WorldWideScience

Sample records for thermal system analysis

  1. Thermal energy systems design and analysis

    CERN Document Server

    Penoncello, Steven G

    2015-01-01

    IntroductionThermal Energy Systems Design and AnalysisSoftwareThermal Energy System TopicsUnits and Unit SystemsThermophysical PropertiesEngineering DesignEngineering EconomicsIntroductionCommon Engineering Economics NomenclatureEconomic Analysis Tool: The Cash Flow DiagramTime Value of MoneyTime Value of Money ExamplesUsing Software to Calculate Interest FactorsEconomic Decision MakingDepreciation and TaxesProblemsAnalysis of Thermal Energy SystemsIntroductionNomenclatureThermophysical Properties of SubstancesSuggested Thermal Energy Systems Analysis ProcedureConserved and Balanced QuantitiesConservation of MassConservation of Energy (The First Law of Thermodynamics)Entropy Balance (The Second Law of Thermodynamics)Exergy Balance: The Combined LawEnergy and Exergy Analysis of Thermal Energy CyclesDetailed Analysis of Thermal Energy CyclesProblemsFluid Transport in Thermal Energy SystemsIntroductionPiping and Tubing StandardsFluid Flow FundamentalsValves and FittingsDesign and Analysis of Pipe NetworksEconomi...

  2. NUMERICAL THERMAL ANALYSIS OF A CAR BRAKING SYSTEM

    Directory of Open Access Journals (Sweden)

    Patryk Różyło

    2017-06-01

    Full Text Available The study involved performing a numerical thermal analysis of selected components in a car braking system. The primary goal of the study was to determine the regions which are the most susceptible to variations in temperature, and to determine the degree of thermal impact upon them. The analysis was performed using the Abaqus environment. The examined components of the braking system were made of materials reflecting the mechanical properties of the real subassemblies. The FEM analysis enabled determination of the distribution of temperature in the system with respect to the properties of the investigated materials and applied boundary conditions.

  3. Performance analysis of a lunar based solar thermal power system with regolith thermal storage

    International Nuclear Information System (INIS)

    Lu, Xiaochen; Ma, Rong; Wang, Chao; Yao, Wei

    2016-01-01

    The manned deep-space exploration is a hot topic of the current space activities. The continuous supply of thermal and electrical energy for the scientific equipment and human beings is a crucial issue for the lunar outposts. Since the night lasts for periods of about 350 h at most locations on the lunar surface, massive energy storage is required for continuous energy supply during the lengthy lunar night and the in-situ resource utilization is demanded. A lunar based solar thermal power system with regolith thermal storage is presented in this paper. The performance analysis is carried out by the finite-time thermodynamics to take into account major irreversible losses. The influences of some key design parameters are analyzed for system optimization. The analytical results shows that the lunar based solar thermal power system with regolith thermal storage can meet the requirement of the continuous energy supply for lunar outposts. - Highlights: • A lunar based solar thermal power system with regolith thermal storage is presented. • The performance analysis is carried out by the finite-time thermodynamics. • The influences of some key design parameters are analyzed.

  4. Thermal Analysis of Fluidized Bed and Fixed Bed Latent Heat Thermal Storage System

    Science.gov (United States)

    Beemkumar, N.; Karthikeyan, A.; Shiva Keshava Reddy, Kota; Rajesh, Kona; Anderson, A.

    2017-05-01

    Thermal energy storage technology is essential because its stores available energy at low cost. Objective of the work is to store the thermal energy in a most efficient method. This work is deal with thermal analysis of fluidized bed and fixed bed latent heat thermal storage (LHTS) system with different encapsulation materials (aluminium, brass and copper). D-Mannitol has been used as phase change material (PCM). Encapsulation material which is in orbicular shape with 4 inch diameter and 2 mm thickness orbicular shaped product is used. Therminol-66 is used as a heat transfer fluid (HTF). Arrangement of encapsulation material is done in two ways namely fluidized bed and fixed bed thermal storage system. Comparison was made between the performance of fixed bed and fluidized bed with different encapsulation material. It is observed that from the economical point of view aluminium in fluidized bed LHTS System has highest efficiency than copper and brass. The thermal energy storage system can be analyzed with fixed bed by varying mass flow rate of oil paves a way to find effective heat energy transfer.

  5. Thermal stress analysis of gravity support system for ITER based on ANSYS

    International Nuclear Information System (INIS)

    Liang Shangming; Yan Xijiang; Huang Yufeng; Wang Xianzhou; Hou Binglin; Li Pengyuan; Jian Guangde; Liu Dequan; Zhou Caipin

    2009-01-01

    A method for building the finite element model of the gravity support system for International Thermonuclear Experimental Reactor (ITER) was proposed according to the characteristics of the gravity support system with the cyclic symmetry. A mesh dividing method, which has high precision and an acceptable calculating scale, was used, and a three dimensional finite element model for the toroidal 20 degree sector of the gravity support system was built by using ANSYS. Meantime, the steady-state thermal analysis and thermal-structural coupling analysis of the gravity support system were performed. The thermal stress distributions and the maximal thermal stress values of all parts of the gravity support system were obtained, and the stress intensity of parts of the gravity support system was analyzed. The results of thermal stress analysis lay the solid foundation for design and improvement for gravity supports system for ITER. (authors)

  6. Thermal protection system gap analysis using a loosely coupled fluid-structural thermal numerical method

    Science.gov (United States)

    Huang, Jie; Li, Piao; Yao, Weixing

    2018-05-01

    A loosely coupled fluid-structural thermal numerical method is introduced for the thermal protection system (TPS) gap thermal control analysis in this paper. The aerodynamic heating and structural thermal are analyzed by computational fluid dynamics (CFD) and numerical heat transfer (NHT) methods respectively. An interpolation algorithm based on the control surface is adopted for the data exchanges on the coupled surface. In order to verify the analysis precision of the loosely coupled method, a circular tube example was analyzed, and the wall temperature agrees well with the test result. TPS gap thermal control performance was studied by the loosely coupled method successfully. The gap heat flux is mainly distributed in the small region at the top of the gap which is the high temperature region. Besides, TPS gap temperature and the power of the active cooling system (CCS) calculated by the traditional uncoupled method are higher than that calculated by the coupled method obviously. The reason is that the uncoupled method doesn't consider the coupled effect between the aerodynamic heating and structural thermal, however the coupled method considers it, so TPS gap thermal control performance can be analyzed more accurately by the coupled method.

  7. Development of realistic thermal hydraulic system analysis code

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Jae; Chung, B. D; Kim, K. D. [and others

    2002-05-01

    The realistic safety analysis system is essential for nuclear safety research, advanced reactor development, safety analysis in nuclear industry and 'in-house' plant design capability development. In this project, we have developed a best-estimate multi-dimensional thermal-hydraulic system code, MARS, which is based on the integrated version of the RELAP5 and COBRA-TF codes. To improve the realistic analysis capability, we have improved the models for multi-dimensional two-phase flow phenomena and for advanced two-phase flow modeling. In addition, the GUI (Graphic User Interface) feature were developed to enhance the user's convenience. To develop the coupled analysis capability, the MARS code were linked with the three-dimensional reactor kinetics code (MASTER), the core thermal analysis code (COBRA-III/CP), and the best-estimate containment analysis code (CONTEMPT), resulting in MARS/MASTER/COBRA/CONTEMPT. Currently, the MARS code system has been distributed to 18 domestic organizations, including research, industrial, regulatory organizations and universities. The MARS has been being widely used for the safety research of existing PWRs, advanced PWR, CANDU and research reactor, the pre-test analysis of TH experiments, and others.

  8. Development of realistic thermal hydraulic system analysis code

    International Nuclear Information System (INIS)

    Lee, Won Jae; Chung, B. D; Kim, K. D.

    2002-05-01

    The realistic safety analysis system is essential for nuclear safety research, advanced reactor development, safety analysis in nuclear industry and 'in-house' plant design capability development. In this project, we have developed a best-estimate multi-dimensional thermal-hydraulic system code, MARS, which is based on the integrated version of the RELAP5 and COBRA-TF codes. To improve the realistic analysis capability, we have improved the models for multi-dimensional two-phase flow phenomena and for advanced two-phase flow modeling. In addition, the GUI (Graphic User Interface) feature were developed to enhance the user's convenience. To develop the coupled analysis capability, the MARS code were linked with the three-dimensional reactor kinetics code (MASTER), the core thermal analysis code (COBRA-III/CP), and the best-estimate containment analysis code (CONTEMPT), resulting in MARS/MASTER/COBRA/CONTEMPT. Currently, the MARS code system has been distributed to 18 domestic organizations, including research, industrial, regulatory organizations and universities. The MARS has been being widely used for the safety research of existing PWRs, advanced PWR, CANDU and research reactor, the pre-test analysis of TH experiments, and others

  9. Thermal resistance analysis and optimization of photovoltaic-thermoelectric hybrid system

    International Nuclear Information System (INIS)

    Yin, Ershuai; Li, Qiang; Xuan, Yimin

    2017-01-01

    Highlights: • A detailed thermal resistance analysis of the PV-TE hybrid system is proposed. • c-Si PV and p-Si PV cells are proved to be inapplicable for the PV-TE hybrid system. • Some criteria for selecting coupling devices and optimal design are obtained. • A detailed process of designing the practical PV-TE hybrid system is provided. - Abstract: The thermal resistance theory is introduced into the theoretical model of the photovoltaic-thermoelectric (PV-TE) hybrid system. A detailed thermal resistance analysis is proposed to optimize the design of the coupled system in terms of optimal total conversion efficiency. Systems using four types of photovoltaic cells are investigated, including monocrystalline silicon photovoltaic cell, polycrystalline silicon photovoltaic cell, amorphous silicon photovoltaic cell and polymer photovoltaic cell. Three cooling methods, including natural cooling, forced air cooling and water cooling, are compared, which demonstrates a significant superiority of water cooling for the concentrating photovoltaic-thermoelectric hybrid system. Influences of the optical concentrating ratio and velocity of water are studied together and the optimal values are revealed. The impacts of the thermal resistances of the contact surface, TE generator and the upper heat loss thermal resistance on the property of the coupled system are investigated, respectively. The results indicate that amorphous silicon PV cell and polymer PV cell are more appropriate for the concentrating hybrid system. Enlarging the thermal resistance of the thermoelectric generator can significantly increase the performance of the coupled system using amorphous silicon PV cell or polymer PV cell.

  10. Development of MARS for multi-dimensional and multi-purpose thermal-hydraulic system analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Jae; Chung, Bub Dong; Kim, Kyung Doo; Hwang, Moon Kyu; Jeong, Jae Jun; Ha, Kwi Seok; Joo, Han Gyu [Korea Atomic Energy Research Institute, T/H Safety Research Team, Yusung, Daejeon (Korea)

    2000-10-01

    MARS (Multi-dimensional Analysis of Reactor Safety) code is being developed by KAERI for the realistic thermal-hydraulic simulation of light water reactor system transients. MARS 1.4 has been developed as a final version of basic code frame for the multi-dimensional analysis of system thermal-hydraulics. Since MARS 1.3, MARS 1.4 has been improved to have the enhanced code capability and user friendliness through the unification of input/output features, code models and code functions, and through the code modernization. Further improvements of thermal-hydraulic models, numerical method and user friendliness are being carried out for the enhanced code accuracy. As a multi-purpose safety analysis code system, a coupled analysis system, MARS/MASTER/CONTEMPT, has been developed using multiple DLL (Dynamic Link Library) techniques of Windows system. This code system enables the coupled, that is, more realistic analysis of multi-dimensional thermal-hydraulics (MARS 2.0), three-dimensional core kinetics (MASTER) and containment thermal-hydraulics (CONTEMPT). This paper discusses the MARS development program, and the developmental progress of the MARS 1.4 and the MARS/MASTER/CONTEMPT focusing on major features of the codes and their verification. It also discusses thermal hydraulic models and new code features under development. (author)

  11. Development of MARS for multi-dimensional and multi-purpose thermal-hydraulic system analysis

    International Nuclear Information System (INIS)

    Lee, Won Jae; Chung, Bub Dong; Kim, Kyung Doo; Hwang, Moon Kyu; Jeong, Jae Jun; Ha, Kwi Seok; Joo, Han Gyu

    2000-01-01

    MARS (Multi-dimensional Analysis of Reactor Safety) code is being developed by KAERI for the realistic thermal-hydraulic simulation of light water reactor system transients. MARS 1.4 has been developed as a final version of basic code frame for the multi-dimensional analysis of system thermal-hydraulics. Since MARS 1.3, MARS 1.4 has been improved to have the enhanced code capability and user friendliness through the unification of input/output features, code models and code functions, and through the code modernization. Further improvements of thermal-hydraulic models, numerical method and user friendliness are being carried out for the enhanced code accuracy. As a multi-purpose safety analysis code system, a coupled analysis system, MARS/MASTER/CONTEMPT, has been developed using multiple DLL (Dynamic Link Library) techniques of Windows system. This code system enables the coupled, that is, more realistic analysis of multi-dimensional thermal-hydraulics (MARS 2.0), three-dimensional core kinetics (MASTER) and containment thermal-hydraulics (CONTEMPT). This paper discusses the MARS development program, and the developmental progress of the MARS 1.4 and the MARS/MASTER/CONTEMPT focusing on major features of the codes and their verification. It also discusses thermal hydraulic models and new code features under development. (author)

  12. Thermal-hydraulics Analysis of a Radioisotope-powered Mars Hopper Propulsion System

    International Nuclear Information System (INIS)

    O'Brien, Robert C.; Klein, Andrew C.; Taitano, William T.; Gibson, Justice; Myers, Brian; Howe, Steven D.

    2011-01-01

    Thermal-hydraulics analyses results produced using a combined suite of computational design and analysis codes are presented for the preliminary design of a concept Radioisotope Thermal Rocket (RTR) propulsion system. Modeling of the transient heating and steady state temperatures of the system is presented. Simulation results for propellant blow down during impulsive operation are also presented. The results from this study validate the feasibility of a practical thermally capacitive RTR propulsion system.

  13. Thermal stress analysis of space shuttle orbiter wing skin panel and thermal protection system

    Science.gov (United States)

    Ko, William L.; Jenkins, Jerald M.

    1987-01-01

    Preflight thermal stress analysis of the space shuttle orbiter wing skin panel and the thermal protection system (TPS) was performed. The heated skin panel analyzed was rectangular in shape and contained a small square cool region at its center. The wing skin immediately outside the cool region was found to be close to the state of elastic instability in the chordwise direction based on the conservative temperature distribution. The wing skin was found to be quite stable in the spanwise direction. The potential wing skin thermal instability was not severe enough to tear apart the strain isolation pad (SIP) layer. Also, the preflight thermal stress analysis was performed on the TPS tile under the most severe temperature gradient during the simulated reentry heating. The tensile thermal stress induced in the TPS tile was found to be much lower than the tensile strength of the TPS material. The thermal bending of the TPS tile was not severe enough to cause tearing of the SIP layer.

  14. Thermal Management Tools for Propulsion System Trade Studies and Analysis

    Science.gov (United States)

    McCarthy, Kevin; Hodge, Ernie

    2011-01-01

    Energy-related subsystems in modern aircraft are more tightly coupled with less design margin. These subsystems include thermal management subsystems, vehicle electric power generation and distribution, aircraft engines, and flight control. Tighter coupling, lower design margins, and higher system complexity all make preliminary trade studies difficult. A suite of thermal management analysis tools has been developed to facilitate trade studies during preliminary design of air-vehicle propulsion systems. Simulink blocksets (from MathWorks) for developing quasi-steady-state and transient system models of aircraft thermal management systems and related energy systems have been developed. These blocksets extend the Simulink modeling environment in the thermal sciences and aircraft systems disciplines. The blocksets include blocks for modeling aircraft system heat loads, heat exchangers, pumps, reservoirs, fuel tanks, and other components at varying levels of model fidelity. The blocksets have been applied in a first-principles, physics-based modeling and simulation architecture for rapid prototyping of aircraft thermal management and related systems. They have been applied in representative modern aircraft thermal management system studies. The modeling and simulation architecture has also been used to conduct trade studies in a vehicle level model that incorporates coupling effects among the aircraft mission, engine cycle, fuel, and multi-phase heat-transfer materials.

  15. CFD Analysis of Thermal Control System Using NX Thermal and Flow

    Science.gov (United States)

    Fortier, C. R.; Harris, M. F. (Editor); McConnell, S. (Editor)

    2014-01-01

    The Thermal Control Subsystem (TCS) is a key part of the Advanced Plant Habitat (APH) for the International Space Station (ISS). The purpose of this subsystem is to provide thermal control, mainly cooling, to the other APH subsystems. One of these subsystems, the Environmental Control Subsystem (ECS), controls the temperature and humidity of the growth chamber (GC) air to optimize the growth of plants in the habitat. The TCS provides thermal control to the ECS with three cold plates, which use Thermoelectric Coolers (TECs) to heat or cool water as needed to control the air temperature in the ECS system. In order to optimize the TCS design, pressure drop and heat transfer analyses were needed. The analysis for this system was performed in Siemens NX Thermal/Flow software (Version 8.5). NX Thermal/Flow has the ability to perform 1D or 3D flow solutions. The 1D flow solver can be used to represent simple geometries, such as pipes and tubes. The 1D flow method also has the ability to simulate either fluid only or fluid and wall regions. The 3D flow solver is similar to other Computational Fluid Dynamic (CFD) software. TCS performance was analyzed using both the 1D and 3D solvers. Each method produced different results, which will be evaluated and discussed.

  16. Preliminary hazards analysis of thermal scrap stabilization system. Revision 1

    International Nuclear Information System (INIS)

    Lewis, W.S.

    1994-01-01

    This preliminary analysis examined the HA-21I glovebox and its supporting systems for potential process hazards. Upon further analysis, the thermal stabilization system has been installed in gloveboxes HC-21A and HC-21C. The use of HC-21C and HC-21A simplified the initial safety analysis. In addition, these gloveboxes were cleaner and required less modification for operation than glovebox HA-21I. While this document refers to glovebox HA-21I for the hazards analysis performed, glovebox HC-21C is sufficiently similar that the following analysis is also valid for HC-21C. This hazards analysis document is being re-released as revision 1 to include the updated flowsheet document (Appendix C) and the updated design basis (Appendix D). The revised Process Flow Schematic has also been included (Appendix E). This Current revision incorporates the recommendations provided from the original hazards analysis as well. The System Design Description (SDD) has also been appended (Appendix H) to document the bases for Safety Classification of thermal stabilization equipment

  17. Thermal Analysis of Ball screw Systems by Explicit Finite Difference Method

    Energy Technology Data Exchange (ETDEWEB)

    Min, Bog Ki [Hanyang Univ., Seoul (Korea, Republic of); Park, Chun Hong; Chung, Sung Chong [KIMM, Daejeon (Korea, Republic of)

    2016-01-15

    Friction generated from balls and grooves incurs temperature rise in the ball screw system. Thermal deformation due to the heat degrades positioning accuracy of the feed drive system. To compensate for the thermal error, accurate prediction of the temperature distribution is required first. In this paper, to predict the temperature distribution according to the rotational speed, solid and hollow cylinders are applied for analysis of the ball screw shaft and nut, respectively. Boundary conditions such as the convective heat transfer coefficient, friction torque, and thermal contact conductance (TCC) between balls and grooves are formulated according to operating and fabrication conditions of the ball screw. Explicit FDM (finite difference method) is studied for development of a temperature prediction simulator. Its effectiveness is verified through numerical analysis.

  18. CASKETSS: a computer code system for thermal and structural analysis of nuclear fuel shipping casks

    International Nuclear Information System (INIS)

    Ikushima, Takeshi

    1989-02-01

    A computer program CASKETSS has been developed for the purpose of thermal and structural analysis of nuclear fuel shipping casks. CASKETSS measn a modular code system for CASK Evaluation code system Thermal and Structural Safety. Main features of CASKETSS are as follow; (1) Thermal and structural analysis computer programs for one-, two-, three-dimensional geometries are contained in the code system. (2) Some of the computer programs in the code system has been programmed to provide near optimal speed on vector processing computers. (3) Data libralies fro thermal and structural analysis are provided in the code system. (4) Input data generator is provided in the code system. (5) Graphic computer program is provided in the code system. In the paper, brief illustration of calculation method, input data and sample calculations are presented. (author)

  19. System Level Analysis of a Water PCM HX Integrated into Orion's Thermal Control System

    Science.gov (United States)

    Navarro, Moses; Hansen, Scott; Seth, Rubik; Ungar, Eugene

    2015-01-01

    In a cyclical heat load environment such as low Lunar orbit, a spacecraft's radiators are not sized to reject the full heat load requirement. Traditionally, a supplemental heat rejection device (SHReD) such as an evaporator or sublimator is used to act as a "topper" to meet the additional heat rejection demands. Utilizing a Phase Change Material (PCM) heat exchanger (HX) as a SHReD provides an attractive alternative to evaporators and sublimators as PCM HXs do not use a consumable, thereby leading to reduced launch mass and volume requirements. In continued pursuit of water PCM HX development an Orion system level analysis was performed using Thermal Desktop for a water PCM HX integrated into Orion's thermal control system in a 100km Lunar orbit. The study verified of the thermal model by using a wax PCM and analyzed 1) placing the PCM on the Internal Thermal Control System (ITCS) versus the External Thermal Control System (ETCS) 2) use of 30/70 PGW verses 50/50 PGW and 3) increasing the radiator area in order to reduce PCM freeze times. The analysis showed that for the assumed operating and boundary conditions utilizing a water PCM HX on Orion is not a viable option for any case. Additionally, it was found that the radiator area would have to be increased by at least 40% in order to support a viable water-based PCM HX.

  20. JAERI thermal reactor standard code system for reactor design and analysis SRAC

    International Nuclear Information System (INIS)

    Tsuchihashi, Keichiro

    1985-01-01

    SRAC, JAERI thermal reactor standard code system for reactor design and analysis, developed in Japan Atomic Energy Research Institute, is for all types of thermal neutron nuclear design and analysis. The code system has undergone extensive verifications to confirm its functions, and has been used in core modification of the research reactor, detailed design of the multi-purpose high temperature gas reactor and analysis of the experiment with a critical assembly. In nuclear calculation with the code system, multi-group lattice calculation is first made with the libraries. Then, with the resultant homogeneous equivalent group constants, reactor core calculation is made. Described are the following: purpose and development of the code system, functions of the SRAC system, bench mark tests and usage state and future development. (Mori, K.)

  1. Development of realistic thermal-hydraulic system analysis codes ; development of thermal hydraulic test requirements for multidimensional flow modeling

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Kune Yull; Yoon, Sang Hyuk; Noh, Sang Woo; Lee, Il Suk [Seoul National University, Seoul (Korea)

    2002-03-01

    This study is concerned with developing a multidimensional flow model required for the system analysis code MARS to more mechanistically simulate a variety of thermal hydraulic phenomena in the nuclear stem supply system. The capability of the MARS code as a thermal hydraulic analysis tool for optimized system design can be expanded by improving the current calculational methods and adding new models. In this study the relevant literature was surveyed on the multidimensional flow models that may potentially be applied to the multidimensional analysis code. Research items were critically reviewed and suggested to better predict the multidimensional thermal hydraulic behavior and to identify test requirements. A small-scale preliminary test was performed in the downcomer formed by two vertical plates to analyze multidimensional flow pattern in a simple geometry. The experimental result may be applied to the code for analysis of the fluid impingement to the reactor downcomer wall. Also, data were collected to find out the controlling parameters for the one-dimensional and multidimensional flow behavior. 22 refs., 40 figs., 7 tabs. (Author)

  2. The ITER thermal shields for the magnet system: Design evolution and analysis

    International Nuclear Information System (INIS)

    Bykov, V.; Krasikov, Yu.; Grigoriev, S.; Komarov, V.; Krylov, V.; Labusov, A.; Pyrjaev, V.; Chiocchio, S.; Smirnov, V.; Sorin, V.; Tanchuk, V.

    2005-01-01

    The thermal shield (TS) system provides the required reduction of thermal loads to the cold structures operating at 4.5 K. This paper presents the rationale for the TS design evolution, details of the recent modifications that affect the TS cooling panels, the central TS ports and support system, interface labyrinths and TS structural joints. The modern results of thermal-hydraulic, thermal, seismic, static and dynamic structural analyses, that involve sub-modeling and sub-structuring finite element analysis techniques, are also reported. The modifications result in considerable reduction of TS mass, surface area and heat loads to/from the TS, simplification of TS assembly procedure and in-cryostat maintenance

  3. Thermal-CFD Analysis of Combined Solar-Nuclear Cycle Systems.

    Energy Technology Data Exchange (ETDEWEB)

    Fathi, Nima [Univ. of New Mexico, Albuquerque, NM (United States); McDaniel, Patrick [Univ. of New Mexico, Albuquerque, NM (United States); Vorobieff, Peter [Univ. of New Mexico, Albuquerque, NM (United States); de Oliveira, Cassiano [Univ. of New Mexico, Albuquerque, NM (United States); Rodriguez, Salvador B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Aleyasin, Seyed Sobhan [Univ. of Manitoba (Canada)

    2015-09-01

    The aim of this paper is evaluating the efficiency of a novel combined solar-nuclear cycle. CFD-Thermal analysis is performed to apply the available surplus heat from the nuclear cycle and measure the available kinetic energy of air for the turbine of a solar chimney power plant system (SCPPS). The presented idea helps to decrease the thermal pollution and handle the water shortage supply for water plant by replacing the cooling tower by solar chimney power plant to get the surplus heat from the available warm air in the secondary loop of the reactor. By applying this idea to a typical 1000 MW nuclear power plant with a 0.33 thermal efficiency, we can increase it to 0.39.

  4. Thermal and structural analysis of a cryogenic conduction cooling system for a HTS NMR magnet

    Energy Technology Data Exchange (ETDEWEB)

    In, Se Hwan; Hong, Yong Jun; Yeom, Han Kil; Ko, Hyo Bong; Park, Seong Je [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of)

    2016-03-15

    The superconducting NMR magnets have used cryogen such as liquid helium for their cooling. The conduction cooling method using cryocoolers, however, makes the cryogenic cooling system for NMR magnets more compact and user-friendly than the cryogen cooling method. This paper describes the thermal and structural analysis of a cryogenic conduction cooling system for a 400 MHz HTS NMR magnet, focusing on the magnet assembly. The highly thermo-conductive cooling plates between HTS double pancake coils are used to transfer the heat generated in coils, namely Joule heating at lap splice joints, to thermal link blocks and finally the cryocooler. The conduction cooling structure of the HTS magnet assembly preliminarily designed is verified by thermal and structural analysis. The orthotropic thermal properties of the HTS coil, thermal contact resistance and radiation heat load are considered in the thermal analysis. The thermal analysis confirms the uniform temperature distribution for the present thermal design of the NMR magnet within 0.2 K. The mechanical stress and the displacement by the electromagnetic force and the thermal contraction are checked to verify structural stability. The structural analysis indicates that the mechanical stress on each component of the magnet is less than its material yield strength and the displacement is acceptable in comparison with the magnet dimension.

  5. Status and subjects of thermal-hydraulic analysis for next-generation LWRs with passive safety systems

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The present status and subjects on thermal-hydraulic analysis for next-generation light water reactors (LWRs) with passive safety systems were summarized based on survey results and discussion by subcommittee on improvement of reactor thermal-hydraulic analysis codes under nuclear code committee in Japan Atomic Energy Research Institute. This survey was performed to promote the research of improvement of reactor thermal-hydraulic analysis codes in future. In the first part of this report, the status and subjects on system analysis and those on evaluation of passive safety system performance are summarized for various types of reactor proposed before. In the second part, the status and subjects on multidimensional two-phase flow analysis are reviewed, since the multidimensional analysis was recognized as one of most important subjects through the investigation in the first part. Besides, databases for bubbly flow and annular dispersed flow were explored, those are needed to assess and verify each multidimensional analytical method. The contents in this report are the forefront of thermal-hydraulic analysis for LWRs and those include current findings for the development of multidimensional two-phase flow analytical method. Thus, we expect that the contents can offer various useful information against the improvement of reactor thermal-hydraulic analysis codes in future. (author)

  6. The performance analysis of the Trough Concentrating Solar Photovoltaic/Thermal system

    Energy Technology Data Exchange (ETDEWEB)

    Li, M., E-mail: liming@ynnu.edu.c [Solar Energy Research Institute, Yunnan Normal University, 650092 Kunming (China); Li, G.L. [School of Physics and Electronic Information, Yunnan Normal University, Kunming 650092 (China); Ji, X.; Yin, F.; Xu, L. [Solar Energy Research Institute, Yunnan Normal University, 650092 Kunming (China)

    2011-06-15

    Research highlights: {yields} A 2 m{sup 2} Trough Concentrating Photovoltaic/Thermal (TCPV/T) system is built, a single crystalline silicon solar cell array, a polycrystalline silicon cell array, a Super cell array and a GaAs cell array are respectively used in the experiments. {yields} Another 10 m{sup 2} TCPV/T system using the GaAs cell array and a concentrating silicon cell array are also constructed and characterized. {yields} The economic performance analysis show the electricity generating cost of the TCPV/T system with the concentrating silicon cell array can catch up with flat-plate PV system. -- Abstract: The electrical and thermal performance of a 2 m{sup 2} Trough Concentrating Photovoltaic/Thermal (TCPV/T) system with an energy flux ratio 10.27 are characterized by experiments. A single crystalline silicon solar cell array, a polycrystalline silicon cell array, a Super cell array and a GaAs cell array are respectively used in the experiments. The experimental results show that the electrical performance of the system with the GaAs cell array is better than that of crystal silicon solar cell arrays. The superior output performance of the GaAs cell array mainly benefits from its lower series resistance. But the thermal performances of the system using the single crystal silicon solar cell array and the polycrystalline silicon solar cell array are better. It results from the widths of the two types of cells in the system close to that of the focal line. Another 10 m{sup 2} TCPV/T system with an energy flux ratio of 20 using the GaAs cell array and a concentrating silicon cell array are also constructed and characterized. The experimental results indicate that the photoelectric efficiency of the GaAs cell array is 23.83%, and the instantaneous electrical efficiency and thermal efficiency of the system are 9.88% and 49.84% respectively. While the instantaneous electrical efficiency and thermal efficiency of the system using the low-cost concentrating

  7. The performance analysis of the Trough Concentrating Solar Photovoltaic/Thermal system

    International Nuclear Information System (INIS)

    Li, M.; Li, G.L.; Ji, X.; Yin, F.; Xu, L.

    2011-01-01

    Research highlights: → A 2 m 2 Trough Concentrating Photovoltaic/Thermal (TCPV/T) system is built, a single crystalline silicon solar cell array, a polycrystalline silicon cell array, a Super cell array and a GaAs cell array are respectively used in the experiments. → Another 10 m 2 TCPV/T system using the GaAs cell array and a concentrating silicon cell array are also constructed and characterized. → The economic performance analysis show the electricity generating cost of the TCPV/T system with the concentrating silicon cell array can catch up with flat-plate PV system. -- Abstract: The electrical and thermal performance of a 2 m 2 Trough Concentrating Photovoltaic/Thermal (TCPV/T) system with an energy flux ratio 10.27 are characterized by experiments. A single crystalline silicon solar cell array, a polycrystalline silicon cell array, a Super cell array and a GaAs cell array are respectively used in the experiments. The experimental results show that the electrical performance of the system with the GaAs cell array is better than that of crystal silicon solar cell arrays. The superior output performance of the GaAs cell array mainly benefits from its lower series resistance. But the thermal performances of the system using the single crystal silicon solar cell array and the polycrystalline silicon solar cell array are better. It results from the widths of the two types of cells in the system close to that of the focal line. Another 10 m 2 TCPV/T system with an energy flux ratio of 20 using the GaAs cell array and a concentrating silicon cell array are also constructed and characterized. The experimental results indicate that the photoelectric efficiency of the GaAs cell array is 23.83%, and the instantaneous electrical efficiency and thermal efficiency of the system are 9.88% and 49.84% respectively. While the instantaneous electrical efficiency and thermal efficiency of the system using the low-cost concentrating silicon cell array are 7.51% and 42

  8. System Level Analysis of a Water PCM HX Integrated Into Orion's Thermal Control System Abstract

    Science.gov (United States)

    Navarro, Moses; Hansen, Scott; Ungar, Eugene; Sheth, Rubik

    2015-01-01

    In a cyclical heat load environment such as low Lunar orbit, a spacecraft's radiators are not sized to reject the full heat load requirement. Traditionally, a supplemental heat rejection device (SHReD) such as an evaporator or sublimator is used to act as a "topper" to meet the additional heat rejection demands. Utilizing a Phase Change Material (PCM) heat exchanger (HX) as a SHReD provides an attractive alternative to evaporators and sublimators as PCM HXs do not use a consumable, thereby leading to reduced launch mass and volume requirements. In continued pursuit of water PCM HX development an Orion system level analysis was performed using Thermal Desktop for a water PCM HX integrated into Orion's thermal control system and in a 100km Lunar orbit. The study analyzed 1) placing the PCM on the Internal Thermal Control System (ITCS) versus the External Thermal Control System (ETCS) 2) use of 30/70 PGW verses 50/50 PGW and 3) increasing the radiator area in order to reduce PCM freeze times. The analysis showed that for the assumed operating and boundary conditions utilizing a water PCM HX on Orion is not a viable option. Additionally, it was found that the radiator area would have to be increased over 20% in order to have a viable water-based PCM HX.

  9. Stability, rheology and thermal analysis of functionalized alumina- thermal oil-based nanofluids for advanced cooling systems

    International Nuclear Information System (INIS)

    Ilyas, Suhaib Umer; Pendyala, Rajashekhar; Narahari, Marneni; Susin, Lim

    2017-01-01

    Highlights: • Alumina nanoparticles are functionalized with oleic acid. • Functionalization of alumina nanoparticles gives better dispersion in thermal oil. • Thermophysical properties of nanofluids are experimentally measured. • TGA confirms the improvement in life of nanofluids. - Abstract: Thermal oils are widely used as cooling media in heat transfer processes. However, their potential has not been utilised exquisitely in many applications due to low thermal properties. Thermal oil-based nanofluids are prepared by dispersing functionalized alumina with varying concentrations of 0.5–3 wt.% to enhance thermal properties of oil for advanced cooling systems. The oleic acid coated alumina is prepared and then dispersed in the oil to overcome the aggregation of nanoparticles in base fluid. The surface characterizations of functionalized nanoparticles are performed using different analysis such as XRD, EDS, SEM, TEM and FTIR. Dispersion behaviour and agglomeration studies are conducted at natural and functionalized conditions using different analysis to ensure long-term stability of nanofluids. In addition, rheological behaviour of non-Newtonian nanofluids is studied at high shear rates (100–2000 s"−"1). Effective densities and enhancement in thermal conductivities are measured for different nanofluids concentrations. Specific heat capacity is measured using Differential Scanning Calorimetry. The correlations are developed for thermophysical properties of nanofluids. Thermogravimetric analysis is performed with respect to temperature and time to exploit the effect of the addition of nanoparticles on the degradation of nanofluids. Significant improvement in the thermal properties of oil is observed using highly stable functionalized alumina nano-additives.

  10. Entransy: A misleading concept for the analysis and optimization of thermal systems

    International Nuclear Information System (INIS)

    Sekulic, Dusan P.; Sciubba, Enrico; Moran, Michael J.

    2015-01-01

    The purpose of this article is to assess the value of entransy for use in the thermal system engineering domain and in particular for design. The conclusion is that use of entransy is not recommended. This finding is in keeping with increasing uneasiness that has emerged recently in the technical literature about this concept. Throughout this article emphasis is on concise discussions of salient entransy aspects and the presentation is shaped to reach a broad technical audience. Accordingly, because secondary entransy aspects do not play a central role in reaching the above recommendation, they are considered only in passing or deferred. - Highlights: • A methodology for analysis, design, and optimization of thermal systems. • Entransy is not recommended for use in thermal system engineering. • Components of actual thermal systems do not operate ideally on any basis. • Entropy and exergy rest firmly on the second law of thermodynamics. • Entransy arises by analogy

  11. Thermal Characteristic Analysis and Experimental Study of a Spindle-Bearing System

    Directory of Open Access Journals (Sweden)

    Li Wu

    2016-07-01

    Full Text Available In this paper, a thermo-mechanical coupling analysis model of the spindle-bearing system based on Hertz’s contact theory and a point contact non-Newtonian thermal elastohydrodynamic lubrication (EHL theory are developed. In this model, the effect of preload, centrifugal force, the gyroscopic moment, and the lubrication state of the spindle-bearing system are considered. According to the heat transfer theory, the mathematical model for the temperature field of the spindle system is developed and the effect of the spindle cooling system on the spindle temperature distribution is analyzed. The theoretical simulations and the experimental results indicate that the bearing preload has great effect on the frictional heat generation; the cooling fluid has great effect on the heat balance of the spindle system. If a steady-state heat balance between the friction heat generation and the cooling system cannot be reached, thermally-induced preload will lead to a further increase of the frictional heat generation and then cause the thermal failure of the spindle.

  12. Thermal analysis of CANDU6 moderator system for loss of cooling

    International Nuclear Information System (INIS)

    Xu Zhen

    2012-01-01

    The coolant system and moderator system of CANDU6 are independent. The prompt neutrons are moderated as thermal neutrons by the moderator and the continuous nuclear fission in the reactor is maintained. At the same time the moderator system supplies the heat sink for the heat produced by the neutrons moderation. During the in-service maintenance of plant, the standby RCW which will only cool down reactor coolant system operates instead of RCW and can not supply heat sink for moderator system heat exchanger. As the result, the moderator system will lose heat sink during the operation of standby RCW. To estimate the moderator temperature, the thermal analysis of moderator system for loss of cooling was compared with the experiment data and the system failure caused by the temperature raising was evaluated in this paper. (author)

  13. International Space Station Passive Thermal Control System Analysis, Top Ten Lessons-Learned

    Science.gov (United States)

    Iovine, John

    2011-01-01

    The International Space Station (ISS) has been on-orbit for over 10 years, and there have been numerous technical challenges along the way from design to assembly to on-orbit anomalies and repairs. The Passive Thermal Control System (PTCS) management team has been a key player in successfully dealing with these challenges. The PTCS team performs thermal analysis in support of design and verification, launch and assembly constraints, integration, sustaining engineering, failure response, and model validation. This analysis is a significant body of work and provides a unique opportunity to compile a wealth of real world engineering and analysis knowledge and the corresponding lessons-learned. The analysis lessons encompass the full life cycle of flight hardware from design to on-orbit performance and sustaining engineering. These lessons can provide significant insight for new projects and programs. Key areas to be presented include thermal model fidelity, verification methods, analysis uncertainty, and operations support.

  14. Conceptual assessment and thermal hydraulic analysis of MVDS system for the dry storage of reduced metal fuel

    International Nuclear Information System (INIS)

    Lee, J. C.; Bang, K. S.; Shin, H. S.; Joo, J. S.; Su, K. S.; Kim, H. D.

    2003-01-01

    Conceptual assessment and thermal hydraulic analysis of MVDS storage system have been carried out for application of reduced metal fuel. The storage concept was established considering the optimum weight, storage volume and thermal efficiency. The capacity of MVDS system for loading the reduced metal fuel has four times as compared with existing PWR fuel storage system. In the results of thermal analysis, the maximum temperature of metal fuel was estimated to be 110 .deg. C which is lower than the allowable value under normal operation condition. Therefore, it is shown that the MVDS system can feasibly accomodate the reduced metal fuel in aspect of thermal safety

  15. Thermal analysis of a conceptual design for a 250 W(e) GPHS/FPSE space power system

    International Nuclear Information System (INIS)

    Mccomas, T.J.; Dugan, E.T.

    1991-01-01

    A thermal analysis has been performed for a 250-W(e) space nuclear power system which combines the US Department of Energy's general purpose heat source (GPHS) modules with a state-of-the-art free-piston Stirling engine (FPSE). The focus of the analysis is on the temperature of the indium fuel clad within the GPHS modules. The thermal analysis results indicate fuel clad temperatures slightly higher than the design goal temperature of 1573 K. The results are considered favorable due to numerous conservative assumptions used. To demonstrate the effects of the conservatism, a brief sensitivity analysis is performed in which a few of the key system parameters are varied to determine their effect on the fuel clad temperatures. It is shown that thermal analysis of a more detailed thermal mode should yield fuel clad temperatures below 1573 K. 3 refs

  16. Development of intelligent system for a thermal analysis instrument

    International Nuclear Information System (INIS)

    Xu Xiaoli; Wu Guoxin; Shi Yongchao

    2005-01-01

    The key techniques for the intelligent analysis instrument developed are proposed. Based on the technique of virtual instrumentation, the intelligent PID control algorithm to control the temperature of thermal analysis instrument is described. The dynamic character and the robust performance of traditional PID controls are improved through the dynamic gain factor, temperature rate change factor, the forecast factor, and the temperature correction factor is introduced. Using the graphic development environment of LabVIEW, the design of system modularization and the graphic display are implemented. By means of multiple mathematical modules, intelligent data processing is realized

  17. Thermal-hydraulic analysis of the improved TOPAZ-II power system using a heat pipe radiator

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wenwen; Zhang, Dalin, E-mail: dlzhang@mail.xjtu.edu.cn; Tian, Wenxi; Qiu, Suizheng; Su, G.H.

    2016-10-15

    Highlights: • The system thermal-hydraulic model of the improved space thermionic reactor is developed. • The temperature reactivity feedback effects of the moderator, UO2 fuel, electrodes and reflector are considered. • The alkali metal heat pipe radiator is modeled with the two dimensional heat pipe model. • The steady state and the start-up procedure of the system are analyzed. - Abstract: A system analysis code coupled with the heat pipe model is developed to analyze the thermal-hydraulic characteristics of the improved TOPAZ-II reactor power system with a heat pipe radiator. The core thermal-hydraulic model, neutron physics model, and the coolant loop component models (including pump, volume accumulator, pipes and plenums) are established. The designed heat pipe radiator, which replaces the original pumped loop radiator, is also modeled, including two-dimensional heat pipe analysis model, fin model and coolant transport duct model. The system analysis code and the heat pipe model is coupled in the transport duct model. Steady state condition and start-up procedure of the improved TOPAZ-II system are calculated. The results show that the designed radiator can satisfy the waste heat rejection requirement of the improved power system. Meanwhile, the code can be used to obtained the thermal characteristics of the system transients such as the start-up process.

  18. Thermal Hydraulic Analysis on Containment Filtered Venting System

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Young Suk; Park, Tong Kyu; Lee, Doo Yong; Lee, Byung Chul [FNC Technology Co. Ltd., Yongin (Korea, Republic of); Lee, Sang Won; Kim, Hyeong Taek [KHNP-Central Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    In this study, the thermal hydraulic conditions (e. g. pressure and flow rate) at each component have been examined and the sensitivity analysis on CFVS design parameters (e. g. water inventory, volumetric flow rate). The purpose is to know the possible range of flow conditions at each component to determine the optimum size of filtration system. GOTHIC code has been used to simulate the thermal-hydraulic behavior inside of CFVS. The behavior of flows in the CFVS has been investigated. The vessel water level and the flow rates during the CFVS operation are examined. It was observed that the vessel water level would be changed significantly due to steam condensation/thermal expansion and steam evaporation. Therefore, the vessel size and the initial water inventory should be carefully determined to keep the minimum water level required for filtration components and not to flood the components in the upper side of the vessel. It has been also observed that the volumetric flow rate is maintained during the CFVS operation, which is beneficial for pool scrubbing units. However, regarding the significant variations at the orifice downstream, careful design would be necessary.

  19. Parametric performance analysis of a concentrated photovoltaic co-generation system equipped with a thermal storage tank

    International Nuclear Information System (INIS)

    Imtiaz Hussain, M.; Lee, Gwi Hyun

    2015-01-01

    Highlights: • Both thermal and electrical powers varied by changing surface area of collector. • Thermal stratification and total system power were increased at critical flow rate. • Parametric analysis of the CPVC system offers to determine the desired outcome. • Thermal and electrical outputs varied by changing the focal length of Fresnel lens. - Abstract: This article presents a parametric study of a concentrated photovoltaic co-generation (CPVC) system with an attached thermal storage tank. The CPVC system utilized dual-axis tracker and multiple solar energy collector (SEC) modules and forced cooling system. Each SEC module comprised 16 triple-junction solar cells, copper tube absorbers, and 16 Fresnel lenses were aligned against each solar cell. This study investigated all possible parameters that can affect the CPVC system performance, including the collector area, solar irradiation, inlet temperature, and mass flow rate. The surface area of the collector and the thermal power were increased by increasing the number of SEC modules connected in series; however, the electrical power output decreased from the first to the fourth SEC module consecutively. At the measured optimal flow rate, mixing and thermal diffusion in the storage tank were decreased, and the total power generation from the CPVC system was increased. Variations in the thermal and electrical power outputs were also observed when the focal length of the Fresnel lens was changed. This parametric analysis enables the CPVC system to obtain the desired output by varying the combination of operational and geometrical parameters

  20. Thermal analysis of an HVAC system with TRV controlled hydronic radiator

    DEFF Research Database (Denmark)

    Tahersima, Fatemeh; Stoustrup, Jakob; Rasmussen, Henrik

    2010-01-01

    A model for an HVAC system is derived in this paper. The HVAC system consists of a room and a hydronic radiator with temperature regulating valve (TRV) which has a step motor to adjust the valve opening. The heating system and the room are simulated as a unit entity for thermal analysis and contr......A model for an HVAC system is derived in this paper. The HVAC system consists of a room and a hydronic radiator with temperature regulating valve (TRV) which has a step motor to adjust the valve opening. The heating system and the room are simulated as a unit entity for thermal analysis...... and controller design. A discrete-element model with interconnected small scaled elements is proposed for the radiator. This models the radiator more precisely than that of a lumped model in terms of transfer delay and radiator gain. This precise modeling gives us an intuition into a regular unwanted phenomenon...... which occurs in low demand situations. When flow is very low in radiator and the supply water temperature and the pressure drop across the valve is constant, oscillation in room temperature occurs. One reason could be the large gain of radiator in low demand conditions compared to the high demand...

  1. CASKETSS-2: a computer code system for thermal and structural analysis of nuclear fuel shipping casks (version 2)

    International Nuclear Information System (INIS)

    Ikushima, Takeshi

    1991-08-01

    A computer program CASKETSS-2 has been developed for the purpose of thermal and structural analysis of nuclear fuel shipping casks. CASKETSS-2 means a modular code system for CASK Evaluation code system Thermal and Structural Safety (Version 2). Main features of CASKETSS-2 are as follow; (1) Thermal and structural analysis computer programs for one-, two-, three-dimensional geometries are contained in the code system. (2) There are simplified computer programs and a detailed one in the structural analysis part in the code system. (3) Input data generator is provided in the code system. (4) Graphic computer program is provided in the code system. In the paper, brief illustration of calculation method, input data and sample calculations are presented. (author)

  2. Thermal analysis of the conduction cooling system for HTS SMES system of 600 kJ class

    International Nuclear Information System (INIS)

    Hong, Yong Ju; Yeom, Han Kil; Park, Seong Je; Kim, Hyo Bong; Koh, Deuk Yong

    2007-01-01

    SMES systems need cryogenic cooling systems. Conduction cooling system has more effective, compact structure than cryogen. In general, 2 stage GM cryocoolers are used for conduction cooling of HTS SMES system. 1st stages of cryocoolers are used for the cooling of current leads and radiation shields, and 2nd stages of cryocoolers for HTS coil. For the effective conduction cooling of the HTS SMES system, the temperature difference between the cryocooler and HTS coil should be minimized. In this paper, a cryogenic conduction cooling system for HTS SMES is analyzed to evaluate the performance of the cooling system. The analysis is carried out for the steady state with the heat generation of the HTS coil and effects of the thermal contact resistance. The results show the effects of the heat generation and thermal contact resistance on the temperature distribution

  3. A thermal analysis study on proprietary quick-setting mixed binder system

    International Nuclear Information System (INIS)

    Deneanu, N.; Dulama, M.; Diaconescu, C.

    2013-01-01

    The present paper presents a study, by thermal analysis, of the hydration of a mixed binder system consist of Portland composite cement type CEM II/A-M(S-LL) 32,5 R and calcium aluminate cement type GORKAL 70, patented by the authors for embedding spent radioactive solvents. Cement hydration reactions are often affected by the presence of a spent radioactive solvent, usually retarded. This process can be monitored by thermal analysis and often quantified. The data are being used as a reference to compare the changes in the cement blend hydration during the solidification caused by the presence of the spent radioactive solvents itself or by emulsifier additives which are being availed. Detailed analysis of DTG (derivative thermo gravimetric) decomposition profiles of portlandite and carbonate enabled the evaluation of admixture-related parameters concerning portlandite formation and also indicated the behaviour of specific carbonates during the hydration process. (authors)

  4. Exergy analysis of building integrated semitransparent photovoltaic thermal (BiSPVT system

    Directory of Open Access Journals (Sweden)

    Neha Gupta

    2017-02-01

    Full Text Available In this paper, an exergy analysis of building integrated semitransparent photovoltaic thermal (BiSPVT system has been carried out. In the proposed system, the room below building integrated semitransparent photovoltaic thermal system has been considered as an air-conditioned (constant room temperature. Energy balance equation for each components namely semitransparent photovoltaic roof, floor and room air have been given. Based on energy balance, an analytical expression for room air, solar cell and room floor temperatures have been derived along with solar cell electrical efficiency. Further by considering the day lighting parameters, an overall exergy of the proposed system has been derived for different number of air change between the room and ambient air. It has been observed that there is reduction in room air and solar cell temperatures with an increase of number of air changes. However, solar cell electrical efficiency increases with decrease in temperature of solar cell. Further, it is found that an electrical power and illumination inside the room are more dominating in comparison with thermal exergy. An increase of 1.15% in an overall exergy is observed for the number of air changes varies from 0 to 4. Experimental validation of theoretical model has also been carried out.

  5. Comparison for the interfacial and wall friction models in thermal-hydraulic system analysis codes

    International Nuclear Information System (INIS)

    Hwang, Moon Kyu; Park, Jee Won; Chung, Bub Dong; Kim, Soo Hyung; Kim, See Dal

    2007-07-01

    The average equations employed in the current thermal hydraulic analysis codes need to be closed with the appropriate models and correlations to specify the interphase phenomena along with fluid/structure interactions. This includes both thermal and mechanical interactions. Among the closure laws, an interfacial and wall frictions, which are included in the momentum equations, not only affect pressure drops along the fluid flow, but also have great effects for the numerical stability of the codes. In this study, the interfacial and wall frictions are reviewed for the commonly applied thermal-hydraulic system analysis codes, i.e. RELAP5-3D, MARS-3D, TRAC-M, and CATHARE

  6. Thermal energy storages analysis for high temperature in air solar systems

    International Nuclear Information System (INIS)

    Andreozzi, Assunta; Buonomo, Bernardo; Manca, Oronzio; Tamburrino, Salvatore

    2014-01-01

    In this paper a high temperature thermal storage in a honeycomb solid matrix is numerically investigated and a parametric analysis is accomplished. In the formulation of the model it is assumed that the system geometry is cylindrical, the fluid and the solid thermo physical properties are temperature independent and radiative heat transfer is taken into account whereas the effect of gravity is neglected. Air is employed as working fluid and the solid material is cordierite. The evaluation of the fluid dynamic and thermal behaviors is accomplished assuming the honeycomb as a porous medium. The Brinkman–Forchheimer–extended Darcy model is used in the governing equations and the local thermal non equilibrium is assumed. The commercial CFD Fluent code is used to solve the governing equations in transient regime. Numerical simulations are carried out with storage medium for different mass flow rates of the working fluid and different porosity values. Results in terms of temperature profiles, temperatures fields and stored thermal energy as function of time are presented. The effects of storage medium, different porosity values and mass flow rate on stored thermal energy and storage time are shown. - Highlights: • HTTES in a honeycomb solid matrix is numerically investigated. • The numerical analysis is carried out assuming the honeycomb as a porous medium. • The Brinkman–Forchheimer–extended Darcy model is used in the governing equations. • Results are carried out for different mass flow rates and porosity values. • The main effect is due to the porosity which set the thermal energy storage value

  7. Cna 1 spent fuel element interim dry storage system thermal analysis

    International Nuclear Information System (INIS)

    Hilal, R. E; Garcia, J. C; Delmastro, D. F

    2006-01-01

    At the moment, the Atucha I Nuclear Power Plant (Cnea-I) located in the city of Lima, has enough room to store its spent fuel (Sf) in their two pools spent fuel until about 2015.In case of life extension a spend fuel element interim dry storage system is needed.Nucleolectrica Argentina S.A. (N A-S A) and the Comision Nacional de Energia Atomica (Cnea), have proposed different interim dry storage systems.These systems have to be evaluated in order to choose one of them.The present work's objective is the thermal analysis of one dry storage alternative for the Sf element of Cna 1.In this work a simple model was developed and used to perform the thermal calculations corresponding to the system proposed by Cnea.This system considers the store of sealed containers with 37 spent fuels in concrete modules.Each one of the containers is filled in the pool houses and transported to the module in a transference cask with lead walls.Fulfill the maximum cladding temperature requirement ( [es

  8. Optimization of a waste heat recovery system with thermoelectric generators by three-dimensional thermal resistance analysis

    International Nuclear Information System (INIS)

    Huang, Gia-Yeh; Hsu, Cheng-Ting; Fang, Chun-Jen; Yao, Da-Jeng

    2016-01-01

    Highlights: • The waste heat recovery system is modeled by three-dimensional thermal resistance. • This is a time-saving and efficient method to estimate power generation from TEGs. • Relations between power generation and varied factors can be rapidly revealed. • TEGs positions and uniformity of velocity profile should be considered together. • Power generation is more sensitive to either internal or external flow velocity. - Abstract: Three-dimensional (3D) thermal resistance analysis provides a rapid and simple method to estimate the power generated from a waste heat recovery system with thermoelectric generators (TEGs), and facilitates an optimization of the system. Such a system comprises three parts – a waste heat recovery chamber, TEG modules and a cooling system. A fin-structured duct serves as a waste heat recovery chamber, which is attached to the hot sides of the TEGs; the cold sides of the TEGs are attached to a cooling system. The waste heat recovery chamber harvests energy from exhaust heat that the TEGs convert into electricity. The estimation of generated power is an important part of the system design. Methods of Computational Fluid Dynamics (CFD) assist the analysis and improve the performance with great accuracy but great computational duration. The use of this method saves much time relative to such CFD methods. In 3D thermal resistance analysis, a node of unknown temperature is located at the centroid of each cell into which the system is divided. The relations of unknown temperatures at the cells are based on the energy conservation and the definition of thermal resistance. The temperatures of inlet waste hot gas and ambient fluid are known. With these boundary conditions, the unknown temperatures in the system are solved, enabling estimation of the power generated with TEGs. A 3D model of the system was simulated with FloTHERM; its numerical solution matched the solution of the 3D thermal resistance analysis within 6%. The power

  9. Thermal analysis and design of passive solar buildings

    CERN Document Server

    Athienitis, AK

    2013-01-01

    Passive solar design techniques are becoming increasingly important in building design. This design reference book takes the building engineer or physicist step-by-step through the thermal analysis and design of passive solar buildings. In particular it emphasises two important topics: the maximum utilization of available solar energy and thermal storage, and the sizing of an appropriate auxiliary heating/cooling system in conjunction with good thermal control.Thermal Analysis and Design of Passive Solar Buildings is an important contribution towards the optimization of buildings as systems th

  10. Development of numerical simulation system for thermal-hydraulic analysis in fuel assembly of sodium-cooled fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ohshima, Hiroyuki; Uwaba, Tomoyuki [Japan Atomic Energy Agency (4002 Narita, O-arai, Ibaraki 311-1393, Japan) (Japan); Hashimoto, Akihiko; Imai, Yasutomo [NDD Corporation (1-1-6 Jounan, Mito, Ibaraki 310-0803, Japan) (Japan); Ito, Masahiro [NESI Inc. (4002 Narita, O-arai, Ibaraki 311-1393, Japan) (Japan)

    2015-12-31

    A numerical simulation system, which consists of a deformation analysis program and three kinds of thermal-hydraulics analysis programs, is being developed in Japan Atomic Energy Agency in order to offer methodologies to clarify thermal-hydraulic phenomena in fuel assemblies of sodium-cooled fast reactors under various operating conditions. This paper gives the outline of the system and its applications to fuel assembly analyses as a validation study.

  11. Energy demand and thermal comfort of HVAC systems with thermally activated building systems as a function of user profile

    Science.gov (United States)

    Pałaszyńska, Katarzyna; Bandurski, Karol; Porowski, Mieczysław

    2017-11-01

    Thermally Activated Building Systems (TABS) are a way to use building structure as a thermal energy storage. As a result, renewable energy sources may be used more efficiently. The paper presents numerical analysis of a HVAC system with TABS energy demand and indoor thermal comfort of a representative room in a non-residential building (governmental, commercial, educational). The purpose of analysis is to investigate the influence of a user profile on system performance. The time span of the analysis is one year - a typical meteorological year. The model was prepared using a generally accepted simulation tool - TRNSYS 17. The results help to better understand the interaction of a user profile with TABS. Therefore they are important for the development of optimal control algorithms for energy efficient buildings equipped with such systems.

  12. Optimal controls of building storage systems using both ice storage and thermal mass – Part II: Parametric analysis

    International Nuclear Information System (INIS)

    Hajiah, Ali; Krarti, Moncef

    2012-01-01

    Highlights: ► A detailed analysis is presented to assess the performance of thermal energy storage (TES) systems. ► Utility rates have been found to be significant in assessing the operation of TES systems. ► Optimal control strategies for TES systems can save up to 40% of total energy cost of office buildings. - Abstract: This paper presents the results of a series of parametric analysis to investigate the factors that affect the effectiveness of using simultaneously building thermal capacitance and ice storage system to reduce total operating costs (including energy and demand costs) while maintaining adequate occupant comfort conditions in buildings. The analysis is based on a validated model-based simulation environment and includes several parameters including the optimization cost function, base chiller size, and ice storage tank capacity, and weather conditions. It found that the combined use of building thermal mass and active thermal energy storage system can save up to 40% of the total energy costs when integrated optimal control are considered to operate commercial buildings.

  13. Application of Functional Analysis on a SCADA System of a Thermal Power Plant

    Directory of Open Access Journals (Sweden)

    LAKHOUA, M. N.

    2009-06-01

    Full Text Available The aim of this paper is to present firstly the functionality of a supervisory system for complex processes, and secondly to present the concepts of SCADA (supervisory control and data acquisition systems. A functional analysis technique SADT (Structured Analysis and Design Technique has been applied on an example of a SCADA system of a thermal power plant. This technique allows a functional description of a SCADA system. The paper briefly discusses the functions of a SCADA system and some advantages of the application of functional analysis for the design of a human centered supervisory system. Then the basic principles of the SADT technique applied on the SCADA system are presented. Finally, the different results obtained from the SADT technique are discussed.

  14. Design optimization and sensitivity analysis of a biomass-fired combined cooling, heating and power system with thermal energy storage systems

    International Nuclear Information System (INIS)

    Caliano, Martina; Bianco, Nicola; Graditi, Giorgio; Mongibello, Luigi

    2017-01-01

    Highlights: • A novel operation strategy for biomass-fired combined cooling, heating and power system is presented. • A design optimization of the system is conducted. • The effects of variation of the incentive for the electricity generation are evaluated. • The effects of the variation of the absorption chiller size and the thermal energy storage system one are evaluated. • The inclusion of a cold storage system into the combined cooling, heating and power system is also analyzed. - Abstract: In this work, an operation strategy for a biomass-fired combined cooling, heating and power system, composed of a cogeneration unit, an absorption chiller, and a thermal energy storage system, is formulated in order to satisfy time-varying energy demands of an Italian cluster of residential multi-apartment buildings. This operation strategy is adopted for performing the economical optimization of the design of two of the devices composing the combined cooling, heating and power system, namely the absorption chiller and the storage system. A sensitivity analysis is carried out in order to evaluate the impact of the incentive for the electricity generation on the optimized results, and also to evaluate, separately, the effects of the variation of the absorption chiller size, and the effects of the variation of the thermal energy storage system size on the system performance. In addition, the inclusion into the system of a cold thermal energy storage system is analyzed, as well, assuming different possible values for the cold storage system cost. The results of the sensitivity analysis indicate that the most influencing factors from the economical point of view are represented by the incentive for the electricity generation and the absorption chiller power. Results also show that the combined use of a thermal energy storage and of a cold thermal energy storage during the hot season could represent a viable solution from the economical point of view.

