WorldWideScience

Sample records for estimate recoverable heat

  1. An Estimate of Recoverable Heavy Oil Resources of the Orinoco Oil Belt, Venezuela

    Science.gov (United States)

    Schenk, Christopher J.; Cook, Troy A.; Charpentier, Ronald R.; Pollastro, Richard M.; Klett, Timothy R.; Tennyson, Marilyn E.; Kirschbaum, Mark A.; Brownfield, Michael E.; Pitman, Janet K.

    2009-01-01

    The Orinoco Oil Belt Assessment Unit of the La Luna-Quercual Total Petroleum System encompasses approximately 50,000 km2 of the East Venezuela Basin Province that is underlain by more than 1 trillion barrels of heavy oil-in-place. As part of a program directed at estimating the technically recoverable oil and gas resources of priority petroleum basins worldwide, the U.S. Geological Survey estimated the recoverable oil resources of the Orinoco Oil Belt Assessment Unit. This estimate relied mainly on published geologic and engineering data for reservoirs (net oil-saturated sandstone thickness and extent), petrophysical properties (porosity, water saturation, and formation volume factors), recovery factors determined by pilot projects, and estimates of volumes of oil-in-place. The U.S. Geological Survey estimated a mean volume of 513 billion barrels of technically recoverable heavy oil in the Orinoco Oil Belt Assessment Unit of the East Venezuela Basin Province; the range is 380 to 652 billion barrels. The Orinoco Oil Belt Assessment Unit thus contains one of the largest recoverable oil accumulations in the world.

  2. Shale Gas Boom or Bust? Estimating US and Global Economically Recoverable Resources

    Science.gov (United States)

    Brecha, R. J.; Hilaire, J.; Bauer, N.

    2014-12-01

    One of the most disruptive energy system technological developments of the past few decades is the rapid expansion of shale gas production in the United States. Because the changes have been so rapid there are great uncertainties as to the impacts of shale production for medium- and long-term energy and climate change mitigation policies. A necessary starting point for incorporating shale resources into modeling efforts is to understand the size of the resource, how much is technically recoverable (TRR), and finally, how much is economically recoverable (ERR) at a given cost. To assess production costs of shale gas, we combine top-down data with detailed bottom-up information. Studies solely based on top-down approaches do not adequately account for the heterogeneity of shale gas deposits and are unlikely to appropriately estimate extraction costs. We design an expedient bottom-up method based on publicly available US data to compute the levelized costs of shale gas extraction. Our results indicate the existence of economically attractive areas but also reveal a dramatic cost increase as lower-quality reservoirs are exploited. Extrapolating results for the US to the global level, our best estimate suggests that, at a cost of 6 US$/GJ, only 39% of the technically recoverable resources reported in top-down studies should be considered economically recoverable. This estimate increases to about 77% when considering optimistic TRR and estimated ultimate recovery parameters but could be lower than 12% for more pessimistic parameters. The current lack of information on the heterogeneity of shale gas deposits as well as on the development of future production technologies leads to significant uncertainties regarding recovery rates and production costs. Much of this uncertainty may be inherent, but for energy system planning purposes, with or without climate change mitigation policies, it is crucial to recognize the full ranges of recoverable quantities and costs.

  3. Recoverable Resource Estimate of Identified Onshore Geopressured Geothermal Energy in Texas and Louisiana (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Esposito, A.; Augustine, C.

    2012-04-01

    Geopressured geothermal reservoirs are characterized by high temperatures and high pressures with correspondingly large quantities of dissolved methane. Due to these characteristics, the reservoirs provide two sources of energy: chemical energy from the recovered methane, and thermal energy from the recovered fluid at temperatures high enough to operate a binary power plant for electricity production. Formations with the greatest potential for recoverable energy are located in the gulf coastal region of Texas and Louisiana where significantly overpressured and hot formations are abundant. This study estimates the total recoverable onshore geopressured geothermal resource for identified sites in Texas and Louisiana. In this study a geopressured geothermal resource is defined as a brine reservoir with fluid temperature greater than 212 degrees F and a pressure gradient greater than 0.7 psi/ft.

  4. Estimating technically recoverable reserves in the Faja Petrolifera del Orinoco : FPO

    Energy Technology Data Exchange (ETDEWEB)

    Dusseault, M.B. [Waterloo Univ., ON (Canada); Zambrano, A.; Barrios, J.R.; Guerra, C. [PDVSA, La Campina, Caracas (Venezuela)

    2008-07-01

    In Venezuela, the Faja Petrolifera del Orinoco (FPO) is the largest hydrocarbon accumulation. This paper reported on a methodology to determine the proportion that was technically recoverable with existing production methods. The approach was described using an example from Carabobo region and was based on geophysical, geological and log data. The paper discussed technology suitability for the FPO including field trial recommendations; a review and rationale for PPT trials; a review and rationale for cold heavy oil production with sand (CHOPS) trials; steam assisted gravity drainage (SAGD) potential in the FPO; and rationale for horizontal steam stimulation (HCS) to SAGD trials. Stratigraphy of the Carabobo area and sedimentation and facies summary were presented. Last, the paper discussed a technology screening exercise. It was concluded that a reasonable recoverable reserves estimate for the Venezuelan FPO was an overall recovery for the entire FPO of approximately 20 per cent and that pilot tests in the FPO have shown good responses. 10 refs., 5 tabs., 5 figs.

  5. Shared Recoverable Objects

    OpenAIRE

    Kienzle, Jörg; Strohmeier, Alfred; Harbour, Michael Gonzalez; de la Puente, Juan A.

    1999-01-01

    This document describes an implementation of recoverable objects that can be accessed concurrently. After a brief description of the possible uses of recoverable objects and after reviewing some of the new features of Ada 95 used in the implementation, the design issues are discussed and the interface of the recoverable object class is presented. An example application using multitasking demonstrates its applicability.

  6. Magnetically recoverable nanocatalysts

    KAUST Repository

    Polshettiwar, Vivek

    2011-05-11

    A broad overview on magnetically recoverable nanocatalysts is presented and the use of magnetic nanomaterials as catalysts is discussed. Magnetic materials are used as organocatalysts and their applications range to challenging reactions, such as hydroformylation and olefin metathesis. Magnetic nanomaterials are also being used in environmental applications, such as for photo- and biocatalysis and for the adsorption and removal of pollutants from air and water. These materials show great promise as enantioselective catalysts, which are used extensively for the synthesis of medicines, drugs, and other bioactive molecules. By functionalizing these materials using chiral ligands, a series of chiral nanocatalysts can be designed, offering great potential to reuse these otherwise expensive catalyst systems. Characterization of magnetic catalysts is often a challenging task, and NMR characterization of these catalysts is difficult because the magnetic nature of the materials interferes with the magnetic field of the spectrometer.

  7. Renewable and recoverable energies. ADEME's views

    International Nuclear Information System (INIS)

    2017-12-01

    This report presents the opinion (December 2017) of ADEME, the French office for energy management and sustainable development, on the future prospects of renewable and recoverable energies in France for 2050. It is assessed that, if associated to a firm energy conservation policy, the renewable and recoverable energies will have the ability to cover more than two thirds of the French energy needs in 2050, while ensuring energy supply security and price stability, a high level of energy independence, the preservation of the environment and a re-localization of the production value and of the employment. The report then presents the various renewable and recoverable energies, the assessment of the potential resources, the applications in the residential (individual and collective), industrial and commercial sectors, the comparison with other European countries, the public financial incentives and support, cost estimations of each energy source, assessments of the markets and of the potential economic impacts, etc. Some recommendations are given, notably concerning the necessary public support for the renewable and recoverable energy sectors, and the synergy between power distribution systems and the energy systems. An annex gives details on the environmental impacts of renewable and recoverable energy sources

  8. Fault Recoverability Analysis via Cross-Gramian

    DEFF Research Database (Denmark)

    Shaker, Hamid Reza

    2016-01-01

    Engineering systems are vulnerable to different kinds of faults. Faults may compromise safety, cause sub-optimal operation and decline in performance if not preventing the whole system from functioning. Fault tolerant control (FTC) methods ensure that the system performance maintains within...... an acceptable level at the occurrence of the faults. These techniques cannot be successful if the necessary redundancy does not exist in the system. Fault recoverability which is also known as control reconfigurability is a mathematical measure which quantifies the level of redundancy in connection...... with feedback control. Fault recoverability provides important and useful information which could be used in analysis and design. However, computing fault recoverability is numerically expensive. In this paper, a new approach for computation of fault recoverability for bilinear systems is proposed...

  9. Potential for technically recoverable unconventional gas and oil resources in the Polish-Ukrainian Foredeep, Poland, 2012

    Science.gov (United States)

    Gautier, Donald L.; Pitman, Janet K.; Charpentier, Ronald R.; Cook, Troy; Klett, Timothy R.; Schenk, Christopher J.

    2012-01-01

    Using a performance-based geological assessment methodology, the U.S. Geological Survey estimated mean volumes of 1,345 billion cubic feet of potentially technically recoverable gas and 168 million barrels of technically recoverable oil and natural gas liquids in Ordovician and Silurian age shales in the Polish- Ukrainian Foredeep basin of Poland.

  10. Residual stresses estimation in tubes after rapid heating of surface

    International Nuclear Information System (INIS)

    Serikov, S.V.

    1992-01-01

    Results are presented on estimation of residual stresses in tubes of steel types ShKh15, EhP836 and 12KIMF after heating by burning pyrotechnic substance inside tubes. External tube surface was heated up to 400-450 deg C under such treatment. Axial stresses distribution over tube wall thickness was determined for initial state, after routine heat treatment and after heating with the use of fireworks. Inner surface heating was shown to essentially decrease axial stresses in tubes

  11. Estimating heat-to-heat variation from a statistician's point of view

    International Nuclear Information System (INIS)

    Hebble, T.L.

    1976-01-01

    Heat-to-heat variability is the change in results that occurs when the same tests under the same conditions are applied to samples from different heats of the same material. Heat-to-heat variability reflects, among other things, difference in chemistry and in processing history. Published Japanese tensile and creep tests on types 304 and 316 stainless steel tube are used to illustrate the analysis of variance technique as a tool for isolating heat-to-heat variation. The importance of the underlying model and the role of replication are indicated. Finally, confidence intervals and tolerance limits are computed from numerical estimates of heat-to-heat variation. 17 tables

  12. Anthropogenic heat flux estimation from space

    NARCIS (Netherlands)

    Chrysoulakis, Nektarios; Marconcini, Mattia; Gastellu-Etchegorry, Jean Philippe; Grimmond, C.S.B.; Feigenwinter, Christian; Lindberg, Fredrik; Frate, Del Fabio; Klostermann, Judith; Mitraka, Zina; Esch, Thomas; Landier, Lucas; Gabey, Andy; Parlow, Eberhard; Olofson, Frans

    2016-01-01

    H2020-Space project URBANFLUXES (URBan ANthrpogenic heat FLUX from Earth observation Satellites) investigates the potential of Copernicus Sentinels to retrieve anthropogenic heat flux, as a key component of the Urban Energy Budget (UEB). URBANFLUXES advances the current knowledge of the impacts

  13. ANthropogenic heat FLUX estimation from Space

    NARCIS (Netherlands)

    Chrysoulakis, Nektarios; Marconcini, Mattia; Gastellu-Etchegorry, Jean Philippe; Grimmong, C.S.B.; Feigenwinter, Christian; Lindberg, Fredrik; Frate, Del Fabio; Klostermann, Judith; Mi, Zina; Esch, Thomas; Landier, Lucas; Gabey, Andy; Parlow, Eberhard; Olofson, Frans

    2017-01-01

    The H2020-Space project URBANFLUXES (URBan ANthrpogenic heat FLUX from Earth observation Satellites) investigates the potential of Copernicus Sentinels to retrieve anthropogenic heat flux, as a key component of the Urban Energy Budget (UEB). URBANFLUXES advances the current knowledge of the

  14. Surface renewal method for estimating sensible heat flux | Mengistu ...

    African Journals Online (AJOL)

    For short canopies, latent energy flux may be estimated using a shortened surface energy balance from measurements of sensible and soil heat flux and the net irradiance at the surface. The surface renewal (SR) method for estimating sensible heat, latent energy, and other scalar fluxes has the advantage over other ...

  15. Gradient estimates on the weighted p-Laplace heat equation

    Science.gov (United States)

    Wang, Lin Feng

    2018-01-01

    In this paper, by a regularization process we derive new gradient estimates for positive solutions to the weighted p-Laplace heat equation when the m-Bakry-Émery curvature is bounded from below by -K for some constant K ≥ 0. When the potential function is constant, which reduce to the gradient estimate established by Ni and Kotschwar for positive solutions to the p-Laplace heat equation on closed manifolds with nonnegative Ricci curvature if K ↘ 0, and reduce to the Davies, Hamilton and Li-Xu's gradient estimates for positive solutions to the heat equation on closed manifolds with Ricci curvature bounded from below if p = 2.

  16. Estimating the Heat of Formation of Foodstuffs and Biomass

    Energy Technology Data Exchange (ETDEWEB)

    Burnham, Alan K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2010-11-23

    Calorie estimates for expressing the energy content of food are common, however they are inadequate for the purpose of estimating the chemically defined heat of formation of foodstuffs for two reasons. First, they assume utilization factors by the body.1,2,3 Second, they are usually based on average values for their components. The best way to solve this problem would be to measure the heat of combustion of each material of interest. The heat of formation can then be calculated from the elemental composition and the heats of formation of CO2, H2O, and SO2. However, heats of combustion are not always available. Sometimes elemental analysis only is available, or in other cases, a breakdown into protein, carbohydrates, and lipids. A simple way is needed to calculate the heat of formation from various sorts of data commonly available. This report presents improved correlations for relating the heats of combustion and formation to the elemental composition, moisture content, and ash content. The correlations are also able to calculate heats of combustion of carbohydrates, proteins, and lipids individually, including how they depend on elemental composition. The starting point for these correlations are relationships commonly used to estimate the heat of combustion of fossil fuels, and they have been modified slightly to agree better with the ranges of chemical structures found in foodstuffs and biomass.

  17. Recoverable Robustness in Shunting and Timetabling

    Science.gov (United States)

    Cicerone, Serafino; D'Angelo, Gianlorenzo; di Stefano, Gabriele; Frigioni, Daniele; Navarra, Alfredo; Schachtebeck, Michael; Schöbel, Anita

    In practical optimization problems, disturbances to a given instance are unavoidable due to unpredictable events which can occur when the system is running. In order to face these situations, many approaches have been proposed during the last years in the area of robust optimization. The basic idea of robustness is to provide a solution which is able to keep feasibility even if the input instance is disturbed, at the cost of optimality. However, the notion of robustness in every day life is much broader than that pursued in the area of robust optimization so far. In fact, robustness is not always suitable unless some recovery strategies are introduced. Recovery strategies are some capabilities that can be used when disturbing events occur, in order to keep the feasibility of the pre-computed solution. This suggests to study robustness and recoverability in a unified framework. Recently, a first tentative of unifying the notions of robustness and recoverability into a new integrated notion of recoverable robustness has been done in the context of railway optimization.

  18. Estimating local heat transfer coefficients from thin wall temperature measurements

    Science.gov (United States)

    Gazizov, I. M.; Davletshin, I. A.; Paereliy, A. A.

    2017-09-01

    An approach to experimental estimation of local heat transfer coefficient on a plane wall has been described. The approach is based on measurements of heat-transfer fluid and wall temperatures during some certain time of wall cooling. The wall was a thin plate, a printed circuit board, made of composite epoxy material covered with a copper layer. The temperature field can be considered uniform across the plate thickness when heat transfer is moderate and thermal resistance of the plate in transversal direction is low. This significantly simplifies the heat balance written for the wall sections that is used to estimate the heat transfer coefficient. The copper layer on the plate etched to form a single strip acted as resistance thermometers that measured the local temperature of the wall.

  19. Coupling heat and chemical tracer experiments for estimating heat transfer parameters in shallow alluvial aquifers.

    Science.gov (United States)

    Wildemeersch, S; Jamin, P; Orban, P; Hermans, T; Klepikova, M; Nguyen, F; Brouyère, S; Dassargues, A

    2014-11-15

    Geothermal energy systems, closed or open, are increasingly considered for heating and/or cooling buildings. The efficiency of such systems depends on the thermal properties of the subsurface. Therefore, feasibility and impact studies performed prior to their installation should include a field characterization of thermal properties and a heat transfer model using parameter values measured in situ. However, there is a lack of in situ experiments and methodology for performing such a field characterization, especially for open systems. This study presents an in situ experiment designed for estimating heat transfer parameters in shallow alluvial aquifers with focus on the specific heat capacity. This experiment consists in simultaneously injecting hot water and a chemical tracer into the aquifer and monitoring the evolution of groundwater temperature and concentration in the recovery well (and possibly in other piezometers located down gradient). Temperature and concentrations are then used for estimating the specific heat capacity. The first method for estimating this parameter is based on a modeling in series of the chemical tracer and temperature breakthrough curves at the recovery well. The second method is based on an energy balance. The values of specific heat capacity estimated for both methods (2.30 and 2.54MJ/m(3)/K) for the experimental site in the alluvial aquifer of the Meuse River (Belgium) are almost identical and consistent with values found in the literature. Temperature breakthrough curves in other piezometers are not required for estimating the specific heat capacity. However, they highlight that heat transfer in the alluvial aquifer of the Meuse River is complex and contrasted with different dominant process depending on the depth leading to significant vertical heat exchange between upper and lower part of the aquifer. Furthermore, these temperature breakthrough curves could be included in the calibration of a complex heat transfer model for

  20. Maximum Recoverable Gas from Hydrate Bearing Sediments by Depressurization

    KAUST Repository

    Terzariol, Marco

    2017-11-13

    The estimation of gas production rates from hydrate bearing sediments requires complex numerical simulations. This manuscript presents a set of simple and robust analytical solutions to estimate the maximum depressurization-driven recoverable gas. These limiting-equilibrium solutions are established when the dissociation front reaches steady state conditions and ceases to expand further. Analytical solutions show the relevance of (1) relative permeabilities between the hydrate free sediment, the hydrate bearing sediment, and the aquitard layers, and (2) the extent of depressurization in terms of the fluid pressures at the well, at the phase boundary, and in the far field. Close form solutions for the size of the produced zone allow for expeditious financial analyses; results highlight the need for innovative production strategies in order to make hydrate accumulations an economically-viable energy resource. Horizontal directional drilling and multi-wellpoint seafloor dewatering installations may lead to advantageous production strategies in shallow seafloor reservoirs.

  1. Anthropogenic heat flux estimation from space: first results

    Science.gov (United States)

    Chrysoulakis, Nektarios; Heldens, Wieke; Gastellu-Etchegorry, Jean-Philippe; Grimmond, Sue; Feigenwinter, Christian; Lindberg, Fredrik; Del Frate, Fabio; Klostermann, Judith; Mitraka, Zina; Esch, Thomas; Albitar, Ahmad; Gabey, Andrew; Parlow, Eberhard; Olofson, Frans

    2016-04-01

    While Earth Observation (EO) has made significant advances in the study of urban areas, there are several unanswered science and policy questions to which it could contribute. To this aim the recently launched Horizon 2020 project URBANFLUXES (URBan ANthrpogenic heat FLUX from Earth observation Satellites) investigates the potential of EO to retrieve anthropogenic heat flux, as a key component in the urban energy budget. The anthropogenic heat flux is the heat flux resulting from vehicular emissions, space heating and cooling of buildings, industrial processing and the metabolic heat release by people. Optical, thermal and SAR data from existing satellite sensors are used to improve the accuracy of the radiation balance spatial distribution calculation, using also in-situ reflectance measurements of urban materials are for calibration. EO-based methods are developed for estimating turbulent sensible and latent heat fluxes, as well as urban heat storage flux and anthropogenic heat flux spatial patterns at city scale and local scale by employing an energy budget closure approach. Independent methods and models are engaged to evaluate the derived products and statistical analyses provide uncertainty measures as well. Ultimate goal of the URBANFLUXES is to develop a highly automated method for estimating urban energy budget components to use with Copernicus Sentinel data, enabling its integration into applications and operational services. Thus, URBANFLUXES prepares the ground for further innovative exploitation of European space data in scientific activities (i.e. Earth system modelling and climate change studies in cities) and future and emerging applications (i.e. sustainable urban planning) by exploiting the improved data quality, coverage and revisit times of the Copernicus data. The URBANFLUXES products will therefore have the potential to support both sustainable planning strategies to improve the quality of life in cities, as well as Earth system models to

  2. Simple future weather files for estimating heating and cooling demand

    DEFF Research Database (Denmark)

    Cox, Rimante Andrasiunaite; Drews, Martin; Rode, Carsten

    2015-01-01

    Estimations of the future energy consumption of buildings are becoming increasingly important as a basis for energy management, energy renovation, investment planning, and for determining the feasibility of technologies and designs. Future weather scenarios, where the outdoor climate is usually...... useful estimates of future energy demand of a building. Experimental results based on both the degree-day method and dynamic simulations suggest that this is indeed the case. Specifically, heating demand estimates were found to be within a few per cent of one another, while estimates of cooling demand...... were slightly more varied. This variation was primarily due to the very few hours of cooling that were required in the region examined. Errors were found to be most likely when the air temperatures were close to the heating or cooling balance points, where the energy demand was modest and even...

  3. Estimation of bulk transfer coefficient for latent heat flux (Ce)

    Digital Repository Service at National Institute of Oceanography (India)

    Sadhuram, Y.

    The bulk transfer coefficient for latent heat flux (Ce) has been estimated over the Arabian Sea from the moisture budget during the pre-monsoon season of 1988. The computations have been made over two regions (A: 0-8 degrees N: 60-68 degrees E: B: 0...

  4. Recov'Heat: An estimation tool of urban waste heat recovery potential in sustainable cities

    Science.gov (United States)

    Goumba, Alain; Chiche, Samuel; Guo, Xiaofeng; Colombert, Morgane; Bonneau, Patricia

    2017-02-01

    Waste heat recovery is considered as an efficient way to increase carbon-free green energy utilization and to reduce greenhouse gas emission. Especially in urban area, several sources such as sewage water, industrial process, waste incinerator plants, etc., are still rarely explored. Their integration into a district heating system providing heating and/or domestic hot water could be beneficial for both energy companies and local governments. EFFICACITY, a French research institute focused on urban energy transition, has developed an estimation tool for different waste heat sources potentially explored in a sustainable city. This article presents the development method of such a decision making tool which, by giving both energetic and economic analysis, helps local communities and energy service companies to make preliminary studies in heat recovery projects.

  5. Heat experiment design to estimate temperature dependent thermal properties

    International Nuclear Information System (INIS)

    Romanovski, M

    2008-01-01

    Experimental conditions are studied to optimize transient experiments for estimating temperature dependent thermal conductivity and volumetric heat capacity. A mathematical model of a specimen is the one-dimensional heat equation with boundary conditions of the second kind. Thermal properties are assumed to vary nonlinearly with temperature. Experimental conditions refer to the thermal loading scheme, sampling times and sensor location. A numerical model of experimental configurations is studied to elicit the optimal conditions. The numerical solution of the design problem is formulated on a regularization scheme with a stabilizer minimization without a regularization parameter. An explicit design criterion is used to reveal the optimal sensor location, heating duration and flux magnitude. Results obtained indicate that even the strongly nonlinear experimental design problem admits the aggregation of its solution and has a strictly defined optimal measurement scheme. Additional region of temperature measurements with allowable identification error is revealed.

  6. Spectral estimates of net radiation and soil heat flux

    International Nuclear Information System (INIS)

    Daughtry, C.S.T.; Kustas, W.P.; Moran, M.S.; Pinter, P.J. Jr.; Jackson, R.D.; Brown, P.W.; Nichols, W.D.; Gay, L.W.

    1990-01-01

    Conventional methods of measuring surface energy balance are point measurements and represent only a small area. Remote sensing offers a potential means of measuring outgoing fluxes over large areas at the spatial resolution of the sensor. The objective of this study was to estimate net radiation (Rn) and soil heat flux (G) using remotely sensed multispectral data acquired from an aircraft over large agricultural fields. Ground-based instruments measured Rn and G at nine locations along the flight lines. Incoming fluxes were also measured by ground-based instruments. Outgoing fluxes were estimated using remotely sensed data. Remote Rn, estimated as the algebraic sum of incoming and outgoing fluxes, slightly underestimated Rn measured by the ground-based net radiometers. The mean absolute errors for remote Rn minus measured Rn were less than 7%. Remote G, estimated as a function of a spectral vegetation index and remote Rn, slightly overestimated measured G; however, the mean absolute error for remote G was 13%. Some of the differences between measured and remote values of Rn and G are associated with differences in instrument designs and measurement techniques. The root mean square error for available energy (Rn - G) was 12%. Thus, methods using both ground-based and remotely sensed data can provide reliable estimates of the available energy which can be partitioned into sensible and latent heat under non advective conditions

  7. The Impacts of Heating Strategy on Soil Moisture Estimation Using Actively Heated Fiber Optics.

    Science.gov (United States)

    Dong, Jianzhi; Agliata, Rosa; Steele-Dunne, Susan; Hoes, Olivier; Bogaard, Thom; Greco, Roberto; van de Giesen, Nick

    2017-09-13

    Several recent studies have highlighted the potential of Actively Heated Fiber Optics (AHFO) for high resolution soil moisture mapping. In AHFO, the soil moisture can be calculated from the cumulative temperature ( T cum ), the maximum temperature ( T max ), or the soil thermal conductivity determined from the cooling phase after heating ( λ ). This study investigates the performance of the T cum , T max and λ methods for different heating strategies, i.e., differences in the duration and input power of the applied heat pulse. The aim is to compare the three approaches and to determine which is best suited to field applications where the power supply is limited. Results show that increasing the input power of the heat pulses makes it easier to differentiate between dry and wet soil conditions, which leads to an improved accuracy. Results suggest that if the power supply is limited, the heating strength is insufficient for the λ method to yield accurate estimates. Generally, the T cum and T max methods have similar accuracy. If the input power is limited, increasing the heat pulse duration can improve the accuracy of the AHFO method for both of these techniques. In particular, extending the heating duration can significantly increase the sensitivity of T cum to soil moisture. Hence, the T cum method is recommended when the input power is limited. Finally, results also show that up to 50% of the cable temperature change during the heat pulse can be attributed to soil background temperature, i.e., soil temperature changed by the net solar radiation. A method is proposed to correct this background temperature change. Without correction, soil moisture information can be completely masked by the background temperature error.

  8. Pipeline heating method based on optimal control and state estimation

    Energy Technology Data Exchange (ETDEWEB)

    Vianna, F.L.V. [Dept. of Subsea Technology. Petrobras Research and Development Center - CENPES, Rio de Janeiro, RJ (Brazil)], e-mail: fvianna@petrobras.com.br; Orlande, H.R.B. [Dept. of Mechanical Engineering. POLI/COPPE, Federal University of Rio de Janeiro - UFRJ, Rio de Janeiro, RJ (Brazil)], e-mail: helcio@mecanica.ufrj.br; Dulikravich, G.S. [Dept. of Mechanical and Materials Engineering. Florida International University - FIU, Miami, FL (United States)], e-mail: dulikrav@fiu.edu

    2010-07-01

    In production of oil and gas wells in deep waters the flowing of hydrocarbon through pipeline is a challenging problem. This environment presents high hydrostatic pressures and low sea bed temperatures, which can favor the formation of solid deposits that in critical operating conditions, as unplanned shutdown conditions, may result in a pipeline blockage and consequently incur in large financial losses. There are different methods to protect the system, but nowadays thermal insulation and chemical injection are the standard solutions normally used. An alternative method of flow assurance is to heat the pipeline. This concept, which is known as active heating system, aims at heating the produced fluid temperature above a safe reference level in order to avoid the formation of solid deposits. The objective of this paper is to introduce a Bayesian statistical approach for the state estimation problem, in which the state variables are considered as the transient temperatures within a pipeline cross-section, and to use the optimal control theory as a design tool for a typical heating system during a simulated shutdown condition. An application example is presented to illustrate how Bayesian filters can be used to reconstruct the temperature field from temperature measurements supposedly available on the external surface of the pipeline. The temperatures predicted with the Bayesian filter are then utilized in a control approach for a heating system used to maintain the temperature within the pipeline above the critical temperature of formation of solid deposits. The physical problem consists of a pipeline cross section represented by a circular domain with four points over the pipe wall representing heating cables. The fluid is considered stagnant, homogeneous, isotropic and with constant thermo-physical properties. The mathematical formulation governing the direct problem was solved with the finite volume method and for the solution of the state estimation problem

  9. Quantifying the Recoverable Resources of Companion Metals: A Preliminary Study of Australian Mineral Resources

    Directory of Open Access Journals (Sweden)

    Gavin M. Mudd

    2014-12-01

    Full Text Available The long-term availability of mineral resources is crucial in underpinning human society, technology, and economic activity, and in managing anthropogenic environmental impacts. This is increasingly true for metals that do not generally form the primary product of mines (“host” metals, such as copper or iron, but are recovered as by-products (or sometimes co-products during the processing of primary ores. For these “companion” metals, it is therefore useful to develop methodologies to estimate the recoverable resource, i.e., the amount that could, if desired, be extracted and put into use over the next several decades. We describe here a methodological approach to estimating the recoverable resources of companion metals in metal ores, using preliminary data for some particular host/companion pairs in Australia as examples.

  10. SPECTRAL data-based estimation of soil heat flux

    Science.gov (United States)

    Singh, Ramesh K.; Irmak, A.; Walter-Shea, Elizabeth; Verma, S.B.; Suyker, A.E.

    2011-01-01

    Numerous existing spectral-based soil heat flux (G) models have shown wide variation in performance for maize and soybean cropping systems in Nebraska, indicating the need for localized calibration and model development. The objectives of this article are to develop a semi-empirical model to estimate G from a normalized difference vegetation index (NDVI) and net radiation (Rn) for maize (Zea mays L.) and soybean (Glycine max L.) fields in the Great Plains, and present the suitability of the developed model to estimate G under similar and different soil and management conditions. Soil heat fluxes measured in both irrigated and rainfed fields in eastern and south-central Nebraska were used for model development and validation. An exponential model that uses NDVI and Rn was found to be the best to estimate G based on r2 values. The effect of geographic location, crop, and water management practices were used to develop semi-empirical models under four case studies. Each case study has the same exponential model structure but a different set of coefficients and exponents to represent the crop, soil, and management practices. Results showed that the semi-empirical models can be used effectively for G estimation for nearby fields with similar soil properties for independent years, regardless of differences in crop type, crop rotation, and irrigation practices, provided that the crop residue from the previous year is more than 4000 kg ha-1. The coefficients calibrated from particular fields can be used at nearby fields in order to capture temporal variation in G. However, there is a need for further investigation of the models to account for the interaction effects of crop rotation and irrigation. Validation at an independent site having different soil and crop management practices showed the limitation of the semi-empirical model in estimating G under different soil and environment conditions.

  11. Series load induction heating inverter state estimator using Kalman filter

    Directory of Open Access Journals (Sweden)

    Szelitzky T.

    2011-12-01

    Full Text Available LQR and H2 controllers require access to the states of the controlled system. The method based on description function with Fourier series results in a model with immeasurable states. For this reason, we proposed a Kalman filter based state estimator, which not only filters the input signals, but also computes the unobservable states of the system. The algorithm of the filter was implemented in LabVIEW v8.6 and tested on recorded data obtained from a 10-40 kHz series load frequency controlled induction heating inverter.

  12. Estimation of Residential Heat Pump Consumption for Flexibility Market Applications

    DEFF Research Database (Denmark)

    Kouzelis, Konstantinos; Tan, Zheng-Hua; Bak-Jensen, Birgitte

    2015-01-01

    load of a flexible device, namely a Heat Pump (HP), out of the aggregated energy consumption of a house. The main idea for accomplishing this, is a comparison of the flexible consumer with electrically similar non-flexible consumers. The methodology is based on machine learning techniques, probability...... theory and statistics. After presenting this methodology, the general trend of the HP consumption is estimated and an hour-ahead forecast is conducted by employing Seasonal Autoregressive Integrated Moving Average modeling. In this manner, the flexible consumption is predicted, establishing the basis...

  13. Estimation of respiratory heat flows in prediction of heat strain among Taiwanese steel workers.

    Science.gov (United States)

    Chen, Wang-Yi; Juang, Yow-Jer; Hsieh, Jung-Yu; Tsai, Perng-Jy; Chen, Chen-Peng

    2017-01-01

    International Organization for Standardization 7933 standard provides evaluation of required sweat rate (RSR) and predicted heat strain (PHS). This study examined and validated the approximations in these models estimating respiratory heat flows (RHFs) via convection (C res ) and evaporation (E res ) for application to Taiwanese foundry workers. The influence of change in RHF approximation to the validity of heat strain prediction in these models was also evaluated. The metabolic energy consumption and physiological quantities of these workers performing at different workloads under elevated wet-bulb globe temperature (30.3 ± 2.5 °C) were measured on-site and used in the calculation of RHFs and indices of heat strain. As the results show, the RSR model overestimated the C res for Taiwanese workers by approximately 3 % and underestimated the E res by 8 %. The C res approximation in the PHS model closely predicted the convective RHF, while the E res approximation over-predicted by 11 %. Linear regressions provided better fit in C res approximation (R 2  = 0.96) than in E res approximation (R 2  ≤ 0.85) in both models. The predicted C res deviated increasingly from the observed value when the WBGT reached 35 °C. The deviations of RHFs observed for the workers from those predicted using the RSR or PHS models did not significantly alter the heat loss via the skin, as the RHFs were in general of a level less than 5 % of the metabolic heat consumption. Validation of these approximations considering thermo-physiological responses of local workers is necessary for application in scenarios of significant heat exposure.

  14. Estimation of low-potential heat recuperation efficiency of smoke fumes in a condensation heat utilizer under various operation conditions of a boiler and a heating system

    Science.gov (United States)

    Ionkin, I. L.; Ragutkin, A. V.; Luning, B.; Zaichenko, M. N.

    2016-06-01

    For enhancement of the natural gas utilization efficiency in boilers, condensation heat utilizers of low-potential heat, which are constructed based on a contact heat exchanger, can be applied. A schematic of the contact heat exchanger with a humidifier for preheating and humidifying of air supplied in the boiler for combustion is given. Additional low-potential heat in this scheme is utilized for heating of the return delivery water supplied from a heating system. Preheating and humidifying of air supplied for combustion make it possible to use the condensation utilizer for heating of a heat-transfer agent to temperature exceeding the dewpoint temperature of water vapors contained in combustion products. The decision to mount the condensation heat utilizer on the boiler was taken based on the preliminary estimation of the additionally obtained heat. The operation efficiency of the condensation heat utilizer is determined by its structure and operation conditions of the boiler and the heating system. The software was developed for the thermal design of the condensation heat utilizer equipped by the humidifier. Computation investigations of its operation are carried out as a function of various operation parameters of the boiler and the heating system (temperature of the return delivery water and smoke fumes, air excess, air temperature at the inlet and outlet of the condensation heat utilizer, heating and humidifying of air in the humidifier, and portion of the circulating water). The heat recuperation efficiency is estimated for various operation conditions of the boiler and the condensation heat utilizer. Recommendations on the most effective application of the condensation heat utilizer are developed.

  15. A new method for estimating heat flux in superheater and reheater tubes

    Energy Technology Data Exchange (ETDEWEB)

    Purbolaksono, J. [Department of Mechanical Engineering, Universiti Tenaga Nasional, km 7 Jalan Kajang-Puchong, Kajang 43009, Selangor (Malaysia)], E-mail: judha@uniten.edu.my; Khinani, A.; Rashid, A.Z.; Ali, A.A. [Department of Mechanical Engineering, Universiti Tenaga Nasional, km 7 Jalan Kajang-Puchong, Kajang 43009, Selangor (Malaysia); Ahmad, J. [Kapar Energy Ventures Sdn Bhd, Jalan Tok Muda, Kapar 42200, Selangor (Malaysia); Nordin, N.F. [TNB Research Sdn Bhd, No. 1 Lorong Air Hitam, Kajang 43000, Selangor (Malaysia)

    2009-10-15

    In this paper a procedure on how to estimate the heat flux in superheater and reheater tubes utilizing the empirical formula and the finite element modeling is proposed. An iterative procedure consisting of empirical formulae and numerical simulation is used to determine heat flux as both temperature and scale thickness increase over period of time. Estimation results of the heat flux over period of time for two different design temperatures of the steam and different heat transfer parameters are presented.

  16. Cost Estimates Of Concentrated Photovoltaic Heat Sink Production

    Science.gov (United States)

    2016-06-01

    water heating , but the majority of installed solar systems , are PV (EIA, 2015). Solar power generation has great benefits for the DON considering the...Current CPV systems use basic heat sink designs to increase efficiency. Modern heat sink design can achieve greater overall efficiencies of electricity...professionally developed cost analysis of adding optimized cooling technologies to concentrated photovoltaic (CPV) systems . Current CPV systems use basic heat

  17. Estimation of surface heat flux and temperature distributions in a multilayer tissue based on the hyperbolic model of heat conduction.

    Science.gov (United States)

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

    2015-01-01

    In this study, an inverse algorithm based on the conjugate gradient method and the discrepancy principle is applied to solve the inverse hyperbolic heat conduction problem in estimating the unknown time-dependent surface heat flux in a skin tissue, which is stratified into epidermis, dermis, and subcutaneous layers, from the temperature measurements taken within the medium. Subsequently, the temperature distributions in the tissue can be calculated as well. The concept of finite heat propagation velocity is applied to the modeling of the bioheat transfer problem. The inverse solutions will be justified based on the numerical experiments in which two different heat flux distributions are to be determined. The temperature data obtained from the direct problem are used to simulate the temperature measurements. The influence of measurement errors on the precision of the estimated results is also investigated. Results show that an excellent estimation on the time-dependent surface heat flux can be obtained for the test cases considered in this study.

  18. Estimation of transient heat flux density during the heat supply of a catalytic wall steam methane reformer

    Science.gov (United States)

    Settar, Abdelhakim; Abboudi, Saïd; Madani, Brahim; Nebbali, Rachid

    2018-02-01

    Due to the endothermic nature of the steam methane reforming reaction, the process is often limited by the heat transfer behavior in the reactors. Poor thermal behavior sometimes leads to slow reaction kinetics, which is characterized by the presence of cold spots in the catalytic zones. Within this framework, the present work consists on a numerical investigation, in conjunction with an experimental one, on the one-dimensional heat transfer phenomenon during the heat supply of a catalytic-wall reactor, which is designed for hydrogen production. The studied reactor is inserted in an electric furnace where the heat requirement of the endothermic reaction is supplied by electric heating system. During the heat supply, an unknown heat flux density, received by the reactive flow, is estimated using inverse methods. In the basis of the catalytic-wall reactor model, an experimental setup is engineered in situ to measure the temperature distribution. Then after, the measurements are injected in the numerical heat flux estimation procedure, which is based on the Function Specification Method (FSM). The measured and estimated temperatures are confronted and the heat flux density which crosses the reactor wall is determined.

  19. Regional heat flux over the NOPEX area estimated from the evolution of the mixed-layer

    DEFF Research Database (Denmark)

    Gryning, Sven-Erik; Batchvarova, E.

    1999-01-01

    of forest, agricultural fields, mires and lakes within the boreal zone, was determined for 3 days of the campaign in 1994. It was found to be lower than the heat flux over forest and higher than the heat Aux over agricultural fields. The regional heat flux estimated by the mixed-layer evolution method...

  20. Estimation of a Moving Heat Source due to a Micromilling Process Using the Modified TFBGF Technique

    Directory of Open Access Journals (Sweden)

    Sidney Ribeiro

    2018-01-01

    Full Text Available Moving heat sources are present in numerous engineering problems as welding and machining processes, heat treatment, or biological heating. In all these cases, the heat input identification represents an important factor in the optimization of the process. The aim of this study is to investigate the heat flux delivered to a workpiece during a micromilling process. The temperature measurements were obtained using a thermocouple at an accessible region of the workpiece surface while micromilling a small channel. The analytical solution is calculated from a 3D transient heat conduction model with a moving heat source, called direct problem. The estimation of the moving heat source uses the Transfer Function Based on Green’s Function Method. This method is based on Green’s function and the equivalence between thermal and dynamic systems. The technique is simple without iterative processes and extremely fast. From the temperature on accessible regions it is possible to estimate the heat flux by an inverse procedure of the Fast Fourier Transform. A test of micromilling of 6365 aluminium alloy was made and the heat delivered to the workpiece was estimated. The estimation of the heat without use of optimization technique is the great advantage of the technique proposed.

  1. Multi Function Heat Pulse Probes (MFHPP) to Estimate Ground Heat Flux and Reduce Surface Energy Budget Errors

    Science.gov (United States)

    Ciocca, Francesco; Sharma, Varun; Lunati, Ivan; Parlange, Marc B.

    2013-04-01

    Ground heat flux plays a crucial role in surface energy budget: an incorrect estimation of energy storage and heat fluxes in soils occur when probes such as heat flux plates are adopted, and these mistakes can account for up to 90% of the residual variance (Higgins, GRL, 2012). A promising alternative to heat flux plates is represented by Multi Function Heat Pulse Probes (MFHPP). They have proven to be accurate in thermal properties and heat fluxes estimation (e.g. Cobos, VZJ, 2003) and can be used to monitor and quantify subsurface evaporation in field experiments (Xiao et al., VZJ, 2011). We perform a laboratory experiment with controlled temperature in a small Plexiglas column (20cm diameter and 40cm height). The column is packed with homogeneously saturated sandy soil and equipped with three MFHPPs in the upper 4cm and thermocouples and dielectric soil moisture probes deeper. This configuration allows for accurate and simultaneous ground heat flux, soil moisture and subsurface evaporation measurements. Total evaporation is monitored using a precision scale, while an infrared gun and a long wave radiometer measure the soil skin temperature and the outgoing long-short wave radiation, respectively. A fan and a heat lamp placed above the column allow to mimick on a smaller and more controlled scale the field conditions induced by the diurnal cycle. At a reference height above the column relative humidity, wind speed and air temperature are collected. Results are interpreted by means of numerical simulations performed with an ad-hoc-developed numerical model that simulates coupled heat and moisture transfer in soils and is used to match and interpolate the temperature and soil moisture values got at finite depths within the column. Ground heat fluxes are then estimated by integrating over almost continuous, numerically simulated temperature profiles, which avoids errors due to use of discrete data (Lunati et al., WRR, 2012) and leads to a more reliable estimate of

  2. Anthropogenic Heat Flux Estimation from Space: Results of the second phase of the URBANFLUXES Project

    Science.gov (United States)

    Chrysoulakis, Nektarios; Marconcini, Mattia; Gastellu-Etchegorry, Jean-Philippe; Grimmond, Sue; Feigenwinter, Christian; Lindberg, Fredrik; Del Frate, Fabio; Klostermann, Judith; Mitraka, Zina; Esch, Thomas; Landier, Lucas; Gabey, Andy; Parlow, Eberhard; Olofson, Frans

    2017-04-01

    The H2020-Space project URBANFLUXES (URBan ANthrpogenic heat FLUX from Earth observation Satellites) investigates the potential of Copernicus Sentinels to retrieve anthropogenic heat flux, as a key component of the Urban Energy Budget (UEB). URBANFLUXES advances the current knowledge of the impacts of UEB fluxes on urban heat island and consequently on energy consumption in cities. In URBANFLUXES, the anthropogenic heat flux is estimated as a residual of UEB. Therefore, the rest UEB components, namely, the net all-wave radiation, the net change in heat storage and the turbulent sensible and latent heat fluxes are independently estimated from Earth Observation (EO), whereas the advection term is included in the error of the anthropogenic heat flux estimation from the UEB closure. The Discrete Anisotropic Radiative Transfer (DART) model is employed to improve the estimation of the net all-wave radiation balance, whereas the Element Surface Temperature Method (ESTM), adjusted to satellite observations is used to improve the estimation the estimation of the net change in heat storage. Furthermore the estimation of the turbulent sensible and latent heat fluxes is based on the Aerodynamic Resistance Method (ARM). Based on these outcomes, QF is estimated by regressing the sum of the turbulent heat fluxes versus the available energy. In-situ flux measurements are used to evaluate URBANFLUXES outcomes, whereas uncertainties are specified and analyzed. URBANFLUXES is expected to prepare the ground for further innovative exploitation of EO in scientific activities (climate variability studies at local and regional scales) and future and emerging applications (sustainable urban planning, mitigation technologies) to benefit climate change mitigation/adaptation. This study presents the results of the second phase of the project and detailed information on URBANFLUXES is available at: http://urbanfluxes.eu

  3. An Estimate of Chromospheric Heating by Acoustic Waves

    Czech Academy of Sciences Publication Activity Database

    Sobotka, Michal; Švanda, Michal; Jurčák, Jan; Heinzel, Petr; Del Moro, D.; Berrilli, F.

    2014-01-01

    Roč. 38, č. 1 (2014), s. 53-58 ISSN 1845-8319 R&D Projects: GA ČR(CZ) GA14-04338S; GA ČR GPP209/12/P568; GA ČR GAP209/12/0287 Institutional support: RVO:67985815 Keywords : Sun * chromosphere * heating Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  4. Evaluation of Criticality of Self-Heating of Polymer Composites by Estimating the Heat Dissipation Rate

    Science.gov (United States)

    Katunin, A.

    2018-03-01

    The critical self-heating temperature at which the structural degradation of polymer composites under cyclic loading begins is evaluated by analyzing the heat dissipation rate. The method proposed is an effective tool for evaluating the degradation degree of such structures.

  5. A Bayesian inference approach: estimation of heat flux from fin for ...

    Indian Academy of Sciences (India)

    Harsha Kumar

    2018-04-16

    Apr 16, 2018 ... The effect of a-priori information on the estimated parameter is also addressed. The standard deviation in the estimation process is referred to as the uncertainty associated with the estimated parameters. Keywords. Mild steel fin; heat flux; ANN; Bayesian inference; MCMC; standard deviation. 1. Introduction.

  6. Estimation of Surface Temperature and Heat Flux by Inverse Heat Transfer Methods Using Internal Temperatures Measured While Radiantly Heating a Carbon/Carbon Specimen up to 1920 F

    Science.gov (United States)

    Pizzo, Michelle; Daryabeigi, Kamran; Glass, David

    2015-01-01

    The ability to solve the heat conduction equation is needed when designing materials to be used on vehicles exposed to extremely high temperatures; e.g. vehicles used for atmospheric entry or hypersonic flight. When using test and flight data, computational methods such as finite difference schemes may be used to solve for both the direct heat conduction problem, i.e., solving between internal temperature measurements, and the inverse heat conduction problem, i.e., using the direct solution to march forward in space to the surface of the material to estimate both surface temperature and heat flux. The completed research first discusses the methods used in developing a computational code to solve both the direct and inverse heat transfer problems using one dimensional, centered, implicit finite volume schemes and one dimensional, centered, explicit space marching techniques. The developed code assumed the boundary conditions to be specified time varying temperatures and also considered temperature dependent thermal properties. The completed research then discusses the results of analyzing temperature data measured while radiantly heating a carbon/carbon specimen up to 1920 F. The temperature was measured using thermocouple (TC) plugs (small carbon/carbon material specimens) with four embedded TC plugs inserted into the larger carbon/carbon specimen. The purpose of analyzing the test data was to estimate the surface heat flux and temperature values from the internal temperature measurements using direct and inverse heat transfer methods, thus aiding in the thermal and structural design and analysis of high temperature vehicles.

  7. A New Entropy Formula and Gradient Estimates for the Linear Heat Equation on Static Manifold

    Directory of Open Access Journals (Sweden)

    Abimbola Abolarinwa

    2014-08-01

    Full Text Available In this paper we prove a new monotonicity formula for the heat equation via a generalized family of entropy functionals. This family of entropy formulas generalizes both Perelman’s entropy for evolving metric and Ni’s entropy on static manifold. We show that this entropy satisfies a pointwise differential inequality for heat kernel. The consequences of which are various gradient and Harnack estimates for all positive solutions to the heat equation on compact manifold.

  8. Estimating Heat and Mass Transfer Processes in Green Roof Systems: Current Modeling Capabilities and Limitations (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Tabares Velasco, P. C.

    2011-04-01

    This presentation discusses estimating heat and mass transfer processes in green roof systems: current modeling capabilities and limitations. Green roofs are 'specialized roofing systems that support vegetation growth on rooftops.'

  9. Estimation of shutdown heat generation rates in GHARR-1 due to ...

    African Journals Online (AJOL)

    Fission products decay power and residual fission power generated after shutdown of Ghana Research Reactor-1 (GHARR-1) by reactivity insertion accident were estimated by solution of the decay and residual heat equations. A Matlab program code was developed to simulate the heat generation rates by fission product ...

  10. Geothermal Heat Flux Underneath Ice Sheets Estimated From Magnetic Satellite Data

    DEFF Research Database (Denmark)

    Fox Maule, Cathrine; Purucker, M.E.; Olsen, Nils

    The geothermal heat flux is an important factor in the dynamics of ice sheets, and it is one of the important parameters in the thermal budgets of subglacial lakes. We have used satellite magnetic data to estimate the geothermal heat flux underneath the ice sheets in Antarctica and Greenland...

  11. Estimation of boundary heat flux using experimental temperature data in turbulent forced convection flow

    Science.gov (United States)

    Parwani, Ajit K.; Talukdar, Prabal; Subbarao, P. M. V.

    2015-03-01

    Heat flux at the boundary of a duct is estimated using the inverse technique based on conjugate gradient method (CGM) with an adjoint equation. A two-dimensional inverse forced convection hydrodynamically fully developed turbulent flow is considered. The simulations are performed with temperature data measured in the experimental test performed on a wind tunnel. The results show that the present numerical model with CGM is robust and accurate enough to estimate the strength and position of boundary heat flux.

  12. Estimation of pressure drop in gasket plate heat exchangers

    Directory of Open Access Journals (Sweden)

    Neagu Anisoara Arleziana

    2016-06-01

    Full Text Available In this paper, we present comparatively different methods of pressure drop calculation in the gasket plate heat exchangers (PHEs, using correlations recommended in literature on industrial data collected from a vegetable oil refinery. The goal of this study was to compare the results obtained with these correlations, in order to choose one or two for practical purpose of pumping power calculations. We concluded that pressure drop values calculated with Mulley relationship and Buonopane & Troupe correlation were close and also Bond’s equation gave results pretty close to these but the pressure drop is slightly underestimated. Kumar correlation gave results far from all the others and its application will lead to oversize. In conclusion, for further calculations we will chose either the Mulley relationship or the Buonopane & Troupe correlation.

  13. Geothermal hydrothermal direct heat use: US market size and market penetration estimates

    Energy Technology Data Exchange (ETDEWEB)

    El Sawy, A.H.; Entingh, D.J.

    1980-09-01

    This study estimates the future regional and national market penetration path of hydrothermal geothermal direct heat applications in the United States. A Technology Substitution Model (MARPEN) is developed and used to estimate the energy market shares captured by low-temperature (50 to 150/sup 0/C) hydrothermal geothermal energy systems over the period 1985 to 2020. The sensitivity of hydrothermal direct heat market shares to various government hydrothermal commercialization policies is examined. Several substantive recommendations to help accelerate commercialization of geothermal direct heat utilization in the United States are indicated and possible additional analyses are discussed.

  14. ROPE: Recoverable Order-Preserving Embedding of Natural Language

    Energy Technology Data Exchange (ETDEWEB)

    Widemann, David P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wang, Eric X. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Thiagarajan, Jayaraman J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-02-11

    We present a novel Recoverable Order-Preserving Embedding (ROPE) of natural language. ROPE maps natural language passages from sparse concatenated one-hot representations to distributed vector representations of predetermined fixed length. We use Euclidean distance to return search results that are both grammatically and semantically similar. ROPE is based on a series of random projections of distributed word embeddings. We show that our technique typically forms a dictionary with sufficient incoherence such that sparse recovery of the original text is possible. We then show how our embedding allows for efficient and meaningful natural search and retrieval on Microsoft’s COCO dataset and the IMDB Movie Review dataset.

  15. Estimation of the Relationship Between Remotely Sensed Anthropogenic Heat Discharge and Building Energy Use

    Science.gov (United States)

    Zhou, Yuyu; Weng, Qihao; Gurney, Kevin R.; Shuai, Yanmin; Hu, Xuefei

    2012-01-01

    This paper examined the relationship between remotely sensed anthropogenic heat discharge and energy use from residential and commercial buildings across multiple scales in the city of Indianapolis, Indiana, USA. The anthropogenic heat discharge was estimated with a remote sensing-based surface energy balance model, which was parameterized using land cover, land surface temperature, albedo, and meteorological data. The building energy use was estimated using a GIS-based building energy simulation model in conjunction with Department of Energy/Energy Information Administration survey data, the Assessor's parcel data, GIS floor areas data, and remote sensing-derived building height data. The spatial patterns of anthropogenic heat discharge and energy use from residential and commercial buildings were analyzed and compared. Quantitative relationships were evaluated across multiple scales from pixel aggregation to census block. The results indicate that anthropogenic heat discharge is consistent with building energy use in terms of the spatial pattern, and that building energy use accounts for a significant fraction of anthropogenic heat discharge. The research also implies that the relationship between anthropogenic heat discharge and building energy use is scale-dependent. The simultaneous estimation of anthropogenic heat discharge and building energy use via two independent methods improves the understanding of the surface energy balance in an urban landscape. The anthropogenic heat discharge derived from remote sensing and meteorological data may be able to serve as a spatial distribution proxy for spatially-resolved building energy use, and even for fossil-fuel CO2 emissions if additional factors are considered.

  16. Assessment of undiscovered technically recoverable oil and gas resources of Puerto Rico and the Puerto Rico-U.S. Virgin Islands Exclusive Economic Zone, 2013

    Science.gov (United States)

    Schenk, Christopher J.; Charpentier, Ronald R.; Klett, Timothy R.; Gaswirth, Stephanie B.; Pitman, Janet K.; Brownfield, Michael E.; Mercier, Tracey J.; Wandrey, Craig J.; Weaver, Jean N.

    2013-01-01

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated means of 19 million barrels of undiscovered, technically recoverable oil and 244 billion cubic feet of undiscovered natural gas in the Puerto Rico–U.S. Virgin Islands Exclusive Economic Zone.

  17. Estimating end-use emissions factors for policy analysis: the case of space cooling and heating.

    Science.gov (United States)

    Jacobsen, Grant D

    2014-06-17

    This paper provides the first estimates of end-use specific emissions factors, which are estimates of the amount of a pollutant that is emitted when a unit of electricity is generated to meet demand from a specific end-use. In particular, this paper provides estimates of emissions factors for space cooling and heating, which are two of the most significant end-uses. The analysis is based on a novel two-stage regression framework that estimates emissions factors that are specific to cooling or heating by exploiting variation in cooling and heating demand induced by weather variation. Heating is associated with similar or greater CO2 emissions factor than cooling in all regions. The difference is greatest in the Midwest and Northeast, where the estimated CO2 emissions factor for heating is more than 20% larger than the emissions factor for cooling. The minor differences in emissions factors in other regions, combined with the substantial difference in the demand pattern for cooling and heating, suggests that the use of overall regional emissions factors is reasonable for policy evaluations in certain locations. Accurately quantifying the emissions factors associated with different end-uses across regions will aid in designing improved energy and environmental policies.

  18. The Concept of Recoverable Robustness, Linear Programming Recovery, and Railway Applications

    Science.gov (United States)

    Liebchen, Christian; Lübbecke, Marco; Möhring, Rolf; Stiller, Sebastian

    We present a new concept for optimization under uncertainty: recoverable robustness. A solution is recovery robust if it can be recovered by limited means in all likely scenarios. Specializing the general concept to linear programming we can show that recoverable robustness combines the flexibility of stochastic programming with the tractability and performances guarantee of the classical robust approach. We exemplify recoverable robustness in delay resistant, periodic and aperiodic timetabling problems, and train platforming.

  19. A Bayesian approach to estimate sensible and latent heat over vegetated land surface

    Directory of Open Access Journals (Sweden)

    C. van der Tol

    2009-06-01

    Full Text Available Sensible and latent heat fluxes are often calculated from bulk transfer equations combined with the energy balance. For spatial estimates of these fluxes, a combination of remotely sensed and standard meteorological data from weather stations is used. The success of this approach depends on the accuracy of the input data and on the accuracy of two variables in particular: aerodynamic and surface conductance. This paper presents a Bayesian approach to improve estimates of sensible and latent heat fluxes by using a priori estimates of aerodynamic and surface conductance alongside remote measurements of surface temperature. The method is validated for time series of half-hourly measurements in a fully grown maize field, a vineyard and a forest. It is shown that the Bayesian approach yields more accurate estimates of sensible and latent heat flux than traditional methods.

  20. Methodology for estimation of potential for solar water heating in a target area

    International Nuclear Information System (INIS)

    Pillai, Indu R.; Banerjee, Rangan

    2007-01-01

    Proper estimation of potential of any renewable energy technology is essential for planning and promotion of the technology. The methods reported in literature for estimation of potential of solar water heating in a target area are aggregate in nature. A methodology for potential estimation (technical, economic and market potential) of solar water heating in a target area is proposed in this paper. This methodology links the micro-level factors and macro-level market effects affecting the diffusion or adoption of solar water heating systems. Different sectors with end uses of low temperature hot water are considered for potential estimation. Potential is estimated at each end use point by simulation using TRNSYS taking micro-level factors. The methodology is illustrated for a synthetic area in India with an area of 2 sq. km and population of 10,000. The end use sectors considered are residential, hospitals, nursing homes and hotels. The estimated technical potential and market potential are 1700 m 2 and 350 m 2 of collector area, respectively. The annual energy savings for the technical potential in the area is estimated as 110 kW h/capita and 0.55 million-kW h/sq. km. area, with an annual average peak saving of 1 MW. The annual savings is 650-kW h per m 2 of collector area and accounts for approximately 3% of the total electricity consumption of the target area. Some of the salient features of the model are the factors considered for potential estimation; estimation of electrical usage pattern for typical day, amount of electricity savings and savings during the peak load. The framework is general and enables accurate estimation of potential of solar water heating for a city, block. Energy planners and policy makers can use this framework for tracking and promotion of diffusion of solar water heating systems. (author)

  1. Estimate of Joule Heating in a Flat Dechirper

    Energy Technology Data Exchange (ETDEWEB)

    Bane, Karl [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stupakov, Gennady [SLAC National Accelerator Lab., Menlo Park, CA (United States); Gjonaj, Erion [Technical Univ. of Darmstadt (Germany)

    2017-02-10

    We have performed Joule power loss calculations for a flat dechirper. We have considered the configurations of the beam on-axis between the two plates—for chirp control—and for the beam especially close to one plate—for use as a fast kicker. Our calculations use a surface impedance approach, one that is valid when corrugation parameters are small compared to aperture (the perturbative parameter regime). In our model we ignore effects of field reflections at the sides of the dechirper plates, and thus expect the results to underestimate the Joule losses. The analytical results were also tested by numerical, time-domain simulations. We find that most of the wake power lost by the beam is radiated out to the sides of the plates. For the case of the beam passing by a single plate, we derive an analytical expression for the broad-band impedance, and—in Appendix B—numerically confirm recently developed, analytical formulas for the short-range wakes. While our theory can be applied to the LCLS-II dechirper with large gaps, for the nominal apertures we are not in the perturbative regime and the reflection contribution to Joule losses is not negligible. With input from computer simulations, we estimate the Joule power loss (assuming bunch charge of 300 pC, repetition rate of 100 kHz) is 21 W/m for the case of two plates, and 24 W/m for the case of a single plate.

  2. Estimating Risks of Heat Strain by Age and Sex: A Population-Level Simulation Model

    Directory of Open Access Journals (Sweden)

    Kathryn Glass

    2015-05-01

    Full Text Available Individuals living in hot climates face health risks from hyperthermia due to excessive heat. Heat strain is influenced by weather exposure and by individual characteristics such as age, sex, body size, and occupation. To explore the population-level drivers of heat strain, we developed a simulation model that scales up individual risks of heat storage (estimated using Myrup and Morgan’s man model “MANMO” to a large population. Using Australian weather data, we identify high-risk weather conditions together with individual characteristics that increase the risk of heat stress under these conditions. The model identifies elevated risks in children and the elderly, with females aged 75 and older those most likely to experience heat strain. Risk of heat strain in males does not increase as rapidly with age, but is greatest on hot days with high solar radiation. Although cloudy days are less dangerous for the wider population, older women still have an elevated risk of heat strain on hot cloudy days or when indoors during high temperatures. Simulation models provide a valuable method for exploring population level risks of heat strain, and a tool for evaluating public health and other government policy interventions.

  3. 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)

  4. Satellite air temperature estimation for monitoring the canopy layer heat island of Milan

    DEFF Research Database (Denmark)

    Pichierri, Manuele; Bonafoni, Stefania; Biondi, Riccardo

    2012-01-01

    across the city center from June to September confirming that, in Milan, urban heating is not an occasional phenomenon. Furthermore, this study shows the utility of space missions to monitor the metropolis heat islands if they are able to provide nighttime observations when CLHI peaks are generally......In this work, satellite maps of the urban heat island of Milan are produced using satellite-based infrared sensor data. For this aim, we developed suitable algorithms employing satellite brightness temperatures for the direct air temperature estimation 2 m above the surface (canopy layer), showing...... 2007 and 2010 were processed. Analysis of the canopy layer heat island (CLHI) maps during summer months reveals an average heat island effect of 3–4K during nighttime (with some peaks around 5K) and a weak CLHI intensity during daytime. In addition, the satellite maps reveal a well defined island shape...

  5. Estimation of heat load in waste tanks using average vapor space temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Crowe, R.D.; Kummerer, M.; Postma, A.K.

    1993-12-01

    This report describes a method for estimating the total heat load in a high-level waste tank with passive ventilation. This method relates the total heat load in the tank to the vapor space temperature and the depth of waste in the tank. Q{sub total} = C{sub f} (T{sub vapor space {minus}} T{sub air}) where: C{sub f} = Conversion factor = (R{sub o}k{sub soil}{sup *}area)/(z{sub tank} {minus} z{sub surface}); R{sub o} = Ratio of total heat load to heat out the top of the tank (function of waste height); Area = cross sectional area of the tank; k{sub soil} = thermal conductivity of soil; (z{sub tank} {minus} z{sub surface}) = effective depth of soil covering the top of tank; and (T{sub vapor space} {minus} T{sub air}) = mean temperature difference between vapor space and the ambient air at the surface. Three terms -- depth, area and ratio -- can be developed from geometrical considerations. The temperature difference is measured for each individual tank. The remaining term, the thermal conductivity, is estimated from the time-dependent component of the temperature signals coming from the periodic oscillations in the vapor space temperatures. Finally, using this equation, the total heat load for each of the ferrocyanide Watch List tanks is estimated. This provides a consistent way to rank ferrocyanide tanks according to heat load.

  6. Heat loss and hypothermia in free diving: Estimation of survival time under water

    Science.gov (United States)

    Aguilella-Arzo, Marcel; Alcaraz, Antonio; Aguilella, Vicente M.

    2003-04-01

    The heat exchange between a diver and the colder surrounding water is analyzed on the basis of the fundamental equations of thermal transport. To estimate the decrease in the diver's body temperature as a function of time, we discuss the complex interplay of several factors including the body heat production rate, the role of the diver's wet suit, and the way different heat exchange mechanisms (conduction, convection, and radiation) contribute to thermal transport. This knowledge could be useful to prevent physiological disorders that occur when the human body temperature drops below 35 °C.

  7. Satellite data based approach for the estimation of anthropogenic heat flux over urban areas

    Science.gov (United States)

    Nitis, Theodoros; Tsegas, George; Moussiopoulos, Nicolas; Gounaridis, Dimitrios; Bliziotis, Dimitrios

    2017-09-01

    Anthropogenic effects in urban areas influence the thermal conditions in the environment and cause an increase of the atmospheric temperature. The cities are sources of heat and pollution, affecting the thermal structure of the atmosphere above them which results to the urban heat island effect. In order to analyze the urban heat island mechanism, it is important to estimate the anthropogenic heat flux which has a considerable impact on the urban energy budget. The anthropogenic heat flux is the result of man-made activities (i.e. traffic, industrial processes, heating/cooling) and thermal releases from the human body. Many studies have underlined the importance of the Anthropogenic Heat Flux to the calculation of the urban energy budget and subsequently, the estimation of mesoscale meteorological fields over urban areas. Therefore, spatially disaggregated anthropogenic heat flux data, at local and city scales, are of major importance for mesoscale meteorological models. The main objectives of the present work are to improve the quality of such data used as input for mesoscale meteorological models simulations and to enhance the application potential of GIS and remote sensing in the fields of climatology and meteorology. For this reason, the Urban Energy Budget concept is proposed as the foundation for an accurate determination of the anthropogenic heat discharge as a residual term in the surface energy balance. The methodology is applied to the cities of Athens and Paris using the Landsat ETM+ remote sensing data. The results will help to improve our knowledge on Anthropogenic Heat Flux, while the potential for further improvement of the methodology is also discussed.

  8. Estimation of the relationship between remotely sensed anthropogenic heat discharge and building energy use

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yuyu; Weng, Qihao; Gurney, Kevin R.; Shuai, Yanmin; Hu, Xuefei

    2012-01-01

    This paper examined the relationship between remotely sensed anthropogenic heat discharge and energy use from residential and commercial buildings across multiple scales in the city of Indianapolis, Indiana, USA. Anthropogenic heat discharge was estimated based on a remote sensing-based surface energy balance model, which was parameterized using land cover, land surface temperature, albedo, and meteorological data. Building energy use was estimated using a GIS-based building energy simulation model in conjunction with Department of Energy/ Energy Information Administration survey data, Assessor's parcel data, GIS floor areas data, and remote sensing-derived building height data.

