse mode particles from the tunnel seems unavoidable, indicating the need for measures to decrease the PM generated there to lower subway user exposure since those particles cannot be reduced by mechanical ventilation alone. This research implicate that coarse PM containing heavy metals (generated from tunnel side) proliferated especially during rush hours, during which it is very important to control those PM in order to reduce subway user exposure to this hazardous PM.

  16. Heated electron distributions from resonant absorption

    International Nuclear Information System (INIS)

    DeGroot, J.S.; Tull, J.E.

    1975-01-01

    A simplified model of resonant absorption of obliquely incident laser light has been developed. Using a 1.5 dimensional electrostatic simulation computer code, it is shown that the inclusion of ion motion is critically important in determining the heated electron distributions from resonant absorption. The electromagnetic wave drives up an electron plasma wave. For long density scale lengths (Lapprox. =10 3 lambda/subD//sube/), the phase velocity of this wave is very large (ω/kapproximately-greater-than10V/sub th/) so that if heating does occur, a suprathermal tail of very energetic electrons is produced. However, the pressure due to this wave steepens the density profile until the density gradient scale length near the critical density (where the local plasma frequency equals the laser frequency) is of order 20lambda/subD//sube/. The electrostatic wave is thus forced to have a much lower phase velocity (ω/kapprox. =2.5V/sub th/). In this case, more electrons are heated to much lower velocities. The heated electron distributions are exponential in velocity space. Using a simple theory it is shown that this property of profile steepening applies to most of a typical laser fusion pulse. This steepening raises the threshold for parametric instabilities near the critical surface. Thus, the extensive suprathermal electron distributions typically produced by these parametric instabilities can be drastically reduced

  17. A risk measurement tool for an underground electricity distribution system considering the consequences and uncertainties of manhole events

    International Nuclear Information System (INIS)

    Garcez, Thalles Vitelli; Teixeira de Almeida, Adiel

    2014-01-01

    This paper explores a risk measure of underground vaults that considers the consequences of arc faults. The increasing use of underground systems, together with the aging of networks, the lack of maintenance and interference from other (third party) underground systems nearby have caused many accidents in urban areas, thus endangering human life. The involvement of a large number (hundreds or thousands) of underground vaults with different characteristics, the lack of historical data on modes of failure, the rarity of the occurrence of some faults, the magnitude of their consequences and the involvement of a complex environment surrounding the hazard zone make risk management even more complex and uncertain. Furthermore, given that the (monetary, time, staff, etc.) resources of an electrical power company are limited and scarce, it is necessary to use decision-making tools that aggregate the consequences and the uncertainties to assess the risks jointly with the preference structure of the company, thus solving the problem more realistically. Therefore, this paper puts forward the use of an additional risk analysis for manhole events in underground electrical distribution networks with a view to its being used as a decision aid tool in risk management. As an illustration of the use of the risk measurement tool proposed, a numerical application is presented. The result rather than showing a ranking of underground vaults, gives a measure of the risk used that can show the decision-maker (DM) how much better one group of alternatives (formed by alternatives with quite similar risk values) is than other groups, based on the DM’s attitude to risk and grounded on the axiomatic structure of utility theory. - Highlights: • The paper proposes a risk measure of underground vaults for manhole events. • It makes risk analysis in underground electrical distribution networks. • It makes more than show a risk ranking of underground vaults. • It can show to the DM how

  18. Lateral distribution of cosmic ray muons underground. Results from the CosmoALEPH experiment

    International Nuclear Information System (INIS)

    Tcaciuc, R.

    2006-01-01

    The CosmoALEPH experiment, located underground at the LEP e + e - storage ring at CERN at a depth of 320 m water equivalent, was used to study the chemical composition of primary cosmic rays up to 10 PeV energies from the measurement of high energy muons, created in extensive air showers by interactions of primary nuclei in the atmosphere. The Time Projection Chamber (TPC) and the Hadron Calorimeter of the ALEPH detector and six scintillator stations located at distances up to 1 km from each other were used to analyse the decoherence curve, multiplicity and transverse momentum distributions of energetic cosmic muons. The experimental data were compared with predictions from different Monte Carlo (MC) models and mass composition approaches. From a comparison between the measured decoherence distribution with CosmoALEPH and the MC predicted decoherence curves for proton, helium and iron, a primary composition of (77±11) % protons and (23±11) % iron nuclei with a χ 2 -probability of 84 % was determined, based on the predictions of the VENUS model with the constant mass composition approach. The analysis of the decoherence curve, with consideration of correlations between the measured CosmoALEPH parameters, leads to a composition of (88±8) % protons and (12±8) % iron nuclei for cosmic rays with a χ 2 -probability of 53 %. The absolute comparison between the measured multiplicity and transverse momentum distributions in the TPC and those predicted by different Monte Carlo models results also in a dominant light composition. The experimental data are in a good agreement with MC data lying between proton and helium primaries. The results obtained for the primary composition of cosmic rays up to the knee region are consistent with the results from other experiments. (orig.)

  19. Lateral distribution of cosmic ray muons underground. Results from the CosmoALEPH experiment

    Energy Technology Data Exchange (ETDEWEB)

    Tcaciuc, R.

    2006-07-01

    The CosmoALEPH experiment, located underground at the LEP e{sup +}e{sup -} storage ring at CERN at a depth of 320 m water equivalent, was used to study the chemical composition of primary cosmic rays up to 10 PeV energies from the measurement of high energy muons, created in extensive air showers by interactions of primary nuclei in the atmosphere. The Time Projection Chamber (TPC) and the Hadron Calorimeter of the ALEPH detector and six scintillator stations located at distances up to 1 km from each other were used to analyse the decoherence curve, multiplicity and transverse momentum distributions of energetic cosmic muons. The experimental data were compared with predictions from different Monte Carlo (MC) models and mass composition approaches. From a comparison between the measured decoherence distribution with CosmoALEPH and the MC predicted decoherence curves for proton, helium and iron, a primary composition of (77{+-}11) % protons and (23{+-}11) % iron nuclei with a {chi}{sup 2}-probability of 84 % was determined, based on the predictions of the VENUS model with the constant mass composition approach. The analysis of the decoherence curve, with consideration of correlations between the measured CosmoALEPH parameters, leads to a composition of (88{+-}8) % protons and (12{+-}8) % iron nuclei for cosmic rays with a {chi}{sup 2} -probability of 53 %. The absolute comparison between the measured multiplicity and transverse momentum distributions in the TPC and those predicted by different Monte Carlo models results also in a dominant light composition. The experimental data are in a good agreement with MC data lying between proton and helium primaries. The results obtained for the primary composition of cosmic rays up to the knee region are consistent with the results from other experiments. (orig.)

  20. Lateral distribution of cosmic ray muons underground: Results from the CosmoALEPH experiment

    CERN Document Server

    Tcaciuc, Rodica

    2006-01-01

    The CosmoALEPH experiment, located underground at the LEP e + e − storage ring at CERN at a depth of 320 m water equivalent, was used to study the chemical composition of primary cosmic rays up to 10 PeV e nergies from the measurement of high energy muons, created in extensive a ir showers by interactions of primary nuclei in the atmosphere. The Time Projection Chamber (TPC) and the Hadron Calorimete r of the ALEPH detector and six scintillator stations located at dis tances up to 1 km from each other were used to analyse the decoherence curve, m ultiplicity and transverse momentum distributions of energetic cosmic muo ns. The experimental data were compared with predictions from d ifferent Monte Carlo (MC) models and mass composition approaches. From a comparison between the measured decoherence distrib ution with CosmoALEPH and the MC predicted decoherence curves for prot on, helium and iron, a primary composition of (77 ± 11) % protons and (23 ± 11) % iron nuclei with a χ 2 - probability of 84 % was d...

  1. The underground heat storage for solar-assisted district heating in Neckarsulm. First measuring results; Der Erdsonden-Waermespeicher fuer die solarunterstuetzte Nahwaermeversorgung in Neckarsulm. Erste Messergebnisse

    Energy Technology Data Exchange (ETDEWEB)

    Seiwald, H.; Hahne, E. [Stuttgart Univ. (Germany). Inst. fuer Thermodynamik und Waermetechnik

    1998-12-31

    A solar-assisted district heating system with seasonal underground heat storage is currently under construction in Neckarsulm (Baden-Wurttemberg). In the new residential area approximately 1,300 flats are going to be built during the next years. The overall energy demand (hot water and space heating) is supposed to be covered by 50% with solar energy. During the first phase the project will be subsidised in the frame of the BMBF programme `Solarthermie 2000, Teilprogramm III`. A solar plant consisting of 2,700 square metres of collectors, a buffer tank (100 cubic metre) and an underground heat storage with a volume of approx. 20,000 cubic metres will be constructed by the end of 1998. It will be the first plant in Germany where thermal energy generated of solar energy is stored at high temperatures (up to 80 C) directly in the earth and utilised without a heat pump. (orig.) [Deutsch] In Neckarsulm (Baden-Wuerttemberg) befindet sich derzeit eine solar unterstuetzte Nahwaermeversorgung mit saisonalem Endsonden-Waermespeicher im Aufbau. Im Neubaugebiet Amorbach werden in den naechsten Jahren rund 1300 Wohneinheiten entstehen, deren Gesamtwaermebedarf (Warmwasser und Raumheizung) zu rund 50% mit Sonnenenergie gedeckt werden soll. In der ersten Phase wird das Projekt im Rahmen des BMBF-Programms `Solarthermie 2000, Teilprogramm III` gefoerdert. Bis Ende 1998 wird eine Solaranlage bestehend aus 2.700 m{sup 2} Kollektoren, einem Pufferspeicher (100 m{sup 3}) und einem Endsonden-Waermespeicher mit einem Volumen von ca. 20.000 m{sup 3} erstellt. Damit wird in Deutschland erstmalig eine Anlage realisiert, bei der solar erzeugte Waerme auf hohem Temperaturniveau (bis zu 80 C) direkt im Erdreich gespeichert und ohne Waermepumpe genutzt werden soll. (orig.)

  2. High-temperature acquifer thermal storage and underground heat storage; IEA ECES Annex 12: Hochtemperatur-Erdwaermesonden- und Aquiferwaermespeicher

    Energy Technology Data Exchange (ETDEWEB)

    Sanner, B.; Knoblich, K. [Giessen Univ. (Germany). Inst. fuer Angewandte Geowissenschaften; Koch, M.; Adinolfi, M. [Stuttgart Univ. (Germany). Inst. fuer Siedlungswasserbau, Wasserguete und Abfallwirtschaft

    1998-12-31

    Heat storage is essential for the reconciliation of heat supply and demand. The earth has already proved to be an excellent medium for storing large amounts of heat over longer periods of time, for instance during the cold and hot season. The efficiency of the storage is the better the lower storage losses are at high temperature levels. Unfortunately this can not be easily achieved. While thermal underground stores, which are widely used for cold storage, have proved to perform quite well at temperatures between 10 C - 40 C, it has been rather difficult to achieve similar results at higher temperatures up to 150 C as test and demonstration plants of the 1980s proved. This issue has again attracted so much interest that the IEA launched a project on high temperature underground storage in December 1998. (orig.) [Deutsch] Waermespeicherung ist von entscheidender Bedeutung, wenn es darum geht, ein Waermeangebot mit einer Waermenachfrage zeitlich zur Deckung zu bringen. Der Untergrund hat sich schon seit vielen Jahren als ein geeignetes Medium erwiesen, groessere Waermepumpen ueber laengere Zeitraeume wie etwa die kalten und warmen Jahreszeiten zu speichern. Die Effizienz eines solchen Speichers steigt mit der Hoehe des erreichten Temperaturniveaus und mit sinkenden Speicherverlusten, was leider eher gegenlaeufige Erscheinungen sind. Waehrend thermische Untergrundspeicher im Temperaturbereich von 10-40 C inzwischen erfolgreich demonstriert wurden und vor allem zur Kaeltespeicherung auch bereits vielfach eingesetzt werden, haben hoehere Temperaturen bis etwa 150 C in den Versuchs- und Demonstrationsanlagen der 80er Jahre vielfaeltige Probleme bereitet. Im Gefolge eines erneuten Interesses an unterirdischer thermischer Energiespeicherung wurde im Dezember 1997 ein Vorhaben des IEA Energiespeicherprogramms zu Untergrund-Waermespeichern hoeherer Temperatur eingerichtet. (orig.)

  3. Barriers of repository under the conditions of underground isolation of heat releasing radioactive waste in permafrost

    International Nuclear Information System (INIS)

    Kazakov, A.N.; Fedorovich, L.N.

    1995-01-01

    The main positions and the leading principle of the ensuring of the environmental safety of the method of the underground isolation of radioactive waste in permafrost rock are presented in this work and it is shown here the peculiarities in realization of the principle of the multibarrier protection. It is substantiated here the principle of the optimal time of the capacity for work of the repository's engineered barriers. The possibility of the exclusion of the radionuclides migration beyond the working volume of the repository during the time of the potential danger of radioactive waste is also substantiated in these papers

  4. Analysis of an underground electric heating system with short-term energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Ramadan, B.H. [Michigan State Univ., East Lansing, MI (United States). Dept. of Mechanical Engineering

    1994-12-31

    The principal commercially active heat storage application in which concrete is used as the storage medium is in the use of subfloor electric heaters embedded in a layer of sand. The resistance heaters are energized when utility offpeak rates are in effect. The sand bed and the concrete floor are then heated to some predetermined temperature, and the floor releases heat slowly and remains warm during the subsequent period of high demand. Analysis of the slab-heating system for varying design parameters, such as the depth of the placement of the heaters, the sand properties, the energy input, and the insulation thickness, was considered. The system was also optimized based on life-cycle costs. The suitability of using this system for heating a warehouse in four representative cities in the United States was also considered The response of the system was found to be greatly influenced by the depth of the placement of the heaters, the sand`s moisture content, and the heating strategy. Optimum insulation levels were determined for the prototypical building in all four of the representative cities. Because of the difficulty of controlling the energy release from the heating mats, this system may not be suitable for heating residential and office buildings but may be more appropriate for heating maintenance and storage facilities.

  5. Application of a Novel Liquid Nitrogen Control Technique for Heat Stress and Fire Prevention in Underground Mines.

    Science.gov (United States)

    Shi, Bobo; Ma, Lingjun; Dong, Wei; Zhou, Fubao

    2015-01-01

    With the continually increasing mining depths, heat stress and spontaneous combustion hazards in high-temperature mines are becoming increasingly severe. Mining production risks from natural hazards and exposures to hot and humid environments can cause occupational diseases and other work-related injuries. Liquid nitrogen injection, an engineering control developed to reduce heat stress and spontaneous combustion hazards in mines, was successfully utilized for environmental cooling and combustion prevention in an underground mining site named "Y120205 Working Face" (Y120205 mine) of Yangchangwan colliery. Both localized humidities and temperatures within the Y120205 mine decreased significantly with liquid nitrogen injection. The maximum percentage drop in temperature and humidity of the Y120205 mine were 21.9% and 10.8%, respectively. The liquid nitrogen injection system has the advantages of economical price, process simplicity, energy savings and emission reduction. The optimized heat exchanger used in the liquid nitrogen injection process achieved superior air-cooling results, resulting in considerable economic benefits.

  6. Households' willingness to pay for overhead-to-underground conversion of electricity distribution networks

    Energy Technology Data Exchange (ETDEWEB)

    McNair, Ben J., E-mail: Ben.McNair@anu.edu.a [Crawford School of Economics and Government, Australian National University, Crawford Building, Lennox Crossing, Canberra ACT 0200 (Australia); Bennett, Jeff [Crawford School of Economics and Government, Australian National University, Crawford Building, Lennox Crossing, Canberra ACT 0200 (Australia); Hensher, David A.; Rose, John M. [Institute of Transport and Logistics Studies, The Business School, University of Sydney, NSW 2006 (Australia)

    2011-05-15

    Underground low-voltage electricity networks have several advantages over overhead networks including reliability of supply, safety and improved visual amenity. The economic viability of replacing existing overhead networks with new underground networks depends on the value of these benefits to households, but no complete value estimates are available in the literature. This paper represents a contribution towards addressing this research gap. A stated choice survey is used to estimate willingness to pay for undergrounding in established residential areas in Canberra, Australia. Average willingness to pay is at least A$6838 per household and there is significant variation in preferences over the population. The results suggest that benefits would be highest in areas with higher household income and older residents where visual amenity, safety, tree trimming, or restrictions on the use of yard space are of concern. - Research highlights: {yields} A choice experiment is used to estimate values for undergrounding electricity wires. {yields} Average willingness to pay is at least A$6838 per household in Canberra, Australia. {yields} Preferences vary considerably over the population. {yields} Benefits would be highest in areas with higher income and older residents.

  7. Underground disposal of UK heat-generating wastes: repository design considerations

    International Nuclear Information System (INIS)

    Steadman, J.A.

    1993-12-01

    The report discusses the likely differences in design between a deep repository for disposal of UK heat-generating radioactive wastes and that of the planned Nirex ILW/LLW repository at Sellafield, based on a review of international published information. The main differences arise from the greater heat and radiation outputs of the waste, and in the case of intact PWR spent fuel elements, the greater length and weight of the disposal packages. Published cost estimates for other OECD countries for disposal of heat-generating wastes are considerably lower than that for the UK, partly because in most cases they are for co-disposal with a larger quantity of ILW. (author)

  8. Particle size distribution of the radon progeny and ambient aerosols in the Underground Tourist Route "Liczyrzepa" Mine in Kowary Adit

    Science.gov (United States)

    Wołoszczuk, Katarzyna; Skubacz, Krystian

    2018-01-01

    Central Laboratory for Radiological Protection, in cooperation with Central Mining Institute performed measurements of radon concentration in air, potential alpha energy concentration (PAEC), particle size distribution of the radon progeny and ambient aerosols in the Underground Tourist-Educational Route "Liczyrzepa" Mine in Kowary Adit. A research study was developed to investigate the appropriate dose conversion factors for short-lived radon progeny. The particle size distribution of radon progeny was determined using Radon Progeny Particle Size Spectrometer (RPPSS). The device allows to receive the distribution of PAEC in the particle size range from 0.6 nm to 2494 nm, based on their activity measured on 8 stages composed of impaction plates or diffusion screens. The measurements of the ambient airborne particle size distribution were performed in the range from a few nanometres to about 20 micrometres using Aerodynamic Particle Sizer (APS) spectrometer and the Scanning Mobility Particle Sizer Spectrometer (SMPS).

  9. Cognitive consequences of sleep deprivation, shiftwork, and heat exposure for underground miners.

    Science.gov (United States)

    Legault, Glenn; Clement, Alexandra; Kenny, Glen P; Hardcastle, Stephen; Keller, Nancy

    2017-01-01

    Sleep deprivation, abnormal sleep patterns arising from working rotating shifts, and exposure to high ambient temperatures contribute to physical and cognitive dysfunction. We examined the effects of these on 19 (41.5 ± 5.1 years) male underground miners. Data were collected for 28 to 30 consecutive days such that the participants experienced their full rotating shift schedule, including days off. Objective measures of sleep quality (actigraphy), attentional capacity (psychomotor vigilance task), core body temperature (visceral pill), executive function (BRIEF-A) and subjective measures of fatigue (Karolinska and Epworth Sleepiness scales) were obtained over the 28-30 day period. Non-parametric analyses (χ(2), Wilcoxen Signed ranks) were used to determine differences between shift types and days off. Z-tests were used to compare sample data to population norms. These revealed that the participants experienced poor quality of sleep relative to age-matched norms irrespective of the shift being worked or if the participant was on a scheduled day off [30-39 year olds: z = -14.62, p sleep prior to beginning work compared to their days off or night shift; however, no differences in total sleep time between when participants worked day or night shifts were observed [χ(2) (2, n = 18) = 13.44, p attentional capacity showed best performance at the beginning of night shifts in contrast to any other time that the task was completed; however, performance degraded dramatically over the course of the night shift [χ(2) (2, n = 12) = 6.50, p sleep deprived. The cognitive consequences of this poor sleep were most pronounced during night shift when their attentional capacity declined rapidly over the course of the night shift. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Simulation and energy analysis of distributed electric heating system

    Science.gov (United States)

    Yu, Bo; Han, Shenchao; Yang, Yanchun; Liu, Mingyuan

    2018-02-01

    Distributed electric heating system assistssolar heating systemby using air-source heat pump. Air-source heat pump as auxiliary heat sourcecan make up the defects of the conventional solar thermal system can provide a 24 - hour high - efficiency work. It has certain practical value and practical significance to reduce emissions and promote building energy efficiency. Using Polysun software the system is simulated and compared with ordinary electric boiler heating system. The simulation results show that upon energy request, 5844.5kW energy is saved and 3135kg carbon - dioxide emissions are reduced and5844.5 kWhfuel and energy consumption is decreased with distributed electric heating system. Theeffect of conserving energy and reducing emissions using distributed electric heating systemis very obvious.

  11. Coupling Geothermal Heat Pumps with Underground Seasonal Thermal Energy Storage (EW-201135)

    Science.gov (United States)

    2017-03-01

    with the addition of the adiabatic pads, a water supply connection and a drainage system . During the baseline data-logging period at MCLB-B3700, an... system . Rainwater and near surface water will always contain some oxygen due to the presence of atmospheric oxygen. Deep (100+ ft. deep) groundwater...loop Heat Exchangers (GHX) with closed loop systems or via direct ground water use with open-loop systems , which conventional GHP systems in the U.S

  12. Study of dissolution precipitation phenomena related to heat generated by underground disposal

    International Nuclear Information System (INIS)

    Fabriol, R.

    1987-01-01

    This study is composed of two parts developed in two separated volumes. The first part is a bibliographical research concerning the behaviour of waste analog elements during hydrothermal alteration in active geothermal fields. The second part is an experimental and theoretical simulation of dissolution-precipitation phenomena related to heat generated in the vicinity of a nuclear waste repository located in granitic formations. This work is part of the CEC project MIRAGE on natural geological migration systems [fr

  13. Distributed heat generation in a district heating system

    OpenAIRE

    Lennermo, Gunnar; Lauenberg, Patrick

    2016-01-01

    District heating (OH) systems need to be improved  regarding integration  of decentralised  heat generation. Micro production, prosumers and smart grids are terms becoming more and more common  in  connection  to  the  power  grid.  Concerning district  heating,  the  development  is slower, although improving. Today there are a number of such decentralised units for heat generation,  mainly  solar,  that have been partly evaluated.  Previous  studies  have shown  that there is a need to deve...

  14. Coupling Geothermal Heat Pumps (GHP) With Underground Seasonal Thermal Energy Storage (USTES)

    Science.gov (United States)

    2017-03-21

    subsurface geology as a thermal battery, as opposed to a radiator . BTES is a design solution in areas where there are not aquifers suitable for ATES...Wells are defined by DC Law § 8-103.01(26A) as any test hole, shaft, or soil excavation created by any means including, but not limited to, drilling...Resources An annual sampling requirement for non-residential systems. Driller or installer is required to hold a "heat pump installation" permit through

  15. Distribution of radium-226 body burden among workers in an underground uranium mine in India

    International Nuclear Information System (INIS)

    Patnaik, R.L.; Srivastava, V.S.; Kumar, Rajesh; Shukla, A.K.; Tripathi, R.M.; Puranik, V.D.

    2007-01-01

    Workers are exposed to ore dust containing uranium and its daughter products during mining and processing of uranium ore. These radio nuclides may be an inhalation hazard to the workers during the course of their occupation. The most significant among these radio nuclides is 226 Ra. Measurement of radium body burden of uranium mine and mill workers are important to control the exposure of workers within the prescribed limit. Radon-in-breath measurement technique is used for measurement of radium body burden. Workers associated with different category of underground mining operations were monitored. The measurement results indicate that workers associated with different category of underground mining operations are having 226 Ra body burden ranging from 0.15 - 2.85 kBq. It was also observed that workers involved in timbering operation are having maximum average 226 Ra body burden of 0.97 ± 0.54 kBq. Overall average radium body burden observed for 683 workers is 0.80 kBq. (author)

  16. Impact of Next Generation District Heating Systems on Distribution Network Heat Losses: A Case Study Approach

    Science.gov (United States)

    Li, Yu; Rezgui, Yacine

    2018-01-01

    District heating (DH) is a promising energy pathway to alleviate environmental negative impacts induced by fossil fuels. Improving the performance of DH systems is one of the major challenges facing its wide adoption. This paper discusses the heat losses of the next generation DH based on the constructed Simulink model. Results show that lower distribution temperature and advanced insulation technology greatly reduce network heat losses. Also, the network heat loss can be further minimized by a reduction of heat demand in buildings.

  17. Real-time modeling of heat distributions

    Science.gov (United States)

    Hamann, Hendrik F.; Li, Hongfei; Yarlanki, Srinivas

    2018-01-02

    Techniques for real-time modeling temperature distributions based on streaming sensor data are provided. In one aspect, a method for creating a three-dimensional temperature distribution model for a room having a floor and a ceiling is provided. The method includes the following steps. A ceiling temperature distribution in the room is determined. A floor temperature distribution in the room is determined. An interpolation between the ceiling temperature distribution and the floor temperature distribution is used to obtain the three-dimensional temperature distribution model for the room.

  18. LPV Identification of a Heat Distribution System

    DEFF Research Database (Denmark)

    Trangbæk, K; Bendtsen, Jan Dimon

    2010-01-01

    This paper deals with incremental system identification of district heating systems to improve control performance. As long as various parameters, e.g. valve settings, are kept fixed, the dynamics of district heating systems can be approximated well by linear models; however, the dynamics change ....... The approach is tested on a laboratory setup emulating a district heating system, where local controllers regulate pumps connected to a common supply. Experiments show that cross-couplings in the system can indeed be identified in closed-loop operation....

  19. Distribution of heating costs in multi-story apartment buildings

    DEFF Research Database (Denmark)

    Rose, Jørgen; Kragh, Jesper

    2017-01-01

    Under current rules in the Danish Meter Order at least 40% of the total heating costs in multi-story blocks of flats should be distributed by metering the consumption in individual apartments. This fixed share is the result of a previous study that showed that 40% of the total heating costs were...... used for space heating, 35% for production and heat loss associated with hot water consumption and finally 25% of heat losses in the heating system. It is interesting to investigate whether this distribution remains representative in both existing buildings, where older buildings still dominate......, as in newer and future standard of blocks of flats. Intuitively, we would like to settle 100% of the costs attributable to space heating, by individual meters. Thereby, tenants will pay for their own consumption which encourages energy savings. This is an excellent method for electricity, gas and water...

  20. Application of 'SPICE' to predict temperature distribution in heat pipes

    Energy Technology Data Exchange (ETDEWEB)

    Li, H M; Liu, Y; Damodaran, M [Nanyang Technological Univ., Singapore (SG). School of Mechanical and Production Engineering

    1991-11-01

    This article presents a new alternative approach to predict temperature distribution in heat pipes. In this method, temperature distribution in a heat pipe, modelled as an analogous electrical circuit, is predicted by applying SPICE, a general-purpose circuit simulation program. SPICE is used to simulate electrical circuit designs before the prototype is assembled. Useful predictions are obtained for heat pipes with and without adiabatic sections and for heat pipes with various evaporator and condenser lengths. Comparison of the predicted results with experiments demonstrates fairly good agreement. It is also shown how interdisciplinary developments could be used appropriately. (author).

  1. Impact of In Situ Stress Distribution Characteristics on Jointed Surrounding Rock Mass Stability of an Underground Cavern near a Hillslope Surface

    Directory of Open Access Journals (Sweden)

    Bangxiang Li

    2017-01-01

    Full Text Available In this paper, a series of numerical simulations are performed to analyze the in situ stress distribution characteristics of the rock mass near different slope angles hillslope surfaces, which are subjected to the vertical gravity stress and different horizontal lateral stresses and the influence which the in situ stress distribution characteristics of 45° hillslope to the integral stability of surrounding rock mass when an underground cavern is excavated considering three different horizontal distances from the underground cavern to the slope surface. It can be concluded from the numerical results that different slope angles and horizontal lateral stresses have a strong impact on the in situ stress distribution and the integral surrounding rock mass stability of the underground cavern when the horizontal distance from the underground cavern to the slope surface is approximately 100 m to 200 m. The relevant results would provide some important constructive suggestions to the engineering site selection and optimization of large-scale underground caverns in hydropower stations.

  2. Influence of a source line position on results of EM observations applied to the diagnostics of underground heating system pipelines in urban area

    Science.gov (United States)

    Vetrov, A.

    2009-05-01

    The condition of underground constructions, communication and supply systems in the cities has to be periodically monitored and controlled in order to prevent their breakage, which can result in serious accident, especially in urban area. The most risk of damage have the underground construction made of steal such as pipelines widely used for water, gas and heat supply. To ensure the pipeline survivability it is necessary to carry out the operative and inexpensive control of pipelines condition. Induced electromagnetic methods of geophysics can be applied to provide such diagnostics. The highly developed surface in urbane area is one of cause hampering the realization of electromagnetic methods of diagnostics. The main problem is in finding of an appropriate place for the source line and electrodes on a limited surface area and their optimal position relative to the observation path to minimize their influence on observed data. Author made a number of experiments of an underground heating system pipeline diagnostics using different position of the source line and electrodes. The experiments were made on a 200 meters section over 2 meters deep pipeline. The admissible length of the source line and angle between the source line and the observation path were determined. The minimal length of the source line for the experiment conditions and accuracy made 30 meters, the maximum admissible angle departure from the perpendicular position made 30 degrees. The work was undertaken in cooperation with diagnostics company DIsSO, Saint-Petersburg, Russia.

  3. Effect of axial heat flux distribution on CHF

    Energy Technology Data Exchange (ETDEWEB)

    Park, Cheol

    2000-10-01

    Previous investigations for the effect of axial heat flux distributions on CHF and the prediction methods are reviewed and summarized. A total of 856 CHF data in a tube with a non-uniform axial heat flux distribution has been compiled from the articles and analyzed using the 1995 Groeneveld look-up table. The results showed that two representative correction factors, K5 of the look-up table and Tongs F factor, can be applied to describe the axial heat flux distribution effect on CHF. However, they overpredict slightly the measured CHF, depending on the quality and flux peak shape. Hence, a corrected K5 factor, which accounts for the axial heat flux distribution effect is suggested to correct these trends. It predicted the CHF power for the compiled data with an average error of 1.5% and a standard deviation of 10.3%, and also provides a reasonable prediction of CHF locations.

  4. Temperature field distribution of coal seam in heat injection

    OpenAIRE

    Zhang Zhizhen; Peng Weihong; Shang Xiaoji; Wang Kun; Li Heng; Ma Wenming

    2017-01-01

    In this article, we present a natural boundary element method (NBEM) to solve the steady heat flow problem with heat sources in a coal seam. The boundary integral equation is derived to obtain the temperature filed distribution of the coal seam under the different injecting conditions.

  5. Distributed Generation with Heat Recovery and Storage

    OpenAIRE

    Siddiqui, Afzal; Marnay, Chris; Firestone, Ryan M.; Zhou, Nan

    2005-01-01

    Electricity produced by distributed energy resources (DER) located close to end-use loads has the potential to meet consumer requirements more efficiently than the existing centralized grid. Installation of DER allows consumers to circumvent the costs associated with transmission congestion and other non-energy costs of electricity delivery and potentially to take advantage of market opportunities to purchase energy when attractive. On-site, single-cycle thermal power generation is typic...

  6. Investigation of the tube side flow distribution in heat exchangers

    International Nuclear Information System (INIS)

    AbuRomia, M.M.; Pyare, R.

    1977-01-01

    The tube side flow distribution in heat exchangers is being investigated through the solution of the governing equations of fluid mechanics with distributed resistances that simulate the presence of the tubes. The modeling scheme used in the analysis and the numerical methods of solving the governing equations are described. The analysis is applied to the CRBRP-Intermediate Heat Exchanger (IHX), where its tube side plenum is simulated by several models that approximate its spherical boundary. The flow field within the plenum and the distribution of the total flow rate among the tubes are determined by the analysis

  7. Locating underground uranium deposits

    International Nuclear Information System (INIS)

    Felice, P.E.

    1979-01-01

    Underground uranium deposits are located by placing wires of dosimeters each about 5 to 18 mg/cm 2 thick underground in a grid pattern. Each dosimeter contains a phosphor which is capable of storing the energy of alpha particles. In each pair one dosimeter is shielded from alpha particles with more than 18 mg/cm 2 thick opaque material but not gamma and beta rays and the other dosimeter is shielded with less than 1 mg/cm 2 thick opaque material to exclude dust. After a period underground the dosimeters are heated which releases the stored energy as light. The amount of light produced from the heavily shielded dosimeter is subtracted from the amount of light produced from the thinly shielded dosimeter to give an indication of the location and quantity of uranium underground

  8. Poloidal and toroidal heat flux distribution in the CCT tokamak

    International Nuclear Information System (INIS)

    Brown, M.L.; Dhir, V.K.; Taylor, R.J.

    1990-01-01

    Plasma heat flux to the Faraday shield panels of the UCLA Continuous Current Tokamak (CCT) has been measured calorimetrically in order to identify the dominant parameters affecting the spatial distribution of heat deposition. Three heating methods were investigated: audio frequency discharge cleaning, RF heating, and AC ohmic. Significant poloidal asymmetry is present in the heat flux distribution. On the average, the outer panels received 25-30% greater heat flux than the inner ones, with the ratio of maximum to minimum values attaining a difference of more than a factor of 2. As a diagnostic experiment the current to a selected toroidal field coil was reduced in order to locally deflect the toroidal field lines outward in a ripple-like fashion. Greatly enhanced heat deposition (up to a factor of 4) was observed at this location on the outside Faraday panels. The enhancement was greatest for conditions of low toroidal field and low neutral pressure, leading to low plasma densities, for which Coulomb collisions are the smallest. An exponential model based on a heat flux e-folding length describes the experimentally found localization of thermal energy quite adequately. (orig.)

  9. The concept of underground nuclear heat and power plants (UNHPP) of upgraded safety, developed on the basis of ship-building technologies

    International Nuclear Information System (INIS)

    Pashin, V.M.; Petrov, Eh.L.; Shalik, G.P.; Khazov, B.S.; Malyshev, S.P.

    1996-01-01

    A concept of underground nuclear heat and power plants (UNHPP) of upgraded safety on the basis of ship-building technologies is considered, in which the priority is set to population security and environmental protection. Ways of realization of ziro radiation risk for the population residing in a close vicinity of UNHPP are substantiated. basic principles of the concept are formulated which envisage the use of ship propulsion reactor facilities that have been multiply tested in operation. The sources of economic competitiveness of UNHPPs, as compared with the existing NPPs, are shown

  10. Tropical Gravity Wave Momentum Fluxes and Latent Heating Distributions

    Science.gov (United States)

    Geller, Marvin A.; Zhou, Tiehan; Love, Peter T.

    2015-01-01

    Recent satellite determinations of global distributions of absolute gravity wave (GW) momentum fluxes in the lower stratosphere show maxima over the summer subtropical continents and little evidence of GW momentum fluxes associated with the intertropical convergence zone (ITCZ). This seems to be at odds with parameterizations forGWmomentum fluxes, where the source is a function of latent heating rates, which are largest in the region of the ITCZ in terms of monthly averages. The authors have examined global distributions of atmospheric latent heating, cloud-top-pressure altitudes, and lower-stratosphere absolute GW momentum fluxes and have found that monthly averages of the lower-stratosphere GW momentum fluxes more closely resemble the monthly mean cloud-top altitudes rather than the monthly mean rates of latent heating. These regions of highest cloud-top altitudes occur when rates of latent heating are largest on the time scale of cloud growth. This, plus previously published studies, suggests that convective sources for stratospheric GW momentum fluxes, being a function of the rate of latent heating, will require either a climate model to correctly model this rate of latent heating or some ad hoc adjustments to account for shortcomings in a climate model's land-sea differences in convective latent heating.

  11. Forming the Composition of Underground Coal Gasification Products in the Simulation of Various Heat and Mass Transfer Conditions in the Coal Seam

    Directory of Open Access Journals (Sweden)

    Masanik A.S.

    2016-01-01

    Full Text Available The mathematical model describing the heat and mass transfer processes in underground coal gasification is proposed. Numerical studies have allowed to determine the composition of gases depending on the temperature, pressure products of gasification, and the composition of the heated oxidant injected. Relations the composition of the concentration of combustible gas component of the oxidant injected: dry air, a mixture of oxygen, nitrogen and water vapor in different proportions were prepared. It is found that, depending on the oxygen content in the oxidizer low-temperature gasification mode is implemented (up to 15%. At higher values of the oxygen concentration in the oxidizer the high-temperature mode is realized, in which the fuel gas output increases significantly.

  12. Analysis of temperature distribution in a heat conducting fiber with ...

    African Journals Online (AJOL)

    The temperature distribution in a heat conducting fiber is computed using the Galerkin Finite Element Method in the present study. The weak form of the governing differential equation is obtained and nodal temperatures for linear and quadratic interpolation functions for different mesh densities are calculated for Neumann ...

  13. Electron-cyclotron-resonant-heated electron distribution functions

    International Nuclear Information System (INIS)

    Matsuda, Y.; Nevins, W.M.; Cohen, R.H.

    1981-01-01

    Recent studies at Lawrence Livermore National Laboratory (LLNL) with a bounce-averaged Fokker-Planck code indicate that the energetic electron tail formed by electron-cyclotron resonant heating (ECRH) at the second harmonic is not Maxwellian. We present the results of our bounce-averaged Fokker-Planck code along with some simple analytic models of hot-electron distribution functions

  14. Dynamic Underground Stripping Project

    International Nuclear Information System (INIS)

    Aines, R.; Newmark, R.; McConachie, W.; Udell, K.; Rice, D.; Ramirez, A.; Siegel, W.; Buettner, M.; Daily, W.; Krauter, P.; Folsom, E.; Boegel, A.J.; Bishop, D.; Udell, K.

    1992-01-01

    LLNL is collaborating with the UC Berkeley College of Engineering to develop and demonstrate a system of thermal remediation and underground imaging techniques for use in rapid cleanup of localized underground spills. Called ''Dynamic Stripping'' to reflect the rapid and controllable nature of the process, it will combine steam injection, direct electrical heating, and tomographic geophysical imaging in a cleanup of the LLNL gasoline spill. In the first 8 months of the project, a Clean Site engineering test was conducted to prove the field application of the techniques before moving the contaminated site in FY 92

  15. 30 CFR 75.804 - Underground high-voltage cables.

    Science.gov (United States)

    2010-07-01

    ... AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Underground High-Voltage Distribution § 75.804 Underground high-voltage cables. (a) Underground high-voltage cables used in resistance... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Underground high-voltage cables. 75.804 Section...

  16. Leak Detection in Heat Exchangers and Underground Pipelines Using Radiotracers. Material for Education and On-The-Job Training for Practitioners of Radiotracer Technology

    International Nuclear Information System (INIS)

    2009-01-01

    The International Atomic Energy Agency plays a major role in facilitating the transfer of radiotracer technology to developing Member States. The use of radiotracer techniques is well established in many Member States; some hundred radiotracer and end user specialists have been trained in radiotracer techniques and their applications; nearly 50 radiotracer laboratories have been working in this field. The training of radiotracer practitioners is vital for the provision of quality services to industry. Leak detection using radiotracer techniques is probably one of the most widespread applications of radiotracers in industrial troubleshooting. Radiotracer techniques are the most competitive for online leak inspection of heat exchangers and buried pipelines. Radiotracers help in early detection of leaks in heat exchangers and underground transporting pipelines, thus saving money, reducing shutdown time, ensuring safe operation and protecting the environment from pollution. The training course series on leak detection in heat exchangers and underground pipelines using radiotracers addresses the needs of the radiotracer groups and their end users. Besides training purposes, this material will assist radiotracer groups in establishing their quality control and accreditation systems. This training course material is based on lecture notes and practical work delivered by many experts in IAEA-supported activities. In particular, the Technical Cooperation Projects implemented under the Regional Cooperative Agreement (RCA) of the IAEA Member States in the Asia and the Pacific Region have been successful in transferring and implementing radiotracer techniques for leak detection to many end users from oil and gas production, oil refineries and the petrochemical industry. The experience obtained in the RCA Region is presented in the training material illustrated with many case studies carried out in several RCA Member States. Lectures and case studies were reviewed by a number

  17. A new method for distribution of consumed heat in a fuel and costs in power and heating plants

    Energy Technology Data Exchange (ETDEWEB)

    Kadrnozka, J [Technical Univ., Brno (Czech Republic)

    1993-09-01

    There is described a new method for distribution of consumed heat in a fuel and costs in the power and heating plants, which is based on the relatively the same proportion of advantages followed from combine generation of electricity and heat on electricity and heat. The method is physically substantiated, it is very universal and it is applied for new types of power and heating plants and for distribution of investment costs and other costs. (orig./GL)

  18. Design of internally heat-integrated distillation column (HIDiC): Uniform heat transfer area versus uniform heat distribution

    Energy Technology Data Exchange (ETDEWEB)

    Suphanit, B. [Department of Chemical Engineering, Faculty of Engineering, King Mongkut' s University of Technology Thonburi, Pracha Utit Rd., Tungkru, Bangkok 10140 (Thailand)

    2010-03-15

    The internally heat-integrated distillation column (HIDiC) is a complex column configuration which is more energy efficient than the equivalent conventional column or the distillation column with direct vapor recompression scheme (VRC). Exploiting the heat integration between two diabatic sections operating at different pressures of the HIDiC can greatly enhance the energy performance of the system. On the other hand, the design and optimization of HIDiC is more difficult than those of the conventional distillation column or the column with VRC. The former involves many design parameters, and the most critical one is the pressure ratio between both diabatic sections. However, the heat distribution along the diabatic sections is also another significant factor not yet thoroughly investigated. In this work, two typical distribution schemes, i.e. uniform heat transfer area and uniform heat distribution, are studied by applying a novel approach to solve the simulation problem in Aspen Plus 2004.1. The comparison of both distributing schemes is discussed via two widely-used case studies, namely benzene-toluene separation and propylene-propane splitter. (author)

  19. Predicted and measured velocity distribution in a model heat exchanger

    International Nuclear Information System (INIS)

    Rhodes, D.B.; Carlucci, L.N.

    1984-01-01

    This paper presents a comparison between numerical predictions, using the porous media concept, and measurements of the two-dimensional isothermal shell-side velocity distributions in a model heat exchanger. Computations and measurements were done with and without tubes present in the model. The effect of tube-to-baffle leakage was also investigated. The comparison was made to validate certain porous media concepts used in a computer code being developed to predict the detailed shell-side flow in a wide range of shell-and-tube heat exchanger geometries

  20. Natural and Artificial Methods for Regeneration of Heat Resources for Borehole Heat Exchangers to Enhance the Sustainability of Underground Thermal Storages: A Review

    Directory of Open Access Journals (Sweden)

    Tomasz Sliwa

    2015-09-01

    Full Text Available The concept of borehole heat exchanger (BHE field exploitation is described, along with problems regarding the sustainability of heat resources in rock masses. A BHE field sometimes has problems with the stability of the heat carrier temperature during long-term exploitation. The main reason for this is an insufficient heat stream with which to transfer heat by conduction in rock. Possibilities for the regeneration of heat in rock masses, based on experiences at the Geoenergetics Laboratory (Drilling, Oil and Gas Faculty, AGH University of Science and Technology, are described.

  1. On Chaotic Behavior of Temperature Distribution in a Heat Exchanger

    Science.gov (United States)

    Bagyalakshmi, Morachan; Gangadharan, Saisundarakrishnan; Ganesh, Madhu

    The objective of this paper is to introduce the notion of fractional derivatives in the energy equations and to study the chaotic nature of the temperature distribution in a heat exchanger with variation of temperature dependent transport properties. The governing fractional partial differential equations are transformed to a set of recurrence relations using fractional differential transform method and solved using inverse transform. The approximate analytical solution obtained by the proposed method has good agreement with the existing results.

  2. Selective Internal Heat Distribution in Modified Trombe Wall

    Science.gov (United States)

    Szyszka, Jerzy; Kogut, Janusz; Skrzypczak, Izabela; Kokoszka, Wanda

    2017-12-01

    At present, the requirements for thermal insulation of the external walls in buildings are being increased. There is a need to reduce energy consumption for heating rooms during the winter season. This may be achieved by increasing the thermal resistance of the outer partitions, using solutions that utilize either recuperation or solar radiation. The most popular systems include either solar collectors, or heat pump links or ground exchangers. Trombe walls (TW) are a very promising passive heating system, which requires little or no effort to operate, and may be very convenient in different climate conditions. A typical TW consists of a masonry wall painted a dark, heat absorbing paint colour and faced with a single or double layer of glass. The principle of operation is based on the photothermal conversion of solar radiation. There are various modifications of TW. They may improve the energy efficiency in relation to the climate conditions in which they operate. The hybrid solutions are also known. The efficiency of walls is related to the use of proper materials. In TW, the compromise should be sought between the thermal resistance and the ability to distribute heat from the absorbed energy of solar radiation. The paper presents an overview of the most commonly used solutions and discusses its own concept dedicated to the climate conditions of Central Europe.

  3. Temperature distribution in spouted bed and heat transfer

    International Nuclear Information System (INIS)

    Takeda, Hiroshi; Yamamoto, Yutaka

    1976-01-01

    Temperature distribution in spouted bed was measured by using brass and graphite spouted beds so as to investigate heat transfer characteristic of spouted bed applied to an apparatus of PyC coating. These spouted beds are batch type and are spouted by air or nitrogen gas of room temperature, and the outer wall of beds are heated by nichrome or graphite heater. Particles used for experiments are alumina spherical particles and the diameter is 0.80 -- 1.12 mm. Temperature condition is in the range of 400 -- 1,400 0 C. In the neighborhood of 400 0 C, the spouting condition is stable, while the spouting condition becomes unstable in the case of above 1,000 0 C. This is caused by abrupt temperature increase of spouting gas. It was found that heat transfer coefficient h sub(w) of our low temperature experiments was closer to the calculated from Malek et al.'s equation, h sub(p) of our experiments was several times greater than the calculated from Uemaki et al.'s equation. On the other hand, h sub(p) of high temperature experiments was compared with an experimental relation for convective heat transfer of fluidized bed, it was found that Nu sub(p) of our experiments was nearly equal to or greater than the calculated from the relation, this would be caused by radiant heat transfer. (auth.)

  4. Quasilinear ion distribution function during first harmonic ion cyclotron heating

    International Nuclear Information System (INIS)

    Brambilla, M.

    1993-12-01

    The quasilinear modification of the ion distribution function during first harmonic ion cyclotron (FHIC) heating is investigated both with a simple already well established analytic one-dimensional approach, and with a new two dimensional steady state solver of the quasilinear kinetic equation, SSFPQL. By accepting to disregard the effects of ion trapping in banana orbits, but including finite Larmor radius effects, the latter code has been made much faster than full surface-averaged codes; yet it can provide most of the relevant information on the suprathermal ion tail produced by this heating method. With SSFPQL we confirm that the one-dimensional model gives fair approximations for global properties of the distribution function, such as the average energy content of the tail and the fusion reactivity. On the other hand the tail is found to be very anisotropic, the increase of the parallel effective temperature being a small fraction of the total energy increase. Information on the anisotropy is essential to study the feedback of the fast ion tail on wave propagation and absorption, which is quite sensitive to the distribution of parallel velocities. The insight gained in the derivation and discussion of this model can be used to build a selfconsistent description of this heating scenario, whose implementation requires only a reasonable numerical effort. (orig.)

  5. Flue gas recovery system for natural gas combined heat and power plant with distributed peak-shaving heat pumps

    International Nuclear Information System (INIS)

    Zhao, Xiling; Fu, Lin; Wang, Xiaoyin; Sun, Tao; Wang, Jingyi; Zhang, Shigang

    2017-01-01

    Highlights: • A flue gas recovery system with distributed peak-shaving heat pumps is proposed. • The system can improve network transmission and distribution capacity. • The system is advantageous in energy saving, emission reduction and economic benefits. - Abstract: District heating systems use distributed heat pump peak-shaving technology to adjust heat in secondary networks of substations. This technology simultaneously adjusts the heat of the secondary network and reduces the return-water temperature of the primary network by using the heat pump principle. When optimized, low temperature return-water is able to recycle more waste heat, thereby further improving the heating efficiency of the system. This paper introduces a flue gas recovery system for a natural gas combined heat and power plant with distributed peak-shaving heat pumps. A pilot system comprising a set of two 9F gas-steam combined cycle-back pressure heating units was used to analyse the system configuration and key parameters. The proposed system improved the network transmission and distribution capacity, increased heating capacity, and reduced heating energy consumption without compromising heating safety issues. As such, the proposed system is advantageous in terms of energy saving, emission reduction, and economic benefits.

  6. Characteristics on the heat storage and recovery by the underground spiral heat exchange pipe; Chichu maisetsu spiral kan ni yoru chikunetsu shunetsu tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Imai, I [Kure National College of Technology, Hiroshima (Japan); Taga, M [Kinki University, Osaka (Japan)

    1996-10-27

    The consistency between the experimental value of a soil temperature and the calculation value of a soil temperature given by a non-steady heat conduction equation was confirmed. The experimental value is obtained by laying a spiral heat exchange pipe in the heat-insulated soil box and circulating hot water forcibly in the pipe. The temperature conductivity in soil significantly influences the heat transfer in soil. The storage performance is improved when the temperature conductivity increases because of the contained moisture. As the difference between the initial soil temperature and circulating water temperature becomes greater, the heat storage and recovery values increase. A thermal core heat transfer is done in the spiral pipe. Therefore, the diameter of the pipe little influences the heat storage performance, and the pitch influences largely. About 50 hours after heat is stored, the storage performance is almost the same as for a straight pipe that uses the spiral diameter as a pipe diameter. To obtain the same heat storage value, the spiral pipe is made of fewer materials than the straight pipe and low in price. The spiral pipe is more advantageous than the straight pipe in the necessary motive power and supply heat of a pump. 1 ref., 11 figs., 1 tab.

  7. Particle size distribution of the radon progeny and ambient aerosols in the Underground Tourist Route “Liczyrzepa” Mine in Kowary Adit

    Directory of Open Access Journals (Sweden)

    Wołoszczuk Katarzyna

    2018-01-01

    Full Text Available Central Laboratory for Radiological Protection, in cooperation with Central Mining Institute performed measurements of radon concentration in air, potential alpha energy concentration (PAEC, particle size distribution of the radon progeny and ambient aerosols in the Underground Tourist-Educational Route “Liczyrzepa” Mine in Kowary Adit. A research study was developed to investigate the appropriate dose conversion factors for short-lived radon progeny. The particle size distribution of radon progeny was determined using Radon Progeny Particle Size Spectrometer (RPPSS. The device allows to receive the distribution of PAEC in the particle size range from 0.6 nm to 2494 nm, based on their activity measured on 8 stages composed of impaction plates or diffusion screens. The measurements of the ambient airborne particle size distribution were performed in the range from a few nanometres to about 20 micrometres using Aerodynamic Particle Sizer (APS spectrometer and the Scanning Mobility Particle Sizer Spectrometer (SMPS.

  8. Annex 1: Simulation of the Serso underground heat storage - Calibration using data from two-years measurements; Annexe 1: simulation du stockage de chaleur dans le terrain de l'installation Serso et calibrage sur deux ans de mesure

    Energy Technology Data Exchange (ETDEWEB)

    Pahud, D.

    2006-12-15

    This is the Annex 1 of the annual report 2006 of the Serso project. The basic idea of the Serso project is to defrost a road bridge in winter with heat produced by the bridge in summer by solar radiation absorption and stored in a diffusive underground store. Pipes are imbedded in the bridge surface material and connected to a set of underground borehole heat exchangers ('geothermal probes'). A heat transfer fluid is circulated by a pump. The store is loaded in summer and discharged in winter. In the present Annex the computer code developed to simulate the underground heat store is validated and tuned on the basis of a two-years series of field measurements. The agreement between predicted and measured values is good. A limitation of the computer model is that it cannot simulate only a part of the borehole heat exchangers, a feature that were implemented in the pilot store, to enable discharging the peripheral heat exchangers and leave the central ones untouched. The authors investigated the relevance of such a feature and found out that it does not significantly improve the store efficiency. As it is an additional hardware complication they recommend to ignore such a feature in future projects.

  9. Ground source geothermal heat. Ground source heat pumps and underground thermal energy storage systems. Proceedings; Oberflaechennahe Geothermie. Erdgekoppelte Waermepumpen und unterirdische thermische Energiespeicher. Tagungsband

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    At the ninth international user forum on shallow geothermal heat on 28th and 29th April, 2009, at BadStaffelstein (Federal Republic of Germany), the following lectures were held: (1) Information system on shallow geothermal heat for Bavaria (Marcellus Schulze); (2) Calculation of the spreading of temperature anomalies in groundwater as an instrument of planning of heat pump systems (Wolfgang Rauch); (3) Comparison of models for simulation of deep geothermal probes (Markus Proell); (4) Impact of the geometry of boreholes and probes on heat transport (Manfred Reuss); (5) Thermal respond tests and temperature depth profiles - Experience from research and practice (Markus Kuebert); (6) A model of simulation for the investigation of the impact of different heat transfer fluids on the efficiency of ground source heat pump devices (Roland Koenigsdorff); (7) The research project EWSplus - Investigations for quality assurance of geothermal probes (Mathieu Riegger); (8) Quality management of plants for the utilization of shallow geothermal heat with geothermal probes - the example of Baden-Wuerttemberg (Bruno Lorinser, Ingrid Stober); (9) Not every heat pump contributes to climate protection (Falk Auer); (10) Field measurements of heat pumps in residential buildings with modern standard and in older buildings (Marek Miara); (11) System technology for a great annual performance factor (Werner Schenk); (12) Modification of older geothermal heat probe devices for use with modern heat pumps (Klaus Friedrich Staerk); (13) Energy-efficient modernisation of a pensioners' condominium from the 1970s with solar-geothermal-air (Michael Guigas); (14) Evaluation and optimization of operation of seasonal storage systems in the foundations of office buildings (Herdis Kipry); (15) Evaluation of an innovative heating and cooling concept with rain water vessels, thermo-active building components and phase change materials in a residential building (Doreen Kalz); (16) Contracts for ground

  10. Heat and work distributions for mixed Gauss–Cauchy process

    International Nuclear Information System (INIS)

    Kuśmierz, Łukasz; Gudowska-Nowak, Ewa; Rubi, J Miguel

    2014-01-01

    We analyze energetics of a non-Gaussian process described by a stochastic differential equation of the Langevin type. The process represents a paradigmatic model of a nonequilibrium system subject to thermal fluctuations and additional external noise, with both sources of perturbations considered as additive and statistically independent forcings. We define thermodynamic quantities for trajectories of the process and analyze contributions to mechanical work and heat. As a working example we consider a particle subjected to a drag force and two statistically independent Lévy white noises with stability indices α = 2 and α = 1. The fluctuations of dissipated energy (heat) and distribution of work performed by the force acting on the system are addressed by examining contributions of Cauchy fluctuations (α = 1) to either bath or external force acting on the system. (paper)

  11. Deeper underground

    Energy Technology Data Exchange (ETDEWEB)

    Brearley, D. [Pantek Ltd. (United Kingdom)

    2005-12-01

    The paper describes how efficient data gathering has led to production and uptime improvements in UK Coal's Daw Mill colliery in Warwickshire. Software called FactorySuite A{sup 2} from Wonderware is being used to control and monitor all underground production and conveying. 3 photos.