  15. Thermal Management and Thermal Protection Systems

    Science.gov (United States)

    Hasnain, Aqib

    2016-01-01

    During my internship in the Thermal Design Branch (ES3), I contributed to two main projects: i) novel passive thermal management system for future human exploration, ii) AVCOAT undercut thermal analysis. i) As NASA prepares to further expand human and robotic presence in space, it is well known that spacecraft architectures will be challenged with unprecedented thermal environments. Future exploration activities will have the need of thermal management systems that can provide higher reliability, mass and power reduction and increased performance. In an effort to start addressing the current technical gaps the NASA Johnson Space Center Passive Thermal Discipline has engaged in technology development activities. One of these activities was done through an in-house Passive Thermal Management System (PTMS) design for a lunar lander. The proposed PTMS, functional in both microgravity and gravity environments, consists of three main components: a heat spreader, a novel hybrid wick Variable Conductance Heat Pipe (VCHP), and a radiator. The aim of this PTMS is to keep electronics on a vehicle within their temperature limits (0 and 50 C for the current design) during all mission phases including multiple lunar day/night cycles. The VCHP was tested to verify its thermal performance. I created a thermal math model using Thermal Desktop (TD) and analyzed it to predict the PTMS performance. After testing, the test data provided a means to correlate the thermal math model. This correlation took into account conduction and convection heat transfer, representing the actual benchtop test. Since this PTMS is proposed for space missions, a vacuum test will be taking place to provide confidence that the system is functional in space environments. Therefore, the model was modified to include a vacuum chamber with a liquid nitrogen shroud while taking into account conduction and radiation heat transfer. Infrared Lamps were modelled and introduced into the model to simulate the sun

  16. Feasibility study for objective oriented design of system thermal hydraulic analysis program

    International Nuclear Information System (INIS)

    Chung, Bub Dong; Jeong, Jae Jun; Hwang, Moon Kyu

    2008-01-01

    The system safety analysis code, such as RELAP5, TRAC, CATHARE etc. have been developed based on Fortran language during the past few decades. Refactoring of conventional codes has been also performed to improve code readability and maintenance. However the programming paradigm in software technology has been changed to use objects oriented programming (OOP), which is based on several techniques, including encapsulation, modularity, polymorphism, and inheritance. In this work, objective oriented program for system safety analysis code has been tried utilizing modernized C language. The analysis, design, implementation and verification steps for OOP system code development are described with some implementation examples. The system code SYSTF based on three-fluid thermal hydraulic solver has been developed by OOP design. The verifications of feasibility are performed with simple fundamental problems and plant models. (author)

  17. Progressive reduction of the thermal wall system by modal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Mokhtari, A.; Meslem, A.; Bounif, A.; Kadi, L. [Universite des Sciences et de la Technologie, Oran (Algeria)

    1993-12-31

    A reduction method of thermal systems called ``progress`` using the modal Analysis is presented. It allows to do, at each time of simulation, a synthesis information in the system evolution. Consequently, the limited number of descriptive and significant parameters (proper modes), can produce some extremely useful indication about dynamic evolution. However this method can eliminate proper modes of which the energetic contribution will be neglected or amortized. Some examples were studied, showing the efficiency of this method by reducing the computing time, as well as, having high precision on predicted dynamic response over time of simulation. (Authors). 4 refs., 4 figs.

  18. Transient thermal analysis of Vega launcher structures

    Energy Technology Data Exchange (ETDEWEB)

    Gori, F. [University of Rome ' Tor Vergata' , Rome (Italy); De Stefanis, M. [Thales Alenia Space Italia, Rome (Italy); Worek, W.M. [University of Illinois at Chicago, Chicago (United States)], E-mail: wworek@uic.edu; Minkowycz, W.J. [University of Illinois at Chicago, Chicago (United States)

    2008-12-15

    A transient thermal analysis is carried out to verify the base cover thermal protection system of Vega 2nd stage Solid Rocket Motor (SRM) and the flange coupling of the inter-stage 2/3. The analysis is performed with a finite element code. The work has developed suitable numerical Fortran subroutines to assign radiation and convection boundary conditions. The thermal behaviour of the structures is presented.

  19. Thermal-hydraulic unreliability of passive systems

    International Nuclear Information System (INIS)

    Tzanos, C.P.; Saltos, N.T.

    1995-01-01

    Advanced light water reactor designs like AP600 and the simplified boiling water reactor (SBWR) use passive safety systems for accident prevention and mitigation. Because these systems rely on natural forces for their operation, their unavailability due to hardware failures and human error is significantly smaller than that of active systems. However, the coolant flows predicted to be delivered by these systems can be subject to significant uncertainties, which in turn can lead to a significant uncertainty in the predicted thermal-hydraulic performance of the plant under accident conditions. Because of these uncertainties, there is a probability that an accident sequence for which a best estimate thermal-hydraulic analysis predicts no core damage (success sequence) may actually lead to core damage. For brevity, this probability will be called thermal-hydraulic unreliability. The assessment of this unreliability for all the success sequences requires very expensive computations. Moreover, the computational cost increases drastically as the required thermal-hydraulic reliability increases. The required computational effort can be greatly reduced if a bounding approach can be used that either eliminates the need to compute thermal-hydraulic unreliabilities, or it leads to the analysis of a few bounding sequences for which the required thermal-hydraulic reliability is relatively small. The objective of this paper is to present such an approach and determine the order of magnitude of the thermal-hydraulic unreliabilities that may have to be computed

  20. Thermal Hydraulic Analysis of RPV Support Cooling System for HTGR

    International Nuclear Information System (INIS)

    Min Qi; Wu Xinxin; Li Xiaowei; Zhang Li; He Shuyan

    2014-01-01

    Passive safety is now of great interest for future generation reactors because of its reduction of human interaction and avoidance of failures of active components. reactor pressure vessel (RPV) support cooling system (SCS) for high temperature gas-cooled reactor (HTGR) is a passive safety system and is used to cool the concrete seats for the four RPV supports at its bottom. The SCS should have enough cooling capacity to ensure the temperature of the concrete seats for the supports not exceeding the limit temperature. The SCS system is composed of a natural circulation water loop and an air cooling tower. In the water loop, there is a heat exchanger embedded in the concrete seat, heat is transferred by thermal conduction and convection to the cooling water. Then the water is cooled by the air cooler mounted in the air cooling tower. The driving forces for water and air are offered by the density differences caused by the temperature differences. In this paper, the thermal hydraulic analysis for this system was presented. Methods for decoupling the natural circulation and heat transfer between the water loop and air flow were introduced. The operating parameters for different working conditions and environment temperatures were calculated. (author)

  1. Energy demand and thermal comfort of HVAC systems with thermally activated building systems as a function of user profile

    Directory of Open Access Journals (Sweden)

    Pałaszyńska Katarzyna

    2017-01-01

    Full Text Available Thermally Activated Building Systems (TABS are a way to use building structure as a thermal energy storage. As a result, renewable energy sources may be used more efficiently. The paper presents numerical analysis of a HVAC system with TABS energy demand and indoor thermal comfort of a representative room in a non-residential building (governmental, commercial, educational. The purpose of analysis is to investigate the influence of a user profile on system performance. The time span of the analysis is one year – a typical meteorological year. The model was prepared using a generally accepted simulation tool – TRNSYS 17. The results help to better understand the interaction of a user profile with TABS. Therefore they are important for the development of optimal control algorithms for energy efficient buildings equipped with such systems.

  2. Thermal systems; Systemes thermiques

    Energy Technology Data Exchange (ETDEWEB)

    Lalot, S. [Valenciennes Univ. et du Hainaut Cambresis, LME, 59 (France); Lecoeuche, S. [Ecole des Mines de Douai, Dept. GIP, 59 - Douai (France)]|[Lille Univ. des Sciences et Technologies, 59 - Villeneuve d' Ascq (France); Ahmad, M.; Sallee, H.; Quenard, D. [CSTB, 38 - Saint Martin d' Heres (France); Bontemps, A. [Universite Joseph Fourier, LEGI/GRETh, 38 - Grenoble (France); Gascoin, N.; Gillard, P.; Bernard, S. [Laboratoire d' Energetique, Explosion, Structure, 18 - Bourges (France); Gascoin, N.; Toure, Y. [Laboratoire Vision et Robotique, 18 - Bourges (France); Daniau, E.; Bouchez, M. [MBDA, 18 - Bourges (France); Dobrovicescu, A.; Stanciu, D. [Bucarest Univ. Polytechnique, Faculte de Genie Mecanique (Romania); Stoian, M. [Reims Univ. Champagne Ardenne, Faculte des Sciences, UTAP/LTM, 51 (France); Bruch, A.; Fourmigue, J.F.; Colasson, S. [CEA Grenoble, Lab. Greth, 38 (France); Bontemps, A. [Universite Joseph Fourier, LEGI/GRETh, 38 - Grenoble (France); Voicu, I.; Mare, T.; Miriel, J. [Institut National des Sciences Appliquees (INSA), LGCGM, IUT, 35 - Rennes (France); Galanis, N. [Sherbrooke Univ., Genie Mecanique, QC (Canada); Nemer, M.; Clodic, D. [Ecole des Mines de Paris, Centre Energetique et Procedes, 75 (France); Lasbet, Y.; Auvity, B.; Castelain, C.; Peerhossaini, H. [Nantes Univ., Ecole Polytechnique, Lab. de Thermocinetiquede Nantes, UMR-CNRS 6607, 44 (France)

    2005-07-01

    This session about thermal systems gathers 26 articles dealing with: neural model of a compact heat exchanger; experimental study and numerical simulation of the thermal behaviour of test-cells with walls made of a combination of phase change materials and super-insulating materials; hydraulic and thermal modeling of a supercritical fluid with pyrolysis inside a heated channel: pre-dimensioning of an experimental study; energy analysis of the heat recovery devices of a cryogenic system; numerical simulation of the thermo-hydraulic behaviour of a supercritical CO{sub 2} flow inside a vertical tube; mixed convection inside dual-tube exchangers; development of a nodal approach with homogenization for the simulation of the brazing cycle of a heat exchanger; chaotic exchanger for the cooling of low temperature fuel cells; structural optimization of the internal fins of a cylindrical generator; a new experimental approach for the study of the local boiling inside the channels of exchangers with plates and fins; experimental study of the flow regimes of boiling hydrocarbons on a bundle of staggered tubes; energy study of heat recovery exchangers used in Claude-type refrigerating systems; general model of Carnot engine submitted to various operating constraints; the free pistons Stirling cogeneration system; natural gas supplied cogeneration system with polymer membrane fuel cell; influence of the CRN coating on the heat flux inside the tool during the wood unrolling process; transport and mixture of a passive scalar injected inside the wake of a Ahmed body; control of a laser welding-brazing process by infrared thermography; 2D self-adaptative method for contours detection: application to the images of an aniso-thermal jet; exergy and exergy-economical study of an 'Ericsson' engine-based micro-cogeneration system; simplified air-conditioning of telephone switching equipments; parametric study of the 'low-energy' individual dwelling; brief synthesis of

  3. Thermal analysis and prediction of phase equilibria in ternary Pb-Zn-Ag System

    Czech Academy of Sciences Publication Activity Database

    Živković, D.; Minić, D.; Manasijević, D.; Šesták, Jaroslav; Živković, Ž.

    2011-01-01

    Roč. 47, č. 1 (2011), 23-30 ISSN 1450-5339 Institutional research plan: CEZ:AV0Z10100521 Keywords : Pb-Zn-Ag system * thermal analysis * phase equilibrium Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.317, year: 2011

  4. Interaction between thermal/hydraulics, human factors and system analysis for assessing feed and bleed risk benefits

    International Nuclear Information System (INIS)

    Lanore, J.M.; Caron, J.L.

    1987-11-01

    For probabilistic analysis of accident sequences, thermal/hydraulics, human factors and systems operation problems are frequently closely interrelated. This presentation will discuss a typical example which illustrates this interrelation: total loss of feedwater flow. It will present thermal/hydraulic analysises performed, how the T/H analysises are related to human factors and systems operation, and how, based on this, the failure probability of the feed and bleed cooling mode was evaluated

  5. Performance analysis of different ORC configurations for thermal energy and LNG cold energy hybrid power generation system

    Science.gov (United States)

    Sun, Zhixin; Wang, Feng; Wang, Shujia; Xu, Fuquan; Lin, Kui

    2017-01-01

    This paper presents a thermal energy and Liquefied natural gas (LNG) cold energy hybrid power generation system. Performances of four different Organic Rankine cycle (ORC) configurations (the basic, the regenerative, the reheat and the regenerative-reheat ORCs) are studied based on the first and the second law of thermodynamics. Dry organic fluid R245fa is selected as the typical working fluid. Parameter analysis is also conducted in this paper. The results show that regeneration could not increase the thermal efficiency of the thermal and cold energy hybrid power generation system. ORC with the reheat process could produce more specific net power output but it may also reduce the system thermal efficiency. The basic and the regenerative ORCs produce higher thermal efficiency while the regenerative-reheat ORC performs best in the exergy efficiency. A preheater is necessary for the thermal and cold energy hybrid power generation system. And due to the presence of the preheater, there will be a step change of the system performance as the turbine inlet pressure rises.

  6. Thermal photovoltaic solar integrated system analysis using neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Ashhab, S. [Hashemite Univ., Zarqa (Jordan). Dept. of Mechanical Engineering

    2007-07-01

    The energy demand in Jordan is primarily met by petroleum products. As such, the development of renewable energy systems is quite attractive. In particular, solar energy is a promising renewable energy source in Jordan and has been used for food canning, paper production, air-conditioning and sterilization. Artificial neural networks (ANNs) have received significant attention due to their capabilities in forecasting, modelling of complex nonlinear systems and control. ANNs have been used for forecasting solar energy. This paper presented a study that examined a thermal photovoltaic solar integrated system that was built in Jordan. Historical input-output system data that was collected experimentally was used to train an ANN that predicted the collector, PV module, pump and total efficiencies. The model predicted the efficiencies well and can therefore be utilized to find the operating conditions of the system that will produce the maximum system efficiencies. The paper provided a description of the photovoltaic solar system including equations for PV module efficiency; pump efficiency; and total efficiency. The paper also presented data relevant to the system performance and neural networks. The results of a neural net model were also presented based on the thermal PV solar integrated system data that was collected. It was concluded that the neural net model of the thermal photovoltaic solar integrated system set the background for achieving the best system performance. 10 refs., 6 figs.

  7. Analysis of thermal systems using the entropy balance method

    Energy Technology Data Exchange (ETDEWEB)

    Huang, C L.D.; Fartaj, S A; Fenton, D L [Kansas State Univ., Manhattan, KS (United States). Dept. of Mechanical Engineering

    1992-04-01

    This study investigates the applicability of the second law of thermodynamics using an entropy balance method to analyse and design thermal systems. As examples, the entropy balance method is used to analyse a single stage chiller system and a single stage heat transformer, both with lithium-bromide/water as the working fluid. The entropy method yields not only the same information as is conveyed by the methods of energy and exergy analysis, but it also predicts clearly the influence of irreversibilities of individual components on the coefficient of performance and its effectiveness, based on the process properties, rather than on ambient conditions. Furthermore, this method is capable of presenting the overall distribution of the heat input by displaying the additional heat required to overcome irreversibility of each component without ambiguity. (Author).

  8. Experiment Investigation on Electrical and Thermal Performances of a Semitransparent Photovoltaic/Thermal System with Water Cooling

    Directory of Open Access Journals (Sweden)

    Guiqiang Li

    2014-01-01

    Full Text Available Different from the semitransparent building integrated photovoltaic/thermal (BIPV/T system with air cooling, the semitransparent BIPV/T system with water cooling is rare, especially based on the silicon solar cells. In this paper, a semitransparent photovoltaic/thermal system (SPV/T with water cooling was set up, which not only would provide the electrical power and hot water, but also could attain the natural illumination for the building. The PV efficiency, thermal efficiency, and exergy analysis were all adopted to illustrate the performance of SPV/T system. The results showed that the PV efficiency and the thermal efficiency were about 11.5% and 39.5%, respectively, on the typical sunny day. Furthermore, the PV and thermal efficiencies fit curves were made to demonstrate the SPV/T performance more comprehensively. The performance analysis indicated that the SPV/T system has a good application prospect for building.

  9. Thermal coupling system analysis of a nuclear desalination plant

    International Nuclear Information System (INIS)

    Adak, A.K.; Srivastava, V.K.; Tewari, P.K.

    2010-01-01

    When a nuclear reactor is used to supply steam for desalination plant, the method of coupling has a significant technical and economic impact. The exact method of coupling depends upon the type of reactor and type of desalination plant. As a part of Nuclear Desalination Demonstration Project (NDDP), BARC has successfully commissioned a 4500 m 3 /day MSF desalination plant coupled to Madras Atomic Power Station (MAPS) at Kalpakkam. Desalination plant coupled to nuclear power plant of Pressurized Heavy Water Reactor (PHWR) type is a good example of dual-purpose nuclear desalination plant. This paper presents the thermal coupling system analysis of this plant along with technical and safety aspects. (author)

  10. Thermal Properties and Thermal Analysis:

    Science.gov (United States)

    Kasap, Safa; Tonchev, Dan

    The chapter provides a summary of the fundamental concepts that are needed to understand the heat capacity C P, thermal conductivity κ, and thermal expansion coefficient α L of materials. The C P, κ, and α of various classes of materials, namely, semiconductors, polymers, and glasses, are reviewed, and various typical characteristics are summarized. A key concept in crystalline solids is the Debye theory of the heat capacity, which has been widely used for many decades for calculating the C P of crystals. The thermal properties are interrelated through Grüneisen's theorem. Various useful empirical rules for calculating C P and κ have been used, some of which are summarized. Conventional differential scanning calorimetry (DSC) is a powerful and convenient thermal analysis technique that allows various important physical and chemical transformations, such as the glass transition, crystallization, oxidation, melting etc. to be studied. DSC can also be used to obtain information on the kinetics of the transformations, and some of these thermal analysis techniques are summarized. Temperature-modulated DSC, TMDSC, is a relatively recent innovation in which the sample temperature is ramped slowly and, at the same time, sinusoidally modulated. TMDSC has a number of distinct advantages compared with the conventional DSC since it measures the complex heat capacity. For example, the glass-transition temperature T g measured by TMDSC has almost no dependence on the thermal history, and corresponds to an almost step life change in C P. The new Tzero DSC has an additional thermocouple to calibrate better for thermal lags inherent in the DSC measurement, and allows more accurate thermal analysis.

  11. Thermal-Acoustic Fatigue of a Multilayer Thermal Protection System in Combined Extreme Environments

    Directory of Open Access Journals (Sweden)

    Liu Liu

    2014-06-01

    Full Text Available In order to ensure integrity of thermal protection system (TPS structure for hypersonic vehicles exposed to severe operating environments, a study is undertaken to investigate the response and thermal-acoustic fatigue damage of a representative multilayer TPS structure under combined thermal and acoustic loads. An unsteady-state flight of a hypersonic vehicle is composed of a series of steady-state snapshots, and for each snapshot an acoustic load is imposed to a static steady-state TPS structure. A multistep thermal-acoustic fatigue damage intensity analysis procedure is given and consists of a heat transfer analysis, a nonlinear thermoelastic analysis, and a random response analysis under a combined loading environment and the fatigue damage intensity has been evaluated with two fatigue analysis techniques. The effects of thermally induced deterministic stress and nondeterministic dynamic stress due to the acoustic loading have been considered in the damage intensity estimation with a maximum stress fatigue model. The results show that the given thermal-acoustic fatigue intensity estimation procedure is a viable approach for life prediction of TPS structures under a typical mission cycle with combined loadings characterized by largely different time-scales. A discussion of the effects of the thermal load, the acoustic load, and fatigue analysis methodology on the fatigue damage intensity has been provided.

  12. Use of MSC/NASTRAN for the thermal analysis of the Space Shuttle Orbiter braking system

    Science.gov (United States)

    Shu, James; Mccann, David

    1987-01-01

    A description is given of the thermal modeling and analysis effort being conducted to investigate the transient temperature and thermal stress characteristics of the Space Shuttle Orbiter brake components and subsystems. Models are constructed of the brake stator as well as of the entire brake assembly to analyze the temperature distribution and thermal stress during the landing and braking process. These investigations are carried out on a UNIVAC computer system with MSC/NASTRAN Version 63. Analytical results and solution methods are presented and comparisons are made with SINDA results.

  13. Status and subjects of thermal-hydraulic analysis for next-generation LWRs

    International Nuclear Information System (INIS)

    2000-03-01

    The status and subjects on thermal-hydraulic analysis for next-generation light water reactors (LWRs) with passive safety systems were surveyed through about 5 years until March 1999 by subcommittee on improvement of reactor thermal-hydraulic analysis codes under the nuclear code committee in Japan Atomic Energy Research Institute. Based on the survey results and discussion, the status and subjects on system analysis for various types of proposed reactor were summarized in 1998 and those on multidimensional two-phase flow analysis were also reviewed, since the multidimensional analysis was recognized as one of the most important subjects through the investigation on system analysis. In this report, the status and subjects for the following were summarized from the survey results and discussion in 1998 and 1999; (1) BWR neutronic/thermal-hydraulic coupled analysis, (2) Evaluation of passive safety system performance and (3) Gas-liquid two-phase flow analysis. The contents in this report are the forefront of thermal-hydraulic analysis for LWRs including test results from several large-scale facilities. We expect that the contents can offer a guideline to improve reactor thermal-hydraulic analysis codes in future. (author)

  14. Thermal-hydraulic calculation and water hammer analysis on CEFR loop system

    International Nuclear Information System (INIS)

    Hao Pengfei; Zhang Xiwen; Cai Weidong; Wang Xuefang

    1997-01-01

    China Experimental Fast Reactor (CEFR) is one of the '863' High-technical Projects. It is necessary to study the hydraulic and thermal Characteristic of CEFR loop system in order to guarantee the safety of operation. The results of the thermal-hydraulic calculation have been given. The main points are as follows: 1. The simplified model is built according to the loop system of CEFR, and the calculation method which is called 'NODE'-'BRANCH' is applied. This method includes two aspects, one is the theoretical analysis that is based on fluid mechanics and heat transfer theory. The other is the engineering calculation. These two aspects are connected in the computation. On the basis of the work mentioned above, the stable state computation is presented. In order to prevent serious damage caused by power failure accident, the courses of surplus reactor heat removing through two different systems have been simulated in the computation. 2. By using the fluid dynamics theory, the simplified model and the equipment boundary conditions of loop system are given. The water hammer computation is processed during the valve closing and pump stopping accidents. Some pictures of water hammer wave are presented, and the most dangerous state in the accident is also given

  15. Cost and performance analysis of concentrating solar power systems with integrated latent thermal energy storage

    International Nuclear Information System (INIS)

    Nithyanandam, K.; Pitchumani, R.

    2014-01-01

    Integrating TES (thermal energy storage) in a CSP (concentrating solar power) plant allows for continuous operation even during times when solar irradiation is not available, thus providing a reliable output to the grid. In the present study, the cost and performance models of an EPCM-TES (encapsulated phase change material thermal energy storage) system and HP-TES (latent thermal storage system with embedded heat pipes) are integrated with a CSP power tower system model utilizing Rankine and s-CO 2 (supercritical carbon-dioxide) power conversion cycles, to investigate the dynamic TES-integrated plant performance. The influence of design parameters of the storage system on the performance of a 200 MW e capacity power tower CSP plant is studied to establish design envelopes that satisfy the U.S. Department of Energy SunShot Initiative requirements, which include a round-trip annualized exergetic efficiency greater than 95%, storage cost less than $15/kWh t and LCE (levelized cost of electricity) less than 6 ¢/kWh. From the design windows, optimum designs of the storage system based on minimum LCE, maximum exergetic efficiency, and maximum capacity factor are reported and compared with the results of two-tank molten salt storage system. Overall, the study presents the first effort to construct and analyze LTES (latent thermal energy storage) integrated CSP plant performance that can help assess the impact, cost and performance of LTES systems on power generation from molten salt power tower CSP plant. - Highlights: • Presents technoeconomic analysis of thermal energy storage integrated concentrating solar power plants. • Presents a comparison of different storage options. • Presents optimum design of thermal energy storage system for steam Rankine and supercritical carbon dioxide cycles. • Presents designs for maximizing exergetic efficiency while minimizing storage cost and levelized cost of energy

  16. Advanced Fuel Cell System Thermal Management for NASA Exploration Missions

    Science.gov (United States)

    Burke, Kenneth A.

    2009-01-01

    The NASA Glenn Research Center is developing advanced passive thermal management technology to reduce the mass and improve the reliability of space fuel cell systems for the NASA exploration program. An analysis of a state-of-the-art fuel cell cooling systems was done to benchmark the portion of a fuel cell system s mass that is dedicated to thermal management. Additional analysis was done to determine the key performance targets of the advanced passive thermal management technology that would substantially reduce fuel cell system mass.

  17. Baking system for ports of experimental advanced super-conducting tokamak vacuum vessel and thermal stress analysis

    International Nuclear Information System (INIS)

    Cheng Yali; Bao Liman; Song Yuntao; Yao Damao

    2006-01-01

    The baking system of Experimental Advanced Super-Conducting Toakamk (EAST) vacuum vessel is necessary to obtain the baking temperature of 150 degree C. In order to define suitable alloy heaters and achieve their reasonable layouts, thermal analysis was carried out with ANSYS code. The analysis results indicate that the temperature distribution and thermal stress of most parts of EAST vacuum vessel ports are uniform, satisfied for the requirement, and are safe based on ASME criterion. Feasible idea on reducing the stress focus is also considered. (authors)

  18. Thermal analysis of dry concrete canister storage system for CANDU spent fuel

    International Nuclear Information System (INIS)

    Ryu, Yong Ho

    1992-02-01

    This paper presents the results of a thermal analysis of the concrete canisters for interim dry storage of spent, irradiated Canadian Deuterium Uranium(CANDU) fuel. The canisters are designed to contain 6-year-old fuel safely for periods of 50 years in stainless steel baskets sealed inside a steel-lined concrete shield. In order to assure fuel integrity during the storage, fuel rod temperature shall not exceed the temperature limit. The contents of thermal analysis include the following : 1) Steady state temperature distributions under the conservative ambient temperature and insolation load. 2) Transient temperature distributions under the changes in ambient temperature and insolation load. Accounting for the coupled heat transfer modes of conduction, convection, and radiation, the computer code HEATING5 was used to predict the thermal response of the canister storage system. As HEATING5 does not have the modeling capability to compute radiation heat transfer on a rod-to-rod basis, a separate calculating routine was developed and applied to predict temperature distribution in a fuel bundle. Thermal behavior of the canister is characterized by the large thermal mass of the concrete and radiative heat transfer within the basket. The calculated results for the worst case (steady state with maximum ambient temperature and design insolation load) indicated that the maximum temperature of the 6 year cooled fuel reached to 182.4 .deg. C, slightly above the temperature limit of 180 .deg. C. However,the thermal inertia of the thick concrete wall moderates the internal changes and prevents a rise in fuel temperature in response to ambient changes. The maximum extent of the transient zone was less than 75% of the concrete wall thickness for cyclic insolation changes. When transient nature of ambient temperature and insolation load are considered, the fuel temperature will be a function of the long term ambient temperature as opposed to daily extremes. The worst design

  19. Preliminary thermal-hydraulic and safety analysis of China DFLL-TBM system

    Energy Technology Data Exchange (ETDEWEB)

    Li, Wei [School of Nuclear Science and Technology, Xi’an Jiaotong University, No. 28, Xianning West Road, Xi’an, Shanxi 710049 (China); Tian, Wenxi, E-mail: wxtian@mail.xjtu.edu.cn [School of Nuclear Science and Technology, Xi’an Jiaotong University, No. 28, Xianning West Road, Xi’an, Shanxi 710049 (China); Qiu, Suizheng; Su, Guanghui; Jiao, Hong [School of Nuclear Science and Technology, Xi’an Jiaotong University, No. 28, Xianning West Road, Xi’an, Shanxi 710049 (China); Bai, Yunqing; Chen, Hongli [Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Wu, Yican, E-mail: yican.Wu@Fds.Org.Cn [Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, Hefei, Anhui 230031 (China)

    2013-06-15

    Highlights: • Thermal-hydraulic and safety analysis on DFLL-TBM system is performed. • The TBM FW maximum temperature is 541 °C under steady state condition. • The TBM FW maximum temperature does not exceed the melt point of CLAM steel 1500 °C. • Neither the VV pressurization nor vault pressure build-up goes beyond 0.2 MPa. -- Abstract: China has proposed the dual-functional lithium-lead (DFLL) tritium breeding blanket concept for testing in ITER as a test blanket module (TBM), to demonstrate the technologies of tritium self-sufficiency, high-grade heat extraction and efficient electricity production which are needed for DEMO and fusion power plant. Safety assessment of the TBM and its auxiliary system should be conducted to deal with ITER safety issues directly caused by the TBM system failure during the design process. In this work, three potential initial events (PIEs) – in-vessel loss of helium (He) coolant and ex-vessel loss of He coolant and loss of flow without scram (LOFWS) – were analyzed for the TBM system with a modified version of the RELAP5/MOD3 code containing liquid lithium-lead eutectic (LiPb). The code also comprised an empirical expression for MHD pressure drop relevant to three-dimensional (3D) effect, the Lubarsky–Kaufman convective heat transfer correlation for LiPb flow and the Gnielinski convective heat transfer correlation for He flow. Since both LiPb and He serve as TBM coolants, the LiPb and He ancillary cooling systems were modeled to investigate the thermal-hydraulic characteristic of the TBM system and its influence on ITER safety under those accident conditions. The TBM components and the coolants flow within the TBM were simulated with one-dimensional heat structures and their associated hydrodynamic components. ITER enclosures including vacuum vessel (VV), port cell and TCWS vault were also covered in the model for accident analyses. Through this best estimate approach, the calculation indicated that the current

  20. Interior thermal insulation systems for historical building envelopes

    Science.gov (United States)

    Jerman, Miloš; Solař, Miloš; Černý, Robert

    2017-11-01

    The design specifics of interior thermal insulation systems applied for historical building envelopes are described. The vapor-tight systems and systems based on capillary thermal insulation materials are taken into account as two basic options differing in building-physical considerations. The possibilities of hygrothermal analysis of renovated historical envelopes including laboratory methods, computer simulation techniques, and in-situ tests are discussed. It is concluded that the application of computational models for hygrothermal assessment of interior thermal insulation systems should always be performed with a particular care. On one hand, they present a very effective tool for both service life assessment and possible planning of subsequent reconstructions. On the other, the hygrothermal analysis of any historical building can involve quite a few potential uncertainties which may affect negatively the accuracy of obtained results.

  1. Thermal analysis with expendable cartridge

    International Nuclear Information System (INIS)

    Susaki, K.; Landgraf, F.J.G.

    1981-01-01

    The pratical method of thermal analysis with expendable cartridge and some aspects of its use are presented. The results of the method applied to the system Nb-Mn are presented together with data from microprobe. (Author) [pt

  2. Automated thermal mapping techniques using chromatic image analysis

    Science.gov (United States)

    Buck, Gregory M.

    1989-01-01

    Thermal imaging techniques are introduced using a chromatic image analysis system and temperature sensitive coatings. These techniques are used for thermal mapping and surface heat transfer measurements on aerothermodynamic test models in hypersonic wind tunnels. Measurements are made on complex vehicle configurations in a timely manner and at minimal expense. The image analysis system uses separate wavelength filtered images to analyze surface spectral intensity data. The system was initially developed for quantitative surface temperature mapping using two-color thermographic phosphors but was found useful in interpreting phase change paint and liquid crystal data as well.

  3. Challenges in thermal and hydraulic analysis of ADS target systems

    International Nuclear Information System (INIS)

    Groetzbach, G.; Batta, A.; Lefhalm, C.-H.; Otic, I.

    2004-01-01

    The liquid metal cooled spallation targets of Accelerator Driven nuclear reactor Systems obey high thermal loads; in addition some flow and cooling conditions are of a prototypical character; in contrast the operating conditions for the engaged materials are narrow; thus, the target development requires a very careful analysis by experimental and numerical means. Especially the cooling of the steel window, which is heated by the proton beam, needs special care. Some of the main goals of the experimental and numerical analyses of the thermal dynamics of those systems are discusses. The prediction of locally detached flows and of flows with larger recirculation areas suffers from insufficient turbulence modeling; this has to be compensated by using prototypical model experiments, e.g. with water, to select the adequate models and numerical schemes. The well known problems with the Reynolds analogy in predicting the heat transfer in liquid metals requires always prototypic liquid metal experiments to select and adapt the turbulent heat flux models. The uncertainties in liquid metal experiments cannot be neglected; so it is necessary to perform CFD calculations and experiments always hand in hand and to develop improve turbulent heat flux models. One contribution to an improved 3 or 4-equation model is deduced from recent Direct Numerical Simulation (DNS) data. (author)

  4. Power and Thermal Management of System-on-Chip

    DEFF Research Database (Denmark)

    Liu, Wei

    , are necessary at the chip design level. In this work, we investigate the power and thermal management of System-on- Chips (SoCs). Thermal analysis is performed in a SPICE simulation approach based on the electrical-thermal analogy. We investigate the impact of inter- connects on heat distribution...

  5. Improving Thermal and Electrical Efficiency in Photovoltaic Thermal Systems for Sustainable Cooling System Integration

    Directory of Open Access Journals (Sweden)

    Mohammad Alobaid

    2018-06-01

    Full Text Available Research into photovoltaic thermal systems is important in solar technologies as photovoltaic thermal systems are designed to produce both electrical and thermal energy, this can lead to improved performance of the overall system. The performance of photovoltaic thermal systems is based on several factors that include photovoltaic thermal materials, design, ambient temperature, inlet and outlet fluid temperature and photovoltaic cell temperature. The aim of this study is to investigate the effect of photovoltaic thermal outlet water temperatures and solar cell temperature on both electrical and thermal efficiency for different range of inlet water temperature. To achieve this, a mathematical model of a photovoltaic thermal system was developed to calculate the anticipated system performance. The factors that affect the efficiency of photovoltaic thermal collectors were discussed and the outlet fluid temperature from the photovoltaic thermal is investigated in order to reach the highest overall efficiency for the solar cooling system. An average thermal and electrical efficiency of 65% and 13.7%, respectively, was achieved and the photovoltaic thermal mathematical model was validated with experimental data from literature.

  6. Finite mixture models for sensitivity analysis of thermal hydraulic codes for passive safety systems analysis

    Energy Technology Data Exchange (ETDEWEB)

    Di Maio, Francesco, E-mail: francesco.dimaio@polimi.it [Energy Department, Politecnico di Milano, Via La Masa 34, 20156 Milano (Italy); Nicola, Giancarlo [Energy Department, Politecnico di Milano, Via La Masa 34, 20156 Milano (Italy); Zio, Enrico [Energy Department, Politecnico di Milano, Via La Masa 34, 20156 Milano (Italy); Chair on System Science and Energetic Challenge Fondation EDF, Ecole Centrale Paris and Supelec, Paris (France); Yu, Yu [School of Nuclear Science and Engineering, North China Electric Power University, 102206 Beijing (China)

    2015-08-15

    Highlights: • Uncertainties of TH codes affect the system failure probability quantification. • We present Finite Mixture Models (FMMs) for sensitivity analysis of TH codes. • FMMs approximate the pdf of the output of a TH code with a limited number of simulations. • The approach is tested on a Passive Containment Cooling System of an AP1000 reactor. • The novel approach overcomes the results of a standard variance decomposition method. - Abstract: For safety analysis of Nuclear Power Plants (NPPs), Best Estimate (BE) Thermal Hydraulic (TH) codes are used to predict system response in normal and accidental conditions. The assessment of the uncertainties of TH codes is a critical issue for system failure probability quantification. In this paper, we consider passive safety systems of advanced NPPs and present a novel approach of Sensitivity Analysis (SA). The approach is based on Finite Mixture Models (FMMs) to approximate the probability density function (i.e., the uncertainty) of the output of the passive safety system TH code with a limited number of simulations. We propose a novel Sensitivity Analysis (SA) method for keeping the computational cost low: an Expectation Maximization (EM) algorithm is used to calculate the saliency of the TH code input variables for identifying those that most affect the system functional failure. The novel approach is compared with a standard variance decomposition method on a case study considering a Passive Containment Cooling System (PCCS) of an Advanced Pressurized reactor AP1000.

  7. Current lead thermal analysis code 'CURRENT'

    International Nuclear Information System (INIS)

    Yamaguchi, Masahito; Tada, Eisuke; Shimamoto, Susumu; Hata, Kenichiro.

    1985-08-01

    Large gas-cooled current lead with the capacity more than 30 kA and 22 kV is required for superconducting toroidal and poloidal coils for fusion application. The current lead is used to carry electrical current from the power supply system at room temperature to the superconducting coil at 4 K. Accordingly, the thermal performance of the current lead is significantly important to determine the heat load requirements of the coil system at 4 K. Japan Atomic Energy Research Institute (JAERI) has being developed the large gas-cooled current leads with the optimum condition in which the heat load is around 1 W per 1 kA at 4 K. In order to design the current lead with the optimum thermal performances, JAERI developed thermal analysis code named as ''CURRENT'' which can theoretically calculate the optimum geometric shape and cooling conditions of the current lead. The basic equations and the instruction manual of the analysis code are described in this report. (author)

  8. Mitigation method of thermal transient stress by thermalhydraulic-structure total analysis

    International Nuclear Information System (INIS)

    Kasahara, Naoto; Jinbo, Masakazu; Hosogai, Hiromi

    2003-01-01

    This study proposes a rational evaluation and mitigation method of thermal transient loads in fast reactor components by utilizing relationships among plant system parameters and stresses induced by thermal transients of plants. A thermalhydraulic-structure total analysis procedure helps us to grasp relationship among system parameters and thermal stresses. Furthermore, it enables mitigation of thermal transient loads by adjusting system parameters. In order to overcome huge computations, a thermalhydraulic-structure total analysis code and the Design of Experiments methodology are utilized. The efficiency of the proposed mitigation method is validated through thermal stress evaluation of an intermediate heat exchanger in Japanese demonstration fast reactor. (author)

  9. Thermal analysis and prediction of phase equilibria in ternary Pb-Zn-Ag system

    Directory of Open Access Journals (Sweden)

    Živković D.

    2011-01-01

    Full Text Available Ternary Pb-Zn-Ag system is typical for some physicochemical processes going on in refining phase in the extractive metallurgy of lead. Therefore, investigation of mentioned system is important from both theoretical and practical research of the phenomena occurring during the lead desilverizing process. The results of experimental investigation using differential thermal analysis (DTA and thermodynamic calculation of phase equilibria in Pb-Zn-Ag system according to CALPHAD method, in the sections with Zn:Ag mass ratio equal to 90:10, 70:30 and 50:50, are presented in this paper.

  10. Thermal and microstructural analysis of alloys of Al-Mg-Li system

    International Nuclear Information System (INIS)

    Ovsyannikov, B.V.; Zamaytin, V.M.; Smirnov, V.L.; Mushnikov, V.S.

    2008-01-01

    By means of the thermal analysis one investigated into melting and solidification of Al-Mg-Li system 1420, 1421 and 1424 aluminum-lithium alloys. One determined the temperature values of the nonequilibrium and the equilibrium solidus, the initiation of the liquidus linear shrinkage of the listed alloys. Making use of a scanning electron microscope with a microanalyser unit one studied the microstructure of the alloys and determined the local chemical composition of the phases unsoluble under homogenization of ingots along the aluminum matrix grain boundaries [ru

  11. Development of whole core thermal-hydraulic analysis program ACT. 3. Coupling core module with primary heat transport system module

    International Nuclear Information System (INIS)

    Ohtaka, Masahiko; Ohshima, Hiroyuki

    1998-10-01

    A whole core thermal-hydraulic analysis program ACT is being developed for the purpose of evaluating detailed in-core thermal hydraulic phenomena of fast reactors including inter-wrapper flow under various reactor operation conditions. In this work, the core module as a main part of the ACT developed last year, which simulates thermal-hydraulics in the subassemblies and the inter-subassembly gaps, was coupled with an one dimensional plant system thermal-hydraulic analysis code LEDHER to simulate transients in the primary heat transport system and to give appropriate boundary conditions to the core model. The effective algorithm to couple these two calculation modules was developed, which required minimum modification of them. In order to couple these two calculation modules on the computing system, parallel computing technique using PVM (Parallel Virtual Machine) programming environment was applied. The code system was applied to analyze an out-of-pile sodium experiment simulating core with 7 subassemblies under transient condition for code verification. It was confirmed that the analytical results show a similar tendency of experimental results. (author)

  12. Thermal and Alignment Analysis of the Instrument-Level ATLAS Thermal Vacuum Test

    Science.gov (United States)

    Bradshaw, Heather

    2012-01-01

    This paper describes the thermal analysis and test design performed in preparation for the ATLAS thermal vacuum test. NASA's Advanced Topographic Laser Altimeter System (ATLAS) will be flown as the sole instrument aboard the Ice, Cloud, and land Elevation Satellite-2 (ICESat-2). It will be used to take measurements of topography and ice thickness for Arctic and Antarctic regions, providing crucial data used to predict future changes in worldwide sea levels. Due to the precise measurements ATLAS is taking, the laser altimeter has very tight pointing requirements. Therefore, the instrument is very sensitive to temperature-induced thermal distortions. For this reason, it is necessary to perform a Structural, Thermal, Optical Performance (STOP) analysis not only for flight, but also to ensure performance requirements can be operationally met during instrument-level thermal vacuum testing. This paper describes the thermal model created for the chamber setup, which was used to generate inputs for the environmental STOP analysis. This paper also presents the results of the STOP analysis, which indicate that the test predictions adequately replicate the thermal distortions predicted for flight. This is a new application of an existing process, as STOP analyses are generally performed to predict flight behavior only. Another novel aspect of this test is that it presents the opportunity to verify pointing results of a STOP model, which is not generally done. It is possible in this case, however, because the actual pointing will be measured using flight hardware during thermal vacuum testing and can be compared to STOP predictions.

  13. Multicriteria analysis of thermal and energy systems for tourist facilities

    International Nuclear Information System (INIS)

    Raguzin, I.

    1999-01-01

    The introductory part of the paper briefly presents the technological, economic and environmental optimisation procedure of thermal and energy systems for tourist facilities with the multicriteria ranging method when choosing an optimum solution. The procedure described includes a systematic analysis of the system's structure, energy-mass balance, balance of costs, environmental impact analysis and the choice of an optimum solution. Special attention was paid to criteria quantification for the choice of solution and the most appropriate ranging method.The procedure's application has been illustrated on an example of a potential tourist facility on the Island of Loinj, i.e. the locality with a potential highest category tourist development. This example includes (a) consumers (heating of rooms, preparation of hot water, heating of swimming pool water and cooling of rooms), and (b) producers (boiler room, cooling engine-rooms, a cogeneration plant and heat pumps). The data have been supplied from the project documentation for the reconstruction of the existing facilities mainly preliminary designs. The multicriteria ranging was conducted based on an appropriate computer programme for problem solution. (author)

  14. Design and simulation of a low concentrating photovoltaic/thermal system

    International Nuclear Information System (INIS)

    Rosell, J.I.; Vallverdu, X.; Lechon, M.A.; Ibanez, M.

    2005-01-01

    The advantages of photovoltaic/thermal (PV/T) collectors and low solar concentration technologies are combined into a photovoltaic/thermal system to increase the solar energy conversion efficiency. This paper presents a prototype 11X concentration rate and two axis tracking system. The main novelty is the coupling of a linear Fresnel concentrator with a channel photovoltaic/thermal collector. An analytical model to simulate the thermal behaviour of the prototype is proposed and validated. Measured thermal performance of the solar system gives values above 60%. Theoretical analysis confirms that thermal conduction between the PV cells and the absorber plate is a critical parameter

  15. Investigation of effective factors of transient thermal stress of the MONJU-System components

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Masaaki; Hirayama, Hiroshi; Kimura, Kimitaka; Jinbo, M. [Toshiba Corp., Kawasaki, Kanagawa (Japan)

    1999-03-01

    Transient thermal stress of each system Component in the fast breeder reactor is an uncertain factor on it's structural design. The temperature distribution in a system component changes over a wide range in time and in space. An unified evaluation technique of thermal, hydraulic, and structural analysis, in which includes thermal striping, temperature stratification, transient thermal stress and the integrity of the system components, is required for the optimum design of tho fast reactor plant. Thermal boundary conditions should be set up by both the transient thermal stress analysis and the structural integrity evaluation of each system component. The reasonable thermal boundary conditions for the design of the MONJU and a demonstration fast reactor, are investigated. The temperature distribution analysis models and the thermal boundary conditions on the Y-piece structural parts of each system component, such as reactor vessel, intermediate heat exchanger, primary main circulation pump, steam generator, superheater and upper structure of reactor core, are illustrated in the report. (M. Suetake)

  16. Photovoltaic Thermal panels in collective thermal solar systems

    International Nuclear Information System (INIS)

    Elswijk, M.J.; Strootman, K.J.; Jong, M.J.M.; De Lange, E.T.N.; Smit, W.F.

    2003-12-01

    A feasibility study has been carried out to assess the options to apply photovoltaic/thermal panels (PVT-panels) in collective solar thermal systems in urban areas in the Netherlands. The study was focused on the technical (architecture and installations) and the economical feasibility of collective PVT-systems in comparison with conventional solar thermal systems and combinations of photovoltaic (PV) panels and solar collectors. The results of the study also give insight into cost and the market for PVT-panels. Three case studies in which collective solar collector systems were applied are analyzed again by simulating the installation of a PVT-panels system and a separate solar thermal PV system [nl

  17. Analysis of Reactor Pressurized Thermal Shock Conditions Considering Upgrading of Systems Important to Safety

    International Nuclear Information System (INIS)

    Mazurok, A.S; Vyshemirskyij, M.P.

    2015-01-01

    The paper analyzes conditions of pressurized thermal shock on the reactor pressure vessel taking into account upgrading of the emergency core cooling system and primary overpressure protection system. For representative accident scenarios, calculation and comparative analysis was carried out. These scenarios include a small leak from the hot leg and PRZ SV stuck opening with re closure after 3600 sec and 3 SG heat transfer tube rupture. The efficiency of mass flow control by valves on the pump head (emergency core cooling systems) and cold overpressure protection (primary overpressure protection system) was analyzed. The thermal hydraulic model for RELAP5/Mod3.2 code with detailed downcomer (DC) model and changes in accordance with upgrades was used for calculations. Detailed (realistic) modeling of piping and equipment was performed. The upgrades prevent excessive primary cooling and, consequently, help to preserve the RPV integrity and to avoid the formation of a through crack, which can lead to a severe accident

  18. Molecular thermal transistor: Dimension analysis and mechanism

    Science.gov (United States)

    Behnia, S.; Panahinia, R.

    2018-04-01

    Recently, large challenge has been spent to realize high efficient thermal transistors. Outstanding properties of DNA make it as an excellent nano material in future technologies. In this paper, we introduced a high efficient DNA based thermal transistor. The thermal transistor operates when the system shows an increase in the thermal flux despite of decreasing temperature gradient. This is what called as negative differential thermal resistance (NDTR). Based on multifractal analysis, we could distinguish regions with NDTR state from non-NDTR state. Moreover, Based on dimension spectrum of the system, it is detected that NDTR state is accompanied by ballistic transport regime. The generalized correlation sum (analogous to specific heat) shows that an irregular decrease in the specific heat induces an increase in the mean free path (mfp) of phonons. This leads to the occurrence of NDTR.

  19. Acquisition of an Advanced Thermal Analysis andImaging System for Integration with Interdisciplinary Researchand Education in Low Density Organic Inorganic Materials

    Science.gov (United States)

    2017-12-02

    Report: Acquisition of an Advanced Thermal Analysis and Imaging System for Integration with Interdisciplinary Research and Education in Low Density...Agreement Number: W911NF-16-1-0475 Organization: University of Texas at El Paso Title: Acquisition of an Advanced Thermal Analysis and Imaging System ...for Integration with Interdisciplinary Research and Education in Low Density Organic-Inorganic Materials Report Term: 0-Other Email: dmisra2

  20. Numerical modeling of aquifer thermal energy storage system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jongchan [Korea Institute of Geoscience and Mineral Resources, Geothermal Resources Department, 92 Gwahang-no, Yuseong-gu, Daejeon 305-350 (Korea, Republic of); Kongju National University, Department of Geoenvironmental Sciences, 182 Singwan-dong, Gongju-si, Chungnam 314-701 (Korea, Republic of); Lee, Youngmin [Korea Institute of Geoscience and Mineral Resources, Geothermal Resources Department, 92 Gwahang-no, Yuseong-gu, Daejeon 305-350 (Korea, Republic of); Yoon, Woon Sang; Jeon, Jae Soo [nexGeo Inc., 134-1 Garak 2-dong, Songpa-gu, Seoul 138-807 (Korea, Republic of); Koo, Min-Ho; Keehm, Youngseuk [Kongju National University, Department of Geoenvironmental Sciences, 182 Singwan-dong, Gongju-si, Chungnam 314-701 (Korea, Republic of)

    2010-12-15

    The performance of the ATES (aquifer thermal energy storage) system primarily depends on the thermal interference between warm and cold thermal energy stored in an aquifer. Additionally the thermal interference is mainly affected by the borehole distance, the hydraulic conductivity, and the pumping/injection rate. Thermo-hydraulic modeling was performed to identify the thermal interference by three parameters and to estimate the system performance change by the thermal interference. Modeling results indicate that the thermal interference grows as the borehole distance decreases, as the hydraulic conductivity increases, and as the pumping/injection rate increases. The system performance analysis indicates that if {eta} (the ratio of the length of the thermal front to the distance between two boreholes) is lower than unity, the system performance is not significantly affected, but if {eta} is equal to unity, the system performance falls up to {proportional_to}22%. Long term modeling for a factory in Anseong was conducted to test the applicability of the ATES system. When the pumping/injection rate is 100 m{sup 3}/day, system performances during the summer and winter after 3 years of operation are estimated to be {proportional_to}125 kW and {proportional_to}110 kW, respectively. Therefore, 100 m{sup 3}/day of the pumping/injection rate satisfies the energy requirements ({proportional_to}70 kW) for the factory. (author)

  1. A numerical simulation package for analysis of neutronics and thermal fluids of space nuclear power and propulsion systems

    International Nuclear Information System (INIS)

    Anghaie, S.; Feller, G.J.; Peery, S.D.; Parsley, R.C.

    1993-01-01

    A system of computer codes for engineering simulation and in-depth analysis of nuclear and thermal fluid design of nuclear thermal rockets is developed. The computational system includes a neutronic solver package, a thermal fluid solver package and a propellant and materials property package. The Rocket Engine Transient Simulation (ROCETS) system code is incorporated with computational modules specific to nuclear powered engines. ROCETS features a component based performance architecture that interfaces component modules into the user designed configuration, interprets user commands, creates an executable FORTRAN computer program, and executes the program to provide output to the user. Basic design features of the Pratt ampersand Whitney XNR2000 nuclear rocket concept and its operational performance are analyzed and simulated

  2. A performance analysis of solar chimney thermal power systems

    Directory of Open Access Journals (Sweden)

    Al-Dabbas Awwad Mohammed

    2011-01-01

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

  3. Thermal-hydraulic analysis of spent fuel storage systems

    International Nuclear Information System (INIS)

    Rector, D.R.; Wheeler, C.L.; Lombardo, N.J.

    1987-01-01

    This paper describes the COBRA-SFS (Spent Fuel Storage) computer code, which is designed to predict flow and temperature distributions in spent nuclear fuel storage and transportation systems. The decay heat generated by spent fuel in a dry storage cask is removed through a combination of conduction, natural convection, and thermal radiation. One major advantage of COBRA-SFS is that fluid recirculation within the cask is computed directly by solving the mass and momentum conservation equations. In addition, thermal radiation heat transfer is modeled using detailed radiation exchange factors based on quarter-rod segments. The equations governing mass, momentum, and energy conservation for incompressible flows are presented, and the semi-implicit solution method is described. COBRA-SFS predictions are compared to temperature data from a spent fuel storage cask test and the effect of different fill media on the cladding temperature distribution is discussed. The effect of spent fuel consolidation on cask thermal performance is also investigated. 16 refs., 6 figs., 2 tabs

  4. Thermal Analysis of the Receiver of a Standalone Pilot Solar Dish–Stirling System

    Directory of Open Access Journals (Sweden)

    Ehsan Gholamalizadeh

    2018-06-01

    Full Text Available Recent developments in solar thermal systems have aroused considerable interest in several countries with high solar potential. One of the most promising solar driven technologies is the solar thermal dish-Stirling system. One of the main issues of the solar dish–Stirling system is thermal losses from its components. The majority of the thermal losses of the system occur through its receiver before the thermal energy is converted to electrical energy by the Stirling engine. The goal of this investigation is to analyze the thermal performance of the receiver of a standalone pilot solar dish–Stirling system installed in Kerman City, Iran, to be used in remote off-grid areas of the Kerman Province. An analytical model was developed to predict the input energy, thermal losses, and thermal efficiency of the receiver. The receiver thermal model was first validated by comparing simulation results to experimental measurements for the EuroDish project. Then, the incident flux intensity intercepted by the receiver aperture, the thermal losses through the receiver (including conduction, convection, and radiation losses, and the power output during daytime hours (average day of each month for a year were predicted. The results showed that the conduction loss was small, while the convection and radiation losses played major roles in the total thermal losses through the receiver. The convection loss is dominant during the early morning and later evening hours, while radiation loss reaches its highest value near midday. Finally, the thermal efficiency of the receiver and the power output for each working hour throughout the year were calculated. The maximum performance of the system occurred at midday in the middle of July, with a predicted power output of 850 W, and a receiver efficiency of about 60%. At this time, a conduction loss of about 266 W, a convection loss of 284 W, and a radiation loss of about 2000 W were estimated.

  5. Bimodal Nuclear Thermal Rocket Analysis Developments

    Science.gov (United States)

    Belair, Michael; Lavelle, Thomas; Saimento, Charles; Juhasz, Albert; Stewart, Mark

    2014-01-01

    Nuclear thermal propulsion has long been considered an enabling technology for human missions to Mars and beyond. One concept of operations for these missions utilizes the nuclear reactor to generate electrical power during coast phases, known as bimodal operation. This presentation focuses on the systems modeling and analysis efforts for a NERVA derived concept. The NERVA bimodal operation derives the thermal energy from the core tie tube elements. Recent analysis has shown potential temperature distributions in the tie tube elements that may limit the thermodynamic efficiency of the closed Brayton cycle used to generate electricity with the current design. The results of this analysis are discussed as well as the potential implications to a bimodal NERVA type reactor.

  6. Thermal hydraulic analysis of BWR containment venting system

    International Nuclear Information System (INIS)

    Baburajan, P.K.; Sharma, Prashant; Paul, U.K.; Gaikwad, Avinash

    2015-01-01

    Installation of additional containment filtered venting system (CFVS) is necessary to depressurize the containment to maintain its mechanical integrity due to over pressurization during severe accident condition. A typical venting system for BWR is modelled using RELAP5 and analysed to investigate the effect of various thermal hydraulic parameters on the operational parameters of the venting system. The venting system consists of piping from the containment to the scrubber tank and exit line from the scrubber tank. The scrubber tank is partially filled with water to enable the scrubbing action to remove the particulate radionuclides from the incoming containment air. The pipe line from the containment is connected to the venturi inlet and the throat of the venturi is open to the scrubber tank water inventory at designed submergence level. The exit of the venturi is open to scrubber tank water. Filters are used in the upper air space of the scrubber tank as mist separator before venting out the air into the atmosphere through the exit vent line. The effect of thermal hydraulic parameters such as inlet fluid temperature, inlet steam content and venturi submergence in the scrubber tank on the venting flow rate, exit steam content, scrubber tank inventory, overflow line and siphon breaker flow rate is analysed. Results show that inlet steam content and the venturi nozzle submergence influence the venting system parameters. (author)

  7. A computational model for thermal fluid design analysis of nuclear thermal rockets

    International Nuclear Information System (INIS)

    Given, J.A.; Anghaie, S.

    1997-01-01

    A computational model for simulation and design analysis of nuclear thermal propulsion systems has been developed. The model simulates a full-topping expander cycle engine system and the thermofluid dynamics of the core coolant flow, accounting for the real gas properties of the hydrogen propellant/coolant throughout the system. Core thermofluid studies reveal that near-wall heat transfer models currently available may not be applicable to conditions encountered within some nuclear rocket cores. Additionally, the possibility of a core thermal fluid instability at low mass fluxes and the effects of the core power distribution are investigated. Results indicate that for tubular core coolant channels, thermal fluid instability is not an issue within the possible range of operating conditions in these systems. Findings also show the advantages of having a nonflat centrally peaking axial core power profile from a fluid dynamic standpoint. The effects of rocket operating conditions on system performance are also investigated. Results show that high temperature and low pressure operation is limited by core structural considerations, while low temperature and high pressure operation is limited by system performance constraints. The utility of these programs for finding these operational limits, optimum operating conditions, and thermal fluid effects is demonstrated

  8. Modeling and analysis of a robust thermal control system based on forced convection thermal switches

    Science.gov (United States)

    Williams, Andrew D.; Palo, Scott E.

    2006-05-01

    There is a critical need, not just in the Department of Defense (DOD) but the entire space industry, to reduce the development time and overall cost of satellite missions. To that end, the DOD is actively pursuing the capability to reduce the deployment time of a new system from years to weeks or even days. The goal is to provide the advantages space affords not just to the strategic planner but also to the battlefield commanders. One of the most challenging aspects of this problem is the satellite's thermal control system (TCS). Traditionally the TCS must be vigorously designed, analyzed, tested, and optimized from the ground up for every satellite mission. This "reinvention of the wheel" is costly and time intensive. The next generation satellite TCS must be modular and scalable in order to cover a wide range of applications, orbits, and mission requirements. To meet these requirements a robust thermal control system utilizing forced convection thermal switches was investigated. The problem was investigated in two separate stages. The first focused on the overall design of the bus. The second stage focused on the overarching bus architecture and the design impacts of employing a thermal switch based TCS design. For the hot case, the fan provided additional cooling to increase the heat transfer rate of the subsystem. During the cold case, the result was a significant reduction in survival heater power.

  9. Thermal analysis and modeling of a swimming pool heating system by utilizing waste energy rejected from a chiller unit of an ice rink

    OpenAIRE

    Kuyumcu Muhammed Enes; Yumrutaş Recep

    2017-01-01

    This study deals with the thermal analysis and modeling of a swimming pool heating system in which the waste energy rejected from the chiller unit of an ice rink is used as an energy source. The system consists of a swimming pool and an ice rink coupled by a chiller unit. The swimming pool and the ice rink both indoor types and were constructed in city of Gaziantep, Turkey. The thermal energy requirement for each section is determined by thermal analysis of each component of the system. Effec...

  10. Thermal analysis of heat storage canisters for a solar dynamic, space power system

    Science.gov (United States)

    Wichner, R. P.; Solomon, A. D.; Drake, J. B.; Williams, P. T.

    1988-01-01

    A thermal analysis was performed of a thermal energy storage canister of a type suggested for use in a solar receiver for an orbiting Brayton cycle power system. Energy storage for the eclipse portion of the cycle is provided by the latent heat of a eutectic mixture of LiF and CaF2 contained in the canister. The chief motivation for the study is the prediction of vapor void effects on temperature profiles and the identification of possible differences between ground test data and projected behavior in microgravity. The first phase of this study is based on a two-dimensional, cylindrical coordinates model using an interim procedure for describing void behavor in 1-g and microgravity. The thermal analysis includes the effects of solidification front behavior, conduction in liquid/solid salt and canister materials, void growth and shrinkage, radiant heat transfer across the void, and convection in the melt due to Marangoni-induced flow and, in 1-g, flow due to density gradients. A number of significant differences between 1-g and o-g behavior were found. This resulted from differences in void location relative to the maximum heat flux and a significantly smaller effective conductance in 0-g due to the absence of gravity-induced convection.

  11. Cross-cutting european thermal-hydraulics research for innovative nuclear systems

    International Nuclear Information System (INIS)

    Roelofs, F.; Class, A.; Cheng, X.; Meloni, P.; Van Tichelen, K.; Boudier, P.; Prasser, M.