  9. Crustal heat production and estimate of terrestrial heat flow in central East Antarctica, with implications for thermal input to the East Antarctic ice sheet

    Science.gov (United States)

    Goodge, John W.

    2018-02-01

    Terrestrial heat flow is a critical first-order factor governing the thermal condition and, therefore, mechanical stability of Antarctic ice sheets, yet heat flow across Antarctica is poorly known. Previous estimates of terrestrial heat flow in East Antarctica come from inversion of seismic and magnetic geophysical data, by modeling temperature profiles in ice boreholes, and by calculation from heat production values reported for exposed bedrock. Although accurate estimates of surface heat flow are important as an input parameter for ice-sheet growth and stability models, there are no direct measurements of terrestrial heat flow in East Antarctica coupled to either subglacial sediment or bedrock. As has been done with bedrock exposed along coastal margins and in rare inland outcrops, valuable estimates of heat flow in central East Antarctica can be extrapolated from heat production determined by the geochemical composition of glacial rock clasts eroded from the continental interior. In this study, U, Th, and K concentrations in a suite of Proterozoic (1.2-2.0 Ga) granitoids sourced within the Byrd and Nimrod glacial drainages of central East Antarctica indicate average upper crustal heat production (Ho) of about 2.6 ± 1.9 µW m-3. Assuming typical mantle and lower crustal heat flux for stable continental shields, and a length scale for the distribution of heat production in the upper crust, the heat production values determined for individual samples yield estimates of surface heat flow (qo) ranging from 33 to 84 mW m-2 and an average of 48.0 ± 13.6 mW m-2. Estimates of heat production obtained for this suite of glacially sourced granitoids therefore indicate that the interior of the East Antarctic ice sheet is underlain in part by Proterozoic continental lithosphere with an average surface heat flow, providing constraints on both geodynamic history and ice-sheet stability. The ages and geothermal characteristics of the granites indicate that crust in central

  10. Estimate of thermoelastic heat production from superconducting composites in pulsed poloidal coil systems

    International Nuclear Information System (INIS)

    Ballou, J.K.; Gray, W.H.

    1976-01-01

    In the design of the cryogenic system and superconducting magnets for the poloidal field system in a tokamak, it is important to have an accurate estimate of the heat produced in superconducting magnets as a result of rapidly changing magnetic fields. A computer code, PLASS (Pulsed Losses in Axisymmetric Superconducting Solenoids), was written to estimate the contributions to the heat production from superconductor hysteresis losses, superconductor coupling losses, stabilizing material eddy current losses, and structural material eddy current losses. Recently, it has been shown that thermoelastic dissipation in superconducting composites can contribute as much to heat production as the other loss mechanisms mentioned above. A modification of PLASS which takes into consideration thermoelastic dissipation in superconducting composites is discussed. A comparison between superconductor thermoelastic dissipation and the other superconductor loss mechanisms is presented in terms of the poloidal coil system of the ORNL Experimental Power Reactor design

  11. Heat flux estimates from the Gakkel Ridge 85E vent field from the AGAVE 2007 expedition

    Science.gov (United States)

    Stranne, C.; Winsor, P.; Sohn, R. A.; Liljebladh, B.

    2009-04-01

    During the Arctic Gakkel Vents Expedition (AGAVE) 2007, abundant hydrothermal venting was discovered on the Gakkel Ridge at 85E. Hydrothermal vents on the sea floor give rise to buoyant plumes which, when reaching neutral buoyancy, spreads horizontally over areas with length scales on the order of several kilometres and are therefore easily detected with a CTD rosette. The detected anomalies are consistent with the findings 6 years earlier during the Arctic Mid-Ocean Ridge Expedition (AMORE) 2001. The horizontal and vertical distribution of the anomalies is considered in order to establish the number of individual plumes detected. The objective of this paper is to estimate the minimum heat input required to reproduce the observed plumes, using a turbulent entrainment model. The model was run with a large number of combinations of boundary conditions (nozzle area, vertical velocity and temperature) in order to see which combinations that give rise to the observed plume characteristics (level of neutral buoyancy and temperature anomaly). For each individual plume, we estimate the minimum heat flux required to obtain the observed temperature anomaly. Adding the minimum heat flux from each vent together, the total heat flux for the vent field is estimated to be ~ 2 GW. The estimated value is comparable or larger than any other known vent field.

  12. Estimation of eddy diffusivity coefficient of heat in the upper layers of equatorial Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Zavialov, P.O.; Murty, V.S.N.

    in the Central Equatorial Arabian Sea (CEAS). A comparison of the model computed K sub(h) values with those estimated from the heat balance of the upper layer (50 m) of the sea shows good agreement in the region of weak winds (CEAS) or low turbulent mixing regime...

  13. Condition monitoring of steam generator by estimating the overall heat transfer coefficient

    International Nuclear Information System (INIS)

    Furusawa, Hiroaki; Gofuku, Akio

    2013-01-01

    This study develops a technique for monitoring in on-line the state of the steam generator of the fast-breeder reactor (FBR) “Monju”. Because the FBR uses liquid sodium as coolant, it is necessary to handle liquid sodium with caution due to its chemical characteristics. The steam generator generates steam by the heat of secondary sodium coolant. The sodium-water reaction may happen if a pinhole or crack occurs at the thin metal tube wall that separates the secondary sodium coolant and water/steam. Therefore, it is very important to detect an anomaly of the wall of heat transfer tubes at an early stage. This study aims at developing an on-line condition monitoring technique of the steam generator by estimating overall heat transfer coefficient from process signals. This paper describes simplified mathematical models of superheater and evaporator to estimate the overall heat transfer coefficient and a technique to diagnose the state of the steam generator. The applicability of the technique is confirmed by several estimations using simulated process signals with artificial noises. The results of the estimations show that the developed technique can detect the occurrence of an anomaly. (author)

  14. Estimation of the Heat Flow Variation in the Chad Basin Nigeria ...

    African Journals Online (AJOL)

    Wireline logs from 14 oil wells from the Nigerian sector of the Chad Basin were analyzed and interpreted to estimate the heat flow trend in the basin. Geothermal gradients were computed from corrected bottom hole temperatures while the bulk effective thermal conductivity for the different stratigraphic units encountered in ...

  15. Evaluation of segmented gamma scanner measurements on cans of recoverable scrap

    International Nuclear Information System (INIS)

    Shull, A.H.; Weber, J.H.; MacMurdo, K.W.; Baker, L.B.

    1991-01-01

    Savannah River Site (SRS) has had a long-standing concern about the inability to measure recoverable scrap. A segmented gamma scanner (SGS) was evaluated for use in measuring cans of scrap materials. Four scrap cans were selected and re-packaged into containers that could be measured using calorimetry and gamma spectrometry. These scrap cans were later used as working standards for the SGS. In addition, replicate measurements were made on all cans of scrap currently stored with estimated values. Before accepting the SGS measurements on the cans, data from the replicate measurements of the standards and a limited number of process cans were analyzed to determine if there was a significant bias between the SGS and the calorimeter-gamma spectrometer measurements, if the random replication error would be acceptable for accountability, to set control limits for the workings standards, and to determine acceptable differences between replicate measurements. After completing the measurement of all process scrap cans in the inventory, the the final data were analyzed and estimates based on the two sets of data compared. The methodology used to determine the appropriate measurement error model, to estimate the measurement errors, to set control limits, and to determine the significance of the bias will be described as well as a comparison of the error estimates based on the preliminary versus final data

  16. Correcting anthropogenic ocean heat uptake estimates for the Little Ice Age

    Science.gov (United States)

    Gebbie, Geoffrey

    2017-04-01

    Estimates of anthropogenic ocean heat uptake typically assume that the ocean was in equilibrium during the pre-industrial era. Recent reconstructions of the Common Era, however, show a multi-century surface cooling trend before the Industrial Revolution. Using a time-evolving state estimation method, we find that the 1750 C.E. ocean must have been out of equilibrium in order to fit the H.M.S. Challenger, WOCE, and Argo hydrographic data. When the disequilibrated ocean conditions are taken into account, the inferred ocean heat uptake from 1750-2014 C.E. is revised due to the deep ocean memory of Little Ice Age surface forcing. These effects of ocean disequilibrium should also be considered when interpreting climate sensitivity estimates.

  17. A new global anthropogenic heat estimation based on high-resolution nighttime light data

    Science.gov (United States)

    Yang, Wangming; Luan, Yibo; Liu, Xiaolei; Yu, Xiaoyong; Miao, Lijuan; Cui, Xuefeng

    2017-08-01

    Consumption of fossil fuel resources leads to global warming and climate change. Apart from the negative impact of greenhouse gases on the climate, the increasing emission of anthropogenic heat from energy consumption also brings significant impacts on urban ecosystems and the surface energy balance. The objective of this work is to develop a new method of estimating the global anthropogenic heat budget and validate it on the global scale with a high precision and resolution dataset. A statistical algorithm was applied to estimate the annual mean anthropogenic heat (AH-DMSP) from 1992 to 2010 at 1×1 km2 spatial resolution for the entire planet. AH-DMSP was validated for both provincial and city scales, and results indicate that our dataset performs well at both scales. Compared with other global anthropogenic heat datasets, the AH-DMSP has a higher precision and finer spatial distribution. Although there are some limitations, the AH-DMSP could provide reliable, multi-scale anthropogenic heat information, which could be used for further research on regional or global climate change and urban ecosystems.

  18. Capabilities of VOS-based fluxes for estimating ocean heat budget and its variability

    Science.gov (United States)

    Gulev, S.; Belyaev, K.

    2016-12-01

    We consider here the perspective of using VOS observations by merchant ships available form the ICOADS data for estimating ocean surface heat budget at different time scale. To this purpose we compute surface turbulent heat fluxes as well as short- and long-wave radiative fluxes from the ICOADS reports for the last several decades in the North Atlantic mid latitudes. Turbulent fluxes were derived using COARE-3 algorithm and for computation of radiative fluxes new algorithms accounting for cloud types were used. Sampling uncertainties in the VOS-based fluxes were estimated by sub-sampling of the recomputed reanalysis (ERA-Interim) fluxes according to the VOS sampling scheme. For the turbulent heat fluxes we suggest an approach to minimize sampling uncertainties. The approach is based on the integration of the turbulent heat fluxes in the coordinates of steering parameters (vertical surface temperature and humidity gradients on one hand and wind speed on the other) for which theoretical probability distributions are known. For short-wave radiative fluxes sampling uncertainties were minimized by "rotating local observation time around the clock" and using probability density functions for the cloud cover occurrence distributions. Analysis was performed for the North Atlantic latitudinal band from 25 N to 60 N, for which also estimates of the meridional heat transport are available from the ocean cross-sections. Over the last 35 years turbulent fluxes within the region analysed increase by about 6 W/m2 with the major growth during the 1990s and early 2000s. Decreasing incoming short wave radiation during the same time (about 1 W/m2) implies upward change of the ocean surface heat loss by about 7-8 W/m2. We discuss different sources of uncertainties of computations as well as potential of the application of the analysis concept to longer time series going back to 1920s.

  19. Correlation Lengths for Estimating the Large-Scale Carbon and Heat Content of the Southern Ocean

    Science.gov (United States)

    Mazloff, M. R.; Cornuelle, B. D.; Gille, S. T.; Verdy, A.

    2018-02-01

    The spatial correlation scales of oceanic dissolved inorganic carbon, heat content, and carbon and heat exchanges with the atmosphere are estimated from a realistic numerical simulation of the Southern Ocean. Biases in the model are assessed by comparing the simulated sea surface height and temperature scales to those derived from optimally interpolated satellite measurements. While these products do not resolve all ocean scales, they are representative of the climate scale variability we aim to estimate. Results show that constraining the carbon and heat inventory between 35°S and 70°S on time-scales longer than 90 days requires approximately 100 optimally spaced measurement platforms: approximately one platform every 20° longitude by 6° latitude. Carbon flux has slightly longer zonal scales, and requires a coverage of approximately 30° by 6°. Heat flux has much longer scales, and thus a platform distribution of approximately 90° by 10° would be sufficient. Fluxes, however, have significant subseasonal variability. For all fields, and especially fluxes, sustained measurements in time are required to prevent aliasing of the eddy signals into the longer climate scale signals. Our results imply a minimum of 100 biogeochemical-Argo floats are required to monitor the Southern Ocean carbon and heat content and air-sea exchanges on time-scales longer than 90 days. However, an estimate of formal mapping error using the current Argo array implies that in practice even an array of 600 floats (a nominal float density of about 1 every 7° longitude by 3° latitude) will result in nonnegligible uncertainty in estimating climate signals.

  20. A new method to estimate heat source parameters in gas metal arc welding simulation process

    International Nuclear Information System (INIS)

    Jia, Xiaolei; Xu, Jie; Liu, Zhaoheng; Huang, Shaojie; Fan, Yu; Sun, Zhi

    2014-01-01

    Highlights: •A new method for accurate simulation of heat source parameters was presented. •The partial least-squares regression analysis was recommended in the method. •The welding experiment results verified accuracy of the proposed method. -- Abstract: Heat source parameters were usually recommended by experience in welding simulation process, which induced error in simulation results (e.g. temperature distribution and residual stress). In this paper, a new method was developed to accurately estimate heat source parameters in welding simulation. In order to reduce the simulation complexity, a sensitivity analysis of heat source parameters was carried out. The relationships between heat source parameters and welding pool characteristics (fusion width (W), penetration depth (D) and peak temperature (T p )) were obtained with both the multiple regression analysis (MRA) and the partial least-squares regression analysis (PLSRA). Different regression models were employed in each regression method. Comparisons of both methods were performed. A welding experiment was carried out to verify the method. The results showed that both the MRA and the PLSRA were feasible and accurate for prediction of heat source parameters in welding simulation. However, the PLSRA was recommended for its advantages of requiring less simulation data

  1. Estimating the potential for solar thermal applications in the industrial process heat market 1990-2030

    International Nuclear Information System (INIS)

    Demeter, C.P.; Gray, E.E.; Carwile, C.

    1991-01-01

    This paper reports the results of a preliminary evaluation of the potential domestic market for solar thermal energy supply technologies matched to industrial process heat applications. The study estimates current and projects future industrial process heat demand to the year 2030 by two-digit standard industrial classification code for the manufacturing industrial sector and discusses the potential to displace conventional fossil fuel sources such as natural gas with alternative sources of supply. The PC Industrial Model, used by DOE's Energy Information Administration in support of the National Energy Strategy (NES) is used for forecast industrial energy demand. Demand is disaggregated by census region to account for geographic variations in solar insolation, and by heat medium and temperature to facilitate end-use matching with appropriate solar energy supply technologies. Levelized energy costs (LEC) are calculated for flat plate collectors for low- temperature preheat applications, parabolic troughs for intermediate temperature process steam and direct heat, and parabolic dish technologies for high-temperature, direct heat applications. LEC is also developed for a conventional natural gas-fueled Industrial Process Heat (IPH) supply source assuming natural gas price escalation consistent with NES forecasts to develop a relative figure of merit used in a market penetration model

  2. Estimating population heat exposure and impacts on working people in conjunction with climate change.

    Science.gov (United States)

    Kjellstrom, Tord; Freyberg, Chris; Lemke, Bruno; Otto, Matthias; Briggs, David

    2017-08-01

    Increased environmental heat levels as a result of climate change present a major challenge to the health, wellbeing and sustainability of human communities in already hot parts of this planet. This challenge has many facets from direct clinical health effects of daily heat exposure to indirect effects related to poor air quality, poor access to safe drinking water, poor access to nutritious and safe food and inadequate protection from disease vectors and environmental toxic chemicals. The increasing environmental heat is a threat to environmental sustainability. In addition, social conditions can be undermined by the negative effects of increased heat on daily work and life activities and on local cultural practices. The methodology we describe can be used to produce quantitative estimates of the impacts of climate change on work activities in countries and local communities. We show in maps the increasing heat exposures in the shade expressed as the occupational heat stress index Wet Bulb Globe Temperature. Some tropical and sub-tropical areas already experience serious heat stress, and the continuing heating will substantially reduce work capacity and labour productivity in widening parts of the world. Southern parts of Europe and the USA will also be affected. Even the lowest target for climate change (average global temperature change = 1.5 °C at representative concentration pathway (RCP2.6) will increase the loss of daylight work hour output due to heat in many tropical areas from less than 2% now up to more than 6% at the end of the century. A global temperature change of 2.7 °C (at RCP6.0) will double this annual heat impact on work in such areas. Calculations of this type of heat impact at country level show that in the USA, the loss of work capacity in moderate level work in the shade will increase from 0.17% now to more than 1.3% at the end of the century based on the 2.7 °C temperature change. The impact is naturally mainly occurring in the

  3. Estimating population heat exposure and impacts on working people in conjunction with climate change

    Science.gov (United States)

    Kjellstrom, Tord; Freyberg, Chris; Lemke, Bruno; Otto, Matthias; Briggs, David

    2018-03-01

    Increased environmental heat levels as a result of climate change present a major challenge to the health, wellbeing and sustainability of human communities in already hot parts of this planet. This challenge has many facets from direct clinical health effects of daily heat exposure to indirect effects related to poor air quality, poor access to safe drinking water, poor access to nutritious and safe food and inadequate protection from disease vectors and environmental toxic chemicals. The increasing environmental heat is a threat to environmental sustainability. In addition, social conditions can be undermined by the negative effects of increased heat on daily work and life activities and on local cultural practices. The methodology we describe can be used to produce quantitative estimates of the impacts of climate change on work activities in countries and local communities. We show in maps the increasing heat exposures in the shade expressed as the occupational heat stress index Wet Bulb Globe Temperature. Some tropical and sub-tropical areas already experience serious heat stress, and the continuing heating will substantially reduce work capacity and labour productivity in widening parts of the world. Southern parts of Europe and the USA will also be affected. Even the lowest target for climate change (average global temperature change = 1.5 °C at representative concentration pathway (RCP2.6) will increase the loss of daylight work hour output due to heat in many tropical areas from less than 2% now up to more than 6% at the end of the century. A global temperature change of 2.7 °C (at RCP6.0) will double this annual heat impact on work in such areas. Calculations of this type of heat impact at country level show that in the USA, the loss of work capacity in moderate level work in the shade will increase from 0.17% now to more than 1.3% at the end of the century based on the 2.7 °C temperature change. The impact is naturally mainly occurring in the southern

  4. Estimating population heat exposure and impacts on working people in conjunction with climate change

    Science.gov (United States)

    Kjellstrom, Tord; Freyberg, Chris; Lemke, Bruno; Otto, Matthias; Briggs, David

    2017-08-01

    Increased environmental heat levels as a result of climate change present a major challenge to the health, wellbeing and sustainability of human communities in already hot parts of this planet. This challenge has many facets from direct clinical health effects of daily heat exposure to indirect effects related to poor air quality, poor access to safe drinking water, poor access to nutritious and safe food and inadequate protection from disease vectors and environmental toxic chemicals. The increasing environmental heat is a threat to environmental sustainability. In addition, social conditions can be undermined by the negative effects of increased heat on daily work and life activities and on local cultural practices. The methodology we describe can be used to produce quantitative estimates of the impacts of climate change on work activities in countries and local communities. We show in maps the increasing heat exposures in the shade expressed as the occupational heat stress index Wet Bulb Globe Temperature. Some tropical and sub-tropical areas already experience serious heat stress, and the continuing heating will substantially reduce work capacity and labour productivity in widening parts of the world. Southern parts of Europe and the USA will also be affected. Even the lowest target for climate change (average global temperature change = 1.5 °C at representative concentration pathway (RCP2.6) will increase the loss of daylight work hour output due to heat in many tropical areas from less than 2% now up to more than 6% at the end of the century. A global temperature change of 2.7 °C (at RCP6.0) will double this annual heat impact on work in such areas. Calculations of this type of heat impact at country level show that in the USA, the loss of work capacity in moderate level work in the shade will increase from 0.17% now to more than 1.3% at the end of the century based on the 2.7 °C temperature change. The impact is naturally mainly occurring in the southern

  5. Surface layer scintillometry for estimating the sensible heat flux component of the surface energy balance

    Directory of Open Access Journals (Sweden)

    M. J. Savage

    2010-01-01

    Full Text Available The relatively recently developed scintillometry method, with a focus on the dual-beam surface layer scintillometer (SLS, allows boundary layer atmospheric turbulence, surface sensible heat and momentum flux to be estimated in real-time. Much of the previous research using the scintillometer method has involved the large aperture scintillometer method, with only a few studies using the SLS method. The SLS method has been mainly used by agrometeorologists, hydrologists and micrometeorologists for atmospheric stability and surface energy balance studies to obtain estimates of sensible heat from which evaporation estimates representing areas of one hectare or larger are possible. Other applications include the use of the SLS method in obtaining crucial input parameters for atmospheric dispersion and turbulence models. The SLS method relies upon optical scintillation of a horizontal laser beam between transmitter and receiver for a separation distance typically between 50 and 250 m caused by refractive index inhomogeneities in the atmosphere that arise from turbulence fluctuations in air temperature and to a much lesser extent the fluctuations in water vapour pressure. Measurements of SLS beam transmission allow turbulence of the atmosphere to be determined, from which sub-hourly, real-time and in situ path-weighted fluxes of sensible heat and momentum may be calculated by application of the Monin-Obukhov similarity theory. Unlike the eddy covariance (EC method for which corrections for flow distortion and coordinate rotation are applied, no corrections to the SLS measurements, apart from a correction for water vapour pressure, are applied. Also, path-weighted SLS estimates over the propagation path are obtained. The SLS method also offers high temporal measurement resolution and usually greater spatial coverage compared to EC, Bowen ratio energy balance, surface renewal and other sensible heat measurement methods. Applying the shortened surface

  6. Estimating thermal diffusivity and specific heat from needle probe thermal conductivity data

    Science.gov (United States)

    Waite, W.F.; Gilbert, L.Y.; Winters, W.J.; Mason, D.H.

    2006-01-01

    Thermal diffusivity and specific heat can be estimated from thermal conductivity measurements made using a standard needle probe and a suitably high data acquisition rate. Thermal properties are calculated from the measured temperature change in a sample subjected to heating by a needle probe. Accurate thermal conductivity measurements are obtained from a linear fit to many tens or hundreds of temperature change data points. In contrast, thermal diffusivity calculations require a nonlinear fit to the measured temperature change occurring in the first few tenths of a second of the measurement, resulting in a lower accuracy than that obtained for thermal conductivity. Specific heat is calculated from the ratio of thermal conductivity to diffusivity, and thus can have an uncertainty no better than that of the diffusivity estimate. Our thermal conductivity measurements of ice Ih and of tetrahydrofuran (THF) hydrate, made using a 1.6 mm outer diameter needle probe and a data acquisition rate of 18.2 pointss, agree with published results. Our thermal diffusivity and specific heat results reproduce published results within 25% for ice Ih and 3% for THF hydrate. ?? 2006 American Institute of Physics.

  7. Using forecast and observed weather data to assess performance of forecast products in identifying heat waves and estimating heat wave effects on mortality.

    Science.gov (United States)

    Zhang, Kai; Chen, Yeh-Hsin; Schwartz, Joel D; Rood, Richard B; O'Neill, Marie S

    2014-09-01

    Heat wave and health warning systems are activated based on forecasts of health-threatening hot weather. We estimated heat-mortality associations based on forecast and observed weather data in Detroit, Michigan, and compared the accuracy of forecast products for predicting heat waves. We derived and compared apparent temperature (AT) and heat wave days (with heat waves defined as ≥ 2 days of daily mean AT ≥ 95th percentile of warm-season average) from weather observations and six different forecast products. We used Poisson regression with and without adjustment for ozone and/or PM10 (particulate matter with aerodynamic diameter ≤ 10 μm) to estimate and compare associations of daily all-cause mortality with observed and predicted AT and heat wave days. The 1-day-ahead forecast of a local operational product, Revised Digital Forecast, had about half the number of false positives compared with all other forecasts. On average, controlling for heat waves, days with observed AT = 25.3°C were associated with 3.5% higher mortality (95% CI: -1.6, 8.8%) than days with AT = 8.5°C. Observed heat wave days were associated with 6.2% higher mortality (95% CI: -0.4, 13.2%) than non-heat wave days. The accuracy of predictions varied, but associations between mortality and forecast heat generally tended to overestimate heat effects, whereas associations with forecast heat waves tended to underestimate heat wave effects, relative to associations based on observed weather metrics. Our findings suggest that incorporating knowledge of local conditions may improve the accuracy of predictions used to activate heat wave and health warning systems.

  8. An Improved Heat Budget Estimation Including Bottom Effects for General Ocean Circulation Models

    Science.gov (United States)

    Carder, Kendall; Warrior, Hari; Otis, Daniel; Chen, R. F.

    2001-01-01

    This paper studies the effects of the underwater light field on heat-budget calculations of general ocean circulation models for shallow waters. The presence of a bottom significantly alters the estimated heat budget in shallow waters, which affects the corresponding thermal stratification and hence modifies the circulation. Based on the data collected during the COBOP field experiment near the Bahamas, we have used a one-dimensional turbulence closure model to show the influence of the bottom reflection and absorption on the sea surface temperature field. The water depth has an almost one-to-one correlation with the temperature rise. Effects of varying the bottom albedo by replacing the sea grass bed with a coral sand bottom, also has an appreciable effect on the heat budget of the shallow regions. We believe that the differences in the heat budget for the shallow areas will have an influence on the local circulation processes and especially on the evaporative and long-wave heat losses for these areas. The ultimate effects on humidity and cloudiness of the region are expected to be significant as well.

  9. Real-Time Personalized Monitoring to Estimate Occupational Heat Stress in Ambient Assisted Working

    Directory of Open Access Journals (Sweden)

    Pablo Pancardo

    2015-07-01

    Full Text Available Ambient Assisted Working (AAW is a discipline aiming to provide comfort and safety in the workplace through customization and technology. Workers’ comfort may be compromised in many labor situations, including those depending on environmental conditions, like extremely hot weather conduces to heat stress. Occupational heat stress (OHS happens when a worker is in an uninterrupted physical activity and in a hot environment. OHS can produce strain on the body, which leads to discomfort and eventually to heat illness and even death. Related ISO standards contain methods to estimate OHS and to ensure the safety and health of workers, but they are subjective, impersonal, performed a posteriori and even invasive. This paper focuses on the design and development of real-time personalized monitoring for a more effective and objective estimation of OHS, taking into account the individual user profile, fusing data from environmental and unobtrusive body sensors. Formulas employed in this work were taken from different domains and joined in the method that we propose. It is based on calculations that enable continuous surveillance of physical activity performance in a comfortable and healthy manner. In this proposal, we found that OHS can be estimated by satisfying the following criteria: objective, personalized, in situ, in real time, just in time and in an unobtrusive way. This enables timely notice for workers to make decisions based on objective information to control OHS.

  10. A new approach to the joined estimation of the heat generated by a semicontiunuous emulsion polymerization Qr and the overall heat exchange parameter UA

    Directory of Open Access Journals (Sweden)

    Freire F. B.

    2004-01-01

    Full Text Available This work is concerned with the coupled estimation of the heat generated by the reaction (Qr and the overall heat transfer parameter (UA during the terpolymerization of styrene, butyl acrylate and methyl methacrylate from temperature measurements and the reactor heat balance. By making specific assumptions about the dynamics of the evolution of UA and Q R, we propose a cascade of observers to successively estimate these two parameters without the need for additional measurements of on-line samples. One further aspect of our approach is that only the energy balance around the reactor was employed. It means that the flow rate of the cooling jacket fluid was not required.

  11. Mathematical model of cycad cones' thermogenic temperature responses: inverse calorimetry to estimate metabolic heating rates.

    Science.gov (United States)

    Roemer, R B; Booth, D; Bhavsar, A A; Walter, G H; Terry, L I

    2012-12-21

    A mathematical model based on conservation of energy has been developed and used to simulate the temperature responses of cones of the Australian cycads Macrozamia lucida and Macrozamia. macleayi during their daily thermogenic cycle. These cones generate diel midday thermogenic temperature increases as large as 12 °C above ambient during their approximately two week pollination period. The cone temperature response model is shown to accurately predict the cones' temperatures over multiple days as based on simulations of experimental results from 28 thermogenic events from 3 different cones, each simulated for either 9 or 10 sequential days. The verified model is then used as the foundation of a new, parameter estimation based technique (termed inverse calorimetry) that estimates the cones' daily metabolic heating rates from temperature measurements alone. The inverse calorimetry technique's predictions of the major features of the cones' thermogenic metabolism compare favorably with the estimates from conventional respirometry (indirect calorimetry). Because the new technique uses only temperature measurements, and does not require measurements of oxygen consumption, it provides a simple, inexpensive and portable complement to conventional respirometry for estimating metabolic heating rates. It thus provides an additional tool to facilitate field and laboratory investigations of the bio-physics of thermogenic plants. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Thermal Profile of the Lunar Interior Constrained by Revised Estimates of Concentrations of Heat Producing Elements

    Science.gov (United States)

    Fuqua-Haviland, H.; Panovska, S.; Mallik, A.; Bremner, P. M.; McDonough, W. F.

    2017-12-01

    Constraining the heat producing element (HPE) concentrations of the Moon is important for understanding the thermal state of the interior. The lunar HPE budget is debated to be suprachondritic [1] to chondritic [2]. The Moon is differentiated, thus, each reservoir has a distinct HPE signature complicating this effort. The thermal profile of the lunar interior has been constructed using HPE concentrations of an ordinary chondrite (U = 0.0068 ppm; Th = 0.025 ppm; K = 17 ppm) which yields a conservative low estimate [2, 3, 4]. A later study estimated the bulk lunar mantle HPE concentrations (U = 0.039 ppm; Th = 0.15 ppm; K = 212 ppm) based on measurements of Apollo pyroclastic glasses [5] assuming that these glasses represent the least fractionated, near-primary lunar mantle melts, hence, are the best proxies for capturing mantle composition. In this study, we independently validate the revised estimate by using HPE concentrations [5] to construct a conductive lunar thermal profile, or selenotherm. We compare our conductive profile to the range of valid temperatures. We demonstrate the HPE concentrations reported by [5], when used in a simple 1D spherical thermal conduction equation, yield an impossibly hot mantle with temperatures in excess of 4,000 K (Fig 1). This confirms their revised estimate is not representative of the bulk lunar mantle, and perhaps only representative of a locally enriched mantle domain. We believe that their Low-Ti avg. source estimate (Th = 0.055 ppm, Th/U=4; K/U=1700), with the least KREEP assimilation is the closest representation of the bulk lunar mantle, producing 3E-12 W/kg of heat. This estimate is close to that of the Earth (5E-12 W/kg), indicating that the bulk Earth and lunar mantles are similar in their HPE constituents. We have used the lunar mantle heat production, in conjunction with HPE estimates of the Fe-Ti-rich cumulates (high Ti-source estimate from [5]) and measurements of crustal ferroan anorthite [6], to capture the

  13. Estimating the Condition of the Heat Resistant Lining in an Electrical Reduction Furnace

    Directory of Open Access Journals (Sweden)

    Jan G. Waalmann

    1988-01-01

    Full Text Available This paper presents a system for estimating the condition of the heat resistant lining in an electrical reduction furnace for ferrosilicon. The system uses temperature measured with thermocouples placed on the outside of the furnace-pot. These measurements are used together with a mathematical model of the temperature distribution in the lining in a recursive least squares algorithm to estimate the position of 'the transformation front'. The system is part of a monitoring system which is being developed in the AIP-project: 'Condition monitoring of strongly exposed process equipment in thc ferroalloy industry'. The estimator runs on-line, and results arc presented in colour-graphics on a display unit. The goal is to locate the transformation front with an accuracy of +- 5cm.

  14. An improved routine for the fast estimate of ion cyclotron heating efficiency in tokamak plasmas

    International Nuclear Information System (INIS)

    Brambilla, M.

    1992-02-01

    The subroutine ICEVAL for the rapid simulation of Ion Cyclotron Heating in tokamak plasmas is based on analytic estimates of the wave behaviour near resonances, and on drastic but reasonable simplifications of the real geometry. The subroutine has been rewritten to improve the model and to facilitate its use as input in transport codes. In the new version the influence of quasilinear minority heating on the damping efficiency is taken into account using the well-known Stix analytic approximation. Among other improvements are: a) the possibility of considering plasmas with more than two ion species; b) inclusion of Landau, Transit Time and collisional damping on the electrons non localised at resonances; c) better models for the antenna spectrum and for the construction of the power deposition profiles. The results of ICEVAL are compared in detail with those of the full-wave code FELICE for the case of Hydrogen minority heating in a Deuterium plasma; except for details which depend on the excitation of global eigenmodes, agreement is excellent. ICEVAL is also used to investigate the enhancement of the absorption efficiency due to quasilinear heating of the minority ions. The effect is a strongly non-linear function of the available power, and decreases rapidly with increasing concentration. For parameters typical of Asdex Upgrade plasmas, about 4 MW are required to produce a significant increase of the single-pass absorption at concentrations between 10 and 20%. (orig.)

  15. Estimation of catchment averaged sensible heat fluxes using a large aperture scintillometer

    Directory of Open Access Journals (Sweden)

    Samain Bruno

    2012-05-01

    Full Text Available Evapotranspiration rates at the catchment scale are very difficult to quantify. One possible manner to continuously observe this variable could be the estimation of sensible heat fluxes (H across large distances (in the order of kilometers using a large aperture scintillometer (LAS, and inverting these observations into evapotranspiration rates, under the assumption that the LAS observations are representative for the entire catchment. The objective of this paper is to assess whether measured sensible heat fluxes from a LAS over a long distance (9.5 km can be assumed to be valid for a 102.3 km2 heterogeneous catchment. Therefore, a fully process-based water and energy balance model with a spatial resolution of 50 m has been thoroughly calibrated and validated for the Bellebeek catchmentin Belgium. A footprint analysis has been performed. In general, the sensible heat fluxes from the LAS compared well with the modeled sensible heat fluxes within the footprint. Moreover, as the modeled Hwithin the footprint has been found to be almost equal to the modeled catchment averaged H, it can be concluded that the scintillometer measurements over a distance of 9.5 km and an effective heightof 68 m are representative for the entire catchment.

  16. A single-probe heat pulse method for estimating sap velocity in trees.

    Science.gov (United States)

    López-Bernal, Álvaro; Testi, Luca; Villalobos, Francisco J

    2017-10-01

    Available sap flow methods are still far from being simple, cheap and reliable enough to be used beyond very specific research purposes. This study presents and tests a new single-probe heat pulse (SPHP) method for monitoring sap velocity in trees using a single-probe sensor, rather than the multi-probe arrangements used up to now. Based on the fundamental conduction-convection principles of heat transport in sapwood, convective velocity (V h ) is estimated from the temperature increase in the heater after the application of a heat pulse (ΔT). The method was validated against measurements performed with the compensation heat pulse (CHP) technique in field trees of six different species. To do so, a dedicated three-probe sensor capable of simultaneously applying both methods was produced and used. Experimental measurements in the six species showed an excellent agreement between SPHP and CHP outputs for moderate to high flow rates, confirming the applicability of the method. In relation to other sap flow methods, SPHP presents several significant advantages: it requires low power inputs, it uses technically simpler and potentially cheaper instrumentation, the physical damage to the tree is minimal and artefacts caused by incorrect probe spacing and alignment are removed. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  17. Crustal heat production and estimate of terrestrial heat flow in central East Antarctica, with implications for thermal input to the East Antarctic ice sheet

    Directory of Open Access Journals (Sweden)

    J. W. Goodge

    2018-02-01

    Full Text Available Terrestrial heat flow is a critical first-order factor governing the thermal condition and, therefore, mechanical stability of Antarctic ice sheets, yet heat flow across Antarctica is poorly known. Previous estimates of terrestrial heat flow in East Antarctica come from inversion of seismic and magnetic geophysical data, by modeling temperature profiles in ice boreholes, and by calculation from heat production values reported for exposed bedrock. Although accurate estimates of surface heat flow are important as an input parameter for ice-sheet growth and stability models, there are no direct measurements of terrestrial heat flow in East Antarctica coupled to either subglacial sediment or bedrock. As has been done with bedrock exposed along coastal margins and in rare inland outcrops, valuable estimates of heat flow in central East Antarctica can be extrapolated from heat production determined by the geochemical composition of glacial rock clasts eroded from the continental interior. In this study, U, Th, and K concentrations in a suite of Proterozoic (1.2–2.0 Ga granitoids sourced within the Byrd and Nimrod glacial drainages of central East Antarctica indicate average upper crustal heat production (Ho of about 2.6  ±  1.9 µW m−3. Assuming typical mantle and lower crustal heat flux for stable continental shields, and a length scale for the distribution of heat production in the upper crust, the heat production values determined for individual samples yield estimates of surface heat flow (qo ranging from 33 to 84 mW m−2 and an average of 48.0  ±  13.6 mW m−2. Estimates of heat production obtained for this suite of glacially sourced granitoids therefore indicate that the interior of the East Antarctic ice sheet is underlain in part by Proterozoic continental lithosphere with an average surface heat flow, providing constraints on both geodynamic history and ice-sheet stability. The ages and geothermal

  18. Estimated heats of fusion of fluoride salt mixtures suitable for thermal energy storage applications

    Science.gov (United States)

    Misra, A. K.; Whittenberger, J. D.

    1986-01-01

    The heats of fusion of several fluoride salt mixtures with melting points greater than 973 K were estimated from a coupled analysis of the available thermodynamic data and phase diagrams. Simple binary eutectic systems with and without terminal solid solutions, binary eutectics with congruent melting intermediate phases, and ternary eutectic systems were considered. Several combinations of salts were identified, most notable the eutectics LiF-22CaF2 and NaF-60MgF2 which melt at 1039 and 1273 K respectively which posses relatively high heats of fusion/gm (greater than 0.7 kJ/g). Such systems would seemingly be ideal candidates for the light weight, high energy storage media required by the thermal energy storage unit in advanced solar dynamic power systems envisioned for the future space missions.

  19. Study of Nuclear Decay Data Contribution to Uncertainties in Heat Load Estimations for Spent Fuel Pools

    Science.gov (United States)

    Ferroukhi, H.; Leray, O.; Hursin, M.; Vasiliev, A.; Perret, G.; Pautz, A.

    2014-04-01

    At the Paul Scherrer Institut (PSI), a methodology for nuclear data uncertainty propagation in CASMO-5M (C5M) assembly calculations is under development. This paper presents a preliminary application of this methodology to C5M decay heat calculations. Applying a stochastic sampling method, nuclear decay data uncertainties are first propagated for the cooling phase only. Thereafter, the uncertainty propagation is enlarged to gradually account for cross-section as well as fission yield uncertainties during the depletion phase. On that basis, assembly heat load uncertainties as well as total uncertainty for the entire pool are quantified for cooling times up to one year. The relative contributions from the various types of nuclear data uncertainties are in this context also estimated.

  20. Resolving the Mantle Heat Transfer Discrepancy by Reassessing Buoyancy Flux Estimates of Upwelling Plumes

    Science.gov (United States)

    Hoggard, Mark; Parnell-Turner, Ross; White, Nicky

    2017-04-01

    The size and relative importance of mantle plumes is a controversial topic within the geodynamics community. Numerical experiments of mantle convection suggest a wide range of possible behaviours, from minor plumelets through to large scale, whole-mantle upwellings. In terms of observations, recent seismic tomographic models have identified many large, broad plume-like features within the lower mantle. In contrast, existing estimates of buoyancy flux calculated from plume swells have suggested that these upwellings transfer a relatively minor amount of material and heat into the uppermost mantle. Here, we revisit these calculations of buoyancy flux using a global map of plume swells based upon new observations of dynamic topography. Usually, plume flux is calculated from the cross-sectional area of a swell multiplied by either plate velocity or spreading rate. A key assumption is that plume head material flows laterally at or below the velocity of the overriding plate. Published results are dominated by contributions from the Pacific Ocean and suggest that a total of ˜ 2 TW of heat is carried by plumes into the uppermost mantle. An alternative approach exploits swell volume scaled by a characteristic decay time, which removes the reliance on plate velocities. The main assumption of this method is that plumes are in quasi-steady state. In this study, we have applied this volumetric approach in a new global analysis. Our results indicate that the Icelandic plume has a buoyancy flux of ˜ 27 ± 4 Mg s-1 and the Hawaiian plume is ˜ 2.9 ± 0.6 Mg s-1. These revised values are consistent with independent geophysical constraints from the North Atlantic Ocean and Hawaii. All magmatic and amagmatic swells have been included, suggesting that the total heat flux carried to the base of the plates is ˜ 10 ± 2 TW. This revised value is a five-fold increase compared with previous estimates and provides an improved match to published predictions of basal heat flux across the

  1. Inverse heat conduction estimation of inner wall temperature fluctuations under turbulent penetration

    Science.gov (United States)

    Guo, Zhouchao; Lu, Tao; Liu, Bo

    2017-04-01

    Turbulent penetration can occur when hot and cold fluids mix in a horizontal T-junction pipe at nuclear plants. Caused by the unstable turbulent penetration, temperature fluctuations with large amplitude and high frequency can lead to time-varying wall thermal stress and even thermal fatigue on the inner wall. Numerous cases, however, exist where inner wall temperatures cannot be measured and only outer wall temperature measurements are feasible. Therefore, it is one of the popular research areas in nuclear science and engineering to estimate temperature fluctuations on the inner wall from measurements of outer wall temperatures without damaging the structure of the pipe. In this study, both the one-dimensional (1D) and the two-dimensional (2D) inverse heat conduction problem (IHCP) were solved to estimate the temperature fluctuations on the inner wall. First, numerical models of both the 1D and the 2D direct heat conduction problem (DHCP) were structured in MATLAB, based on the finite difference method with an implicit scheme. Second, both the 1D IHCP and the 2D IHCP were solved by the steepest descent method (SDM), and the DHCP results of temperatures on the outer wall were used to estimate the temperature fluctuations on the inner wall. Third, we compared the temperature fluctuations on the inner wall estimated by the 1D IHCP with those estimated by the 2D IHCP in four cases: (1) when the maximum disturbance of temperature of fluid inside the pipe was 3°C, (2) when the maximum disturbance of temperature of fluid inside the pipe was 30°C, (3) when the maximum disturbance of temperature of fluid inside the pipe was 160°C, and (4) when the fluid temperatures inside the pipe were random from 50°C to 210°C.

  2. Estimation of instantaneous heat transfer coefficients for a direct-injection stratified-charge rotary engine

    Science.gov (United States)

    Lee, C. M.; Addy, H. E.; Bond, T. H.; Chun, K. S.; Lu, C. Y.

    1987-01-01

    The main objective of this report was to derive equations to estimate heat transfer coefficients in both the combustion chamber and coolant pasage of a rotary engine. This was accomplished by making detailed temperature and pressure measurements in a direct-injection stratified-charge rotary engine under a range of conditions. For each sppecific measurement point, the local physical properties of the fluids were calculated. Then an empirical correlation of the coefficients was derived by using a multiple regression program. This correlation expresses the Nusselt number as a function of the Prandtl number and Reynolds number.

  3. Capture of Heat Energy from Diesel Engine Exhaust

    Energy Technology Data Exchange (ETDEWEB)

    Chuen-Sen Lin

    2008-12-31

    Diesel generators produce waste heat as well as electrical power. About one-third of the fuel energy is released from the exhaust manifolds of the diesel engines and normally is not captured for useful applications. This project studied different waste heat applications that may effectively use the heat released from exhaust of Alaskan village diesel generators, selected the most desirable application, designed and fabricated a prototype for performance measurements, and evaluated the feasibility and economic impact of the selected application. Exhaust flow rate, composition, and temperature may affect the heat recovery system design and the amount of heat that is recoverable. In comparison with the other two parameters, the effect of exhaust composition may be less important due to the large air/fuel ratio for diesel engines. This project also compared heat content and qualities (i.e., temperatures) of exhaust for three types of fuel: conventional diesel, a synthetic diesel, and conventional diesel with a small amount of hydrogen. Another task of this project was the development of a computer-aided design tool for the economic analysis of selected exhaust heat recovery applications to any Alaskan village diesel generator set. The exhaust heat recovery application selected from this study was for heating. An exhaust heat recovery system was fabricated, and 350 hours of testing was conducted. Based on testing data, the exhaust heat recovery heating system showed insignificant effects on engine performance and maintenance requirements. From measurements, it was determined that the amount of heat recovered from the system was about 50% of the heat energy contained in the exhaust (heat contained in exhaust was evaluated based on environment temperature). The estimated payback time for 100% use of recovered heat would be less than 3 years at a fuel price of $3.50 per gallon, an interest rate of 10%, and an engine operation of 8 hours per day. Based on experimental data

  4. Estimation and optimization of heat transfer and overall presure drop for a shell and tube heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Bala Bhaskara [Dept. of Mechanical Engineering, SISTAM College, JNTU, Kakinada (India); Raju, V. Ramachandra [Dept. of Mechanical Engineering, JNTU, Kakinada (India); Deepak, B. B V. L. [Dept. of Industrial Design, National Institute of Technology, Rourkela (India)

    2017-01-15

    Most thermal/chemical industries are equipped with heat exchangers to enhance thermal efficiency. The performance of heat exchangers highly depends on design modifications in the tube side, such as the cross-sectional area, orientation, and baffle cut of the tube. However, these parameters do not exhibit a specific relation to determining the optimum design condition for shell and tube heat exchangers with a maximum heat transfer rate and reduced pressure drops. Accordingly, experimental and numerical simulations are performed for a heat exchanger with varying tube geometries. The heat exchanger considered in this investigation is a single-shell, multiple-pass device. A Generalized regression neural network (GRNN) is applied to generate a relation among the input and output process parameters for the experimental data sets. Then, an Artificial immune system (AIS) is used with GRNN to obtain optimized input parameters. Lastly, results are presented for the developed hybrid GRNN-AIS approach.

  5. An improved model for sensible heat flux estimation based on landcover classification

    Science.gov (United States)

    Zhou, Ti; Xin, Xiaozhou; Jiao, Jingjun; Peng, Zhiqing

    2014-10-01

    Remote sensing (RS) has been recognized as the most feasible means to provide spatially distributed regional evapotranspiration (ET). However, classical RS flux algorithms (SEBS, S-SEBI, SEBAL, etc.) can hardly be used with coarser resolution RS data from sensors like MODIS or AVHRR for no consideration of surface heterogeneity in mixed pixels even they are suitable for assessing the surface fluxes with high resolution RS data.A new model named FAFH is developed in this study to enhance the accuracy of flux estimation in mixed pixels based on high resolution landcover classification data. The area fraction and relative sensible heat fraction of each heterogeneous land use type calculated within coarse resolution pixels are calculated firstly, and then used for the weighted average of modified sensible heat. The study is carried out in the core agricultural land of Zhangye, the middle reaches of Heihe river based on the flux and landcover classification product of HJ-1B in our earlier work. The result indicates that FAFH increases the accuracy of sensible heat by 5% absolutely, 10.64% relatively in the whole research area.

  6. Estimated work ability in warm outdoor environments depends on the chosen heat stress assessment metric

    Science.gov (United States)

    Bröde, Peter; Fiala, Dusan; Lemke, Bruno; Kjellstrom, Tord

    2017-04-01

    With a view to occupational effects of climate change, we performed a simulation study on the influence of different heat stress assessment metrics on estimated workability (WA) of labour in warm outdoor environments. Whole-day shifts with varying workloads were simulated using as input meteorological records for the hottest month from four cities with prevailing hot (Dallas, New Delhi) or warm-humid conditions (Managua, Osaka), respectively. In addition, we considered the effects of adaptive strategies like shielding against solar radiation and different work-rest schedules assuming an acclimated person wearing light work clothes (0.6 clo). We assessed WA according to Wet Bulb Globe Temperature (WBGT) by means of an empirical relation of worker performance from field studies (Hothaps), and as allowed work hours using safety threshold limits proposed by the corresponding standards. Using the physiological models Predicted Heat Strain (PHS) and Universal Thermal Climate Index (UTCI)-Fiala, we calculated WA as the percentage of working hours with body core temperature and cumulated sweat loss below standard limits (38 °C and 7.5% of body weight, respectively) recommended by ISO 7933 and below conservative (38 °C; 3%) and liberal (38.2 °C; 7.5%) limits in comparison. ANOVA results showed that the different metrics, workload, time of day and climate type determined the largest part of WA variance. WBGT-based metrics were highly correlated and indicated slightly more constrained WA for moderate workload, but were less restrictive with high workload and for afternoon work hours compared to PHS and UTCI-Fiala. Though PHS showed unrealistic dynamic responses to rest from work compared to UTCI-Fiala, differences in WA assessed by the physiological models largely depended on the applied limit criteria. In conclusion, our study showed that the choice of the heat stress assessment metric impacts notably on the estimated WA. Whereas PHS and UTCI-Fiala can account for

  7. Estimated work ability in warm outdoor environments depends on the chosen heat stress assessment metric

    Science.gov (United States)

    Bröde, Peter; Fiala, Dusan; Lemke, Bruno; Kjellstrom, Tord

    2018-03-01

    With a view to occupational effects of climate change, we performed a simulation study on the influence of different heat stress assessment metrics on estimated workability (WA) of labour in warm outdoor environments. Whole-day shifts with varying workloads were simulated using as input meteorological records for the hottest month from four cities with prevailing hot (Dallas, New Delhi) or warm-humid conditions (Managua, Osaka), respectively. In addition, we considered the effects of adaptive strategies like shielding against solar radiation and different work-rest schedules assuming an acclimated person wearing light work clothes (0.6 clo). We assessed WA according to Wet Bulb Globe Temperature (WBGT) by means of an empirical relation of worker performance from field studies (Hothaps), and as allowed work hours using safety threshold limits proposed by the corresponding standards. Using the physiological models Predicted Heat Strain (PHS) and Universal Thermal Climate Index (UTCI)-Fiala, we calculated WA as the percentage of working hours with body core temperature and cumulated sweat loss below standard limits (38 °C and 7.5% of body weight, respectively) recommended by ISO 7933 and below conservative (38 °C; 3%) and liberal (38.2 °C; 7.5%) limits in comparison. ANOVA results showed that the different metrics, workload, time of day and climate type determined the largest part of WA variance. WBGT-based metrics were highly correlated and indicated slightly more constrained WA for moderate workload, but were less restrictive with high workload and for afternoon work hours compared to PHS and UTCI-Fiala. Though PHS showed unrealistic dynamic responses to rest from work compared to UTCI-Fiala, differences in WA assessed by the physiological models largely depended on the applied limit criteria. In conclusion, our study showed that the choice of the heat stress assessment metric impacts notably on the estimated WA. Whereas PHS and UTCI-Fiala can account for

  8. Recoverable and reusable hydrochloric acid used as a homogeneous catalyst for biodiesel production

    International Nuclear Information System (INIS)

    Su, Chia-Hung

    2013-01-01

    Highlights: ► The recoverability and reusability of several acid catalysts was studied. ► HCl was the only recoverable and reusable catalyst for the reaction. ► The reaction factors for HCl-catalyzed esterification were optimized. - Abstract: Several homogeneous acid catalysts (nitric, sulfuric, and hydrochloric acids), were selected to investigate their recoverability and reusability for esterifying enzyme-hydrolyzed FFAs and methanol to produce biodiesel. Although all of the three catalysts drove the reaction at high yield, hydrochloric acid is the only recoverable and reusable catalyst, as indicated by partitioning data. Hence, esterifying FFAs and methanol was catalyzed using hydrochloric acid; and the reaction conversion, which was affected by the reaction conditions, was optimized using response surface methodology. A maximal reaction conversion of 98.19% was obtained at 76.67 °C, at a methanol/FFAs molar ratio of 7.92, a catalyst concentration of 0.54 M, and after a reaction time of 103.57 min. The catalyst could be reused at least five times to drive the reaction to a conversion of 97%. This study demonstrated that recoverable and reusable hydrochloric acid is promising for potential applications, including biodiesel production

  9. Attribute Synthetic Evaluation Model for the CBM Recoverability and Its Application

    Directory of Open Access Journals (Sweden)

    Xiao-gang Xia

    2015-01-01

    Full Text Available The coal-bed methane (CBM recoverability is the basic premise of CBM development practice; in order to effectively evaluate the CBM recoverability, the attribute synthetic evaluation model is established based on the theory and method of attribute mathematics. Firstly, five indexes are chosen to evaluate the recoverability through analyzing the influence factors of CBM, including seam thickness, gas saturation, permeability, reservoir pressure gradient, and hydrogeological conditions. Secondly, the attribute measurement functions of each index are constructed based on the attribute mathematics theory, and the calculation methods of the single index attribute measurement and the synthetic attribute measurement also are provided. Meanwhile, the weight of each index is given with the method of similar number and similar weight; the evaluation results also are determined by the confidence criterion reliability code. At last, according to the application results of the model in some coal target area of Fuxin and Hancheng mine, the evaluation results are basically consistent with the actual situation, which proves that the evaluation model can be used in the CBM recoverability prediction, and an effective method of the CBM recoverability evaluation is also provided.

  10. A reduced theoretical model for estimating condensation effects in combustion-heated hypersonic tunnel

    Science.gov (United States)

    Lin, L.; Luo, X.; Qin, F.; Yang, J.

    2018-03-01

    As one of the combustion products of hydrocarbon fuels in a combustion-heated wind tunnel, water vapor may condense during the rapid expansion process, which will lead to a complex two-phase flow inside the wind tunnel and even change the design flow conditions at the nozzle exit. The coupling of the phase transition and the compressible flow makes the estimation of the condensation effects in such wind tunnels very difficult and time-consuming. In this work, a reduced theoretical model is developed to approximately compute the nozzle-exit conditions of a flow including real-gas and homogeneous condensation effects. Specifically, the conservation equations of the axisymmetric flow are first approximated in the quasi-one-dimensional way. Then, the complex process is split into two steps, i.e., a real-gas nozzle flow but excluding condensation, resulting in supersaturated nozzle-exit conditions, and a discontinuous jump at the end of the nozzle from the supersaturated state to a saturated state. Compared with two-dimensional numerical simulations implemented with a detailed condensation model, the reduced model predicts the flow parameters with good accuracy except for some deviations caused by the two-dimensional effect. Therefore, this reduced theoretical model can provide a fast, simple but also accurate estimation of the condensation effect in combustion-heated hypersonic tunnels.

  11. How Reliable Are Heat Pulse Velocity Methods for Estimating Tree Transpiration?

    Directory of Open Access Journals (Sweden)

    Michael A. Forster

    2017-09-01

    Full Text Available Transpiration is a significant component of the hydrologic cycle and its accurate quantification is critical for modelling, industry, and policy decisions. Sap flow sensors provide a low cost and practical method to measure transpiration. Various methods to measure sap flow are available and a popular family of methods is known as heat pulse velocity (HPV. Theory on thermal conductance and convection, that underpins HPV methods, suggests transpiration can be directly estimated from sensor measurements without the need for laborious calibrations. To test this accuracy, transpiration estimated from HPV sensors is compared with an independent measure of plant water use such as a weighing lysimeter. A meta-analysis of the literature that explicitly tested the accuracy of a HPV sensors against an independent measure of transpiration was conducted. Data from linear regression analysis was collated where an R2 of 1 indicates perfect precision and a slope of 1 of the linear regression curve indicates perfect accuracy. The average R2 and slope from all studies was 0.822 and 0.860, respectively. However, the overall error, or deviation from real transpiration values, was 34.706%. The results indicate that HPV sensors are precise in correlating heat velocity with rates of transpiration, but poor in quantifying transpiration. Various sources of error in converting heat velocity into sap velocity and sap flow are discussed including probe misalignment, wound corrections, thermal diffusivity, stem water content, placement of sensors in sapwood, and scaling of point measurements to whole plants. Where whole plant water use or transpiration is required in a study, it is recommended that all sap flow sensors are calibrated against an independent measure of transpiration.

  12. Estimating the health benefits from natural gas use in transport and heating in Santiago, Chile.

    Science.gov (United States)

    Mena-Carrasco, Marcelo; Oliva, Estefania; Saide, Pablo; Spak, Scott N; de la Maza, Cristóbal; Osses, Mauricio; Tolvett, Sebastián; Campbell, J Elliott; Tsao, Tsao Es Chi-Chung; Molina, Luisa T

    2012-07-01

    Chilean law requires the assessment of air pollution control strategies for their costs and benefits. Here we employ an online weather and chemical transport model, WRF-Chem, and a gridded population density map, LANDSCAN, to estimate changes in fine particle pollution exposure, health benefits, and economic valuation for two emission reduction strategies based on increasing the use of compressed natural gas (CNG) in Santiago, Chile. The first scenario, switching to a CNG public transportation system, would reduce urban PM2.5 emissions by 229 t/year. The second scenario would reduce wood burning emissions by 671 t/year, with unique hourly emission reductions distributed from daily heating demand. The CNG bus scenario reduces annual PM2.5 by 0.33 μg/m³ and up to 2 μg/m³ during winter months, while the residential heating scenario reduces annual PM2.5 by 2.07 μg/m³, with peaks exceeding 8 μg/m³ during strong air pollution episodes in winter months. These ambient pollution reductions lead to 36 avoided premature mortalities for the CNG bus scenario, and 229 for the CNG heating scenario. Both policies are shown to be cost-effective ways of reducing air pollution, as they target high-emitting area pollution sources and reduce concentrations over densely populated urban areas as well as less dense areas outside the city limits. Unlike the concentration rollback methods commonly used in public policy analyses, which assume homogeneous reductions across a whole city (including homogeneous population densities), and without accounting for the seasonality of certain emissions, this approach accounts for both seasonality and diurnal emission profiles for both the transportation and residential heating sectors. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Estimates of error introduced when one-dimensional inverse heat transfer techniques are applied to multi-dimensional problems

    International Nuclear Information System (INIS)

    Lopez, C.; Koski, J.A.; Razani, A.

    2000-01-01

    A study of the errors introduced when one-dimensional inverse heat conduction techniques are applied to problems involving two-dimensional heat transfer effects was performed. The geometry used for the study was a cylinder with similar dimensions as a typical container used for the transportation of radioactive materials. The finite element analysis code MSC P/Thermal was used to generate synthetic test data that was then used as input for an inverse heat conduction code. Four different problems were considered including one with uniform flux around the outer surface of the cylinder and three with non-uniform flux applied over 360 deg C, 180 deg C, and 90 deg C sections of the outer surface of the cylinder. The Sandia One-Dimensional Direct and Inverse Thermal (SODDIT) code was used to estimate the surface heat flux of all four cases. The error analysis was performed by comparing the results from SODDIT and the heat flux calculated based on the temperature results obtained from P/Thermal. Results showed an increase in error of the surface heat flux estimates as the applied heat became more localized. For the uniform case, SODDIT provided heat flux estimates with a maximum error of 0.5% whereas for the non-uniform cases, the maximum errors were found to be about 3%, 7%, and 18% for the 360 deg C, 180 deg C, and 90 deg C cases, respectively

  14. Assessment of undiscovered conventionally recoverable petroleum resources of the Arabian-Iranian Basin

    Science.gov (United States)

    Masters, Charles D.; Klemme, H. Douglas; Coury, Anny B.

    1982-01-01

    The estimates of undiscovered conventionally recoverable petroleum resources in the Arabian-Iranian basin at probability levels of 95 percent, 5 percent, and statistical mean are for oil (in billions of barrels): 72, 337, and 174; and for gas (in trillions of cubic feet): 299, 1792, and 849. The occurrence of petroleum can be accounted for in five definitive geological settings or plays. The assessment of undiscovered resource potential assumes that the new discoveries will expand the occurrence of petroleum in these basic plays; no additional plays with significant petroleum potential were recognized. The five plays listed by geologic age are: (I) Upper Cretaceous and Tertiary, (II) Lower and Middle Cretaceous sandstone, (III) Lower and Middle Cretaceous limestone, (IV) Jurassic, and (V) Permian. The Permian play, located in the south-central Arabian Gulf region and extending northeast-southwest from southern Iran to the Ar Rub' al Khali in Saudi Arabia, accounts for over four-fifths of the mean estimate of undiscovered gas. The remainder of the gas is divided about equally among the other four plays. The Jurassic play, located on the south side of the Arabian Gulf, accounts for slightly less than one-third of the estimated undiscovered oil, which is split equally between Saudi Arabia and Iraq. The Lower and Middle Cretaceous limestone play is located in the southern Gulf region and accounts for about one-fifth of the undiscovered oil, most of which is located in Saudi Arabia and the remainder in the United Arab Emirates. The Lower and Middle Cretaceous sandstone play is centralized in Kuwait at the head of the Arabian Gulf with significant potential extending to the northwest in Iraq; the play accounts for about one-third of the undiscovered oil, the great majority of which is estimated to be in Iraq with the remainder divided between Saudi Arabia and Kuwait. The upper Cretaceous-Tertiary play is located in the Zagros fold belt of Iran and Iraq and accounts for

  15. A One-Source Approach for Estimating Land Surface Heat Fluxes Using Remotely Sensed Land Surface Temperature

    Directory of Open Access Journals (Sweden)

    Yongmin Yang

    2017-01-01

    Full Text Available The partitioning of available energy between sensible heat and latent heat is important for precise water resources planning and management in the context of global climate change. Land surface temperature (LST is a key variable in energy balance process and remotely sensed LST is widely used for estimating surface heat fluxes at regional scale. However, the inequality between LST and aerodynamic surface temperature (Taero poses a great challenge for regional heat fluxes estimation in one-source energy balance models. To address this issue, we proposed a One-Source Model for Land (OSML to estimate regional surface heat fluxes without requirements for empirical extra resistance, roughness parameterization and wind velocity. The proposed OSML employs both conceptual VFC/LST trapezoid model and the electrical analog formula of sensible heat flux (H to analytically estimate the radiometric-convective resistance (rae via a quartic equation. To evaluate the performance of OSML, the model was applied to the Soil Moisture-Atmosphere Coupling Experiment (SMACEX in United States and the Multi-Scale Observation Experiment on Evapotranspiration (MUSOEXE in China, using remotely sensed retrievals as auxiliary data sets at regional scale. Validated against tower-based surface fluxes observations, the root mean square deviation (RMSD of H and latent heat flux (LE from OSML are 34.5 W/m2 and 46.5 W/m2 at SMACEX site and 50.1 W/m2 and 67.0 W/m2 at MUSOEXE site. The performance of OSML is very comparable to other published studies. In addition, the proposed OSML model demonstrates similar skills of predicting surface heat fluxes in comparison to SEBS (Surface Energy Balance System. Since OSML does not require specification of aerodynamic surface characteristics, roughness parameterization and meteorological conditions with high spatial variation such as wind speed, this proposed method shows high potential for routinely acquisition of latent heat flux estimation

  16. Energy Balance Comparison and Closure at a Moist Desert Playa: The Importance of Ground Heat Storage and Flux Estimation

    Science.gov (United States)

    Huntington, J. L.; Rajagopal, S.; Allen, R. G.; Mihevc, T. M.; Schumer, R.; Caldwell, T.; deBruin, H.

    2012-12-01

    Given increasing demands on finite water supplies in arid environments, the need for accurate estimates of sustainable groundwater resources is greater than ever. Many drainages in desert environments are considered hydrologically closed, where the entire groundwater recharge volume is consumed by evaporation and evapotranspiration along mountain front and valley floor areas. The amount of groundwater recharge that occurs in a given hydrographic basin is difficult to accurately estimate and is therefore commonly quantified by estimating the groundwater discharge using micrometeorological, and remote and in situ energy balance methods. Large playas are common features in desert environments, and the phreatic surface is often less than a few meters below land surface, creating nearly saturated conditions at the land surface through capillary rise. At first glance one might conclude that evaporation is high due to the nearly saturated surface, however, playa surfaces are commonly sealed by thin salt crusts, inhibiting evaporation. In this work we use eddy covariance, scintillometer, and four component radiometer measurements, and present a novel ground heat flux analysis using multiple ground heat flux plates and heat-pulse sensors to assess energy balance closure and uncertainties on estimated evaporation in Dixie Valley, Nevada. Results indicate that greater than 50 percent of daytime net radiation is partitioned into ground heat flux, and almost all of the available energy is portioned into sensible heat as determined from eddy covariance, and confirmed with scintillometer estimates. Utilizing heat pulse derived soil thermal properties and high density discrete soil temperature measurements allowed for estimation of soil heat storage and flux using a finite difference solution to the transient heat flow equation. This approach improved energy balance closure by 20 percent (achieving 90 percent closure) when compared to traditional calorimetric soil heat storage and

  17. Eddy heat flux across the Antarctic Circumpolar Current estimated from sea surface height standard deviation

    Science.gov (United States)

    Foppert, Annie; Donohue, Kathleen A.; Watts, D. Randolph; Tracey, Karen L.

    2017-08-01

    Eddy heat flux (EHF) is a predominant mechanism for heat transport across the zonally unbounded mean flow of the Antarctic Circumpolar Current (ACC). Observations of dynamically relevant, divergent, 4 year mean EHF in Drake Passage from the cDrake project, as well as previous studies of atmospheric and oceanic storm tracks, motivates the use of sea surface height (SSH) standard deviation, H*, as a proxy for depth-integrated, downgradient, time-mean EHF (>[EHF>¯>]) in the ACC. Statistics from the Southern Ocean State Estimate corroborate this choice and validate throughout the ACC the spatial agreement between H* and >[EHF>¯>] seen locally in Drake Passage. Eight regions of elevated >[EHF>¯>] are identified from nearly 23.5 years of satellite altimetry data. Elevated cross-front exchange usually does not span the full latitudinal width of the ACC in each region, implying a hand-off of heat between ACC fronts and frontal zones as they encounter the different >[EHF>¯>] hot spots along their circumpolar path. Integrated along circumpolar streamlines, defined by mean SSH contours, there is a convergence of ∮>[EHF>¯>] in the ACC: 1.06 PW enters from the north and 0.02 PW exits to the south. Temporal trends in low-frequency [EHF] are calculated in a running-mean sense using H* from overlapping 4 year subsets of SSH. Significant increases in downgradient [EHF] magnitude have occurred since 1993 at Kerguelen Plateau, Southeast Indian Ridge, and the Brazil-Malvinas Confluence, whereas the other five >[EHF>¯>] hot spots have insignificant trends of varying sign.