  12. Experimental data on heat flux distribution from a volumetrically heated pool with frozen boundaries

    International Nuclear Information System (INIS)

    Helle, Maria; Kymaelaeinen, Olli; Tuomisto, Harri

    1999-01-01

    The COPO II experiments are confirmatory experiments and a continuation project to the earlier COPO I experiments. As in COPO 1, a molten corium pool on the lower head of a RPV is simulated by a two - dimensional slice of it in linear scale 1:2. The corium is simulated by water-zinc sulfate solution with volumetric Joule heating. The heat flux distribution on the boundaries and the temperature distribution in the pool are measured. The major new feature in COPO II is the cooling arrangement which is based on circulation of liquid nitrogen on the outside of the pool boundaries. The use of liquid nitrogen leads to formation of ice on the inside of boundaries. Two geometrically different versions of the COPO II facility have been constructed: one with a tori-spherical bottom shape, simulating the RPV of a VVER-440 reactor as COPO I, and another one with semicircular bottom simulating a western PWR such as AP600. The modified Rayleigh number in the COPO II experiments corresponds to the one in a prototypic corium pool (∼ 10 15 ). This paper reports results from the COPO II-Lo and COPO II-AP experiments with homogenous pool. Results indicate that the upward heat fluxes are in agreement with the results of the COPO I experiments. Also, as expected, the time averaged upward heat flux profile was relatively flat. On the other hand, the heat fluxes at the side and bottom boundaries of the pool were slightly higher in COPO II-Lo than in COPO I. In COPO II-AP, the average heat transfer coefficients to the curved boundary were higher than predicted by Jahn's and Mayinger's correlation, but slightly lower than in BALI experiments. (authors)

  13. Underground treatment of combustible minerals

    Energy Technology Data Exchange (ETDEWEB)

    Sarapuu, E

    1954-10-14

    A process is described for treating oil underground, consisting in introducing several electrodes spaced one from the other in a bed of combustibles underground so that they come in electric contact with this bed of combustibles remaining insulated from the ground, and applying to the electrodes a voltage sufficient to produce an electric current across the bed of combustibles, so as to heat it and create an electric connection between the electrodes on traversing the bed of combustibles.

  14. Rokibaar Underground = Rock bar Underground

    Index Scriptorium Estoniae

    2008-01-01

    Rokibaari Underground (Küütri 7, Tartu) sisekujundus, mis pälvis Eesti Sisearhitektide Liidu 2007. a. eripreemia. Sisearhitekt: Margus Mänd (Tammat OÜ). Margus Männist, tema tähtsamad tööd. Plaan, 5 värv. vaadet, foto M. Männist

  15. Analysis and optimization of the thermal behaviour of a sprinkled greenhouse with underground heating: Increased value of power station waste heat -Application to greenhouse cultivation energy independence

    International Nuclear Information System (INIS)

    Lemaitre, P.

    1986-12-01

    A global thermal approach to sprinkled greenhouse cultivation was developed, which led to monographs which can be used for preliminary studies. As a second step, the thermal behaviour of this particular greenhouse was used to define the relevant parameters for the optimisation of the procedure and the ideal characteristics of the material to be used for the shelter. At the same time, a physical model of a buried tubular heat exchanger was built, together with a flexible and thoroughly tested computer program. An example of its use to help determine the dimensions for ground heating systems is presented. The various waste heat recovery procedures described have been studied, leading to an internal economic study including a comparison with other means of greenhouse heating [fr

  16. Comparison of Distributed Acoustic Sensing (DAS) from Fiber-Optic Cable to Three Component Geophones in an Underground Mine

    Science.gov (United States)

    Speece, M. A.; Nesladek, N. J.; Kammerer, C.; Maclaughlin, M.; Wang, H. F.; Lord, N. E.

    2017-12-01

    We conducted experiments in the Underground Education Mining Center on the Montana Tech campus, Butte, Montana, to make a direct comparison between Digital Acoustic Sensing (DAS) and three-component geophones in a mining setting. The sources used for this project where a vertical sledgehammer, oriented shear sledgehammer, and blasting caps set off in both unstemmed and stemmed drillholes. Three-component Geospace 20DM geophones were compared with three different types of fiber-optic cable: (1) Brugg strain, (2) Brugg temperature, and (3) Optical Cable Corporation strain. We attached geophones to the underground mine walls and on the ground surface above the mine. We attached fiber-optic cables to the mine walls and placed fiber-optic cable in boreholes drilled through an underground pillar. In addition, we placed fiber-optic cables in a shallow trench at the surface of the mine. We converted the DAS recordings from strain rate to strain prior to comparison with the geophone data. The setup of the DAS system for this project led to a previously unknown triggering problem that compromised the early samples of the DAS traces often including the first-break times on the DAS records. Geophones clearly recorded the explosives; however, the large amount of energy and its close distance from the fiber-optic cables seemed to compromise the entire fiber loop. The underground hammer sources produced a rough match between the DAS records and the geophone records. However, the sources on the surface of the mine, specifically the sources oriented inline with the fiber-optic cables, produced a close match between the fiber-optic traces and the geophone traces. All three types of fiber-optic cable that were in the mine produced similar results, and one type did not clearly outperform the others. Instead, the coupling of the cable to rock appears to be the most important factor determining DAS data quality. Moreover, we observed the importance of coupling in the boreholes, where

  17. Underground Politics

    DEFF Research Database (Denmark)

    Galis, Vasilis; Summerton, Jane

    Public spaces are often contested sites involving the political use of sociomaterial arrangements to check, control and filter the flow of people (see Virilio 1977, 1996). Such arrangements can include configurations of state-of-the-art policing technologies for delineating and demarcating borders...... status updates on identity checks at the metro stations in Stockholm and reports on locations and time of ticket controls for warning travelers. Thus the attempts by authorities to exert control over the (spatial) arena of the underground is circumvented by the effective developing of an alternative...... infrastructural "underground" consisting of assemblages of technologies, activists, immigrants without papers, texts and emails, homes, smart phones and computers. Investigating the embedded politics of contested spatial arrangements as characteristic of specific societies one can discover not only the uses...

  18. Underground laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Bettini, A., E-mail: Bettini@pd.infn.i [Padua University and INFN Section, Dipartimento di Fisca G. Galilei, Via Marzolo 8, 35131 Padova (Italy); Laboratorio Subterraneo de Canfranc, Plaza Ayuntamiento n1 2piso, Canfranc (Huesca) (Spain)

    2011-01-21

    Underground laboratories provide the low radioactive background environment necessary to frontier experiments in particle and nuclear astrophysics and other disciplines, geology and biology, that can profit of their unique characteristics. The cosmic silence allows to explore the highest energy scales that cannot be reached with accelerators by searching for extremely rare phenomena. I will briefly review the facilities that are operational or in an advanced status of approval around the world.

  19. High power RF heating and nonthermal distributions in tokamak plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Peeters, A.G.

    1994-12-13

    This thesis discusses the nonthermal effects in the electron population of a tokamak, that are generated by the inductive electric field and electron cyclotron resonant heating. The kinetic description of the plasma is given by a Boltzmann equation for the electron velocity distribution, in which the many small angle scattering Coulomb collisions that occur in the plasma are modelled by a Fokker-Planck collision term. These collisions drive the distribution towards the Maxwellian distribution of thermodynamic equilibrium. The energy absorption from the electron cyclotron waves and the acceleration by the toroidal electric field lead to deviations from the Maxwellian destribution. The interaction of the electron cyclotron waves with the plasma is treated within quasilinear theory. Resonant interaction occurs when the wave frequency matches one of the harmonics of the gyration frequency of the electrons in the static magnetic field. The waves generate a diffusion of resonant electrons in velocity space. The inductive electric field accelerates the electrons in the direction prallel to the magnetic field and leads to a convection in velocity space. The equilibrium that is reached between the driving forces of the electric field and the electron cyclotron waves and the restoring force of the collisions is studied in this thesis. The specific geometry of the tokamak is incorporated in the model through an average of the kinetic equation over the electron orbits. (orig./WL).

  20. High power RF heating and nonthermal distributions in tokamak plasmas

    International Nuclear Information System (INIS)

    Peeters, A.G.

    1994-01-01

    This thesis discusses the nonthermal effects in the electron population of a tokamak, that are generated by the inductive electric field and electron cyclotron resonant heating. The kinetic description of the plasma is given by a Boltzmann equation for the electron velocity distribution, in which the many small angle scattering Coulomb collisions that occur in the plasma are modelled by a Fokker-Planck collision term. These collisions drive the distribution towards the Maxwellian distribution of thermodynamic equilibrium. The energy absorption from the electron cyclotron waves and the acceleration by the toroidal electric field lead to deviations from the Maxwellian destribution. The interaction of the electron cyclotron waves with the plasma is treated within quasilinear theory. Resonant interaction occurs when the wave frequency matches one of the harmonics of the gyration frequency of the electrons in the static magnetic field. The waves generate a diffusion of resonant electrons in velocity space. The inductive electric field accelerates the electrons in the direction prallel to the magnetic field and leads to a convection in velocity space. The equilibrium that is reached between the driving forces of the electric field and the electron cyclotron waves and the restoring force of the collisions is studied in this thesis. The specific geometry of the tokamak is incorporated in the model through an average of the kinetic equation over the electron orbits. (orig./WL)

  1. Heat tranfer decrease during water boiling in a tube for the heat flux step distribution by the tube length

    International Nuclear Information System (INIS)

    Remizov, O.V.; Sergeev, V.V.; Yurkov, Yu.I.

    1983-01-01

    The effect of the heat flux distribution along the circular tube length on supercritical convective heat transfer at parameters typical for steam generators heated by liquid metal is studied. The effect of conditions in a under- and a supercritical zones of a vertical tube with independently heated lower and upper sections on supercritical convective heat transfer is studied on a water circulation loop at 9.8-17.7 MPa pressure and 330-1000 kg/m 2 s mass velocities. The experimental heat fluxes varied within the following limits: at the upper section from 0 to 474 kW/m 2 , at the lower section from 190 to 590 kW/m 2 . Analysis of the obtained data shows that when heat flux changes in the supercritical zone rewetting of the heated surface and simultaneous existence of two critical zones are observed. The effect of heat flux in the supercritical zone on convective heat transfer is ambiguous: the heat flux growth up to 60-100 kW/m 2 leads to increasing minimum values of the heat transfer factor in the supercritical zone, and a further heat flux growth - to their reduction. The conclusion is made that the value of heat flux in the undercritical zone affects convective heat transfer in the supercritical zone mainly through changing the value of critical vapour content

  2. Control of distributed heat transfer mechanisms in membrane distillation plants

    KAUST Repository

    Laleg-Kirati, Taous-Meriem

    2017-01-05

    Various examples are provided that are related to boundary control in membrane distillation (MD) processes. In one example, a system includes a membrane distillation (MD) process comprising a feed side and a permeate side separated by a membrane boundary layer; and processing circuitry configured to control a water production rate of the MD process based at least in part upon a distributed heat transfer across the membrane boundary layer. In another example, a method includes determining a plurality of estimated temperature states of a membrane boundary layer separating a feed side and a permeate side of a membrane distillation (MD) process; and adjusting inlet flow rate or inlet temperature of at least one of the feed side or the permeate side to maintain a difference temperature along the membrane boundary layer about a defined reference temperature based at least in part upon the plurality of estimated temperature states.

  3. ECRH [electron-cyclotron resonance heating]-heated distributions in thermal-barrier tandem mirrors

    International Nuclear Information System (INIS)

    Cohen, R.H.; LoDestro, L.L.

    1987-01-01

    The distribution function is calculated for electrons subjected to strong electron-cyclotron resonance heating (ECRH) at the plug and barrier in a tandem-mirror thermal-barrier cell. When ECRH diffusion locally dominates over collisions and a boundary condition (associated with electrons passing to the center cell) imposes variations on the distribution function rapid compared to the variation of the ECRH and collisional diffusion coefficients, the kinetic equation can be reduced approximately to Laplace's equation. For the typical case where velocity space is divided into distinct regions in which plug and barrier ECRH dominate, the solution in each region can be expressed in terms of the plasma dispersion function or exponential integrals, according to whether the passing electrons are dominated by collisions or ECRH, respectively. The analytic results agree well with Fokker-Planck code results, in terms of both velocity-space structure and values of moments. 10 refs., 4 figs

  4. Global heating distributions for January 1979 calculated from GLA assimilated and simulated model-based datasets

    Science.gov (United States)

    Schaack, Todd K.; Lenzen, Allen J.; Johnson, Donald R.

    1991-01-01

    This study surveys the large-scale distribution of heating for January 1979 obtained from five sources of information. Through intercomparison of these distributions, with emphasis on satellite-derived information, an investigation is conducted into the global distribution of atmospheric heating and the impact of observations on the diagnostic estimates of heating derived from assimilated datasets. The results indicate a substantial impact of satellite information on diagnostic estimates of heating in regions where there is a scarcity of conventional observations. The addition of satellite data provides information on the atmosphere's temperature and wind structure that is important for estimation of the global distribution of heating and energy exchange.

  5. Underground storage

    Energy Technology Data Exchange (ETDEWEB)

    1965-06-10

    A procedure is described for making an underground storage cavity in a soluble formation. Two holes are drilled, and fluid is pumped into the first hole. This fluid is a non-solute for the formation material. Then pressure is applied to the fluid until the formation is fractured in the direction of the second hole. More non-solute fluid is injected to complete the fracture between the 2 holes. A solute fluid is then circulated between the 2 holes, which results in removal of that part of the formation next to the fracture and the forming of a chamber.

  6. Geospatial Analysis of the Building Heat Demand and Distribution Losses in a District Heating Network

    Directory of Open Access Journals (Sweden)

    Tobias Törnros

    2016-11-01

    Full Text Available The district heating (DH demand of various systems has been simulated in several studies. Most studies focus on the temporal aspects rather than the spatial component. In this study, the DH demand for a medium-sized DH network in a city in southern Germany is simulated and analyzed in a spatially explicit approach. Initially, buildings are geo-located and attributes obtained from various sources including building type, ground area, and number of stories are merged. Thereafter, the annual primary energy demand for heating and domestic hot water is calculated for individual buildings. Subsequently, the energy demand is aggregated on the segment level of an existing DH network and the water flow is routed through the system. The simulation results show that the distribution losses are overall the highest at the end segments (given in percentage terms. However, centrally located pipes with a low throughflow are also simulated to have high losses. The spatial analyses are not only useful when addressing the current demand. Based on a scenario taking into account the refurbishment of buildings and a decentralization of energy production, the future demand was also addressed. Due to lower demand, the distribution losses given in percentage increase under such conditions.

  7. The three-dimensional distribution of atmospheric heating during the GWE

    OpenAIRE

    SCHAACK, TODD K.; JOHNSON, DONALD R.; WEI, MING-YING

    2011-01-01

    The three-dimensional global distributions of time-averaged atmospheric heating for January, April, July and October 1979 are estimated from the ECMWF GWE Level IIIb data set. Heating rates are calculated through a vertical integration of the isentropic equation of mass continuity. Estimates of the vertical variation of heating are presented in isobaric coordinates through interpolation of the vertical profiles of heating from isentropic to isobaric coordinates. The horizontal distributions o...

  8. Seasonal distributions of diabatic heating during the First GARP Global Experiment

    OpenAIRE

    Ying Wei, Ming; Johnson, Donald R.; Townsend, Ronald D.

    2011-01-01

    The seasonal and annual global distributions of diabatic heating during the First GARP Global Experiment (FGGE) are estimated using the isentropic mass continuity equation. The data used are from the FGGE Level IIIa analyses generated by the United States National Meteorological Center. Spatially and temporally coherent diabatic heating distributions are obtained from the isentropic planetary scale mass circulation that is forced by large-scale heat sources and sinks. The diabatic heating in...

  9. Heat transport and storage

    International Nuclear Information System (INIS)

    Despois, J.

    1977-01-01

    Recalling the close connections existing between heat transport and storage, some general considerations on the problem of heat distribution and transport are presented 'in order to set out the problem' of storage in concrete form. This problem is considered in its overall plane, then studied under the angle of the different technical choices it involves. The two alternatives currently in consideration are described i.e.: storage in a mined cavity and underground storage as captive sheet [fr

  10. Earth heat exchangers - function and interaction with the geologic underground. Erdwaermesonden - Funktionsweise und Wechselwirkung mit dem geologischen Untergrund; Feldmessungen und Modellsimulation

    Energy Technology Data Exchange (ETDEWEB)

    Eugster, W J

    1991-01-01

    Since 1980 almost 4'000 space heating systems using vertical earth heat exchangers (VHE's) have been commissioned in Switzerland, the majority for private houses. Probe lengths vary between 30 and 150 m. A VHE extracts heat from the ground, supplying a heat pump, which then provides energy to the heating system at an appropriate temperature. For the study reported in this thesis a commercially supplied plant in Elgg in the canton of Zurich equipped with a single 103 m long VHE has been investigated in detail. The temperatures in the ground at 10 different depths and 2 different radial distances from the VHE have been measured at 30 minute intervals over a five year period. In addition, the atmospheric temperature and all parameters relevant to the operation of the entire system have also been monitored. In the selection of equipment, special attention was given to ensuring high absolute precision temperature measurement over the extended period of study. The platinum resistance sensors were carefully pre-aged and individually calibrated. The resulting accuracy of measurement in the field has been better than [+-]0.1[sup o]C. The development of the software for data acquisition and processing has formed part of this work. Measured data were used to calibrate a two-dimensional, cylindrical coordinate numerical computer model. This model was selected because of the coaxial construction of the VHE. The model treats conduction in the ground formation, advection in the heat exchanger tubes and heat exchange between ground and atmosphere. Measurements and computations both indicate the development of a permanent, cusp-like distribution of temperature deficit around the VHE during the first two years of operation. (author) figs., tabs., 45 refs.

  11. Study on drop pressure and flow distribution of double-tube heat exchanger

    International Nuclear Information System (INIS)

    Liu Junqiang; Chen Minghui; Hu Yumin; Li Rizhu; Kong Dechun; Zhang Weijie

    2007-01-01

    The parallel connection channel pressure drop characters of the double-tube bundle heat exchange were experimentally investigated in this paper in order to find out how the flow of the heat exchanger is distributed and then to optimize the structure of heat exchanger according to the flow distribution. A double-tube bundle heat exchanger was built according to the similarity criteria. The experiment system was also built to test the optimization of the heat exchanger. The experiment results reveal that the calculating model is reliable and decreasing pipe space to optimize the heat exchanger is reasonable. (authors)

  12. Flow and heat distribution analysis of different transformer sub-stations

    International Nuclear Information System (INIS)

    Hasini, H; Shuaib, N H; Yogendran, S B; Toh, K B

    2013-01-01

    This paper describes CFD investigation on the flow and heat transfer in transformers at different sub-station buildings. The analysis aimed to determine the cooling capability of the existing transformer building employing natural ventilation system to dissipate heat sufficiently when new dry-type transformer operating under full load condition is used. The transformer and building models were developed based on the actual transformer configuration in operation at three different locations in Malaysia. The calculation was carried out on three different types of sub-stations namely stand-alone, attach-to-building and underground. The effect of natural ventilation speed and building volume on the transformer surfaces temperature are also investigated. It was predicted that the existing sub-station configuration is able to dissipate heat produced from the dry type transformer by using its natural ventilation system regardless of the sub-station types. However, the smallest building case shows relatively high surrounding temperature

  13. Nuclear district heating. 1. Process heat reactors and transmission and distribution networks

    International Nuclear Information System (INIS)

    Caizergues, R.

    1979-01-01

    Three kinds of production station are considered: joint electricity and heat-producing stations, heat-producing stations with CAS reactors and heat-producing stations with Thermos reactors. The thermal energy supply possibilities of these stations, the cost price of this energy and the cost price per therm produced by the district heating source and conveyed to the user are studied [fr

  14. Underground gasification and combustion brown with the use of groundwater

    Directory of Open Access Journals (Sweden)

    Zholudyev S.V.

    2011-11-01

    Full Text Available The problems of coal excavation and environement protection are priority for Ukraine. Underground coal gasification (UCG and underground coal incineration (UCI are combining excavation with simultaneous underground processing in entire technological process, capable to solve this problem. Using an intermediate heat carrier - ground water may optimisating of these processes.

  15. Research on suitable heating conditions during local PWHT. Pt. 1. Influence of heating conditions on temperature distribution

    International Nuclear Information System (INIS)

    Tanaka, Jinkichi; Horii, Yukihiko; Sato, Masanobu; Murakawa, Hidekazu; Wang Jianhua

    1999-01-01

    To improve weld joint properties a heat treatment so called post weld heat treatment (PWHT) is often implemented for steel weldment. Generally, the PWHT is conducted in a furnace at a factory. But in site welds such as the girth joint of pipe, a local PWHT is applied using electric heater and so on. In the local PWHT steep temperature gradient occurs depending on the heating condition and it leads to rise of the thermal stress in addition to the welding residual stress. However, heating condition is not always defined the same in some standards. Therefore, suitable heat conditions for the local PWHT were studied supposing the power plant and so on experimentally and theoretically. Temperature distribution and thermal strains under different heating conditions were measured during the local PWHT using carbon steel pipes of 340 mm in diameter and 53 mm in wall thickness. The temperature gradient, thermal strain were also analyzed using Finite Element Method (FEM) as axis-symmetric model. Further, the influences of pipe size and heat transfer coefficient on the temperature distribution were analyzed and suitable heating source widths for various pipe sizes were proposed from the viewpoint of temperature distribution. (orig.)

  16. Analytical and numerical treatment of the heat conduction equation obtained via time-fractional distributed-order heat conduction law

    Science.gov (United States)

    Želi, Velibor; Zorica, Dušan

    2018-02-01

    Generalization of the heat conduction equation is obtained by considering the system of equations consisting of the energy balance equation and fractional-order constitutive heat conduction law, assumed in the form of the distributed-order Cattaneo type. The Cauchy problem for system of energy balance equation and constitutive heat conduction law is treated analytically through Fourier and Laplace integral transform methods, as well as numerically by the method of finite differences through Adams-Bashforth and Grünwald-Letnikov schemes for approximation derivatives in temporal domain and leap frog scheme for spatial derivatives. Numerical examples, showing time evolution of temperature and heat flux spatial profiles, demonstrate applicability and good agreement of both methods in cases of multi-term and power-type distributed-order heat conduction laws.

  17. Underground gasification in Russia

    Energy Technology Data Exchange (ETDEWEB)

    1956-11-21

    A paper in Pravda by the Deputy Chief Engineer of the Underground Gasification Department indicates that there are at least three or four pilot plants in operation; one plant near Moscow has operated for 14 years and one in the Donbas for 8 years. The first plant has a daily output of gas corresponding to 400 tons of coal a day and produces a gas of low calorific value. A plant opened in 1956 in the Kuzbas to produce gas of a higher quality. A plant, being built near Moscow in conjunction with a gas turbine electrical power station, will produce gas equivalent in heating value to 220,000 tons of coal a year. A larger plant, being built at Angren in central Asia, will produce gas equivalent in heating value to 700,000 tons of coal a year.

  18. Dynamic Underground Stripping Demonstration Project

    International Nuclear Information System (INIS)

    Aines, R.; Newmark, R.; McConachie, W.; Rice, D.; Ramirez, A.; Siegel, W.; Buettner, M.; Daily, W.; Krauter, P.; Folsom, E.; Boegel, A.J.; Bishop, D.; udel, K.

    1992-03-01

    LLNL is collaborating with the UC Berkeley College of Engineering to develop and demonstrate a system of thermal remediation and underground imaging techniques for use in rapid cleanup of localized underground spills. Called ''Dynamic Stripping'' to reflect the rapid and controllable nature of the process, it will combine steam injection, direct electrical heating, and tomographic geophysical imaging in a cleanup of the LLNL gasoline spill. In the first 8 months of the project, a Clean Site engineering test was conducted to prove the field application of the techniques before moving to the contaminated site in FY 92

  19. Water underground

    Science.gov (United States)

    de Graaf, Inge

    2015-04-01

    The world's largest assessable source of freshwater is hidden underground, but we do not know what is happening to it yet. In many places of the world groundwater is abstracted at unsustainable rates: more water is used than being recharged, leading to decreasing river discharges and declining groundwater levels. It is predicted that for many regions of the world unsustainable water use will increase, due to increasing human water use under changing climate. It would not be long before shortage causes widespread droughts and the first water war begins. Improving our knowledge about our hidden water is the first step to stop this. The world largest aquifers are mapped, but these maps do not mention how much water they contain or how fast water levels decline. If we can add a third dimension to the aquifer maps, so a thickness, and add geohydrological information we can estimate how much water is stored. Also data on groundwater age and how fast it is refilled is needed to predict the impact of human water use and climate change on the groundwater resource.

  20. Integration of Heat Pumps in Distribution Grids: Economic Motivation for Grid Control

    NARCIS (Netherlands)

    Nykamp, Stefan; Molderink, Albert; Bakker, Vincent; Toersche, Hermen; Hurink, Johann L.; Smit, Gerardus Johannes Maria

    2012-01-01

    Electric heat pumps combined with heat buffers are important elements in smart grids since they together allow to shift the consumption of electricity in time. In this paper the effects of different control algorithms for heat pumps on the investment costs for distribution grids are investigated.

  1. Integration of heat pumps in distribution grids: economic motivation for grid control

    NARCIS (Netherlands)

    Nykamp, Stefan; Molderink, Albert; Bakker, Vincent; Toersche, Hermen; Hurink, Johann L.; Smit, Gerardus Johannes Maria

    2012-01-01

    Electric heat pumps combined with heat buffers are important elements in smart grids since they together allow to shift the consumption of electricity in time. In this paper the effects of different control algorithms for heat pumps on the investment costs for distribution grids are investigated.

  2. The flow distribution in the parallel tubes of the cavity receiver under variable heat flux

    International Nuclear Information System (INIS)

    Hao, Yun; Wang, Yueshe; Hu, Tian

    2016-01-01

    Highlights: • An experimental loop is built to find the flow distribution in the parallel tubes. • With the concentration of heat flux, two-phase flow makes distribution more uneven. • The total flow rate is chosen appropriately for a wider heat flux distribution. • A suitable system pressure is essential for the optimization of flow distribution. - Abstract: As an optical component of tower solar thermal power station, the heliostat mirror reflects sunlight to one point of the heated surface in the solar cavity receiver, called as one-point focusing system. The radiation heat flux concentrated in the cavity receiver is always non-uniform temporally and spatially, which may lead to extremely local over-heat on the receiver evaporation panels. In this paper, an electrical heated evaporating experimental loop, including five parallel vertical tubes, is set up to evaluate the hydrodynamic characteristics of evaporation panels in a solar cavity receiver under various non-uniform heat flux. The influence of the heat flux concentration ratio, total flow rate, and system pressure on the flow distribution of parallel tubes is discussed. It is found that the flow distribution becomes significantly worse with the increase of heat flux and concentration ratio; and as the system pressure decreased, the flow distribution is improved. It is extremely important to obtain these interesting findings for the safe and stable operation of solar cavity receiver, and can also provide valuable references for the design and optimization of operating parameters solar tower power station system.

  3. The Canfranc Underground Laboratory

    International Nuclear Information System (INIS)

    Amare, J.; Beltran, B.; Carmona, J.M.; Cebrian, S.; Garcia, E.; Irastorza, I.G.; Gomez, H.; Luzon, G.; Martinez, M.; Morales, J.; Ortiz de Solorzano, A.; Pobes, C.; Puimedon, J.; Rodriguez, A.; Ruz, J.; Sarsa, M.L.; Torres, L.; Villar, J.A.

    2005-01-01

    This paper describes the forthcoming enlargement of the Canfranc Underground Laboratory (LSC) which will allow to host new international Astroparticle Physics experiments and therefore to broaden the European underground research area. The new Canfranc Underground Laboratory will operate in coordination (through the ILIAS Project) with the Gran Sasso (Italy), Modane (France) and Boulby (UK) underground laboratories

  4. An lesson learned from the consultation activity with community regarding the Mizunami Underground Laboratory project. From a viewpoint of procedural and distributive justice

    International Nuclear Information System (INIS)

    Nishio, Kazuhisa; Osawa, Hideaki

    2016-01-01

    Japan Atomic Energy Agency (JAEA) has promoted the Mizunami Underground Research Laboratory (Mizunami URL) as one of generic URL to perform basic research of waste disposal technology for about twenty years. JAEA had carried out consultation activities with local people and community from 1995 when the plan of Mizunami URL opened at the time, because an early approach of JAEA caused a sense of social distrust and concern, which the study area of Mizunami URL would be candidate site of real repository. In this paper, we conducted normative analysis intended for the consultation activities from a viewpoint of procedural justice and distributed justice, used as the social psychological framework in terms of public NIMBY facility. The results show that it is important to develop local partnership, composed of representative local people and organization, at early start in the light of procedural justice and to support deliberation regarding distributive justice and so on by local partnership in the aspect of information and financial administration. (author)

  5. France's State of the Art Distributed Optical Fibre Sensors Qualified for the Monitoring of the French Underground Repository for High Level and Intermediate Level Long Lived Radioactive Wastes.

    Science.gov (United States)

    Delepine-Lesoille, Sylvie; Girard, Sylvain; Landolt, Marcel; Bertrand, Johan; Planes, Isabelle; Boukenter, Aziz; Marin, Emmanuel; Humbert, Georges; Leparmentier, Stéphanie; Auguste, Jean-Louis; Ouerdane, Youcef

    2017-06-13

    This paper presents the state of the art distributed sensing systems, based on optical fibres, developed and qualified for the French Cigéo project, the underground repository for high level and intermediate level long-lived radioactive wastes. Four main parameters, namely strain, temperature, radiation and hydrogen concentration are currently investigated by optical fibre sensors, as well as the tolerances of selected technologies to the unique constraints of the Cigéo's severe environment. Using fluorine-doped silica optical fibre surrounded by a carbon layer and polyimide coating, it is possible to exploit its Raman, Brillouin and Rayleigh scattering signatures to achieve the distributed sensing of the temperature and the strain inside the repository cells of radioactive wastes. Regarding the dose measurement, promising solutions are proposed based on Radiation Induced Attenuation (RIA) responses of sensitive fibres such as the P-doped ones. While for hydrogen measurements, the potential of specialty optical fibres with Pd particles embedded in their silica matrix is currently studied for this gas monitoring through its impact on the fibre Brillouin signature evolution.

  6. Design of distributed JT (Joule-Thomson) effect heat exchanger for superfluid 2 K cooling device

    Science.gov (United States)

    Jeong, S.; Park, C.; Kim, K.

    2018-03-01

    Superfluid at 2 K or below is readily obtained from liquid helium at 4.2 K by reducing its vapour pressure. For better cooling performance, however, the cold energy of vaporized helium at 2 K chamber can be effectively utilized in a recuperator which is specially designed in this paper for accomplishing so-called the distributed Joule-Thomson (JT) expansion effect. This paper describes the design methodology of distributed JT effect heat exchanger for 2 K JT cooling device. The newly developed heat exchanger allows continuous significant pressure drop at high-pressure part of the recuperative heat exchanger by using a capillary tube. Being different from conventional recuperative heat exchangers, the efficient JT effect HX must consider the pressure drop effect as well as the heat transfer characteristic. The heat exchanger for the distributed JT effect actively utilizes continuous pressure loss at the hot stream of the heat exchanger by using an OD of 0.64 mm and an ID of 0.4 mm capillary tube. The analysis is performed by dividing the heat exchanger into the multiple sub-units of the heat exchange part and JT valve. For more accurate estimation of the pressure drop of spirally wound capillary tube, preliminary experiments are carried out to investigate the friction factor at high Reynolds number. By using the developed pressure drop correlation and the heat transfer correlation, the specification of the heat exchanger with distributed JT effect for 2 K JT refrigerator is determined.

  7. Heat savings in energy systems with substantial distributed generation

    DEFF Research Database (Denmark)

    Østergaard, PA

    2003-01-01

    In Denmark, the integration of wind power is affected by a large amount of cogeneration of heat and power. With ancillary services supplied by large-scale condensation and combined heat and power (CHP) plants, a certain degree of large-scale generation is required regardless of momentary wind input......, if a certain production is required regardless of whether over-all electricity generation is sufficient. This article analyses this and although heat savings do have a negative impact on the amount of wind power the system may integrate a given moment in certain cases, associated fuel savings are notable...

  8. Temperature distribution of the energy consumed as heat in Canada

    International Nuclear Information System (INIS)

    Puttagunta, V.R.

    1974-10-01

    The amount of energy consumed as heat (excluding thermal generation of electricity) in Canada is estimated from statistical data available on the total consumption of energy for the years 1958 to 2000. Based on some actual plant data and other statistical information this energy consumption is sub-divided into four temperature categories: high (>260 degrees C), intermediate (140-260 degrees C), low (100-140 degrees C), and space heating (<100 degrees C). The results of this analysis show that approximately half of all the energy consumed in Canada has an end use as heat. Less than 10 percent of the energy consumed as heat is in the high temperature category, 12 to 14 percent is in the intermediate temperature range, 21 to 27 percent is in the low temperature range, and 50 to 58 percent is used for space heating. Over 90 percent of the energy consumed as heat in Canada is within the temperature capability of the CANDU-PHW reactor. (author)

  9. Transient thermal stress distribution in a circular pipe heated externally with a periodically moving heat source

    International Nuclear Information System (INIS)

    Özışık, Gülşah; Genç, M. Serdar; Yapıcı, Hüseyin

    2012-01-01

    This study presents the effects of periodically moving heat source on a circular steel pipe heated partly from its outer surface under stagnant ambient conditions. While the pipe is heated with this heat source applied on a certain section having a thickness of heat flux, the water flows through it to transfer heat. It is assumed that the flow is a fully-developed laminar flow. The heat source moves along from one end of the outer to the other end with a constant speed and then returns to the first end with the same speed. It is assumed that the heat transfer rate has a constant value, and that the thermo-physical properties of the steel do not change with temperature (elastic analysis). The numerical calculations have been performed individually for a wide range of thermal conductivity of steel and for different thicknesses of heat flux. The moving heat source produces the non-uniform temperature gradient and the non-uniform effective thermal stress, and when it arrives at the ends of the pipe, the temperature and effective thermal stress ratio profiles rise more excessively. The tangential component is more dominant in the effective thermal stress than the radial component. Highlights: ► Moving heat source produces non-uniform temperature gradients and thermal stresses. ► When moving heat source arrives at ends of pipe, temperature gradients rise excessively. ► With increasing of heat flux thickness and thermal conductivity, the temperature gradients reduce. ► Temperature gradients in thermal boundary layers slightly increase. ► Tangential component is more dominant in thermal stress than radial component.

  10. Diffuse Ceiling Ventilation and the Influence of Room Height and Heat Load Distribution

    DEFF Research Database (Denmark)

    Nielsen, Peter Vilhelm; Vilsbøll, Rasmus W; Liu, Li

    2015-01-01

    Diffuse ceiling (inlet) ventilation is an air distribution system that supplies air from the entire ceiling surface, giving a low supply velocity. The flow pattern in the room is controlled by the heat sources. The system generates high mixing flow and the air velocities in the room are expected...... to be not much influenced by the flow rate to the room but dependent on the heat load. Previous studies have shown that diffuse ceiling ventilation has an ability to remove large heat loads without compromising the indoor climate. However, recent experiments indicate that the maximum accepted heat load decreases...... with a large room height and it decreases in connection with certain heat load distributions. Room geometries and heat load distributions that are optimal for diffuse ceiling ventilation are discussed. A simplified design procedure is introduced....

  11. Model-based energy performance assessment of the world largest underground seasonal thermal energy storage in a pilot district heating system in Chifeng City

    NARCIS (Netherlands)

    Xu, L.; Torrens Galdiz, J.I.; Guo, F.; Yang, X.; Hensen, J.L.M.

    2017-01-01

    District heating systems play an important role in supporting energy transition by using and storing energy delivered by renewable and other low-grade energy sources such as industrial waste heat. However, this low-grade heat is not always able to satisfy the heating demand, including space heating

  12. Effects of the distribution density of a biomass combined heat and power plant network on heat utilisation efficiency in village-town systems.

    Science.gov (United States)

    Zhang, Yifei; Kang, Jian

    2017-11-01

    The building of biomass combined heat and power (CHP) plants is an effective means of developing biomass energy because they can satisfy demands for winter heating and electricity consumption. The purpose of this study was to analyse the effect of the distribution density of a biomass CHP plant network on heat utilisation efficiency in a village-town system. The distribution density is determined based on the heat transmission threshold, and the heat utilisation efficiency is determined based on the heat demand distribution, heat output efficiency, and heat transmission loss. The objective of this study was to ascertain the optimal value for the heat transmission threshold using a multi-scheme comparison based on an analysis of these factors. To this end, a model of a biomass CHP plant network was built using geographic information system tools to simulate and generate three planning schemes with different heat transmission thresholds (6, 8, and 10 km) according to the heat demand distribution. The heat utilisation efficiencies of these planning schemes were then compared by calculating the gross power, heat output efficiency, and heat transmission loss of the biomass CHP plant for each scenario. This multi-scheme comparison yielded the following results: when the heat transmission threshold was low, the distribution density of the biomass CHP plant network was high and the biomass CHP plants tended to be relatively small. In contrast, when the heat transmission threshold was high, the distribution density of the network was low and the biomass CHP plants tended to be relatively large. When the heat transmission threshold was 8 km, the distribution density of the biomass CHP plant network was optimised for efficient heat utilisation. To promote the development of renewable energy sources, a planning scheme for a biomass CHP plant network that maximises heat utilisation efficiency can be obtained using the optimal heat transmission threshold and the nonlinearity

  13. Effects of Leak Detection/Location on Underground Heat Distribution System (UHDS) Life Cycle Costs: A Probabilistic Model

    Science.gov (United States)

    1991-12-01

    ADA167556 (USACERL, March 1986). E. Segan and C. Chen ’K. Cooper et a]. 9 spots associated with leaks are detected with either a digital temperature...HSHG.DEX ATTN: NAPEN-FL Walte Road AMC 20307 Norto APB. CA 92409 ATTN: Faciliion Ensgime ATIN: APRC-MX4DB US Ary Roagr Diviaiur AWlN: Libary (13

  14. Atlas of the global distribution of atmospheric heating during the global weather experiment

    Science.gov (United States)

    Schaack, Todd K.; Johnson, Donald R.

    1991-01-01

    Global distributions of atmospheric heating for the annual cycle of the Global Weather Experiment are estimated from the European Centre for Medium-Range Weather Forecasts (ECMWF) Level 3b data set. Distributions of monthly, seasonally, and annually averaged heating are presented for isentropic and isobaric layers within the troposphere and for the troposphere as a whole. The distributions depict a large-scale structure of atmospheric heating that appears spatially and temporally consistent with known features of the global circulation and the seasonal evolution.

  15. Logistics background study: underground mining

    Energy Technology Data Exchange (ETDEWEB)

    Hanslovan, J. J.; Visovsky, R. G.

    1982-02-01

    Logistical functions that are normally associated with US underground coal mining are investigated and analyzed. These functions imply all activities and services that support the producing sections of the mine. The report provides a better understanding of how these functions impact coal production in terms of time, cost, and safety. Major underground logistics activities are analyzed and include: transportation and personnel, supplies and equipment; transportation of coal and rock; electrical distribution and communications systems; water handling; hydraulics; and ventilation systems. Recommended areas for future research are identified and prioritized.

  16. Benefits of Integrating Geographically Distributed District Heating Systems

    DEFF Research Database (Denmark)

    Dominkovic, Dominik Franjo; Bačeković, I.; Sveinbjörnsson, Dadi Þorsteinn

    2016-01-01

    Although liberalization of the electricity day-ahead markets has gained pace throughout the Europe, district heating markets are often dominated by lack of competition between suppliers, which curbs the potential of having cheaper systems in terms of socio-economic costs, and technically better s...

  17. TEMPERATURE DISTRIBUTION MONITORING AND ANALYSES AT DIFFERENT HEATING CONTROL PRINCIPLES

    DEFF Research Database (Denmark)

    Simone, Angela; Rode, Carsten; Olesen, Bjarne W.

    2010-01-01

    under different control strategies of the heating system (Pseudo Random Binary Sequence signal controlling all the heaters (PRBS) or thermostatic control of the heaters (THERM)). A comparison of the measured temperatures within the room, for the five series of experiments, shows a better correlation...

  18. Underground Layout Configuration

    International Nuclear Information System (INIS)

    A. Linden

    2003-01-01

    The purpose of this analysis was to develop an underground layout to support the license application (LA) design effort. In addition, the analysis will be used as the technical basis for the underground layout general arrangement drawings

  19. A system design for distributed energy generation in low temperature district heating (LTDH) networks

    OpenAIRE

    Jones, Sean; Gillott, Mark C.; Boukhanouf, Rabah; Walker, Gavin S.; Tunzi, Michele; Tetlow, David; Rodrigues, Lucélia Taranto; Sumner, M.

    2017-01-01

    Project SCENIC (Smart Controlled Energy Networks Integrated in Communities) involves connecting properties at the University of Nottingham’s Creative Energy Homes test site in a community scale, integrated heat and power network. Controls will be developed to allow for the most effective heat load allocation and power distribution scenarios. Furthermore, the system will develop the prosumer concept, where consumers are both buyers and sellers of energy in both heat and power systems. \\ud \\ud ...

  20. Underground pipeline corrosion

    CERN Document Server

    Orazem, Mark

    2014-01-01

    Underground pipelines transporting liquid petroleum products and natural gas are critical components of civil infrastructure, making corrosion prevention an essential part of asset-protection strategy. Underground Pipeline Corrosion provides a basic understanding of the problems associated with corrosion detection and mitigation, and of the state of the art in corrosion prevention. The topics covered in part one include: basic principles for corrosion in underground pipelines, AC-induced corrosion of underground pipelines, significance of corrosion in onshore oil and gas pipelines, n

  1. Heat savings in energy systems with substantial distributed generation

    DEFF Research Database (Denmark)

    Østergaard, Poul Alberg

    2004-01-01

    The integration of flutuating wind power is an important issue for the future development of sustainable energy systems. In Denmark, the integration is affected by a large amount of cogeneration of heat and power. This gives possibilities as well as sets restraints. The paper shows that with anci...... that with ancillary services supplied by large-scale condensation and CHP-plants, a certain degree of large-scale generation is required regardless of momentary wind input....

  2. Void fraction distribution in a heated rod bundle under flow stagnation conditions

    Energy Technology Data Exchange (ETDEWEB)

    Herrero, V.A.; Guido-Lavalle, G.; Clausse, A. [Centro Atomico Bariloche and Instituto Balseiro, Bariloche (Argentina)

    1995-09-01

    An experimental study was performed to determine the axial void fraction distribution along a heated rod bundle under flow stagnation conditions. The development of the flow pattern was investigated for different heat flow rates. It was found that in general the void fraction is overestimated by the Zuber & Findlay model while the Chexal-Lellouche correlation produces a better prediction.

  3. Equipment for secondary water distribution in heat exchanger, especially saturated steam generator for nuclear power plants and heat plants

    Energy Technology Data Exchange (ETDEWEB)

    Riman, J; Manek, O; Rybnicek, J

    1979-09-15

    A special structure consisting of a system of channels and a distribution plate with ports in-built above the tube-plate of a vertical-type steam generator prevents secondary water vaporization in the space above the tube-plate and thus also salt and sludge sedimentation which causes increased corrosion of heat transfer tubes. The size of the distribution plate ports is variable in the radial direction. The distribution plate is divided by means of the system of channels into at least two parts. The middle section of each part is of the through-flow type.

  4. Underground laboratories in Europe

    International Nuclear Information System (INIS)

    Coccia, E

    2006-01-01

    The only clear evidence today for physics beyond the standard model comes from underground experiments and the future activity of underground laboratories appears challenging and rich. I review here the existing underground research facilities in Europe. I present briefly the main characteristics, scientific activity and perspectives of these Laboratories and discuss the present coordination actions in the framework of the European Union

  5. Mathematical model of heat transfer to predict distribution of hardness through the Jominy bar

    International Nuclear Information System (INIS)

    Lopez, E.; Hernandez, J. B.; Solorio, G.; Vergara, H. J.; Vazquez, O.; Garnica, F.

    2013-01-01

    The heat transfer coefficient was estimated at the bottom surface at Jominy bar end quench specimen by solution of the heat inverse conduction problem. A mathematical model based on the finite-difference method was developed to predict thermal paths and volume fraction of transformed phases. The mathematical model was codified in the commercial package Microsoft Visual Basic v. 6. The calculated thermal path and final phase distribution were used to evaluate the hardness distribution along the AISI 4140 Jominy bar. (Author)

  6. Minimization of transport and distribution cost for district heating study of particular cases

    International Nuclear Information System (INIS)

    Barreau, A.; Caizergues, R.; Moret Bailly, J.

    1977-01-01

    The transport and distribution of hot pressurized water involve different sets of criteria: transport networks, heat distribution networks, storages. The minimization of transport cost is studied together with the distribution of thermal energy. The same parameters are introduced into these programs. The same method is used for rate of flow calculations, but mathematical methods of pipe diameter calculation are different. Some transport and distribution networks are studied with the corresponding computed programs: 52 branches networks-27 terminations; 287 branches networks-148 terminations

  7. An analysis of the temperature distribution in the pipe bending using high frequency induction heating

    International Nuclear Information System (INIS)

    Fukue, Hisayoshi; Mochizuki, Yoji; Nakamura, Harushige; Kobo, Hiroshi; Nitta, Tetsuo; Kawakami, Kiyoshi

    1986-01-01

    A pipe bending apparatus has recently been developed by applying high frequency induction heating. However, the smaller the radius of pipe bending, the greater becomes the reduction in wall thickness and the ovality of the pipe form. This makes it impossible to manufacture pipe bending which will meet the nuclear pipe design code. In order to solve this problem it is crucial to obtain a temperature distributions in a pipe which is moving. It is calculated by giving the following boundary conditions : distribution of the heat generation rate, and that of heat transfer of cooling water. In the process of analyzing these distributions, the following results were obtained. (1) The distribution of the heat generation rate is determined by the sink of energy flux of Poynting vectors. The coil efficiency thus calculated was sixty percent. This figure accords with the test data. (2) The distribution of heat transfer coefficient of cooling water is mainly determined by the rate of liquid film heat transfer, but departure from nucleate boiling and dryout has to be taken into consideration. (3) TRUMP CODE is modified so that the temperature distribution in moving pipes can be calculated by taking the boundary conditions into account. The calculated results were in accordance with the test data. (author)

  8. Physics of multiple muons in underground detectors

    International Nuclear Information System (INIS)

    Gaisser, T.K.; Stanev, T.

    1982-01-01

    We summarize results of Monte Carlo simulations of underground muons with a set of parametrizations for number and lateral distribution of muons at various detector depths. We also describe the size distributions of accompanying showers at the surface. We give some illustrations of the use of these results to study the surface-underground correlation and to interpret preliminary results of the Soudan-I detector presented at this conference

  9. Inverse heat transfer analysis of a functionally graded fin to estimate time-dependent base heat flux and temperature distributions

    International Nuclear Information System (INIS)

    Lee, Haw-Long; Chang, Win-Jin; Chen, Wen-Lih; Yang, Yu-Ching

    2012-01-01

    Highlights: ► Time-dependent base heat flux of a functionally graded fin is inversely estimated. ► An inverse algorithm based on the conjugate gradient method and the discrepancy principle is applied. ► The distributions of temperature in the fin are determined as well. ► The influence of measurement error and measurement location upon the precision of the estimated results is also investigated. - Abstract: In this study, an inverse algorithm based on the conjugate gradient method and the discrepancy principle is applied to estimate the unknown time-dependent base heat flux of a functionally graded fin from the knowledge of temperature measurements taken within the fin. Subsequently, the distributions of temperature in the fin can be determined as well. It is assumed that no prior information is available on the functional form of the unknown base heat flux; hence the procedure is classified as the function estimation in inverse calculation. The temperature data obtained from the direct problem are used to simulate the temperature measurements. The influence of measurement errors and measurement location upon the precision of the estimated results is also investigated. Results show that an excellent estimation on the time-dependent base heat flux and temperature distributions can be obtained for the test case considered in this study.

  10. Towards an intermittency-friendly energy system: Comparing electric boilers and heat pumps in distributed cogeneration

    International Nuclear Information System (INIS)

    Blarke, Morten B.

    2012-01-01

    Highlights: ► We propose an “intermittency-friendly” energy system design. ► We compare intermittency-friendly concepts in distributed cogeneration. ► We investigate a new concept involving a heat pump and intermediate cold storage. ► We find significant improvements in operational intermittency-friendliness. ► Well-designed heat pump concepts are more cost-effective than electric boilers. -- Abstract: Distributed cogeneration has played a key role in the implementation of sustainable energy policies for three decades. However, increasing penetration levels of intermittent renewables is challenging that position. The paradigmatic case of West Denmark indicates that distributed operators are capitulating as wind power penetration levels are moving above 25%; some operators are retiring cogeneration units entirely, while other operators are making way for heat-only boilers. This development is jeopardizing the system-wide energy, economic, and environmental benefits that distributed cogeneration still has to offer. The solution is for distributed operators to adapt their technology and operational strategies to achieve a better co-existence between cogeneration and wind power. Four options for doing so are analysed including a new concept that integrates a high pressure compression heat pump using low-temperature heat recovered from flue gasses in combination with an intermediate cold storage, which enables the independent operation of heat pump and cogenerator. It is found that an electric boiler provides consistent improvements in the intermittency-friendliness of distributed cogeneration. However, well-designed heat pump concepts are more cost-effective than electric boilers, and in future markets where the gas/electricity price ratio is likely to increase, compression heat pumps in combination with intermediate thermal storages represent a superior potential for combining an intermittency-friendly pattern of operation with the efficient use of

  11. Heat recovery networks synthesis of large-scale industrial sites: Heat load distribution problem with virtual process subsystems

    International Nuclear Information System (INIS)

    Pouransari, Nasibeh; Maréchal, Francois

    2015-01-01

    Highlights: • Synthesizing industrial size heat recovery network with match reduction approach. • Targeting TSI with minimum exchange between process subsystems. • Generating a feasible close-to-optimum network. • Reducing tremendously the HLD computational time and complexity. • Generating realistic network with respect to the plant layout. - Abstract: This paper presents a targeting strategy to design a heat recovery network for an industrial plant by dividing the system into subsystems while considering the heat transfer opportunities between them. The methodology is based on a sequential approach. The heat recovery opportunity between process units and the optimal flow rates of utilities are first identified using a Mixed Integer Linear Programming (MILP) model. The site is then divided into a number of subsystems where the overall interaction is resumed by a pair of virtual hot and cold stream per subsystem which is reconstructed by solving the heat cascade inside each subsystem. The Heat Load Distribution (HLD) problem is then solved between those packed subsystems in a sequential procedure where each time one of the subsystems is unpacked by switching from the virtual stream pair back into the original ones. The main advantages are to minimize the number of connections between process subsystems, to alleviate the computational complexity of the HLD problem and to generate a feasible network which is compatible with the minimum energy consumption objective. The application of the proposed methodology is illustrated through a number of case studies, discussed and compared with the relevant results from the literature

  12. On the burnout in annular channels at non-uniform heat release distribution in length

    International Nuclear Information System (INIS)

    Ornatskij, A.P.; Chernobaj, V.A.; Vasil'ev, A.F.; Struts, G.V.

    1982-01-01

    The effect of axial heat release non-uniformity on the conditions of the burnout in annular channels is investigated. The investigation is carried out in annular channels with different laws of heat flux density distribution by channel length. The heat release non-uniformity coefficient was varied from 4.4 to 10, the pressure from 9.8 to 17.6 MPa, mass rate from 500 to 1700 kg (m 2 xS), liquid temperature (chemically desalted water) at the channel inlet constituted 30-300 deg C. The experiments have been performed at the test bench with a closed circulation circuit. The data obtained testify to the fact that under non-uniform heat release the influence of main operating parameters on the value of critical power is of the same character as under uniform heat release. The character of wall temperature variation by channel length before the burnout is determined by the form of heat supply temperature profile. The temperature maximum is observed in the region lying behind the cross section with maximum heat flux. The conclusion is drawn that the dominant influence on the position of the cross section in which the burnout arises is exerted by the form of heat flux density distribution by length. Independently of this distribution form the burnout developes when the vapour content near the wall reaches a limiting value

  13. Application of large underground seasonal thermal energy storage in district heating system : a model-based energy performance assessment of a pilot system in Chifeng, China

    NARCIS (Netherlands)

    Xu, L.; Torrens Galdiz, J.I.; Guo, F.; Yang, X.; Hensen, J.L.M.

    Seasonal thermal energy storage (STES) technology is a proven solution to resolve the seasonal discrepancy between heating energy generation from renewables and building heating demands. This research focuses on the performance assessment of district heating (DH) systems powered by low-grade energy

  14. Study of temperature distribution of pipes heated by moving rectangular gauss distribution heat source. Development of pipe outer surface irradiated laser stress improvement process (L-SIP)

    International Nuclear Information System (INIS)

    Ohta, Takahiro; Kamo, Kazuhiko; Asada, Seiji; Terasaki, Toshio

    2009-01-01

    The new process called L-SIP (outer surface irradiated Laser Stress Improvement Process) is developed to improve the tensile residual stress of the inner surface near the butt welded joints of pipes in the compression stress. The temperature gradient occurs in the thickness of pipes in heating the outer surface rapidly by laser beam. By the thermal expansion difference between the inner surface and the outer surface, the compression stress occurs near the inner surface of pipes. In this paper, the theoretical equation for the temperature distributions of pipes heated by moving rectangular Gauss distribution heat source on the outer surface is derived. The temperature histories of pipes calculated by theoretical equation agree well with FEM analysis results. According to the theoretical equation, the controlling parameters of temperature distributions and histories are q/2a y , vh, a x /h and a y /h, where q is total heat input, a y is heat source length in the axial direction, a x is Gaussian radius of heat source in the hoop direction, ν is moving velocity, and h is thickness of the pipe. The essential variables for L-SIP, which are defined on the basis of the measured temperature histories on the outer surface of the pipe, are Tmax, F 0 =kτ 0 /h 2 , vh, W Q and L Q , where Tmax is maximum temperature on the monitor point of the outer surface, k is thermal diffusivity coefficient, τ 0 is the temperature rise time from 100degC to maximum temperature on the monitor point of the outer surface, W Q is τ 0 x ν, and L Q is the uniform temperature length in the axial direction. It is verified that the essential variables for L-SIP match the controlling parameters by the theoretical equation. (author)

  15. Temperature distribution due to the heat generation in nuclear reactor shielding

    International Nuclear Information System (INIS)

    Torres, L.M.R.