    2010-01-01

    Thermal-hydraulics is recognized as a key scientific subject in the development of different innovative nuclear reactor systems. From the thermal-hydraulic point of view, different innovative reactors are mainly characterized by their coolants (gas, water, liquid metals and molten salt). This results in different micro- and macroscopic behavior of flow and heat transfer and requires specific models and advanced analysis tools. However, many common thermal-hydraulic issues are identified among various innovative nuclear systems. In Europe, such cross-cutting thermal-hydraulic issues are the subject of the 7. framework programme THINS (Thermal-Hydraulics of Innovative Nuclear Systems) project which runs from 2010 until 2014. This paper will describe the activities in this project which address the main identified thermal hydraulics issues for innovative nuclear systems. (authors)

  12. Thermal Distribution System | Energy Systems Integration Facility | NREL

    Science.gov (United States)

    Thermal Distribution System Thermal Distribution System The Energy Systems Integration Facility's . Photo of the roof of the Energy Systems Integration Facility. The thermal distribution bus allows low as 10% of its full load level). The 60-ton chiller cools water with continuous thermal control

  13. Lighting system with thermal management system

    Science.gov (United States)

    Arik, Mehmet; Weaver, Stanton; Stecher, Thomas; Seeley, Charles; Kuenzler, Glenn; Wolfe, Jr., Charles; Utturkar, Yogen; Sharma, Rajdeep; Prabhakaran, Satish; Icoz, Tunc

    2013-05-07

    Lighting systems having unique configurations are provided. For instance, the lighting system may include a light source, a thermal management system and driver electronics, each contained within a housing structure. The light source is configured to provide illumination visible through an opening in the housing structure. The thermal management system is configured to provide an air flow, such as a unidirectional air flow, through the housing structure in order to cool the light source. The driver electronics are configured to provide power to each of the light source and the thermal management system.

  14. Optimization analysis of thermal management system for electric vehicle battery pack

    Science.gov (United States)

    Gong, Huiqi; Zheng, Minxin; Jin, Peng; Feng, Dong

    2018-04-01

    Electric vehicle battery pack can increase the temperature to affect the power battery system cycle life, charge-ability, power, energy, security and reliability. The Computational Fluid Dynamics simulation and experiment of the charging and discharging process of the battery pack were carried out for the thermal management system of the battery pack under the continuous charging of the battery. The simulation result and the experimental data were used to verify the rationality of the Computational Fluid Dynamics calculation model. In view of the large temperature difference of the battery module in high temperature environment, three optimization methods of the existing thermal management system of the battery pack were put forward: adjusting the installation position of the fan, optimizing the arrangement of the battery pack and reducing the fan opening temperature threshold. The feasibility of the optimization method is proved by simulation and experiment of the thermal management system of the optimized battery pack.

  15. Energetic performance analysis of a commercial water-based photovoltaic thermal system (PV/T) under summer conditions

    Science.gov (United States)

    Nardi, I.; Ambrosini, D.; de Rubeis, T.; Paoletti, D.; Muttillo, M.; Sfarra, S.

    2017-11-01

    In the last years, the importance of integrating the production of electricity with the production of sanitary hot water led to the development of new solutions, i.e. PV/T systems. It is well known that hybrid photovoltaic-thermal systems, able to produce electricity and thermal energy at the same time with better energetic performance in comparison with two separate systems, present many advantages for application in a residential building. A PV/T is constituted generally by a common PV panel with a metallic pipe, in which fluid flows. Pipe accomplishes two roles: it absorbs the heat from the PV panel, thus increasing, or at least maintaining its efficiency; furthermore, it stores the heat for sanitary uses. In this work, the thermal and electrical efficiencies of a commercial PV/T panel have been evaluated during the summer season in different days, to assess the effect of environmental conditions on the system total efficiency. Moreover, infrared thermographic diagnosis in real time has been effected during the operating mode in two conditions: with cooling and without cooling; cooling was obtained by natural flowing water. This analysis gave information about the impact of a non-uniform temperature distribution on the thermal and electrical performance. Furthermore, measurements have been performed in two different operating modes: 1) production of solely electrical energy and 2) simultaneous production of thermal and electrical energy. Finally, total efficiency is largely increased by using a simple solar concentrator nearby the panel.

  16. Thermal analysis and microstructural characterization of Mg-Al-Zn system alloys

    Science.gov (United States)

    Król, M.; Tański, T.; Sitek, W.

    2015-11-01

    The influence of Zn amount and solidification rate on the characteristic temperature of the evaluation of magnesium dendrites during solidification at different cooling rates (0.6-2.5°C) were examined by thermal derivative analysis (TDA). The dendrite coherency point (DCP) is presented with a novel approach based on second derivative cooling curve. Solidification behavior was examined via one thermocouple thermal analysis method. Microstructural assessments were described by optical light microscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy. These studies showed that utilization of d2T/dt2 vs. the time curve methodology provides for analysis of the dendrite coherency point

  17. Pressurized Thermal Shock Analysis for OPR1000 Pressure Vessel

    Energy Technology Data Exchange (ETDEWEB)

    Bhowmik, P. K.; Shamim, J. A.; Gairola, A.; Suh, Kune Y. [Seoul National Univ., Seoul (Korea, Republic of)

    2014-10-15

    The study provides a brief understanding of the analysis procedure and techniques using ANSYS, such as the acceptance criteria, selection and categorization of events, thermal analysis, structural analysis including fracture mechanics assessment, crack propagation and evaluation of material properties. PTS may result from instrumentation and control malfunction, inadvertent steam dump, and postulated accidents such as smallbreak (SB) LOCA, large-break (LB) LOCA, main steam line break (MSLB), feedwater line breaks and steam generator overfill. In this study our main focus is to consider only the LB LOCA due to a cold leg break of the Optimized Power Reactor 1000 MWe (OPR1000). Consideration is given as well to the emergency core cooling system (ECCS) specific sequence with the operating parameters like pressure, temperature and time sequences. The static structural and thermal analysis to investigate the effects of PTS on RPV is the main motivation of this study. Specific surface crack effects and its propagation is also considered to measure the integrity of the RPV. This study describes the procedure for pressurized thermal shock analysis due to a loss of coolant accidental condition and emergency core cooling system operation for reactor pressure vessel.. Different accidental events that cause pressurized thermal shock to nuclear RPV that can also be analyzed in the same way. Considering the limitations of low speed computer only the static analysis is conducted. The modified LBLOCA phases and simplified geometry can is utilized to analyze the effect of PTS on RPV for general understanding not for specific specialized purpose. However, by integrating the disciplines of thermal and structural analysis, and fracture mechanics analysis a clearer understanding of the total aspect of the PTS problem has resulted. By adopting the CFD, thermal hydraulics, uncertainties and risk analysis for different type of accidental conditions, events and sequences with proper

  18. Development of a multi-dimensional realistic thermal-hydraulic system analysis code, MARS 1.3 and its verification

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Jae; Chung, Bub Dong; Jeong, Jae Jun; Ha, Kwi Seok [Korea Atomic Energy Research Institute, Taejon (Korea)

    1998-06-01

    A multi-dimensional realistic thermal-hydraulic system analysis code, MARS version 1.3 has been developed. Main purpose of MARS 1.3 development is to have the realistic analysis capability of transient two-phase thermal-hydraulics of Pressurized Water Reactors (PWRs) especially during Large Break Loss of Coolant Accidents (LBLOCAs) where the multi-dimensional phenomena domain the transients. MARS code is a unified version of USNRC developed COBRA-TF, domain the transients. MARS code is a unified version of USNRC developed COBRA-TF, three-dimensional (3D) reactor vessel analysis code, and RELAP5/MOD3.2.1.2, one-dimensional (1D) reactor system analysis code., Developmental requirements for MARS are chosen not only to best utilize the existing capability of the codes but also to have the enhanced capability in code maintenance, user accessibility, user friendliness, code portability, code readability, and code flexibility. For the maintenance of existing codes capability and the enhancement of code maintenance capability, user accessibility and user friendliness, MARS has been unified to be a single code consisting of 1D module (RELAP5) and 3D module (COBRA-TF). This is realized by implicitly integrating the system pressure matrix equations of hydrodynamic models and solving them simultaneously, by modifying the 1D/3D calculation sequence operable under a single Central Processor Unit (CPU) and by unifying the input structure and the light water property routines of both modules. In addition, the code structure of 1D module is completely restructured using the modular data structure of standard FORTRAN 90, which greatly improves the code maintenance capability, readability and portability. For the code flexibility, a dynamic memory management scheme is applied in both modules. MARS 1.3 now runs on PC/Windows and HP/UNIX platforms having a single CPU, and users have the options to select the 3D module to model the 3D thermal-hydraulics in the reactor vessel or other

  19. Thermal analysis of cement pastes with superabsorbent polymers

    DEFF Research Database (Denmark)

    Esteves, Luis Pedro; Jensen, Ole Mejlhede; Lukosiute, Irena

    2013-01-01

    Thermal analysis of cement systems is very helpful in the understanding of many different properties of cementitious compounds, both for the original reacting compounds, and also for the resulting hydration products. Superabsorbent polymers can be added to cement systems with many different reasons......, so it is relevant that fundamental knowledge of this new compound on the development of hydration is well understood [1-3]. This paper reports research on thermal analysis of cement pastes with superabsorbent polymers. We have studied several parameters: the concentration of SAP in the system......, the effect of particle size distribution, and their influence on the hydration process with focus on cement-silica systems. This is done at different thermodynamic conditions, so the energy of activation in the different systems can be accessed. This paper provides information relevant to hydration modelling...

  20. Transient thermal-hydraulic characteristics analysis software for PWR nuclear power systems

    International Nuclear Information System (INIS)

    Wu Yingwei; Zhuang Chengjun; Su Guanghui; Qiu Suizheng

    2010-01-01

    A point reactor neutron kinetics model, a two-phase drift-flow U-tube steam generator model, an advanced non-equilibrium three regions pressurizer model, and a passive emergency core decay heat-removed system model are adopted in the paper to develop the computerized analysis code for PWR transient thermal-hydraulic characteristics, by Compaq Visual Fortran 6.0 language. Visual input, real-time processing and dynamic visualization output are achieved by Microsoft Visual Studio. NET language. The reliability verification of the soft has been conducted by RELAP 5, and the verification results show that the software is with high calculation precision, high calculation speed, modern interface, luxuriant functions and strong operability. The software was applied to calculate the transient accident conditions for QSNP, and the analysis results are significant to the practical engineering applications. (authors)

  1. Dynamic thermal analysis of machines in running state

    CERN Document Server

    Wang, Lihui

    2014-01-01

    With the increasing complexity and dynamism in today’s machine design and development, more precise, robust and practical approaches and systems are needed to support machine design. Existing design methods treat the targeted machine as stationery. Analysis and simulation are mostly performed at the component level. Although there are some computer-aided engineering tools capable of motion analysis and vibration simulation etc., the machine itself is in the dry-run state. For effective machine design, understanding its thermal behaviours is crucial in achieving the desired performance in real situation. Dynamic Thermal Analysis of Machines in Running State presents a set of innovative solutions to dynamic thermal analysis of machines when they are put under actual working conditions. The objective is to better understand the thermal behaviours of a machine in real situation while at the design stage. The book has two major sections, with the first section presenting a broad-based review of the key areas of ...

  2. Analysis of a Concentrated Solar Thermophotovoltaic System with Thermal Energy Storage

    Science.gov (United States)

    Seyf, Hamid Reza; Henry, Asegun

    2017-01-01

    We analyzed a high temperature concentrated solar thermophotovoltaic (TPV) system with thermal energy storage (TES), which is enabled by the potential usage of liquid metal as a high temperature heat transfer fluid. The system concept combines the great advantages of TES with the potential for low cost and high performance derived from photovoltaic cells fabricated on reusable substrates, with a high reflectivity back reflector for photon recycling. The TES makes the electricity produced dispatchable, and thus the system studied should be compared to technologies such as concentrated solar power (CSP) with TES (e.g., using a turbine) or PV with electrochemical batteries, instead of direct and intermittent electricity generation from flat plate PV alone. Thus, the addition of TES places the system in a different class than has previously been considered and based on the model results, appears worthy of increased attention. The system level analysis presented identifies important cell level parameters that have the greatest impact on the overall system performance, and as a result can help to set the priorities for future TPV cell development.

  3. Nonlinear Transient Thermal Analysis by the Force-Derivative Method

    Science.gov (United States)

    Balakrishnan, Narayani V.; Hou, Gene

    1997-01-01

    High-speed vehicles such as the Space Shuttle Orbiter must withstand severe aerodynamic heating during reentry through the atmosphere. The Shuttle skin and substructure are constructed primarily of aluminum, which must be protected during reentry with a thermal protection system (TPS) from being overheated beyond the allowable temperature limit, so that the structural integrity is maintained for subsequent flights. High-temperature reusable surface insulation (HRSI), a popular choice of passive insulation system, typically absorbs the incoming radiative or convective heat at its surface and then re-radiates most of it to the atmosphere while conducting the smallest amount possible to the structure by virtue of its low diffusivity. In order to ensure a successful thermal performance of the Shuttle under a prescribed reentry flight profile, a preflight reentry heating thermal analysis of the Shuttle must be done. The surface temperature profile, the transient response of the HRSI interior, and the structural temperatures are all required to evaluate the functioning of the HRSI. Transient temperature distributions which identify the regions of high temperature gradients, are also required to compute the thermal loads for a structural thermal stress analysis. Furthermore, a nonlinear analysis is necessary to account for the temperature-dependent thermal properties of the HRSI as well as to model radiation losses.

  4. Remote Thermal Analysis Through the Internet

    Science.gov (United States)

    Malroy, Eric T.

    2002-07-01

    The Heater of the Hypersonic Tunnel Facility (HTF) was modeled using SINDA/FLUINT thermal software. A description of the model is given. The project presented the opportunity of interfacing the thermal model with the Internet and was a demonstration that complex analysis is possible through the Internet. Some of the issues that need to be addressed related to interfacing software with the Internet are the following: justification for using the Internet, selection of the web server, choice of the CGI language, security of the system, communication among the parties, maintenance of state between web pages, and simultaneous users on the Internet system. The opportunities available for using the Internet for analysis are many and can present a significant jump in technology. This paper presents a vision how interfacing with the Internet could develop in the future. Using a separate Optical Internet (OI) for analysis, coupled with virtual reality analysis rooms (VRAR), could provide a synergistic environment to couple together engineering analysis within industry, academia, and government. The process of analysis could be broken down into sub-components so that specialization could occur resulting in superior quality, minimized cost and reduced time for engineering analysis and manufacturing. Some possible subcomponents of the system are solver routines, databases, Graphical User Interfaces, engineering design software, VRARs, computer processing, CAD systems, manufacturing, and a plethora of other options only limited by ones imagination. On a larger scope, the specialization of companies on the optical network would allow companies to rapidly construct and reconstruct their infrastructure based on changing economic conditions. This could transform business.

  5. Dynamic simulation and thermo-economic analysis of a PhotoVoltaic/Thermal collector heating system for an indoor–outdoor swimming pool

    International Nuclear Information System (INIS)

    Buonomano, Annamaria; De Luca, Giuseppina; Figaj, Rafal Damian; Vanoli, Laura

    2015-01-01

    Highlights: • A PV/T heating system for indoor–outdoor swimming pools is proposed. • A comparison among some thermal pool models available in literature is carried out. • Dynamic simulations of the thermal behavior of the swimming-pools are performed. • PV/T thermal energy is used to heat the swimming pool and for DHW production. • Energy and economic parametric analyses of the proposed system are presented. - Abstract: This paper presents an analysis of an innovative renewable energy plant serving an existing indoor/outdoor swimming pool located in Naples. The proposed solar hybrid system is designed in order to balance the remarkable energy demand of the swimming pool facility and to ensure suitable comfort conditions for swimmers. With the aim to accomplish such goals, the dynamic thermal behavior of the swimming pool was analyzed as a function of the thermo-hygrometric conditions of the indoor space and on the meteorological conditions of the pool site. In order to properly design and size the proposed renewable energy system, different thermal pool loss formulations for the calculation of the swimming pool thermal balance, in indoor and outdoor regimes, are adopted. The solar hybrid system consists of a water cooled photovoltaic/thermal collectors plant (PV/T), designed to meet a part of the facility demands of electricity and heat. Electricity is completely utilized by the facility, while the produced thermal energy is primarily used to meet the pool thermal demand and secondarily for sanitary hot water scopes. In order to carry out dynamic simulations and sensitivity analyses, the system performance is designed and dynamically simulated in TRNSYS environment. The developed simulation model enables the calculation of both the indoor and outdoor swimming pool thermal losses and the overall energy and economic system performance. Such results are obtained as a function of the thermo-hygrometric conditions of the environment, of the occupants and the

  6. Experimental investigation and exergy analysis on thermal storage integrated micro-cogeneration system

    International Nuclear Information System (INIS)

    Johar, Dheeraj Kishor; Sharma, Dilip; Soni, Shyam Lal; Gupta, Pradeep K.; Goyal, Rahul

    2017-01-01

    Highlights: • Energy Storage System is integrated with Micro cogeneration system. • Erythritol is used as Phase Change Material. • Maximum energy saved is 15.2%. • Maximum exergy saved is 4.22%. • Combined systems are feasible to increase energy and exergy efficiency. - Abstract: This paper describes the performance of thermal storage integrated micro-cogeneration system based on single cylinder diesel engine. In addition to electricity generated from genset, waste heat from hot exhaust of diesel engine was used to heat water in a double pipe heat exchanger of 67.70 cm length with inside tube diameter of 3.81 cm and outside tube diameter of 5.08 cm. Additionally, a latent heat thermal energy storage system was also integrated with this cogeneration system. A shell and tube type heat exchanger of 346 mm diameter and 420 mm height with 45 tubes of 18 mm diameter each was designed and fabricated, to store thermal energy, in which Erythritol (C_4H_1_0O_4) was used as phase changing material. The test results show that micro capacity (4.4 kW), stationary, single cylinder, diesel engine can be successfully utilized to simultaneously produce power as well as heating, and to also store thermal energy. Slight decrease in engine performance was observed when double pipe heat exchanger and latent heat thermal energy storage system was integrated with engine but the amount of energy which could be recovered was significant. Maximum percentage of energy saved was obtained at a load of 3.6 kW and was 15.2%.

  7. Dynamic thermal performance of alveolar brick construction system

    International Nuclear Information System (INIS)

    Gracia, A. de; Castell, A.; Medrano, M.; Cabeza, L.F.

    2011-01-01

    Highlights: → Even though U-value does not measure thermal inertia, it is the commonly used parameter. → The thermal performance analysis of buildings must include the evaluation of transient parameters. → Transient parameters of alveolar brick constructive system show good agreement with its low energy consumption. -- Abstract: Alveolar bricks are being introduced in building sector due to the simplicity of their construction system and to the elimination of the insulation material. Nevertheless, it is not clear if this new system is energetically efficient and which is its thermal behaviour. This paper presents an experimental and theoretical study to evaluate the thermal behaviour of the alveolar brick construction system, compared with a traditional Mediterranean brick system with insulation. The experimental study consists of measuring the thermal performance of four real house-like cubicles. The thermal transmittance in steady-state, also known as U-value, is calculated theoretically and experimentally for each cubicle, presenting the insulated cubicles as the best construction system, with differences around 45% in comparison to the alveolar one. On the other hand, experimental results show significantly smaller differences on the energy consumption between the alveolar and insulated construction systems during summer period (around 13% higher for the alveolar cubicle). These values demonstrate the high thermal efficiency of the alveolar system. In addition, the lack of agreement between the measured energy consumption and the calculated U-values, guides the authors to analyze the thermal inertia of the different building components. Therefore, several transient parameters, extracted from the heat transfer matrix and from experimental data, are also evaluated. It can be concluded that the alveolar brick construction system presents higher thermal inertia than the insulated one, justifying the low measured energy consumption.

  8. Comparative study of Thermal Hydraulic Analysis Codes for Pressurized Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yang Hoon; Jang, Mi Suk; Han, Kee Soo [Nuclear Engineering Service and Solution Co. Ltd., Daejeon (Korea, Republic of)

    2015-05-15

    Various codes are used for the thermal hydraulic analysis of nuclear reactors. The use of some codes among these is limited by user and some codes are not even open to general person. Thus, the use of alternative code is considered for some analysis. In this study, simple thermal hydraulic behaviors are analyzed using three codes to show that alternative codes are possible for the analysis of nuclear reactors. We established three models of the simple u-tube manometer using three different codes. RELAP5 (Reactor Excursion and Leak Analysis Program), SPACE (Safety and Performance Analysis CodE for nuclear power Plants), GOTHIC (Generation of Thermal Hydraulic Information for Containments) are selected for this analysis. RELAP5 is widely used codes for the analysis of system behavior of PWRs. SPACE has been developed based on RELAP5 for the analysis of system behavior of PWRs and licensing of the code is in progress. And GOTHIC code also has been widely used for the analysis of thermal hydraulic behavior in the containment system. The internal behavior of u-tube manometer was analyzed by RELAP5, SPACE and GOTHIC codes. The general transient behavior was similar among 3 codes. However, the stabilized status of the transient period analyzed by REPAP5 was different from the other codes. It would be resulted from the different physical models used in the other codes, which is specialized for the multi-phase thermal hydraulic behavior analysis.

  9. Analysis of the Effects of Thermal Environment on Optical Systems for Navigation Guidance and Control in Supersonic Aircraft Based on Empirical Equations.

    Science.gov (United States)

    Cheng, Xuemin; Yang, Yikang; Hao, Qun

    2016-10-17

    The thermal environment is an important factor in the design of optical systems. This study investigated the thermal analysis technology of optical systems for navigation guidance and control in supersonic aircraft by developing empirical equations for the front temperature gradient and rear thermal diffusion distance, and for basic factors such as flying parameters and the structure of the optical system. Finite element analysis (FEA) was used to study the relationship between flying and front dome parameters and the system temperature field. Systematic deduction was then conducted based on the effects of the temperature field on the physical geometry and ray tracing performance of the front dome and rear optical lenses, by deriving the relational expressions between the system temperature field and the spot size and positioning precision of the rear optical lens. The optical systems used for navigation guidance and control in supersonic aircraft when the flight speed is in the range of 1-5 Ma were analysed using the derived equations. Using this new method it was possible to control the precision within 10% when considering the light spot received by the four-quadrant detector, and computation time was reduced compared with the traditional method of separately analysing the temperature field of the front dome and rear optical lens using FEA. Thus, the method can effectively increase the efficiency of parameter analysis and computation in an airborne optical system, facilitating the systematic, effective and integrated thermal analysis of airborne optical systems for navigation guidance and control.

  10. Analysis of Medium-Scale Solar Thermal Systems and Their Potential in Lithuania

    Directory of Open Access Journals (Sweden)

    Rokas Valančius

    2015-06-01

    Full Text Available Medium-scale solar hot water systems with a total solar panel area varying from 60 to 166 m2 have been installed in Lithuania since 2002. However, the performance of these systems varies depending on the type of energy users, equipment and design of the systems, as well as their maintenance. The aim of this paper was to analyse operational SHW systems from the perspective of energy production and economic benefit as well as to outline the differences of their actual performance compared to the numerical simulation results. Three different medium-scale solar thermal systems in Lithuania were selected for the analysis varying in both equipment used (flat type solar collectors, evacuated tube collectors and type of energy user (swimming pool building, domestic hot water heating, district heating. The results of the analysis showed that in the analysed cases the gap between measured and modelled data of heat energy produced by SHW systems was approx. 11%. From the economical perspective, the system with flat type solar collectors used for domestic hot water production was proved to be most efficient. However, calculation of Internal Rate of Return showed that a grant of 35% is required for this project to be fully profitable.

  11. High heat flux thermal-hydraulic analysis of ITER divertor and blanket systems

    International Nuclear Information System (INIS)

    Raffray, A.R.; Chiocchio, S.; Ioki, K.; Tivey, R.; Krassovski, D.; Kubik, D.

    1998-01-01

    Three separate cooling systems are used for the divertor and blanket components, based mainly on flow routing access and on grouping together components with the highest heat load levels and uncertainties: divertor, limiter/outboard baffle, and primary first wall/inboard baffle. The coolant parameters for these systems are set to accommodate peak heat load conditions with a reasonable critical heat flux (CHF) margin. Material temperature constraints and heat transport system space and cost requirements are also taken into consideration. This paper summarises the three cooling system designs and highlights the high heat flux thermal-hydraulic analysis carried out in converging on the design values for the coolant operating parameters. Application of results from on-going high heat flux R and D and a brief description of future R and D effort to address remaining issues are also included. (orig.)

  12. Analysis and optimization of hybrid electric vehicle thermal management systems

    Science.gov (United States)

    Hamut, H. S.; Dincer, I.; Naterer, G. F.

    2014-02-01

    In this study, the thermal management system of a hybrid electric vehicle is optimized using single and multi-objective evolutionary algorithms in order to maximize the exergy efficiency and minimize the cost and environmental impact of the system. The objective functions are defined and decision variables, along with their respective system constraints, are selected for the analysis. In the multi-objective optimization, a Pareto frontier is obtained and a single desirable optimal solution is selected based on LINMAP decision-making process. The corresponding solutions are compared against the exergetic, exergoeconomic and exergoenvironmental single objective optimization results. The results show that the exergy efficiency, total cost rate and environmental impact rate for the baseline system are determined to be 0.29, ¢28 h-1 and 77.3 mPts h-1 respectively. Moreover, based on the exergoeconomic optimization, 14% higher exergy efficiency and 5% lower cost can be achieved, compared to baseline parameters at an expense of a 14% increase in the environmental impact. Based on the exergoenvironmental optimization, a 13% higher exergy efficiency and 5% lower environmental impact can be achieved at the expense of a 27% increase in the total cost.

  13. Thermal Storage Systems Assessment for Energy Sustainability in Housing Units

    Directory of Open Access Journals (Sweden)

    Tania I. Lagunes Vega

    2016-04-01

    Full Text Available In order to achieve greater enhancements in energy sustainability for housing, the function and efficiency of two different passive cooling systems were studied: encapsulated water in recycled bottles of Polyethylene terephthalate (PET and polystyrene plates, in comparison with standard concrete slab systems, which are customarily used in housing. Experiments were placed over a tile surface, in which temperature changes were monitored for a period of 20 days from 08:00 to 20:00. The efficiency of passive thermal storage systems was endorsed through statistical analysis using the “SPSS” software. This resulted in a 17% energy saving, thus promoting energy sustainability in housing units, which reduces the use of electrical appliances required to stabilize conditions to achieve optimum thermal comfort for the human body inside a house, therefore, reducing electrical power consumption, CO2 emissions to the atmosphere and generating savings. Due to the complexity of a system with temperature changes, a fractal analysis was performed for each experimental system, using the “Benoit” software (V.1.3 with self-compatible tools of rescaled range (R/S and a wavelets method, showing that the thermal fluctuations on the tiles with the thermal storage system adapt to the rescaled range analysis and the regular tiles adapt to the wavelets method.

  14. LOFT blowdown loop piping thermal analysis Class I review

    International Nuclear Information System (INIS)

    Kinnaman, T.L.

    1978-01-01

    In accordance with ASME Code, Section III requirements, all analyses of Class I components must be independently reviewed. Since the LOFT blowdown loop piping up through the blowdown valve is a Class I piping system, the thermal analyses are reviewed. The Thermal Analysis Branch comments to this review are also included. It is the opinion of the Thermal Analysis Branch that these comments satisfy all of the reviewers questions and that the analyses should stand as is, without additional considerations in meeting the ASME Code requirements and ANC Specification 60139

  15. Displacements of Metallic Thermal Protection System Panels During Reentry

    Science.gov (United States)

    Daryabeigi, Kamran; Blosser, Max L.; Wurster, Kathryn E.

    2006-01-01

    Bowing of metallic thermal protection systems for reentry of a previously proposed single-stage-to-orbit reusable launch vehicle was studied. The outer layer of current metallic thermal protection system concepts typically consists of a honeycomb panel made of a high temperature nickel alloy. During portions of reentry when the thermal protection system is exposed to rapidly varying heating rates, a significant temperature gradient develops across the honeycomb panel thickness, resulting in bowing of the honeycomb panel. The deformations of the honeycomb panel increase the roughness of the outer mold line of the vehicle, which could possibly result in premature boundary layer transition, resulting in significantly higher downstream heating rates. The aerothermal loads and parameters for three locations on the centerline of the windward side of this vehicle were calculated using an engineering code. The transient temperature distributions through a metallic thermal protection system were obtained using 1-D finite volume thermal analysis, and the resulting displacements of the thermal protection system were calculated. The maximum deflection of the thermal protection system throughout the reentry trajectory was 6.4 mm. The maximum ratio of deflection to boundary layer thickness was 0.032. Based on previously developed distributed roughness correlations, it was concluded that these defections will not result in tripping the hypersonic boundary layer.

  16. Comparative analysis of thermally activated, environmentally friendly cooling systems

    International Nuclear Information System (INIS)

    Gupta, Y.; Metchop, L.; Frantzis, A.; Phelan, P.E.

    2008-01-01

    This paper compares the relative performances of three different thermally activated, environmentally friendly cooling systems, e.g. a silica-gel-water adsorption system, a LiBr-H 2 O absorption system and a desiccant air system. The adsorption and absorption systems in the current study employ water as the refrigerant, while the desiccant system cools atmospheric air directly. Each of these systems can be utilized at relatively low heat source temperatures such as achieved by flat plate solar collectors, but it is unclear which of these systems is best suited to what range of heat source temperature. Our study explores answers to this question by generating quantitative results comparing their relative thermal performance, i.e. COP and refrigeration capacity, and a qualitative comparison based on the size, maturity of technology, safe operation etc. In order to provide a fair comparison between the fundamentally different systems, a UA (overall heat transfer coefficient multiplied by the heat transfer area) value of 1.0 kW deg. C -1 is considered for the heat exchanger that transfers heat from the supplied hot water. Furthermore, to compare systems of similar size, the mass of silica-gel in the adsorption and desiccant systems and the mass of LiBr-H 2 O solution in the absorption system were specified such that each system provides the same amount of refrigeration (8.0 kW) at a source temperature of 90 deg. C. It is found that the absorption and adsorption cooling systems have a higher refrigeration capacity at heat source temperatures below 90 deg. C, while the desiccant air system outperforms the others at temperatures above 90 deg. C

  17. The Earth Observing System AM Spacecraft - Thermal Control Subsystem

    Science.gov (United States)

    Chalmers, D.; Fredley, J.; Scott, C.

    1993-01-01

    Mission requirements for the EOS-AM Spacecraft intended to monitor global changes of the entire earth system are considered. The spacecraft is based on an instrument set containing the Advanced Spaceborne Thermal Emission and Reflection radiometer (ASTER), Clouds and Earth's Radiant Energy System (CERES), Multiangle Imaging Spectro-Radiometer (MISR), Moderate-Resolution Imaging Spectrometer (MODIS), and Measurements of Pollution in the Troposphere (MOPITT). Emphasis is placed on the design, analysis, development, and verification plans for the unique EOS-AM Thermal Control Subsystem (TCS) aimed at providing the required environments for all the onboard equipment in a densely packed layout. The TCS design maximizes the use of proven thermal design techniques and materials, in conjunction with a capillary pumped two-phase heat transport system for instrument thermal control.

  18. Analysis of the Effects of Thermal Environment on Optical Systems for Navigation Guidance and Control in Supersonic Aircraft Based on Empirical Equations

    Directory of Open Access Journals (Sweden)

    Xuemin Cheng

    2016-10-01

    Full Text Available The thermal environment is an important factor in the design of optical systems. This study investigated the thermal analysis technology of optical systems for navigation guidance and control in supersonic aircraft by developing empirical equations for the front temperature gradient and rear thermal diffusion distance, and for basic factors such as flying parameters and the structure of the optical system. Finite element analysis (FEA was used to study the relationship between flying and front dome parameters and the system temperature field. Systematic deduction was then conducted based on the effects of the temperature field on the physical geometry and ray tracing performance of the front dome and rear optical lenses, by deriving the relational expressions between the system temperature field and the spot size and positioning precision of the rear optical lens. The optical systems used for navigation guidance and control in supersonic aircraft when the flight speed is in the range of 1–5 Ma were analysed using the derived equations. Using this new method it was possible to control the precision within 10% when considering the light spot received by the four-quadrant detector, and computation time was reduced compared with the traditional method of separately analysing the temperature field of the front dome and rear optical lens using FEA. Thus, the method can effectively increase the efficiency of parameter analysis and computation in an airborne optical system, facilitating the systematic, effective and integrated thermal analysis of airborne optical systems for navigation guidance and control.

  19. Thermal Analysis of Iodine Satellite (iSAT)

    Science.gov (United States)

    Mauro, Stephanie

    2015-01-01

    This paper presents the progress of the thermal analysis and design of the Iodine Satellite (iSAT). The purpose of the iSAT spacecraft (SC) is to demonstrate the ability of the iodine Hall Thruster propulsion system throughout a one year mission in an effort to mature the system for use on future satellites. The benefit of this propulsion system is that it uses a propellant, iodine, that is easy to store and provides a high thrust-to-mass ratio. The spacecraft will also act as a bus for an earth observation payload, the Long Wave Infrared (LWIR) Camera. Four phases of the mission, determined to either be critical to achieving requirements or phases of thermal concern, are modeled. The phases are the Right Ascension of the Ascending Node (RAAN) Change, Altitude Reduction, De-Orbit, and Science Phases. Each phase was modeled in a worst case hot environment and the coldest phase, the Science Phase, was also modeled in a worst case cold environment. The thermal environments of the spacecraft are especially important to model because iSAT has a very high power density. The satellite is the size of a 12 unit cubesat, and dissipates slightly more than 75 Watts of power as heat at times. The maximum temperatures for several components are above their maximum operational limit for one or more cases. The analysis done for the first Design and Analysis Cycle (DAC1) showed that many components were above or within 5 degrees Centigrade of their maximum operation limit. The battery is a component of concern because although it is not over its operational temperature limit, efficiency greatly decreases if it operates at the currently predicted temperatures. In the second Design and Analysis Cycle (DAC2), many steps were taken to mitigate the overheating of components, including isolating several high temperature components, removal of components, and rearrangement of systems. These changes have greatly increased the thermal margin available.

  20. Thermal Analysis of the Fastrac Chamber/Nozzle

    Science.gov (United States)

    Davis, Darrell

    2001-01-01

    This paper will describe the thermal analysis techniques used to predict temperatures in the film-cooled ablative rocket nozzle used on the Fastrac 60K rocket engine. A model was developed that predicts char and pyrolysis depths, liner thermal gradients, and temperatures of the bondline between the overwrap and liner. Correlation of the model was accomplished by thermal analog tests performed at Southern Research, and specially instrumented hot fire tests at the Marshall Space Flight Center. Infrared thermography was instrumental in defining nozzle hot wall surface temperatures. In-depth and outboard thermocouple data was used to correlate the kinetic decomposition routine used to predict char and pyrolysis depths. These depths were anchored with measured char and pyrolysis depths from cross-sectioned hot-fire nozzles. For the X-34 flight analysis, the model includes the ablative Thermal Protection System (TPS) material that protects the overwrap from the recirculating plume. Results from model correlation, hot-fire testing, and flight predictions will be discussed.

  1. Thermal analysis elements of liquefied gas storage tanks

    Science.gov (United States)

    Yanvarev, I. A.; Krupnikov, A. V.

    2017-08-01

    Tasks of solving energy and resource efficient usage problems, both for oil producing companies and for companies extracting and transporting natural gas, are associated with liquefied petroleum gas technology development. Improving the operation efficiency of liquefied products storages provides for conducting structural, functional, and appropriate thermal analysis of tank parks in the general case as complex dynamic thermal systems.

  2. Analysis of uncertainties of thermal hydraulic calculations

    International Nuclear Information System (INIS)

    Macek, J.; Vavrin, J.

    2002-12-01

    In 1993-1997 it was proposed, within OECD projects, that a common program should be set up for uncertainty analysis by a probabilistic method based on a non-parametric statistical approach for system computer codes such as RELAP, ATHLET and CATHARE and that a method should be developed for statistical analysis of experimental databases for the preparation of the input deck and statistical analysis of the output calculation results. Software for such statistical analyses would then have to be processed as individual tools independent of the computer codes used for the thermal hydraulic analysis and programs for uncertainty analysis. In this context, a method for estimation of a thermal hydraulic calculation is outlined and selected methods of statistical analysis of uncertainties are described, including methods for prediction accuracy assessment based on the discrete Fourier transformation principle. (author)

  3. Use of thermal sieve to allow optical testing of cryogenic optical systems.

    Science.gov (United States)

    Kim, Dae Wook; Cai, Wenrui; Burge, James H

    2012-05-21

    Full aperture testing of large cryogenic optical systems has been impractical due to the difficulty of operating a large collimator at cryogenic temperatures. The Thermal Sieve solves this problem by acting as a thermal barrier between an ambient temperature collimator and the cryogenic system under test. The Thermal Sieve uses a set of thermally controlled baffles with array of holes that are lined up to pass the light from the collimator without degrading the wavefront, while attenuating the thermal background by nearly 4 orders of magnitude. This paper provides the theory behind the Thermal Sieve system, evaluates the optimization for its optical and thermal performance, and presents the design and analysis for a specific system.

  4. Thermal Insulation System Analysis Tool (TISTool) User's Manual. Version 1.0.0

    Science.gov (United States)

    Johnson, Wesley; Fesmire, James; Leucht, Kurt; Demko, Jonathan

    2010-01-01

    The Thermal Insulation System Analysis Tool (TISTool) was developed starting in 2004 by Jonathan Demko and James Fesmire. The first edition was written in Excel and Visual BasIc as macros. It included the basic shapes such as a flat plate, cylinder, dished head, and sphere. The data was from several KSC tests that were already in the public literature realm as well as data from NIST and other highly respectable sources. More recently, the tool has been updated with more test data from the Cryogenics Test Laboratory and the tank shape was added. Additionally, the tool was converted to FORTRAN 95 to allow for easier distribution of the material and tool. This document reviews the user instructions for the operation of this system.

  5. Preliminary thermal sizing of intermediate heat exchanger for NHDD system

    International Nuclear Information System (INIS)

    Kim, Chan Soo; Hong, Sung Deok; Kim, Yong Wan; Chang, Jongh Wa

    2009-01-01

    Nuclear Hydrogen Development and Demonstration (NHDD) system is a Very High Temperature gascooled Reactor (VHTR) coupled with hydrogen production systems. Intermediate heat exchanger transfers heat from the nuclear reactor to the hydrogen production system. This study presented the sensitivity analysis on a preliminary thermal sizing of the intermediate heat exchanger. Printed Circuit Heat Exchanger (PCHE) was selected for the thermal sizing because the printed circuit heat exchanger has the largest compactness among the heat exchanger types. The analysis was performed to estimate the effect of key parameters including the operating condition of the intermediate system, the geometrical factors of the PCHE, and the working fluid of the intermediate system.

  6. Use of labelled atoms in thermal analysis

    International Nuclear Information System (INIS)

    Balek, V.; Beckman, I.N.

    1985-01-01

    The article informs of the preparation of labelled samples for which the most frequently used radionuclides are 14 C, 3 H or 2 H, 32 P, 35 S and others as well as radioactive gases such as 85 Kr, 133 Xe or 220 Rn and 222 Rn. The equipment is described for the application of labelled atoms in thermal analysis consisting of a detector for measuring radioactivity and a system for measuring thermal analysis parameters. Examples are given of the use of labelled atoms in the study of chemical reactions of solids, in autoradiography or in Moessbauer spectroscopy. The greatest attention is devoted to the use of labelled atoms in emanation thermal analysis. By this technique it is possible to study chemical reactions and phase transformations, to continuously monitor changes in the surface and morphology of dispersion substances, to characterize the mobility of defects in the structure of solids and the active state of the structure of solids and to ascertain mechanical, radiation and chemical effects on solids. Attention is also devoted to the technological applications of emanation thermal analysis (the solidification of cement paste, calcination and the firing of the mixture of oxides for the manufacture of ferrites). (E.S.)

  7. The Peltier driven frequency domain approach in thermal analysis.

    Science.gov (United States)

    De Marchi, Andrea; Giaretto, Valter

    2014-10-01

    The merits of Frequency Domain analysis as a tool for thermal system characterization are discussed, and the complex thermal impedance approach is illustrated. Pure AC thermal flux generation with negligible DC component is possible with a Peltier device, differently from other existing methods in which a significant DC component is intrinsically attached to the generated AC flux. Such technique is named here Peltier Driven Frequency Domain (PDFD). As a necessary prerequisite, a novel one-dimensional analytical model for an asymmetrically loaded Peltier device is developed, which is general enough to be useful in most practical situations as a design tool for measurement systems and as a key for the interpretation of experimental results. Impedance analysis is possible with Peltier devices by the inbuilt Seebeck effect differential thermometer, and is used in the paper for an experimental validation of the analytical model. Suggestions are then given for possible applications of PDFD, including the determination of thermal properties of materials.

  8. Thermal conductivity in one-dimensional nonlinear systems

    Science.gov (United States)

    Politi, Antonio; Giardinà, Cristian; Livi, Roberto; Vassalli, Massimo

    2000-03-01

    Thermal conducitivity of one-dimensional nonlinear systems typically diverges in the thermodynamic limit, whenever the momentum is conserved (i.e. in the absence of interactions with an external substrate). Evidence comes from detailed studies of Fermi-Pasta-Ulam and diatomic Toda chains. Here, we discuss the first example of a one-dimensional system obeying Fourier law : a chain of coupled rotators. Numerical estimates of the thermal conductivity obtained by simulating a chain in contact with two thermal baths at different temperatures are found to be consistent with those ones based on linear response theory. The dynamics of the Fourier modes provides direct evidence of energy diffusion. The finiteness of the conductivity is traced back to the occurrence of phase-jumps. Our conclusions are confirmed by the analysis of two variants of the rotator model.

  9. Thermal-hydraulic analysis of an innovative decay heat removal system for lead-cooled fast reactors

    International Nuclear Information System (INIS)

    Giannetti, Fabio; Vitale Di Maio, Damiano; Naviglio, Antonio; Caruso, Gianfranco

    2016-01-01

    Highlights: • LOOP thermal-hydraulic transient analysis for lead-cooled fast reactors. • Passive decay heat removal system concept to avoid lead freezing. • Solution developed for the diversification of the decay heat removal functions. • RELAP5 vs. RELAP5-3D comparison for lead applications. - Abstract: Improvement of safety requirements in GEN IV reactors needs more reliable safety systems, among which the decay heat removal system (DHR) is one of the most important. Complying with the diversification criteria and based on pure passive and very reliable components, an additional DHR for the ALFRED reactor (Advanced Lead Fast Reactor European Demonstrator) has been proposed and its thermal-hydraulic performances are analyzed. It consists in a coupling of two innovative subsystems: the radiative-based direct heat exchanger (DHX), and the pool heat exchanger (PHX). Preliminary thermal-hydraulic analyses, by using RELAP5 and RELAP5-3D© computer programs, have been carried out showing that the whole system can safely operate, in natural circulation, for a long term. Sensitivity analyses for: the emissivity of the DHX surfaces, the PHX water heat transfer coefficient (HTC) and the lead HTC have been carried out. In addition, the effects of the density variation uncertainty on the results has been analyzed and compared. It allowed to assess the feasibility of the system and to evaluate the acceptable range of the studied parameters. A comparison of the results obtained with RELAP5 and RELAP5-3D© has been carried out and the analysis of the differences of the two codes for lead is presented. The features of the innovative DHR allow to match the decay heat removal performance with the trend of the reactor decay heat power after shutdown, minimizing at the same time the risk of lead freezing. This system, proposed for the diversification of the DHR in the LFRs, could be applicable in the other pool-type liquid metal fast reactors.

  10. Thermal-hydraulic analysis of an innovative decay heat removal system for lead-cooled fast reactors

    Energy Technology Data Exchange (ETDEWEB)

    Giannetti, Fabio; Vitale Di Maio, Damiano; Naviglio, Antonio; Caruso, Gianfranco, E-mail: gianfranco.caruso@uniroma1.it

    2016-08-15

    Highlights: • LOOP thermal-hydraulic transient analysis for lead-cooled fast reactors. • Passive decay heat removal system concept to avoid lead freezing. • Solution developed for the diversification of the decay heat removal functions. • RELAP5 vs. RELAP5-3D comparison for lead applications. - Abstract: Improvement of safety requirements in GEN IV reactors needs more reliable safety systems, among which the decay heat removal system (DHR) is one of the most important. Complying with the diversification criteria and based on pure passive and very reliable components, an additional DHR for the ALFRED reactor (Advanced Lead Fast Reactor European Demonstrator) has been proposed and its thermal-hydraulic performances are analyzed. It consists in a coupling of two innovative subsystems: the radiative-based direct heat exchanger (DHX), and the pool heat exchanger (PHX). Preliminary thermal-hydraulic analyses, by using RELAP5 and RELAP5-3D© computer programs, have been carried out showing that the whole system can safely operate, in natural circulation, for a long term. Sensitivity analyses for: the emissivity of the DHX surfaces, the PHX water heat transfer coefficient (HTC) and the lead HTC have been carried out. In addition, the effects of the density variation uncertainty on the results has been analyzed and compared. It allowed to assess the feasibility of the system and to evaluate the acceptable range of the studied parameters. A comparison of the results obtained with RELAP5 and RELAP5-3D© has been carried out and the analysis of the differences of the two codes for lead is presented. The features of the innovative DHR allow to match the decay heat removal performance with the trend of the reactor decay heat power after shutdown, minimizing at the same time the risk of lead freezing. This system, proposed for the diversification of the DHR in the LFRs, could be applicable in the other pool-type liquid metal fast reactors.

  11. Preliminary analysis of K-DEMO thermal hydraulic system using MELCOR; Parametric study of hydrogen explosion

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Sung Bo; Lim, Soo Min; Bang, In Cheol [UNIST, Ulsan (Korea, Republic of)

    2016-10-15

    K-DEMO (Korean fusion demonstration reactor) is future reactor for the commercializing the fusion power generation. The Design of K-DEMO is similar to that of ITER but the fusion energy generation is much bigger because ITER is experimental reactor. For this reason, K-DEMO uses more fusion reaction with bigger amount of tritium. Higher fusion power means more neutron generation that can irradiate the structure around fusion plasma. Fusion reactor can produce many kinds of radioactive material in the accident. Because of this hazard, preliminary safety analysis is mandatory before its construction. Concern for safety problem of accident of fusion/fission reactor has been growing after Fukushima accident which is severe accident from unexpected disaster. To model the primary heat transfer system, in this study, MARS-KS thermal hydraulic analysis is referred. Lee et al. and Kim et al. conducted thermal hydraulic analysis using MARS-KS and multiple module simulation to deal with the phenomena of first wall corrosion for each plasma pulse. This study shows the relationship between vacuum vessel rupture area and source term leakage after hydrogen explosion. For the conservative study, first wall heating is not terminated because the heating inside the vacuum vessel increase the pressure inside VV. Pressurizer, steam generator and turbine is not damaged. 6.69 kg of tritiated water (HTO) and 1 ton of dust is modeled which is ITER guideline. The entire system of K-DEMO is smaller than that of ITER. For this reason, lots of aerosol is release into environment although the safety system like DS is maintained. This result shows that the safety system of K-DEMO should use much more safety system.

  12. Thermal analysis and modeling of a swimming pool heating system by utilizing waste energy rejected from a chiller unit of an ice rink

    Directory of Open Access Journals (Sweden)

    Kuyumcu Muhammed Enes

    2017-01-01

    Full Text Available This study deals with the thermal analysis and modeling of a swimming pool heating system in which the waste energy rejected from the chiller unit of an ice rink is used as an energy source. The system consists of a swimming pool and an ice rink coupled by a chiller unit. The swimming pool and the ice rink both indoor types and were constructed in city of Gaziantep, Turkey. The thermal energy requirement for each section is determined by thermal analysis of each component of the system. Effects of different design parameters such as ceiling insulation thickness, ceiling emissivity, Carnot efficiency factor and size of the ice rink on the thermal energy requirements and coefficient of performance of the chiller unit are investigated. As a result of analyses of the system, the minimum ice rink area is determined in order to meet annual total heat energy demand of the olympic-sized swimming pool.

  13. Heat Exchange in “Human body - Thermal protection - Environment” System

    Science.gov (United States)

    Khromova, I. V.

    2017-11-01

    This article is devoted to the issues of simulation and calculation of thermal processes in the system called “Human body - Thermal protection - Environment” under low temperature conditions. It considers internal heat sources and convective heat transfer between calculated elements. Overall this is important for the Heat Transfer Theory. The article introduces complex heat transfer calculation method and local thermophysical parameters calculation method in the system called «Human body - Thermal protection - Environment», considering passive and active thermal protections, thermophysical and geometric properties of calculated elements in a wide range of environmental parameters (water, air). It also includes research on the influence that thermal resistance of modern materials, used in special protective clothes development, has on heat transfer in the system “Human body - Thermal protection - Environment”. Analysis of the obtained results allows adding of the computer research data to experiments and optimizing of individual life-support system elements, which are intended to protect human body from exposure to external factors.

  14. Exergy analysis of thermal management system for range-extended electric vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Hamut, H. S.; Dincer, I.; Naterer, G. F. [Faculty of Engineering and Applied Science, University of Ontario Institute of Technology (Canada)], email: Ibrahim.Dincer@uoit.ca

    2011-07-01

    In the last few decades, the energy crisis, increasing gas prices and concerns over environmental pollution have encouraged the development of electric vehicle (EV) and hybrid electric vehicle (HEV) technologies. In this paper, a thermal management system (TMS) installed in a range-extended electric vehicle is examined and is found to have a substantial impact on battery efficiency and vehicle performance. An exergy analysis was conducted on the refrigeration and coolant circuits and the Coefficient of Performance (COP) of the baseline system was determined to be 2.0 with a range of 1.8 to 2.4. The overall exergy was found to be 32% with a range of 26% to 39%. Ambient temperature had the largest impact on overall exergy efficiency but there is a need to further investigate temperature effects on battery efficiency, since the battery's performance has such a high impact on vehicle performance overall.

  15. Thermal Power Plant Performance Analysis

    CERN Document Server

    2012-01-01

    The analysis of the reliability and availability of power plants is frequently based on simple indexes that do not take into account the criticality of some failures used for availability analysis. This criticality should be evaluated based on concepts of reliability which consider the effect of a component failure on the performance of the entire plant. System reliability analysis tools provide a root-cause analysis leading to the improvement of the plant maintenance plan.   Taking in view that the power plant performance can be evaluated not only based on  thermodynamic related indexes, such as heat-rate, Thermal Power Plant Performance Analysis focuses on the presentation of reliability-based tools used to define performance of complex systems and introduces the basic concepts of reliability, maintainability and risk analysis aiming at their application as tools for power plant performance improvement, including: ·         selection of critical equipment and components, ·         defini...

  16. Experimental study and performance analysis of a thermoelectric cooling and heating system driven by a photovoltaic/thermal system in summer and winter operation modes

    International Nuclear Information System (INIS)

    He, Wei; Zhou, JinZhi; Chen, Chi; Ji, Jie

    2014-01-01

    Highlights: • Thermoelectric heating system driven by heat pipe PV/T system was built and test. • Theoretical analysis has been done and simulation results have been validated by experiments. • The energetic efficiency and exergetic efficiency in summer and winter operation mode was analyzed and compared. - Abstract: This paper presents theoretical and experimental investigations of the winter operation mode of a thermoelectric cooling and heating system driven by a heat pipe photovoltaic/thermal (PV/T) panel. And the energy and exergy analysis of this system in summer and winter operation modes are also done. The winter operation mode of this system is tested in an experimental room which temperature is controlled at 18 °C. The results indicate the average coefficient of performance (COP) of thermoelectric module of this system can be about 1.7, the electrical efficiency of the PV/T panel can reach 16.7%, and the thermal efficiency of this system can reach 23.5%. The energy and exergy analysis show the energetic efficiency of the system in summer operation mode is higher than that of it in winter operation mode, but the exergetic efficiency in summer operation mode is lower than that in winter operation mode, on the contrary

  17. Development of system analysis code for thermal-hydraulic simulation of integral reactor, Rex-10

    International Nuclear Information System (INIS)

    Lee, Y. G.; Kim, J. W.; Yoon, S. J.; Park, G. C.

    2010-10-01

    Rex-10 is an environment-friendly and economical small-scale nuclear reactor to provide the energy for district heating as well as the electric power in micro-grid. This integral reactor comprises several innovative concepts supported by advanced primary circuit components, low coolant parameters and natural circulation cooling. To evaluate the system performance and thermal-hydraulic behavior of the reactor, a system analysis code is being developed so that the new designs and technologies adopted in Rex-10 can be reflected. The research efforts are absorbed in programming the simple and fast-running thermal-hydraulic analysis software. The details of hydrodynamic governing equations component models and numerical solution scheme used in this code are presented in this paper. On the basis of one-dimensional momentum integral model, the models of point reactor neutron kinetics for thorium-fueled core, physical processes in the steam-gas pressurizer, and heat transfers in helically coiled steam generator are implemented to the system code. Implicit numerical scheme is employed to momentum and energy equations to assure the numerical stability. The accuracy of simulation is validated by applying the solution method to the Rex-10 test facility. Calculated natural circulation flow rate and coolant temperature at steady-state are compared to the experimental data. The validation is also carried out for the transients in which the sudden reduction in the core power or the feedwater flow takes place. The code's capability to predict the steady-state flow by natural convection and the qualitative behaviour of the primary system in the transients is confirmed. (Author)

  18. Development of system analysis code for thermal-hydraulic simulation of integral reactor, Rex-10

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-10-15

    Rex-10 is an environment-friendly and economical small-scale nuclear reactor to provide the energy for district heating as well as the electric power in micro-grid. This integral reactor comprises several innovative concepts supported by advanced primary circuit components, low coolant parameters and natural circulation cooling. To evaluate the system performance and thermal-hydraulic behavior of the reactor, a system analysis code is being developed so that the new designs and technologies adopted in Rex-10 can be reflected. The research efforts are absorbed in programming the simple and fast-running thermal-hydraulic analysis software. The details of hydrodynamic governing equations component models and numerical solution scheme used in this code are presented in this paper. On the basis of one-dimensional momentum integral model, the models of point reactor neutron kinetics for thorium-fueled core, physical processes in the steam-gas pressurizer, and heat transfers in helically coiled steam generator are implemented to the system code. Implicit numerical scheme is employed to momentum and energy equations to assure the numerical stability. The accuracy of simulation is validated by applying the solution method to the Rex-10 test facility. Calculated natural circulation flow rate and coolant temperature at steady-state are compared to the experimental data. The validation is also carried out for the transients in which the sudden reduction in the core power or the feedwater flow takes place. The code's capability to predict the steady-state flow by natural convection and the qualitative behaviour of the primary system in the transients is confirmed. (Author)

  19. Thermal analysis of W VII-AS limiter system and presentation of a graphite-block concept

    International Nuclear Information System (INIS)

    Mukherjee, S.; Grigull, P.

    1989-01-01

    A 2D-finite element thermal analysis of the initial W VII-AS limiter system has been performed and is discussed. Furhter to this analysis a graphite block concept is presented. This concept has been numerically analyzed for applications as a limiter in plasma and nuclear fusion experimental devices. The results are described in this paper. This block concept seems to be also applicable to first wall and divertor designs; the graphite elements could be replaced by ceramic ones. (author). 10 refs.; 13 figs

  20. Thermal performance analysis of reciprocating compressor with stepless capacity control system

    International Nuclear Information System (INIS)

    Bin, Tang; Yuanyang, Zhao; Liansheng, Li; Guangbin, Liu; Le, Wang; Qichao, Yang; Haiping, Xu; Feng, Zhu; Wenhui, Meng

    2013-01-01

    On the basic principle of stepless capacity control system for large reciprocating compressor, the thermal cycle was analyzed. The equations for the process of suction, reverse flow, compression, discharge and expansion of clearance gas were established. According to these equations, p–V diagrams at various situations were simulated. An experimental platform was setup and the compressor with designed stepless capacity control system run well. The experimental results show that the capacity of compressor can be regulated steplessly, and the motor power is reduced proportionally with respect to the reduction of capacity. During the suction process, both the flow resistance of valve and the pressure fluctuation in cylinder can be reduced by opening the suction valves with the actuators. The simulated and experimental results showed good coincidence. The clearance volume and valve clearance Mach number had a negative influence on the thermal performance of compressor with stepless capacity control system. -- Highlights: ► Flow resistance of valve can be reduced and pressure fluctuation can be reduced. ► Equivalent Mach number of reverse flow is much higher than that of suction process. ► Response of stepless capacity control system is important for regulation accuracy. ► Clearance and valve clearance Mach number have influence on thermal performance

  1. Thermal-hydraulic simulation and analysis of Research Reactor Cooling Systems

    International Nuclear Information System (INIS)

    EL Khatib, H.H.A.

    2013-01-01

    The objective of the present study is to formulate a model to simulate the thermal hydraulic behavior of integrated cooling system in a typical material testing reactor (MTR) under loss of ultimate heat sink, the model involves three interactively coupled sub-models for reactor core, heat exchanger and cooling tower. The developed model predicts the temperature profiles in addition it predicts inlet and outlet temperatures of the hot and cold stream as well as the heat exchangers and cooling tower. The model is validated against PARET code for steady-state operation and also verified by the reactor operational records, and then the model is used to simulate the thermal-hydraulic behavior of the reactor under a loss of ultimate heat sink. The simulation is performed for two operational regimes named regime I of (11 MW) thermal power and three operated cooling tower cells and regime II of (22 MW) thermal power and six operated cooling tower cells. In regime I, the simulation is performed for 1, 2 and 3 cooling tower failed cells while in regime II, it is performed for 1, 2, 3, 4, 5 and 6 cooling tower failed cells. The safety action is conducted by the reactor protection system (RPS) named power reduction safety action, it is triggered to decrease the reactor power by amount of 20% of the present power when the water inlet temperature to the core reaches 43 degree C and a scram (emergency shutdown) is triggered in case of the inlet temperature reaches 44 degree C. The model results are analyzed and discussed. The temperature profiles of fuel, clad and coolant are predicted during transient where its maximum values are far from thermal hydraulic limits.

  2. Mathematical modeling of photovoltaic thermal PV/T system with v-groove collector

    Science.gov (United States)

    Zohri, M.; Fudholi, A.; Ruslan, M. H.; Sopian, K.

    2017-07-01

    The use of v-groove in solar collector has a higher thermal efficiency in references. Dropping the working heat of photovoltaic panel was able to raise the electrical efficiency performance. Electrical and thermal efficiency were produced by photovoltaic thermal (PV/T) system concurrently. Mathematical modeling based on steady-state thermal analysis of PV/T system with v-groove was conducted. With matrix inversion method, the energy balance equations are explained by means of the investigative method. The comparison results show that in the PV/T system with the V-groove collector is higher temperature, thermal and electrical efficiency than other collectors.

  3. Analysis of piping response to thermal and operational transients

    International Nuclear Information System (INIS)

    Wang, C.Y.

    1987-01-01

    The reactor piping system is an extremely complex three-dimensional structure. Maintaining its structural integrity is essential to the safe operation of the reactor and the steam-supply system. In the safety analysis, various transient loads can be imposed on the piping which may cause plastic deformation and possible damage to the system, including those generated from hydrodynamic wave propagations, thermal and operational transients, as well as the seismic events. At Argonne National Laboratory (ANL), a three-dimensional (3-D) piping code, SHAPS, aimed for short-duration transients due to wave propagation, has been developed. Since 1984, the development work has been shifted to the long-duration accidents originating from the thermal and operational transient. As a result, a new version of the code, SHAPS-2, is being established. This paper describes many features related to this later development. To analyze piping response generated from thermal and operational transients, a 3-D implicit finite element algorithm has been developed for calculating the hoop, flexural, axial, and torsional deformations induced by the thermomechanical loads. The analysis appropriately accounts for stresses arising from the temperature dependence of the elastic material properties, the thermal expansion of the materials, and the changes in the temperature-dependent yield surface. Thermal softening, failure, strain rate, creep, and stress ratching can also be considered

  4. Thermal analysis of annular fins with temperature-dependent thermal properties

    Institute of Scientific and Technical Information of China (English)

    I. G. AKSOY

    2013-01-01

    The thermal analysis of the annular rectangular profile fins with variable thermal properties is investigated by using the homotopy analysis method (HAM). The thermal conductivity and heat transfer coefficient are assumed to vary with a linear and power-law function of temperature, respectively. The effects of the thermal-geometric fin parameter and the thermal conductivity parameter variations on the temperature distribution and fin efficiency are investigated for different heat transfer modes. Results from the HAM are compared with numerical results of the finite difference method (FDM). It can be seen that the variation of dimensionless parameters has a significant effect on the temperature distribution and fin efficiency.

  5. Modeling thermal effects in braking systems of railway vehicles

    Directory of Open Access Journals (Sweden)

    Milošević Miloš S.