  18. Heat as a Tracer for Estimation of Soil Drainage Following Irrigation Above a Tile Drain System

    Science.gov (United States)

    Callaghan, M. V.; Bentley, L. R.; Cey, E. E.

    2009-05-01

    Salt-affected soil is one of the most common environmental issues facing the petroleum hydrocarbon industry. Large quantities of brines are often co-produced with gas and oil and have been introduced into the environment through, for example, flare pits, drilling operations and pipe line breaks. Salt must be flushed from the soil and tile drain systems can be used to collect salt water which is then be routed for disposal. An accelerated remediation experiment by soil flushing over a 2 m deep tile drain system was monitored by tensiometers, and thermocouples. Water table elevation was monitored with pressure transducers. A 20 m by 20 m experimental plot was irrigated with 10 m3 of water on each of three consecutive days for an approximate total of 75 mm of water. The irrigation event was repeated three times over a period of 4 weeks. Due to a lack of access to the individual tile drains, direct measurement of drainage rates was not possible. One component of evaluating the success of the accelerated remediation experiment is the fraction of applied irrigation water that infiltrated to depth. Drainage rates beneath the irrigated plot were estimated by heat transport modeling using HYDRUS-1D, a numerical code for the solution of Richards unsaturated flow equation and the heat equation. Temperature and soil matric potential time series were recorded beneath the irrigated plot and at a control location at four depths, 0.3, 0.6, 1.0, and 1.5 m, at 15 minute intervals. Data was recorded for the duration of the irrigation period and for 8 weeks following. The temperature time series beneath the irrigated plot shows a broad increase relative to the control and shorter duration increases in direct response to the irrigation events. Heat modelling results are compared to field measurements.

  19. Diabatic heating rate estimates from European Centre for Medium-Range Weather Forecasts analyses

    Science.gov (United States)

    Christy, John R.

    1991-01-01

    Vertically integrated diabatic heating rate estimates (H) calculated from 32 months of European Center for Medium-Range Weather Forecasts daily analyses (May 1985-December 1987) are determined as residuals of the thermodynamic equation in pressure coordinates. Values for global, hemispheric, zonal, and grid point H are given as they vary over the time period examined. The distribution of H is compared with previous results and with outgoing longwave radiation (OLR) measurements. The most significant negative correlations between H and OLR occur for (1) tropical and Northern-Hemisphere mid-latitude oceanic areas and (2) zonal and hemispheric mean values for periods less than 90 days. Largest positive correlations are seen in periods greater than 90 days for the Northern Hemispheric mean and continental areas of North Africa, North America, northern Asia, and Antarctica. The physical basis for these relationships is discussed. An interyear comparison between 1986 and 1987 reveals the ENSO signal.

  20. Simple equation for estimating actual evapotranspiration using heat units for wheat in arid regions

    Directory of Open Access Journals (Sweden)

    M.A. Salama

    2015-07-01

    Application of treatment (B resulted in highly significant increase in yield production of Gemmeza10 and Misr2 as compared to treatment (A. Grain yield of different wheat varieties grown under treatment (B could be ranked in the following descending order: Misr2 > Gemmeza10 > Sids12. While under treatment (A it could be arranged in the following descending order: Misr2 > Sids12 > Gemmeza10. On the other hand, the overall means indicated non-significant difference between all wheat verities. The highest values of water and irrigation use efficiency as well as heat use efficiency were obtained with treatment (B. The equation used in the present study is available to estimate ETa under arid climate with drip irrigation system.

  1. Assessment of Residual Strength Based on Estimated Temperature of Post-Heated RC Columns

    Directory of Open Access Journals (Sweden)

    Muhammad Yaqub

    2013-01-01

    Full Text Available The experience shows that fire-damaged concrete structures both technically and economically can be reinstated after fire due to high fire resistance and high residual strength. The residual strength of fire-damaged concrete structural member depends on the peak temperature reached during fire, fire duration and the distribution of temperature within the structural member. The assessment of the residual strength of post-heated concrete structural members in a professional way is a prime factor to take a decision about the reinstatement or demolition of fire-damaged structure. This paper provides an easy and efficient approach to predict the residual strength of reinforced concrete columns based on the estimated temperature which may have occurred within the concrete cross-section during a fire. A finite element model was developed to evaluate the distribution of temperature within the cross-section of the reinforced concrete columns. Twelve reinforced concrete square columns were heated experimentally up to 500°C at 150°C/hour. A comparison of the experimental temperature values of the tested columns was made with the model results. A good agreement was found between the experimental and the finite model results. Based on the temperature distribution obtained from the finite element model, the residual strength of concrete and reinforcement could be evaluated by using the relationships for concrete, steel and temperature proposed by various researchers.

  2. Estimation of solar collector area for water heating in buildings of Malaysia

    Science.gov (United States)

    Manoj Kumar, Nallapaneni; Sudhakar, K.; Samykano, M.

    2018-04-01

    Solar thermal energy (STE) utilization for water heating at various sectorial levels became popular and still growing especially for buildings in the residential area. This paper aims to study and identify the solar collector area needed based on the user requirements in an efficient manner. A step by step mathematical approach is followed to estimate the area in Sq. m. Four different cases each having different hot water temperatures (45°, 50°C, 55°C, and 60°C) delivered by the solar water heating system (SWHS) for typical residential application at Kuala Lumpur City, Malaysia is analysed for the share of hot and cold water mix. As the hot water temperature levels increased the share of cold water mix is increased to satisfy the user requirement temperature, i.e. 40°C. It is also observed that as the share of hot water mix is reduced, the collector area can also be reduced. Following this methodology at the installation stage would help both the user and installers in the effective use of the solar resource.

  3. Simultaneous estimation of strength and position of a heat source in a participating medium using DE algorithm

    Science.gov (United States)

    Parwani, Ajit K.; Talukdar, Prabal; Subbarao, P. M. V.

    2013-09-01

    An inverse heat transfer problem is discussed to estimate simultaneously the unknown position and timewise varying strength of a heat source by utilizing differential evolution approach. A two dimensional enclosure with isothermal and black boundaries containing non-scattering, absorbing and emitting gray medium is considered. Both radiation and conduction heat transfer are included. No prior information is used for the functional form of timewise varying strength of heat source. The finite volume method is used to solve the radiative transfer equation and the energy equation. In this work, instead of measured data, some temperature data required in the solution of the inverse problem are taken from the solution of the direct problem. The effect of measurement errors on the accuracy of estimation is examined by introducing errors in the temperature data of the direct problem. The prediction of source strength and its position by the differential evolution (DE) algorithm is found to be quite reasonable.

  4. Uncertainties in the estimation of specific absorption rate during radiofrequency alternating magnetic field induced non-adiabatic heating of ferrofluids

    International Nuclear Information System (INIS)

    Lahiri, B B; Ranoo, Surojit; Philip, John

    2017-01-01

    Magnetic fluid hyperthermia (MFH) is becoming a viable cancer treatment methodology where the alternating magnetic field induced heating of magnetic fluid is utilized for ablating the cancerous cells or making them more susceptible to the conventional treatments. The heating efficiency in MFH is quantified in terms of specific absorption rate (SAR), which is defined as the heating power generated per unit mass. In majority of the experimental studies, SAR is evaluated from the temperature rise curves, obtained under non-adiabatic experimental conditions, which is prone to various thermodynamic uncertainties. A proper understanding of the experimental uncertainties and its remedies is a prerequisite for obtaining accurate and reproducible SAR. Here, we study the thermodynamic uncertainties associated with peripheral heating, delayed heating, heat loss from the sample and spatial variation in the temperature profile within the sample. Using first order approximations, an adiabatic reconstruction protocol for the measured temperature rise curves is developed for SAR estimation, which is found to be in good agreement with those obtained from the computationally intense slope corrected method. Our experimental findings clearly show that the peripheral and delayed heating are due to radiation heat transfer from the heating coils and slower response time of the sensor, respectively. Our results suggest that the peripheral heating is linearly proportional to the sample area to volume ratio and coil temperature. It is also observed that peripheral heating decreases in presence of a non-magnetic insulating shielding. The delayed heating is found to contribute up to ∼25% uncertainties in SAR values. As the SAR values are very sensitive to the initial slope determination method, explicit mention of the range of linear regression analysis is appropriate to reproduce the results. The effect of sample volume to area ratio on linear heat loss rate is systematically studied and

  5. Uncertainties in the estimation of specific absorption rate during radiofrequency alternating magnetic field induced non-adiabatic heating of ferrofluids

    Science.gov (United States)

    Lahiri, B. B.; Ranoo, Surojit; Philip, John

    2017-11-01

    Magnetic fluid hyperthermia (MFH) is becoming a viable cancer treatment methodology where the alternating magnetic field induced heating of magnetic fluid is utilized for ablating the cancerous cells or making them more susceptible to the conventional treatments. The heating efficiency in MFH is quantified in terms of specific absorption rate (SAR), which is defined as the heating power generated per unit mass. In majority of the experimental studies, SAR is evaluated from the temperature rise curves, obtained under non-adiabatic experimental conditions, which is prone to various thermodynamic uncertainties. A proper understanding of the experimental uncertainties and its remedies is a prerequisite for obtaining accurate and reproducible SAR. Here, we study the thermodynamic uncertainties associated with peripheral heating, delayed heating, heat loss from the sample and spatial variation in the temperature profile within the sample. Using first order approximations, an adiabatic reconstruction protocol for the measured temperature rise curves is developed for SAR estimation, which is found to be in good agreement with those obtained from the computationally intense slope corrected method. Our experimental findings clearly show that the peripheral and delayed heating are due to radiation heat transfer from the heating coils and slower response time of the sensor, respectively. Our results suggest that the peripheral heating is linearly proportional to the sample area to volume ratio and coil temperature. It is also observed that peripheral heating decreases in presence of a non-magnetic insulating shielding. The delayed heating is found to contribute up to ~25% uncertainties in SAR values. As the SAR values are very sensitive to the initial slope determination method, explicit mention of the range of linear regression analysis is appropriate to reproduce the results. The effect of sample volume to area ratio on linear heat loss rate is systematically studied and the

  6. Assessment of in-place oil shale resources of the Eocene Green River Formation, a foundation for calculating recoverable resources

    Science.gov (United States)

    Johnson, Ronald C.; Mercier, Tracy

    2011-01-01

    The recently completed assessment of in-place resources of the Eocene Green River Formation in the Piceance Basin, Colorado; the Uinta Basin, Utah and Colorado; and the Greater Green River Basin Wyoming, Colorado, and Utah and their accompanying ArcGIS projects will form the foundation for estimating technically-recoverable resources in those areas. Different estimates will be made for each of the various above-ground and in-situ recovery methodologies currently being developed. Information required for these estimates include but are not limited to (1) estimates of the amount of oil shale that exceeds various grades, (2) overburden calculations, (3) a better understanding of oil shale saline facies, and (4) a better understanding of the distribution of various oil shale mineral facies. Estimates for the first two are on-going, and some have been published. The present extent of the saline facies in all three basins is fairly well understood, however, their original extent prior to ground water leaching has not been studied in detail. These leached intervals, which have enhanced porosity and permeability due to vugs and fractures and contain significant ground water resources, are being studied from available core descriptions. A database of all available xray mineralogy data for the oil shale interval is being constructed to better determine the extents of the various mineral facies. Once these studies are finished, the amount of oil shale with various mineralogical and physical properties will be determined.

  7. Recoverability in the future: Damage control & fire fighting in 21st century

    NARCIS (Netherlands)

    Smit, C.S.; Zor, H.

    2008-01-01

    Survivability of a costly Naval Vessel and its crew is an essential capability. The survivability depends on susceptibility of a Naval ship against weapons and weapon systems, vulnerability of the platform and its systems against the effect of the weapons and the recoverability after the hit by a

  8. Remaining recoverable petroleum in giant oil fields of the Los Angeles Basin, southern California

    Science.gov (United States)

    Gautier, Donald L.; Tennyson, Marilyn E.; Cook, Troy A.; Charpentier, Ronald R.; Klett, Timothy R.

    2012-01-01

    Using a probabilistic geology-based methodology, a team of U.S. Geological Survey (USGS) scientists recently assessed the remaining recoverable oil in 10 oil fields of the Los Angeles Basin in southern California. The results of the assessment suggest that between 1.4 and 5.6 billion barrels of additional oil could be recovered from those fields with existing technology.

  9. Lévy matters VI Lévy-type processes moments, construction and heat kernel estimates

    CERN Document Server

    Kühn, Franziska

    2017-01-01

    Presenting some recent results on the construction and the moments of Lévy-type processes, the focus of this volume is on a new existence theorem, which is proved using a parametrix construction. Applications range from heat kernel estimates for a class of Lévy-type processes to existence and uniqueness theorems for Lévy-driven stochastic differential equations with Hölder continuous coefficients. Moreover, necessary and sufficient conditions for the existence of moments of Lévy-type processes are studied and some estimates on moments are derived. Lévy-type processes behave locally like Lévy processes but, in contrast to Lévy processes, they are not homogeneous in space. Typical examples are processes with varying index of stability and solutions of Lévy-driven stochastic differential equations. This is the sixth volume in a subseries of the Lecture Notes in Mathematics called Lévy Matters. Each volume describes a number of important topics in the theory or applicati ons of Lévy processes and pays ...

  10. Determination of recoverable wind energy for electricity generation ...

    African Journals Online (AJOL)

    fundamental step in planning a wind energy project and exhaustive knowledge of the wind characteristic at a site of installation is needed to estimate the performance of a wind energy conversion system. The current paper presents an investigation of the wind power potential using real wind data for five sites in Tunisia: ...

  11. Analysis of Heat Flow to Estimate Percolation Flux in the Unsaturated Zone Beneath an Ephemeral Stream at Yucca Mountain, Nevada

    Science.gov (United States)

    Rousseau, J. P.; Kwicklis, E. M.

    2001-05-01

    Temperature data from a well-documented site in Pagany Wash at Yucca Mountain, Nevada indicate the presence of a significant heat-flow deficit between the Paintbrush nonwelded and underlying Topopah Spring welded hydrogeologic units that most likely is due to nonconductive heat-flow processes with substantial capacity to extract heat. Percolation fluxes on the order of 10 to 20 millimeters per year beneath Pagany Wash and on the order of 5 millimeters per year beneath the hillslopes bordering the channel can account for this apparent heat-flow deficit. Total heat flow within the unsaturated zone is the sum of its convective and conductive components. The conductive component can be calculated from the temperature gradient and thermal conductivity of the rocks comprising the section of interest. The convective component can be inferred from any observed decrease in the conductive component with increasing elevation in a borehole. Because the enthalpy and specific heat of water are well known, identification of the convectively transported heat component is equivalent to determining the percolation flux. Temperature data from two 120-meter deep boreholes, UZ#4 and UZ#5, in Pagany Wash were examined to determine the vertical distribution of upward, conductive heat flow in the unsaturated zone. The temperature data, in combination with estimates of thermal conductivity, adjusted for ambient saturation and porosity, indicated that upward conductive heat flow was approximately 15.5 mJ/s/m2 within the Pah Canyon Tuff. This heat flow estimate represents a substantial reduction in heat flow from the deeper unsaturated-zone(32 to 40 mJ/s/m2), as indicated on a map of regional heat-flow across the water table beneath Pagany Wash. Percolation fluxes of between 12.4 and 18.4 mm/yr for the depth interval between the Pah Canyon Tuff and the water table at UZ#4 and UZ#5 can account for the apparent heat-flow deficit in the deeper unsaturated zone. Two-dimensional numerical

  12. Recoverable immobilization of transuranic elements in sulfate ash

    Science.gov (United States)

    Greenhalgh, Wilbur O.

    1985-01-01

    Disclosed is a method of reversibly immobilizing sulfate ash at least about 20% of which is sulfates of transuranic elements. The ash is mixed with a metal which can be aluminum, cerium, samarium, europium, or a mixture thereof, in amounts sufficient to form an alloy with the transuranic elements, plus an additional amount to reduce the transuranic element sulfates to elemental form. Also added to the ash is a fluxing agent in an amount sufficient to lower the percentage of the transuranic element sulfates to about 1% to about 10%. The mixture of the ash, metal, and fluxing agent is heated to a temperature sufficient to melt the fluxing agent and the metal. The mixture is then cooled and the alloy is separated from the remainder of the mixture.

  13. Heat

    CERN Document Server

    Lawrence, Ellen

    2016-01-01

    Is it possible to make heat by rubbing your hands together? Why does an ice cube melt when you hold it? In this title, students will conduct experiments to help them understand what heat is. Kids will also investigate concepts such as which materials are good at conducting heat and which are the best insulators. Using everyday items that can easily be found around the house, students will transform into scientists as they carry out step-by-step experiments to answer interesting questions. Along the way, children will pick up important scientific skills. Heat includes seven experiments with detailed, age-appropriate instructions, surprising facts and background information, a "conclusions" section to pull all the concepts in the book together, and a glossary of science words. Colorful, dynamic designs and images truly put the FUN into FUN-damental Experiments.

  14. Novel activity classification and occupancy estimation methods for intelligent HVAC (heating, ventilation and air conditioning) systems

    International Nuclear Information System (INIS)

    Rana, Rajib; Kusy, Brano; Wall, Josh; Hu, Wen

    2015-01-01

    Reductions in HVAC (heating, ventilation and air conditioning) energy consumption can be achieved by limiting heating in the winter or cooling in the summer. However, the resulting low thermal comfort of building occupants may lead to an override of the HVAC control, which revokes its original purpose. This has led to an increased interest in modeling and real-time tracking of location, activity, and thermal comfort of building occupants for HVAC energy management. While thermal comfort is well understood, it is difficult to measure in real-time environments where user context changes dynamically. Encouragingly, plethora of sensors available on smartphone unleashes the opportunity to measure user contexts in real-time. An important contextual information for measuring thermal comfort is Metabolism rate, which changes based on current physical activities. To measure physical activity, we develop an activity classifier, which achieves 10% higher accuracy compared to Support Vector Machine and k-Nearest Neighbor. Office occupancy is another contextual information for energy-efficient HVAC control. Most of the phone based occupancy estimation techniques will fail to determine occupancy when phones are left at desk while sitting or attending meetings. We propose a novel sensor fusion method to detect if a user is near the phone, which achieves more than 90% accuracy. Determining activity and occupancy our proposed algorithms can help maintaining thermal comfort while reducing HVAC energy consumptions. - Highlights: • We propose activity and occupancy detection for efficient HVAC control. • Activity classifier achieves 10% higher accuracy than SVM and kNN. • For occupancy detection we propose a novel sensor fusion method. • Using Weighted Majority Voting we fuse microphone and accelerometer data on phone. • We achieve more than 90% accuracy in detecting occupancy.

  15. Estimation of the temperature, heat gain and heat loss by solar parabolic trough collector under Algerian climate using different thermal oils

    International Nuclear Information System (INIS)

    Ouagued, Malika; Khellaf, Abdallah; Loukarfi, Larbi

    2013-01-01

    Highlights: • Estimation of direct solar radiations for different tracking systems at six typical locations in Algeria. • PTC thermal model uses energy balances from the HTF to the atmosphere. • The model depends on the collector type, nature of HTF, optical properties, and ambient conditions. • Estimation of temperature, heat gain and energy cost of thermal oils used in the model. • Comparison between monthly mean heat gain of the various thermal oils for six Algerian locations. - Abstract: Algeria is blessed with a very important renewable, and more particularly solar, energy potential. This potential opens for Algeria reel opportunities to cope with the increasing energy demand and the growing environmental problems link to the use of fossil fuel. In order to develop and to promote concrete actions in the areas of renewable energy and energy efficiency, Algeria has introduced a national daring program for the period 2011–2030. In this program, solar energy, and more particularly solar thermal energy plays an important role. In this paper, the potential of direct solar irradiance in Algeria and the performance of solar parabolic trough collector (PTC) are estimated under the climate conditions of the country. These two factors are treated as they play an important role in the design of solar thermal plant. In order to determine the most promising solar sites in Algeria, monthly mean daily direct solar radiation have been estimated and compared for different locations corresponding to different climatic region. Different tilted and tracking collectors are considered so as to determine the most efficient system for the PTC. In order to evaluate the performance of a tracking solar parabolic trough collector, a heat transfer model is developed. The receiver, heat collector element (HCE), is divided into several segments and heat balance is applied in each segment over a section of the solar receiver. Different oils are considered to determine the thermal

  16. Local heat transfer estimation in microchannels during convective boiling under microgravity conditions: 3D inverse heat conduction problem using BEM techniques

    Science.gov (United States)

    Luciani, S.; LeNiliot, C.

    2008-11-01

    Two-phase and boiling flow instabilities are complex, due to phase change and the existence of several interfaces. To fully understand the high heat transfer potential of boiling flows in microscale's geometry, it is vital to quantify these transfers. To perform this task, an experimental device has been designed to observe flow patterns. Analysis is made up by using an inverse method which allows us to estimate the local heat transfers while boiling occurs inside a microchannel. In our configuration, the direct measurement would impair the accuracy of the searched heat transfer coefficient because thermocouples implanted on the surface minichannels would disturb the established flow. In this communication, we are solving a 3D IHCP which consists in estimating using experimental data measurements the surface temperature and the surface heat flux in a minichannel during convective boiling under several gravity levels (g, 1g, 1.8g). The considered IHCP is formulated as a mathematical optimization problem and solved using the boundary element method (BEM).

  17. Temperature based validation of the analytical model for the estimation of the amount of heat generated during friction stir welding

    Directory of Open Access Journals (Sweden)

    Milčić Dragan S.

    2012-01-01

    Full Text Available Friction stir welding is a solid-state welding technique that utilizes thermomechanical influence of the rotating welding tool on parent material resulting in a monolith joint - weld. On the contact of welding tool and parent material, significant stirring and deformation of parent material appears, and during this process, mechanical energy is partially transformed into heat. Generated heat affects the temperature of the welding tool and parent material, thus the proposed analytical model for the estimation of the amount of generated heat can be verified by temperature: analytically determined heat is used for numerical estimation of the temperature of parent material and this temperature is compared to the experimentally determined temperature. Numerical solution is estimated using the finite difference method - explicit scheme with adaptive grid, considering influence of temperature on material's conductivity, contact conditions between welding tool and parent material, material flow around welding tool, etc. The analytical model shows that 60-100% of mechanical power given to the welding tool is transformed into heat, while the comparison of results shows the maximal relative difference between the analytical and experimental temperature of about 10%.

  18. Analytical and experimental stiffness estimation of heat pipe supporter for nuclear power plant through a homogenization process

    Directory of Open Access Journals (Sweden)

    Sang-Young Kim

    2015-07-01

    Full Text Available This article aims to study the in-plane stiffness estimation of heat pipe supporter (a large lattice structure using experimental and numerical methods. The in-plane stiffness of heat pipe supporter for nuclear power plant is very important because of the safety against natural disasters, such as seismic load or tsunami, and has to be evaluated because it greatly affects the durability of the heat exchanger. However, the modeling process of the whole lattice structure for finite element analysis increases resources needed caused by too many nodes and elements. In this study, the mechanical properties of large lattice structures are determined by a unit cell finite element analysis. The mechanical behavior of a large lattice structure has been estimated by finite element analysis through a homogenization process for reducing analysis time and efforts. The finite element analysis results have been verified and show a good agreement with the experimental results.

  19. An Assessment of Transport Property Estimation Methods for Ammonia–Water Mixtures and Their Influence on Heat Exchanger Size

    DEFF Research Database (Denmark)

    Kærn, Martin Ryhl; Modi, Anish; Jensen, Jonas Kjær

    2015-01-01

    Transport properties of fluids are indispensable for heat exchanger design. The methods for estimating the transport properties of ammonia–water mixtures are not well established in the literature. The few existent methods are developed from none or limited, sometimes inconsistent experimental...... of ammonia–water mixtures. Firstly, the different methods are introduced and compared at various temperatures and pressures. Secondly, their individual influence on the required heat exchanger size (surface area) is investigated. For this purpose, two case studies related to the use of the Kalina cycle...... the interpolative methods in contrast to the corresponding state methods. Nevertheless, all possible mixture transport property combinations used herein resulted in a heat exchanger size within 4.3 % difference for the flue-gas heat recovery boiler, and within 12.3 % difference for the oil-based boiler....

  20. Mortality in Portugal associated with the heat wave of August 2003: early estimation of effect, using a rapid method.

    Science.gov (United States)

    Nogueira, P J; Falcão, J M; Contreiras, M T; Paixão, E; Brandão, João; Batista, I

    2005-07-01

    During the first two weeks of August 2003, Portugal was affected by a severe heat wave. Following the identification in Portugal of the influence of heat waves on mortality in 1981 and 1991 (estimated excess of about 1900 and 1000 deaths respectively), the Observatorio Nacional de Saude (ONSA) - Instituto Nacional de Saude Dr. Ricardo Jorge, together with the Vigilancia Previsao e Informacao - Instituto de Meteorologia, created a surveillance system called iCARO, which has been in operation since 1999. iCARO identifies heat waves with potential influence on mortality [1]. Before the end of the 2003 heat wave, ONSA had produced a preliminary estimate of its effect on mortality. The results based on daily number of deaths from 1 June to 12 August 2003 were presented within 4 working days. Data was gathered from 31 National Civil registrars, covering the district capitals of all 18 districts of mainland Portugal, and representing approximately 40% of the mainland's mortality. The number of deaths registered in the period 30 July to 12 August was compared with the ones registered during 3 comparison periods: (in July): 1-14 July, 1-28 July, and 15-28 July). 15-28 July, the period best resembling the heat wave in time and characteristics, produced an estimation of 37.7% higher mortality rate then the value expected under normal temperature conditions. From this value, an estimate of 1316 death excess was obtained for mainland Portugal. The main purpose of this article is to present the method used to identify and assess the occurrence of an effect (excess mortality) during the heat wave of summer 2003.

  1. A multi-method and multi-scale approach for estimating city-wide anthropogenic heat fluxes

    Science.gov (United States)

    Chow, Winston T. L.; Salamanca, Francisco; Georgescu, Matei; Mahalov, Alex; Milne, Jeffrey M.; Ruddell, Benjamin L.

    2014-12-01

    A multi-method approach estimating summer waste heat emissions from anthropogenic activities (QF) was applied for a major subtropical city (Phoenix, AZ). These included detailed, quality-controlled inventories of city-wide population density and traffic counts to estimate waste heat emissions from population and vehicular sources respectively, and also included waste heat simulations derived from urban electrical consumption generated by a coupled building energy - regional climate model (WRF-BEM + BEP). These component QF data were subsequently summed and mapped through Geographic Information Systems techniques to enable analysis over local (i.e. census-tract) and regional (i.e. metropolitan area) scales. Through this approach, local mean daily QF estimates compared reasonably versus (1.) observed daily surface energy balance residuals from an eddy covariance tower sited within a residential area and (2.) estimates from inventory methods employed in a prior study, with improved sensitivity to temperature and precipitation variations. Regional analysis indicates substantial variations in both mean and maximum daily QF, which varied with urban land use type. Average regional daily QF was ∼13 W m-2 for the summer period. Temporal analyses also indicated notable differences using this approach with previous estimates of QF in Phoenix over different land uses, with much larger peak fluxes averaging ∼50 W m-2 occurring in commercial or industrial areas during late summer afternoons. The spatio-temporal analysis of QF also suggests that it may influence the form and intensity of the Phoenix urban heat island, specifically through additional early evening heat input, and by modifying the urban boundary layer structure through increased turbulence.

  2. Heating of field-reversed plasma rings estimated with two scaling models

    Energy Technology Data Exchange (ETDEWEB)

    Shearer, J.W.

    1978-05-18

    Scaling calculations are presented of the one temperature heating of a field-reversed plasma ring. Two sharp-boundary models of the ring are considered: the long thin approximation and a pinch model. Isobaric, adiabatic, and isovolumetric cases are considered, corresponding to various ways of heating the plasma in a real experiment by using neutral beams, or by raising the magnetic field. It is found that the shape of the plasma changes markedly with heating. The least sensitive shape change (as a function of temperature) is found for the isovolumetric heating case, which can be achieved by combining neutral beam heating with compression. The complications introduced by this heating problem suggest that it is desirable, if possible, to create a field reversed ring which is already quite hot, rather than cold.

  3. Heating of field-reversed plasma rings estimated with two scaling models

    International Nuclear Information System (INIS)

    Shearer, J.W.

    1978-01-01

    Scaling calculations are presented of the one temperature heating of a field-reversed plasma ring. Two sharp-boundary models of the ring are considered: the long thin approximation and a pinch model. Isobaric, adiabatic, and isovolumetric cases are considered, corresponding to various ways of heating the plasma in a real experiment by using neutral beams, or by raising the magnetic field. It is found that the shape of the plasma changes markedly with heating. The least sensitive shape change (as a function of temperature) is found for the isovolumetric heating case, which can be achieved by combining neutral beam heating with compression. The complications introduced by this heating problem suggest that it is desirable, if possible, to create a field reversed ring which is already quite hot, rather than cold

  4. Addressing uncertainties in estimates of recoverable gas for underexplored Shale gas Basins

    NARCIS (Netherlands)

    Heege, J.H. ter; Zijp, M.H.A.A.; Bruin, G. de; Veen, J.H. ten

    2014-01-01

    Uncertainties in upfront predictions of hydraulic fracturing and gas production of underexplored shale gas targets are important as often large potential resources are deduced based on limited available data. In this paper, uncertainties are quantified by using normal distributions of different

  5. A Bayesian analysis of sensible heat flux estimation: Quantifying uncertainty in meteorological forcing to improve model prediction

    KAUST Repository

    Ershadi, Ali

    2013-05-01

    The influence of uncertainty in land surface temperature, air temperature, and wind speed on the estimation of sensible heat flux is analyzed using a Bayesian inference technique applied to the Surface Energy Balance System (SEBS) model. The Bayesian approach allows for an explicit quantification of the uncertainties in input variables: a source of error generally ignored in surface heat flux estimation. An application using field measurements from the Soil Moisture Experiment 2002 is presented. The spatial variability of selected input meteorological variables in a multitower site is used to formulate the prior estimates for the sampling uncertainties, and the likelihood function is formulated assuming Gaussian errors in the SEBS model. Land surface temperature, air temperature, and wind speed were estimated by sampling their posterior distribution using a Markov chain Monte Carlo algorithm. Results verify that Bayesian-inferred air temperature and wind speed were generally consistent with those observed at the towers, suggesting that local observations of these variables were spatially representative. Uncertainties in the land surface temperature appear to have the strongest effect on the estimated sensible heat flux, with Bayesian-inferred values differing by up to ±5°C from the observed data. These differences suggest that the footprint of the in situ measured land surface temperature is not representative of the larger-scale variability. As such, these measurements should be used with caution in the calculation of surface heat fluxes and highlight the importance of capturing the spatial variability in the land surface temperature: particularly, for remote sensing retrieval algorithms that use this variable for flux estimation.

  6. ANCCLI White Paper IV. Cigeo: the challenges of reversibility and recoverability

    International Nuclear Information System (INIS)

    Delalonde, Jean-Claude; Sene, Monique

    2017-01-01

    This white paper aims at providing useful elements for a better understanding, debate and implication of everyone in the preparation of a governance regarding very long life radioactive wastes. The authors first make a set of recommendations for a pluralist governance in decisions, for the creation of permanent pluralist bodies at the local and national levels, for the guarantee of the sustainability of governance structures, for the building up of a citizen vigilance, and for the taking of specific needs of location territories into account. Then, the report describes the different stages of development of a reversible storage, discusses the different definitions of reversibility and the benefits and drawbacks of reversibility and recoverability. It addresses technical and related aspects of parcel recoverability, outlines how to achieve sustainable vigilance and governance. It indicates the role of the different institutional actors (ANDRA, ASN, IRSN) as they themselves define it regarding the issue of reversibility and recoverability. It states the point of view of the ANCCLI's GPMDR (Permanent group for radioactive materials and wastes) about the Cigeo project, about the issue of reversibility, and about the involvement of civil society on the long term. An appendix discusses the issue of waste inventory and classification. Some current research works on these issues are briefly mentioned

  7. Adaptive neuro-fuzzy based inferential sensor model for estimating the average air temperature in space heating systems

    Energy Technology Data Exchange (ETDEWEB)

    Jassar, S.; Zhao, L. [Department of Electrical and Computer Engineering, Ryerson University, 350 Victoria Street, Toronto, ON (Canada); Liao, Z. [Department of Architectural Science, Ryerson University (Canada)

    2009-08-15

    The heating systems are conventionally controlled by open-loop control systems because of the absence of practical methods for estimating average air temperature in the built environment. An inferential sensor model, based on adaptive neuro-fuzzy inference system modeling, for estimating the average air temperature in multi-zone space heating systems is developed. This modeling technique has the advantage of expert knowledge of fuzzy inference systems (FISs) and learning capability of artificial neural networks (ANNs). A hybrid learning algorithm, which combines the least-square method and the back-propagation algorithm, is used to identify the parameters of the network. This paper describes an adaptive network based inferential sensor that can be used to design closed-loop control for space heating systems. The research aims to improve the overall performance of heating systems, in terms of energy efficiency and thermal comfort. The average air temperature results estimated by using the developed model are strongly in agreement with the experimental results. (author)

  8. On the estimation of heating effects in the atmosphere because of seismic activities

    Science.gov (United States)

    Meister, Claudia-Veronika; Hoffmann, Dieter H. H.

    2014-05-01

    The dielectric model for waves in the Earth's ionosphere is further developed and applied to possible electro-magnetic phenomena in seismic regions. In doing so, in comparison to the well-known dielectric wave model by R.O. Dendy [Plasma dynamics, Oxford University Press, 1990] for homogeneous systems, the stratification of the atmosphere is taken into account. Moreover, within the frame of many-fluid magnetohydrodynamics also the momentum transfer between the charged and neutral particles is considered. Discussed are the excitation of Alfvén and magnetoacoustic waves, but also their variations by the neutral gas winds. Further, also other current driven waves like Farley-Buneman ones are studied. In the work, models of the altitudinal scales of the plasma parameters and the electromagnetic wave field are derived. In case of the electric wave field, a method is given to calculate the altitudinal scale based on the Poisson equation for the electric field and the magnetohydrodynamic description of the particles. Further, expressions are derived to estimate density, pressure, and temperatur changes in the E-layer because of the generation of the electromagnetic waves. Last not least, formulas are obtained to determine the dispersion and polarisation of the excited electromagnetic waves. These are applied to find quantitative results for the turbulent heating of the ionospheric E-layer. Concerning the calculation of the dispersion relation, in comparison to a former work by Meister et al. [Contr. Plasma Phys. 53 (4-5), 406-413, 2013], where a numerical double-iteration method was suggested to obtain results for the wave dispersion relations, now further analytical calculations are performed. In doing so, different polynomial dependencies of the wave frequencies from the wave vectors are treated. This helped to restrict the numerical calculations to only one iteration process.

  9. Estimating the workpiece-backingplate heat transfer coefficient in friction stirwelding

    DEFF Research Database (Denmark)

    Larsen, Anders; Stolpe, Mathias; Hattel, Jesper Henri

    2012-01-01

    Purpose - The purpose of this paper is to determine the magnitude and spatial distribution of the heat transfer coefficient between the workpiece and the backingplate in a friction stir welding process using inverse modelling. Design/methodology/approach - The magnitude and distribution of the heat...... in an inverse modeling approach to determine the heat transfer coefficient in friction stir welding. © Emerald Group Publishing Limited....... transfer coefficient are the variables in an optimisation problem. The objective is to minimise the difference between experimentally measured temperatures and temperatures obtained using a 3D finite element model. The optimisation problem is solved using a gradient based optimisation method. This approach...

  10. Temperature Observation Time and Type Influence Estimates of Heat-Related Mortality in Seven U.S. Cities.

    Science.gov (United States)

    Davis, Robert E; Hondula, David M; Patel, Anjali P

    2016-06-01

    Extreme heat is a leading weather-related cause of mortality in the United States, but little guidance is available regarding how temperature variable selection impacts heat-mortality relationships. We examined how the strength of the relationship between daily heat-related mortality and temperature varies as a function of temperature observation time, lag, and calculation method. Long time series of daily mortality counts and hourly temperature for seven U.S. cities with different climates were examined using a generalized additive model. The temperature effect was modeled separately for each hour of the day (with up to 3-day lags) along with different methods of calculating daily maximum, minimum, and mean temperature. We estimated the temperature effect on mortality for each variable by comparing the 99th versus 85th temperature percentiles, as determined from the annual time series. In three northern cities (Boston, MA; Philadelphia, PA; and Seattle, WA) that appeared to have the greatest sensitivity to heat, hourly estimates were consistent with a diurnal pattern in the heat-mortality response, with strongest associations for afternoon or maximum temperature at lag 0 (day of death) or afternoon and evening of lag 1 (day before death). In warmer, southern cities, stronger associations were found with morning temperatures, but overall the relationships were weaker. The strongest temperature-mortality relationships were associated with maximum temperature, although mean temperature results were comparable. There were systematic and substantial differences in the association between temperature and mortality based on the time and type of temperature observation. Because the strongest hourly temperature-mortality relationships were not always found at times typically associated with daily maximum temperatures, temperature variables should be selected independently for each study location. In general, heat-mortality was more closely coupled to afternoon and maximum

  11. Estimating the Total Heat Flux from the ASHES Hydrothermal Vent Field Using the Sentry Autonomous Underwater Vehicle

    Science.gov (United States)

    Crone, T. J.; Kinsey, J. C.; Mittelstaedt, E. L.

    2017-12-01

    Hydrothermal venting at mid-ocean ridges influences ocean chemistry, the thermal and chemical structure of the oceanic crust, and the evolution of unique and diverse autolithotrophically-supported ecosystems. Axially-hosted hydrothermal systems are responsible for 20-25% of the total heat flux out of Earth's interior, and likely play a large role in local as well as global biogeochemical cycles. Despite the importance of these systems, only a few studies have attempted to constrain the volume and heat flux of an entire hydrothermal vent field. In July of 2014 we used the Sentry autonomous underwater vehicle (AUV) to survey the water column over the ASHES hydrothermal vent field which is located within the caldera of Axial Seamount, an active submarine volcano located on the Juan de Fuca Ridge. To estimate the total heat and mass flux from this vent field, we equipped Sentry with a Nortek acoustic Doppler velocimeter (ADV), an inertial measurement unit (IMU), two acoustic Doppler current profilers (ADCPs), and two SBE3 temperature probes, allowing us to obtain precise measurements of fluid temperature and water velocity. The survey was designed using a control volume approach in which Sentry was pre-programmed to survey a 150-m-square centered over the vent field flying a grid pattern with 5-m track line spacing followed by a survey of the perimeter. This pattern was repeated multiple times during several 10-h dives at different altitudes, including 10, 20, 40, and 60 m above the seafloor, and during one 40-h survey at an altitude of 10 m. During the 40-h survey, the pattern was repeated nine times allowing us to obtain observations over several tidal cycles. Water velocity data obtained with Sentry were corrected for platform motion and then combined with the temperature measurements to estimate heat flux. The analysis of these data will likely provide the most accurate and highest resolution heat and mass flux estimates at a seafloor hydrothermal field to date.

  12. Estimation of peak heat flux onto the targets for CFETR with extended divertor leg

    International Nuclear Information System (INIS)

    Zhang, Chuanjia; Chen, Bin; Xing, Zhe; Wu, Haosheng; Mao, Shifeng; Luo, Zhengping; Peng, Xuebing; Ye, Minyou

    2016-01-01

    Highlights: • A hypothetical geometry is assumed to extend the outer divertor leg in CFETR. • Density scan SOLPS simulation is done to study the peak heat flux onto target. • Attached–detached regime transition in out divertor occurs at lower puffing rate. • Unexpected delay of attached–detached regime transition occurs in inner divertor. - Abstract: China Fusion Engineering Test Reactor (CFETR) is now in conceptual design phase. CFETR is proposed as a good complement to ITER for demonstrating of fusion energy. Divertor is a crucial component which faces the plasmas and handles huge heat power for CFETR and future fusion reactor. To explore an effective way for heat exhaust, various methods to reduce the heat flux to divertor target should be considered for CFETR. In this work, the effect of extended out divertor leg on the peak heat flux is studied. The magnetic configuration of the long leg divertor is obtained by EFIT and Tokamak Simulation Code (TSC), while a hypothetical geometry is assumed to extend the out divertor leg as long as possible inside vacuum vessel. A SOLPS simulation is performed to study peak heat flux of the long leg divertor for CFETR. D 2 gas puffing is used and increasing of the puffing rate means increase of plasma density. Both peak heat flux onto inner and outer targets are below 10 MW/m 2 is achieved. A comparison between the peak heat flux between long leg and conventional divertor shows that an attached–detached regime transition of out divertor occurs at lower gas puffing gas puffing rate for long leg divertor. While for the inner divertor, even the configuration is almost the same, the situation is opposite.

  13. Estimating the CO2 mitigation potential of horizontal Ground Source Heat Pumps in the UK

    Science.gov (United States)

    Garcia-Gonzalez, R.; Verhoef, A.; Vidale, P. L.; Gan, G.; Chong, A.; Clark, D.

    2012-04-01

    By 2020, the UK will need to generate 15% of its energy from renewables to meet our contribution to the EU renewable energy target. Heating and cooling systems of buildings account for 30%-50% of the global energy consumption; thus, alternative low-carbon technologies such as horizontal Ground Couple Heat Pumps (GCHPs) can contribute to the reduction of anthropogenic CO2 emissions. Horizontal GCHPs currently represent a small fraction of the total energy generation in the UK. However, the fact that semi-detached and detached dwellings represent approximately 40% of the total housing stocks in the UK could make the widespread implementation of this technology particularly attractive in the UK and so could significantly increase its renewable energy generation potential. Using a simulation model, we analysed the dynamic interactions between the environment, the horizontal GCHP heat exchanger and typical UK dwellings, as well as their combined effect on heat pump performance and CO2 mitigation potential. For this purpose, a land surface model (JULES, Joint UK Land Environment Simulator), which calculates coupled soil heat and water fluxes, was combined with a heat extraction model. The analyses took into account the spatio-temporal variability of soil properties (thermal and hydraulic) and meteorological variables, as well as different horizontal GCHP configurations and a variety of building loads and heat demands. Sensitivity tests were performed for four sites in the UK with different climate and soil properties. Our results show that an installation depth of 1.0m would give us higher heat extractions rates, however it would be preferable to install the pipes slightly deeper to avoid the seasonal influence of variable meteorological conditions. A value of 1.5m for the spacing between coils (S) for a slinky configuration type is recommended to avoid thermal disturbances between neighbouring coils. We also found that for larger values of the spacing between the coils

  14. The capability and constraint model of recoverability: An integrated theory of continuity planning.

    Science.gov (United States)

    Lindstedt, David

    2017-01-01

    While there are best practices, good practices, regulations and standards for continuity planning, there is no single model to collate and sort their various recommended activities. To address this deficit, this paper presents the capability and constraint model of recoverability - a new model to provide an integrated foundation for business continuity planning. The model is non-linear in both construct and practice, thus allowing practitioners to remain adaptive in its application. The paper presents each facet of the model, outlines the model's use in both theory and practice, suggests a subsequent approach that arises from the model, and discusses some possible ramifications to the industry.

  15. Comparison of estimated core body temperature measured with the BioHarness and rectal temperature under several heat stress conditions.

    Science.gov (United States)

    Seo, Yongsuk; DiLeo, Travis; Powell, Jeffrey B; Kim, Jung-Hyun; Roberge, Raymond J; Coca, Aitor

    2016-08-01

    Monitoring and measuring core body temperature is important to prevent or minimize physiological strain and cognitive dysfunction for workers such as first responders (e.g., firefighters) and military personnel. The purpose of this study is to compare estimated core body temperature (Tco-est), determined by heart rate (HR) data from a wearable chest strap physiology monitor, to standard rectal thermometry (Tre) under different conditions.  Tco-est and Tre measurements were obtained in thermoneutral and heat stress conditions (high temperature and relative humidity) during four different experiments including treadmill exercise, cycling exercise, passive heat stress, and treadmill exercise while wearing personal protective equipment (PPE).  Overall, the mean Tco-est did not differ significantly from Tre across the four conditions. During exercise at low-moderate work rates under heat stress conditions, Tco-est was consistently higher than Tre at all-time points. Tco-est underestimated temperature compared to Tre at rest in heat stress conditions and at a low work rate under heat stress while wearing PPE. The mean differences between the two measurements ranged from -0.1 ± 0.4 to 0.3 ± 0.4°C and Tco-est correlated well with HR (r = 0.795 - 0.849) and mean body temperature (r = 0.637 - 0.861).  These results indicate that, the comparison of Tco-est to Tre may result in over- or underestimation which could possibly lead to heat-related illness during monitoring in certain conditions. Modifications to the current algorithm should be considered to address such issues.

  16. Estimation of surface Latent Heat Fluxes from IRS-P4/MSMR ...

    Indian Academy of Sciences (India)

    The brightness temperatures of the Microwave sensor MSMR (Multichannel Scanning Microwave Radiometer) launched in May 1999 onboard Indian Oceansat-1 IRS-P4 are used to develop a direct retrieval method for latent heat ux by multivariate regression technique. The MSMR measures the microwave radiances at 8 ...

  17. Estimation of surface latent heat fluxes from IRS-P4/MSMR satellite ...

    Indian Academy of Sciences (India)

    The brightness temperatures of the Microwave sensor MSMR (Multichannel Scanning Microwave Radiometer) launched in May 1999 onboard Indian Oceansat-1 IRS-P4 are used to develop a direct retrieval method for latent heat ux by multivariate regression technique. The MSMR measures the microwave radiances at 8 ...

  18. Application of optimal estimation techniques to FFTF decay heat removal analysis

    International Nuclear Information System (INIS)

    Nutt, W.T.; Additon, S.L.; Parziale, E.A.

    1979-01-01

    The verification and adjustment of plant models for decay heat removal analysis using a mix of engineering judgment and formal techniques from control theory are discussed. The formal techniques facilitate dealing with typical test data which are noisy, redundant and do not measure all of the plant model state variables directly. Two pretest examples are presented. 5 refs

  19. Assessment of undiscovered conventionally recoverable petroleum resources of the Northwest European region

    Science.gov (United States)

    Masters, Charles D.; Klemme, H. Douglas

    1984-01-01

    The estimates of undiscovered conventionally recoverable petroleum resources in the northwest European region at probability levels of 95 percent, 5 percent, statistical mean, and mode are for oil (in billions of barrels): 9, 34, 20, and 15; and for gas (in trillions of cubic feet): 92, 258, 167, and 162. The occurrence of petroleum can be accounted for in two distinct geological plays located in the various subbasins of the region. Play I is associated with the distribution of mature source rocks of Late Jurassic age relative to four distinct trapping conditions. The play has been demonstrated productive mostly in the Viking and Central Grabens of the North Sea, where the shale has been buried to optimum depths for the generation of both oil and gas. To the north of 62 ? N. latitude up to the Barents Sea, source rocks become increasingly deeply buried and are interpreted to be dominantly gas prone; a narrow band of potentially oil-prone shales tracks most of the coast of Norway, but water depths in favorable localities commonly range from 600 to 1,200 feet. To the south of the Central Graben, the Jurassic source rocks are either immature or minimally productive because of a change in facies. Undrilled traps remain within the favorable source-rock area, and exploration will continue to challenge the boundaries of conventional wisdom, especially on the Norwegian side where little has .been reported on the geology of the adjoining Bergen High or Horda Basin, though, reportedly, the Jurassic source rocks are missing on the high and are immature in the southern part of the basin. Play II is associated with the distribution of a coal facies of Carboniferous age that is mature for the generation of gas and locally underlies favorable reservoir and sealing rocks. The play is limited largely by facies development to the present area of discovery and production but is limited as well to the southeast into onshore Netherlands and Germany by the unfavorable economics of an

  20. Heat-Related Deaths in Hot Cities: Estimates of Human Tolerance to High Temperature Thresholds

    Directory of Open Access Journals (Sweden)

    Sharon L. Harlan

    2014-03-01

    Full Text Available In this study we characterized the relationship between temperature and mortality in central Arizona desert cities that have an extremely hot climate. Relationships between daily maximum apparent temperature (ATmax and mortality for eight condition-specific causes and all-cause deaths were modeled for all residents and separately for males and females ages <65 and ≥65 during the months May–October for years 2000–2008. The most robust relationship was between ATmax on day of death and mortality from direct exposure to high environmental heat. For this condition-specific cause of death, the heat thresholds in all gender and age groups (ATmax = 90–97 °F; 32.2‒36.1 °C were below local median seasonal temperatures in the study period (ATmax = 99.5 °F; 37.5 °C. Heat threshold was defined as ATmax at which the mortality ratio begins an exponential upward trend. Thresholds were identified in younger and older females for cardiac disease/stroke mortality (ATmax = 106 and 108 °F; 41.1 and 42.2 °C with a one-day lag. Thresholds were also identified for mortality from respiratory diseases in older people (ATmax = 109 °F; 42.8 °C and for all-cause mortality in females (ATmax = 107 °F; 41.7 °C and males <65 years (ATmax = 102 °F; 38.9 °C. Heat-related mortality in a region that has already made some adaptations to predictable periods of extremely high temperatures suggests that more extensive and targeted heat-adaptation plans for climate change are needed in cities worldwide.

  1. Heat-related deaths in hot cities: estimates of human tolerance to high temperature thresholds.

    Science.gov (United States)

    Harlan, Sharon L; Chowell, Gerardo; Yang, Shuo; Petitti, Diana B; Morales Butler, Emmanuel J; Ruddell, Benjamin L; Ruddell, Darren M

    2014-03-20

    In this study we characterized the relationship between temperature and mortality in central Arizona desert cities that have an extremely hot climate. Relationships between daily maximum apparent temperature (ATmax) and mortality for eight condition-specific causes and all-cause deaths were modeled for all residents and separately for males and females ages <65 and ≥ 65 during the months May-October for years 2000-2008. The most robust relationship was between ATmax on day of death and mortality from direct exposure to high environmental heat. For this condition-specific cause of death, the heat thresholds in all gender and age groups (ATmax = 90-97 °F; 32.2-36.1 °C) were below local median seasonal temperatures in the study period (ATmax = 99.5 °F; 37.5 °C). Heat threshold was defined as ATmax at which the mortality ratio begins an exponential upward trend. Thresholds were identified in younger and older females for cardiac disease/stroke mortality (ATmax = 106 and 108 °F; 41.1 and 42.2 °C) with a one-day lag. Thresholds were also identified for mortality from respiratory diseases in older people (ATmax = 109 °F; 42.8 °C) and for all-cause mortality in females (ATmax = 107 °F; 41.7 °C) and males <65 years (ATmax = 102 °F; 38.9 °C). Heat-related mortality in a region that has already made some adaptations to predictable periods of extremely high temperatures suggests that more extensive and targeted heat-adaptation plans for climate change are needed in cities worldwide.

  2. Diagnosis of Heat Exchanger Tube Failure in Fossil Fuel Boilers Through Estimation of Steady State Operating Conditions

    International Nuclear Information System (INIS)

    Herszage, A.; Toren, M.

    1998-01-01

    Estimation of operating conditions for fossil fuel boiler heat exchangers is often required due to changes in working conditions, design modifications and especially for monitoring performance and failure diagnosis. Regular heat exchangers in fossil fuel boilers are composed of tube banks through which water or steam flow, while hot combustion (flue) gases flow outside the tubes. This work presents a top-down approach to operating conditions estimation based on field measurements. An example for a 350 MW unit superheater is thoroughly discussed. Integral calculations based on measurements for all unit heat exchangers (reheaters, superheaters) were performed first. Based on these calculations a scheme of integral conservation equations (lumped parameter) was then formulated at the single tube level. Steady state temperatures of superheater tube walls were obtained as a main output, and were compared to the maximum allowable operating temperatures of the tubes material. A combined lumped parameter - CFD (Computational Fluid Dynamics, FLUENT code) approach constitutes an efficient tool in certain cases. A brief report of such a case is given for another unit superheater. We conclude that steady state evaluations based on both integral and detailed simulations are a valuable monitoring and diagnosis tool for the power generation industry

  3. Electron-ion temperature ratio estimations in the summer polar mesosphere when subject to HF radio wave heating

    Science.gov (United States)

    Pinedo, H.; La Hoz, C.; Havnes, O.; Rietveld, M.

    2014-10-01

    We have inferred the electron temperature enhancements above mesospheric altitudes under Polar Mesospheric Summer Echoes (PMSE) conditions when the ionosphere is exposed to artificial HF radio wave heating. The proposed method uses the dependence of the radar cross section on the electron-to-ion temperature ratio to infer the heating factor from incoherent scatter radar (ISR) power measurements above 90 km. Model heating temperatures match our ISR estimations between 90 and 130 km with 0.94 Pearson correlation index. The PMSE strength measured by the MORRO MST radar is about 50% weaker during the heater-on period when the modeled electron-to-ion mesospheric temperature is approximately 10 times greater than the unperturbed value. No PMSE weakening is found when the mesospheric temperature enhancement is by a factor of three or less. The PMSE weakening and its absence are consistent with the modeled mesospheric electron temperatures. This consistency supports to the proposed method for estimating mesospheric electron temperatures achieved by independent MST and ISR radar measurements.

  4. Opportunities for low-grade heat recovery in the UK food processing industry

    International Nuclear Information System (INIS)

    Law, Richard; Harvey, Adam; Reay, David

    2013-01-01

    Energy efficiency in the process industry is becoming an increasingly important issue due to the rising costs of both electricity and fossil fuel resources, as well as the tough targets for the reduction in greenhouse gas emissions outlined in the Climate Change Act 2008. Utilisation of waste heat sources is key to improving industrial energy efficiency, with an estimated 11.4 TWh of recoverable heat being wasted each year, a quarter of which is from the food and drinks processing sector. This paper examines the low-grade waste heat sources common to the food and drinks processing sector and the various opportunities for the use of this heat. A review of the best available technologies for recovery of waste heat is provided, ranging from heat transfer between source and sink, to novel technologies for the generation of electricity and refrigeration. Generally, the most economic option for waste heat recovery is heat exchange between nearby/same process source and sink, with a number of well-developed heat exchangers widely available for purchase. More novel options, such as the use of organic Rankine cycles for electricity generation prove to be less economical due to high capital outlays. However, with additional funding provision for demonstration of such projects and development of modular units, such technologies would become more common

  5. Fission yields data generation and benchmarks of decay heat estimation of a nuclear fuel

    Directory of Open Access Journals (Sweden)

    Gil Choong-Sup

    2017-01-01

    Full Text Available Fission yields data with the ENDF-6 format of 235U, 239Pu, and several actinides dependent on incident neutron energies have been generated using the GEF code. In addition, fission yields data libraries of ORIGEN-S, -ARP modules in the SCALE code, have been generated with the new data. The decay heats by ORIGEN-S using the new fission yields data have been calculated and compared with the measured data for validation in this study. The fission yields data ORIGEN-S libraries based on ENDF/B-VII.1, JEFF-3.1.1, and JENDL/FPY-2011 have also been generated, and decay heats were calculated using the ORIGEN-S libraries for analyses and comparisons.

  6. Estimating the potential for industrial waste heat reutilization in urban district energy systems: method development and implementation in two Chinese provinces

    Science.gov (United States)

    Tong, Kangkang; Fang, Andrew; Yu, Huajun; Li, Yang; Shi, Lei; Wang, Yangjun; Wang, Shuxiao; Ramaswami, Anu

    2017-12-01

    Utilizing low-grade waste heat from industries to heat and cool homes and businesses through fourth generation district energy systems (DES) is a novel strategy to reduce energy use. This paper develops a generalizable methodology to estimate the energy saving potential for heating/cooling in 20 cities in two Chinese provinces, representing cold winter and hot summer regions respectively. We also conduct a life-cycle analysis of the new infrastructure required for energy exchange in DES. Results show that heating and cooling energy use reduction from this waste heat exchange strategy varies widely based on the mix of industrial, residential and commercial activities, and climate conditions in cities. Low-grade heat is found to be the dominant component of waste heat released by industries, which can be reused for both district heating and cooling in fourth generation DES, yielding energy use reductions from 12%-91% (average of 58%) for heating and 24%-100% (average of 73%) for cooling energy use in the different cities based on annual exchange potential. Incorporating seasonality and multiple energy exchange pathways resulted in energy savings reductions from 0%-87%. The life-cycle impact of added infrastructure was small (<3% for heating) and 1.9% ~ 6.5% (cooling) of the carbon emissions from fuel use in current heating or cooling systems, indicating net carbon savings. This generalizable approach to delineate waste heat potential can help determine suitable cities for the widespread application of industrial waste heat re-utilization.

  7. Recoverable Wire-Shaped Supercapacitors with Ultrahigh Volumetric Energy Density for Multifunctional Portable and Wearable Electronics.

    Science.gov (United States)

    Shi, Minjie; Yang, Cheng; Song, Xuefeng; Liu, Jing; Zhao, Liping; Zhang, Peng; Gao, Lian

    2017-05-24

    Wire-shaped supercapacitors (SCs) based on shape memory materials are of considerable interest for next-generation portable and wearable electronics. However, the bottleneck in this field is how to develop the devices with excellent electrochemical performance while well-maintaining recoverability and flexibility. Herein, a unique asymmetric electrode concept is put forward to fabricate smart wire-shaped SCs with ultrahigh energy density, which is realized by using porous carbon dodecahedra coated on NiTi alloy wire and flexible graphene fiber as yarn electrodes. Notably, the wire-shaped SCs not only exhibit high flexibility that can be readily woven into real clothing but also represent the available recoverable ability. When irreversible plastic deformations happen, the deformed shape of the devices can automatically resume the initial predesigned shape in a warm environment (about 35 °C). More importantly, the wire-shaped SCs act as efficient energy storage devices, which display high volumetric energy density (8.9 mWh/cm 3 ), volumetric power density (1080 mW/cm 3 ), strong durability in multiple mechanical states, and steady electrochemical behavior after repeated shape recovery processes. Considering their relative facile fabrication technology and excellent electrochemical performance, this asymmetric electrode strategy produced smart wire-shaped supercapacitors desirable for multifunctional portable and wearable electronics.

  8. Kinetic study of free fatty acid esterification reaction catalyzed by recoverable and reusable hydrochloric acid.

    Science.gov (United States)

    Su, Chia-Hung

    2013-02-01

    The catalytic performance and recoverability of several homogeneous acid catalysts (hydrochloric, sulfuric, and nitric acids) for the esterification of enzyme-hydrolyzed free fatty acid (FFA) and methanol were studied. Although all tested catalysts drove the reaction to a high yield, hydrochloric acid was the only catalyst that could be considerably recovered and reused. The kinetics of the esterification reaction catalyzed by hydrochloric acid was investigated under varying catalyst loading (0.1-1M), reaction temperature (303-343K), and methanol/FFA molar ratio (1:1-20:1). In addition, a pseudo-homogeneous kinetic model incorporating the above factors was developed. A good agreement (r(2)=0.98) between the experimental and calculated data was obtained, thus proving the reliability of the model. Furthermore, the reusability of hydrochloric acid in FFA esterification can be predicted by the developed model. The recoverable hydrochloric acid achieved high yields of FFA esterification within five times of reuse. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. On the estimation of the worst-case implant-induced RF-heating in multi-channel MRI

    Science.gov (United States)

    Córcoles, Juan; Zastrow, Earl; Kuster, Niels

    2017-06-01

    The increasing use of multiple radiofrequency (RF) transmit channels in magnetic resonance imaging (MRI) systems makes it necessary to rigorously assess the risk of RF-induced heating. This risk is especially aggravated with inclusions of medical implants within the body. The worst-case RF-heating scenario is achieved when the local tissue deposition in the at-risk region (generally in the vicinity of the implant electrodes) reaches its maximum value while MRI exposure is compliant with predefined general specific absorption rate (SAR) limits or power requirements. This work first reviews the common approach to estimate the worst-case RF-induced heating in multi-channel MRI environment, based on the maximization of the ratio of two Hermitian forms by solving a generalized eigenvalue problem. It is then shown that the common approach is not rigorous and may lead to an underestimation of the worst-case RF-heating scenario when there is a large number of RF transmit channels and there exist multiple SAR or power constraints to be satisfied. Finally, this work derives a rigorous SAR-based formulation to estimate a preferable worst-case scenario, which is solved by casting a semidefinite programming relaxation of this original non-convex problem, whose solution closely approximates the true worst-case including all SAR constraints. Numerical results for 2, 4, 8, 16, and 32 RF channels in a 3T-MRI volume coil for a patient with a deep-brain stimulator under a head imaging exposure are provided as illustrative examples.

  10. Estimation and Analysis of Cucumber (Cucumis sativus L.) Leaf Cellular Heat Sensitivity.

    Science.gov (United States)

    Caldwell, C. R.

    1993-01-01

    Triphenyl tetrazolium chloride (TTC) reduction by cucumber (Cucumis sativus L. cv Poinsett 76 and cv Ashley) leaf discs was used as a viability assay to examine the effect of temperature pretreatment on the tissue response to acute hyperthermia. Semi-logarithmic plots of TTC reduction as a function of incubation time at different temperatures from 40 to 60[deg]C resembled the heat survival curves of animal cells. Heat inactivation rates were obtained and subjected to "quasi" Arrhenius analyses by analytical methods derived from the animal studies. The Arrhenius plots of TTC reduction rates for cv Ashley leaf discs preincubated at 25 or 37[deg]C and for cv Poinsett 76 preincubated at 37[deg]C were linear with the same activation energy (Ea) of about 80 kcal mol-1. The Arrhenius plot of cv Poinsett 76 preincubated at 25[deg]C was nonlinear with an Ea of about 80 kcal mol-1 at temperatures below 46[deg]C and an Ea of about 27.5 kcal mol-1 at temperatures above 47[deg]C. The significance of these differences is discussed in terms of the role of protein denaturation in the thermal sensitivity of cucumber disc reduction of TTC and the applicability of these methods to the analysis of plant cellular heat sensitivity. PMID:12231745

  11. Initial estimates of anthropogenic heat emissions for the City of Durban

    CSIR Research Space (South Africa)

    Padayachi, Yerdashin R

    2018-03-01

    Full Text Available of empirical evidence to identify policy measures that are most likely to simultaneously meet development needs that allow for societal wellbeing and economic growth whilst living within environmental thresholds. This study provides an initial estimate of AH...

  12. Estimating surface turbulent heat fluxes from land surface temperature and soil moisture using the particle batch smoother

    Science.gov (United States)

    Lu, Yang; Dong, Jianzhi; Steele-Dunne, Susan; van de Giesen, Nick

    2016-04-01

    This study is focused on estimating surface sensible and latent heat fluxes from land surface temperature (LST) time series and soil moisture observations. Surface turbulent heat fluxes interact with the overlying atmosphere and play a crucial role in meteorology, hydrology and other climate-related fields, but in-situ measurements are costly and difficult. It has been demonstrated that the time series of LST contains information of energy partitioning and that surface turbulent heat fluxes can be determined from assimilation of LST. These studies are mainly based on two assumptions: (1) a monthly value of bulk heat transfer coefficient under neutral conditions (CHN) which scales the sum of the fluxes, and (2) an evaporation fraction (EF) which stays constant during the near-peak hours of the day. Previous studies have applied variational and ensemble approaches to this problem. Here the newly developed particle batch smoother (PBS) algorithm is adopted to test its capability in this application. The PBS can be seen as an extension of the standard particle filter (PF) in which the states and parameters within a fix window are updated in a batch using all observations in the window. The aim of this study is two-fold. First, the PBS is used to assimilate only LST time series into the force-restore model to estimate fluxes. Second, a simple soil water transfer scheme is introduced to evaluate the benefit of assimilating soil moisture observations simultaneously. The experiments are implemented using the First ISLSCP (International Satellite Land Surface Climatology Project) (FIFE) data. It is shown that the restored LST time series using PBS agrees very well with observations, and that assimilating LST significantly improved the flux estimation at both daily and half-hourly time scales. When soil moisture is introduced to further constrain EF, the accuracy of estimated EF is greatly improved. Furthermore, the RMSEs of retrieved fluxes are effectively reduced at both

  13. Estimation on Achievable Parameter Regime of Warm Dense Matter Generated by Isochoric Heating Discharge using Intense Pulsed Power Generator

    Science.gov (United States)

    Hayashi, Ryota; Kashine, Kenji; Tokuchi, Akira; Tamura, Fumihiro; Watabe, Arata; Kudo, Takahiro; Takahashi, Kazumasa; Sasaki, Toru; Kikuchi, Takashi; Aso, Tsukasa; Harada, Nob.; Jiang, Weihua

    2016-03-01

    An evaluation method for warm dense matter (WDM) with similar timescale in inertial confinement fusion (ICF) by isochoric heating using intense pulsed power generator ETIGO-II is considered for evaluating target behavior. The temperature increase of the sample is estimated from the numerical calculation using the measured current. As a result, in the case that the shape of sample is ϕ2 mm x 10 mm and the density is 0.01 times solid density of copper, the temperature of sample increases up to 30000 K. It is expected that the WDM is generated using the proposed method with ICF implosion timescale.

  14. Estimation of tropical cyclone heat potential in the Bay of Bengal and its role in the genesis and intensification of storms

    Digital Repository Service at National Institute of Oceanography (India)

    Sadhuram, Y.; Murthy, T.V.R.; Somayajulu, Y.K.