    1985-01-01

    A study is performed for calculating nuclear heating due to the interaction of neutrons and gamma-rays with matter. Modifications were implemented in the ANISN and DOT 3.5 codes, that solve the transport equation using the discrete ordinate method, in one two-dimensions respectively, to include nuclear heating calculations in these codes. In order to determine the temperature distribution, using the finite difference method, a numerical model was developed for solving the heat conduction equation in one-dimension, in plane, cylindrical and spherical geometries, and in two-dimensions, X-Y and R-Z geometries. Based on these models, computer programs were developed for calculating the temperature distribution. Tests and applications of the implemented modifications were performed in problems of nuclear heating and temperature distribution due to radiation energy deposition in fission and fusion reactor shields. (Author) [pt

  16. Benchmark numerical solutions for radiative heat transfer in two-dimensional medium with graded index distribution

    Energy Technology Data Exchange (ETDEWEB)

    Liu, L.H. [School of Energy Science and Engineering, Harbin Institute of Technology, 92 West Dazhi Street, Harbin 150001 (China)]. E-mail: lhliu@hit.edu.cn

    2006-11-15

    In graded index media, the ray goes along a curved path determined by Fermat principle. Generally, the curved ray trajectory in graded index media is a complex implicit function, and the curved ray tracing is very difficult and complex. Only for some special refractive index distributions, the curved ray trajectory can be expressed as a simple explicit function. Two important examples are the layered and the radial graded index distributions. In this paper, the radiative heat transfer problems in two-dimensional square semitransparent with layered and radial graded index distributions are analyzed. After deduction of the ray trajectory, the radiative heat transfer problems are solved by using the Monte Carlo curved ray-tracing method. Some numerical solutions of dimensionless net radiative heat flux and medium temperature are tabulated as the benchmark solutions for the future development of approximation techniques for multi-dimensional radiative heat transfer in graded index media.

  17. After heat distribution of a mobile nuclear power plant

    Science.gov (United States)

    Parker, W. G.; Vanbibber, L. E.; Tang, Y. S.

    1971-01-01

    A computer program was developed to analyze the transient afterheat temperature and pressure response of a mobile gas-cooled reactor power plant following impact. The program considers (in addition to the standard modes of heat transfer) fission product decay and transport, metal-water reactions, core and shield melting and displacement, and pressure and containment vessel stress response. Analyses were performed for eight cases (both deformed and undeformed models) to verify operability of the program options. The results indicated that for a 350 psi (241 n/sq cm) initial internal pressure, the containment vessel can survive over 100,000 seconds following impact before creep rupture occurs. Recommendations were developed as to directions for redesign to extend containment vessel life.

  18. Heating and cooling distribution in residential and non-residential premises; Distribution av kyla och vaerme i bostaeder och lokaler

    Energy Technology Data Exchange (ETDEWEB)

    Jardeby, Aasa; Soleimani-Mohseni, Mohsen; Axell, Monica

    2009-08-15

    The building sector accounts for approximately 40% of energy use in Europe, and about the same ratio applies to Sweden. Distribution systems for heating and cooling are an important part of the building's heating and cooling systems. The desired indoor climate can not be achieved without a properly sized distribution system. The aim of this report is to highlight the opportunities for energy efficiency with a properly designed distribution system by identifying and comparing different system solutions for the distribution of heating and cooling in residential and non-residential premises. The report presents which affect various factors have on the system as a whole, such as media selection, sizing of the piping system, heat transfer surface and regulation and control strategies. It also gives a picture of the possibilities and limitations of different needs and requirements of indoor environment (such as requirements for the thermal environment, air quality, noise, space, etc.). By having a systems perspective at the heating and/or cooling, energy efficiency is achieved. There are possibilities of big gains with a systems approach, since the choices made in designing a distribution system, affects many other parts of the system and there is a risk of poor optimization. A first step in reducing the energy use is to reduce the cooling and heating loads in the building. A heating and cooling systems should be designed properly so as not to consume excessive energy. There are other strategies to reduce energy consumption, e.g. by allowing more variations in temperature. However, it is important that it is not at the expense of the needs and requirements of the building. If the building has a cooling requirement that can be covered by the air flow required for ventilation it is recommended to provide under tempered air. In addition, the air can be cooled by free cooling from outside over large parts of the year. If the building has greater cooling requirements

  19. Electric field analysis of extra high voltage (EHV) underground cables using finite element method

    DEFF Research Database (Denmark)

    Kumar, Mantosh; Bhaskar, Mahajan Sagar; Padmanaban, Sanjeevikumar

    2017-01-01

    used for the insulator due electrical, thermal or environmental stress. Most of these problems are related to the electric field stress on the insulation of the underground cables. The objective of the electric field analysis by using different numerical techniques is to find electric field stress...... electric field stress and other parameters of EHV underground cables with given boundary conditions using 2-D electric field analysis software package (IES-ELECTRO module) which is based on the finite element method (FEM).......Transmission and Distribution of electric power through underground cables is a viable alternative to overhead lines, particularly in residential or highly populated areas. The electrical stresses are consequences of regular voltages and over voltages and the thermal stresses are related to heat...

  20. Investigation of heat distribution during magnetic heating treatment using a polyurethane–ferrofluid phantom-model

    International Nuclear Information System (INIS)

    Henrich, F.; Rahn, H.; Odenbach, S.

    2014-01-01

    Magnetic heating treatment can be used as an adjuvant treatment for cancer therapy. In this therapy, magnetic nanoparticles are enriched inside the tumour and exposed to an alternating magnetic field. Due to magnetic losses the temperature in the tumour rises. The resulting temperature profile inside the tumour is useful for the therapeutic success. In this context heat transfer between tissue with nanoparticles and tissue without nanoparticles is a highly important feature which is actually not understood in detail. In order to investigate this, a phantom has been created which can be used to measure the temperature profile around a region enriched with magnetic nanoparticles. This phantom is composed of a material, which has similar thermal conductivity as human tissue. A tempered water bath surrounds the phantom to establish a constant surrounding temperature simulating the heat sink provided by the human body in a real therapeutic application. It has been found that even at a low concentration of magnetic nanoparticles around 13 mg/ml, sufficient heating of the enriched region can be achieved. Moreover it has been observed that the temperature drops rapidly in the material surrounding the enriched region. Corresponding numerical investigations provide a basis for future recalculations of the temperature inside the tumour using temperature data obtained in the surrounding tissue. - Highlights: • The temperature profile by magnetic hyperthermia was examined. • A model was built to get a deeper understanding of the temperature profile. • The temperature profile of the model inside magnetic fields was measured. • Based on the model a simulation of the temperature profile was performed. • The simulated temperature profile agreed well with the measured profile

  1. A heat conduction simulator to estimate lung temperature distribution during percutaneous transthoracic cryoablation for lung cancer

    International Nuclear Information System (INIS)

    Futami, Hikaru; Arai, Tsunenori; Yashiro, Hideki; Nakatsuka, Seishi; Kuribayashi, Sachio; Izumi, Youtaro; Tsukada, Norimasa; Kawamura, Masafumi

    2006-01-01

    To develop an evaluation method for the curative field when using X-ray CT imaging during percutaneous transthoracic cryoablation for lung cancer, we constructed a finite-element heat conduction simulator to estimate temperature distribution in the lung during cryo-treatment. We calculated temperature distribution using a simple two-dimensional finite element model, although the actual temperature distribution spreads in three dimensions. Temperature time-histories were measured within 10 minutes using experimental ex vivo and in vivo lung cryoablation conditions. We adjusted specific heat and thermal conductivity in the heat conduction calculation and compared them with measured temperature time-histories ex vivo. Adjusted lung specific heat was 3.7 J/ (g·deg C) for unfrozen lung and 1.8 J/ (g·deg C) for frozen lung. Adjusted lung thermal conductivity in our finite element model fitted proportionally to the exponential function of lung density. We considered the heat input by blood flow circulation and metabolic heat when we calculated the temperature time-histories during in vivo cryoablation of the lung. We assumed that the blood flow varies in inverse proportion to the change in blood viscosity up to the maximum blood flow predicted from cardiac output. Metabolic heat was set as heat generation in the calculation. The measured temperature time-histories of in vivo cryoablation were then estimated with an accuracy of ±3 deg C when calculated based on this assumption. Therefore, we successfully constructed a two-dimensional heat conduction simulator that is capable of estimating temperature distribution in the lung at the time of first freezing during cryoablation. (author)

  2. Production and Distribution Planning in District Heating Systems; Produktions- och distributionsplanering av fjaerrvaerme

    Energy Technology Data Exchange (ETDEWEB)

    Kvarnstroem, Johan; Dotzauer, Erik; Dahlquist, Erik

    2006-12-15

    To produce heat and power is costly. Therefore it is important for the district heating companies to plan and optimize the production. The aim with the present project is to find out how also the distribution of heat can be considered in the planning. The principal procedure is to first construct a prediction of the heat demand, and then, given the demand prediction, construct the production plan. Due to the complexity of the problem, the need for mathematical models is obvious. The report gives a survey introduction to production planning in district heating systems and presents a model for the purpose. The model is developed for one of the district heating systems in Stockholm owned by the energy company Fortum. Traditionally, models for production planning do not consider the distribution network. In such models, usually the methodology Mixed Integer Programming (MIP) is used. The report suggests how the distribution network can be modeled as a MIP; it shall be possible to link the network model to existing software that models the production plants as MIP. The model is developed in the programming language GAMS. Analysis and results are presented. The results show that the suggested plans vary depending on if the distribution network is considered or not. The report also suggests how a simple sensitivity analysis of the production plans can be performed. This is necessary since there are always uncertainties associated with weather- and load predictions.

  3. Surface-near geothermal energy. Ground coupled heat pumps and underground thermal energy storage; Oberflaechennahe Geothermie. Erdgekoppelte Waermepumpen und unterirdische thermische Energiespeicher

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    Within the eleventh International User Forum at 27th/28th September, 2011 in Regensburg (Federal Republic of Germany) the following lectures were held: (1) Ecologic evaluation of heat pumps - a question of approach (Roland Koenigsdorff); (2) An actual general comment to WHG, the preparations for the new VAUwS and possible consequences on the surface-near geothermal energy (Walker-Hertkorn); (3) Field-test experiences: Ground source heat pumps in small residential buildings (Jeannette Wapler); (4) GeoT*SOL basic - Program for the evaluation and simulation of heat pump systems (Bernhard Gatzka); (5) Monitoring and modelling of geothermal heat exchanger systems (Fabian Ochs); (6) Thermal response tests for the quality assurance of geothermal heat probes (Markus Proell); (7) Process of determining an untroubled soil temperature in comparison (Andreas Koehler); (8) Borehole resistance - Is the TRT measured value also the planning value? (Roland Koenigsdorff); (9) Consideration of the heat transport in geothermal probes (Martin Konrad); (10) Process of evaluation the sealing of geothermal probes with backfilling materials (Manfred Reuss); (11) Quality assessment of geothermal probes in real standard (Mathieu Riegger); (12) Comparison of flat collectors salt water and direct evaporation, design, impacs, consequences (Bernhard Wenzel); (13) Non-covered photovoltaic thermal collectors in heat pump systems (Erik Bertram); (14) Seasonal geothermal probe-heat storage - Heat supply concepts for objects with overbalancing heating level of more than 100 kW (Volker Liebel); (15) Application of geothermal probe fields as a cold storage (Rolf Wagner); (16) Geothermal energy and waste water warmth: State of the art and new technologies for a combined utilization (Wolfram Stodtmeister); (17) Integration of a heat pump into a solar supported local heat supply in Neckarsulm (Janet Nussbicker-Lux); (18) Regenerative heating with photovoltaics and geothermal energy (Christoph Rosinski

  4. Distributed Roughness Effects on Blunt-Body Transition and Turbulent Heating

    Science.gov (United States)

    Hollis, Brian R.

    2014-01-01

    An experimental program has been conducted to obtain data on the effects of surface roughness on blunt bodies at laminar, transitional, and turbulent conditions. Wind tunnel models with distributed surface roughness heights from 0.06 mm to 1.75 mm were tested and heating data were obtained using global surface thermography. Heating rates of up to 85% higher than predicted, smooth-surface turbulent levels were measured.

  5. Thermionic nuclear reactor with internal heat distribution and multiple duct cooling

    Science.gov (United States)

    Fisher, C.R.; Perry, L.W. Jr.

    1975-11-01

    A Thermionic Nuclear Reactor is described having multiple ribbon-like coolant ducts passing through the core, intertwined among the thermionic fuel elements to provide independent cooling paths. Heat pipes are disposed in the core between and adjacent to the thermionic fuel elements and the ribbon ducting, for the purpose of more uniformly distributing the heat of fission among the thermionic fuel elements and the ducts.

  6. Underground laboratories in Asia

    International Nuclear Information System (INIS)

    Lin, Shin Ted; Yue, Qian

    2015-01-01

    Deep underground laboratories in Asia have been making huge progress recently because underground sites provide unique opportunities to explore the rare-event phenomena for the study of dark matter searches, neutrino physics and nuclear astrophysics as well as the multi-disciplinary researches based on the low radioactive environments. The status and perspectives of Kamioda underground observatories in Japan, the existing Y2L and the planned CUP in Korea, India-based Neutrino Observatory (INO) in India and China JinPing Underground Laboratory (CJPL) in China will be surveyed

  7. Underground laboratories in Asia

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Shin Ted, E-mail: linst@mails.phys.sinica.edu.tw [College of Physical Science and Technology, Sichuan University, Chengdu 610064 China (China); Yue, Qian, E-mail: yueq@mail.tsinghua.edu.cn [Key Laboratory of Particle and Radiation Imaging (Ministry of Education) and Department of Engineering Physics, Tsinghua University, Beijing 100084 China (China)

    2015-08-17

    Deep underground laboratories in Asia have been making huge progress recently because underground sites provide unique opportunities to explore the rare-event phenomena for the study of dark matter searches, neutrino physics and nuclear astrophysics as well as the multi-disciplinary researches based on the low radioactive environments. The status and perspectives of Kamioda underground observatories in Japan, the existing Y2L and the planned CUP in Korea, India-based Neutrino Observatory (INO) in India and China JinPing Underground Laboratory (CJPL) in China will be surveyed.

  8. Air distribution and ventilation effectiveness in an occupied room heated by warm air

    DEFF Research Database (Denmark)

    Krajcik, Michal; Simone, Angela; Olesen, Bjarne W.

    2012-01-01

    and at different simulated outside conditions, internal heat gains and air change rates. Floor heating was also simulated and compared with the warm air heating system. Vertical air temperature profiles, air velocity profiles and equivalent temperatures were derived in order to describe the thermal environment...... floor heating system was simulated, the cooler ventilation air introduced to the room mixed well and created uniform conditions with a ventilation effectiveness of about 1.......Air distribution, ventilation effectiveness and thermal environment were experimentally studied in a simulated room in a low-energy building heated and ventilated by warm air supplied by a mixing ventilation system. Measurements were performed for various positions of the air terminal devices...

  9. Temperature distribution and heat radiation of patterned surfaces at short wavelengths

    Science.gov (United States)

    Emig, Thorsten

    2017-05-01

    We analyze the equilibrium spatial distribution of surface temperatures of patterned surfaces. The surface is exposed to a constant external heat flux and has a fixed internal temperature that is coupled to the outside heat fluxes by finite heat conductivity across the surface. It is assumed that the temperatures are sufficiently high so that the thermal wavelength (a few microns at room temperature) is short compared to all geometric length scales of the surface patterns. Hence the radiosity method can be employed. A recursive multiple scattering method is developed that enables rapid convergence to equilibrium temperatures. While the temperature distributions show distinct dependence on the detailed surface shapes (cuboids and cylinder are studied), we demonstrate robust universal relations between the mean and the standard deviation of the temperature distributions and quantities that characterize overall geometric features of the surface shape.

  10. Critical heat fluxes and liquid distribution in annular channels in the dispersion-annular flow

    International Nuclear Information System (INIS)

    Boltenko, Eh.A.; Pomet'ko, R.S.

    1984-01-01

    On the basis of using the dependence of intensity of total mass transfer between the flux nucleus and wall film obtained for tubes with uniform heat release and taking into account the peculiarities of mass transfer between the flux nucleus and wall film in annular channels the technique for calculating the liquid distribution and critical capacity of annular channels with internal, external and bilateral heating at uniform and non-uniform heat release over the length is proposed. The calculation of annular channels critical capacity according to the suggested technique is performed. A satisfactory agreement of calculation results with the experimental data is attained

  11. January and July global distributions of atmospheric heating for 1986, 1987, and 1988

    Science.gov (United States)

    Schaack, Todd K.; Johnson, Donald R.

    1994-01-01

    Three-dimensional global distributions of atmospheric heating are estimated for January and July of the 3-year period 1986-88 from the European Center for Medium Weather Forecasts (ECMWF) Tropical Ocean Global Atmosphere (TOGA) assimilated datasets. Emphasis is placed on the interseasonal and interannual variability of heating both locally and regionally. Large fluctuations in the magnitude of heating and the disposition of maxima/minima in the Tropics occur over the 3-year period. This variability, which is largely in accord with anomalous precipitation expected during the El Nino-Southern Oscillation (ENSO) cycle, appears realistic. In both January and July, interannual differences of 1.0-1.5 K/day in the vertically averaged heating occur over the tropical Pacific. These interannual regional differences are substantial in comparison with maximum monthly averaged heating rates of 2.0-2.5 K/day. In the extratropics, the most prominent interannual variability occurs along the wintertime North Atlantic cyclone track. Vertical profiles of heating from selected regions also reveal large interannual variability. Clearly evident is the modulation of the heating within tropical regions of deep moist convection associated with the evolution of the ENSO cycle. The heating integrated over continental and oceanic basins emphasizes the impact of land and ocean surfaces on atmospheric energy balance and depicts marked interseasonal and interannual large-scale variability.

  12. In Situ Corrosion and Heat Loss Assessment of Two Nonstandard Underground Heat Distribution System Piping Designs: Supplement-Appendices for Final Report on Project F07-AR01

    Science.gov (United States)

    2011-06-01

    negative mission impacts . This report documents the assessment of two similar nonstandard UHDS piping system designs — one at Fort Carson, CO, and one at...psig and monitored for 2 hours to determine whether the conduit piping system is protected from ground water infiltration and its degrading impacts ...Conduits to/from this pit were tested from adjacent pits. 2. Supply, Return drains tested on 8/15/07: All Dry N S EW MH-3N ERDC/CERL TR-11-14 H13

  13. The effects of off-center pellets on the temperature distribution and the heat flux distribution of fuel rods in nuclear reactors

    International Nuclear Information System (INIS)

    Peng Muzhang; Xing Jianhua

    1986-01-01

    This paper analyzes the effects of off-center pellets on the steady state temperature distribution and heat flux distribution of fuel rods in the nuclear reactors, and derives the dimensionless temperature distribution relationships and the dimensionless heat flux distribution relationship from the fuel rods with off-center pellets. The calculated results show that the effects of off-center will result in not only deviations of the highest temperature placement in the fuel pellets, but also the circumferentially nonuniform distributions of the temperatures and heat fluxes of the fuel rod surfaces

  14. Groundwater and underground coal gasification in Alberta

    International Nuclear Information System (INIS)

    Haluszka, A.; MacMillan, G.; Maev, S.

    2010-01-01

    Underground coal gasification has potential in Alberta. This presentation provided background information on underground coal gasification and discussed groundwater and the Laurus Energy demonstration project. A multi-disciplined approach to project assessment was described with particular reference to geologic and hydrogeologic setting; geologic mapping; and a hydrogeologic numerical model. Underground coal gasification involves the conversion of coal into synthesis gas or syngas. It can be applied to mined coal at the surface or applied to non-mined coal seams using injection and production wells. Underground coal gasification can effect groundwater as the rate of water influx into the coal seams influences the quality and composition of the syngas. Byproducts created include heat as well as water with dissolved concentrations of ammonia, phenols, salts, polyaromatic hydrocarbons, and liquid organic products from the pyrolysis of coal. A process overview of underground coal gasification was also illustrated. It was concluded that underground coal gasification has the potential in Alberta and risks to groundwater could be minimized by a properly designed project. refs., figs.

  15. Anisotropic distribution function of minority tail ions generated by strong ion-cyclotron resonance heating

    International Nuclear Information System (INIS)

    Chang, C.S.; Colestock, P.

    1989-05-01

    The highly anisotropic particle distribution function of minority tail ions driven by ion-cyclotron resonance heating at the fundamental harmonic is calculated in a two-dimensional velocity space. It is assumed that the heating is strong enough to drive most of the resonant ions above the in-electron critical slowing-down energy. Simple analytic expressions for the tail distribution are obtained fro the case when the Doppler effect is sufficiently large to flatten the sharp pitch angle dependence in the bounce averaged qualilinear heating coefficient, D/sub b/, and for the case when D/sub b/ is assumed to be constant in pitch angle and energy. It is found that a simple constant-D/sub b/ solution can be used instead of the more complicated sharp-D/sub b/ solution for many analytic purposes. 4 refs., 4 figs

  16. 2-D temperature distribution and heat flux of PFC in 2011 KSTAR campaign

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Eunnam, E-mail: bang14@nfri.re.kr; Hong, Suk-Ho; Yu, Yaowei; Kim, Kyungmin; Kim, Hongtack; Kim, Hakkun; Lee, Kunsu; Yang, Hyunglyul

    2013-10-15

    Highlights: • The heat flux on PFC tiles of 12 s pulse duration and 630 kA plasma current is about 0.02 MW/m{sup 2}. • When the cryopump is operated, the heat flux of CD is higher than without cryopump. • The more H-mode duration is long, the more heat flux on divertor is high. -- Abstract: KSTAR has reached a plasma current up to 630 kA, plasma duration up to 12 s, and has achieved high confinement mode (H-mode) in 2011 campaign. The heat flux of PFC tile was estimated from the temperature increase of PFC since 2010. The heat flux of PFC tiles increases significantly with higher plasma current and longer pulse duration. The time-averaged heat flux of shots in 2010 campaign (with 3 s pulse durations and I{sub p} of 611 kA) is 0.01 MW/m{sup 2} while that in 2011 campaign (with 12 s pulse duration and I{sub p} of 630 kA) is about 0.02 MW/m{sup 2}. The heat flux at divertor is 1.4–2 times higher than that at inboard limiter or passive stabilizer. With the cryopump operation, the heat flux at the central divertor is higher than that without cryopump. The heat flux at divertor is proportional to, of course, the duration of H-mode. Furthermore, a software tool, which visualizes the 2D temperature distribution of PFC tile and estimates the heat flux in real time, is developed.

  17. Simulation study of energetic ion distribution during combined NBI and ICRF heating in LHD

    International Nuclear Information System (INIS)

    Murakami, S.; Fukuyama, A.; Kasilov, V.

    2006-01-01

    In the LHD, significant performances of ICRF heating (fundamental, minority heating regime) have been demonstrated and up to 500keV of energetic tail ions have been observed by fast neutral particle analysis (NPA). These measured results indicate a good property of energetic ion confinement in helical systems. From the 9th campaign of LHD experiment (FY2005) a new perpendicular NBI heating system (P<3MW) has been installed and an effective heating of perpendicularly injected beam ions by the higher harmonics ICRF heating is expected. ICRF heating generates highly energetic tail ions, which drift around the torus for a long time (typically on a collisional time scale). Thus, the behavior of these energetic ions is strongly affected by the characteristics of the drift motions, which depend on the magnetic field configuration. In particular, in a three-dimensional (3D) magnetic configuration, complicated drift motions of trapped particles would play an important role in the confinement of the energetic ions and the ICRF heating process. Therefore a global simulation of ICRF heating is necessary for the accurate modeling of the plasma heating process in a 3D magnetic configuration. In this paper we study the energetic ion distribution during combined NBI and 2nd harmonics ICRF heating in LHD using two global simulation codes: a full wave field solver TASK/WK and a drift kinetic equation solver GNET. GNET solves a linearized drift kinetic equation for energetic ions including complicated behavior of trapped particles in 5-D phase space. TASK/WM solves Maxwell's equation for RF wave electric field with complex frequency as a boundary value problem in the 3D magnetic configuration. (author)

  18. Life expectancy impacts due to heating energy utilization in China: Distribution, relations, and policy implications.

    Science.gov (United States)

    Wang, Shaobin; Luo, Kunli

    2018-01-01

    The relation between life expectancy and energy utilization is of particular concern. Different viewpoints concerned the health impacts of heating policy in China. However, it is still obscure that what kind of heating energy or what pattern of heating methods is the most related with the difference of life expectancies in China. The aim of this paper is to comprehensively investigate the spatial relations between life expectancy at birth (LEB) and different heating energy utilization in China by using spatial autocorrelation models including global spatial autocorrelation, local spatial autocorrelation and hot spot analysis. The results showed that: (1) Most of heating energy exhibit a distinct north-south difference, such as central heating supply, stalks and domestic coal. Whereas spatial distribution of domestic natural gas and electricity exhibited west-east differences. (2) Consumption of central heating, stalks and domestic coal show obvious spatial dependence. Whereas firewood, natural gas and electricity did not show significant spatial autocorrelation. It exhibited an extinct south-north difference of heat supply, stalks and domestic coal which were identified to show significant positive spatial autocorrelation. (3) Central heating, residential boilers and natural gas did not show any significant correlations with LEB. While, the utilization of domestic coal and biomass showed significant negative correlations with LEB, and household electricity shows positive correlations. The utilization of domestic coal in China showed a negative effect on LEB, rather than central heating. To improve the solid fuel stoves and control consumption of domestic coal consumption and other low quality solid fuel is imperative to improve the public health level in China in the future. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Image Registration of Cochlear µCT Data Using Heat Distribution Similarity

    DEFF Research Database (Denmark)

    Kjer, Hans Martin; Vera, Sergio; Fagertun, Jens

    2015-01-01

    Better understanding of the anatomical variability of the human cochlear is important for the design and function of Cochlear Implants. Good non-rigid alignment of high-resolution cochlear μCT data is a challenging task. In this paper we study the use of heat distribution similarity between sampl...

  20. Reliability evaluation of power supply and distribution for special heat removal systems in nuclear power stations

    International Nuclear Information System (INIS)

    Jazbec, D.

    1982-01-01

    An example of the power supply and distribution of a Special Emergency Heat Removal System (SEHR) shows how an engineering organization may, with the aid of the analytical method of min-cut sets optimize the system reliability. Herein are given the necessary simple calculation methods. (Auth.)

  1. SiC heat pump converters with support for voltage unbalance in distribution grids

    DEFF Research Database (Denmark)

    Trintis, Ionut; Douglass, Philip; Maheshwari, Ramkrishan

    2015-01-01

    This paper studies the impact of involving the demand side of the LV grid into the grid conditioning process. Heat pumps are distribution loads with a substation capacity increase in the last years, with expectancy of growth in the coming years. Controlling the loads is the first step in the tran...

  2. Expressed sequence tags from heat-shocked seagrass Zostera noltii (Hornemann) from its southern distribution range

    NARCIS (Netherlands)

    Massa, Sonia I.; Pearson, Gareth A.; Aires, Tania; Kube, Michael; Olsen, Jeanine L.; Reinhardt, Richard; Serrao, Ester A.; Arnaud-Haond, Sophie

    Predicted global climate change threatens the distributional ranges of species worldwide. We identified genes expressed in the intertidal seagrass Zostera midi during recovery from a simulated low tide heat-shock exposure. Five Expressed Sequence Tag (EST) libraries were compared, corresponding to

  3. Analytical models for predicting the ion velocity distributions in JET in the presence of ICRF heating

    International Nuclear Information System (INIS)

    Anderson, A.; Eriksson, L.G.; Lisak, M.

    1986-01-01

    The present report summarizes the work performed within the contract JT4/9008, the aim of which is to derive analytical models for ion velocity distributions resulting from ICRF heating on JET. The work has been performed over a two-year-period ending in August 1986 and has involved a total effort of 2.4 man years. (author)

  4. Thermally determining flow and/or heat load distribution in parallel paths

    Science.gov (United States)

    Chainer, Timothy J.; Iyengar, Madhusudan K.; Parida, Pritish R.

    2016-12-13

    A method including obtaining calibration data for at least one sub-component in a heat transfer assembly, wherein the calibration data comprises at least one indication of coolant flow rate through the sub-component for a given surface temperature delta of the sub-component and a given heat load into said sub-component, determining a measured heat load into the sub-component, determining a measured surface temperature delta of the sub-component, and determining a coolant flow distribution in a first flow path comprising the sub-component from the calibration data according to the measured heat load and the measured surface temperature delta of the sub-component.

  5. Distribution characteristics of terrestrial heat flow density in Jiyang depression of Shengli Oilfield, East China

    Institute of Scientific and Technical Information of China (English)

    GONG; Yuling; WANG; Liangshu; LIU; Shaowen; LI; Cheng; HAN

    2004-01-01

    Based on the geo-temperature data of 13 systematically continuous temperature log curves and 700 testing oil boreholes in Jiyang depression, Shengli Oilfield, and the measured thermal conductivities of 47 rock samples, the terrestrial heat flow densities of 114 boreholes of Jiyang depression and its surrounding areas are determined, including 13 of those data derived from systemically continuous temperature logging. The results show that Jiyang depression has a relatively high background heat flow with an average value (65.8 ± 5.4) mW/m2. The lateral variation of heat flow in basin has negative correlation with basement depth. Moreover, heat flow of uplift areas with shallower basement is high, so are those of regions with volcanic rocks, and those of depression areas with deep basement are relatively low. The heat flow densities of different structural units of Jiyang depression can be summarized as follows: The average heat flow value of Zhanhua sag is (67.4 ± 5.3) mW/m2, higher than that of the whole basin, that of Dongying sag is (66.0 ± 6.1) mW/m2, and that of Chezhen sag is (65.1 ± 3.7) mW/m2. It is apparent that these latter two values are approximate to the average value of the whole Jiyang depression,while the average value of Huimin sag is (63.6±5.0) mW/m2, lower than that of the whole basin. In fact, the basement depth and the distribution framework of uplift and depression areas are all controlled by the process of lithosphere extension. In addition, the distribution of volcanic rocks in basin is also relatively close to this extension geodynamic process. In summary, the distribution characteristics of terrestrial heat flow of Jiyang depression is determined by the Cenozoic tectono-thermal events of this region.

  6. Case histories in scientific and pseudo-scientific mass-media communication in energy/heat production from underground (geogas storage, geothermics, hydrocarbons), in the frame of Nimby Sindrome enhancement in Europe: the proposal of a new European Direct

    Science.gov (United States)

    Quattrocchi, Fedora; Boschi, Enzo

    2014-05-01

    In the frame of energy/heat production from underground, the paper considers some European case histories and the needs of a complex and motley stakeholders community, made by scientific-industry-institutions, involved in the difficult task to study and accept (or refuse) projects strongly impacting the lived territory & underground, in densely populate countries, as Italy, in terms of appropriate public communication and sound deontological behaviour. Successively, the paper recalls years of "scientific" communication within the mass-media, highlighting the positive and negative messages, in comparison to the true and objective experimental data gathered by the real scientific work, as perceived by citizens of medium scholastic culture, which not delve the geologic disciplines, but receive simply the journalistic front-end, very often as sensationalist scoop. The authors retrace case histories of heuristic-participatory communication with the citizenship about the scientific results on challenges raised by certain technologies. The objective and rational communication is often impeded by local interests and by local journalism, which prefers to create sensationalist news more than scientific truths. This path progressively tangles as a consequence of the complex and with conflicting use of underground to produce energy (heat as gas storage, geothermical, unconventional gas exploitation, mining, etc…). Even the chain of renewables meets by now serious issues, exacerbated also by the need to start mining and drilling for the smart grids materials too (metals, rare Earths, etc..). A new text for a smart and innovative European Directivity is discussed, starting from the Italian regulatory issue. The review efforts for a "paper" on both a newspaper or a blog could be more difficult than the review a scientific paper, as a consequence of the peculiar situations behind the scenes and the conflicts of interests staying in the nest in a newspaper article or in a blog

  7. Sustainable energy supply for mushroom cultivation. Application of underground energy storage. Application of a heat pump for heat production. Feasibility study; Duurzame energievoorziening paddestoelen kwekerij. toepassing van energieopslag in de bodem. Toepassing van warmtepomp voor warmteopwekking. Een haalbaarheidsstudie

    Energy Technology Data Exchange (ETDEWEB)

    Koel, J.J. [EBS-Adviseurs, Veenendaal (Netherlands)

    2001-02-26

    The results of a feasibility study on the use of heat and cold storage and the use of an electric heat pump for the energy supply of a mushroom cultivation business (Verbruggen paddestoelen in Erp, Netherlands) are presented.

  8. Underground storage tanks

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Environmental contamination from leaking underground storage tanks poses a significant threat to human health and the environment. An estimated five to six million underground storage tanks containing hazardous substances or petroleum products are in use in the US. Originally placed underground as a fire prevention measure, these tanks have substantially reduced the damages from stored flammable liquids. However, an estimated 400,000 underground tanks are thought to be leaking now, and many more will begin to leak in the near future. Products released from these leaking tanks can threaten groundwater supplies, damage sewer lines and buried cables, poison crops, and lead to fires and explosions. As required by the Hazardous and Solid Waste Amendments (HSWA), the EPA has been developing a comprehensive regulatory program for underground storage tanks. The EPA proposed three sets of regulations pertaining to underground tanks. The first addressed technical requirements for petroleum and hazardous substance tanks, including new tank performance standards, release detection, release reporting and investigation, corrective action, and tank closure. The second proposed regulation addresses financial responsibility requirements for underground petroleum tanks. The third addressed standards for approval of state tank programs

  9. Numerical Study of the Inertia Effect on Flow Distribution in Micro-gap Plate Heat Exchanger

    International Nuclear Information System (INIS)

    Park, Jang Min; Yoon, Seok Ho; Lee, Kong Hoon; Song Chan Ho

    2014-01-01

    This paper presents numerical study on flow and heat transfer characteristics in micro-gap plate heat exchanger. In particular, we investigate the effect of flow inertia on the flow distribution from single main channel to multiple parallel micro-gaps. The flow regime of the main channel is varied from laminar regime (Reynolds number of 100) to turbulent regime (Reynolds number of 10000) by changing the flow rate, and non-uniformity of the flow distribution and temperature field is evaluated quantitatively based on the standard deviation. The flow distribution is found to be significantly affected by not only the header design but also the flow rate of the main channel. It is also observed that the non-uniformity of the temperature field has its maximum at the intermediate flow regime

  10. Temperature distributions in boreholes of a vertical ground-coupled heat pump system

    Energy Technology Data Exchange (ETDEWEB)

    Esen, Hikmet [Department of Mechanical Education, Faculty of Technical Education, Firat University, 23119 Elazig (Turkey); Inalli, Mustafa [Department of Mechanical Engineering, Faculty of Engineering, Firat University, 23279 Elazig (Turkey); Esen, Yuksel [Department of Construction Education, Faculty of Technical Education, Firat University, 23119 Elazig (Turkey)

    2009-12-15

    The objective of this study is to show the temperature distribution development in the borehole of the ground-coupled heat pump systems (GCHPs) with time. The time interval for the study is 48 h. The vertical GCHP system using R-22 as refrigerant has a three single U-tube ground heat exchanger (GHE) made of polyethylene pipe with a 40 mm outside diameter. The GHE was placed in a vertical borehole (VB) with 30 (VB1), 60 (VB2) and 90 (VB3) m depths and 150 mm diameters. The experimental results were obtained in cooling and heating seasons of 2006-2007. A two-dimensional finite element model (FEM) was developed to simulate temperature distribution development in the soil surrounding the GHEs of GCHPs operating in the cooling and the heating modes. The finite element modelling of the GCHP system was performed using the ANSYS code. The FEM incorporated pipes, the grout and the surrounding formation. From the cases studied, this approach appears to be the most promising for estimation the temperature distribution response of GHEs to thermal loading. (author)

  11. Simple method for highlighting the temperature distribution into a liquid sample heated by microwave power field

    International Nuclear Information System (INIS)

    Surducan, V.; Surducan, E.; Dadarlat, D.

    2013-01-01

    Microwave induced heating is widely used in medical treatments, scientific and industrial applications. The temperature field inside a microwave heated sample is often inhomogenous, therefore multiple temperature sensors are required for an accurate result. Nowadays, non-contact (Infra Red thermography or microwave radiometry) or direct contact temperature measurement methods (expensive and sophisticated fiber optic temperature sensors transparent to microwave radiation) are mainly used. IR thermography gives only the surface temperature and can not be used for measuring temperature distributions in cross sections of a sample. In this paper we present a very simple experimental method for temperature distribution highlighting inside a cross section of a liquid sample, heated by a microwave radiation through a coaxial applicator. The method proposed is able to offer qualitative information about the heating distribution, using a temperature sensitive liquid crystal sheet. Inhomogeneities as smaller as 1°-2°C produced by the symmetry irregularities of the microwave applicator can be easily detected by visual inspection or by computer assisted color to temperature conversion. Therefore, the microwave applicator is tuned and verified with described method until the temperature inhomogeneities are solved

  12. A new hydraulic regulation method on district heating system with distributed variable-speed pumps

    International Nuclear Information System (INIS)

    Wang, Hai; Wang, Haiying; Zhu, Tong

    2017-01-01

    Highlights: • A hydraulic regulation method was presented for district heating with distributed variable speed pumps. • Information and automation technologies were utilized to support the proposed method. • A new hydraulic model was developed for distributed variable speed pumps. • A new optimization model was developed based on genetic algorithm. • Two scenarios of a multi-source looped system was illustrated to validate the method. - Abstract: Compared with the hydraulic configuration based on the conventional central circulating pump, a district heating system with distributed variable-speed-pumps configuration can often save 30–50% power consumption on circulating pumps with frequency inverters. However, the hydraulic regulations on distributed variable-speed-pumps configuration could be more complicated than ever while all distributed pumps need to be adjusted to their designated flow rates. Especially in a multi-source looped structure heating network where the distributed pumps have strongly coupled and severe non-linear hydraulic connections with each other, it would be rather difficult to maintain the hydraulic balance during the regulations. In this paper, with the help of the advanced automation and information technologies, a new hydraulic regulation method was proposed to achieve on-site hydraulic balance for the district heating systems with distributed variable-speed-pumps configuration. The proposed method was comprised of a new hydraulic model, which was developed to adapt the distributed variable-speed-pumps configuration, and a calibration model with genetic algorithm. By carrying out the proposed method step by step, the flow rates of all distributed pumps can be progressively adjusted to their designated values. A hypothetic district heating system with 2 heat sources and 10 substations was taken as a case study to illustrate the feasibility of the proposed method. Two scenarios were investigated respectively. In Scenario I, the

  13. Character and levels of radioactive contamination of underground waters at Semipalatinsk test site

    Energy Technology Data Exchange (ETDEWEB)

    Subbotin, S.; Lukashenko, S.; Turchenko, Y. [Institute of radiation safety and ecology (Kazakhstan)

    2014-07-01

    According to the data of RK government commission, 470 explosions have been set off at the Semipalatinsk Test Site (STS), inclusive of 26 surface, 90 in the air and 354 underground nuclear explosions (UNE), 103 of those have been conducted in tunnels and 251 - in boreholes. Underground nuclear explosions have been conducted at STS in horizontal mines, called - 'tunnels' ('Degelen' test site) and vertical mines called 'boreholes' ('Balapan' and 'Sary-Uzen' test sites). Gopher cavities of boreholes and tunnels are in different geotechnical conditions, that eventually specify migration of radioactive products with underground waters. Central cavities of UNE in holes are located significantly below the level of distribution of underground water. High temperature remains for a long time due to presence of overlying rock mass. High temperatures contribute to formation of thermal convection. When reaching the cavity, the water heat up, dissolve chemical elements and radionuclides and return with them to the water bearing formation. In the major part of 'Balapan' site for underground water of regional basin is characterized by low concentrations of radionuclides. High concentrations of {sup 137}Cs in underground water have been found only in immediate vicinity to 'warfare' boreholes. Formation of radiation situation in the 'Balapan' test site area is also affected by local area of underground water discharge. It is located in the valley of Shagan creek, where the concentration of {sup 3}H reaches 700 kBq/l. Enter of underground water contaminated with tritium into surface water well continue. In this case it is expected that tritium concentration in discharge zone can significantly change, because this migration process depends on hydro geological factors and the amount of atmospheric precipitation. Central cavities of nuclear explosions, made in tunnels, are above the level of underground

  14. Controlling Price-Responsive Heat Pumps for Overload Elimination in Distribution Systems

    DEFF Research Database (Denmark)

    Csetvei, Zsuzsa; Østergaard, Jacob; Nyeng, Preben

    2011-01-01

    This paper investigates the possibility of applying electric heat pumps with the control-by-price-concept in order to avoid overload in a local distribution system. The proposed control algorithm is based upon a centrally dispatched real-time market price, reflecting the state of a larger power...... system, and is extended with a local price control for overload elimination on the corresponding feeder. The paper presents the mathematical models of a two-node system with price-responsive heat pumps, the chosen methodology of the central price calculation, and the proposed local feedback control...

  15. Distributed Nonstationary Heat Model of Two-Channel Solar Air Heater

    International Nuclear Information System (INIS)

    Klychev, Sh. I.; Bakhramov, S. A.; Ismanzhanov, A. I.; Tashiev, N.N.

    2011-01-01

    An algorithm for a distributed nonstationary heat model of a solar air heater (SAH) with two operating channels is presented. The model makes it possible to determine how the coolant temperature changes with time along the solar air heater channel by considering its main thermal and ambient parameters, as well as variations in efficiency. Examples of calculations are presented. It is shown that the time within which the mean-day efficiency of the solar air heater becomes stable is significantly higher than the time within which the coolant temperature reaches stable values. The model can be used for investigation of the performances of solar water-heating collectors. (authors)

  16. The underground macroeconomics

    Directory of Open Access Journals (Sweden)

    Marin Dinu

    2013-01-01

    Full Text Available Like Physics, which cannot yet explain 96% of the substance in the Universe, so is Economics, unprepared to understand and to offer a rational explicative model to the underground economy.

  17. Analysis of the temperature and stress distributions in ceramic window materials subjected to microwave heating

    International Nuclear Information System (INIS)

    Ferber, M.K.; Kimrey, H.D.; Becher, P.F.

    1983-07-01

    The temperature and stress and distributions generated in ceramic materials currently employed in microwave gyrotron tube windows were determined for a variety of operating conditions. Both edge- and face-cooled windows of either polycrystalline BeO or polycrystalline Al 2 O 3 were considered. The actual analysis involved three steps. First, a computer program was used to determine the electric field distribution within the window at a given power level and frequency (TE 02 wave propagation assumed). This program was capable of describing both the radial and axial dependence of the electric field. The effects of multiple internal reflections at the various dielectric interfaces were also accounted for. Secondly, the field distribution was used to derive an expression for the heat generated per unit volume per unit time within the window due to dieletric losses. A generalized heat conduction computer code was then used to compute the temperature distribution based on the heat generation function. Third, the stresses were determined from the temperature profiles using analytical expression or a finite-element computer program. Steady-state temperature and stress profiles were computed for the face-cooled and edge-cooled windows

  18. Noninvasive ultrasonic measurements of temperature distribution and heat fluxes in nuclear systems

    International Nuclear Information System (INIS)

    Jia, Yunlu; Skliar, Mikhail

    2015-01-01

    Measurements of temperature and heat fluxes through structural materials are important in many nuclear systems. One such example is dry storage casks (DSC) that are built to store highly radioactive materials, such as spent nuclear reactor fuel. The temperature inside casks must be maintained within allowable limits of the fuel assemblies and the DSC components because many degradation mechanisms are thermally controlled. In order to obtain direct, real-time measurements of temperature distribution without insertion of sensing elements into harsh environment of storage casks, we are developing noninvasive ultrasound (US) methods for measuring spatial distribution of temperature inside solid materials, such as concrete overpacks, steel casings, thimbles, and rods. The measured temperature distribution can then be used to obtain heat fluxes that provide calorimetric characterisation of the fuel decay, fuel distribution inside the cask, its integrity, and accounting of nuclear materials. The physical basis of the proposed approach is the temperature dependence of the speed of sound in solids. By measuring the time it takes an ultrasound signal to travel a known distance between a transducer and a receiver, the indication about the temperature distribution along the path of the ultrasound propagation may be obtained. However, when temperature along the path of US propagation is non-uniform, the overall time of flight of an ultrasound signal depends on the temperature distribution in a complex and unknown way. To overcome this difficulty, the central idea of our method is to create an US propagation path inside material of interest which incorporates partial ultrasound reflectors (back scatterers) at known locations and use the train of created multiple echoes to estimate the temperature distribution. In this paper, we discuss experimental validation of this approach, the achievable accuracy and spatial resolution of the measured temperature profile, and stress the

  19. Orpheus in the Underground

    Directory of Open Access Journals (Sweden)

    Puskás Dániel

    2015-12-01

    Full Text Available In my study I deal with descents to the underworld and hell in literature in the 20th century and in contemporary literature. I will focus on modem literary reinterpretations of the myth of Orpheus, starting with Rilke’s Orpheus. Eurydice. Hermes. In Seamus Heaney’s The Underground. in the Hungarian Istvan Baka’s Descending to the Underground of Moscow and in Czesław Miłosz’s Orpheus and Eurydice underworld appears as underground, similarly to the contemporary Hungarian János Térey’s play entitled Jeramiah. where underground will also be a metaphorical underworld which is populated with the ghosts of the famous deceased people of Debrecen, and finally, in Péter Kárpáti’s Everywoman the grave of the final scene of the medieval Everyman will be replaced with a contemporary underground station. I analyse how an underground station could be parallel with the underworld and I deal with the role of musicality and sounds in the literary works based on the myth of Orpheus.

  20. Dynamic underground stripping. Innovative technology summary report

    International Nuclear Information System (INIS)

    1995-04-01

    Dynamic Underground Stripping (DUS) is a combination of technologies targeted to remediate soil and ground water contaminated with organic compounds. DUS is effective both above and below the water table and is especially well suited for sites with interbedded sand and clay layers. The main technologies comprising DUS are steam injection at the periphery of a contaminated area to heat permeable subsurface areas, vaporize volatile compounds bound to the soil, and drive contaminants to centrally located vacuum extraction wells; electrical heating of less permeable sediments to vaporize contaminants and drive them into the steam zone; and underground imaging such as Electrical Resistance Tomography to delineate heated areas to ensure total cleanup and process control. A full-scale demonstration was conducted on a gasoline spill site at Lawrence Livermore National Laboratory in Livermore, California from November 1992 through December 1993

  1. Impact of process parameters and design options on heat leaks of straight cryogenic distribution lines

    Directory of Open Access Journals (Sweden)

    P. Duda

    2017-03-01

    Full Text Available The Future Circular Collider (FCC accelerator will require a helium distribution system that will exceed the presently exploited transfer lines by almost 1 order of magnitude. The helium transfer line will contain five process pipes protected against heat leaks by a common thermal shield. The design pressure of the FCC process pipe with supercritical helium will be equal to 5.0 MPa, significantly exceeding the 2.0 MPa value in the present, state-of–art transfer lines. The increase of the design pressure requires construction changes to be introduced to the support system, the vacuum barriers and the compensation bellows. This will influence heat flows to the helium. The paper analyses the impact of the increased design pressure on the heat flow. The paper also offers a discussion of the design modifications to the compensation system, including the replacement of stainless steel with Invar®—aimed at mitigating the pressure increase.

  2. Finite Element Modelling of a Pattern of Temperature Distribution during Travelling Heat Source from Oxyacetylene Flame

    Directory of Open Access Journals (Sweden)

    Alkali Adam Umar

    2014-07-01

    Full Text Available A 3D Finite element model was developed to analyse the conduction temperature distribution on type 304 stainless steel workpiece. An experimental heating-only test was conducted using the input parameters from FEM model which predicted the temperature field on the 304 stainless steel work pieces. Similar temperature pattern was noticed for both the FEM model as well as the experimental. Conduction was observed to be the dominant heat transfer mode. Maximum temperatures were observed to occur at the regions of contact between flame heat and the work pieces. Maximum temperature attained during the two investigated runs was 355°C. Even so austenite crystal morphology was retained on the preheated workpiece.

  3. Impact of process parameters and design options on heat leaks of straight cryogenic distribution lines

    CERN Document Server

    Duda, Pawel; Chorowski, Maciej Pawel; Polinski, J

    2017-01-01

    The Future Circular Collider (FCC) accelerator will require a helium distribution system that will exceed the presently exploited transfer lines by almost 1 order of magnitude. The helium transfer line will contain five process pipes protected against heat leaks by a common thermal shield. The design pressure of the FCC process pipe with supercritical helium will be equal to 5.0 MPa, significantly exceeding the 2.0 MPa value in the present, state-of–art transfer lines. The increase of the design pressure requires construction changes to be introduced to the support system, the vacuum barriers and the compensation bellows. This will influence heat flows to the helium. The paper analyses the impact of the increased design pressure on the heat flow. The paper also offers a discussion of the design modifications to the compensation system, including the replacement of stainless steel with Invar—aimed at mitigating the pressure increase.

  4. Autonomous distributed temperature sensing for long-term heated applications in remote areas

    Directory of Open Access Journals (Sweden)

    A.-M. Kurth

    2013-02-01

    Full Text Available Distributed temperature sensing (DTS is a fiber-optical method enabling simultaneous temperature measurements over long distances. Electrical resistance heating of the metallic components of the fiber-optic cable provides information on the thermal characteristics of the cable's environment, providing valuable insight into processes occurring in the surrounding medium, such as groundwater–surface water interactions, dam stability or soil moisture. Until now, heated applications required direct handling of the DTS instrument by a researcher, rendering long-term investigations in remote areas impractical due to the often difficult and time-consuming access to the field site. Remote control and automation of the DTS instrument and heating processes, however, resolve the issue with difficult access. The data can also be remotely accessed and stored on a central database. The power supply can be grid independent, although significant infrastructure investment is required here due to high power consumption during heated applications. Solar energy must be sufficient even in worst case scenarios, e.g. during long periods of intense cloud cover, to prevent system failure due to energy shortage. In combination with storage batteries and a low heating frequency, e.g. once per day or once per week (depending on the season and the solar radiation on site, issues of high power consumption may be resolved. Safety regulations dictate adequate shielding and ground-fault protection, to safeguard animals and humans from electricity and laser sources. In this paper the autonomous DTS system is presented to allow research with heated applications of DTS in remote areas for long-term investigations of temperature distributions in the environment.

  5. Ionic Liquids for Utilization of Waste Heat from Distributed Power Generation Systems

    Energy Technology Data Exchange (ETDEWEB)

    Joan F. Brennecke; Mihir Sen; Edward J. Maginn; Samuel Paolucci; Mark A. Stadtherr; Peter T. Disser; Mike Zdyb

    2009-01-11

    The objective of this research project was the development of ionic liquids to capture and utilize waste heat from distributed power generation systems. Ionic Liquids (ILs) are organic salts that are liquid at room temperature and they have the potential to make fundamental and far-reaching changes in the way we use energy. In particular, the focus of this project was fundamental research on the potential use of IL/CO2 mixtures in absorption-refrigeration systems. Such systems can provide cooling by utilizing waste heat from various sources, including distributed power generation. The basic objectives of the research were to design and synthesize ILs appropriate for the task, to measure and model thermophysical properties and phase behavior of ILs and IL/CO2 mixtures, and to model the performance of IL/CO2 absorption-refrigeration systems.

  6. Effect of heat shock on ultrastructure and calcium distribution in Lavandula pinnata L. glandular trichomes.

    Science.gov (United States)

    Huang, S S; Kirchoff, B K; Liao, J P

    2013-02-01

    The effects of heat shock (HS) on the ultrastructure and calcium distribution of Lavandula pinnata secretory trichomes are examined using transmission electron microscopy and potassium antimonate precipitation. After 48-h HS at 40°C, plastids become distorted and lack stroma and osmiophilic deposits, the cristae of the mitochondria become indistinct, the endoplasmic reticulum acquires a chain-like appearance with ribosomes prominently attached to the lamellae, and the plasma and organelle membranes become distorted. Heat shock is associated with a decrease in calcium precipitates in the trichomes, while the number of precipitates increases in the mesophyll cells. Prolonged exposure to elevated calcium levels may be toxic to the mesophyll cells, while the lack of calcium in the glands cell may deprive them of the normal protective advantages of elevated calcium levels. The inequality in calcium distribution may result not only from uptake from the transpiration stream, but also from redistribution of calcium from the trichomes to the mesophyll cells.

  7. Conjugated heat transfer and temperature distributions in a gas turbine combustion liner under base-load operation

    International Nuclear Information System (INIS)

    Kim, Kyung Min; Yun, Nam Geon; Jeon, Yun Heung; Lee, Dong Hyun; Cho, Yung Hee

    2010-01-01

    Prediction of temperature distributions on hot components is important in development of a gas turbine combustion liner. The present study investigated conjugated heat transfer to obtain temperature distributions in a combustion liner with six combustion nozzles. 3D numerical simulations using FVM commercial codes, Fluent and CFX were performed to calculate combustion and heat transfer distributions. The temperature distributions in the combustor liner were calculated by conjugation of conduction and convection (heat transfer coefficients) obtained by combustion and cooling flow analysis. The wall temperature was the highest on the attachment points of the combustion gas from combustion nozzles, but the temperature gradient was high at the after shell section with low wall temperature

  8. An axial heat transfer analytical model for capillary-pumped loop vapor line temperature distributions

    International Nuclear Information System (INIS)

    Lin, H.-W.; Lin, W.-K.

    2007-01-01

    This paper aims to study the capillary-pumped loop (CPL) vapor line temperature distributions. A simple axial heat transfer method is developed to predict the vapor line temperature from evaporator outlet to condenser inlet. CPL is a high efficiency two-phase heat transfer device. Since it does not need any other mechanical force such as pump, furthermore, it might be used to do the thermal management of high power electronic component such as spacecraft, notebook and computer servers. It is a cyclic circulation pumped by capillary force, and this force is generated from the fine porous structure in evaporator. A novel semi-arc porous evaporator to CPL in 1U server is designed on the ground with a horizontal position and scale down the whole device to the miniature size. From the experimental results, the CPL could remove heat 90 W in steady-state and keep the heat source temperature about 70 deg. C. Finally, a good agreement between the simulation and experimental values has been achieved. Comparing with experiment and simulation results, the deviation values of the distributions of the condenser inlet temperature are less than 8%

  9. Residual Stress Distribution In Heat Affected Zone Of Welded Steel By Means Of Neutron Diffraction Method

    International Nuclear Information System (INIS)

    Fajar, Andika; Prasuad; Gunawan; Muslich, M. Rifai

    1996-01-01

    Three dimensional residual stress distribution in the heat affected zone of 10 mm thick welded steel by means of neutron diffraction technique has been measured. The results showed that the residual stress was distributed near the welded metal, namely within about 46,25 mm. The major tensile stresses occurred in the X-direction, and they attained a level greater than 2000 MPa through the position far away fram the weld. The tensile stresses in the Y and Z- directions lied between 500 and 1500 MPa, The results also suggest that the stress in the surface was greater than that in the middle of the sample

  10. Heat transfer and temperature distribution in fuel; Odredjivanje parametara prenosa toplote i raspodele temperatura u gorivu

    Energy Technology Data Exchange (ETDEWEB)

    Katanic-Popovic, J; Stevanovic, M [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

    1966-11-15

    This paper describes methods and procedures for determining the integral, mean and effective heat conductivity and temperature distribution in fuel, with the experimental solutions for measuring these parameters. A procedure for measuring the integral conductivity by measuring the power generated in the fuel is given. Prikazane su metode i postupci odredjivanja integralne, srednje i efektivne toplotne provodljivosti i temperaturne raspodele u gorivu i data eksperimentalna resenja za njihovo odredjivanje. Izlozen je postupak za odredjivanje integralne provodljivosti preko generisane snage u gorivu (author)

  11. Behaviors of radionuclides in wet underground soil

    International Nuclear Information System (INIS)

    Inoue, Y.; Morisawa, S.