    2012-01-01

    Full Text Available The modeling of thermal effects has become increasingly important in product design in different transport means, road vehicles, airplanes, railway vehicles, and so forth. The thermal analysis is a very important stage in the study of braking systems, especially of railway vehicles, where it is necessary to brake huge masses, because the thermal load of a braked railway wheel prevails compared to other types of loads. In the braking phase, kinetic energy transforms into thermal energy resulting in intense heating and high temperature states of railway wheels. Thus induced thermal loads determine thermomechanical behavior of the structure of railway wheels. In cases of thermal overloads, which mainly occur as a result of long-term braking on down-grade railroads, the generation of stresses and deformations occurs, whose consequences are the appearance of cracks on the rim of a wheel and the final total wheel defect. The importance to precisely determine the temperature distribution caused by the transfer process of the heat generated during braking due to the friction on contact surfaces of the braking system makes it a challenging research task. Therefore, the thermal analysis of a block-braked solid railway wheel of a 444 class locomotive of the national railway operator Serbian Railways is processed in detail in this paper, using analytical and numerical modeling of thermal effects during long-term braking for maintaining a constant speed on a down-grade railroad.

  6. Dynamic thermal analysis of a concentrated photovoltaic system

    Science.gov (United States)

    Avrett, John T., II; Cain, Stephen C.; Pochet, Michael

    2012-02-01

    Concentrated photovoltaic (PV) technology represents a growing market in the field of terrestrial solar energy production. As the demand for renewable energy technologies increases, further importance is placed upon the modeling, design, and simulation of these systems. Given the U.S. Air Force cultural shift towards energy awareness and conservation, several concentrated PV systems have been installed on Air Force installations across the country. However, there has been a dearth of research within the Air Force devoted to understanding these systems in order to possibly improve the existing technologies. This research presents a new model for a simple concentrated PV system. This model accurately determines the steady state operating temperature as a function of the concentration factor for the optical part of the concentrated PV system, in order to calculate the optimum concentration that maximizes power output and efficiency. The dynamic thermal model derived is validated experimentally using a commercial polysilicon solar cell, and is shown to accurately predict the steady state temperature and ideal concentration factor.

  7. Solar radiation transfer and performance analysis of an optimum photovoltaic/thermal system

    International Nuclear Information System (INIS)

    Zhao Jiafei; Song Yongchen; Lam, Wei-Haur; Liu Weiguo; Liu Yu; Zhang Yi; Wang DaYong

    2011-01-01

    This paper presents the design optimization of a photovoltaic/thermal (PV/T) system using both non-concentrated and concentrated solar radiation. The system consists of a photovoltaic (PV) module using silicon solar cell and a thermal unit based on the direct absorption collector (DAC) concept. First, the working fluid of the thermal unit absorbs the solar infrared radiation. Then, the remaining visible light is transmitted and converted into electricity by the solar cell. This arrangement prevents excessive heating of the solar cell which would otherwise negatively affects its electrical efficiency. The optical properties of the working fluid were modeled based on the damped oscillator Lorentz-Drude model satisfying the Kramers-Kroenig relations. The coefficients of the model were retrieved by inverse method based on genetic algorithm, in order to (i) maximize transmission of solar radiation between 200 nm and 800 nm and (ii) maximize absorption in the infrared part of the spectrum from 800 nm to 2000 nm. The results indicate that the optimum system can effectively and separately use the visible and infrared part of solar radiation. The thermal unit absorbs 89% of the infrared radiation for photothermal conversion and transmits 84% of visible light to the solar cell for photoelectric conversion. When reducing the mass flow rate, the outflow temperature of the working fluid reaches 74 o C, the temperature of the PV module remains around 31 o C at a constant electrical efficiency about 9.6%. Furthermore, when the incident solar irradiance increases from 800 W/m 2 to 8000 W/m 2 , the system generates 196 o C working fluid with constant thermal efficiency around 40%, and the exergetic efficiency increases from 12% to 22%.

  8. Methods of forming thermal management systems and thermal management methods

    Science.gov (United States)

    Gering, Kevin L.; Haefner, Daryl R.

    2012-06-05

    A thermal management system for a vehicle includes a heat exchanger having a thermal energy storage material provided therein, a first coolant loop thermally coupled to an electrochemical storage device located within the first coolant loop and to the heat exchanger, and a second coolant loop thermally coupled to the heat exchanger. The first and second coolant loops are configured to carry distinct thermal energy transfer media. The thermal management system also includes an interface configured to facilitate transfer of heat generated by an internal combustion engine to the heat exchanger via the second coolant loop in order to selectively deliver the heat to the electrochemical storage device. Thermal management methods are also provided.

  9. Lead-Bismuth Eutectic cooled experimental Accelerator Driven System. Windowless target unit thermal-hydraulic analysis

    International Nuclear Information System (INIS)

    Bianchi, F.; Ferri, R.; Moreau, V.

    2004-01-01

    A main concern related to the peaceful use of nuclear energy is the safe management of nuclear wastes, with particular attention to long-lived fission products. An increasing attention has recently been addressed to transmutation systems (Accelerator Driven System: ADS) able to 'burn' the actinides and some of the long-lived fission products (High-Level Waste: HLW), transforming them in short or medium-lived wastes that may be easier managed and stored in the geological disposal, with the consequent easier acceptability by population. An ADS consists of a subcritical-core coupled with an accelerator by means of a target. This paper deals with the thermal-hydraulic analysis, performed with STAR-CD and RELAP5 codes for the windowless target unit of Lead-Bismuth Eutectic (LBE) cooled experimental ADS (XADS), both to assess its behaviour during operational and accident sequences and to provide input data for the thermal-mechanical analyses. It also reports a description of modifications properly implemented in the codes used for the assessment of this kind of plants. (author)

  10. Thermal management evaluation of the complex electro-optical system

    Directory of Open Access Journals (Sweden)

    Nijemčević Srećko S.

    2017-01-01

    Full Text Available The thermal management of a complex electro-optical system aimed for outdoor application is challenging task due to the requirement of having an air-sealed enclosure, harsh working environment, and an additional thermal load generated by sunlight. It is essential to consider the effect of heating loads in the system components, as well as the internal temperature distribution, that can have influence on the system life expectancy, operational readiness and parameters, and possibility for catastrophic failure. The main objective of this paper is to analyze internal temperature distribution and evaluate its influence on system component operation capability. The electro-optical system simplified model was defined and related thermal balance simulation model based on Solid Works thermal analysis module was set and applied for temperature distribution calculation. Various outdoor environment scenarios were compared to evaluate system temperature distribution and evaluate its influence on system operation, reliability, and life time in application environment. This work was done during the design process as a part of the electro-optical system optimization. The results show that temperature distribution will not be cause for catastrophic failure and malfunction operation during operation in the expected environment.

  11. Study on development of virtual reactor core laboratory (1). Development of prototype coupled neutronic, thermal-hydraulic and structural analysis system

    International Nuclear Information System (INIS)

    Uto, Nariaki; Sugaya, Toshio; Tsukimori, Kazuyuki; Negishi, Hitoshi; Enuma, Yasuhiro; Sakai, Takaaki

    1999-09-01

    A study on development of virtual reactor core laboratory, which is to conduct numerical experiments representative of complicated physical phenomena in practical reactor core systems on a computational environment, has progressed at Japan Nuclear Cycle Development Institute (JNC). The study aims at systematic evaluation of these phenomena into which nuclear reactions, thermal-hydraulic characteristics, structural responses and fuel behaviors combine, and effective utilization of the obtained comprehension for core design. This report presents a production of a prototype computational system which is required to construct the virtual reactor core laboratory. This system is to evaluate reactor core performance under the coupled neutronic, thermal-hydraulic and structural phenomena, and is composed of two analysis tools connected by a newly developed interface program; 1) an existing space-dependent coupled neutronic and thermal-hydraulic analysis system arranged at JNC and 2) a core deformation analysis code. It acts on a cluster of several DEC/Alpha workstations. A specific library called MPI1 (Message Passing Interface 1) is incorporated as a tool for communicating among the analysis modules consisting of the system. A series of calculations for simulating a sequence of Unprotected Loss Of Heat Sink (ULOHS) coupled with rapid drop of some neutron absorber devices in a prototype fast reactor is tried to investigate how the system works. The obtained results show the core deformation behavior followed by the reactivity change that can be properly evaluated. The results of this report show that the system is expected to be useful for analyzing sensitivity of reactor core performance with respect to uncertainties of various design parameters and establishing a concept of passive safety reactor system, taking into account space distortion of neutron flux distribution during abnormal events as well as reactivity feedback from core deformation. (author)

  12. Thermal energy storage devices, systems, and thermal energy storage device monitoring methods

    Science.gov (United States)

    Tugurlan, Maria; Tuffner, Francis K; Chassin, David P.

    2016-09-13

    Thermal energy storage devices, systems, and thermal energy storage device monitoring methods are described. According to one aspect, a thermal energy storage device includes a reservoir configured to hold a thermal energy storage medium, a temperature control system configured to adjust a temperature of the thermal energy storage medium, and a state observation system configured to provide information regarding an energy state of the thermal energy storage device at a plurality of different moments in time.

  13. Development of thermal fatigue evaluation methods of piping systems

    International Nuclear Information System (INIS)

    Kasahara, Naoto; Itoh, Takamoto; Okazaki, Masakazu; Okuda, Yukihiko; Kamaya, Masayuki; Nakamura, Akira; Nakamura, Hitoshi; Machida, Hideo; Matsumoto, Masaaki

    2013-01-01

    Nuclear piping has various kinds of thermal fatigue failure modes. Main causes of thermal loads are structural responses to fluid temperature changes during plant operation. These phenomena have complex mechanisms and so many patterns, that their problems still occur even though well-known issues. To prevent thermal fatigue due to above thermal loads, the JSME guideline is adopted. Both thermal load and fatigue failure mechanism have been investigated and summarized into the knowledgebase. Based on above knowledge, improved methods for the JSME guideline and Numerical simulation methods for thermal fatigue evaluation were studied. Furthermore, probabilistic failure analysis approach with main influence parameters were investigated to be applied for the plant system safety. (author)

  14. Thermal Analysis of the MC-1 Chamber/Nozzle

    Science.gov (United States)

    Davis, Darrell W.; Phelps, Lisa H. (Technical Monitor)

    2001-01-01

    This paper will describe the thermal analysis techniques used to predict temperatures in the film-cooled ablative rocket nozzle used on the MC-1 60K rocket engine. A model was developed that predicts char and pyrolysis depths, liner thermal gradients, and temperatures of the bondline between the overwrap and liner. Correlation of the model was accomplished by thermal analog tests performed at Southern Research, and specially instrumented hot fire tests at the Marshall Space Flight Center. Infrared thermography was instrumental in defining nozzle hot wall surface temperatures. In-depth and outboard thermocouple data was used to correlate the kinetic decomposition routine used to predict char and pyrolysis depths. These depths were anchored with measured char and pyrolysis depths from cross-sectioned hot-fire nozzles. For the X-34 flight analysis, the model includes the ablative Thermal Protection System (TPS) material that protects the overwrap from the recirculating plume. Results from model correlation, hot-fire testing, and flight predictions will be discussed.

  15. Apollo telescope mount thermal systems unit thermal vacuum test

    Science.gov (United States)

    Trucks, H. F.; Hueter, U.; Wise, J. H.; Bachtel, F. D.

    1971-01-01

    The Apollo Telescope Mount's thermal systems unit was utilized to conduct a full-scale thermal vacuum test to verify the thermal design and the analytical techniques used to develop the thermal mathematical models. Thermal vacuum test philosophy, test objectives configuration, test monitoring, environment simulation, vehicle test performance, and data correlation are discussed. Emphasis is placed on planning and execution of the thermal vacuum test with particular attention on problems encountered in conducting a test of this maguitude.

  16. Transient Thermal Analyses of Passive Systems on SCEPTOR X-57

    Science.gov (United States)

    Chin, Jeffrey C.; Schnulo, Sydney L.; Smith, Andrew D.

    2017-01-01

    As efficiency, emissions, and noise become increasingly prominent considerations in aircraft design, turning to an electric propulsion system is a desirable solution. Achieving the intended benefits of distributed electric propulsion (DEP) requires thermally demanding high power systems, presenting a different set of challenges compared to traditional aircraft propulsion. The embedded nature of these heat sources often preclude the use of traditional thermal management systems in order to maximize performance, with less opportunity to exhaust waste heat to the surrounding environment. This paper summarizes the thermal analyses of X-57 vehicle subsystems that don't employ externally air-cooled heat sinks. The high-power battery, wires, high-lift motors, and aircraft outer surface are subjected to heat loads with stringent thermal constraints. The temperature of these components are tracked transiently, since they never reach a steady-state equilibrium. Through analysis and testing, this report demonstrates that properly characterizing the material properties is key to accurately modeling peak temperature of these systems, with less concern for spatial thermal gradients. Experimentally validated results show the thermal profile of these systems can be sufficiently estimated using reduced order approximations.

  17. Optimization of thermal systems based on finite-time thermodynamics and thermoeconomics

    Energy Technology Data Exchange (ETDEWEB)

    Durmayaz, A. [Istanbul Technical University (Turkey). Department of Mechanical Engineering; Sogut, O.S. [Istanbul Technical University, Maslak (Turkey). Department of Naval Architecture and Ocean Engineering; Sahin, B. [Yildiz Technical University, Besiktas, Istanbul (Turkey). Department of Naval Architecture; Yavuz, H. [Istanbul Technical University, Maslak (Turkey). Institute of Energy

    2004-07-01

    The irreversibilities originating from finite-time and finite-size constraints are important in the real thermal system optimization. Since classical thermodynamic analysis based on thermodynamic equilibrium do not consider these constraints directly, it is necessary to consider the energy transfer between the system and its surroundings in the rate form. Finite-time thermodynamics provides a fundamental starting point for the optimization of real thermal systems including the fundamental concepts of heat transfer and fluid mechanics to classical thermodynamics. In this study, optimization studies of thermal systems, that consider various objective functions, based on finite-time thermodynamics and thermoeconomics are reviewed. (author)

  18. Geant4 Analysis of a Thermal Neutron Real-Time Imaging System

    Science.gov (United States)

    Datta, Arka; Hawari, Ayman I.

    2017-07-01

    Thermal neutron imaging is a technique for nondestructive testing providing complementary information to X-ray imaging for a wide range of applications in science and engineering. Advancement of electronic imaging systems makes it possible to obtain neutron radiographs in real time. This method requires a scintillator to convert neutrons to optical photons and a charge-coupled device (CCD) camera to detect those photons. Alongside, a well collimated beam which reduces geometrical blurriness, the use of a thin scintillator can improve the spatial resolution significantly. A representative scintillator that has been applied widely for thermal neutron imaging is 6LiF:ZnS (Ag). In this paper, a multiphysics simulation approach for designing thermal neutron imaging system is investigated. The Geant4 code is used to investigate the performance of a thermal neutron imaging system starting with a neutron source and including the production of charged particles and optical photons in the scintillator and their transport for image formation in the detector. The simulation geometry includes the neutron beam collimator and sapphire filter. The 6LiF:ZnS (Ag) scintillator is modeled along with a pixelated detector for image recording. The spatial resolution of the system was obtained as the thickness of the scintillator screen was varied between 50 and 400 μm. The results of the simulation were compared to experimental results, including measurements performed using the PULSTAR nuclear reactor imaging beam, showing good agreement. Using the established model, further examination showed that the resolution contribution of the scintillator screen is correlated with its thickness and the range of the neutron absorption reaction products (i.e., the alpha and triton particles). Consequently, thinner screens exhibit improved spatial resolution. However, this will compromise detection efficiency due to the reduced probability of neutron absorption.

  19. Thermal analysis of hybrid single-phase, two-phase and heat pump thermal control system (TCS) for future spacecraft

    International Nuclear Information System (INIS)

    Lee, S.H.; Mudawar, I.; Hasan, Mohammad M.

    2016-01-01

    Highlights: • Hybrid Thermal Control System (H-TCS) is proposed for future spacecraft. • Thermodynamic performance of H-TCS is examined for different space missions. • Operational modes including single-phase, two-phase and heat pump are explored. • R134a is deemed most appropriate working fluid. - Abstract: An urgent need presently exists to develop a new class of versatile spacecraft capable of conducting different types of missions and enduring varying gravitational and temperature environments, including Lunar, Martian and Near Earth Object (NEOs). This study concerns the spacecraft's Thermal Control System (TCS), which tackles heat acquisition, especially from crew and avionics, heat transport, and ultimate heat rejection by radiation. The primary goal of the study is to explore the design and thermal performance of a Hybrid Thermal Control System (H-TCS) that would satisfy the diverse thermal requirements of the different space missions. The H-TCS must endure both ‘cold’ and ‘hot’ environments, reduce weight and size, and enhance thermodynamic performance. Four different operational modes are considered: single-phase, two-phase, basic heat pump and heat pump with liquid-side, suction-side heat exchanger. A thermodynamic trade study is conducted for six different working fluids to assess important performance parameters including mass flow rate of the working fluid, maximum pressure, radiator area, compressor/pump work, and coefficient of performance (COP). R134a is determined to be most suitable based on its ability to provide a balanced compromise between reducing flow rate and maintaining low system pressure, and a moderate coefficient of performance (COP); this fluid is also both nontoxic and nonflammable, and features zero ozone depletion potential (ODP) and low global warming potential (GWP). It is shown how specific mission stages dictate which mode of operation is most suitable, and this information is used to size the radiator for the

  20. Development of thermal fatigue evaluation methods of piping systems

    International Nuclear Information System (INIS)

    Kasahara, Naoto; Itoh, Takamoto; Okazaki, Masakazu; Okuda, Yukihiko; Kamaya, Masayuki; Nakamura, Akira; Nakamura, Hitoshi; Machida, Hideo; Matsumoto, Masaaki

    2014-01-01

    Nuclear piping has various kinds of thermal fatigue failure modes. Main causes of thermal loads are structural responses to fluid temperature changes during plant operation. These phenomena have complex mechanisms and many patterns, so that their problems still occur in spite of well-known issues. The guideline of the JSME (Japan Society of Mechanical Engineering) for estimation of thermal fatigue failures in piping system is employed as Japanese regulation. To improve this guideline, generation mechanisms of thermal load and fatigue failure have been investigated and summarized into the knowledgebase. And numerical simulation methods to replace experimental based methods were studied. Furthermore, probabilistic failure analysis approach with main influence parameters was investigated to be applied for the plant system safety. Thus, based on the knowledge, estimation methods revised from the JSME guideline were proposed. (author)

  1. Review of the integrated thermal and nonthermal treatment system studies

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-08-01

    This report contains a review and evaluation of three systems analysis studies performed by LITCO on integrated thermal treatment systems and integrated nonthermal treatment systems for the remediation of mixed low-level waste stored throughout the US Department of Energy weapons complex. The review was performed by an independent team of nine researchers from the Energy and Environmental Research Center, Science Applications International Corporation, the Waste Policy Institute, and Virginia Tech. The three studies reviewed were as follows: Integrated Thermal Treatment System Study, Phase 1--issued July 1994; Integrated Thermal Treatment System Study, Phase 2--issued February 1996; and Integrated Nonthermal Treatment System Study--drafted March 1996. The purpose of this review was to (1) determine whether the assumptions of the studies were adequate to produce an unbiased review of both thermal and nonthermal systems, (2) to identify the critical areas of the studies that would benefit from further investigation, and (3) to develop a standard template that could be used in future studies to assure a sound application of systems engineering.

  2. Review of the integrated thermal and nonthermal treatment system studies

    International Nuclear Information System (INIS)

    1996-08-01

    This report contains a review and evaluation of three systems analysis studies performed by LITCO on integrated thermal treatment systems and integrated nonthermal treatment systems for the remediation of mixed low-level waste stored throughout the US Department of Energy weapons complex. The review was performed by an independent team of nine researchers from the Energy and Environmental Research Center, Science Applications International Corporation, the Waste Policy Institute, and Virginia Tech. The three studies reviewed were as follows: Integrated Thermal Treatment System Study, Phase 1--issued July 1994; Integrated Thermal Treatment System Study, Phase 2--issued February 1996; and Integrated Nonthermal Treatment System Study--drafted March 1996. The purpose of this review was to (1) determine whether the assumptions of the studies were adequate to produce an unbiased review of both thermal and nonthermal systems, (2) to identify the critical areas of the studies that would benefit from further investigation, and (3) to develop a standard template that could be used in future studies to assure a sound application of systems engineering

  3. Comparative exergetic performance analysis for certain thermal power plants in Serbia

    Directory of Open Access Journals (Sweden)

    Mitrović Dejan M.

    2016-01-01

    Full Text Available Traditional methods of analysis and calculation of complex thermal systems are based on the first law of thermodynamics. These methods use energy balance for a system. In general, energy balances do not provide any information about internal losses. In contrast, the second law of thermodynamics introduces the concept of exergy, which is useful in the analysis of thermal systems. Exergy is a measure for assessing the quality of energy, and allows one to determine the location, cause, and real size of losses incurred as well as residues in a thermal process. The purpose of this study is to comparatively analyze the performance of four thermal power plants from the energetic and exergetic viewpoint. Thermodynamic models of the plants are developed based on the first and second law of thermodynamics. The primary objectives of this paper are to analyze the system components separately and to identify and quantify the sites having largest energy and exergy losses. Finally, by means of these analyses, the main sources of thermodynamic inefficiencies as well as a reasonable comparison of each plant to others are identified and discussed. As a result, the outcomes of this study can provide a basis for the improvement of plant performance for the considered thermal power plants.

  4. Lead coolant test facility systems design, thermal hydraulic analysis and cost estimate

    Energy Technology Data Exchange (ETDEWEB)

    Khericha, Soli, E-mail: slk2@inel.gov [Battelle Energy Alliance, LLC, Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Harvego, Edwin; Svoboda, John; Evans, Robert [Battelle Energy Alliance, LLC, Idaho National Laboratory, Idaho Falls, ID 83415 (United States); Dalling, Ryan [ExxonMobil Gas and Power Marketing, Houston, TX 77069 (United States)

    2012-01-15

    The Idaho National Laboratory prepared a preliminary technical and functional requirements (T and FR), thermal hydraulic design and cost estimate for a lead coolant test facility. The purpose of this small scale facility is to simulate lead coolant fast reactor (LFR) coolant flow in an open lattice geometry core using seven electrical rods and liquid lead or lead-bismuth eutectic coolant. Based on review of current world lead or lead-bismuth test facilities and research needs listed in the Generation IV Roadmap, five broad areas of requirements were identified as listed below: Bullet Develop and demonstrate feasibility of submerged heat exchanger. Bullet Develop and demonstrate open-lattice flow in electrically heated core. Bullet Develop and demonstrate chemistry control. Bullet Demonstrate safe operation. Bullet Provision for future testing. This paper discusses the preliminary design of systems, thermal hydraulic analysis, and simplified cost estimated. The facility thermal hydraulic design is based on the maximum simulated core power using seven electrical heater rods of 420 kW; average linear heat generation rate of 300 W/cm. The core inlet temperature for liquid lead or Pb/Bi eutectic is 4200 Degree-Sign C. The design includes approximately seventy-five data measurements such as pressure, temperature, and flow rates. The preliminary estimated cost of construction of the facility is $3.7M (in 2006 $). It is also estimated that the facility will require two years to be constructed and ready for operation.

  5. Thermal Analysis of the Divertor Primary Heat Transfer System Piping During the Gas Baking Process

    International Nuclear Information System (INIS)

    Yoder, Graydon L. Jr.; Harvey, Karen; Ferrada, Juan J.

    2011-01-01

    A preliminary analysis has been performed examining the temperature distribution in the Divertor Primary Heat Transfer System (PHTS) piping and the divertor itself during the gas baking process. During gas baking, it is required that the divertor reach a temperature of 350 C. Thermal losses in the piping and from the divertor itself require that the gas supply temperature be maintained above that temperature in order to ensure that all of the divertor components reach the required temperature. The analysis described in this report was conducted in order to estimate the required supply temperature from the gas heater.

  6. Analysis of the thermal balance characteristics for multiple-connected piezoelectric transformers.

    Science.gov (United States)

    Park, Joung-Hu; Cho, Bo-Hyung; Choi, Sung-Jin; Lee, Sang-Min

    2009-08-01

    Because the amount of power that a piezoelectric transformer (PT) can handle is limited, multiple connections of PTs are necessary for the power-capacity improvement of PT-applications. In the connection, thermal imbalance between the PTs should be prevented to avoid the thermal runaway of each PT. The thermal balance of the multiple-connected PTs is dominantly affected by the electrothermal characteristics of individual PTs. In this paper, the thermal balance of both parallel-parallel and parallel-series connections are analyzed by electrical model parameters. For quantitative analysis, the thermal-balance effects are estimated by the simulation of the mechanical loss ratio between the PTs. The analysis results show that with PTs of similar characteristics, the parallel-series connection has better thermal balance characteristics due to the reduced mechanical loss of the higher temperature PT. For experimental verification of the analysis, a hardware-prototype test of a Cs-Lp type 40 W adapter system with radial-vibration mode PTs has been performed.

  7. Thermal modeling of a hydraulic hybrid vehicle transmission based on thermodynamic analysis

    International Nuclear Information System (INIS)

    Kwon, Hyukjoon; Sprengel, Michael; Ivantysynova, Monika

    2016-01-01

    Hybrid vehicles have become a popular alternative to conventional powertrain architectures by offering improved fuel efficiency along with a range of environmental benefits. Hydraulic Hybrid Vehicles (HHV) offer one approach to hybridization with many benefits over competing technologies. Among these benefits are lower component costs, more environmentally friendly construction materials, and the ability to recover a greater quantity of energy during regenerative braking which make HHVs partially well suited to urban environments. In order to further the knowledge base regarding HHVs, this paper explores the thermodynamic characteristics of such a system. A system model is detailed for both the hydraulic and thermal components of a closed circuit hydraulic hybrid transmission following the FTP-72 driving cycle. Among the new techniques proposed in this paper is a novel method for capturing rapid thermal transients. This paper concludes by comparing the results of this model with experimental data gathered on a Hardware-in-the-Loop (HIL) transmission dynamometer possessing the same architecture, components, and driving cycle used within the simulation model. This approach can be used for several applications such as thermal stability analysis of HHVs, optimal thermal management, and analysis of the system's thermodynamic efficiency. - Highlights: • Thermal modeling for HHVs is introduced. • A model for the hydraulic and thermal system is developed for HHVs. • A novel method for capturing rapid thermal transients is proposed. • The thermodynamic system diagram of a series HHV is predicted.

  8. FY 93 thermal loading systems study final report: Volume 1. Revision 1

    International Nuclear Information System (INIS)

    Saterlie, S.F.; Thomson, B.H.

    1994-01-01

    The ability to meet the overall performance requirements for the proposed Mined Geology Disposal System at Yucca Mountain, Nevada requires the two major subsystem (natural barriers and engineered barriers) to positively contribute to containment and radionuclide isolation. In addition to the postclosure performance the proposed repository must meet preclosure requirements of safety, retrievability, and operability. Cost and schedule were also considered. The thermal loading strategy chosen may significantly affect both the postclosure and preclosure performance of the proposed repository. Although the current Site Characterization Plan reference case is 57 kilowatts (kW)/acre, other thermal loading strategies (different areal mass loadings) have been proposed which possess both advantages and disadvantages. The objectives of the FY 1993 Thermal Loading Study were to (1) place bounds on the thermal loading which would establish the loading regime that is ''too hot'' and the loading regime that is ''too cold'', to (2) ''grade'' or evaluate the performance, as a function of thermal loading, of the repository to contain high level wastes against performance criteria and to (3) evaluate the performance of the various options with respect to cost, safety, and operability. Additionally, the effort was to (4) identify important uncertainties that need to be resolved by tests and/or analyses in order to complete a performance assessment on the effects of thermal loading. The FY 1993 Thermal Loading Study was conducted from December 1, 1992 to December 30, 1993 and this final report provides the findings of the study. Volume 1 contains the Introduction; Performance requirements; Input and assumptions; Near-field thermal analysis; Far-field thermal analysis; Cost analysis; Other considerations; System analysis; Additional thermal analysis; and Conclusions and recommendations. 71 refs., 54 figs

  9. Application of Thermal Network Model to Transient Thermal Analysis of Power Electronic Package Substrate

    Directory of Open Access Journals (Sweden)

    Masaru Ishizuka

    2011-01-01

    Full Text Available In recent years, there is a growing demand to have smaller and lighter electronic circuits which have greater complexity, multifunctionality, and reliability. High-density multichip packaging technology has been used in order to meet these requirements. The higher the density scale is, the larger the power dissipation per unit area becomes. Therefore, in the designing process, it has become very important to carry out the thermal analysis. However, the heat transport model in multichip modules is very complex, and its treatment is tedious and time consuming. This paper describes an application of the thermal network method to the transient thermal analysis of multichip modules and proposes a simple model for the thermal analysis of multichip modules as a preliminary thermal design tool. On the basis of the result of transient thermal analysis, the validity of the thermal network method and the simple thermal analysis model is confirmed.

  10. Temperature Distribution and Thermal Performance of an Aquifer Thermal Energy Storage System

    Science.gov (United States)

    Ganguly, Sayantan

    2017-04-01

    Energy conservation and storage has become very crucial to make use of excess energy during times of future demand. Excess thermal energy can be captured and stored in aquifers and this technique is termed as Aquifer Thermal Energy Storage (ATES). Storing seasonal thermal energy in water by injecting it into subsurface and extracting in time of demand is the principle of an ATES system. Using ATES systems leads to energy savings, reduces the dependency on fossil fuels and thus leads to reduction in greenhouse gas emission. This study numerically models an ATES system to store seasonal thermal energy and evaluates the performance of it. A 3D thermo-hydrogeological numerical model for a confined ATES system is presented in this study. The model includes heat transport processes of advection, conduction and heat loss to confining rock media. The model also takes into account regional groundwater flow in the aquifer, geothermal gradient and anisotropy in the aquifer. Results show that thermal injection into the aquifer results in the generation of a thermal-front which grows in size with time. Premature thermal-breakthrough causes thermal interference in the system when the thermal-front reaches the production well and consequences in the fall of system performance and hence should be avoided. This study models the transient temperature distribution in the aquifer for different flow and geological conditions. This may be effectively used in designing an efficient ATES project by ensuring safety from thermal-breakthrough while catering to the energy demand. Based on the model results a safe well spacing is proposed. The thermal energy discharged by the system is determined and strategy to avoid the premature thermal-breakthrough in critical cases is discussed. The present numerical model is applied to simulate an experimental field study which is found to approximate the field results quite well.

  11. Nondestructive elemental analysis of coins using accelerator-based thermal neutrons

    International Nuclear Information System (INIS)

    Khairi, F.Z.; Aksoy, A.; Al-Haddad, M.N.

    2007-01-01

    The accelerator-based thermal-neutrons activation analysis setup at KFUPM has an adequate thermal -neutron flux that can be advantageously used for the elemental analysis of a variety of samples including archeological ones. The thermal neutrons are derived from the moderation of fast neutrons from the D (d, n) He reaction which produces fast 2.5 MeV neutrons. A maximum thermals flux of about 2.5x10 n/m-s was achieved. For the purpose of determining the suitability of the set up for the analysis of contemporary and ancient coins, we carried out a feasibility study by irradiating a selected number of Saudi Arabian coins dating from 1958 to 1987 in the thermal-neutron flux. The induced gamma-ray activities were then counted using a HP-GMX detector coupled to a PC-based data acquisition and analysis system. The elements that were determined in the coins were copper (75%), nickel (around 25%) and manganese (<0.5%). Calibration curves were also established for these elements. The determined concentrations are in agreement with the data published by the Standard Catalogue of World Coins. (author)

  12. The analysis of thermal network of district heating system from investor point of view

    Science.gov (United States)

    Takács, Ján; Rácz, Lukáš

    2016-06-01

    The hydraulics of a thermal network of a district heating system is a very important issue, to which not enough attention is often paid. In this paper the authors want to point out some of the important aspects of the design and operation of thermal networks in district heating systems. The design boundary conditions of a heat distribution network and the requirements on active pressure - circulation pump - influencing the operation costs of the centralized district heating system as a whole, are analyzed in detail. The heat generators and the heat exchange stations are designed according to the design heat loads after thermal insulation, and modern boiler units are installed in the heating plant.

  13. Utilizing primary energy savings and exergy destruction to compare centralized thermal plants and cogeneration/trigeneration systems

    International Nuclear Information System (INIS)

    Espirito Santo, Denilson Boschiero do; Gallo, Waldyr Luiz Ribeiro

    2017-01-01

    Rising energy conversion processes efficiencies reduces CO_2 emissions and global warming implications. Decentralized electricity production through cogeneration/trigeneration systems can save primary energy if it operates with high efficiency. High efficiency is obtained when the system produces electricity and a substantial amount of the energy rejected by the prime mover is used to meet site thermal demands. Environmental concerns and international agreements are directing governments of different countries to incentive high efficiency solutions. Centralized thermal plants and cogeneration/trigeneration efficiency are compared through efficiency indicators using the first law of thermodynamics and the second law of thermodynamics. This paper proposes the use of the primary energy savings analysis and the exergy destruction analysis to compare decentralized power production through cogeneration/trigeneration systems and centralized thermal plants. The analysis concluded that both methods achieve the same results if the thermal efficiency indicator is used to compare the methods. The analysis also revealed that trigeneration systems with the same energy input are comparable with quite different thermal efficiency centralized thermal plants. Case 1 is comparable to a 53% thermal efficiency power plant and case 2 is comparable to a 77% thermal efficiency power plant. - Highlights: • Trigeneration and thermal plants are compared using PES and exergy destruction. • The thermal efficiency indicator is used to compare both methods. • The same equivalent thermal efficiency is achieved by both methods. • Same energy input trigeneration is similar to different thermal efficiency plants. • Evaluated trigeneration are comparable to a 53–77% thermal efficiency power plant.

  14. Analysis of dynamic effects in solar thermal energy conversion systems

    Science.gov (United States)

    Hamilton, C. L.

    1978-01-01

    The paper examines a study the purpose of which is to assess the performance of solar thermal power systems insofar as it depends on the dynamic character of system components and the solar radiation which drives them. Using a dynamic model, the daily operation of two conceptual solar conversion systems was simulated under varying operating strategies and several different time-dependent radiation intensity functions. These curves ranged from smoothly varying input of several magnitudes to input of constant total energy whose intensity oscillated with periods from 1/4 hour to 6 hours.

  15. Simulation-based optimization of thermal systems

    International Nuclear Information System (INIS)

    Jaluria, Yogesh

    2009-01-01

    This paper considers the design and optimization of thermal systems on the basis of the mathematical and numerical modeling of the system. Many complexities are often encountered in practical thermal processes and systems, making the modeling challenging and involved. These include property variations, complicated regions, combined transport mechanisms, chemical reactions, and intricate boundary conditions. The paper briefly presents approaches that may be used to accurately simulate these systems. Validation of the numerical model is a particularly critical aspect and is discussed. It is important to couple the modeling with the system performance, design, control and optimization. This aspect, which has often been ignored in the literature, is considered in this paper. Design of thermal systems based on concurrent simulation and experimentation is also discussed in terms of dynamic data-driven optimization methods. Optimization of the system and of the operating conditions is needed to minimize costs and improve product quality and system performance. Different optimization strategies that are currently used for thermal systems are outlined, focusing on new and emerging strategies. Of particular interest is multi-objective optimization, since most thermal systems involve several important objective functions, such as heat transfer rate and pressure in electronic cooling systems. A few practical thermal systems are considered in greater detail to illustrate these approaches and to present typical simulation, design and optimization results

  16. RAMONA-3B/MINET composite representation of BWR thermal-hydraulic systems

    International Nuclear Information System (INIS)

    Van Tuyle, G.J.; Slovik, G.; Cazzoli, E.G.; Nepsee, T.C.; Guppy, J.G.

    1985-01-01

    The modification and interfacing of two computer codes, RAMONA-3B and MINET, for the thermal hydraulic transient analysis of a Boiling Water Reactor nuclear steam supply system, is described. The RAMONA-3B code provides for multi-channel thermal hydraulics and three-dimensional (or one-dimensional) neutron kinetics analysis of a boiling water reactor core. The RAMONA-3B system representation terminates at the end of the steam line and at the junction of the feedwater line at the vessel inlet. By interfacing RAMONA-3B with MINET, a generic balance-of-plant systems analysis code, a complete BWR systems code with detailed core modeling was obtained. The result is a code of particular importance to the analysis of transients such as ATWS. A comparison between the 3-D and 1-D neutronics representation is provided, along with a test case utilizing the composite RAMONA-3B/MINET code

  17. Computational Analysis of Nanoparticles-Molten Salt Thermal Energy Storage for Concentrated Solar Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Vinod [Univ. of Texas, El Paso, TX (United States)

    2017-05-05

    High fidelity computational models of thermocline-based thermal energy storage (TES) were developed. The research goal was to advance the understanding of a single tank nanofludized molten salt based thermocline TES system under various concentration and sizes of the particles suspension. Our objectives were to utilize sensible-heat that operates with least irreversibility by using nanoscale physics. This was achieved by performing computational analysis of several storage designs, analyzing storage efficiency and estimating cost effectiveness for the TES systems under a concentrating solar power (CSP) scheme using molten salt as the storage medium. Since TES is one of the most costly but important components of a CSP plant, an efficient TES system has potential to make the electricity generated from solar technologies cost competitive with conventional sources of electricity.

  18. Exergy analysis of the FIGUEIRA thermal power plant operation - state of Parana, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Stanescu, George; Lima, Joao E. [Parana Univ., Curitiba, PR (Brazil). Dept. de Engenharia Mecanica]. E-mails: stanescu@demec.ufpr.br; joeduli@demec.ufpr.br; Andrade, Carlos de [FIGUEIRA Thermal Power Plant, Figueira, PR (Brazil)]. E-mail: ccarlosaandrade@zipmail.com.br

    2000-07-01

    Exergy analysis is a powerful tool to evaluate, design and improve the thermal systems. The method of exergy analysis or availability analysis is well suited for furthering the goal of increasing the efficiency of existing power generation systems, and the capability of more effective energy resource use. Exergy analysis of the FIGUEIRA thermal power plant is presented. Exergy losses occurring in various components are considered and the exergy balance is shown in tabular form. Results clearly reveal that the steam generator is the principal site of thermodynamic losses, while the condenser is relatively unimportant. (author)

  19. Thermal-hydraulics for space power, propulsion, and thermal management system design

    International Nuclear Information System (INIS)

    Krotiuk, W.J.

    1990-01-01

    The present volume discusses thermal-hydraulic aspects of current space projects, Space Station thermal management systems, the thermal design of the Space Station Free-Flying Platforms, the SP-100 Space Reactor Power System, advanced multi-MW space nuclear power concepts, chemical and electric propulsion systems, and such aspects of the Space Station two-phase thermal management system as its mechanical pumped loop and its capillary pumped loop's supporting technology. Also discussed are the startup thaw concept for the SP-100 Space Reactor Power System, calculational methods and experimental data for microgravity conditions, an isothermal gas-liquid flow at reduced gravity, low-gravity flow boiling, computations of Space Shuttle high pressure cryogenic turbopump ball bearing two-phase coolant flow, and reduced-gravity condensation

  20. Root cause analysis of thermal sleeve separation

    Energy Technology Data Exchange (ETDEWEB)

    Jo, J. C.; Jhung, M. J.; Yu, S. O.; Kim, H. J.; Yune, Y. K.; Park, J. Y

    2006-01-15

    Thermal sleeves in the shape of thin wall cylinder seated inside the nozzle part of each Safety Injection (SI) line at Pressurized Water Reactors (PWRs) have such functions as prevention and relief of potential excessive transient thermal stress in the wall of SI line nozzle part which is initially heated up with hot water flowing in the primary coolant piping system when cold water is injected into the system through the SI nozzles during the SI operation mode. Recently, mechanical failures that the sleeves were separated from the SI branch pipe and fell into the connected cold leg main pipe occurred in sequence at some typical PWR plants in Korea. To find out the root cause of thermal sleeve breakaway failures, the flow situation in the junction of primary coolant main pipe and SI branch pipe, and the vibration modal characteristics of the thermal sleeve are investigated in detail by using both Computational Fluid Dynamic (CFD) code and structure analysis finite element code. As the results, the transient response in fluid force exerting on the local part of thermal sleeve wall surface to the primary coolant flow through the pipe junction area during the normal reactor operation mode shows oscillatory characteristics with frequencies ranging from 17 to 18, which coincide with one of the lower mode natural frequencies of thermal sleeve having a pinned support condition on the circumferential prominence on the outer surface of thermal sleeve which is put into the circumferential groove on the inner surface of SI nozzle at the mid-height of the thermal sleeve. In addition, the variation of force on the thermal sleeve surface yields alternating torques in the directions of two rectangular axes which are perpendicular to the longitudinal axis of cylindrical thermal sleeve, which cause rolling, pitching and rotating motions of the thermal sleeve. Consequently, it is seen that this flow situation surrounding the thermal sleeve during the normal reactor operation can

  1. Remote sensing analysis of thermal plumes at the Savannah River Plant

    International Nuclear Information System (INIS)

    Doak, E.L.

    1985-01-01

    The nuclear reactors of the Savannah River Plant (SRP) in Aiken, South Carolina, use cold water diverted from the Savannah River to dissipate unused thermal energy. This water is heated by heat exchangers of the reactors during the materials production process, and then returned to the natural drainage system. Thermal effluents were monitored by an airborne thermal infrared scanner during predawn overlights. Images were generated to show the surface temperature distribution of the thermal outfall plumes into the Savannah River. The thermal analysis provides information related to compliance with permit requirements of the regulatory agencies

  2. Availability Performance Analysis of Thermal Power Plants

    Science.gov (United States)

    Bhangu, Navneet Singh; Singh, Rupinder; Pahuja, G. L.

    2018-03-01

    This case study presents the availability evaluation method of thermal power plants for conducting performance analysis in Indian environment. A generic availability model has been proposed for a maintained system (thermal plants) using reliability block diagrams and fault tree analysis. The availability indices have been evaluated under realistic working environment using inclusion exclusion principle. Four year failure database has been used to compute availability for different combinatory of plant capacity, that is, full working state, reduced capacity or failure state. Availability is found to be very less even at full rated capacity (440 MW) which is not acceptable especially in prevailing energy scenario. One of the probable reason for this may be the difference in the age/health of existing thermal power plants which requires special attention of each unit from case to case basis. The maintenance techniques being used are conventional (50 years old) and improper in context of the modern equipment, which further aggravate the problem of low availability. This study highlights procedure for finding critical plants/units/subsystems and helps in deciding preventive maintenance program.

  3. Thermoeconomic analysis of an integrated multi-effect desalination thermal vapor compression (MED-TVC) system with a trigeneration system using triple-pressure HRSG

    Science.gov (United States)

    Ghaebi, Hadi; Abbaspour, Ghader

    2018-05-01

    In this research, thermoeconomic analysis of a multi-effect desalination thermal vapor compression (MED-TVC) system integrated with a trigeneration system with a gas turbine prime mover is carried out. The integrated system comprises of a compressor, a combustion chamber, a gas turbine, a triple-pressure (low, medium and high pressures) heat recovery steam generator (HRSG) system, an absorption chiller cycle (ACC), and a multi-effect desalination (MED) system. Low pressure steam produced in the HRSG is used to drive absorption chiller cycle, medium pressure is used in desalination system and high pressure superheated steam is used for heating purposes. For thermodynamic and thermoeconomic analysis of the proposed integrated system, Engineering Equation Solver (EES) is used by employing mass, energy, exergy, and cost balance equations for each component of system. The results of the modeling showed that with the new design, the exergy efficiency in the base design will increase to 57.5%. In addition, thermoeconomic analysis revealed that the net power, heating, fresh water and cooling have the highest production cost, respectively.

  4. Thermal Stabilization of Cryogenic System in Superconducting Cyclotron

    International Nuclear Information System (INIS)

    Shin, Seung Jae; Kim, Kyung Min; Cho, Hyung Hee; Hong, Bong Hwan; Kang, Joon Sun; Ahn, Dong Hyun

    2011-01-01

    Radiology has some useful applications for medical purpose. For cancer therapy, the superconducting cyclotron should generate heavy ion beams. It radiates heavy ion beams to cancer patients. In order to make cyclotron system stable, the cryogenic system which makes superconducting state should work constantly. However, radiation heat transfer of cryogenic system should be considered because liquid helium's boiling point is extremely low and there is huge temperature difference between the cryogenic system and ambient temperature. Accordingly, thermal analysis should be carried out. In this paper, the numerical analysis of the cryogenic system in practical superconducting cyclotron show temperature distribution and suggest the number of coolers using ANSYS Workbench program

  5. Exergy analysis and optimization of a thermal management system with phase change material for hybrid electric vehicles

    International Nuclear Information System (INIS)

    Javani, N.; Dincer, I.; Naterer, G.F.; Yilbas, B.S.

    2014-01-01

    In the present study, energy and exergy analyses are conducted to investigate a new cooling system of hybrid electric vehicles (HEVs). A latent heat thermal energy storage system is integrated with an active refrigeration cycle where octadecane is selected as the phase change material (PCM). The liquid cooling system flows through the chiller following a conventional vapor compression cooling cycle. The latent heat shell and the tube heat exchanger operate in parallel with the chiller and a fraction of coolant enters the heat exchanger and, therefore, decreases the heat load of the chiller, leading to a lower work required by the compressor. The exergy destruction rate and the exergy efficiency of each component in a hybrid thermal management system (TMS) are calculated. In addition, the effects of parameters such as the fraction of coolant entering the heat storage system (PCM mass fraction), evaporator temperature, and compressor pressure ratio on the system performance are investigated. The findings of the exergy analysis reveal that the overall exergy efficiency of the system with PCM presence is 31%, having the largest exergy destruction rate of 0.4 kW and the heat exchangers have lower exergy efficiency as compared to other components. In addition, the results of the parametric study show that an increase in PCM mass fraction results in an increase in exergy efficiency of the system. An environmental impact assessment is also conducted and the results show that an increase in exergy efficiency of the cooling system reduces greenhouse gasses and also increases the sustainability of the system. Moreover, a multi-objective optimization using the genetic algorithm is performed by incorporating two objective functions, namely exergy efficiency to be maximized and total cost rate of the system to be minimized. A Pareto frontier is obtained and a single desirable optimal solution is selected based on LINMAP decision-making process. The results show that the maximum

  6. Residential Solar-Based Seasonal Thermal Storage Systems in Cold Climates: Building Envelope and Thermal Storage

    Directory of Open Access Journals (Sweden)

    Alexandre Hugo

    2012-10-01

    Full Text Available The reduction of electricity use for heating and domestic hot water in cold climates can be achieved by: (1 reducing the heating loads through the improvement of the thermal performance of house envelopes, and (2 using solar energy through a residential solar-based thermal storage system. First, this paper presents the life cycle energy and cost analysis of a typical one-storey detached house, located in Montreal, Canada. Simulation of annual energy use is performed using the TRNSYS software. Second, several design alternatives with improved thermal resistance for walls, ceiling and windows, increased overall air tightness, and increased window-to-wall ratio of South facing windows are evaluated with respect to the life cycle energy use, life cycle emissions and life cycle cost. The solution that minimizes the energy demand is chosen as a reference house for the study of long-term thermal storage. Third, the computer simulation of a solar heating system with solar thermal collectors and long-term thermal storage capacity is presented. Finally, the life cycle cost and life cycle energy use of the solar combisystem are estimated for flat-plate solar collectors and evacuated tube solar collectors, respectively, for the economic and climatic conditions of this study.

  7. POST-CASKETSS: a graphic computer program for thermal and structural analysis of nuclear fuel shipping casks

    International Nuclear Information System (INIS)

    Ikushima, Takeshi

    1988-12-01

    A computer program POST-CASKETSS has been developed for the purpose of calculation result representation for thermal and structural analysis computer code system CASKETSS (CASKETSS means a modular code system for CASK Evaluation code system for Thermal and Structural Safety). Main features of POST-CASKETSS are as follows; (1) Function of calculation result representation for thermal and structural analysis computer programs is provided in the program. (2) Two and three dimensional graphic representation for finite element and finite difference programs are available in the program. (3) The capacity of graphics of geometry, temperature contor and temperature-time curve are provided for thermal analysis. (4) The capacity of graphics of geometry, deformation, stress contor, displacement-time curve, velocity-time curve, acceleration-time curve, stress-time curve, force-time curve and moment-time curve are provided for structural analysis. (5) This computer program operates both the time shearing system and the batch system. In the paper, brief illustration of calculation method, input data and sample calculations are presented. (author)

  8. Use of the Long Duration Exposure Facility's thermal measurement system for the verification of thermal models

    Science.gov (United States)

    Berrios, William M.

    1992-01-01

    The Long Duration Exposure Facility (LDEF) postflight thermal model predicted temperatures were matched to flight temperature data recorded by the Thermal Measurement System (THERM), LDEF experiment P0003. Flight temperatures, recorded at intervals of approximately 112 minutes for the first 390 days of LDEF's 2105 day mission were compared with predictions using the thermal mathematical model (TMM). This model was unverified prior to flight. The postflight analysis has reduced the thermal model uncertainty at the temperature sensor locations from +/- 40 F to +/- 18 F. The improved temperature predictions will be used by the LDEF's principal investigators to calculate improved flight temperatures experienced by 57 experiments located on 86 trays of the facility.

  9. Comparative analysis on operation strategies of CCHP system with cool thermal storage for a data center

    International Nuclear Information System (INIS)

    Song, Xu; Liu, Liuchen; Zhu, Tong; Zhang, Tao; Wu, Zhu

    2016-01-01

    Highlights: • Load characteristics of the data center make a good match with CCHP systems. • TRNSYS models was used to simulate the discussed CCHP system in a data center. • Comprehensive system performance under two operation strategies were evaluated. • Cool thermal storage was introduced to reuse the energy surplus by FEL system. • The suitable principle of equipment selection for a FEL system were proposed. - Abstract: Combined Cooling, Heating, and Power (CCHP) systems with cool thermal storage can provide an appropriate energy supply for data centers. In this work, we evaluate the CCHP system performance under two different operation strategies, i.e., following thermal load (FTL) and following electric load (FEL). The evaluation is performed through a case study by using TRNSYS software. In the FEL system, the amount of cool thermal energy generated by the absorption chillers is larger than the cooling load and it can be therefore stored and reused at the off-peak times. Results indicate that systems under both operation strategies have advantages in the fields of energy saving and environmental protection. The largest percentage of reduction of primary energy consumption, CO_2 emissions, and operation cost for the FEL system, are 18.5%, 37.4% and 46.5%, respectively. Besides, the system performance is closely dependent on the equipment selection. The relation between the amount of energy recovered through cool thermal storage and the primary energy consumption has also been taken into account. Moreover, the introduction of cool thermal storage can adjust the heat to power ratio on the energy supply side close to that on the consumer side and consequently promote system flexibility and energy efficiency.

  10. From the direct numerical simulation to system codes-perspective for the multi-scale analysis of LWR thermal hydraulics

    International Nuclear Information System (INIS)

    Bestion, D.

    2010-01-01

    A multi-scale analysis of water-cooled reactor thermal hydraulics can be used to take advantage of increased computer power and improved simulation tools, including Direct Numerical Simulation (DNS), Computational Fluid Dynamics (CFD) (in both open and porous mediums), and system thermalhydraulic codes. This paper presents a general strategy for this procedure for various thermalhydraulic scales. A short state of the art is given for each scale, and the role of the scale in the overall multi-scale analysis process is defined. System thermalhydraulic codes will remain a privileged tool for many investigations related to safety. CFD in porous medium is already being frequently used for core thermal hydraulics, either in 3D modules of system codes or in component codes. CFD in open medium allows zooming on some reactor components in specific situations, and may be coupled to the system and component scales. Various modeling approaches exist in the domain from DNS to CFD which may be used to improve the understanding of flow processes, and as a basis for developing more physically based models for macroscopic tools. A few examples are given to illustrate the multi-scale approach. Perspectives for the future are drawn from the present state of the art and directions for future research and development are given

  11. Thermodynamical analysis of human thermal comfort

    International Nuclear Information System (INIS)

    Prek, Matjaz

    2006-01-01

    Traditional methods of human thermal comfort analysis are based on the first law of thermodynamics. These methods use an energy balance of the human body to determine heat transfer between the body and its environment. By contrast, the second law of thermodynamics introduces the useful concept of exergy. It enables the determination of the exergy consumption within the human body dependent on human and environmental factors. Human body exergy consumption varies with the combination of environmental (room) conditions. This process is related to human thermal comfort in connection with temperature, heat, and mass transfer. In this paper a thermodynamic analysis of human heat and mass transfer based on the 2nd law of thermodynamics in presented. It is shown that the human body's exergy consumption in relation to selected human parameters exhibits a minimal value at certain combinations of environmental parameters. The expected thermal sensation also shows that there is a correlation between exergy consumption and thermal sensation. Thus, our analysis represents an improvement in human thermal modelling and gives more information about the environmental impact on expected human thermal sensation

  12. Thermal analysis and phase diagrams of the LiF BiF3 e NaF BiF3 systems

    International Nuclear Information System (INIS)

    Nakamura, Gerson Hiroshi de Godoy

    2013-01-01

    Investigations of the binary systems LiF-BiF 3 and NaF-BiF 3 were performed with the objective of clarifying the thermal behavior and phase equilibria of these systems and their intermediary phases, an important requisite for high-quality crystal growth. Several samples in the entire range of compositions (0 to 100 mol% BiF 3 ) of both systems were subjected to experiments of differential thermal analysis (DTA) and thermogravimetry (TG), and also of differential scanning calorimetry (DSC). A few specific compositions were selected for X-ray diffraction to supplement the experimental data. Due to the high vulnerability of BiF 3 to oxygen contamination, its volatility and propensity to destroy metal parts upon heating, it was necessary to determine the optimal conditions for thermal analysis before investigating the systems themselves. Phase relations in the system LiF-BiF 3 were completely clarified and a phase diagram was calculated and evaluated via the commercial software Factsage. The diagram itself consists in a simple peritectic system in which the only intermediary compound, LiBiF 4 , decomposes into LiF and a liquid phase. The NaF-BiF 3 system could not be completely elucidated and the phase relations in the NaF poor side (> 50% BiF 3 ) are still unknown. In the NaF rich side, however, the possible peritectoid decomposition of the compound NaBiF 4 was identified. In both systems X-ray diffraction yielded crystal structures discrepant with the literature for the intermediary phases, LiBiF 4 , NaBiF 4 and a solid solution of NaF and BiF 3 called I. The observed structures remain unknown and explanations for the discrepancies were proposed. (author)

  13. Numerical Analysis and Design of Thermal Management System for Lithium Ion Battery Pack Using Thermoelectric Coolers

    Directory of Open Access Journals (Sweden)

    Yong Liu

    2014-08-01

    Full Text Available A new design of thermal management system for lithium ion battery pack using thermoelectric coolers (TECs is proposed. Firstly, the 3D thermal model of a high power lithium ion battery and the TEC is elaborated. Then the model is calibrated with experiment results. Finally, the calibrated model is applied to investigate the performance of a thermal management system for a lithium ion battery pack. The results show that battery thermal management system (BTMS with TEC can cool the battery in very high ambient temperature. It can also keep a more uniform temperature distribution in the battery pack than common BTMS, which will extend the life of the battery pack and may save the expensive battery equalization system.

  14. Analysis of economic characteristics of a tariff system for thermal energy activities

    Energy Technology Data Exchange (ETDEWEB)

    Banovac, Eraldo [Croatian Energy Regulatory Agency, Zagreb (Croatia); Gelo, Tomislav; Simurina, Jurica [University of Zagreb (Croatia). Faculty of Economics and Business

    2007-11-15

    Generally speaking, the creation of tariff systems for energy activities carried out as regulated or public service obligation is becoming professionally challenging. The Croatian Energy Regulatory Agency (CERA) created the methodology of the tariff system for thermal energy activities and passed this tariff system (without tariff element amounts) in May 2006. The background of the tariff system for thermal energy activities (heat generation, heat distribution and heat supply) including a legislative framework relevant for passing the tariff system, terminology, matrix of the tariff models, tariff elements and amounts of tariff entries are analyzed in this paper. Special attention is paid to the economic characteristics of the tariff system, such as the capital asset pricing model (CAPM), which is chosen among several models of the weighted average of cost of capital (WACC). Using the WACC, the regulatory authorities ensure returns to be equal to the opportunity cost of capital. Furthermore, main formulae and procedures for submitting the proposal for changing the amounts of tariff elements are analyzed as well. (author)

  15. Analysis of economic characteristics of a tariff system for thermal energy activities

    International Nuclear Information System (INIS)

    Banovac, Eraldo; Gelo, Tomislav; Simurina, Jurica

    2007-01-01

    Generally speaking, the creation of tariff systems for energy activities carried out as regulated or public service obligation is becoming professionally challenging. The Croatian Energy Regulatory Agency (CERA) created the methodology of the tariff system for thermal energy activities and passed this tariff system (without tariff element amounts) in May 2006. The background of the tariff system for thermal energy activities (heat generation, heat distribution and heat supply) including a legislative framework relevant for passing the tariff system, terminology, matrix of the tariff models, tariff elements and amounts of tariff entries are analyzed in this paper. Special attention is paid to the economic characteristics of the tariff system, such as the capital asset pricing model (CAPM), which is chosen among several models of the weighted average of cost of capital (WACC). Using the WACC, the regulatory authorities ensure returns to be equal to the opportunity cost of capital. Furthermore, main formulae and procedures for submitting the proposal for changing the amounts of tariff elements are analyzed as well

  16. Failure mechanism for thermal fatigue of thermal barrier coating systems

    Energy Technology Data Exchange (ETDEWEB)

    Giolli, C.; Scrivani, A.; Rizzi, G. [Turbocoating S.p.A., Rubbiano di Solignano (Italy); Borgioli, F. [Firenze Univ., Sesto Fiorentino (Italy); Bolelli, G.; Lusvarghi, L. [Univ. di Modena e Reggio Emilia, Modena (Italy)

    2008-07-01

    High temperature thermal fatigue causes the failure of Thermal Barrier Coating (TBC) systems. Due to the difference in thickness and microstructure between thick TBCs and traditional thin TBCs, they cannot be assumed a-priori to possess the same failure mechanisms. Thick TBCs, consisting of a CoNiCrAlY bond coat and Yttria Partially Stabilised Zirconia top coat with different values of porosity, were produced by Air Plasma Spray. Thermal fatigue resistance limit of TBCs was tested by Furnace Cycling Tests (FCT) according to the specifications of an Original Equipment Manufacturer (OEM). TBC systems were analyzed before and after FCT. The morphological and chemical evolution of CoNiCrAlY/TGO microstructure was studied. Sintering effect, residual stress, phase transformation and fracture toughness were evaluated in the ceramic Top Coat. All the tested samples passed FCT according to the specification of an important OEM. Thermal fatigue resistance increases with the amount of porosity in the top coat. The compressive in-plane stresses increase in the TBC systems after thermal cycling, nevertheless the increasing rate has a trend contrary to the porosity level of top coat. The data suggest that the spallation happens at the TGO/Top Coat interface. The failure mechanism of thick TBCs subjected to thermal fatigue was eventually found to be similar to the failure mechanism of thin TBC systems made by APS. (orig.)

  17. Thermal Analysis of TRIO-CINEMA Mission

    Directory of Open Access Journals (Sweden)

    Jaegun Yoo

    2012-03-01

    Full Text Available Thermal analysis and control design are prerequisite essential to design the satellite. In the space environment, it makes satellite survive from extreme hot and cold conditions. In recent years CubeSat mission is developed for many kinds of purpose. Triplet Ionospheric Observatory (TRIO–CubeSat for Ion, Neutral, Electron, MAgnetic fields (CINEMA is required to weigh less than 3 kg and operate on minimal 3 W power. In this paper we describe the thermal analysis and control design for TRIO-CINEMA mission. For this thermal analysis, we made a thermal model of the CubeSat with finite element method and NX6.0 TMG software is used to simulate this analysis model. Based on this result, passive thermal control method has been applied to thermal design of CINEMA. In order to get the better conduction between solar panel and chassis, we choose aluminum 6061-T6 for the material property of standoff. We can increase the average temperature of top and bottom solar panels from -70°C to -40°C and decrease the average temperature of the magnetometer from +93°C to -4°C using black paint on the surface of the chassis, inside of top & bottom solar panels, and magnetometer.

  18. Thermal Analysis of the Driving Component Based on the Thermal Network Method in a Lunar Drilling System and Experimental Verification

    Directory of Open Access Journals (Sweden)

    Dewei Tang

    2017-03-01

    Full Text Available The main task of the third Chinese lunar exploration project is to obtain soil samples that are greater than two meters in length and to acquire bedding information from the surface of the moon. The driving component is the power output unit of the drilling system in the lander; it provides drilling power for core drilling tools. High temperatures can cause the sensors, permanent magnet, gears, and bearings to suffer irreversible damage. In this paper, a thermal analysis model for this driving component, based on the thermal network method (TNM was established and the model was solved using the quasi-Newton method. A vacuum test platform was built and an experimental verification method (EVM was applied to measure the surface temperature of the driving component. Then, the TNM was optimized, based on the principle of heat distribution. Through comparative analyses, the reasonableness of the TNM is validated. Finally, the static temperature field of the driving component was predicted and the “safe working times” of every mode are given.