    In the present study, cyclone heat potential (CHP) in the Bay of Bengal has been estimated for different seasons using Levitus climatology. A good association was noticed between CHP and the efficiency of intensification (i.e the ratio between...

  15. On the accuracy of the simple ocean data assimilation analysis for estimating heat Budgets of the Near-Surface Arabian Sea and Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Shenoi, S.S.C.; Shankar, D.; Shetye, S.R.

    The accuracy of data from the Simple Ocean Data Assimilation (SODA) model for estimating the heat budget of the upper ocean is tested in the Arabian Sea and the Bay of Bengal. SODA is able to reproduce the changes in heat content when...

  16. GPM SLH: Convective Latent Heating Estimated with GPM Dual-frequency Precipitation Radar Data

    Science.gov (United States)

    Takayabu, Y. N.; Hamada, A.; Yokoyama, C.; Ikuta, Y.; Shige, S.; Yamaji, M.; Kubota, T.

    2017-12-01

    Three dimensional diabatic heating distribution plays essential roles to determine large-scale circulation, as well as to generate mesoscale circulation associated with tropical convection (e.g. Hartmann et al., 1984; Houze et al. 1982). For mid-latitude systems also, diabatic heating contributes to generate PVs resulting in, for example, explosive intensifications of mid-lattitude storms (Boettcher and Wernli, 2011). Previously, with TRMM PR data, we developed a Spectral Latent Heating algorithm (SLH; Shige et al. 2004, etc.) for 36N-36S region. It was based on the spectral LH tables produced from a simulation utilizing the Goddard Cloud Ensemble Model forced with the TOGA-COARE data. With GPM DPR, the observation region is extended to 65N-65S. Here, we introduce a new version of SLH algorithm which is applicable also to the mid-latitude precipitation. A new global GPM SLH ver.5 product is released as one of NASA/JAXA GPM standard products on July 11, 2017. For GPM SLH mid-latitude algorithm, we employ the Japan Meteorological Agency (JMA)'s high resolution (horizontally 2km) Local Forecast Model (LFM) to construct the LUTs. With collaborations of JMA's forecast group, forecast data for 8 extratropical cyclone cases are collected and utilized. For mid-latitude precipitation, we have to deal with large temperature gradients and complex relationship between the freezing level and cloud base levels. LUTs are constructed for LH, Q1-QR, and Q2 (Yanai et al. 1973), for six different precipitation types: Convective and shallow stratiform LUTs are made against precipitation top heights. For deep stratiform and other precipitation, LUTs are made against maximum precipitation to handle the unknown cloud-bases. Finally, three-dimensional convective latent heating is retrieved, utilizing the LUTs and precipitation profile data from GPM 2AKu. We can confirm that retrieved LH looks very similar to simulated LH, for a consistency check. We also confirm a good continuities of

  17. METHOD OF ESTIMATION FREQUENCY PROPERTIES OF THE PREINSULATED PIPES FOR MONITORING THE STATUS OF HEATING NETWORKS

    Directory of Open Access Journals (Sweden)

    E. N. Taletskiy

    2014-01-01

    Full Text Available Proposed approximate method for the preliminary assessment of the frequency properties unadapted guiding system for monitoring the status of the organization of preinsulated pipes. Guide system elements  formed  tubes  placed  in  a  lossy  medium  (soil.  A  theoretical  analysis  shows  the  frequency dependence of the propagation constant components: the damping coefficient and the phase coefficient, take advantage of these characteristics of the system for monitoring the status heating networks.

  18. Surface Resistance Measurements and Estimate of the Beam-Induced Resistive Wall Heating of the LHC Dipole Beam Screen

    CERN Document Server

    Caspers, Friedhelm; Ruggiero, F; Tan, J

    1999-01-01

    An estimate of the resistive losses in the LHC beam screen is given from cold surface resistance measurements using the shielded pair technique, with particular emphasis on the effect of a high magnetic field. Two different copper coating methods, namely electro-deposition and co-lamination, have been evaluated. Experimental data are compared with theories including the anomalous skin effect and the magneto-resistance effect. It is shown whether the theory underestimates or not the losses depends strongly on the RRR value, on the magnetic field and on the surface characteristics. In the pessimistic case and for nominal machine parameters, the estimated beam-induced resistive wall heating can be as large as 260 mW/m for two circulating beams.

  19. Experimental estimation of the heat energy dissipated in a volume surrounding the tip of a fatigue crack

    Directory of Open Access Journals (Sweden)

    G. Meneghetti

    2016-01-01

    Full Text Available Fatigue crack initiation and propagation involve plastic strains that require some work to be done on the material. Most of this irreversible energy is dissipated as heat and consequently the material temperature increases. The heat being an indicator of the intense plastic strains occurring at the tip of a propagating fatigue crack, when combined with the Neuber’s structural volume concept, it might be used as an experimentally measurable parameter to assess the fatigue damage accumulation rate of cracked components. On the basis of a theoretical model published previously, in this work the heat energy dissipated in a volume surrounding the crack tip is estimated experimentally on the basis of the radial temperature profiles measured by means of an infrared camera. The definition of the structural volume in a fatigue sense is beyond the scope of the present paper. The experimental crack propagation tests were carried out on hot-rolled, 6-mm-thick AISI 304L stainless steel specimens subject to completely reversed axial fatigue loading.

  20. Physical parameter estimation in spatial heat transport models with an application to food storage

    NARCIS (Netherlands)

    van Mourik, S.; Vries, Dirk; Ploegaert, Johan P. M.; Zwart, Heiko J.; Keesman, Karel J.

    Parameter estimation plays an important role in physical modelling, but can be problematic due to the complexity of spatiotemporal models that are used for analysis, control and design in industry. In this paper we aim to circumvent these problems by using a methodology that approximates a model, or

  1. Physical parameter estimation in spatial heat transport models with an application to food storage

    NARCIS (Netherlands)

    Mourik, van S.; Vries, D.; Ploegaert, J.P.M.; Zwart, H.; Keesman, K.J.

    2012-01-01

    Parameter estimation plays an important role in physical modelling, but can be problematic due to the complexity of spatiotemporal models that are used for analysis, control and design in industry. In this paper we aim to circumvent these problems by using a methodology that approximates a model, or

  2. Heat kernel estimates for pseudodifferential operators, fractional Laplacians and Dirichlet-to-Neumann operators

    DEFF Research Database (Denmark)

    Gimperlein, Heiko; Grubb, Gerd

    2014-01-01

    The purpose of this article is to establish upper and lower estimates for the integral kernel of the semigroup exp(−t P) associated to a classical, strongly elliptic pseudodifferential operator P of positive order on a closed manifold. The Poissonian bounds generalize those obtained for perturbat...

  3. Estimation of surface Latent Heat Fluxes from IRS-P4/MSMR ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging Solutions)

    this case the errors were higher apparently due to the errors involved in derivation of the geophysical ... On this account, the exchange of energy between the sea surface and atmosphere is a major energy source for the atmospheric circulation. The exchange of ... rate estimates of LHF at the sea surface (together with other ...

  4. Bayesian fuzzy logic-based estimation of electron cyclotron heating (ECH) power deposition in MHD control systems

    Energy Technology Data Exchange (ETDEWEB)

    Davoudi, Mehdi, E-mail: mehdi.davoudi@polimi.it [Department of Electrical and Computer Engineering, Buein Zahra Technical University, Buein Zahra, Qazvin (Iran, Islamic Republic of); Davoudi, Mohsen, E-mail: davoudi@eng.ikiu.ac.ir [Department of Electrical Engineering, Imam Khomeini International University, Qazvin, 34148-96818 (Iran, Islamic Republic of)

    2017-06-15

    Highlights: • A couple of algorithms to diagnose if Electron Cyclotron Heating (ECH) power is deposited properly on the expected deposition minor radius are proposed. • The algorithms are based on Bayesian theory and Fuzzy logic. • The algorithms are tested on the off-line experimental data acquired from Frascati Tokamak Upgrade (FTU), Frascati, Italy. • Uncertainties and evidences derived from the combination of online information formed by the measured diagnostic data and the prior information are also estimated. - Abstract: In the thermonuclear fusion systems, the new plasma control systems use some measured on-line information acquired from different sensors and prior information obtained by predictive plasma models in order to stabilize magnetic hydro dynamics (MHD) activity in a tokamak. Suppression of plasma instabilities is a key issue to improve the confinement time of controlled thermonuclear fusion with tokamaks. This paper proposes a couple of algorithms based on Bayesian theory and Fuzzy logic to diagnose if Electron Cyclotron Heating (ECH) power is deposited properly on the expected deposition minor radius (r{sub DEP}). Both algorithms also estimate uncertainties and evidences derived from the combination of the online information formed by the measured diagnostic data and the prior information. The algorithms have been employed on a set of off-line ECE channels data which have been acquired from the experimental shot number 21364 at Frascati Tokamak Upgrade (FTU), Frascati, Italy.

  5. OligoHeatMap (OHM): an online tool to estimate and display hybridizations of oligonucleotides onto DNA sequences.

    Science.gov (United States)

    Croce, Olivier; Chevenet, François; Christen, Richard

    2008-07-01

    The efficiency of molecular methods involving DNA/DNA hybridizations depends on the accurate prediction of the melting temperature (T(m)) of the duplex. Many softwares are available for T(m) calculations, but difficulties arise when one wishes to check if a given oligomer (PCR primer or probe) hybridizes well or not on more than a single sequence. Moreover, the presence of mismatches within the duplex is not sufficient to estimate specificity as it does not always significantly decrease the T(m). OHM (OligoHeatMap) is an online tool able to provide estimates of T(m) for a set of oligomers and a set of aligned sequences, not only as text files of complete results but also in a graphical way: T(m) values are translated into colors and displayed as a heat map image, either stand alone or to be used by softwares such as TreeDyn to be included in a phylogenetic tree. OHM is freely available at http://bioinfo.unice.fr/ohm/, with links to the full source code and online help.

  6. MODIS-Based Estimation of Terrestrial Latent Heat Flux over North America Using Three Machine Learning Algorithms

    Directory of Open Access Journals (Sweden)

    Xuanyu Wang

    2017-12-01

    Full Text Available Terrestrial latent heat flux (LE is a key component of the global terrestrial water, energy, and carbon exchanges. Accurate estimation of LE from moderate resolution imaging spectroradiometer (MODIS data remains a major challenge. In this study, we estimated the daily LE for different plant functional types (PFTs across North America using three machine learning algorithms: artificial neural network (ANN; support vector machines (SVM; and, multivariate adaptive regression spline (MARS driven by MODIS and Modern Era Retrospective Analysis for Research and Applications (MERRA meteorology data. These three predictive algorithms, which were trained and validated using observed LE over the period 2000–2007, all proved to be accurate. However, ANN outperformed the other two algorithms for the majority of the tested configurations for most PFTs and was the only method that arrived at 80% precision for LE estimation. We also applied three machine learning algorithms for MODIS data and MERRA meteorology to map the average annual terrestrial LE of North America during 2002–2004 using a spatial resolution of 0.05°, which proved to be useful for estimating the long-term LE over North America.

  7. Estimation of heat transfer rates to droplets under the conditions of a LOCA in a PWR in the ballooned zone

    Energy Technology Data Exchange (ETDEWEB)

    Gradeck, Michel; Maillet, Denis [LEMTA Nancy-University CNRS, 2 av de la foret de Haye, BP160, 54504 Vandoeuvre cedex (France); Lelong, Franck [LEMTA Nancy-University CNRS, 2 av de la foret de Haye, BP160, 54504 Vandoeuvre cedex (France)]|[IRSN/DPAM/SEMCA/LEIDC, Cadarache Batiment 700, BP3 - 13 115 Saint Paul lez Durance cedex (France); Seiler, Nathalie [IRSN/DPAM/SEMCA/LEIDC, Cadarache Batiment 700, BP3 - 13 115 Saint Paul lez Durance cedex (France)

    2008-07-01

    Full text of publication follows: During a LOCA (Loss Of Coolant Accident), the critical regions (in terms of safety) of the fuel assemblies could be ballooned. The cooling of theses partially blocked fuel assemblies depends on the coolant flow characteristics in the blockage region. Most models for heat transfer concentrate on cooling of the ballooned walls by vapor convection. Since a two-phase mist flow occurs when reflooding, the possibility of additional cooling by direct liquid droplet impingement on the blockage surfaces must be investigated. As the temperature of the fuel assemblies is higher than the Leidenfrost temperature, the impact regime should be only the bouncing one. Up to now, no model of heat transfer of droplet impacts has been developed for that regime. As the coolability from droplet impacts must be modeled, we realize an experimental study with droplets and wall characteristics (velocity, diameter, temperature) close to the LOCA ones. As the interaction between the droplet and the wall is very short (a few of ms), the estimation of the heat flux during the resident time of the droplet at the wall must be accurately designed. The purpose of this work is to show how such heat flux can be experimentally estimated used an adapted inverse heat conduction model. The final goal of the present collaboration between LEMTA (Laboratory of Applied and Theoretical Energy and Mechanic) and IRSN (Institut of Radioprotection and Nuclear Safety) is to introduce the cooling model within NEPTUNE-CFD code of the NEPTUNE thermal-hydraulic platform, a joint project of CEA, EDF, IRSN and AREVA. (authors) [French] Dans le cas d'un APRP (Accident de Perte de Refrigerant Primaire), les zones critiques de l'assemblage combustible peuvent etre deformees. Le refroidissement de ces zones depend de l'importance du blocage qui affectera l'ecoulement diphasique les traversant. La plupart des modeles de refroidissement de ces zones assechees, a hautes

  8. Some estimates of mirror plasma startup by neutral beam heating of pellet and gas cloud targets

    International Nuclear Information System (INIS)

    Shearer, J.W.; Willmann, P.A.

    1978-01-01

    Hot plasma buildup by neutral beam injection into an initially cold solid or gaseous target is found to be conceivable in large mirror machine experiments such as 2XIIB or MFTF. A simple analysis shows that existing neutral beam intensities are sufficient to ablate suitable targets to form a gas or vapor cloud. An approximate rate equation model is used to follow the subsequent processes of ionization, heating, and hot plasma formation. Solutions of these rate equations are obtained by means of the ''GEAR'' techniques for solving ''stiff'' systems of differential equations. These solutions are in rough agreement with the 2XIIB stream plasma buildup experiment. They also predict that buildup on a suitable nitrogen-like target will occur in the MFTF geometry. In 2XIIB the solutions are marginal; buildup may be possible, but is not certain

  9. Validation of Temperature Histories for Structural Steel Welds Using Estimated Heat-Affected-Zone Edges

    Science.gov (United States)

    2016-10-12

    possibly not convenient. A classification of steels that can be characterized for quantitative estimation of solidification and HAZ edge boundaries is...Naval Research Laboratory Washington, DC 20375-5320 NRL/MR/6394--16-9690 Validation of Temperature Histories for Structural Steel Welds Using...SECURITY CLASSIFICATION OF: a. REPORT 19a. NAME OF RESPONSIBLE PERSON 19b. TELEPHONE NUMBER (include area code) b. ABSTRACT c. THIS PAGE 18. NUMBER OF

  10. Ru-Containing Magnetically Recoverable Catalysts: A Sustainable Pathway from Cellulose to Ethylene and Propylene Glycols.

    Science.gov (United States)

    Manaenkov, Oleg V; Mann, Joshua J; Kislitza, Olga V; Losovyj, Yaroslav; Stein, Barry D; Morgan, David Gene; Pink, Maren; Lependina, Olga L; Shifrina, Zinaida B; Matveeva, Valentina G; Sulman, Esther M; Bronstein, Lyudmila M

    2016-08-24

    Biomass processing to value-added chemicals and biofuels received considerable attention due to the renewable nature of the precursors. Here, we report the development of Ru-containing magnetically recoverable catalysts for cellulose hydrogenolysis to low alcohols, ethylene glycol (EG) and propylene glycol (PG). The catalysts are synthesized by incorporation of magnetite nanoparticles (NPs) in mesoporous silica pores followed by formation of 2 nm Ru NPs. The latter are obtained by thermal decomposition of ruthenium acetylacetonate in the pores. The catalysts showed excellent activities and selectivities at 100% cellulose conversion, exceeding those for the commercial Ru/C. High selectivities as well as activities are attributed to the influence of Fe3O4 on the Ru(0)/Ru(4+) NPs. A facile synthetic protocol, easy magnetic separation, and stability of the catalyst performance after magnetic recovery make these catalysts promising for industrial applications.

  11. Method and system for redundancy management of distributed and recoverable digital control system

    Science.gov (United States)

    Stange, Kent (Inventor); Hess, Richard (Inventor); Kelley, Gerald B (Inventor); Rogers, Randy (Inventor)

    2012-01-01

    A method and system for redundancy management is provided for a distributed and recoverable digital control system. The method uses unique redundancy management techniques to achieve recovery and restoration of redundant elements to full operation in an asynchronous environment. The system includes a first computing unit comprising a pair of redundant computational lanes for generating redundant control commands. One or more internal monitors detect data errors in the control commands, and provide a recovery trigger to the first computing unit. A second redundant computing unit provides the same features as the first computing unit. A first actuator control unit is configured to provide blending and monitoring of the control commands from the first and second computing units, and to provide a recovery trigger to each of the first and second computing units. A second actuator control unit provides the same features as the first actuator control unit.

  12. Monitoring system and methods for a distributed and recoverable digital control system

    Science.gov (United States)

    Stange, Kent (Inventor); Hess, Richard (Inventor); Kelley, Gerald B (Inventor); Rogers, Randy (Inventor)

    2010-01-01

    A monitoring system and methods are provided for a distributed and recoverable digital control system. The monitoring system generally comprises two independent monitoring planes within the control system. The first monitoring plane is internal to the computing units in the control system, and the second monitoring plane is external to the computing units. The internal first monitoring plane includes two in-line monitors. The first internal monitor is a self-checking, lock-step-processing monitor with integrated rapid recovery capability. The second internal monitor includes one or more reasonableness monitors, which compare actual effector position with commanded effector position. The external second monitor plane includes two monitors. The first external monitor includes a pre-recovery computing monitor, and the second external monitor includes a post recovery computing monitor. Various methods for implementing the monitoring functions are also disclosed.

  13. A recoverable gas-cell diagnostic for the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Ratkiewicz, A., E-mail: ratkiewicz1@llnl.gov; Berzak Hopkins, L.; Bleuel, D. L.; Cassata, W. S.; Velsko, C. A.; Yeamans, C. B. [Lawrence Livermore National Laboratory, Livermore, California 95440 (United States); Bernstein, L. A.; Bibber, K. van; Goldblum, B. L. [University of California, Berkeley, California 94720 (United States); Siem, S. [University of Oslo, N-0316 Oslo (Norway); Wiedeking, M. [iThemba LABS, Somerset West 7129 (South Africa)

    2016-11-15

    The high-fluence neutron spectrum produced by the National Ignition Facility (NIF) provides an opportunity to measure the activation of materials by fast-spectrum neutrons. A new large-volume gas-cell diagnostic has been designed and qualified to measure the activation of gaseous substances at the NIF. This in-chamber diagnostic is recoverable, reusable and has been successfully fielded. Data from the qualification of the diagnostic have been used to benchmark an Monte Carlo N-Particle Transport Code simulation describing the downscattered neutron spectrum seen by the gas cell. We present early results from the use of this diagnostic to measure the activation of {sup nat}Xe and discuss future work to study the strength of interactions between plasma and nuclei.

  14. A recoverable gas-cell diagnostic for the National Ignition Facility.

    Science.gov (United States)

    Ratkiewicz, A; Berzak Hopkins, L; Bleuel, D L; Bernstein, L A; van Bibber, K; Cassata, W S; Goldblum, B L; Siem, S; Velsko, C A; Wiedeking, M; Yeamans, C B

    2016-11-01

    The high-fluence neutron spectrum produced by the National Ignition Facility (NIF) provides an opportunity to measure the activation of materials by fast-spectrum neutrons. A new large-volume gas-cell diagnostic has been designed and qualified to measure the activation of gaseous substances at the NIF. This in-chamber diagnostic is recoverable, reusable and has been successfully fielded. Data from the qualification of the diagnostic have been used to benchmark an Monte Carlo N-Particle Transport Code simulation describing the downscattered neutron spectrum seen by the gas cell. We present early results from the use of this diagnostic to measure the activation of nat Xe and discuss future work to study the strength of interactions between plasma and nuclei.

  15. Estimates of paramters of hot electrons during beam heating of plasma in a magnetic field

    Science.gov (United States)

    Breyzman, B. N.; Yerofeev, V. I.

    1986-02-01

    The dynamics of high-energy electrons formed in Langmuir turbulence and excited in a plasma by a relativistic electron beam is examined. The density perturbations that cause waves to move from one region of the phase space to another, and to maintain balance between pumping and attenuation, are assumed to be generated by the high frequency pressure of the Langmuir waves themselves. A kinetic equation is derived for the excitation, attenuation, and elastic scattering of Langmuir waves. The concentration and characteristic energy of the hot electrons is found within the framework of the proposed model. The estimates are compared with the results of experiments conducted on the INAR and GOL-1 installations.

  16. Estimating spatially distributed turbulent heat fluxes from high-resolution thermal imagery acquired with a UAV system.

    Science.gov (United States)

    Brenner, Claire; Thiem, Christina Elisabeth; Wizemann, Hans-Dieter; Bernhardt, Matthias; Schulz, Karsten

    2017-05-19

    In this study, high-resolution thermal imagery acquired with a small unmanned aerial vehicle (UAV) is used to map evapotranspiration (ET) at a grassland site in Luxembourg. The land surface temperature (LST) information from the thermal imagery is the key input to a one-source and two-source energy balance model. While the one-source model treats the surface as a single uniform layer, the two-source model partitions the surface temperature and fluxes into soil and vegetation components. It thus explicitly accounts for the different contributions of both components to surface temperature as well as turbulent flux exchange with the atmosphere. Contrary to the two-source model, the one-source model requires an empirical adjustment parameter in order to account for the effect of the two components. Turbulent heat flux estimates of both modelling approaches are compared to eddy covariance (EC) measurements using the high-resolution input imagery UAVs provide. In this comparison, the effect of different methods for energy balance closure of the EC data on the agreement between modelled and measured fluxes is also analysed. Additionally, the sensitivity of the one-source model to the derivation of the empirical adjustment parameter is tested. Due to the very dry and hot conditions during the experiment, pronounced thermal patterns developed over the grassland site. These patterns result in spatially variable turbulent heat fluxes. The model comparison indicates that both models are able to derive ET estimates that compare well with EC measurements under these conditions. However, the two-source model, with a more complex treatment of the energy and surface temperature partitioning between the soil and vegetation, outperformed the simpler one-source model in estimating sensible and latent heat fluxes. This is consistent with findings from prior studies. For the one-source model, a time-variant expression of the adjustment parameter (to account for the difference between

  17. Irrigation scheduling of green areas based on soil moisture estimation by the active heated fiber optic distributed temperature sensing AHFO

    Science.gov (United States)

    Zubelzu, Sergio; Rodriguez-Sinobas, Leonor; Sobrino, Fernando; Sánchez, Raúl

    2017-04-01

    Irrigation programing determines when and how much water apply to fulfill the plant water requirements depending of its phenology stage and location, and soil water content. Thus, the amount of water, the irrigation time and the irrigation frequency are variables that must be estimated. Likewise, irrigation programing has been based in approaches such as: the determination of plant evapotranspiration and the maintenance of soil water status between a given interval or soil matrix potential. Most of these approaches are based on the measurements of soil water sensors (or tensiometers) located at specific points within the study area which lack of the spatial information of the monitor variable. The information provided in such as few points might not be adequate to characterize the soil water distribution in irrigation systems with poor water application uniformity and thus, it would lead to wrong decisions in irrigation scheduling. Nevertheless, it can be overcome if the active heating pulses distributed fiber optic temperature measurement (AHFO) is used. This estimates the temperature variation along a cable of fiber optic and then, it is correlated with the soil water content. This method applies a known amount of heat to the soil and monitors the temperature evolution, which mainly depends on the soil moisture content. Thus, it allows estimations of soil water content every 12.5 cm along the fiber optic cable, as long as 1500 m (with 2 % accuracy) , every second. This study presents the results obtained in a green area located at the ETSI Agronómica, Agroalimentaria y Biosistesmas in Madrid. The area is irrigated by an sprinkler irrigation system which applies water with low uniformity. Also, it has deployed and installation of 147 m of fiber optic cable at 15 cm depth. The Distribute Temperature Sensing unit was a SILIXA ULTIMA SR (Silixa Ltd, UK) with spatial and temporal resolution of 0.29 m and 1 s, respectively. In this study, heat pulses of 7 W/m for 2

  18. Estimation of metabolic heat production and methane emission in Sahiwal and Karan Fries heifers under different feeding regimes

    Directory of Open Access Journals (Sweden)

    Sunil Kumar

    2016-05-01

    Full Text Available Aim: The objective of this study was designed to estimate the metabolic heat production and methane emission in Sahiwal and Karan Fries (Holstein-Friesian X Tharparkar heifers under two different feeding regimes, i.e., feeding regime-1 as per the National Research Council (NRC (2001 and feeding regime-2 having 15% higher energy (supplementation of molasses than NRC (2001. Materials and Methods: Six (n = 6 healthy heifers of Sahiwal and Karan Fries with 18-24 months of age were selected from Indian Council of Agricultural Research-National Dairy Research Institute, Karnal. An initial 15 days was maintained under feeding regime-1 and feeding regime-2 as adaptation period; actual experiment was conducted from 16th day onward for next 15 days. At the end of feeding regimes (on day 15th and 16th, expired air and volume were collected in Douglas bag for two consecutive days (morning [6:00 am] and evening [4:00 pm]. The fraction of methane and expired air volume were measured by methane analyzer and wet test meter, respectively. The oxygen consumption and carbon dioxide production were measured by iWorx LabScribe2. Results: The heat production (kcal/day was significantly (p0.05. The energy loss as methane (% from total heat production was significantly (p<0.05 higher in feeding regime-1. The body weight (kg, metabolic body weight (W0.75, and basal metabolic rate (kcal/kg0.75 were significantly (p<0.05 higher in feeding regime-2 in both breeds. Conclusions: This study indicates that higher energy diet by supplementing molasses may reduce energy loss as methane and enhance the growth of Sahiwal and Karan Fries heifers.

  19. Estimation of the dust production rate from the tungsten armour after repetitive ELM-like heat loads

    Science.gov (United States)

    Pestchanyi, S.; Garkusha, I.; Makhlaj, V.; Landman, I.

    2011-12-01

    Experimental simulations for the erosion rate of tungsten targets under ITER edge-localized mode (ELM)-like surface heat loads of 0.75 MJ m-2 causing surface melting and of 0.45 MJ m-2 without melting have been performed in the QSPA-Kh50 plasma accelerator. Analytical considerations allow us to conclude that for both energy deposition values the erosion mechanism is solid dust ejection during surface cracking under the action of thermo-stress. Tungsten influx into the ITER containment of NW~5×1018 W per medium size ELM of 0.75 MJ m-2 and 0.25 ms time duration has been estimated. The radiation cooling power of Prad=150-300 MW due to such influx of tungsten is intolerable: it should cool the ITER core to 1 keV within a few seconds.

  20. Estimation of the dust production rate from the tungsten armour after repetitive ELM-like heat loads

    International Nuclear Information System (INIS)

    Pestchanyi, S; Landman, I; Garkusha, I; Makhlaj, V

    2011-01-01

    Experimental simulations for the erosion rate of tungsten targets under ITER edge-localized mode (ELM)-like surface heat loads of 0.75 MJ m - 2 causing surface melting and of 0.45 MJ m - 2 without melting have been performed in the QSPA-Kh50 plasma accelerator. Analytical considerations allow us to conclude that for both energy deposition values the erosion mechanism is solid dust ejection during surface cracking under the action of thermo-stress. Tungsten influx into the ITER containment of N W ∼5×10 18 W per medium size ELM of 0.75 MJ m - 2 and 0.25 ms time duration has been estimated. The radiation cooling power of P rad =150-300 MW due to such influx of tungsten is intolerable: it should cool the ITER core to 1 keV within a few seconds.

  1. Monte Carlo estimation of the dose and heating of cobalt adjuster rods irradiated in the CANDU 6 reactor core

    International Nuclear Information System (INIS)

    Gugiu, D.; Dumitrache, I.

    2005-01-01

    The present work is a part of a more complex project related to the replacement of the original stainless steel adjuster rods with cobalt assemblies in the CANDU 6 reactor core. The 60 Co produced by 59 Co irradiation could be used extensively in medicine and industry. The paper will mainly describe some of the reactor physics and safety requirements that must be carried into practice for the Co adjuster rods. The computations related to the neutronic equivalence of the stainless steel adjusters with the Co adjuster assemblies, as well as the estimations of the activity and heating of the irradiated cobalt rods, are performed using the Monte Carlo codes MCNP5 and MONTEBURNS 2.1. The activity values are used to evaluate the dose at the surface of the device designed to transport the cobalt adjusters. (authors)

  2. Measurement of Magnetic Field From an Induction Heating Hob and Estimation of Induced Current Density in Human Body

    Science.gov (United States)

    Suzuki, Yukihisa; Taki, Masao

    Magnetic fields around induction heating hobs are measured and evaluated with regard to the compliance with safety guidelines of human exposure. The magnetic flux density distributions are highly inhomogeneous and the maximum can exceed the reference levels of the guideline at the very proximity to the device. The induced current densities in human body exposed to these magnetic fields are estimated by numerical calculations by means of impedance method with an anatomical human model. The results indicate that induced currents are sufficiently lower than the basic restriction of the ICNIRP guideline. It is shown that the spatially peak incident field does not provide a relevant reference to compare with the reference level of guideline because it is too conservative but spatially averaged incident magnetic field provides much more relevant reference.

  3. Estimating heat stress from climate-based indicators: present-day biases and future spreads in the CMIP5 global climate model ensemble

    Science.gov (United States)

    Zhao, Y.; Ducharne, A.; Sultan, B.; Braconnot, P.; Vautard, R.

    2015-08-01

    The increased exposure of human populations to heat stress is one of the likely consequences of global warming, and it has detrimental effects on health and labor capacity. Here, we consider the evolution of heat stress under climate change using 21 general circulation models (GCMs). Three heat stress indicators, based on both temperature and humidity conditions, are used to investigate present-day model biases and spreads in future climate projections. Present day estimates of heat stress indicators from observational data shows that humid tropical areas tend to experience more frequent heat stress than other regions do, with a total frequency of heat stress 250-300 d yr-1. The most severe heat stress is found in the Sahel and south India. Present-day GCM simulations tend to underestimate heat stress over the tropics due to dry and cold model biases. The model based estimates are in better agreement with observation in mid to high latitudes, but this is due to compensating errors in humidity and temperature. The severity of heat stress is projected to increase by the end of the century under climate change scenario RCP8.5, reaching unprecedented levels in some regions compared with observations. An analysis of the different factors contributing to the total spread of projected heat stress shows that spread is primarily driven by the choice of GCMs rather than the choice of indicators, even when the simulated indicators are bias-corrected. This supports the utility of the multi-model ensemble approach to assess the impacts of climate change on heat stress.

  4. Estimates of land surface heat fluxes of the Mt. Everest region over the Tibetan Plateau utilizing ASTER data

    Science.gov (United States)

    Han, Cunbo; Ma, Yaoming; Chen, Xuelong; Su, Zhongbo

    2016-02-01

    Regional land surface albedo, land surface temperature, net radiation flux, ground heat flux, sensible heat flux, and latent heat flux were derived in the Mt. Everest area utilizing topographical enhanced surface energy balance system (TESEBS) model and nine scenes of ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) data under clear-sky and in-situ measurements at the QOMS station (the Qomolangma Station for Atmospheric Environmental Observation and Research, Chinese Academy of Sciences). The parameterization schemes for diffused and reflected downward shortwave radiation flux of the TESEBS model were improved by introducing the parameters sky-view factor (SVF) and terrain configuration factor (Ct). Then, a so-called C-correction method for land surface albedo was coupled into the TESEBS model to reduce the influences of topography. After topographical correction, the albedo of the dark tilted surface facing away from the Sun was compensated and albedo of the brightness surface facing the Sun was restrained. The downward shortwave radiation flux was broken down into three components including solar direct radiation flux, solar diffused radiation flux, and reflected solar radiation flux by surrounding terrain. The solar diffused radiation flux ranges from about 30 to 60 W/m2 at the satellite passing time on 6 January 2008. The reflected solar radiation flux changes from 0 to more than 100 W/m2 in the area covered by glaciers and snows. Thus, it is important to take the topographical effects into account in estimation of surface radiation balance in the mountainous area, especially in the glacier area. The retrieved land surface parameters, land surface radiation balance components, and the land surface energy balance components were evaluated by the field measurements in the QOMS station. The estimated results were very close to the in-situ observations with low mean bias errors, low root mean square errors and high correlation coefficients

  5. The Heat Resistance of Microbial Cells Represented by D Values Can be Estimated by the Transition Temperature and the Coefficient of Linear Expansion.

    Science.gov (United States)

    Nakanishi, Koichi; Kogure, Akinori; Deuchi, Keiji; Kuwana, Ritsuko; Takamatsu, Hiromu; Ito, Kiyoshi

    2015-01-01

    We previously developed a method for evaluating the heat resistance of microorganisms by measuring the transition temperature at which the coefficient of linear expansion of a cell changes. Here, we performed heat resistance measurements using a scanning probe microscope with a nano thermal analysis system. The microorganisms studied included six strains of the genus Bacillus or related genera, one strain each of the thermophilic obligate anaerobic bacterial genera Thermoanaerobacter and Moorella, two strains of heat-resistant mold, two strains of non-sporulating bacteria, and one strain of yeast. Both vegetative cells and spores were evaluated. The transition temperature at which the coefficient of linear expansion due to heating changed from a positive value to a negative value correlated strongly with the heat resistance of the microorganism as estimated from the D value. The microorganisms with greater heat resistance exhibited higher transition temperatures. There was also a strong negative correlation between the coefficient of linear expansion and heat resistance in bacteria and yeast, such that microorganisms with greater heat resistance showed lower coefficients of linear expansion. These findings suggest that our method could be useful for evaluating the heat resistance of microorganisms.

  6. On the estimation of heat-intensity and heat-duration effects in time series models of temperature-related mortality in Stockholm, Sweden

    Science.gov (United States)

    2012-01-01

    Background We examine the effect of heat waves on mortality, over and above what would be predicted on the basis of temperature alone. Methods Present modeling approaches may not fully capture extra effects relating to heat wave duration, possibly because the mechanisms of action and the population at risk are different under more extreme conditions. Modeling such extra effects can be achieved using the commonly left-out effect-modification between the lags of temperature in distributed lag models. Results Using data from Stockholm, Sweden, and a variety of modeling approaches, we found that heat wave effects amount to a stable and statistically significant 8.1-11.6% increase in excess deaths per heat wave day. The effects explicitly relating to heat wave duration (2.0–3.9% excess deaths per day) were more sensitive to the degrees of freedom allowed for in the overall temperature-mortality relationship. However, allowing for a very large number of degrees of freedom indicated over-fitting the overall temperature-mortality relationship. Conclusions Modeling additional heat wave effects, e.g. between lag effect-modification, can give a better description of the effects from extreme temperatures, particularly in the non-elderly population. We speculate that it is biologically plausible to differentiate effects from heat and heat wave duration. PMID:22490779

  7. Estimates of Evapotranspiration with a One- and Two-Layer Model of Heat Transfer over Partial Canopy Cover.

    Science.gov (United States)

    Kustas, William P.

    1990-08-01

    One of the applications of remotely sensed surface temperature is to determine the latent heat flux (LE) or evapotranspiration (ET) from held to regional scales. A common approach has been to use surface-air temperature differences in a bulk resistance equation for estimating sensible beat flux, H, and to subsequently solve for LE as a residual in the one-dimensional energy balance equation. This approach has been successfully applied over uniform terrain with nearly full, actively transpiring vegetative cover; however, serious discrepancies between estimated and measured ET have been observed when there is partial canopy cover.In an attempt to improve the estimates of H and as a result compute more accurate values of ET over partial canopy cover, one- and two-layer resistance models are developed to account for some of the factors causing the poor agreement between computed and measured ET.The utility of these two approaches for estimating ET at the field scale is tested with remotely sensed and micrometeorological data collected in an and environment from a furrowed cotton field with 20 percent cover and a dry soil surface. The estimates of LE are compared with values measured using eddy correlation and energy balance methods. It is found that the one-layer model generally performed better than the two-layer model under thew conditions; but only when using a bluff-body correction to the resistance based on a conceptual model of beat and water vapor transfer at the surface taking place by molecular diffusion into Kolmogorov-scale eddies. The empirical adjustment to the surface resistance with the one-layer approach assumed to be applicable for a fairly wide range of conditions was found to be inappropriate. This result is attributed to the significant size of the furrows relative to the height of the vegetation.Furthermore, a sensitivity analysis showed that the one-layer model with the empirical adjustment for the resistance was significantly affected by the

  8. Procedures for Efficient and Economic Recovery of Heat for Reuse in Batch Processes for Cleaning

    DEFF Research Database (Denmark)

    Qvale, Einar Bjørn

    2005-01-01

    (TES) may be required to achieve these improvements. Further improvements may be achieved if there is a need, in the plant, for heating water at low-or-medium-level temperatures for cleaning purposes and there are significant quantities of medium-to-lowtemperature heat recoverable. Such conditions...

  9. Synthesis and Photocatalytic Activity of Magnetically Recoverable Core-Shell Nanoparticles

    Directory of Open Access Journals (Sweden)

    Zhen Peng

    2014-01-01

    Full Text Available TiO2/SiO2/Fe3O4 (TSF core-shell nanoparticles with good photocatalytic activity that are capable of fast magnetic separation have been successfully prepared by chemical coprecipitation and two-step sol-gel process. The as-prepared TSF nanoparticles were calcined at high temperature in order to transform the amorphous titanium dioxide into a photoactive crystalline phase. The calcined nanoparticles are composed of a Fe3O4 core with a strong response to external magnetic fields, a SiO2 intermediary layer, and a TiO2 outshell. Vibration sample magnetometer (VSM analysis confirms the superparamagnetism of calcined nanoparticles, which can enhance the recoverable properties of the novel photocatalyst. When the TiO2/SiO2/Fe3O4 core-shell nanoparticles are added to the crude oily wastewater, they exhibit high photocatalytic activity in the degradation of crude oily wastewater. The oil concentration could be reduced to lower than 30 ppm within 20 minutes for the case of initial oil concentration less than 350 ppm. It has been found that the TSF nanoparticles could be easily separated from the wastewater and withdrawn by using an external magnetic field. The recovered TSF nanoparticles possess high efficiency in the degradation of crude oily wastewater even after three times successive reuse. The present results indicate that TSF core-shell nanoparticles possess great application perspectives in the degradation of crude oily wastewater.

  10. Egg eviction imposes a recoverable cost of virulence in chicks of a brood parasite.

    Directory of Open Access Journals (Sweden)

    Michael G Anderson

    2009-11-01

    Full Text Available Chicks of virulent brood parasitic birds eliminate their nestmates and avoid costly competition for foster parental care. Yet, efforts to evict nest contents by the blind and naked common cuckoo Cuculus canorus hatchling are counterintuitive as both adult parasites and large older cuckoo chicks appear to be better suited to tossing the eggs and young of the foster parents.Here we show experimentally that egg tossing imposed a recoverable growth cost of mass gain in common cuckoo chicks during the nestling period in nests of great reed warbler Acrocephalus arundinaceus hosts. Growth rates of skeletal traits and morphological variables involved in the solicitation of foster parental care remained similar between evictor and non-evictor chicks throughout development. We also detected no increase in predation rates for evicting nests, suggesting that egg tossing behavior by common cuckoo hatchlings does not increase the conspicuousness of nests.The temporary growth cost of egg eviction by common cuckoo hatchlings is the result of constraints imposed by rejecter host adults and competitive nestmates on the timing and mechanism of parasite virulence.

  11. A constitutive equation of creep based on recoverable creep hardening range

    International Nuclear Information System (INIS)

    Murakami, Sumio; Ohno, Nobutada

    1982-01-01

    In case of the stress reverse test of 304 stainless steel under constant stress, the creep curve after stress reverse is not much different from that for the initial state, accordingly, the state of hardening of the material is restored almost to that in the initial state by stress reverse. Creep depends on past loading history, and essentially is anisotropic phenomenon. In this study, by extending the strain hardening theory to general multi-axial stress condition, a constitutive formula for creep without any difficulty was determined. For the purpose, as the main change of microscopic structure at the time of stress reverse in mono-axial creep, the effect of the reactivation of passive dislocations was considered. At this time, the range of recoverable creep hardening was assumed, in which irreversible dislocation arrangement does not occur after stress reverse. In order to examine the propriety of this theory, the multi-axial creep deformation, of which the principal stress direction changes periodically, was calculated by the derived constitutive formula, and the result was compared with the experimental result of 304 stainless steel tube at 650 deg C and the theoretical result of ORNL. (Kako, I.)

  12. National inventory of radioactive wastes and recoverable materials 2006. Descriptive catalogue of radioactive waste families

    International Nuclear Information System (INIS)

    2006-01-01

    Real comprehensive overview of radioactive wastes, the national inventory of radioactive wastes and recoverable materials describes the situation in France of the wastes that can be conditioned (in their definitive form) or not. It presents also the waste production quantities foreseen for 2010, 2020 and beyond. This document is a complement to the synthesis report and to the geographic inventory of radioactive wastes in France and details the classification of wastes by families (wastes with similar characteristics). For each family of wastes, the description comprises a general presentation and some photos. It comprises also some data such as the position of the family in the French classification, the industrial activity at the origin of the waste, the production situation of the waste in concern (finished, in progress, not started). Some information about the raw waste are given and the conditioning process used is described. Some figures complete the description, like: the past and future production quantities, the evaluation of the radioactivity of the waste family in 2004 and 2020, and the evaluation of the thermal power when available. Finally, some information are given about the presence of compounds with a specific risk of toxicity. (J.S.)

  13. Water-level and recoverable water in storage changes, High Plains aquifer, predevelopment to 2015 and 2013–15

    Science.gov (United States)

    McGuire, Virginia L.

    2017-06-01

    The High Plains aquifer underlies 111.8 million acres (about 175,000 square miles) in parts of eight States—Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. Water-level declines began in parts of the High Plains aquifer soon after the beginning of substantial irrigation with groundwater in the aquifer area (about 1950). This report presents water-level changes and change in recoverable water in storage in the High Plains aquifer from predevelopment (about 1950) to 2015 and from 2013 to 2015.The methods to calculate area-weighted, average water-level changes; change in recoverable water in storage; and total recoverable water in storage used geospatial data layers organized as rasters with a cell size of 500 meters by 500 meters, which is an area of about 62 acres. Raster datasets of water-level changes are provided for other uses.Water-level changes from predevelopment to 2015, by well, ranged from a rise of 84 feet to a decline of 234 feet. Water-level changes from 2013 to 2015, by well, ranged from a rise of 24 feet to a decline of 33 feet. The area-weighted, average water-level changes in the aquifer were an overall decline of 15.8 feet from predevelopment to 2015 and a decline of 0.6 feet from 2013 to 2015. Total recoverable water in storage in the aquifer in 2015 was about 2.91 billion acre-feet, which was a decline of about 273.2 million acre-feet since predevelopment and a decline of 10.7 million acre-feet from 2013 to 2015.

  14. Recent Advances in Recoverable Systems for the Copper-Catalyzed Azide-Alkyne Cycloaddition Reaction (CuAAC

    Directory of Open Access Journals (Sweden)

    Alessandro Mandoli

    2016-09-01

    Full Text Available The explosively-growing applications of the Cu-catalyzed Huisgen 1,3-dipolar cycloaddition reaction between organic azides and alkynes (CuAAC have stimulated an impressive number of reports, in the last years, focusing on recoverable variants of the homogeneous or quasi-homogeneous catalysts. Recent advances in the field are reviewed, with particular emphasis on systems immobilized onto polymeric organic or inorganic supports.

  15. A Bayesian model averaging approach for estimating the relative risk of mortality associated with heat waves in 105 U.S. cities.

    Science.gov (United States)

    Bobb, Jennifer F; Dominici, Francesca; Peng, Roger D

    2011-12-01

    Estimating the risks heat waves pose to human health is a critical part of assessing the future impact of climate change. In this article, we propose a flexible class of time series models to estimate the relative risk of mortality associated with heat waves and conduct Bayesian model averaging (BMA) to account for the multiplicity of potential models. Applying these methods to data from 105 U.S. cities for the period 1987-2005, we identify those cities having a high posterior probability of increased mortality risk during heat waves, examine the heterogeneity of the posterior distributions of mortality risk across cities, assess sensitivity of the results to the selection of prior distributions, and compare our BMA results to a model selection approach. Our results show that no single model best predicts risk across the majority of cities, and that for some cities heat-wave risk estimation is sensitive to model choice. Although model averaging leads to posterior distributions with increased variance as compared to statistical inference conditional on a model obtained through model selection, we find that the posterior mean of heat wave mortality risk is robust to accounting for model uncertainty over a broad class of models. © 2011, The International Biometric Society.

  16. Spontaneous synthesis of gold nanoparticles on gum arabic-modified iron oxide nanoparticles as a magnetically recoverable nanocatalyst

    Science.gov (United States)

    2012-01-01

    A novel magnetically recoverable Au nanocatalyst was fabricated by spontaneous green synthesis of Au nanoparticles on the surface of gum arabic-modified Fe3O4 nanoparticles. A layer of Au nanoparticles with thickness of about 2 nm was deposited on the surface of gum arabic-modified Fe3O4 nanoparticles, because gum arabic acted as a reducing agent and a stabilizing agent simultaneously. The resultant magnetically recoverable Au nanocatalyst exhibited good catalytic activity for the reduction of 4-nitrophenol with sodium borohydride. The rate constants evaluated in terms of pseudo-first-order kinetic model increased with increase in the amount of Au nanocatalyst or decrease in the initial concentration of 4-nitrophenol. The kinetic data suggested that this catalytic reaction was diffusion-controlled, owing to the presence of gum arabic layer. In addition, this nanocatalyst exhibited good stability. Its activity had no significant decrease after five recycles. This work is useful for the development and application of magnetically recoverable Au nanocatalyst on the basis of green chemistry principles. PMID:22713480

  17. Analysis of recoverable and permanent components of threshold voltage shift in NBT stressed p-channel power VDMOSFET

    Science.gov (United States)

    Danijel, Danković; Ninoslav, Stojadinović; Zoran, Prijić; Ivica, Manić; Vojkan, Davidović; Aneta, Prijić; Snežana, Djorić-Veljković; Snežana, Golubović

    2015-10-01

    In this study we investigate the dynamic recovery effects in IRF9520 commercial p-channel power vertical double diffused metal-oxide semiconductor field-effect transistors (VDMOSFETs) subjected to negative bias temperature (NBT) stressing under the particular pulsed bias. Particular values of the pulsed stress voltage frequency and duty cycle are chosen in order to analyze the recoverable and permanent components of stress-induced threshold voltage shift in detail. The results are discussed in terms of the mechanisms responsible for buildup of oxide charge and interface traps. The partial recovery during the low level of pulsed gate voltage is ascribed to the removal of recoverable component of degradation, i.e., to passivation/neutralization of shallow oxide traps that are not transformed into the deeper traps (permanent component). Considering the value of characteristic time constant associated with complete removal of the recoverable component of degradation, it is shown that by selecting an appropriate combination of the frequency and duty cycle, the threshold voltage shifts induced under the pulsed negative bias temperature stress conditions can be significantly reduced, which may be utilized for improving the device lifetime in real application circuits. Project supported by the Fund from the Ministry of Education, Science and Technological Development of the Republic of Serbia (Grant Nos. OI-171026 and TR-32026) and the Ei PCB Factory, Niš.

  18. Evaluation of three energy balance-based evaporation models for estimating monthly evaporation for five lakes using derived heat storage changes from a hysteresis model

    NARCIS (Netherlands)

    Duan, Z.; Bastiaanssen, W.G.M.

    2017-01-01

    The heat storage changes (Qt) can be a significant component of the energy balance in lakes, and it is important to account for Qt for reasonable estimation of evaporation at monthly and finer timescales if the energy balance-based evaporation models are used. However, Qt has been often neglected in

  19. Continuous reduction of tellurite to recoverable tellurium nanoparticles using an upflow anaerobic sludge bed (UASB) reactor.

    Science.gov (United States)

    Ramos-Ruiz, Adriana; Sesma-Martin, Juan; Sierra-Alvarez, Reyes; Field, Jim A

    2017-01-01

    According to the U.S. Department of Energy and the European Union, tellurium is a critical element needed for energy and defense technology. Thus methods are needed to recover tellurium from waste streams. The objectives of this study was to determine the feasibility of utilizing upflow anaerobic sludge bed (UASB) reactors to convert toxic tellurite (Te IV ) oxyanions to non-toxic insoluble elemental tellurium (Te 0 ) nanoparticles (NP) that are amendable to separation from aqueous effluents. The reactors were supplied with ethanol as the electron donating substrate to promote the biological reduction of Te IV . One reactor was additionally amended with the redox mediating flavonoid compound, riboflavin (RF), with the goal of enhancing the bioreduction of Te IV . Its performance was compared to a control reactor lacking RF. The continuous formation of Te 0 NPs using the UASB reactors was found to be feasible and remarkably improved by the addition of RF. The presence of this flavonoid was previously shown to enhance the conversion rate of Te IV by approximately 11-fold. In this study, we demonstrated that this was associated with the added benefit of reducing the toxic impact of Te IV towards the methanogenic consortium in the UASB and thus enabled a 4.7-fold higher conversion rate of the chemical oxygen demand. Taken as a whole, this work demonstrates the potential of a methanogenic granular sludge to be applied as a bioreactor technology producing recoverable Te 0 NPs in a continuous fashion. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Numerical estimation of phase transformations in solid state during Yb:YAG laser heating of steel sheets

    International Nuclear Information System (INIS)

    Kubiak, Marcin; Piekarska, Wiesława; Domański, Tomasz; Saternus, Zbigniew; Stano, Sebastian

    2015-01-01

    This work concerns the numerical modeling of heat transfer and phase transformations in solid state occurring during the Yb:YAG laser beam heating process. The temperature field is obtained by the numerical solution into transient heat transfer equation with convective term. The laser beam heat source model is developed using the Kriging interpolation method with experimental measurements of Yb:YAG laser beam profile taken into account. Phase transformations are calculated on the basis of Johnson - Mehl - Avrami (JMA) and Koistinen - Marburger (KM) kinetics models as well as continuous heating transformation (CHT) and continuous cooling transformation (CCT) diagrams for S355 steel. On the basis of developed numerical algorithms 3D computer simulations are performed in order to predict temperature history and phase transformations in Yb:YAG laser heating process

  1. Numerical estimation of phase transformations in solid state during Yb:YAG laser heating of steel sheets

    Energy Technology Data Exchange (ETDEWEB)

    Kubiak, Marcin, E-mail: kubiak@imipkm.pcz.pl; Piekarska, Wiesława; Domański, Tomasz; Saternus, Zbigniew [Institute of Mechanics and Machine Design Foundations, Częstochowa University of Technology, Dąbrowskiego 73, 42-200 Częstochowa (Poland); Stano, Sebastian [Welding Technologies Department, Welding Institute, Błogosławionego Czesława 16-18, 44-100 Gliwice (Poland)

    2015-03-10

    This work concerns the numerical modeling of heat transfer and phase transformations in solid state occurring during the Yb:YAG laser beam heating process. The temperature field is obtained by the numerical solution into transient heat transfer equation with convective term. The laser beam heat source model is developed using the Kriging interpolation method with experimental measurements of Yb:YAG laser beam profile taken into account. Phase transformations are calculated on the basis of Johnson - Mehl - Avrami (JMA) and Koistinen - Marburger (KM) kinetics models as well as continuous heating transformation (CHT) and continuous cooling transformation (CCT) diagrams for S355 steel. On the basis of developed numerical algorithms 3D computer simulations are performed in order to predict temperature history and phase transformations in Yb:YAG laser heating process.

  2. Development of a program for estimating air-to-air sensible heat recovery energy savings reduction due to frost control and comparison with EE4

    Energy Technology Data Exchange (ETDEWEB)

    Ball, I. [GES Technologies Inc., Montreal, PQ (Canada)

    2006-07-01

    Air-to-air heat recovery is an important energy savings measure for new or existing buildings. However, frost formation in cold climates limits the use of air-to-air heat recovery for HVAC applications. This study examined the methodology for estimating heat recovery energy savings in the program EE4, the main building energy modelling tool used in Canada. The EE4 is used together with the Modeling National Energy Building code to evaluate building energy performance for the Commercial Building Incentive Program. It is the basis for calculating the resulting financial incentives for building owners. The main objective of the study was to present a more realistic algorithm for estimating energy savings in relation to sensible air-to-air heat recovery accounting for two types of conventional frost control methods: face and bypass and outdoor air preheat. This algorithm was developed into a computer program called HRSIM that performs hourly calculations and contains an option for air-to-air heat recovery. Results from the simulations demonstrate that when accounting for frost control, the annual energy savings calculated in EE4 were 10 to 53 per cent higher than with HRSIM. 6 refs., 1 tab., 7 figs.

  3. Influence of inhomogeneous surface heat capacity on the estimation of radiative response coefficients in a two-zone energy balance model

    Science.gov (United States)

    Park, Jungmin; Choi, Yong-Sang

    2018-04-01

    Observationally constrained values of the global radiative response coefficient are pivotal to assess the reliability of modeled climate feedbacks. A widely used approach is to measure transient global radiative imbalance related to surface temperature changes. However, in this approach, a potential error in the estimate of radiative response coefficients may arise from surface inhomogeneity in the climate system. We examined this issue theoretically using a simple two-zone energy balance model. Here, we dealt with the potential error by subtracting the prescribed radiative response coefficient from those calculated within the two-zone framework. Each zone was characterized by the different magnitude of the radiative response coefficient and the surface heat capacity, and the dynamical heat transport in the atmosphere between the zones was parameterized as a linear function of the temperature difference between the zones. Then, the model system was forced by randomly generated monthly varying forcing mimicking time-varying forcing like an observation. The repeated simulations showed that inhomogeneous surface heat capacity causes considerable miscalculation (down to -1.4 W m-2 K-1 equivalent to 31.3% of the prescribed value) in the global radiative response coefficient. Also, the dynamical heat transport reduced this miscalculation driven by inhomogeneity of surface heat capacity. Therefore, the estimation of radiative response coefficients using the surface temperature-radiation relation is appropriate for homogeneous surface areas least affected by the exterior.

  4. Estimation of Joule heating and its role in nonlinear electrical response of Tb0.5Sr0.5MnO3 single crystal

    Science.gov (United States)

    Nhalil, Hariharan; Elizabeth, Suja

    2016-12-01

    Highly non-linear I-V characteristics and apparent colossal electro-resistance were observed in non-charge ordered manganite Tb0.5Sr0.5MnO3 single crystal in low temperature transport measurements. Significant changes were noticed in top surface temperature of the sample as compared to its base while passing current at low temperature. By analyzing these variations, we realize that the change in surface temperature (ΔTsur) is too small to have caused by the strong negative differential resistance. A more accurate estimation of change in the sample temperature was made by back-calculating the sample temperature from the temperature variation of resistance (R-T) data (ΔTcal), which was found to be higher than ΔTsur. This result indicates that there are large thermal gradients across the sample. The experimentally derived ΔTcal is validated with the help of a simple theoretical model and estimation of Joule heating. Pulse measurements realize substantial reduction in Joule heating. With decrease in sample thickness, Joule heating effect is found to be reduced. Our studies reveal that Joule heating plays a major role in the nonlinear electrical response of Tb0.5Sr0.5MnO3. By careful management of the duty cycle and pulse current I-V measurements, Joule heating can be mitigated to a large extent.

  5. Estimation of droplets/wall heat transfer under LOCA conditions in a PWR; Estimation du transfert de chaleur gouttes/paroi en situation d'APRP pour un REP

    Energy Technology Data Exchange (ETDEWEB)

    GrAdeck, M.; Maillet, D. [CNRS UMR 7563 2, 54 - Vandoeuvre les Nancy (France); Lelong, F.; Seiler, N.; Repetto, G. [IRSN Cadarache, 13 - Saint Paul lez Durance (France)

    2009-07-01

    During a LOCA (Loss Of Coolant Accident) in a PWR, the fuel assemblies could be locally severely ballooned. The transient is ended by the injection of water initiated the safety system. The cooling of theses partially blocked fuel assemblies depends on the coolant flow characteristics in the blockage region. Most models for heat transfers concentrate on cooling of the ballooned walls by vapor convection. Since a two-phase mist flow occurs when reflooding, the possibility of additional cooling by direct liquid droplet impingement on the blockage surfaces must be investigated. As the temperature of the fuel assemblies is higher than the Leidenfrost temperature, the impact regime should be only the bouncing one. Up to now, no model of heat transfer of droplet impacts has been developed for that regime. As the coolability from droplet impacts must be modeled, an experimental program was proposed with droplets and wall characteristics (velocity, diameter, temperature) close to the LOCA ones. As the interaction between the droplet and the wall is very short (a few of ms), the estimation of the heat flux during the resident time of the droplet at the wall must be accurately designed. The purpose of this work is to show how such heat flux can be experimentally estimated used an adapted inverse heat conduction model. The final goal of the present collaboration between LEMTA and IRSN is to introduce the cooling model within NEPTUNE-CFD code, a joint project of CEA, EDF, AREVA and IRSN. (authors)

  6. Does quality control matter? Surface urban heat island intensity variations estimated by satellite-derived land surface temperature products

    Science.gov (United States)

    Lai, Jiameng; Zhan, Wenfeng; Huang, Fan; Quan, Jinling; Hu, Leiqiu; Gao, Lun; Ju, Weimin

    2018-05-01

    The temporally regular and spatially comprehensive monitoring of surface urban heat islands (SUHIs) have been extremely difficult, until the advent of satellite-based land surface temperature (LST) products. However, these LST products have relatively higher errors compared to in situ measurements. This has resulted in comparatively inaccurate estimations of SUHI indicators and, consequently, may have distorted interpretations of SUHIs. Although reports have shown that LST qualities are important for SUHI interpretations, systematic investigations of the response of SUHI indicators to LST qualities across cities with dissimilar bioclimates are rare. To address this issue, we chose eighty-six major cities across mainland China and analyzed SUHI intensity (SUHII) derived from Moderate Resolution Imaging Spectroradiometer (MODIS) LST data. The LST-based SUHII differences due to inclusion or exclusion of MODIS quality control (QC) flags (i.e., ΔSUHII) were evaluated. Our major findings included, but are not limited to, the following four aspects: (1) SUHIIs can be significantly impacted by MODIS QC flags, and the associated QC-induced ΔSUHIIs generally accounted for 24.3% (29.9%) of the total SUHII value during the day (night); (2) the ΔSUHIIs differed between seasons, with considerable differences between transitional (spring and autumn) and extreme (summer and winter) seasons; (3) significant discrepancies also appeared among cities located in northern and southern regions, with northern cities often possessing higher annual mean ΔSUHIIs. The internal variations of ΔSUHIIs within individual cities also showed high heterogeneity, with ΔSUHII variations that generally exceeded 5.0 K (3.0 K) in northern (southern) cities; (4) ΔSUHIIs were negatively related to SUHIIs and cloud cover percentages (mostly in transitional seasons). No significant relationship was found in the extreme seasons. Our findings highlight the need to be extremely cautious when using LST

  7. Combining in situ measurements and altimetry to estimate volume, heat and salt transport variability through the Faroe–Shetland Channel

    Directory of Open Access Journals (Sweden)

    B. Berx

    2013-07-01

    Full Text Available From 1994 to 2011, instruments measuring ocean currents (Acoustic Doppler Current Profilers; ADCPs have been moored on a section crossing the Faroe–Shetland Channel. Together with CTD (Conductivity Temperature Depth measurements from regular research vessel occupations, they describe the flow field and water mass structure in the channel. Here, we use these data to calculate the average volume transport and properties of the flow of warm water through the channel from the Atlantic towards the Arctic, termed the Atlantic inflow. We find the average volume transport of this flow to be 2.7 ± 0.5 Sv (1 Sv = 106 m3 s–1 between the shelf edge on the Faroe side and the 150 m isobath on the Shetland side. The average heat transport (relative to 0 °C was estimated to be 107 ± 21 TW (1 TW = 1012 W and the average salt import to be 98 ± 20 × 106 kg s−1. Transport values for individual months, based on the ADCP data, include a large level of variability, but can be used to calibrate sea level height data from satellite altimetry. In this way, a time series of volume transport has been generated back to the beginning of satellite altimetry in December 1992. The Atlantic inflow has a seasonal variation in volume transport that peaks around the turn of the year and has an amplitude of 0.7 Sv. The Atlantic inflow has become warmer and more saline since 1994, but no equivalent trend in volume transport was observed.

  8. Influence of Mean Rooftop-Level Estimation Method on Sensible Heat Flux Retrieved from a Large-Aperture Scintillometer Over a City Centre

    Science.gov (United States)

    Zieliński, Mariusz; Fortuniak, Krzysztof; Pawlak, Włodzimierz; Siedlecki, Mariusz

    2017-08-01

    The sensible heat flux ( H) is determined using large-aperture scintillometer (LAS) measurements over a city centre for eight different computation scenarios. The scenarios are based on different approaches of the mean rooftop-level (zH) estimation for the LAS path. Here, zH is determined separately for wind directions perpendicular (two zones) and parallel (one zone) to the optical beam to reflect the variation in topography and building height on both sides of the LAS path. Two methods of zH estimation are analyzed: (1) average building profiles; (2) weighted-average building height within a 250 m radius from points located every 50 m along the optical beam, or the centre of a certain zone (in the case of a wind direction perpendicular to the path). The sensible heat flux is computed separately using the friction velocity determined with the eddy-covariance method and the iterative procedure. The sensitivity of the sensible heat flux and the extent of the scintillometer source area to different computation scenarios are analyzed. Differences reaching up to 7% between heat fluxes computed with different scenarios were found. The mean rooftop-level estimation method has a smaller influence on the sensible heat flux (-4 to 5%) than the area used for the zH computation (-5 to 7%). For the source-area extent, the discrepancies between respective scenarios reached a similar magnitude. The results demonstrate the value of the approach in which zH is estimated separately for wind directions parallel and perpendicular to the LAS optical beam.

  9. Comparative Assessment of Two Vegetation Fractional Cover Estimating Methods and Their Impacts on Modeling Urban Latent Heat Flux Using Landsat Imagery

    Directory of Open Access Journals (Sweden)

    Kai Liu

    2017-05-01

    Full Text Available Quantifying vegetation fractional cover (VFC and assessing its role in heat fluxes modeling using medium resolution remotely sensed data has received less attention than it deserves in heterogeneous urban regions. This study examined two approaches (Normalized Difference Vegetation Index (NDVI-derived and Multiple Endmember Spectral Mixture Analysis (MESMA-derived methods that are commonly used to map VFC based on Landsat imagery, in modeling surface heat fluxes in urban landscape. For this purpose, two different heat flux models, Two-source energy balance (TSEB model and Pixel Component Arranging and Comparing Algorithm (PCACA model, were adopted for model evaluation and analysis. A comparative analysis of the NDVI-derived and MESMA-derived VFCs showed that the latter achieved more accurate estimates in complex urban regions. When the two sources of VFCs were used as inputs to both TSEB and PCACA models, MESMA-derived urban VFC produced more accurate urban heat fluxes (Bowen ratio and latent heat flux relative to NDVI-derived urban VFC. Moreover, our study demonstrated that Landsat imagery-retrieved VFC exhibited greater uncertainty in obtaining urban heat fluxes for the TSEB model than for the PCACA model.

  10. Estimation of the effective heating systems radius as a method of the reliability improving and energy efficiency

    Science.gov (United States)

    Akhmetova, I. G.; Chichirova, N. D.

    2017-11-01

    When conducting an energy survey of heat supply enterprise operating several boilers located not far from each other, it is advisable to assess the degree of heat supply efficiency from individual boiler, the possibility of energy consumption reducing in the whole enterprise by switching consumers to a more efficient source, to close in effective boilers. It is necessary to consider the temporal dynamics of perspective load connection, conditions in the market changes. To solve this problem the radius calculation of the effective heat supply from the thermal energy source can be used. The disadvantage of existing methods is the high complexity, the need to collect large amounts of source data and conduct a significant amount of computational efforts. When conducting an energy survey of heat supply enterprise operating a large number of thermal energy sources, rapid assessment of the magnitude of the effective heating radius requires. Taking into account the specifics of conduct and objectives of the energy survey method of calculation of effective heating systems radius, to use while conducting the energy audit should be based on data available heat supply organization in open access, minimize efforts, but the result should be to match the results obtained by other methods. To determine the efficiency radius of Kazan heat supply system were determined share of cost for generation and transmission of thermal energy, capital investment to connect new consumers. The result were compared with the values obtained with the previously known methods. The suggested Express-method allows to determine the effective radius of the centralized heat supply from heat sources, in conducting energy audits with the effort minimum and the required accuracy.

  11. Towards More Comprehensive Projections of Urban Heat-Related Mortality: Estimates for New York City Under Multiple Population, Adaptation, and Climate Scenarios

    Science.gov (United States)

    Petkova, Elisaveta P.; Vink, Jan K.; Horton, Radley M.; Gasparrini, Antonio; Bader, Daniel A.; Francis, Joe D.; Kinney, Patrick L.