    Experimental studies were made of the variations of the distribution coefficient of 65 Zn, 60 Co, and /sup 110 m/Ag with Ca ion contents in sand--water and resin--water systems. It is concluded that: (1) The distribution coefficient of a radionuclide is not constant but varies greatly especially with calcium ion concentration in underground water. (2) The Saturation Index I=pH-pHs can be used as a parameter to indicate such variations. (3) Some radionuclides, existing as radiocolloids like (sup 110m/Ag and 59 Fe, are inactive toward ion exchange reactions as with hydroxide. In such cases, the nuclides migrate underground as fast as underground water

  12. Energy saving analyses on the reconstruction project in district heating system with distributed variable speed pumps

    International Nuclear Information System (INIS)

    Sheng, Xianjie; Lin, Duanmu

    2016-01-01

    Highlights: • The mathematical model of economic frictional factor based on DVFSP DHS is established. • Influence factors of economic frictional factor are analyzed. • Energy saving in a DVFSP district heating system is presented and analyzed. - Abstract: Optimization of the district heating (DH) piping network is of vital importance to the economics of the whole DH system. The application of distributed variable frequency speed pump (DVFSP) in the district heating network has been considered as a technology improvement that has a potential in saving energy compared to the conventional central circulating pump (CCCP) district heating system (DHS). Economic frictional factor is a common design parameter used in DH pipe network design. In this paper, the mathematical model of economic frictional factor based on DVFSP DHS is established, and influence factors are analyzed, providing a reference for engineering designs for the system. According to the analysis results, it is studied that the energy efficiency in the DH system with the DVFSP is compared with the one in the DH system with conventional central circulating pump (CCCP) using a case based on a district heating network in Dalian, China. The results of the study on the case show that the average electrical energy saved is 49.41% of the one saved by the DH system with conventional central circulating pump in the primary network.

  13. Dynamic Models of Heating and Cooling Coils with One—Dimensional Air Distribution

    Institute of Scientific and Technical Information of China (English)

    WangZijie; G.Krauss

    1993-01-01

    This paper presents the simulation models of the plate-fin,air-to-water(or water vapour) heat exchangers used as air-heating or air-cooling and dehumidifying colis in the HVAC(Heating,Ventilation and AIr-Conditioning)systems.The thermal models are used to calculate the heat exchange between distributing air and coil pipes and outlet temperatures of air and heat or chilled fluid.The aerodynamic models are used to account for the pressure drop of the air crossing the coil tubes,They can also be used to optimize the structres of such coils.The models are based on principal laws of teat and mass conservation and fluid mechanics.They are transparent and easy to use.In our work,a coil is considered as an assembly of numbers of basic elements in which all the state variables are unique.Therefore we can conveniently simulate the coils with different structures and different geometric parameters.Two modular programs TRNSYS(Transient System Simulation)and ESACAP are utilized as supporting softwares which make the programming and simulation greatly simplified.The coil elements and a real coil were simulated.The results were compared with the data offered by the manufacturer(company SOFICA) and also with those obtained using critical methods such as NTU method ,etc.and good agreement is attained.

  14. Distributed Control of Heat Conduction in Thermal Inductive Materials with 2D Geometrical Isomorphism

    Directory of Open Access Journals (Sweden)

    Chia-Yu Chou

    2014-09-01

    Full Text Available In a previous study we provided analytical and experimental evidence that some materials are able to store entropy-flow, of which the heat-conduction behaves as standing waves in a bounded region small enough in practice. In this paper we continue to develop distributed control of heat conduction in these thermal-inductive materials. The control objective is to achieve subtle temperature distribution in space and simultaneously to suppress its transient overshoots in time. This technology concerns safe and accurate heating/cooling treatments in medical operations, polymer processing, and other prevailing modern day practices. Serving for distributed feedback, spatiotemporal H ∞ /μ control is developed by expansion of the conventional 1D-H ∞ /μ control to a 2D version. Therein 2D geometrical isomorphism is constructed with the Laplace-Galerkin transform, which extends the small-gain theorem into the mode-frequency domain, wherein 2D transfer-function controllers are synthesized with graphical methods. Finally, 2D digital-signal processing is programmed to implement 2D transfer-function controllers, possibly of spatial fraction-orders, into DSP-engine embedded microcontrollers.

  15. Air Distribution and Ventilation Effectiveness in a room with Floor/Ceiling Heating and Mixing/Displacement Ventilation

    DEFF Research Database (Denmark)

    Wu, Xiaozhou; Fang, Lei; Olesen, Bjarne W.

    2014-01-01

    vertical air temperature differences and air velocities for different hybrid systems are less than 3 C and 0.2 m/s when supply air temperature is 19 C, air change rate is 4.2 h-1, and heated surface temperature of floor/ceiling heating system is 25 C. Ventilation effectiveness of mixing ventilation system...... combined with floor/ceiling heating systems is approximately equal to 1.0, and ventilation effectiveness of displacement ventilation system combined with floor/ceiling heating systems ranges from 1.0 to 1.2. The floor/ceiling heating systems combined with mixing ventilation system have more uniform indoor...... air distribution but smaller ventilation effectiveness compared with the floor/ceiling heating systems combined with displacement ventilation system. With regard to the building heat loss increased by non-uniform indoor air distribution and small ventilation effectiveness, there should be an optimal...

  16. A prediction method of the effect of radial heat flux distribution on critical heat flux in CANDU fuel bundles

    International Nuclear Information System (INIS)

    Yuan, Lan Qin; Yang, Jun; Harrison, Noel

    2014-01-01

    Fuel irradiation experiments to study fuel behaviors have been performed in the experimental loops of the National Research Universal (NRU) Reactor at Atomic Energy of Canada Limited (AECL) Chalk River Laboratories (CRL) in support of the development of new fuel technologies. Before initiating a fuel irradiation experiment, the experimental proposal must be approved to ensure that the test fuel strings put into the NRU loops meet safety margin requirements in critical heat flux (CHF). The fuel strings in irradiation experiments can have varying degrees of fuel enrichment and burnup, resulting in large variations in radial heat flux distribution (RFD). CHF experiments performed in Freon flow at CRL for full-scale bundle strings with a number of RFDs showed a strong effect of RFD on CHF. A prediction method was derived based on experimental CHF data to account for the RFD effect on CHF. It provides good CHF predictions for various RFDs as compared to the data. However, the range of the tested RFDs in the CHF experiments is not as wide as that required in the fuel irradiation experiments. The applicability of the prediction method needs to be examined for the RFDs beyond the range tested by the CHF experiments. The Canadian subchannel code ASSERT-PV was employed to simulate the CHF behavior for RFDs that would be encountered in fuel irradiation experiments. The CHF predictions using the derived method were compared with the ASSERT simulations. It was observed that the CHF predictions agree well with the ASSERT simulations in terms of CHF, confirming the applicability of the prediction method in fuel irradiation experiments. (author)

  17. Numerical Analysis on Heat Flux Distribution through the Steel Liner of the Ex-vessel Core Catcher

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Se Hong; Choi, Choeng Ryul [ELSOLTEC, Yongin (Korea, Republic of); Kim, Byung Jo; Lee, Kyu Bok [KEPCO, Gimcheon (Korea, Republic of); Hwang, Do Hyun [KHNP-CRI, Daejeon (Korea, Republic of)

    2016-05-15

    In order to prevent material failure of steel container of the core catcher system due to high temperatures, heat flux through the steel liner wall must be kept below the critical heat flux (CHF), and vapor dry-out of the cooling channel must be avoided. In this study, CFD methodology has been developed to simulate the heat flux distribution in the core catcher system, involving following physical phenomena: natural convection in the corium pool, boiling heat transfer and solidification/melting of the corium. A CFD methodology has been developed to simulate the thermal/hydraulic phenomena in the core catcher system, and a numerical analysis has been carried out to estimate the heat flux through the steel liner of the core catcher. High heat flux values are formed at the free surface of the corium pool. However, the heat flux through the steel liner is maintained below the critical heat flux.

  18. EAS selection in the EMMA underground array

    DEFF Research Database (Denmark)

    Sarkamo, J.; Bezrukov, L.; Enqvist, T.

    2013-01-01

    The first measurements of the Experiment with MultiMuon Array (EMMA) have been analyzed for the selection of the Extensive Air Showers (EAS). Test data were recorded with an underground muon tracking station and a satellite station separated laterally by 10 metres. Events with tracks distributed...

  19. Effects of heat stress on dynamic absorption process, tissue distribution and utilization efficiency of vitamin C in broilers

    International Nuclear Information System (INIS)

    Liu Guohua; Chen Guosheng; Cai Huiyi

    1998-01-01

    The experiment was conducted to determine the effects of heat stress on ascorbic acid nutritional physiology of broilers with radioisotope technology. 3 H-Vc was fed to broilers and then the blood, liver, kidney, breast muscle, and excreta were sampled to determine the dynamic absorption process, the tissue distribution and the utilization efficiency of vitamin C. The results indicated that the absorption, metabolism and mobilization of supplemented vitamin C in broilers with heat stress was faster than that in broilers without heat stress. However, the utilization efficiency of supplemented vitamin C in broilers with heat stress was not higher than that of broilers without heat stress

  20. Effect of non-equilibrium flow chemistry on the heating distribution over the MESUR forebody during a Martian entry

    Science.gov (United States)

    Chen, Yih-Kang

    1992-01-01

    Effect of flow field properties on the heating distribution over a 140 deg blunt cone was determined for a Martian atmosphere using Euler, Navier-Stokes (NS), viscous shock layer (VSL), and reacting boundary layer (BLIMPK) equations. The effect of gas kinetics on the flow field and the surface heating distribution were investigated. Gas models with nine species and nine reactions were implemented into the codes. Effects of surface catalysis on the heating distribution were studied using a surface kinetics model having five reactions.

  1. A new model for heat conduction of nanofluids based on fractal distributions of nanoparticles

    International Nuclear Information System (INIS)

    Xu Jie; Yu Boming; Zou Mingqing; Xu Peng

    2006-01-01

    In this paper we report a new model for predicting the thermal conductivity of nanofluids by taking into account the fractal distribution of nanoparticle sizes and heat convection between nanoparticles and liquids due to the Brownian motion of nanoparticles in fluids. The proposed model is expressed as a function of the average size of nanoparticles, fractal dimension, concentration of nanoparticles, temperature and properties of fluids. The model shows the reasonable dependences of the thermal conductivity on the temperature of nanofluids, nanoparticle size and concentration. The parameter c introduced in thermal boundary layer depends on fluids, but is independent of nanoparticles added in the fluids. The model predictions are in good agreement with the available experimental data. The model also reveals that there is a critical concentration of 12.6% of nanoparticles at which the contribution from heat convection due to the Brownian movement of nanoparticles reaches the maximum value, below which the contribution from heat convection decreases with the decrease in concentration and above which the contribution from heat convection decreases with the increase in concentration

  2. Spatial distributions of heating, cooling, and industrial degree-days in Turkey

    Science.gov (United States)

    Yildiz, I.; Sosaoglu, B.

    2007-11-01

    The degree-day method is commonly used to estimate energy consumption for heating and cooling in residential, commercial and industrial buildings, as well as in greenhouses, livestock facilities, storage facilities and warehouses. This article presents monthly and yearly averages and spatial distributions of heating, cooling, and industrial degree-days at the base temperatures of 18 °C and 20 °C, 18 °C and 24 °C, and 7 °C and 13 °C, respectively; as well as the corresponding number of days in Turkey. The findings presented here will facilitate the estimation of heating and cooling energy consumption for any residential, commercial and industrial buildings in Turkey, for any period of time (monthly, seasonal, etc.). From this analysis it will also be possible to compare and design alternative building systems in terms of energy efficiencies. If one prefers to use set point temperatures to indicate the resumption of the heating season would also be possible using the provided information in this article. In addition, utility companies and manufacturing/marketing companies of HVAC systems would be able to easily determine the demand, marketing strategies and policies based on the findings in this study.

  3. Heat flux distribution on an optimised limiter surface and structure of the scrape-off-layer

    International Nuclear Information System (INIS)

    Denner, T.

    1998-12-01

    The heat load on plasma-facing components is a key issue for forthcoming fusion experiments. In this work the heat flux on the pump limiter in TEXTOR-94 is measured by a newly developed digital thermography system and these results are compared with theoretical models. The limiter is shaped in such a way as to keep the heat load of the plasma-wetted area low; this is achieved by reducing the angle of incidence of the magnetic field lines with respect to the limiter surface to less than 1 for the first 10 mm of the scrape-off-layer (SOL). This small angle of incidence enhances all effects of toroidal non-uniformity as given e.g. by the magnetic field ripple. Extensive modelling explains well the observed heating pattern on the limiter surface due to the ripple effect. In contrast to expectations from density and temperature distributions in the SOL and at the edge of the confined region, an excessive power density is deposited on the first few millimetres near the roof tip of the limiter. Physical effects which could cause this phenomenon are discussed. (orig.)

  4. Economics of long-distance transmission, storage, and distribution of heat from nuclear plants with existing and newer techniques

    International Nuclear Information System (INIS)

    Margen, P.H.

    1978-01-01

    Conventional and newer types of hot-water pipes are applied to the bulk transport of reject heat from central nuclear power plants to the district heating network of cities or groups of cities. With conventional pipes, the transport of 300 to 2000 MW of heat over distances of 30 to 100 km can be justified, while with newer pipe types, even longer distances would often be economic. For medium-size district heating schemes, low-temperature heat transport from simple heat-only reactors suitable for closer location to cities is of interest. For daily storage of heat on district heating systems, steel heat accumulators are currently used in Sweden. The development of more advanced cheaper heat accumulators, such as lake storage schemes, could make even seasonal heat storage economic. Newer distribution technology extends the economic field of penetration of district heating even to suburban one-family house districts. With proper design and optimization, nuclear district heating can be competitive in a wide market and achieve very substantial fossil-fuel savings

  5. Status of the ITER full-tungsten divertor shaping and heat load distribution analysis

    International Nuclear Information System (INIS)

    Carpentier-Chouchana, S; Hirai, T; Escourbiac, F; Durocher, A; Fedosov, A; Ferrand, L; Kocan, M; Kukushkin, A S; Jokinen, T; Komarov, V; Lehnen, M; Merola, M; Mitteau, R; Pitts, R A; Sugihara, M; Firdaouss, M; Stangeby, P C

    2014-01-01

    In September 2011, the ITER Organization (IO) proposed to begin operation with a full-tungsten (W) armoured divertor, with the objective of taking a decision on the final target material (carbon fibre composite or W) by the end of 2013. This period of 2 years would enable the development of a full-W divertor design compatible with nuclear operations, the investigation of further several physics R and D aspects associated with the use of W targets and the completion of technology qualification. Beginning with a brief overview of the reference heat load specifications which have been defined for the full-W engineering activity, this paper will report on the current status of the ITER divertor shaping and will summarize the results of related three-dimensional heat load distribution analysis performed as part of the design validation. (paper)

  6. Spatial distribution of urban heat island in Hangzhou and its mitigation countermeasures

    DEFF Research Database (Denmark)

    Wang, W.-W.; Li, G.-L.; Xue, J.

    2009-01-01

    of the evolution of urban landuse types, the changes of urban spatial pattern, the rationality of the urban land layout, and the emission of anthropogenic heat. Finally, in the perspective of urban planning, some mitigation countermeasures including the reasonable control of the expansion of urban landuse......, construction of the urban ecological open space, optimization of the layout of urban landuse, and planning for underlaying surface were put forward. This aims to provide a reference to work in improving the thermal environment of Hangzhou City.......Taking Hangzhou City in summer as a case, the thermal infrared remote sensing image (Landsat 5 TM) was used to extract and inverse the surface land cover types and surface temperature of Hangzhou City. The spatial distribution characteristics of urban heat island was analyzed in the city...

  7. Evaluation of induced activity, decay heat and dose rate distribution after shutdown in ITER

    Energy Technology Data Exchange (ETDEWEB)

    Maki, Koichi [Hitachi Ltd., Ibaraki (Japan). Hitachi Research Lab.; Satoh, Satoshi; Hayashi, Katsumi; Yamada, Koubun; Takatsu, Hideyuki; Iida, Hiromasa

    1997-03-01

    Induced activity, decay heat and dose rate distributions after shutdown were estimated for 1MWa/m{sup 2} operation in ITER. The activity in the inboard blanket one day after shutdown is 1.5x10{sup 11}Bq/cm{sup 3}, and the average decay heating rate 0.01w/cm{sup 3}. The dose rate outside the 120cm thick concrete biological shield is two order higher than the design criterion of 5{mu}Sv/h. This indicates that the biological shield thickness should be enhanced by 50cm in concrete, that is, total thickness 170cm for workers to enter the reactor room and to perform maintenance. (author)

  8. Participation of an Energy Hub in Electricity and Heat Distribution Markets: An MPEC Approach

    DEFF Research Database (Denmark)

    Li, Rui; Wu, Qiuwei; Wei, Wei

    2018-01-01

    and thorough mathematical tool for studying the integrated energy system from a deregulated market perspective. A mathematic program with equilibrium constraints (MPEC) model is proposed to study the strategic behaviors of a profit-driven energy hub in the electricity market and heating market under...... the background of energy system integration. In the upper level, the EH submits bids of prices and quantities to a distribution power market and a heating market; in the lower level, the two markets are cleared and energy contracts between the EH and two energy markets are determined. Network constraints...... of physical systems are explicitly represented by an optimal power flow problem and an optimal thermal flow problem. The proposed MPEC formulation is approximated by a mixed-integer linear program via performing integer disjunctions on the complementarity and slackness conditions and binary expansion...

  9. Impact of Air Distribution on Heat Transfer during Night-Time Ventilation

    DEFF Research Database (Denmark)

    Heiselberg, Per; Artmann, Nikolai; Jensen, Rasmus Lund

    2009-01-01

    Passive cooling by night-time ventilation is seen as a promising approach for energy efficient cooling of buildings. However, uncertainties in prediction of cooling potential and consequenses for thermal comfort restrain architects and engineers from applying this technique. Heat transfer...... at internal room surfaces determines the performance of night-time ventilation. In order to improve predictability, heat transfer mechanism in case of either mixing or displacement ventilation has been investigated in a full scale test room with an exposed ceiling as the dominating thermal mass. The influence...... of air distribution principle, air flow rate and inlet air temperature were investigated. Results show that for low air flow rates displacement ventilation is more efficient than mixing ventilation. For higher airflow rates the air jet flowing along the ceiling has a significant effect, and mixing...

  10. Economics of long distance transmission, storage and distribution of heat from nuclear plants with existing and newer techniques

    International Nuclear Information System (INIS)

    Margen, Peter

    1977-01-01

    Nuclear plants can provide heat for district heating in mainly two ways. Central nuclear power plants sufficiently large to be economic as electricity producers could instead be designed for heat extraction at temperatures useful for district heating. The second promising way is to design simple low temperature reactors, so simple and safe that near urban location becomes feasible. The manner of transport distribution and storage of heat is discussed in this paper which are very important especially in the cost calculations. The economic objectives can often be attained already with conventional technigues even when transport distances are large. But newer techniques of transport promise to make even cities at greater distances from major nuclear power plants economically connectible whilst new techniques for small distribution pipes help to extend the economic distribution area to the less dense one-family house districts. (M.S.)

  11. Spatial fluxes and energy distributions of reactor fast neutrons in two types of heat resistant concretes

    International Nuclear Information System (INIS)

    Akki, T.S.; Benayad, S.A.; Megahid, R.M.

    1992-01-01

    Measurements have been carried out to study the spatial fluxes and energy distributions of reactor fast neutrons transmitted through two types of heat resistant concretes, serpentine concrete and magnetic lemonite concrete. The physical, chemical and mechanical properties of these concretes were checked by well known techniques. In addition, the effect of heating at temperatures up to 500deg C on the crystaline water content was checked by the method of differential thermal analysis. Measurements were performed using a collimated beam of reactor neutrons emitted from a 10 MW research reactor. The neutron spectra transmitted through concrete barriers of different thickness were measured by a scintillation spectrometer with NE-213 liquid organic scintillator. Discrimination against undesired pulses due to gamma-rays was achieved by a method based on pulse shape discrimination technique. The operating principle of this technique is based on the comparison of two weighted time integrals of the detector signal. The measured pulse amplitude distribution was converted to neutron energy distribution by a computational code based on double differentiation technique. The spectrometer workability and the accuracy of the unfolding technique were checked by measuring the neutron spectra of neutrons from Pu-α-Be and 252 Cf neutron sources. The obtained neutron spectra for the two concretes were used to derive the total cross sections for neutrons of different energies. (orig.)

  12. Temperature distribution of a simplified rotor due to a uniform heat source

    Science.gov (United States)

    Welzenbach, Sarah; Fischer, Tim; Meier, Felix; Werner, Ewald; kyzy, Sonun Ulan; Munz, Oliver

    2018-03-01

    In gas turbines, high combustion efficiency as well as operational safety are required. Thus, labyrinth seal systems with honeycomb liners are commonly used. In the case of rubbing events in the seal system, the components can be damaged due to cyclic thermal and mechanical loads. Temperature differences occurring at labyrinth seal fins during rubbing events can be determined by considering a single heat source acting periodically on the surface of a rotating cylinder. Existing literature analysing the temperature distribution on rotating cylindrical bodies due to a stationary heat source is reviewed. The temperature distribution on the circumference of a simplified labyrinth seal fin is calculated using an available and easy to implement analytical approach. A finite element model of the simplified labyrinth seal fin is created and the numerical results are compared to the analytical results. The temperature distributions calculated by the analytical and the numerical approaches coincide for low sliding velocities, while there are discrepancies of the calculated maximum temperatures for higher sliding velocities. The use of the analytical approach allows the conservative estimation of the maximum temperatures arising in labyrinth seal fins during rubbing events. At the same time, high calculation costs can be avoided.

  13. Numerical analysis of temperature distribution due to basement radiogenic heat production, St. Lawrence Lowlands, eastern Canada

    Science.gov (United States)

    Liu, Hejuan; Giroux, Bernard; Harris, Lyal B.; Mansour, John

    2017-04-01

    Although eastern Canada is considered as having a low potential for high-temperature geothermal resources, the possibility for additional localized radioactive heat sources in Mesoproterozoic Grenvillian basement to parts of the Palaeozoic St. Lawrence Lowlands in Quebec, Canada, suggests that this potential should be reassessed. However, such a task remains hard to achieve due to scarcity of heat flow data and ambiguity about the nature of the basement. To get an appraisal, the impact of radiogenic heat production for different Grenville Province crystalline basement units on temperature distribution at depth was simulated using the Underworld Geothermal numerical modelling code. The region south of Trois-Rivières was selected as representative for the St. Lawrence Lowlands. An existing 3D geological model based on well log data, seismic profiles and surface geology was used to build a catalogue of plausible thermal models. Statistical analyses of radiogenic element (U, Th, K) concentrations from neighbouring outcropping Grenville domains indicate that the radiogenic heat production of rocks in the modelled region is in the range of 0.34-3.24 μW/m3, with variations in the range of 0.94-5.83 μW/m3 for the Portneuf-Mauricie (PM) Domain, 0.02-4.13 μW/m3 for the Shawinigan Domain (Morin Terrane), and 0.34-1.96 μW/m3 for the Parc des Laurentides (PDL) Domain. Various scenarios considering basement characteristics similar to the PM domain, Morin Terrane and PDL Domain were modelled. The results show that the temperature difference between the scenarios can be as much as 12 °C at a depth of 5 km. The results also show that the temperature distribution is strongly affected by both the concentration of radiogenic elements and the thermal conductivity of the basement rocks. The thermal conductivity in the basement affects the trend of temperature change between two different geological units, and the spatial extent of thermal anomalies. The validity of the results was

  14. Expressed sequence tags from heat-shocked seagrass Zostera noltii (Hornemann) from its southern distribution range.

    Science.gov (United States)

    Massa, Sónia I; Pearson, Gareth A; Aires, Tânia; Kube, Michael; Olsen, Jeanine L; Reinhardt, Richard; Serrão, Ester A; Arnaud-Haond, Sophie

    2011-09-01

    Predicted global climate change threatens the distributional ranges of species worldwide. We identified genes expressed in the intertidal seagrass Zostera noltii during recovery from a simulated low tide heat-shock exposure. Five Expressed Sequence Tag (EST) libraries were compared, corresponding to four recovery times following sub-lethal temperature stress, and a non-stressed control. We sequenced and analyzed 7009 sequence reads from 30min, 2h, 4h and 24h after the beginning of the heat-shock (AHS), and 1585 from the control library, for a total of 8594 sequence reads. Among 51 Tentative UniGenes (TUGs) exhibiting significantly different expression between libraries, 19 (37.3%) were identified as 'molecular chaperones' and were over-expressed following heat-shock, while 12 (23.5%) were 'photosynthesis TUGs' generally under-expressed in heat-shocked plants. A time course analysis of expression showed a rapid increase in expression of the molecular chaperone class, most of which were heat-shock proteins; which increased from 2 sequence reads in the control library to almost 230 in the 30min AHS library, followed by a slow decrease during further recovery. In contrast, 'photosynthesis TUGs' were under-expressed 30min AHS compared with the control library, and declined progressively with recovery time in the stress libraries, with a total of 29 sequence reads 24h AHS, compared with 125 in the control. A total of 4734 TUGs were screened for EST-Single Sequence Repeats (EST-SSRs) and 86 microsatellites were identified. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Underground Storage Tanks in Iowa

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — Underground storage tank (UST) sites which store petroleum in Iowa. Includes sites which have been reported to DNR, and have active or removed underground storage...

  16. Underground gasification in Britain

    Energy Technology Data Exchange (ETDEWEB)

    1952-08-29

    A report of the discussion held on the paper Underground Gasification in Britain, by C.A. Masterman (Iron and Coal Trades Rev., Vol. 165, Aug. 22, 1952, pp. 413-422). The water question, preheating the air, controlling the gas, using the product, choosing the site, thickness of seam and faulted areas are discussed.

  17. Underground nuclear power plant

    International Nuclear Information System (INIS)

    Takahashi, Hideo.

    1997-01-01

    In an underground-type nuclear power plant, groups of containing cavities comprising a plurality of containing cavities connected in series laterally by way of partition walls are disposed in parallel underground. Controlled communication tunnels for communicating the containing cavities belonging to a control region to each other, and non-controlled communication tunnels for communicating containing cavities belonging to a non-controlled area to each other are disposed underground. A controlled corridor tunnel and a non-controlled corridor tunnel extended so as to surround the containing cavity groups are disposed underground, and the containing cavities belonging to the controlled area are connected to the controlled corridor tunnel respectively, and the containing cavities belonging to the non-controlled area are connected to the non-controlled corridor tunnel respectively. The excavating amount of earth and sand upon construction can be reduced by disposing the containing cavity groups comprising a plurality of containing cavities connected in series laterally. The time and the cost for the construction can be reduced, and various excellent effects can be provided. (N.H.)

  18. Underground neutrino astronomy

    International Nuclear Information System (INIS)

    Schramm, D.N.

    1983-02-01

    A review is made of possible astronomical neutrino sources detectable with underground facilities. Comments are made about solar neutrinos and gravitational-collapse neutrinos, and particular emphasis is placed on ultra-high-energy astronomical neutrino sources. An appendix mentions the exotic possibility of monopolonium

  19. Measurements of the fast ion distribution during neutral beam injection and ion cyclotron heating in ATF [Advanced Toroidal Facility

    International Nuclear Information System (INIS)

    Wade, M.R.; Kwon, M.; Thomas, C.E.; Colchin, R.J.; England, A.C.; Gossett, J.M.; Horton, L.D.; Isler, R.C.; Lyon, J.F.; Rasmussen, D.A.; Rayburn, T.M.; Shepard, T.D.; Bell, G.L.; Fowler, R.H.; Morris, R.N.

    1990-01-01

    A neutral particle analyzer (NPA) with horizontal and vertical scanning capability has been used to make initial measurements of the fast ion distribution during neutral beam injection (NBI) and ion cyclotron heating (ICH) on the Advanced Toroidal Facility (ATF). These measurements are presented and compared with the results of modeling codes that predict the analyzer signals during these heating processes. 6 refs., 5 figs

  20. Possibility to explain the temperature distribution in sunspots by an anisotropic heat transfer

    Energy Technology Data Exchange (ETDEWEB)

    Eschrich, K O; Krause, F [Akademie der Wissenschaften der DDR, Potsdam. Zentralinstitut fuer Astrophysik

    1977-01-01

    Numerical solutions of a heat conduction problem in an anisotropic medium are used for a discussion of the possibility to explain the temperature distribution in sunspots and their environment. The anisotropy is assumed being due to the strong magnetic field in sunspots and the region below. This magnetic field forces the convection to take an anisotropic structure (two-dimensional turbulence) and thus the region gets anisotropic conduction properties, on the average. The discussion shows that the observed temperature profiles can be explained in the case the depth of the region of anisotropy is about as large as the diameter of the spot or larger.

  1. Natural ventilation in an enclosure induced by a heat source distributed uniformly over a vertical wall

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Z.D.; Li, Y.; Mahoney, J. [CSIRO Building, Construction and Engineering, Advanced Thermo-Fluids Technologies Lab., Highett, VIC (Australia)

    2001-05-01

    A simple multi-layer stratification model is suggested for displacement ventilation in a single-zone building driven by a heat source distributed uniformly over a vertical wall. Theoretical expressions are obtained for the stratification interface height and ventilation flow rate and compared with those obtained by an existing model available in the literature. Experiments were also carried out using a recently developed fine-bubble modelling technique. It was shown that the experimental results obtained using the fine-bubble technique are in good agreement with the theoretical predictions. (Author)

  2. Residual stress distribution analysis of heat treated APS TBC using image based modelling.

    Science.gov (United States)

    Li, Chun; Zhang, Xun; Chen, Ying; Carr, James; Jacques, Simon; Behnsen, Julia; di Michiel, Marco; Xiao, Ping; Cernik, Robert

    2017-08-01

    We carried out a residual stress distribution analysis in a APS TBC throughout the depth of the coatings. The samples were heat treated at 1150 °C for 190 h and the data analysis used image based modelling based on the real 3D images measured by Computed Tomography (CT). The stress distribution in several 2D slices from the 3D model is included in this paper as well as the stress distribution along several paths shown on the slices. Our analysis can explain the occurrence of the "jump" features near the interface between the top coat and the bond coat. These features in the residual stress distribution trend were measured (as a function of depth) by high-energy synchrotron XRD (as shown in our related research article entitled 'Understanding the Residual Stress Distribution through the Thickness of Atmosphere Plasma Sprayed (APS) Thermal Barrier Coatings (TBCs) by high energy Synchrotron XRD; Digital Image Correlation (DIC) and Image Based Modelling') (Li et al., 2017) [1].

  3. Inverse Estimation of Heat Flux and Temperature Distribution in 3D Finite Domain

    International Nuclear Information System (INIS)

    Muhammad, Nauman Malik

    2009-02-01

    Inverse heat conduction problems occur in many theoretical and practical applications where it is difficult or practically impossible to measure the input heat flux and the temperature of the layer conducting the heat flux to the body. Thus it becomes imperative to devise some means to cater for such a problem and estimate the heat flux inversely. Adaptive State Estimator is one such technique which works by incorporating the semi-Markovian concept into a Bayesian estimation technique thereby developing an inverse input and state estimator consisting of a bank of parallel adaptively weighted Kalman filters. The problem presented in this study deals with a three dimensional system of a cube with one end conducting heat flux and all the other sides are insulated while the temperatures are measured on the accessible faces of the cube. The measurements taken on these accessible faces are fed into the estimation algorithm and the input heat flux and the temperature distribution at each point in the system is calculated. A variety of input heat flux scenarios have been examined to underwrite the robustness of the estimation algorithm and hence insure its usability in practical applications. These include sinusoidal input flux, a combination of rectangular, linearly changing and sinusoidal input flux and finally a step changing input flux. The estimator's performance limitations have been examined in these input set-ups and error associated with each set-up is compared to conclude the realistic application of the estimation algorithm in such scenarios. Different sensor arrangements, that is different sensor numbers and their locations are also examined to impress upon the importance of number of measurements and their location i.e. close or farther from the input area. Since practically it is both economically and physically tedious to install more number of measurement sensors, hence optimized number and location is very important to determine for making the study more

  4. Heat transfer enhancement in a natural draft dry cooling tower under crosswind operation with heterogeneous water distribution

    Energy Technology Data Exchange (ETDEWEB)

    Goodarzi, Mohsen; Amooie, Hossein [Bu-Ali Sina Univ., Hamedan (Iran, Islamic Republic of). Dept. of Mechanical Engineering

    2016-04-15

    Crosswind significantly decreases cooling efficiency of a natural draft dry cooling tower. The possibility of improving cooling efficiency with heterogeneous water distribution within the cooling tower radiators under crosswind condition is analysed. A CFD approach was used to model the flow field and heat transfer phenomena within the cooling tower and airflow surrounding the cooling tower. A mathematical model was developed from various CFD results. Having used a trained Genetic Algorithm with the result of mathematical model, the best water distribution was found among the others. Remodeling the best water distribution with the CFD approach showed that the highest enhancement of the heat transfer compared to the usual uniform water distribution.

  5. Heat transfer enhancement in a natural draft dry cooling tower under crosswind operation with heterogeneous water distribution

    International Nuclear Information System (INIS)

    Goodarzi, Mohsen; Amooie, Hossein

    2016-01-01

    Crosswind significantly decreases cooling efficiency of a natural draft dry cooling tower. The possibility of improving cooling efficiency with heterogeneous water distribution within the cooling tower radiators under crosswind condition is analysed. A CFD approach was used to model the flow field and heat transfer phenomena within the cooling tower and airflow surrounding the cooling tower. A mathematical model was developed from various CFD results. Having used a trained Genetic Algorithm with the result of mathematical model, the best water distribution was found among the others. Remodeling the best water distribution with the CFD approach showed that the highest enhancement of the heat transfer compared to the usual uniform water distribution.

  6. Analysis of resonant fast ion distributions during combined ICRF and NBI heating with transients using neutron emission spectroscopy

    Science.gov (United States)

    Hellesen, C.; Mantsinen, M.; Conroy, S.; Ericsson, G.; Eriksson, J.; Kiptily, V. G.; Nabais, F.; Contributors, JET

    2018-05-01

    ICRF heating at the fundamental cyclotron frequency of a hydrogen minority ion species also gives rise to a partial power absorption by deuterium ions at their second harmonic resonance. This paper studies the deuterium distributions resulting from such 2nd harmonic heating at JET using neutron emission spectroscopy data from the time of flight spectrometer TOFOR. The fast deuterium distributions are obtained over the energy range 100 keV to 2 MeV. Specifically, we study how the fast deuterium distributions vary as ICRF heating is used alone as well as in combination with NBI heating. When comparing the different heating scenarios, we observed both a difference in the shapes of the distributions as well as in their absolute level. The differences are most pronounced below 0.5 MeV. Comparisons are made with corresponding distributions calculated with the code PION. We find a good agreement between the measured distributions and those calculated with PION, both in terms of their shapes as well as their amplitudes. However, we also identified a period with signs of an inverted fast ion distribution, which showed large disagreements between the modeled and measured results. Resonant interactions with tornado modes, i.e. core localized toroidal alfven eigenmodes (TAEs), are put forward as a possible explanation for the inverted distribution.

  7. Global Pursuits: The Underground Railroad

    Science.gov (United States)

    School Arts: The Art Education Magazine for Teachers, 2004

    2004-01-01

    This brief article describes Charles T. Webber's oil on canvas painting, "The Underground Railroad, 1893." The subject of this painting is the Underground Railroad, which today has become an American legend. The Underground Railroad was not a systematic means of transportation, but rather a secretive process that allowed fugitive slaves…

  8. Output feedback control of heat transport mechanisms in parabolic distributed solar collectors

    KAUST Repository

    Elmetennani, Shahrazed

    2016-08-05

    This paper presents an output feedback control for distributed parabolic solar collectors. The controller aims at forcing the outlet temperature to track a desired reference in order to manage the produced heat despite the external disturbances. The proposed control strategy is derived using the distributed physical model of the system to avoid the loss of information due to model approximation schemes. The system dynamics are driven to follow reference dynamics defined by a transport equation with a constant velocity, which allows to control the transient behavior and the response time of the closed loop. The designed controller depends only on the accessible measured variables which makes it easy for real time implementation and useful for industrial plants. Simulation results show the efficiency of the reference tracking closed loop under different working conditions.

  9. Influence of heat consumers distribution and flashing vapours effect on steam consumption of evaporation plant of sugar factory

    Directory of Open Access Journals (Sweden)

    A. A. Gromkovskii

    2016-01-01

    Full Text Available The article considered the influence of the heat consumers distribution and the flashing vapours effect juice for multipleevaporator sugar factory on the consumption the main production flow of heat transfer agent – water vapor. The problem of rational distribution of heat transfer agent for of the corps multiple-evaporator is relevant from point of view of energy saving and energysaving heat of the sugar factory. The solution to this problem is advantageously carried out on the basis of quantitative mathematical description of the distribution of vapor on the corps of the evaporation plant. The heat consumers distribution should be based on technical and economic calculation. To solve this problem it is advisable to use a single equation that determines the dependence of the steam flow in the first unit evaporator on the amount of evaporated water and the method of heat consumers distribution for housing. Evaporators sugar factory has two functions – technology and heat, each of which is described by its equation. On the basis of the material and heat balance equations for the realization of the basic functions of the system evaporator written multipleevaporator equations. The solution of this system allows you to obtain the equation of the steam flow and the amount of evaporated water, taking into account the flashing vapours effect. Solution of the system should take into account the accepted design standards of sugar factories. As a result of solving the system of equation is obtained, which allows you to organize and optimize the heat consumers distribution of the corps evaporator. The equation can be used for any number of units evaporator. This equation allows you to assess the efficiency of the evaporation plant of a sugar factory. This is of great practical importance in the modernization of thermal schemes of sugar factories.

  10. Measurement of fast minority /sub 3/He/sup + +/ energy distribution during ICRF heating

    Science.gov (United States)

    Post, D.E. Jr.; Grisham, L.R.; Medley, S.S.

    A method and means for measuring the fast /sub 3/He/sup + +/ distribution during /sub 3/He/sup + +/ minority Ion Cyclotron Resonance Frequency (ICRF) heating is disclosed. The present invention involves the use of 10 to 100 keV beams of neutral helium atoms to neutralize the fast /sub 3/He/sup + +/ ions in a heated plasma by double charge exchange (/sub 3/He/sup + +/ + /sub 4/He/sup 0/ ..-->.. /sub 3/He/sup 0/ + /sub 4/He/sup + +/). The neutralized fast /sub 3/He/sup 0/ atoms then escape from the hot plasma confined by a magnetic field and are detected by conventional neutral particle analyzing means. This technique permits the effectiveness of the coupling of the ion cyclotron waves to the /sub 3/He/sup + +/ minority ions to be accurately measured. The present invention is particularly adapted for use in evaluating the effectiveness of the intermediate coupling between the RF heating and the /sub 3/He/sup + +/ in an energetic toroidal plasma.

  11. Resources and geothermal heat in the Netherlands. Annual report 2011. An overview of exploration and exploitation activities and of underground gas storage; Delfstoffen en Aardwarmte in Nederland. Jaarverslag 2011. Een overzicht van opsporings- en winningsactiviteiten en van ondergrondse gasopslag

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-15

    Traditionally, this annual report publishes the activities and results of the exploration and extraction of hydrocarbons in the Netherlands. Starting this year the report will be expanded with the exploration and extraction activities of rock salt and geothermal heat and the underground storage of resources (natural gas, nitrogen, CO2 and water). The first part of the annual report addresses the developments in the year 2011. This part also includes a prognosis for the extraction of natural gas for the next 25 years. Next, a number of tables illustrate developments in the field of licenses and exploration activities (seismic research and drilling) in 2011. The chapter on hydrocarbons is concluded with an overview of the extracted volumes of natural gas, condensate and petroleum and the gas flows in storage facilities. There are new chapters on exploration and extraction of rock salt and geothermal heat. Another new chapter addresses storage of resources. The second part of the annual report illustrates the situation per 1 January 2012 and the developments over the last decades in a number of overviews. The annexes, finally, include general maps of the situation as of 1 January 2012 [Dutch] Het Jaarverslag rapporteert over de activiteiten en resultaten van de opsporing en winning van koolwaterstoffen, steenzout en aardwarmte in Nederland. Daarnaast komt de ondergrondse opslag van stoffen (aardgas, stikstof, CO2 en water) aan de orde. Daarmee worden alle opsporings-, winnings- en opslagactiviteiten in Nederland en het Nederlandse deel van het Continentaal plat, vallend onder het regime van de Mijnbouwwet, gezamenlijk gerapporteerd. Het eerste deel van het jaarverslag gaat in op de ontwikkelingen in het jaar 2011. Zoals in voorgaande jaren richt dit deel zich op de opsporing, winning en de ondergrondse opslag van koolwaterstoffen. Dit betreft een overzicht van de veranderingen in de aardgas- en aardolievoorraden gedurende 2011 en de daaruit volgende situatie per 1

  12. Influence of RF heating and MHD instabilities on the fast-ion distribution in ASDEX upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Weiland, Markus

    2016-06-07

    Fast, supra-thermal ions provide a powerful mechanism to heat fusion plasmas. Through Coulomb collisions with the thermal bulk plasma, they slow down and transfer their energy to the plasma. In present-day devices, fast ions are generated by neutral beam injection (NBI) and ion cyclotron resonance heating (ICRH). In future fusion reactors, the dominant heating source, which allows the ignition of a burning plasma, will be fast a-particles resulting from fusion reactions. In addition to plasma heating, fast ions can be utilized to drive plasma currents and rotation. It is therefore crucial for the success of future fusion devices (such as ITER and DEMO) to understand the physics of fast ions and ensure their safe confinement. This thesis focuses both on modeling and experimental aspects. A model to calculate the NBI fast-ion distribution rapidly has been developed. It is based on a combination of existing codes and analytic solutions. Due to the comparably low numerical effort, it can be used to calculate the fast-ion distribution in a large set of discharges, which is used to e.g. improve plasma equilibrium reconstructions. Experimentally, the physics of fast ions is investigated at the tokamak ASDEX Upgrade, using a FIDA (Fast-Ion D-Alpha) spectroscopy diagnostic. This diagnostic technique is based on charge-exchange reactions, that convert the ions into neutral atoms (keeping their momenta). The light emission from these neutral atoms can be collected by optics in the machine and analyzed with spectrometers. Here, the fast-ion contribution can be identified due to large Doppler shifts, and the shape of the spectrum yields information about the velocity distribution. The Doppler shift is given by a projection of the ion velocity vector onto the line of sight, such that observation from different viewing angles is needed to cover the entire velocity space. Therefore, the FIDA diagnostic has been upgraded from three viewing arrays to five, and the spectrometer has

  13. Influence of RF heating and MHD instabilities on the fast-ion distribution in ASDEX upgrade

    International Nuclear Information System (INIS)

    Weiland, Markus

    2016-01-01

    Fast, supra-thermal ions provide a powerful mechanism to heat fusion plasmas. Through Coulomb collisions with the thermal bulk plasma, they slow down and transfer their energy to the plasma. In present-day devices, fast ions are generated by neutral beam injection (NBI) and ion cyclotron resonance heating (ICRH). In future fusion reactors, the dominant heating source, which allows the ignition of a burning plasma, will be fast a-particles resulting from fusion reactions. In addition to plasma heating, fast ions can be utilized to drive plasma currents and rotation. It is therefore crucial for the success of future fusion devices (such as ITER and DEMO) to understand the physics of fast ions and ensure their safe confinement. This thesis focuses both on modeling and experimental aspects. A model to calculate the NBI fast-ion distribution rapidly has been developed. It is based on a combination of existing codes and analytic solutions. Due to the comparably low numerical effort, it can be used to calculate the fast-ion distribution in a large set of discharges, which is used to e.g. improve plasma equilibrium reconstructions. Experimentally, the physics of fast ions is investigated at the tokamak ASDEX Upgrade, using a FIDA (Fast-Ion D-Alpha) spectroscopy diagnostic. This diagnostic technique is based on charge-exchange reactions, that convert the ions into neutral atoms (keeping their momenta). The light emission from these neutral atoms can be collected by optics in the machine and analyzed with spectrometers. Here, the fast-ion contribution can be identified due to large Doppler shifts, and the shape of the spectrum yields information about the velocity distribution. The Doppler shift is given by a projection of the ion velocity vector onto the line of sight, such that observation from different viewing angles is needed to cover the entire velocity space. Therefore, the FIDA diagnostic has been upgraded from three viewing arrays to five, and the spectrometer has

  14. Lower pressure heating steam is practical for the distributed dry dilute sulfuric acid pretreatment.

    Science.gov (United States)

    Shao, Shuai; Zhang, Jian; Hou, Weiliang; Qureshi, Abdul Sattar; Bao, Jie

    2017-08-01

    Most studies paid more attention to the pretreatment temperature and the resulted pretreatment efficiency, while ignored the heating media and their scalability to an industry scale. This study aimed to use a relative low pressure heating steam easily provided by steam boiler to meet the requirement of distributed dry dilute acid pretreatment. The results showed that the physical properties of the pretreated corn stover were maintained stable using the steam pressure varying from 1.5, 1.7, 1.9 to 2.1MPa. Enzymatic hydrolysis and high solids loading simultaneous saccharification and fermentation (SSF) results were also satisfying. CFD simulation indicated that the high injection velocity of the low pressure steam resulted in a high steam holdup and made the mixing time of steam and solid corn stover during pretreatment much shorter in comparison with the higher pressure steam. This study provides a design basis for the boiler requirement in distributed pretreatment concept. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Mixed-mode distribution systems for high average power electron cyclotron heating

    International Nuclear Information System (INIS)

    White, T.L.; Kimrey, H.D.; Bigelow, T.S.

    1984-01-01

    The ELMO Bumpy Torus-Scale (EBT-S) experiment consists of 24 simple magnetic mirrors joined end-to-end to form a torus of closed magnetic field lines. In this paper, we first describe an 80% efficient mixed-mode unpolarized heating system which couples 28-GHz microwave power to the midplane of the 24 EBT-S cavities. The system consists of two radiused bends feeding a quasi-optical mixed-mode toroidal distribution manifold. Balancing power to the 24 cavities is determined by detailed computer ray tracing. A second 28-GHz electron cyclotron heating (ECH) system using a polarized grid high field launcher is described. The launcher penetrates the fundamental ECH resonant surface without a vacuum window with no observable breakdown up to 1 kW/cm 2 (source limited) with 24 kW delivered to the plasma. This system uses the same mixed-mode output as the first system but polarizes the launched power by using a grid of WR42 apertures. The efficiency of this system is 32%, but can be improved by feeding multiple launchers from a separate distribution manifold

  16. Reliability assessment - for production and distribution of heat; Riskbaserad tillfoerlitlighet - i produktion och leverans av vaerme

    Energy Technology Data Exchange (ETDEWEB)

    Transtroem, Christoffer; Joerud, Fredrik; Ehrstedt, Thomas

    2006-06-15

    The content of this project gives the basic framework of a guideline in how to study the reliability of both production and distribution of heat, i.e. the report forms the developing phase of a methodology for identification of potential risks in a system for district heat. The risks are prioritized and used as a decision tool to design a program for mitigation of the risk exposure. This report also describes a basic idea of how to further develop this methodology. The methodology is based on an initial screening with an optional phase of detailed analysis for weak links identified in the initial screening process. The methodology is different to previous tools as it facilitate an efficient approach to identify weak links in all parts of the system for district heat. The objective is to clearly describe the methodology in order to enable performance, also without support from experts in risk engineering. The practicing personnel intend to be technical staff from both the operational- and maintenance departments of a district heat company in general. During the project, several technical meetings were performed and interviews also took place, with engineers intended to be the typical end users of this tool. As a basic part of the methodology, established methodologies of risk assessment were studied. The studies have been a part of the design to achieve a method well adjusted for the end user group. Some parts of the methodology have already been tested in real cases, as several regular analyses have been performed in parallel with the development of this methodology.

  17. Intracorporeal Heat Distribution from Fully Implantable Energy Sources for Mechanical Circulatory Support: A Computational Proof-of-Concept Study

    Directory of Open Access Journals (Sweden)

    Jacopo Biasetti

    2017-10-01

    Full Text Available Mechanical circulatory support devices, such as total artificial hearts and left ventricular assist devices, rely on external energy sources for their continuous operation. Clinically approved power supplies rely on percutaneous cables connecting an external energy source to the implanted device with the associated risk of infections. One alternative, investigated in the 70s and 80s, employs a fully implanted nuclear power source. The heat generated by the nuclear decay can be converted into electricity to power circulatory support devices. Due to the low conversion efficiencies, substantial levels of waste heat are generated and must be dissipated to avoid tissue damage, heat stroke, and death. The present work computationally evaluates the ability of the blood flow in the descending aorta to remove the locally generated waste heat for subsequent full-body distribution and dissipation, with the specific aim of investigating methods for containment of local peak temperatures within physiologically acceptable limits. To this aim, coupled fluid–solid heat transfer computational models of the blood flow in the human aorta and different heat exchanger architectures are developed. Particle tracking is used to evaluate temperature histories of cells passing through the heat exchanger region. The use of the blood flow in the descending aorta as a heat sink proves to be a viable approach for the removal of waste heat loads. With the basic heat exchanger design, blood thermal boundary layer temperatures exceed 50°C, possibly damaging blood cells and proteins. Improved designs of the heat exchanger, with the addition of fins and heat guides, allow for drastically lower blood temperatures, possibly leading to a more biocompatible implant. The ability to maintain blood temperatures at biologically compatible levels will ultimately allow for the body-wise distribution, and subsequent dissipation, of heat loads with minimum effects on the human physiology.

  18. Intracorporeal Heat Distribution from Fully Implantable Energy Sources for Mechanical Circulatory Support: A Computational Proof-of-Concept Study.

    Science.gov (United States)

    Biasetti, Jacopo; Pustavoitau, Aliaksei; Spazzini, Pier Giorgio

    2017-01-01

    Mechanical circulatory support devices, such as total artificial hearts and left ventricular assist devices, rely on external energy sources for their continuous operation. Clinically approved power supplies rely on percutaneous cables connecting an external energy source to the implanted device with the associated risk of infections. One alternative, investigated in the 70s and 80s, employs a fully implanted nuclear power source. The heat generated by the nuclear decay can be converted into electricity to power circulatory support devices. Due to the low conversion efficiencies, substantial levels of waste heat are generated and must be dissipated to avoid tissue damage, heat stroke, and death. The present work computationally evaluates the ability of the blood flow in the descending aorta to remove the locally generated waste heat for subsequent full-body distribution and dissipation, with the specific aim of investigating methods for containment of local peak temperatures within physiologically acceptable limits. To this aim, coupled fluid-solid heat transfer computational models of the blood flow in the human aorta and different heat exchanger architectures are developed. Particle tracking is used to evaluate temperature histories of cells passing through the heat exchanger region. The use of the blood flow in the descending aorta as a heat sink proves to be a viable approach for the removal of waste heat loads. With the basic heat exchanger design, blood thermal boundary layer temperatures exceed 50°C, possibly damaging blood cells and proteins. Improved designs of the heat exchanger, with the addition of fins and heat guides, allow for drastically lower blood temperatures, possibly leading to a more biocompatible implant. The ability to maintain blood temperatures at biologically compatible levels will ultimately allow for the body-wise distribution, and subsequent dissipation, of heat loads with minimum effects on the human physiology.

  19. The underground research laboratories

    International Nuclear Information System (INIS)

    1997-06-01

    This educational booklet is a general presentation of the selected sites for the installation of underground research laboratories devoted to the feasibility studies of deep repositories for long-life radioactive wastes. It describes the different type of wastes and their management, the management of long life radioactive wastes, the site selection and the 4 sites retained, the preliminary research studies, and the other researches carried out in deep disposal facilities worldwide. (J.S.)

  20. Nuclear plant undergrounding

    International Nuclear Information System (INIS)

    Brown, R.C.; Bastidas, C.P.

    1978-01-01

    Under Section 25524.3 of the Public Resources Code, the California Energy Resources Conservation and Development Commission (CERCDC) was directed to study ''the necessity for '' and the effectiveness and economic feasibility of undergrounding and berm containment of nuclear reactors. The author discusses the basis for the study, the Sargent and Lundy (S and L) involvement in the study, and the final conclusions reached by S and L

  1. A nodal model to predict vertical temperature distribution in a room with floor heating and displacement ventilation

    DEFF Research Database (Denmark)

    Wu, Xiaozhou; Olesen, Bjarne W.; Fang, Lei

    2013-01-01

    In this paper, the development of a nodal model that predicts vertical temperature distribution in a typical office room with floor heating and displacement ventilation (FHDV) is described. The vertical air flow distribution is first determined according to the principle of displacement ventilati...

  2. France’s State of the Art Distributed Optical Fibre Sensors Qualified for the Monitoring of the French Underground Repository for High Level and Intermediate Level Long Lived Radioactive Wastes

    Science.gov (United States)

    Delepine-Lesoille, Sylvie; Girard, Sylvain; Landolt, Marcel; Bertrand, Johan; Planes, Isabelle; Boukenter, Aziz; Marin, Emmanuel; Humbert, Georges; Leparmentier, Stéphanie; Auguste, Jean-Louis; Ouerdane, Youcef

    2017-01-01

    This paper presents the state of the art distributed sensing systems, based on optical fibres, developed and qualified for the French Cigéo project, the underground repository for high level and intermediate level long-lived radioactive wastes. Four main parameters, namely strain, temperature, radiation and hydrogen concentration are currently investigated by optical fibre sensors, as well as the tolerances of selected technologies to the unique constraints of the Cigéo’s severe environment. Using fluorine-doped silica optical fibre surrounded by a carbon layer and polyimide coating, it is possible to exploit its Raman, Brillouin and Rayleigh scattering signatures to achieve the distributed sensing of the temperature and the strain inside the repository cells of radioactive wastes. Regarding the dose measurement, promising solutions are proposed based on Radiation Induced Attenuation (RIA) responses of sensitive fibres such as the P-doped ones. While for hydrogen measurements, the potential of specialty optical fibres with Pd particles embedded in their silica matrix is currently studied for this gas monitoring through its impact on the fibre Brillouin signature evolution. PMID:28608831

  3. France’s State of the Art Distributed Optical Fibre Sensors Qualified for the Monitoring of the French Underground Repository for High Level and Intermediate Level Long Lived Radioactive Wastes

    Directory of Open Access Journals (Sweden)

    Sylvie Delepine-Lesoille

    2017-06-01

    Full Text Available This paper presents the state of the art distributed sensing systems, based on optical fibres, developed and qualified for the French Cigéo project, the underground repository for high level and intermediate level long-lived radioactive wastes. Four main parameters, namely strain, temperature, radiation and hydrogen concentration are currently investigated by optical fibre sensors, as well as the tolerances of selected technologies to the unique constraints of the Cigéo’s severe environment. Using fluorine-doped silica optical fibre surrounded by a carbon layer and polyimide coating, it is possible to exploit its Raman, Brillouin and Rayleigh scattering signatures to achieve the distributed sensing of the temperature and the strain inside the repository cells of radioactive wastes. Regarding the dose measurement, promising solutions are proposed based on Radiation Induced Attenuation (RIA responses of sensitive fibres such as the P-doped ones. While for hydrogen measurements, the potential of specialty optical fibres with Pd particles embedded in their silica matrix is currently studied for this gas monitoring through its impact on the fibre Brillouin signature evolution.