  19. Availability of steam generator against thermal disturbance of hydrogen production system coupled to HTGR

    International Nuclear Information System (INIS)

    Shibata, Taiju; Nishihara, Tetsuo; Hada, Kazuhiko; Shiozawa, Shusaku

    1996-01-01

    One of the safety issues to couple a hydrogen production system to an HTGR is how the reactor coolability can be maintained against anticipated abnormal reduction of heat removal (thermal disturbance) of the hydrogen production system. Since such a thermal disturbance is thought to frequently occur, it is desired against the thermal disturbance to keep reactor coolability by means other than reactor scram. Also, it is thought that the development of a passive cooling system for such a thermal disturbance will be necessary from a public acceptance point of view in a future HTGR-hydrogen production system. We propose a SG as the passive cooling system which can keep the reactor coolability during a thermal disturbance of a hydrogen production system. This paper describes the proposed steam generator (SG) for the HTGR-hydrogen production system and a result of transient thermal-hydraulic analysis of the total system, showing availability of the SG against a thermal disturbance of the hydrogen production system in case of the HTTR-steam reforming hydrogen production system. (author)

  20. Thermal management of EV battery systems

    Energy Technology Data Exchange (ETDEWEB)

    Birch, P.K.

    1984-01-01

    The thermal limitations of the actual design and the benefits of more extensive thermal management of electric vehicle systems are described. During this work a number of practical limitations in vehicle design, which has to be frozen relatively early in the project, made it impossible to take advantage of the benefits of thermal management in connection with the design of the modular battery system. This study, therfore, deals only very briefly with the actual project. The aim has been to show the possibilities of improvement based on traditional electrochemical systems (e.g., all lead-acid) by means of thermal management.

  1. Financial analysis on the proposed renewable heat incentive for residential houses in the United Kingdom: A case study on the solar thermal system

    International Nuclear Information System (INIS)

    Abu-Bakar, Siti Hawa; Muhammad-Sukki, Firdaus; Ramirez-Iniguez, Roberto; Munir, Abu Bakar; Mohd Yasin, Siti Hajar; Mallick, Tapas Kumar; McLennan, Campbell; Abdul Rahim, Ruzairi

    2014-01-01

    This short communication paper focuses on the renewable heat incentive (RHI) scheme in the United Kingdom (UK); and in particular, on its implication on domestic installations of solar thermal systems (STSs). First, a short review on the STS in the UK is provided. Then, a detailed description of the RHI is discussed. A financial analysis is presented afterwards, analysing the impact of the RHI scheme on the applicants, in terms of the net present value and the internal rate of return. From the financial analysis it has been found that the RHI scheme for domestic installations is only attractive if a longer period of RHI payment, i.e. 17 years, or a higher RHI rate i.e. £0.32 per kW h is implemented. The current proposal from the UK government is not financially viable, and as a result, it may hinder the penetration of domestic solar thermal systems in the residential sector in the UK. - Highlights: • A short review on solar thermal system (STS) is presented. • The renewable heat incentive (RHI) scheme is discussed. • A financial analysis is evaluated under the RHI scheme in the UK. • The analysis indicates the current proposal is not desirable to consumers

  2. System Design Description PFP Thermal Stabilization

    International Nuclear Information System (INIS)

    RISENMAY, H.R.

    2000-01-01

    The purpose of this document is to provide a system design description (SDD) and design basis for the Plutonium Finishing Plant (PFP) Thermal Stabilization project. The chief objective of the SDD is to document the Structures, Systems, and Components (SSCs) that establish and maintain the facility Safety Envelope necessary for normal safe operation of the facility; as identified in the FSAR, the OSRs, and Safety Assessment Documents (SADs). This safety equipment documentation should satisfy guidelines for the SDD given in WHC-SD-CP-TI-18 1, Criteria for Identification and Control of Equipment Necessary for Preservation of the Safety Envelope and Safe Operation of PFP. The basis for operational, alarm response, maintenance, and surveillance procedures are also identified and justified in this document. This document and its appendices address the following elements of the PFP Thermal Stabilization project: Functional and design requirements; Design description; Safety Envelope Analysis; Safety Equipment Class; and Operational, maintenance and surveillance procedures

  3. Solar energy thermally powered electrical generating system

    Science.gov (United States)

    Owens, William R. (Inventor)

    1989-01-01

    A thermally powered electrical generating system for use in a space vehicle is disclosed. The rate of storage in a thermal energy storage medium is controlled by varying the rate of generation and dissipation of electrical energy in a thermally powered electrical generating system which is powered from heat stored in the thermal energy storage medium without exceeding a maximum quantity of heat. A control system (10) varies the rate at which electrical energy is generated by the electrical generating system and the rate at which electrical energy is consumed by a variable parasitic electrical load to cause storage of an amount of thermal energy in the thermal energy storage system at the end of a period of insolation which is sufficient to satisfy the scheduled demand for electrical power to be generated during the next period of eclipse. The control system is based upon Kalman filter theory.

  4. Thermal performance analysis of a phase change thermal storage unit for space heating

    Energy Technology Data Exchange (ETDEWEB)

    Halawa, E.; Saman, W. [Institute for Sustainable Systems and Technologies School of Advanced Manufacturing and Mechanical Engineering, University of South Australia, Mawson Lakes SA 5095 (Australia)

    2011-01-15

    This paper presents the results of a comprehensive numerical study on the thermal performance of an air based phase change thermal storage unit (TSU) for space heating. The unit is designed for integration into space heating and cooling systems. The unit consists of a number of one dimensional phase change material (PCM) slabs contained in a rectangular duct where air passes between the slabs. The numerical analysis was based on an experimentally validated model. A parametric study has been carried out including the study on the effects of charge and discharge temperature differences, air mass flow rate, slab thicknesses, air gaps and slab dimensions on the air outlet temperatures and heat transfer rates of the thermal storage unit. The paper introduces and discusses quantities called charge and discharge temperature differences which play an important role in the melting and freezing processes. (author)

  5. Investigation of thermal fatigue behavior of thermal barrier coating systems

    International Nuclear Information System (INIS)

    Zhu Dongming; Miller, R.A.

    1997-01-01

    In the present study, the mechanisms of fatigue crack initiation and propagation, and of coating failure under thermal loads that simulate those in diesel engines are investigated. Surface cracks initiate early and grow continuously under thermal low cycle fatigue (LCF) and high cycle fatigue (HCF) stresses. It is found that, in the absence of interfacial oxidation, the failure associated with LCF is closely related to coating sintering and creep at high temperatures. Significant LCF and HCF interactions have been observed in the thermal fatigue tests. The fatigue crack growth rate in the ceramic coating strongly depends on the characteristic HCF cycle number, N* HCF which is defined as the number of HCF cycles per LCF cycle. The crack growth rate is increased from 0.36 μm/LCF cycle for a pure LCF test to 2.8 μm/LCF cycle for a combined LCF and HCF test at N* HCF about 20 000. A surface wedging model has been proposed to account for the HCF crack growth in the coating systems. This mechanism predicts that the HCF damage effect increases with heat flux and thus with increasing surface temperature swing, thermal expansion coefficient and elastic modulus of the ceramic coating, as well as with the HCF interacting depth. Good correlation has been found between the analysis and experimental evidence. (orig.)

  6. Solar thermal power systems point-focusing thermal and electric applications projects. Volume 1: Executive summary

    Science.gov (United States)

    Marriott, A.

    1980-01-01

    The activities of the Point-Focusing Thermal and Electric Applications (PETEA) project for the fiscal year 1979 are summarized. The main thrust of the PFTEA Project, the small community solar thermal power experiment, was completed. Concept definition studies included a small central receiver approach, a point-focusing distributed receiver system with central power generation, and a point-focusing distributed receiver concept with distributed power generation. The first experiment in the Isolated Application Series was initiated. Planning for the third engineering experiment series, which addresses the industrial market sector, was also initiated. In addition to the experiment-related activities, several contracts to industry were let and studies were conducted to explore the market potential for point-focusing distributed receiver (PFDR) systems. System analysis studies were completed that looked at PFDR technology relative to other small power system technology candidates for the utility market sector.

  7. Thermal modeling and design of electronic systems and devices

    International Nuclear Information System (INIS)

    Wirtz, R.A.; Lehmann, G.L.

    1990-01-01

    The thermal control electronic devices, particularly those in complex systems with high heat flux density, continues to be of interest to engineers involved in system cooling design and analysis. This volume contains papers presented at the 1990 ASME Winter Annual Meeting in two K-16 sponsored sessions: Empirical Modeling of Heat Transfer in Complex Electronic Systems and Design and Modeling of Heat Transfer Devices in High-Density Electronics. The first group deals with understanding the heat transfer processes in these complex systems. The second group focuses on the use of analysis techniques and empirically determined data in predicting device and system operating performance

  8. Occupancy Analysis of Sports Arenas Using Thermal Imaging

    DEFF Research Database (Denmark)

    Gade, Rikke; Jørgensen, Anders; Moeslund, Thomas B.

    2012-01-01

    This paper presents a system for automatic analysis of the occupancy of sports arenas. By using a thermal camera for image capturing the number of persons and their location on the court are found without violating any privacy issues. The images are binarised with an automatic threshold method...

  9. Performance Analysis of a Photovoltaic-Thermal Integrated System

    International Nuclear Information System (INIS)

    Radziemska, E.

    2009-01-01

    The present commercial photovoltaic solar cells (PV) converts solar energy into electricity with a relatively low efficiency, less than 20%. More than 80% of the absorbed solar energy is dumped to the surroundings again after photovoltaic conversion. Hybrid PV/T systems consist of PV modules coupled with the heat extraction devices. The PV/T collectors generate electric power and heat simultaneously. Stabilizing temperature of photovoltaic modules at low level is highly desirable to obtain efficiency increase. The total efficiency of 60-80% can be achieved with the whole PV/T system provided that the T system is operated near ambient temperature. The value of the low-T heat energy is typically much smaller than the value of the PV electricity. The PV/T systems can exist in many designs, but the most common models are with the use of water or air as a working fuid. Efficiency is the most valuable parameter for the economic analysis. It has substantial meaning in the case of installations with great nominal power, as air-cooled Building Integrated Photovoltaic Systems (BIPV). In this paper the performance analysis of a hybrid PV/T system is presented: an energetic analysis as well as an exergetic analysis. Exergy is always destroyed when a process involves a temperature change. This destruction is proportional to the entropy increase of the system together with its surroundings the destroyed exergy has been called energy. Exergy analysis identifies the location, the magnitude, and the sources of thermodynamic inefficiencies in a system. This information, which cannot be provided by other means (e.g., an energy analysis), is very useful for the improvement and cost-effectiveness of the system. Calculations were carried out for the tested water-cooled ASE-100-DGL-SM Solar watt module.

  10. Performance Analysis of a Photovoltaic-Thermal Integrated System

    Directory of Open Access Journals (Sweden)

    Ewa Radziemska

    2009-01-01

    Full Text Available The present commercial photovoltaic solar cells (PV converts solar energy into electricity with a relatively low efficiency, less than 20%. More than 80% of the absorbed solar energy is dumped to the surroundings again after photovoltaic conversion. Hybrid PV/T systems consist of PV modules coupled with the heat extraction devices. The PV/T collectors generate electric power and heat simultaneously. Stabilizing temperature of photovoltaic modules at low level is higly desirable to obtain efficiency increase. The total efficiency of 60–80% can be achieved with the whole PV/T system provided that the T system is operated near ambient temperature. The value of the low-T heat energy is typically much smaller than the value of the PV electricity. The PV/T systems can exist in many designs, but the most common models are with the use of water or air as a working fuid. Efficiency is the most valuable parameter for the economic analysis. It has substantial meaning in the case of installations with great nominal power, as air-cooled Building Integrated Photovoltaic Systems (BIPV. In this paper the performance analysis of a hybrid PV/T system is presented: an energetic analysis as well as an exergetic analysis. Exergy is always destroyed when a process involves a temperature change. This destruction is proportional to the entropy increase of the system together with its surroundings—the destroyed exergy has been called anergy. Exergy analysis identifies the location, the magnitude, and the sources of thermodynamic inefficiences in a system. This information, which cannot be provided by other means (e.g., an energy analysis, is very useful for the improvement and cost-effictiveness of the system. Calculations were carried out for the tested water-cooled ASE-100-DGL-SM Solarwatt module.

  11. One-Dimensional Analysis of Thermal Stratification in AHTR and SFR Coolant Pools

    International Nuclear Information System (INIS)

    Haihua Zhao; Per F. Peterson

    2007-01-01

    Thermal stratification phenomena are very common in pool type reactor systems, such as the liquid-salt cooled Advanced High Temperature Reactor (AHTR) and liquid-metal cooled fast reactor systems such as the Sodium Fast Reactor (SFR). It is important to accurately predict the temperature and density distributions both for design optimation and accident analysis. Current major reactor system analysis codes such as RELAP5 (for LWR's, and recently extended to analyze high temperature reactors), TRAC (for LWR's), and SASSYS (for liquid metal fast reactors) only provide lumped-volume based models which can only give very approximate results and can only handle simple cases with one mixing source. While 2-D or 3-D CFD methods can be used to analyze simple configurations, these methods require very fine grid resolution to resolve thin substructures such as jets and wall boundaries, yet such fine grid resolution is difficult or impossible to provide for studying the reactor response to transients due to computational expense. Therefore, new methods are needed to support design optimization and safety analysis of Generation IV pool type reactor systems. Previous scaling has shown that stratified mixing processes in large stably stratified enclosures can be described using one-dimensional differential equations, with the vertical transport by free and wall jets modeled using standard integral techniques. This allows very large reductions in computational effort compared to three-dimensional numerical modeling of turbulent mixing in large enclosures. The BMIX++ (Berkeley mechanistic MIXing code in C++) code was originally developed at UC Berkeley to implement such ideas. This code solves mixing and heat transfer problems in stably stratified enclosures. The code uses a Lagrangian approach to solve 1-D transient governing equations for the ambient fluid and uses analytical or 1-D integral models to compute substructures. By including liquid salt properties, BMIX++ code is

  12. Validation study of FLUENT for the application of dry-storage system thermal analysis

    International Nuclear Information System (INIS)

    Tseng Yungshin; Wang Jongrong; Cheng Yihsiang; Shih Chunkuan

    2009-01-01

    In this study, the commercial CFD code, FLUENT, has been selected to evaluate the accuracy of the temperature prediction for nuclear fuel dry storage system (DSS). The experimental results of VSC-17 DSS were employed for such purposes. Through a minimal assumptions and necessary simplifications (e.g., the lumped model of fuel), a high integrity geometry model with about 4.0 million meshes was employed to solve the conjugate heat transfer coupled with thermal radiation problem. First, the general scheme validation indicates that FLUENT can provide a result which agrees well with analytical solution. It means that the numerical scheme included in FLUENT is reliable and accurate. The comparisons with VSC-17 further points out that the maximum temperature difference between simulation and experimental solution is less than 10degC and the maximum deviation for whole DSS is less than 5%. Those findings mentioned above imply that FLUENT can be a highly accurate thermal analysis tool for d DSS design. Through a series modeling and scheme selecting, this code can be an efficient tool for the new DSS development in the future. (author)

  13. Hydrocarbon Fuel Thermal Performance Modeling based on Systematic Measurement and Comprehensive Chromatographic Analysis

    Science.gov (United States)

    2016-07-31

    distribution unlimited Hydrocarbon Fuel Thermal Performance Modeling based on Systematic Measurement and Comprehensive Chromatographic Analysis Matthew...vital importance for hydrocarbon -fueled propulsion systems: fuel thermal performance as indicated by physical and chemical effects of cooling passage... analysis . The selection and acquisition of a set of chemically diverse fuels is pivotal for a successful outcome since test method validation and

  14. Passive thermal management system for downhole electronics in harsh thermal environments

    International Nuclear Information System (INIS)

    Shang, Bofeng; Ma, Yupu; Hu, Run; Yuan, Chao; Hu, Jinyan; Luo, Xiaobing

    2017-01-01

    Highlights: • A passive thermal management system is proposed for downhole electronics. • Electronics temperature can be maintained within 125 °C for six-hour operating time. • The result shows potential application for the logging tool in oil and gas industry. - Abstract: The performance and reliability of downhole electronics will degrade in high temperature environments. Various active cooling techniques have been proposed for thermal management of such systems. However, these techniques require additional power input, cooling liquids and other moving components which complicate the system. This study presents a passive Thermal Management System (TMS) for downhole electronics. The TMS includes a vacuum flask, Phase Change Material (PCM) and heat pipes. The thermal characteristics of the TMS is evaluated experimentally. The results show that the system maintains equipment temperatures below 125 °C for a six-hour operating period in a 200 °C downhole environment, which will effectively protect the downhole electronics.

  15. Thermal comfort analysis of a low temperature waste energy recovery system. SIECHP

    Energy Technology Data Exchange (ETDEWEB)

    Herrero Martin, R. [Departamento de Ingenieria Termica y de Fluidos, Universidad Politecnica de Cartagena, C/Dr. Fleming, s/n (Campus Muralla), 30202 Cartagena, Murcia (Spain); Rey Martinez, F.J.; Velasco Gomez, E. [Departamento de Ingenieria Energetica y Fluidomecanica, ETSII, Universidad de Valladolid, Paseo del Cauce s/n, 47011 Valladolid (Spain)

    2008-07-01

    The use of a recovery device is justified in terms of energy savings and environmental concerns. But it is clear that the use of a recovery system also has to lead to controlling indoor environmental quality, nowadays a priority concern. In this article, experimental research has been carried out whose aim is to study the thermal comfort provided by a combined recovery equipment (SIECHP), consisting of a ceramic semi-indirect evaporative cooler (SIEC) and a heat pipe device (HP) to recover energy at low temperature in air-conditioning systems. To characterize this device empirically in terms of thermal comfort (TC), Fanger's predicted mean vote (PMV), draught rate, and vertical air temperature difference were used in this study as the TC criteria. (author)

  16. Experimental investigation of thermal neutron analysis based landmine detection technology

    International Nuclear Information System (INIS)

    Zeng Jun; Chu Chengsheng; Ding Ge; Xiang Qingpei; Hao Fanhua; Luo Xiaobing

    2013-01-01

    Background: Recently, the prompt gamma-rays neutron activation analysis method is wildly used in coal analysis and explosive detection, however there were less application about landmine detection using neutron method especially in the domestic research. Purpose: In order to verify the feasibility of Thermal Neutron Analysis (TNA) method used in landmine detection, and explore the characteristic of this technology. Methods: An experimental system of TNA landmine detection was built based on LaBr 3 (Ce) fast scintillator detector and 252 Cf isotope neutron source. The system is comprised of the thermal neutron transition system, the shield system, and the detector system. Results: On the basis of the TNA, the wide energy area calibration method especially to the high energy area was investigated, and the least detection time for a typical mine was defined. In this study, the 72-type anti-tank mine, the 500 g TNT sample and several interferential objects are tested in loess, red soil, magnetic soil and sand respectively. Conclusions: The experimental results indicate that TNA is a reliable demining method, and it can be used to confirm the existence of Anti-Tank Mines (ATM) and large Anti-Personnel Mines (APM) in complicated condition. (authors)

  17. Recommendations on the choice of gas analysis equipment for systems of continuous monitoring and accounting of emissions from thermal power plants

    Science.gov (United States)

    Kondrat'eva, O. E.; Roslyakov, P. V.; Burdyukov, D. A.; Khudolei, O. D.; Loktionov, O. A.

    2017-10-01

    According to Federal Law no. 219-FZ, dated July 21, 2014, all enterprises that have a significant negative impact on the environment shall continuously monitor and account emissions of harmful substances into the atmospheric air. The choice of measuring equipment that is included in continuous emission monitoring and accounting systems (CEM&ASs) is a complex technical problem; in particular, its solution requires a comparative analysis of gas analysis systems; each of these systems has its advantages and disadvantages. In addition, the choice of gas analysis systems for CEM&ASs should be maximally objective and not depend on preferences of separate experts and specialists. The technique of choosing gas analysis equipment that was developed in previous years at Moscow Power Engineering Institute (MPEI) has been analyzed and the applicability of the mathematical tool of a multiple criteria analysis to choose measuring equipment for the continuous emission monitoring and accounting system have been estimated. New approaches to the optimal choice of gas analysis equipment for systems of the continuous monitoring and accounting of harmful emissions from thermal power plants have been proposed, new criteria of evaluation of gas analysis systems have been introduced, and weight coefficients have been determined for these criteria. The results of this study served as a basis for the Preliminary National Standard of the Russian Federation "Best Available Technologies. Automated Systems of Continuous Monitoring and Accounting of Emissions of Harmful (Polluting) Substances from Thermal Power Plants into the Atmospheric Air. Basic Requirements," which was developed by the Moscow Power Engineering Institute, National Research University, in cooperation with the Council of Power Producers and Strategic Electric Power Investors Association and the All-Russia Research Institute for Materials and Technology Standardization.

  18. Thermal design, analysis and comparison on three concepts of space solar power satellite

    Science.gov (United States)

    Yang, Chen; Hou, Xinbin; Wang, Li

    2017-08-01

    Space solar power satellites (SSPS) have been widely studied as systems for collecting solar energy in space and transmitting it wirelessly to earth. A previously designed planar SSPS concept collects solar power in two huge arrays and then transmits it through one side of the power-conduction joint to the antenna. However, the system's one group of power-conduction joints may induce a single point of failure. As an SSPS concept, the module symmetrical concentrator (MSC) architecture has many advantages. This architecture can help avoid the need for a large, potentially failure-prone conductive rotating joint and limit wiring mass. However, the thermal control system has severely restricted the rapid development of MSC, especially in the sandwich module. Because of the synchronous existence of five suns concentration and solar external heat flux, the sandwich module will have a very high temperature, which will surpass the permissible temperature of the solar cells. Recently, an alternate multi-rotary joints (MR) SSPS concept was designed by the China Academy of Space Technology (CAST). This system has multiple joints to avoid the problem of a single point of failure. Meanwhile, this concept has another advantage for reducing the high power and heat removal in joints. It is well known to us that, because of the huge external flux in SSPS, the thermal management sub-system is an important component that cannot be neglected. Based on the three SSPS concepts, this study investigated the thermal design and analysis of a 1-km, gigawatt-level transmitting antenna in SSPS. This study compares the thermal management sub-systems of power-conduction joints in planar and MR SSPS. Moreover, the study considers three classic thermal control architectures of the MSC's sandwich module: tile, step, and separation. The study also presents an elaborate parameter design, analysis and discussion of step architecture. Finally, the results show the thermal characteristics of each SSPS

  19. Thermal-Hydraulic Experiments and Modelling for Advanced Nuclear Reactor Systems

    International Nuclear Information System (INIS)

    Song, C. H.; Chung, M. K.; Park, C. K. and others

    2005-04-01

    The objectives of the project are to study thermal hydraulic characteristics of reactor primary system for the verification of the reactor safety and to evaluate new safety concepts of new safety design features. To meet the research goal, several thermal hydraulic experiments were performed and related thermal hydraulic models were developed with the experimental data which were produced through the thermal hydraulic experiments. Followings are main research topics; - Multi-dimensional Phenomena in a Reactor Vessel Downcomer - Condensation Load and Thermal Mixing in the IRWST - Development of Thermal-Hydraulic Models for Two-Phase Flow - Development of Measurement Techniques for Two-Phase Flow - Supercritical Reactor T/H Characteristics Analysis From the above experimental and analytical studies, new safety design features of the advanced power reactors were verified and lots of the safety issues were also resolved

  20. Thermal-Hydraulic Experiments and Modelling for Advanced Nuclear Reactor Systems

    Energy Technology Data Exchange (ETDEWEB)

    Song, C. H.; Chung, M. K.; Park, C. K. and others

    2005-04-15

    The objectives of the project are to study thermal hydraulic characteristics of reactor primary system for the verification of the reactor safety and to evaluate new safety concepts of new safety design features. To meet the research goal, several thermal hydraulic experiments were performed and related thermal hydraulic models were developed with the experimental data which were produced through the thermal hydraulic experiments. Followings are main research topics; - Multi-dimensional Phenomena in a Reactor Vessel Downcomer - Condensation Load and Thermal Mixing in the IRWST - Development of Thermal-Hydraulic Models for Two-Phase Flow - Development of Measurement Techniques for Two-Phase Flow - Supercritical Reactor T/H Characteristics Analysis From the above experimental and analytical studies, new safety design features of the advanced power reactors were verified and lots of the safety issues were also resolved.

  1. Transient Thermal Analysis of 3-D Integrated Circuits Packages by the DGTD Method

    KAUST Repository

    Li, Ping; Dong, Yilin; Tang, Min; Mao, Junfa; Jiang, Li Jun; Bagci, Hakan

    2017-01-01

    Since accurate thermal analysis plays a critical role in the thermal design and management of the 3-D system-level integration, in this paper, a discontinuous Galerkin time-domain (DGTD) algorithm is proposed to achieve this purpose

  2. Thermal and hydraulic analyses of the System 81 cold traps

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K.

    1977-06-15

    Thermal and hydraulic analyses of the System 81 Type I and II cold traps were completed except for thermal transients analysis. Results are evaluated, discussed, and reported. Analytical models were developed to determine the physical dimensions of the cold traps and to predict the performance. The FFTF cold trap crystallizer performances were simulated using the thermal model. This simulation shows that the analytical model developed predicts reasonably conservative temperatures. Pressure drop and sodium residence time calculations indicate that the present design will meet the requirements specified in the E-Specification. Steady state temperature data for the critical regions were generated to assess the magnitude of the thermal stress.

  3. TRANSPA: a code for transient thermal analysis of a single fuel pin

    International Nuclear Information System (INIS)

    Prenger, F.C.

    1985-02-01

    An analytical model (TRANSPA) for the transient thermal analysis of a single uranium carbide fuel pin was developed. This model uses thermal boundary conditions obtained from COBRA-WC output and calculates the transient thermal response of a single fuel pin to changes in internal power generation, coolant flowrate, or fuel pin physical configuration. The model uses the MITAS finite difference thermal analyzer. MITAS provides the means to input separate conductance models through the use of a user subroutine input capability. The model is a lumped-mass representation of the fuel pin using 26 nodes and 42 conductors. Run time for each transient analysis is approximately one minute of central processor time on the NOS operating system

  4. Integrated Software Environment for Pressurized Thermal Shock Analysis

    Directory of Open Access Journals (Sweden)

    Dino Araneo

    2011-01-01

    Full Text Available The present paper describes the main features and an application to a real Nuclear Power Plant (NPP of an Integrated Software Environment (in the following referred to as “platform” developed at University of Pisa (UNIPI to perform Pressurized Thermal Shock (PTS analysis. The platform is written in Java for the portability and it implements all the steps foreseen in the methodology developed at UNIPI for the deterministic analysis of PTS scenarios. The methodology starts with the thermal hydraulic analysis of the NPP with a system code (such as Relap5-3D and Cathare2, during a selected transient scenario. The results so obtained are then processed to provide boundary conditions for the next step, that is, a CFD calculation. Once the system pressure and the RPV wall temperature are known, the stresses inside the RPV wall can be calculated by mean a Finite Element (FE code. The last step of the methodology is the Fracture Mechanics (FM analysis, using weight functions, aimed at evaluating the stress intensity factor (KI at crack tip to be compared with the critical stress intensity factor KIc. The platform automates all these steps foreseen in the methodology once the user specifies a number of boundary conditions at the beginning of the simulation.

  5. Simulation modeling and analysis of a complex system of a thermal power plant

    Directory of Open Access Journals (Sweden)

    Sorabh Gupta

    2009-09-01

    Full Text Available The present paper deals with the opportunities for the modeling of flue gas and air system of a thermal power plant by making the performance evaluation using probabilistic approach. The present system of thermal plant under study consists of four subsystems with three possible states: full working, reduced capacity working and failed. Failure and repair rates for all the subsystems are assumed to be constant. Formulation of the problem is carried out using Markov Birth-Death process using probabilistic approach and a transition diagram represents the operational behavior of the system. Interrelationship among the full working and reduced working has been developed. A probabilistic model has been developed, considering some assumptions. Data in feasible range are selected from a survey of thermal plant and the effect of each subsystem on the system availability is tabulated in the form of availability matrices, which provides various performance/availability levels for different combinations of failure and repair rates of all subsystems. Based upon various availability values obtained in availability matrices and graphs of failure/repair rates of different subsystems, performance and optimum values of failure/repair rates for maximum availability, of each subsystem is analyzed and then maintenance priorities are decided for all subsystems.

  6. Thermal Design of a Protomodel Space Infrared Cryogenic System

    Directory of Open Access Journals (Sweden)

    Hyung Suk Yang

    2006-06-01

    Full Text Available A Protomodel Space Infrared Cryogenic System (PSICS cooled by a stirling cryocooler has been designed. The PSICS has an IR sensor inside the cold box which is cooled by a stirling cryocooler with refrigeration capacity of 500mW at 80K in a vacuum vessel. It is important to minimize the heat load so that the background thermal noise can be reduced. In order to design the cryogenic system with low heat load and to reduce the remained heat load, we have performed numerical analyses. In this paper, we present the design factors and the results obtained by the thermal analysis of the PSICS.

  7. Determination of γ′+γ / γ Phase Boundary in Ni-Al-Cr System Using DTA Thermal Analysis

    Directory of Open Access Journals (Sweden)

    Maciąg T.

    2016-03-01

    Full Text Available Mechanical properties at elevated temperature, in modern alloys based on intermetallic phase Ni3Al are connected with phase composition, especially with proportion of ordered phase γ′ (L12 and disordered phase γ (A1. In this paper, analysis of one key systems for mentioned alloys - Ni-Al-Cr, is presented. A series of alloys with chemical composition originated from Ni-rich part of Ni-Al-Cr system was prepared. DTA thermal analysis was performed on all samples. Based on shape of obtained curves, characteristic for continuous order-disorder transition, places of course of phase boundaries γ′+γ / γ were determined. Moreover, temperature of melting and freezing of alloys were obtained. Results of DTA analysis concerning phase boundary γ′+γ / γ indicated agreement with results obtained by authors using calorimetric solution method.

  8. How Accurately can we Calculate Thermal Systems?

    International Nuclear Information System (INIS)

    Cullen, D; Blomquist, R N; Dean, C; Heinrichs, D; Kalugin, M A; Lee, M; Lee, Y; MacFarlan, R; Nagaya, Y; Trkov, A

    2004-01-01

    I would like to determine how accurately a variety of neutron transport code packages (code and cross section libraries) can calculate simple integral parameters, such as K eff , for systems that are sensitive to thermal neutron scattering. Since we will only consider theoretical systems, we cannot really determine absolute accuracy compared to any real system. Therefore rather than accuracy, it would be more precise to say that I would like to determine the spread in answers that we obtain from a variety of code packages. This spread should serve as an excellent indicator of how accurately we can really model and calculate such systems today. Hopefully, eventually this will lead to improvements in both our codes and the thermal scattering models that they use in the future. In order to accomplish this I propose a number of extremely simple systems that involve thermal neutron scattering that can be easily modeled and calculated by a variety of neutron transport codes. These are theoretical systems designed to emphasize the effects of thermal scattering, since that is what we are interested in studying. I have attempted to keep these systems very simple, and yet at the same time they include most, if not all, of the important thermal scattering effects encountered in a large, water-moderated, uranium fueled thermal system, i.e., our typical thermal reactors

  9. Thermal-hydraulic analysis of SMART steam generator tube rupture using TASS/SMR-S code

    International Nuclear Information System (INIS)

    Kim, Hee-Kyung; Kim, Soo Hyoung; Chung, Young-Jong; Kim, Hyeon-Soo

    2013-01-01

    Highlights: ► The analysis was performed from the viewpoint of primary coolant leakage. ► The thermal hydraulic responses and the maximum leakage have been identified. ► There is no direct release into the atmosphere caused by an SGTR accident. ► SMART safety system works well against an SGTR accident. - Abstract: A steam generator tube rupture (SGTR) accident analysis for SMART was performed using the TASS/SMR-S code. SMART with a rated thermal power of 330 MWt has been developed at the Korea Atomic Energy Research Institute. The TASS/SMR-S code can analyze the thermal hydraulic phenomena of SMART in a full range of reactor operating conditions. An SGTR is one of the most important accidents from a thermal hydraulic and radiological viewpoint. A conservative analysis against a SMART SGTR was performed. The major concern of this analysis is to find the thermal hydraulic responses and maximum leakage amount from a primary to a secondary side caused by an SGTR accident. A sensitivity study searching for the conservative thermal hydraulic conditions, break locations, reactivity and other conditions was performed. The dominant parameters related with the integral leak are the high RCS pressure, low core inlet coolant temperature and low break location of the SG cassette. The largest integral leak comes to 28 tons in the most conservative case during 1 h. But there is no direct release into the atmosphere because the secondary system pressure is maintained with a sufficient margin for the design pressure. All leaks go to the condenser. The analysis results show that the primary and secondary system pressures are maintained below the design pressure and the SMART safety system is working well against an SGTR accident

  10. Integration of a solar thermal system in a medium-sized brewery using pinch analysis: Methodology and case study

    International Nuclear Information System (INIS)

    Eiholzer, Tobias; Olsen, Donald; Hoffmann, Sebastian; Sturm, Barbara; Wellig, Beat

    2017-01-01

    Highlights: • Methodologies to reduce energy consumption in batch processes are presented. • Pinch analysis is used to improve energy efficiency. • Integration potential for solar heat is presented on a Scottish brewery case study. • Governmental support is important in a company’s investment in renewables. - Abstract: In the food industry a major portion of thermal energy is required for low temperature applications (below 100 °C). As a consequence, there is a significant potential to substitute fossil fuels by the use of solar heat. This paper presents a methodology that first uses pinch analysis to optimize a medium-sized Scottish brewery from a direct heat recovery perspective followed by the integration of a solar thermal system. Both the time average model and time slice model were used to determine direct and indirect heat recovery potentials. In a second stage, an optimization of a chosen integration point was conducted to assess the viability of the resulting design concept. The economic analysis includes an assessment of the impact of restrictions in the UK government’s Renewable Heat Incentive program. It was determined that since solar thermal systems are financially supported up to an installed capacity of 200 kW, solar heat can only account for a maximum of 7.7% of the heat demand based on the investigated brewery. However, if there was no limitation in capacity, from an economic point of view, the solar fraction could almost be doubled drawing into question the need for the restriction. Nevertheless, a CO_2 saving potential of approximately 38 tons per year in conjunction with a payback period of 6.4 years was determined.

  11. Potential application of solar thermal systems for hot water production in Hong Kong

    International Nuclear Information System (INIS)

    Li Hong; Yang Hongxing

    2009-01-01

    This paper presents the evaluation results of conventional solar water heater (SWH) systems and solar assisted heat pump (SAHP) systems for hot water production in Hong Kong. An economic comparison and global warming impact analysis are conducted among the two kinds of solar thermal systems and traditional water heating systems (i.e. electric water heaters and towngas water heaters). The economic comparison results show that solar thermal systems have greater economic benefits than traditional water heating systems. In addition, conventional SWH systems are comparable with the SAHP systems when solar fractions are above 50%. Besides, analysis on the sensitivity of the total equivalent warming impact (TEWI) indicates that the towngas boosted SWH system has the greatest potential in greenhouse gas emission reduction with various solar collector areas and the electricity boosted SWH system has the comparative TEWI with the SAHP systems if its solar fraction is above 50%. As for SAHP systems, the solar assisted air source heat pump (SA-ASHP) system has the least global warming impact. Based on all investigation results, suggestions are given on the selection of solar thermal systems for applications in Hong Kong

  12. Maximizing the energy storage performance of phase change thermal storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Amin, N.A.M.; Bruno, F.; Belusko, M. [South Australia Univ., Mawson Lakes, South Australia (Australia). Inst. for Sustainable Systems and Technologies

    2009-07-01

    The demand for electricity in South Australia is highly influenced by the need for refrigeration and air-conditioning. An extensive literature review has been conducted on the use of phase change materials (PCMs) in thermal storage systems. PCMs use latent heat at the solid-liquid phase transition point to store thermal energy. They are considered to be useful as a thermal energy storage (TES) material because they can provide much higher energy storage densities compared to conventional sensible thermal storage materials. This paper reviewed the main disadvantages of using PCMs for energy storage, such as low heat transfer, super cooling and system design issues. Other issues with PCMs include incongruence and corrosion of heat exchanger surfaces. The authors suggested that in order to address these problems, future research should focus on maximizing heat transfer by optimizing the configuration of the encapsulation through a parametric analysis using a PCM numerical model. The effective conductivity in encapsulated PCMs in a latent heat thermal energy storage (LHTES) system can also be increased by using conductors in the encapsulation that have high thermal conductivity. 47 refs., 1 tab., 1 fig.

  13. Review of the integrated thermal and nonthermal treatment system studies. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-01

    This report contains a review and evaluation of three systems analysis studies performed by LITCO on integrated thermal treatment systems and integrated nonthermal treatment systems for the remediation of mixed low-level waste stored throughout the US Department of Energy weapons complex. The review was performed by an independent team of nine researchers from the Energy and Environmental Research Center, Science Applications International Corporation, the Waste Policy Institute, and Virginia Tech. The three studies reviewed were as follows: Integrated Thermal Treatment System Study, Phase 1 -- issued July 1994; Integrated Thermal Treatment System Study, Phase 2 -- issued February 1996; and Integrated Nonthermal Treatment System Study -- drafted March 1996. The purpose of this review was to (1) determine whether the assumptions of the studies were adequate to produce an unbiased review of both thermal and nonthermal systems, (2) to identify the critical areas of the studies that would benefit from further investigation, and (3) to develop a standard template that could be used in future studies to assure a sound application of systems engineering.

  14. Review of the integrated thermal and nonthermal treatment system studies. Final report

    International Nuclear Information System (INIS)

    1996-10-01

    This report contains a review and evaluation of three systems analysis studies performed by LITCO on integrated thermal treatment systems and integrated nonthermal treatment systems for the remediation of mixed low-level waste stored throughout the US Department of Energy weapons complex. The review was performed by an independent team of nine researchers from the Energy and Environmental Research Center, Science Applications International Corporation, the Waste Policy Institute, and Virginia Tech. The three studies reviewed were as follows: Integrated Thermal Treatment System Study, Phase 1 -- issued July 1994; Integrated Thermal Treatment System Study, Phase 2 -- issued February 1996; and Integrated Nonthermal Treatment System Study -- drafted March 1996. The purpose of this review was to (1) determine whether the assumptions of the studies were adequate to produce an unbiased review of both thermal and nonthermal systems, (2) to identify the critical areas of the studies that would benefit from further investigation, and (3) to develop a standard template that could be used in future studies to assure a sound application of systems engineering

  15. Drift scale thermomechanical analysis for thermal loading and retrievability studies

    International Nuclear Information System (INIS)

    Tsai, F.C.

    1995-01-01

    The repository portion of the Mined Geologic Disposal System for the disposal of spent nuclear fuel and high-level radioactive waste is currently in the advanced conceptual design stage. In support of systems studies, a numerical method was used to estimate the stability of emplacement drifts. Thermomechanical analyses, using the Discontinuous Deformation Analysis code, were performed using input data from Yucca Mountain documents. The analysis found that the stresses produced in the rock at thermal loads of 27.4 kilograms uranium per m2 (KgU/m2) would exceed stability criteria and could result in tunnel instability. At thermal loads between 20.5 KgU/m2, the drift is predicted to be stable and its structural integrity remains after thermal loading. In this case, the smaller diameter drift emplacement appears to have better stability. However, local rock spalling may occur. According to the numerical prediction, more rock fall may occur during the retrieval period due to the stress relaxation caused by the rapid cooling in the immediate drift area

  16. Thermal stratification and fatigue stress analysis for pressurizer surge line

    International Nuclear Information System (INIS)

    Yu Xiaofei; Zhang Yixiong

    2011-01-01

    Thermal stratification of pressurizer surge line induced by the inside fluid results in the global bending moments, local thermal stresses, unexpected displacements and support loadings of the pipe system. In order to avoid a costly three-dimensional computation, a combined 1D/2D technique has been developed and implemented to analyze the thermal stratification and fatigue stress of pressurize surge line of QINSHAN Phase II Extension Nuclear Power Project in this paper, using the computer codes SYSTUS and ROCOCO. According to the mechanical analysis results of stratification, the maximum stress and cumulative usage factor are obtained. The results indicate that the stress and fatigue intensity considering thermal stratification satisfies RCC-M criterion. (authors)

  17. Foundation heat transfer analysis for buildings with thermal piles

    International Nuclear Information System (INIS)

    Almanza Huerta, Luis Enrique; Krarti, Moncef

    2015-01-01

    Highlights: • A numerical transient thermal model for thermo-active foundations is developed. • Thermal interactions between thermal piles and building foundations are evaluated. • A simplified analysis method of thermal interactions between thermal piles and building foundations is developed. - Abstract: Thermal piles or thermo-active foundations utilize heat exchangers embedded within foundation footings to heat and/or cool buildings. In this paper, the impact of thermal piles on building foundation heat transfer is investigated. In particular, a simplified analysis method is developed to estimate the annual ground-coupled foundation heat transfer when buildings are equipped with thermal piles. First, a numerical analysis of the thermal performance of thermo-active building foundations is developed and used to assess the interactions between thermal piles and slab-on-grade building foundations. The impact of various design parameters and operating conditions is evaluated including foundation pile depth, building slab width, foundation insulation configuration, and soil thermal properties. Based on the results of a series of parametric analyses, a simplified analysis method is presented to assess the impact of the thermal piles on the annual heat fluxes toward or from the building foundations. A comparative evaluation of the predictions of the simplified analysis method and those obtained from the detailed numerical analysis indicated good agreement with prediction accuracy lower than 5%. Moreover, it is found that thermal piles can affect annual building foundation heat loss/gain by up to 30% depending on foundation size and insulation level

  18. Exergoeconomic analysis of glycol cold thermal energy storage systems for building applications. Paper no. IGEC-1-155

    International Nuclear Information System (INIS)

    Bakan, K.; Dincer, I.; Rosen, M.A.

    2005-01-01

    An exergoeconomic analysis is reported of glycol cold thermal energy storage (CTES) systems. Exergoeconomics combines thermodynamic analysis (using both the first and second laws of thermodynamics) with principles of economics, mostly cost accounting. Exergy analysis provides more meaningful and useful information than energy analysis about the efficiency and performance of glycol CTES. The main reason is that traditional analyses are based on mass and energy balances and only external losses can be detected, while exergy analysis measures the quality of energy and includes irreversibility's that occur during any process. According to simulation results, the exergy efficiency of the glycol CTES is roughly 75% less than the energy efficiency due to irreversibility's, and the system efficiency is less than the tank efficiency. Irreversibility's for the overall system are higher than for the tank. Also, the reference ambient temperature has an effect on exergy destruction and efficiency. A 5 o C change in ambient temperature causes a 25% change in exergy efficiency. This result implies that cold energy is more efficient at higher ambient temperatures. Heat losses from the tank depend on the ambient temperature; a 5 o C increase in ambient temperature causes a heat loss increase of 6%. (author)

  19. Inserts thermal coupling analysis in hexagonal honeycomb plates used for satellite structural design

    International Nuclear Information System (INIS)

    Boudjemai, A.; Mankour, A.; Salem, H.; Amri, R.; Hocine, R.; Chouchaoui, B.

    2014-01-01

    Mechanical joints and fasteners are essential elements in joining structural components in mechanical systems. The thermal coupling effect between the adjacent inserts depends to a great extent on the thermal properties of the inserts and the clearance. In this paper the Finite-Element Method (FEM) has been employed to study the insert thermal coupling behaviour of the hexagonal honeycomb panel. Fully coupled thermal analysis was conducted in order to predict thermal coupling phenomena caused by the adjacent inserts under extreme thermal loading conditions. Detailed finite elements models for a honeycomb panel are developed in this study including the insert joints. New approach of the adhesive joint is modelled. Thermal simulations showed that the adjacent inserts cause thermal interference and the adjacent inserts are highly sensitive to the effect of high temperatures. The clearance and thermal interference between the adjacent inserts have an important influence on the satellite equipments (such as the electronics box), which can cause the satellite equipments failures. The results of the model presented in this analysis are significant in the preliminary satellites structural dimensioning which present an effective approach of development by reducing the cost and the time of analysis. - Highlights: •In this work we perform thermal analysis of honeycomb plates using finite element method. •Detailed finite elements models for honeycomb panel are developed in this study including the insert joints. •New approach of the adhesive joint is modelled. •The adjacent inserts cause the thermal interference. •We conclude that this work will help in the analysis and the design of complex satellite structures

  20. Thermal compatibility of dental ceramic systems using cylindrical and spherical geometries

    Science.gov (United States)

    DeHoff, Paul H.; Barrett, Allyson A.; Lee, Robert B.; Anusavice, Kenneth J.

    2009-01-01

    Objective To test the hypothesis that bilayer ceramic cylinders and spheres can provide valid confirmation of thermal incompatibility stresses predicted by finite element analyses. Methods A commercial core ceramic and an experimental core ceramic were used to fabricate open-ended cylinders and core ceramic spheres. The core cylinders and spheres were veneered with one of four commercial dental ceramics representing four thermally compatible groups and four thermally incompatible groups. Axisymmetric thermal and viscoelastic elements in the ANSYS finite element program were used to calculate temperatures and stresses for each geometry and ceramic combination. This process required a transient heat transfer analysis for each combination to determine input temperatures for the structural model. Results After fabrication, each specimen was examined visually using fiberoptic transillumination for evidence of cracking. There were 100% failures of the thermally incompatible cylinders while none of the thermally compatible combinations failed. Among the spheres, 100% of the thermally incompatible systems failed, 16% of one of the thermally compatible systems failed, and none of the remaining compatible combinations failed. The calculated stress values were in general agreement with the experimental observations, i.e., low residual stresses for the specimens that did not fail and high residual stresses for the specimens that did fail. Significance Simple screening geometries can be used to identify highly incompatible ceramic combinations, but they do not identify marginally incompatible systems. PMID:17949805

  1. Analysis of Thermal Design of Heating Units with Meteorological Climate Peculiarities

    Science.gov (United States)

    Seminenko, A. S.; Elistratova, Y. V.; Pererva, M. I.; Moiseev, M. V.

    2018-03-01

    This article is devoted to the analysis of thermal design of heating units, one of the compulsory calculations of heating systems, which ensures their stable and efficient operation. The article analyses the option of a single-pipe heating system with shifted end-capping areas and the overhead supply main; the difference is shown in the calculation results between heat balance equation of the heating unit and calculation of the actual heat flux (heat transfer coefficient) taking into account deviation from the standardized (technical passport) operating conditions. The calculation of the thermal conditions of residential premises is given, the deviation of the internal air temperature is shown taking into account the discrepancy between the calculation results for thermal energy.

  2. SBWR core thermal hydraulic analysis during startup

    International Nuclear Information System (INIS)

    Lin, J.H.; Huang, R.L.; Sawyer, C.D.

    1993-01-01

    This paper reports on a thermal hydraulic analysis of the SIMPLIFIED BOILING WATER REACTOR (SBWR) during startup. The potential instability during a SBWR startup has drawn the attention of designers, researchers, and engineers. It has not been a concern for a Boiling Water Reactor (BWR) with forced recirculation; however, for SBWR with natural circulation the concern exists. The concern is about the possibility of a geysering mode oscillation during SBWR startup from a cold temperature and a low system pressure with a low natural circulation flow rate. A thermal hydraulic analysis of the SBWR is performed in simulation of the startup using the TRACG computer code. The temperature, pressure, and reactor power profiles of SBWR during the startup are presented. The results are compared with the data of a natural circulation boiling water reactor, the DODEWAARD plant, in which no instabilities have been observed during many startups. It is shown that a SBWR startup which follows proper procedures, geysering and other modes of oscillations can be avoided

  3. Thermal Analysis of Solar Panels

    Science.gov (United States)

    Barth, Nicolas; de Correia, João Pedro Magalhães; Ahzi, Saïd; Khaleel, Mohammad Ahmed

    In this work, we propose to analyze the thermal behavior of PV panels using finite element simulations (FEM). We applied this analysis to compute the temperature distribution in a PV panel BP 350 subjected to different atmospheric conditions. This analysis takes into account existing formulations in the literature and, based on NOCT conditions, meteorological data was used to validate our approach for different wind speed and solar irradiance. The electrical performance of the PV panel was also studied. The proposed 2D FEM analysis is applied to different region's climates and was also used to consider the role of thermal inertia on the optimization of the PV device efficiency.

  4. PSA-2, Stress Analysis, Thermal Expansion and Loads in Multi Anchor Piping System

    Energy Technology Data Exchange (ETDEWEB)

    Nickols, A N [Codes Coordinator, Atomics International, P. O. Box 309, Canoga Park, California 91304 (United States)

    1975-03-01

    1 - Description of problem or function: PSA2 computes the reactions and stresses caused by thermal expansion and loads in a multi-anchor piping system which may contain loops and may be partially restrained at any point in any direction. 2 - Method of solution: The linear equations for the statically indeterminate pipe system are set up by a generalization of Brock's matrix method. By a systematic use of linear transforms, the matrix of the system of linear equations can be obtained by incidence algebra in the form of a symmetric banded matrix. 2 - Restrictions on the complexity of the problem - Maximum of: 36 sections. 3 - Unusual features of the program - PSA2 takes into account: (a) elasticity of the attachment of the pipe to the foundation, (b) restraints on pipe displacements by anchors and intermediate partial constraints of linear type, (c) given constant forces and moments acting upon the pipe system, (d) thermal expansion, (e) any geometrical structure of the pipe system, (f) several cases of stressing per pipe system, and (g) both metric and English units.

  5. PSA-2, Stress Analysis, Thermal Expansion and Loads in Multi Anchor Piping System

    International Nuclear Information System (INIS)

    Nickols, A.N.

    1975-01-01

    1 - Description of problem or function: PSA2 computes the reactions and stresses caused by thermal expansion and loads in a multi-anchor piping system which may contain loops and may be partially restrained at any point in any direction. 2 - Method of solution: The linear equations for the statically indeterminate pipe system are set up by a generalization of Brock's matrix method. By a systematic use of linear transforms, the matrix of the system of linear equations can be obtained by incidence algebra in the form of a symmetric banded matrix. 2 - Restrictions on the complexity of the problem - Maximum of: 36 sections. 3 - Unusual features of the program - PSA2 takes into account: (a) elasticity of the attachment of the pipe to the foundation, (b) restraints on pipe displacements by anchors and intermediate partial constraints of linear type, (c) given constant forces and moments acting upon the pipe system, (d) thermal expansion, (e) any geometrical structure of the pipe system, (f) several cases of stressing per pipe system, and (g) both metric and English units

  6. Nonablative lightweight thermal protection system for Mars Aeroflyby Sample collection mission

    Science.gov (United States)

    Suzuki, Toshiyuki; Aoki, Takuya; Ogasawara, Toshio; Fujita, Kazuhisa

    2017-07-01

    In this study, the concept of a nonablative lightweight thermal protection system (NALT) were proposed for a Mars exploration mission currently under investigation in Japan. The NALT consists of a carbon/carbon (C/C) composite skin, insulator tiles, and a honeycomb sandwich panel. Basic thermal characteristics of the NALT were obtained by conducting heating tests in high-enthalpy facilities. Thermal conductivity values of the insulator tiles as well as the emissivity values of the C/C skin were measured to develop a numerical analysis code for predicting NALT's thermal performance in flight environments. Finally, a breadboard model of a 600-mm diameter NALT aeroshell was developed and qualified through vibration and thermal vacuum tests.

  7. Modelling study, efficiency analysis and optimisation of large-scale Adiabatic Compressed Air Energy Storage systems with low-temperature thermal storage

    International Nuclear Information System (INIS)

    Luo, Xing; Wang, Jihong; Krupke, Christopher; Wang, Yue; Sheng, Yong; Li, Jian; Xu, Yujie; Wang, Dan; Miao, Shihong; Chen, Haisheng

    2016-01-01

    Highlights: • The paper presents an A-CAES system thermodynamic model with low temperature thermal energy storage integration. • The initial parameter value ranges for A-CAES system simulation are identified from the study of a CAES plant in operation. • The strategies of system efficiency improvement are investigated via a parametric study with a sensitivity analysis. • Various system configurations are discussed for analysing the efficiency improvement potentials. - Abstract: The key feature of Adiabatic Compressed Air Energy Storage (A-CAES) is the reuse of the heat generated from the air compression process at the stage of air expansion. This increases the complexity of the whole system since the heat exchange and thermal storage units must have the capacities and performance to match the air compression/expansion units. Thus it raises a strong demand in the whole system modelling and simulation tool for A-CAES system optimisation. The paper presents a new whole system mathematical model for A-CAES with simulation implementation and the model is developed with consideration of lowing capital cost of the system. The paper then focuses on the study of system efficiency improvement strategies via parametric analysis and system structure optimisation. The paper investigates how the system efficiency is affected by the system component performance and parameters. From the study, the key parameters are identified, which give dominant influences in improving the system efficiency. The study is extended onto optimal system configuration and the recommendations are made for achieving higher efficiency, which provides a useful guidance for A-CAES system design.

  8. Modelling and Control of Thermal System

    Directory of Open Access Journals (Sweden)

    Vratislav Hladky

    2014-01-01

    Full Text Available Work presented here deals with the modelling of thermal processes in a thermal system consisting of direct and indirect heat exchangers. The overal thermal properties of the medium and the system itself such as liquid mixing or heat capacity are shortly analysed and their features required for modelling are reasoned and therefore simplified or neglected. Special attention is given to modelling heat losses radiated into the surroundings through the walls as they are the main issue of the effective work with the heat systems. Final part of the paper proposes several ways of controlling the individual parts’ temperatures as well as the temperature of the system considering heating elements or flowage rate as actuators.

  9. Steady-state thermal hydraulic analysis and flow channel blockage accident analysis of JRR-3 silicide core

    International Nuclear Information System (INIS)

    Kaminaga, Masanori

    1997-03-01

    JRR-3 is a light water moderated and cooled, beryllium and heavy water reflected pool type research reactor using low enriched uranium (LEU) plate-type fuels. Its thermal power is 20 MW. The core conversion program from uranium-aluminum (UAl x -Al) dispersion type fuel (aluminide fuel) to uranium-silicon-aluminum (U 3 Si 2 -Al) dispersion type fuel (silicide fuel) is currently conducted at the JRR-3. This report describes about the steady-state thermal hydraulic analysis results and the flow channel blockage accident analysis result. In JRR-3, there are two operation mode. One is high power operation mode up to 20 MW, under forced convection cooling using the primary and the secondary cooling systems. The other is low power operation mode up to 200 kW, under natural circulation cooling between the reactor core and the reactor pool without the primary and the secondary cooling systems. For the analysis of the flow channel blockage accident, COOLOD code was used. On the other hand, steady-state thermal hydraulic analysis for both of the high power operation mode under forced convection cooling and low power operation under natural convection cooling, COOLOD-N2 code was used. From steady-state thermal hydraulic analysis results of both forced and natural convection cooling, fuel temperature, minimum DNBR etc. meet the design criteria and JRR-3 LEU silicide core has enough safety margin under normal operation conditions. Furthermore, flow channel blockage accident analysis results show that one channel flow blockage accident meet the safety criteria for accident conditions which have been established for JRR-3 LEU silicide core. (author)

  10. Investigation on the effect of thermal resistances on a highly concentrated photovoltaic-thermoelectric hybrid system

    International Nuclear Information System (INIS)

    Zhang, Jin; Xuan, Yimin

    2016-01-01

    Highlights: • The highly concentrated PV-TE hybrid system is studied. • The performances of different cooling systems are analyzed and compared. • Sandwiching a copper plate between the PV and TE can improve the efficiency. • Four thermal design principles of the system are proposed. - Abstract: A thermal analysis of a highly concentrated photovoltaic-thermoelectric (PV-TE) hybrid system is carried out in this paper. Both the output power and the temperature distribution in the hybrid system are calculated by means of a three-dimensional numerical model. Three possible approaches for designing the highly concentrated PV-TE hybrid system are presented by analyzing the thermal resistance of the whole system. First, the sensitivity analysis shows that the thermal resistance between the TE module and the environment has a more great effect on the output power than the thermal resistance between the PV and the TE. The influence of the natural convection and the radiation can be ignored for the highly concentrated PV-TE hybrid system. Second, it is necessary to sandwich a copper plate between the PV and the TE for decreasing the thermal resistance between the PV and the TE. The role of the copper plate is to improve the temperature uniformity. Third, decreasing the area of PV cells can improve the efficiency of the highly concentrated PV-TE hybrid system. It should be pointed out that decreasing the area of PV cells also increases the total thermal resistance, but the raise of the efficiency is caused by the reduction of the heat transfer rate of the system. Therefore, the principle of minimizing the total thermal resistance may not be suitable for optimizing the area of PV cells.

  11. Interim report on nuclear waste depository thermal analysis

    International Nuclear Information System (INIS)

    Altenbach, T.J.

    1978-01-01

    A thermal analysis of a deep geologic depository for spent nuclear fuel is being conducted. The TRUMP finite difference heat transfer code is used to analyze a 3-dimensional model of the depository. The model uses a unit cell consisting of one spent fuel canister buried in salt beneath a ventilated room in the depository. A base case was studied along with several parametric variations. It is concluded that this method is appropriate for analyzing the thermal response of the system, and that the most important parameter in determining the maximum temperatures is the canister heat generation rate. The effects of room ventilation and different depository media are secondary

  12. Thermal sine-Gordon system in the presence of different types of dissipation

    DEFF Research Database (Denmark)

    Salerno, M.; Samuelsen, Mogens Rugholm; Svensmark, Henrik

    1988-01-01

    The effects of thermal fluctuations on solitons and phonons of the sine-Gordon system are investigated in the presence of a αφt-βφxxt dissipation. The analysis requires the assumption of a more general autocorrelation function for the noise than the one used in previous works. We verify that this......The effects of thermal fluctuations on solitons and phonons of the sine-Gordon system are investigated in the presence of a αφt-βφxxt dissipation. The analysis requires the assumption of a more general autocorrelation function for the noise than the one used in previous works. We verify...

  13. Integrated operation of hydro thermal system

    International Nuclear Information System (INIS)

    Nanthakumar, J.

    1994-01-01

    Long-term power system expansion planning studies are carried out to meet the electricity requirement in the future. Prior to the expansion planning studies, it is essential to know the energy potential of the existing generating system, especially the hydro power plants. Detailed hydro thermal stimulation studies of the integrated system is therefore carried out to determine the best way to maximise the hydro energy of the existing and committed plants. The results of the integrated system simulated model are stored in numerous files and are available for retrieval. Most important output used for expansion analysis is the energy production of each hydro plant. The annual hydro energy potential of the total hydro system of Sri Lanka for the hydrological year from 1949 to 1988 is given. Hydro condition data with different probability levels are also indicated

  14. Econometric modelling of certain nuclear power systems based on thermal and fast breeder reactors

    International Nuclear Information System (INIS)

    Pavelescu, M.; Pioaru, C.; Ursu, I.

    1988-01-01

    Certain known economic analysis models for a LMFBR fast breeder and CANDU thermal solitary reactors are presented, based on the concepts of discounting and levelization. These models are subsequently utilized as a basis for establishing an original model for the econometric analysis of certain thermal reactor systems or/and fast breeder reactors. Case studies are subsequently conducted with the systems: 1-CANDU, 2-LMFBR, 3-CANDU + LMFBR which enables us to draw certain interesting conclusions for a long range nuclear power policy. (author)

  15. Development of numerical simulation technology for high resolution thermal hydraulic analysis

    International Nuclear Information System (INIS)

    Yoon, Han Young; Kim, K. D.; Kim, B. J.; Kim, J. T.; Park, I. K.; Bae, S. W.; Song, C. H.; Lee, S. W.; Lee, S. J.; Lee, J. R.; Chung, S. K.; Chung, B. D.; Cho, H. K.; Choi, S. K.; Ha, K. S.; Hwang, M. K.; Yun, B. J.; Jeong, J. J.; Sul, A. S.; Lee, H. D.; Kim, J. W.

    2012-04-01

    A realistic simulation of two phase flows is essential for the advanced design and safe operation of a nuclear reactor system. The need for a multi dimensional analysis of thermal hydraulics in nuclear reactor components is further increasing with advanced design features, such as a direct vessel injection system, a gravity driven safety injection system, and a passive secondary cooling system. These features require more detailed analysis with enhanced accuracy. In this regard, KAERI has developed a three dimensional thermal hydraulics code, CUPID, for the analysis of transient, multi dimensional, two phase flows in nuclear reactor components. The code was designed for use as a component scale code, and/or a three dimensional component, which can be coupled with a system code. This report presents an overview of the CUPID code development and preliminary assessment, mainly focusing on the numerical solution method and its verification and validation. It was shown that the CUPID code was successfully verified. The results of the validation calculations show that the CUPID code is very promising, but a systematic approach for the validation and improvement of the physical models is still needed

  16. Combined photovoltaic and solar-thermal systems: overcoming barriers to market acceptance

    International Nuclear Information System (INIS)

    Collins, M.R.