    2016-01-01

    High temperatures have substantial impacts on mortality and, with growing concerns about climate change, numerous studies have developed projections of future heat-related deaths around the world. Projections of temperature-related mortality are often limited by insufficient information necessary to formulate hypotheses about population sensitivity to high temperatures and future demographics. This study has derived projections of temperature-related mortality in New York City by taking into account future patterns of adaptation or demographic change, both of which can have profound influences on future health burdens. We adopt a novel approach to modeling heat adaptation by incorporating an analysis of the observed population response to heat in New York City over the course of eight decades. This approach projects heat-related mortality until the end of the 21st century based on observed trends in adaptation over a substantial portion of the 20th century. In addition, we incorporate a range of new scenarios for population change until the end of the 21st century. We then estimate future heat-related deaths in New York City by combining the changing temperature-mortality relationship and population scenarios with downscaled temperature projections from the 33 global climate models (GCMs) and two Representative Concentration Pathways (RCPs).The median number of projected annual heat-related deaths across the 33 GCMs varied greatly by RCP and adaptation and population change scenario, ranging from 167 to 3331 in the 2080s compared to 638 heat-related deaths annually between 2000 and 2006.These findings provide a more complete picture of the range of potential future heat-related mortality risks across the 21st century in New York, and highlight the importance of both demographic change and adaptation responses in modifying future risks.

  12. Protective coating as a factor to ensure the strength and hydraulic performance of recoverable pipelines

    Directory of Open Access Journals (Sweden)

    Orlov Vladimir Aleksandrovich

    2015-01-01

    Full Text Available The authors present an analysis of various types of internal protective pipeline coatings to ensure the strength and hydraulic characteristics of a remodeled pipeline and related coating methods for effective trenchless renovation of engineering systems, water supply systems and sanitation. As protective coating the authors considered a round profile tube of a smaller diameter than of the old pipe, close to the old pipe, sprayed lining on the basis of inorganic and inorganic materials. The article analyzes the methods of trenchless renovation for applying protective coatings: routing in the old pipeline of new pipes made of polymeric materials or polymeric sleeves, centrifugal spraying on the inner surface of pipelines’ inorganic and organic protective coatings. Special attention was paid to bag technology, providing the required strength properties at specific values of the modulus of elasticity and a number of external factors such as the depth of the existing pipe, the existence and magnitude of the horizon groundwater over it. Also attention is paid to the application technology of tape coatings ribbed profile on the inner surface of pipelines. This technology has a unique feature, which is the ability of recoverable pipeline functioning during its renovation by winding an endless belt and the formation of a new pipe. The tape coating winding is carried out by different types of spiral winding machines. The thickness of the protective coating layer forming the tube remains minimal. Inorganic cement-sand and organic coatings were considered as alternative options for repair of pipelines, which allow to localize the defects in the form of a fistula, minor cracks and other damages. However it is noted that a cement-sandy covering is inferior to organic, because it does not provide the strength characteristics of the pipeline system. The main advantage of the organic coating is mudding fistula of a large diameter, making a high wear

  13. Overview of a compre­hensive resource database for the assessment of recoverable hydrocarbons produced by carbon dioxide enhanced oil recovery

    Science.gov (United States)

    Carolus, Marshall; Biglarbigi, Khosrow; Warwick, Peter D.; Attanasi, Emil D.; Freeman, Philip A.; Lohr, Celeste D.

    2017-10-24

    A database called the “Comprehensive Resource Database” (CRD) was prepared to support U.S. Geological Survey (USGS) assessments of technically recoverable hydrocarbons that might result from the injection of miscible or immiscible carbon dioxide (CO2 ) for enhanced oil recovery (EOR). The CRD was designed by INTEK Inc., a consulting company under contract to the USGS. The CRD contains data on the location, key petrophysical properties, production, and well counts (number of wells) for the major oil and gas reservoirs in onshore areas and State waters of the conterminous United States and Alaska. The CRD includes proprietary data on petrophysical properties of fields and reservoirs from the “Significant Oil and Gas Fields of the United States Database,” prepared by Nehring Associates in 2012, and proprietary production and drilling data from the “Petroleum Information Data Model Relational U.S. Well Data,” prepared by IHS Inc. in 2012. This report describes the CRD and the computer algorithms used to (1) estimate missing reservoir property values in the Nehring Associates (2012) database, and to (2) generate values of additional properties used to characterize reservoirs suitable for miscible or immiscible CO2 flooding for EOR. Because of the proprietary nature of the data and contractual obligations, the CRD and actual data from Nehring Associates (2012)

  14. Attempts of Thermal Imaging Camera Usage in Estimations of the Convective Heat Loss From a Vertical Plate

    Directory of Open Access Journals (Sweden)

    Denda Hubert

    2014-01-01

    Full Text Available In this paper a new method for determining heat transfer coefficients using a gradient method has been developed. To verify accuracy of the proposed method vertical isothermal heating plate with natural convection mechanism has been examined. This configuration was deliberately chosen, because of the fact that such case is historically the earliest and most thoroughly studied and its rich scientific documentation – the most reliable. New method is based on temperature field visualization made in perpendicular plane to the heating surface of the plate using infrared camera. Because the camera does not record temperature of air itself but the surface only, therefore plastic mesh with low thermal conductivity has been used as a detector. Temperature of each mesh cell, placed perpendicular to the vertical heating surface and rinsed with convection stream of heated air could be already recorded by infrared camera. In the same time using IR camera surface of heating plate has been measured. By numerical processing of the results matrix temperature gradient on the surface ∂T/∂x │ x=0, local heat transfer coefficients αy, and local values of Nusselt number Nuy, can be calculated. After integration the average Nusselt number for entire plate can be calculated. Obtained relation characteristic numbers Nu = 0.647 Ra 0.236 (R2 = 0.943, has a good correlation with literature reports and proves usefulness of the method.

  15. Introducing a novel method to estimate the total heat transfer coefficient inside irregular-shape cavities utilizing thermoelectric modules; Special application in solar engineering

    DEFF Research Database (Denmark)

    Asadi, Amin; Rahbar, Nader; Rezaniakolaei, Alireza

    The main objective of the present study is to introduce a novel method to measure the total heat transfer coefficient inside irregular-shape cavities, used in solar applications, utilizing thermoelectric modules. Applying mathematical and thermodynamics modeling, the governing equations related...... to the total heat transfer coefficient between thermoelectric and glass cover as a function of ambient temperature, glass temperature, and output voltage has been derived. Investigating the accuracy of the proposed equation, an experimental case study has been performed. The experimental setup consists...... transfer coefficient inside irregular-shape cavities. The average deviation between experimental data and the output of the proposed equation is approximately 9 %, which shows the good ability of the equation in estimating the total heat transfer coefficient....

  16. Heat flux estimate of warm water flow in a low-temperature diffuse flow site, southern East Pacific Rise 17°25‧ S

    Science.gov (United States)

    Goto, Shusaku; Kinoshita, Masataka; Mitsuzawa, Kyohiko

    2003-09-01

    A low-temperature diffuse flow site associated with abundant vent fauna was found by submersible observations on the southern East Pacific Rise at 17°25‧ S in 1997. This site was characterized by thin sediment covered pillow and sheet lavas with collapsed pits up to ˜15 m in diameter. There were three warm water vents (temperature: 6.5 to 10.5 °C) within the site above which the vented fluids rise as plumes. To estimate heat flux of the warm water vents, a temperature logger array was deployed and the vertical temperature distribution in the water column up to 38 m above the seafloor was monitored. A stationary deep seafloor observatory system was also deployed to monitor hydrothermal activity in this site. The temperature logger array measured temperature anomalies, while the plumes from the vents passed through the array. Because the temperature anomalies were measured in only specific current directions, we identified one of the vents as the source. Heat flux from the vent was estimated by applying a plume model in crossflow in a density-stratified environment. The average heat flux from September 13 to October 18, 1997 was 39 MW. This heat flux is as same order as those of high-temperature black smokers, indicating that a large volume flux was discharged from the vent (1.9 m3/s). Previous observations found many similar warm water flow vents along the spreading axis between 17°20‧ S 30‧ S. The total heat flux was estimated to be at least a few hundred mega-watts. This venting style would contribute to form effluent hydrothermal plumes extended above the spreading axis.

  17. Quick estimate of the heat transfer characteristics of annular fins of hyperbolic profile with the power series method

    International Nuclear Information System (INIS)

    Arauzo, Inmaculada; Campo, Antonio; Cortes, Cristobal

    2005-01-01

    This technical paper addresses an elementary analytic procedure for the approximate solution of the quasi-one-dimensional heat conduction equation (a generalized Bessel equation) that governs the temperature variation in annular fins of hyperbolic profile. This fin shape is of remarkable importance because its heat transfer performance is close to that of the annular fin of convex parabolic profile, the so-called optimal annular fin that is capable of delivering maximum heat transfer for a given volume of material [Zeitschrift des Vereines Deutscher Ingenieure 70 (1926) 885]. The salient feature of the analytic procedure developed here is that for realistic combinations of the two parameters: the enlarged Biot number and the normalized radii ratio, the truncated power series solutions embracing a moderate number of terms yields unprecedented results of excellent quality. The analytic results are conveniently presented in terms of the two primary quantities of interest in thermal design applications, namely the heat transfer rates and the tip temperature

  18. Estimation of heat rejection based on the air conditioner use time and its mitigation from buildings in Taipei City

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, Chun-Ming; Aramaki, Toshiya; Hanaki, Keisuke [The University of Tokyo, Bunkyo-ku, Tokyo (Japan). Department of Urban Engineering

    2007-09-15

    The main work in the research focuses on the analysis and mitigation of the anthropogenic heat discharged from buildings, which is one of the main reasons leading to the heat island effect. The residential and commercial buildings, divided into 10 categories, with HVAC systems were analyzed by the building energy program, EnergyPlus. With the help of GIS, the heat rejection of all the residential and commercial buildings in DaAn Ward of Taipei City were evaluated, in which the spatial data and diurnal variation of the heat rejection were described by 3-h time periods. Furthermore, the effect of mitigation strategies was discussed. The first strategy was to change the wall/roof material of building envelope. The second and third strategies, from the viewpoint of energy saving, were to change the temperature setting of air conditioners and to turn off the lighting and equipment when not in use. The fourth strategy was to use a better efficiency of the cooling systems. Finally, the evaluation of installing the water-cooled cooling system, which discharges heat in the form of sensible and latent heat, was also included. (author)

  19. A direct estimate of poleward volume, heat, and freshwater fluxes at 59.5°N between Greenland and Scotland

    Science.gov (United States)

    Rossby, T.; Reverdin, Gilles; Chafik, Leon; Søiland, Henrik

    2017-07-01

    The meridional overturning circulation (MOC) in the North Atlantic plays a major role in the transport of heat from low to high latitudes. In this study, we combine recent measurements of currents from the surface to >700 m from a shipboard acoustic Doppler current profiler with Argo profiles (to 2000 m) to estimate poleward volume, heat, and freshwater flux at 59.5°N between Greenland and Scotland. This is made possible thanks to the vessel Nuka Arctica that operates on a 3 week schedule between Greenland and Denmark. For the period late 2012 to early 2016, the deseasoned mean meridional overturning circulation reaches a 18.4 ± 3.4 Sv maximum at the σθ = 27.55 kg m-3 isopycnal, which varies in depth from near the surface in the western Irminger Sea to 1000 m in Rockall Trough. The total heat and freshwater fluxes across 59.5°N = 399 ± 74 TW and -0.20 ± 0.04 Sv, where the uncertainties are principally due to that of the MOC. Analysis of altimetric sea surface height variations along exactly the same route reveals a somewhat stronger geostrophic flow north during this period compared to the 23 year mean suggesting that for a long-term mean the above flux estimates should be reduced slightly to 17.4 Sv, 377 TW, and -0.19 Sv, respectively, with the same estimate uncertainties. The ADCP program is ongoing.

  20. Occupational heat stress and associated productivity loss estimation using the PHS model (ISO 7933: a case study from workplaces in Chennai, India

    Directory of Open Access Journals (Sweden)

    Karin Lundgren

    2014-11-01

    Full Text Available Background: Heat stress is a major occupational problem in India that can cause adverse health effects and reduce work productivity. This paper explores this problem and its impacts in selected workplaces, including industrial, service, and agricultural sectors in Chennai, India. Design: Quantitative measurements of heat stress, workload estimations, and clothing testing, and qualitative information on health impacts, productivity loss, etc., were collected. Heat strain and associated impacts on labour productivity between the seasons were assessed using the International Standard ISO 7933:2004, which applies the Predicted Heat Strain (PHS model. Results and conclusions: All workplaces surveyed had very high heat exposure in the hot season (Wet Bulb Globe Temperature x¯ =29.7, often reaching the international standard safe work values (ISO 7243:1989. Most workers had moderate to high workloads (170–220 W/m2, with some exposed to direct sun. Clothing was found to be problematic, with high insulation values in relation to the heat exposure. Females were found to be more vulnerable because of the extra insulation added from wearing a protective shirt on top of traditional clothing (0.96 clo while working. When analysing heat strain – in terms of core temperature and dehydration – and associated productivity loss in the PHS model, the parameters showed significant impacts that affected productivity in all workplaces, apart from the laundry facility, especially during the hot season. For example, in the canteen, the core temperature limit of 38°C predicted by the model was reached in only 64 min for women. With the expected increases in temperature due to climate change, additional preventive actions have to be implemented to prevent further productivity losses and adverse health impacts. Overall, this study presented insight into using a thermo-physiological model to estimate productivity loss due to heat exposure in workplaces. This is the

  1. Occupational heat stress and associated productivity loss estimation using the PHS model (ISO 7933): a case study from workplaces in Chennai, India

    Science.gov (United States)

    Lundgren, Karin; Kuklane, Kalev; Venugopal, Vidhya

    2014-01-01

    Background Heat stress is a major occupational problem in India that can cause adverse health effects and reduce work productivity. This paper explores this problem and its impacts in selected workplaces, including industrial, service, and agricultural sectors in Chennai, India. Design Quantitative measurements of heat stress, workload estimations, and clothing testing, and qualitative information on health impacts, productivity loss, etc., were collected. Heat strain and associated impacts on labour productivity between the seasons were assessed using the International Standard ISO 7933:2004, which applies the Predicted Heat Strain (PHS) model. Results and conclusions All workplaces surveyed had very high heat exposure in the hot season (Wet Bulb Globe Temperature x¯ =29.7), often reaching the international standard safe work values (ISO 7243:1989). Most workers had moderate to high workloads (170–220 W/m2), with some exposed to direct sun. Clothing was found to be problematic, with high insulation values in relation to the heat exposure. Females were found to be more vulnerable because of the extra insulation added from wearing a protective shirt on top of traditional clothing (0.96 clo) while working. When analysing heat strain – in terms of core temperature and dehydration – and associated productivity loss in the PHS model, the parameters showed significant impacts that affected productivity in all workplaces, apart from the laundry facility, especially during the hot season. For example, in the canteen, the core temperature limit of 38°C predicted by the model was reached in only 64 min for women. With the expected increases in temperature due to climate change, additional preventive actions have to be implemented to prevent further productivity losses and adverse health impacts. Overall, this study presented insight into using a thermo-physiological model to estimate productivity loss due to heat exposure in workplaces. This is the first time the PHS

  2. Urban mining: quality and quantity of recyclable and recoverable material mechanically and physically extractable from residual waste.

    Science.gov (United States)

    Di Maria, Francesco; Micale, Caterina; Sordi, Alessio; Cirulli, Giuseppe; Marionni, Moreno

    2013-12-01

    The mechanically sorted dry fraction (MSDF) and Fines (waste (RMSW) contains respectively about 11% w/w each of recyclable and recoverable materials. Processing a large sample of MSDF in an existing full-scale mechanical sorting facility equipped with near infrared and 2-3 dimensional selectors led to the extraction of about 6% w/w of recyclables with respect to the RMSW weight. Maximum selection efficiency was achieved for metals, about 98% w/w, whereas it was lower for Waste Electrical and Electronic Equipment (WEEE), about 2% w/w. After a simulated lab scale soil washing treatment it was possible to extract about 2% w/w of inert exploitable substances recoverable as construction materials, with respect to the amount of RMSW. The passing curve showed that inert materials were mainly sand with a particle size ranging from 0.063 to 2mm. Leaching tests showed quite low heavy metal concentrations with the exception of the particles retained by the 0.5mm sieve. A minimum pollutant concentration was in the leachate from the 10 and 20mm particle size fractions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. On-line estimation of the metabolic burden resulting from the synthesis of plasmid-encoded and heat-shock proteins by monitoring respiratory energy generation.

    Science.gov (United States)

    Hoffmann, F; Rinas, U

    2001-12-01

    Human basic fibroblast growth factor (hFGF-2) was produced in high-cell density cultures of recombinant Escherichia coli using a temperature-inducible expression system. The synthesis rates of proteins were followed by two-dimensional gel electrophoresis of the (35)S-methionine-labeled proteom. After temperature induction of hFGF-2 synthesis, the rate of total protein synthesis per biomass increased by a factor of three, mainly as a result of the additional synthesis of hFGF-2 and heat-shock proteins. The synthesis rates of heat-shock proteins and constitutive plasmid-encoded proteins increased after the temperature upshift also in the control strain without hFGF-2 gene but followed time profiles different from the producing strain. The energy demand for the extra synthesis of plasmid-encoded and heat-shock proteins resulted in an elevated respiratory activity and, consequently, in a reduction of the growth rate and the biomass yield. A procedure was developed to relate the energy demand for the additional synthesis of these proteins to the generation of energy in the respiratory pathway. Specific energy production was estimated based on on-line measurable rates of oxygen consumption, or carbondioxide evolution and growth, respectively. In this way, the metabolic burden resulting from the synthesis of plasmid-encoded and heat-shock proteins was quantified from on-line accessible data. Copyright 2001 John Wiley & Sons, Inc.

  4. Estimation of time to rupture in a fire using 6FIRE, a lumped parameter UF6 cylinder transient heat transfer/stress analysis model

    International Nuclear Information System (INIS)

    Williams, W.R.; Anderson, J.C.

    1995-01-01

    The transportation of UF 6 is subject to regulations requiring the evaluation of packaging under a sequence of hypothetical accident conditions including exposure to a 30-min 800 degree C (1475 degree F) fire [10 CFR 71.73(c)(3)]. An issue of continuing interest is whether bare cylinders can withstand such a fire without rupturing. To address this issue, a lumped parameter heat transfer/stress analysis model (6FIRE) has been developed to simulate heating to the point of rupture of a cylinder containing UF 6 when it is exposed to a fire. The model is described, then estimates of time to rupture are presented for various cylinder types, fire temperatures, and fill conditions. An assessment of the quantity of UF 6 released from containment after rupture is also presented. Further documentation of the model is referenced

  5. On the Equality Assumption of Latent and Sensible Heat Energy Transfer Coefficients of the Bowen Ratio Theory for Evapotranspiration Estimations: Another Look at the Potential Causes of Inequalities

    Directory of Open Access Journals (Sweden)

    Suat Irmak

    2014-08-01

    Full Text Available Evapotranspiration (ET and sensible heat (H flux play a critical role in climate change; micrometeorology; atmospheric investigations; and related studies. They are two of the driving variables in climate impact(s and hydrologic balance dynamics. Therefore, their accurate estimate is important for more robust modeling of the aforementioned relationships. The Bowen ratio energy balance method of estimating ET and H diffusions depends on the assumption that the diffusivities of latent heat (KV and sensible heat (KH are always equal. This assumption is re-visited and analyzed for a subsurface drip-irrigated field in south central Nebraska. The inequality dynamics for subsurface drip-irrigated conditions have not been studied. Potential causes that lead KV to differ from KH and a rectification procedure for the errors introduced by the inequalities were investigated. Actual ET; H; and other surface energy flux parameters using an eddy covariance system and a Bowen Ratio Energy Balance System (located side by side on an hourly basis were measured continuously for two consecutive years for a non-stressed and subsurface drip-irrigated maize canopy. Most of the differences between KV and KH appeared towards the higher values of KV and KH. Although it was observed that KV was predominantly higher than KH; there were considerable data points showing the opposite. In general; daily KV ranges from about 0.1 m2∙s−1 to 1.6 m2∙s−1; and KH ranges from about 0.05 m2∙s−1 to 1.1 m2∙s−1. The higher values for KV and KH appear around March and April; and around September and October. The lower values appear around mid to late December and around late June to early July. Hourly estimates of KV range between approximately 0 m2∙s−1 to 1.8 m2∙s−1 and that of KH ranges approximately between 0 m2∙s−1 to 1.7 m2∙s−1. The inequalities between KV and KH varied diurnally as well as seasonally. The inequalities were greater during the non

  6. A simple mathematical procedure to estimate heat flux in machining using measured surface temperature with infrared laser

    Directory of Open Access Journals (Sweden)

    Hocine Mzad

    2015-09-01

    Full Text Available Several techniques have been developed over time for the measurement of heat and the temperatures generated in various manufacturing processes and tribological applications. Each technique has its own advantages and disadvantages. The appropriate technique for temperature measurement depends on the application under consideration as well as the available tools for measurement. This paper presents a procedure for a simple and accurate determination of the time-varying heat flux at the workpiece–tool interface of three different metals under known cutting conditions. A portable infrared thermometer is used for surface temperature measurements. A spline smoothing interpolation of the surface temperature history enables to determine the local heat flux produced during stock removal. The measured temperature is represented by a third-order spline approximation. Nonetheless, the accuracy of polynomial interpolation depends on how close are the interpolated points; an increase in degree cannot be used to increase the accuracy. Although the data analysis is relatively complicated, the computing time is very small.

  7. The direction of turbulent heat flux by a direct measurement was opposite to an indirect estimation over calm oceans in summer

    Science.gov (United States)

    Ando, Y.; Tachibana, Y.; Konda, M.; Maekawa, Y.; Nakamura, T.; Okada, K.

    2016-12-01

    In order to understand the air-sea interaction in the climate system, a direct measurement of turbulent flux (the eddy covariance method) is necessary as well as an indirect estimate of that, for example, the bulk method. However, it is rarely experienced due to many difficulties over a long period. The most of the difficulties comes from the moving platform, which is not fixed as over land because the anemometer moves with the platform as the ship moves. The ship motion correction for the wind velocity is a very difficult issue. On the top of the foremast of the training ship SEISUIMARU (Mie University, Japan), the developed on-board eddy covariance system was installed in 2009. The training ship SEISUIMARU cruises the northwest Pacific Ocean, especially the coast of Japan every year. This system is routinely operating in her whole cruises. When these kind of continuous measurements are integrated in these areas, reliable direct measurement of turbulent flux database can be established.We compared the turbulent heat fluxes using the bulk method and those of the eddy covariance method using this database. The results were some differences in certain conditions. In some cases, the direction of the turbulent heat fluxes was opposite. This might be caused by the sea surface temperatures (SSTs) using the bulk method were temperatures at the depth of 3 meter instead of the surface temperatures. SSTs are warmer than bulk 3 meter temperatures in high-level solar radiation and low-wind conditions, as expected due to the sea surface warming effects over calm oceans in summer. The difference of the turbulent heat fluxes using the eddy covariance method and those of the bulk method was positively correlated with the solar radiation. Moreover, the difference was negatively correlated with the surface wind speed. These results were more clear in the sensible heat fluxes than that of the latent heat fluxes. These results suggest one of difference of the turbulent heat fluxes

  8. Urban Mining: Quality and quantity of recyclable and recoverable material mechanically and physically extractable from residual waste

    International Nuclear Information System (INIS)

    Di Maria, Francesco; Micale, Caterina; Sordi, Alessio; Cirulli, Giuseppe; Marionni, Moreno

    2013-01-01

    Highlights: • Material recycling and recovery from residual waste by physical and mechanical process has been investigated. • About 6% of recyclable can be extracted by NIR and 2-3Dimension selector. • Another 2% of construction materials can be extracted by adopting modified soil washing process. • Extracted material quality is quite high even some residual heavy metal have been detected by leaching test. - Abstract: The mechanically sorted dry fraction (MSDF) and Fines (<20 mm) arising from the mechanical biological treatment of residual municipal solid waste (RMSW) contains respectively about 11% w/w each of recyclable and recoverable materials. Processing a large sample of MSDF in an existing full-scale mechanical sorting facility equipped with near infrared and 2-3 dimensional selectors led to the extraction of about 6% w/w of recyclables with respect to the RMSW weight. Maximum selection efficiency was achieved for metals, about 98% w/w, whereas it was lower for Waste Electrical and Electronic Equipment (WEEE), about 2% w/w. After a simulated lab scale soil washing treatment it was possible to extract about 2% w/w of inert exploitable substances recoverable as construction materials, with respect to the amount of RMSW. The passing curve showed that inert materials were mainly sand with a particle size ranging from 0.063 to 2 mm. Leaching tests showed quite low heavy metal concentrations with the exception of the particles retained by the 0.5 mm sieve. A minimum pollutant concentration was in the leachate from the 10 and 20 mm particle size fractions

  9. Estimation of grass reference evaporation and sensible heat flux using surface renewal and Monin-Obukhov similarity theory: A simple implementation of an iterative method

    Science.gov (United States)

    Savage, M. J.

    2017-04-01

    An iterative method was applied to daily crop reference evaporation ETo. The method correctly evaluated the slope of the saturation water vapour pressure vs temperature relationship between surface temperature and air temperature. Using daily meterological data spanning several decades from four selected locations in Australia, South Africa and USA, differences in ETo estimates were noted with and without the iteration method applied. The largest difference, which occurred under high water vapour pressure deficit conditions, ranged from 1.65 mm/day for Griffith, Australia to 0.51 mm/day for Pretoria, South Africa. The aerodynamic component of the ETo equation was more affected by not applying the spreadsheet iterative procedure compared to the radiative component. Other spreadsheet examples of the iterative method employed included obtaining the roots of a depressed cubic polynomial in the air temperature surface renewal (SR) ramp. This value was used for the measurement of sensible heat flux using surface renewal. An iterative method, together with Monin-Obukhov similarity theory (MOST) and surface-layer scintillometer (SLS) measurements in a mesic grassland, was also used to calculate the sensible heat flux. The simple iterative method is quick, accurate and convenient, easy to repeat following changes to equations or data, allows easy manipulation and allows convenient visual inspection of data and graphics. Sub-hourly measurements of sensible heat flux for the mesic grassland using SR and SLS MOST iterative methods compared favourably with Bowen ratio and eddy covariance measurements.

  10. A direct estimate of poleward volume, heat and fresh water flux at 59.5°N between Greenland and Scotland

    Science.gov (United States)

    Rossby, Thomas; Reverdin, Gilles; Chafik, Leon; Søiland, Henrik

    2017-04-01

    The meridional overturning circulation (MOC) in the North Atlantic plays a major role in the transport of heat from low latitudes to high. In this study we combine recent measurements of currents from the surface to >700 m from a shipboard acoustic Doppler current profiler on the Nuka Arctica, a freighter in regular service between Greenland and Denmark with Argo profiles (to 2000 m) to estimate poleward volume, heat and freshwater flux at 59.5°N between Greenland and Scotland. For the period late 2012 to early 2016 the de-seasoned mean meridional overturning circulation reaches a 14.9±1.7 Sv maximum at the σθ = 27.55 kg m-3 isopycnal, which varies in depth from near the surface in the western Irminger Sea to 1000 m in Rockall Trough. The surface to bottom transport has a -0.44 Sv (southward) residual, which is not significantly different from zero. The total heat and fresh water fluxes across 59.5°N = 307 PW and 0.15 Sv, both with a 12% uncertainty principally due to uncertainties of the MOC. Comparing this ADCP dataset with an earlier one of comparable size from 1999-2002 (to 400 m depth only) shows strikingly similar transports in both west and east of the Reykjanes Ridge suggesting at least for these two periods 13 years apart very little difference in the strength of the MOC.

  11. The effect of misleading surface temperature estimations on the sensible heat fluxes at a high Arctic site – the Arctic Turbulence Experiment 2006 on Svalbard (ARCTEX-2006

    Directory of Open Access Journals (Sweden)

    J. Lüers

    2010-01-01

    Full Text Available The observed rapid climate warming in the Arctic requires improvements in permafrost and carbon cycle monitoring, accomplished by setting up long-term observation sites with high-quality in-situ measurements of turbulent heat, water and carbon fluxes as well as soil physical parameters in Arctic landscapes. But accurate quantification and well adapted parameterizations of turbulent fluxes in polar environments presents fundamental problems in soil-snow-ice-vegetation-atmosphere interaction studies. One of these problems is the accurate estimation of the surface or aerodynamic temperature T(0 required to force most of the bulk aerodynamic formulae currently used. Results from the Arctic-Turbulence-Experiment (ARCTEX-2006 performed on Svalbard during the winter/spring transition 2006 helped to better understand the physical exchange and transport processes of energy. The existence of an atypical temperature profile close to the surface in the Arctic spring at Svalbard could be proven to be one of the major issues hindering estimation of the appropriate surface temperature. Thus, it is essential to adjust the set-up of measurement systems carefully when applying flux-gradient methods that are commonly used to force atmosphere-ocean/land-ice models. The results of a comparison of different sensible heat-flux parameterizations with direct measurements indicate that the use of a hydrodynamic three-layer temperature-profile model achieves the best fit and reproduces the temporal variability of the surface temperature better than other approaches.

  12. Latent Heat Flux Estimate Through an Energy Water Balance Model and Land Surface Temperature from Remote Sensing

    Science.gov (United States)

    Corbari, Chiara; Sobrino, Jose A.; Mancini, Marco; Hidalgo, Victoria

    2011-01-01

    Soil moisture plays a key role in the terrestrial water cycle and is responsible for the partitioning of precipitation between runoff and infiltration. Moreover, surface soil moisture controls the redistribution of the incoming solar radiation on land surface into sensible and latent heat fluxes. Recent developments have been made to improve soil moisture dynamics predictions with hydrologic land surface models (LSMs) that compute water and energy balances between the land surface and the low atmosphere. However, most of the time soil moisture is confined to an internal numerical model variable mainly due to its intrinsic space and time variability and to the well known difficulties in assessing its value from remote sensing as from in situ measurements. In order to exploit the synergy between hydrological distributed models and thermal remote sensed data, FEST-EWB, a land surface model that solves the energy balance equation, was developed. In this hydrological model, the energy budget is solved looking for the representative thermodynamic equilibrium temperature (RET) defined as the land surface temperature that closes the energy balance equation. So using this approach, soil moisture is linked to the latent heat flux and then to LST. In this work the relationship between land surface temperature and soil moisture is analysed using LST from AHS (airborne hyperspectral scanner), with a spatial resolution of 2-4 m, LST from MODIS, with a spatial resolution of 1000 m, and thermal infrared radiometric ground measurements that are compared with the thermodynamic equilibrium temperature from the energy water balance model. Moreover soil moisture measurements were carried out during the airborne overpasses and then compared with SM from the hydrological model. An improvement of this well known inverse relationship between soil moisture and land surface temperature is obtained when the thermodynamic approach is used. The analysis of the scale effects of the different

  13. Estimation of the soil heat flux/net radiation ratio based on spectral vegetation indexes in high-latitude Arctic areas

    International Nuclear Information System (INIS)

    Jacobsen, A.; Hansen, B.U.

    1999-01-01

    The vegetation communities in the Arctic environment are very sensitive to even minor climatic variations and therefore the estimation of surface energy fluxes from high-latitude vegetated areas is an important subject to be pursued. This study was carried out in July-August and used micro meteorological data, spectral reflectance signatures, and vegetation biomass to establish the relation between the soil heat flux/net radiation (G / Rn) ratio and spectral vegetation indices (SVIs). Continuous measurements of soil temperature and soil heat flux were used to calculate the surface ground heat flux by use of conventional methods, and the relation to surface temperature was investigated. Twenty-seven locations were established, and six samples per location, including the measurement of the surface temperature and net radiation to establish the G/Rn ratio and simultaneous spectral reflectance signatures and wet biomass estimates, were registered. To obtain regional reliability, the locations were chosen in order to represent the different Arctic vegetation communities in the study area; ranging from dry tundra vegetation communities (fell fields and dry dwarf scrubs) to moist/wet tundra vegetation communities (snowbeds, grasslands and fens). Spectral vegetation indices, including the simple ratio vegetation index (RVI) and the normalized difference vegetation index (NDVI), were calculated. A comparison of SVIs to biomass proved that RVI gave the best linear expression, and NDVI the best exponential expression. A comparison of SVIs and the surface energy flux ratio G / Rn proved that NDVI gave the best linear expression. SPOT HRV images from July 1989 and 1992 were used to map NDVI and G / Rn at a regional scale. (author)

  14. Estimation of non-linear continuous time models for the heat exchange dynamics of building integrated photovoltaic modules

    DEFF Research Database (Denmark)

    Jimenez, M.J.; Madsen, Henrik; Bloem, J.J.

    2008-01-01

    This paper focuses on a method for linear or non-linear continuous time modelling of physical systems using discrete time data. This approach facilitates a more appropriate modelling of more realistic non-linear systems. Particularly concerning advanced building components, convective and radiative...... heat interchanges are non-linear effects and represent significant contributions in a variety of components such as photovoltaic integrated facades or roofs and those using these effects as passive cooling strategies, etc. Since models are approximations of the physical system and data is encumbered...... with measurement errors it is also argued that it is important to consider stochastic models. More specifically this paper advocates for using continuous-discrete stochastic state space models in the form of non-linear partially observed stochastic differential equations (SDE's)-with measurement noise...

  15. Estimation of energetic efficiency of heat supply in front of the aircraft at supersonic accelerated flight. Part II. Mathematical model of the trajectory boost part and computational results

    Science.gov (United States)

    Latypov, A. F.

    2009-03-01

    The fuel economy was estimated at boost trajectory of aerospace plane during energy supply to the free stream. Initial and final velocities of the flight were given. A model of planning flight above cold air in infinite isobaric thermal wake was used. The comparison of fuel consumption was done at optimal trajectories. The calculations were done using a combined power plant consisting of ramjet and liquid-propellant engine. An exergy model was constructed in the first part of the paper for estimating the ramjet thrust and specific impulse. To estimate the aerodynamic drag of aircraft a quadratic dependence on aerodynamic lift is used. The energy for flow heating is obtained at the sacrifice of an equivalent decrease of exergy of combustion products. The dependencies are obtained for increasing the range coefficient of cruise flight at different Mach numbers. In the second part of the paper, a mathematical model is presented for the boost part of the flight trajectory of the flying vehicle and computational results for reducing the fuel expenses at the boost trajectory at a given value of the energy supplied in front of the aircraft.

  16. Gene expression programming approach for the estimation of moisture ratio in herbal plants drying with vacuum heat pump dryer

    Science.gov (United States)

    Dikmen, Erkan; Ayaz, Mahir; Gül, Doğan; Şahin, Arzu Şencan

    2017-07-01

    The determination of drying behavior of herbal plants is a complex process. In this study, gene expression programming (GEP) model was used to determine drying behavior of herbal plants as fresh sweet basil, parsley and dill leaves. Time and drying temperatures are input parameters for the estimation of moisture ratio of herbal plants. The results of the GEP model are compared with experimental drying data. The statistical values as mean absolute percentage error, root-mean-squared error and R-square are used to calculate the difference between values predicted by the GEP model and the values actually observed from the experimental study. It was found that the results of the GEP model and experimental study are in moderately well agreement. The results have shown that the GEP model can be considered as an efficient modelling technique for the prediction of moisture ratio of herbal plants.

  17. Regional Economic Resilience: Resistance and Recoverability of Resource-Based Cities during Economic Crises in Northeast China

    Directory of Open Access Journals (Sweden)

    Juntao Tan

    2017-11-01

    Full Text Available This paper quantitatively analyzes the economic resilience of resource-based cities (RBCs in Northeast China in terms of resistance and recoverability during two economic crises: the Asian financial crisis and the global financial crisis. Moreover, it analyzes the main factors that affected regional resilience. There are three main findings. First, the RBCs in general demonstrated poor resistance during both recessions, but there were variations among the different types of RBCs. Petroleum and metal cities demonstrated the most resistance, whereas coal cities performed the worst. Second, the influential factors affecting economic resilience varied across the two economic cycles, but location advantage, research and development (R and D intensity, foreign trade dependence ratio, and supporting policies had positive effects on resilience during both economic cycles, while the proportion of employed persons in resource industries had a negative effect. Industrial diversity had a weak and ambiguous effect on resilience. Third, the secondary industry was more resilient during the Asian financial crisis, but the tertiary industry was more resilient during the global financial crisis. This shift may be attributed to both the nature of the crises and the strength of the sectors at the time of the crises.

  18. Magnetic recoverable Fe3O4-TiO2:Eu composite nanoparticles with enhanced photocatalytic activity

    Science.gov (United States)

    Stefan, M.; Leostean, C.; Pana, O.; Toloman, D.; Popa, A.; Perhaita, I.; Senilă, M.; Marincas, O.; Barbu-Tudoran, L.

    2016-12-01

    This work refers to the influence of Eu doping on the morphologic, structural and compositional properties of magnetic separable Fe3O4-TiO2 composite nanoparticles with photocatalytic activity. In this respect, Fe3O4-TiO2:Eu nanocomposites were prepared by seed mediated growth of TiO2:Eu through a sol-gel method onto preformed magnetite resulted from co-precipitation method. Different Eu concentration precursors were used for doping. The thermal behavior and the conversion of precursors into corresponding Fe3O4-TiO2:Eu composite nanoparticles were evidenced by FT-IR spectra and thermal analysis. The XRD, XPS and HRTEM investigations results indicate that nanocomposites contain besides Fe3O4-TiO2:Eu some amounts of iron titanate. Formation of FeTiO3 is suppressed by the increase of Eu doping level. Magnetic studies also indicated that nanocomposite exhibit superparamagnetic behavior at room temperature. The large surface area and mesoporous structure of magnetic nanocomposite were confirmed by the surface area (BET) and porosity measurements. It was demonstrated that the composite nanoparticles exhibit good photocatalytic activity toward the degradation of RhB solution and they can be used as efficient and conveniently recoverable photocatalyst.

  19. Photocatalytic degradation of organic contaminants by g-C3N4/EPDM nanocomposite film: Viable, efficient and facile recoverable.

    Science.gov (United States)

    Selvam, V; Senthil Kumar, P; Navaneetha Krishnan, G; Senthil Andavan, G T

    2018-03-01

    The original metal free graphitic carbon nitride/ethylene propylene diene monomer nanocomposite film (g-C 3 N 4 /EPDM NCF) was fabricated by facile solution cast method. g-C 3 N 4 /EPDM NCF with diameter (50mm) and thickness (4mm) was investigated towards the photocatalytic degradation of methylene blue (MB) and methyl orange (MO) dye solution under visible light irradiation. The as synthesized g-C 3 N 4 /EPDM NCF was exhibited high crystalline nature with the crystalline size of 21.53nm, the smooth surface nature and the particle size was observed from the TEM analysis is 20nm. Furthermore, the influence of operational parameters was carried out which demonstrated that 100mg photocatalyst and 25μM of dye concentration were obtained as an optimized condition for the best photocatalytic degradation results. As a result of scavenger experiment, it was concluded that the hydroxyl radical (OH) was actively involved in the photocatalytic degradation. The g-C 3 N 4 /EPDM NCF were recoverable from the photocatalytic reaction system and the present find findings may open up a new platform for the simple handpicked photocatalyst. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. The impact of in-canopy wind profile formulations on heat flux estimation in an open orchard using the remote sensing-based two-source model

    Directory of Open Access Journals (Sweden)

    C. Cammalleri

    2010-12-01

    Full Text Available For open orchard and vineyard canopies containing significant fractions of exposed soil (>50%, typical of Mediterranean agricultural regions, the energy balance of the vegetation elements is strongly influenced by heat exchange with the bare soil/substrate. For these agricultural systems a "two-source" approach, where radiation and turbulent exchange between the soil and canopy elements are explicitly modelled, appears to be the only suitable methodology for reliably assessing energy fluxes. In strongly clumped canopies, the effective wind speed profile inside and below the canopy layer can strongly influence the partitioning of energy fluxes between the soil and vegetation components. To assess the impact of in-canopy wind profile on model flux estimates, an analysis of three different formulations is presented, including algorithms from Goudriaan (1977, Massman (1987 and Lalic et al. (2003. The in-canopy wind profile formulations are applied to the thermal-based two-source energy balance (TSEB model developed by Norman et al. (1995 and modified by Kustas and Norman (1999. High resolution airborne remote sensing images, collected over an agricultural area located in the western part of Sicily (Italy comprised primarily of vineyards, olive and citrus orchards, are used to derive all the input parameters needed to apply the TSEB. The images were acquired from June to October 2008 and include a relatively wide range of meteorological and soil moisture conditions. A preliminary sensitivity analysis of the three wind profile algorithms highlights the dependence of wind speed just above the soil/substrate to leaf area index and canopy height over the typical range of canopy properties encountered in these agricultural areas. It is found that differences among the models in wind just above the soil surface are most significant under sparse and medium fractional cover conditions (15–50%. The TSEB model heat flux estimates are compared with micro

  1. Heat Roadmap Europe

    DEFF Research Database (Denmark)

    Hansen, Kenneth; Connolly, David; Lund, Henrik

    2015-01-01

    The cost of heat savings in buildings increase as more heat savings are achieved due to the state of the building stock and hence, alternatives other than savings typically become more economically feasible at a certain level of heat reductions. It is important to identify when the cost of heat...... savings become more expensive than the cost of sustainable heat supply, so society does not overinvest in heat saving measures. This study first investigates the heat saving potentials for different countries in Europe, along with their associated costs, followed by a comparison with alternative ways...... of supplying sustainable heating. Different heat production options are included in terms of individual and community heating systems. Furthermore, the levelised cost of supplying sustainable heat is estimated for both a single technology and from an energy system perspective. The results are analysed...

  2. One-pot hydrothermal synthesis and characterization of CoFe{sub 2}O{sub 4} nanoparticles and its application as magnetically recoverable catalyst in oxidation of alcohols by periodic acid

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Bappi; Purkayastha, Debraj Dhar; Dhar, Siddhartha Sankar, E-mail: ssd_iitg@hotmail.com

    2016-09-15

    A novel and facile approach for one-pot synthesis of spinel cobalt ferrite (CoFe{sub 2}O{sub 4}) nanoparticles (NPs) is presented here. The synthesis involves homogeneous chemical precipitation followed by hydrothermal heating, using tributylamine (TBA) as a hydroxylating agent. Polyethylene glycol (PEG) 4000 was used as surfactant. As-synthesized CoFe{sub 2}O{sub 4} NPs were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), N{sub 2} adsorption-desorption isotherm (BET) and vibrating sample magnetometry (VSM). TEM image showed formation of spherical particles of sizes 2–30 nm. These NPs were used as magnetically recoverable catalyst in oxidation of alcohols to their corresponding aldehydes by periodic acid. This oxidative procedure is found to be highly efficient affording products in very high yield and selectivity. The easy magnetic separation of the catalyst and efficient reusability are key features of this methodology. - Highlights: • Hydrothermal synthesis of CoFe{sub 2}O{sub 4} NPs with (C{sub 4}H{sub 9}){sub 3}N as hydroxylating agent. • The TEM images showed the particles to be spherical in shape with sizes 2–30 nm. • CoFe{sub 2}O{sub 4} was used as recyclable catalyst for oxidation of alcohols by periodic acid.

  3. Resource Assessment of the In-Place and Potentially Recoverable Deep Natural Gas Resource of the Onshore Interior Salt Basins, North Central and Northeastern Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini

    2006-09-30

    rock from depths below 12,000 feet in this basin is 4,800 TCF. Assuming an expulsion, migration and trapping efficiency of 1 to 5%, 48 to 240 TCF of gas is potentially available. The final recoverable gas is some percent of this estimated thermogenic gas resource based on the recovery factor for the specific reservoir. To date, some 29 TCF of gas have been produced from this basin. Also, the thermogenic gas, whether generated from late secondary cracking of oil to gas in the source rock or from oil to gas conversion in deeply buried reservoirs, migrated updip into shallower reservoirs, including the Monroe gas rock at depths of some 2,000 feet.

  4. Method to allow the estimation of heat transfer coefficients in solar stills; Metodo para determinar coeficientes locales de transferencia de calor en destiladores solares

    Energy Technology Data Exchange (ETDEWEB)

    Rubio Cerda, Eduardo; Porta Gandara, Miguel A [CIBNOR, Mexico D.F (Mexico); Fernandez Zayas, Jose Luis [UNAM Mexico, D.F. (Mexico)

    2000-07-01

    This work reports an experimental method that allows to estimate the heat transfer coefficients in the neighborhood of walls or flat plates subject to convective transport phenomena. This method can be applied to a great variety of thermal systems since it is based on the knowledge of the border condition for the temperature at the surface of the plate, and the temperature profile that characterize the dimensionless coefficient of heat transfer in the fluid, according to its definition given by the Nusselt number. The approach of this work are the foundations of the method and the system that has been developed to apply it, that incorporates automatic acquisition equipment for continuos monitoring of the information and elements to control the parameters of interest. In addition, the experimental cavities on which the method will be evaluated are discussed, considering two different scales, as well as experiments in cavities filled with air, and with a mixture of air and steam water, as is the case for solar distillation. [Spanish] En este trabajo se presenta un metodo que permite determinar de manera experimental coeficientes de transferencia de calor por conveccion. Este metodo puede ser aplicado a una gran variedad de sistemas termicos ya que se fundamenta en el conocimiento de la condicion de frontera para la temperatura en la superficie de la placa, y del perfil de temperaturas que caracteriza el coeficiente adimensional de transferencia de calor en el fluido, de acuerdo a la definicion de este, dada por el numero de Nusselt. El trabajo que aqui se reporta esta enfocado a la fundamentacion del metodo y al equipamiento que se ha desarrollado para instrumentarlo, que incorpora equipos automaticos de adquisicion continua de informacion y elementos de control para los parametros de interes. Se presentan ademas, las cavidades experimentales sobre las que sera evaluado el metodo, que considera dos escalas diferentes, asi como experimentos en cavidades llenas de aire

  5. Meta-analysis of non-renewable energy resource estimates

    International Nuclear Information System (INIS)

    Dale, Michael

    2012-01-01

    This paper offers a review of estimates of ultimately recoverable resources (URR) of non-renewable energy sources: coal, conventional and unconventional oil, conventional and unconventional gas, and uranium for nuclear fission. There is a large range in the estimates of many of the energy sources, even those that have been utilized for a long time and, as such, should be well understood. If it is assumed that the estimates for each resource are normally distributed, then the total value of ultimately recoverable fossil and fissile energy resources is 70,592 EJ. If, on the other hand, the best fitting distribution from each of the resource estimate populations is used, a the total value is 50,702 EJ, a factor of around 30% smaller. - Highlights: ► Brief introduction to categorization of resources. ► Collated over 380 estimates of ultimately recoverable global resources for all non-renewable energy sources. ► Extensive statistical analysis and distribution fitting conducted. ► Cross-energy source comparison of resource magnitudes.

  6. Recoverable neutron absorbers

    International Nuclear Information System (INIS)

    Keay, R.T.; Williams, J.A.

    1982-01-01

    In the reprocessing of irradiated nuclear fuel elements the nuclear fuel material is separated from the material which forms the remainder of the elements by dissolving the nuclear fuel material in nitric acid. Neutron absorbers are added to control criticality. The neutron absorbers comprise pellets each having a core of neutron absorbing material encased in a sheath of a material which is resistant to attack by acid, the core or sheath being magnetic. The sheath protects the core of neutron absorbing material from attack by the acid and the magnetic content of the core or sheath enables the absorbers to be recovered for reuse by magnetic separation techniques. (author)

  7. For a Better Estimation of Gamma Heating in Experimental Reactors and Devices: Stakes and Work Plan from Calculation Methods to Nuclear Data

    International Nuclear Information System (INIS)

    Lemaire, Matthieu; Vaglio-Gaudard, Claire; Lyoussi, Abdallah; Reynard-Carette, Christelle

    2013-06-01

    The Jules Horowitz Reactor (JHR) is an international Material-Testing Reactor currently under construction at CEA Cadarache. The determination of gamma heating levels in this future commercial reactor is of crucial importance as gamma heating affects both safety and performance parameters of the JHR. Required accuracy (5% at one standard deviation) makes it necessary to calibrate bias and uncertainty associated with JHR gamma-heating calculations. Main steps of bias determination for gamma-heating calculations include, firstly, the development of a calculation methodology with controlled use of physical approximations; secondly, the interpretation of gamma-heating measurements so as to determine bias supposed to be only due to nuclear data. (authors)

  8. Preliminary study on peroxidase isoenzyme detection and RAPD molecular verification for sweet pepper 87-2 carried by a recoverable satellite

    International Nuclear Information System (INIS)

    Liu Min; Li Jinguo; Wang Yalin; Zhang Zan; Xue Huai; Zhang Chunhua; Li Sherong

    1999-01-01

    The detection technology of peroxidase isoenzyme pattern and RAPD (Randomly Amplified Polymorphic DNA) analysis were used to space-flown sweet pepper variety of 87-2 carried by a recoverable satellite, and its correspondent ground control Longjiao-2. Determination of peroxidase isoenzyme revealed that the physiological activities of space-flown sweet pepper were significantly higher than those of its ground control. To detect the polymorphism of gene sequence and the difference in molecular level. 42 primers were used, among them, 38 primers amplified polymorphic products, and the amplified products from 5 primers of sweet pepper 87-2 differed from those of ground control

  9. An ensemble estimation of the variability of upper-ocean heat content over the tropical Atlantic Ocean with multi-ocean reanalysis products

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Jieshun [Institute of Global Environment and Society, Center for Ocean-Land-Atmosphere Studies, Calverton, MD (United States); Huang, Bohua [Institute of Global Environment and Society, Center for Ocean-Land-Atmosphere Studies, Calverton, MD (United States); George Mason University, Department of Atmospheric, Oceanic, and Earth Sciences, College of Science, Fairfax, VA (United States); Balmaseda, Magdalena A. [European Center for Medium-Range Weather Forecasts, Reading (United Kingdom)

    2012-08-15

    Current ocean reanalysis systems contain considerable uncertainty in estimating the subsurface oceanic state, especially in the tropical Atlantic Ocean. Given this level of uncertainty, it is important to develop useful strategies to identify realistic low-frequency signals optimally from these analyses. In this paper, we present an ''ensemble'' method to estimate the variability of upper-ocean heat content (HC) in the tropical Atlantic based on multiple-ocean reanalysis products. Six state-of-the-art global ocean reanalysis products, all of which are widely used in the climate research community, are examined in terms of their HC variability from 1979 to 2007. The conventional empirical orthogonal function (EOF) analysis of the HC anomalies from each individual analysis indicates that their leading modes show significant qualitative differences among analyses, especially for the first modes, although some common characteristics are discernable. Then, the simple arithmetic average (or ensemble mean) is applied to produce an ensemble dataset, i.e., the EM analysis. The leading EOF modes of the EM analysis show quantitatively consistent spatial-temporal patterns with those derived from an alternative EOF technique that maximizes signal-to-noise ratio of the six analyses, which suggests that the ensemble mean generates HC fields with the noise reduced to an acceptable level. The quality of the EM analysis is further validated against AVISO altimetry sea level anomaly (SLA) data and PIRATA mooring station data. A regression analysis with the AVISO SLA data proved that the leading modes in the EM analysis are realistic. It also demonstrated that some reanalysis products might contain higher level of intrinsic noise than others. A quantitative correlation analysis indicates that the HC fields are more realistic in the EM analysis than in individual products, especially over the equatorial regions, with signals contributed from all ensemble members. A

  10. Estimation of tracheal pressure and imposed expiratory work of breathing by the endotracheal tube, heat and moisture exchanger, and ventilator during mechanical ventilation.

    Science.gov (United States)

    Uchiyama, Akinori; Yoshida, Takeshi; Yamanaka, Hidenori; Fujino, Yuji

    2013-07-01

    The resistance of the endotracheal tube (ETT), the heat and moisture exchanger (HME), and the ventilator may affect the patient's respiratory status. Although previous studies examined the inspiratory work of breathing (WOB), investigation of WOB in the expiratory phase is rare. We estimated tracheal pressure at the tip of the ETT (Ptrach) and calculated expiratory WOB imposed by the ETT, the HME, and the expiratory valve. We examined imposed expiratory WOB in patients under a continuous mandatory ventilation (CMV) mode and during spontaneous breathing trials (SBTs). We hypothesized that imposed expiratory WOB would increase with heightened ventilatory demand. We measured airway pressure (Paw) and respiratory flow (V). We estimated Ptrach using the equation Ptrach = Paw - K1 × V(K2) - 2.70 × V(L/s)(1.42). K1 and K2 were determined by the inner diameter (ID) of the ETT. Imposed expiratory WOB was calculated from the area of Ptrach above PEEP versus lung volume. We examined imposed expiratory WOB and imposed expiratory resistance in relation to mean expiratory flow. We examined 28 patients under CMV mode, and 29 during SBT. During both CMV and SBT, as mean expiratory flow increased, imposed expiratory WOB increased. The regression curves between mean expiratory flow (x) (L/s) and imposed expiratory WOB (y) (J/L) were y = 1.35x(0.83) (R(2) = 0.79) for 7 mm ID ETT under CMV, y = 1.12x(0.82) (R(2) = 0.73) for 8 mm ID ETT under CMV, y = 1.07x(1.04) (R(2) = 0.85) for 7 mm ID ETT during SBT, and y = 0.84x(0.93) (R(2) = 0.75) for 8 mm ID ETT during SBT. Levels of imposed expiratory WOB were affected by ETT diameter and ventilator mode. The reason for increasing imposed expiratory WOB was an increase in expiratory resistance imposed by the ETT and HME. Under mechanical ventilation, imposed expiratory WOB should be considered in patients with higher minute ventilation.

  11. Crank-Nicholson Scheme for the Estimation of Thermal Disturbance on the Peripheral Tissues of Human Body Subjected to Oscillatory Boundary Condition and Time Dependent Heat Source

    Science.gov (United States)

    Khanday, M. A.; Hussain, Fida

    2015-07-01

    To predict the behaviour of thermal physiology of a finite biological tissue in severe cold climatic conditions, a mathematical model has been established based on Pennes' bio-heat transfer equation with oscillatory boundary condition and time dependent heat source term. Crank-Nicholson scheme has been employed to obtain the solution of the boundary value problem to understand the change in stable temperature profiles at the peripheral tissues of human body subjected to forced convection due to cold. Thermal stress at these regions with respect to different input parameters has been computed under extreme environmental conditions using MATLAB Software. The results have shown a relative significance and provide a reasonable outcome in terms of variable metabolic heat generation and oscillatory heat source. The oscillations of the temperature profiles from the mean temperatures were computed in relation with tissue medium and other physiological parameters.

  12. Heat Islands

    Science.gov (United States)

    EPA's Heat Island Effect Site provides information on heat islands, their impacts, mitigation strategies, related research, a directory of heat island reduction initiatives in U.S. communities, and EPA's Heat Island Reduction Program.

  13. District heating

    International Nuclear Information System (INIS)

    1989-03-01

    The papers presented at this meeting dealt with an international comparison of district heating, the Swiss district heating network, political aspects of nuclear district heating, nuclear and non-nuclear sources for district heating. 17 figs., 6 tabs

  14. Quantifying canal leakage rates using a mass-balance approach and heat-based hydraulic conductivity estimates in selected irrigation canals, western Nebraska, 2007 through 2009

    Science.gov (United States)

    Hobza, Christopher M.; Andersen, Michael J.

    2010-01-01

    The water supply in areas of the North Platte River Basin in the Nebraska Panhandle has been designated as fully appropriated or overappropriated by the Nebraska Department of Natural Resources (NDNR). Enacted legislation (Legislative Bill 962) requires the North Platte Natural Resources District (NPNRD) and the NDNR to develop an Integrated Management Plan (IMP) to balance groundwater and surface-water supply and demand in the NPNRD. A clear understanding of the groundwater and surface-water systems is critical for the development of a successful IMP. The primary source of groundwater recharge in parts of the NPNRD is from irrigation canal leakage. Because canal leakage constitutes a large part of the hydrologic budget, spatially distributing canal leakage to the groundwater system is important to any management strategy. Surface geophysical data collected along selected reaches of irrigation canals has allowed for the spatial distribution of leakage on a relative basis; however, the actual magnitude of leakage remains poorly defined. To address this need, the U.S. Geological Survey, in cooperation with the NPNRD, established streamflow-gaging stations at upstream and downstream ends from two selected canal reaches to allow a mass-balance approach to be used to calculate daily leakage rates. Water-level and sediment temperature data were collected and simulated at three temperature monitoring sites to allow the use of heat as a tracer to estimate the hydraulic conductivity of canal bed sediment. Canal-leakage rates were estimated by applying Darcy's Law to modeled vertical hydraulic conductivity and either the estimated or measured hydraulic gradient. This approach will improve the understanding of the spatial and temporal variability of canal leakage in varying geologic settings identified in capacitively coupled resistivity surveys. The high-leakage potential study reach of the Tri-State Canal had two streamflow-gaging stations and two temperature monitoring

  15. District heating

    International Nuclear Information System (INIS)

    2005-01-01

    By request of the Dutch Lower House the Netherlands Court of Audit examined the profitability or loss-making of district heating projects between 2001 and 2003. District heating supplies heat to consumers for heating their houses and providing warm tap water. The heat is supplied via warm water that runs through a network of pipes. In the Netherlands, about 250,000 households use district heating. The request by the Dutch Lower House to conduct research on district heating coheres with the initiative District Heating Bill. The bill aims to legally guarantee the supply and affordability of heat for consumers of district heating. [mk] [nl

  16. Synthesis and characterization of ZnO incorporated magnetically recoverable KIT-6 as a novel and efficient catalyst in the preparation of symmetrical N, N‧-alkylidene bisamides

    Science.gov (United States)

    Saadati-Moshtaghin, Hamid Reza; Zonoz, Farrokhzad Mohammadi; Amini, Mostafa M.

    2018-04-01

    A novel magnetically recoverable nanocomposite consisting of the NiFe2O4 core and KIT-6 mesoporous silica shell incorporated with ZnO nanoparticles was constructed. This nanocomposite was characterized by Fourier transform infrared (FT-IR), powder X-ray diffraction (XRD), Brunauer Emmett Teller (BET), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). This new nanocomposite demonstrated a catalytic performance in the synthesis of symmetrical N,N‧-alkylidene bisamides at the condensation reaction under solvent-free conditions. The nanocatalyst could simply be recovered from the reaction environment by using an exterior magnet and reused five times without a remarkable losing in the catalytic property.

  17. A facile one-pot solvothermal method for synthesis of magnetically recoverable Pd-Fe3O4 hybrid nanocatalysts for the Mizoroki-Heck reaction

    Science.gov (United States)

    Zhen, Fangchen; Ran, Maofei; Chu, Wei; Jiang, Chengfa; Sun, Wenjing

    2018-03-01

    Pd-Fe3O4 hybrid nanostructures were prepared using a simple one-pot hydrothermal method. The prepared materials were characterized by Fourier transform-infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, inductively coupled plasma, N2 adsorption-desorption, and vibrating sample magnetometry. This self-assembled nanosystem acted as an efficient magnetically recyclable noble metal-based multi-functional nanocatalyst. It showed excellent catalytic activity and stability for the Heck reaction of iodobenzene and styrene under mild conditions. The methods used to prepare the Pd-Fe3O4 catalysts were simple and low-cost, which will be useful for the large-scale development and application of a magnetically recoverable Pd catalyst.

  18. Magnetic iron oxide/phenylsulfonic acid: A novel, efficient and recoverable nanocatalyst for green synthesis of tetrahydrobenzo[b]pyrans under ultrasonic conditions.

    Science.gov (United States)

    Elhamifar, Dawood; Ramazani, Zahra; Norouzi, Meysam; Mirbagheri, Reza

    2018-02-01

    A novel magnetic iron oxide supported phenylsulfonic acid (Fe 3 O 4 @Ph-SO 3 H) with core-shell structure is prepared, characterized and applied as efficient nanocatalyst for green synthesis of tetrahydrobenzo[b]pyrans. The Fe 3 O 4 @Ph-SO 3 H was prepared via modification of magnetic iron oxide cores with 1,4-bis(triethoxysilyl)benzene (BTEB) followed by sulfonation of aromatic rings. The Fe 3 O 4 @Ph-SO 3 H was characterized using FTIR, TGA, PXRD, SEM, TEM, VSM and EDX techniques. This was effectively applied for synthesis of tetrahydrobenzo[b]pyrans in water as green solvent at room temperature under ultrasonic conditions. The products were obtained in high to excellent yields at short times. The recoverability, reusability and durability of this nanocatalyst were studied under applied reaction conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Environmental data book 2011. Estimated emission factors for fuels, electricity, heat and transport in Sweden; Miljoefaktaboken 2011. Uppskattade emissionsfaktorer foer braenslen, el, vaerme och transporter

    Energy Technology Data Exchange (ETDEWEB)

    Gode, Jenny; Martinsson, Fredrik; Hagberg, Linus; Oeman, Andreas; Hoeglund, Jonas; Palm, David

    2011-04-15

    The environmental data book summarizes current and general emission factors for most fuels and sources of Swedish electricity and heat and to power vehicles. Emission data are compiled for wood fuels, energy crops, bio-oils, waste fuels, fossil fuels and peat, biofuels, wind power, hydro power, nuclear power and solar power

  20. Basic approach to estimate subsidence and effective palaeo-heat flow of sediment basins using maturity data. Evaluation of selected regions of the Rhine Valley Graben

    Energy Technology Data Exchange (ETDEWEB)

    Stiller, E.; Berner, U. [Federal Institute for Geosciences and Natural Resources, Hannover (Germany)

    2013-08-01

    Jurassic sediments of the Rhine Valley Graben (RVG) are recognised by Ladage and Berner (2012) as potential shale gas targets. The geological and tectonic development of the region is complicated, which also holds true for the past and present-day heat flow systems, which have a major imprint on the hydrocarbon generation of the region. We focus on the evaluation of the palaeo-heat flow of the RVG using thermal maturities of organic matter applying the method of Stiller and Berner (2012) which facilitates basin modeling through easy to generate pre-modeling information. Palaeo-subsurface temperatures and related heat flows of selected boreholes at the flanks and the center of the RVG have been restored. However, the reconstruction of a maximum burial is a challenge, because high temperatures within the RVG affected the physical properties of the sediments. Restored palaeo-temperatures and heat flows indicate high temperatures in the graben center and lower values at the graben flanks, however they appear to be lower then present-day temperature conditions in certain regions. The temperature distribution of the RVG has been and is still affected by circulating hot fluids and cold meteoric waters. Present-day thermal effects were not quantified by our method and complicate the reconstruction of the palaeo-temperature conditions. The results of our approach are validated using basin modeling.

  1. Efficiency improvement in multi-sensor wireless network based estimation algorithms for distributed parameter systems with application at the heat transfer

    Science.gov (United States)

    Volosencu, Constantin; Curiac, Daniel-Ioan

    2013-12-01

    This paper gives a technical solution to improve the efficiency in multi-sensor wireless network based estimation for distributed parameter systems. A complex structure based on some estimation algorithms, with regression and autoregression, implemented using linear estimators, neural estimators and ANFIS estimators, is developed for this purpose. The three kinds of estimators are working with precision on different parts of the phenomenon characteristic. A comparative study of three methods - linear and nonlinear based on neural networks and adaptive neuro-fuzzy inference system - to implement these algorithms is made. The intelligent wireless sensor networks are taken in consideration as an efficient tool for measurement, data acquisition and communication. They are seen as a "distributed sensor", placed in the desired positions in the measuring field. The algorithms are based on regression using values from adjacent and also on auto-regression using past values from the same sensor. A modelling and simulation for a case study is presented. The quality of estimation is validated using a quadratic criterion. A practical implementation is made using virtual instrumentation. Applications of this complex estimation system are in fault detection and diagnosis of distributed parameter systems and discovery of malicious nodes in wireless sensor networks.

  2. Reserve estimates in western basins: Unita Basin. Final report, Part III

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-01

    This study characterizes an extremely large gas resource located in low permeability, sandstone reservoirs of the Mesaverde group and Wasatch formation in the Uinta Basin, Utah. Total in-place resource is estimated at 395.5 Tcf. Via application of geologic, engineering and economic criteria, the portion of this resource potentially recoverable as reserves is estimated. Those volumes estimated include probable, possible and potential categories and total 3.8 Tcf as a mean estimate of recoverable gas for all plays considered in the basin. Two plays were included in this study and each was separately analyzed in terms of its tight gas resource, established productive characteristics and future reserves potential based on a constant $2/Mcf wellhead gas price scenario. A scheme has been developed to break the overall resource estimate down into components that can be considered as differing technical and economic challenges that must be overcome in order to exploit such resources; in other words, to convert those resources to economically recoverable reserves. About 82.1% of the total evaluated resource is contained within sandstones that have extremely poor reservoir properties with permeabilities considered too low for commerciality using current frac technology.

  3. Heat Roadmap Europe

    DEFF Research Database (Denmark)

    David, Andrei; Mathiesen, Brian Vad; Averfalk, Helge

    2017-01-01

    The Heat Roadmap Europe (HRE) studies estimated a potential increase of the district heating (DH) share to 50% of the entire heat demand by 2050, with approximately 25–30% of it being supplied using large-scale electric heat pumps. This study builds on this potential and aims to document that suc......The Heat Roadmap Europe (HRE) studies estimated a potential increase of the district heating (DH) share to 50% of the entire heat demand by 2050, with approximately 25–30% of it being supplied using large-scale electric heat pumps. This study builds on this potential and aims to document......, refrigerants, efficiency and types of operation of 149 units with 1580 MW of thermal output, the study further uses this data to analyze if the deployment of this technology on a large-scale is possible in other locations in Europe. It finally demonstrates that the technical level of the existing heat pumps...... is mature enough to make them suitable for replication in other locations in Europe....