  4. Monitoring underground movements

    CERN Multimedia

    Antonella Del Rosso

    2015-01-01

    On 16 September 2015 at 22:54:33 (UTC), an 8.3-magnitude earthquake struck off the coast of Chile. 11,650 km away, at CERN, a new-generation instrument – the Precision Laser Inclinometer (PLI) – recorded the extreme event. The PLI is being tested by a JINR/CERN/ATLAS team to measure the movements of underground structures and detectors.   The Precision Laser Inclinometer during assembly. The instrument has proven very accurate when taking measurements of the movements of underground structures at CERN.    The Precision Laser Inclinometer is an extremely sensitive device capable of monitoring ground angular oscillations in a frequency range of 0.001-1 Hz with a precision of 10-10 rad/Hz1/2. The instrument is currently installed in one of the old ISR transfer tunnels (TT1) built in 1970. However, its final destination could be the ATLAS cavern, where it would measure and monitor the fine movements of the underground structures, which can affect the precise posi...

  5. Purmerend wants to heat city of the Netherlands. Efficient distribution of sustainable heat; Purmerend wil warmtestad van Nederland worden. Efficiente distributie van duurzame warmte

    Energy Technology Data Exchange (ETDEWEB)

    Stollmeyer, A. [Stadsverwarming Purmerend, Purmerend (Netherlands)

    2010-09-15

    Stadsverwarming Purmerend (District heating) is working on realizing the most sustainable heating company in the Netherlands. This is to be realized by means of an energy transition: the transition from grey waste heat to green energy sources such as biomass and deep geothermal energy. Moreover, the SlimNet program is used to efficiently distribute heat generated from sustainable sources. The system will enter into operation in 2014. [Dutch] Stadsverwarming Purmerend werkt aan het duurzaamste warmtebedrijf van Nederland. Een en ander wordt gerealiseerd via een energietransitie: de overstap van grijze restwarmte naar groene energiebronnen als biomassa en diepe geothermie. Ook wordt het programma SlimNet ingezet om de duurzaam geproduceerde warmte efficient te distribueren. Het systeem wordt in 2014 operationeel.

  6. Energy distributions in a diesel engine using low heat rejection (LHR) concepts

    International Nuclear Information System (INIS)

    Li, Tingting; Caton, Jerald A.; Jacobs, Timothy J.

    2016-01-01

    Highlights: • Altering coolant temperature was employed to devise low heat rejection concept. • The energy distributions at different engine coolant temperatures were analyzed. • Raising coolant temperature yields improvements in fuel conversion efficiency. • The exhaust energy is highly sensitive to the variations in exhaust temperature. • Effects of coolant temperature on mechanical efficiency were examined. - Abstract: The energy balance analysis is recognized as a useful method for aiding the characterization of the performance and efficiency of internal combustion (IC) engines. Approximately one-third of the total fuel energy is converted to useful work in a conventional IC engine, whereas the major part of the energy input is rejected to the exhaust gas and the cooling system. The idea of a low heat rejection (LHR) engine (also called “adiabatic engine”) was extensively developed in the 1980s due to its potential in improving engine thermal efficiency via reducing the heat losses. In this study, the LHR operating condition is implemented by increasing the engine coolant temperature (ECT). Experimentally, the engine is overcooled to low ECTs and then increased to 100 °C in an effort to get trend-wise behavior without exceeding safe ECTs. The study then uses an engine simulation of the conventional multi-cylinder, four-stroke, 1.9 L diesel engine operating at 1500 rpm to examine the five cases having different ECTs. A comparison between experimental and simulation results show the effects of ECT on fuel conversion efficiency. The results demonstrate that increasing ECT yields slight improvements in net indicated fuel conversion efficiency, with larger improvements observed in brake fuel conversion efficiency.

  7. A Geospatial Comparison of Distributed Solar Heat and Power in Europe and the US

    Science.gov (United States)

    Norwood, Zack; Nyholm, Emil; Otanicar, Todd; Johnsson, Filip

    2014-01-01

    The global trends for the rapid growth of distributed solar heat and power in the last decade will likely continue as the levelized cost of production for these technologies continues to decline. To be able to compare the economic potential of solar technologies one must first quantify the types and amount of solar resource that each technology can utilize; second, estimate the technological performance potential based on that resource; and third, compare the costs of each technology across regions. In this analysis, we have performed the first two steps in this process. We use physical and empirically validated models of a total of 8 representative solar system types: non-tracking photovoltaics, 2d-tracking photovoltaics, high concentration photovoltaics, flat-plate thermal, evacuated tube thermal, concentrating trough thermal, concentrating solar combined heat and power, and hybrid concentrating photovoltaic/thermal. These models are integrated into a simulation that uses typical meteorological year weather data to create a yearly time series of heat and electricity production for each system over 12,846 locations in Europe and 1,020 locations in the United States. Through this simulation, systems composed of various permutations of collector-types and technologies can be compared geospatially and temporally in terms of their typical production in each location. For example, we see that silicon solar cells show a significant advantage in yearly electricity production over thin-film cells in the colder climatic regions, but that advantage is lessened in regions that have high average irradiance. In general, the results lead to the conclusion that comparing solar technologies across technology classes simply on cost per peak watt, as is usually done, misses these often significant regional differences in annual performance. These results have implications for both solar power development and energy systems modeling of future pathways of the electricity system. PMID

  8. Electric space heating scheduling for real-time explicit power control in active distribution networks

    DEFF Research Database (Denmark)

    Costanzo, Giuseppe Tommaso; Bernstein, Andrey; Chamorro, Lorenzo Reyes

    2015-01-01

    This paper presents a systematic approach for abstracting the flexibility of a building space heating system and using it within a composable framework for real-time explicit power control of microgrids and, more in general, active distribution networks. In particular, the proposed approach...... is developed within the context of a previously defined microgrid control framework, called COMMELEC, conceived for the explicit and real-time control of these specific networks. The designed control algorithm is totally independent from the need of a building model and allows exploiting the intrinsic thermal...... inertia for real-time control. The paper first discusses the general approach, then it proves its validity via dedicated simulations performed on specific case study composed by the CIGRE LV microgrid benchmark proposed by the Cigré TF C6.04.02....

  9. Unleashing Flexibility from Electric Boilers and Heat Pumps in Danish Residential Distribution Network

    DEFF Research Database (Denmark)

    Sinha, Rakesh; Bak-Jensen, Birgitte; Pillai, Jayakrishnan Radhakrishna

    2018-01-01

    and thereby improving its techno-economic efficiency. The data used for the evaluation are also from the real household sites in Denmark provided by the district heating utility. Focus is on the low-voltage grid, and that’s very relevant since many doesn’t expect any flexibility from that voltage level. Study...... this model is compared to responses from an average model of the hot water storage tank to evaluate the benefit of the more detailed model. Finally, analysis on consumption patterns of electrical and thermal loads in residential buildings in Northern Jutland, Denmark, are used for analysis of the system...... and use of thermal units as flexible consumer loads in the low voltage (LV) distribution network grid. The models of EB and HP with storage tank are briefly discussed in relation to the actual control and flexibility based on grid condition and status of storage tank temperature or position...

  10. Creating markets for combined heat and power and clean distributed generation in New York State

    International Nuclear Information System (INIS)

    Bourgeois, Thomas G.; Hedman, Bruce; Zalcman, Fred

    2003-01-01

    Combined heat and power has been indentified as a central component in state and national energy strategy to lower power prices and reduce environmental impacts. - Combined heat and power (CHP) is the simultaneous production of electrical or mechanical power and thermal energy from in a single process. Because thermal output from the generation of electricity is captured and utilized onsite, CHP systems can achieve efficiencies from 60% to as high as 90%. In contrast generation of electric power at sites remote from the loads served often results in efficiencies of 33% or less due to losses in generation and transmission and distribution of the power to ultimate end users. A well designed CHP system is the essence of energy efficiency. It may also provide significant environmental benefits. However, the full promise of CHP for improving the efficiency and productivity of businesses and the quality of the environment is unlikely to be realized given the current market structure and regulatory environment in which CHP projects are forced to compete. This paper examines the market structure and regulatory obstacles that hinder the development of more robust markets for CHP in New York State

  11. Effects of transient and non-uniform distribution of heat flux on intensity of heat transfer and burnout conditions in the channels of nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Vitaly Osmachkin [Russian Research Center ' Kurchatov Institute' 1, Kurchatov sq, Moscow 123182 (Russian Federation)

    2005-07-01

    Full text of publication follows: The influence of power transient, changes of flow rate, inlet temperatures or pressure in cores of nuclear reactors on heat transfer and burnout conditions in channels depend on rate of such violations. Non-uniform distribution of the heat flux is also important factor for heat transfer and development of crisis phenomenon. Such effects may be significant for NPPs safety. But they have not yet generally accepted interpretation. Steady state approach is often recommended for use in calculations. In the paper a review of experimental observed so-called non-equilibrium effects is presented. The effects of space and time factors are displaying due delay in reformation turbulence intensity, velocity, temperatures or void fraction profiles, water film flow on the surface of heated channels. For estimation of such effect different methods are used. Modern computer codes based on two or three fluids approaches are considered as most effective. But simple and clear correlations may light up the mechanics of effects on heat transfer and improve general understanding of scale and significance of the transient events. In the paper the simplified methods for assessment the influence of lags in the development of distributions of parameters of flow, the relaxation of temporal or space violations are considered. They are compared with more sophisticated approaches. Velocities of disturbance fronts moving along the channels are discussed also. (author)

  12. Environment Of Underground Water And Pollution

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jeong Sang

    1998-02-15

    This book deals with environment of underground water and pollution, which introduces the role of underground water in hydrology, definition of related study of under water, the history of hydro-geology, basic conception of underground water such as origin of water, and hydrogeologic characteristic of aquifers, movement of underground water, hydrography of underground water and aquifer test analysis, change of an underground water level, and water balance analysis and development of underground water.

  13. Neutron albedo effects of underground nuclear explosion

    International Nuclear Information System (INIS)

    Yang Bo; Ying Yangjun; Li Jinhong; Bai Yun

    2013-01-01

    The neutron field distribution is affected by the surrounding medium in the underground nuclear explosion. It will influence the radiation chemical diagnosis. By Monte Carlo simulation, the fuel burnup induced by device and neutron albedo was calculated. The analysis method of albedo effect on radiation chemical diagnosis result under special environment was proposed. Neutron albedo should be considered when capture reaction burnup fraction is used, and then correct analysis can be carried out on the nuclear device.The neutron field distribution is affected by the surrounding medium in the underground nuclear explosion. It will influence the radiation chemical diagnosis. By Monte Carlo simulation, the fuel burnup induced by device and neutron albedo was calculated. The analysis method of albedo effect on radiation chemical diagnosis result under special environment was proposed. Neutron albedo should be considered when capture reaction burnup fraction is used, and then correct analysis can be carried out on the nuclear device. (authors)

  14. Dynamic Modeling and Control of Distributed Heat Transfer Mechanisms: Application to a Membrane Distillation Module

    KAUST Repository

    Eleiwi, Fadi

    2015-12-01

    Sustainable desalination technologies are the smart solution for producing fresh water and preserve the environment and energy by using sustainable renewable energy sources. Membrane distillation (MD) is an emerging technology which can be driven by renewable energy. It is an innovative method for desalinating seawater and brackish water with high quality production, and the gratitude is to its interesting potentials. MD includes a transfer of water vapor from a feed solution to a permeate solution through a micro-porous hydrophobic membrane, rejecting other non-volatile constituents present in the influent water. The process is driven by the temperature difference along the membrane boundaries. Different control applications and supervision techniques would improve the performance and the efficiency of the MD process, however controlling the MD process requires comprehensive mathematical model for the distributed heat transfer mechanisms inside the process. Our objective is to propose a dynamic mathematical model that accounts for the time evolution of the involved heat transfer mechanisms in the process, and to be capable of hosting intermittent energy supplies, besides managing the production rate of the process, and optimizing its energy consumption. Therefore, we propose the 2D Advection-Diffusion Equation model to account for the heat diffusion and the heat convection mechanisms inside the process. Furthermore, experimental validations have proved high agreement between model simulations and experiments with less than 5% relative error. Enhancing the MD production is an anticipated goal, therefore, two main control strategies are proposed. Consequently, we propose a nonlinear controller for a semi-discretized version of the dynamic model to achieve an asymptotic tracking for a desired temperature difference. Similarly, an observer-based feedback control is used to track sufficient temperature difference for better productivity. The second control strategy

  15. Engineering effects of underground nuclear explosions

    Energy Technology Data Exchange (ETDEWEB)

    Boardman, Charles R [CER Geonuclear Corporation, Las Vegas, NV (United States)

    1970-05-01

    Useful effects of contained underground nuclear explosions are discussed in light of today's most promising potential applications. Relevant data obtained through exploration of explosion environments of nine U.S. tests in competent rock are summarized and presented as a practical basis for estimating magnitudes of effects. Effects discussed include chimney configuration, permeability, and volume as well as rubble particle size distributions and extents of permeability change in the chimney wall rock. Explosion mediums include shale, granite, dolomite, and salt. (author)

  16. Engineering effects of underground nuclear explosions

    International Nuclear Information System (INIS)

    Boardman, Charles R.

    1970-01-01

    Useful effects of contained underground nuclear explosions are discussed in light of today's most promising potential applications. Relevant data obtained through exploration of explosion environments of nine U.S. tests in competent rock are summarized and presented as a practical basis for estimating magnitudes of effects. Effects discussed include chimney configuration, permeability, and volume as well as rubble particle size distributions and extents of permeability change in the chimney wall rock. Explosion mediums include shale, granite, dolomite, and salt. (author)

  17. Optimisation of single-tube heating systems with distribution of heating cost; Optimierung von Einrohrheizungsanlagen mit Heizkostenverteilung

    Energy Technology Data Exchange (ETDEWEB)

    Knabe, G.; Kremonke, A. [Technische Univ. Dresden (Germany). Inst. fuer Thermodynamik und Technische Gebaeudeausruestung; Bach, H.; Bauer, M.; Eisenmann, G.; Haupt, C.; Tritschler, M. [Stuttgart Univ. (Germany). Lehrstuhl fuer Heiz- und Raumlufttechnik

    1997-12-31

    The work had the aim to study the following modernization measures in a large-panel building: enhancement of thermal insulation provided by the shell of the building, enhancement of heating system efficiency, influence on user behaviour of just heating cost allocation systems. Further, general statements are made regarding the following aspects of building modernization: energy consumption analysis, planning, user behaviour and system management. (MSK) [Deutsch] Ziel der Untersuchungen war es an einem Plattenbau folgende Modernisierungsmassnahmen zu untersuchen: Verbesserung der Waermedaemmung der Gebaeudehuellkonstruktion, Effizienzsteigerung des Heizsystems, Beeinflussung des Nutzerverhaltens durch gerechte Heizkostenverteilsysteme. Zudem werden allgemeine Aussagen zur Modernisierung von Gebaeuden zu folgenden Bereichen vorgelegt: Energiediagnose, Planung, Nutzerverhalten sowie Betriebsmangement.

  18. Underground engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Nordyke, M D [Lawrence Radiation Laboratory, Livermore, CA (United States)

    1969-07-01

    Developments of any underground engineering application utilizing nuclear explosives involve answering the same questions one encounters in any new area of technology: What are the characteristics of the new tool? How is it applicable to the job to be done? Is it safe to use? and, most importantly, is its use economically acceptable? The many facets of the answers to these questions will be explored. The general types of application presently under consideration will also be reviewed, with particular emphasis on those specific projects actively being worked on by commercial interests and by the U.S. Atomic Energy Commission. (author)

  19. Underground engineering applications

    International Nuclear Information System (INIS)

    Nordyke, M.D.

    1969-01-01

    Developments of any underground engineering application utilizing nuclear explosives involve answering the same questions one encounters in any new area of technology: What are the characteristics of the new tool? How is it applicable to the job to be done? Is it safe to use? and, most importantly, is its use economically acceptable? The many facets of the answers to these questions will be explored. The general types of application presently under consideration will also be reviewed, with particular emphasis on those specific projects actively being worked on by commercial interests and by the U.S. Atomic Energy Commission. (author)

  20. Regulated underground storage tanks

    International Nuclear Information System (INIS)

    1992-06-01

    This guidance package is designed to assist DOE Field operations by providing thorough guidance on the underground storage tank (UST) regulations. [40 CFR 280]. The guidance uses tables, flowcharts, and checklists to provide a ''roadmap'' for DOE staff who are responsible for supervising UST operations. This package is tailored to address the issues facing DOE facilities. DOE staff should use this guidance as: An overview of the regulations for UST installation and operation; a comprehensive step-by-step guidance for the process of owning and operating an UST, from installation to closure; and a quick, ready-reference guide for any specific topic concerning UST ownership or operation

  1. A theoretical study of the possibilities for localization of anomalous density distribution in rock by means of underground cosmic ray muon intensity measurements

    International Nuclear Information System (INIS)

    Jacobsson, L.; Joensson, G.; Kristiansson, K.; Malmqvist, L.

    1977-05-01

    The possibilities for in situ rock density determinations by means of sub-surface cosmic ray muon intensity measurements have been studied. The calculations are based on an hypothetical scintillation counter telescope intended for registration in a gallery. It is shown that fairly accurate density measurements are possible and that a certain spatial resolution can be achieved. The measurements are only influenced by the density distribution in the forward direction which can make the muon technique valuable in connection with gravity measurements. Different prospecting situations have been studied. It is found that in certain prospecting situations the accuracy needed for the indication of a massive ore body can be reached within an acceptable registration period. (Auth.)

  2. Fish abundance and distribution near three heated effluents to Lake Michigan

    International Nuclear Information System (INIS)

    Spigarelli, S.A.; Goldstein, R.M.; Prepejchal, W.; Thommes, M.M.

    1982-01-01

    A combined echo location-temperature mapping technique was used to determine the abundance and distribution of fish with depth and temperature in locally heated and unheated areas of Lake Michigan. Surveys were conducted between April and October at two adjacent power plants in the southern basin and at one plant in the northern basin of the lake. Fish densities in plume and reference areas differed seasonally. Densities typically differed by a factor of 2-4 although on one occasion plume area density was 90 times greater. Highest plume densities occurred during late spring when alewife (Alosa pseudoharengus) were spawning inshore. Consistently dense congregations of fish were found downstream of the interfaces between ambient shore-parallel currents and discharge flows. The general distribution of fish with depth was similar in all areas. Differences between plume and reference areas were related to the discharge type: at canal discharges fish tended to congregate inshore while at the offshore discharge they congregated in deeper zones. Fish also tended to occupy shallower depth strata in all plume areas. Positive correlation between fish density and increasing temperature was common at both plume and reference areas during all three seasons, but more frequent at plume areas. Temperatures selected by fish in plume areas were 1-3 0 C higher than maximum ambient temperatures

  3. Numerical simulation of temperature distribution in cylindrical ilmenite (FeTiO3) due to microwave heating

    Science.gov (United States)

    Hidayat, Mas Irfan P.; Fellicia, Dian Mughni; Rafandi, Ferdiansyah Iqbal

    2018-04-01

    Microwave assisted heating has been extensively used in materials processing particularly in extraction of TiO2 from Ilmenite (FeTiO3) minerals. Nevertheless, this method could generate non-uniform temperature distribution during the heating process. The observation of this phenomena in cylindrical ilmenite has been conducted by numerical simulation using finite element method according to the Poynthing's theorem. Four different cylinders with variation on its height were simulated in ANSYS 17 with input microwave power of 5.5 Kw. The results indicated that height of heated object could vigorously influence the uniformity of temperature inside the body.

  4. Conventional heat distribution systems and their control for room cooling; Konventionelle Waermeabgabesysteme und deren Regulierung fuer die Raumkuehlung - Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Schnyder, J. [Schnyder-Energie, Energie-Dienstleistungen, Bronschhofen (Switzerland); Feger, D.; Graf, J.; Rusterholtz, R. [Interstaatliche Hochschule fuer Technik Buchs NTB, Buchs (Switzerland); Schoeringhumer, D.; Cenci, D. [Arbonia AG, Arbon (Switzerland); Heule, D. [hps energieconsulting ag, Ingenieurbuero fuer nachhaltige Energie- und Gebaeudetechnik, Kuesnacht (Switzerland)

    2009-12-15

    This final report for the Swiss Federal Office of Energy (SFOE) examines how conventional heat distribution systems such as radiators and floor heating systems can be used for room cooling and the appropriate control requirements. Thermostatic valves used 'in reverse', their functional testing and the results obtained are discussed. Possibilities for their optimisation are examined. The apparatus used for the measurements made on both radiator and floor-heating systems is reported on and the results obtained are presented and discussed. Further, simulations used are looked at and examples of the results obtained for rooms with varying glazed surfaces are presented and discussed.

  5. Underground water stress release models

    Science.gov (United States)

    Li, Yong; Dang, Shenjun; Lü, Shaochuan

    2011-08-01

    The accumulation of tectonic stress may cause earthquakes at some epochs. However, in most cases, it leads to crustal deformations. Underground water level is a sensitive indication of the crustal deformations. We incorporate the information of the underground water level into the stress release models (SRM), and obtain the underground water stress release model (USRM). We apply USRM to the earthquakes occurred at Tangshan region. The analysis shows that the underground water stress release model outperforms both Poisson model and stress release model. Monte Carlo simulation shows that the simulated seismicity by USRM is very close to the real seismicity.

  6. Control of Hyperbolic Heat Transfer Mechanisms Application to the Distributed Concentrated Solar Collectors

    KAUST Repository

    Elmetennani, Shahrazed

    2017-04-01

    This dissertation addresses the flow control problem in hyperbolic heat transfer mechanisms. It raises in concentrated distributed solar collectors to enhance their production efficiency under the unpredictable variations of the solar energy and the external disturbances. These factors which are either locally measured (the solar irradiance) or inaccessible for measurement (the collectors’ cleanliness) affect the source term of the distributed model and represent a major difficulty for the control design. Moreover, the temperature in the collector can only be measured at the boundaries. In this dissertation, we propose new adaptive control approaches to provide the adequate level of heat while coping with the unpredictable varying disturbances. First, we design model based control strategies for a better efficiency, in terms of accuracy and response time, with a relatively reduced complexity. Second, we enhance the controllers with on-line adaptation laws to continuously update the efficient value of the external conditions. In this study, we approach the control problem using both, the infinite dimensional model (late lumping) and a finite dimensional approximate representation (early lumping). For the early lumping approach, we introduce a new reduced order bilinear approximate model for system analysis and control design. This approximate state representation is then used to derive a nonlinear state feedback resorting to Lyapunov stability theory. To compensate for the external disturbances and the approximation uncertainties, an adaptive controller is developed based on a phenomenological representation of the system dynamics. For the late lumping approach, we propose two PDE based controllers by stabilization of the reference tracking error distributed profile. The control laws are explicitly defined as functions of the available measurement. The first one is obtained using a direct approach for error stabilization while the second one is derived through a

  7. Transient critical heat flux under flow coast-down in vertical annulus with non-uniform heat flux distribution

    International Nuclear Information System (INIS)

    Moon, S.K.; Chun, S.Y.; Choi, K.Y.; Yang, S.K.

    2001-01-01

    An experimental study on transient critical heat flux (CHF) under flow coast-down has been performed for water flow in a non-uniformly heated vertical annulus under low flow and a wide range of pressure conditions. The objectives of this study are to systematically investigate the effect of the flow transient on the CHF and to compare the transient CHF with steady state CHF. The transient CHF experiments have been performed for three kinds of flow transient modes based on the coast-down data of the Kori 3/4 nuclear power plant reactor coolant pump. Most of the CHFs occurred in the annular-mist flow regime. Thus, it means that the possible CHF mechanism might be the liquid film dryout in the annular-mist flow regime. For flow transient mode with the smallest flow reduction rate, the time-to-CHF is the largest. At the same inlet subcooling, system pressure and heat flux, the effect of the initial mass flux on the critical mass flux can be negligible. However, the effect of the initial mass flux on the time-to-CHF becomes large as the heat flux decreases. Usually, the critical mass flux is large for slow flow reduction. There is a pressure effect on the ratio of the transient CHF data to steady state CHF data. Some conventional correlations show relatively better CHF prediction results for high system pressure, high quality and slow transient modes than for low system pressure, low quality and fast transient modes. (author)

  8. Modelling of coupled heat and electric field distribution during ohmic heating of solid foods with varying sizes

    DEFF Research Database (Denmark)

    Feyissa, Aberham Hailu; Bøknæs, Niels; Nielsen, P.L.

    factors leading to variations and uncertainties in prediction of the right process parameters. The current work is focused on modelling of OH of solid food pieces of varying sizes cooked in one batch. A 3D mathematical model of coupled heat transfer and electric field during OH of shrimps has been...

  9. Fission products distributions in Candu primary heat transport and Candu containment systems during a severe accident

    International Nuclear Information System (INIS)

    Constantin, Marin; Rizoiu, Andrei

    2005-01-01

    The paper is intended to analyse the distribution of the fission products (FPs) in CANDU Primary Heat Transport (PHT) and CANDU Containment Systems by using the ASTEC code (Accident Source Term Evaluation Code). The complexity of the data required by ASTEC and the complexity both of CANDU PHT and Containment System were strong motivations to begin with a simplified geometry in order to avoid the introducing of unmanageable errors at the level of input deck. Thus only 1/4 of the PHT circuit was simulated and a simplified FPs inventory, some simplifications in the feeders geometry and containment were used. The circuit consists of 95 horizontal fuel channels connected to 95 horizontal out-feeders, then through vertical feeders to the outlet-header (a big pipe that collects the water from feeders); the circuit continues from the outlet-header with a riser and then with the steam generator and a pump. After this pump, the circuit was broken; in this point the FPs are transferred to the containment. The containment model consists of 4 rooms connected between by 6 links. The data related to the nodes' definitions, temperatures and pressure conditions were chosen as possible as real data from CANDU NPP loss of coolant accident sequence. Temperature and pressure conditions in the time of the accident were calculated by the CATHENA code and the source term of FPs introduced into the PHT was estimated by the ORIGEN code. The FPs distribution in the nodes of the circuit and the FPs mass transfer per isotope and chemical species are obtained by using SOPHAEROS module of ASTEC code. The distributions into the containment are obtained by the CPA module of ASTEC code (thermalhydraulics calculations in the containment and FPs aerosol transport). The results consist of mass distributions in the nodes of the circuit and the transferred mass to the containment through the break for different species (FPs and chemical species) and mass distributions in the different parts and

  10. RP delves underground

    CERN Document Server

    Anaïs Schaeffer

    2011-01-01

    The LHC’s winter technical stop is rapidly approaching. As in past years, technical staff in their thousands will be flocking to the underground areas of the LHC and the Linac2, Booster, PS and SPS injectors. To make sure they are protected from ionising radiation, members of the Radiation Protection Group will perform an assessment of the levels of radioactivity in the tunnels as soon as the beams have stopped.   Members of the Radiation Protection Group with their precision instruments that measure radioactivity. At 7-00 a.m. on 8 December the LHC and all of the upstream accelerators will begin their technical stop. At 7-30 a.m., members of the Radiation Protection Group will enter the tunnel to perform a radiation mapping, necessary so that the numerous teams can do their work in complete safety. “Before we proceed underground, we always check first to make sure that the readings from the induced radioactivity monitors installed in the tunnels are all normal,&rdqu...

  11. Multinational underground nuclear parks

    Energy Technology Data Exchange (ETDEWEB)

    Myers, C.W. [Nuclear Engineering and Nonproliferation Division, Los Alamos National Laboratory, MS F650, Los Alamos, NM 87544 (United States); Giraud, K.M. [Wolf Creek Nuclear Operating Corporation, 1550 Oxen Lane NE, P.O. Box 411, Burlington, KS 66839-0411 (United States)

    2013-07-01

    Newcomer countries expected to develop new nuclear power programs by 2030 are being encouraged by the International Atomic Energy Agency to explore the use of shared facilities for spent fuel storage and geologic disposal. Multinational underground nuclear parks (M-UNPs) are an option for sharing such facilities. Newcomer countries with suitable bedrock conditions could volunteer to host M-UNPs. M-UNPs would include back-end fuel cycle facilities, in open or closed fuel cycle configurations, with sufficient capacity to enable M-UNP host countries to provide for-fee waste management services to partner countries, and to manage waste from the M-UNP power reactors. M-UNP potential advantages include: the option for decades of spent fuel storage; fuel-cycle policy flexibility; increased proliferation resistance; high margin of physical security against attack; and high margin of containment capability in the event of beyond-design-basis accidents, thereby reducing the risk of Fukushima-like radiological contamination of surface lands. A hypothetical M-UNP in crystalline rock with facilities for small modular reactors, spent fuel storage, reprocessing, and geologic disposal is described using a room-and-pillar reference-design cavern. Underground construction cost is judged tractable through use of modern excavation technology and careful site selection. (authors)

  12. Going Underground in Singapore

    CERN Multimedia

    John Osborne (GS/SEM)

    2010-01-01

    Singapore has plans to build a massive Underground Science City (USC) housing R&D laboratories and IT data centres. A delegation involved in the planning to build the subterranean complex visited CERN on 18 October 2010 to learn from civil engineers and safety experts about how CERN plans and constructs its underground facilities.   The delegation from Singapore. The various bodies and corporations working on the USC project are currently studying the feasibility of constructing up to 40 caverns (60 m below ground) similar in size to an LHC experiment hall, in a similar type of rock. Civil engineering and geotechnical experts are calculating the maximum size of the cavern complex that can be safely built. The complex could one day accommodate between 3000 and 5000 workers on a daily basis, so typical issues of size and number of access shafts need to be carefully studied. At first glance, you might not think the LHC has much in common with the USC project; as Rolf Heuer pointed out: &ldq...

  13. CASPAR - Nuclear Astrophysics Underground

    Science.gov (United States)

    Senarath, Chamaka; Caspar Collaboration

    2017-09-01

    The CASPAR mainly focuses on Stellar Nucleosynthesis, its impact on the production of heavy elements and study the strength of stellar neutron sources that propels the s-process, 13C(α,n)16O and 22Ne(α,n)25Mg. Currently, implementation of a 1MV fully refurbished Van de Graaff accelerator that can provide a high intensity Î+/- beam, is being done at the Sanford Underground Research Facility (SURF). The accelerator is built among a collaboration of South Dakota School of Mines and Technology, University of Notre Dame and Colorado School of Mines. It is understood that cosmic ray neutron background radiation hampers experimental Nucleosynthesis studies, hence the need to go underground in search for a neutron free environment, to study these reactions at low energies is evident. The first beam was produced in the middle of summer 2017. The entire accelerator will be run before the end of this year. A detailed overview of goals of CASPAR will be presented. NFS Grant-1615197.

  14. Underground storage tank program

    International Nuclear Information System (INIS)

    Lewis, M.W.

    1994-01-01

    Underground storage tanks, UST'S, have become a major component of the Louisville District's Environmental Support Program. The District's Geotechnical and Environmental Engineering Branch has spear-headed an innovative effort to streamline the time, effort and expense for removal, replacement, upgrade and associated cleanup of USTs at military and civil work installations. This program, called Yank-A-Tank, creates generic state-wide contracts for removal, remediation, installation and upgrade of storage tanks for which individual delivery orders are written under the basic contract. The idea is to create a ''JOC type'' contract containing all the components of work necessary to remove, reinstall or upgrade an underground or above ground tank. The contract documents contain a set of generic specifications and unit price books in addition to the standard ''boiler plate'' information. Each contract requires conformance to the specific regulations for the state in which it is issued. The contractor's bid consists of a bid factor which in the multiplier used with the prices in the unit price book. The solicitation is issued as a Request for Proposal (RPP) which allows the government to select a contractor based on technical qualification an well as bid factor. Once the basic contract is awarded individual delivery orders addressing specific areas of work are scoped, negotiated and awarded an modifications to the original contract. The delivery orders utilize the prepriced components and the contractor's factor to determine the value of the work

  15. Computer program MCAP-TOSS calculates steady-state fluid dynamics of coolant in parallel channels and temperature distribution in surrounding heat-generating solid

    Science.gov (United States)

    Lee, A. Y.

    1967-01-01

    Computer program calculates the steady state fluid distribution, temperature rise, and pressure drop of a coolant, the material temperature distribution of a heat generating solid, and the heat flux distributions at the fluid-solid interfaces. It performs the necessary iterations automatically within the computer, in one machine run.

  16. Numerical research on natural convection in molten salt reactor with non-uniformly distributed volumetric heat generation

    International Nuclear Information System (INIS)

    Qian Libo; Qiu Suizheng; Zhang Dalin; Su Guanghui; Tian Wenxi

    2010-01-01

    Molten salt reactor is one of the six Generation IV systems capable of breeding and transmutation of actinides and long-lived fission products, which uses the liquid molten salt as the fuel solvent, coolant and heat generation simultaneously. The present work presents a numerical investigation on natural convection with non-uniform heat generation through which the heat generated by the fluid fuel is removed out of the core region when the reactor is under post-accident condition or zero-power condition. The two-group neutron diffusion equation is applied to calculated neutron flux distribution, which leads to non-uniform heat generation. The SIMPLER algorithm is used to calculate natural convective heat transfer rate with isothermal or adiabatic rigid walls. These two models are coupled through the temperature field and heat sources. The peculiarities of natural convection with non-uniform heat generation are investigated in a range of Ra numbers (10 3 ∼ 10 7 ) for the laminar regime of fluid motion. In addition, the numerical results are also compared with those containing uniform heat generation.

  17. Dynamic underground stripping demonstration project

    International Nuclear Information System (INIS)

    Newmark, R.L.

    1992-04-01

    LLNL is collaborating with the UC Berkeley College of Engineering to develop and demonstrate a system of thermal remediation techniques for rapid cleanup of localized underground spills. Called dynamic stripping to reflect the rapid and controllable nature of the process, it will combine steam injection, direct electrical heating, and tomographic geophysical imaging in a cleanup of the LLNL gasoline spill. In the first eight months of the project, a Clean Site engineering test was conducted to prove the field application of the techniques. Tests then began on the contaminated site in FY 1992. This report describes the work at the Clean Site, including design and performance criteria, test results, interpretations, and conclusions. We fielded 'a wide range of new designs and techniques, some successful and some not. In this document, we focus on results and performance, lessons learned, and design and operational changes recommended for work at the contaminated site. Each section focuses on a different aspect of the work and can be considered a self-contained contribution

  18. In situ post-weld heat treatment on martensitic stainless steel turbine runners using a robotic induction heating process to control temperature distribution

    Science.gov (United States)

    Boudreault, E.; Hazel, B.; Côté, J.; Godin, S.

    2014-03-01

    A new robotic heat treatment process is developed. Using this solution it is now possible to perform local heat treatment on large steel components. Crack, cavitation and erosion repairs on turbine blades and Pelton buckets are among the applications of this technique. The proof of concept is made on a 13Cr-4Ni stainless steel designated "CA6NM". This alloy is widely used in the power industry for modern system components. Given the very tight temperature tolerance (600 to 630 °C) for post-weld heat treatment on this alloy, 13Cr-4Ni stainless steel is very well suited for demonstrating the possibilities of this process. To achieve heat treatment requirements, an induction heating system is mounted on a compact manipulator named "Scompi". This robot moves a pancake coil in order to control the temperature distribution. A simulator using thermal finite element analysis is first used for path planning. A feedback loop adjusts parameters in function of environmental conditions.

  19. In situ post-weld heat treatment on martensitic stainless steel turbine runners using a robotic induction heating process to control temperature distribution

    International Nuclear Information System (INIS)

    Boudreault, E; Hazel, B; Côté, J; Godin, S

    2014-01-01

    A new robotic heat treatment process is developed. Using this solution it is now possible to perform local heat treatment on large steel components. Crack, cavitation and erosion repairs on turbine blades and Pelton buckets are among the applications of this technique. The proof of concept is made on a 13Cr-4Ni stainless steel designated C A6NM . This alloy is widely used in the power industry for modern system components. Given the very tight temperature tolerance (600 to 630 °C) for post-weld heat treatment on this alloy, 13Cr-4Ni stainless steel is very well suited for demonstrating the possibilities of this process. To achieve heat treatment requirements, an induction heating system is mounted on a compact manipulator named S compi . This robot moves a pancake coil in order to control the temperature distribution. A simulator using thermal finite element analysis is first used for path planning. A feedback loop adjusts parameters in function of environmental conditions

  20. Spatial Distribution of Volcanic Hotspots and Paterae on Io: Implications for Tidal Heating Models and Magmatic Pathways

    Science.gov (United States)

    Hamilton, C. W.; Beggan, C. D.; Lopes, R.; Williams, D. A.; Radenbaugh, J.

    2011-01-01

    Io, the innermost of Jupiter's Galilean satellites, is the most volcanically active body in the Solar. System. Io's global mean heat flow is approximately 2 W/square m, which is approximately 20 times larger than on Earth. High surface temperatures concentrate within "hotspots" and, to date, 172 Ionian hotspots have been identified by spacecraft and Earth-based telescopes. The Laplace resonance between Io, Europa, and Ganymede maintains these satellites in noncircular orbits and causes displacement of their tidal bulges as the overhead position of Jupiter changes for each moon. Gravitational interactions between Jupiter and Io dominate the orbital evolution of the Laplacian system and generate enormous heat within to as tidal energy is dissipated. If this energy were transferred out of Io at the same rate as it is generated, then the associated surface heat flux would be 2.24 +/- 0.45 W/square m. This estimate is in good agreement with observed global heat flow, but to better constrain tidal dissipation mechanisms and infer how thermal energy is transferred to Io's surface, it is critical to closely examine the spatial distribution of volcanic features. End-member tidal dissipation models either consider that heating occurs completely in the mantle, or completely in the asthenosphere. Mixed models typically favor one-third mantle and two-thirds asthenosphere heating. Recent models also consider the effects of mantle-asthenosphere boundary permeability and asthenospheric instabilities. Deep-mantle heating models predict maximum surface heat flux near the poles, whereas asthenosphere heating models predict maxima near the equator-particularly in the Sub-Jovian and Anti-Jovian hemispheres, with smaller maxima occurring at orbit tangent longitudes. Previous studies have examined the global distribution of Ionian hotspots and patera (i.e., irregular or complex craters with scalloped edges that are generally interpreted to be volcanic calderas), but in this study, we

  1. The effect of the volumetric heat source distribution of the fuel pellet on the minimum DNBR ratio

    International Nuclear Information System (INIS)

    Hordosy, G.; Kereszturi, A.; Maroti, L.; Trosztel, I.

    1995-01-01

    The radial power distribution in a VVER-440 type fuel assembly is strongly non-uniform as a result of the water-gap between the shrouds and the moderator filled central tube. Consequently, it can be expected that the power density inside a single fuel rod is inhomogeneous, as well. In the paper the methodology and the results of coupled thermohydraulic and neutronic calculations are presented. The objective of the analysis was the investigation of the heat source distribution and the determination of the possible extent of the power non-uniformity in a corner rod which has always the highest peaking factor in a VVER-440 type assembly. The results of the analysis revealed that there can be a strong non-uniformity of power distribution inside a fuel pellet, and the effect depends first of all on the general assembly conditions, while the local subchannel parameters have only a slight influence on the pellet heat source distribution. (author)

  2. Regulating and Combating Underground Banking

    NARCIS (Netherlands)

    Borgers, M.J.

    2009-01-01

    In combating and regulating underground banking, a choice can be made of roughly two models, the risk model and the assimilation model. The risk model comes down to a complete prohibition of underground banking combined with an active investigation and prosecution policy. In the assimilation model,

  3. The Earth's mantle in a microwave oven: thermal convection driven by a heterogeneous distribution of heat sources

    Science.gov (United States)

    Fourel, Loïc; Limare, Angela; Jaupart, Claude; Surducan, Emanoil; Farnetani, Cinzia G.; Kaminski, Edouard C.; Neamtu, Camelia; Surducan, Vasile

    2017-08-01

    Convective motions in silicate planets are largely driven by internal heat sources and secular cooling. The exact amount and distribution of heat sources in the Earth are poorly constrained and the latter is likely to change with time due to mixing and to the deformation of boundaries that separate different reservoirs. To improve our understanding of planetary-scale convection in these conditions, we have designed a new laboratory setup allowing a large range of heat source distributions. We illustrate the potential of our new technique with a study of an initially stratified fluid involving two layers with different physical properties and internal heat production rates. A modified microwave oven is used to generate a uniform radiation propagating through the fluids. Experimental fluids are solutions of hydroxyethyl cellulose and salt in water, such that salt increases both the density and the volumetric heating rate. We determine temperature and composition fields in 3D with non-invasive techniques. Two fluorescent dyes are used to determine temperature. A Nd:YAG planar laser beam excites fluorescence, and an optical system, involving a beam splitter and a set of colour filters, captures the fluorescence intensity distribution on two separate spectral bands. The ratio between the two intensities provides an instantaneous determination of temperature with an uncertainty of 5% (typically 1K). We quantify mixing processes by precisely tracking the interfaces separating the two fluids. These novel techniques allow new insights on the generation, morphology and evolution of large-scale heterogeneities in the Earth's lower mantle.

  4. Size distribution of salbutamol/ipratropium aerosols produced by different nebulizers in the absence and presence of heat and humidification.

    Science.gov (United States)

    Yang, Ssu-Han; Yang, Tsung-Ming; Lin, Hui-Ling; Tsai, Ying-Huang; Fang, Tien-Pei; Wan, Gwo-Hwa

    2018-02-01

    Few studies have evaluated the size distribution of inhaled and exhaled aerosolized drugs, or the effect of heated humidification on particle size and lung deposition. The present study evaluated these aspects of bronchodilator (salbutamol/ipratropium) delivery using a lung model in the absence and presence of heat and humidification. We positioned filters to collect and measure the initial drug, inhaled drug, and exhaled drug. Particle size distribution was evaluated using an 8-stage Marple personal cascade impactor with 0.2-μm polycarbonate filters. A greater inhaled drug mass was delivered using a vibrating mesh nebulizer (VMN) than by using a small volume nebulizer (SVN), when heated humidifiers were not employed. When heated and humidified medical gas was used, there was no significant difference between the inhaled drug mass delivered by the VMN and that delivered by the SVN. A significantly greater mass of inhaled 1.55-μm drug particles was produced by the VMN than with the SVN, under heated and humidified conditions. However, the mass median aerodynamic diameters (MMADs) of the aerosolized drug produced by the SVN and VMN did not differ significantly under the same conditions. The VMN produced more fine particles of salbutamol/ipratropium, and the drug particle size clearly increased in the presence of heat and humidification. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. The underground economy in Romania

    Directory of Open Access Journals (Sweden)

    Adriana Veronica LITRA

    2016-07-01

    Full Text Available The paper aims at covering issues related to the underground economy, activities that compound this phenomenon, its magnitude in Romania and reported to the European average. Underground economy in Romania consists of undeclared work (2/3 from the total and unreported income; it decreased from 33.6% of GDP in 2003 to 28% in 2014, but remained over EU-28 average with about 10 p.p. Among EU-28 countries, only Bulgaria exceeds the size of the underground economy of Romania. The underground economy is a challenge for the leadership of the state which must act simultaneously to stop illegal activities, and to discourage non-declaration of the legal activities. Corruption favours maintaining the underground economy, delays economic development, obstructs democratic processes and affects justice and the law state.

  6. Underground risk management information systems

    Energy Technology Data Exchange (ETDEWEB)

    Matsuyama, S.; Inoue, M.; Sakai, T.

    2006-03-15

    JCOAL has conducted Joint Research on an Underground Communication and Risk Management Information System with CSIRO of Australia under a commissioned study project for the promotion of coal use starting in fiscal 2002. The goal of this research project is the establishment of a new Safety System focusing on the comprehensive risk management information system by the name of Nexsys. The main components of the system are the Ethernet type underground communication system that represents the data communication base, and the risk management information system that permits risk analysis in real-time and provides decision support based on the collected data. The Nexsys is an open system and is a core element of the underground monitoring system. Using a vast amount of underground data, it is capable of accommodating a wide range of functions that were not available in the past. Because of it, it is possible to construct an advanced underground safety system. 14 figs., 4 tabs.

  7. Underground transmission tomography

    International Nuclear Information System (INIS)

    Geibka, C.

    1990-01-01

    Several underground tomographic transmission surveys have been carried out. Targets were cavities, ore veins and fault zones. Examples from measurements in a german heavy/fluor spar mine a lead/zinc mine and a rock laboratory of the Swiss National Cooperative for the Storage of Radioactive waste are presented. Measurements were carried out between boreholes and road ways. The recording equipment was the intrinsically safe SEAMEX85 system built and sold by WBK. Receivers were mounted in a chain of 6 two-component probes. Sources were an inhole hammer a sledge hammer a sparker and explosives from a single detonator to 180 g depending on the distance and absorption of the rock material. Cavities showed very distinct velocity reductions between 30 and 50%. Different vein material showed velocity reduction as well as velocity increase relative to the surrounding rock

  8. Underground layout tradeoff study

    International Nuclear Information System (INIS)

    1988-01-01

    This report presents the results of a technical and economic comparative study of four alternative underground layouts for a nuclear waste geologic repository in salt. The four alternatives considered in this study are (1) separate areas for spent fuel (SF) and commercial high-level waste (CHLW); (2) panel alternation, in which SF and CHLW are emplaced in adjacent panels of rooms; (3) room alternation, in which SF and CHLW are emplaced in adjacent rooms within each panel; and (4) intimate mixture, in which SF and CHLW are emplaced in random order within each storage room. The study concludes that (1) cost is not an important factor; (2) the separate-areas and intimate-mixture alternatives appear, technically, to be more desirable than the other alternatives; and (3) the selection between the separate-areas and intimate mixture alternatives depends upon future resolution of site-specific and reprocessing questions. 5 refs., 6 figs., 12 tabs

  9. Optimum load distribution between heat sources based on the Cournot model

    Science.gov (United States)

    Penkovskii, A. V.; Stennikov, V. A.; Khamisov, O. V.

    2015-08-01

    One of the widespread models of the heat supply of consumers, which is represented in the "Single buyer" format, is considered. The methodological base proposed for its description and investigation presents the use of principles of the theory of games, basic propositions of microeconomics, and models and methods of the theory of hydraulic circuits. The original mathematical model of the heat supply system operating under conditions of the "Single buyer" organizational structure provides the derivation of a solution satisfying the market Nash equilibrium. The distinctive feature of the developed mathematical model is that, along with problems solved traditionally within the bounds of bilateral relations of heat energy sources-heat consumer, it considers a network component with its inherent physicotechnical properties of the heat network and business factors connected with costs of the production and transportation of heat energy. This approach gives the possibility to determine optimum levels of load of heat energy sources. These levels provide the given heat energy demand of consumers subject to the maximum profit earning of heat energy sources and the fulfillment of conditions for formation of minimum heat network costs for a specified time. The practical realization of the search of market equilibrium is considered by the example of a heat supply system with two heat energy sources operating on integrated heat networks. The mathematical approach to the solution search is represented in the graphical form and illustrates computations based on the stepwise iteration procedure for optimization of levels of loading of heat energy sources (groping procedure by Cournot) with the corresponding computation of the heat energy price for consumers.

  10. Underground space planning in Helsinki

    Directory of Open Access Journals (Sweden)

    Ilkka Vähäaho

    2014-10-01

    Full Text Available This paper gives insight into the use of underground space in Helsinki, Finland. The city has an underground master plan (UMP for its whole municipal area, not only for certain parts of the city. Further, the decision-making history of the UMP is described step-by-step. Some examples of underground space use in other cities are also given. The focus of this paper is on the sustainability issues related to urban underground space use, including its contribution to an environmentally sustainable and aesthetically acceptable landscape, anticipated structural longevity and maintaining the opportunity for urban development by future generations. Underground planning enhances overall safety and economy efficiency. The need for underground space use in city areas has grown rapidly since the 21st century; at the same time, the necessity to control construction work has also increased. The UMP of Helsinki reserves designated space for public and private utilities in various underground areas of bedrock over the long term. The plan also provides the framework for managing and controlling the city's underground construction work and allows suitable locations to be allocated for underground facilities. Tampere, the third most populated city in Finland and the biggest inland city in the Nordic countries, is also a good example of a city that is taking steps to utilise underground resources. Oulu, the capital city of northern Finland, has also started to ‘go underground’. An example of the possibility to combine two cities by an 80-km subsea tunnel is also discussed. A new fixed link would generate huge potential for the capital areas of Finland and Estonia to become a real Helsinki-Tallinn twin city.

  11. Reliability assessment of underground shaft closure

    International Nuclear Information System (INIS)

    Fossum, A.F.; Munson, D.E.

    1994-01-01

    The intent of the WIPP, being constructed in the bedded geologic salt deposits of Southeastern New Mexico, is to provide the technological basis for the safe disposal of radioactive Transuranic (TRU) wastes generated by the defense programs of the United States. In determining this technological basis, advanced reliability and structural analysis techniques are used to determine the probability of time-to-closure of a hypothetical underground shaft located in an argillaceous salt formation and filled with compacted crushed salt. Before being filled with crushed salt for sealing, the shaft provides access to an underground facility. Reliable closure of the shaft depends upon the sealing of the shaft through creep closure and recompaction of crushed backfill. Appropriate methods are demonstrated to calculate cumulative distribution functions of the closure based on laboratory determined random variable uncertainty in salt creep properties

  12. Integration of 100% heat pumps and electric vehicles in the low voltage distribution network: A Danish case story

    DEFF Research Database (Denmark)

    Shao, Nan; You, Shi; Segerberg, Helena

    2013-01-01

    The existing electricity infrastructure may to a great extent limit a high penetration of micro-sized Distributed Energy Rescores (DERs), due to physical bottlenecks, e.g. load capacities of cables and transformers and voltage limitations. In this study, integration impacts of heat pumps (HPs) an...

  13. Thermal interaction of underground pipeline with freezing heaving soil

    Science.gov (United States)

    Podorozhnikov, S. Y.; Mikhailov, P.; Puldas, L.; Shabarov, A.

    2018-05-01

    A mathematical model and a method for calculating the stress-strain state of a pipeline describing the heat-power interaction in the "underground pipeline - soil" system in the conditions of negative temperatures in the soils of soils are offered. Some results of computational-parametric research are presented.

  14. Investigating Water Movement Within and Near Wells Using Active Point Heating and Fiber Optic Distributed Temperature Sensing

    Directory of Open Access Journals (Sweden)

    Frank Selker

    2018-03-01

    Full Text Available There are few methods to provide high-resolution in-situ characterization of flow in aquifers and reservoirs. We present a method that has the potential to quantify lateral and vertical (magnitude and direction components of flow with spatial resolution of about one meter and temporal resolution of about one day. A fiber optic distributed temperature sensor is used with a novel heating system. Temperatures before heating may be used to evaluate background geothermal gradient and vertical profile of thermal diffusivity. The innovation presented is the use of variable energy application along the well, in this case concentrated heating at equally-spaced (2 m localized areas (0.5 m. Relative to uniform warming this offers greater opportunity to estimate water movement, reduces required heating power, and increases practical length that can be heated. Numerical simulations are presented which illustrate expected behaviors. We estimate relative advection rates near the well using the times at which various locations diverge from a heating trajectory expected for pure conduction in the absence of advection. The concept is demonstrated in a grouted 600 m borehole with 300 heated patches, though evidence of vertical water movement was not seen.

  15. Investigating Water Movement Within and Near Wells Using Active Point Heating and Fiber Optic Distributed Temperature Sensing.

    Science.gov (United States)

    Selker, Frank; Selker, John S

    2018-03-29

    There are few methods to provide high-resolution in-situ characterization of flow in aquifers and reservoirs. We present a method that has the potential to quantify lateral and vertical (magnitude and direction) components of flow with spatial resolution of about one meter and temporal resolution of about one day. A fiber optic distributed temperature sensor is used with a novel heating system. Temperatures before heating may be used to evaluate background geothermal gradient and vertical profile of thermal diffusivity. The innovation presented is the use of variable energy application along the well, in this case concentrated heating at equally-spaced (2 m) localized areas (0.5 m). Relative to uniform warming this offers greater opportunity to estimate water movement, reduces required heating power, and increases practical length that can be heated. Numerical simulations are presented which illustrate expected behaviors. We estimate relative advection rates near the well using the times at which various locations diverge from a heating trajectory expected for pure conduction in the absence of advection. The concept is demonstrated in a grouted 600 m borehole with 300 heated patches, though evidence of vertical water movement was not seen.

  16. Model for Determining Geographical Distribution of Heat Saving Potentials in Danish Building Stock

    DEFF Research Database (Denmark)

    Petrovic, Stefan; Karlsson, Kenneth Bernard

    2014-01-01

    Since the global oil crisis in the 1970s, Denmark has followed a path towards energy independency by continuously improving its energy efficiency and energy conservation. Energy efficiency was mainly tackled by introducing a high number of combined heat and power plants in the system, while energy...... conservation was predominantly approached by implementing heat saving measures. Today, with the goal of 100% renewable energy within the power and heat sector by the year 2035, reductions in energy demand for space heating and the preparation of domestic hot water remain at the top of the agenda in Denmark....... A highly detailed model for determining heat demand, possible heat savings and associated costs in the Danish building stock is presented. Both scheduled and energy-saving renovations until year 2030 have been analyzed. The highly detailed GIS-based heat atlas for Denmark is used as a container for storing...