    2005-01-01

    Combined Photovoltaic and Solar-Thermal Systems (PV/T Systems) combine Photovoltaic (PV) and solar thermal technologies into one system with both electrical and thermal energy output. PV/T systems have several perceived advantages to stand-alone PV or solar-thermal systems. The increased efficiency and dual nature of the systems make suitable for situations where installation space is limited, and for homeowners who are forced to decide between meeting thermal or electrical needs. The financial benefit of the combined system is also significant, as the long payback of PV systems is joined with a relatively short payback of solar thermal systems. A background of PV/T was presented, with details of classifications and the International Energy Association's program to evaluate the technical status of PV/T systems and formulate a roadmap for future development. It was noted that input from the Solar Heating and Cooling Program (SHCP) is needed to help identify market barriers in PV/T systems. This paper reviewed existing and potential PV/T systems and their technical status, and reported on the methodology established by IEA group 35. The systems were grouped according to thermal collector types of unglazed water collectors, glazed water collectors, unglazed air collectors, glazed air collectors, air-flow windows, and concentrating collectors. It was noted that a number of new systems are currently being developed, including concentrating collectors with water and air heating, unglazed air heating systems, and unglazed water heating systems. It was noted that apart from technical barriers, efficient design and performance prediction are also problematic, as tools for predicting performance do not exist. The same tools will be used to optimize PV/T system designs. It was suggested that standardized reporting methods, simulation and sizing tools and demonstration products need to be created and that regional certification issues need to be identified. Environmental

  17. 21 CFR 870.5900 - Thermal regulating system.

    Science.gov (United States)

    2010-04-01

    ... system. (a) Identification. A thermal regulating system is an external system consisting of a device that is placed in contact with the patient and a temperature controller for the device. The system is used... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Thermal regulating system. 870.5900 Section 870...

  18. Analysis of molten salt thermal-hydraulics using computational fluid dynamics

    International Nuclear Information System (INIS)

    Yamaji, B.; Csom, G.; Aszodi, A.

    2003-01-01

    To give a good solution for the problem of high level radioactive waste partitioning and transmutation is expected to be a pro missing option. Application of this technology also could extend the possibilities of nuclear energy. Large number of liquid-fuelled reactor concepts or accelerator driven subcritical systems was proposed as transmutors. Several of these consider fluoride based molten salts as the liquid fuel and coolant medium. The thermal-hydraulic behaviour of these systems is expected to be fundamentally different than the behaviour of widely used water-cooled reactors with solid fuel. Considering large flow domains three-dimensional thermal-hydraulic analysis is the method seeming to be applicable. Since the fuel is the coolant medium as well, one can expect a strong coupling between neutronics and thermal-hydraulics too. In the present paper the application of Computational Fluid Dynamics for three-dimensional thermal-hydraulics simulations of molten salt reactor concepts is introduced. In our past and recent works several calculations were carried out to investigate the capabilities of Computational Fluid Dynamics through the analysis of different molten salt reactor concepts. Homogenous single region molten salt reactor concept is studied and optimised. Another single region reactor concept is introduced also. This concept has internal heat exchanges in the flow domain and the molten salt is circulated by natural convection. The analysis of the MSRE experiment is also a part of our work since it may form a good background from the validation point of view. In the paper the results of the Computational Fluid Dynamics calculations with these concepts are presented. In the further work our objective is to investigate the thermal-hydraulics of the multi-region molten salt reactor (Authors)

  19. Efficient thermal management for multiprocessor systems

    OpenAIRE

    Coşkun, Ayşe Kıvılcım

    2009-01-01

    High temperatures and large thermal variations on the die create severe challenges in system reliability, performance, leakage power, and cooling costs. Designing for worst-case thermal conditions is highly costly and time-consuming. Therefore, dynamic thermal management methods are needed to maintain safe temperature levels during execution. Conventional management techniques sacrifice performance to control temperature and only consider the hot spots, neglecting the effects of thermal varia...

  20. Contact Thermal Analysis and Wear Simulation of a Brake Block

    Directory of Open Access Journals (Sweden)

    Nándor Békési

    2013-01-01

    Full Text Available The present paper describes an experimental test and a coupled contact-thermal-wear analysis of a railway wheel/brake block system through the braking process. During the test, the friction, the generated heat, and the wear were evaluated. It was found that the contact between the brake block and the wheel occurs in relatively small and slowly moving hot spots, caused by the wear and the thermal effects. A coupled simulation method was developed including numerical frictional contact, transient thermal and incremental wear calculations. In the 3D simulation, the effects of the friction, the thermal expansion, the wear, and the temperature-dependent material properties were also considered. A good agreement was found between the results of the test and the calculations, both for the thermal and wear results. The proposed method is suitable for modelling the slowly oscillating wear caused by the thermal expansions in the contact area.

  1. Mathematical model for thermal and entropy analysis of thermal solar collectors by using Maxwell nanofluids with slip conditions, thermal radiation and variable thermal conductivity

    Science.gov (United States)

    Aziz, Asim; Jamshed, Wasim; Aziz, Taha

    2018-04-01

    In the present research a simplified mathematical model for the solar thermal collectors is considered in the form of non-uniform unsteady stretching surface. The non-Newtonian Maxwell nanofluid model is utilized for the working fluid along with slip and convective boundary conditions and comprehensive analysis of entropy generation in the system is also observed. The effect of thermal radiation and variable thermal conductivity are also included in the present model. The mathematical formulation is carried out through a boundary layer approach and the numerical computations are carried out for Cu-water and TiO2-water nanofluids. Results are presented for the velocity, temperature and entropy generation profiles, skin friction coefficient and Nusselt number. The discussion is concluded on the effect of various governing parameters on the motion, temperature variation, entropy generation, velocity gradient and the rate of heat transfer at the boundary.

  2. Cyclic elastic analysis of a PWR nozzle subjected to a repeated thermal shock

    International Nuclear Information System (INIS)

    Locci, J.M.; Prost, J.P.

    1979-01-01

    In the primary piping system of a PWR nuclear power plant, some nozzles are subjected to strong thermal shocks due to sudden thermal variations in the internal water flow. The thermal gradients are sufficiently high to induce general elastic plastic behaviour. The design of these nozzles using the simplified elastic plastic analysis given in the ASME III Code NB-3200 generally leads to a very high usage factor. The aim of this work is to show by giving an example that a complete cyclic elastic plastic analysis makes it possible to considerably reduce the usage factor. (orig.)

  3. A critical review on energy, exergy, exergoeconomic and economic (4-E analysis of thermal power plants

    Directory of Open Access Journals (Sweden)

    Ravinder Kumar

    2017-02-01

    Full Text Available The growing energy supply, demand has created an interest towards the plant equipment efficiency and the optimization of existing thermal power plants. Also, a thermal power plant dependency on fossil fuel makes it a little bit difficult, because of environmental impacts has been always taken into consideration. At present, most of the power plants are going to be designed by the energetic performance criterion which is based on the first law of thermodynamics. Sometimes, the system energy balance is not sufficient for the possible finding of the system imperfections. Energy losses taking place in a system can be easily determined by using exergy analysis. Hence, it is a powerful tool for the measurement of energy quality, thereby helps to make complex thermodynamic systems more efficient. Nowadays, economic optimization of plant is also a big problem for researchers because of the complex nature. At a viewpoint of this, a comprehensive literature review over the years of energy, exergy, exergoeconomic and economic (4-E analysis and their applications in thermal power plants stimulated by coal, gas, combined cycle and cogeneration system have been done thoroughly. This paper is addressed to those researchers who are doing their research work on 4-E analysis in various thermal power plants. If anyone extracts an idea for the development of the concept of 4-E analysis using this article, we will achieve our goal. This review also indicates the scope of future research in thermal power plants.

  4. Dynamic response analysis of an aircraft structure under thermal-acoustic loads

    International Nuclear Information System (INIS)

    Cheng, H; Li, H B; Zhang, W; Wu, Z Q; Liu, B R

    2016-01-01

    Future hypersonic aircraft will be exposed to extreme combined environments includes large magnitude thermal and acoustic loads. It presents a significant challenge for the integrity of these vehicles. Thermal-acoustic test is used to test structures for dynamic response and sonic fatigue due to combined loads. In this research, the numerical simulation process for the thermal acoustic test is presented, and the effects of thermal loads on vibro-acoustic response are investigated. To simulate the radiation heating system, Monte Carlo theory and thermal network theory was used to calculate the temperature distribution. Considering the thermal stress, the high temperature modal parameters are obtained with structural finite element methods. Based on acoustic finite element, modal-based vibro-acoustic analysis is carried out to compute structural responses. These researches are very vital to optimum thermal-acoustic test and structure designs for future hypersonic vehicles structure (paper)

  5. Review of the integrated thermal and nonthermal treatment system studies

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-01

    This report contains a review and evaluation of three systems analysis studies performed by LITCO on integrated thermal treatment systems and integrated nonthermal treatment systems for the remediation of mixed low-level waste stored throughout the US Department of Energy weapons complex. The review was performed by an independent team of nine researchers from the Energy and Environmental Research Center, Science Applications International Corporation, the Waste Policy Institute, and Virginia Tech. The purpose of this review was to (1) determine whether the assumptions of the studies were adequate to produce an unbiased review of both thermal and nonthermal systems, (2) to identify the critical areas of the studies that would benefit from further investigation, and (3) to develop a standard template that could be used in future studies to assure a sound application of systems engineering.

  6. Review of the integrated thermal and nonthermal treatment system studies

    International Nuclear Information System (INIS)

    1996-01-01

    This report contains a review and evaluation of three systems analysis studies performed by LITCO on integrated thermal treatment systems and integrated nonthermal treatment systems for the remediation of mixed low-level waste stored throughout the US Department of Energy weapons complex. The review was performed by an independent team of nine researchers from the Energy and Environmental Research Center, Science Applications International Corporation, the Waste Policy Institute, and Virginia Tech. The purpose of this review was to (1) determine whether the assumptions of the studies were adequate to produce an unbiased review of both thermal and nonthermal systems, (2) to identify the critical areas of the studies that would benefit from further investigation, and (3) to develop a standard template that could be used in future studies to assure a sound application of systems engineering

  7. Development of a direct push based in-situ thermal conductivity measurement system

    Science.gov (United States)

    Chirla, Marian Andrei; Vienken, Thomas; Dietrich, Peter; Bumberger, Jan

    2016-04-01

    Heat pump systems are commonly utilized in Europe, for the exploitation of the shallow geothermal potential. To guarantee a sustainable use of the geothermal heat pump systems by saving resources and minimizing potential negative impacts induced by temperature changes within soil and groundwater, new geothermal exploration methods and tools are required. The knowledge of the underground thermal properties is a necessity for a correct and optimum design of borehole heat exchangers. The most important parameter that indicates the performance of the systems is thermal conductivity of the ground. Mapping the spatial variability of thermal conductivity, with high resolution in the shallow subsurface for geothermal purposes, requires a high degree of technical effort to procure adequate samples for thermal analysis. A collection of such samples from the soil can disturb sample structure, so great care must be taken during collection to avoid this. Factors such as transportation and sample storage can also influence measurement results. The use of technologies like Thermal Response Test (TRT) require complex mechanical and electrical systems for convective heat transport in the subsurface and longer monitoring times, often three days. Finally, by using thermal response tests, often only one integral value is obtained for the entire coupled subsurface with the borehole heat exchanger. The common thermal conductivity measurement systems (thermal analyzers) can perform vertical thermal conductivity logs only with the aid of sample procurement, or by integration into a drilling system. However, thermal conductivity measurements using direct push with this type of probes are not possible, due to physical and mechanical limitations. Applying vertical forces using direct push technology, in order to penetrate the shallow subsurface, can damage the probe and the sensors systems. The aim of this study is to develop a new, robust thermal conductivity measurement probe, for direct

  8. Status and topics of thermal-hydraulic analysis for next-generation LWRs with passive safety systems

    International Nuclear Information System (INIS)

    Aritomi, Masanori; Ohnuki, Akira; Arai, Kenji; Kikuta, Michitaka; Yonomoto, Taisuke; Araya, Fumimasa; Akimoto, Hajime

    1999-01-01

    For increasing of electric power demand and reducing of carbon dioxide exhaust in the 21st century, studies of the next-generation light water reactor (LWR) with passive safety systems are developing in the world: AP-600 (by Westing House Co.); SBWR (by General Electric Co.); SWR1000 (by Siemens Co.); NP21 (by Mitsubishi Heavy Industry Co., et al.); JPSR (by JAERI). The passive equipment using natural circulation and natural convection are installed in the passive safety system, instead of active safety equipment, such as pumps, etc. It remains still as a important issue, however, to verify the reliability on the functions of the passive equipment, since that the driving forces of the passive equipment are small at comparison with the active safety equipment. The various subjects of thermal-hydraulic analysis for the next-generation light water reactors, such as temperature stratification in the passive safety systems, vapor condensation in the mixture of non-condensable gases and the interactions of the passive safety system with the primary cooling system, are illustrated and discussed in the paper. (M. Suetake)

  9. Thermal analysis studies of ammonium uranyl carbonate

    International Nuclear Information System (INIS)

    Cao Xinsheng; Ma Xuezhong; Wang Fapin; Liu Naixin; Ji Changhong

    1988-01-01

    The simultaneous thermogravimetry and differential thermal analysis of the ammonium uranyl carbonate powder were performed with heat balance in the following atmosphers: Air, Ar and Ar-8%H 2 . The thermogravimetry and differential thermal analysis curves of the ammonium uranyl carbonate powder obtained from different source were reported and discussed

  10. Experimental analysis of a low cost phase change material emulsion for its use as thermal storage system

    International Nuclear Information System (INIS)

    Delgado, Mónica; Lázaro, Ana; Mazo, Javier; Peñalosa, Conchita; Dolado, Pablo; Zalba, Belén

    2015-01-01

    Highlights: • A low cost PCM emulsion has been analyzed as thermal energy storage system. • Its thermophysical and rheological properties have been determined. • The system shows advantages in terms of energy density and heat transfer rate. • The PCM emulsion system has been compared to other thermal energy storage systems. - Abstract: A 46 l commercial tank with a helical coil heat exchanger and containing a low cost phase change material emulsion has been experimentally analyzed as a thermal energy storage system in terms of volumetric energy density and heat transfer rate, for its subsequent comparison with other thermal energy storage systems. This phase change material emulsion shows a phase change temperature range between 30 and 50 °C, its solids content is about 60% with an average particle size of 1 μm. The low cost phase change material emulsion shows a thermal storage capacity by mass 50% higher than water and an increase in viscosity up to 2–5 orders of magnitude. The results have shown that the global heat transfer coefficient of the phase change material emulsion tank is around 2–6 times higher than for conventional latent systems previously analyzed in literature, although 5 times lower than if it contains water. The phase change material emulsion tank presents an energy density 34% higher than the water tank, which makes it a promising solution. Measures to improve its performance are also studied in this work.

  11. Thermal transient analysis applied to horizontal wells

    Energy Technology Data Exchange (ETDEWEB)

    Duong, A.N. [Society of Petroleum Engineers, Canadian Section, Calgary, AB (Canada)]|[ConocoPhillips Canada Resources Corp., Calgary, AB (Canada)

    2008-10-15

    Steam assisted gravity drainage (SAGD) is a thermal recovery process used to recover bitumen and heavy oil. This paper presented a newly developed model to estimate cooling time and formation thermal diffusivity by using a thermal transient analysis along the horizontal wellbore under a steam heating process. This radial conduction heating model provides information on the heat influx distribution along a horizontal wellbore or elongated steam chamber, and is therefore important for determining the effectiveness of the heating process in the start-up phase in SAGD. Net heat flux estimation in the target formation during start-up can be difficult to measure because of uncertainties regarding heat loss in the vertical section; steam quality along the horizontal segment; distribution of steam along the wellbore; operational conditions; and additional effects of convection heating. The newly presented model can be considered analogous to pressure transient analysis of a buildup after a constant pressure drawdown. The model is based on an assumption of an infinite-acting system. This paper also proposed a new concept of a heating ring to measure the heat storage in the heated bitumen at the time of testing. Field observations were used to demonstrate how the model can be used to save heat energy, conserve steam and enhance bitumen recovery. 18 refs., 14 figs., 2 appendices.

  12. System-Level Heat Transfer Analysis, Thermal- Mechanical Cyclic Stress Analysis, and Environmental Fatigue Modeling of a Two-Loop Pressurized Water Reactor. A Preliminary Study

    Energy Technology Data Exchange (ETDEWEB)

    Mohanty, Subhasish [Argonne National Lab. (ANL), Argonne, IL (United States); Soppet, William [Argonne National Lab. (ANL), Argonne, IL (United States); Majumdar, Saurin [Argonne National Lab. (ANL), Argonne, IL (United States); Natesan, Ken [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-01-03

    This report provides an update on an assessment of environmentally assisted fatigue for light water reactor components under extended service conditions. This report is a deliverable in April 2015 under the work package for environmentally assisted fatigue under DOE's Light Water Reactor Sustainability program. In this report, updates are discussed related to a system level preliminary finite element model of a two-loop pressurized water reactor (PWR). Based on this model, system-level heat transfer analysis and subsequent thermal-mechanical stress analysis were performed for typical design-basis thermal-mechanical fatigue cycles. The in-air fatigue lives of components, such as the hot and cold legs, were estimated on the basis of stress analysis results, ASME in-air fatigue life estimation criteria, and fatigue design curves. Furthermore, environmental correction factors and associated PWR environment fatigue lives for the hot and cold legs were estimated by using estimated stress and strain histories and the approach described in NUREG-6909. The discussed models and results are very preliminary. Further advancement of the discussed model is required for more accurate life prediction of reactor components. This report only presents the work related to finite element modelling activities. However, in between multiple tensile and fatigue tests were conducted. The related experimental results will be presented in the year-end report.

  13. Improved Thermal-Insulation Systems for Low Temperatures

    Science.gov (United States)

    Fesmire, James E.; Augustynowicz, Stanislaw D.

    2003-01-01

    Improved thermal-insulation materials and structures and the techniques for manufacturing them are undergoing development for use in low-temperature applications. Examples of low-temperature equipment for which these thermal insulation systems could provide improved energy efficiency include storage tanks for cryogens, superconducting electric-power-transmission equipment, containers for transport of food and other perishable commodities, and cold boxes for low-temperature industrial processes. These systems could also be used to insulate piping used to transfer cryogens and other fluids, such as liquefied natural gas, refrigerants, chilled water, crude oil, or low-pressure steam. The present thermal-insulation systems are layer composites based partly on the older class of thermal-insulation systems denoted generally as multilayer insulation (MLI). A typical MLI structure includes an evacuated jacket, within which many layers of radiation shields are stacked or wrapped close together. Low-thermal-conductivity spacers are typically placed between the reflection layers to keep them from touching. MLI can work very well when a high vacuum level (less than 10(exp-4) torr) is maintained and utmost care is taken during installation, but its thermal performance deteriorates sharply as the pressure in the evacuated space rises into the soft vacuum range [pressures greater than 0.1 torr (greater than 13 Pa)]. In addition, the thermal performance of MLI is extremely sensitive to mechanical compression and edge effects and can easily decrease from one to two orders of magnitude from its ideal value even when the MLI is kept under high vacuum condition. The present thermal-insulation systems are designed to perform well under soft vacuum level, in particular the range of 1 to 10 torr. They are also designed with larger interlayer spacings to reduce vulnerability to compression (and consequent heat leak) caused by installation and use. The superiority of these systems is the

  14. Coupled Cryogenic Thermal and Electrical Models for Transient Analysis of Superconducting Power Devices with Integrated Cryogenic Systems

    Science.gov (United States)

    Satyanarayana, S.; Indrakanti, S.; Kim, J.; Kim, C.; Pamidi, S.

    2017-12-01

    Benefits of an integrated high temperature superconducting (HTS) power system and the associated cryogenic systems on board an electric ship or aircraft are discussed. A versatile modelling methodology developed to assess the cryogenic thermal behavior of the integrated system with multiple HTS devices and the various potential configurations are introduced. The utility and effectiveness of the developed modelling methodology is demonstrated using a case study involving a hypothetical system including an HTS propulsion motor, an HTS generator and an HTS power cable cooled by an integrated cryogenic helium circulation system. Using the methodology, multiple configurations are studied. The required total cooling power and the ability to maintain each HTS device at the required operating temperatures are considered for each configuration and the trade-offs are discussed for each configuration. Transient analysis of temperature evolution in the cryogenic helium circulation loop in case of a system failure is carried out to arrive at the required critical response time. The analysis was also performed for a similar liquid nitrogen circulation for an isobaric condition and the cooling capacity ratio is used to compare the relative merits of the two cryogens.

  15. Evaluation of Thermal Margin Analysis Models for SMART

    International Nuclear Information System (INIS)

    Seo, Kyong Won; Kwon, Hyuk; Hwang, Dae Hyun

    2011-01-01

    Thermal margin of SMART would be analyzed by three different methods. The first method is subchannel analysis by MATRA-S code and it would be a reference data for the other two methods. The second method is an on-line few channel analysis by FAST code that would be integrated into SCOPS/SCOMS. The last one is a single channel module analysis by safety analysis. Several thermal margin analysis models for SMART reactor core by subchannel analysis were setup and tested. We adopted a strategy of single stage analysis for thermal analysis of SMART reactor core. The model should represent characteristics of the SMART reactor core including hot channel. The model should be simple as possible to be evaluated within reasonable time and cost

  16. Photovoltaic thermal module concepts and their performance analysis: A review

    International Nuclear Information System (INIS)

    Hasan, M. Arif; Sumathy, K.

    2010-01-01

    This paper presents a review of the available literature covering the latest module aspects of different photovoltaic/thermal (PV/T) collectors and their performances in terms of electrical as well as thermal output. The review covers detailed description of flat-plate and concentrating PV/T systems, using liquid or air as the working fluid, numerical model analysis, experimental work and qualitative evaluation of thermal and electrical output. Also an in-depth review on the performance parameters such as, optimum mass flow rate, PV/T dimensions, air channel geometry is presented in this study. Based on the thorough review, it is clear that PV/T modules are very promising devices and there exists lot of scope to further improve their performances. Appropriate recommendations are made which will aid PV/T systems to improve their efficiency and reducing their cost, making them more competitive in the present market. (author)

  17. Photovoltaic thermal module concepts and their performance analysis: A review

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, M. Arif; Sumathy, K. [Department of Mechanical Engineering, North Dakota State University, Fargo, ND (United States)

    2010-09-15

    This paper presents a review of the available literature covering the latest module aspects of different photovoltaic/thermal (PV/T) collectors and their performances in terms of electrical as well as thermal output. The review covers detailed description of flat-plate and concentrating PV/T systems, using liquid or air as the working fluid, numerical model analysis, experimental work and qualitative evaluation of thermal and electrical output. Also an in-depth review on the performance parameters such as, optimum mass flow rate, PV/T dimensions, air channel geometry is presented in this study. Based on the thorough review, it is clear that PV/T modules are very promising devices and there exists lot of scope to further improve their performances. Appropriate recommendations are made which will aid PV/T systems to improve their efficiency and reducing their cost, making them more competitive in the present market. (author)

  18. Thermal characterizations analysis of high-power ThinGaN cool-white light-emitting diodes

    Science.gov (United States)

    Raypah, Muna E.; Devarajan, Mutharasu; Ahmed, Anas A.; Sulaiman, Fauziah

    2018-03-01

    Analysis of thermal properties plays an important role in the thermal management of high-power (HP) lighting-emitting diodes (LEDs). Thermal resistance, thermal capacitance, and thermal time constant are essential parameters for the optimal design of the LED device and system, particularly for dynamic performance study. In this paper, thermal characterization and thermal time constant of ThinGaN HP LEDs are investigated. Three HP cool-white ThinGaN LEDs from different manufacturers are used in this study. A forward-voltage method using thermal transient tester (T3Ster) system is employed to determine the LEDs' thermal parameters at various operating conditions. The junction temperature transient response is described by a multi-exponential function model to extract thermal time constants. The transient response curve is divided into three layers and expressed by three exponential functions. Each layer is associated with a particular thermal time constant, thermal resistance, and thermal capacitance. It is found that the thermal time constant of LED package is on the order of 22 to 100 ms. Comparison between the experimental results is carried out to show the design effects on thermal performance of the LED package.

  19. Thermal analysis, optimization and design of a Martian oxygen production plant

    Science.gov (United States)

    Iyer, Venkatesh A.; Sridhar, K. R.

    1991-01-01

    The objective is to optimally design the thermal components of a system that uses carbon dioxide (CO2) from the Martian atmosphere to produce oxygen (O2) for spacecraft propulsion and/or life-support. Carbon dioxide is thermally decomposed into carbon monoxide (CO) and O2 followed by the electrochemical separation of O2. The design of the overall system and its various individual components depends on, among other things, the fraction of the stoichiometric yield of O2 that can be realized in the system and the temperature of operation of the electrochemical separation membrane. The analysis indicates that a substantial reduction could be obtained in the mass and power requirements of the system if the unreacted CO2 were to be recycled. The concepts of an optimum temperature of the zirconia cell and impracticality of plant operation at low cell efficiencies are also discussed. The design of the thermal equipment is such that the mass and power requirements of the individual components and of the overall system are optimized.

  20. Performance analysis of an integrated energy storage and energy upgrade thermochemical solid–gas sorption system for seasonal storage of solar thermal energy

    International Nuclear Information System (INIS)

    Li, Tingxian; Wang, Ruzhu; Kiplagat, Jeremiah K.; Kang, YongTae

    2013-01-01

    An innovative dual-mode thermochemical sorption energy storage method is proposed for seasonal storage of solar thermal energy with little heat losses. During the charging phase in summer, solar thermal energy is stored in form of chemical bonds resulting from thermochemical decomposition process, which enables the stored energy to be kept several months at ambient temperature. During the discharging phase in winter, the stored thermal energy is released in the form of chemical reaction heat resulting from thermochemical synthesis process. Thermodynamic analysis showed that the advanced dual-mode thermochemical sorption energy storage is an effective method for the long-term seasonal storage of solar energy. A coefficient of performance (COP h ) of 0.6 and energy density higher than 1000 kJ/kg of salt can be attained from the proposed system. During the discharging phase at low ambient temperatures, the stored thermal energy can be upgraded by use of a solid–gas thermochemical sorption heat transformer cycle. The proposed thermochemical sorption energy storage has distinct advantages over the conventional sensible heat and latent heat storage, such as higher energy storage density, little heat losses, integrated energy storage and energy upgrade, and thus it can contribute to improve the seasonal utilization of solar thermal energy. - Highlights: ► A dual-mode solid thermochemical sorption is proposed for seasonal solar thermal energy storage. ► Energy upgrade techniques into the energy storage system are integrated. ► Performance of the proposed seasonal energy storage system is evaluated. ► Energy density and COP h from the proposed system are as high as 1043 kJ/kg of salt and 0.60, respectively

  1. Investigation and Modelling of Thermal Conditions in Low Flow SDHW Systems

    DEFF Research Database (Denmark)

    Shah, Louise Jivan

    1999-01-01

    and compared with the CFD-predicted flow structures in the mantle. The results showed that the mantle flow was highly dominated by buoyancy and the CFD-models were able to model this flow. With a steel mantle tank, different dynamic thermal experiments were carried out in a heat storage test facility....... This simulation program predicts the yearly thermal performance of low flow SDHW systems based on mantle tanks. MANTLSIM was verified and afterwards used as a tool for parameter analysis. This analysis showed that MANTLSIM predicted expected tendencies. Only for the mantle gap variations, results in poor...

  2. Conceptual design and analysis of a Dish-Rankine solar thermal power system

    Science.gov (United States)

    Pons, R. L.

    1980-08-01

    A Point Focusing Distributed Receiver (PFDR) solar thermal electric system which employs small Organic Rankine Cycle (ORC) engines is examined with reference to its projected technical/economic performance. With mass-produced power modules (about 100,000 per year), the projected life-cycle energy cost for an optimized no-storage system is estimated at 67 mills/kWh (Levelized Busbar Energy Cost) without the need for advanced development of any of its components. At moderate production rates (about 50 MWe/yr) system energy costs are competitive with conventional power generation systems in special remote-site types of applications.

  3. CFD and thermal analysis applications at General Motors

    International Nuclear Information System (INIS)

    Johnson, J.P.

    2002-01-01

    The presentation will include a brief history of the growth of CFD and thermal analysis in GM's vehicle program divisions. Its relationship to the underlying computer infrastructure will be sketched. Application results will be presented for calculations in aerodynamics, flow through heat exchangers, engine compartment thermal studies, HVAC systems and others. Current technical challenges will be outlined including grid generation, turbulence modeling, heat transfer, and solution algorithms. The introduction of CFD and heat transfer results into Virtual Vehicle Reviews, and its potential impact on a company's CAE infrastructure will be noted. Finally, some broad comments will be made on the management of CFD and heat transfer technology across a global corporate enterprise. (author)

  4. Thermal and Performance Analysis of a Photovoltaic Module with an Integrated Energy Storage System

    Directory of Open Access Journals (Sweden)

    Manel Hammami

    2017-10-01

    Full Text Available This paper is proposing and analyzing an electric energy storage system fully integrated with a photovoltaic PV module, composed by a set of lithium-iron-phosphate (LiFePO4 flat batteries, which constitutes a generation-storage PV unit. The batteries were surface-mounted on the back side of the PV module, distant from the PV backsheet, without exceeding the PV frame size. An additional low-emissivity sheet was introduced to shield the batteries from the backsheet thermal irradiance. The challenge addressed in this paper is to evaluate the PV cell temperature increase, due to the reduced thermal exchanges on the back of the module, and to estimate the temperature of the batteries, verifying their thermal constraints. Two one-dimensional (1D thermal models, numerically implemented by using the thermal library of Simulink-Matlab accounting for all the heat exchanges, are here proposed: one related to the original PV module, the other related to the portion of the area of the PV module in correspondence of the proposed energy-storage system. Convective and radiative coefficients were then calculated in relation to different configurations and ambient conditions. The model validation has been carried out considering the PV module to be at the nominal operating cell temperature (NOCT, and by specific experimental measurements with a thermographic camera. Finally, appropriate models were used to evaluate the increasing cell batteries temperature in different environmental conditions.

  5. Thermal analysis of a direct evaporative cooling system enhancement with desiccant dehumidification for vehicular air conditioning

    International Nuclear Information System (INIS)

    Alahmer, Ali

    2016-01-01

    Highlights: • Thermal analysis was conducted to design a desiccant evaporative cooling system for vehicular air conditioning. • EC is more efficient than the conventional air conditioning when the gasoline price is more than 0.34 $/liter. • Drawbacks of evaporative cooler of increased weight and reduced COP. • A rotary desiccant dehumidifier with generation was combined with evaporative cooling to be more efficient. - Abstract: This manuscript analyzes the sub-systems of evaporative cooler (EC) combined with desiccant dehumidification and regeneration for automotive air conditioning purpose. The thermodynamic and psychometric analysis was conducted to design all evaporative cooling system components in terms of desiccant selection, regeneration process, compact heat exchanger and evaporative cooler. Moreover, the effect of the desiccant, heat exchanger and evaporative performances on the mass flow rate and water sprayed required for evaporative cooling system was investigated. The results show that the theoretical evaporative cooling design will achieve two main objectives: lower fuel consumption and less environmental pollutants. However, it has the two drawbacks in terms of increased weight and reduces the coefficient of performance (COP). The main remark is that evaporating cooling system is more efficient than the conventional air conditioning when the gasoline price is more than 0.34 $/liter.

  6. Transient thermal performance analysis of micro heat pipes

    International Nuclear Information System (INIS)

    Liu, Xiangdong; Chen, Yongping

    2013-01-01

    A theoretical analysis of transient fluid flow and heat transfer in a triangular micro heat pipes (MHP) has been conducted to study the thermal response characteristics. By introducing the system identification theory, the quantitative evaluation of the MHP's transient thermal performance is realized. The results indicate that the evaporation and condensation processes are both extended into the adiabatic section. During the start-up process, the capillary radius along axial direction of MHP decreases drastically while the liquid velocity increases quickly at the early transient stage and an approximately linear decrease in wall temperature arises along the axial direction. The MHP behaves as a first-order LTI control system with the constant input power as the 'step input' and the evaporator wall temperature as the 'output'. Two corresponding evaluation criteria derived from the control theory, time constant and temperature constant, are able to quantitatively evaluate the thermal response speed and temperature level of MHP under start-up, which show that a larger triangular groove's hydraulic diameter within 0.18–0.42 mm is able to accelerate the start-up and decrease the start-up temperature level of MHP. Additionally, the MHP starts up fastest using the fluid of ethanol and most slowly using the working fluid of methanol, and the start-up temperature reaches maximum level for acetone and minimum level for the methanol. -- Highlights: • Transient thermal response of micro heat pipe is simulated by an improved model. • Control theory is introduced to quantify the thermal response of micro heat pipe. • Evaluation criteria are proposed to represent thermal response of micro heat pipe. • Effects of groove dimensions and working fluids on start-up of micro heat pipe are evaluated

  7. Full-energy-chain analysis of greenhouse gas emissions for solar thermal electric power generation systems

    International Nuclear Information System (INIS)

    Norton, B.; Lawson, W.R.

    1997-01-01

    Technical attributes and environmental impacts of solar thermal options for centralized electricity generation are discussed. In particular, the full-energy-chain, including embodied energy and energy production, is considered in relation to greenhouse gas emission arising from solar thermal electricity generation. Central receiver, parabolic dish, parabolic trough and solar pond systems are considered. (author)

  8. Dynamic modeling and sensitivity analysis of solar thermal energy conversion systems

    Science.gov (United States)

    Hamilton, C. L.

    1977-01-01

    Since the energy input to solar thermal conversion systems is both time variant and probabilistic, it is unlikely that simple steady-state methods for estimating lifetime performance will provide satisfactory results. The work described here uses dynamic modeling to begin identifying what must be known about input radiation and system dynamic characteristics to estimate performance reliably. Daily operation of two conceptual solar energy systems was simulated under varying operating strategies with time-dependent radiation intensity ranging from smooth input of several magnitudes to input of constant total energy whose intensity oscillated with periods from 1/4 hour to 6 hours. Integrated daily system output and efficiency were functions of both level and dynamic characteristics of insolation. Sensitivity of output to changes in total input was greater than one.

  9. RETRAN-02: a program for transient thermal-hydraulic analysis of complex fluid-flow systems. Volume 4. Applications

    International Nuclear Information System (INIS)

    Peterson, C.E.; Gose, G.C.; McFadden, J.H.

    1983-01-01

    RETRAN-02 represents a significant achievement in the development of a versatile and reliable computer program for use in best estimate transient thermal-hydraulic analysis of light water reactor systems. The RETRAN-02 computer program is an extension of the RETRAN-01 program designed to provide analysis capabilities for 1) BWR and PWR transients, 2) small break loss of coolant accidents, 3) balance of plant modeling, and 4) anticipated transients without scram, while maintaining the analysis capabilities of the predecessor code. The RETRAN-02 computer code is constructed in a semimodular and dynamic dimensioned form where additions to the code can be easily carried out as new and improved models are developed. This report (the fourth of a five volume computer code manual) describes the verification and validation of RETRAN-02

  10. Optical pump-and-probe test system for thermal characterization of thin metal and phase-change films

    International Nuclear Information System (INIS)

    Watabe, Kazuo; Polynkin, Pavel; Mansuripur, Masud

    2005-01-01

    A single-shot optical pump-and-probe test system is reported. The system is designed for thermal characterization of thin-film samples that can change their phase state under the influence of a short and intense laser pulse on a subnanosecond time scale. In combination with numerical analysis, the system can be used to estimate thermal constants of thin films, such as specific heat and thermal conductivity. In-plane and out-of plane thermal conductivity can be estimated independently. The system is intended for use in research on optical data storage and material processing with pulsed laser light. The system design issues are discussed. As application examples, we report on using the system to study thermal dynamics in two different thin-film samples: a gold film on a glass substrate (a single-phase system) and the quadrilayer phase-change stack typical in optical data-storage applications

  11. Quaternion Based Thermal Condition Monitoring System

    Science.gov (United States)

    Wong, Wai Kit; Loo, Chu Kiong; Lim, Way Soong; Tan, Poi Ngee

    In this paper, we will propose a new and effective machine condition monitoring system using log-polar mapper, quaternion based thermal image correlator and max-product fuzzy neural network classifier. Two classification characteristics namely: peak to sidelobe ratio (PSR) and real to complex ratio of the discrete quaternion correlation output (p-value) are applied in the proposed machine condition monitoring system. Large PSR and p-value observe in a good match among correlation of the input thermal image with a particular reference image, while small PSR and p-value observe in a bad/not match among correlation of the input thermal image with a particular reference image. In simulation, we also discover that log-polar mapping actually help solving rotation and scaling invariant problems in quaternion based thermal image correlation. Beside that, log-polar mapping can have a two fold of data compression capability. Log-polar mapping can help smoother up the output correlation plane too, hence makes a better measurement way for PSR and p-values. Simulation results also show that the proposed system is an efficient machine condition monitoring system with accuracy more than 98%.

  12. Thermal processing systems for TRU mixed waste

    International Nuclear Information System (INIS)

    Eddy, T.L.; Raivo, B.D.; Anderson, G.L.

    1992-01-01

    This paper presents preliminary ex situ thermal processing system concepts and related processing considerations for remediation of transuranic (TRU)-contaminated wastes (TRUW) buried at the Radioactive Waste Management Complex (RWMC) of the Idaho National Engineering Laboratory (INEL). Anticipated waste stream components and problems are considered. Thermal processing conditions required to obtain a high-integrity, low-leachability glass/ceramic final waste form are considered. Five practical thermal process system designs are compared. Thermal processing of mixed waste and soils with essentially no presorting and using incineration followed by high temperature melting is recommended. Applied research and development necessary for demonstration is also recommended

  13. Artificial heart system thermal insulation component development

    International Nuclear Information System (INIS)

    Svedberg, R.C.; Buckman, R.W. Jr.

    1975-01-01

    A concentric cup vacuum multifoil insulation system has been selected by virtue of its size, weight, and thermal performance to insulate the hot radioisotope portion of the thermal converter of an artificial implantable heart system. A factor of 2 improvement in thermal performance, based on the heat loss per number of foil layers (minimum system weight and volume) has been realized over conventional spiral wrapped multifoil vacuum insulation. This improvement is the result of the concentric cup construction to maintain a uniform interfoil spacing and the elimination of corner heat losses. Based on external insulation system dimensions (surface area in contact with host body), heat losses of 0.019 W/ cm 2 at 1140 0 K (1600 0 F) and 0.006 W/cm 2 at 920 0 K (1200 0 F) have been achieved. Factors which influence thermal performance of the nickel foil concentric cup insulation system include the number of cups, configuration and method of application of zirconia (ZrO 2 ) spacer material, system pressure, emittance of the cups, and operating temperature

  14. Thermal Analysis of a Nuclear Waste Repository in Argillite Host Rock

    Science.gov (United States)

    Hadgu, T.; Gomez, S. P.; Matteo, E. N.

    2017-12-01

    Disposal of high-level nuclear waste in a geological repository requires analysis of heat distribution as a result of decay heat. Such an analysis supports design of repository layout to define repository footprint as well as provide information of importance to overall design. The analysis is also used in the study of potential migration of radionuclides to the accessible environment. In this study, thermal analysis for high-level waste and spent nuclear fuel in a generic repository in argillite host rock is presented. The thermal analysis utilized both semi-analytical and numerical modeling in the near field of a repository. The semi-analytical method looks at heat transport by conduction in the repository and surroundings. The results of the simulation method are temperature histories at selected radial distances from the waste package. A 3-D thermal-hydrologic numerical model was also conducted to study fluid and heat distribution in the near field. The thermal analysis assumed a generic geological repository at 500 m depth. For the semi-analytical method, a backfilled closed repository was assumed with basic design and material properties. For the thermal-hydrologic numerical method, a repository layout with disposal in horizontal boreholes was assumed. The 3-D modeling domain covers a limited portion of the repository footprint to enable a detailed thermal analysis. A highly refined unstructured mesh was used with increased discretization near heat sources and at intersections of different materials. All simulations considered different parameter values for properties of components of the engineered barrier system (i.e. buffer, disturbed rock zone and the host rock), and different surface storage times. Results of the different modeling cases are presented and include temperature and fluid flow profiles in the near field at different simulation times. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and

  15. Thermally conductive, dielectric PCM-boron nitride nanosheet composites for efficient electronic system thermal management.

    Science.gov (United States)

    Yang, Zhi; Zhou, Lihui; Luo, Wei; Wan, Jiayu; Dai, Jiaqi; Han, Xiaogang; Fu, Kun; Henderson, Doug; Yang, Bao; Hu, Liangbing

    2016-11-24

    Phase change materials (PCMs) possessing ideal properties, such as superior mass specific heat of fusion, low cost, light weight, excellent thermal stability as well as isothermal phase change behavior, have drawn considerable attention for thermal management systems. Currently, the low thermal conductivity of PCMs (usually less than 1 W mK -1 ) greatly limits their heat dissipation performance in thermal management applications. Hexagonal boron nitride (h-BN) is a two-dimensional material known for its excellent thermally conductive and electrically insulating properties, which make it a promising candidate to be used in electronic systems for thermal management. In this work, a composite, consisting of h-BN nanosheets (BNNSs) and commercialized paraffin wax was developed, which inherits high thermally conductive and electrically insulating properties from BNNSs and substantial heat of fusion from paraffin wax. With the help of BNNSs, the thermal conductivity of wax-BNNS composites reaches 3.47 W mK -1 , which exhibits a 12-time enhancement compared to that of pristine wax (0.29 W mK -1 ). Moreover, an 11.3-13.3 MV m -1 breakdown voltage of wax-BNNS composites was achieved, which shows further improved electrical insulating properties. Simultaneously enhanced thermally conductive and electrically insulating properties of wax-BNNS composites demonstrate their promising application for thermal management in electronic systems.

  16. European activities on crosscutting thermal-hydraulic phenomena for innovative nuclear systems

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, X., E-mail: xu.cheng@kit.edu [Karlsruhe Institute of Technology (KIT) (Germany); Batta, A. [Karlsruhe Institute of Technology (KIT) (Germany); Bandini, G. [Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA) (Italy); Roelofs, F. [Nuclear Research and Consultancy Group (NRG) (Netherlands); Van Tichelen, K. [Studiecentrum voor Kernenergie – Centre d’étude de l’Energie Nucléaire (SCK-CEN) (Belgium); Gerschenfeld, A. [Commissariat à l’Energie Atomique (CEA) (France); Prasser, M. [Paul Scherrer Institute (PSI) (Switzerland); Papukchiev, A. [Gesellschaft für Anlagen- und Reaktorsicherheit mbH (GRS) (Germany); Hampel, U. [Helmholtz-Zentrum Dresden-Rossendorf e.V. (HZDR) (Germany); Ma, W.M. [Kungliga Tekniska Högskolan (KTH) (Sweden)

    2015-08-15

    Highlights: • This paper serves as a guidance of the special issue. • The technical tasks and methodologies applied to achieve the objectives have been described. • Main results achieved so far are summarized. - Abstract: Thermal-hydraulics is recognized as a key scientific subject in the development of innovative reactor systems. In Europe, a consortium is established consisting of 24 institutions of universities, research centers and nuclear industries with the main objectives to identify and to perform research activities on important crosscutting thermal-hydraulic issues encountered in various innovative nuclear systems. For this purpose the large-scale integrated research project THINS (Thermal-Hydraulics of Innovative Nuclear Systems) is launched in the 7th Framework Programme FP7 of European Union. The main topics considered in the THINS project are (a) advanced reactor core thermal-hydraulics, (b) single phase mixed convection, (c) single phase turbulence, (d) multiphase flow, and (e) numerical code coupling and qualification. The main objectives of the project are: • Generation of a data base for the development and validation of new models and codes describing the selected crosscutting thermal-hydraulic phenomena. • Development of new physical models and modeling approaches for more accurate description of the crosscutting thermal-hydraulic phenomena. • Improvement of the numerical engineering tools for the design analysis of the innovative nuclear systems. This paper describes the technical tasks and methodologies applied to achieve the objectives. Main results achieved so far are summarized. This paper serves also as a guidance of this special issue.

  17. Thermal/structural analysis of radiators for heavy-duty trucks

    International Nuclear Information System (INIS)

    Mao Shaolin; Cheng, Changrui; Li Xianchang; Michaelides, Efstathios E.

    2010-01-01

    A thermal/structural coupling approach is applied to analyze thermal performance and predict the thermal stress of a radiator for heavy-duty transportation cooling systems. Bench test and field test data show that non-uniform temperature gradient and dynamic pressure loads may induce large thermal stress on the radiator. A finite element analysis (FEA) tool is used to predict the strains and displacement of radiator based on the solid wall temperature, wall-based fluid film heat transfer coefficient and pressure drop. These are obtained from a computational fluid dynamics (CFD) simulation. A 3D simulation of turbulent flow and coupled heat transfer between the working fluids poses a major difficulty because the range of length scales involved in heavy-duty radiators varies from few millimeters of the fin pitch and/or tube cross-section to several meters for the overall size of the radiator. It is very computational expensive, if not impossible, to directly simulate the turbulent heat transfer between fins and the thermal boundary layer in each tube. In order to overcome the computational difficulties, a dual porous zone (DPZ) method is applied, in which fins in the air side and turbulators in the water side are treated as porous region. The parameters involved in the DPZ method are tuned based on experimental data in prior. A distinguished advantage of the porous medium method is its effectiveness of modeling wide-range characteristic scale problems. A parametric study of the impact of flow rate on the heat transfer coefficient is presented. The FEA results predict the maximum value of stress/strain and target locations for possible structural failure and the results obtained are consistent with experimental observations. The results demonstrate that the coupling thermal/structural analysis is a powerful tool applied to heavy-duty cooling product design to improve the radiator thermal performance, durability and reliability under rigid working environment.

  18. Thermal analysis of a hybrid solar energy saving system inside a greenhouse

    International Nuclear Information System (INIS)

    Ntinas, G.K.; Fragos, V.P.; Nikita-Martzopoulou, Ch.

    2014-01-01

    Highlights: • A hybrid solar system consisted of water filled polyethylene sleeves was examined. • The thermal behaviour of the system was studied based on the sleeves energy balance. • Water temperature and heat exchanges of the sleeves were dynamically estimated. • Experimental data used to validate the predictions of the mathematical model. • The use of the system led to an energy saving of 23% inside a heated greenhouse. - Abstract: The intensive greenhouse energy requirements are a major operational and economical problem for producers around the world. Energy conservation techniques and innovative applications of solar energy for heating are being employed in greenhouse operation to reduce heating costs during cold periods. The present study investigated the development of a mathematical model to predict the thermal efficiency of a novel hybrid solar energy saving system inside a heated greenhouse. The solar system consisted of a transparent water-filled polyethylene sleeve and two perforated air-filled polyethylene tubes on the top peripheral sides of it. Above the sleeve and between the two tubes, rockwool substrates were placed for hydroponic cultivation of tomato crop. In order to validate this model, experiments were carried out in two identical parts of a polyethylene arched-type greenhouse to obtain data during winter. By comparing the measured and the predicted values, a correlation of 95% was found, indicating that the model can simulate the water temperature inside the hybrid solar sleeves. Moreover, the additional energy provided by the hybrid solar system reached approximately 23% during the examined period, depending on solar radiation levels

  19. Coupled electrochemical thermal modelling of a novel Li-ion battery pack thermal management system

    International Nuclear Information System (INIS)

    Basu, Suman; Hariharan, Krishnan S.; Kolake, Subramanya Mayya; Song, Taewon; Sohn, Dong Kee; Yeo, Taejung

    2016-01-01

    Highlights: • Three-dimensional electrochemical thermal model of Li-ion battery pack using computational fluid dynamics (CFD). • Novel pack design for compact liquid cooling based thermal management system. • Simple temperature estimation algorithm for the cells in the pack using the results from the model. • Sensitivity of the thermal performance to contact resistance has been investigated. - Abstract: Thermal management system is of critical importance for a Li-ion battery pack, as high performance and long battery pack life can be simultaneously achieved when operated within a narrow range of temperature around the room temperature. An efficient thermal management system is required to keep the battery temperature in this range, despite widely varying operating conditions. A novel liquid coolant based thermal management system, for 18,650 battery pack has been introduced herein. This system is designed to be compact and economical without compromising safety. A coupled three-dimensional (3D) electrochemical thermal model is constructed for the proposed Li-ion battery pack. The model is used to evaluate the effects of different operating conditions like coolant flow-rate and discharge current on the pack temperature. Contact resistance is found to have the strongest impact on the thermal performance of the pack. From the numerical solution, a simple and novel temperature correlation of predicting the temperatures of all the individual cells given the temperature measurement of one cell is devised and validated with experimental results. Such coefficients have great potential of reducing the sensor requirement and complexity in a large Li-ion battery pack, typical of an electric vehicle.

  20. Visual and intelligent transients and accidents analyzer based on thermal-hydraulic system code

    International Nuclear Information System (INIS)

    Meng Lin; Rui Hu; Yun Su; Ronghua Zhang; Yanhua Yang

    2005-01-01

    Full text of publication follows: Many thermal-hydraulic system codes were developed in the past twenty years, such as RELAP5, RETRAN, ATHLET, etc. Because of their general and advanced features in thermal-hydraulic computation, they are widely used in the world to analyze transients and accidents. But there are following disadvantages for most of these original thermal-hydraulic system codes. Firstly, because models are built through input decks, so the input files are complex and non-figurative, and the style of input decks is various for different users and models. Secondly, results are shown in off-line data file form. It is not convenient for analysts who may pay more attention to dynamic parameters trend and changing. Thirdly, there are few interfaces with other program in these original thermal-hydraulic system codes. This restricts the codes expanding. The subject of this paper is to develop a powerful analyzer based on these thermal-hydraulic system codes to analyze transients and accidents more simply, accurately and fleetly. Firstly, modeling is visual and intelligent. Users build the thermalhydraulic system model using component objects according to their needs, and it is not necessary for them to face bald input decks. The style of input decks created automatically by the analyzer is unified and can be accepted easily by other people. Secondly, parameters concerned by analyst can be dynamically communicated to show or even change. Thirdly, the analyzer provide interface with other programs for the thermal-hydraulic system code. Thus parallel computation between thermal-hydraulic system code and other programs become possible. In conclusion, through visual and intelligent method, the analyzer based on general and advanced thermal-hydraulic system codes can be used to analysis transients and accidents more effectively. The main purpose of this paper is to present developmental activities, assessment and application results of the visual and intelligent

  1. Studies of the thermal properties of horn keratin by dielectric spectroscopy, thermogravimetric analysis and differential thermal analysis

    International Nuclear Information System (INIS)

    Marzec, E.; Piskunowicz, P.; Jaroszyk, F.

    2002-01-01

    The dielectric and thermal properties of horn keratin have been studied bu dielectric spectroscopy in the frequency range 10 1 -10 5 Hz, thermogravimetric analysis (TG) and different thermal analysis (DTA). Measurement of non-irradiated and g amma - irradiated keratin with doses 5, 50 kGy were performed at temperature from 22 to 260 o C. The results revealed the occurrence of phase transitions related to release of loosely bound water and bound water up to 200 o Cand the denaturation of the crystalline structure above this temperature. The influence of γ-irradiation on the thermal behaviour of keratin is significant only in the temperature range of denaturation. The decrease in the temperature of denaturation would suggest that γ-irradiation initiates main-chain degradation. (authors)

  2. Phase Equilibria in the Bi-In-Sn-Zn System. Thermal Analysis vs. Calculations

    Directory of Open Access Journals (Sweden)

    Dębski A.

    2017-12-01

    Full Text Available With the use of the differential thermal analysis (DTA, studies of the phase transitions were conducted for 90 of alloys from the quaternary Bi-In-Sn-Zn system and for the constant ratio of Bi:In and Bi:Sn. The studies were conducted for the alloys prepared from the purity metals (Bi, In, Sn, Zn = 99.999 mas. % by way of melting in a graphite crucible in a glove-box filled with Ar, in which the impurities level was less than 0.1 ppm. After melting and thorough mixing, the liquid alloys were poured out into a graphite test mold. The phase transition temperature data obtained from the DTA investigations were next confronted with those determined from the calculations based on the binary and ternary optimized thermodynamic parameters available in the literature. It was found that the experimental and the calculated phase transition temperatures were in good agreement.

  3. A miniature concentrating photovoltaic and thermal system

    International Nuclear Information System (INIS)

    Kribus, Abraham; Kaftori, Daniel; Mittelman, Gur; Hirshfeld, Amir; Flitsanov, Yuri; Dayan, Abraham

    2006-01-01

    A novel miniature concentrating PV (MCPV) system is presented and analyzed. The system is producing both electrical and thermal energy, which is supplied to a nearby consumer. In contrast to PV/thermal (PV/T) flat collectors, the heat from an MCPV collector is not limited to low-temperature applications. The work reported here refers to the evaluation and preliminary design of the MCPV approach. The heat transport system, the electric and thermal performance, the manufacturing cost, and the resulting cost of energy in case of domestic water heating have been analyzed. The results show that the new approach has promising prospects

  4. Improvement of multi-dimensional realistic thermal-hydraulic system analysis code, MARS 1.3

    International Nuclear Information System (INIS)

    Lee, Won Jae; Chung, Bub Dong; Jeong, Jae Jun; Ha, Kwi Seok

    1998-09-01

    The MARS (Multi-dimensional Analysis of Reactor Safety) code is a multi-dimensional, best-estimate thermal-hydraulic system analysis code. This report describes the new features that have been improved in the MARS 1.3 code since the release of MARS 1.3 in July 1998. The new features include: - implementation of point kinetics model into the 3D module - unification of the heat structure model - extension of the control function to the 3D module variables - improvement of the 3D module input check function. Each of the items has been implemented in the developmental version of the MARS 1.3.1 code and, then, independently verified and assessed. The effectiveness of the new features is well verified and it is shown that these improvements greatly extend the code capability and enhance the user friendliness. Relevant input data changes are also described. In addition to the improvements, this report briefly summarizes the future code developmental activities that are being carried out or planned, such as coupling of MARS 1.3 with the containment code CONTEMPT and the three-dimensional reactor kinetics code MASTER 2.0. (author). 8 refs

  5. Improvement of multi-dimensional realistic thermal-hydraulic system analysis code, MARS 1.3

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Jae; Chung, Bub Dong; Jeong, Jae Jun; Ha, Kwi Seok

    1998-09-01

    The MARS (Multi-dimensional Analysis of Reactor Safety) code is a multi-dimensional, best-estimate thermal-hydraulic system analysis code. This report describes the new features that have been improved in the MARS 1.3 code since the release of MARS 1.3 in July 1998. The new features include: - implementation of point kinetics model into the 3D module - unification of the heat structure model - extension of the control function to the 3D module variables - improvement of the 3D module input check function. Each of the items has been implemented in the developmental version of the MARS 1.3.1 code and, then, independently verified and assessed. The effectiveness of the new features is well verified and it is shown that these improvements greatly extend the code capability and enhance the user friendliness. Relevant input data changes are also described. In addition to the improvements, this report briefly summarizes the future code developmental activities that are being carried out or planned, such as coupling of MARS 1.3 with the containment code CONTEMPT and the three-dimensional reactor kinetics code MASTER 2.0. (author). 8 refs.

  6. System evaluation of improved thermal stability jet fuels

    Energy Technology Data Exchange (ETDEWEB)

    Binns, K.E.; Dieterle, G.L.; Williams, T. [Univ. of Dayton Research Institute, OH (United States)

    1995-05-01

    A single-pass, single-tube heat exchanger device called the Phoenix rig and a single-pass, dual-heat exchanger system called the Extended Duration Thermal Stability Test system are specific devices/systems developed for evaluating jet fuel thermal stability. They have been used extensively in the evaluation of various jet fuels and thermal stability additives. The test results have indicated that additives can substantially improve the thermal stability of conventional jet fuels. Relationships of oxygen consumption, residence time, bulk, and wetted wall temperatures on coking deposits that form in the heated tubes have also been investigated.

  7. Energetic and exergetic performances analysis of a PV/T (photovoltaic thermal) solar system tested and simulated under to Tunisian (North Africa) climatic conditions

    International Nuclear Information System (INIS)

    Hazami, Majdi; Riahi, Ali; Mehdaoui, Farah; Nouicer, Omeima; Farhat, Abdelhamid

    2016-01-01

    The endeavor of this paper is to study the potential offered by the expenditure of a PV/T (photovoltaic thermal) solar system in Tunisian households. This investigation is performed according to two-folded approaches. Firstly, outdoor experiments were carried out during July 2014 for both passive and active mode. An exhaustive energy and exergy analysis was then performed to evaluate the instantaneous thermal and the electrical exergy outputs of the PV/T solar system. The results showed that the maximum instantaneous thermal and electric energy efficiency in active mode are about 50 and 15%, respectively. It was found also that the maximum thermal and electric exergy efficiencies were about 50 and 14.8%, respectively. The second approach is the evaluation of the monthly/annual performances of the PV/T solar system under typical climate area of Tunisia by using TRNSYS program. The results showed that the active mode enhances the electric efficiency and the exergy of the PV/T system by 3 and 2.5% points, respectively. The results showed that the optimized PV/T solar system covert the major part of the hot water and the electric needs of Tunisian household's with an expected annual average gain of about 14.60 and 5.33%, respectively. An economic appraisal was performed. - Highlights: • The present work studies the potential of using PV/T solar collector in Tunisian. • The maximum thermal and electric efficiencies are 50 and 15%, respectively. • The maximum thermal and electric exergy efficiencies were 50 and 14.8%. • The results showed that the expected annual gain are 14.60 and 5.33%. • The PV/T is compared to a high quality commercial solar collectors and a PV panel.

  8. Thermal Analysis for Condition Monitoring of Machine Tool Spindles

    International Nuclear Information System (INIS)

    Clough, D; Fletcher, S; Longstaff, A P; Willoughby, P

    2012-01-01

    Decreasing tolerances on parts manufactured, or inspected, on machine tools increases the requirement to have a greater understanding of machine tool capabilities, error sources and factors affecting asset availability. Continuous usage of a machine tool during production processes causes heat generation typically at the moving elements, resulting in distortion of the machine structure. These effects, known as thermal errors, can contribute a significant percentage of the total error in a machine tool. There are a number of design solutions available to the machine tool builder to reduce thermal error including, liquid cooling systems, low thermal expansion materials and symmetric machine tool structures. However, these can only reduce the error not eliminate it altogether. It is therefore advisable, particularly in the production of high value parts, for manufacturers to obtain a thermal profile of their machine, to ensure it is capable of producing in tolerance parts. This paper considers factors affecting practical implementation of condition monitoring of the thermal errors. In particular is the requirement to find links between temperature, which is easily measureable during production and the errors which are not. To this end, various methods of testing including the advantages of thermal images are shown. Results are presented from machines in typical manufacturing environments, which also highlight the value of condition monitoring using thermal analysis.

  9. Thermal analysis of iron hydroxide microspheres

    International Nuclear Information System (INIS)

    Turcanu, C.N.; Cornescu, M.

    1979-03-01

    The thermal treatment is an important step in the preparative technology of the iron oxids microspheres with well established mechanical, physical and chemical characteristics. The first indications on the heating procedure have been obtained from the thermal analysis on iron hydroxide microspheres prepared by the support precipitation and internal gelification methods. (author)

  10. ATWS thermal-hydraulic analysis for Krsko Full Scope Simulator validation

    International Nuclear Information System (INIS)

    Parzer, I.; Kljenak, I.

    2005-01-01

    The purpose of this analysis was to simulate Anticipated Transient without Scram transient for Krsko NPP. The results of these calculations were used for annual ANSI/ANS validation of reactor coolant system thermal-hydraulic response predicted by Krsko Full Scope Simulator. For the thermal-hydraulic analyses the RELAP5/MOD3.3 code and the input model for NPP Krsko, delivered by NPP Krsko, was used. In the presented paper the most severe ATWS scenario has been analyzed, starting with the loss of Main Feedwater at both steam generators. Thus, gradual loss of secondary heat sink occurred. On top of that, control rods were not supposed to scram, leaving the chain reaction to be controlled only by inherent physical properties of the fuel and moderator and eventual actions of the BOP system. The primary system response has been studied assuming AMSAC availability. (author)

  11. Real-time thermal neutron radiographic detection systems

    International Nuclear Information System (INIS)

    Berger, H.; Bracher, D.A.