  4. Heat Stress

    Science.gov (United States)

    ... Publications and Products Programs Contact NIOSH NIOSH HEAT STRESS Recommend on Facebook Tweet Share Compartir NEW OSHA- ... hot environments may be at risk of heat stress. Exposure to extreme heat can result in occupational ...

  5. Heat Capacity Analysis Report

    International Nuclear Information System (INIS)

    Findikakis, A.

    2004-01-01

    The purpose of this report is to provide heat capacity values for the host and surrounding rock layers for the waste repository at Yucca Mountain. The heat capacity representations provided by this analysis are used in unsaturated zone (UZ) flow, transport, and coupled processes numerical modeling activities, and in thermal analyses as part of the design of the repository to support the license application. Among the reports that use the heat capacity values estimated in this report are the ''Multiscale Thermohydrologic Model'' report, the ''Drift Degradation Analysis'' report, the ''Ventilation Model and Analysis Report, the Igneous Intrusion Impacts on Waste Packages and Waste Forms'' report, the ''Dike/Drift Interactions report, the Drift-Scale Coupled Processes (DST and TH Seepage) Models'' report, and the ''In-Drift Natural Convection and Condensation'' report. The specific objective of this study is to determine the rock-grain and rock-mass heat capacities for the geologic stratigraphy identified in the ''Mineralogic Model (MM3.0) Report'' (BSC 2004 [DIRS 170031], Table 1-1). This report provides estimates of the heat capacity for all stratigraphic layers except the Paleozoic, for which the mineralogic abundance data required to estimate the heat capacity are not available. The temperature range of interest in this analysis is 25 C to 325 C. This interval is broken into three separate temperature sub-intervals: 25 C to 95 C, 95 C to 114 C, and 114 C to 325 C, which correspond to the preboiling, trans-boiling, and postboiling regimes. Heat capacity is defined as the amount of energy required to raise the temperature of a unit mass of material by one degree (Nimick and Connolly 1991 [DIRS 100690], p. 5). The rock-grain heat capacity is defined as the heat capacity of the rock solids (minerals), and does not include the effect of water that exists in the rock pores. By comparison, the rock-mass heat capacity considers the heat capacity of both solids and pore

  6. Heat pumps

    CERN Document Server

    Macmichael, DBA

    1988-01-01

    A fully revised and extended account of the design, manufacture and use of heat pumps in both industrial and domestic applications. Topics covered include a detailed description of the various heat pump cycles, the components of a heat pump system - drive, compressor, heat exchangers etc., and the more practical considerations to be taken into account in their selection.

  7. Estimation of the most influential factors on the laser cutting process heat affected zone (HAZ) by adaptive neuro-fuzzy technique

    Science.gov (United States)

    Petković, Dalibor; Nikolić, Vlastimir; Milovančević, Miloš; Lazov, Lyubomir

    2016-07-01

    Heat affected zone (HAZ) of the laser cutting process may be developed on the basis on combination of different factors. In this investigation was analyzed the HAZ forecasting based on the different laser cutting parameters. The main aim in this article was to analyze the influence of three inputs on the HAZ of the laser cutting process. The method of ANFIS (adaptive neuro fuzzy inference system) was applied to the data in order to select the most influential factors for HAZ forecasting. Three inputs are considered: laser power, cutting speed and gas pressure. According the results the cutting speed has the highest influence on the HAZ forecasting (RMSE: 0.0553). Gas pressure has the smallest influence on the HAZ forecasting (RMSE: 0.0801). The results can be used in order to simplify HAZ prediction and analyzing.

  8. NCSX Plasma Heating Methods

    International Nuclear Information System (INIS)

    Kugel, H.W.; Spong, D.; Majeski, R.; Zarnstorff, M.

    2003-01-01

    The NCSX (National Compact Stellarator Experiment) has been designed to accommodate a variety of heating systems, including ohmic heating, neutral-beam injection, and radio-frequency. Neutral beams will provide one of the primary heating methods for NCSX. In addition to plasma heating, beams are also expected to provide a means for external control over the level of toroidal plasma rotation velocity and its profile. The plan is to provide 3 MW of 50 keV balanced neutral-beam tangential injection with pulse lengths of 500 msec for initial experiments, and to be upgradeable to pulse lengths of 1.5 sec. Subsequent upgrades will add 3 MW of neutral-beam injection. This Chapter discusses the NCSX neutral-beam injection requirements and design issues, and shows how these are provided by the candidate PBX-M (Princeton Beta Experiment-Modification) neutral-beam injection system. In addition, estimations are given for beam-heating efficiencies, scaling of heating efficiency with machine size an d magnetic field level, parameter studies of the optimum beam-injection tangency radius and toroidal injection location, and loss patterns of beam ions on the vacuum chamber wall to assist placement of wall armor and for minimizing the generation of impurities by the energetic beam ions. Finally, subsequent upgrades could add an additional 6 MW of radio-frequency heating by mode-conversion ion-Bernstein wave (MCIBW) heating, and if desired as possible future upgrades, the design also will accommodate high-harmonic fast-wave and electron-cyclotron heating. The initial MCIBW heating technique and the design of the radio-frequency system lend themselves to current drive, so that if current drive became desirable for any reason only minor modifications to the heating system described here would be needed. The radio-frequency system will also be capable of localized ion heating (bulk or tail), and possibly ion-Bernstein-wave-generated sheared flows

  9. NCSX Plasma Heating Methods

    International Nuclear Information System (INIS)

    Kugel, H.W.; Spong, D.; Majeski, R.; Zarnstorff, M.

    2008-01-01

    The National Compact Stellarator Experiment (NCSX) has been designed to accommodate a variety of heating systems, including ohmic heating, neutral beam injection, and radio-frequency (rf). Neutral beams will provide one of the primary heating methods for NCSX. In addition to plasma heating, neutral beams are also expected to provide a means for external control over the level of toroidal plasma rotation velocity and its profile. The experimental plan requires 3 MW of 50-keV balanced neutral beam tangential injection with pulse lengths of 500 ms for initial experiments, to be upgradeable to pulse lengths of 1.5 s. Subsequent upgrades will add 3MW of neutral beam injection (NBI). This paper discusses the NCSX NBI requirements and design issues and shows how these are provided by the candidate PBX-M NBI system. In addition, estimations are given for beam heating efficiencies, scaling of heating efficiency with machine size and magnetic field level, parameter studies of the optimum beam injection tangency radius and toroidal injection location, and loss patterns of beam ions on the vacuum chamber wall to assist placement of wall armor and for minimizing the generation of impurities by the energetic beam ions. Finally, subsequent upgrades could add an additional 6 MW of rf heating by mode conversion ion Bernstein wave (MCIBW) heating, and if desired as possible future upgrades, the design also will accommodate high-harmonic fast-wave and electron cyclotron heating. The initial MCIBW heating technique and the design of the rf system lend themselves to current drive, so if current drive became desirable for any reason, only minor modifications to the heating system described here would be needed. The rf system will also be capable of localized ion heating (bulk or tail), and possibly IBW-generated sheared flows

  10. NCSX Plasma Heating Methods

    Energy Technology Data Exchange (ETDEWEB)

    Kugel, H. W.; Spong, D.; Majeski, R.; Zarnstorff, M.

    2008-01-18

    The National Compact Stellarator Experiment (NCSX) has been designed to accommodate a variety of heating systems, including ohmic heating, neutral beam injection, and radio-frequency (rf). Neutral beams will provide one of the primary heating methods for NCSX. In addition to plasma heating, neutral beams are also expected to provide a means for external control over the level of toroidal plasma rotation velocity and its profile. The experimental plan requires 3 MW of 50-keV balanced neutral beam tangential injection with pulse lengths of 500 ms for initial experiments, to be upgradeable to pulse lengths of 1.5 s. Subsequent upgrades will add 3MW of neutral beam injection (NBI). This paper discusses the NCSX NBI requirements and design issues and shows how these are provided by the candidate PBX-M NBI system. In addition, estimations are given for beam heating efficiencies, scaling of heating efficiency with machine size and magnetic field level, parameter studies of the optimum beam injection tangency radius and toroidal injection location, and loss patterns of beam ions on the vacuum chamber wall to assist placement of wall armor and for minimizing the generation of impurities by the energetic beam ions. Finally, subsequent upgrades could add an additional 6 MW of rf heating by mode conversion ion Bernstein wave (MCIBW) heating, and if desired as possible future upgrades, the design also will accommodate high-harmonic fast-wave and electron cyclotron heating. The initial MCIBW heating technique and the design of the rf system lend themselves to current drive, so if current drive became desirable for any reason, only minor modifications to the heating system described here would be needed. The rf system will also be capable of localized ion heating (bulk or tail), and possiblyIBW-generated sheared flows.

  11. Heat pumps

    CERN Document Server

    Brodowicz, Kazimierz; Wyszynski, M L; Wyszynski

    2013-01-01

    Heat pumps and related technology are in widespread use in industrial processes and installations. This book presents a unified, comprehensive and systematic treatment of the design and operation of both compression and sorption heat pumps. Heat pump thermodynamics, the choice of working fluid and the characteristics of low temperature heat sources and their application to heat pumps are covered in detail.Economic aspects are discussed and the extensive use of the exergy concept in evaluating performance of heat pumps is a unique feature of the book. The thermodynamic and chemical properties o

  12. WAYS TO MANAGE HEATING INERTIA

    Directory of Open Access Journals (Sweden)

    E. V. Biloshytskyi

    2017-08-01

    Full Text Available Purpose. The research paper proposes to estimate the effect of heat inertia of the water heating system, in transient operation modes, on the temperature condition in the passenger car, as well as to offer technical solutions intended to reduce the heating system inertia effect and to maintain a stable temperature condition in the passenger car premises in transitional modes of the heating system. Methodology. The author developed the method for controlling the heat transfer of heating system pipes with the help of regulating casing. To control the heating system and the heat transfer of heating pipes, two types of temperature control sensors were used in the passenger car: certain sensors interacted with regulatory casings, while the others interacted with high-voltage tubular heating element control devices. To assess the efficiency of heat interchange regulation of heating pipes and the heating system control, with installed regulating casings, the operation of the heating system with regulating casings and two types of sensors was mathematically modelled. Mathematical modelling used the experimental test data. The results of experimental tests and mathematical modelling were compared. Findings. Currently in operated passenger cars, control of heating appliances is not constructively provided. Automatic maintenance of the set temperature in a passenger car is limited to switching on and off of high-voltage tubular heating elements. The use of regulating casings on heating pipes allows reducing the effects of heat inertia and maintaining stable thermal conditions in a passenger car, using the heating system as a heat accumulator, and also provides the opportunity to realize an individual control of air temperature in the compartment. Originality. For the first time, the paper studied the alternative ways of regulating the temperature condition in a passenger car. Using of the heating system as a heat accumulator. Practical value. The

  13. Using heat as a tracer to estimate spatially distributed mean residence times in the hyporheic zone of a riffle-pool sequence

    Science.gov (United States)

    Naranjo, Ramon C.

    2013-01-01

    Biochemical reactions that occur in the hyporheic zone are highly dependent on the time solutes that are in contact with sediments of the riverbed. In this investigation, we developed a 2-D longitudinal flow and solute-transport model to estimate the spatial distribution of mean residence time in the hyporheic zone. The flow model was calibrated using observations of temperature and pressure, and the mean residence times were simulated using the age-mass approach for steady-state flow conditions. The approach used in this investigation includes the mixing of different ages and flow paths of water through advection and dispersion. Uncertainty of flow and transport parameters was evaluated using standard Monte Carlo and the generalized likelihood uncertainty estimation method. Results of parameter estimation support the presence of a low-permeable zone in the riffle area that induced horizontal flow at a shallow depth within the riffle area. This establishes shallow and localized flow paths and limits deep vertical exchange. For the optimal model, mean residence times were found to be relatively long (9–40.0 days). The uncertainty of hydraulic conductivity resulted in a mean interquartile range (IQR) of 13 days across all piezometers and was reduced by 24% with the inclusion of temperature and pressure observations. To a lesser extent, uncertainty in streambed porosity and dispersivity resulted in a mean IQR of 2.2 and 4.7 days, respectively. Alternative conceptual models demonstrate the importance of accounting for the spatial distribution of hydraulic conductivity in simulating mean residence times in a riffle-pool sequence.

  14. Estimativa do fluxo de calor latente pelo balanço de energia em cultivo protegido de pimentão Estimate of the latent heat flux by the energy balance in protected cultivation of sweet pepper

    Directory of Open Access Journals (Sweden)

    Antonio Ribeiro da Cunha

    2002-06-01

    Full Text Available O objetivo deste trabalho foi caracterizar e relacionar a radiação líquida com o calor latente equivalente, em mm de água, nos cultivos protegido e de campo, na cultura de pimentão. O experimento foi feito em Botucatu, SP. A estimativa do fluxo de calor latente foi feita pelo método do balanço de energia, por meio da razão de Bowen. Foram feitas medidas instantâneas da radiação líquida (Rn, dos fluxos convectivos de calor latente (LE e sensível (H, do fluxo de calor no solo (G, e dos gradientes psicrométricos sobre a cultura. O cultivo protegido, apesar de receber menor quantidade de radiação solar global, foi mais eficiente na conversão da radiação líquida disponível em matéria seca total e na produtividade de frutos. No balanço de energia, o cultivo protegido apresentou razões G/Rn e LE/Rn inferiores e H/Rn superior, com um fluxo de calor latente, equivalente em milímetros, 45,43% menor que no cultivo no campo. Apresentou, ainda, menor quantidade de radiação líquida disponível e menores perdas de energia, mostrando-se mais eficiente no uso da água.The aim of this work was to characterize and bring into relationship the net radiation with the latent heat flux equivalent to water mm, in sweet pepper crops in the field and in protected cultivation. The estimate of latent heat flux was made by the energy balance method through the Bowen ratio. Instantaneous measures were made of net radiation (Rn, sensitive (H and latent (LE heat fluxes, heat flux into the soil (G, and of psychrometers gradients in the crop canopy. In protected cultivation, the conversion of the available net radiation in total dry matter and fruit productivity was more efficient than in the field, in spite of lower amounts of global solar radiation received by the crop. Ratios of G/Rn and LE/Rn were lower, and that of H/Rn was higher in protected cultivation, with an equivalent latent heat flux in millimeters, 45.43% lower than that determined in the

  15. Development and application of artificial neural network models to estimate values of a complex human thermal comfort index associated with urban heat and cool island patterns using air temperature data from a standard meteorological station.

    Science.gov (United States)

    Moustris, Konstantinos; Tsiros, Ioannis X; Tseliou, Areti; Nastos, Panagiotis

    2018-04-11

    The present study deals with the development and application of artificial neural network models (ANNs) to estimate the values of a complex human thermal comfort-discomfort index associated with urban heat and cool island conditions inside various urban clusters using as only inputs air temperature data from a standard meteorological station. The index used in the study is the Physiologically Equivalent Temperature (PET) index which requires as inputs, among others, air temperature, relative humidity, wind speed, and radiation (short- and long-wave components). For the estimation of PET hourly values, ANN models were developed, appropriately trained, and tested. Model results are compared to values calculated by the PET index based on field monitoring data for various urban clusters (street, square, park, courtyard, and gallery) in the city of Athens (Greece) during an extreme hot weather summer period. For the evaluation of the predictive ability of the developed ANN models, several statistical evaluation indices were applied: the mean bias error, the root mean square error, the index of agreement, the coefficient of determination, the true predictive rate, the false alarm rate, and the Success Index. According to the results, it seems that ANNs present a remarkable ability to estimate hourly PET values within various urban clusters using only hourly values of air temperature. This is very important in cases where the human thermal comfort-discomfort conditions have to be analyzed and the only available parameter is air temperature.

  16. Characterization of industrial process waste heat and input heat streams

    Energy Technology Data Exchange (ETDEWEB)

    Wilfert, G.L.; Huber, H.B.; Dodge, R.E.; Garrett-Price, B.A.; Fassbender, L.L.; Griffin, E.A.; Brown, D.R.; Moore, N.L.

    1984-05-01

    The nature and extent of industrial waste heat associated with the manufacturing sector of the US economy are identified. Industry energy information is reviewed and the energy content in waste heat streams emanating from 108 energy-intensive industrial processes is estimated. Generic types of process equipment are identified and the energy content in gaseous, liquid, and steam waste streams emanating from this equipment is evaluated. Matchups between the energy content of waste heat streams and candidate uses are identified. The resultant matrix identifies 256 source/sink (waste heat/candidate input heat) temperature combinations. (MHR)

  17. District heating in sequential energy supply

    International Nuclear Information System (INIS)

    Persson, Urban; Werner, Sven

    2012-01-01

    Highlights: ► European excess heat recovery and utilisation by district heat distribution. ► Heat recovery in district heating systems – a structural energy efficiency measure. ► Introduction of new theoretical concepts to express excess heat recovery. ► Fourfold potential for excess heat utilisation in EU27 compared to current levels. ► Large scale excess heat recovery – a collaborative challenge for future Europe. -- Abstract: Increased recovery of excess heat from thermal power generation and industrial processes has great potential to reduce primary energy demands in EU27. In this study, current excess heat utilisation levels by means of district heat distribution are assessed and expressed by concepts such as recovery efficiency, heat recovery rate, and heat utilisation rate. For two chosen excess heat activities, current average EU27 heat recovery levels are compared to currently best Member State practices, whereby future potentials of European excess heat recovery and utilisation are estimated. The principle of sequential energy supply is elaborated to capture the conceptual idea of excess heat recovery in district heating systems as a structural and organisational energy efficiency measure. The general conditions discussed concerning expansion of heat recovery into district heating systems include infrastructure investments in district heating networks, collaboration agreements, maintained value chains, policy support, world market energy prices, allocation of synergy benefits, and local initiatives. The main conclusion from this study is that a future fourfold increase of current EU27 excess heat utilisation by means of district heat distribution to residential and service sectors is conceived as plausible if applying best Member State practice. This estimation is higher than the threefold increase with respect to direct feasible distribution costs estimated by the same authors in a previous study. Hence, no direct barriers appear with

  18. Does Quality Control Matter? a Revisit of Surface Urban Heat Island Intensity Estimated by Satellite-Derived Land Surface Temperature Products

    Science.gov (United States)

    Lai, J.; Zhan, W.; Huang, F.

    2017-09-01

    Temporally regular and spatially continuous monitoring of surface urban heat island (SUHI) has been extremely difficult until the advent of spaceborne land surface temperature (LST) products. The higher errors of these LST products compared with in-situ measurements, nevertheless, have resulted in a comparatively inaccuracy and may distort the interpretation of SUHI. Although reports have shown that LST quality matters to the SUHI interpretation, a systematic investigation on how the SUHI indicators are responsive to the LST quality across cities within dissimilar bioclimates remains rare. With regard to this issue, our study chose eighty-six major cities across the mainland China and analyzed the SUHI intensity (SUHII) discrepancies (referred to as ΔSUHII) between using and not using quality control (QC) flags from Moderate Resolution Imaging Spectroradiometer data. Our major findings include: (1) the SUHII can be significantly impacted by the MODIS QC flags, and the associated seasonal ΔSUHIIs generally account for 25.5 % (29.6 %) of the total intensity in the day (night). (2) The ΔSUHIIs differ season-by-season and significant discrepancies also appear among northern and southern cities, with northern ones often possessing a higher annual mean ΔSUHII. (3) The internal ΔSUHIIs within an individual city are also heterogeneous, with the variations exceeding 5.0 K (3.0 K) in northern (southern) cities. (4) The ΔSUHII is significantly negatively related to the SUHII and cloud cover percentage mostly in transitional seasons. Our findings highlight that one needs to be very careful when using the LST-product-based SUHII to interpret the SUHI.

  19. HEAT RECUPERATION

    Directory of Open Access Journals (Sweden)

    S. L. Rovin

    2011-01-01

    Full Text Available Heat recovery is an effective method of shortening specific energy consumption. new constructions of recuperators for heating and cupola furnaces have been designed and successfully introduced. two-stage recuperator with computer control providing blast heating up to 600 °C and reducing fuel consumption by 30% is of special interest.

  20. Planetary heat flow measurements.

    Science.gov (United States)

    Hagermann, Axel

    2005-12-15

    The year 2005 marks the 35th anniversary of the Apollo 13 mission, probably the most successful failure in the history of manned spaceflight. Naturally, Apollo 13's scientific payload is far less known than the spectacular accident and subsequent rescue of its crew. Among other instruments, it carried the first instrument designed to measure the flux of heat on a planetary body other than Earth. The year 2005 also should have marked the launch of the Japanese LUNAR-A mission, and ESA's Rosetta mission is slowly approaching comet Churyumov-Gerasimenko. Both missions carry penetrators to study the heat flow from their target bodies. What is so interesting about planetary heat flow? What can we learn from it and how do we measure it?Not only the Sun, but all planets in the Solar System are essentially heat engines. Various heat sources or heat reservoirs drive intrinsic and surface processes, causing 'dead balls of rock, ice or gas' to evolve dynamically over time, driving convection that powers tectonic processes and spawns magnetic fields. The heat flow constrains models of the thermal evolution of a planet and also its composition because it provides an upper limit for the bulk abundance of radioactive elements. On Earth, the global variation of heat flow also reflects the tectonic activity: heat flow increases towards the young ocean ridges, whereas it is rather low on the old continental shields. It is not surprising that surface heat flow measurements, or even estimates, where performed, contributed greatly to our understanding of what happens inside the planets. In this article, I will review the results and the methods used in past heat flow measurements and speculate on the targets and design of future experiments.

  1. Enceladus' Enigmatic Heat Flow

    Science.gov (United States)

    Howett, C.; Spencer, J. R.; Spencer, D.; Verbiscer, A.; Hurford, T.; Segura, M.

    2013-12-01

    Accurate knowledge of Enceladus' heat flow is important because it provides a vital constraint on Enceladus' tidal dissipation mechanisms, orbital evolution, and the physical processes that generate the plumes. In 2011 we published an estimate of the current heat flow from Enceladus' active south polar terrain: 15.8 +/- 3.1 GW (Howett et al., 2011). This value was calculated by first estimating by modeling, and then removing, the passive component from 17 to 1000 micron observations made of the entire south polar terrain by Cassini's Composite Infrared Spectrometer (CIRS). The heat flow was then directly calculated from the residual, assumed endogenic, component. The derived heat flow of 15.8 GW was surprisingly high, about 10 times greater than that predicted by steady-state tidal heating (Meyer and Wisdom, 2007). CIRS has also returned high spatial resolution observations of Enceladus' active south polar terrain. Two separate observations are used: 9 to 16 micron observations taken over nearly the complete south polar terrain and a single 17 to 1000 micron scan over Damascus, Baghdad and Cairo. The shorter wavelength observations are only sensitive to high temperature emission (>70 K), and so longer wavelength observations are required (despite their limited spatial coverage) to estimate the low temperature emission from the stripes. Analysis of these higher resolution observations tells a different story of Enceladus' endogenic heat flow: the preliminary estimate of the heat flow from the active tiger stripes using these observations is 4.2 GW. An additional 0.5 GW must be added to this number to account for the latent heat release by the plumes (Ingersoll and Pankine 2009), giving a total preliminary estimate of 4.9 GW. The discrepancy in these two numbers is significant and we are currently investigating the cause. One possible reason is that there is significantly higher endogenic emission from the regions between the tiger stripes than we currently estimate

  2. Thermodynamic Behaviors of Macroscopic Liquid Droplets Evaporation from Heated Substrates

    Science.gov (United States)

    Chen, Xue; Zhu, Zhi-Qiang; Liu, Qiu-Sheng; Wang, Xu-Wen

    2015-09-01

    Evaporation of a macroscopic-scale sessile droplet on different hot isothermal substrates has been experimentally investigated, for the framework of planning space experiments onboard Chinese recoverable satellite to explore the interface effect, heat and mass transfer during the phase transition process. Undoubtedly, the evaporation phenomenon of a sessile drop on heated substrates is a complex problem which involves the behavior of triple line, heat transfer with thermal conduction and convection, mass transfer into the vapor phase. Therefore, preparations from scientific view have been carried out to validate setup of the space experiment modes. Based on the experiments performed in the terrestrial gravity, we found that the evolution of a water droplet could be separated into three stages, began with the constant contact area, then switched to the depin stage and ended up with the flushing stage. The average evaporation rate was measured and the thermal effects of different substrates were studied. Results revealed a linear variation of contact diameter with its average evaporation rate, which has the similar tendency with small drops. The varieties of the heat flux density during evaporating showed that droplet absorbed energy from the heated substrate, then with the help of the internal flow of thermocaplliry and buoyant convection, heat was transported to the liquid-vapor interface providing the energy for evaporation.

  3. Study of waste-heat recovery and utilization at the Farmington Municipal Power Plant. Final report, December 1, 1980-June 30, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Leigh, G.G.; Edgel, W.R.; Feldman, K.T. Jr.; Moss, E.J.

    1982-03-01

    An examination was made of the technical and economc feasibility of utilizing waste heat from the Farmington Municipal Power Plant. First, the production cycles of the natural-gas-fired plant were assessed to determine the quantity and quality of recoverable waste heat created by the plant during its operation. Possibilities for utilizing waste heat from the exhaust gases and the cooling water were then reviewed. Hot water systems that can be used to retrieve heat from hot flue gases were investigated; the heated water can then be used for space heating of nearby buildings. The potential use of waste heat to operate a refrigeration plant was also analyzed. The use of discharged cooling water for hydroelectric generation was studied, as well as its application for commercial agricultural and aquaculture enterprises.

  4. Estimation of uranium resources by life-cycle or discovery-rate models: a critique

    International Nuclear Information System (INIS)

    Harris, D.P.

    1976-10-01

    This report was motivated primarily by M. A. Lieberman's ''United States Uranium Resources: An Analysis of Historical Data'' (Science, April 30). His conclusion that only 87,000 tons of U 3 O 8 resources recoverable at a forward cost of $8/lb remain to be discovered is criticized. It is shown that there is no theoretical basis for selecting the exponential or any other function for the discovery rate. Some of the economic (productivity, inflation) and data issues involved in the analysis of undiscovered, recoverable U 3 O 8 resources on discovery rates of $8 reserves are discussed. The problem of the ratio of undiscovered $30 resources to undiscovered $8 resources is considered. It is concluded that: all methods for the estimation of unknown resources must employ a model of some form of the endowment-exploration-production complex, but every model is a simplification of the real world, and every estimate is intrinsically uncertain. The life-cycle model is useless for the appraisal of undiscovered, recoverable U 3 O 8 , and the discovery rate model underestimates these resources

  5. Simultaneousness of room heating and ventilation air heating

    International Nuclear Information System (INIS)

    Mathisen, Hans Martin

    2006-01-01

    The report is part of NTNU-SINTEF's Smart Buildings program, Smart Energy Efficient Buildings (2002-2006), subprogram 3.1 Heating, ventilation and cooling systems. An important part of this subprogram is the development and implementation of heating distribution systems with low return temperature. A comparison has been made of the simultaneousness of room heating and ventilation air heating in six buildings. Existing measuring data with hourly measurements of effect requirements for the different purposes have been employed. Based on the measuring data the relation between the requirements for room heating and ventilation is estimated. A 'fictitious' return temperature has also been estimated. The result shows a significant variation between the buildings. For all there are short periods where the efficiency need for room heating and ventilation is equal (ml)

  6. Recoverability in quantum information theory

    Science.gov (United States)

    Wilde, Mark

    The fact that the quantum relative entropy is non-increasing with respect to quantum physical evolutions lies at the core of many optimality theorems in quantum information theory and has applications in other areas of physics. In this work, we establish improvements of this entropy inequality in the form of physically meaningful remainder terms. One of the main results can be summarized informally as follows: if the decrease in quantum relative entropy between two quantum states after a quantum physical evolution is relatively small, then it is possible to perform a recovery operation, such that one can perfectly recover one state while approximately recovering the other. This can be interpreted as quantifying how well one can reverse a quantum physical evolution. Our proof method is elementary, relying on the method of complex interpolation, basic linear algebra, and the recently introduced Renyi generalization of a relative entropy difference. The theorem has a number of applications in quantum information theory, which have to do with providing physically meaningful improvements to many known entropy inequalities. This is based on arXiv:1505.04661, now accepted for publication in Proceedings of the Royal Society A. I acknowledge support from startup funds from the Department of Physics and Astronomy at LSU, the NSF under Award No. CCF-1350397, and the DARPA Quiness Program through US Army Research Office award W31P4Q-12-1-0019.

  7. Heat Stroke

    DEFF Research Database (Denmark)

    Mørch, Sofie Søndergaard; Andersen, Johnny Dohn Holmgren; Bestle, Morten Heiberg

    2017-01-01

    and mortality. This case report describes two Danish patients diagnosed with heat stroke syndrome during a heat wave in the summer of 2014. Both patients were morbidly obese and had several predisposing illnesses. However since heat stroke is a rare condition in areas with temperate climate, they were...... not diagnosed until several days after admittance; hence treatment with cooling was delayed. Both patients were admitted to the intensive care unit, where they were treated with an external cooling device and received treatment for complications. Both cases ended fatally. As global warming continues, more heat...

  8. Heat exchanger

    International Nuclear Information System (INIS)

    Watabe, Ichiro.

    1996-01-01

    An inner cylinder is disposed coaxially in a vertical vessel, and a plurality of heat transfer pipes are wound spirally on the outer circumference of the inner cylinder. High temperature sodium descends on the outer side of the inner cylinder while exchanging heat with water in the heat transfer pipes and becomes low temperature sodium. The low temperature sodium turns at the lower portion of the vessel, rises in a sodium exit pipe inserted to the inner cylinder and is discharged from the top of the vessel to the outside of the vessel. A portion of a cover gas (an inert gas such as argon) filled to the upper portion of the vessel intrudes into the space between the outer circumference of the sodium exit pipe and the inner circumference of the inner cylinder to form a heat insulation layer of the inert gas. This prevents heat exchange between the high temperature sodium before heat exchange and low temperature sodium after heat exchange. The heat exchanger is used as a secondary heat exchanger for coolants (sodium) of an FBR type reactor. (I.N.)

  9. A one-dimensional heat transfer model for parallel-plate thermoacoustic heat exchangers

    NARCIS (Netherlands)

    de Jong, Anne; Wijnant, Ysbrand H.; de Boer, Andries

    2014-01-01

    A one-dimensional (1D) laminar oscillating flow heat transfer model is derived and applied to parallel-plate thermoacoustic heat exchangers. The model can be used to estimate the heat transfer from the solid wall to the acoustic medium, which is required for the heat input/output of thermoacoustic

  10. Heat exchanger

    International Nuclear Information System (INIS)

    Leigh, D.G.

    1976-01-01

    The arrangement described relates particularly to heat exchangers for use in fast reactor power plants, in which heat is extracted from the reactor core by primary liquid metal coolant and is then transferred to secondary liquid metal coolant by means of intermediate heat exchangers. One of the main requirements of such a system, if used in a pool type fast reactor, is that the pressure drop on the primary coolant side must be kept to a minimum consistent with the maintenance of a limited dynamic head in the pool vessel. The intermediate heat exchanger must also be compact enough to be accommodated in the reactor vessel, and the heat exchanger tubes must be available for inspection and the detection and plugging of leaks. If, however, the heat exchanger is located outside the reactor vessel, as in the case of a loop system reactor, a higher pressure drop on the primary coolant side is acceptable, and space restriction is less severe. An object of the arrangement described is to provide a method of heat exchange and a heat exchanger to meet these problems. A further object is to provide a method that ensures that excessive temperature variations are not imposed on welded tube joints by sudden changes in the primary coolant flow path. Full constructional details are given. (U.K.)

  11. Direct Heat

    Energy Technology Data Exchange (ETDEWEB)

    Lienau, P.J.

    1990-01-01

    Potential resources and applications of earth heat in the form of geothermal energy are large. United States direct uses amount to 2,100 MWt thermal and worldwide 8,850 MWt above a reference temperature of 35 degrees Celsius. Space and district heating are the major direct uses of geothermal energy. Equipment employed in direct use projects is of standard manufacture and includes downhole and circulation pumps, transmission and distribution pipelines, heat exchangers and convectors, heat pumps and chillers. Direct uses of earth heat discussed are space and district heating, greenhouse heating and fish farming, process and industrial applications. The economic feasibility of direct use projects is governed by site specific factors such as location of user and resource, resource quality, system load factor and load density, as well as financing. Examples are presented of district heating in Klamath Falls, and Elko. Further developments of direct uses of geothermal energy will depend on matching user needs to the resource, and improving load factors and load density.

  12. Performance of casting aluminum-silicon alloy condensing heating exchanger for gas-fired boiler

    Science.gov (United States)

    Cao, Weixue; Liu, Fengguo; You, Xue-yi

    2018-01-01

    Condensing gas boilers are widely used due to their high heat efficiency, which comes from their ability to use the recoverable sensible heat and latent heat in flue gas. The condensed water of the boiler exhaust has strong corrosion effect on the heat exchanger, which restricts the further application of the condensing gas boiler. In recent years, a casting aluminum-silicon alloy (CASA), which boasts good anti-corrosion properties, has been introduced to condensing hot water boilers. In this paper, the heat transfer performance, CO and NOx emission concentrations and CASA corrosion resistance of a heat exchanger are studied by an efficiency bench test of the gas-fired boiler. The experimental results are compared with heat exchangers produced by Honeywell and Beka. The results show that the excess air coefficient has a significant effect on the heat efficiency and CO and NOx emission of the CASA water heater. When the excess air coefficient of the CASA gas boiler is 1.3, the CO and NOx emission concentration of the flue gas satisfies the design requirements, and the heat efficiency of water heater is 90.8%. In addition, with the increase of heat load rate, the heat transfer coefficient of the heat exchanger and the heat efficiency of the water heater are increased. However, when the heat load rate is at 90%, the NOx emission in the exhaust gas is the highest. Furthermore, when the temperature of flue gas is below 57 °C, the condensation of water vapor occurs, and the pH of condensed water is in the 2.5 5.5 range. The study shows that CASA water heater has good corrosion resistance and a high heat efficiency of 88%. Compared with the heat exchangers produced by Honeywell and Beka, there is still much work to do in optimizing and improving the water heater.

  13. Geothermal heating saves energy

    International Nuclear Information System (INIS)

    Romsaas, Tor

    2003-01-01

    The article reviews briefly a pioneer project for a construction area of 200000 m''2 with residences, business complexes, a hotel and conference centre and a commercial college in Oslo. The energy conservation potential is estimated to be about 60-70 % compared to direct heating with oil, gas or electricity as sources. There will also be substantial reduction in environmentally damaging emissions. The proposed energy central combines geothermal energy sources with heat pump technology, utilises water as energy carrier and uses terrestrial wells for energy storage. A cost approximation is presented

  14. Heating performance of air-air heat pumps

    Energy Technology Data Exchange (ETDEWEB)

    Carrington, C.G.; Offen, R.J.; Sandle, W.J.; Meyer, L.

    1980-03-01

    Progress is reported on monitoring the heating performance of existing commercially manufactured heat pumps, reappraising existing calculations for optimum heat exchanger sizing, and investigating the performance of an air-to-air heat pump sized and constructed for optimum long term economic performance design information. Two heat pumps were monitored using multi-point recorders and (for one of the heat pumps) a magnetic tape recorder data logger designed and built under contract support. Statistical information on heat pump operation is presented and heat pump performance to date is appraised. Seasonal coefficients of performance of not less than 2.1 and 2.3 are estimated from the data. Expected annual electricity savings are 4763 kWh and 6695 kWh. Design modifications are suggested which may well increase the seasonal coefficient of performance to 3 and need not necessarily involve increased first cost. Heat pumps costing (estimated) $1000 with a coefficient of performance of 3 are expected to be economically attractive.

  15. Recovery of heat from the refrigeration plant at the Bjoerkaeng stadium in Huddinge

    Energy Technology Data Exchange (ETDEWEB)

    Glas, L.O.

    1984-01-01

    The report describes an investigation of heat recovery from the refrigeration plant at the ice hockey rinks outdoors and in the stadium building at the Bjoerkaeng athletics centre. Heat emitted by the refrigeration plant is utilized for heating of the stadium building and for heating water. The heat recovery was measured and analysed over the period 1.12.78-30.11.79, a net energy saving of approximately 380,000 kWh being achieved. The heat recovery analysis comprises a complete heat balance for the ice hockey rinks, the ice stadium, the water heating and the refrigeration plant. On average, test results are very near the figures produced by calculations. The calculation method described should therfore reproduce with good accuracy the possible energy savings in refrigeration plants for ice rinks both indoors and outdoors, of widely differing sizes and geographical location. For instance, the calculation takes into account the effect of the ice stadium temperature selected on the net energy saving and the recoverable quantity of heat.

  16. Waste heat recovery system

    International Nuclear Information System (INIS)

    Phi Wah Tooi

    2010-01-01

    Full text: The Konzen in-house designed anaerobic digester system for the POME (Palm Oil Mill Effluent) treatment process is one of the registered Clean Development Mechanism (CDM) projects in Malaysia. It is an organic wastewater treatment process which achieves excellent co-benefits objectives through the prevention of water pollution and reduction of greenhouse gas emissions, which is estimated to be 40,000 to 50,000 t-CO 2 per year. The anaerobic digester was designed in mesophile mode with temperature ranging from 37 degree Celsius to 45 degree Celsius. A microorganisms growth is optimum under moderately warm temperature conditions. The operating temperature of the anaerobic digester needs to be maintained constantly. There are two waste heat recovery systems designed to make the treatment process self-sustaining. The heat recovered will be utilised as a clean energy source to heat up the anaerobic digester indirectly. The first design for the waste heat recovery system utilises heat generated from the flue gas of the biogas flaring system. A stainless steel water tank with an internal water layer is installed at the top level of the flare stack. The circulating water is heated by the methane enriched biogas combustion process. The second design utilizes heat generated during the compression process for the biogas compressor operation. The compressed biogas needs to be cooled before being recycled back into the digester tank for mixing purposes. Both the waste heat recovery systems use a design which applies a common water circulation loop and hot water tank to effectively become a closed loop. The hot water tank will perform both storage and temperature buffer functions. The hot water is then used to heat up recycled sludge from 30 degree Celsius to 45 degree Celsius with the maximum temperature setting at 50 degree Celsius. The recycled sludge line temperature will be measured and monitored by a temperature sensor and transmitter, which will activate the

  17. Heating entrepreneur activity in 2003

    International Nuclear Information System (INIS)

    Nikkola, A.; Solmio, H.

    2004-01-01

    According to TTS Institute information, at the end of 2003 there were heating entrepreneurs responsible for fuel management and heat production in at least 212 heating plants in Finland. The number of operative plants increased by 36 from the previous year. At the end of 2003, the total boiler capacity for solid fuel in the plants managed by the heating entrepreneurs exceeded 100 megawatts. The average boiler capacity of the plants was 0.5 megawatts. Heating entrepreneur-ship was most common in west Finland, where 40 percent of the plants are located. There were some 94 heating plants managed by cooperatives or limited companies. Single entrepre neurs or entrepreneur networks consisting of several entrepreneurs were responsible for heat production in 117 plants. Heating entrepreneurs used approximately 290,000 loose cubic metres of forest chips, which is about seven percent of the volume used for heating and power plant energy production in 2003. In addition, the heating entrepreneurs used a total of 40,000 loose cubic metres of other wood fuel and an estimated 20,000 loose cubic metres of sod and milled peat. Municipalities are still the most important customer group for heating entrepreneurs. However, thenumber of private customers is growing. Industrial company, other private company or properly was the main customer already for every fourth plant established during 2003. (orig.)

  18. Heat source versus heat sink

    International Nuclear Information System (INIS)

    Aussourd, P.

    1977-01-01

    This paper is a presentation of the method by which Electricite de France proposes to satisfy industrial, urban or agricultural heat needs if these prove economically justified. The arguments in the paper demonstrate the usefulness of studies on heat take-off from standardised nuclear units. General principles for extracting heat from nuclear power stations and the limit to the amount of steam that may be tapped off each unit are discussed. A diagram describes the heat production from a nuclear power station and shows the steam take-off where it emerges from the steam generators with or without back-pressure turbine. The connection principle for heat production from several nuclear units, separate nuclear-unit circuits and one common user circuit, is presented. (M.S.)

  19. Heat pipes

    CERN Document Server

    Dunn, Peter D

    1994-01-01

    It is approximately 10 years since the Third Edition of Heat Pipes was published and the text is now established as the standard work on the subject. This new edition has been extensively updated, with revisions to most chapters. The introduction of new working fluids and extended life test data have been taken into account in chapter 3. A number of new types of heat pipes have become popular, and others have proved less effective. This is reflected in the contents of chapter 5. Heat pipes are employed in a wide range of applications, including electronics cooling, diecasting and injection mo

  20. Supply of Prague with heat from a nuclear heat source

    International Nuclear Information System (INIS)

    Poul, F.

    1976-01-01

    The proposals are discussed of supplying Prague, the Czechoslovak Capital, with nuclear reactor-generated heat energy. The proposals meet the requirements of the general urban plan of development. The first nuclear heating plant is to be sited in the Kojetice locality, in the northern Prague suburb. It will be commissioned by 1984 and 1985. It is estimated that the maximum heat output in form of hot water will be 821 MW. By 1995 the construction of the second nuclear heating plant should be started southeast or east of Prague. The connection of these two nuclear plants to the hot water mains together with other conventional heating plants will secure the heat supply for Prague and its new housing estates and industrial works. (Oy)

  1. Stem heat balance method to estimate transpiration of young orange and mango plants Balanço de calor caulinar para estimativa da transpiração de plantas jovens de laranja e manga

    Directory of Open Access Journals (Sweden)

    Lucas M. Vellame

    2010-01-01

    Full Text Available The present study had as its main objective the evaluation of the heat balance method in young orange and mango plants under protected environment. The work was carried out at Embrapa Cassava and Tropical Fruits, Cruz das Almas, BA. Later on, estimates of sap flow were conducted for two mango plants cultivated in pots of 15 and 50 L installed on weighting platforms of 45 and 140 kg; sap flow was determined in three orange plants, two of which were also installed on weighing platforms. The values of sap flow were compared to the transpiration measured by lysimeters at integrated intervals of 1, 2, 4 and 24 h. The heat balance method showed good precision for estimating daily transpiration (R² = 0.95 and R² = 0.90, accompaning the availability of energy in the system, underestimating on average 4.6% of the daily transpiration in orange plants and overestimating in about 0.3% the daily transpiration of mango plants under conditions of good water supply. The heat balance method underestimated by 16% the transpiration in orange under conditions of water deficit.Com o presente estudo se objetivou avaliar o método de balanço de calor em plantas jovens de laranja e manga em ambiente protegido. O trabalho foi conduzido na Embrapa Mandioca e Fruticultura, Cruz das Almas, BA. Realizaram-se estimativas de fluxo de seiva em duas plantas de manga plantadas em vasos de 15 e 50 L, instalados sobre plataformas de pesagem de 45 e 140 kg; posteriormente, o fluxo de seiva foi determinado em três plantas de laranja, duas também instaladas em lisímetros de pesagem. Os valores de fluxo de seiva obtidos foram comparados com a transpiração medida pelos lisímetros em intervalos de integração de 1, 2, 4 e 24 h. O método do balanço de calor mostrou-se preciso na estimativa da transpiração diária (R² = 0,95 e R² = 0,90, que acompanhou a disponibilidade de energia do sistema, subestimando em média, 4,6% a transpiração diária em plantas de laranja e

  2. Reduced exposure evaluation of an Electrically Heated Cigarette Smoking System. Part 8: Nicotine bridging--estimating smoke constituent exposure by their relationships to both nicotine levels in mainstream cigarette smoke and in smokers.

    Science.gov (United States)

    Urban, H-Jörg; Tricker, Anthony R; Leyden, Donald E; Forte, Natasa; Zenzen, Volker; Feuersenger, Astrid; Assink, Mareike; Kallischnigg, Gerd; Schorp, Matthias K

    2012-11-01

    A modeling approach termed 'nicotine bridging' is presented to estimate exposure to mainstream smoke constituents. The method is based on: (1) determination of harmful and potentially harmful constituents (HPHC) and in vitro toxicity parameter-to-nicotine regressions obtained using multiple machine-smoking protocols, (2) nicotine uptake distributions determined from 24-h excretion of nicotine metabolites in a clinical study, and (3) modeled HPHC uptake distributions using steps 1 and 2. An example of 'nicotine bridging' is provided, using a subset of the data reported in Part 2 of this supplement (Zenzen et al., 2012) for two conventional lit-end cigarettes (CC) and the Electrically Heated Cigarette Smoking System (EHCSS) series-K6 cigarette. The bridging method provides justified extrapolations of HPHC exposure distributions that cannot be obtained for smoke constituents due to the lack of specific biomarkers of exposure to cigarette smoke constituents in clinical evaluations. Using this modeling approach, exposure reduction is evident when the HPHC exposure distribution curves between the MRTP and the CC users are substantially separated with little or no overlap between the distribution curves. Copyright © 2012 Elsevier Inc. All rights reserved.

  3. Water pipe network as a heat source for heat pump integrated into a district heating

    Science.gov (United States)

    Jadwiszczak, Piotr; Niemierka, Elżbieta

    2017-11-01

    The paper will present a technical analysis of the performance of the Heat Pumps (HP) installed in the domestic water pipe network for a big city scale. The HP integration scheme predicts the domestic water flow as a heat source and the district heating as a heat sink. The technical factors which influence on the estimated thermal power and performance of HP unit will be identified. Additionally, the pros and cons of HP operation in water intake will be determined. The analysis will be based on long-term measurement data from Głogów city.

  4. Heat distribution and the future competitiveness of district heating

    Energy Technology Data Exchange (ETDEWEB)

    Persson, Urban; Werner, Sven [School of Business and Engineering, Halmstad University, PO Box 823, SE-30118 Halmstad (Sweden)

    2011-03-15

    The competitiveness of present and future district heating systems can be at risk when residential and service sector heat demands are expected to decrease in the future. In this study, the future competitiveness of district heating has been examined by an in depth analysis of the distribution capital cost at various city characteristics, city sizes, and heat demands. Hereby, this study explores an important market condition often neglected or badly recognised in traditional comparisons between centralised and decentralised heat supply. By a new theoretical approach, the traditional and empirical expression for linear heat density is transformed into an analytical expression that allows modelling of future distribution capital cost levels also in areas where no district heating exists today. The independent variables in this new analytical expression are population density, specific building space, specific heat demand and effective width. Model input data has primarily been collected from national and European statistical sources on heat use, city populations, city districts and residential living areas. Study objects were 83 cities in Belgium, Germany, France, and the Netherlands. The average heat market share for district heat within these cities was 21% during 2006. The main conclusion is that the future estimated capital costs for district heat distribution in the study cities are rather low, since the cities are very dense. At the current situation, a market share of 60% can be reached with a marginal distribution capital cost of only 2.1 EUR/GJ, corresponding to an average distribution capital cost of 1.6 EUR/GJ. The most favourable conditions appear in large cities and in inner city areas. In the future, there is a lower risk for reduced competitiveness due to reduced heat demands in these areas, since the increased distribution capital cost is low compared to the typical prices of district heat and competing heat supply. However, district heating will lose

  5. Heat Waves

    Science.gov (United States)

    ... quickly. - Drink plenty of water regularly and often. - Eat small meals and eat more often. - Avoid using salt tablets ... plenty of water during a heat wave and eat smaller, more frequent meals. Text from "Are You Prepared?" by the Cass ( ...

  6. Heat storage in the Andaman Sea

    Digital Repository Service at National Institute of Oceanography (India)

    RameshBabu, V.; Sastry, J.S.

    Heat storage in the Andaman Sea in upper 20 m, where a strong halocline seems to inhibit vertical heat transport has been evaluated and discussed in relation to the other parameters of heat budget. Estimation of annual evaporation gives rise to 137...

  7. HEAT EXCHANGER

    Science.gov (United States)

    Fox, T.H. III; Richey, T. Jr.; Winders, G.R.

    1962-10-23

    A heat exchanger is designed for use in the transfer of heat between a radioactive fiuid and a non-radioactive fiuid. The exchanger employs a removable section containing the non-hazardous fluid extending into the section designed to contain the radioactive fluid. The removable section is provided with a construction to cancel out thermal stresses. The stationary section is pressurized to prevent leakage of the radioactive fiuid and to maintain a safe, desirable level for this fiuid. (AEC)

  8. Shape memory heat engines

    Science.gov (United States)

    Salzbrenner, R.

    1984-06-01

    The mechanical shape memory effect associated with a thermoelastic martensitic transformation can be used to convert heat directly into mechanical work. Laboratory simulation of two types of heat engine cycles (Stirling and Ericsson) has been performed to measure the amount of work available/cycle in a Ni-45 at. pct Ti alloy. Tensile deformations at ambient temperature induced martensite, while a subsequent increase in temperature caused a reversion to the parent phase during which a load was carried through the strain recovery (i.e., work was accomplished). The amount of heat necessary to carry the engines through a cycle was estimated from calorimeter measurements and the work performed/cycle. The measured efficiency of the system tested reached a maximum of 1.4 percent, which was well below the theoretical (Carnot) maximum efficiency of 35.6 percent.

  9. Heat tracer methods

    Science.gov (United States)

    Healy, Richard W.; Scanlon, Bridget R.

    2010-01-01

    The flow of heat in the subsurface is closely linked to the movement of water (Ingebritsen et al., 2006). As such, heat has been used as a tracer in groundwater studies for more than 100 years (Anderson, 2005). As with chemical and isotopic tracers (Chapter 7), spatial or temporal trends in surface and subsurface temperatures can be used to infer rates of water movement. Temperature can be measured accurately, economically, at high frequencies, and without the need to obtain water samples, facts that make heat an attractive tracer. Temperature measurements made over space and time can be used to infer rates of recharge from a stream or other surface water body (Lapham, 1989; Stonestrom and Constantz, 2003); measurements can also be used to estimate rates of steady drainage through depth intervals within thick unsaturated zones (Constantz et al., 2003; Shan and Bodvarsson, 2004). Several thorough reviews of heat as a tracer in hydrologic studies have recently been published (Constantz et al., 2003; Stonestrom and Constantz, 2003; Anderson, 2005; Blasch et al., 2007; Constantz et al., 2008). This chapter summarizes heat-tracer approaches that have been used to estimate recharge.Some clarification in terminology is presented here to avoid confusion in descriptions of the various approaches that follow. Diffuse recharge is that which occurs more or less uniformly across large areas in response to precipitation, infiltration, and drainage through the unsaturated zone. Estimates of diffuse recharge determined using measured temperatures in the unsaturated zone are referred to as potential recharge because it is possible that not all of the water moving through the unsaturated zone will recharge the aquifer; some may be lost to the atmosphere by evaporation or plant transpiration. Estimated fluxes across confining units in the saturated zone are referred to as interaquifer flow (Chapter 1). Focused recharge is that which occurs directly from a point or line source, such

  10. Combination solar photovoltaic heat engine energy converter

    Science.gov (United States)

    Chubb, Donald L.

    1987-01-01

    A combination solar photovoltaic heat engine converter is proposed. Such a system is suitable for either terrestrial or space power applications. The combination system has a higher efficiency than either the photovoltaic array or the heat engine alone can attain. Advantages in concentrator and radiator area and receiver mass of the photovoltaic heat engine system over a heat-engine-only system are estimated. A mass and area comparison between the proposed space station organic Rankine power system and a combination PV-heat engine system is made. The critical problem for the proposed converter is the necessity for high temperature photovoltaic array operation. Estimates of the required photovoltaic temperature are presented.

  11. Unwanted heat

    International Nuclear Information System (INIS)

    Benka, M.

    2006-01-01

    The number of small heating plants using biomass is growing. According to TREND's information, Hrinovska energeticka, is the only one that controls the whole supplier chain in cooperation with its parent company in Bratislava. Starting with the collection and processing of wood chips by burning, heat production and heat distribution to the end user. This gives the company better control over costs and consequently its own prices. Last year, the engineering company, Hrinovske storjarne, decided to focus only on its core business and sold its heating plant, Hrinovske tepelne hospodarstvo, to Intech Slovakia and changed the company name to Hrinovska energeticka. Local companies and inhabitants were concerned that the new owner would increase prices. But the company publicly declared and kept promises that the heat price for households would remain at 500 Slovak crowns/gigajoule (13.33 EUR/gigajoule ), one of the lowest prices in Slovakia. This year the prices increased slightly to 570 Slovak crowns (15.2 EUR). 'We needed - even at the cost of lower profit - to satisfy our customers so that we would not lose them. We used this time for transition to biomass. This will allow us to freeze our prices in the coming years,' explained the statutory representative of the company, Ivan Dudak. (authors)

  12. Data mining to estimate broiler mortality when exposed to heat wave Mineração de dados e estimativa da mortalidade alta de frangos quando expostos a onda de calor

    Directory of Open Access Journals (Sweden)

    Marcos Martinez Vale

    2008-01-01

    Full Text Available Heat waves usually result in losses of animal production since they are exposed to thermal stress inducing an increase in mortality and consequent economical losses. Animal science and meteorological databases from the last years contain enough data in the poultry production business to allow the modeling of mortality losses due to heat wave incidence. This research analyzes a database of broiler production associated to climatic data, using data mining techniques such as attribute selection and data classification (decision tree to model the impact of heat wave incidence on broiler mortality. The temperature and humidity index (THI was used for screening environmental data. The data mining techniques allowed the development of three comprehensible models for estimating specifically high mortality during broiler production. Two models yielded a classification accuracy of 89.3% by using Principal Component Analysis (PCA and Wrapper feature selection approaches. Both models obtained a class precision of 0.83 for classifying high mortality. When the feature selection was made by the domain experts, the model accuracy reached 85.7%, while the class precision of high mortality was 0.76. Meteorological data and the calculated THI from meteorological stations were helpful to select the range of harmful environmental conditions for broilers 29 and 42 days old. The data mining techniques were useful for building animal production models.As ondas de calor provocam perdas na produção animal pela sua exposição ao estresse por calor aumentando a mortalidade, e consequentemente, perdas econômicas. Bancos de dados zootécnicos e meteorológicos históricos podem conter informações que permitem modelar a mortalidade de frangos devido à incidência de ondas de calor. O objetivo foi analisar bancos de dados de frangos de corte associados a dados meteorológicos utilizando técnicas de mineração de dados, seleção de atributos e classificação (

  13. TDC Offset Estimation from Motored Cylinder Pressure Data based on Heat Release Shaping Estimation du décalage de PMH à partir de données de pression de cylindre moteur basées sur la conformation de libération de chaleur

    Directory of Open Access Journals (Sweden)

    Tunestål P.

    2011-10-01

    Full Text Available Finding the correct Top Dead Center (TDC offset for an internal combustion engine is harder than it seems. This study introduces a novel method to find the TDC offset based on the simple assumption that the heat loss power through the combustion chamber walls is constant for motored cycles in a narrow Crank Angle interval around TDC. The proposed method uses nonlinear least squares optimization to find the combination of specific heat ratio and TDC offset that makes the heat loss power as constant as possible. An important subproblem is to determine the peak pressure location with high accuracy. Fitting a third order Fourier series to the motored cylinder pressure allows the pressure maximum to be estimated with a standard deviation of 0.005° Crank Angle (CA and it can also be used instead of the measured pressure to reduce the uncertainty of the TDC estimate by approximately 50%. The standard deviation of a single-cycle TDC estimate is approximately 0.025° CA when using a crank resolution of 0.2° CA for the measurements. The bias of the TDC estimate is in the 0-0.02° CA range both when comparing to measurements with a TDC sensor and with simulated motored cycles. The method can be used both for calibration and on-board diagnostics purposes e.g. during cranking, fuel cut-off or engine switch-off. The third order Fourier series fit comes with a significant computational penalty but since it is only applied very intermittently this does not have to be a serious issue. La détermination du décalage de Point Mort Haut (PMH correct d’un moteur à combustion interne est plus difficile qu’il n’y paraît. Cette étude introduit une nouvelle méthode destinée à déterminer le décalage de PMH sur la base de la simple supposition que la puissance de perte de chaleur à travers les parois de la chambre de combustion soit constante pour des cycles moteur selon un intervalle d’angle de bras de manivelle étroit autour du PMH. La m

  14. Heat convection

    Energy Technology Data Exchange (ETDEWEB)

    Jiji, L.M. [City Univ. of New York, NY (United States). Dept. of Mechanical Engineering

    2006-07-01

    Professor Jiji's broad teaching experience lead him to select the topics for this book to provide a firm foundation for convection heat transfer with emphasis on fundamentals, physical phenomena, and mathematical modelling of a wide range of engineering applications. Reflecting recent developments, this textbook is the first to include an introduction to the challenging topic of microchannels. The strong pedagogic potential of Heat Convection is enhanced by the following ancillary materials: (1) Power Point lectures, (2) Problem Solutions, (3) Homework Facilitator, and, (4) Summary of Sections and Chapters. (orig.)

  15. Heat Convection

    Science.gov (United States)

    Jiji, Latif M.

    Professor Jiji's broad teaching experience lead him to select the topics for this book to provide a firm foundation for convection heat transfer with emphasis on fundamentals, physical phenomena, and mathematical modelling of a wide range of engineering applications. Reflecting recent developments, this textbook is the first to include an introduction to the challenging topic of microchannels. The strong pedagogic potential of Heat Convection is enhanced by the follow ing ancillary materials: (1) Power Point lectures, (2) Problem Solutions, (3) Homework Facilitator, and, (4) Summary of Sections and Chapters.

  16. Renewable Heating And Cooling

    Science.gov (United States)

    Renewable heating and cooling is a set of alternative resources and technologies that can be used in place of conventional heating and cooling technologies for common applications such as water heating, space heating, space cooling and process heat.

  17. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... for signs of heat stroke or exhaustion. Heat Stroke and Exhaustion Symptoms of early heat exhaustion symptoms ... heavy sweating; nausea; and giddiness. Symptoms of heat stroke (late stage of heat illness) include flushed, hot, ...

  18. Improved Heat-Stress Algorithm

    Science.gov (United States)

    Teets, Edward H., Jr.; Fehn, Steven

    2007-01-01

    NASA Dryden presents an improved and automated site-specific algorithm for heat-stress approximation using standard atmospheric measurements routinely obtained from the Edwards Air Force Base weather detachment. Heat stress, which is the net heat load a worker may be exposed to, is officially measured using a thermal-environment monitoring system to calculate the wet-bulb globe temperature (WBGT). This instrument uses three independent thermometers to measure wet-bulb, dry-bulb, and the black-globe temperatures. By using these improvements, a more realistic WBGT estimation value can now be produced. This is extremely useful for researchers and other employees who are working on outdoor projects that are distant from the areas that the Web system monitors. Most importantly, the improved WBGT estimations will make outdoor work sites safer by reducing the likelihood of heat stress.

  19. Reserve estimates in western basins. Part 2: Piceance Basin

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-01

    This study characterizes an extremely large gas resource located in low permeability, sandstone reservoirs of the Mesaverde group in the Piceance Basin, Colorado. Total in place resource is estimated at 307.3 Tcf. Via application of geologic, engineering and economic criteria, the portion of this resource potentially recoverable as reserves is estimated. Those volumes estimated include probable, possible and potential categories and total 5.8 Tcf as a mean estimate of recoverable gas for all plays considered in the basin. About 82.6% of the total evaluated resource is contained within sandstones that have extremely poor reservoir properties with permeabilities considered too low for commerciality using current frac technology. Cost reductions and technology improvements will be required to unlock portions of this enormous resource. Approximately 2.7% of the total resource is contained within sandstone reservoirs which do not respond to massive hydraulic fracture treatments, probably due to their natural lenticular nature. Approximately 6.8% of the total resource is located in deeply buried settings below deepest established production. Approximately 7.9% of the total resource is considered to represent tight reservoirs that may be commercially exploited using today`s hydraulic fracturing technology. Recent technology advances in hydraulic fracturing practices in the Piceance Basin Mesaverde has resulted in a marked improvement in per well gas recovery which, where demonstrated, has been incorporated into the estimates provided in this report. This improvement is so significant in changing the risk-reward relationship that has historically characterized this play, that previously uneconomic areas and resources will graduate to the economically exploitable category. 48 refs., 96 figs., 18 tabs.

  20. Heat exchangers

    International Nuclear Information System (INIS)

    1975-01-01

    The tubes of a heat exchanger tube bank have a portion thereof formed in the shape of a helix, of effective radius equal to the tube radius and the space between two adjacent tubes, to tangentially contact the straight sections of the tubes immediately adjacent thereto and thereby provide support, maintain the spacing and account for differential thermal expansion thereof

  1. Heat Rash

    Science.gov (United States)

    ... too much. The sweat gets trapped under your skin and blocks your sweat glands. If your pores cannot clear out the sweat, you may get ... irritation caused by clothing that rubs against the skin. If your rash is severe, ... can block pores even more. Living with heat rash Whether you ...

  2. Heat exchanger

    International Nuclear Information System (INIS)

    Wolowodiuk, W.

    1976-01-01

    A heat exchanger of the straight tube type is described in which different rates of thermal expansion between the straight tubes and the supply pipes furnishing fluid to those tubes do not result in tube failures. The supply pipes each contain a section which is of helical configuration

  3. A Piezoelectric Cryogenic Heat Switch

    Science.gov (United States)

    Jahromi, Amir E.; Sullivan, Dan F.

    2014-01-01

    We have measured the thermal conductance of a mechanical heat switch actuated by a piezoelectric positioner, the PZHS (PieZo electric Heat Switch), at cryogenic temperatures. The thermal conductance of the PZHS was measured between 4 K and 10 K, and on/off conductance ratios greater than 100 were achieved when the positioner applied its maximum force of 8 N. We discuss the advantages of using this system in cryogenic applications, and estimate the ultimate performance of an optimized PZHS.

  4. Prediction of critical heat flux for water in uniformly heated vertical ...

    African Journals Online (AJOL)

    This paper includes the prediction of critical heat flux (CHF) for uniformly heated vertical porous coated tubes at pressures between 0,1 to 0,7 MPa. In this study, we use a total of 742 data points of CHF for water in uniformly heated vertical porous coated tubes obtained from literature. Accuracy of correlations was estimated ...

  5. Heat cost in a Swedish agrothermal plant

    International Nuclear Information System (INIS)

    Christensen, J.

    1978-01-01

    Low-grade heat is of rapidly increasing importance in Sweden and, therefore, so is the economic evaluation of such heat. The present heat cost is based on a detailed feasibility study of large-scale heated horticulture combined with electricity production from a Swedish boiling water reactor power plant. To estimate judiciously the cost of heat from a dual-purpose plant--such as a large-scale horticultural installation combined with and using low-grade waste heat from an electric power plant--is an almost classical problem: a measure of arbitrarity is unavoidable. The opportunity cost approach shown has presumably some new features. It results in an estimated cost of heat delivered from the turbine condenser heater in the power plant of 1.4 $/GJ (or 6.1 Swedish Crwn/GJ) in 1980, which is less than one-third of the cost of fuel only with conventional oil-fired heaters

  6. Heat exchanger

    International Nuclear Information System (INIS)

    Bennett, J.C.

    1975-01-01

    A heat exchanger such as forms, for example, part of a power steam boiler is made up of a number of tubes that may be arranged in many different ways, and it is necessary that the tubes be properly supported. The means by which the tubes are secured must be as simple as possible so as to facilitate construction and must be able to continue to function effectively under the varying operating conditions to which the heat exchanger is subject. The arrangement described is designed to meet these requirements, in an improved way. The tubes are secured to a member extending past several tubes and abutment means are provided. At least some of the abutment means comprise two abutment pieces and a wedge secured to the supporting member, that acts on these pieces to maintain the engagement. (U.K.)

  7. Urban Heat Wave Hazard Assessment

    Science.gov (United States)

    Quattrochi, D. A.; Jedlovec, G.; Crane, D. L.; Meyer, P. J.; LaFontaine, F.

    2016-12-01

    Heat waves are one of the largest causes of environmentally-related deaths globally and are likely to become more numerous as a result of climate change. The intensification of heat waves by the urban heat island effect and elevated humidity, combined with urban demographics, are key elements leading to these disasters. Better warning of the potential hazards may help lower risks associated with heat waves. Moderate resolution thermal data from NASA satellites is used to derive high spatial resolution estimates of apparent temperature (heat index) over urban regions. These data, combined with demographic data, are used to produce a daily heat hazard/risk map for selected cities. MODIS data are used to derive daily composite maximum and minimum land surface temperature (LST) fields to represent the amplitude of the diurnal temperature cycle and identify extreme heat days. Compositing routines are used to generate representative daily maximum and minimum LSTs for the urban environment. The limited effect of relative humidity on the apparent temperature (typically 10-15%) allows for the use of modeled moisture fields to convert LST to apparent temperature without loss of spatial variability. The daily max/min apparent temperature fields are used to identify abnormally extreme heat days relative to climatological values in order to produce a heat wave hazard map. Reference to climatological values normalizes the hazard for a particular region (e.g., the impact of an extreme heat day). A heat wave hazard map has been produced for several case study periods and then computed on a quasi-operational basis during the summer of 2016 for Atlanta, GA, Chicago, IL, St. Louis, MO, and Huntsville, AL. A hazard does not become a risk until someone or something is exposed to that hazard at a level that might do harm. Demographic information is used to assess the urban risk associated with the heat wave hazard. Collectively, the heat wave hazard product can warn people in urban

  8. The Heat and Momentum Transfers Relation in Channels of Plate Heat Exchangers

    OpenAIRE

    Kapustenko, Petro O.; Arsenyeva, Olga P.; Dolgonosova, Olena

    2011-01-01

    The link between heat transfer intensity and hydraulic resistance of PHE channels is determined with the use of modified Reynolds analogy of heat and momentum transfer. The formula to estimate the share in total hydraulic resistance of pressure loss due to friction is proposed. The resulting model enables to calculate film heat transfer coefficients in PHE channels on a data of hydraulic resistance of the main heat transfer field. The calculations are compared with the available in literature...