  17. Heat pump and PV impact on residential low-voltage distribution grids as a function of building and district properties

    International Nuclear Information System (INIS)

    Protopapadaki, Christina; Saelens, Dirk

    2017-01-01

    Highlights: • Comprehensive method includes variability in building and feeder characteristics. • Detailed, 10-min, Modelica-based simulation of buildings, heat pumps and networks. • Overloading and voltage issues appear from 30% heat pumps in rural Belgian feeders. • Analysis of load profiles reveals great impact of heat pump back-up heaters. • High correlation of building neighborhood properties with grid impact indicators. - Abstract: Heating electrification powered by distributed renewable energy generation is considered among potential solutions towards mitigation of greenhouse gas emissions. Roadmaps propose a wide deployment of heat pumps and photovoltaics in the residential sector. Since current distribution grids are not designed to accommodate these loads, potential benefits of such policies might be compromised. However, in large-scale analyses, often grid constraints are neglected. On the other hand, grid impact of heat pumps and photovoltaics has been investigated without considering the influence of building characteristics. This paper aims to assess and quantify in a probabilistic way the impact of these technologies on the low-voltage distribution grid, as a function of building and district properties. The Monte Carlo approach is used to simulate an assortment of Belgian residential feeders, with varying size, cable type, heat pump and PV penetration rates, and buildings of different geometry and insulation quality. Modelica-based models simulate the dynamic behavior of both buildings and heating systems, as well as three-phase unbalanced loading of the network. Additionally, stochastic occupant behavior is taken into account. Analysis of neighborhood load profiles puts into perspective the importance of demand diversity in terms of building characteristics and load simultaneity, highlighting the crucial role of back-up electrical loads. It is shown that air-source heat pumps have a greater impact on the studied feeders than PV, in terms

  18. A GIS-based 3D online information system for underground energy storage in northern Germany

    Science.gov (United States)

    Nolde, Michael; Malte, Schwanebeck; Ehsan, Biniyaz; Rainer, Duttmann

    2015-04-01

    We would like to present the concept and current state of development of a GIS-based 3D online information system for underground energy storage. Its aim is to support the local authorities through pre-selection of possible sites for thermal, electrical and substantial underground energy storages. Since the extension of renewable energies has become legal requirement in Germany, the underground storing of superfluously produced green energy (such as during a heavy wind event) in the form of compressed air, gas or heated water has become increasingly important. However, the selection of suitable sites is a complex task. The presented information system uses data of geological features such as rock layers, salt domes and faults enriched with attribute data such as rock porosity and permeability. This information is combined with surface data of the existing energy infrastructure, such as locations of wind and biogas stations, powerline arrangement and cable capacity, and energy distribution stations. Furthermore, legal obligations such as protected areas on the surface and current underground mining permissions are used for the process of pre-selecting sites suitable for energy storage. Not only the current situation but also prospective scenarios, such as expected growth in produced amount of energy are incorporated in the system. While the process of pre-selection itself is completely automated, the user has full control of the weighting of the different factors via the web interface. The system is implemented as an online 3D server GIS environment, so that it can easily be utilized in any web browser. The results are visualized online as interactive 3d graphics. The information system is implemented in the Python programming language in combination with current Web standards, and is build using only free and open source software. It is being developed at Kiel University as part of the ANGUS+ project (lead by Prof. Sebastian Bauer) for the federal state of

  19. Comparison of indoor air distribution and thermal environment for different combinations of radiant heating systems with mechanical ventilation systems

    DEFF Research Database (Denmark)

    Wu, Xiaozhou; Fang, Lei; Olesen, Bjarne W.

    2018-01-01

    A hybrid system with a radiant heating system and a mechanical ventilation system, which is regarded as an advanced heating, ventilation and air-conditioning (HVAC) system, has been applied in many modern buildings worldwide. To date, almost no studies focused on comparative analysis of the indoor...... air distribution and the thermal environment for all combinations of radiant heating systems with mechanical ventilation systems. Therefore, in this article, the indoor air distribution and the thermal environment were comparatively analyzed in a room with floor heating (FH) or ceiling heating (CH......) and mixing ventilation (MV) or displacement ventilation (DV) when the supply air temperature ranged from 15.0°C to 19.0°C. The results showed that the temperature effectiveness values were 1.05–1.16 and 0.95–1.02 for MV+ FH and MV+ CH, respectively, and they were 0.78–0.91 and 0.51–0.67 for DV + FH and DV...

  20. Model for Determining Geographical Distribution of Heat Saving Potentials in Danish Building Stock

    Directory of Open Access Journals (Sweden)

    Stefan Petrovic

    2014-02-01

    Full Text Available Since the global oil crisis in the 1970s, Denmark has followed a path towards energy independency by continuously improving its energy efficiency and energy conservation. Energy efficiency was mainly tackled by introducing a high number of combined heat and power plants in the system, while energy conservation was predominantly approached by implementing heat saving measures. Today, with the goal of 100% renewable energy within the power and heat sector by the year 2035, reductions in energy demand for space heating and the preparation of domestic hot water remain at the top of the agenda in Denmark. A highly detailed model for determining heat demand, possible heat savings and associated costs in the Danish building stock is presented. Both scheduled and energy-saving renovations until year 2030 have been analyzed. The highly detailed GIS-based heat atlas for Denmark is used as a container for storing data about physical properties for 2.5 million buildings in Denmark. Consequently, the results of the analysis can be represented on a single building level. Under the assumption that buildings with the most profitable heat savings are renovated first, the consequences of heat savings for the economy and energy system have been quantified and geographically referenced. The possibilities for further improvements of the model and the application to other geographical regions have been discussed.

  1. Innovative research reactor core designed. Estimation and analysis of gamma heating distribution

    International Nuclear Information System (INIS)

    Setiyanto

    2014-01-01

    The Gamma heating value is an important factor needed for safety analysis of each experiments that will be realized on research reactor core. Gamma heat is internal heat source occurs in each irradiation facilities or any material irradiated in reactor core. This value should be determined correctly because of the safety related problems. The gamma heating value is in general depend on. reactor core characteristics, different one and other, and then each new reactor design should be completed by gamma heating data. The Innovative Research Reactor is one of the new reactor design that should be completed with any safety data, including the gamma heating value. For this reasons, calculation and analysis of gamma heating in the hole of reactor core and irradiation facilities in reflector had been done by using of modified and validated Gamset computer code. The result shown that gamma heating value of 11.75 W/g is the highest value at the center of reactor core, higher than gamma heating value of RSG-GAS. However, placement of all irradiation facilities in reflector show that safety characteristics for irradiation facilities of innovative research reactor more better than RSG-GAS reactor. Regarding the results obtained, and based on placement of irradiation facilities in reflector, can be concluded that innovative research reactor more safe for any irradiation used. (author)

  2. Design study of underground facility of the Underground Research Laboratory

    International Nuclear Information System (INIS)

    Hibiya, Keisuke; Akiyoshi, Kenji; Ishizuka, Mineo; Anezaki, Susumu

    1998-03-01

    Geoscientific research program to study deep geological environment has been performed by Power Reactor and Nuclear Fuel Development Corporation (PNC). This research is supported by 'Long-Term Program for Research, Development and Utilization of Nuclear Energy'. An Underground Research Laboratory is planned to be constructed at Shoma-sama Hora in the research area belonging to PNC. A wide range of geoscientific research and development activities which have been previously studied at the Tono Area is planned in the laboratory. The Underground Research Laboratory is consisted of Surface Laboratory and Underground Research Facility located from the surface down to depth between several hundreds and 1,000 meters. Based on the results of design study in last year, the design study performed in this year is to investigate the followings in advance of studies for basic design and practical design: concept, design procedure, design flow and total layout. As a study for the concept of the underground facility, items required for the facility are investigated and factors to design the primary form of the underground facility are extracted. Continuously, design methods for the vault and the underground facility are summarized. Furthermore, design procedures of the extracted factors are summarized and total layout is studied considering the results to be obtained from the laboratory. (author)

  3. Acceleration of calculation of nuclear heating distributions in ITER toroidal field coils using hybrid Monte Carlo/deterministic techniques

    International Nuclear Information System (INIS)

    Ibrahim, Ahmad M.; Polunovskiy, Eduard; Loughlin, Michael J.; Grove, Robert E.; Sawan, Mohamed E.

    2016-01-01

    Highlights: • Assess the detailed distribution of the nuclear heating among the components of the ITER toroidal field coils. • Utilize the FW-CADIS method to dramatically accelerate the calculation of detailed nuclear analysis. • Compare the efficiency and reliability of the FW-CADIS method and the MCNP weight window generator. - Abstract: Because the superconductivity of the ITER toroidal field coils (TFC) must be protected against local overheating, detailed spatial distribution of the TFC nuclear heating is needed to assess the acceptability of the designs of the blanket, vacuum vessel (VV), and VV thermal shield. Accurate Monte Carlo calculations of the distributions of the TFC nuclear heating are challenged by the small volumes of the tally segmentations and by the thick layers of shielding provided by the blanket and VV. To speed up the MCNP calculation of the nuclear heating distribution in different segments of the coil casing, ground insulation, and winding packs of the ITER TFC, the ITER Organization (IO) used the MCNP weight window generator (WWG). The maximum relative uncertainty of the tallies in this calculation was 82.7%. In this work, this MCNP calculation was repeated using variance reduction parameters generated by the Oak Ridge National Laboratory AutomateD VAriaNce reducTion Generator (ADVANTG) code and both MCNP calculations were compared in terms of computational efficiency and reliability. Even though the ADVANTG MCNP calculation used less than one-sixth of the computational resources of the IO calculation, the relative uncertainties of all the tallies in the ADVANTG MCNP calculation were less than 6.1%. The nuclear heating results of the two calculations were significantly different by factors between 1.5 and 2.3 in some of the segments of the furthest winding pack turn from the plasma neutron source. Even though the nuclear heating in this turn may not affect the ITER design because it is much smaller than the nuclear heating in the

  4. Acceleration of calculation of nuclear heating distributions in ITER toroidal field coils using hybrid Monte Carlo/deterministic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, Ahmad M., E-mail: ibrahimam@ornl.gov [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Polunovskiy, Eduard; Loughlin, Michael J. [ITER Organization, Route de Vinon Sur Verdon, 13067 St. Paul Lez Durance (France); Grove, Robert E. [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Sawan, Mohamed E. [University of Wisconsin-Madison, 1500 Engineering Dr., Madison, WI 53706 (United States)

    2016-11-01

    Highlights: • Assess the detailed distribution of the nuclear heating among the components of the ITER toroidal field coils. • Utilize the FW-CADIS method to dramatically accelerate the calculation of detailed nuclear analysis. • Compare the efficiency and reliability of the FW-CADIS method and the MCNP weight window generator. - Abstract: Because the superconductivity of the ITER toroidal field coils (TFC) must be protected against local overheating, detailed spatial distribution of the TFC nuclear heating is needed to assess the acceptability of the designs of the blanket, vacuum vessel (VV), and VV thermal shield. Accurate Monte Carlo calculations of the distributions of the TFC nuclear heating are challenged by the small volumes of the tally segmentations and by the thick layers of shielding provided by the blanket and VV. To speed up the MCNP calculation of the nuclear heating distribution in different segments of the coil casing, ground insulation, and winding packs of the ITER TFC, the ITER Organization (IO) used the MCNP weight window generator (WWG). The maximum relative uncertainty of the tallies in this calculation was 82.7%. In this work, this MCNP calculation was repeated using variance reduction parameters generated by the Oak Ridge National Laboratory AutomateD VAriaNce reducTion Generator (ADVANTG) code and both MCNP calculations were compared in terms of computational efficiency and reliability. Even though the ADVANTG MCNP calculation used less than one-sixth of the computational resources of the IO calculation, the relative uncertainties of all the tallies in the ADVANTG MCNP calculation were less than 6.1%. The nuclear heating results of the two calculations were significantly different by factors between 1.5 and 2.3 in some of the segments of the furthest winding pack turn from the plasma neutron source. Even though the nuclear heating in this turn may not affect the ITER design because it is much smaller than the nuclear heating in the

  5. Energetics and performance of a microscopic heat engine based on exact calculations of work and heat distributions

    International Nuclear Information System (INIS)

    Chvosta, Petr; Holubec, Viktor; Ryabov, Artem; Einax, Mario; Maass, Philipp

    2010-01-01

    We investigate a microscopic motor based on an externally controlled two-level system. One cycle of the motor operation consists of two strokes. Within each stroke, the two-level system is in contact with a given thermal bath and its energy levels are driven at a constant rate. The time evolutions of the occupation probabilities of the two states are controlled by one rate equation and represent the system's response with respect to the external driving. We give the exact solution of the rate equation for the limit cycle and discuss the emerging thermodynamics: the work done on the environment, the heat exchanged with the baths, the entropy production, the motor's efficiency, and the power output. Furthermore we introduce an augmented stochastic process which reflects, at a given time, both the occupation probabilities for the two states and the time spent in the individual states during the previous evolution. The exact calculation of the evolution operator for the augmented process allows us to discuss in detail the probability density for the work performed during the limit cycle. In the strongly irreversible regime, the density exhibits important qualitative differences with respect to the more common Gaussian shape in the regime of weak irreversibility

  6. Underground Facilities, Technological Challenges

    CERN Document Server

    Spooner, N

    2010-01-01

    This report gives a summary overview of the status of international under- ground facilities, in particular as relevant to long-baseline neutrino physics and neutrino astrophysics. The emphasis is on the technical feasibility aspects of creating the large underground infrastructures that will be needed in the fu- ture to house the necessary detectors of 100 kton to 1000 kton scale. There is great potential in Europe to build such a facility, both from the technical point of view and because Europe has a large concentration of the necessary engi- neering and geophysics expertise. The new LAGUNA collaboration has made rapid progress in determining the feasibility for a European site for such a large detector. It is becoming clear in fact that several locations are technically fea- sible in Europe. Combining this with the possibility of a new neutrino beam from CERN suggests a great opportunity for Europe to become the leading centre of neutrino studies, combining both neutrino astrophysics and neutrino beam stu...

  7. ATLAS solenoid operates underground

    CERN Multimedia

    2006-01-01

    A new phase for the ATLAS collaboration started with the first operation of a completed sub-system: the Central Solenoid. Teams monitoring the cooling and powering of the ATLAS solenoid in the control room. The solenoid was cooled down to 4.5 K from 17 to 23 May. The first current was established the same evening that the solenoid became cold and superconductive. 'This makes the ATLAS Central Solenoid the very first cold and superconducting magnet to be operated in the LHC underground areas!', said Takahiko Kondo, professor at KEK. Though the current was limited to 1 kA, the cool-down and powering of the solenoid was a major milestone for all of the control, cryogenic, power and vacuum systems-a milestone reached by the hard work and many long evenings invested by various teams from ATLAS, all of CERN's departments and several large and small companies. Since the Central Solenoid and the barrel liquid argon (LAr) calorimeter share the same cryostat vacuum vessel, this achievement was only possible in perfe...

  8. FAST goes underground

    International Nuclear Information System (INIS)

    Fridlund, P.S.

    1985-01-01

    The FAST-M Cost Estimating Model is a parametric model designed to determine the costs associated with mining and subterranean operations. It is part of the FAST (Freiman Analysis of Systems Techniques) series of parametric models developed by Freiman Parametric Systems, Inc. The rising cost of fossil fuels has created a need for a method which could be used to determine and control costs in mining and subterranean operations. FAST-M fills this need and also provides scheduling information. The model works equally well for a variety of situations including underground vaults for hazardous waste storage, highway tunnels, and mass transit tunnels. In addition, costs for above ground structures and equipment can be calculated. The input for the model may be on a macro or a micro level. This allows the model to be used at various stages in a project. On the macro level, only general conditions and specifications need to be known. On the micro level, the smallest details may be included. As with other FAST models, reference cases are used to more accurately predict costs and scheduling. This paper will address how the model can be used for a variety of subterranean purposes

  9. Underground storage of radioactive wastes

    International Nuclear Information System (INIS)

    Dietz, D.N.

    1977-01-01

    An introductory survey of the underground disposal of radioactive wastes is given. Attention is paid to various types of radioactive wastes varying from low to highly active materials, as well as mining techniques and salt deposits

  10. Temperature and blood flow distribution in the human leg during passive heat stress.

    Science.gov (United States)

    Chiesa, Scott T; Trangmar, Steven J; González-Alonso, José

    2016-05-01

    The influence of temperature on the hemodynamic adjustments to direct passive heat stress within the leg's major arterial and venous vessels and compartments remains unclear. Fifteen healthy young males were tested during exposure to either passive whole body heat stress to levels approaching thermal tolerance [core temperature (Tc) + 2°C; study 1; n = 8] or single leg heat stress (Tc + 0°C; study 2; n = 7). Whole body heat stress increased perfusion and decreased oscillatory shear index in relation to the rise in leg temperature (Tleg) in all three major arteries supplying the leg, plateauing in the common and superficial femoral arteries before reaching severe heat stress levels. Isolated leg heat stress increased arterial blood flows and shear patterns to a level similar to that obtained during moderate core hyperthermia (Tc + 1°C). Despite modest increases in great saphenous venous (GSV) blood flow (0.2 l/min), the deep venous system accounted for the majority of returning flow (common femoral vein 0.7 l/min) during intense to severe levels of heat stress. Rapid cooling of a single leg during severe whole body heat stress resulted in an equivalent blood flow reduction in the major artery supplying the thigh deep tissues only, suggesting central temperature-sensitive mechanisms contribute to skin blood flow alone. These findings further our knowledge of leg hemodynamic responses during direct heat stress and provide evidence of potentially beneficial vascular alterations during isolated limb heat stress that are equivalent to those experienced during exposure to moderate levels of whole body hyperthermia. Copyright © 2016 the American Physiological Society.

  11. Thermal Effect of Ceramic Substrate on Heat Distribution in Thermoelectric Generators

    DEFF Research Database (Denmark)

    Kolaei, Alireza Rezania; Rosendahl, Lasse

    2012-01-01

    in the heat sink, a parallel microchannel heat sink is applied to a real TEG. The focus of this study is a discussion of the temperature difference variation between the cold/hot sides of the TEG legs versus the variation of the thermal conductivity of the ceramic substrate and the thickness of the substrate...... that the temperature difference is affected remarkably by the pressure drops in the heat sink, the thermal conductivity of the ceramic substrate, and the thickness of the substrate on the hot side....

  12. Source Distribution Method for Unsteady One-Dimensional Flows With Small Mass, Momentum, and Heat Addition and Small Area Variation

    Science.gov (United States)

    Mirels, Harold

    1959-01-01

    A source distribution method is presented for obtaining flow perturbations due to small unsteady area variations, mass, momentum, and heat additions in a basic uniform (or piecewise uniform) one-dimensional flow. First, the perturbations due to an elemental area variation, mass, momentum, and heat addition are found. The general solution is then represented by a spatial and temporal distribution of these elemental (source) solutions. Emphasis is placed on discussing the physical nature of the flow phenomena. The method is illustrated by several examples. These include the determination of perturbations in basic flows consisting of (1) a shock propagating through a nonuniform tube, (2) a constant-velocity piston driving a shock, (3) ideal shock-tube flows, and (4) deflagrations initiated at a closed end. The method is particularly applicable for finding the perturbations due to relatively thin wall boundary layers.

  13. Determination of mass flow rate and quality distributions between the subchannels of a heated bundle. [BWR; PWR

    Energy Technology Data Exchange (ETDEWEB)

    Bayoumi, M.; Charlot, R.; Ricque, R.

    1976-05-01

    For analyzing, correlating and extrapolating experimental burn-out results obtained with LWR rod bundles, it is necessary to know the distributions of mass flow rate and quality between the subchannels. A description is presented of an experimental study in progress at the CEN-Grenoble for determining and adjusting the laws of mixing in the FLICA Code which is used to predict these distributions. The experiments are performed on the FRENESIE loop with Freon 12. The test section, in vertical position, consists of a four rod bundle in a channel with square section. The heat flux is axially uniform. The flow of each subchannel can be sampled in ''isokinetic conditions,'' at the end of the heating length. Thermodynamic quality and mass flow rate of the samplings are measured in steady state conditions by using respectively a calorimeter and a turbine flow meter. The test facility is described and experimental data are presented and discussed.

  14. Magnetic Pumping as a Source of Particle Heating and Power-law Distributions in the Solar Wind

    Science.gov (United States)

    Lichko, E.; Egedal, J.; Daughton, W.; Kasper, J.

    2017-12-01

    Based on the rate of expansion of the solar wind, the plasma should cool rapidly as a function of distance to the Sun. Observations show this is not the case. In this work, a magnetic pumping model is developed as a possible explanation for the heating and the generation of power-law distribution functions observed in the solar wind plasma. Most previous studies in this area focus on the role that the dissipation of turbulent energy on microscopic kinetic scales plays in the overall heating of the plasma. However, with magnetic pumping, particles are energized by the largest-scale turbulent fluctuations, thus bypassing the energy cascade. In contrast to other models, we include the pressure anisotropy term, providing a channel for the large-scale fluctuations to heat the plasma directly. A complete set of coupled differential equations describing the evolution, and energization, of the distribution function are derived, as well as an approximate closed-form solution. Numerical simulations using the VPIC kinetic code are applied to verify the model’s analytical predictions. The results of the model for realistic solar wind scenario are computed, where thermal streaming of particles are important for generating a phase shift between the magnetic perturbations and the pressure anisotropy. In turn, averaged over a pump cycle, the phase shift permits mechanical work to be converted directly to heat in the plasma. The results of this scenario show that magnetic pumping may account for a significant portion of the solar wind energization.

  15. Expanding photovoltaic penetration with residential distributed generation from hybrid solar photovoltaic and combined heat and power systems

    International Nuclear Information System (INIS)

    Pearce, J.M.

    2009-01-01

    The recent development of small scale combined heat and power (CHP) systems has provided the opportunity for in-house power backup of residential-scale photovoltaic (PV) arrays. This paper investigates the potential of deploying a distributed network of PV + CHP hybrid systems in order to increase the PV penetration level in the U.S. The temporal distribution of solar flux, electrical and heating requirements for representative U.S. single family residences were analyzed and the results clearly show that hybridizing CHP with PV can enable additional PV deployment above what is possible with a conventional centralized electric generation system. The technical evolution of such PV + CHP hybrid systems was developed from the present (near market) technology through four generations, which enable high utilization rates of both PV-generated electricity and CHP-generated heat. A method to determine the maximum percent of PV-generated electricity on the grid without energy storage was derived and applied to an example area. The results show that a PV + CHP hybrid system not only has the potential to radically reduce energy waste in the status quo electrical and heating systems, but it also enables the share of solar PV to be expanded by about a factor of five. (author)

  16. A survey of the underground siting of nuclear power plants

    International Nuclear Information System (INIS)

    Pinto, S.

    1979-12-01

    The idea of locating nuclear power plants underground is not new, since in the period of time between the late fifties and the early sixties, four small nuclear plants have been built in Europe in rock cavities. Safety has been, in general, the main motivation for such a siting solution. In the last years several factors such as increasing power transmission costs, decreasing number of suitable sites above ground, increased difficulties in obtaining site approval by the licensing authorities, increasing opposition to nuclear power, increasing concern for extreme - but highly improbable - accidents, together with the possibility of utilizing the waste heat and the urban siting concept have renewed the interest for the underground siting as an alternative to surface siting. The author presents a survey of the main studies carried out on the subject of underground siting. (Auth.)

  17. Underground laboratories for rock mechanics before radioactive waste

    International Nuclear Information System (INIS)

    Duffaut, P.

    1985-01-01

    Many rock mechanics tests are performed in situ, most of them underground since 1936 at the Beni Bahdel dam. The chief tests for understanding the rock mass behaviour are deformability tests (plate test and pressure cavern test, including creep experiments) and strength tests (compression of a mine pillar, shear test on rock mass or joint). Influence of moisture, heat, cold and freeze are other fields of investigation which deserve underground laboratories. Behaviour of test galleries, either unsupported or with various kinds of support, often is studied along time, and along the work progression, tunnel face advance, enlargement or deepening of the cross section. The examples given here help to clarify the concept of underground laboratory in spite of its many different objectives. 38 refs.; 1 figure; 1 table

  18. Proximity detection system underground

    Energy Technology Data Exchange (ETDEWEB)

    Denis Kent [Mine Site Technologies (Australia)

    2008-04-15

    Mine Site Technologies (MST) with the support ACARP and Xstrata Coal NSW, as well as assistance from Centennial Coal, has developed a Proximity Detection System to proof of concept stage as per plan. The basic aim of the project was to develop a system to reduce the risk of the people coming into contact with vehicles in an uncontrolled manner (i.e. being 'run over'). The potential to extend the developed technology into other areas, such as controls for vehicle-vehicle collisions and restricting access of vehicle or people into certain zones (e.g. non FLP vehicles into Hazardous Zones/ERZ) was also assessed. The project leveraged off MST's existing Intellectual Property and experience gained with our ImPact TRACKER tagging technology, allowing the development to be fast tracked. The basic concept developed uses active RFID Tags worn by miners underground to be detected by vehicle mounted Readers. These Readers in turn provide outputs that can be used to alert a driver (e.g. by light and/or audible alarm) that a person (Tag) approaching within their vicinity. The prototype/test kit developed proved the concept and technology, the four main components being: Active RFID Tags to send out signals for detection by vehicle mounted receivers; Receiver electronics to detect RFID Tags approaching within the vicinity of the unit to create a long range detection system (60 m to 120 m); A transmitting/exciter device to enable inner detection zone (within 5 m to 20 m); and A software/hardware device to process & log incoming Tags reads and create certain outputs. Tests undertaken in the laboratory and at a number of mine sites, confirmed the technology path taken could form the basis of a reliable Proximity Detection/Alert System.

  19. Neutrino burst identification in underground detectors

    International Nuclear Information System (INIS)

    Fulgione, W.; Mengotti-Silva, N.; Panaro, L.

    1996-01-01

    We discuss the problem of neutrino burst identification in underground ν-telescopes. First the usual statistical analysis based on the time structure of the events is reviewed, with special attention to the statistical significance of burst candidates. Next, we propose a second level analysis that can provide independent confirmation of burst detection. This exploits the spatial distribution of the single events of a burst candidate, and uses the formalism of the entropy of information. Examples of both techniques are shown, based on the LVD experiment at Gran Sasso. (orig.)

  20. Nonlinear observer-based Lyapunov boundary control of distributed heat transfer mechanisms for membrane distillation plant

    KAUST Repository

    Eleiwi, Fadi; Laleg-Kirati, Taous-Meriem

    2016-01-01

    , and seeks to maintain the temperature difference along the membrane boundaries around a sufficient level to promote water production. MD process is modeled with advection diffusion equation model in two dimensions, where the diffusion and convection heat

  1. Nonlinear Lyapunov-based boundary control of distributed heat transfer mechanisms in membrane distillation plant

    KAUST Repository

    Eleiwi, Fadi; Laleg-Kirati, Taous-Meriem

    2015-01-01

    This paper presents a nonlinear Lyapunov-based boundary control for the temperature difference of a membrane distillation boundary layers. The heat transfer mechanisms inside the process are modeled with a 2D advection-diffusion equation. The model

  2. A method for distributed power consumption based on the combined heat and power system

    Science.gov (United States)

    Li, Si-wei; Han, Shen-zhao; Yu, Bo; Lu, Xin; Qi, Wen

    2018-02-01

    With the development of the society and human progress, now resource problems has become one of the major problems faced by people all over the world, the development of new energy and clean energy is the priority now, is now the main power system. Winter heating is one of the main sources of pollution now, so it is very important to study the electric heating system.

  3. Temperature distributions in pavement and bridge slabs heated by using vertical ground-source heat pump systems - doi: 10.4025/actascitechnol.v35i4.15712

    Directory of Open Access Journals (Sweden)

    Asım Balbay

    2013-10-01

    Full Text Available Temperature distribution which occurs in pavement and bridge slabs heated for de-icing and snow melting during cold periods is determined by using vertical ground-source heat pump (GSHP systems with U-tube ground heat exchanger (GHE. The bridge and pavement models (slabs for de-icing and snow melting were constructed. A three-dimensional finite element model (FEM was developed to simulate temperature distribution of bridge slab (BS and pavement slab (PS. The temperature distribution simulations of PS and BS were conducted numerically by computational fluid dynamics (CFD program named ‘Fluent’. Congruence between the simulations and experimental data was determined.   

  4. Evaluation and analysis of underground brine resources in the southern coastal area of Laizhou Bay

    Science.gov (United States)

    Tian, M.; Zhu, H. T.; Feng, J.; Zhao, Q. S.

    2016-08-01

    The southern coastal districts of Laizhou Bay are some of the most important areas for underground brine exploitation in Shandong Province. Recently, these areas have been gradually developed by the underground brine mining industry. Such economic interest has led to brine exploitation so that underground brine resources are running out. Based on this phenomenon, this study describes the supply, runoff and draining conditions of the area by collecting and organizing the background information of the studied area. Hydrogeological parameters are then calculated according to pumping tests, and the amount of sustainable resources in the coastal areas of the Southern Bank of Laizhou Bay are then calculated based on the uniform distribution of wells. Under the circumstances of underground brine mining, the exploitation potential of the underground brine is evaluated in accordance with the calculation results of exploitation quantum. Finally, suggestions are provided for the sustainable exploitation of underground brine in the area.

  5. Potential Advantages of Underground Nuclear Parks

    International Nuclear Information System (INIS)

    Myers, Carl W.; Elkins, Ned Z.; Kunze, Jay F.; Mahar, James M.

    2006-01-01

    In this paper we argue that an underground nuclear park (UNP) could potentially lead to lower capital and operating cost for the reactors installed in the UNP compared to the traditional approach, which would be to site the reactors at the earth's surface at distributed locations. The UNP approach could also lead to lower waste management cost. A secondary benefit would be the increased margins of safety and security that would be realized simply as a consequence of siting the reactors underground. Lowered capital and operating cost for a UNP relative to traditional reactor siting is possible through the aggregate effect of the elimination of containment structures, in-place decommissioning, reduced physical security costs, reduced weather-related costs, reduced cost of liability insurance and reduced unit-cost for the nth reactor made possible through the continuous construction of multiple reactors at the same underground location. Other cost reductions might be possible through the transfer of the capital cost for part of the underground construction from the reactor owners to the owners of the UNP. Lower waste management cost is possible by siting the UNP at a location where there are geological and hydrological conditions suitable for hosting both the reactors and the repository for the waste from those reactors. After adequate storage and cooling, and assuming direct disposal, this would enable the spent fuel from the reactors to be transported directly to the repository and remain entirely underground during the transport process. Community concerns and transportation costs would be significantly reduced relative to current situations where the reactors are separated from the repository by long distances and populated areas. The concept for a UNP in bedded salt is used to develop a rough order of magnitude cost estimate for excavation of the reactor array portion of a UNP. Excavation costs appear to be only a small fraction of the overall power plant costs

  6. Studies on muon showers underground

    Energy Technology Data Exchange (ETDEWEB)

    Bergamasco, L; Castagnoli, C; Dardo, M; D' Ettorre Piazzoli, B; Mannocchi, G [Consiglio Nazionale delle Ricerche, Turin (Italy). Lab. di Cosmo-Geofisica; Picchi, P; Visentin, R [Comitato Nazionale per l' Energia Nucleare, Frascati (Italy). Laboratori Nazionali di Frascati; Sitte, K [Freiburg Univ. (Germany, F.R.). Fakultaet fuer Physik

    1976-08-21

    The 4 m/sup 2/ spark chamber telescope array of the Mt. Cappuccini Laboratory, Torino, At 40 m w.e. underground was operated for about 830 h recording muon showers. The data were analysed with respect to the multiplicity distribution of the shower particles, and to local interactions initiated in the chamber absorbers. Regarding the multiplicity analysis a semi-empirical expression for the likely shower size dependence of a structure function of the analytical form proposed by Vernov et al., was derived and applied with systematically varied parameters. The comparison of the observed rates of multiples with those calculated with a variety of parameters showed that a satisfactory agreement can be attained only if one admits a variation with the shower size of the parameters, and an enhanced muon/electron ratio at the lower primary energies, possibly indicative of an increased abundance of primary heavy nuclei. This would conform with the idea of a two-component primary composition in which a pulsar-produced fraction, enriched in heavy nuclei, dominated only at medium energies. The records on multiplicative interactions, and on large-angle scattering, were analysed by comparing their rates observed for shower particles with those found in single-muon check runs. The results are consistent with the assumption that all shower particle interactions are electromagnetic in nature, and that nonconventional components like mandelas are absent. Only making extreme allowances for statistical fluctuations the data can be made compatible with a mandela flux as large as that suggested by Baruch et al., provided that the mandela attenuation length is less than 1 500g/cm/sup 2/ of rock.

  7. Studies on muon showers underground

    International Nuclear Information System (INIS)

    Bergamasco, L.; Castagnoli, C.; Dardo, M.; D'Ettorre Piazzoli, B.; Mannocchi, G.; Picchi, P.; Visentin, R.; Sitte, K.

    1976-01-01

    The 4 m 2 spark chamber telescope array of the Mt. Cappuccini Laboratory, Torino, At 40 m w.e. underground was operated for about 830 h recording muon showers. The data were analysed with respect to the multiplicity distribution of the shower particles, adn to local interactions initiated in the chamber absorbers. Regarding the multiplicity analysis a semi-empirical expression for the likely shower size dependence of a structure function of the analytical form proposed by Vernov et al., was derived and applied with systematically varied parameters. The comparison of the observed rates of multiples with those calculated with a variety of parameters showed that a satisfactory agreement can be attained only if one admits a variation with the shower size of the parameters, and an enhanced muon/electron ratio at the lower primary energies, possibly indicative of an increased abundance of primary heavy nuclei. This would conform with the idea of a two-component primary composition in which a pulsar-produced fraction, enriched in heavy nuclei, dominated only at medium energies. The records on multiplicative interactions, and on large-angle scattering, were analysed by comparing their rates observed for shower particles with those found in single-muon check runs. The results are consistent with the assumption that all shower particle interactions are electromagnetic in nature, and that nonconventional components like mandelas are absent. Only making extreme allowances for statistical fluctuations the data can be made compatible with a mandela flux as large as that suggested by Baruch et al., provided that the mandela attenuation length is less than 1 500g/cm 2 of rock

  8. Electron energy distribution function in the divertor region of the COMPASS tokamak during neutral beam injection heating

    Science.gov (United States)

    Hasan, E.; Dimitrova, M.; Havlicek, J.; Mitošinková, K.; Stöckel, J.; Varju, J.; Popov, Tsv K.; Komm, M.; Dejarnac, R.; Hacek, P.; Panek, R.; the COMPASS Team

    2018-02-01

    This paper presents the results from swept probe measurements in the divertor region of the COMPASS tokamak in D-shaped, L-mode discharges, with toroidal magnetic field BT = 1.15 T, plasma current Ip = 180 kA and line-average electron densities varying from 2 to 8×1019 m-3. Using neutral beam injection heating, the electron energy distribution function is studied before and during the application of the beam. The current-voltage characteristics data are processed using the first-derivative probe technique. This technique allows one to evaluate the plasma potential and the real electron energy distribution function (respectively, the electron temperatures and densities). At the low average electron density of 2×1019 m-3, the electron energy distribution function is bi-Maxwellian with a low-energy electron population with temperatures 4-6 eV and a high-energy electron group 12-25 eV. As the line-average electron density is increased, the electron temperatures decrease. At line-average electron densities above 7×1019 m-3, the electron energy distribution function is found to be Maxwellian with a temperature of 6-8.5 eV. The effect of the neutral beam injection heating power in the divertor region is also studied.

  9. Underground disposal of radioactive wastes

    International Nuclear Information System (INIS)

    1981-01-01

    This report is an overview document for the series of IAEA reports dealing with underground waste disposal to be prepared in the next few years. It provides an introduction to the general considerations involved in implementing underground disposal of radioactive wastes. It suggests factors to be taken into account for developing and assessing waste disposal concepts, including the conditioned waste form, the geological containment and possible additional engineered barriers. These guidelines are general so as to cover a broad range of conditions. They are generally applicable to all types of underground disposal, but the emphasis is on disposal in deep geological formations. Some information presented here may require slight modifications when applied to shallow ground disposal or other types of underground disposal. Modifications may also be needed to reflect local conditions. In some specific cases it may be that not all the considerations dealt with in this book are necessary; on the other hand, while most major considerations are believed to be included, they are not meant to be all-inclusive. The book primarily concerns only underground disposal of the wastes from nuclear fuel cycle operations and those which arise from the use of isotopes for medical and research activities

  10. Distribution of tritium in a nuclear process heat plant with HTR

    International Nuclear Information System (INIS)

    Steinwarz, W.; Stoever, D.; Hecker, R.; Thiele, W.

    1984-01-01

    The application of HTR-process heat in chemical processes involves low contamination of the product by tritium permeation through the heat exchanger walls. According to conservative assumptions for the tritium release rate and based on experimental permeation data of the German R und D-program a tritium concentration in the PNP-product gas of about 10 pCi/g was calculated. The domestic use of the product gas in unvented kitchen ranges as the most important direct radiation exposure pathway then leads to an effective equivalent radiation dose of only 20 μrem/a. (orig.)

  11. Unsteady temperature distribution in bars of arbitrary cross section with heat generation

    International Nuclear Information System (INIS)

    Laura, P.A.A.; Sanchez Sarmiento, G.

    1983-01-01

    In general, numerical schemes such as the finite-difference method, the Monte-Carlo approach or the finite element technique must be applied when solving boundary value problems of heat conduction theory in the case of complex geometries quite common in nuclear reactor technology. It is shown in the present paper that an alternative analytical approach based on conformal mapping techniques and a variational formulation is quite convenient for the complicated domains considered herewith and for a type of unsteady state thermal field situation when heat generation takes place. (orig.)

  12. Model studies of bubble size distribution and sound propagation at microleaks in sodium-heated steam generators

    International Nuclear Information System (INIS)

    Uhlmann, G.

    1979-01-01

    The reaction zone of a small water leak in a sodium-heated steam generator (microleak) has been simulated by jet gassing or argon in water. The bubble diameter distribution in the bubble flow has been measured using a photoelectric method. The bubble size distribution obtained can be approached by an exponential distribution. For this case, phase velocity and sound damping have been calculated in the two-phase mixture. In the case of small ratios of sound frequency to the expected value of bubble resonance frequency, the frequency-independent sound velocity of the homogeneous mixture is obtained as a function of the gas volume fraction. In the case of very high frequencies, the sound velocity of the pure liquid is obtained for any gas volume fractions. In the whole range investigated damping is strongly dependent on the frequency. (author)

  13. β-distribution for Reynolds stress and turbulent heat flux in relaxation turbulent boundary layer of compression ramp

    Science.gov (United States)

    Hu, YanChao; Bi, WeiTao; Li, ShiYao; She, ZhenSu

    2017-12-01

    A challenge in the study of turbulent boundary layers (TBLs) is to understand the non-equilibrium relaxation process after sep-aration and reattachment due to shock-wave/boundary-layer interaction. The classical boundary layer theory cannot deal with the strong adverse pressure gradient, and hence, the computational modeling of this process remains inaccurate. Here, we report the direct numerical simulation results of the relaxation TBL behind a compression ramp, which reveal the presence of intense large-scale eddies, with significantly enhanced Reynolds stress and turbulent heat flux. A crucial finding is that the wall-normal profiles of the excess Reynolds stress and turbulent heat flux obey a β-distribution, which is a product of two power laws with respect to the wall-normal distances from the wall and from the boundary layer edge. In addition, the streamwise decays of the excess Reynolds stress and turbulent heat flux also exhibit power laws with respect to the streamwise distance from the corner of the compression ramp. These results suggest that the relaxation TBL obeys the dilation symmetry, which is a specific form of self-organization in this complex non-equilibrium flow. The β-distribution yields important hints for the development of a turbulence model.

  14. Análise comparativa dos custos de diferentes redes de distribuição de energia elétrica no contexto da arborização urbana Costs of aerial electricity conventional distribution networks, aerial compact distribution networks and underground networks in arboriculture context

    Directory of Open Access Journals (Sweden)

    Giuliana Del Nero Velasco

    2006-08-01

    Full Text Available Com o intuito de estudar as podas feitas em árvores urbanas e analisar novas técnicas possíveis de serem utilizadas para reduzir o número de podas e melhorar a convivência das espécies com a fiação elétrica, além de permitir à árvore desempenhar plenamente suas funções ecológicas, buscou-se levantar dados referentes aos três tipos principais de redes de distribuição de energia elétrica (aérea convencional, aérea compacta e subterrânea, em quatro concessionárias de energia elétrica, a fim de compilá-los em um só trabalho. Foram levantados custos de implantação das redes convencional, compacta e subterrânea, assim como custos de manutenção e de poda de árvores. O custo de implantação de rede convencional (primária e secundária variou de R$54.188,39 a R$67.571,43. O custo de implantação da rede compacta (primária e secundária foi em média R$62.215,99. Já o custo de implantação de uma rede subterrânea é, em média, de R$436.585,04. A rede compacta já é totalmente viável, principalmente por ter custo de implantação praticamente igual à rede convencional e ter custo de manutenção 80% menor. A rede subterrânea, embora com custo de implantação aproximadamente 10 vezes maior quando comparado com o custo da convencional, por ter reduzido custo de manutenção e alta confiabilidade do sistema elétrico, seu uso já pode ser viável em diversas ocasiões.In order to study the pruning carried out in urban trees and analyze new techniques that may be used to reduce pruning, improve the relationship between the species and the networks, and allow trees to fulfill their proper ecological functions, studies concerning the three main types of electric power distribution were carried out: aerial conventional distribution networks, aerial compact distribution networks and underground networks in four electric power companies. The study showed the implementation costs of the three named networks as well as

  15. Comparison of the Performance of Chilled Beam with Swirl Jet and Diffuse Ceiling Air Supply: Impact of Heat Load Distribution

    DEFF Research Database (Denmark)

    Bertheussen, Bård; Mustakallio, Panu; Kosonen, Risto

    2013-01-01

    The impact of heat load strength and positioning on the indoor environment generated by diffuse ceiling air supply and chilled beam with radial swirl jet was studied and compared. An office room with two persons and a meeting room with six persons were simulated in a test room (4.5 x 3.95 x 3.5 m3......) and Category B thermal environment in the meeting room at high heat load of 94 W∙m−2. The air distribution pattern was influenced by the convective flows from the heat sources. The maximum local velocity in the occupied zone was 0.23–0.26 m∙s−1. The diffuse ceiling supply did not ensure complete mixing...... temperature was controlled at 24 °C. The quality of the generated indoor environment as defined in ISO standard 7730 (2005) was assessed based on comprehensive physical measurements. The systems created Category A thermal environment in cooling situations at heat load of 50 W∙m−2 and 78 W∙m−2 (office room...

  16. Transient natural ventilation of a room with a distributed heat source

    Science.gov (United States)

    Fitzgerald, Shaun D.; Woods, Andrew W.

    We report on an experimental and theoretical study of the transient flows which develop as a naturally ventilated room adjusts from one temperature to another. We focus on a room heated from below by a uniform heat source, with both high- and low-level ventilation openings. Depending on the initial temperature of the room relative to (i) the final equilibrium temperature and (ii) the exterior temperature, three different modes of ventilation may develop. First, if the room temperature lies between the exterior and the equilibrium temperature, the interior remains well-mixed and gradually heats up to the equilibrium temperature. Secondly, if the room is initially warmer than the equilibrium temperature, then a thermal stratification develops in which the upper layer of originally hot air is displaced upwards by a lower layer of relatively cool inflowing air. At the interface, some mixing occurs owing to the effects of penetrative convection. Thirdly, if the room is initially cooler than the exterior, then on opening the vents, the original air is displaced downwards and a layer of ambient air deepens from above. As this lower layer drains, it is eventually heated to the ambient temperature, and is then able to mix into the overlying layer of external air, and the room becomes well-mixed. For each case, we present new laboratory experiments and compare these with some new quantitative models of the transient flows. We conclude by considering the implications of our work for natural ventilation of large auditoria.

  17. District heating and cooling systems for communities through power plant retrofit and distribution network. Final report. Volume I. Text

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-09-15

    An analysis was performed investigating the potential of retrofitting Detroit Edison's Conners Creek power plant to supply district heating and cooling to an area surrounding the plant and within the City of Detroit. A detailed analysis was made of the types and ages of the buildings in the service area as a basis for establishing loads. The analysis of the power plant established possible modifications to the turbines to serve the load in the area. Based upon the service area data and plant retrofit schemes, a distribution system was developed incrementally over a 20-y period. An economic analysis of the system was performed to provide cash flows and payback periods for a variety of energy costs, system costs, and escalation rates to determine the economic viability of the system analyzed. The legal and regulatory requirements required of the district heating and cooling system owner in Michigan were also analyzed to determine what conditions must be met to own and operate the system.

  18. Numerical simulation of a fractional model of temperature distribution and heat flux in the semi infinite solid

    Directory of Open Access Journals (Sweden)

    Anupama Choudhary

    2016-03-01

    Full Text Available In this paper, a fractional model for the computation of temperature and heat flux distribution in a semi-infinite solid is discussed which is subjected to spatially decomposing, time-dependent laser source. The apt dimensionless parameters are identified and the reduced temperature and heat flux as a function of these parameters are presented in a numerical form. Some special cases of practical interest are also discussed. The solution is derived by the application of the Laplace transform, the Fourier sine transform and their derivatives. Also, we developed an alternative solution of it by using the Sumudu transform, the Fourier transform and their derivatives. These results are received in compact and graceful forms in terms of the generalized Mittag-Leffler function, which are suitable for numerical computation.

  19. Heat-transfer distributions on biconics at incidence in hypersonic-hypervelocity He, N2, air, and CO2 flows

    Science.gov (United States)

    Miller, C. G.; Micol, J. R.; Gnoffo, P. A.; Wilder, S.E.

    1983-01-01

    Laminar heat-transfer rates were measured on spherically blunted, 13 degrees/F degrees on-axis and bent biconics (fore cone bent 7 degrees upward relative to aft cone) at hypersonic-hypervelocity flow conditions in the Langley Expansion Tube. Freestream velocities from 4.5 to 6.9 km/sec and Mach numbers from 6 to 9 were generated using helium, nitrogen, air, and carbon dioxide test gases, resulting in normal shock density ratios from 4 to 19. Angle of attack, referenced to the axis of the aft cone, was varied from zero to 20 degrees in 4 degree increments. The effect of nose bend, angle of attack, and real-gas phenomena on heating distributions are presented along with comparisons of measurement to prediction from a code which solves the three-dimensional 'parabolized Navier-Stokes' equations.

  20. The utilization of the storage of thermal energy in buildings. Underground heat storages - thermic simulation and profitability; Termisen energian varastoinnin hyvaeksikaeyttoemahdollisuudet rakennusten laemmityksessae ja jaeaehdytyksessae. Maanalaiset varastot - laempoetekninen simulointi ja taloudellinen kannattavuus

    Energy Technology Data Exchange (ETDEWEB)

    Suokas, M.; Heinonen, J.; Karola, A.; Laine, T.; Siren, K.

    1998-12-31

    Interest in different sources of free energy has significantly increased due to the possibility to decrease the consumption of fossil fuels and nuclear power. This can be reached, for example, with waste heat recovery and by utilising natural heat and cool energy sources. The main problem is that the supply and use of energy do not encounter and this causes a need for thermal energy storage. The earlier heat storage systems have utilised compressor heat pumps because the temperature levels of heat storages are not high enough for the ordinary heating and cooling systems. The disadvantage is the complexity of these systems which leads to increasing building costs. Therefore, this study deals with systems of low temperature levels used mainly for cooling purposes. The aim was to find out their usability, savings and profitability. The function and energy consumption of systems were simulated with models of buildings, soil heat storage and climate. The soil model simulates heat dynamic behaviour of the masses of soil. With the climate model it was possible to simulate transient heat losses of the storage and building. It was also possible to simulate various climatic conditions by changing input data of the climate model. In the simulated systems the emphasis is on the production of cooling energy by utilising the low temperature of the ground. The systems consist of heat storage and building. The cooling energy will be charged in winter to the storage when the heat energy charged in summer will be transferred to the supply air of ventilating unit. After the energy simulations the investment and usage costs of this kind of systems were compared with costs of ordinary compressor cooling systems. The buildings studied were an imaginary LVIS 2000 office building and the Messukeskus in Helsinki which is a large hall built for exhibitions. The types of soil were wet clay and granite. The LVIS 2000 office building needs a rock heat storage with capacity of 8 000-30 000 m

  1. Optimisation of single-pipe heating systems with heating cost distribution and supporting room air processes in industrial housing construction in the new Laender. Pt. 2. Heating cost distribution and energy diagnosis; Optimierung von Einrohrheizungsanlagen mit Heizkostenverteilung sowie flankierenden Raumluftprozessen im industriellen Wohnungsbau der NBL. T. 2. Heizkostenverteilung und Energiediagnose

    Energy Technology Data Exchange (ETDEWEB)

    Bach, H; Bauer, M; Eisenmann, G; Haupt, C; Tritschler, M

    1996-12-01

    The second part of the present research report focusses on energy diagnosis and heating cost distribution in single-pipe heating systems. It describes energy diagnosis with regard to its aims and methods. The subject of heating cost distribution is addressed with a statistical evaluation of the field studies carried out in the course of the research project. The use of heating cost distributors is examined by simulation calculations and assessed on this basis. (HW) [Deutsch] Die Themenschwerpunkte des 2. Teils des Forschungsberichtes sind die Energiediagnose und die Heizkostenverteilung in Einrohranlagen. Bezueglich der Energiediagnose werden Ziel und Methoden beschrieben. Zur Thematik Heizkostenverteilung werden die durchgefuehrten Feldversuche statistisch ausgewertet. Der Einsatz der Heizkostenverteilsysteme wird durch Simulationsrechnungen untersucht und beurteilt. (HW)

  2. Experimental study of humidity distribution inside electronic enclosure and effect of internal heating

    DEFF Research Database (Denmark)

    Conseil, Helene; Jellesen, Morten Stendahl; Ambat, Rajan

    2016-01-01

    on the humidity and temperature profile inside typical electronic enclosures. Defined parameters include external temperature and humidity conditions, temperature and time of the internal heat cycle, thermal mass, and ports/openings size. The effect of the internal humidity on electronic reliability has been......Corrosion reliability of electronic products is a key factor for electronics industry, and today there is a large demand for performance reliability in a wide range of temperature and humidity during day and night time periods. Corrosion failures are still a challenge due to the combined effects...... of temperature, humidity and corrosion accelerating species in the atmosphere. Moreover the surface region of printed circuit board assemblies is often contaminated by various aggressive chemical species.This study describes the overall effect of the exposure to severe climate conditions and internal heat cycles...

  3. Surface Heat Flux and Pressure Distribution on a Hypersonic Blunt Body With DEAS

    Science.gov (United States)

    Salvador, I. I.; Minucci, M. A. S.; Toro, P. G. P.; Oliveira, A. C.; Channes, J. B.

    2008-04-01

    With the currently growing interest for advanced technologies to enable hypersonic flight comes the Direct Energy Air Spike concept, where pulsed beamed laser energy is focused upstream of a blunt flight vehicle to disrupt the flow structure creating a virtual, slender body geometry. This allies in the vehicle both advantages of a blunt body (lower thermal stresses) to that of a slender geometry (lower wave drag). The research conducted at the Henry T. Nagamatsu Laboratory for Aerodynamics and Hypersonics focused on the measurement of the surface pressure and heat transfer rates on a blunt model. The hypersonic flight conditions were simulated at the HTN Laboratory's 0.3 m T2 Hypersonic Shock Tunnel. During the tests, the laser energy was focused upstream the model by an infrared telescope to create the DEAS effect, which was supplied by a TEA CO2 laser. Piezoelectric pressure transducers were used for the pressure measurements and fast response coaxial thermocouples were used for the measurement of surface temperature, which was later used for the estimation of the wall heat transfer using the inverse heat conduction theory.

  4. Dynamic analysis and structural design of underground nuclear reactor containments

    International Nuclear Information System (INIS)

    Kierans, T.W.; Reddy, D.V.

    1975-01-01

    All concept options are assumed to be similar in design criteria for structural competence to contain radioactivity and fuel heat and meet the functional, servicing, protective and aesthetic requirements. The choice of underground siting should be based on criteria developed from the sequential consideration of load-causing phenomena, concept and site characteristics. From the criteria, loads for a particular concept and site are calculated and the design formulated. (orig./ORU) [de

  5. Spatial distribution of {gamma} emissivity and fast ions during ({sup 3}He)D ICRF heating experiments on JET

    Energy Technology Data Exchange (ETDEWEB)

    Start, D F.H. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Righi, E [Imperial Coll. of Science and Technology, London (United Kingdom); Warrick, C [UKAEA Culham Lab., Abingdon (United Kingdom)

    1994-07-01

    A model is presented that can simulate the {gamma} emissivity in the poloidal cross-section during ({sup 3}He)D ICRF heated discharges in JET plasmas, by merging information obtained from the fast ion distribution and from nuclear reactions producing the observed {gamma} emissivity (production of {gamma} photons during {sup 3}He-{sup 9}Be reactions). This technique can play an important role in the identification of plasma instabilities that affect the redistribution of the fast ions in the plasma, like the TAE modes and the ripple in the tokamak magnetic field. 9 refs., 4 figs., 1 tab.

  6. Isotope distributions in primary heat transport and containment systems during a severe accident in CANDU type reactor

    International Nuclear Information System (INIS)

    Constantin, M.

    2005-01-01

    The paper is intended to analyse the distribution of the fission products (FPs) in CANDU Primary Heat Transport (PHT) and CANDU Containment Systems by using the ASTEC code. The complexity of the data required by ASTEC and the complexity both of CANDU PHT and Containment System were strong motivation to begin with a simplified model. The data related to the nodes' definitions, temperatures and pressure conditions were chosen as possible as real data from CANDU loss of coolant accident sequence (CATHENA code results). The source term of FPs introduced into the PHT was estimated by ORIGEN code. The FPs distribution in the nodes of the circuit and the FPs mass transfer per isotope and chemical species were obtained by using SOPHAEROS module. The distributions within the containment are obtained by the CPA module (thermalhydraulic calculations in the containment and FPs aerosol transport). The results consist of mass distributions in the nodes of the circuit and the transferred mass to the containment through the break for different species (FPs and chemical species) and mass distributions in the different parts of the containment and different hosts. (authors)

  7. Slavery and the Underground Railroad.

    Science.gov (United States)

    Anderson, Nancy Comfort

    2000-01-01

    Presents a bibliography of sources to help children understand slavery and the Underground Railroad and recommends a combination of fiction and nonfiction for a better understanding. Includes picture books, biographies of people who played prominent roles during the time of slavery, nonfiction books for older readers, and videotape. (LRW)

  8. Uranium extraction from underground deposits

    International Nuclear Information System (INIS)

    Wolfe, C.R.

    1982-01-01

    Uranium is extracted from underground deposits by passing an aqueous oxidizing solution of carbon dioxide over the ore in the presence of calcium ions. Complex uranium carbonate or bicarbonate ions are formed which enter the solution. The solution is forced to the surface and the uranium removed from it

  9. Earthquake damage to underground facilities

    International Nuclear Information System (INIS)

    Pratt, H.R.; Stephenson, D.E.; Zandt, G.; Bouchon, M.; Hustrulid, W.A.

    1980-01-01

    In order to assess the seismic risk for an underground facility, a data base was established and analyzed to evaluate the potential for seismic disturbance. Substantial damage to underground facilities is usually the result of displacements primarily along pre-existing faults and fractures, or at the surface entrance to these facilities. Evidence of this comes from both earthquakes and large explosions. Therefore, the displacement due to earthquakes as a function of depth is important in the evaluation of the hazard to underground facilities. To evaluate potential displacements due to seismic effects of block motions along pre-existing or induced fractures, the displacement fields surrounding two types of faults were investigated. Analytical models were used to determine relative displacements of shafts and near-surface displacement of large rock masses. Numerical methods were used to determine the displacement fields associated with pure strike-slip and vertical normal faults. Results are presented as displacements for various fault lengths as a function of depth and distance. This provides input to determine potential displacements in terms of depth and distance for underground facilities, important for assessing potential sites and design parameters

  10. High Temperature Superconducting Underground Cable

    International Nuclear Information System (INIS)

    Farrell, Roger A.

    2010-01-01

    The purpose of this Project was to design, build, install and demonstrate the technical feasibility of an underground high temperature superconducting (HTS) power cable installed between two utility substations. In the first phase two HTS cables, 320 m and 30 m in length, were constructed using 1st generation BSCCO wire. The two 34.5 kV, 800 Arms, 48 MVA sections were connected together using a superconducting joint in an underground vault. In the second phase the 30 m BSCCO cable was replaced by one constructed with 2nd generation YBCO wire. 2nd generation wire is needed for commercialization because of inherent cost and performance benefits. Primary objectives of the Project were to build and operate an HTS cable system which demonstrates significant progress towards commercial progress and addresses real world utility concerns such as installation, maintenance, reliability and compatibility with the existing grid. Four key technical areas addressed were the HTS cable and terminations (where the cable connects to the grid), cryogenic refrigeration system, underground cable-to-cable joint (needed for replacement of cable sections) and cost-effective 2nd generation HTS wire. This was the worlds first installation and operation of an HTS cable underground, between two utility substations as well as the first to demonstrate a cable-to-cable joint, remote monitoring system and 2nd generation HTS.