    1976-01-01

    Systems for real-time detection of thermal neutron images are reviewed. Characteristics of one system are presented; the data include contrast, resolution and speed of response over the thermal neutron intensity range 2.5 10 3 n/cm 2 -sec to 10 7 n/cm 2 -sec

  12. Thermal analysis of HNPF spent fuel shipping container in torch environments

    International Nuclear Information System (INIS)

    Eggers, P.E.; Crawford, H.L.; Trujillo, A.A.; Pope, R.B.; Yoshimura, H.R.

    1980-01-01

    A thermal analysis of a modified HNPF cask has been performed to predict cask temperatures in simulated torch fire environments. A portion of this analysis also provided a basis for the modifications leading to the design of external cooling fins, a pressure relief valve system, a spent fuel torch fire analyses will provide comparison with experimentally measured temperatures of the HNPF cask, in torch fire environments, which will be obtained in the future. Scope of this study was analytical in nature and involved the use of a computer-based heat transfer analysis methods. Product of this study is the prediction of cask temperatures and internal pressures under normal and torch-fire accident conditions. This study also involved an analysis of the torch fire literature in order to develop an empirically based thermal model for the torch environment. 8 figures, 3 tables

  13. Electromagnetic and thermal analysis for development of the CRDM for SMART

    International Nuclear Information System (INIS)

    Kim, Hyun Min; Kim, In Yong; Kim, Hyun Min; Lee, Myoung Goo; Park, Jin Seok

    2008-08-01

    The objective of the electromagnetic and thermal analysis is to evaluate the feasibility of the CRDM for SMART by calculating the lifting force and the heat distribution of the coil and reviewing the agreement between the result and the design condition. Electromagnetic and thermal analysis of the CRDM are performed based on the pre-design data provided by KAERI. Lifting force and thermal distribution of the CRDM are reviewed as the analysis results and some design improvement methods are suggested for the detail design to be performed in the future. As a result of electromagnetic analysis, the lifting force was calculated to meet the design condition of 2000 N when 36 A of input current is applied to the lifting coil. However, the lifting force could increase by design change of the armature, pole, coil, flux ring, coil housing and relative position of those components. Therefore, it is concluded that the more improved CRDM can be developed by the design optimization in the detail design. As the result of thermal analysis, the coil temperature increases 89 .deg. C relative to the circumferential temperature when the input current to exert 2000 N of lifting force is applied. The temperature increase of the coil for the case of considering the RCS temperature is 3 - 4 times more than the case of not considering the RCS temperature. This should be considered in the detail design of the coil stack assembly and the cooling system

  14. Seasonal thermal energy storage in shallow geothermal systems: thermal equilibrium stage

    Directory of Open Access Journals (Sweden)

    Nowamooz Hossein

    2016-01-01

    Full Text Available This paper is dedicated to the study of seasonal heat storage in shallow geothermal installations in unsaturated soils for which hydrothermal properties such as degree of saturation and thermal conductivity vary with time throughout the profile. In the model, a semi-analytical model which estimates time-spatial thermal conductivity is coupled with a 2D cylindrical heat transfer modeling using finite difference method. The variation of temperature was obtained after 3 heating and cooling cycles for the different types of loads with maximum thermal load of qmax = 15 W.m−1 with variable angular frequency (8 months of heating and 4 months of cooling.and constant angular frequency (6 months of heating and 6 months of cooling to estimate the necessary number of cycles to reach the thermal equilibrium stage. The results show that we approach a thermal equilibrium stage where the same variation of temperature can be observed in soils after several heating and cooling cycles. Based on these simulations, the necessary number of cycles can be related to the total applied energy on the system and the minimum number of cycles is for a system with the total applied energy of 1.9qmax.

  15. Stand Alone Battery Thermal Management System

    Energy Technology Data Exchange (ETDEWEB)

    Brodie, Brad [Denso International America, Incorporated, Southfield, MI (United States)

    2015-09-30

    The objective of this project is research, development and demonstration of innovative thermal management concepts that reduce the cell or battery weight, complexity (component count) and/or cost by at least 20%. The project addresses two issues that are common problems with current state of the art lithium ion battery packs used in vehicles; low power at cold temperatures and reduced battery life when exposed to high temperatures. Typically, battery packs are “oversized” to satisfy the two issues mentioned above. The first phase of the project was spent making a battery pack simulation model using AMEsim software. The battery pack used as a benchmark was from the Fiat 500EV. FCA and NREL provided vehicle data and cell data that allowed an accurate model to be created that matched the electrical and thermal characteristics of the actual battery pack. The second phase involved using the battery model from the first phase and evaluate different thermal management concepts. In the end, a gas injection heat pump system was chosen as the dedicated thermal system to both heat and cool the battery pack. Based on the simulation model. The heat pump system could use 50% less energy to heat the battery pack in -20°C ambient conditions, and by keeping the battery cooler at hot climates, the battery pack size could be reduced by 5% and still meet the warranty requirements. During the final phase, the actual battery pack and heat pump system were installed in a test bench at DENSO to validate the simulation results. Also during this phase, the system was moved to NREL where testing was also done to validate the results. In conclusion, the heat pump system can improve “fuel economy” (for electric vehicle) by 12% average in cold climates. Also, the battery pack size, or capacity, could be reduced 5%, or if pack size is kept constant, the pack life could be increased by two years. Finally, the total battery pack and thermal system cost could be reduced 5% only if the

  16. Thermal Stress Analysis of Medium-Voltage Converters for Smart Transformers

    DEFF Research Database (Denmark)

    Andresen, Markus; Ma, Ke; De Carne, Giovanni

    2017-01-01

    . To address this concern, this work conducts thermal stress analysis for a modular multilevel converter (MMC), which is a promising solution for the medium voltage stage of the ST. The focus is put on the mission profiles of the transformer and the impact on the thermal stress of power semiconductor devices......A smart transformer (ST) can take over an important managing role in the future electrical distribution grid system and can provide many advanced grid services compared to the traditional transformer. However, the risk is that the advanced functionality is balanced out by a lower reliability....... Normal operation at different power levels and medium voltage grid faults in a feeder fed by a traditional transformer are considered as well as the electrical and the thermal stress of the disconnection and the reconnection procedures. For the validation, the thermal stress of one MMC cell is reproduced...

  17. Development of the finite element method in the thermal field. TRIO-EF software for thermal and radiation analysis

    International Nuclear Information System (INIS)

    Casalotti, N.; Magnaud, J.P.

    1989-01-01

    The possibilities of the TRIO-EF software in the thermal field are presented. The TRIO-EF is a computer program based on the finite element method and used for three-dimensional incompressible flow analysis. It enables the calculation of three-dimensional heat transfer and the fluid/structure analysis. The geometrically complex radiative reactor systems are taken into account in the form factor calculation. The implemented algorithms are described [fr

  18. A novel polygeneration system integrating photovoltaic/thermal collectors, solar assisted heat pump, adsorption chiller and electrical energy storage: Dynamic and energy-economic analysis

    International Nuclear Information System (INIS)

    Calise, Francesco; Figaj, Rafal Damian; Vanoli, Laura

    2017-01-01

    Highlights: • Space heating/cooling, domestic hot water and electrical energy are provided by the system. • Two different users are investigated: fitness center and office. • The influence of the battery system on system economic performance is scarce. • Net metering contract is more profitable compared to simplified purchase/resale arrangement one. - Abstract: In this paper a dynamic simulation model and a thermo-economic analysis of a novel polygeneration system are presented. The system includes photovoltaic/thermal collectors coupled with a solar-assisted heat pump, an adsorption chiller and an electrical energy storage. The modelled plant supplies electrical energy, space heating and cooling and domestic hot water. The produced solar thermal energy is used during the winter to supply the heat pump evaporator, providing the required space heating. In summer, solar thermal energy is used to drive an adsorption chiller providing the required space cooling. All year long, solar thermal energy in excess, with respect to the space heating and cooling demand, is used to produce domestic hot water. The produced electrical energy is self-consumed by both user and system auxiliary equipment and/or supplied to the grid. The system model includes a detailed electrical energy model for user storage and exchange with the grid along with a detailed building model. This study is a continuation of previous works recently presented by the authors. In particular, the present paper focuses on the real electrical demands of several types of users and on the analysis of the comfort of building users. Differently from the works previously published by the authors, the present work bases the calculations on measured electrical demands of real users (fitness center and offices). The system performance is analyzed with two different electricity supply contracts: net metering and simplified purchase/resale arrangement. Daily, weekly and yearly results are presented. Finally, a

  19. Thermal Analysis of Concrete Storage Cask with Bird Screen Meshes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ju-Chan; Bang, K.S.; Yu, S.H.; Cho, S.S.; Choi, W.S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    In this study, a thermal analysis of the cask with bird screen meshes has been performed using a porous media model. The overpack consists of a structural material, a concrete shielding, and a ventilation system. Heat is removed from the cask to the environment by a passive means only. Air inlet and outlet ducts are installed at the bottom and top of the cask for a ventilation system. Bird screen meshes are installed at the air inlet and outlet ducts to inhibit intrusion of debris from the external environment. The presence of this screens introduce an additional resistance to air flow through the ducts. Five types of meshes for bird screen were considered in this study. The bird screen meshes at the inlet and outlet vents reduce the open area for flow by about 44 - 79 %. Flow resistance coefficients for porous media model were deduced from the fluid flow analysis of bird screen meshes. Thermal analyses for the concrete cask have been carried out using a porous media model. The analysis results agreed well with the test results. Therefore, it was shown that the porous media model for the screen mesh was established to estimate the cask temperatures.

  20. Thermal Analysis of Concrete Storage Cask with Bird Screen Meshes

    International Nuclear Information System (INIS)

    Lee, Ju-Chan; Bang, K.S.; Yu, S.H.; Cho, S.S.; Choi, W.S.

    2016-01-01

    In this study, a thermal analysis of the cask with bird screen meshes has been performed using a porous media model. The overpack consists of a structural material, a concrete shielding, and a ventilation system. Heat is removed from the cask to the environment by a passive means only. Air inlet and outlet ducts are installed at the bottom and top of the cask for a ventilation system. Bird screen meshes are installed at the air inlet and outlet ducts to inhibit intrusion of debris from the external environment. The presence of this screens introduce an additional resistance to air flow through the ducts. Five types of meshes for bird screen were considered in this study. The bird screen meshes at the inlet and outlet vents reduce the open area for flow by about 44 - 79 %. Flow resistance coefficients for porous media model were deduced from the fluid flow analysis of bird screen meshes. Thermal analyses for the concrete cask have been carried out using a porous media model. The analysis results agreed well with the test results. Therefore, it was shown that the porous media model for the screen mesh was established to estimate the cask temperatures

  1. Methodology of Supervision by Analysis of Thermal Flux for Thermal Conduction of a Batch Chemical Reactor Equipped with a Monofluid Heating/Cooling System

    Directory of Open Access Journals (Sweden)

    Ghania Henini

    2012-01-01

    Full Text Available We present the thermal behavior of a batch reactor to jacket equipped with a monofluid heating/cooling system. Heating and cooling are provided respectively by an electrical resistance and two plate heat exchangers. The control of the temperature of the reaction is based on the supervision system. This strategy of management of the thermal devices is based on the usage of the thermal flux as manipulated variable. The modulation of the monofluid temperature by acting on the heating power or on the opening degrees of an air-to-open valve that delivers the monofluid to heat exchanger. The study shows that the application of this method for the conduct of the pilot reactor gives good results in simulation and that taking into account the dynamics of the various apparatuses greatly improves ride quality of conduct. In addition thermal control of an exothermic reaction (mononitration shows that the consideration of heat generated in the model representation improve the results by elimination any overshooting of the set-point temperature.

  2. Thermal analysis of the in-vessel components of the ITER plasma-position reflectometry

    Energy Technology Data Exchange (ETDEWEB)

    Quental, P. B., E-mail: pquental@ipfn.tecnico.ulisboa.pt; Policarpo, H.; Luís, R.; Varela, P. [Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa (Portugal)

    2016-11-15

    The ITER plasma position reflectometry system measures the edge electron density profile of the plasma, providing real-time supplementary contribution to the magnetic measurements of the plasma-wall distance. Some of the system components will be in direct sight of the plasma and therefore subject to plasma and stray radiation, which may cause excessive temperatures and stresses. In this work, thermal finite element analysis of the antenna and adjacent waveguides is conducted with ANSYS V17 (ANSYS® Academic Research, Release 17.0, 2016). Results allow the identification of critical temperature points, and solutions are proposed to improve the thermal behavior of the system.

  3. Cost/benefit comparison of thermal solar energy systems in Switzerland

    International Nuclear Information System (INIS)

    Suter, J.M.

    1991-10-01

    A comparison is made between thermal solar energy systems of different size for five different applications in the three main climatic zones in Switzerland. Conventional ways of energy conservation are also included in the comparison. A cost/benefit ratio is calculated for each system. The investment is used as a cost indicator whereas the useful solar heat or the conventional energy saving is chosen as benefit. It is shown that the most systems sold today in Switzerland - combined hot water and space heating systems for single family houses - have the poorest cost/benefit ratio among all systems considered in the analysis. Four applications with more favourable cost/benefit ratio are identified. Large systems have generally a better cost/benefit ratio than smaller ones, although the total investment is higher. Photovoltaics is even less favourable than all thermal systems considered. The large scale penetration of technologies with good cost/benefit ratio lies in the public interest. Supporting activities should consider the priority set by the cost/benefit ratio. (author) 1 fig., 14 refs

  4. Thermal performance of a radiatively cooled system for quantum optomechanical experiments in space

    International Nuclear Information System (INIS)

    Pilan Zanoni, André; Burkhardt, Johannes; Johann, Ulrich; Aspelmeyer, Markus; Kaltenbaek, Rainer; Hechenblaikner, Gerald

    2016-01-01

    Highlights: • We improved performance and design aspects of a radiatively cooled instrument. • A heat-flow analysis showed near optimal performance of the shield design. • A simple modification to imaging optics allowed further improvements. • We studied the thermal behavior for different orbital cases. • A transfer-function analysis showed strong attenuation of thermal variations. - Abstract: Passive cooling of scientific instruments via thermal radiation to deep space offers many advantages over active cooling in terms of mission cost, lifetime and the achievable quality of vacuum and microgravity. Motivated by the mission proposal MAQRO to test the foundations of quantum physics harnessing a deep-space environment, we investigate the performance of a radiatively cooled instrument, where the environment of a test particle in a quantum superposition has to be cooled to less than 20 K. We perform a heat-transfer analysis between the instrument components and a transfer-function analysis on thermal oscillations induced by the spacecraft interior and dissipative sources. The thermal behavior of the instrument is discussed for an orbit around a Lagrangian point and for a highly elliptical Earth orbit. Finally, we investigate possible design improvements. These include a mirror-based design of the imaging system on the optical bench (OB) and an extension of the heat shields.

  5. A 3-D Thermal Analysis of the HANARO Cold Neutron Moderator Cell

    International Nuclear Information System (INIS)

    Han, Gee Y.; Kim, Heo Nil

    2007-01-01

    Fundamental studies on a thermal analysis of a cryogenic system such as a cold neutron source (CNS) have increased significantly for a successful CNS design in cold neutron research during recent years. A three-dimensional (3-D) thermal analysis model for the HANARO CNS was developed and used to accurately predict a temperature distribution between the hydrogen inside and the entire inner and outer surfaces of a moderator cell, whose moderator and cell walls are heated differently, under a steady-state operating condition by using the HEATING 7 code. The objective of this study is primarily to predict a temperature distribution through a heat flow in a cold neutron moderator cell heated from a nuclear heating and cooled by a cryogenic coolant. This paper presents satisfactory results of a steady-state temperature distribution in a cryogenic moderator cell. They are used to support the thermal stress analysis of the moderator cell walls and to provide a safe operation for the HANARO CNS facility

  6. Thermal analysis of building roof assisted with water heater and ...

    Indian Academy of Sciences (India)

    D Prakash

    2018-03-14

    Mar 14, 2018 ... Thermal analysis; building roof; solar water heating system; roof ... These solar collec- ... several benefits, such as its wide range of storage temper- ... rugated plate, rear plate and back insulation material [12]. ..... [7] Weiss W and Rommel M 2008 Process heat collectors. State of the art within Task 33/IV.

  7. Thermal analysis of transportation packaging for nuclear spent fuel

    International Nuclear Information System (INIS)

    Akamatsu, Hiroshi; Taniuchi, Hiroaki

    1989-01-01

    Safety analysis of transportation packaging for nuclear spent fuel comprises structural, thermal, containment, shielding and criticality factors, and the safety of a packaging is verified by these analyses. In thermal analysis, the temperature of each part of the packaging is calculated under normal and accident test conditions. As an example of thermal analysis, the temperature distribution of a packaging being subjected to a normal test was calculated by the TRUMP code and compared with measured data. (author)

  8. Effective methods of solving of model equations of certain class of thermal systems

    International Nuclear Information System (INIS)

    Lach, J.

    1985-01-01

    A number of topics connected with solving of model equations of certain class of thermal systems by the method of successive approximations is touched. A system of partial differential equations of the first degree, appearing most frequently in practical applications of heat and mass transfer theory is reduced to an equivalent system of Volterra integral equations of the second kind. Among a few sample applications the thermal processes appearing in the fuel channel of nuclear reactor are solved. The theoretical analysis is illustrated by the results of numerical calculations given in tables and diagrams. 111 refs., 17 figs., 16 tabs. (author)

  9. Method for automated building of spindle thermal model with use of CAE system

    Science.gov (United States)

    Kamenev, S. V.

    2018-03-01

    The spindle is one of the most important units of the metal-cutting machine tool. Its performance is critical to minimize the machining error, especially the thermal error. Various methods are applied to improve the thermal behaviour of spindle units. One of the most important methods is mathematical modelling based on the finite element analysis. The most common approach for its realization is the use of CAE systems. This approach, however, is not capable to address the number of important effects that need to be taken into consideration for proper simulation. In the present article, the authors propose the solution to overcome these disadvantages using automated thermal model building for the spindle unit utilizing the CAE system ANSYS.

  10. Lighting system with thermal management system having point contact synthetic jets

    Science.gov (United States)

    Arik, Mehmet; Weaver, Stanton Earl; Kuenzler, Glenn Howard; Wolfe, Jr., Charles Franklin; Sharma, Rajdeep

    2013-12-10

    Lighting system having unique configurations are provided. For instance, the lighting system may include a light source, a thermal management system and driver electronics, each contained within a housing structure. The light source is configured to provide illumination visible through an opening in the housing structure. The thermal management system includes a plurality of synthetic jets. The synthetic jets are arranged within the lighting system such that they are secured at contact points.

  11. Thermal test and analysis of a spent fuel storage cask

    International Nuclear Information System (INIS)

    Yamakawa, H.; Gomi, Y.; Ozaki, S.; Kosaki, A.

    1993-01-01

    A thermal test simulated with full-scale cask model for the normal storage was performed to verify the storage skill of the spent fuels of the cask. The maximum temperature at each point in the test was lower than the allowable temperature. The integrity of the cask was maintained. It was observed that the safety of containment system was also kept according to the check of the seal before and after the thermal test. Therefore it was shown that using the present skill, it is possible to store spent fuels in the dry-type cask safely. Moreover, because of the good agreement between analysis and experimental results, it was shown that the analysis model was successfully established to estimate the temperature distribution of the fuel cladding and the seal portion. (J.P.N.)

  12. Investigation and modelling of thermal conditions in low flow SDHW systems

    Energy Technology Data Exchange (ETDEWEB)

    Shah, L.J.

    1999-07-01

    The purpose of this study was to characterise the thermal conditions in low flow SDHW systems. As the heat storage has proved to be the most important system component, there has been an emphasis on this component in the study. A literature survey revealed that the mantle tank heat storage type is one of the most promising storage designs and therefore only the mantle tank is investigated in this study. To optimise the design of mantle tanks and low flow SDHW systems, it was found necessary to understand how the thermal stratification is built up in the heat storage. In addition, it was necessary to model the flow and heat transfer in the tanks. Due to the complexity of the problems, CFD-models were used to take mantle tanks into calculation. Two CFD programs were used to model the mantle tank: CFX and Fluent. As the CFD-models formed the basis for the theoretical work, they were validated with experiments. In this study, both thermal measurements and experimentally visualised flow patterns were compared with CFD-predictions. The experimental flow visualisation was carried out with Particle image Velocimetry (PIV). With a transparent glass mantle tank, the structures in the mantle were visualised and compared with the CFD-predicted flow structures in the mantle. The results showed that the mantle flow was highly dominated by buoyancy and the CFD-models were able to model this flow. With a steel mantle tank, different dynamic thermal experiments were carried out in a heat storage test facility. These results were used to evaluate the CFD-predicted temperatures. Inner tank and mantle outlet temperatures were compared to the similar CFD-predictions and a good degree of similarity was found between measured and calculated temperatures. With the verified CFX models a parameter analysis was carried out. Based on this analysis, two Nusselt-Rayleigh heat transfer correlations were developed - one for the convective heat transfer in the mantle and one for the convective

  13. Physical, thermal and structural properties of Calcium Borotellurite glass system

    Energy Technology Data Exchange (ETDEWEB)

    Paz, E.C. [CCSST – UFMA, Imperatriz, MA (Brazil); IFMA, Açailândia, MA (Brazil); Dias, J.D.M. [CCSST – UFMA, Imperatriz, MA (Brazil); Melo, G.H.A. [CCSST – UFMA, Imperatriz, MA (Brazil); IFMA, Imperatriz, MA (Brazil); Lodi, T.A. [CCSST – UFMA, Imperatriz, MA (Brazil); Carvalho, J.O. [CCSST – UFMA, Imperatriz, MA (Brazil); IFTO, Araguaína, TO (Brazil); Façanha Filho, P.F.; Barboza, M.J.; Pedrochi, F. [CCSST – UFMA, Imperatriz, MA (Brazil); Steimacher, A., E-mail: steimacher@hotmail.com [CCSST – UFMA, Imperatriz, MA (Brazil)

    2016-08-01

    In this work the glass forming ability in Calcium Borotellurite (CBTx) glass system was studied. Six glass samples were prepared by melt-quenching technique and the obtained samples are transparent, lightly yellowish, with no visible crystallites. The structural studies were carried out by using XRD, FTIR, Raman Spectra, density measurements, and the thermal analysis by using DTA and specific heat. The results are discussed in terms of tellurium oxide content and their changes in structural and thermal properties of glass samples. The addition of TeO{sub 2} increased the density and thermal stability values and decreased glass transition temperature (Tg). Raman and FTIR spectroscopies indicated that the network structure of CBTx glasses is formed by BO{sub 3}, BO{sub 4}, TeO{sub 3}, TeO{sub 3+1} and TeO{sub 4} units. CBTx system showed good glass formation ability and good thermal stability, which make CBTx glasses suitable for manufacturing process and a candidate for rare-earth doping for several optical applications. - Highlights: • Glass forming ability on Calcium Borotellurite system was studied. • The glass structure was investigated by XRD, Raman and FTIR. • The glass network structure of the CBTx glasses is formed by BO{sub 3}, BO{sub 4}, TeO{sub 3}, TeO{sub 3+1} and TeO{sub 4} units. • The density and thermal stability of the CBTx glass decreases with TeO{sub 2} while the Cp and the Tg decreases. • The obtained CBTx glasses are suitable for manufacturing process and rare-earth doping for several optical applications.

  14. Proceedings of transient thermal-hydraulics and coupled vessel and piping system responses 1991

    International Nuclear Information System (INIS)

    Wang, G.Y.; Shin, Y.W.; Moody, F.J.

    1991-01-01

    This book reports on transient thermal-hydraulics and coupled vessel and piping system responses. Topics covered include: nuclear power plant containment designs; analysis of control rods; gate closure of hydraulic turbines; and shock wave solutions for steam water mixtures in piping systems

  15. Pressurized Thermal Shock, Pts

    International Nuclear Information System (INIS)

    Boyd, C.

    2008-01-01

    Pressurized Thermal Shock (Pts) refers to a condition that challenges the integrity of the reactor pressure vessel. The root cause of this problem is the radiation embrittlement of the reactor vessel. This embrittlement leads to an increase in the reference temperature for nil ductility transition (RTNDT). RTNDT can increase to the point where the reactor vessel material can loose fracture toughness during overcooling events. The analysis of the risk of having a Pts for a specific plant is a multi-disciplinary problem involving probabilistic risk analysis (PRA), thermal-hydraulic analysis, and ultimately a structural and fracture analysis of the vessel wall. The PRA effort involves the postulation of overcooling events and ultimately leads to an integrated risk analysis. The thermal-hydraulic effort involves the difficult task of predicting the system behavior during a postulated overcooling scenario with a special emphasis on predicting the thermal and mechanic loadings on the reactor pressure vessel wall. The structural and fracture analysis of the reactor vessel wall relies on the thermal-hydraulic conditions as boundary conditions. The US experience has indicated that medium and large diameter primary system breaks dominate the risk of Pts along with scenarios that involve a stuck open valve (and associated system cooldown) that recloses resulting in system re-pressurization while the vessel wall is cool.

  16. Interaction between daily load demand curve and management of hydro-thermal generation system

    International Nuclear Information System (INIS)

    Granelli, G.; Montagna, M.; Pasini, G.; Innorta, M.; Marannino, P.

    1993-01-01

    The influence that the behaviour of the daily load demand curve has on the management of a hydro-thermal generation system is considered. The aim of this paper is to show the improvements that can be achieved by suitable load management techniques capable of flattening the load demand curve. The analysis is carried out by using a hydro-thermal scheduling program and a thermal unit dynamic dispatch procedure. The possibility of properly re-committing the available thermal units is also taken into account. The economical and technical convenience of shutting down less economical thermal units operating near the lower generations limits is verified. Finally, some considerations are made about the possible use of the thermal generation incremental costs as a tool for planning the end users' kWh prices, even in the short term. The results refer to a system with characteristics similar to those of the Italian one. In determining the daily load demand curves, the characteristics of load demand in Italy as well as in other European countries are taken into account

  17. Development and Testing of a Variable Conductance Thermal Acquisition, Transport, and Switching System

    Science.gov (United States)

    Bugby, David C.; Farmer, Jeffery T.; Stouffer, Charles J.

    2013-01-01

    This paper describes the development and testing of a scalable thermal management architecture for instruments, subsystems, or systems that must operate in severe space environments with wide variations in sink temperature. The architecture involves a serial linkage of one or more hot-side variable conductance heat pipes (VCHPs) to one or more cold-side loop heat pipes (LHPs). The VCHPs provide wide area heat acquisition, limited distance thermal transport, modest against gravity pumping, concentrated LHP startup heating, and high switching ratio variable conductance operation. The LHPs provide localized heat acquisition, long distance thermal transport, significant against gravity pumping, and high switching ratio variable conductance operation. The single-VCHP, single-LHP system described herein was developed to maintain thermal control of a small robotic lunar lander throughout the lunar day-night thermal cycle. It is also applicable to other variable heat rejection space missions in severe environments. Operationally, despite a 60-70% gas blocked VCHP condenser during ON testing, the system was still able to provide 2-4 W/K ON conductance, 0.01 W/K OFF conductance, and an end-to-end switching ratio of 200-400. The paper provides a detailed analysis of VCHP condenser performance, which quantified the gas blockage situation. Future multi-VCHP/multi-LHP thermal management system concepts that provide power/transport length scalability are also discussed.

  18. Automatic Thermal Control System with Temperature Difference or Derivation Feedback

    Directory of Open Access Journals (Sweden)

    Darina Matiskova

    2016-02-01

    Full Text Available Automatic thermal control systems seem to be non-linear systems with thermal inertias and time delay. A controller is also non-linear because its information and power signals are limited. The application of methods that are available to on-linear systems together with computer simulation and mathematical modelling creates a possibility to acquire important information about the researched system. This paper provides a new look at the heated system model and also designs the structure of the thermal system with temperature derivation feedback. The designed system was simulated by using a special software in Turbo Pascal. Time responses of this system are compared to responses of a conventional thermal system. The thermal system with temperature derivation feedback provides better transients, better quality of regulation and better dynamical properties.

  19. Numerical analysis of unsteady conjugate heat transfer for initial evolution of thermal stratification in a curved pipe

    International Nuclear Information System (INIS)

    Jo, Jong Chull; Kim, Wee Kyung; Kim, Yun Il; Cho, Sang Jin; Choi, Seok Ki

    2000-01-01

    A detailed numerical analysis of initial evolution of thermal stratification in a curved pipe with a finite wall thickness is performed. A primary emphasis of the present study is placed on the investigation of the effect of existence of pipe wall thickness on the evolution of thermal stratification. A simple and convenient numerical method of treating the unsteady conjugate heat transfer in Cartesian as well as non-orthogonal coordinate systems is presented. The proposed unsteady conjugate heat transfer analysis method is implemented in a finite volume thermal-hydraulic computer code based on a cell-centered, non-staggered grid arrangement, the SIMPLEC algorithm and a higher-order bounded convection scheme. Calculations are performed for initial evolution of thermal stratification with high Richardson number in a curved pipe. The predicted results show that the thermally stratified flow and transient conjugate heat transfer in a curved pipe with a specified wall thickness can be satisfactorily analyzed by using the numerical method presented in this paper. As the result, the present analysis method is considered to be effective for the determination of transient temperature distributions in the wall of curved piping system subjected to internally thermal stratification. In addition, the method can be extended to be applicable for the simulation of turbulent flow of thermally stratified fluid

  20. Monitoring system for thermal plasma

    International Nuclear Information System (INIS)

    Romero G, M.; Vilchis P, A.E.

    1999-01-01

    In the Thermal plasma applications laboratory it has been the degradation project of oils for isolation in transformers. These are a very hazardous residues and at this time in the country they are stored in metal barrels. It has been the intention to undergo the oils to plasma for degradate them to non-hazardous residues. The system behavior must be monitored to establish the thermal plasma behavior. (Author)

  1. Summary of comparative results integrated nonthermal treatment and integrated thermal treatment systems studies

    International Nuclear Information System (INIS)

    1996-12-01

    In July 1994, the Idaho National Engineering Laboratory (INEL), under a contract from U.S. Department of Energy's (DOE) Environment Management Office of Science and Technology (OST, EM-50) published a report entitled open-quotes Integrated Thermal Treatment System Study - Phase 1 Resultsclose quotes (EGG-MS-11211). This report was the culmination of over a year of analysis involving scientists and engineers within the DOE complex and from private industry. The purpose of that study was open-quotes to conduct a systematic engineering evaluation of a variety of mixed low level waste (MLLW) treatment system alternatives.close quotes The study also open-quotes identified the research and development, demonstrations, and testing and evaluation needed to assure unit operability in the most promising alternative system.close quotes This study evaluated ten primary thermal treatment technologies, organized into complete open-quotes cradle-to-graveclose quotes systems (including complete engineering flow sheets), to treat DOE MLLW and calculated mass balances and 20-year total life cycle costs (TLCC) for all systems. The waste input used was a representative heterogenous mixture of typical DOE MLLW. An additional study was conducted, and then, based on response to these studies, additional work was started to investigate and evaluate non-thermal treatment options on a footing comparable to the effort devoted to thermal options. This report attempts to present a summary overview of the thermal and non-thermal treatment technologies which were examined in detail in the process of the above mentioned reviews

  2. Transmutation technology development; thermal hydraulic power analysis and structure analysis of the HYPER target beam window

    Energy Technology Data Exchange (ETDEWEB)

    Choi, J. H.; Ju, E. S.; Song, M. K.; Jeon, Y. Z. [Gyeongsang National University, Jinju (Korea)

    2002-03-01

    A thermal hydraulic power analysis, a structure analysis and optimization computation for some design factor for the design of spallation target suitable for HYPER with 1000 MW thermal power in this study was performed. Heat generation formula was used which was evaluated recently based on the LAHET code, mainly to find the maximum beam current under given computation conditions. Thermal hydraulic power of HYPER target system was calculated using FLUENT code, structure conducted by inputting the data into ANSYS. On the temp of beam windows and the pressure distribution calculated using FLUENT. Data transformation program was composed apply the data calculated using FLUENT being commercial CFD code and ANSYS being FEM code for CFX structure analysis. A basic study was conducted on various singular target to obtain fundamental data on the shape for optimum target design. A thermal hydraulic power analysis and structure analysis were conducted on the shapes of parabolic, uniform, scanning beams to choose the optimum shape of beam current analysis was done according to some turbulent model to simulate the real flow. To evaluate the reliability of numerical analysis result, benchmarking of FLUENT code reformed at SNU and Korea Advanced Institute of Science and Technology and it was compared to CFX in the possession of Korea Atomic Energy Research Institute and evaluated. Reliable deviation was observed in the results calculated using FLUENT code, but temperature deviation of about 200 .deg. C was observed in the result from CFX analysis at optimum design condition. Several benchmarking were performed on the basis of numerical analysis concerning conventional HYPER. It was possible to allow a beam arrests of 17.3 mA in the case of the {phi} 350 mm parabolic beam suggested to the optimum in nuclear transmutation when stress equivalent to VON-MISES was calculated to be 140 MPa. 29 refs., 109 figs. (Author)

  3. Thermal hydraulics of accelerator driven system: validation and analysis

    International Nuclear Information System (INIS)

    Kumari, I.; Khanna, A.

    2014-01-01

    This paper presents validation of RELAP5/Mod4.0 code modified to incorporate Lead Bismuth Eutectic (LBE)fluid properties for simulation of Accelerator Driven System (ADS) against Barone's NACIE facility.Results of mass flow rates (MFR), Reynolds number, heat transfer coefficients, temperatures and temperature difference for three powers (10.8, 21.7 and 32.5 kW) under natural circulation of LBE match with Barone's values within 7%,18%,37%, 5% and 8% of relative error respectively. After this validation Indian ADS for thermal power of 15 kW has been simulated. Simulated profiles of temperature, MFR and pressure drop LBE and air are reported. Air and LBE temperatures of present work match with literature design values within 5% of relative error. (author)

  4. Thermal and mechanical analysis of the Faraday shield for the Compact Ignition Tokamak

    International Nuclear Information System (INIS)

    Vesey, R.A.

    1988-02-01

    The antenna for the ion cyclotron resonance heating (ICRH) system of the Compact Ignition Tokamak (CIT) is protected from the plasma environment by a Faraday shield, an array of gas-cooled metallic tubes. The plasma side of the tubes is armored with graphite tiles, which can be either brazed or mechanically attached to the tube. The Faraday shield has been analyzed using finite element codes to model thermal and mechanical responses to typical CIT heating and disruption loads. Four representative materials (Inconel 718, tantalum-10 tungsten, copper alloy C17510, and molybdenum alloy TZM) and several combinations of tube and armor thicknesses were used in the thermal analysis, which revealed that maximum allowable temperatures were not exceeded for any of the four materials considered. The two-dimensional thermal stress analysis indicated Von Mises stresses greater than twice the yield stress for a tube constructed of Inconel 718 (the original design material) for the brazed-graphite design. Analysis of stresses caused by plasma disruption (/rvec J/ /times/ /rvec B/) loads eliminated the copper and molybdenum alloys as candidate tube materials. Of the four materials considered, tantalum-10 tungsten performed the best for a brazed graphite design, showing acceptable thermal stresses (69% of yield) and disruption stresses (42% of yield). A preliminary thermal analysis of the mechanically attached graphite scheme predicts minimal thermal stresses in the tube. The survivability of the graphite tubes in this scheme is yet to be analyzed. 8 refs., 19 figs., 2 tabs

  5. submitter Thermal, Hydraulic, and Electromagnetic Modeling of Superconducting Magnet Systems

    CERN Document Server

    Bottura, L

    2016-01-01

    Modeling techniques and tailored computational tools are becoming increasingly relevant to the design and analysis of large-scale superconducting magnet systems. Efficient and reliable tools are useful to provide an optimal forecast of the envelope of operating conditions and margins, which are difficult to test even when a prototype is available. This knowledge can be used to considerably reduce the design margins of the system, and thus the overall cost, or increase reliability during operation. An integrated analysis of a superconducting magnet system is, however, a complex matter, governed by very diverse physics. This paper reviews the wide spectrum of phenomena and provides an estimate of the time scales of thermal, hydraulic, and electromagnetic mechanisms affecting the performance of superconducting magnet systems. The analysis is useful to provide guidelines on how to divide the complex problem into building blocks that can be integrated in a design and analysis framework for a consistent multiphysic...

  6. Turbopump Design and Analysis Approach for Nuclear Thermal Rockets

    International Nuclear Information System (INIS)

    Chen, Shucheng S.; Veres, Joseph P.; Fittje, James E.

    2006-01-01

    A rocket propulsion system, whether it is a chemical rocket or a nuclear thermal rocket, is fairly complex in detail but rather simple in principle. Among all the interacting parts, three components stand out: they are pumps and turbines (turbopumps), and the thrust chamber. To obtain an understanding of the overall rocket propulsion system characteristics, one starts from analyzing the interactions among these three components. It is therefore of utmost importance to be able to satisfactorily characterize the turbopump, level by level, at all phases of a vehicle design cycle. Here at the NASA Glenn Research Center, as the starting phase of a rocket engine design, specifically a Nuclear Thermal Rocket Engine design, we adopted the approach of using a high level system cycle analysis code (NESS) to obtain an initial analysis of the operational characteristics of a turbopump required in the propulsion system. A set of turbopump design codes (PumpDes and TurbDes) were then executed to obtain sizing and performance parameters of the turbopump that were consistent with the mission requirements. A set of turbopump analyses codes (PUMPA and TURBA) were applied to obtain the full performance map for each of the turbopump components; a two dimensional layout of the turbopump based on these mean line analyses was also generated. Adequacy of the turbopump conceptual design will later be determined by further analyses and evaluation. In this paper, descriptions and discussions of the aforementioned approach are provided and future outlooks are discussed

  7. Analysis of Non-contact Acousto Thermal Signature Data (Postprint)

    Science.gov (United States)

    2016-02-01

    AFRL-RX-WP-JA-2016-0321 ANALYSIS OF NON-CONTACT ACOUSTO-THERMAL SIGNATURE DATA (POSTPRINT) Amanda K. Criner AFRL/RX...October 2014 – 16 September 2015 4. TITLE AND SUBTITLE ANALYSIS OF NON-CONTACT ACOUSTO-THERMAL SIGNATURE DATA (POSTPRINT) 5a. CONTRACT NUMBER...words) The non-contact acousto-thermal signature (NCATS) is a nondestructive evaluation technique with potential to detect fatigue in materials such as

  8. The Evaluation of Feasibility of Thermal Energy Storage System at Riga TPP-2

    Science.gov (United States)

    Ivanova, P.; Linkevics, O.; Cers, A.

    2015-12-01

    The installation of thermal energy storage system (TES) provides the optimisation of energy source, energy security supply, power plant operation and energy production flexibility. The aim of the present research is to evaluate the feasibility of thermal energy system installation at Riga TPP-2. The six modes were investigated: four for non-heating periods and two for heating periods. Different research methods were used: data statistic processing, data analysis, analogy, forecasting, financial method and correlation and regression method. In the end, the best mode was chosen - the increase of cogeneration unit efficiency during the summer.

  9. Thermal analysis of epidermal electronic devices integrated with human skin considering the effects of interfacial thermal resistance

    Science.gov (United States)

    Li, Yuhang; Zhang, Jianpeng; Xing, Yufeng; Song, Jizhou

    2018-05-01

    Epidermal electronic devices (EEDs) have similar mechanical properties as those of human skin such that they can be integrated with human skin for potential applications in monitoring of human vital signs for diagnostic, therapeutic or surgical functions. Thermal management is critical for EEDs in these applications since excessive heating may cause discomfort. Comprehensive analytical studies, finite element analysis and experiments are carried out to study the effects of interfacial thermal resistance between EEDs and human skin on thermal properties of the EED/skin system in this paper. The coupling between the Fourier heat transfer in EEDs and the bio-heat transfer in human skin is accounted in the analytical model based on the transfer matrix method to give accurate predictions on temperatures, which agree well with finite element analysis and experimental measurements. It is shown that the maximum temperature increase of the EED for the case of imperfect bonding between EED and skin is much higher than that of perfect bonding. These results may help the design of EEDs in bi-integrated applications and suggest a valuable route to evaluate the bonding condition between EEDs and biological tissues.

  10. Transient thermal-hydraulic/neutronic analysis in a VVER-1000 reactor core

    International Nuclear Information System (INIS)

    Seyed khalil Mousavian; Mohammad Mohsen Ertejaei; Majid Shahabfar

    2005-01-01

    Full text of publication follows: Nowadays, coupled thermal-hydraulic and three-dimensional neutronic codes in order to consider different feedback effects is state of the art subject in nuclear engineering researches. In this study, RELAP5/COBRA and WIMS/CITATION codes are implemented to investigate the VVER-1000 reactor core parameters during Large Break Loss of Coolant Accident (LB-LOCA). In a LB-LOCA, the primary side pressure, coolant density and fuel temperature strongly decrease but the cladding temperature experiences a strong peak. For this purpose, the RELAP5 Best Estimate (BE) system code is used to simulate the LB-LOCA analysis in VVER-1000 nuclear thermal-hydraulic loops. Also, the modified COBRA-IIIc software as a sub-channel analysis code is applied for modeling of VVER-1000 reactor core. Moreover, WIMS and CITATION as a cross section and 3-D neutron flux codes are coupled with thermal-hydraulic codes with the aim of consider the spatial effects through the reactor core. For this reason, suitable software is developed to link and speed up the coupled thermalhydraulic and three-dimensional neutronic calculations. This software utilizes of external coupling concept in order to integrate thermal-hydraulic and neutronic calculations. (authors)

  11. Analysis of the impact of storage conditions on the thermal recovery efficiency of low-temperature ATES systems

    NARCIS (Netherlands)

    Bloemendal, Martin; Hartog, Niels

    Aquifer thermal energy storage (ATES) is a technology with worldwide potential to provide sustainable space heating and cooling using groundwater stored at different temperatures. The thermal recovery efficiency is one of the main parameters that determines the overall energy savings of ATES systems

  12. Analysis of the impact of storage conditions on the thermal recovery efficiency of low-temperature ATES systems

    NARCIS (Netherlands)

    Bloemendal, J.M.; Hartog, Niels

    2018-01-01

    Aquifer thermal energy storage (ATES) is a technology with worldwide potential to provide sustainable space heating and cooling using groundwater stored at different temperatures. The thermal recovery efficiency is one of the main parameters that determines the overall energy savings of ATES systems

  13. Human emotions detection based on a smart-thermal system of thermographic images

    Science.gov (United States)

    Cruz-Albarran, Irving A.; Benitez-Rangel, Juan P.; Osornio-Rios, Roque A.; Morales-Hernandez, Luis A.

    2017-03-01

    This work presents a noninvasive methodology to obtain biomedical thermal imaging which provide relevant information that may assist in the diagnosis of emotions. Biomedical thermal images of the facial expressions of 44 subjects were captured experiencing joy, disgust, anger, fear and sadness. The analysis of these thermograms was carried out through its thermal value not with its intensity value. Regions of interest were obtained through image processing techniques that allow to differentiate between the subject and the background, having only the subject, the centers of each region of interest were obtained in order to get the same region of the face for each subject. Through the thermal analysis a biomarker for each region of interest was obtained, these biomarkers can diagnose when an emotion takes place. Because each subject tends to react differently to the same stimuli, a self-calibration phase is proposed, its function is to have the same thermal trend for each subject in order to make a decision so that the five emotions can be correctly diagnosed through a top-down hierarchical classifier. As a final result, a smart-thermal system that diagnose emotions was obtained and it was tested on twenty-five subjects (625 thermograms). The results of this test were 89.9% successful.

  14. Thermal fatigue evaluation of piping system Tee-connections

    International Nuclear Information System (INIS)

    Metzner, K.J.; Braillard, O.; Faidy, C.; Marcelles, I.; Solin, J.; Stumpfrock, L.

    2004-01-01

    Thermal fatigue is one significant long-term degradation mechanism nuclear power plants (NPP), in particular, as operating plants become older and life time extension activities have been initiated. In general, the common thermal fatigue issues are understood and controlled by plant instrumentation systems. However, incidents in some plants indicate that certain piping system Tees are susceptible to turbulent temperature mixing effects that cannot be adequately monitored by common thermocouple instrumentation. The THERFAT project has been initiated to advance the accuracy and reliability of thermal fatigue load determination in engineering tools and research oriented approaches to outline a science based practical methodology for managing thermal fatigue risks in Tee-connections susceptible to high cyclic thermal fatigue. (orig.)

  15. Acoustic Emission Analysis of Damage Progression in Thermal Barrier Coatings Under Thermal Cyclic Conditions

    Science.gov (United States)

    Appleby, Matthew; Zhu, Dongming; Morscher, Gregory

    2015-01-01

    Damage evolution of electron beam-physical vapor deposited (EBVD-PVD) ZrO2-7 wt.% Y2O3 thermal barrier coatings (TBCs) under thermal cyclic conditions was monitored using an acoustic emission (AE) technique. The coatings were heated using a laser heat flux technique that yields a high reproducibility in thermal loading. Along with AE, real-time thermal conductivity measurements were also taken using infrared thermography. Tests were performed on samples with induced stress concentrations, as well as calcium-magnesium-alumino-silicate (CMAS) exposure, for comparison of damage mechanisms and AE response to the baseline (as-produced) coating. Analysis of acoustic waveforms was used to investigate damage development by comparing when events occurred, AE event frequency, energy content and location. The test results have shown that AE accumulation correlates well with thermal conductivity changes and that AE waveform analysis could be a valuable tool for monitoring coating degradation and provide insight on specific damage mechanisms.

  16. Thermal-economic analysis of cogeneration systems

    International Nuclear Information System (INIS)

    Walter, A.C.S.; Bajay, S.V.

    1992-01-01

    Approximately 80 countries produce sugar, and fortuitously alcohol, from sugar cane. In all these countries the cogeneration technology of steam turbines is utilized, although almost always inefficient. The greater potential of cogeneration in Brazil is in sugar and alcohol sector, because of the use of sugar cane bagasse as combustible. This work applies the techniques of simulation and economic analysis to different configuration of plants, to determine power generation and associated costs of each alternative. The application of the same procedure at operating condition of several configurations in transient system permits the determination of production profile of exceeding during one day. (C.M.)

  17. A simplified computational scheme for thermal analysis of LWR spent fuel dry storage and transportation casks

    International Nuclear Information System (INIS)

    Kim, Chang Hyun

    1997-02-01

    A simplified computational scheme for thermal analysis of the LWR spent fuel dry storage and transportation casks has been developed using two-step thermal analysis method incorporating effective thermal conductivity model for the homogenized spent fuel assembly. Although a lot of computer codes and analytical models have been developed for application to the fields of thermal analysis of dry storage and/or transportation casks, some difficulties in its analysis arise from the complexity of the geometry including the rod bundles of spent fuel and the heat transfer phenomena in the cavity of cask. Particularly, if the disk-type structures such as fuel baskets and aluminium heat transfer fins are included, the thermal analysis problems in the cavity are very complex. To overcome these difficulties, cylindrical coordinate system is adopted to calculate the temperature profile of a cylindrical cask body using the multiple cylinder model as the step-1 analysis of the present study. In the step-2 analysis, Cartesian coordinate system is adopted to calculate the temperature distributions of the disk-type structures such as fuel basket and aluminium heat transfer fin using three- dimensional conduction analysis model. The effective thermal conductivity for homogenized spent fuel assembly based on Manteufel and Todreas model is incorporated in step-2 analysis to predict the maximum fuel temperature. The presented two-step computational scheme has been performed using an existing HEATING 7.2 code and the effective thermal conductivity for the homogenized spent fuel assembly has been calculated by additional numerical analyses. Sample analyses of five cases are performed for NAC-STC including normal transportation condition to examine the applicability of the presented simplified computational scheme for thermal analysis of the large LWR spent fuel dry storage and transportation casks and heat transfer characteristics in the cavity of the cask with the disk-type structures

  18. Thermal performance advisor expert system development

    International Nuclear Information System (INIS)

    McClintock, M.; Hirota, N.; Metzinger, R.

    1991-01-01

    In recent years the electric industry has developed an increased interest in improving efficiency of nuclear power plants. EPRI has embarked upon a research project RP2407, Nuclear Plant Performance Improvements which is designed to address needs in this area. One product of this project has been the Thermal Performance Diagnostic Manual for Nuclear Power Plants (NP-4990P). The purpose of this manual is to provide engineering personnel at nuclear power plants with a consistent way in which to identify thermal performance problems. General Physics is also involved in the development of another computer system called Fossil Thermal Performance Advisor (FTPA) which helps operators improve performance for fossil power plants. FTPA is a joint venture between General Physics and New York State Electric and Gas Company. This paper describes both of these computer systems and uses the FTPA as an interesting comparison that illustrates the considerations required for the development of a computer system that effectively addresses the needs of the users

  19. Development of high flux thermal neutron generator for neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Vainionpaa, Jaakko H., E-mail: hannes@adelphitech.com [Adelphi Technology, 2003 E Bayshore Rd, Redwood City, CA 94063 (United States); Chen, Allan X.; Piestrup, Melvin A.; Gary, Charles K. [Adelphi Technology, 2003 E Bayshore Rd, Redwood City, CA 94063 (United States); Jones, Glenn [G& J Jones Enterprice, 7486 Brighton Ct, Dublin, CA 94568 (United States); Pantell, Richard H. [Department of Electrical Engineering, Stanford University, Stanford, CA (United States)

    2015-05-01

    The new model DD110MB neutron generator from Adelphi Technology produces thermal (<0.5 eV) neutron flux that is normally achieved in a nuclear reactor or larger accelerator based systems. Thermal neutron fluxes of 3–5 · 10{sup 7} n/cm{sup 2}/s are measured. This flux is achieved using four ion beams arranged concentrically around a target chamber containing a compact moderator with a central sample cylinder. Fast neutron yield of ∼2 · 10{sup 10} n/s is created at the titanium surface of the target chamber. The thickness and material of the moderator is selected to maximize the thermal neutron flux at the center. The 2.5 MeV neutrons are quickly thermalized to energies below 0.5 eV and concentrated at the sample cylinder. The maximum flux of thermal neutrons at the target is achieved when approximately half of the neutrons at the sample area are thermalized. In this paper we present simulation results used to characterize performance of the neutron generator. The neutron flux can be used for neutron activation analysis (NAA) prompt gamma neutron activation analysis (PGNAA) for determining the concentrations of elements in many materials. Another envisioned use of the generator is production of radioactive isotopes. DD110MB is small enough for modest-sized laboratories and universities. Compared to nuclear reactors the DD110MB produces comparable thermal flux but provides reduced administrative and safety requirements and it can be run in pulsed mode, which is beneficial in many neutron activation techniques.

  20. Thermal animal detection system (TADS)

    Energy Technology Data Exchange (ETDEWEB)

    Desholm, M

    2003-03-01

    This report presents data from equipment tests and software development for the Thermal Animal Detection System (TADS) development project: 'Development of a method for estimating collision frequency between migrating birds and offshore wind turbines'. The technical tests were performed to investigate the performance of remote controlling, video file compression tool and physical stress of the thermal camera when operating outdoors and under the real time vibration conditions at a 2 MW turbine. Furthermore, experimental tests on birds were performed to describe the decreasing detectability with distance on free flying birds, the performance of the thermal camera during poor visibility, and finally, the performance of the thermal sensor software developed for securing high -quality data. In general, it can be concluded that the thermal camera and its related hardware and software, the TADS, are capable of recording migrating birds approaching the rotating blades of a turbine, even under conditions with poor visibility. If the TADS is used in a vertical viewing scenario it would comply with the requirements for a setup used for estimating the avian collision frequency at offshore wind turbines. (au)

  1. Optimised design and thermal-hydraulic analysis of the IFMIF/HFTM test section

    Energy Technology Data Exchange (ETDEWEB)

    Gordeev, S.; Heinzel, V.; Lang, K.H.; Moeslang, A.; Schleisiek, K.; Slobodtchouk, V.; Stratmanns, E.

    2003-10-01

    On the basis of previous concepts, analyses and experiments, the high flux test module (HFTM) for the International Fusion Materials Irradiation Facility (IFMIF) was further optimised. The work focused on the design and the thermal hydraulic analysis of the HFTM section containing the material specimens to be irradiated, the ''test section'', with the main objective to improve the concept with respect to the optimum use of the available irradiation volume and to the temperature of the specimens. Particular emphasis was laid on the application of design principles which assure stable and reproducible thermal conditions. The present work has confirmed the feasibility and suitability of the optimised design of the HFTM test section with chocolate plate like shaped rigs. In particular it has been shown that the envisaged irradiation temperatures can be reached with acceptable temperature differences inside the specimen stack. The latter can be achieved only by additional electrical heating of the axial ends of the capsules. Division of the heater in three sections with separate power supply and control units is necessary. Maintaining of the temperatures during beam-off periods likewise requires electrical heating. The required electrical heaters - mineral isolated wires - are commercially available. The potential of the CFD code STAR-CD for the thermal hydraulic analysis of complex systems like the HFTM was confirmed. Nevertheless, experimental confirmation is desirable. Suitable experiments are under preparation. To verify the assumptions made on the thermal conductivity of the contact faces and layers between the two shells of the rig, dedicated experiments are suggested. The present work must be complemented by a thermal mechanical analysis of the module. Most critical component in this respect seems to be the rig wall. Furthermore, it will be necessary to investigate the response of the HFTM to power transients, and to determine the requirements

  2. Optimised design and thermal-hydraulic analysis of the IFMIF/HFTM test section

    International Nuclear Information System (INIS)

    Gordeev, S.; Heinzel, V.; Lang, K.H.; Moeslang, A.; Schleisiek, K.; Slobodtchouk, V.; Stratmanns, E.

    2003-10-01

    On the basis of previous concepts, analyses and experiments, the high flux test module (HFTM) for the International Fusion Materials Irradiation Facility (IFMIF) was further optimised. The work focused on the design and the thermal hydraulic analysis of the HFTM section containing the material specimens to be irradiated, the ''test section'', with the main objective to improve the concept with respect to the optimum use of the available irradiation volume and to the temperature of the specimens. Particular emphasis was laid on the application of design principles which assure stable and reproducible thermal conditions. The present work has confirmed the feasibility and suitability of the optimised design of the HFTM test section with chocolate plate like shaped rigs. In particular it has been shown that the envisaged irradiation temperatures can be reached with acceptable temperature differences inside the specimen stack. The latter can be achieved only by additional electrical heating of the axial ends of the capsules. Division of the heater in three sections with separate power supply and control units is necessary. Maintaining of the temperatures during beam-off periods likewise requires electrical heating. The required electrical heaters - mineral isolated wires - are commercially available. The potential of the CFD code STAR-CD for the thermal hydraulic analysis of complex systems like the HFTM was confirmed. Nevertheless, experimental confirmation is desirable. Suitable experiments are under preparation. To verify the assumptions made on the thermal conductivity of the contact faces and layers between the two shells of the rig, dedicated experiments are suggested. The present work must be complemented by a thermal mechanical analysis of the module. Most critical component in this respect seems to be the rig wall. Furthermore, it will be necessary to investigate the response of the HFTM to power transients, and to determine the requirements on the electrical

  3. Thermal analysis and two-directional air flow thermal management for lithium-ion battery pack

    Science.gov (United States)

    Yu, Kuahai; Yang, Xi; Cheng, Yongzhou; Li, Changhao

    2014-12-01

    Thermal management is a routine but crucial strategy to ensure thermal stability and long-term durability of the lithium-ion batteries. An air-flow-integrated thermal management system is designed in the present study to dissipate heat generation and uniformize the distribution of temperature in the lithium-ion batteries. The system contains of two types of air ducts with independent intake channels and fans. One is to cool the batteries through the regular channel, and the other minimizes the heat accumulations in the middle pack of batteries through jet cooling. A three-dimensional anisotropic heat transfer model is developed to describe the thermal behavior of the lithium-ion batteries with the integration of heat generation theory, and validated through both simulations and experiments. Moreover, the simulations and experiments show that the maximum temperature can be decreased to 33.1 °C through the new thermal management system in comparison with 42.3 °C through the traditional ones, and temperature uniformity of the lithium-ion battery packs is enhanced, significantly.

  4. Ablation, Thermal Response, and Chemistry Program for Analysis of Thermal Protection Systems

    Science.gov (United States)

    Milos, Frank S.; Chen, Yih-Kanq

    2010-01-01

    In previous work, the authors documented the Multicomponent Ablation Thermochemistry (MAT) and Fully Implicit Ablation and Thermal response (FIAT) programs. In this work, key features from MAT and FIAT were combined to create the new Fully Implicit Ablation, Thermal response, and Chemistry (FIATC) program. FIATC is fully compatible with FIAT (version 2.5) but has expanded capabilities to compute the multispecies surface chemistry and ablation rate as part of the surface energy balance. This new methodology eliminates B' tables, provides blown species fractions as a function of time, and enables calculations that would otherwise be impractical (e.g. 4+ dimensional tables) such as pyrolysis and ablation with kinetic rates or unequal diffusion coefficients. Equations and solution procedures are presented, then representative calculations of equilibrium and finite-rate ablation in flight and ground-test environments are discussed.

  5. HANARO thermal hydraulic accident analysis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Chul; Kim, Heon Il; Lee, Bo Yook; Lee, Sang Yong [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1996-06-01

    For the safety assessment of HANARO, accident analyses for the anticipated operational transients, accident scenarios and limiting accident scenarios were conducted. To do this, the commercial nuclear reactor system code. RELAP5/MOD2 was modified to RELAP5/KMRR; the thermal hydraulic correlations and the heat exchanger model was changed to incorporate HANARO characteristics. This report summarizes the RELAP/KMRR calculation results and the subchannel analyses results based on the RELAP/KMRR results. During the calculation, major concern was placed on the integrity of the fuel. For all the scenarios, the important accident analysis parameters, i.e., fuel centerline temperatures and the minimum critical heat flux ratio(MCHFR), satisfied safe design limits. It was verified, therefore, that the HANARO was safely designed. 21 tabs., 89 figs., 39 refs. (Author) .new.

  6. Thermal Insulation System for Non-Vacuum Applications Including a Multilayer Composite

    Science.gov (United States)

    Fesmire, James E. (Inventor)

    2017-01-01

    The thermal insulation system of the present invention is for non-vacuum applications and is specifically tailored to the ambient pressure environment with any level of humidity or moisture. The thermal insulation system includes a multilayered composite including i) at least one thermal insulation layer and at least one compressible barrier layer provided as alternating, successive layers, and ii) at least one reflective film provided on at least one surface of the thermal insulation layer and/or said compressible barrier layer. The different layers and materials and their combinations are designed to provide low effective thermal conductivity for the system by managing all modes of heat transfer. The thermal insulation system includes an optional outer casing surrounding the multilayered composite. The thermal insulation system is particularly suited for use in any sub-ambient temperature environment where moisture or its adverse effects are a concern. The thermal insulation system provides physical resilience against damaging mechanical effects including compression, flexure, impact, vibration, and thermal expansion/contraction.

  7. Numerical Modeling of a Shallow Borehole Thermal Energy Storage System

    Science.gov (United States)

    Catolico, N.; Ge, S.; Lu, N.; McCartney, J. S.

    2014-12-01

    Borehole thermal energy storage (BTES) combined with solar thermal energy harvesting is an economic technological system to garner and store energy as well as an environmentally-sustainable alternative for the heating of buildings. The first community-scale BTES system in North America was installed in 2007 in the Drake Landing Solar Community (DLSC), about 35 miles south of Calgary, Canada. The BTES system involves direct circulation of water heated from solar thermal panels in the summer into a storage tank, after which it is circulate within an array of 144 closed-loop geothermal heat exchangers having a depth of 35 m and a spacing of 2.5 m. In the winter the circulation direction is reversed to supply heat to houses. Data collection over a six year period indicates that this system can supply more than 90% of the winter heating energy needs for 52 houses in the community. One major challenge facing the BTES system technology is the relatively low annual efficiency, i.e., the ratio of energy input and output is in the range of 15% to 40% for the system in Drake Landing. To better understand the working principles of BTES and to improve BTES performance for future applications at larger scales, a three-dimensional transient coupled fluid and heat transfer model is established using TOUGH2. The time-dependent injection temperatures and circulation rate measured over the six years of monitoring are used as model input. The simulations are calibrated using soil temperature data measured at different locations over time. The time-dependent temperature distributions within the borehole region agree well with the measured temperatures for soil with an intrinsic permeability of 10e-19 m2, an apparent thermal conductivity of 2.03 W/m°C, and a volumetric heat capacity of 2.31 MJ/m-3°C. The calibrated model serves as the basis for a sensitivity analysis of soil and operational parameters on BTES system efficiency preformed with TOUGH2. Preliminary results suggest 1) BTES

  8. Optimisation of accelerators and vulcanising systems on thermal stability of natural rubber/recycled ethylene–propylene–diene-monomer blends

    International Nuclear Information System (INIS)

    Nabil, H.; Ismail, H.; Azura, A.R.