  9. Parametric simulation and experimental analysis of earth air heat exchanger with solar air heating duct

    OpenAIRE

    Sanjeev Jakhar; Rohit Misra; M.S. Soni; Nikhil Gakkhar

    2016-01-01

    Earth air heat exchanger (EAHE) systems are insufficient to meet the thermal comfort requirements in winter conditions. The low heating potential of such systems can be improved by integrating the system with solar air heating duct (SAHD). The aim of this paper is to present a model to estimate the heating potential for EAHE system with and without SAHD. The model is generated using TRNSYS 17 simulation tool and validated against experimental investigation on an experimental set-up in Ajmer, ...

  10. Modelling of Ammonia Heat Pump Desuperheaters

    DEFF Research Database (Denmark)

    Christensen, Stefan Wuust; Elmegaard, Brian; Markussen, Wiebke Brix

    2015-01-01

    This paper presents a study of modelling desuperheating in ammonia heat pumps. Focus is on the temperature profile of the superheated refrigerant. Typically, the surface area of a heat exchanger is estimated using the Log Mean Temperature Difference (LMTD) method. The assumption of this method...... is that the specific heat is constant throughout the temperature glide of the refrigerant in the heat exchanger. However, considering ammonia as refrigerant, the LMTD method does not give accurate results due to significant variations of the specific heat. By comparing the actual temperature profiles from a one...

  11. Heat-Exchanger/Heat-Pipe Interface

    Science.gov (United States)

    Snyder, H. J.; Van Hagan, T. H.

    1987-01-01

    Monolithic assembly reliable and light in weight. Heat exchanger and evaporator ends of heat pipes integrated in monolithic halves welded together. Interface assembly connects heat exchanger of furnace, reactor, or other power source with heat pipes carrying heat to radiator or power-consuming system. One of several concepts proposed for nuclear power supplies aboard spacecraft, interface useful on Earth in solar thermal power systems, heat engines, and lightweight cooling systems.

  12. Performance of a LiBr-water absorption chiller operating with plate heat exchangers

    International Nuclear Information System (INIS)

    Vega, M. de; Almendros-Ibanez, J.A.; Ruiz, G.

    2006-01-01

    This paper studies the performance of a lithium bromide-water absorption chiller operating with plate heat exchangers (PHE). The overall heat transfer coefficients in the desorber, the condenser and the solution heat recoverer are calculated using the correlations provided in the literature for evaporation, condensation and liquid to liquid heat transfer in PHEs. The variable parameters are the external driving temperatures. In the desorber, the inlet temperature of the hot fluid ranges from 75 deg. C to 105 deg. C. In the condenser and the absorber, the inlet temperature of the cooling water goes from 20 deg. C to 40 deg. C. The coefficient of performance (COP) obtained ranges from 0.5 to 0.8 for cooling duties ranging from 2 kW to 12 kW. The chiller response to different hot fluid temperatures and circulated mass flow rates is also presented. The performance and the internal parameters of the chiller at part load are, therefore, calculated. A higher efficiency results when the solution pumped from the absorber to the desorber decreases. The heat transfer analysis of the PHEs is also presented. The overall heat transfer coefficient in the desorber, equal to 790 W/m 2 K at the design conditions, is also analysed at part load. The condenser performance can be represented by a similar relationship found in conventional air cooled condensers

  13. Performance of a LiBr-water absorption chiller operating with plate heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Vega, M. de; Almendros-Ibanez, J.A. [Departamento de Ingenieria Termica y de Fluidos, Universidad Carlos III de Madrid, Avda. Universidad 30, 28911 Leganes, Madrid (Spain); Ruiz, G.

    2006-11-15

    This paper studies the performance of a lithium bromide-water absorption chiller operating with plate heat exchangers (PHE). The overall heat transfer coefficients in the desorber, the condenser and the solution heat recoverer are calculated using the correlations provided in the literature for evaporation, condensation and liquid to liquid heat transfer in PHEs. The variable parameters are the external driving temperatures. In the desorber, the inlet temperature of the hot fluid ranges from 75{sup o}C to 105{sup o}C. In the condenser and the absorber, the inlet temperature of the cooling water goes from 20{sup o}C to 40{sup o}C. The coefficient of performance (COP) obtained ranges from 0.5 to 0.8 for cooling duties ranging from 2kW to 12kW. The chiller response to different hot fluid temperatures and circulated mass flow rates is also presented. The performance and the internal parameters of the chiller at part load are, therefore, calculated. A higher efficiency results when the solution pumped from the absorber to the desorber decreases. The heat transfer analysis of the PHEs is also presented. The overall heat transfer coefficient in the desorber, equal to 790W/m{sup 2}K at the design conditions, is also analysed at part load. The condenser performance can be represented by a similar relationship found in conventional air cooled condensers. (author)

  14. Heating systems for heating subsurface formations

    Science.gov (United States)

    Nguyen, Scott Vinh [Houston, TX; Vinegar, Harold J [Bellaire, TX

    2011-04-26

    Methods and systems for heating a subsurface formation are described herein. A heating system for a subsurface formation includes a sealed conduit positioned in an opening in the formation and a heat source. The sealed conduit includes a heat transfer fluid. The heat source provides heat to a portion of the sealed conduit to change phase of the heat transfer fluid from a liquid to a vapor. The vapor in the sealed conduit rises in the sealed conduit, condenses to transfer heat to the formation and returns to the conduit portion as a liquid.

  15. Heat exchanger

    International Nuclear Information System (INIS)

    Dostatni, A.W.; Dostatni, Michel.

    1976-01-01

    In the main patent, a description was given of a heat exchanger with an exchange surface in preformed sheet metal designed for the high pressure and temperature service particularly encountered in nuclear pressurized water reactors and which is characterised by the fact that it is composed of at least one exchanger bundle sealed in a containment, the said bundle or bundles being composed of numerous juxtaposed individual compartments whose exchange faces are built of preformed sheet metal. The present addendun certificate concerns shapes of bundles and their positioning methods in the exchanger containment enabling its compactness to be increased [fr

  16. Heat pipes

    CERN Document Server

    Dunn, Peter D

    1982-01-01

    A comprehensive, up-to-date coverage of the theory, design and manufacture of heat pipes and their applications. This latest edition has been thoroughly revised, up-dated and expanded to give an in-depth coverage of the new developments in the field. Significant new material has been added to all the chapters and the applications section has been totally rewritten to ensure that topical and important applications are appropriately emphasised. The bibliography has been considerably enlarged to incorporate much valuable new information. Thus readers of the previous edition, which has established

  17. Numerical Analysis of Heat Storage and Heat Conductivity in the Concrete Hollow Core Deck Element

    DEFF Research Database (Denmark)

    Pomianowski, Michal Zbigniew; Heiselberg, Per; Jensen, Rasmus Lund

    2011-01-01

    In order to minimize energy used for cooling and heating, one of the passive solutions is to efficiently utilize heat storage of a building construction. Presently, heat storage calculations in whole building simulation programs are based on 1D heat transfer models. This paper investigates to what...... extent these simplified models estimate the heat storage potential of precast hollow-core concrete decks correctly. This study investigates various approaches on how to model the heat transfer within the air void in the deck. Furthermore, it is analysed how different heat transfer models influence...... method in BSim for the concrete deck element with air voids. Finally, this paper presents a comparison of the calculated heat conductivity of the hollow-core concrete deck and the measured heat conductivity for the same deck by using hot box apparatus....

  18. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... Emergencies A-Z Share this! Home » Emergency 101 Heat-Related Illnesses Dr. Glenn Mitchell , Emergency physician at ... about heat cramps and heat stroke and exhaustion. Heat Cramps Symptoms include muscle spasms, usually in the ...

  19. Radiofrequency plasma heating: proceedings

    International Nuclear Information System (INIS)

    Swenson, D.G.

    1985-01-01

    The conference proceedings include sessions on Alfven Wave Heating, ICRF Heating and Current Drive, Lower Hybrid Heating and Current Drive, and ECRF Heating. Questions of confinement, diagnostics, instabilities and technology are considered. Individual papers are cataloged separately

  20. Low temperature nuclear heat

    Energy Technology Data Exchange (ETDEWEB)

    Kotakorpi, J.; Tarjanne, R. (comps.)

    1977-08-01

    The meeting was concerned with the use of low grade nuclear heat for district heating, desalination, process heat, and agriculture and aquaculture. The sessions covered applications and demand, heat sources, and economics.

  1. Polar heating in Saturn's thermosphere

    Directory of Open Access Journals (Sweden)

    C. G. A. Smith

    2005-10-01

    Full Text Available A 3-D numerical global circulation model of the Kronian thermosphere has been used to investigate the influence of polar heating. The distributions of temperature and winds resulting from a general heat source in the polar regions are described. We show that both the total energy input and its vertical distribution are important to the resulting thermal structure. We find that the form of the topside heating profile is particularly important in determining exospheric temperatures. We compare our results to exospheric temperatures from Voyager occultation measurements (Smith et al., 1983; Festou and Atreya, 1982 and auroral H3+ temperatures from ground-based spectroscopic observations (e.g. Miller et al., 2000. We find that a polar heat source is consistent with both the Smith et al. determination of T∞~400 K at ~30° N and auroral temperatures. The required heat source is also consistent with recent estimates of the Joule heating rate at Saturn (Cowley et al., 2004. However, our results show that a polar heat source can probably not explain the Festou and Atreya determination of T∞~800 K at ~4° N and the auroral temperatures simultaneously. Keywords. Ionosphere (Planetary ionosphere – Magnetospherica physics (Planetary magnetospheres – Meterology and atmospheric dynamics (Thermospheric dynamics

  2. Heat-driven spin torques in antiferromagnets

    Science.gov (United States)

    Białek, Marcin; Bréchet, Sylvain; Ansermet, Jean-Philippe

    2018-04-01

    Heat-driven magnetization damping, which is a linear function of a temperature gradient, is predicted in antiferromagnets by considering the sublattice dynamics subjected to a heat-driven spin torque. This points to the possibility of achieving spin torque oscillator behavior. The model is based on the magnetic Seebeck effect acting on sublattices which are exchange coupled. The heat-driven spin torque is estimated and the feasibility of detecting this effect is discussed.

  3. Segmented heat exchanger

    Science.gov (United States)

    Baldwin, Darryl Dean; Willi, Martin Leo; Fiveland, Scott Byron; Timmons, Kristine Ann

    2010-12-14

    A segmented heat exchanger system for transferring heat energy from an exhaust fluid to a working fluid. The heat exchanger system may include a first heat exchanger for receiving incoming working fluid and the exhaust fluid. The working fluid and exhaust fluid may travel through at least a portion of the first heat exchanger in a parallel flow configuration. In addition, the heat exchanger system may include a second heat exchanger for receiving working fluid from the first heat exchanger and exhaust fluid from a third heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the second heat exchanger in a counter flow configuration. Furthermore, the heat exchanger system may include a third heat exchanger for receiving working fluid from the second heat exchanger and exhaust fluid from the first heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the third heat exchanger in a parallel flow configuration.

  4. Modeling of development and projection of the accumulated recoverable oil volume: methodology and application; Modelagem da evolucao e projecao de volume de oleo recuperavel acumulado: metodologia e aplicacao

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Luciana Cavalcanti de; Ferreira Filho, Virgilio Jose Martins; Rocha, Vinicius Brito [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE)

    2004-07-01

    A relevant problem that petroleum companies deal is the estimate of the future levels of reserves The objective of the reserve forecasting is pursued through the construction of mathematical models. Considering that the exploration process is an informed and controlled process, in order to reach the exploration targets, the exploration process is lead inside of a sequence of decisions based on the reached results. Such decisions are taken surrounded by an uncertain environment added to the random nature of the process. Another important assumption that must be taken into consideration is the dependency of the exploration on the conditions, or structure, of the discovered resources and the final potential. The modeling starts with the establishment of a general problem, when the models are being constructed, based on suppositions associated to the main concepts, and ends with the attainment of specific solutions, when the best description, or model, is selected through the estimate of the respective parameters and of the measurement adjustments. The result of this approach reflects the essence of the exploration process and how it is reflected in the incorporation of reserves and history of field discoveries. A case study is used for validation of the models and the estimates. (author)

  5. Proposal for a district heat supply system

    International Nuclear Information System (INIS)

    Alefeld, G.

    1976-01-01

    A district heating scheme is proposed which makes it possible to use the waste heat from power stations for the supply of households and industry. The heat is stored by evaporation of ammonia salts or liquids with dissolved salts. Both substances are transported on existing rail- or waterways to heating stations near the consumers, and the heat recovered by reaction of the two components. Then the product of reaction is transported back to the power stations, and reactivated by heat again. Based on a cost estimation, it can be shown that the proposed heat transport with heat trains or ships, at distances up to 100 km, results in heat costs which are to-day already below that of heat from fuel oil. The investment required for the heat transport system is unusually low due to the use of transport ways which already exist. The district heating system is not only favourable in respect of the environment, but actually reduces its present strain, both at the consumer and at the power stations. The technical advantages of the suggested concept, especially the possibility of introducing it in stages, are discussed. The consequences for the national economy regarding the safety of supply and the trade balance, as well as for the public transport undertakings, are obvious, and therefore not included in the paper. (orig.) [de

  6. Comprehensive areal model of residential heating demands

    Energy Technology Data Exchange (ETDEWEB)

    Tessmer, R.G. Jr.

    1978-01-01

    Data sources and methodology for modeling annual residential heating demands are described. A small areal basis is chosen, census tract or minor civil division, to permit estimation of demand densities and economic evaluation of community district heating systems. The demand model is specified for the entire nation in order to provide general applicability and to permit validation with other published fuel consumption estimates for 1970.

  7. Parameter Estimation

    DEFF Research Database (Denmark)

    Sales-Cruz, Mauricio; Heitzig, Martina; Cameron, Ian

    2011-01-01

    In this chapter the importance of parameter estimation in model development is illustrated through various applications related to reaction systems. In particular, rate constants in a reaction system are obtained through parameter estimation methods. These approaches often require the application...... of algebraic equations as the basis for parameter estimation.These approaches are illustrated using estimations of kinetic constants from reaction system models....

  8. Resource Assessment of the In-Place and Potentially Recoverable Deep Natural Gas Resource of the Onshore Interior Salt Basins, North Central and Northeastern Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini; Paul Aharon; Donald A. Goddard; Roger Barnaby

    2006-04-26

    The principal research effort for the first half of Year 3 of the project has been resource assessment. Emphasis has been on estimating the total volume of hydrocarbons generated and the potential amount of this resource that is classified as deep (>15,000 ft) gas in the North Louisiana Salt Basin, the Mississippi Interior Salt Basin, the Manila Subbasin and the Conecuh Subbasin. The amount of this resource that has been expelled, migrated and entrapped is also the focus of the first half of Year 3 of this study.

  9. Subseabed Disposal Program In-Situ Heat Transfer Experiment (ISHTE)

    International Nuclear Information System (INIS)

    Percival, C.M.

    1983-05-01

    A heat transfer experiment is being developed in support of the Subseabed Disposal Program. The primary objectives of this experiment are: to provide information on the in situ response of seabed sediment to localized heating; to provide an opportunity to evaluate theoretical models of the response and to observe any unanticipated phenomena which may occur; and to develop and demonstrate the technology necessary to perform waste isolation oriented experiments on the seafloor at depths up to 6000 m. As presently envisaged, the heat transfer experiment will be conducted at a location in the central North Pacific though it could be performed anywhere that the ocean bottom is of the type deemed suitable for the disposal of nuclear waste material. The experiment will be conducted of the seafloor from a recoverable space-frame platform at a depth of approximately 6000 m. A 400-W isotopic heat source will be implanted in the illite sediment and the subsequent response of the sediment to the induced thermal field evaluated. After remote initiation of the experiment, a permanent record of the data obtained will be recorded on board the platform, with selected information transmitted to a surface vessel by acoustic telemetry. The experiment will be operational for one year, after which the entire platform will be recovered. Current plans call for the deployment of the experiment in 1986. Specific activities which will be pursued during the course of the experiment include: measurement of the thermal field; determination of the effective thermal conductivity of the sediment; measurement of pore pressure; evaluation of radionuclide migration processes; pore water sampling; sediment chemistry studies; sediment shear strength measurements; and coring operations in the immediate vicinity of the experiment for postexperiment analysis

  10. A one-dimensional heat transfer model for parallel-plate thermoacoustic heat exchangers.

    Science.gov (United States)

    de Jong, J A; Wijnant, Y H; de Boer, A

    2014-03-01

    A one-dimensional (1D) laminar oscillating flow heat transfer model is derived and applied to parallel-plate thermoacoustic heat exchangers. The model can be used to estimate the heat transfer from the solid wall to the acoustic medium, which is required for the heat input/output of thermoacoustic systems. The model is implementable in existing (quasi-)1D thermoacoustic codes, such as DeltaEC. Examples of generated results show good agreement with literature results. The model allows for arbitrary wave phasing; however, it is shown that the wave phasing does not significantly influence the heat transfer.

  11. HEAT RECOVERY FROM A NATURAL GAS POWERED INTERNAL COMBUSTION ENGINE BY CO2 TRANSCRITICAL POWER CYCLE

    Directory of Open Access Journals (Sweden)

    Mahmood Farzaneh-Gord

    2010-01-01

    Full Text Available The present work provides details of energy accounting of a natural gas powered internal combustion engine and achievable work of a utilized CO2 power cycle. Based on experimental performance analysis of a new designed IKCO (Iran Khodro Company 1.7 litre natural gas powered engine, full energy accounting of the engine were carried out on various engine speeds and loads. Further, various CO2 transcritical power cycle configurations have been appointed to take advantages of exhaust and coolant water heat lost. Based on thermodynamic analysis, the amount of recoverable work obtainable by CO2 transcritical power cycles have been calculated on various engine conditions. The results show that as much as 18 kW power could be generated by the power cycle. This would be considerable amount of power especially if compared with the engine brake power.

  12. Automation of heating system with heat pump

    OpenAIRE

    Ferdin, Gašper

    2016-01-01

    Because of high prices of energy, we are upgrading our heating systems with newer, more fuel efficient heating devices. Each new device has its own control system, which operates independently from other devices in a heating system. With a relatively low investment costs in automation, we can group devices in one central control system and increase the energy efficiency of a heating system. In this project, we show how to connect an oil furnace, a sanitary heat pump, solar panels and a heat p...

  13. Application of decline curve analysis to estimate recovery factors for carbon dioxide enhanced oil recovery

    Science.gov (United States)

    Jahediesfanjani, Hossein

    2017-07-17

    IntroductionIn the decline curve analysis (DCA) method of estimating recoverable hydrocarbon volumes, the analyst uses historical production data from a well, lease, group of wells (or pattern), or reservoir and plots production rates against time or cumu­lative production for the analysis. The DCA of an individual well is founded on the same basis as the fluid-flow principles that are used for pressure-transient analysis of a single well in a reservoir domain and therefore can provide scientifically reasonable and accurate results. However, when used for a group of wells, a lease, or a reservoir, the DCA becomes more of an empirical method. Plots from the DCA reflect the reservoir response to the oil withdrawal (or production) under the prevailing operating and reservoir conditions, and they continue to be good tools for estimating recoverable hydrocarbon volumes and future production rates. For predicting the total recov­erable hydrocarbon volume, the DCA results can help the analyst to evaluate the reservoir performance under any of the three phases of reservoir productive life—primary, secondary (waterflood), or tertiary (enhanced oil recovery) phases—so long as the historical production data are sufficient to establish decline trends at the end of the three phases.

  14. Heat pump technology

    CERN Document Server

    Von Cube, Hans Ludwig; Goodall, E G A

    2013-01-01

    Heat Pump Technology discusses the history, underlying concepts, usage, and advancements in the use of heat pumps. The book covers topics such as the applications and types of heat pumps; thermodynamic principles involved in heat pumps such as internal energy, enthalpy, and exergy; and natural heat sources and energy storage. Also discussed are topics such as the importance of the heat pump in the energy industry; heat pump designs and systems; the development of heat pumps over time; and examples of practical everyday uses of heat pumps. The text is recommended for those who would like to kno

  15. Cryogenic heat transfer

    CERN Document Server

    Barron, Randall F

    2016-01-01

    Cryogenic Heat Transfer, Second Edition continues to address specific heat transfer problems that occur in the cryogenic temperature range where there are distinct differences from conventional heat transfer problems. This updated version examines the use of computer-aided design in cryogenic engineering and emphasizes commonly used computer programs to address modern cryogenic heat transfer problems. It introduces additional topics in cryogenic heat transfer that include latent heat expressions; lumped-capacity transient heat transfer; thermal stresses; Laplace transform solutions; oscillating flow heat transfer, and computer-aided heat exchanger design. It also includes new examples and homework problems throughout the book, and provides ample references for further study.

  16. Fully recoverable rigid shape memory foam based on copper-catalyzed azide-alkyne cycloaddition (CuAAC) using a salt leaching technique.

    Science.gov (United States)

    Alzahrani, Abeer A; Saed, Mohand; Yakacki, Christopher M; Song, Han Byul; Sowan, Nancy; Walston, Joshua J; Shah, Parag K; McBride, Matthew K; Stansbury, Jeffrey W; Bowman, Christopher N

    2018-01-07

    This study is the first to employ the use of the copper-catalyzed azide-alkyne cycloaddition (CuAAC) polymerization to form a tough and stiff, porous material from a well-defined network possessing a high glass transition temperature. The effect of the network linkages formed as a product of the CuAAC reaction, i.e., the triazoles, on the mechanical behavior at high strain was evaluated by comparing the CuAAC foam to an epoxy-amine-based foam, which consisted of monomers with similar backbone structures and mechanical properties (i.e., T g of 115 °C and a rubbery modulus of 1.0 MPa for the CuAAC foam, T g of 125 °C and a rubbery modulus of 1.2 MPa for the epoxy-amine foam). When each foam was compressed uniformly to 80% strain at ambient temperature, the epoxy-amine foam was severely damaged after only reaching 70% strain in the first compression cycle with a toughness of 300 MJ/m 3 . In contrast, the CuAAC foam exhibited pronounced ductile behavior in the glassy state with three times higher toughness of 850 MJ/m 3 after the first cycle of compression to 80% strain. Additionally, when the CuAAC foam was heated above T g after each of five compression cycles to 80% strain at ambient temperature, the foam completely recovered its original shape while exhibiting a gradual decrease in mechanical performance over the multiple compression cycles. The foam demonstrated almost complete shape fixity and recovery ratios even through five successive cycles, indicative of "reversible plasticity", making it highly desirable as a glassy shape memory foams.

  17. Thermal Models for Intelligent Heating of Buildings

    DEFF Research Database (Denmark)

    Thavlov, Anders; Bindner, Henrik W.

    2012-01-01

    using a grey box approach, i.e. by formulating the model using physical knowledge about heat flow, while the parameters in the model are estimated using collected data and statistics. The physical parameters in the model, e.g. heat capacities and resistances to transfer heat, have been estimated...... share of renewable power generation, which is in general intermittent and non-controllable, the consumption side has to be much more flexible than today. To achieve such flexibility, methods for moving power consumption in time, within the hourly timescale, have to be developed. One approach currently...

  18. Turbulent energy losses during orchard heating

    Energy Technology Data Exchange (ETDEWEB)

    Bland, W.L.

    1979-01-01

    Two rapid-response drag anemometers and low time constant thermocouples, all at 4 m above a heated orchard floor, sampled wind component in the vertical direction and temperature at 30 Hz. The turbulent heat flux calculated revealed not more than 10% of the heat lost from the orchard was via turbulent transort. The observations failed to support previous estimates that at least a third of the energy applied was lost through turbulent transport. Underestimation of heat loss due to mean flow and a newly revealed flux due to spatial variations in the mean flow may explain the unaccounted for loss.

  19. Investigation and optimization of the depth of flue gas heat recovery in surface heat exchangers

    Science.gov (United States)

    Bespalov, V. V.; Bespalov, V. I.; Melnikov, D. V.

    2017-09-01

    Economic issues associated with designing deep flue gas heat recovery units for natural gas-fired boilers are examined. The governing parameter affecting the performance and cost of surface-type condensing heat recovery heat exchangers is the heat transfer surface area. When firing natural gas, the heat recovery depth depends on the flue gas temperature at the condenser outlet and determines the amount of condensed water vapor. The effect of the outlet flue gas temperature in a heat recovery heat exchanger on the additionally recovered heat power is studied. A correlation has been derived enabling one to determine the best heat recovery depth (or the final cooling temperature) maximizing the anticipated reduced annual profit of a power enterprise from implementation of energy-saving measures. Results of optimization are presented for a surface-type condensing gas-air plate heat recovery heat exchanger for the climatic conditions and the economic situation in Tomsk. The predictions demonstrate that it is economically feasible to design similar heat recovery heat exchangers for a flue gas outlet temperature of 10°C. In this case, the payback period for the investment in the heat recovery heat exchanger will be 1.5 years. The effect of various factors on the optimal outlet flue gas temperature was analyzed. Most climatic, economical, or technological factors have a minor effect on the best outlet temperature, which remains between 5 and 20°C when varying the affecting factors. The derived correlation enables us to preliminary estimate the outlet (final) flue gas temperature that should be used in designing the heat transfer surface of a heat recovery heat exchanger for a gas-fired boiler as applied to the specific climatic conditions.

  20. Heat pumps in district heating networks

    DEFF Research Database (Denmark)

    Ommen, Torben Schmidt; Markussen, Wiebke Brix; Elmegaard, Brian

    In the current Danish energy system, the majority of electricity and heat is produced in combined heat and power plants. With increasing shares of intermittent renewable power production, it becomes a challenging task to match power and heat production, as heat demand and production capacity...... constraints limit the power plants. Efficient heat pumps can be used to decouple the constraints of electricity and heat production, while maintaining the high energy efficiency needed to match the politically agreed carbon emission goals. The requirements in terms of COP, location, capacity and economy...... are calculated using an energy system model which includes power plants, heat pumps and district heating consumption profiles. The model is developed with focus on accurate representation of the performance of the units in different locations and operating modes. The model can assist in investment decisions...

  1. Heat pipe heat exchanger and its potential to energy recovery in the tropics

    Directory of Open Access Journals (Sweden)

    Yau Yat H.

    2015-01-01

    Full Text Available The heat recovery by the heat pipe heat exchangers was studied in the tropics. Heat pipe heat exchangers with two, four, six, and eight numbers of rows were examined for this purpose. The coil face velocity was set at 2 m/s and the temperature of return air was kept at 24°C in this study. The performance of the heat pipe heat exchangers was recorded during the one week of operation (168 hours to examine the performance data. Then, the collected data from the one week of operation were used to estimate the amount of energy recovered by the heat pipe heat exchangers annually. The effect of the inside design temperature and the coil face velocity on the energy recovery for a typical heat pipe heat exchanger was also investigated. In addition, heat pipe heat exchangers were simulated based on the effectiveness-NTU method, and their theoretical values for the thermal performance were compared with the experimental results.

  2. Heat sources for heat pumps in the energetic and economic comparison

    International Nuclear Information System (INIS)

    Bockelmann, Franziska; Fisch, M. Norbert; Schlosser, Mathias; Peter, Markus

    2016-01-01

    Because of the growing application of heat pumps also the number of potentially usable low-temperature heat sources and corresponding heat exchangers for heat-pump systems present in the market increases. Thereby products like energy fences, high-power piles, ore ice reservoir come into applications without any knowledge ab out their power or the cost-profit ratio. The optimized lay-out of the coupling to the building are however essential conditions in order to reach an energy-efficient and durable operation of the facilities. The research project ''future heat pump'' sponsored by the BMWi is dedicated to the energetic and economic evaluation of heat sources for heat pumps. In this connection a pre-check-tool for the preliminary selection of low-temperature heat sources and connected, suitable heat-exchange systems is developed and their actual status of development presented. The holistic, comparing consideration of the different heat sources and heat-exchanger systems is related among others to the power numbers of the heat pumps, the entry and withdrawal services of the heat-exchangers, and the general performance of the systems. Additionally an estimation of economic and ecologic aspects (investment and operation costs, CO 2 emissions) is made. Aim is the determination of the plausibility of applications and essential boundary conditions of single source systems. For the qualitative comparison in a project-accompanying monitoring different facilities and source systems are measurement-technically comprehended.

  3. Oscillating heat pipes

    CERN Document Server

    Ma, Hongbin

    2015-01-01

    This book presents the fundamental fluid flow and heat transfer principles occurring in oscillating heat pipes and also provides updated developments and recent innovations in research and applications of heat pipes. Starting with fundamental presentation of heat pipes, the focus is on oscillating motions and its heat transfer enhancement in a two-phase heat transfer system. The book covers thermodynamic analysis, interfacial phenomenon, thin film evaporation,  theoretical models of oscillating motion and heat transfer of single phase and two-phase flows, primary  factors affecting oscillating motions and heat transfer,  neutron imaging study of oscillating motions in an oscillating heat pipes, and nanofluid’s effect on the heat transfer performance in oscillating heat pipes.  The importance of thermally-excited oscillating motion combined with phase change heat transfer to a wide variety of applications is emphasized. This book is an essential resource and learning tool for senior undergraduate, gradua...

  4. Multidimensional Heat Conduction

    DEFF Research Database (Denmark)

    Rode, Carsten

    1998-01-01

    Analytical theory of multidimensional heat conduction. General heat conduction equation in three dimensions. Steay state, analytical solutions. The Laplace equation. Method of separation of variables. Principle of superposition. Shape factors. Transient, multidimensional heat conduction....

  5. Heat Roadmap Europe 1

    DEFF Research Database (Denmark)

    Connolly, David; Mathiesen, Brian Vad; Østergaard, Poul Alberg

    2012-01-01

    Heat Roadmap Europe (Pre-study 1) investigates the role of district heating in the EU27 energy system by mapping local conditions across Europe, identifying the potential for district heating expansion, and subsequently simulating the potential resource in an hourly model of the EU27 energy system....... In 2010, approximately 12% of the space heating demand in Europe is met by district heating, but in this study four alternative scenarios are considered for the EU27 energy system: 1. 2010 with 30% district heating 2. 2010 with 50% district heating 3. 2030 with 30% district heating 4. 2050 with 50......% district heating These scenarios are investigated in two steps. Firstly, district heating replaces individual boilers by converting condensing power plants to combined heat and power plants (CHP) to illustrate how district heating improves the overall efficiency of the energy system. In the second step...

  6. Heat Related Illnesses

    National Research Council Canada - National Science Library

    Carter, R; Cheuvront, S. N; Sawka, M. N

    2006-01-01

    .... The risk of serious heat illness can be markedly reduced by implementing a variety of countermeasures, including becoming acclimated to the heat, managing heat stress exposure, and maintaining hydration...

  7. National inventory of radioactive wastes and recoverable materials 2006. Descriptive catalogue of radioactive waste families; Inventaire national des dechets radioactifs et des matieres valorisables 2006. Catalogue descriptif des familles de dechets radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    Real comprehensive overview of radioactive wastes, the national inventory of radioactive wastes and recoverable materials describes the situation in France of the wastes that can be conditioned (in their definitive form) or not. It presents also the waste production quantities foreseen for 2010, 2020 and beyond. This document is a complement to the synthesis report and to the geographic inventory of radioactive wastes in France and details the classification of wastes by families (wastes with similar characteristics). For each family of wastes, the description comprises a general presentation and some photos. It comprises also some data such as the position of the family in the French classification, the industrial activity at the origin of the waste, the production situation of the waste in concern (finished, in progress, not started). Some information about the raw waste are given and the conditioning process used is described. Some figures complete the description, like: the past and future production quantities, the evaluation of the radioactivity of the waste family in 2004 and 2020, and the evaluation of the thermal power when available. Finally, some information are given about the presence of compounds with a specific risk of toxicity. (J.S.)

  8. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of whole-water recoverable arsenic, boron, and vanadium using inductively coupled plasma-mass spectrometry

    Science.gov (United States)

    Garbarino, John R.

    2000-01-01

    Analysis of in-bottle digestate by using the inductively coupled plasma?mass spectrometric (ICP?MS) method has been expanded to include arsenic, boron, and vanadium. Whole-water samples are digested by using either the hydrochloric acid in-bottle digestion procedure or the nitric acid in-bottle digestion procedure. When the hydrochloric acid in-bottle digestion procedure is used, chloride must be removed from the digestate by subboiling evaporation before arsenic and vanadium can be accurately determined. Method detection limits for these elements are now 10 to 100 times lower than U.S. Geological Survey (USGS) methods using hydride generation? atomic absorption spectrophotometry (HG? AAS) and inductively coupled plasma? atomic emission spectrometry (ICP?AES), thus providing lower variability at ambient concentrations. The bias and variability of the methods were determined by using results from spike recoveries, standard reference materials, and validation samples. Spike recoveries in reagent-water, surface-water, ground-water, and whole-water recoverable matrices averaged 90 percent for seven replicates; spike recoveries were biased from 25 to 35 percent low for the ground-water matrix because of the abnormally high iron concentration. Results for reference material were within one standard deviation of the most probable value. There was no significant difference between the results from ICP?MS and HG?AAS or ICP?AES methods for the natural whole-water samples that were analyzed.

  9. Contact Heat Exchanger

    Science.gov (United States)

    Fleming, M. L.; Stalmach, D. D.; Cox, R. L.

    1985-01-01

    Fluid pressure controls contact between heat pipe and heat exchanger. Heat exchanger system in cross section provides contact interface between fluid system and heat pipe with easy assembly/disassembly of heat-pipe/ pumped-liquid system. Originally developed for use in space, new device applicable on Earth where fluid system is linked with heat pipe, where rapid assembly/disassembly required, or where high pressures or corrosive fluids used.

  10. State of the Irish housing stock—Modelling the heat losses of Ireland's existing detached rural housing stock and estimating the benefit of thermal retrofit measures on this stock

    International Nuclear Information System (INIS)

    Ahern, Ciara; Griffiths, Philip; O'Flaherty, Micheál

    2013-01-01

    Ireland's housing stock has been identified as being amongst the least energy efficient in Northern Europe. Consequently, atmospheric emissions are greater than necessary. Government funded schemes have been introduced to incentivise the uptake of thermal retrofit measures in the domestic Irish market. A study of Ireland's housing highlights the dominance of detached houses (43%), 72% of which are rurally located and are predominantly heated with fuel oil. This paper investigates the economic and carbon case for thermal retrofit measures to the existing detached, oil centrally heated, rural housing stock. The study found the case for energy efficiency measures to be categorical and supports the Irish Government's focus on energy efficiency policy measures. Thermal retrofit measures in the detached housing stock have the potential to realise an averaged 65% theoretical reduction in heating costs and CO 2 emissions for houses constructed prior to 1979 (coinciding with the introduction of building regulations) and around 26% for newer homes, thus offering a significant contribution (44%) to Ireland's residential carbon abatement projections and hence in meeting the EU's directives on energy and carbon. The greatest savings (36%) of Ireland's carbon abatement projections result from improving the energy efficiency of the pre 1979 stock. - Highlights: ► Model constructs base geometry of detached rural Irish dwellings by age band. ► Model quantifies savings to this stock via The National Insulation Scheme. ► Results offer significant contribution to Ireland's carbon abatement projections. ► Greatest savings result from retrofitting the pre 1979 stock. ► Government needs to introduce PAYS scheme or similar to engage public at large

  11. Optimum length of finned pipe for waste heat recovery

    International Nuclear Information System (INIS)

    Soeylemez, M.S.

    2008-01-01

    A thermoeconomic feasibility analysis is presented yielding a simple algebraic optimization formula for estimating the optimum length of a finned pipe that is used for waste heat recovery. A simple economic optimization method is used in the present study by combining it with an integrated overall heat balance method based on fin effectiveness for calculating the maximum savings from a waste heat recovery system

  12. Soil heat flux and day time surface energy balance closure

    Indian Academy of Sciences (India)

    Soil heat flux is an important input component of surface energy balance. Estimates of soil heat flux were made in the year 2008 using soil temperature data at Astronomical Observatory, Thiruvananthapuram, south Kerala. Hourly values of soil heat flux from 00 to 24 LST are presented for selected days typical of the winter, ...

  13. Gasification with nuclear reactor heat

    International Nuclear Information System (INIS)

    Weisbrodt, I.A.

    1977-01-01

    The energy-political ultimate aims for the introduction of nuclear coal gasification and the present state of technology concerning the HTR reactor, concerning gasification and heat exchanging components are outlined. Presented on the plans a) for hydro-gasification of lignite and for steam gasification of pit coal for the production of synthetic natural gas, and b) for the introduction of a nuclear heat system. The safety and environmental problems to be expected are portrayed. The main points of development, the planned prototype plant and the schedule of the project Pototype plant Nuclear Process heat (PNP) are specified. In a market and economic viability study of nuclear coal gasification, the application potential of SNG, the possible construction programme for the FRG, as well as costs and rentability of SNG production are estimated. (GG) [de

  14. Methodologies for Adaptive Flight Envelope Estimation and Protection

    Science.gov (United States)

    Tang, Liang; Roemer, Michael; Ge, Jianhua; Crassidis, Agamemnon; Prasad, J. V. R.; Belcastro, Christine

    2009-01-01

    This paper reports the latest development of several techniques for adaptive flight envelope estimation and protection system for aircraft under damage upset conditions. Through the integration of advanced fault detection algorithms, real-time system identification of the damage/faulted aircraft and flight envelop estimation, real-time decision support can be executed autonomously for improving damage tolerance and flight recoverability. Particularly, a bank of adaptive nonlinear fault detection and isolation estimators were developed for flight control actuator faults; a real-time system identification method was developed for assessing the dynamics and performance limitation of impaired aircraft; online learning neural networks were used to approximate selected aircraft dynamics which were then inverted to estimate command margins. As off-line training of network weights is not required, the method has the advantage of adapting to varying flight conditions and different vehicle configurations. The key benefit of the envelope estimation and protection system is that it allows the aircraft to fly close to its limit boundary by constantly updating the controller command limits during flight. The developed techniques were demonstrated on NASA s Generic Transport Model (GTM) simulation environments with simulated actuator faults. Simulation results and remarks on future work are presented.

  15. Probabilistic estimates of US uranium supply

    International Nuclear Information System (INIS)

    Piepel, G.F.; Long, L.W.; McLaren, R.A.; Ford, C.E.

    1981-02-01

    This report develops and presents probabilistic estimates of total US uranium supply. The word supply is used in the broad sense that both uranium quantity and cost are of interest. Cost implies minimum acceptable selling price rather than market price. Specifically, four types of probability distributions are developed: (1) quantity of US uranium; (2) cost of US uranium; (3) quantity of US uranium available at or below a certain cost; and (4) cost of US uranium given a certain consumption. In this report, uranium refers to recoverable U 3 O 8 (endowment adjusted for mining recovery and milling losses) occurring in both reserve and potential deposits meeting minimum size requirements with minimum grade above 0.01%. Cost includes operating and capital costs, taxes, profit, and cost capital. This definition of cost is often used to better denote this meaning. This definition of cost is contrasted with forward costs, that exclude sunk costs, taxes, and return on investment. Consumption refers to uranium that has been used from the current time to any point in the future. Uranium quantity and consumption are expressed in short tons, while full recovery costs are stated in constant 1980 dollars per pound

  16. Extrapolating phosphorus production to estimate resource reserves.

    Science.gov (United States)

    Vaccari, David A; Strigul, Nikolay

    2011-08-01

    Various indicators of resource scarcity and methods for extrapolating resource availability are examined for phosphorus. These include resource lifetime, and trends in resource price, ore grade and discovery rates, and Hubbert curve extrapolation. Several of these indicate increasing scarcity of phosphate resources. Calculated resource lifetime is subject to a number of caveats such as unanticipated future changes in resource discovery, mining and beneficiation technology, population growth or per-capita demand. Thus it should be used only as a rough planning index or as a relative indicator of potential scarcity. This paper examines the uncertainty in one method for estimating available resources from historical production data. The confidence intervals for the parameters and predictions of the Hubbert curves are computed as they relate to the amount of information available. These show that Hubbert-type extrapolations are not robust for predicting the ultimately recoverable reserves or year of peak production of phosphate rock. Previous successes of the Hubbert curve are for cases in which there exist alternative resources, which is not the situation for phosphate. It is suggested that data other than historical production, such as population growth, identified resources and economic factors, should be included in making such forecasts. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Static Heat Loads in the LHC Arc Cryostats: Final Assessment

    CERN Document Server

    Parma, V

    2010-01-01

    This note presents the final assessment of the static heat loads in the LHC arc cryostats, using different experimental methods during the first commissioning period in 2007. This assessment further develops and completes previous estimates made during the commissioning of sector 7_8 [1]. The estimate of the helium inventory, a prerequisite for the heat load calculation, is also presented. Heat loads to the cold mass are evaluated from the internal energy balance during natural as well as powered warm-ups of the helium baths in different subsector. The helium inventory is calculated from the internal energy balance during powered warm-ups and matched with previous assessments. Furthermore, heat loads to the thermal shield are estimated from the non-isothermal cooling of the supercritical helium in line E. The comparison of measured heat loads with previous estimates and with budgeted values is then presented, while their correlation with some important parameters like insulation vacuum pressure and some heat ...

  18. Heat transfer coefficient as parameter describing ability of insulating liquid to heat transfer

    Science.gov (United States)

    Nadolny, Zbigniew; Gościński, Przemysław; Bródka, Bolesław

    2017-10-01

    The paper presents the results of the measurements of heat transfer coefficient of insulating liquids used in transformers. The coefficient describes an ability of the liquid to heat transport. On the basis of the coefficient, effectiveness of cooling system of electric power devices can be estimated. Following liquids were used for the measurements: mineral oil, synthetic ester and natural ester. It was assumed that surface heat load is about 2500 W·m-2, which is equal the load of transformer windings. A height of heat element was 1.6 m, because it makes possible steady distribution of temperature on its surface. The measurements of heat transfer coefficient was made as a function of various position of heat element (vertical, horizontal). In frame of horizontal position of heat element, three suppositions were analysed: top, bottom, and side.

  19. Heat: not black, not white. It's gray!!!

    Science.gov (United States)

    Singh, Laxmi Prabha; Kapoor, Medha; Singh, Shashi Bala

    2013-01-01

    Heat-related illness (HRI) is a broad term that includes clinical conditions ranging from heat cramps and syncope to heat exhaustion and heatstroke, which may result in death. HRIs are one of the major causes of death worldwide and continue to increase in severity with the rise in global temperature. The identification and estimation of heat-related morbidity and mortality is a major challenge. Heat stress manifests itself into respiratory, cardiovascular, and cerebrovascular disorders, leading to the attribution of the deaths caused by heat stress to these disorders. Although HRIs affect mankind in general, certain occupational workers such as soldiers and athletes are more prone. Various pharmacological and nonpharmacological strategies have been employed to combat HRIs. Despite this, heat exposure results in significant morbidity and mortality. Hence, complete understanding of HRIs at physiological as well as molecular level is required to facilitate design of more efficient preventive and treatment strategies. The impact of heat on mankind is not just restricted to HRIs. Heat treatment, i.e., thermotherapy, has been used extensively since ancient times for relieving pain, making heat a two-edged sword. This review attempts to summarize various HRIs, their physiological and molecular basis, and the state-of-the-art techniques/research initiatives to combat the same. It also illustrates the application of thermotherapy as a means for improving quality of life and morbidity associated with several disease conditions such as fibromyalgia syndrome, heart diseases, cancer, chronic pain, and depression.

  20. Heat exchanger fouling: Prediction, measurement, and mitigation

    Science.gov (United States)

    The US Department of Energy (DOE), Office of Industrial Programs (OIP) sponsors the development of innovative heat exchange systems. Fouling is a major and persistent cost associated with most industrial heat exchangers and nationally wastes an estimated 2.9 Quads per year. To predict and control fouling, three OIP projects are currently exploring heat exchanger fouling in specific industrial applications. A fouling probe has been developed to determine empirically the fouling potential of an industrial gas stream and to derive the fouling thermal resistance. The probe is a hollow metal cylinder capable of measuring the average heat flux along the length of the tube. The local heat flux is also measured by a heat flux meter embedded in the probe wall. The fouling probe has been successfully tested in the laboratory at flue gas temperatures up to 2200 F and a local heat flux up to 41,000 BTU/hr sq ft. The probe has been field tested at a coal-fired boiler plant. Future tests at a municipal waste incinerator are planned. Two other projects study enhanced heat exchanger tubes, specifically the effect of enhanced surface geometries on the tube bundle performance. Both projects include fouling in a liquid heat transfer fluid. Identifying and quantifying the factors affecting fouling in these enhanced heat transfer tubes will lead to techniques to mitigate fouling.

  1. Application possibilities for nuclear heating plants in the energy system of the Federal Republic of Germany

    International Nuclear Information System (INIS)

    Kohler, T.

    1991-01-01

    The field of application for nuclear heating plants is the so-called low-temperature heating market. It includes the energy demand for space heating, hot water an low-temperature process heat. The analysis of technical potentials for heating reactors considers two different levels. The structure of the district heating system determines the technical potential in the now existing energy system, it amounts to a total power of 9,8 to 14,3 GW th of heating reactors. For a possible extended use of heating reactors in future which goes beyond the existing district heating system the technical circumstances and the local distribution of the low-temperature heating market define the technical potential which ranges from 126 to 160 GW th on todays basis. The chance of implementing nuclear heating plants is strongly influenced by the economy of their heat generation. The economic situation of heat generation with heating reactors is estimated in comparison to current fossil district heating production systems. In the low-temperature heating market the heat supply by nuclear fed district heating systems is compared to the heat production in houses. Considering the assumptions the analysis indicates that nuclear heating plants can compete with existing fossil heat sources. The analysis shows that heating reactors are an interesting and powerful option for the supply of the district heating market in future. The underlying economic assumptions would allow the use of nuclear heating plants and it seems that they could contribute to reduce the environmental stress. (orig.) [de

  2. Ground Source Heat Supply in Moscow Oblast: Temperature Potential and Sustainable Depth of Heat Wells

    Science.gov (United States)

    Vasil'ev, G. P.; Gornov, V. F.; Dmitriev, A. N.; Kolesova, M. V.; Yurchenko, V. A.

    2018-01-01

    The paper is devoted to a problem of increasing the efficiency of low-potential geothermal heat in heat pump systems of residential buildings the Moscow oblast of Russia, including Moscow. Estimates of a natural geothermal potential in the Moscow oblast (based on climatological data for the period from 1982 to 2011) are presented and a "Typical climatic year of natural soil temperature variations for the geoclimatic conditions of the Moscow oblast, including the city of Moscow" is proposed. Numerical simulation of the influence of geothermal energy potential and the depth of heat wells on the efficiency of ground source heat pump systems for the heat supply of residential buildings is carried out. Analysis of the numerical simulation showed that the operation of a heat pump system in a house heating mode under the geoclimatic conditions of the Moscow oblast leads to a temperature drop of the heat-exchange medium circulating through heat wells to 5-6°C by the end of the first 10 years of operation, and the process stabilizes by the 15th year of operation, and further changes in the heat-exchange medium temperature do not any longer significantly affect the temperature of the heat-exchange medium in the heat well. In this case, the exact dependence of the heat-exchange medium temperature drop on the depth is not revealed. Data on the economically expedient heat well depth for the conditions of the Moscow oblast ensuring a net present value for the whole residential building life cycle are presented. It is found that the heat well depth of 60 m can be considered as an endpoint for the Moscow oblast, and a further heat well deepening is economically impractical.

  3. Method of calculating heat transfer in furnaces of small power

    Directory of Open Access Journals (Sweden)

    Khavanov Pavel

    2016-01-01

    Full Text Available This publication presents the experiences and results of generalization criterion equation of importance in the analysis of the processes of heat transfer and thermal calculations of low-power heat generators cooled combustion chambers. With generalizing depending estimated contribution of radiation and convective heat transfer component in the complex for the combustion chambers of small capacity boilers. Determined qualitative and quantitative dependence of the integrated radiative-convective heat transfer from the main factors working combustion chambers of small volume.

  4. Solar Heating Equipment

    Science.gov (United States)

    1981-01-01

    Solar Unlimited, Inc.'s suncatcher line includes a variety of solar arrays, derived from NASA's satellite program: water heating only, partial home heating, or water and whole house central heating. Solar Unlimited developed a set of vigorous requirements to avoid problems common to solar heating technologies.

  5. Nature's Heat Exchangers.

    Science.gov (United States)

    Barnes, George

    1991-01-01

    Discusses the heat-transfer systems of different animals. Systems include heat conduction into the ground, heat transferred by convection, heat exchange in lizards, fish and polar animals, the carotid rete system, electromagnetic radiation from animals and people, and plant and animal fiber optics. (MDH)

  6. Transient Heat Conduction

    DEFF Research Database (Denmark)

    Rode, Carsten

    1998-01-01

    Analytical theory of transient heat conduction.Fourier's law. General heat conducation equation. Thermal diffusivity. Biot and Fourier numbers. Lumped analysis and time constant. Semi-infinite body: fixed surface temperature, convective heat transfer at the surface, or constant surface heat flux...

  7. Direct fired heat exchanger

    Science.gov (United States)

    Reimann, Robert C.; Root, Richard A.

    1986-01-01

    A gas-to-liquid heat exchanger system which transfers heat from a gas, generally the combustion gas of a direct-fired generator of an absorption machine, to a liquid, generally an absorbent solution. The heat exchanger system is in a counterflow fluid arrangement which creates a more efficient heat transfer.

  8. Three approaches for estimating recovery factors in carbon dioxide enhanced oil recovery

    Science.gov (United States)

    Verma, Mahendra K.

    2017-07-17

    PrefaceThe Energy Independence and Security Act of 2007 authorized the U.S. Geological Survey (USGS) to conduct a national assessment of geologic storage resources for carbon dioxide (CO2) and requested the USGS to estimate the “potential volumes of oil and gas recoverable by injection and sequestration of industrial carbon dioxide in potential sequestration formations” (42 U.S.C. 17271(b)(4)). Geologic CO2 sequestration associated with enhanced oil recovery (EOR) using CO2 in existing hydrocarbon reservoirs has the potential to increase the U.S. hydrocarbon recoverable resource. The objective of this report is to provide detailed information on three approaches that can be used to calculate the incremental recovery factors for CO2-EOR. Therefore, the contents of this report could form an integral part of an assessment methodology that can be used to assess the sedimentary basins of the United States for the hydrocarbon recovery potential using CO2-EOR methods in conventional oil reservoirs.

  9. District heating in Switzerland

    International Nuclear Information System (INIS)

    Herzog, F.

    1991-01-01

    District heating has been used in Switzerland for more than 50 years. Its share of the heat market is less than 3% today. An analysis of the use of district heating in various European countries shows that a high share of district heating in the heat market is always dependent on ideal conditions for its use. Market prospects and possible future developments in the use of district heating in Switzerland are described in this paper. The main Swiss producers and distributors of district heating are members of the Association of District Heating Producers and Distributors. This association supports the installation of district heating facilities where ecological, energetical and economic aspects indicate that district heating would be a good solution. (author) 2 tabs., 6 refs

  10. Introduction to heat transfer

    CERN Document Server

    SUNDÉN, B

    2012-01-01

    Presenting the basic mechanisms for transfer of heat, Introduction to Heat Transfer gives a deeper and more comprehensive view than existing titles on the subject. Derivation and presentation of analytical and empirical methods are provided for calculation of heat transfer rates and temperature fields as well as pressure drop. The book covers thermal conduction, forced and natural laminar and turbulent convective heat transfer, thermal radiation including participating media, condensation, evaporation and heat exchangers.

  11. Heat Roadmap Europe 2

    DEFF Research Database (Denmark)

    Connolly, David; Mathiesen, Brian Vad; Østergaard, Poul Alberg

    are identified and then, the EU27 energy system is modelled to investigate the impact of district heating. The results indicate that a combination of heat savings, district heating in urban areas, and individual heat pumps in rural areas will enable the EU27 to reach its greenhouse gas emission targets by 2050......, but at a cheaper price than a scenario which focuses primarily on the implementation of heat savings....

  12. Impact of ground control on mining reserve estimation

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, G. [AMC Resource Consultants Pty Ltd., Sydney, NSW (Australia)

    2001-07-01

    The estimation of coal resources and reserves is an important and often critical component of the assessment of a mining operation or project. An accurate estimation of reserves in particular is essential for many stages of a mining project - from initial evaluation of the project potential, commitment to a mine development, approval of capital expenditure and/or project finance, through to mine valuation for sale or public listing. Accurate estimation of reserves is also a compulsory reporting requirement for public listed companies as set out in the Australian Stock Exchange (ASX), listing rules. Under these rules, resources and reserves are reported under the JOC Code that incorporates the 'Australian Code for Reporting Identified Coal Resources and Reserves'. These rules are now also used more frequently for non public listed companies. A number of geotechnical parameters play an important role in the process of converting insitu resources to economically recoverable reserves. Whilst these parameters play a role in opencut mining, this paper covers a number of key geotechnical issues that influence the estimation of underground reserves. 11 figs.

  13. Magnetite Nanoparticles-Supported APTES as a Powerful and Recoverable Nanocatalyst for the Preparation of 2-Amino-5,10-dihydro- 5,10-dioxo-4H-benzo[g]chromenes and Tetrahydrobenzo[g]quinoline-5,10- diones.

    Science.gov (United States)

    Ghasemzadeh, Mohammad Ali; Elyasi, Zahra; Azimi-Nasrabad, Mina; Mirhosseini-Eshkevari, Boshra

    2017-01-01

    This study introduces a green and effective approach for the preparation of biologically-active heterocyclic compounds including 2-amino-5,10-dihydro-5,10-dioxo-4Hbenzo[ g]chromenes and tetrahydrobenzo[g]quinoline-5,10-diones using one-pot multi-component reactions in the presence of Fe3O4@SiO2-NH2 nanocomposite. The preparation and use of aminofunctionalized Fe3O4@SiO2 as a powerful and reusable nanocatalyst is described. The catalyst was characterized by spectral techniques including FT-IR, SEM, XRD, EDX and VSM analysis. This method offers the advantages of high yields, short reaction times, comfortable work-up and reusability of the catalyst. The amino-functionalization silica-coated magnetite nanocomposite was prepared by three step method and the structure elucidation of the nanocatalyst has been done using various spectroscopic analyses. Then, the Fe3O4@SiO2-NH2 nanocomposite was used in the multicomponent synthesis of 2-amino-5,10-dihydro-5,10-dioxo-4H-benzo[g]chromenes and tetrahydrobenzo[g]quinoline-5,10-diones under reflux conditions. All of the products were analyzed with m.p., 1H NMR, 13C NMR and FT-IR spectroscopy techniques. The study on the recoverability of the nanocatalyst showed the recovered Fe3O4@SiO2-NH2 nanocomposite could be reused sixth consecutive times with a little-decreased activity. Amino-functionalized SiO2 coated Fe3O4 nanocomposite exhibited superparamagnetic behavior and strong magnetization at room temperature. The average crystallite sizes of the catalyst was about 50-60 nm. The obtained magnetic nanocomposite showed excellent catalytic activity as a new heterogeneous magnetic catalyst for the synthesis of some benzo[g]chromenes and tetrahydrobenzo[g]quinoline-5,10-diones. We propose that NH2 groups on the surfaces of nanocomposite act as the Brønsted base and cause to dehydrogenation of substrates to promote the reactions. It was found that Fe3O4@SiO2-NH2 nanocomposite act as an eco-friendly and efficient catalyst for one

  14. Induction Heating Process Design Using COMSOL Multiphysics Software

    Directory of Open Access Journals (Sweden)

    Andy Triwinarko

    2011-08-01

    Full Text Available Induction heating is clean environmental heating process due to a non-contact heating process. There is lots of the induction heating type that be used in the home appliance but it is still new technology in Indonesia. The main interesting area of the induction heating design is the efficiency of the usage of energy and choice of the plate material. COMSOL Multiphysics Software can be used to simulate and estimate the induction heating process. Therefore, the software can be used to design the induction heating process that will have a optimum efficiency. The properties of the induction heating design were also simulated and analyzed such as effect of inductors width, inductors distance, and conductive plate material. The result was shown that the good design of induction heating must have a short width and distance inductor and used silicon carbide as material plate with high frequency controller.

  15. Assessment of two-level heat pump installations’ power efficiency for heat supply systems

    Directory of Open Access Journals (Sweden)

    Аlla Е. Denysova

    2015-06-01

    Full Text Available The problem of energy saving becomes one of the most important in power engineering. It is caused by exhaustion of world reserves in hydrocarbon fuel, such as gas, oil and coal representing sources of traditional heat supply. Conventional sources has essential shortcomings: low power, ecological and economic efficiencies, that can be eliminated by using alternative methods of power supply, like the considered one: low-temperature natural heat of ground waters of on the basis of heat pump installations application. The heat supply system considered provides an effective use of two-level heat pump installation operating as heat source the Odessa city ground waters during the lowest ambient temperature period. Proposed is a calculation method of heat pump installations on the basis of geothermal heat supply. Calculated are the values of electric energy consumption N by the compressors’ drive, and the heat supply system transformation coefficient µ for a source of geothermal heat from ground waters of Odessa city allowing to estimate efficiency of two-level heat pump installations.

  16. Extended Heat Deposition in Hot Jupiters: Application to Ohmic Heating

    Science.gov (United States)

    Ginzburg, Sivan; Sari, Re'em

    2016-03-01

    The observed radii of many giant exoplanets in close orbits exceed theoretical predictions. One suggested origin for this discrepancy is heat deposited deep inside the atmospheres of these “hot Jupiters”. Here, we study extended power sources that distribute heat from the photosphere to the deep interior of the planet. Our analytical treatment is a generalization of a previous analysis of localized “point sources”. We model the deposition profile as a power law in the optical depth and find that planetary cooling and contraction halt when the internal luminosity (I.e., cooling rate) of the planet drops below the heat deposited in the planet’s convective region. A slowdown in the evolutionary cooling prior to equilibrium is possible only for sources that do not extend to the planet’s center. We estimate the ohmic dissipation resulting from the interaction between the atmospheric winds and the planet’s magnetic field, and apply our analytical model to ohmically heated planets. Our model can account for the observed radii of most inflated planets, which have equilibrium temperatures of ≈1500-2500 K and are inflated to a radius of ≈ 1.6{R}J. However, some extremely inflated planets remain unexplained by our model. We also argue that ohmically inflated planets have already reached their equilibrium phase, and no longer contract. Following Wu & Lithwick, who argued that ohmic heating could only suspend and not reverse contraction, we calculate the time it takes ohmic heating to re-inflate a cold planet to its equilibrium configuration. We find that while it is possible to re-inflate a cold planet, the re-inflation timescales are longer by a factor of ≈ 30 than the cooling time.

  17. Empirical Analysis for the Heat Exchange Effectiveness of a Thermoelectric Liquid Cooling and Heating Unit

    Directory of Open Access Journals (Sweden)

    Hansol Lim

    2018-03-01

    Full Text Available This study aims to estimate the performance of thermoelectric module (TEM heat pump for simultaneous liquid cooling and heating and propose empirical models for predicting the heat exchange effectiveness. The experiments were conducted to investigate and collect the performance data of TEM heat pump where the working fluid was water. A total of 57 sets of experimental data were statistically analyzed to estimate the effects of each independent variable on the heat exchange effectiveness using analysis of variance (ANOVA. To develop the empirical model, the six design parameters were measured: the number of transfer units (NTU of the heat exchangers (i.e., water blocks, the inlet water temperatures and temperatures of water blocks at the cold and hot sides of the TEM. As a result, two polynomial equations predicting heat exchange effectiveness at the cold and hot sides of the TEM heat pump were derived as a function of the six selected design parameters. Also, the proposed models and theoretical model of conventional condenser and evaporator for heat exchange effectiveness were compared with the additional measurement data to validate the reliability of the proposed models. Consequently, two conclusions have been made: (1 the possibility of using the TEM heat pump for simultaneous cooling and heating was examined with the maximum temperature difference of 30 °C between cold and hot side of TEM, and (2 it is revealed that TEM heat pump has difference with the conventional evaporator and condenser from the comparison results between the proposed models and theoretical model due to the heat conduction and Joule effect in TEM.

  18. Waste heat rejection from geothermal power stations

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, R.C.

    1978-12-01

    This study of waste heat rejection from geothermal power stations is concerned only with the heat rejected from the power cycle. The heat contained in reinjected or otherwise discharged geothermal fluids is not included with the waste heat considered here. The heat contained in the underflow from the flashtanks in such systems is not considered as part of the heat rejected from the power cycle. By following this definition of the waste heat to be rejected, various methods of waste heat dissipation are discussed without regard for the particular arrangement to obtain heat from the geothermal source. Recent conceptual design studies made for 50-MW(e) geothermal power stations at Heber and Niland, California, are of particular interst. The former uses a flashed-steam system and the latter a binary cycle that uses isopentane. In last-quarter 1976 dollars, the total estimated capital costs were about $750/kW and production costs about 50 mills/kWhr. If wet/dry towers were used to conserve 50% of the water evaporation at Heber, production costs would be about 65 mills/kWhr.

  19. Heat pump augmentation of nuclear process heat

    International Nuclear Information System (INIS)

    Koutz, S.L.

    1986-01-01

    A system is described for increasing the temperature of a working fluid heated by a nuclear reactor. The system consists of: a high temperature gas cooled nuclear reactor having a core and a primary cooling loop through which a coolant is circulated so as to undergo an increase in temperature, a closed secondary loop having a working fluid therein, the cooling and secondary loops having cooperative association with an intermediate heat exchanger adapted to effect transfer of heat from the coolant to the working fluid as the working fluid passes through the intermediate heat exchanger, a heat pump connected in the secondary loop and including a turbine and a compressor through which the working fluid passes so that the working fluid undergoes an increase in temperature as it passes through the compressor, a process loop including a process chamber adapted to receive a process fluid therein, the process chamber being connected in circuit with the secondary loop so as to receive the working fluid from the compressor and transfer heat from the working fluid to the process fluid, a heat exchanger for heating the working fluid connected to the process loop for receiving heat therefrom and for transferring heat to the secondary loop prior to the working fluid passing through the compressor, the secondary loop being operative to pass the working fluid from the process chamber to the turbine so as to effect driving relation thereof, a steam generator operatively associated with the secondary loop so as to receive the working fluid from the turbine, and a steam loop having a feedwater supply and connected in circuit with the steam generator so that feedwater passing through the steam loop is heated by the steam generator, the steam loop being connected in circuit with the process chamber and adapted to pass steam to the process chamber with the process fluid

  20. Heat Roadmap Europe

    DEFF Research Database (Denmark)

    Connolly, David; Mathiesen, Brian Vad; Lund, Henrik

    2015-01-01

    This document is a summary of the key technical inputs for the modelling of the heat strategy for Europe outlined in the latest Heat Roadmap Europe studies [1, 2]. These studies quantify the impact of alternative heating strategies for Europe in 2030 and 2050. The study is based on geographical...... information systems (GIS) and energy system analyses. In this report, the inputs for other modelling tools such as PRIMES are presented, in order to enable other researches to generate similar heating scenarios for Europe. Although Heat Roadmap Europe presents a complete heat strategy for Europe, which...... to model increased penetrations of district heating in the EU energy system in other energy planning tools, such as the PRIMES and JRC-EU-TIMES tools. The key results from the Heat Roadmap Europe studies are that:  Heat savings have a key role to play, but there is a socio-economic limit: after reducing...

  1. Basic heat transfer

    CERN Document Server

    Bacon, D H

    2013-01-01

    Basic Heat Transfer aims to help readers use a computer to solve heat transfer problems and to promote greater understanding by changing data values and observing the effects, which are necessary in design and optimization calculations.The book is concerned with applications including insulation and heating in buildings and pipes, temperature distributions in solids for steady state and transient conditions, the determination of surface heat transfer coefficients for convection in various situations, radiation heat transfer in grey body problems, the use of finned surfaces, and simple heat exc

  2. Heat roadmap China

    DEFF Research Database (Denmark)

    Xiong, Weiming; Wang, Yu; Mathiesen, Brian Vad

    2015-01-01

    District heating is regarded as a key element of energy saving actions in the Chinese national energy strategy, while space heating in China is currently still dominated by coal boilers. However, there is no existing quantitative study to analyse the future heat strategy for China. Therefore....... These are compared to each other from the national energy system perspective. The comparison of the three strategies indicates that the new district heating strategy which introduces surplus heat from industry and generation plants is more economically and technically optimal than the individual heat strategy...

  3. Wound tube heat exchanger

    Science.gov (United States)

    Ecker, Amir L.

    1983-01-01

    What is disclosed is a wound tube heat exchanger in which a plurality of tubes having flattened areas are held contiguous adjacent flattened areas of tubes by a plurality of windings to give a double walled heat exchanger. The plurality of windings serve as a plurality of effective force vectors holding the conduits contiguous heat conducting walls of another conduit and result in highly efficient heat transfer. The resulting heat exchange bundle is economical and can be coiled into the desired shape. Also disclosed are specific embodiments such as the one in which the tubes are expanded against their windings after being coiled to insure highly efficient heat transfer.