  11. ANALYSIS OF HYGROTHERMAL CONDITIONS OF EXTERNAL PARTITIONS IN AN UNDERGROUND FRUIT STORE

    Directory of Open Access Journals (Sweden)

    Grzegorz Nawalany

    2016-09-01

    Full Text Available The paper presents the analysis of hygrothermal conditions of external partitions in an underground fruit store. The results of measurements of temperature and humidity of the indoor and outdoor air as well as the surface surrounding temperature and the temperature of the air surrounding the store constituted the boundary conditions for the hygrothermal calculations. The paper presents the calculation of the distribution of the temperature and humidity on the ground floor, the wall contacting the ground, the wall contacting the outside air, and the ceiling above the storage chamber. The heat and moisture calculations have shown high risk of condensation submerged in non-insulated external walls. The condition of the adaptation of a traditional cold store to a simple and atmosphere controlled cold one is to increase the thermal resistance of the partitions. Such a solution will let cut the energy demand in those types of agricultural buildings.

  12. The underground storage tank is the key; Der Speicher ist der Schluessel

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Jens-Peter

    2013-08-06

    Plus energy houses also succeed withoutpassive house insulation. Because the combination of solar collectors, ventilation and heat pump achieves excellent energy efficiency, if one preserves the solar heat in an underground storage tank. [German] Plusenergiehaeuser gelingen auch ohne Passivhausdaemmung. Denn die Kombination von Sonnenkollektoren, Lueftung und Waermepumpe erreicht eine ausgezeichnete energetische Effizienz, sofern man die Solarwaerme in einem Erdspeicher konserviert.

  13. Temperature distribution in Risø Flexhouse Room 3 with different heating control principles

    DEFF Research Database (Denmark)

    Simone, Angela; Rode, Carsten

    2009-01-01

    This report presents the measurements of local thermal conditions in one room (“Room 3”) of the so-called “Flexouse” located at Risø DTU. The house is part of Risø DTU’s SYSLAB facility used to study the interaction of different facilities that supply and use energy. The facility has been used in...... to predict the overall dynamic thermal properties of the building. The project is part of a wider complex of projects on predicting the electricity and heating energy consumption in dwellings....

  14. Temperature distribution of a hot water storage tank in a simulated solar heating and cooling system

    Science.gov (United States)

    Namkoong, D.

    1976-01-01

    A 2,300-liter hot water storage tank was studied under conditions simulating a solar heating and cooling system. The initial condition of the tank, ranging from 37 C at the bottom to 94 C at the top, represented a condition midway through the start-up period of the system. During the five-day test period, the water in the tank gradually rose in temperature but in a manner that diminished its temperature stratification. Stratification was found not to be an important factor in the operation of the particular solar system studied.

  15. Global distribution of moisture, evaporation-precipitation, and diabatic heating rates

    Science.gov (United States)

    Christy, John R.

    1989-01-01

    Global archives were established for ECMWF 12-hour, multilevel analysis beginning 1 January 1985; day and night IR temperatures, and solar incoming and solar absorbed. Routines were written to access these data conveniently from NASA/MSFC MASSTOR facility for diagnostic analysis. Calculations of diabatic heating rates were performed from the ECMWF data using 4-day intervals. Calculations of precipitable water (W) from 1 May 1985 were carried out using the ECMWF data. Because a major operational change on 1 May 1985 had a significant impact on the moisture field, values prior to that date are incompatible with subsequent analyses.

  16. Precipitation and Latent Heating Distributions from Satellite Passive Microwave Radiometry. Part 1; Improved Method and Uncertainties

    Science.gov (United States)

    Olson, William S.; Kummerow, Christian D.; Yang, Song; Petty, Grant W.; Tao, Wei-Kuo; Bell, Thomas L.; Braun, Scott A.; Wang, Yansen; Lang, Stephen E.; Johnson, Daniel E.; hide

    2006-01-01

    A revised Bayesian algorithm for estimating surface rain rate, convective rain proportion, and latent heating profiles from satellite-borne passive microwave radiometer observations over ocean backgrounds is described. The algorithm searches a large database of cloud-radiative model simulations to find cloud profiles that are radiatively consistent with a given set of microwave radiance measurements. The properties of these radiatively consistent profiles are then composited to obtain best estimates of the observed properties. The revised algorithm is supported by an expanded and more physically consistent database of cloud-radiative model simulations. The algorithm also features a better quantification of the convective and nonconvective contributions to total rainfall, a new geographic database, and an improved representation of background radiances in rain-free regions. Bias and random error estimates are derived from applications of the algorithm to synthetic radiance data, based upon a subset of cloud-resolving model simulations, and from the Bayesian formulation itself. Synthetic rain-rate and latent heating estimates exhibit a trend of high (low) bias for low (high) retrieved values. The Bayesian estimates of random error are propagated to represent errors at coarser time and space resolutions, based upon applications of the algorithm to TRMM Microwave Imager (TMI) data. Errors in TMI instantaneous rain-rate estimates at 0.5 -resolution range from approximately 50% at 1 mm/h to 20% at 14 mm/h. Errors in collocated spaceborne radar rain-rate estimates are roughly 50%-80% of the TMI errors at this resolution. The estimated algorithm random error in TMI rain rates at monthly, 2.5deg resolution is relatively small (less than 6% at 5 mm day.1) in comparison with the random error resulting from infrequent satellite temporal sampling (8%-35% at the same rain rate). Percentage errors resulting from sampling decrease with increasing rain rate, and sampling errors in

  17. All fiber cladding mode stripper with uniform heat distribution and high cladding light loss manufactured by CO2 laser ablation

    Science.gov (United States)

    Jebali, M. A.; Basso, E. T.

    2018-02-01

    Cladding mode strippers are primarily used at the end of a fiber laser cavity to remove high-power excess cladding light without inducing core loss and beam quality degradation. Conventional manufacturing methods of cladding mode strippers include acid etching, abrasive blasting or laser ablation. Manufacturing of cladding mode strippers using laser ablation consist of removing parts of the cladding by fused silica ablation with a controlled penetration and shape. We present and characterize an optimized cladding mode stripper design that increases the cladding light loss with a minimal device length and manufacturing time. This design reduces the localized heat generation by improving the heat distribution along the device. We demonstrate a cladding mode stripper written on a 400um fiber with cladding light loss of 20dB, with less than 0.02dB loss in the core and minimal heating of the fiber and coating. The manufacturing process of the designed component is fully automated and takes less than 3 minutes with a very high throughput yield.

  18. DBP formation in hot and cold water across a simulated distribution system: effect of incubation time, heating time, pH, chlorine dose, and incubation temperature.

    Science.gov (United States)

    Liu, Boning; Reckhow, David A

    2013-10-15

    This paper demonstrates that disinfection byproducts (DBP) concentration profiles in heated water were quite different from the DBP concentrations in the cold tap water. Chloroform concentrations in the heated water remained constant or even decreased slightly with increasing distribution system water age. The amount of dichloroacetic acid (DCAA) was much higher in the heated water than in the cold water; however, the maximum levels in heated water with different distribution system water ages did not differ substantially. The levels of trichloroacetic acid (TCAA) in the heated water were similar to the TCAA levels in the tap water, and a slight reduction was observed after the tap water was heated for 24 h. Regardless of water age, significant reductions of nonregulated DBPs were observed after the tap water was heated for 24 h. For tap water with lower water ages, there were significant increases in dichloroacetonitrile (DCAN), chloropicrin (CP), and 1,1-dichloropropane (1,1-DCP) after a short period of heating. Heating of the tap water with low pH led to a more significant increase of chloroform and a more significant short-term increase of DCAN. High pH accelerated the loss of the nonregulated DBPs in the heated water. The results indicated that as the chlorine doses increased, levels of chloroform and DCAA in the heated water increased significantly. However, for TCAA, the thermally induced increase in concentration was only notable for the chlorinated water with very high chlorine dose. Finally, heating may lead to higher DBP concentrations in chlorinated water with lower distribution system temperatures.

  19. Heat transfer models for predicting Salmonella enteritidis in shell eggs through supply chain distribution.

    Science.gov (United States)

    Almonacid, S; Simpson, R; Teixeira, A

    2007-11-01

    Egg and egg preparations are important vehicles for Salmonella enteritidis infections. The influence of time-temperature becomes important when the presence of this organism is found in commercial shell eggs. A computer-aided mathematical model was validated to estimate surface and interior temperature of shell eggs under variable ambient and refrigerated storage temperature. A risk assessment of S. enteritidis based on the use of this model, coupled with S. enteritidis kinetics, has already been reported in a companion paper published earlier in JFS. The model considered the actual geometry and composition of shell eggs and was solved by numerical techniques (finite differences and finite elements). Parameters of interest such as local (h) and global (U) heat transfer coefficient, thermal conductivity, and apparent volumetric specific heat were estimated by an inverse procedure from experimental temperature measurement. In order to assess the error in predicting microbial population growth, theoretical and experimental temperatures were applied to a S. enteritidis growth model taken from the literature. Errors between values of microbial population growth calculated from model predicted compared with experimentally measured temperatures were satisfactorily low: 1.1% and 0.8% for the finite difference and finite element model, respectively.

  20. Study of the distribution of alloying elements between the phases of a heat treated steel

    International Nuclear Information System (INIS)

    Lambert, N.; Greday, T.

    1977-01-01

    The behavior of some low-alloy steels during industrial heat treatments is systematically studied. Firstly, the influence of the chemical analysis of the steel, the shape and size of carbides on the kinetics of the dissolution of these carbides at high temperature is pointed out in the case of steels with a relatively simple chemical analysis. Secondly, the effect of tempering treatments on the mechanical properties and characteristic parameters of the microstructure is studied in the case of three low-alloy steels. Bainitic microstructure appears to be the less disturbed one after a tempering treatment. Against, martensitic microstructures undergo an important softening and the mechanical properties of the pearlite lie as a very low level whatever their heat treatment. Peculiar conditions of tempering promotes a fine precipitation and its combined secondary hardening. These conditions are related to both chemical analysis and initial microstructure of the steel. Besides, some chemical identifications were performed in the scanning electron microscope on alloyed carbides precipitated in the steel during very long time tempering treatments

  1. Life cycle analysis of distributed concentrating solar combined heat and power: economics, global warming potential and water

    Science.gov (United States)

    Norwood, Zack; Kammen, Daniel

    2012-12-01

    We report on life cycle assessment (LCA) of the economics, global warming potential and water (both for desalination and water use in operation) for a distributed concentrating solar combined heat and power (DCS-CHP) system. Detailed simulation of system performance across 1020 sites in the US combined with a sensible cost allocation scheme informs this LCA. We forecast a levelized cost of 0.25 kWh-1 electricity and 0.03 kWh-1 thermal, for a system with a life cycle global warming potential of ˜80 gCO2eq kWh-1 of electricity and ˜10 gCO2eq kWh-1 thermal, sited in Oakland, California. On the basis of the economics shown for air cooling, and the fact that any combined heat and power system reduces the need for cooling while at the same time boosting the overall solar efficiency of the system, DCS-CHP compares favorably to other electric power generation systems in terms of minimization of water use in the maintenance and operation of the plant. The outlook for water desalination coupled with distributed concentrating solar combined heat and power is less favorable. At a projected cost of 1.40 m-3, water desalination with DCS-CHP would be economical and practical only in areas where water is very scarce or moderately expensive, primarily available through the informal sector, and where contaminated or salt water is easily available as feed-water. It is also interesting to note that 0.40-1.90 m-3 is the range of water prices in the developed world, so DCS-CHP desalination systems could also be an economical solution there under some conditions.

  2. Life cycle analysis of distributed concentrating solar combined heat and power: economics, global warming potential and water

    International Nuclear Information System (INIS)

    Norwood, Zack; Kammen, Daniel

    2012-01-01

    We report on life cycle assessment (LCA) of the economics, global warming potential and water (both for desalination and water use in operation) for a distributed concentrating solar combined heat and power (DCS-CHP) system. Detailed simulation of system performance across 1020 sites in the US combined with a sensible cost allocation scheme informs this LCA. We forecast a levelized cost of $0.25 kWh −1 electricity and $0.03 kWh −1 thermal, for a system with a life cycle global warming potential of ∼80 gCO 2 eq kWh −1 of electricity and ∼10 gCO 2 eq kWh −1 thermal, sited in Oakland, California. On the basis of the economics shown for air cooling, and the fact that any combined heat and power system reduces the need for cooling while at the same time boosting the overall solar efficiency of the system, DCS-CHP compares favorably to other electric power generation systems in terms of minimization of water use in the maintenance and operation of the plant. The outlook for water desalination coupled with distributed concentrating solar combined heat and power is less favorable. At a projected cost of $1.40 m −3 , water desalination with DCS-CHP would be economical and practical only in areas where water is very scarce or moderately expensive, primarily available through the informal sector, and where contaminated or salt water is easily available as feed-water. It is also interesting to note that $0.40–$1.90 m −3 is the range of water prices in the developed world, so DCS-CHP desalination systems could also be an economical solution there under some conditions. (letter)

  3. Real-time appraisal of the spatially distributed heat related health risk and energy demand of cities

    Science.gov (United States)

    Keramitsoglou, Iphigenia; Kiranoudis, Chris T.; Sismanidis, Panagiotis

    2016-08-01

    The Urban Heat Island (UHI) is an adverse environmental effect of urbanization that increases the energy demand of cities, impacts the human health, and intensifies and prolongs heatwave events. To facilitate the study of UHIs the Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing of the National Observatory of Athens (IAASARS/NOA) has developed an operational real-time system that exploits remote sensing image data from Meteosat Second Generation - Spinning Enhanced Visible and Infrared Imager (MSG-SEVIRI) and generates high spatiotemporal land surface temperature (LST) and 2 m air temperature (TA) time series. These datasets form the basis for the generation of higher value products and services related to energy demand and heat-related health issues. These products are the heatwave hazard (HZ); the HUMIDEX (i.e. an index that describes the temperature felt by an individual exposed to heat and humidity); and the cooling degrees (CD; i.e. a measure that reflects the energy needed to cool a building). The spatiotemporal characteristics of HZ, HUMIDEX and CD are unique (1 km/5 min) and enable the appraisal of the spatially distributed heat related health risk and energy demand of cities. In this paper, the real time generation of the high spatiotemporal HZ, HUMIDEX and CD products is discussed. In addition, a case study corresponding to Athens' September 2015 heatwave is presented so as to demonstrate their capabilities. The overall aim of the system is to provide high quality data to several different end users, such as health responders, and energy suppliers. The urban thermal monitoring web service is available at http://snf-652558.vm.okeanos.grnet.gr/treasure/portal/info.html.

  4. Output feedback control of heat transport mechanisms in parabolic distributed solar collectors

    KAUST Repository

    Elmetennani, Shahrazed; Kirati, Taous Meriem Laleg

    2016-01-01

    . The proposed control strategy is derived using the distributed physical model of the system to avoid the loss of information due to model approximation schemes. The system dynamics are driven to follow reference dynamics defined by a transport equation with a

  5. Modeling and simulation of heat distribution in human skin caused by laser irradiation

    NARCIS (Netherlands)

    Luan, Y.; Dams, S.D.

    2009-01-01

    Study of light-based skin rejuvenation needs prospective insights of mechanism of laser tissue interaction. A well-built model plays a key role in predicting temperature distribution in human skin exposed to laser irradiation. Therefore, it not only provides guidance for in vitro experiment, but

  6. High temperature underground thermal energy storage system for solar energy

    Science.gov (United States)

    Collins, R. E.

    1980-01-01

    The activities feasibility of high temperature underground thermal storage of energy was investigated. Results indicate that salt cavern storage of hot oil is both technically and economically feasible as a method of storing huge quantities of heat at relatively low cost. One particular system identified utilizes a gravel filled cavern leached within a salt dome. Thermal losses are shown to be less than one percent of cyclically transferred heat. A system like this having a 40 MW sub t transfer rate capability and over eight hours of storage capacity is shown to cost about $13.50 per KWh sub t.

  7. Evolution of the nuclide distribution and heat partition along the dissipation path in heavy ion collisions

    International Nuclear Information System (INIS)

    Planeta, R.

    1990-04-01

    We discuss several problems of nuclear physics with heavy ions. Special attention is paid to close collisions, where impact parameters are considerably smaller than the corresponding grazing values. Such collisions can lead to a formation of a compound nucleus (fusion) or to two body exit channels with a sizable loss of kinetic energy and large transfer of mass and charge between interacting nuclei (damped collisions). A short survey of experimental works done with my participation and devoted to fusion reactions is presented. This is followed by presentation of new experimental results in the field of damped collisions. The data demonstrate that the N/Z equilibration and temperature equilibration are not rapid processes. A distinct correlation between the net nucleon transfer and the heating of the acceptor nucleus is observed. Experimental data are compared with the transport model. Disagreement between model and experiment is discussed. 113 refs. (author)

  8. Modelling and dynamics analysis of heat exchanger as a distributed parameter process

    International Nuclear Information System (INIS)

    Savic, B.; Debeljkovic, D.Lj.

    2004-01-01

    A non-linear and afterwards linearized mathematical model of fuel oil cooling chamber has been developed. This chamber is a part of a recuperative heat exchanger of a tube-in-tube type and of opposite-direction acting, set in a heavy oil fraction discharge tubing. The model is defined as a range of assumptions and simplifications from which energy balance equations under non-stationary operating conditions are derived. The model is in the form of a set of partial differential equations with constant coefficients. Using appropriate numerical simulation of the transfer function, the dynamic of this process has been shown in the form of appropriate transient process responses which quite well correspond to the real process behavior

  9. Nonlinear Lyapunov-based boundary control of distributed heat transfer mechanisms in membrane distillation plant

    KAUST Repository

    Eleiwi, Fadi

    2015-07-01

    This paper presents a nonlinear Lyapunov-based boundary control for the temperature difference of a membrane distillation boundary layers. The heat transfer mechanisms inside the process are modeled with a 2D advection-diffusion equation. The model is semi-descretized in space, and a nonlinear state-space representation is provided. The control is designed to force the temperature difference along the membrane sides to track a desired reference asymptotically, and hence a desired flux would be generated. Certain constraints are put on the control law inputs to be within an economic range of energy supplies. The effect of the controller gain is discussed. Simulations with real process parameters for the model, and the controller are provided. © 2015 American Automatic Control Council.

  10. Modelling and dynamics analysis of heat exchanger as a distributed parameter process

    Energy Technology Data Exchange (ETDEWEB)

    Savic, B.; Debeljkovic, D.Lj. [University of Belgrade, Department of Control Engineering, Belgrade (Yugoslavia)

    2004-07-01

    A non-linear and afterwards linearized mathematical model of fuel oil cooling chamber has been developed. This chamber is a part of a recuperative heat exchanger of a tube-in-tube type and of opposite-direction acting, set in a heavy oil fraction discharge tubing. The model is defined as a range of assumptions and simplifications from which energy balance equations under non-stationary operating conditions are derived. The model is in the form of a set of partial differential equations with constant coefficients. Using appropriate numerical simulation of the transfer function, the dynamic of this process has been shown in the form of appropriate transient process responses which quite well correspond to the real process behavior.

  11. A Corrosion Risk Assessment Model for Underground Piping

    Science.gov (United States)

    Datta, Koushik; Fraser, Douglas R.

    2009-01-01

    The Pressure Systems Manager at NASA Ames Research Center (ARC) has embarked on a project to collect data and develop risk assessment models to support risk-informed decision making regarding future inspections of underground pipes at ARC. This paper shows progress in one area of this project - a corrosion risk assessment model for the underground high-pressure air distribution piping system at ARC. It consists of a Corrosion Model of pipe-segments, a Pipe Wrap Protection Model; and a Pipe Stress Model for a pipe segment. A Monte Carlo simulation of the combined models provides a distribution of the failure probabilities. Sensitivity study results show that the model uncertainty, or lack of knowledge, is the dominant contributor to the calculated unreliability of the underground piping system. As a result, the Pressure Systems Manager may consider investing resources specifically focused on reducing these uncertainties. Future work includes completing the data collection effort for the existing ground based pressure systems and applying the risk models to risk-based inspection strategies of the underground pipes at ARC.

  12. Angular distributions of atomic vapor stream produced by electron beam heating

    Energy Technology Data Exchange (ETDEWEB)

    Ohba, Hironori; Amekawa, Kazuhiro; Shibata, Takemasa [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-03-01

    The angular distributions were measured as a function of deposition rate for aluminium, copper, gadolinium and cerium vapor stream produced by an electron beam gun with water-cooled copper crucible. The distributions were recorded on the mounted on a semicircular (120mm in radius) mask over the evaporation source. The measured distributions were able to be described by a simple cosine law, that is cos{sup n} {theta}, except for the case of extremely high evaporation rate with a porous material, where n is a rate-dependent beaming exponent, {theta} is the angle from the vertical. For many kinds of evaporants, it was confirmed that the beaming exponents increase continuously from unity to 3 or 4 with increasing deposition rate and are approximately proportional to R{sup 0.25} where R is the deposition rate. Moreover, it was found that the beaming exponents n are able to be expressed as n = {alpha} Kn{sub 0}{sup -0.25}, where Kn{sub 0}{sup -1} is the inverse of Knudsen number, which is defined by the mean free path of evaporated atoms and the evaporation spot size, and {alpha} is the constant. (author)

  13. Angular distributions of atomic vapor stream produced by electron beam heating

    International Nuclear Information System (INIS)

    Ohba, Hironori; Amekawa, Kazuhiro; Shibata, Takemasa

    1997-03-01

    The angular distributions were measured as a function of deposition rate for aluminium, copper, gadolinium and cerium vapor stream produced by an electron beam gun with water-cooled copper crucible. The distributions were recorded on the mounted on a semicircular (120mm in radius) mask over the evaporation source. The measured distributions were able to be described by a simple cosine law, that is cos n θ, except for the case of extremely high evaporation rate with a porous material, where n is a rate-dependent beaming exponent, θ is the angle from the vertical. For many kinds of evaporants, it was confirmed that the beaming exponents increase continuously from unity to 3 or 4 with increasing deposition rate and are approximately proportional to R 0.25 where R is the deposition rate. Moreover, it was found that the beaming exponents n are able to be expressed as n = α Kn 0 -0.25 , where Kn 0 -1 is the inverse of Knudsen number, which is defined by the mean free path of evaporated atoms and the evaporation spot size, and α is the constant. (author)

  14. 40 CFR 280.220 - Ownership of an underground storage tank or underground storage tank system or facility or...

    Science.gov (United States)

    2010-07-01

    ... tank or underground storage tank system or facility or property on which an underground storage tank or underground storage tank system is located. 280.220 Section 280.220 Protection of Environment ENVIRONMENTAL... underground storage tank or underground storage tank system or facility or property on which an underground...

  15. Underground spaces/cybernetic spaces

    Directory of Open Access Journals (Sweden)

    Tomaž Novljan

    2000-01-01

    Full Text Available A modern city space is a space where in the vertical and horizontal direction dynamic, non-linear processes exist, similar as in nature. Alongside the “common” city surface, cities have underground spaces as well that are increasingly affecting the functioning of the former. It is the space of material and cybernetic communication/transport. The psychophysical specifics of using underground places have an important role in their conceptualisation. The most evident facts being their limited volume and often limited connections to the surface and increased level of potential dangers of all kinds. An efficient mode for alleviating the effects of these specific features are artistic interventions, such as: shape, colour, lighting, all applications of the basic principles of fractal theory.

  16. Study of underground radon transport

    International Nuclear Information System (INIS)

    Csige, I.; Hakl, J.; Lenart, L.

    1990-01-01

    The soil gas radon content measurements with solid state nuclear track detectors (SSNTDs) are widely used in geoscience, for instance in uranium exploration and earthquake prediction. In these applications the radon frequently is used as a natural tracer of underground fluid transport processes. Obviously, to get the soil radon measuring method more and more effective the study of these transport processes in deeper part of the Earth is fundamental. The Track Detector Group in the Institute of Nuclear Research of the Hungarian Academy of Sciences in Debrecen has been performing environmental radon activity concentration measurements since 1977 with alpha sensitive SSNTDs. These types of measurements were initiated and widely used by the late head of the group Dr. G. Somogyi, who devoted his life to better understanding of the nature. The measurements in caves, springs and drilled wells proved to be effective to study these underground radon transport processes. We are glad to present some results of our investigations. 7 refs, 7 figs

  17. International activities concerning seismic effects on underground structures

    International Nuclear Information System (INIS)

    Hakala, W.W.

    1982-01-01

    At the 5th Annual Meeting of the ITA in Atlanta, Georgia, on June 15-17, 1979, the General Assembly approved the formation of the Working Group Seismic Effects on Underground Structures. The objectives of this Working Group are to: (1) collect data on earthquake damage to underground facilities throughout the world; (2) collect information on aseismic design procedures used within the various countries; and (3) synthesize the information and disseminate the results to the member nations of ITA. William W. Hakala of the US was designated the Animateur of the Working Group. The Working Group decided on the following sequential course of action to achieve the stated objectives: (1) continue to develop a bibliograhy on damages to underground structures by dynamic forces. This will be an ongoing activity of the Working Group; (2) each country is to develop a summary of case histories of earthquake damage to underground structures. These case histories will be discussed at the next meeting of the Working Group in order to identify those parameters that permit or prevent such damage; (3) the state-of-the-art paper on earthquake damage to underground opening being prepared in the US (John A. Blume and Associates, Engineers) is presently being printed and will then be distributed to the membership for comment. This report will form the basis for the activities described below; (4) the above activities should lead to a textbook - like document that provides a design philosophy for underground structures subjected to seismic forces; (5) the work tasks will suggest needed research to solve the identified problems. At each Working Group meeting the member nation delegates will provide a summary of research progress in their countries. These research needs will be documented, reviewed, revised, and disseminated on an annual basis

  18. Office building with an underground storage system. Operational experiences after one year; Buerogebaeude mit Erdspeicher. Betriebserfahrungen nach einem Jahr

    Energy Technology Data Exchange (ETDEWEB)

    Braun, Dorothee; Wehrli, Stefan [Basler und Hofmann AG, Zuerich (Switzerland)

    2011-07-01

    Self-sufficient heating and cooling - that was the principle of Basler paragraph Hofmann AG (Zuerich, Switzerland) and Stuecheli Architects (Zuerich, Switzerland) in the planning and constructing of a new office building in the Canton of Zuerich. For the first time an underground storage system was implemented in a commercial building. This underground storage refuels the solar energy in summer and supplies heating energy in winter. The office building was settled in in September, 2010. The pioneering project now delivers first empirical values with the underground storage system. These empirical values show: The concept comes up, but needs time.

  19. The Underground Economy in Romania

    Directory of Open Access Journals (Sweden)

    Cleopatra Sendroiu

    2006-07-01

    Full Text Available Underground economic activities exist in most countries around the world, and they usually have the same causes: inadequate tax systems, excessive state interference in the economy and the lack of coordination in establishing economic policies. Through this paper, we aim to offer certain recommendations, which, in our opinion, would lead to solving the issue of inadequate allocation of resources and would also contribute to restoration of the worldwide economy.

  20. The stress and underground environment

    Science.gov (United States)

    Chama, A.

    2009-04-01

    Currently,the program of prevention in occupational health needs mainly to identify occupational hazards and strategy of their prevention.Among these risks,the stress represents an important psycho-social hazard in mental health,which unfortunately does not spare no occupation.My Paper attempts to highlight and to develop this hazard in its different aspects even its regulatory side in underground environment as occupational environment.In the interest of better prevention ,we consider "the information" about the impact of stress as the second prevention efficient and no expensive to speleologists,hygienists and workers in the underground areas. In this occasion of this event in Vienna,we also highlight the scientific works on the stress of the famous viennese physician and endocrinologist Doctor Hans Selye (1907-1982),nicknamed "the father of stress" and note on relation between biological rhythms in this underground area and psychological troubles (temporal isolation) (Jurgen Aschoff’s works and experiences out-of time).

  1. First ATLAS Events Recorded Underground

    CERN Multimedia

    Teuscher, R

    As reported in the CERN Bulletin, Issue No.30-31, 25 July 2005 The ATLAS barrel Tile calorimeter has recorded its first events underground using a cosmic ray trigger, as part of the detector commissioning programme. This is not a simulation! A cosmic ray muon recorded by the barrel Tile calorimeter of ATLAS on 21 June 2005 at 18:30. The calorimeter has three layers and a pointing geometry. The light trapezoids represent the energy deposited in the tiles of the calorimeter depicted as a thick disk. On the evening of June 21, the ATLAS detector, now being installed in the underground experimental hall UX15, reached an important psychological milestone: the barrel Tile calorimeter recorded the first cosmic ray events in the underground cavern. An estimated million cosmic muons enter the ATLAS cavern every 3 minutes, and the ATLAS team decided to make good use of some of them for the commissioning of the detector. Although only 8 of the 128 calorimeter slices ('superdrawers') were included in the trigg...

  2. Radionuclides in an underground environment

    International Nuclear Information System (INIS)

    Thompson, J.L.

    1996-01-01

    In the 100 years since Becquerel recognized radioactivity, mankind has been very successful in producing large amounts of radioactive materials. We have been less successful in reaching a consensus on how to dispose of the billions of curies of fission products and transuranics resulting from nuclear weapons testing, electrical power generation, medical research, and a variety of other human endeavors. Many countries, including the United States, favor underground burial as a means of disposing of radioactive wastes. There are, however, serious questions about how such buried wastes may behave in the underground environment and particularly how they might eventually contaminate water, air and soil resources on which we are dependent. This paper describes research done in the United States in the state of Nevada on the behavior of radioactive materials placed underground. During the last thirty years, a series of ''experiments'' conducted for other purposes (testing of nuclear weapons) have resulted in a wide variety of fission products and actinides being injected in rock strata both above and below the water table. Variables which seem to control the movement of these radionuclides include the physical form (occlusion versus surface deposition), the chemical oxidation state, sorption by mineral phases of the host rock, and the hydrologic properties of the medium. The information gained from these studies should be relevant to planning for remediation of nuclear facilities elsewhere in the world and for long-term storage of nuclear wastes

  3. Underground storage of carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Shoichi [Univ. of Tokyo, Hongo, Bunkyo-ku (Japan)

    1993-12-31

    Desk studies on underground storage of CO{sub 2} were carried out from 1990 to 1991 fiscal years by two organizations under contract with New Energy and Indestrial Technology Development Organization (NEDO). One group put emphasis on application of CO{sub 2} EOR (enhanced oil recovery), and the other covered various aspects of underground storage system. CO{sub 2} EOR is a popular EOR method in U.S. and some oil countries. At present, CO{sub 2} is supplied from natural CO{sub 2} reservoirs. Possible use of CO{sub 2} derived from fixed sources of industries is a main target of the study in order to increase oil recovery and storage CO{sub 2} under ground. The feasibility study of the total system estimates capacity of storage of CO{sub 2} as around 60 Gton CO{sub 2}, if worldwide application are realized. There exist huge volumes of underground aquifers which are not utilized usually because of high salinity. The deep aquifers can contain large amount of CO{sub 2} in form of compressed state, liquefied state or solution to aquifer. A preliminary technical and economical survey on the system suggests favorable results of 320 Gton CO{sub 2} potential. Technical problems are discussed through these studies, and economical aspects are also evaluated.

  4. Underground disposal of radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1979-08-15

    Disposal of low- and intermediate-level radioactive wastes by shallow land burial, emplacement in suitable abandoned mines, or by deep well injection and hydraulic fracturing has been practised in various countries for many years. In recent years considerable efforts have been devoted in most countries that have nuclear power programmes to developing and evaluating appropriate disposal systems for high-level and transuranium-bearing waste, and to studying the potential for establishing repositories in geological formations underlaying their territories. The symposium, organized jointly by the IAEA and OECD's Nuclear Energy Agency in cooperation with the Geological Survey of Finland, provided an authoritative account of the status of underground disposal programmes throughout the world in 1979. It was evidence of the experience that has been gained and the comprehensive investigations that have been performed to study various options for the underground disposal of radioactive waste since the last IAEA/NEA symposium on this topic (Disposal of Radioactive Waste into the Ground) was held in 1967 in Vienna. The 10 sessions covered the following topics: National programme and general studies, Disposal of solid waste at shallow depth and in rock caverns, underground disposal of liquid waste by deep well injection and hydraulic fracturing, Disposal in salt formations, Disposal in crystalline rocks and argillaceous sediments, Thermal aspects of disposal in deep geological formations, Radionuclide migration studies, Safety assessment and regulatory aspects.

  5. Feedback control for distributed heat transfer mechanisms in direct-contact membrane distillation system

    KAUST Repository

    Eleiwi, Fadi; N'Doye, Ibrahima; Laleg-Kirati, Taous-Meriem

    2015-01-01

    In this paper, the problem of stabilization and production rate reference tracking for a Direct-Contact Membrane Distillation (DCMD) system is addressed. Sufficient conditions for the asymptotic and exponential stabilization for DCMD system are presented using the Gronwall-Bellman lemma and Linear Matrix Inequalities (LMIs) approaches, respectively. A nonlinear observer is then proposed to estimate the temperature distribution among the DCMD domain. This contributes to propose a reference production rate control design for the DCMD process via observer-based output control approach. Finally, numerical simulations are given to show the effectiveness of the proposed methods.

  6. Drying of brick as a function of heat flows and analysis of moisture and temperature distributions

    DEFF Research Database (Denmark)

    Svendsen, Sv Aa Højgaard; Rudbeck, Claus Christian; Bunch-Nielsen, Tommy

    1997-01-01

    In order to investigate the driving mechanisms for frost damages in brickwork, laboratory tests has been performed on a test brick wall. These test include monitoring of temperature and moisture distribution in the wall as function of the influence of driving rain, wind speed and solar radiation....... After the initial tests the surface of the wall was treated with mortar and a new series of test was performed. The wall with and without treatment performed almost equal during the influence of driving rain, and during the later drying phase, the difference was equally small....

  7. Feedback control for distributed heat transfer mechanisms in direct-contact membrane distillation system

    KAUST Repository

    Eleiwi, Fadi

    2015-09-21

    In this paper, the problem of stabilization and production rate reference tracking for a Direct-Contact Membrane Distillation (DCMD) system is addressed. Sufficient conditions for the asymptotic and exponential stabilization for DCMD system are presented using the Gronwall-Bellman lemma and Linear Matrix Inequalities (LMIs) approaches, respectively. A nonlinear observer is then proposed to estimate the temperature distribution among the DCMD domain. This contributes to propose a reference production rate control design for the DCMD process via observer-based output control approach. Finally, numerical simulations are given to show the effectiveness of the proposed methods.

  8. Nonlinear observer-based Lyapunov boundary control of distributed heat transfer mechanisms for membrane distillation plant

    KAUST Repository

    Eleiwi, Fadi

    2016-09-19

    This paper presents a nonlinear observer-based Lyapunov control for a membrane distillation (MD) process. The control considers the inlet temperatures of the feed and the permeate solutions as inputs, transforming it to boundary control process, and seeks to maintain the temperature difference along the membrane boundaries around a sufficient level to promote water production. MD process is modeled with advection diffusion equation model in two dimensions, where the diffusion and convection heat transfer mechanisms are best described. Model analysis, effective order reduction and parameters physical interpretation, are provided. Moreover, a nonlinear observer has been designed to provide the control with estimates of the temperature evolution at each time instant. In addition, physical constraints are imposed on the control to have an acceptable range of feasible inputs, and consequently, better energy consumption. Numerical simulations for the complete process with real membrane parameter values are provided, in addition to detailed explanations for the role of the controller and the observer. (C) 2016 Elsevier Ltd. All rights reserved.

  9. On the altitude dependence of transversely heated O+ distributions in the cusp/cleft

    Directory of Open Access Journals (Sweden)

    L. Kistler

    2004-04-01

    Full Text Available The present paper focuses on the altitude dependence of oxygen ion conics in the dayside cusp/cleft region. Here, combining oxygen data from the Akebono, Interball-2 and Cluster satellites allows, for the first time, one to follow the global development of energetic (up to ~10keV ion outflow over a continuous and broad altitude range up to about 5.5 Earth radii (RE. According to earlier statistical studies, the results are consistent with a height-integrated energization of ions at altitudes up to 3.5 RE. Higher up, the results inferred from Cluster observations put forward evidence of a saturation of both a transverse energization rate and ion gyroradii. We suggest that such results may be interpreted as finite perpendicular wavelength effects (a few tens of km in the wave-particle interactions. To substantiate the suggestion, we carry out two-dimensional, Monte Carlo simulations of ion conic production that incorporate such effects and limited residence times due to the finite latitudinal extent of the heating region.Key words. Magnetospheric physics (auroral phenomena – Space plasma physics (charged particle motion and acceleration; wave-particle interactions

  10. Underground pipe ventilation in horticulture; Grondbuisventilatie in de glastuinbouw

    Energy Technology Data Exchange (ETDEWEB)

    Raaphorst, M. [Wageningen UR Glastuinbouw, Bleiswijk (Netherlands)

    2012-09-15

    With earth air heat exchangers, greenhouse air or outside air is led through an underground pipe or course system, to exchange heat with the soil. This exploits the thermal storage capacity of the soil to buffer temperature fluctuations, which can save approximately 2 m{sup 3}/m{sup 2} annually on heat demand. With high temperature crops, the heat can preferably be used to warm up injected outside air [Dutch] Met grondbuisventilatie wordt kaslucht of buitenlucht door een ondergrondse buis of gangenstelsel geleid om daar warmte aan af te geven of op te nemen. Hiermee kan de thermische opslagcapaciteit van de bodem worden benut om temperatuurschommelingen op te vangen en daardoor jaarlijks ongeveer 2 m{sup 3}/m{sup 2} te besparen op de warmtevraag. Bij warme teelten is het aan te raden om deze opgeslagen warmte ook te gebruiken om aangezogen buitenlucht op te warmen.

  11. Inter-disciplinary Interactions in Underground Laboratories

    Science.gov (United States)

    Wang, J. S.; Bettini, A.

    2010-12-01

    Many of underground facilities, ranging from simple cavities to fully equipped laboratories, have been established worldwide (1) to evaluate the impacts of emplacing nuclear wastes in underground research laboratories (URLs) and (2) to measure rare physics events in deep underground laboratories (DULs). In this presentation, we compare similarities and differences between URLs and DULs in focus of site characterization, in quantification of quietness, and in improvement of signal to noise ratios. The nuclear waste URLs are located primarily in geological medium with potentials for slow flow/transport and long isolation. The URL medium include plastic salt, hard rock, soft clay, volcanic tuff, basalt and shale, at over ~500 m where waste repositories are envisioned to be excavated. The majority of URLs are dedicated facilities excavated after extensive site characterization. The focuses are on fracture distributions, heterogeneity, scaling, coupled processes, and other fundamental issues of earth sciences. For the physics DULs, the depth/overburden thickness is the main parameter that determines the damping of cosmic rays, and that, consequently, should be larger than, typically, 800m. Radioactivity from rocks, neutron flux, and radon gas, depending on local rock and ventilation conditions (largely independent of depth), are also characterized at different sites to quantify the background level for physics experiments. DULs have been constructed by excavating dedicated experimental halls and service cavities near to a road tunnel (horizontal access) or in a mine (vertical access). Cavities at shallower depths are suitable for experiments on neutrinos from artificial source, power reactors or accelerators. Rocks stability (depth dependent), safe access, and utility supply are among factors of main concerns for DULs. While the focuses and missions of URLs and DULs are very different, common experience and lessons learned may be useful for ongoing development of new

  12. Sinkhole development induced by underground quarrying, and the related hazard

    Science.gov (United States)

    Parise, M.; Delle Rose, M.

    2009-04-01

    . Within the framework of research programs devoted to recognition of sinkholes in Apulia, and addressed to the evaluation of the sinkhole hazard, this paper examines in detail the distribution of sinkholes related to underground quarrying in Salento, the southern part of Apulia, where the presence of subterranean quarries is particularly high. Through description of some case studies, the main problems related to underground quarries, and the development of sinkholes are discussed, even taking into account civil protection issues, that is in terms of the effects these phenomena may have on the local communities.

  13. Effects of heated effluent on the distribution of physicochemical parameters and phytoplankton in the vicinity of Madras Atomic Power Station

    International Nuclear Information System (INIS)

    Saravanane, N.; Durairaj, G.; Satpathy, K.K.; Venugopalan, V.P.; Nair, K.V.K.

    1995-01-01

    The effect of power plant discharge on coastal waters has become an area of considerable scientific interest as well as public concern. With more and more stringent standards being imposed by pollution control boards, monitoring of physico-chemical characteristics of the receiving waters has become an activity of great importance for conforming to standards as well as for impact assessment. The present paper discusses the distribution of temperature, salinity, dissolved oxygen, nutrients, chlorophyll and phytoplankton in the coastal waters near a nuclear plant at Kalpakkam. Results showed that the heated effluents from the plant moved along the direction of the coastal current during the period of the study. It was seen that environmental parameters other than temperature were affected by the effluents from the station. The paper discusses the significance of the changes in the coastal ecology in the vicinity of the out fall. (author). 15 refs., 2 figs

  14. Assessing phase stability and element distribution in Co-base superalloys at elevated temperatures by in situ TEM heating experiments

    Energy Technology Data Exchange (ETDEWEB)

    Eggeler, Yolita; Mueller, Julian; Spiecker, Erdmann [Lehrstuhl fuer Mikro- und Nanostrukturforschung and Center for Nanoanalysis and Electron Microscopy (CENEM), Department Werkstoffwissenschaften, Universitaet Erlangen-Nuernberg, Erlangen (Germany)

    2016-07-01

    Co-based alloys, of a composition of Co-12Al-9W, form a stable two phase γ/γ{sup '} microstructure at 900 C. γ{sup '} cubes, consisting of the L12 crystal structure are coherently embedded in a solid solution fcc (A1) γ matrix. To ensure precipitate hardening at temperatures, which are relevant to practical applications, 700-1100 C, as experienced in gas turbine applications, the stability of the γ/γ{sup '} phases is of fundamental importance. In this analysis in situ TEM studies with chip-based heating systems (by DENS solution) are applied on new Co-based superalloys. After in situ heating at apr. 900 C and controlled quenching with different quenching rates the elemental distribution at the γ/γ{sup '} interface is measured using ChemiSTEM EDX. Exploiting the driving force for interface movement resulting from temperature-dependent volume fraction of γ and γ{sup '} insight into the diffusion of individual alloying elements and the relationship between local chemistry and ordering can be gained from transient phenomena. The experimental results will be compared with theoretical calculations. This work has been carried out within the framework of the SFB-TR 103 ''Single Crystal Superalloys''.

  15. Comparison of Technological Options for Distributed Generation-Combined Heat and Power in Rajasthan State of India

    Directory of Open Access Journals (Sweden)

    Ram Kumar Agrawal

    2013-01-01

    Full Text Available Distributed generation (DG of electricity is expected to become more important in the future electricity generation system. This paper reviews the different technological options available for DG. DG offers a number of potential benefits. The ability to use the waste heat from fuel-operated DG, known as combined heat and power (CHP, offers both reduced costs and significant reductions of CO2 emissions. The overall efficiency of DG-CHP system can approach 90 percent, a significant improvement over the 30 to 35 percent electric grid efficiency and 50 to 90 percent industrial boiler efficiency when separate production is used. The costs of generation of electricity from six key DG-CHP technologies; gas engines, diesel engines, biodiesel CI engines, microturbines, gas turbines, and fuel cells, are calculated. The cost of generation is dependent on the load factor and the discount rate. It is found that annualized life cycle cost (ALCC of the DG-CHP technologies is approximately half that of the DG technologies without CHP. Considering the ALCC of different DG-CHP technologies, the gas I.C. engine CHP is the most effective for most of the cases but biodiesel CI engine CHP seems to be a promising DG-CHP technology in near future for Rajasthan state due to renewable nature of the fuel.

  16. Temperature field downstream of an heated bundle mock-up results for different power distribution

    International Nuclear Information System (INIS)

    Girard, J.P.; Buravand, Y.

    1982-10-01

    The aim of these peculiar experiments performed on the ML4 loop in ISPRA is to evaluate the characteristics of the temperature field over a length of 20 to 30 dias downstream of a rod bundle for different temperatures profiles at the bundle outlet. The final purpose of this work will be to establish either directly or through models whether it is possible or not to detect subassembly failures using suitable of the subassembly outlet temperature signal. 15 hours of digital and analog recording were taped for five different power distributions in the bundle. The total power dissipation remained constant during the whole run. Two flow rates and seven axial location were investigated. It is shown that the different temperature profiles produce slight differences in the variance and skewness of the temperature signal measured along the axis of the pipe over 20 dias

  17. Modeling of heat and high viscous fluid distributions with variable viscosity in a permeable channel

    Directory of Open Access Journals (Sweden)

    J Hona

    2016-10-01

    Full Text Available The flow field under study is characterized by velocity components, temperature and pressure in non-dimensional formulation. The flow is driven by suction through the horizontal channel with permeable walls fixed at different temperatures. In order to ascertain a better understanding of the dynamic behavior of the flow, the Navier-Stokes equations and the energy equation are solved concurrently applying a similarity transformation technique. The hydrodynamic structures obtained from the numerical integration include flow reversal or backward flow, collision zones due to the coexistence of wall suction and flow reversal inside the channel, the inflection through temperature distribution, the growth of thermal gradients near the walls, and the sensitivity of normal pressure gradients to the difference of temperatures at boundaries. These hydrodynamic structures are investigated considering the influences of the Péclet number P and the sensitivity of viscosity to thermal variations α which are the main control parameters of the problem.

  18. A GIS Based 3D Online Decision Assistance System for Underground Energy Storage in Northern Germany

    Science.gov (United States)

    Nolde, M.; Schwanebeck, M.; Biniyaz, E.; Duttmann, R.

    2014-12-01

    We would like to present a GIS-based 3D online decision assistance system for underground energy storage. Its aim is to support the local land use planning authorities through pre-selection of possible sites for thermal, electrical and substantial underground energy storages. Since the extension of renewable energies has become legal requirement in Germany, the underground storing of superfluously produced green energy (such as during a heavy wind event) in the form of compressed air, gas or heated water has become increasingly important. However, the selection of suitable sites is a complex task. The assistance system uses data of geological features such as rock layers, salt caverns and faults enriched with attribute data such as rock porosity and permeability. This information is combined with surface data of the existing energy infrastructure, such as locations of wind and biogas stations, power line arrangement and cable capacity, and energy distribution stations. Furthermore, legal obligations such as protected areas on the surface and current underground mining permissions are used for the decision finding process. Not only the current situation but also prospective scenarios, such as expected growth in produced amount of energy are incorporated in the system. The decision process is carried out via the 'Analytic Hierarchy Process' (AHP) methodology of the 'Multi Object Decision Making' (MODM) approach. While the process itself is completely automated, the user has full control of the weighting of the different factors via the web interface. The system is implemented as an online 3D server GIS environment, with no software needed to be installed on the user side. The results are visualized as interactive 3d graphics. The implementation of the assistance system is based exclusively on free and open source software, and utilizes the 'Python' programming language in combination with current web technologies, such as 'HTML5', 'CSS3' and 'JavaScript'. It is

  19. Borehole heater test at KAERI Underground Research Tunnel

    International Nuclear Information System (INIS)

    Kwon, S. K.; Cho, W. J.; Jeon, S. W.

    2009-09-01

    At HLW repository, the temperature change due to the decay heat in near field can affect the hydraulic, mechanical, and chemical behaviors and influence on the repository safety. Therefore, the understanding of the thermal behavior in near field is essential for the site selection, design, as well as operation of the repository. In this study, various studies for the in situ heater test, which is for the investigation of the thermo-mechanical behavior in rock mass, were carried out. At first, similar in situ tests at foreign URLs were reviewed and summarized the major conclusions from the tests. After then an adequate design of heater, observation sensors, and data logging system were developed and installed with a consideration of the site condition and test purposes. In order to minimize the effect of hydraulic phenomenon, a relatively day zone was chosen for the in situ test. Joint distribution and characteristics in the zone were surveyed and the rock mass properties were determined with various laboratory tests. In this study, an adequate location for an in situ borehole heater test was chosen. Also a heater for the test was designed and manufactured and the sensors for measuring the rock behavior were installed. It was possible to observe that stiff joints are developed overwhelmingly in the test area from the joint survey at the tunnel wall. The major rock and rock mass properties at the test site could be determined from the thermo-mechanical laboratory tests using the rock cores retrieved from the site. The measured data were implemented in the three-dimensional computer simulation. From the modeling using FLAC3D code, it was possible to find that the heat convection through the tunnel wall can influence on temperature distribution in rock. Because of that it was necessary to installed a blocking wall to minimize the effect of ventilation system on the heater test, which is carrying out nearby the tunnel wall. The in situ borehole heater test is the first

  20. Heat pipes for ground heating and cooling

    Energy Technology Data Exchange (ETDEWEB)

    Vasiliev, L L

    1988-01-01

    Different versions of heat pipe ground heating and cooling devices are considered. Solar energy, biomass, ground stored energy, recovered heat of industrial enterprises and ambient cold air are used as energy and cold sources. Heat pipe utilization of air in winter makes it possible to design accumulators of cold and ensures deep freezing of ground in order to increase its mechanical strength when building roadways through the swamps and ponds in Siberia. Long-term underground heat storage systems are considered, in which the solar and biomass energy is accumulated and then transferred to heat dwellings and greenhouses, as well as to remove snow from roadways with the help of heat pipes and solar collectors.

  1. Occurrence, distribution and contamination levels of heat-resistant moulds throughout the processing of pasteurized high-acid fruit products.

    Science.gov (United States)

    Santos, Juliana Lane Paixão Dos; Samapundo, Simbarashe; Biyikli, Ayse; Van Impe, Jan; Akkermans, Simen; Höfte, Monica; Abatih, Emmanuel Nji; Sant'Ana, Anderson S; Devlieghere, Frank

    2018-05-19

    distributions and will ultimately be included as input to spoilage risk assessment models which would allow better control of the spoilage of heat treated fruit products caused by heat-resistant moulds. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. Production of titanium alloys with uniform distribution of heat resisting metals

    International Nuclear Information System (INIS)

    Reznichenko, V.A.; Goncharenko, T.V.; Khalimov, F.B.; Vojtechova, E.A.

    1976-01-01

    Consideration is given to the process of the formation of a titanium sponge alloyed with niobium or tantalum, in the joint metallic reduction of titanium, niobium and tantanum chlorides. A percentage composition of the phases observed and the structure of the alloyed sponge have been studied. It is shown that after one remelting operation of the alloyed sponge the alloys of titanium with niobium and tantalum have a uniform component distribution. At the stage of chloride reduction there appear solid solutions based on titanium and an alloying component. The stage of vacuum separation of the reaction mass is associated with a mutual dissolution of the primary phases and the formation of the solid solutions of the alloyed titanium sponge, which, by their composition, are close to the desired alloy composition. The principal features of the formation of a titanium sponge alloyed with niobium and tantalum are in a perfect agreemet with those typical of Ti-Mo and Ti-W sponges, therefore it can be assumed that these features will be also common to the other cases of the metallic reduction of titanium and refractory metals chlorides

  3. Production of titanium alloys with uniform distribution of heat resisting metals

    Energy Technology Data Exchange (ETDEWEB)

    Reznichenko, V A; Goncharenko, T V; Khalimov, F B; Voitechova, E A

    1976-01-01

    Consideration is given to the process of the formation of a titanium sponge alloyed with niobium or tantalum, in the joint metallic reduction of titanium, niobium and tantanum chlorides. A percentage composition of the phases observed and the structure of the alloyed sponge have been studied. It is shown that after one remelting operation of the alloyed sponge the alloys of titanium with niobium and tantalum have a uniform component distribution. At the stage of chloride reduction there appear solid solutions based on titanium and an alloying component. The stage of vacuum separation of the reaction mass is associated with a mutual dissolution of the primary phases and the formation of the solid solutions of the alloyed titanium sponge, which, by their composition, are close to the desired alloy composition. The principal features of the formation of a titanium sponge alloyed with niobium and tantalum are in a perfect agreemet with those typical of Ti-Mo and Ti-W sponges, therefore it can be assumed that these features will be also common to the other cases of the metallic reduction of titanium and refractory metals chlorides.

  4. A Psychosocial Approach to Understanding Underground Spaces

    Directory of Open Access Journals (Sweden)

    Eun H. Lee

    2017-03-01

    Full Text Available With a growing need for usable land in urban areas, subterranean development has been gaining attention. While construction of large underground complexes is not a new concept, our understanding of various socio-cultural aspects of staying underground is still at a premature stage. With projected emergence of underground built environments, future populations may spend much more of their working, transit, and recreational time in underground spaces. Therefore, it is essential to understand the challenges and advantages that such environments have to improve the future welfare of users of underground spaces. The current paper discusses various psycho-social aspects of underground spaces, the impact they can have on the culture shared among the occupants, and possible solutions to overcome some of these challenges.

  5. Planning geological underground repositories - Communicating with society

    International Nuclear Information System (INIS)

    Schenkel, W.; Gallego Carrera, D.; Renn, O.; Dreyer, M.