  4. Thermometry, calorimetry, and mean body temperature during heat stress.

    Science.gov (United States)

    Kenny, Glen P; Jay, Ollie

    2013-10-01

    Heat balance in humans is maintained at near constant levels through the adjustment of physiological mechanisms that attain a balance between the heat produced within the body and the heat lost to the environment. Heat balance is easily disturbed during changes in metabolic heat production due to physical activity and/or exposure to a warmer environment. Under such conditions, elevations of skin blood flow and sweating occur via a hypothalamic negative feedback loop to maintain an enhanced rate of dry and evaporative heat loss. Body heat storage and changes in core temperature are a direct result of a thermal imbalance between the rate of heat production and the rate of total heat dissipation to the surrounding environment. The derivation of the change in body heat content is of fundamental importance to the physiologist assessing the exposure of the human body to environmental conditions that result in thermal imbalance. It is generally accepted that the concurrent measurement of the total heat generated by the body and the total heat dissipated to the ambient environment is the most accurate means whereby the change in body heat content can be attained. However, in the absence of calorimetric methods, thermometry is often used to estimate the change in body heat content. This review examines heat exchange during challenges to heat balance associated with progressive elevations in environmental heat load and metabolic rate during exercise. Further, we evaluate the physiological responses associated with heat stress and discuss the thermal and nonthermal influences on the body's ability to dissipate heat from a heat balance perspective.

  5. Value of solar thermal industrial process heat

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D.R.; Fassbender, L.L.; Chockie, A.D.

    1986-03-01

    This study estimated the value of solar thermal-generated industrial process heat (IPH) as a function of process heat temperature. The value of solar thermal energy is equal to the cost of producing energy from conventional fuels and equipment if the energy produced from either source provides an equal level of service. This requirement put the focus of this study on defining and characterizing conventional process heat equipment and fuels. Costs (values) were estimated for 17 different design points representing different combinations of conventional technologies, temperatures, and fuels. Costs were first estimated for median or representative conditions at each design point. The cost impact of capacity factor, efficiency, fuel escalation rate, and regional fuel price differences were then evaluated by varying each of these factors within credible ranges.

  6. Observer-based monitoring of heat exchangers.

    Science.gov (United States)

    Astorga-Zaragoza, Carlos-Manuel; Alvarado-Martínez, Víctor-Manuel; Zavala-Río, Arturo; Méndez-Ocaña, Rafael-Maxim; Guerrero-Ramírez, Gerardo-Vicente

    2008-01-01

    The goal of this work is to provide a method for monitoring performance degradation in counter-flow double-pipe heat exchangers. The overall heat transfer coefficient is estimated by an adaptive observer and monitored in order to infer when the heat exchanger needs preventive or corrective maintenance. A simplified mathematical model is used to synthesize the adaptive observer and a more complex model is used for simulation. The reliability of the proposed method was demonstrated via numerical simulations and laboratory experiments with a bench-scale pilot plant.

  7. Heat transfer enhancement

    International Nuclear Information System (INIS)

    Hasatani, Masanobu; Itaya, Yoshinori

    1985-01-01

    In order to develop energy-saving techniques and new energy techniques, and also most advanced techniques by making industrial equipment with high performance, heat transfer performance frequently becomes an important problem. In addition, the improvement of conventional heat transfer techniques and the device of new heat transfer techniques are often required. It is most proper that chemical engineers engage in the research and development for enhancing heat transfer. The research and development for enhancing heat transfer are important to heighten heat exchange efficiency or to cool equipment for preventing overheat in high temperature heat transfer system. In this paper, the techniques of enhancing radiative heat transfer and the improvement of radiative heat transfer characteristics are reported. Radiative heat transfer is proportional to fourth power of absolute temperature, and it does not require any heat transfer medium, but efficient heat-radiation converters are necessary. As the techniques of enhancing radiative heat transfer, the increase of emission and absorption areas, the installation of emissive structures and the improvement of radiative characteristics are discussed. (Kako, I.)

  8. Water Impact Prediction Tool for Recoverable Rockets

    Science.gov (United States)

    Rooker, William; Glaese, John; Clayton, Joe

    2011-01-01

    Reusing components from a rocket launch can be cost saving. NASA's space shuttle system has reusable components that return to the Earth and impact the ocean. A primary example is the Space Shuttle Solid Rocket Booster (SRB) that descends on parachutes to the Earth after separation and impacts the ocean. Water impact generates significant structural loads that can damage the booster, so it is important to study this event in detail in the design of the recovery system. Some recent examples of damage due to water impact include the Ares I-X First Stage deformation as seen in Figure 1 and the loss of the SpaceX Falcon 9 First Stage.To ensure that a component can be recovered or that the design of the recovery system is adequate, an adequate set of structural loads is necessary for use in failure assessments. However, this task is difficult since there are many conditions that affect how a component impacts the water and the resulting structural loading that a component sees. These conditions include the angle of impact with respect to the water, the horizontal and vertical velocities, the rotation rate, the wave height and speed, and many others. There have been attempts to simulate water impact. One approach is to analyze water impact using explicit finite element techniques such as those employed by the LS-Dyna tool [1]. Though very detailed, this approach is time consuming and would not be suitable for running Monte Carlo or optimization analyses. The purpose of this paper is to describe a multi-body simulation tool that runs quickly and that captures the environments a component might see. The simulation incorporates the air and water interaction with the component, the component dynamics (i.e. modes and mode shapes), any applicable parachutes and lines, the interaction of winds and gusts, and the wave height and speed. It is capable of quickly conducting Monte Carlo studies to better capture the environments and genetic algorithm optimizations to reproduce a flight.

  9. Distributed and recoverable digital control system

    Science.gov (United States)

    Stange, Kent (Inventor); Hess, Richard (Inventor); Kelley, Gerald B (Inventor); Rogers, Randy (Inventor)

    2010-01-01

    A real-time multi-tasking digital control system with rapid recovery capability is disclosed. The control system includes a plurality of computing units comprising a plurality of redundant processing units, with each of the processing units configured to generate one or more redundant control commands. One or more internal monitors are employed for detecting data errors in the control commands. One or more recovery triggers are provided for initiating rapid recovery of a processing unit if data errors are detected. The control system also includes a plurality of actuator control units each in operative communication with the computing units. The actuator control units are configured to initiate a rapid recovery if data errors are detected in one or more of the processing units. A plurality of smart actuators communicates with the actuator control units, and a plurality of redundant sensors communicates with the computing units.

  10. Gas Environment Recoverable Detection (GERD) HMI

    CERN Document Server

    Sillat, Mari Liis

    2016-01-01

    Report on the work done during the summer student project. The goal was to produce HMI panels for the GERD smoke detection system. The required platform was WinCC OA and the running sensor data needed to be displayed, pump controls were needed and an alarm was required to be set for the smoke sensors upper limit range.

  11. Climate adaptive action plans to manage heat stress in Indian cities ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Climate adaptive action plans to manage heat stress in Indian cities. The Intergovernmental Panel on Climate Change estimates that rising global temperatures will increase the amount and severity of heat waves. In India, these heat waves are exacerbated by the heat generated by human activities in urban areas. This has ...

  12. Effect of wet bulb depression on heat sterilization time of slash pine lumber

    Science.gov (United States)

    William T. Simpson

    For international trade, heat sterilization of wood products is often required to prevent the spread of insects and pathogens. Application of heat sterilization requires estimates of the time necessary to heat the center of the wood configuration to the temperature required to kill the insect or other pest. The nature of the heating medium was found to have a...

  13. One-Loop Operation of Primary Heat Transport System in MONJU During Heat Transport System Modifications

    International Nuclear Information System (INIS)

    Goto, T.; Tsushima, H.; Sakurai, N.; Jo, T.

    2006-01-01

    MONJU is a prototype fast breeder reactor (FBR). Modification work commenced in March 2005. Since June 2004, MONJU has changed to one-loop operation of the primary heat transport system (PHTS) with all of the secondary heat transport systems (SHTS) drained of sodium. The purposes of this change are to shorten the modification period and to reduce the cost incurred for circuit trace heating electrical consumption. Before changing condition, the following issues were investigated to show that this mode of operation was possible. The heat loss from the reactor vessel and the single primary loop must exceed the decay heat by an acceptable margin but the capacity of pre-heaters to keep the sodium within the primary vessel at about 200 deg. C must be maintained. With regard to the heat loss and the decay heat, the estimated heat loss in the primary system was in the range of 90-170 kW in one-loop operation, and the calculated decay heat was 21.2 kW. Although the heat input of the primary pump was considered, it was clear that circuit heat loss greatly exceeded the decay heat. As for pre-heaters, effective capacity was less than the heat loss. Therefore, the temperature of the reactor vessel room was raised to reduce the heat loss. One-loop operation of the PHTS was able to be executed by means of these measures. The cost of electrical consumption in the power plant has been reduced by one-loop operation of the PHTS and the modification period was shortened. (authors)

  14. Laser Processed Heat Exchangers

    Data.gov (United States)

    National Aeronautics and Space Administration — The considerable mass of Heat Exchangers (HXs) and coldplates on spacecraft as well as the problematic coatings of the Condensing Heat Exchanger (CHX) are among the...

  15. Effective geothermal heat

    International Nuclear Information System (INIS)

    Abelsen, Atle

    2006-01-01

    Scandinavia's currently largest geothermal heating project: the New Ahus hospital, is briefly presented. 300-400 wells on a field outside the hospital are constructed to store energy for both heating and cooling purposes

  16. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... Be Prepared Safe Citizen Day Organize Important Medical Information ER Checklists Preparing for Emergencies Be ready to ... anyone can be affected. Here you will find information about heat cramps and heat stroke and exhaustion. ...

  17. Convective heat transfer

    CERN Document Server

    Kakac, Sadik; Pramuanjaroenkij, Anchasa

    2014-01-01

    Intended for readers who have taken a basic heat transfer course and have a basic knowledge of thermodynamics, heat transfer, fluid mechanics, and differential equations, Convective Heat Transfer, Third Edition provides an overview of phenomenological convective heat transfer. This book combines applications of engineering with the basic concepts of convection. It offers a clear and balanced presentation of essential topics using both traditional and numerical methods. The text addresses emerging science and technology matters, and highlights biomedical applications and energy technologies. What’s New in the Third Edition: Includes updated chapters and two new chapters on heat transfer in microchannels and heat transfer with nanofluids Expands problem sets and introduces new correlations and solved examples Provides more coverage of numerical/computer methods The third edition details the new research areas of heat transfer in microchannels and the enhancement of convective heat transfer with nanofluids....

  18. Paleoclassical electron heat transport

    International Nuclear Information System (INIS)

    Callen, J.D.

    2005-01-01

    Radial electron heat transport in low collisionality, magnetically-confined toroidal plasmas is shown to result from paleoclassical Coulomb collision processes (parallel electron heat conduction and magnetic field diffusion). In such plasmas the electron temperature equilibrates along magnetic field lines a long length L, which is the minimum of the electron collision length and a maximum effective half length of helical field lines. Thus, the diffusing field lines induce a radial electron heat diffusivity M ≅ L/(πR 0q ) ∼ 10 >> 1 times the magnetic field diffusivity η/μ 0 ≅ ν e (c/ω p ) 2 . The paleoclassical electron heat flux model provides interpretations for many features of 'anomalous' electron heat transport: magnitude and radial profile of electron heat diffusivity (in tokamaks, STs, and RFPs), Alcator scaling in high density plasmas, transport barriers around low order rational surfaces and near a separatrix, and a natural heat pinch (or minimum temperature gradient) heat flux form. (author)

  19. Regenerative heat sources for heating networks

    International Nuclear Information System (INIS)

    Huenges, Ernst; Sperber, Evelyn; Eggers, Jan-Bleicke; Noll, Florian; Kallert, Anna Maria; Reuss, Manfred

    2015-01-01

    The ambitious goal, the German Federal Government has set itself, to reduce the emissions of greenhouse gases by 80% to 95% by the year 2050. As there are currently more than half of German energy consumption for the production of heat is required, big contributions to climate protection can be expected from this area if more renewable heat sources are used. Renewable heat sources such as bioenergy, solar thermal and geothermal energy in particular can be provided as compared to fossil fuels with significantly lower specific CO 2 emissions. Objectives in the heating market and scenarios for the transformation of the heat sector have been elaborated in the BMU Lead Study 2011. The main pillar of this scenario is the reduction of final energy consumption for heat by the energy-efficient renovation of existing buildings and further increasing demands on the energetic quality of new buildings. To cover the remaining energy demand, a focus is on the expansion of heating networks based on renewable energies. [de

  20. Study on Surface Heat Budget of Various Pavements for Urban Heat Island Mitigation

    Directory of Open Access Journals (Sweden)

    Hideki Takebayashi

    2012-01-01

    Full Text Available The surface heat budgets of various pavement surfaces are studied with the aim of mitigating the urban heat island effect. In this study, the thermal characteristics of pavements are examined using data from observations. The net radiation, surface temperature, temperature under the surface, conduction heat flux, and core weight for each experimental surface are recorded, together with the weather conditions at the time of observation. The latent heat flux is estimated from the observed weight of the cores. The surface heat budget under the same weather conditions is examined, and the sensible heat flux from each target surface is calculated. The parameters that influence the surface heat budget, for example, solar reflectance (albedo, evaporative efficiency, heat conductivity, and heat capacity, are examined. On a typical summer day, the maximum reduction in the sensible heat flux from that on a normal asphalt surface is about 150 W/m2 for an asphalt surface with water-retaining material and about 100 W/m2 for a cement concrete surface with water-retaining material, depending on the albedo of each surface.

  1. Solar heat receiver

    Science.gov (United States)

    Hunt, Arlon J.; Hansen, Leif J.; Evans, David B.

    1985-01-01

    A receiver for converting solar energy to heat a gas to temperatures from 700.degree.-900.degree. C. The receiver is formed to minimize impingement of radiation on the walls and to provide maximum heating at and near the entry of the gas exit. Also, the receiver is formed to provide controlled movement of the gas to be heated to minimize wall temperatures. The receiver is designed for use with gas containing fine heat absorbing particles, such as carbon particles.

  2. Competition in the household heat product markets in Finland

    International Nuclear Information System (INIS)

    Linden, Mikael; Peltola-Ojala, Paeivi

    2005-01-01

    In the article the market of household heat products is defined independently. The market consists mainly of electricity, district heating, light fuel oil, and wood. Geographically household heat product markets are limited to the area which is covered by the local district heating network. We test indirectly whether this market definition is valid, i.e. do different household heat products act as substitutes to each other. However, the substitution may quite often be limited since the local district heat supplier is the only supplier on the area and also electricity companies have high market shares in the area they are located. The amount of competitors even in these enlarged markets is low. Also the local district heating network gives a technological potential to non-competitive product specific pricing. Thus, a relevant case exists where the district heating company can determine the price of its product without constraints from other firms and heat products. We test empirically whether the local prices of district heating are affected by the local heat product market shares of district heating companies. We use panel data which consists of 75 district heating companies in years 1996 - 2002. The data includes market share, joint production, district heating tariffs, production scale, and raw material input cost variables. The results obtained from different estimations indicate clearly that competitive case is not the prevailing one in the Finnish district heating pricing. The market shares of district heating companies had a positive effect on the district heating prices. The result also does not support the hypothesis that different household heat products belong to same heat product markets. (Author)

  3. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... this! Home » Emergency 101 Heat-Related Illnesses Dr. Glenn Mitchell , Emergency physician at Mercy Health System in Chesterfield, Missouri Heat-related illness can be caused by overexposure to the sun or any situation that involves extreme heat. Young children and the elderly are most at risk, ...

  4. Champagne Heat Pump

    Science.gov (United States)

    Jones, Jack A.

    2004-01-01

    The term champagne heat pump denotes a developmental heat pump that exploits a cycle of absorption and desorption of carbon dioxide in an alcohol or other organic liquid. Whereas most heat pumps in common use in the United States are energized by mechanical compression, the champagne heat pump is energized by heating. The concept of heat pumps based on other absorption cycles energized by heat has been understood for years, but some of these heat pumps are outlawed in many areas because of the potential hazards posed by leakage of working fluids. For example, in the case of the water/ammonia cycle, there are potential hazards of toxicity and flammability. The organic-liquid/carbon dioxide absorption/desorption cycle of the champagne heat pump is similar to the water/ammonia cycle, but carbon dioxide is nontoxic and environmentally benign, and one can choose an alcohol or other organic liquid that is also relatively nontoxic and environmentally benign. Two candidate nonalcohol organic liquids are isobutyl acetate and amyl acetate. Although alcohols and many other organic liquids are flammable, they present little or no flammability hazard in the champagne heat pump because only the nonflammable carbon dioxide component of the refrigerant mixture is circulated to the evaporator and condenser heat exchangers, which are the only components of the heat pump in direct contact with air in habitable spaces.

  5. Microwave processing heats up

    Science.gov (United States)

    Microwaves are a common appliance in many households. In the United States microwave heating is the third most popular domestic heating method food foods. Microwave heating is also a commercial food processing technology that has been applied for cooking, drying, and tempering foods. It's use in ...

  6. Theoretical energy and exergy analyses of solar assisted heat pump space heating system

    Directory of Open Access Journals (Sweden)

    Atmaca Ibrahim

    2014-01-01

    Full Text Available Due to use of alternative energy sources and energy efficient operation, heat pumps come into prominence in recent years. Especially in solar-assisted heat pumps, sizing the required system is difficult and arduous task in order to provide optimum working conditions. Therefore, in this study solar assisted indirect expanded heat pump space heating system is simulated and the results of the simulation are compared with available experimental data in the literature in order to present reliability of the model. Solar radiation values in the selected region are estimated with the simulation. The case study is applied and simulation results are given for Antalya, Turkey. Collector type and storage tank capacity effects on the consumed power of the compressor, COP of the heat pump and the overall system are estimated with the simulation, depending on the radiation data, collector surface area and the heating capacity of the space. Exergy analysis is also performed with the simulation and irreversibility, improvement potentials and exergy efficiencies of the heat pump and system components are estimated.

  7. A corrosive resistant heat exchanger

    Science.gov (United States)

    Richlen, S.L.

    1987-08-10

    A corrosive and erosive resistant heat exchanger which recovers heat from a contaminated heat stream. The heat exchanger utilizes a boundary layer of innocuous gas, which is continuously replenished, to protect the heat exchanger surface from the hot contaminated gas. The innocuous gas is pumped through ducts or perforations in the heat exchanger wall. Heat from the heat stream is transferred by radiation to the heat exchanger wall. Heat is removed from the outer heat exchanger wall by a heat recovery medium. 3 figs., 3 tabs.

  8. Analyzing the Efficiency of Introduction of the Intermittent Heating Mode

    Science.gov (United States)

    Anisimova, E.; Shcherbak, A.

    2017-11-01

    The efficiency of introduction of an optimal intermittent heating mode for a service center building in Chelyabinsk is estimated. The optimal intermittent heating mode ensures heat energy saving while maintaining the required microclimate parameters. The graphical dependencies of the amount of heat energy saving on the heat retention of the building and the outdoor air temperature are shown. The fundamental formulas which were the basis for calculating the periods of cooling, warming and expenditures of heat energy for the two heating modes are given. The literature on the issue is reviewed, the main points, advantages and disadvantages in the works of both Russian and foreign authors are revealed. The calculation was carried out in compliance with the modern state standards and regulatory documents. The capital costs of a system construction with an intermittent heating mode are determined.

  9. Estimativa da transpiração em cafeeiros utilizando-se sensores de dissipação térmica Estimation of transpiration in coffee crop using heat dissipation sensors

    Directory of Open Access Journals (Sweden)

    Jussálvia da S. Pimentel

    2010-02-01

    Full Text Available Alguns métodos são capazes de determinar diretamente a quantidade de água consumida por uma planta, entre eles o "método de dissipação de calor" ou método de Granier. Neste trabalho se propôs, como objetivo, construir e calibrar sensores de dissipação térmica, avaliar a transpiração em função da posição de inserção do sensor na planta (Norte, Sul, Leste ou Oeste e comparar os resultados com os elementos meteorológicos e a evapotranspiração de referência. Em 24 cafeeiros se instalaram sensores de dissipação térmica, adaptados de Granier (1985, em que o conjunto termopar e resistência foi inserido na agulha. Obteve-se a densidade de fluxo de seiva a partir da variação da diferença de temperatura entre as sondas e se acompanhou a transpiração, em função da transição entre os períodos diurno e noturno. O experimento foi avaliado em 3 períodos: antecedente à floração, na floração e no início da frutificação. Não houve diferença significativamente entre os ângulos de inserção para o fluxo de seiva. Quanto aos elementos meteorológicos, a radiação e a umidade relativa foram os fatores mais determinantes da transpiração obtendo-se, por análises de regressão coeficientes r² entre 0,84 e 0,80.Some methods are capable of directly determining the amount of water consumed by a plant, among them, the "heat dissipation method" or Granier method. This study aimed to: build and calibrate sensors of thermal dissipation; to evaluate the transpiration as a function of the position of insertion of the sensor in the plant (North, South, East or West and to compare the results with the meteorological elements and the evapotranspiration of reference. In 24 coffee plants, thermal dissipation sensors adapted from Granier (1985 were installed, where the whole thermocouple and resistance were inserted into the needle. Density of the sap flow was obtained from the variation of the difference in temperature between

  10. Heat Rash (Prickly Heat or Miliaria)

    Science.gov (United States)

    ... Baby rashes Heat rash Symptoms & causes Diagnosis & treatment Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  11. Single Electrode Heat Effects

    DEFF Research Database (Denmark)

    Jacobsen, Torben; Broers, G. H. J.

    1977-01-01

    The heat evolution at a single irreversibly working electrode is treated onthe basis of the Brønsted heat principle. The resulting equation is analogous to the expression for the total heat evolution in a galvanic cellwith the exception that –DeltaS is substituted by the Peltier entropy, Delta......SP, of theelectrode reaction. eta is the overvoltage at the electrode. This equation is appliedto a high temperature carbonate fuel cell. It is shown that the Peltier entropyterm by far exceeds the heat production due to the irreversible losses, and thatthe main part of heat evolved at the cathode is reabsorbed...

  12. Thermodynamic estimation: Ionic materials

    International Nuclear Information System (INIS)

    Glasser, Leslie

    2013-01-01

    Thermodynamics establishes equilibrium relations among thermodynamic parameters (“properties”) and delineates the effects of variation of the thermodynamic functions (typically temperature and pressure) on those parameters. However, classical thermodynamics does not provide values for the necessary thermodynamic properties, which must be established by extra-thermodynamic means such as experiment, theoretical calculation, or empirical estimation. While many values may be found in the numerous collected tables in the literature, these are necessarily incomplete because either the experimental measurements have not been made or the materials may be hypothetical. The current paper presents a number of simple and relible estimation methods for thermodynamic properties, principally for ionic materials. The results may also be used as a check for obvious errors in published values. The estimation methods described are typically based on addition of properties of individual ions, or sums of properties of neutral ion groups (such as “double” salts, in the Simple Salt Approximation), or based upon correlations such as with formula unit volumes (Volume-Based Thermodynamics). - Graphical abstract: Thermodynamic properties of ionic materials may be readily estimated by summation of the properties of individual ions, by summation of the properties of ‘double salts’, and by correlation with formula volume. Such estimates may fill gaps in the literature, and may also be used as checks of published values. This simplicity arises from exploitation of the fact that repulsive energy terms are of short range and very similar across materials, while coulombic interactions provide a very large component of the attractive energy in ionic systems. Display Omitted - Highlights: • Estimation methods for thermodynamic properties of ionic materials are introduced. • Methods are based on summation of single ions, multiple salts, and correlations. • Heat capacity, entropy

  13. One-Particle Representation of Heat Conduction Described within the Scope of the Second Law.

    Science.gov (United States)

    Jesudason, Christopher Gunaseelan

    2016-01-01

    The Carnot cycle and its deduction of maximum conversion efficiency of heat inputted and outputted isothermally at different temperatures necessitated the construction of isothermal and adiabatic pathways within the cycle that were mechanically "reversible", leading eventually to the Kelvin-Clausius development of the entropy function S with differential dS = dq/T such that [symbol: see text]C dS = 0 where the heat absorption occurs at the isothermal paths of the elementary Carnot cycle. Another required condition is that the heat transfer processes take place infinitely slowly and "reversibly", implying that rates of transfer are not explicitly featured in the theory. The definition of 'heat' as that form of energy that is transferred as a result of a temperature difference suggests that the local mode of transfer of "heat" in the isothermal segments of the pathway implies a Fourier-like heat conduction mechanism which is apparently irreversible, leading to an increase in entropy of the combined reservoirs at either end of the conducting material, and which is deemed reversible mechanically. These paradoxes are circumvented here by first clarifying the terms used before modeling heat transfer as a thermodynamically reversible but mechanically irreversible process and applied to a one dimensional atomic lattice chain of interacting particles subjected to a temperature difference exemplifying Fourier heat conduction. The basis of a "recoverable trajectory" i.e. that which follows a zero entropy trajectory is identified. The Second Law is strictly maintained in this development. A corollary to this zero entropy trajectory is the generalization of the Zeroth law for steady state non-equilibrium systems with varying temperature, and thus to a statement about "equilibrium" in steady state non-thermostatic conditions. An energy transfer rate term is explicitly identified for each particle and agrees quantitatively (and independently) with the rate of heat absorbed at the

  14. One-Particle Representation of Heat Conduction Described within the Scope of the Second Law.

    Directory of Open Access Journals (Sweden)

    Christopher Gunaseelan Jesudason

    Full Text Available The Carnot cycle and its deduction of maximum conversion efficiency of heat inputted and outputted isothermally at different temperatures necessitated the construction of isothermal and adiabatic pathways within the cycle that were mechanically "reversible", leading eventually to the Kelvin-Clausius development of the entropy function S with differential dS = dq/T such that [symbol: see text]C dS = 0 where the heat absorption occurs at the isothermal paths of the elementary Carnot cycle. Another required condition is that the heat transfer processes take place infinitely slowly and "reversibly", implying that rates of transfer are not explicitly featured in the theory. The definition of 'heat' as that form of energy that is transferred as a result of a temperature difference suggests that the local mode of transfer of "heat" in the isothermal segments of the pathway implies a Fourier-like heat conduction mechanism which is apparently irreversible, leading to an increase in entropy of the combined reservoirs at either end of the conducting material, and which is deemed reversible mechanically. These paradoxes are circumvented here by first clarifying the terms used before modeling heat transfer as a thermodynamically reversible but mechanically irreversible process and applied to a one dimensional atomic lattice chain of interacting particles subjected to a temperature difference exemplifying Fourier heat conduction. The basis of a "recoverable trajectory" i.e. that which follows a zero entropy trajectory is identified. The Second Law is strictly maintained in this development. A corollary to this zero entropy trajectory is the generalization of the Zeroth law for steady state non-equilibrium systems with varying temperature, and thus to a statement about "equilibrium" in steady state non-thermostatic conditions. An energy transfer rate term is explicitly identified for each particle and agrees quantitatively (and independently with the rate of

  15. Thermodynamic performance analysis of sequential Carnot cycles using heat sources with finite heat capacity

    International Nuclear Information System (INIS)

    Park, Hansaem; Kim, Min Soo

    2014-01-01

    The maximum efficiency of a heat engine is able to be estimated by using a Carnot cycle. Even though, in terms of efficiency, the Carnot cycle performs the role of reference very well, its application is limited to the case of infinite heat reservoirs, which is not that realistic. Moreover, considering that one of the recent key issues is to produce maximum work from low temperature and finite heat sources, which are called renewable energy sources, more advanced theoretical cycles, which can present a new standard, and the research about them are necessary. Therefore, in this paper, a sequential Carnot cycle, where multiple Carnot cycles are connected in parallel, is studied. The cycle adopts a finite heat source, which has a certain initial temperature and heat capacity, and an infinite heat sink, which is assumed to be ambient air. Heat transfer processes in the cycle occur with the temperature difference between a heat reservoir and a cycle. In order to resolve the heat transfer rate in those processes, the product of an overall heat transfer coefficient and a heat transfer area is introduced. Using these conditions, the performance of a sequential Carnot cycle is analytically calculated. Furthermore, as the efforts for enhancing the work of the cycle, the optimization research is also conducted with numerical calculation. - Highlights: • Modified sequential Carnot cycles are proposed for evaluating low grade heat sources. • Performance of sequential Carnot cycles is calculated analytically. • Optimization study for the cycle is conducted with numerical solver. • Maximum work from a heat source under a certain condition is obtained by equations

  16. Experimental study on heat pipe heat removal capacity for passive cooling of spent fuel pool

    International Nuclear Information System (INIS)

    Xiong, Zhenqin; Wang, Minglu; Gu, Hanyang; Ye, Cheng

    2015-01-01

    Highlights: • A passively cooling SFP heat pipe with an 8.2 m high evaporator was tested. • Heat removed by the heat pipe is in the range of 3.1–16.8 kW. • The heat transfer coefficient of the evaporator is 214–414 W/m 2 /K. • The heat pipe performance is sensitive to the hot water temperature. - Abstract: A loop-type heat pipe system uses natural flow with no electrically driven components. Therefore, such a system was proposed to passively cool spent fuel pools during accidents to improve nuclear power station safety especially for station blackouts such as those in Fukushima. The heat pipe used for a spent fuel pool is large due to the spent fuel pool size. An experimental heat pipe test loop was developed to estimate its heat removal capacity from the spent fuel pool during an accident. The 7.6 m high evaporator is heated by hot water flowing vertically down in an assistant tube with a 207-mm inner diameter. R134a was used as the potential heat pipe working fluid. The liquid R134a level was 3.6 m. The tests were performed for water velocities from 0.7 to 2.1 × 10 −2 m/s with water temperatures from 50 to 90 °C and air velocities from 0.5 m/s to 2.5 m/s. The results indicate significant heat is removed by the heat pipe under conditions that may occur in the spent fuel pool

  17. Heat Roadmap Europe

    DEFF Research Database (Denmark)

    Connolly, David; Lund, Henrik; Mathiesen, Brian Vad

    2014-01-01

    indicate that with district heating, the EU energy system will be able to achieve the same reductions in primary energy supply and carbon dioxide emissions as the existing alternatives proposed. However, with district heating these goals can be achieved at a lower cost, with heating and cooling costs......Six different strategies have recently been proposed for the European Union (EU) energy system in the European Commission's report, Energy Roadmap 2050. The objective for these strategies is to identify how the EU can reach its target of an 80% reduction in annual greenhouse gas emissions in 2050...... compared to 1990 levels. None of these scenarios involve the large-scale implementation of district heating, but instead they focus on the electrification of the heating sector (primarily using heat pumps) and/or the large-scale implementation of electricity and heat savings. In this paper, the potential...

  18. Active microchannel heat exchanger

    Science.gov (United States)

    Tonkovich, Anna Lee Y [Pasco, WA; Roberts, Gary L [West Richland, WA; Call, Charles J [Pasco, WA; Wegeng, Robert S [Richland, WA; Wang, Yong [Richland, WA

    2001-01-01

    The present invention is an active microchannel heat exchanger with an active heat source and with microchannel architecture. The microchannel heat exchanger has (a) an exothermic reaction chamber; (b) an exhaust chamber; and (c) a heat exchanger chamber in thermal contact with the exhaust chamber, wherein (d) heat from the exothermic reaction chamber is convected by an exothermic reaction exhaust through the exhaust chamber and by conduction through a containment wall to the working fluid in the heat exchanger chamber thereby raising a temperature of the working fluid. The invention is particularly useful as a liquid fuel vaporizer and/or a steam generator for fuel cell power systems, and as a heat source for sustaining endothermic chemical reactions and initiating exothermic reactions.

  19. Estimation of energy efficiency of residential buildings

    Directory of Open Access Journals (Sweden)

    Glushkov Sergey

    2017-01-01

    Full Text Available Increasing energy performance of the residential buildings by means of reducing heat consumption on the heating and ventilation is the last segment in the system of energy resources saving. The first segments in the energy saving process are heat producing and transportation over the main lines and outside distribution networks. In the period from 2006 to 2013. by means of the heat-supply schemes optimization and modernization of the heating systems. using expensive (200–300 $US per 1 m though hugely effective preliminary coated pipes. the economy reached 2.7 mln tons of fuel equivalent. Considering the multi-stage and multifactorial nature (electricity. heat and water supply of the residential sector energy saving. the reasonable estimate of the efficiency of the saving of residential buildings energy should be performed in tons of fuel equivalent per unit of time.

  20. District heating versus local heating - Social supportability

    International Nuclear Information System (INIS)

    Matei, Magdalena; Enescu, Diana; Varjoghie, Elena; Radu, Florin; Matei, Lucian

    2004-01-01

    District heating, DH, is an energy source which can provide a cost-effective, environmentally friendly source of heat and power for cities, but only in the case of well running systems, with reasonable technological losses. The benefits of DH system are well known: environmental friendly, energy security, economic and social advantages. DH already covers 60% of heating and hot water needs in transition economies. Today, 70 % of Russian, Latvian and Belarus homes use DH, and heating accounts for one-third of total Russian energy consumption. Yet a large number of DH systems in the region face serious financial, marketing or technical problems because of the policy framework. How can DH issues be best addressed in national and local policy? What can governments do to create the right conditions for the sustainable development of DH while improving service quality? What policies can help capture the economic, environmental and energy security benefits of co-generation and DH? To address these questions, the International Energy Agency (IEA) hosted in 2002 and 2004 conference focusing on the crucial importance of well-designed DH policies, for exchanging information on policy approaches. The conclusions of the conference have shown that 'DH systems can do much to save energy and boost energy security, but stronger policy measures are needed to encourage wise management and investment. With a stronger policy framework, DH systems in formerly socialist countries could save the equivalent of 80 billion cubic meters of natural gas a year through supply side efficiency improvements. This is greater than total annual natural gas consumption in Italy'. More efficient systems will also decrease costs, reducing household bills and making DH competitive on long-term. This paper presents the issues: -Theoretical benefits of the district heating and cooling systems; - Municipal heating in Romania; - Technical and economic problems of DH systems and social supportability; - How

  1. Absorption heat pumps

    Science.gov (United States)

    Huhtinen, M.; Heikkilae, M.; Andersson, R.

    1987-03-01

    The aim of the study was to analyze the technical and economic feasibility of absorption heat pumps in Finland. The work was done as a case study: the technical and economic analyses have been carried out for six different cases, where in each the suitable size and type of the heat pump plant and the auxiliary components and connections were specified. The study also detailed the costs concerning the procurement, installation and test runs of the machinery, as well as the savings in energy costs incurred by the introduction of the plant. Conclusions were drawn of the economic viability of the applications studied. The following cases were analyzed: heat recovery from flue gases and productin of district heat in plants using peat, natural gas, and municipal wastes as a fuel. Heat recovery in the pulp and paper industry for the upgrading of pressure of secondary steam and for the heating of white liquor and combustion and drying the air. Heat recovery in a peat-fulled heat and power plant from flue gases that have been used for the drying of peat. According to the study, the absorption heat pump suits best to the production of district heat, when the heat source is the primary energy is steam produced by the boiler. Included in the flue as condensing is the purification of flue gases. Accordingly, benefit is gained on two levels in thick applications. In heat and power plants the use of absorption heat pumps is less economical, due to the fact that the steam used by the pump reduces the production of electricity, which is rated clearly higher than heat.

  2. 24 CFR 3280.506 - Heat loss/heat gain.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Heat loss/heat gain. 3280.506... URBAN DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Thermal Protection § 3280.506 Heat loss/heat gain. The manufactured home heat loss/heat gain shall be determined by methods outlined in...

  3. 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...

  4. Demand modelling for central heating systems

    Energy Technology Data Exchange (ETDEWEB)

    Heller, A.

    2000-07-01

    Most researchers in the field of heat demand estimation have focussed on explaning the load for a given plant based on rather few measurements. This approach is simply the only one adaptable with the very limited data material and limited computer power. This way of dealing with the subject is here called the top-down approach, due to the fact that one tries to explain the load from the overall data. The results of such efforts are discussed in the report, leading to inspiration for own work. Also the significance of the findings to the causes for given heat loads are discussed and summarised. Contrary to the top-down approach applied in literature, a here-called bottom-up approach is applied in this work, describing the causes of a given partial load in detail and combining them to explain the total load for the system. Three partial load 'components' are discussed: 1) Space heating. 2) Hot-Water Consumption. 3) Heat losses in pipe networks. The report is aimed at giving an introduction to these subjects, but at the same time at collecting the previous work done by the author. Space heating is shortly discussed and loads are generated by an advanced simulation model. A hot water consumption model is presented and heat loads, generated by this model, utilised in the overall work. Heat loads due to heat losses in district heating a given a high priority in the current work. Hence a detailed presentation and overview of the subject is given to solar heating experts normally not dealing with district heating. Based on the 'partial' loads generated by the above-mentioned method, an overall load model is built in the computer simulation environment TRNSYS. The final tool is then employed for the generation of time series for heat demand, representing a district heating area. The results are compared to alternative methods for the generation of heat demand profiles. Results form this comparison will be presented. Computerised modelling of systems

  5. Optimization of Heat Exchangers

    International Nuclear Information System (INIS)

    Catton, Ivan

    2010-01-01

    The objective of this research is to develop tools to design and optimize heat exchangers (HE) and compact heat exchangers (CHE) for intermediate loop heat transport systems found in the very high temperature reator (VHTR) and other Generation IV designs by addressing heat transfer surface augmentation and conjugate modeling. To optimize heat exchanger, a fast running model must be created that will allow for multiple designs to be compared quickly. To model a heat exchanger, volume averaging theory, VAT, is used. VAT allows for the conservation of mass, momentum and energy to be solved for point by point in a 3 dimensional computer model of a heat exchanger. The end product of this project is a computer code that can predict an optimal configuration for a heat exchanger given only a few constraints (input fluids, size, cost, etc.). As VAT computer code can be used to model characteristics (pumping power, temperatures, and cost) of heat exchangers more quickly than traditional CFD or experiment, optimization of every geometric parameter simultaneously can be made. Using design of experiment, DOE and genetric algorithms, GE, to optimize the results of the computer code will improve heat exchanger design.

  6. Optimization of Heat Exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Ivan Catton

    2010-10-01

    The objective of this research is to develop tools to design and optimize heat exchangers (HE) and compact heat exchangers (CHE) for intermediate loop heat transport systems found in the very high temperature reator (VHTR) and other Generation IV designs by addressing heat transfer surface augmentation and conjugate modeling. To optimize heat exchanger, a fast running model must be created that will allow for multiple designs to be compared quickly. To model a heat exchanger, volume averaging theory, VAT, is used. VAT allows for the conservation of mass, momentum and energy to be solved for point by point in a 3 dimensional computer model of a heat exchanger. The end product of this project is a computer code that can predict an optimal configuration for a heat exchanger given only a few constraints (input fluids, size, cost, etc.). As VAT computer code can be used to model characteristics )pumping power, temperatures, and cost) of heat exchangers more quickly than traditional CFD or experiment, optimization of every geometric parameter simultaneously can be made. Using design of experiment, DOE and genetric algorithms, GE, to optimize the results of the computer code will improve heat exchanger disign.

  7. Transient critical heat flux and blowdown heat-transfer studies

    Energy Technology Data Exchange (ETDEWEB)

    Leung, J.C.

    1980-05-01

    Objective of this study is to give a best-estimate prediction of transient critical heat flux (CHF) during reactor transients and hypothetical accidents. To accomplish this task, a predictional method has been developed. Basically it involves the thermal-hydraulic calculation of the heated core with boundary conditions supplied from experimental measurements. CHF predictions were based on the instantaneous ''local-conditions'' hypothesis, and eight correlations (consisting of round-tube, rod-bundle, and transient correlations) were tested against most recent blowdown heat-transfer test data obtained in major US facilities. The prediction results are summarized in a table in which both CISE and Biasi correlations are found to be capable of predicting the early CHF of approx. 1 s. The Griffith-Zuber correlation is credited for its prediction of the delay CHF that occurs in a more tranquil state with slowly decaying mass velocity. In many instances, the early CHF can be well correlated by the x = 1.0 criterion; this is certainly indicative of an annular-flow dryout-type crisis. The delay CHF occurred at near or above 80% void fraction, and the success of the modified Zuber pool-boiling correlation suggests that this CHF is caused by flooding and pool-boiling type hydrodynamic crisis.

  8. Play-level distributions of estimates of recovery factors for a miscible carbon dioxide enhanced oil recovery method used in oil reservoirs in the conterminous United States

    Science.gov (United States)

    Attanasi, E.D.; Freeman, P.A.

    2016-03-02

    In a U.S. Geological Survey (USGS) study, recovery-factor estimates were calculated by using a publicly available reservoir simulator (CO2 Prophet) to estimate how much oil might be recovered with the application of a miscible carbon dioxide (CO2) enhanced oil recovery (EOR) method to technically screened oil reservoirs located in onshore and State offshore areas in the conterminous United States. A recovery factor represents the percentage of an oil reservoir’s original oil in place estimated to be recoverable by the application of a miscible CO2-EOR method. The USGS estimates were calculated for 2,018 clastic and 1,681 carbonate candidate reservoirs in the “Significant Oil and Gas Fields of the United States Database” prepared by Nehring Associates, Inc. (2012).

  9. Floor heating maximizes residents` comfort

    Energy Technology Data Exchange (ETDEWEB)

    Tirkkanen, P.; Wikstroem, T.

    1996-11-01

    Storing heat in floors by using economical night-time electricity does not increase the specific consumption of heating. According to studies done by IVO, the optimum housing comfort is achieved if the room is heated mainly by means of floor heating that is evened out by window or ceiling heating, or by a combination of all three forms of heating. (orig.)

  10. District heating and heat storage using the solution heat of an ammonia/water system

    International Nuclear Information System (INIS)

    Taube, M.; Peier, W.; Mayor, J.C.

    1976-01-01

    The article describes a model for the optimum use of the heat energy generated in a nuclear power station for district heating and heat storage taking account of the electricity and heat demand varying with time. (HR/AK) [de

  11. Three-dimensional numerical analysis of heat and mass transfer in heat pipes

    Science.gov (United States)

    Kaya, Tarik; Goldak, John

    2007-06-01

    A three-dimensional finite-element numerical model is presented for simulation of the steady-state performance characteristics of heat pipes. The mass, momentum and energy conservation equations are solved for the liquid and vapor flow in the entire heat pipe domain. The calculated outer wall temperature profiles are in good agreement with the experimental data. The estimations of the liquid and vapor pressure distributions and velocity profiles are also presented and discussed. It is shown that the vapor flow field remains nearly symmetrical about the heat pipe centerline, even under a non-uniform heat load. The analytical method used to predict the heat pipe capillary limit is found to be conservative.

  12. Heat transfer in plate heat exchanger channels: Experimental validation of selected correlation equations

    Directory of Open Access Journals (Sweden)

    Cieśliński Janusz T.

    2016-09-01

    Full Text Available This study is focused on experimental investigation of selected type of brazed plate heat exchanger (PHEx. The Wilson plot approach was applied in order to estimate heat transfer coefficients for the PHEx passages. The main aim of the paper was to experimentally check ability of several correlations published in the literature to predict heat transfer coefficients by comparison experimentally obtained data with appropriate predictions. The results obtained revealed that Hausen and Dittus-Boelter correlations underestimated heat transfer coefficient for the tested PHEx by an order of magnitude. The Aspen Plate code overestimated heat transfer coefficient by about 50%, while Muley-Manglik correlation overestimated it from 1% to 25%, dependent on the value of Reynolds number and hot or cold liquid side.

  13. Quick selection of industrial heat pump types including the impact of thermodynamic losses

    International Nuclear Information System (INIS)

    Bor, D.M. van de; Infante Ferreira, C.A.

    2013-01-01

    Making a rough performance estimate for conventional vapor compression and vapor recompression heat pumps is straight forward: Dividing the Carnot efficiency by 2 results in a reasonable estimate. Still, actual performance of heat pumps could easily vary to a large extent. With new and innovative heat pumps the discrepancies between the rough estimate and actual performance might be even larger as the Carnot efficiency is not the upper limit anymore due to the use of temperature glides. Lack of a simple method to determine the approximate performance of a heat pump will hinder the implementation of these novel types in industry. In this study a performance map is presented and it is shown that, for mechanical heat pumps, making use of the available temperature glide increases performance and reduces the payback period. While at low glides heat driven absorption heat pumps and vapor (re)compression heat pumps show the smallest payback times, mechanical heat pumps with large glides show to be more effective at higher temperature lifts when temperature glides are available. Due to improved performance, these mechanical heat pumps are able to achieve better economical results over their technical life time although they require higher initial investment. - Highlights: • A method is proposed for simple estimation of industrial heat pump performance. • Estimation of economic performance of industrial heat pumps. • No detailed knowledge about heat pumps, working fluids or process required

  14. Heat capacity of poly(lactic acid)

    International Nuclear Information System (INIS)

    Pyda, M.; Bopp, R.C.; Wunderlich, B.

    2004-01-01

    The heat capacity of poly(lactic acid) (PLA) is reported from T=(5 to 600) K as obtained by differential scanning calorimetry (d.s.c.) and adiabatic calorimetry. The heat capacity of solid PLA is linked to its group vibrational spectrum and the skeletal vibrations, the latter being described by a Tarasov equation with Θ 1 =574 K, Θ 2 =Θ 3 =52 K, and nine skeletal vibrations. The calculated and experimental heat capacities agree to ±3% between T=(5 and 300) K. The experimental heat capacity of liquid PLA can be expressed by C p (liquid)=(120.17+0.076T) J · K -1 · mol -1 and has been compared to the ATHAS Data Bank, using contributions of other polymers with the same constituent groups. The glass transition temperature of amorphous PLA occurs at T=332.5 K with a change in heat capacity of 43.8 J · K -1 · mol -1 . Depending on thermal history, semi-crystalline PLA has a melting endotherm between T=(418 and 432) K with variable heats of fusion. For 100% crystalline PLA, the heat of fusion is estimated to be (6.55 ± 0.02) kJ · mol -1 at T=480 K. With these results, the enthalpy, entropy, and Gibbs function of crystalline and amorphous PLA were obtained. For semi-crystalline samples, one can check changes of crystallinity with temperature and judge the presence of rigid-amorphous fractions

  15. Small reactors for low-temperature heating

    International Nuclear Information System (INIS)

    Hilborn, J.W.; Glen, J.S.

    For regions which do not have abundant long term supplies of oil, gas, or electricity, small nuclear reactors for heating large buildings are a future energy option. In Canada, the first installations might be in remote arctic communities where heating costs are highest. Atomic Energy of Canada Limited is studying the feasibility of small units in the range 2 to 20 MWt. Based on the inherently safe SLOWPOKE research reactor, the proposed heating reactor would produce hot water at temperatures less than 100 0 C. It would be unattended most of the time, responding automatically to daily variations in load demand. The reactor core would contain enough uranium fuel to last two heating seasons. Thermohydraulic tests have been carried out on an electrically heated tube simulating a single fuel element, and a 31-element test rig simulating the core and primary coolant circuit is under construction. Preliminary cost estimates indicate that heat from a 2MWt SLOWPOKE-type reactor compares favourably in cost with heat from electricity and imported oil, but is significantly more expensive than the corresponding energy from natural gas. If the current studies at the Chalk River Nuclear Laboratories confirm technical and economic feasibility, a 2 MWt prototype reactor will be built at Chalk River in 1984/85

  16. 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.

  17. Geothermal energy in deep aquifers : A global assessment of the resource base for direct heat utilization

    OpenAIRE

    Limberger, J.; Boxem, T.; Pluymaekers, Maarten; Bruhn, David; Manzella, Adelle; Calcagno, Philippe; Beekman, F.; Cloetingh, S.; van Wees, J.-D.

    2018-01-01

    In this paper we present results of a global resource assessment for geothermal energy within deep aquifers for direct heat utilization. Greenhouse heating, spatial heating, and spatial cooling are considered in this assessment. We derive subsurface temperatures from geophysical data and apply a volumetric heat-in-place method to improve current global geothermal resource base estimates for direct heat applications. The amount of thermal energy stored within aquifers depends on the Earth's he...

  18. Market Potential for Residential Biomass Heating Equipment: Stochastic and Econometric Assessments

    OpenAIRE

    Adee Athiyaman

    2015-01-01

    This paper provides estimates of market potential for biomass-residential-heating equipment in the US: that is, the greatest amount of biomass-residential-heating equipment that can be sold by the industry. The author's analysis is limited to biomass equipment used most to heat the housing unit. Assuming that households equipped with 10+ year old primary heating devices will replace rather than repair the devices he predicts that approximately 1.4 million units of residential home heating equ...

  19. Heat Capacity Mapping Radiometer (HCMR) data processing algorithm, calibration, and flight performance evaluation

    Science.gov (United States)

    Bohse, J. R.; Bewtra, M.; Barnes, W. L.

    1979-01-01

    The rationale and procedures used in the radiometric calibration and correction of Heat Capacity Mapping Mission (HCMM) data are presented. Instrument-level testing and calibration of the Heat Capacity Mapping Radiometer (HCMR) were performed by the sensor contractor ITT Aerospace/Optical Division. The principal results are included. From the instrumental characteristics and calibration data obtained during ITT acceptance tests, an algorithm for post-launch processing was developed. Integrated spacecraft-level sensor calibration was performed at Goddard Space Flight Center (GSFC) approximately two months before launch. This calibration provided an opportunity to validate the data calibration algorithm. Instrumental parameters and results of the validation are presented and the performances of the instrument and the data system after launch are examined with respect to the radiometric results. Anomalies and their consequences are discussed. Flight data indicates a loss in sensor sensitivity with time. The loss was shown to be recoverable by an outgassing procedure performed approximately 65 days after the infrared channel was turned on. It is planned to repeat this procedure periodically.

  20. Comparing heat flow models for interpretation of precast quadratic pile heat exchanger thermal response tests

    DEFF Research Database (Denmark)

    Alberdi Pagola, Maria; Poulsen, Søren Erbs; Loveridge, Fleur

    2018-01-01

    This paper investigates the applicability of currently available analytical, empirical and numerical heat flow models for interpreting thermal response tests (TRT) of quadratic cross section precast pile heat exchangers. A 3D finite element model (FEM) is utilised for interpreting five TRTs...... by inverse modelling. The calibrated estimates of soil and concrete thermal conductivity are consistent with independent laboratory measurements. Due to the computational cost of inverting the 3D model, simpler models are utilised in additional calibrations. Interpretations based on semi-empirical pile G-functions...... the potential of applying TRTs for sizing quadratic, precast pile heat exchanger foundations....

  1. Laser Processed Heat Exchangers

    Science.gov (United States)

    Hansen, Scott

    2017-01-01

    The Laser Processed Heat Exchanger project will investigate the use of laser processed surfaces to reduce mass and volume in liquid/liquid heat exchangers as well as the replacement of the harmful and problematic coatings of the Condensing Heat Exchangers (CHX). For this project, two scale unit test articles will be designed, manufactured, and tested. These two units are a high efficiency liquid/liquid HX and a high reliability CHX.

  2. Counterflow Regolith Heat Exchanger

    Science.gov (United States)

    Zubrin, Robert; Jonscher, Peter

    2013-01-01

    A problem exists in reducing the total heating power required to extract oxygen from lunar regolith. All such processes require heating a great deal of soil, and the heat energy is wasted if it cannot be recycled from processed material back into new material. The counterflow regolith heat exchanger (CoRHE) is a device that transfers heat from hot regolith to cold regolith. The CoRHE is essentially a tube-in-tube heat exchanger with internal and external augers attached to the inner rotating tube to move the regolith. Hot regolith in the outer tube is moved in one direction by a right-hand - ed auger, and the cool regolith in the inner tube is moved in the opposite direction by a left-handed auger attached to the inside of the rotating tube. In this counterflow arrangement, a large fraction of the heat from the expended regolith is transferred to the new regolith. The spent regolith leaves the heat exchanger close to the temperature of the cold new regolith, and the new regolith is pre-heated close to the initial temperature of the spent regolith. Using the CoRHE can reduce the heating requirement of a lunar ISRU system by 80%, reducing the total power consumption by a factor of two. The unique feature of this system is that it allows for counterflow heat exchange to occur between solids, instead of liquids or gases, as is commonly done. In addition, in variants of this concept, the hydrogen reduction can be made to occur within the counterflow heat exchanger itself, enabling a simplified lunar ISRU (in situ resource utilization) system with excellent energy economy and continuous nonbatch mode operation.

  3. Advances in heat transfer

    CERN Document Server

    Hartnett, James P; Cho, Young I; Greene, George A

    2001-01-01

    Heat transfer is the exchange of heat energy between a system and its surrounding environment, which results from a temperature difference and takes place by means of a process of thermal conduction, mechanical convection, or electromagnetic radiation. Advances in Heat Transfer is designed to fill the information gap between regularly scheduled journals and university-level textbooks by providing in-depth review articles over a broader scope than is allowable in either journals or texts.

  4. Heat transfer II essentials

    CERN Document Server

    REA, The Editors of

    1988-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Heat Transfer II reviews correlations for forced convection, free convection, heat exchangers, radiation heat transfer, and boiling and condensation.

  5. Convection heat transfer

    CERN Document Server

    Bejan, Adrian

    2013-01-01

    Written by an internationally recognized authority on heat transfer and thermodynamics, this second edition of Convection Heat Transfer contains new and updated problems and examples reflecting real-world research and applications, including heat exchanger design. Teaching not only structure but also technique, the book begins with the simplest problem solving method (scale analysis), and moves on to progressively more advanced and exact methods (integral method, self similarity, asymptotic behavior). A solutions manual is available for all problems and exercises.

  6. New waste heat district heating system with combined heat and power based on absorption heat exchange cycle in China

    International Nuclear Information System (INIS)

    Sun Fangtian; Fu Lin; Zhang Shigang; Sun Jian

    2012-01-01

    A new waste heat district heating system with combined heat and power based on absorption heat exchange cycle (DHAC) was developed to increase the heating capacity of combined heat and power (CHP) through waste heat recovery, and enhance heat transmission capacity of the existing primary side district heating network through decreasing return water temperature by new type absorption heat exchanger (AHE). The DHAC system and a conventional district heating system based on CHP (CDH) were analyzed in terms of both thermodynamics and economics. Compared to CDH, the DHAC increased heating capacity by 31% and increased heat transmission capacity of the existing primary side district heating network by 75%. The results showed that the exergetic efficiency of DHAC was 10.41% higher and the product exergy monetary cost was 36.6¥/GJ less than a CHD. DHAC is an effective way to increase thermal utilization factor of CHP, and to reduce district heating cost. - Highlights: ► Absorption heat pumps are used to recover waste heat in CHP. ► Absorption heat exchanger can reduce exergy loss in the heat transfer process. ► New waste heat heating system (DHAC) can increase heating capacity of CHP by 31%. ► DHAC can enhance heat transmission capacity of the primary pipe network by 75%. ► DHAC system has the higher exergetic efficiency and the better economic benefit.

  7. Introduction to Heat Pipes

    Science.gov (United States)

    Ku, Jentung

    2015-01-01

    This is the presentation file for the short course Introduction to Heat Pipes, to be conducted at the 2015 Thermal Fluids and Analysis Workshop, August 3-7, 2015, Silver Spring, Maryland. NCTS 21070-15. Course Description: This course will present operating principles of the heat pipe with emphases on the underlying physical processes and requirements of pressure and energy balance. Performance characterizations and design considerations of the heat pipe will be highlighted. Guidelines for thermal engineers in the selection of heat pipes as part of the spacecraft thermal control system, testing methodology, and analytical modeling will also be discussed.

  8. Heat and mass exchanger

    Science.gov (United States)

    Lowenstein, Andrew; Sibilia, Marc J.; Miller, Jeffrey A.; Tonon, Thomas

    2007-09-18

    A mass and heat exchanger includes at least one first substrate with a surface for supporting a continuous flow of a liquid thereon that either absorbs, desorbs, evaporates or condenses one or more gaseous species from or to a surrounding gas; and at least one second substrate operatively associated with the first substrate. The second substrate includes a surface for supporting the continuous flow of the liquid thereon and is adapted to carry a heat exchange fluid therethrough, wherein heat transfer occurs between the liquid and the heat exchange fluid.

  9. Diurnal variability of upper ocean temperature and heat budget in ...

    Indian Academy of Sciences (India)

    These data have been analysed to examine the diurnal variability of upper oceanic heat budget and to estimate the eddy diffusivity coefficient of heat in the upper layer. Diurnal variation of near-surface temperature is typical at northern location (13°N) with a range of 0.5°C while the diurnal range of temperature is enhanced ...

  10. Estimating Utility

    DEFF Research Database (Denmark)

    Arndt, Channing; Simler, Kenneth R.

    2010-01-01

    A fundamental premise of absolute poverty lines is that they represent the same level of utility through time and space. Disturbingly, a series of recent studies in middle- and low-income economies show that even carefully derived poverty lines rarely satisfy this premise. This article proposes...... an information-theoretic approach to estimating cost-of-basic-needs (CBN) poverty lines that are utility consistent. Applications to date illustrate that utility-consistent poverty measurements derived from the proposed approach and those derived from current CBN best practices often differ substantially......, with the current approach tending to systematically overestimate (underestimate) poverty in urban (rural) zones....

  11. Heat index and adjusted temperature as surrogates for wet bulb globe temperature to screen for occupational heat stress.

    Science.gov (United States)

    Bernard, Thomas E; Iheanacho, Ivory

    2015-01-01

    Ambient temperature and relative humidity are readily ava-ilable and thus tempting metrics for heat stress assessment. Two methods of using air temperature and relative humidity to create an index are Heat Index and Adjusted Temperature. The purposes of this article are: (1) to examine how well Heat Index and Adjusted Temperature estimated the wet bulb globe temperature (WBGT) index, and (2) to suggest how Heat Index and Adjusted Temperature can be used to screen for heat stress level. Psychrometric relationships were used to estimate values of actual WBGT for conditions of air temperature, relative humidity, and radiant heat at an air speed of 0.5 m/s. A relationship between Heat Index [°F] and WBGT [°C] was described by WBGT = -0.0034 HI(2) + 0.96 HI - 34. At lower Heat Index values, the equation estimated WBGTs that were ± 2 °C-WBGT around the actual value, and to about ± 0.5 °C-WBGT for Heat Index values > 100 °F. A relationship between Adjusted Temperature [°F] and WBGT [°C] was described by WBGT = 0.45 Tadj - 16. The actual WBGT was between 1 °C-WBGT below the estimated value and 1.4 °C-WBGT above. That is, there was a slight bias toward overestimating WBGT from Adjusted Temperature. Heat stress screening tables were constructed for metabolic rates of 180, 300, and 450 W. The screening decisions were divided into four categories: (1) exposure limit at rest. The authors do not recommend using Heat Index or Adjusted Temperature instead of WBGT, but they may be used to screen for circumstances when a more detailed analysis using WBGT is appropriate. A particular weakness is accounting for radiant heat; and neither air speed nor clothing was considered.

  12. Studies on split heat pipe type adsorption ice-making test unit for fishing boats: Choice of heat pipe medium and experiments under unsteady heating sources

    International Nuclear Information System (INIS)

    Wang, L.W.; Wang, R.Z.; Lu, Z.S.; Chen, C.J.

    2006-01-01

    The split heat pipe type compound adsorption ice maker for fishing boats not only has the advantage of large volume cooling density but also has the advantage of less power consumption and high heat transfer performance. The available heat pipe media for the split heat pipe type compound adsorption ice maker, which are methanol, acetone and water are studied and compared in this paper, and the heat pipe medium of water shows the better performance for the reason of its stable heating and cooling process and high heat transfer performance. Considering the waste heat recovered from the diesel engine on fishing boats varies when the velocity of the fishing boat changes, the refrigeration performances at the condition of different values of heating power are studied while water is used as the heat pipe medium. Results show that the cooling power, as while as COP and SCP decrease when the heating power decreases. The highest COP and SCP are 0.41 and 731 W/kg, respectively, at the highest heating power of 4.2 kW, and the values decrease by 22% and 33%, respectively, when the heating power decreases by 15%. The values decrease by 32% and 51%, respectively, when the heating power decreases by 30%. The performance of the adsorption ice maker for the fishing boat with the 6160A type diesel engine is estimated, and the results show that the cooling power and ice productivity are as high as 5.44 kW and 1032 kg ice per day, respectively, even if the recovered waste heat decreases by 30% compared with the normal value. It can satisfy the ice requirements of such a fishing boat

  13. USGS world petroleum assessment 2000; new estimates of undiscovered oil and natural gas, including reserve growth, outside the United States

    Science.gov (United States)

    ,

    2000-01-01

    Oil and natural gas account for approximately 63 percent of the world’s total energy consumption. The U.S. Geological Survey periodically estimates the amount of oil and gas remaining to be found in the world. Since 1981, each of the last four of these assessments has shown a slight increase in the combined volume of identified reserves and undiscovered resources. The latest assessment estimates the volume of technically recoverable conventional oil and gas that may be added to the world's reserves, exclusive of the United States, in the next 30 years. The USGS World Petroleum Assessment 2000 reports an increase in global petroleum resources, including a 20-percent increase in undiscovered oil and a 14-percent decrease in undiscovered natural gas compared to the previous assessment (table 1). These results have important implications for energy prices, policy, security, and the global resource balance.

  14. Polar cap index as a proxy for hemispheric Joule heating

    DEFF Research Database (Denmark)

    Chun, F.K.; Knipp, D.J.; McHarg, M.G.

    1999-01-01

    input into the polar cap, we propose to use PC as a proxy for the hemispheric Joule heat production rate (JH). In this study, JH is estimated from the Assimilative Mapping of Ionospheric Electrodynamics (AMIE) procedure. We fit hourly PC values to hourly averages of JH. Using a data base approximately...... is as equally accurate. Thus the single station PC index appears to provide a quick estimate of, and is an appropriate proxy for, the hemispheric Joule heating rate....

  15. Solar Heating System with Building-Integrated Heat Storage

    DEFF Research Database (Denmark)

    Heller, Alfred

    1996-01-01

    Traditional solar heating systems cover between 5 and 10% of the heat demand fordomestic hot water and comfort heating. By applying storage capacity this share can beincreased much. The Danish producer of solar heating systems, Aidt-Miljø, markets such a system including storage of dry sand heated...... by PP-pipe heat exchanger. Heat demand is reduced due to direct solar heating, and due to storage. Heat demand is reduced due to direct solar heating, due to storage and due to lower heat losses through the ground. In theory, by running the system flow backwards through the sand storage, active heating...... can be achieved.The objective of the report is to present results from measured system evaluation andcalculations and to give guidelines for the design of such solar heating systems with building integrated sand storage. The report is aimed to non-technicians. In another report R-006 the main results...

  16. Utilising heat from nuclear waste for space heating

    International Nuclear Information System (INIS)

    Deacon, D.

    1982-01-01

    A heating unit utilising the decay heat from irradiated material comprises a storage envelope for the material associated with a heat exchange system, means for producing a flow of air over the heat exchange system to extract heat from the material, an exhaust duct capable of discharging the heated air to the atmosphere, and means for selectively diverting at least some of the heated air to effect the required heating. With the flow of air over the heat exchange system taking place by a natural thermosyphon process the arrangement is self regulating and inherently reliable. (author)

  17. Heat pump system for summer houses if possible combined with solar heating; Varmepumpeanlaeg til fritidshus eventuelt i kombination med solvarme

    Energy Technology Data Exchange (ETDEWEB)

    Ellehauge, K.; Kildemoes, T.; Kristensen, Joern; Bjergen Jensen, T.

    2006-03-15

    Denmark has about 220.000 summer cottages and it is estimated that about 10% of these are for rental. The trend within summer cottages for rental is going towards more and more facilities and intensive rental, and as a consequence of this high energy consumption. A substantial part of the energy use is for heating, i.e. space heating, heating of indoor pool and domestic hot water. Contrary to the other building stock in Denmark summer cottages nearly always use electricity for heating. In the project it is found, that the average yearly electricity use of a summer cottage for rental with indoor pool is about 31.000 kWh. In the project typical energy consumption profiles have been set up from analyses of typical equipment and from simulation of space heat demands in Danish climate. Furthermore a number of heat delivery solutions with heat pumps and solar heating systems have been set up and the performance has been simulated and analysed. As a result of the analyses 2 prototype systems both consisting of an air to air heat pump for space heating and an air to water heat pump for the hot water, the spa and the pool heating has been installed and tested in two summer cottages. There is a good economy in the systems and these are therefore marketed by the project participants, Energi Danmark NRGi (energy utility) and Dansommer (cottage rental company). (au)

  18. Heat-Related Illnesses

    Medline Plus

    Full Text Available ... Dr. Glenn Mitchell , Emergency physician at Mercy Health System in Chesterfield, Missouri Heat-related illness can be caused by overexposure to the sun or any situation that involves extreme heat. Young children and the elderly are most at risk, but anyone can be affected. Here ...

  19. Mechanisms of Coronal Heating

    Indian Academy of Sciences (India)

    The Sun is a mysterious star. The high temperature of the chromosphere and corona present one of the most puzzling problems of solar physics. Observations show that the solar coronal heating problem is highly complex with many different facts. It is likely that different heating mechanisms are at work in solar corona.

  20. Scraped surface heat exchangers.

    Science.gov (United States)

    Rao, Chetan S; Hartel, Richard W

    2006-01-01

    Scraped surface heat exchangers (SSHEs) are commonly used in the food, chemical, and pharmaceutical industries for heat transfer, crystallization, and other continuous processes. They are ideally suited for products that are viscous, sticky, that contain particulate matter, or that need some degree of crystallization. Since these characteristics describe a vast majority of processed foods, SSHEs are especially suited for pumpable food products. During operation, the product is brought in contact with a heat transfer surface that is rapidly and continuously scraped, thereby exposing the surface to the passage of untreated product. In addition to maintaining high and uniform heat exchange, the scraper blades also provide simultaneous mixing and agitation. Heat exchange for sticky and viscous foods such as heavy salad dressings, margarine, chocolate, peanut butter, fondant, ice cream, and shortenings is possible only by using SSHEs. High heat transfer coefficients are achieved because the boundary layer is continuously replaced by fresh material. Moreover, the product is in contact with the heating surface for only a few seconds and high temperature gradients can be used without the danger of causing undesirable reactions. SSHEs are versatile in the use of heat transfer medium and the various unit operations that can be carried out simultaneously. This article critically reviews the current understanding of the operations and applications of SSHEs.