    2009-06-01

    The project 'Planning geological underground repositories: Communicating with society', financed by the Swiss Federal Office for Energy, aimed at identifying basic principles for an appropriate information and communication strategy in the process of finding an underground site to store radioactive wastes. The topic concerns an issue increasingly discussed in modern societies: How to improve the dialogue between science, infrastructure operators, public authorities, groups in civil society and the population to answer complex problems? Against this background, in the project the following questions were taken into account: (i) How can the dialogue between science, politics, economy, and the (non-)organised public be arranged appropriately? Which principles are to be considered in organising this process? How can distrust within the population be reduced and confidence in authorities and scientific expertise be increased? (ii) How can society be integrated in the process of decision-making so that this process is perceived as comprehensible, acceptable and legitimate? To answer these questions, an analysis method based on scientific theory and methodology was developed, which compares national participation and communication processes in finding underground storage sites in selected countries. Case studies have been carried out in Germany, Sweden, Belgium, and Switzerland. By using specific criteria to evaluate communication processes, the strong points as well as the drawbacks of the country-specific concepts of information, communication and participation have been analysed in a comparing dimension. By taking into account the outcomes, prototypical scenarios have been deduced that can serve as a basis for compiling a reference catalogue of measures, which is meant to support the Swiss communication strategy in the finding of an appropriate site for a nuclear waste repository. Following conclusions can be drawn from the international comparison: (i) Open and

  6. Natural radionuclides in Brazilian underground mines

    International Nuclear Information System (INIS)

    Santos, Talita de Oliveira

    2015-01-01

    Rock, soil and water contain "2"3"8U and "2"3"2Th and their decay products. The distribution of these radionuclides differs in terms of activity concentration depending on the mineral type and origin. All ore processing releases long and short half-life radionuclides, mainly radon and its progeny. It is important to monitor this gas and its decay products in underground mines in order to assess the radiological hazards of the exposed workers. On this concern, the present work outlines the characterization of brazilian underground mines with relation to natural radionuclides, specially radon and its progeny. The radon concentration was measured by using E-PERM Electrets Ion Chamber (Radelec), AlphaGUARD (Saphymo GmbH) and CR-39 (Landauer) track etch detectors. The radon progeny was determined by using DOSEman detector. The equilibrium state between radon and its progeny was calculated. Based on these data, the total effective dose for miners was estimated. Moreover, the contribution from the main sources to the radon level inside mines was evaluated. For this, the following detectors were used: measurements of radon concentrations in soil gas were carried out by using AlphaGUARD detector; "2"2"6Ra ("2"1"4Bi), "2"3"2Th e "4"0K specific activity in ore and soil samples were determined by using gamma-ray spectrometry HPGe detector (Canberra); and radon concentration in groundwater samples was performed by using RAD7 (Durridge Inc.). The radon concentration ranged from 113 to 8171 Bq.m"-"3 and the Equilibrium Equivalent Concentration varied from 76 to 1174 Bq.m"-"3. The equilibrium factor mean value was 0.4 (0.2 -0.7). The workers estimated total effective dose ranged from 1 to 22 mSv.a"-"1 (mean 10 mSv.a"-"1). Therefore, results show the importance to assess continually and permanently the radon and its progeny behavior and the need to adopt safety measurements against natural radiation in underground mines environment. (author)

  7. Shape and Reinforcement Optimization of Underground Tunnels

    Science.gov (United States)

    Ghabraie, Kazem; Xie, Yi Min; Huang, Xiaodong; Ren, Gang

    Design of support system and selecting an optimum shape for the opening are two important steps in designing excavations in rock masses. Currently selecting the shape and support design are mainly based on designer's judgment and experience. Both of these problems can be viewed as material distribution problems where one needs to find the optimum distribution of a material in a domain. Topology optimization techniques have proved to be useful in solving these kinds of problems in structural design. Recently the application of topology optimization techniques in reinforcement design around underground excavations has been studied by some researchers. In this paper a three-phase material model will be introduced changing between normal rock, reinforced rock, and void. Using such a material model both problems of shape and reinforcement design can be solved together. A well-known topology optimization technique used in structural design is bi-directional evolutionary structural optimization (BESO). In this paper the BESO technique has been extended to simultaneously optimize the shape of the opening and the distribution of reinforcements. Validity and capability of the proposed approach have been investigated through some examples.

  8. Extension of ANISN and DOT 3.5 transport computer codes to calculate heat generation by radiation and temperature distribution in nuclear reactors

    International Nuclear Information System (INIS)

    Torres, L.M.R.; Gomes, I.C.; Maiorino, J.R.

    1986-01-01

    The ANISN and DOT 3.5 codes solve the transport equation using the discrete ordinate method, in one and two-dimensions, respectively. The objectives of the study were to modify these two codes, frequently used in reactor shielding problems, to include nuclear heating calculations due to the interaction of neutrons and gamma-rays with matter. In order to etermine the temperature distribution, a numerical algorithm was developed using the finite difference method to solve the heat conduction equation, in one and two-dimensions, considering the nuclear heating from neutron and gamma-rays, as the source term. (Author) [pt

  9. Underground storage of nuclear waste

    International Nuclear Information System (INIS)

    Russell, J.E.

    1977-06-01

    The objective of the National Waste Terminal Storage (NWTS) Program is to provide facilities in various deep geologic formations at multiple locations in the United States which will safely dispose of commerical radioactive waste. The NWTS Program is being administered for the Energy Research and Development Administration (ERDA) by the Office of Waste Isolation (OWI), Union Carbide Corporation, Nuclear Division. OWI manages projects that will lead to the location, construction, and operation of repositories, including all surface and underground engineering and facility design projects and technical support projects. 7 refs., 5 figs

  10. Process for fracturing underground formations

    Energy Technology Data Exchange (ETDEWEB)

    Kiel, O M

    1974-01-25

    This invention concerns a process for fracturing underground formations and has as one object the mixing of viscous compositions. Through a borehole, a fluid is injected into the formation. This fluid contains a complex prepared by the reaction of an aliphatic quaternary ammonium compound with a water-soluble compound chosen from monosaccharides, disaccharides, trisaccharides, polysaccharides, and synthetic hydroxylated polymers with long chains. These complexes are formed at temperatures between 20/sup 0/ and 205/sup 0/C. The process also includes production of formation fluid into the borehole.

  11. Third symposium on underground mining

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-01-01

    The Third Symposium on Underground Mining was held at the Kentucky Fair and Exposition Center, Louisville, KY, October 18--20, 1977. Thirty-one papers have been entered individually into EDB and ERA. The topics covered include mining system (longwall, shortwall, room and pillar, etc.), mining equipment (continuous miners, longwall equipment, supports, roof bolters, shaft excavation equipment, monitoring and control systems. Maintenance and rebuilding facilities, lighting systems, etc.), ventilation, noise abatement, economics, accidents (cost), dust control and on-line computer systems. (LTN)

  12. Proposed underground gasification. [United Kingdom

    Energy Technology Data Exchange (ETDEWEB)

    1986-05-01

    An underground coal gasification experiment which could provide the key to recovering the energy in millions of tonnes of otherwise inaccessible undersea coal reserves is proposed by the NCB. The Board's Headquarters Technical Department hope to carry out a field trial in a six foot thick coal seam about 2000 feet beneath a former wartime airfield near the hamlet of Ossington near Newark, Notts, UK. This paper describes briefly the proposed project, which could cost up to 15 million pounds over five years. It has the backing and financial support of the European Economic Community.

  13. Intensive use of diesels underground

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, R W

    1980-07-01

    At a US mine, coal is extracted by room and pillar mining. Tyred diesel vehicles are used to transport men and materials, to spread gravel on the roadway, and to tow and provide hydraulic power to rock dusting machines. Hydraulic power take-offs from the vehicles are used to operate equipment such as drills and chain saws. A deisel ambulance is kept underground, and diesel lubrication units and maintenance tracks are used. A diesel generator provides electrical power when or where no permanent electricity supply is available e.g. for tramming continuous miners in to or out of the mine.

  14. Underground storage of nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Russell, J E

    1977-12-01

    The objective of the National Waste Terminal Storage (NWTS) Program is to provide facilities in various deep geologic formations at multiple locations in the United States which will safely dispose of commercial radioactive waste. The NWTS Program is being administered for the Energy Research and Development Administration (ERDA) by the Office of Waste Isolation (OWI), Union Carbide Corporation, Nuclear Division. OWI manages projects that will lead to the location, construction, and operation of repositories, including all surface and underground engineering and facility design projects and technical support projects.

  15. UNDERGROUND ECONOMY, GDP AND STOCK MARKET

    Directory of Open Access Journals (Sweden)

    Caus Vasile Aurel

    2012-07-01

    Full Text Available Economic growth is affected by the size and dynamics of underground economy. Determining this size is a subject of research for many authors. In this paper we present the relationship between underground economy dynamics and the dynamics of stock markets. The observations are based on regression used by Tanzi (1983 and the relationship between GDP and stock market presented in Tudor (2008. The conclusion of this paper is that the dynamics of underground economy is influenced by dynamic of financial markets. Thus, using specific stock market mathematical tools analysis, one can analyze the dynamic of underground economy

  16. Capital Subsidies and the Underground Economy

    DEFF Research Database (Denmark)

    Busato, Francesco; Chiarini, Bruno; Angelis, Pasquale de

    In this paper we investigate the effects of different fiscal policies on the firm choice to produce underground. We consider a tax evading firm operating simultaneously both in the regular and in the underground economy. We suggest that such a kind of firm, referred to as moonlighting firm, is able...... allocation in the underground production. In fact, a strong and inverse relationship is found, and tax reduction is the best policy to reduce the convenience to produce underground. Wealso confirm the depressing effect on investment of taxation (see, for instance, Summers,1981), so that tax reduction has...

  17. Cathode protection for underground steel tanks

    International Nuclear Information System (INIS)

    Angelovski, Zoran

    1998-01-01

    Cathodic protection of underground petroleum storage tanks and piping systems is acceptable for both economic and ecological reasons. With out the cathodic protection of underground steel reservoirs, short time after the exploitation, there was a bore as a result of underground corrosion. The bore causes ecological consequences and at the same time its repair needs big investments. Furthermore, there are great number of tanks placed near cities, so in the future this problem needs a special attention in order to preserve ecological surrounding. The topic of this paper is underground corrosion as well as cathodic protection of steel tanks for oil derivatives storage. (author)

  18. Underground storage tank management plan

    International Nuclear Information System (INIS)

    1994-09-01

    The Underground Storage Tank (UST) Management Program at the Oak Ridge Y-12 Plant was established to locate UST systems in operation at the facility, to ensure that all operating UST systems are free of leaks, and to establish a program for the removal of unnecessary UST systems and upgrade of UST systems that continue to be needed. The program implements an integrated approach to the management of UST systems, with each system evaluated against the same requirements and regulations. A common approach is employed, in accordance with Tennessee Department of Environment and Conservation (TDEC) regulations and guidance, when corrective action is mandated. This Management Plan outlines the compliance issues that must be addressed by the UST Management Program, reviews the current UST inventory and compliance approach, and presents the status and planned activities associated with each UST system. The UST Management Plan provides guidance for implementing TDEC regulations and guidelines for petroleum UST systems. (There are no underground radioactive waste UST systems located at Y-12.) The plan is divided into four major sections: (1) regulatory requirements, (2) implementation requirements, (3) Y-12 Plant UST Program inventory sites, and (4) UST waste management practices. These sections describe in detail the applicable regulatory drivers, the UST sites addressed under the Management Program, and the procedures and guidance used for compliance with applicable regulations

  19. Underground storage tank management plan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-09-01

    The Underground Storage Tank (UST) Management Program at the Oak Ridge Y-12 Plant was established to locate UST systems in operation at the facility, to ensure that all operating UST systems are free of leaks, and to establish a program for the removal of unnecessary UST systems and upgrade of UST systems that continue to be needed. The program implements an integrated approach to the management of UST systems, with each system evaluated against the same requirements and regulations. A common approach is employed, in accordance with Tennessee Department of Environment and Conservation (TDEC) regulations and guidance, when corrective action is mandated. This Management Plan outlines the compliance issues that must be addressed by the UST Management Program, reviews the current UST inventory and compliance approach, and presents the status and planned activities associated with each UST system. The UST Management Plan provides guidance for implementing TDEC regulations and guidelines for petroleum UST systems. (There are no underground radioactive waste UST systems located at Y-12.) The plan is divided into four major sections: (1) regulatory requirements, (2) implementation requirements, (3) Y-12 Plant UST Program inventory sites, and (4) UST waste management practices. These sections describe in detail the applicable regulatory drivers, the UST sites addressed under the Management Program, and the procedures and guidance used for compliance with applicable regulations.

  20. Earthquake damage to underground facilities

    International Nuclear Information System (INIS)

    Pratt, H.R.; Hustrulid, W.A.; Stephenson, D.E.

    1978-11-01

    The potential seismic risk for an underground nuclear waste repository will be one of the considerations in evaluating its ultimate location. However, the risk to subsurface facilities cannot be judged by applying intensity ratings derived from the surface effects of an earthquake. A literature review and analysis were performed to document the damage and non-damage due to earthquakes to underground facilities. Damage from earthquakes to tunnels, s, and wells and damage (rock bursts) from mining operations were investigated. Damage from documented nuclear events was also included in the study where applicable. There are very few data on damage in the subsurface due to earthquakes. This fact itself attests to the lessened effect of earthquakes in the subsurface because mines exist in areas where strong earthquakes have done extensive surface damage. More damage is reported in shallow tunnels near the surface than in deep mines. In mines and tunnels, large displacements occur primarily along pre-existing faults and fractures or at the surface entrance to these facilities.Data indicate vertical structures such as wells and shafts are less susceptible to damage than surface facilities. More analysis is required before seismic criteria can be formulated for the siting of a nuclear waste repository

  1. Oxidative degradation of atenolol by heat-activated persulfate: Kinetics, degradation pathways and distribution of transformation intermediates.

    Science.gov (United States)

    Miao, Dong; Peng, Jianbiao; Zhou, Xiaohuan; Qian, Li; Wang, Mengjie; Zhai, Li; Gao, Shixiang

    2018-05-17

    Atenolol (ATL) has been widely detected in wastewater and aquatic environment. Although satisfactory removal of ATL from wastewater could be achieved, the mineralization ratio is usually low, which may result in the accumulation of its transformation products in the effluent and cause additional ecological risk to the environment. The aim of this study is to explore the effectiveness of heat activated persulfate (PS) in the removal of ATL from wastewater. Influencing factors including temperature, PS dosage, solution pH, existence of NO 3 - , Cl - , HCO 3 - and Suwannee river fulvic acid (SRFA) were examined. Complete removal of ATL was achieved within 40 min at pH 7.0 and 70 °C by using 0.5 mM PS. Inhibitive effects of HCO 3 - and FA had been observed on ATL oxidation, which was increased with the increase of their concentration. Sulfate radical (SO 4 - ) was determined as the main reactive species by quenching experiment. Eight intermediates produced in ATL degradation were identified, and four degradation pathways were proposed based on the analysis of mass spectrum and frontier electron densities. The distribution of major intermediates was influenced by reaction temperature. Hydroxylation intermediates and deamidation intermediate were the most prominent at 50 °C and 60 °C, respectively. All intermediates were completely degraded in 40 min except P134 at 70 °C. Effective removal of TOC (74.12%) was achieved with 0.5 mM PS, pH 7.0 and 70 °C after 240 min. The results proved that heat activation of PS is a promising method to remove organic pollutants in wastewater. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Geological investigations for geological model of deep underground geoenvironment at the Mizunami Underground Research Laboratory (MIU)

    International Nuclear Information System (INIS)

    Tsuruta, Tadahiko; Tagami, Masahiko; Amano, Kenji; Matsuoka, Toshiyuki; Kurihara, Arata; Yamada, Yasuhiro; Koike, Katsuaki

    2013-01-01

    Japan Atomic Energy Agency (JAEA) is performing a geoscientific research project, the Mizunami Underground Research Laboratory (MIU) project, in order to establish scientific and technological basis for geological disposal of high-level radioactive wastes. The MIU is located in crystalline rock environment, in Mizunami City, central Japan. Field investigations include geological mapping, reflection seismic surveys, several borehole investigations and geological investigations in the research galleries to identify the distribution and heterogeneity of fractures and faults that are potential major flowpaths for groundwater. The results of these field investigations are synthesized and compiled for the purpose of geological modeling. The field investigations indicate that the Main Shaft at the MIU intersected low permeability NNW oriented faults. A high permeability fracture zone in the granite, a significant water inflow point, was observed in the Ventilation Shaft. Development of the geological model focusing 3D spatial relationships at different scales and evolution of the geoenvironment are underway. This paper describes geological investigations applied in the MIU project, focusing on the evaluation of their effectiveness to understand for deep underground geoenvironment. (author)

  3. Researching radioactive waste disposal. [Underground repository

    Energy Technology Data Exchange (ETDEWEB)

    Feates, F; Keen, N [UKAEA Research Group, Harwell. Atomic Energy Research Establishment

    1976-02-16

    At present it is planned to use the vitrification process to convert highly radioactive liquid wastes, arising from nuclear power programme, into glass which will be contained in steel cylinders for storage. The UKAEA in collaboration with other European countries is currently assessing the relative suitability of various natural geological structures as final repositories for the vitrified material. The Institute of Geological Sciences has been commissioned to specify the geological criteria that should be met by a rock structure if it is to be used for the construction of a repository though at this stage disposal sites are not being sought. The current research programme aims to obtain basic geological data about the structure of the rocks well below the surface and is expected to continue for at least three years. The results in all the European countries will then be considered so that the United Kingdom can choose a preferred method for isolating their wastes. It is only at that stage that a firm commitment may be made to select a site for a potential repository, when a far more detailed scientific research study will be instituted. Heat transfer problems and chemical effects which may occur within and around repositories are being investigated and a conceptual design study for an underground repository is being prepared.

  4. Estimating Limits for the Geothermal Energy Potential of Abandoned Underground Coal Mines: A Simple Methodology

    Directory of Open Access Journals (Sweden)

    Rafael Rodríguez Díez

    2014-07-01

    Full Text Available Flooded mine workings have good potential as low-enthalpy geothermal resources, which could be used for heating and cooling purposes, thus making use of the mines long after mining activity itself ceases. It would be useful to estimate the scale of the geothermal potential represented by abandoned and flooded underground mines in Europe. From a few practical considerations, a procedure has been developed for assessing the geothermal energy potential of abandoned underground coal mines, as well as for quantifying the reduction in CO2 emissions associated with using the mines instead of conventional heating/cooling technologies. On this basis the authors have been able to estimate that the geothermal energy available from underground coal mines in Europe is on the order of several thousand megawatts thermal. Although this is a gross value, it can be considered a minimum, which in itself vindicates all efforts to investigate harnessing it.

  5. FY 1999 research and development results. Preparatory study for the underground thermal energy storage system; 1999 nendo chichu jiban chikunetsu system gijutsu sendo kenkyu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-05-01

    The study is conducted for the underground thermal energy storage system which utilizes heat capacity of the underground, e.g., aquifer, to exchange heat with the underground, and the FY 1999 results are described. For establishment of the concept of the underground heat storage systems, 2 sites are selected for each of Tokyo, Osaka and Sapporo for the study as the geological ground models, for their weather characteristics. Two cases are considered for the site where underground heat exchangers are installed, open space and immediately below a building. The heat-storage system comprises a high-efficiency heat pump, water heat-storage tank and cooling tower. The evaluation results indicate that energy saving rate of 37% or more and CO2 reduction rate of 9.5% or more are achievable in all areas except Sapporo, i.e., Tokyo and Osaka. The economic evaluation results indicate that the simple pay-out period is around 100 years for Tokyo and Osaka, and 80 years for Sapporo. The underground heat storage system is approximately 10% lower in life-cycle cost than the conventional system, 3 versus 3.3 billion yen for the period of 60 years. (NEDO)

  6. Fuel-element temperature nonstationary distribution caused by local pulsations of the factor of heat transfer to a coolant

    International Nuclear Information System (INIS)

    Pupko, V.Ya.

    1978-01-01

    The equation of nonstationary heat transfer caused by the appearance of a local pulse jump in the factor of heat transfer to a coolant is solved analytically for a cylindrical fuel element. The problem solution is generalized to a case of the periodically pulsating factor of heat transfer according to its value in an arbitrary point of the fuel element surface

  7. District heating and cooling system for communities through power plant retrofit and distribution network. Final report, Phase I

    Energy Technology Data Exchange (ETDEWEB)

    1979-06-01

    The technical and economic feasibility of retrofitting thermal power plants in Minnesota to accommodate both heat and power generation for district heating was examined and is discussed. Three communities were identified as viable sites for co-generation district heating. (LCL)

  8. Underground laboratories in Japan and North America

    International Nuclear Information System (INIS)

    Sobel, Henry W

    2006-01-01

    There is a blossoming demand for deep underground laboratory space to satisfy the expanding interest in experiments that require significant cosmic-ray shielding. I'll briefly describe the existing deep facilities and their plans for expansion. I will also discuss the planning for a new major underground facility in the U.S

  9. Concept of underground nuclear power plant

    International Nuclear Information System (INIS)

    Onishi, Sotoaki

    1976-01-01

    The concept of constructing nuclear power plants on the sea or underground as the future sitting is based on moving the present power plants on the ground with actual results to the sea or underground without changing the design. The underground nuclear power plants have many similar points to underground hydro-electric power stations with many achievements in the construction viewpoint, though they have their proper difficult problems. Of course, it requires to excavate larger underground caves than the case of underground hydro-electric power plants. The maximum dimensions of the caves have been determined through experience in practice. Therefore the developments of design theory and construction technique are desirable in this field. In discussing underground construction, two evaluating methods are considered for the shielding effect of base rocks. The minimum vertical distance up to ground surface from the center of the cave differs depending upon the in-cave pressure, and the conditions of base rock, soil and underground water in case of the accident assumed in the design, and is approximately 60m, if the cave is assumed to be an indefinite cylindrical shape, by the safer side calculation in the above two evaluations. (Wakatsuki, Y.)

  10. A review of international underground laboratory developments

    International Nuclear Information System (INIS)

    Cheng Jianping; Yue Qian; Wu Shiyong; Shen Manbin

    2011-01-01

    Underground laboratories are essential for various important physics areas such as the search for dark matter, double beta decay, neutrino oscillation, and proton decay. At the same time, they are also a very important location for studying rock mechanics, earth structure evolution,and ecology. It is essential for a nation's basic research capability to construct and develop underground laboratories. In the past, China had no high-quality underground laboratory,in particular no deep underground laboratory,so her scientists could not work independently in major fields such as the search for dark matter,but had to collaborate with foreign scientists and share the space of foreign underground laboratories. In 2009, Tsinghua university collaborated with the Ertan Hydropower Development Company to construct an extremely deep underground laboratory, the first in China and currently the deepest in the world, in the Jinping traffic tunnel which was built to develop hydropower from the Yalong River in Sichuan province. This laboratory is named the China Jinping Underground Laboratory (CJPL) and formally opened on December 12, 2010. It is now a major independent platform in China and can host various leading basic research projects. We present a brief review of the development of various international underground laboratories,and especially describe CJPL in detail. (authors)

  11. UNDERGROUND ECONOMY, INFLUENCES ON NATIONAL ECONOMIES

    Directory of Open Access Journals (Sweden)

    CEAUȘESCU IONUT

    2015-04-01

    Full Text Available The purpose of research is to improve the understanding of nature underground economy by rational justification of the right to be enshrined a reality that, at least statistically, can no longer be neglected. So, we propose to find the answer to the question: has underground economy to stand-alone?

  12. 30 CFR 57.4761 - Underground shops.

    Science.gov (United States)

    2010-07-01

    ... Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Fire Prevention and... toxic gases from a fire originating in an underground shop where maintenance work is routinely done on...

  13. Local distribution of wall static pressure and heat transfer on a rough flat plate impinged by a slot air jet

    Science.gov (United States)

    Meda, Adimurthy; Katti, Vadiraj V.

    2017-08-01

    The present work experimentally investigates the local distribution of wall static pressure and the heat transfer coefficient on a rough flat plate impinged by a slot air jet. The experimental parameters include, nozzle-to-plate spacing (Z /D h = 0.5-10.0), axial distance from stagnation point ( x/D h ), size of detached rib ( b = 4-12 mm) and Reynolds number ( Re = 2500-20,000). The wall static pressure on the surface is recorded using a Pitot tube and a differential pressure transmitter. Infrared thermal imaging technique is used to capture the temperature distribution on the target surface. It is observed that, the maximum wall static pressure occurs at the stagnation point ( x/D h = 0) for all nozzle-to-plate spacing ( Z/D h ) and rib dimensions studied. Coefficient of wall static pressure ( C p ) decreases monotonically with x/D h . Sub atmospheric pressure is evident in the detached rib configurations for jet to plate spacing up to 6.0 for all ribs studied. Sub atmospheric region is stronger at Z/D h = 0.5 due to the fluid accelerating under the rib. As nozzle to plate spacing ( Z/D h ) increases, the sub-atmospheric region becomes weak and vanishes gradually. Reasonable enhancement in both C p as well as Nu is observed for the detached rib configuration. Enhancement is found to decrease with the increase in the rib width. The results of the study can be used in optimizing the cooling system design.

  14. Effect of solar UV/EUV heating on the intensity and spatial distribution of Jupiter's synchrotron radiation

    Science.gov (United States)

    Kita, H.; Misawa, H.; Tsuchiya, F.; Tao, C.; Morioka, A.

    2013-10-01

    We analyzed the Very Large Array archived data observed in 2000 to determine whether solar ultraviolet (UV)/extreme ultraviolet (EUV) heating of the Jovian thermosphere causes variations in the total flux density and dawn-dusk asymmetry (the characteristic differences between the peak emissions at dawn and dusk) of Jupiter's synchrotron radiation (JSR). The total flux density varied by 10% over 6 days of observations and accorded with theoretical expectations. The average dawn-dusk peak emission ratio indicated that the dawn side emissions were brighter than those on the dusk side and this was expected to have been caused by diurnal wind induced by the solar UV/EUV. The daily variations in the dawn-dusk ratio did not correspond to the solar UV/EUV, and this finding did not support the theoretical expectation that the dawn-dusk ratio and diurnal wind velocity varies in correspondence with the solar UV/EUV. We tried to determine whether the average dawn-dusk ratio could be explained by a reasonable diurnal wind velocity. We constructed an equatorial brightness distribution model of JSR using the revised Divine-Garrett particle distribution model and used it to derive a relation between the dawn-dusk ratio and diurnal wind velocity. The estimated diurnal wind velocity reasonably corresponded to a numerical simulation of the Jovian thermosphere. We also found that realistic changes in the diurnal wind velocity could not cause the daily variations in the dawn-dusk ratio. Hence, we propose that the solar UV/EUV related variations were below the detection limit and some other processes dominated the daily variations in the dawn-dusk ratio.

  15. The influence of inner topology of exhaust heat exchanger and thermoelectric module distribution on the performance of automotive thermoelectric generator

    International Nuclear Information System (INIS)

    Wang, Yiping; Li, Shuai; Zhang, Yifeng; Yang, Xue; Deng, Yadong; Su, Chuqi

    2016-01-01

    Highlights: • Cylindrical grooves to improve the performance of TEG were proposed. • Mainly thermal resistance in TEG was the heat convection in heat exchanger. • Proper height of heat exchanger can improve the TEG performance. • Keeping heat exchanger partly covered with TEM can make full use of each TEM. - Abstract: The waste heat of automotive exhaust gas would be directly transferred into electricity by thermoelectric modules (TEM) because of the temperature difference between heat exchanger and water tank. For the vehicle thermoelectric generator (TEG), the electrical power generation was deeply influenced by temperature difference, temperature uniformity and topological structure of TEG. In previous works, increasing the difference of temperature would significantly enhance the power generation of TEG and inserted fins were always applied to enhance heat transfer in heat exchanger. However the fins would result in a large unwanted back pressure which went against to the efficiency of the engine. In current studies, in order to enhance heat transfer rates and to avoid back pressure increase, a heat exchanger containing cylindrical grooves (the depth-to-width ratio is 0.25) on the interior surface of heat exchanger was proposed. The cylindrical grooves could increase the heat transfer area and enhance the turbulence intensity, meanwhile there was no additional inserts in the fluid to block the flow. The surface temperatures of water tank and heat exchanger with three internal structures, such as grooved surface, flat surface and inserted fins, were studied by numerical simulation at each row of thermoelectric modules. The results showed that comparing to other structures, heat exchanger with cylindrical grooves could improve the TEG efficiency at a low back pressure. The influence of the channel height on the TEG performance was investigated and the TEG with a channel height of 8 mm showed the best overall performance. It was also found that a portion

  16. District heating and cooling systems for communities through power plant retrofit distribution network. Final report, September 1, 1978-May 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-10-01

    This Final Report (Volume 2) of Phase 1 of District Heating for Communities Through Power Plant Retrofit Distribution Network contains 3 tasks: (1) Demonstration Team; (2) Identify Thermal Energy Sources and Potential Service Areas; and (3) Energy Market Analysis. Task 2 consists of estimating the thermal load within 5 and 10 miles of Public Service Electric and Gas Company steam power plants, Newark, New Jersey; estimating the costs of supplying thermal services to thermal loads of varying densities; a best case economic analysis of district heating for single-family homes; and some general comments on district-heating system design and development. Task 3 established the potential market for district heating that exists within a 5-mile radius of the selected generating stations; a sample of the questionnaire sent to the customers are shown. (MCW)

  17. Assessment of 12 CHF prediction methods, for an axially non-uniform heat flux distribution, with the RELAP5 computer code

    Energy Technology Data Exchange (ETDEWEB)

    Ferrouk, M. [Laboratoire du Genie Physique des Hydrocarbures, University of Boumerdes, Boumerdes 35000 (Algeria)], E-mail: m_ferrouk@yahoo.fr; Aissani, S. [Laboratoire du Genie Physique des Hydrocarbures, University of Boumerdes, Boumerdes 35000 (Algeria); D' Auria, F.; DelNevo, A.; Salah, A. Bousbia [Dipartimento di Ingegneria Meccanica, Nucleare e della Produzione, Universita di Pisa (Italy)

    2008-10-15

    The present article covers the evaluation of the performance of twelve critical heat flux methods/correlations published in the open literature. The study concerns the simulation of an axially non-uniform heat flux distribution with the RELAP5 computer code in a single boiling water reactor channel benchmark problem. The nodalization scheme employed for the considered particular geometry, as modelled in RELAP5 code, is described. For this purpose a review of critical heat flux models/correlations applicable to non-uniform axial heat profile is provided. Simulation results using the RELAP5 code and those obtained from our computer program, based on three type predictions methods such as local conditions, F-factor and boiling length average approaches were compared.

  18. Design of underground layout and their maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bok Youn; Kang, Chang Hee; Jo, Young Do; Lim, Sang Taek [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

    1997-12-01

    Layout of underground structure has to be designed based on rock mechanical analysis and the concept of active support has to be adopted considering the large openings are requested to accommodate heavy duty diesel equipment in underground. Rock bolt and shotcrete will be the most applicable method to support such a large dimensional tunnels. 1) Direction: The main haulage way of the mines where diesel equipment are operating is ramp way system. For optimizing safety measures, and minimizing maintenance cost of the tunnels, it is strongly recommended that all the tunnels including ramp way, rooms and sublevels should be designed in parallel to the direction of principal stress and perpendicular to the direction of major discontinuity. 2) Inclination: Basically, the inclination of the ramp way depends on the specification of the equipment, but 10-15% is usual. The steep inclination needs less initial investment but there will be an adverse effects such as higher operating and maintenance costs. 3) Profile (Cross section): The maximum dimension of the equipment operating in local mines appeared 12.8m long, 3.705m wide and 3.68m high. Considering the dimension, the requested profile simply can be calculated to 4m x 4m, but it should be decided according to the regulated minimum clearances from the walls and roof. The minimum inner curvature radius of the tunnels should be more than 5.2m, and in this case, the tunnel width of the curved zone should be more than 5.5m. 4) Sight distance and braking distance: For the safe operation of the equipment, the sight distance must be longer than braking distance, so that the driver can hold up the equipment safely after finding the obstacles in front of him. The maximum braking distance without heating of brake shoe is 60m. 5) Support and maintenance: Due to the large dimensional tunnels where diesel equipment are operating, the conventional supporting system is not applicable. Therefore, the active support concept should be

  19. Oxidation of benzoic acid by heat-activated persulfate: Effect of temperature on transformation pathway and product distribution.

    Science.gov (United States)

    Zrinyi, Nick; Pham, Anh Le-Tuan

    2017-09-01

    Heat activates persulfate (S 2 O 8 2- ) into sulfate radical (SO 4 - ), a powerful oxidant capable of transforming a wide variety of contaminants. Previous studies have shown that an increase in temperature accelerates the rates of persulfate activation and contaminant transformation. However, few studies have considered the effect of temperature on contaminant transformation pathway. The objective of this study was to determine how temperature (T = 22-70 °C) influences the activation of persulfate, the transformation of benzoic acid (i.e., a model compound), and the distribution of benzoic acid oxidation products. The time-concentration profiles of the products suggest that benzoic acid was transformed via decarboxylation and hydroxylation mechanisms, with the former becoming increasingly important at elevated temperatures. The pathway through which the products were further oxidized was also influenced by the temperature of persulfate activation. Our findings suggest that the role of temperature in the persulfate-based treatment systems is not limited only to controlling the rates of sulfate and hydroxyl radical generation. The ability of sulfate radical to initiate decarboxylation reactions and, more broadly, fragmentation reactions, as well as the effect of temperature on these transformation pathways could be important to the transformation of a number of organic contaminants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Radionuclide behavior at underground environment

    International Nuclear Information System (INIS)

    Hahn, Phil Soo; Park, Chung Kyun; Keum, Dong Kwon; Cho, Young Hwan; Kang, Moon Ja; Baik, Min Hoon; Hahn, Kyung Won; Chun, Kwan Sik; Park, Hyun Soo

    2000-03-01

    This study of radionuclide behavior at underground environment has been carried out as a part of the study of high-level waste disposal technology development. Therefore, the main objectives of this project are constructing a data-base and producing data for the safety assessment of a high-level radioactive waste, and verification of the objectivity of the assessment through characterization of the geochemical processes and experimental validation of the radionuclide migration. The various results from the this project can be applicable to the preliminary safety and performance assessments of the established disposal concept for a future high-level radioactive waste repository. Providing required data and technical basis for assessment methodologies could be a direct application of the results. In a long-term view, the results can also be utilized as a technical background for the establishment of government policy for high-level radioactive waste disposal

  1. Seismic verification of underground explosions

    International Nuclear Information System (INIS)

    Glenn, L.A.

    1985-06-01

    The first nuclear test agreement, the test moratorium, was made in 1958 and lasted until the Soviet Union unilaterally resumed testing in the atmosphere in 1961. It was followed by the Limited Test Ban Treaty of 1963, which prohibited nuclear tests in the atmosphere, in outer space, and underwater. In 1974 the Threshold Test Ban Treaty (TTBT) was signed, limiting underground tests after March 1976 to a maximum yield of 250 kt. The TTBT was followed by a treaty limiting peaceful nuclear explosions and both the United States and the Soviet Union claim to be abiding by the 150-kt yield limit. A comprehensive test ban treaty (CTBT), prohibiting all testing of nuclear weapons, has also been discussed. However, a verifiable CTBT is a contradiction in terms. No monitoring technology can offer absolute assurance that very-low-yield illicit explosions have not occurred. The verification process, evasion opportunities, and cavity decoupling are discussed in this paper

  2. Toxic hazards of underground excavation

    International Nuclear Information System (INIS)

    Smith, R.; Chitnis, V.; Damasian, M.

    1982-09-01

    Inadvertent intrusion into natural or man-made toxic or hazardous material deposits as a consequence of activities such as mining, excavation or tunnelling has resulted in numerous deaths and injuries in this country. This study is a preliminary investigation to identify and document instances of such fatal or injurious intrusion. An objective is to provide useful insights and information related to potential hazards due to future intrusion into underground radioactive-waste-disposal facilities. The methodology used in this study includes literature review and correspondence with appropriate government agencies and organizations. Key categories of intrusion hazards are asphyxiation, methane, hydrogen sulfide, silica and asbestos, naturally occurring radionuclides, and various mine or waste dump related hazards

  3. Radiogenic cancer in underground miners

    International Nuclear Information System (INIS)

    Radford, E.P.

    1984-01-01

    Multiple studies have yielded remarkably consistent results relating radon daughter exposure to lung cancer risk in underground mining populations. The U.S. uranium miner study appears to be at variance with the other results. The primary reason is that the doses in the U.S. miner study were systematically overestimated, resulting in a risk coefficient that is lower than all the others. The significance of these findings for radiogenic lung cancer goes well beyond mining populations, because one is now aware of the implications of radon daughters detected in homes. The highest cumulative levels from radon exposures within homes have been found in Sweden, evidently because of their unusual geology with uranium-bearing ores near the surface. The Swedish authorities view this as a major public health problem that needs to be addressed

  4. Radioactive wastes: underground laboratories implantation

    International Nuclear Information System (INIS)

    Bataille, Ch.

    1997-01-01

    This article studies the situation of radioactive waste management, more especially the possible storage in deep laboratories. In front of the reaction of public opinion relative to the nuclear waste question, it was essential to begin by a study on the notions of liability, transparence and democracy. At the beginning, it was a matter of underground researches with a view to doing an eventual storage of high level radioactive wastes. The Parliament had to define, through the law, a behaviour able to come to the fore for anybody. A behaviour which won recognition from authorities, from scientists, from industrial people, which guarantees the rights of populations confronted to a problem whom they were not informed, on which they received only few explanations. (N.C.)

  5. Underground radioactive waste disposal concept

    International Nuclear Information System (INIS)

    Frgic, L.; Tor, K.; Hudec, M.

    2002-01-01

    The paper presents some solutions for radioactive waste disposal. An underground disposal of radioactive waste is proposed in deep boreholes of greater diameter, fitted with containers. In northern part of Croatia, the geological data are available on numerous boreholes. The boreholes were drilled during investigations and prospecting of petroleum and gas fields. The available data may prove useful in defining safe deep layers suitable for waste repositories. The paper describes a Russian disposal design, execution and verification procedure. The aim of the paper is to discuss some earlier proposed solutions, and present a solution that has not yet been considered - lowering of containers with high level radioactive waste (HLW) to at least 500 m under the ground surface.(author)

  6. Swedish mines. Underground exploitation methods

    International Nuclear Information System (INIS)

    Paucard, A.

    1960-01-01

    Between 1949 and 1957, 10 engineers of the Mining research and exploitation department of the CEA visited 17 Swedish mines during 5 field trips. This paper presents a compilation of the information gathered during these field trips concerning the different underground mining techniques used in Swedish iron mines: mining with backfilling (Central Sweden and Boliden mines); mining without backfilling (mines of the polar circle area). The following techniques are described successively: pillar drawing and backfilled slices (Ammeberg, Falun, Garpenberg, Boliden group), sub-level pillar drawing (Grangesberg, Bloettberget, Haeksberg), empty room and sub-level pillar drawing (Bodas, Haksberg, Stripa, Bastkarn), storage chamber pillar drawing (Bodas, Haeksberg, Bastkarn), and pillar drawing by block caving (ldkerberget). Reprint of a paper published in Revue de l'Industrie Minerale, vol. 41, no. 12, 1959 [fr

  7. Radionuclide behavior at underground environment

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, Phil Soo; Park, Chung Kyun; Keum, Dong Kwon; Cho, Young Hwan; Kang, Moon Ja; Baik, Min Hoon; Hahn, Kyung Won; Chun, Kwan Sik; Park, Hyun Soo

    2000-03-01

    This study of radionuclide behavior at underground environment has been carried out as a part of the study of high-level waste disposal technology development. Therefore, the main objectives of this project are constructing a data-base and producing data for the safety assessment of a high-level radioactive waste, and verification of the objectivity of the assessment through characterization of the geochemical processes and experimental validation of the radionuclide migration. The various results from the this project can be applicable to the preliminary safety and performance assessments of the established disposal concept for a future high-level radioactive waste repository. Providing required data and technical basis for assessment methodologies could be a direct application of the results. In a long-term view, the results can also be utilized as a technical background for the establishment of government policy for high-level radioactive waste disposal.

  8. Toxic hazards of underground excavation

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.; Chitnis, V.; Damasian, M.; Lemm, M.; Popplesdorf, N.; Ryan, T.; Saban, C.; Cohen, J.; Smith, C.; Ciminesi, F.

    1982-09-01

    Inadvertent intrusion into natural or man-made toxic or hazardous material deposits as a consequence of activities such as mining, excavation or tunnelling has resulted in numerous deaths and injuries in this country. This study is a preliminary investigation to identify and document instances of such fatal or injurious intrusion. An objective is to provide useful insights and information related to potential hazards due to future intrusion into underground radioactive-waste-disposal facilities. The methodology used in this study includes literature review and correspondence with appropriate government agencies and organizations. Key categories of intrusion hazards are asphyxiation, methane, hydrogen sulfide, silica and asbestos, naturally occurring radionuclides, and various mine or waste dump related hazards.

  9. Underground repository for radioactive wastes

    International Nuclear Information System (INIS)

    Cassibba, R.O.

    1989-01-01

    In the feasibility study for an underground repository in Argentina, the conceptual basis for the final disposal of high activity nuclear waste was set, as well as the biosphere isolation, according to the multiple barrier concept or to the engineering barrier system. As design limit, the container shall act as an engineering barrier, granting the isolation of the radionuclides for approximately 1000 years. The container for reprocessed and vitrified wastes shall have three metallic layers: a stainless steel inner layer, an external one of a metal to be selected and a thick intermediate lead layer preselected due to its good radiological protection and corrosion resistance. Therefore, the study of the lead corrosion behaviour in simulated media of an underground repository becomes necessary. Relevant parameters of the repository system such as temperature, pressure, water flux, variation in salt concentrations and oxidants supply shall be considered. At the same time, a study is necessary on the galvanic effect of lead coupled with different candidate metals for external layer of the container in the same experimental conditions. Also temporal evaluation about the engineering barrier system efficiency is presented in this thesis. It was considered the extrapolated results of corrosion rates and literature data about the other engineering barriers. Taking into account that corrosion is of a generalized type, the integrity of the lead shall be maintained for more than 1000 years and according to temporal evaluation, the multiple barrier concept shall retard the radionuclide dispersion to the biosphere for a period of time between 10 4 and 10 6 years. (Author) [es

  10. Seismic effects on underground openings

    International Nuclear Information System (INIS)

    Marine, I.W.; Pratt, H.R.; Wahi, K.K.; Science Applications, Inc., La Jolla, CA; Science Applications, Inc., Albuquerque, NM)

    1982-01-01

    Numerical modeling techniques were used to determine the conditions required for seismic waves generated by an earthquake to cause instability to an underground opening or create fracturing and joint movement that would lead to an increase in the permeability of the rock mass. Three different rock types (salt, granite, and shale) were considered as host media for the repository located at a depth of 600 m. Special material models were developed to account for the nonlinear material behavior of each rock type. The sensitivity analysis included variations in the in situ stress ratio, joint geometry, and pore pressures, and the presence or absence of large fractures. Three different sets of earthquake motions were used to excite the rock mass. The methodology applied was found to be suitable for studying the effects of earthquakes on underground openings. In general, the study showed that moderate earthquakes (up to 0.41 g) did not cause instability of the tunnel or major fracturing of the rock mass; however, a tremor with accelerations up to 0.95 g was amplified around the tunnel, and fracturing occurred as a result of the seismic loading in salt and granite. In situ stress is a critical parameter in determining the subsurface effects of earthquakes but is nonexistent in evaluating the cause for surface damage. In shale with the properties assumed, even the moderate seismic load resulted in tunnel instability. These studies are all generic in nature and do not abrogate the need for site and design studies for specific facilities. 30 references, 14 figures, 8 tables

  11. Underground or aboveground storage tanks - A critical decision

    International Nuclear Information System (INIS)

    Rizzo, J.A.

    1992-01-01

    With the 1988 promulgation of the comprehensive Resource Conservation and Recovery Act (RCRA) regulations for underground storage of petroleum and hazardous substances, many existing underground storage tank (UST) owners have been considering making the move to aboveground storage. While on the surface, this may appear to be the cure-all to avoiding the underground leakage dilemma, there are many other new and different issues to consider with aboveground storage. The greatest misconception is that by storing materials above ground, there is no risk of subsurface environmental problems. It should be noted that with the aboveground storage tank (AGST) systems, there is still considerable risk of environmental contamination, either by the failure of onground tank bottoms or the spillage of product onto the ground surface where it subsequently finds its way to the ground water. In addition, there are added safety concerns that must be addressed. The greatest interest in AGSTs comes from managers with small volumes of used oil, fresh oil, solvents, chemicals, or heating oil. Dealing with small capacity tanks is not so different than large bulk storage - and, in fact, it lends itself to more options, such as portable storage, tank within tank configurations and inside installations. So what are the other specific areas of concern besides environmental to be addressed when making the decision between underground and aboveground tanks? The primary issues that will be addressed in this presentation are: (1) safety; (2) product losses; (3) cost comparison of USTs vs AGSTs; (4) space availability/accessibility; (5) precipitation handling; (6) aesthetics and security; (7) pending and existing regulations

  12. Numerical modeling of underground storage system for natural gas

    Science.gov (United States)

    Ding, J.; Wang, S.

    2017-12-01

    Natural gas is an important type of base-load energy, and its supply needs to be adjusted according to different demands in different seasons. For example, since natural gas is increasingly used to replace coal for winter heating, the demand for natural gas in winter is much higher than that in other seasons. As storage systems are the essential tools for balancing seasonal supply and demand, the design and simulation of natural gas storage systems form an important research direction. In this study, a large-scale underground storage system for natural gas is simulated based on theoretical analysis and finite element modeling.It is proven that the problem of axi-symmetric Darcy porous flow of ideal gas is governed by the Boussinesq equation. In terms of the exact solution to the Boussinesq equation, the basic operating characteristics of the underground storage system is analyzed, and it is demonstrated that the propagation distance of the pore pressure is proportional to the 1/4 power of the mass flow rate and to the 1/2 power of the propagation time. This quantitative relationship can be used to guide the overall design of natural gas underground storage systems.In order to fully capture the two-way coupling between pore pressure and elastic matrix deformation, a poro-elastic finite element model for natural gas storage is developed. Based on the numerical model, the dynamic processes of gas injection, storage and extraction are simulated, and the corresponding time-dependent surface deformations are obtained. The modeling results not only provide a theoretical basis for real-time monitoring for the operating status of the underground storage system through surface deformation measurements, but also demonstrate that a year-round balance can be achieved through periodic gas injection and extraction.This work is supported by the CAS "100 talents" Program and the National Natural Science Foundation of China (41371090).

  13. Numerical Analysis of Flow Distribution in a Sodium Chamber of a Finned-tube Sodium-to-Air Heat Exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Youngchul; Son, Seokkwon; Kim, Hyungmo; Eoh, Jaehyuk; Jeong, Jiyoung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    DHR systems consist of two diverse heat removal loops such as passive and active DHR systems, and the heat load imposed on the primary sodium pool is safely rejected into the environment through different kinds of sodium-to-air heat exchangers, e.g. M-shape and helical-coil type air-coolers. The former is called as an FHX(Forced-draft sodium-to-air Heat Exchanger) and the latter is simply called as an AHX(natural-draft sodium-to-Air Heat Exchanger). In a general sodium-to-air heat exchanger design, convection resistance in a shell-side air flow path becomes dominant factor affecting the mechanism of conjugate heat transfer from the sodium flow inside the tube to the air path across the sodium tube wall. Hence verification of the flow and heat transfer characteristics is one of the most important tasks to demonstrate decay heat removal performance. To confirm a kind of ultimate heat sink heat exchanger, a medium-scale Sodium thermal-hydraulic Experiment Loop for Finned-tube sodium-to-Air Heat exchanger (here after called the SELFA) has been designed and is recently being constructed at KAERI site. The introduction of the flow baffle inside the upper sodium chamber of the model FHX unit in the SELFA facility is briefly proposed and discussed as well. The present study aims at introducing a flow baffle design inside the upper sodium chamber to make more equalized flowrates flowing into each heat transfer tube of the model FHX unit. In the cases without the flow baffle geometry, it was observed lager discrepancies in flowrates at the heat transfer tubes. However it was also found that those kinds of discrepancies could be definitely decreased at around 1/10 by employing a flow baffle.

  14. Experimental study of thermal field deriving from an underground electrical power cable buried in non-homogeneous soils

    International Nuclear Information System (INIS)

    Lieto Vollaro, Roberto de; Fontana, Lucia; Vallati, Andrea

    2014-01-01

    The electrical cables ampacity mainly depends on the cable system operation temperature. To achieve a better cable utilization and reduce the conservativeness typically employed in buried cable design, an accurate evaluation of the heat dissipation through the cables and the surrounding soil is important. In the traditional method adopted by the International Electrotechnical Commission (IEC) and the Institute of Electrical and Electronics Engineers (IEEE) for the computation of the thermal resistance between an existing underground cable system and the external environment, it is still assumed that the soil is homogeneous and has uniform thermal conductivity. Numerical studies have been conducted to predict the temperature distribution around the cable for various configurations and thermal properties of the soil. The paper presents an experimental study conducted on a scale model to investigate the heat transfer of a buried cable, with different geometrical configurations and thermal properties of the soil, and to validate a simplified model proposed by the authors in 2012 for the calculation of the thermal resistance between the underground pipe or electrical cable and the ground surface, in cases where the filling of the trench is filled with layers of materials with different thermal properties. Results show that experimental data are in good agreement with the numerical ones. -- Highlights: • Heat transfer of a buried cable has been experimentally studied on a scale model. • Different configurations and thermal properties of the soil have been tested. • Authors previously proposed a simplified model and obtained numerical results. • Experimental results and numerical ones previously obtained were in accordance

  15. Examination of earthquake Ground Motion in the deep underground environment of Japan

    International Nuclear Information System (INIS)

    Goto, J.; Tsuchi, H.; Mashimo, M.

    2009-01-01

    Among the possible impacts of earthquakes on the geological disposal system, ground motion is not included in the criteria for selecting a candidate repository site because, in general, ground motion deep underground is considered to be smaller than at the surface. Also, after backfilling/closure, the repository moves together with the surrounding rock. We have carried out a detailed examination of earthquake ground motion deep underground using extensive data from recent observation networks to support the above assumption. As a result, it has been reconfirmed that earthquake ground motion deep underground is relatively smaller than at the surface. Through detailed analysis of data, we have identified the following important parameters for evaluating earthquake ground motion deep underground: depth and velocity distribution of the rock formations of interest, the intensity of the short period component of earthquakes and incident angle of seismic waves to the rock formations. (authors)

  16. A Numerical Procedure for Flow Distribution and Pressure Drops for U and Z Type Configurations Plate Heat Exchangers with Variable Coefficients

    International Nuclear Information System (INIS)

    López, R; Lecuona, A; Ventas, R; Vereda, C

    2012-01-01

    In Plate Heat Exchangers it is important to determine the flow distribution and pressure drops, because they affect directly the performance of a heat exchanger. This work proposes an incompressible, one-dimensional, steady state, discrete model allowing for variable overall momentum coefficients to determine these magnitudes. The model consists on a modified version of the Bajura and Jones model for dividing and combining flow manifolds. The numerical procedure is based on the finite differences approximation approach proposed by Datta and Majumdar. A linear overall momentum coefficient distribution is used in the dividing manifold, but the model is not limited to linear distributions. Comparisons are made with experimental, numerical and analytical data, yielding good results.

  17. Study on the thermal ignition of gasoline-air mixture in underground oil depots based on experiment and numerical simulation

    Science.gov (United States)

    Ou, Yihong; Du, Yang; Jiang, Xingsheng; Wang, Dong; Liang, Jianjun

    2010-04-01

    The study on the special phenomenon, occurrence process and control mechanism of gasoline-air mixture thermal ignition in underground oil depots is of important academic and applied value for enriching scientific theories of explosion safety, developing protective technology against fire and decreasing the number of fire accidents. In this paper, the research on thermal ignition process of gasoline-air mixture in model underground oil depots tunnel has been carried out by using experiment and numerical simulation methods. The calculation result has been demonstrated by the experiment data. The five stages of thermal ignition course, which are slow oxidation stage, rapid oxidation stage, fire stage, flameout stage and quench stage, have been firstly defined and accurately descried. According to the magnitude order of concentration, the species have been divided into six categories, which lay the foundation for explosion-proof design based on the role of different species. The influence of space scale on thermal ignition in small-scale space has been found, and the mechanism for not easy to fire is that the wall reflection causes the reflux of fluids and changes the distribution of heat and mass, so that the progress of chemical reactions in the whole space are also changed. The novel mathematical model on the basis of unification chemical kinetics and thermodynamics established in this paper provides supplementary means for the analysis of process and mechanism of thermal ignition.

  18. Evaluation on double-wall-tube residual stress distribution of sodium-heated steam generator by neutron diffraction and numerical analysis

    International Nuclear Information System (INIS)

    Kisohara, N.; Suzuki, H.; Akita, K.; Kasahara, N.

    2012-01-01

    A double-wall-tube is nominated for the steam generator heat transfer tube of future sodium fast reactors (SFRs) in Japan, to decrease the possibility of sodium/water reaction. The double-wall-tube consists of an inner tube and an outer tube, and they are mechanically contacted to keep the heat transfer of the interface between the inner and outer tubes by their residual stress. During long term SG operation, the contact stress at the interface gradually falls down due to stress relaxation. This phenomenon might increase the thermal resistance of the interface and degrade the tube heat transfer performance. The contact stress relaxation can be predicted by numerical analysis, and the analysis requires the data of the initial residual stress distributions in the tubes. However, unclear initial residual stress distributions prevent precious relaxation evaluation. In order to resolve this issue, a neutron diffraction method was employed to reveal the tri-axial (radius, hoop and longitudinal) initial residual stress distributions in the double-wall-tube. Strain gauges also were used to evaluate the contact stress. The measurement results were analyzed using a JAEA's structural computer code to determine the initial residual stress distributions. Based on the stress distributions, the structural computer code has predicted the transition of the relaxation and the decrease of the contact stress. The radial and longitudinal temperature distributions in the tubes were input to the structural analysis model. Since the radial thermal expansion difference between the inner (colder) and outer (hotter) tube reduces the contact stress and the tube inside steam pressure contributes to increasing it, the analytical model also took these effects into consideration. It has been conduced that the inner and outer tubes are contacted with sufficient stresses during the plant life time, and that effective heat transfer degradation dose not occur in the double-wall-tube SG. (authors)

  19. Heat-transfer and pressure distributions for laminar separated flows downstream of rearward-facing steps with and without mass suction

    Science.gov (United States)

    Brown, R. D.; Jakubowski, A. K.

    1974-01-01

    Heat-transfer and pressure distributions were measured for laminar separated flows downstream of rearward-facing steps with and without mass suction. The flow conditions were such that the boundary-layer thickness was comparable to or larger than the step height. For both suction and no-suction cases, an increase in the step height resulted in a sharp decrease in the initial heat-transfer rates behind the step. Downstream, however, the heat transfer gradually recovered back to less than or near attached-flow values. Mass suction from the step base area increased the local heat-transfer rates; however, this effect was relatively weak for the laminar flows considered. Even removal of the entire approaching boundary layer raised the post-step heat-transfer rates only about 10 percent above the flatplate values. Post-step pressure distributions were found to depend on the entrainment conditions at separation. In the case of the solid-faced step, a sharp pressure drop behind the step was followed by a very short plateau and relatively fast recompression. For the slotted-step connected to a large plenum but without suction, the pressure drop at the base was much smaller and the downstream recompression more gradual than that for solid-faced step.

  20. Influence of forced internal air circulation on airflow distribution and heat transfer in a gas double-dynamic solid-state fermentation bioreactor.

    Science.gov (United States)

    Chen, Hongzhang; Qin, Lanzhi; Li, Hongqiang

    2014-02-01

    Internal air circulation affects the temperature field distribution in a gas double-dynamic solid-state fermentation bioreactor (GDSFB). To enhance heat transfer through strengthening internal air circulation in a GDSFB, we put an air distribution plate (ADP) into the bioreactor and studied the effects of forced internal air circulation on airflow, heat transfer, and cellulase activity of Trichoderma viride L3. Results showed that ADP could help form a steady and uniform airflow distribution, and with gas-guide tubes, air reversal was formed inside the bioreactor, thus resulting in a smaller temperature difference between medium and air by enhancing convective heat transfer inside the bioreactor. Using an ADP of 5.35 % aperture ratio caused a 1 °C decrease in the average temperature difference during the solid-state fermentation process of T. viride L3. Meanwhile, the cellulase activity of T. viride L3 increased by 13.5 %. The best heat-transfer effect was attained when using an ADP of 5.35 % aperture ratio and setting the fan power to 125 V (4.81 W) in the gas double-dynamic solid-state fermentation (GDSF) process. An option of suitable aperture ratio and fan power may be conducive to ADPs' industrial amplification.