    2014-01-01

    Highlights: • Accelerator types and vulcanising systems were optimised in NR/R-EPDM blends. • Two methods of thermal analysis namely thermal ageing and TGA were employed. • EV and peroxide provided superior thermal stability due to stable –S–S and –C–C– linkages. • Crosslinking of the blends is a major concern on the retained properties of the blends. • A CBS-vulcanised using EV system is highly recommended for NR/R-EPDM blends. - Abstract: The present paper concerns the thermal stability of natural rubber/recycled ethylene–propylene–diene-monomer (NR/R-EPDM) blends. The blends were prepared using various accelerators and vulcanising systems. Four types of accelerators were selected, i.e., N-tert-butyl-2-benzothiazyl-sulphonamide (TBBS), N-cyclohexyl-benzothiazyl-sulphenamide (CBS), tetramethylthiuram disulphide (TMTD) and 2-mercaptobenzothiazol (MBT). Subsequently, semi-efficient vulcanisation (semi-EV), efficient vulcanisation (EV), peroxide and mixed sulphur/peroxide vulcanising systems (semi-EV/Peroxide and EV/Peroxide) were observed in the latter study. Two methods of thermal analysis namely, thermo-oxidative ageing and thermogravimetric analysis were conducted. The results indicated that TMTD and MBT-vulcanised blends showed slightly higher thermal stability than that of CBS and TBBS vulcanised blends however, CBS-vulcanised blends exhibited satisfactory overall mechanical and thermal stability in comparison to the other accelerators used. In the case of optimisation of vulcanising systems, semi-EV showed the highest un-aged tensile strength when compared against semi-EV/Peroxide, EV, EV/Peroxide and peroxide vulcanising systems, respectively. However, EV, EV/Peroxide and peroxide vulcanising systems provided slightly higher thermal stability, due to the blends consisted of more stable monosulphidic and carbon–carbon linkages in the vulcanised network. The activation energies of degradation of the blends were determined by applying

  9. Detection of low caloric power of coal by pulse fast-thermal neutron analysis

    International Nuclear Information System (INIS)

    Gu De-shan; Sang Hai-feng; Qiao Shuang; Liu Yu-ren, Liu Lin-mao; Jing Shi-wei; Chinese Academy of Sciences, Changchun

    2004-01-01

    Analysis method and principle of pulse fast-thermal neutron analysis (PFTNA) are introduced. A system for the measurement of low caloric power of coal by PFTNA is also presented. The 14 MeV pulse neutron generator and BGO detector and 4096 MCA were applied in this system. A multiple linear regression method applied to the data solved the interferential problem of multiple elements. The error of low caloric power between chemical analysis and experiment was less than 0.4 MJ/kg. (author)

  10. Thermal System Analysis and Optimization of Large-Scale Compressed Air Energy Storage (CAES

    Directory of Open Access Journals (Sweden)

    Zhongguang Fu

    2015-08-01

    Full Text Available As an important solution to issues regarding peak load and renewable energy resources on grids, large-scale compressed air energy storage (CAES power generation technology has recently become a popular research topic in the area of large-scale industrial energy storage. At present, the combination of high-expansion ratio turbines with advanced gas turbine technology is an important breakthrough in energy storage technology. In this study, a new gas turbine power generation system is coupled with current CAES technology. Moreover, a thermodynamic cycle system is optimized by calculating for the parameters of a thermodynamic system. Results show that the thermal efficiency of the new system increases by at least 5% over that of the existing system.

  11. Integrated thermal treatment system sudy: Phase 2, Results

    Energy Technology Data Exchange (ETDEWEB)

    Feizollahi, F.; Quapp, W.J.

    1995-08-01

    This report presents the second phase of a study on thermal treatment technologies. The study consists of a systematic assessment of nineteen thermal treatment alternatives for the contact-handled mixed low-level waste (MLLW) currently stored in the US Department of Energy complex. The treatment alternatives consist of widely varying technologies for safely destroying the hazardous organic components, reducing the volume, and preparing for final disposal of the MLLW. The alternatives considered in Phase 2 were innovative thermal treatments with nine types of primary processing units. Other variations in the study examined the effect of combustion gas, air pollution control system design, and stabilization technology for the treatment residues. The Phase 1 study, the results of which have been published as an interim report, examined ten initial thermal treatment alternatives. The Phase 2 systems were evaluated in essentially the same manner as the Phase 2 systems. The assumptions and methods were the same as for the Phase 1 study. The quantities, and physical and chemical compositions, of the input waste used in he Phase 2 systems differ from those in the Phase 1 systems, which were based on a preliminary waste input database developed at the onset of the Integrated Thermal Treatment System study. The inventory database used in the Phase 2 study incorporates the latest US Department of Energy information. All systems, both primary treatment systems and subsystem inputs, have now been evaluated using the same waste input (2,927 lb/hr).

  12. Integrated thermal treatment system sudy: Phase 2, Results

    International Nuclear Information System (INIS)

    Feizollahi, F.; Quapp, W.J.

    1995-08-01

    This report presents the second phase of a study on thermal treatment technologies. The study consists of a systematic assessment of nineteen thermal treatment alternatives for the contact-handled mixed low-level waste (MLLW) currently stored in the US Department of Energy complex. The treatment alternatives consist of widely varying technologies for safely destroying the hazardous organic components, reducing the volume, and preparing for final disposal of the MLLW. The alternatives considered in Phase 2 were innovative thermal treatments with nine types of primary processing units. Other variations in the study examined the effect of combustion gas, air pollution control system design, and stabilization technology for the treatment residues. The Phase 1 study, the results of which have been published as an interim report, examined ten initial thermal treatment alternatives. The Phase 2 systems were evaluated in essentially the same manner as the Phase 2 systems. The assumptions and methods were the same as for the Phase 1 study. The quantities, and physical and chemical compositions, of the input waste used in he Phase 2 systems differ from those in the Phase 1 systems, which were based on a preliminary waste input database developed at the onset of the Integrated Thermal Treatment System study. The inventory database used in the Phase 2 study incorporates the latest US Department of Energy information. All systems, both primary treatment systems and subsystem inputs, have now been evaluated using the same waste input (2,927 lb/hr)

  13. Numerical analysis of a PCM thermal storage system with varying wall temperature

    International Nuclear Information System (INIS)

    Halawa, E.; Bruno, F.; Saman, W.

    2005-01-01

    Numerical analysis of melting and freezing of a PCM thermal storage unit (TSU) with varying wall temperature is presented. The TSU under analysis consists of several layers of thin slabs of a PCM subjected to convective boundary conditions where air flows between the slabs. The model employed takes into account the variations in wall temperature along the direction of air flow as well as the sensible heat. The paper discusses typical characteristics of the melting/freezing of PCM slabs in an air stream and presents some results of the numerical simulation in terms of air outlet temperatures and heat transfer rates during the whole periods of melting and freezing. Considerations in the design of the TSU are also given

  14. An analysis of system pressure and temperature distribution in self-pressurizer of SMART considering thermal stratification at intermediate cavity

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Yeon Moon; Lee, Doo Jeong; Yoon, Ju Hyun; Kim, Hwan Yeol [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-03-01

    Because the pressurizer is in reactor vessel, the heat transfer from primary water would increase the temperatures of fluids in pressurizer to same temperature of hotleg, if no cooling equipment were supplied. Thus, heat exchanger and thermal insulator are needed to minimize heat transferred from primary water and to remove heat in pressurizer. The temperatures in cavities of pressurizer for normal operation are 70 deg C and 74 deg C for intermediate and end cavity, respectively, which considers the solubility of nitrogen gas in water. Natural convection is the mechanism of heat balance in pressurizer of SMART. In SMART, the heat exchanger in pressurizer is placed in lower part of intermediate cavity, so the heat in upper part of intermediate cavity can't be removed adequately and it can cause thermal stratification. If thermal stratification occurred, it increases heat transfers to nitrogen gas and system pressure increases as the result. Thus, proper evaluation of those effects on system pressure and ways to mitigate thermal stratification should be established. This report estimates the system pressure and temperatures in cavities of pressurizer with considering thermal stratification in intermediate cavity. The system pressure and temperatures for each cavities considered size of wet thermal insulator, temperature of upper plate of reactor vessel, parameters of heat exchanger in intermediate cavity such as flow rate and temperature of cooling water, heat transfer area, effective tube height, and location of cooling tube. In addition to the consideration of thermal stratification thermal mixing of all water in intermediate cavity also considered and compared in this report. (author). 6 refs., 60 figs., 2 tabs.

  15. Value and cost analyses for solar thermal-storage systems

    Energy Technology Data Exchange (ETDEWEB)

    Luft, W.; Copeland, R.J.

    1983-04-01

    Value and cost data for thermal energy storage are presented for solar thermal central receiver systems for which thermal energy storage appears to be attractive. Both solar thermal electric power and industrial process heat applications are evaluated. The value of storage is based on the cost for fossil fuel and solar thermal collector systems in 1990. The costing uses a standard lifetime methodology with the storage capacity as a parameter. Both value and costs are functions of storage capacity. However, the value function depends on the application. Value/cost analyses for first-generation storage concepts for five central receiver systems (molten salt, water/steam, organic fluid, air, and liquid metal) established the reference against which new systems were compared. Some promising second-generation energy storage concepts have been identified, and some more advanced concepts have also been evaluated.

  16. Introduction of thermal-hydraulic analysis code and system analysis code for HTGR

    International Nuclear Information System (INIS)

    Tanaka, Mitsuhiro; Izaki, Makoto; Koike, Hiroyuki; Tokumitsu, Masashi

    1984-01-01

    Kawasaki Heavy Industries Ltd. has advanced the development and systematization of analysis codes, aiming at lining up the analysis codes for heat transferring flow and control characteristics, taking up HTGR plants as the main object. In order to make the model of flow when shock waves propagate to heating tubes, SALE-3D which can analyze a complex system was developed, therefore, it is reported in this paper. Concerning the analysis code for control characteristics, the method of sensitivity analysis in a topological space including an example of application is reported. The flow analysis code SALE-3D is that for analyzing the flow of compressible viscous fluid in a three-dimensional system over the velocity range from incompressibility limit to supersonic velocity. The fundamental equations and fundamental algorithm of the SALE-3D, the calculation of cell volume, the plotting of perspective drawings and the analysis of the three-dimensional behavior of shock waves propagating in heating tubes after their rupture accident are described. The method of sensitivity analysis was added to the analysis code for control characteristics in a topological space, and blow-down phenomena was analyzed by its application. (Kako, I.)

  17. CRYogenic Orbital TEstbed Ground Test Article Thermal Analysis

    Science.gov (United States)

    Piryk, David; Schallhorn, Paul; Walls, Laurie; Stopnitzky, Benny; Rhys, Noah; Wollen, Mark

    2012-01-01

    The purpose of this study was to anchor thermal and fluid system models to CRYOTE ground test data. The CRYOTE ground test artide was jointly developed by Innovative Engineering Solutions, United Launch Alliance and NASA KSC. The test article was constructed out of a titanium alloy tank, Sapphire 77 composite skin (similar to G10), an external secondary payload adapter ring, thermal vent system, multi layer insulation and various data acquisition instrumentation. In efforts to understand heat loads throughout this system, the GTA (filled with liquid nitrogen for safety purposes) was subjected to a series of tests in a vacuum chamber at Marshall Space Flight Center. By anchoring analytical models against test data, higher fidelity thermal environment predictions can be made for future flight articles which would eventually demonstrate critical cryogenic fluid management technologies such as system chilldown, transfer, pressure control and long term storage. Significant factors that influenced heat loads included radiative environments, multi-layer insulation performance, tank fill levels and pressures and even contact conductance coefficients. This report demonstrates how analytical thermal/fluid networks were established and includes supporting rationale for specific thermal responses.

  18. Sustainable earth-based vs. conventional construction systems in the Mediterranean climate: Experimental analysis of thermal performance

    Science.gov (United States)

    Serrano, S.; de Gracia, A.; Pérez, G.; Cabeza, L. F.

    2017-10-01

    The building envelope has high potential to reduce the energy consumption of buildings according to the International Energy Agency (IEA) because it is involved along all the building process: design, construction, use, and end-of-life. The present study compares the thermal behavior of seven different building prototypes tested under Mediterranean climate: two of them were built with sustainable earth-based construction systems and the other five, with conventional brick construction systems. The tested earth-based construction systems consist of rammed earth walls and wooden green roofs, which have been adapted to contemporary requirements by reducing their thickness. In order to balance the thermal response, wooden insulation panels were placed in one of the earth prototypes. All building prototypes have the same inner dimensions and orientation, and they are fully monitored to register inner temperature and humidity, surface walls temperatures and temperatures inside walls. Furthermore, all building prototypes are equipped with a heat pump and an electricity meter to measure the electrical energy consumed to maintain a certain level of comfort. The experimentation was performed along a whole year by carrying out several experiments in free floating and controlled temperature conditions. This study aims at demonstrating that sustainable construction systems can behave similarly or even better than conventional ones under summer and winter conditions. Results show that thermal behavior is strongly penalized when rammed earth wall thickness is reduced. However, the addition of 6 cm of wooden insulation panels in the outer surface of the building prototype successfully improves the thermal response.

  19. An Integrated Approach to Thermal Analysis of Pharmaceutical Solids

    Science.gov (United States)

    Riley, Shelley R. Rabel

    2015-01-01

    A three-tiered experiment for undergraduate Instrumental Analysis students is presented in which students characterize the solid-state thermal behavior of an active pharmaceutical ingredient (acetaminophen) and excipient (a-lactose hydrate) using differential scanning calorimetry, thermogravimetric analysis, and thermal microscopy. Students are…

  20. Performance testing of thermal analysis codes for nuclear fuel casks

    International Nuclear Information System (INIS)

    Sanchez, L.C.

    1987-01-01

    In 1982 Sandia National Laboratories held the First Industry/Government Joint Thermal and Structural Codes Information Exchange and presented the initial stages of an investigation of thermal analysis computer codes for use in the design of nuclear fuel shipping casks. The objective of the investigation was to (1) document publicly available computer codes, (2) assess code capabilities as determined from their user's manuals, and (3) assess code performance on cask-like model problems. Computer codes are required to handle the thermal phenomena of conduction, convection and radiation. Several of the available thermal computer codes were tested on a set of model problems to assess performance on cask-like problems. Solutions obtained with the computer codes for steady-state thermal analysis were in good agreement and the solutions for transient thermal analysis differed slightly among the computer codes due to modeling differences

  1. Thermal and Arc Flash Analysis of Electric Motor Drives in Distribution Networks

    OpenAIRE

    Nikolovski, Srete; Mlakić, Dragan; Alibašić, Emir

    2017-01-01

    The paper presents thermal analysis and arc flash analysis taking care of protection relays coordination settings for electric motor drives connected to the electrical network. Power flow analysis is performed to check if there are any voltage and loading violation conditions in the system. Fault analysis is performed to check the short circuit values and compute arc flash energy dissipated at industrial busbars to eliminate damage to electrical equipment and electrical shocks and hazard to p...

  2. Thermal analysis as an aid to forensics: Alkane melting and oxidative stability of wool

    International Nuclear Information System (INIS)

    Alan Riga, D.

    1998-01-01

    Interdisciplinary methods and thermal analytical techniques in particular are effective tools in aiding the identification and characterization of materials in question involved in civil or criminal law. Forensic material science uses systematic knowledge of the physical or material world gained through analysis, observation and experimentation. Thermal analytical data can be used to aid the legal system in interpreting technical variations in quite often a complex system.Calorimetry and thermal microscopic methods helped define a commercial product composed of alkanes that was involved in a major law suit. The solid-state structures of a number of normal alkanes have unique crystal structures. These alkanes melt and freeze below room temperature to more than 60C below zero. Mixtures of specific alkanes have attributes of pure chemicals. The X-ray diffraction structure of a mixture of alkanes is the same as a pure alkane, but the melting and freezing temperature are significantly lower than predicted. The jury ruled that the product containing n-alkanes had the appropriate melting characteristics. The thermal-physical properties made a commercial fluid truly unique and there was no advertising infringement according to the law and the jury trialA combination of thermogravimetry, differential thermal analysis, infrared spectroscopy and macrophotography were used to conduct an extensive modeling and analysis of physical evidence obtained in a mobile home fire and explosion. A person's death was allegedly linked to the misuse of a kerosene space heater. The thermal analytical techniques showed that external heating was the cause of the space heater's deformation, not a firing of the heater with gasoline and kerosene. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  3. Thermal analysis as an aid to forensics: Alkane melting and oxidative stability of wool

    Energy Technology Data Exchange (ETDEWEB)

    Alan Riga, D. [Professor of Chemistry, Cleveland State University and TechCon Inc., 6325 Aldenham Dr., Cleveland, OH 44143-3331 (United States)

    1998-12-21

    Interdisciplinary methods and thermal analytical techniques in particular are effective tools in aiding the identification and characterization of materials in question involved in civil or criminal law. Forensic material science uses systematic knowledge of the physical or material world gained through analysis, observation and experimentation. Thermal analytical data can be used to aid the legal system in interpreting technical variations in quite often a complex system.Calorimetry and thermal microscopic methods helped define a commercial product composed of alkanes that was involved in a major law suit. The solid-state structures of a number of normal alkanes have unique crystal structures. These alkanes melt and freeze below room temperature to more than 60C below zero. Mixtures of specific alkanes have attributes of pure chemicals. The X-ray diffraction structure of a mixture of alkanes is the same as a pure alkane, but the melting and freezing temperature are significantly lower than predicted. The jury ruled that the product containing n-alkanes had the appropriate melting characteristics. The thermal-physical properties made a commercial fluid truly unique and there was no advertising infringement according to the law and the jury trialA combination of thermogravimetry, differential thermal analysis, infrared spectroscopy and macrophotography were used to conduct an extensive modeling and analysis of physical evidence obtained in a mobile home fire and explosion. A person's death was allegedly linked to the misuse of a kerosene space heater. The thermal analytical techniques showed that external heating was the cause of the space heater's deformation, not a firing of the heater with gasoline and kerosene. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  4. Thermalization and prethermalization in isolated quantum systems: a theoretical overview

    Science.gov (United States)

    Mori, Takashi; Ikeda, Tatsuhiko N.; Kaminishi, Eriko; Ueda, Masahito

    2018-06-01

    The approach to thermal equilibrium, or thermalization, in isolated quantum systems is among the most fundamental problems in statistical physics. Recent theoretical studies have revealed that thermalization in isolated quantum systems has several remarkable features, which emerge from quantum entanglement and are quite distinct from those in classical systems. Experimentally, well isolated and highly controllable ultracold quantum gases offer an ideal testbed to study the nonequilibrium dynamics in isolated quantum systems, promoting intensive recent theoretical endeavors on this fundamental subject. Besides thermalization, many isolated quantum systems show intriguing behavior in relaxation processes, especially prethermalization. Prethermalization occurs when there is a clear separation of relevant time scales and has several different physical origins depending on individual systems. In this review, we overview theoretical approaches to the problems of thermalization and prethermalization.

  5. Probing quantum and thermal noise in an interacting many-body system

    DEFF Research Database (Denmark)

    Hofferberth, S.; Lesanovsky, Igor; Schumm, Thorsten

    2008-01-01

    of the shot-to-shot variations of interference-fringe contrast for pairs of independently created one-dimensional Bose condensates. Analysing different system sizes, we observe the crossover from thermal to quantum noise, reflected in a characteristic change in the distribution functions from poissonian......The probabilistic character of the measurement process is one of the most puzzling and fascinating aspects of quantum mechanics. In many-body systems quantum-mechanical noise reveals non-local correlations of the underlying many-body states. Here, we provide a complete experimental analysis....... Furthermore, our experiments constitute the first analysis of the full distribution of quantum noise in an interacting many-body system....

  6. Outdoor performance analysis of a 1090× point-focus Fresnel high concentrator photovoltaic/thermal system with triple-junction solar cells

    International Nuclear Information System (INIS)

    Xu, Ning; Ji, Jie; Sun, Wei; Han, Lisheng; Chen, Haifei; Jin, Zhuling

    2015-01-01

    Graphical abstract: A high concentrator photovoltaic/thermal (HCPV/T) system based on point-focus Fresnel lens has been set up in this work. The concentrator has a geometric concentration ratio of 1090× and uniform irradiation distribution can be obtained on solar cells. The system produces both electricity and heat. Performance of the system has been investigated based on the outdoor measurement in a clear day. The HCPV/T system presents an instantaneous electrical efficiency of 28% and a highest instantaneous thermal efficiency of 54%, respectively. Experimental results show that direct irradiation affects the electrical performance of the system dominantly. Fitting results of electrical performance offer simple and reliable methods to analyze the system performance. - Highlights: • A point-focus Fresnel lens photovoltaic/thermal system is proposed and studied. • The system presents an instantaneous electrical efficiency of 28%. • The system has a highest instantaneous thermal efficiency of 54%. • Direct irradiation has the dominant effect on the electrical performance. • Fitting results offer simple and reliable methods to analyze system performances. - Abstract: A high concentrator photovoltaic/thermal (HCPV/T) system based on point-focus Fresnel lens has been set up in this work. The concentrator has a geometric concentration ratio of 1090× and uniform irradiation distribution can be obtained on solar cells. The system produces both electricity and heat. Performance of the system has been investigated based on the outdoor measurement in a clear day. The HCPV/T system presents an instantaneous electrical efficiency of 28% and a highest instantaneous thermal efficiency of 54%, which means the overall efficiency of the system can be more than 80%. A mathematical model for calculating cell temperature is proposed to solve difficult measurement of cell temperature in a system. Moreover, characteristics of electrical performance under various direct

  7. Monte Carlo simulations to advance characterisation of landmines by pulsed fast/thermal neutron analysis

    NARCIS (Netherlands)

    Maucec, M.; Rigollet, C.

    The performance of a detection system based on the pulsed fast/thermal neutron analysis technique was assessed using Monte Carlo simulations. The aim was to develop and implement simulation methods, to support and advance the data analysis techniques of the characteristic gamma-ray spectra,

  8. Transient Thermal Analysis of 3-D Integrated Circuits Packages by the DGTD Method

    KAUST Repository

    Li, Ping

    2017-03-11

    Since accurate thermal analysis plays a critical role in the thermal design and management of the 3-D system-level integration, in this paper, a discontinuous Galerkin time-domain (DGTD) algorithm is proposed to achieve this purpose. Such as the parabolic partial differential equation (PDE), the transient thermal equation cannot be directly solved by the DGTD method. To address this issue, the heat flux, as an auxiliary variable, is introduced to reduce the Laplace operator to a divergence operator. The resulting PDE is hyperbolic, which can be further written into a conservative form. By properly choosing the definition of the numerical flux used for the information exchange between neighboring elements, the hyperbolic thermal PDE can be solved by the DGTD together with the auxiliary differential equation. The proposed algorithm is a kind of element-level domain decomposition method, which is suitable to deal with multiscale geometries in 3-D integrated systems. To verify the accuracy and robustness of the developed DGTD algorithm, several representative examples are benchmarked.

  9. Experimental investigation of a two-inlet air-based building integrated photovoltaic/thermal (BIPV/T) system

    International Nuclear Information System (INIS)

    Yang, Tingting; Athienitis, Andreas K.

    2015-01-01

    Highlights: • BIPV/T system thermal efficiency is 5% higher using two inlets compared to one. • BIPV/T thermal efficiency is 7.6% higher using semi-transparent than opaque PV. • Detailed air temperature profile in BIPV/T channel is obtained. • Nusselt number correlations are developed. - Abstract: An experimental study of thermal characteristics of a novel two-inlet air-based open-loop building integrated photovoltaic/thermal (BIPV/T) system using a full-scale solar simulator is presented. Experimental prototypes of one-inlet and two-inlet BIPV/T systems were constructed for conducting comparative experiments. Variations of BIPV/T systems are also investigated including systems employing opaque mono-crystalline silicon photovoltaic (PV) panels and systems employing semi-transparent mono-crystalline PV panels. Experimental results demonstrate that an equivalent two-inlet system with frameless PV panels can increase the thermal efficiency by 5% compared to a conventional one-inlet system, and that the BIPV/T system with semi-transparent PV panels achieves 7.6% higher thermal efficiency due to the absorption of some solar radiation at the bottom surface in the BIPV/T system cavity. Also, the two-inlet BIPV/T design is easily implemented and does not add significant cost. Detailed air temperature measurements reveal that the mixing of the warm outlet air from the first section and the cool ambient air drawn in from the second inlet contributes to the improved performance of the two-inlet system. Based on a thermal network model of the BIPV/T system and experimental data, correlations are developed for the convective heat transfer coefficients in the two sections. These are necessary for further analysis and development of BIPV/T system with multiple inlets.

  10. Thermodynamic aspects of power production in thermal, chemical and electrochemical systems

    International Nuclear Information System (INIS)

    Sieniutycz, Stanisław; Poświata, Artur

    2012-01-01

    We apply optimization methods to study power generation limits for various energy converters, such as thermal, solar, chemical, and electrochemical engines. Methodological similarity is observed when analysing power limits in thermal machines and fuel cells which are electrochemical flow engines. Operative driving forces and voltage are suitable indicators of imperfect phenomena in energy converters. The results obtained generalize our previous findings for power yield limits in purely thermal systems with finite rates. While temperatures T i of participating media were only necessary variables in purely thermal systems, in the present work both temperatures and chemical potentials μ k are essential. This case is associated with engines propelled by fluxes of both energy and substance. In dynamical systems downgrading or upgrading of resources may occur. Energy flux (power) is created in the generator located between the resource fluid (‘upper’ fluid 1) and the environmental fluid (‘lower’ fluid, 2). Fluid properties, transfer mechanisms and conductance values of dissipative layers or conductors influence the rate of power production. Numerical approaches to the dynamical solutions are based on the dynamic programming or maximum principle. Here we focus especially on the latter method, which involves discrete algorithms of Pontryagin’s type. Downgrading or upgrading of resources may also occur in electrochemical systems of fuel cell type. Yet, in this paper we restrict ourselves to the steady-state fuel cells. We present a simple analysis showing that, in linear systems, only at most ¼ of power dissipated in the natural transfer process can be transformed into the noble form of mechanical power.

  11. Thermal rectification and negative differential thermal conductance in harmonic chains with nonlinear system-bath coupling

    Science.gov (United States)

    Ming, Yi; Li, Hui-Min; Ding, Ze-Jun

    2016-03-01

    Thermal rectification and negative differential thermal conductance were realized in harmonic chains in this work. We used the generalized Caldeira-Leggett model to study the heat flow. In contrast to most previous studies considering only the linear system-bath coupling, we considered the nonlinear system-bath coupling based on recent experiment [Eichler et al., Nat. Nanotech. 6, 339 (2011), 10.1038/nnano.2011.71]. When the linear coupling constant is weak, the multiphonon processes induced by the nonlinear coupling allow more phonons transport across the system-bath interface and hence the heat current is enhanced. Consequently, thermal rectification and negative differential thermal conductance are achieved when the nonlinear couplings are asymmetric. However, when the linear coupling constant is strong, the umklapp processes dominate the multiphonon processes. Nonlinear coupling suppresses the heat current. Thermal rectification is also achieved. But the direction of rectification is reversed compared to the results of weak linear coupling constant.

  12. Fluid-structure interaction analysis for pressurizer surge line subjected to thermal stratification

    International Nuclear Information System (INIS)

    Kang, Dong Gu; Jhung, Myung Jo; Chang, Soon Heung

    2011-01-01

    Research highlights: → Temperature of surge line due to stratified flow is defined using CFD analysis. → Fluid-structure interaction analysis is performed to investigate the response characteristics due to thermal stress. → Fatigue usage factors due to thermal stratification are relatively low. → Simplifying temperature distribution in surge line is not always conservative. - Abstract: Serious mechanical damages such as cracks and plastic deformations due to excessive thermal stress caused by thermal stratification have been experienced in several nuclear power plants. In particular, the thermal stratification in the pressurizer surge line has been addressed as one of the significant safety and technical issues. In this study, a detailed unsteady computational fluid dynamics (CFD) analysis involving conjugate heat transfer analysis is performed to obtain the transient temperature distributions in the wall of the pressurizer surge line subjected to stratified internal flows either during out-surge or in-surge operation. The thermal loads from CFD calculations are transferred to the structural analysis code which is employed for the thermal stress analysis to investigate the response characteristics, and the fatigue analysis is ultimately performed. In addition, the thermal stress and fatigue analysis results obtained by applying the realistic temperature distributions from CFD calculations are compared with those by assuming the simplified temperature distributions to identify some requirements for a realistic and conservative thermal stress analysis from a safety point of view.

  13. Proportional and Integral Thermal Control System for Large Scale Heating Tests

    Science.gov (United States)

    Fleischer, Van Tran

    2015-01-01

    The National Aeronautics and Space Administration Armstrong Flight Research Center (Edwards, California) Flight Loads Laboratory is a unique national laboratory that supports thermal, mechanical, thermal/mechanical, and structural dynamics research and testing. A Proportional Integral thermal control system was designed and implemented to support thermal tests. A thermal control algorithm supporting a quartz lamp heater was developed based on the Proportional Integral control concept and a linearized heating process. The thermal control equations were derived and expressed in terms of power levels, integral gain, proportional gain, and differences between thermal setpoints and skin temperatures. Besides the derived equations, user's predefined thermal test information generated in the form of thermal maps was used to implement the thermal control system capabilities. Graphite heater closed-loop thermal control and graphite heater open-loop power level were added later to fulfill the demand for higher temperature tests. Verification and validation tests were performed to ensure that the thermal control system requirements were achieved. This thermal control system has successfully supported many milestone thermal and thermal/mechanical tests for almost a decade with temperatures ranging from 50 F to 3000 F and temperature rise rates from -10 F/s to 70 F/s for a variety of test articles having unique thermal profiles and test setups.

  14. Thermal History Devices, Systems For Thermal History Detection, And Methods For Thermal History Detection

    KAUST Repository

    Caraveo Frescas, Jesus Alfonso; Alshareef, Husam N.

    2015-01-01

    Embodiments of the present disclosure include nanowire field-effect transistors, systems for temperature history detection, methods for thermal history detection, a matrix of field effect transistors, and the like.

  15. Thermal History Devices, Systems For Thermal History Detection, And Methods For Thermal History Detection

    KAUST Repository

    Caraveo Frescas, Jesus Alfonso

    2015-05-28

    Embodiments of the present disclosure include nanowire field-effect transistors, systems for temperature history detection, methods for thermal history detection, a matrix of field effect transistors, and the like.

  16. Techniques for the thermal/hydraulic analysis of LMFBR check valves

    International Nuclear Information System (INIS)

    Cho, S.M.; Kane, R.S.

    1979-01-01

    A thermal/hydraulic analysis of the check valves in liquid sodium service for LMFBR plants is required to provide temperature data for thermal stress analysis of the valves for specified transient conditions. Because of the complex three-dimensional flow pattern within the valve, the heat transfer analysis techniques for less complicated shapes could not be used. This paper discusses the thermal analysis techniques used to assure that the valve stress analysis is conservative. These techniques include a method for evaluating the recirculating flow patterns and for selecting appropriately conservative heat transfer correlations in various regions of the valve

  17. Thermal animal detection system (TADS)

    Energy Technology Data Exchange (ETDEWEB)

    Desholm, M.

    2003-03-01

    This report presents data from equipment tests and software development for the Thermal Animal Detection System (TADS) development project: 'Development of a method for estimating collision frequency between migrating birds and offshore wind turbines'. The technical tests were performed to investigate the performance of remote controlling, video file compression tool and physical stress of the thermal camera when operating outdoors and under the real time vibration conditions at a 2 MW turbine. Furthermore, experimental tests on birds were performed to describe the decreasing detectability with distance on free flying birds, the performance of the thermal camera during poor visibility, and finally, the performance of the thermal sensor software developed for securing high -quality data. In general, it can be concluded that the thermal camera and its related hardware and software, the TADS, are capable of recording migrating birds approaching the rotating blades of a turbine, even under conditions with poor visibility. If the TADS is used in a vertical viewing scenario it would comply with the requirements for a setup used for estimating the avian collision frequency at offshore wind turbines. (au)

  18. Development of the coupled 'system thermal-hydraulics, 3D reactor kinetics, and hot channel' analysis capability of the MARS code

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, J. J.; Chung, B. D.; Lee, W.J

    2005-02-01

    The subchannel analysis capability of the MARS 3D module has been improved. Especially, the turbulent mixing and void drift models for flow mixing phenomena in rod bundles have been assessed using some well-known rod bundle test data. Then, the subchannel analysis feature was combined to the existing coupled 'system Thermal-Hydraulics (T/H) and 3D reactor kinetics' calculation capability of MARS. These features allow the coupled 'system T/H, 3D reactor kinetics, and hot channel' analysis capability and, thus, realistic simulations of hot channel behavior as well as global system T/H behavior. In this report, the MARS code features for the coupled analysis capability are described first. The code modifications relevant to the features are also given. Then, a coupled analysis of the Main Steam Line Break (MSLB) is carried out for demonstration. The results of the coupled calculations are very reasonable and realistic, and show these methods can be used to reduce the over-conservatism in the conventional safety analysis.

  19. A Collaborative Analysis Tool for Thermal Protection Systems for Single Stage to Orbit Launch Vehicles

    Science.gov (United States)

    Alexander, Reginald; Stanley, Thomas Troy

    2001-01-01

    Presented is a design tool and process that connects several disciplines which are needed in the complex and integrated design of high performance reusable single stage to orbit (SSTO) vehicles. Every system is linked to all other systems, as is the case with SSTO vehicles with air breathing propulsion, which is currently being studied by the National Aeronautics and Space Administration (NASA). In particular, the thermal protection system (TPS) is linked directly to almost every major system. The propulsion system pushes the vehicle to velocities on the order of 15 times the speed of sound in the atmosphere before pulling up to go to orbit which results in high temperatures on the external surfaces of the vehicle. Thermal protection systems to maintain the structural integrity of the vehicle must be able to mitigate the heat transfer to the structure and be lightweight. Herein lies the interdependency, in that as the vehicle's speed increases, the TPS requirements are increased. And as TPS masses increase the effect on the propulsion system and all other systems is compounded. To adequately calculate the TPS mass of this type of vehicle several engineering disciplines and analytical tools must be used preferably in an environment that data is easily transferred and multiple iterations are easily facilitated.

  20. Thermal Effect on Fracture Integrity in Enhanced Geothermal Systems

    Science.gov (United States)

    Zeng, C.; Deng, W.; Wu, C.; Insall, M.

    2017-12-01

    In enhanced geothermal systems (EGS), cold fluid is injected to be heated up for electricity generation purpose, and pre-existing fractures are the major conduits for fluid transport. Due to the relative cold fluid injection, the rock-fluid temperature difference will induce thermal stress along the fracture wall. Such large thermal stress could cause the failure of self-propping asperities and therefore change the fracture integrity, which could affect the heat recovery efficiency and fluid recycling. To study the thermal effect on fracture integrity, two mechanisms pertinent to thermal stress are proposed to cause asperity contact failure: (1) the crushing between two pairing asperities leads to the failure at contact area, and (2) the thermal spalling expedites this process. Finite element modeling is utilized to investigate both failure mechanisms by idealizing the asperities as hemispheres. In the numerical analysis, we have implemented meso-scale damage model to investigate coupled failure mechanism induced by thermomechanical stress field and original overburden pressure at the vicinity of contact point. Our results have shown that both the overburden pressure and a critical temperature determine the threshold of asperity failure. Since the overburden pressure implies the depth of fractures in EGS and the critical temperature implies the distance of fractures to the injection well, our ultimate goal is to locate a region of EGS where the fracture integrity is vulnerable to such thermal effect and estimate the influences.

  1. Market potential of solar thermal system in Malaysia

    International Nuclear Information System (INIS)

    Othman, M.Y.H.; Sopian, K.; Dalimin, M.N.

    1992-01-01

    This paper reviews the market potential for solar thermal systems in Malaysia. Our study indicates that solar thermal systems such as solar drying, solar water heating and process heating have a good potential for commercialization. The primary obstacle facing the utilization of these technologies is the financial aspects. (author)

  2. PRE-CASKETSS: an input data generation computer program for thermal and structural analysis of nuclear fuel shipping casks

    International Nuclear Information System (INIS)

    Ikushima, Takeshi

    1988-12-01

    A computer program PRE-CASKETSS has been developed for the purpose of input data generation for thermal and structural analysis computer code system CASKETSS (CASKETSS means a modular code system for CASK Evaluation code system for Thermal and Structural Safety). Main features of PRE-CASKETSS are as follow; (1) Function of input data generation for thermal and structural analysis computer programs is provided in the program. (2) Two- and three-dimensional mesh generation for finite element and finite difference programs are available in the program. (3) The capacity of the material input data generation are provided in the program. (4) The boundary conditions, the load conditions and the initial conditions are capable in the program. (5) This computer program operate both the time shearing system and the batch system. In the paper, brief illustration of calculation method, input data and sample calculations are presented. (author)

  3. Computational Analysis on Performance of Thermal Energy Storage (TES) Diffuser

    Science.gov (United States)

    Adib, M. A. H. M.; Adnan, F.; Ismail, A. R.; Kardigama, K.; Salaam, H. A.; Ahmad, Z.; Johari, N. H.; Anuar, Z.; Azmi, N. S. N.

    2012-09-01

    Application of thermal energy storage (TES) system reduces cost and energy consumption. The performance of the overall operation is affected by diffuser design. In this study, computational analysis is used to determine the thermocline thickness. Three dimensional simulations with different tank height-to-diameter ratio (HD), diffuser opening and the effect of difference number of diffuser holes are investigated. Medium HD tanks simulations with double ring octagonal diffuser show good thermocline behavior and clear distinction between warm and cold water. The result show, the best performance of thermocline thickness during 50% time charging occur in medium tank with height-to-diameter ratio of 4.0 and double ring octagonal diffuser with 48 holes (9mm opening ~ 60%) acceptable compared to diffuser with 6mm ~ 40% and 12mm ~ 80% opening. The conclusion is computational analysis method are very useful in the study on performance of thermal energy storage (TES).

  4. Proceedings of the 11th Thermal and Fluids Analysis Workshop

    Science.gov (United States)

    Sakowski, Barbara

    2002-07-01

    The Eleventh Thermal & Fluids Analysis WorkShop (TFAWS 2000) was held the week of August 21-25 at The Forum in downtown Cleveland. This year's annual event focused on building stronger links between research community and the engineering design/application world and celebrated the theme "Bridging the Gap Between Research and Design". Dr. Simon Ostrach delivered the keynote address "Research for Design (R4D)" and encouraged a more deliberate approach to performing research with near-term engineering design applications in mind. Over 100 persons attended TFAWS 2000, including participants from five different countries. This year's conference devoted a full-day seminar to the discussion of analysis and design tools associated with aeropropulsion research at the Glenn Research Center. As in previous years, the workshop also included hands-on instruction in state-of-the-art analysis tools, paper sessions on selected topics, short courses and application software demonstrations. TFAWS 2000 was co-hosted by the Thermal/Fluids Systems Design and Analysis Branch of NASA GRC and by the Ohio Aerospace Institute and was co-chaired by Barbara A. Sakowski and James R. Yuko. The annual NASA Delegates meeting is a standard component of TFAWS where the civil servants of the various centers represented discuss current and future events which affect the Community of Applied Thermal and Fluid ANalystS (CATFANS). At this year's delegates meeting the following goals (among others) were set by the collective body of delegates participation of all Centers in the NASA material properties database (TPSX) update: (1) developing and collaboratively supporting multi-center proposals; (2) expanding the scope of TFAWS to include other federal laboratories; (3) initiation of a white papers on thermal tools and standards; and (4) formation of an Agency-wide TFAWS steering committee.

  5. Thermal behavior and kinetics assessment of ethanol/gasoline blends during combustion by thermogravimetric analysis

    International Nuclear Information System (INIS)

    3, CEP 12.516-410 Guaratinguetá, SP (Brazil); U.T.P. – Universidad Tecnológica de Pereira, Faculty of Mechanical Engineering, Pereira, Risaralda (Colombia))" data-affiliation=" (UNESP – Univ Estadual Paulista, Campus of Guaratinguetá, Department of Energy, Laboratory of Combustion and Carbon Capture LC3, CEP 12.516-410 Guaratinguetá, SP (Brazil); U.T.P. – Universidad Tecnológica de Pereira, Faculty of Mechanical Engineering, Pereira, Risaralda (Colombia))" >Rios Quiroga, Luis Carlos; 3, CEP 12.516-410 Guaratinguetá, SP (Brazil))" data-affiliation=" (UNESP – Univ Estadual Paulista, Campus of Guaratinguetá, Department of Energy, Laboratory of Combustion and Carbon Capture LC3, CEP 12.516-410 Guaratinguetá, SP (Brazil))" >Balestieri, José 3, CEP 12.516-410 Guaratinguetá, SP (Brazil))" data-affiliation=" (UNESP – Univ Estadual Paulista, Campus of Guaratinguetá, Department of Energy, Laboratory of Combustion and Carbon Capture LC3, CEP 12.516-410 Guaratinguetá, SP (Brazil))" >Antonio Perrella; 3, CEP 12.516-410 Guaratinguetá, SP (Brazil))" data-affiliation=" (UNESP – Univ Estadual Paulista, Campus of Guaratinguetá, Department of Energy, Laboratory of Combustion and Carbon Capture LC3, CEP 12.516-410 Guaratinguetá, SP (Brazil))" >Ávila, Ivonete

    2017-01-01

    Highlights: • Kinetic parameters of thermal decomposition events were obtained. • Thermal analysis was used as a tool for understanding combustion processes. • Blends would be classified using thermogravimetric analysis technics. • Synergistic effect of ethanol mixed with gasoline was studied and defined. • Relative error and activation energy values were used to analyze the synergy. - Abstract: The use of ethanol as a fuel or as an additive blended with gasoline is very important for most countries, which aim to reduce the heavy dependence on fossil fuels and mitigate greenhouse gases emission. An increased use of ethanol-gasoline blends has placed great relevance on acquiring knowledge about their physical and chemical properties. Thus, knowledge of such properties favors a better understanding of the effect of the percentage of ethanol/gasoline blends on engine performance. Thence, the present study has established a correlation between activation energy and synergetic effects, obtained by a thermal analysis, and ethanol content in gasoline for different blends in order to use this technique as a tool to classify these blends in the process in order to obtain useful energy in spark ignition engines. For such a purpose, a kinetic study has been conducted through a simultaneous thermal analysis system – TGA (thermogravimetry analysis) and DTA (differential thermal analysis) by following the methodology of non-isothermal tests. Thermogravimetric tests were performed and fuel activation energies for gasoline, ethanol, and percentages of 5, 10, 15, 20, 25, 30, 50, and 75% (%v) ethanol mixed with gasoline, which was achieved by the model free kinetics. The analysis results suggest that the theoretical curves characteristics of the thermal decomposition of ethanol-gasoline blends are rather different due to their ethanol content. Furthermore, it was observed significant interactions and synergistic effects, especially regarding those with low ethanol

  6. Experimental investigation of thermal storage integrated micro trigeneration system

    International Nuclear Information System (INIS)

    Johar, Dheeraj Kishor; Sharma, Dilip; Soni, Shyam Lal; Goyal, Rahul; Gupta, Pradeep K.

    2017-01-01

    Highlights: • Energy Storage System is integrated with Micro trigeneration system. • Erythritol is used as Phase Change Material. • Maximum energy saved is 15.30%. • Combined systems are feasible to increase energy efficiency. - Abstract: In this study a 4.4 kW stationary compression ignition engine is coupled with a double pipe heat exchanger, vapour absorption refrigeration system and thermal energy storage system to achieve Trigeneration i.e. power, heating and cooling. A shell and tube type heat exchanger filled with erythritol is used to store thermal energy of engine exhaust. Various combinations of thermal energy storage system integrated micro-trigeneration were investigated and results related to performance and emissions are reported in this paper. The test results show that micro capacity (4.4 kW) stationary single cylinder diesel engine can be successfully modified to simultaneously produce power, heating and cooling and also store thermal energy.

  7. Development of best estimate auditing code for CANDU thermal hydraulic safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chung, B. D.; Lee, W. J.; Lim, H. S. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1998-04-15

    The main purpose of this study is to develop a thermal hydraulic auditing code for the CANDU reactor, modifying the model of existing PWR auditing tool, i.e. RELAP5/MOD3. This scope of project is first step of the whole project, thus focus to the establishment of improvement area. The study was performed by reconsideration of the previous code assessment works and investigation of AECL design analysis tools. In order to identify the thermal hydraulic phenomena for events, the whole system of CANDU plant was divided into main functional systems and subcomponents. Each phenomena was addressed to the each subcomponent. FinaIly improvement areas of model development for auditing tool were established based on the identified phenomena.

  8. Thermal analysis of the vertical disposal for HLW

    International Nuclear Information System (INIS)

    Zhao Honggang; Wang Ju; Liu Yuemiao; Su Rui

    2013-01-01

    The temperature on the canister surface is set to be no more than 100℃ in the high level radioactive waste (HLW) repository, it is a criterion to dictate the thermal dimension of the repository. The factors that affect the temperature on the canister surface include the initial power of the canister, the thermal properties of material as the engineered barrier system (EBS), the gaps around the canister in the EBS, the initial ground temperature and thermal properties of the host rock, the repository layout, etc. This article examines the thermal properties of the material in host rock and the EBS, the thermal conductivity properties of the different gaps in the EBS, the temperature evolution around the single canister by using the analysis method and the numerical method. The findings are as follows: 1) The most important and the sensitive parameter is the initial disposal power of the canister; 2) The two key factors that affect the highest temperature on the canister surface are the parameter of uncertainty and nature variability of material as the host rock and the EBS, and the gaps around the canister in the EBS; 3) The temperature difference between the canister and bentonite is no more than 10℃ , and the bigger the inner gaps are, the bigger the temperature difference will be; when the gap between the bentonite and the host rock is filled with water, the temperature difference becomes small, but it will be 1∼3℃ higher than the gaps filled will air. (authors)

  9. Nonequilibrium Distribution of the Microscopic Thermal Current in Steady Thermal Transport Systems

    KAUST Repository

    Yukawa, Satoshi; Ogushi, Fumiko; Shimada, Takashi; Ito, Nobuyasu

    2010-01-01

    Nonequilibrium distribution of the microscopic thermal current is investigated by direct molecular dynamics simulations. The microscopic thermal current in this study is defined by a flow of kinetic energy carried by a single particle. Asymptotic parallel and antiparallel tails of the nonequilibrium distribution to an average thermal current are identical to ones of equilibrium distribution with different temperatures. These temperatures characterizing the tails are dependent on a characteristic length in which a memory of dynamics is completely erased by several particle collisions. This property of the tails of nonequilibrium distribution is confirmed in other thermal transport systems. In addition, statistical properties of a particle trapped by a harmonic potential in a steady thermal conducting state are also studied. This particle feels a finite force parallel to the average thermal current as a consequence of the skewness of the distribution of the current. This force is interpreted as the microscopic origin of thermophoresis.

  10. Coupling analysis of deformation and thermal-hydraulics in a FBR fuel pin bundle using BAMBOO and ASFRE-IV Codes

    International Nuclear Information System (INIS)

    Ito, Masahiro; Imai, Yasutomo; Uwaba, Tomoyuki; Ohshima, Hiroyuki

    2004-03-01

    The bundle-duct interaction may occur in sodium cooled wire-wrapped FBR fuel subassemblies in high burn-up conditions. JNC has been developing a bundle deformation analysis code BAMBOO (Behavior Analysis code for Mechanical interaction of fuel Bundle under On-power Operation), a thermal hydraulics analysis code ASFRE-IV (Analysis of Sodium Flow in Reactor Elements - ver. IV) and their coupling method as a simulation system for the evaluation on the integrity of deformed FBR fuel pin bundles. In this study, the simulation system was applied to a coupling analysis of deformation and thermal-hydraulics in the fuel pin-bundle under a steady-state condition just after startup for the purpose of the verification of the simulation system. The iterative calculations of deformation and thermal-hydraulics employed in the coupling analysis provided numerically unstable solutions. From the result, it was found that improvement of the coupling algorithm of BAMBOO and ASFRE-IV is necessary to reduce numerical fluctuations and to obtain better convergence by introducing such computational technique as the optimized under-relaxation method. (author)

  11. Ablative thermal protection systems

    International Nuclear Information System (INIS)

    Vaniman, J.; Fisher, R.; Wojciechowski, C.; Dean, W.

    1983-01-01

    The procedures used to establish the TPS (thermal protection system) design of the SRB (solid rocket booster) element of the Space Shuttle vehicle are discussed. A final evaluation of the adequacy of this design will be made from data obtained from the first five Shuttle flights. Temperature sensors installed at selected locations on the SRB structure covered by the TPS give information as a function of time throughout the flight. Anomalies are to be investigated and computer design thermal models adjusted if required. In addition, the actual TPS ablator material loss is to be measured after each flight and compared with analytically determined losses. The analytical methods of predicting ablator performance are surveyed. 5 references

  12. Sensitivity analysis of recovery efficiency in high-temperature aquifer thermal energy storage with single well

    International Nuclear Information System (INIS)

    Jeon, Jun-Seo; Lee, Seung-Rae; Pasquinelli, Lisa; Fabricius, Ida Lykke

    2015-01-01

    High-temperature aquifer thermal energy storage system usually shows higher performance than other borehole thermal energy storage systems. Although there is a limitation in the widespread use of the HT-ATES system because of several technical problems such as clogging, corrosion, etc., it is getting more attention as these issues are gradually alleviated. In this study, a sensitivity analysis of recovery efficiency in two cases of HT-ATES system with a single well is conducted to select key parameters. For a fractional factorial design used to choose input parameters with uniformity, the optimal Latin hypercube sampling with an enhanced stochastic evolutionary algorithm is considered. Then, the recovery efficiency is obtained using a computer model developed by COMSOL Multiphysics. With input and output variables, the surrogate modeling technique, namely the Gaussian-Kriging method with Smoothly Clopped Absolute Deviation Penalty, is utilized. Finally, the sensitivity analysis is performed based on the variation decomposition. According to the result of sensitivity analysis, the most important input variables are selected and confirmed to consider the interaction effects for each case and it is confirmed that key parameters vary with the experiment domain of hydraulic and thermal properties as well as the number of input variables. - Highlights: • Main and interaction effects on recovery efficiency in HT-ATES was investigated. • Reliability depended on fractional factorial design and interaction effects. • Hydraulic permeability of aquifer had an important impact on recovery efficiency. • Site-specific sensitivity analysis of HT-ATES was recommended.

  13. Battery management systems with thermally integrated fire suppression

    Science.gov (United States)

    Bandhauer, Todd M.; Farmer, Joseph C.

    2017-07-11

    A thermal management system is integral to a battery pack and/or individual cells. It relies on passive liquid-vapor phase change heat removal to provide enhanced thermal protection via rapid expulsion of inert high pressure refrigerant during abnormal abuse events and can be integrated with a cooling system that operates during normal operation. When a thermal runaway event occurs and sensed by either active or passive sensors, the high pressure refrigerant is preferentially ejected through strategically placed passages within the pack to rapidly quench the battery.

  14. Thermal analysis of the failed equipment storage vault system

    International Nuclear Information System (INIS)

    Jerrell, J.; Lee, S.Y.; Shadday, A.

    1995-07-01

    A storage facility for failed glass melters is required for radioactive operation of the Defense Waste Processing Facility (DWPF). It is currently proposed that the failed melters be stored in the Failed Equipment Storage Vaults (FESV's) in S area. The FESV's are underground reinforced concrete structures constructed in pairs, with adjacent vaults sharing a common wall. A failed melter is to be placed in a steel Melter Storage Box (MSB), sealed, and lowered into the vault. A concrete lid is then placed over the top of the FESV. Two melters will be placed within the FESV/MSB system, separated by the common wall. There is no forced ventilation within the vault so that the melter is passively cooled. Temperature profiles in the Failed Equipment Storage Vault Structures have been generated using the FLOW3D software to model heat conduction and convection within the FESV/MSB system. Due to complexities in modeling radiation with FLOW3D, P/THERMAL software has been used to model radiation using the conduction/convection temperature results from FLOW3D. The final conjugate model includes heat transfer by conduction, convection, and radiation to predict steady-state temperatures. Also, the FLOW3D software has been validated as required by the technical task request

  15. Design and construction of thermal desorption measurement system for tritium contained materials

    International Nuclear Information System (INIS)

    Hara, M.; Hatano, Y.; Calderoni, P.; Shimada, M.

    2014-01-01

    The dual-mode thermal desorption analysis system was designed and built in Idaho National Laboratory (INL) to examine the evolution of the hydrogen isotope gas from materials. The system is equipped with a mass spectrometer for stable hydrogen isotopes and an ionization chamber for tritium components. The performance of the system built was tested with using tritium contained materials. The evolution of tritiated gas species from contaminated materials was measured successfully by using the system. (author)

  16. Thermal Analysis for Ion-Exchange Column System

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Si Y.; King, William D.

    2012-12-20

    Models have been developed to simulate the thermal characteristics of crystalline silicotitanate ion exchange media fully loaded with radioactive cesium either in a column configuration or distributed within a waste storage tank. This work was conducted to support the design and operation of a waste treatment process focused on treating dissolved, high-sodium salt waste solutions for the removal of specific radionuclides. The ion exchange column will be installed inside a high level waste storage tank at the Savannah River Site. After cesium loading, the ion exchange media may be transferred to the waste tank floor for interim storage. Models were used to predict temperature profiles in these areas of the system where the cesium-loaded media is expected to lead to localized regions of elevated temperature due to radiolytic decay. Normal operating conditions and accident scenarios (including loss of solution flow, inadvertent drainage, and loss of active cooling) were evaluated for the ion exchange column using bounding conditions to establish the design safety basis. The modeling results demonstrate that the baseline design using one central and four outer cooling tubes provides a highly efficient cooling mechanism for reducing the maximum column temperature. In-tank modeling results revealed that an idealized hemispherical mound shape leads to the highest tank floor temperatures. In contrast, even large volumes of CST distributed in a flat layer with a cylindrical shape do not result in significant floor heating.

  17. Methodology for thermal hydraulic conceptual design and performance analysis of KALIMER core

    International Nuclear Information System (INIS)

    Young-Gyun Kim; Won-Seok Kim; Young-Jin Kim; Chang-Kue Park

    2000-01-01

    This paper summarizes the methodology for thermal hydraulic conceptual design and performance analysis which is used for KALIMER core, especially the preliminary methodology for flow grouping and peak pin temperature calculation in detail. And the major technical results of the conceptual design for the KALIMER 98.03 core was shown and compared with those of KALIMER 97.07 design core. The KALIMER 98.03 design core is proved to be more optimized compared to the 97.07 design core. The number of flow groups are reduced from 16 to 11, and the equalized peak cladding midwall temperature from 654 deg. C to 628 deg. C. It was achieved from the nuclear and thermal hydraulic design optimization study, i.e. core power flattening and increase of radial blanket power fraction. Coolant flow distribution to the assemblies and core coolant/component temperatures should be determined in core thermal hydraulic analysis. Sodium flow is distributed to core assemblies with the overall goal of equalizing the peak cladding midwall temperatures for the peak temperature pin of each bundle, thus pin cladding damage accumulation and pin reliability. The flow grouping and the peak pin temperature calculation for the preliminary conceptual design is performed with the modules ORFCE-F60 and ORFCE-T60 respectively. The basic subchannel analysis will be performed with the SLTHEN code, and the detailed subchannel analysis will be done with the MATRA-LMR code which is under development for the K-Core system. This methodology was proved practical to KALIMER core thermal hydraulic design from the related benchmark calculation studies, and it is used to KALIMER core thermal hydraulic conceptual design. (author)

  18. [Investigation on Mobile Phone Based Thermal Imaging System and Its Preliminary Application].

    Science.gov (United States)

    Li, Fufeng; Chen, Feng; Liu, Jing

    2015-03-01

    The technical structure of a low-cost thermal imaging system (TIM) lunched on a mobile phone was investigated, which consists of a thermal infrared module and mobile phone and application software. The designing strategies and technical factors toward realizing various TIM array performances are interpreted, including sensor cost and Noise Equivalent Temperature Difference (NETD). In the software algorithm, a mechanism for scene-change detection was implemented to optimize the efficiency of non-uniformity correction (NUC). The performance experiments and analysis indicate that the NETD of the system can be smaller than 150 mK when the integration time is larger than 16 frames. Furthermore, a practical application for human temperature monitoring during physical exercise is proposed and interpreted. The measurement results support the feasibility and facility of the system in the medical application.

  19. Thermal mixing in T-junction piping system concerned with high-cycle thermal fatigue in structure

    International Nuclear Information System (INIS)

    Tanaka, Masaaki; Ohshima, Hiroyuki; Monji, Hideaki

    2008-01-01

    In Japan Atomic Energy Agency (JAEA), a numerical simulation code 'MUGTHES' has been developed to investigate thermal striping phenomena caused by turbulence mixing of fluids in different temperature and to provide transient data for an evaluation method of high-cycle thermal fatigue. MUGTHES adopts Large Eddy Simulation (LES) approach to predict unsteady phenomena in thermal mixing and employs boundary fitted coordinate system to be applied to complex geometry in a power reactor. Numerical simulation of thermal striping phenomena in a T-junction piping system (T-pipe) is conducted. Boundary condition for the simulation is chosen from an existing water experiment in JAEA, named as WATLON experiment. In the numerical simulation, standard Smagorinsky model is employed as eddy viscosity model with the model coefficient of 0.14 (=Cs). Numerical results of MUGTHES are verified by the comparisons with experimental results of velocity and temperature. Through the numerical simulation in the T-pipe, applicability of MUGTHES to the thermal striping phenomena is confirmed and the characteristic large-scale eddy structure which dominates thermal mixing and may cause high-cycle thermal fatigue is revealed. (author)

  20. Thermal treatment investigation of natural lizardite at the atmospheric pressure, based on XRD and differential thermal analysis/thermal gravimetric analysis methods

    International Nuclear Information System (INIS)

    Dabiri, R.; Karimi Shahraki, B.; Mollaei, H.; Ghaffari, M.

    2009-01-01

    Determination of stability limits, mineralogical changes and thermal reaction of serpentine minerals are very important for the investigation of magmatism, mechanism and depth of plates of subduction. During the subduction process, serpentine (Lizardite) minerals will release their water due to thermal reactions. This dehydration can play an important role in volcanism processes related to the subduction, In this study, serpentine minerals (Lizardite) collected from the Neyriz Ophiolite Complex were dehydrated under the constant atmospheric pressure. These mineralogical changes were determined by X-Ray diffraction and differential thermal analysis-thermal gravimetric analyses methods. This study shows natural lizardites that heated for about one hour is stable up to 550 d eg C . Dehydration reactions on lizardite started at approximately between 100 to 150 d eg C and dehydroxylation reactions started at approximately 550-690 d eg C . As a result of thermal reaction, the decomposition of lizardite will take place and then changes in to olivine (forsterite). Crystallization of olivine (forsterite) will start at 600 d eg C . This mineral is stable up to 700 d eg C and then crystallization of enstatite will start at 700 d eg C . During this dehydration and crystallization reaction, amorphous processes will start at 600 d eg C and some amount water and silica will release.

  1. An Approximate Ablative Thermal Protection System Sizing Tool for Entry System Design

    Science.gov (United States)

    Dec, John A.; Braun, Robert D.

    2006-01-01

    A computer tool to perform entry vehicle ablative thermal protection systems sizing has been developed. Two options for calculating the thermal response are incorporated into the tool. One, an industry-standard, high-fidelity ablation and thermal response program was integrated into the tool, making use of simulated trajectory data to calculate its boundary conditions at the ablating surface. Second, an approximate method that uses heat of ablation data to estimate heat shield recession during entry has been coupled to a one-dimensional finite-difference calculation that calculates the in-depth thermal response. The in-depth solution accounts for material decomposition, but does not account for pyrolysis gas energy absorption through the material. Engineering correlations are used to estimate stagnation point convective and radiative heating as a function of time. The sizing tool calculates recovery enthalpy, wall enthalpy, surface pressure, and heat transfer coefficient. Verification of this tool is performed by comparison to past thermal protection system sizings for the Mars Pathfinder and Stardust entry systems and calculations are performed for an Apollo capsule entering the atmosphere at lunar and Mars return speeds.

  2. Thermal error analysis and compensation for digital image/volume correlation

    Science.gov (United States)

    Pan, Bing

    2018-02-01

    Digital image/volume correlation (DIC/DVC) rely on the digital images acquired by digital cameras and x-ray CT scanners to extract the motion and deformation of test samples. Regrettably, these imaging devices are unstable optical systems, whose imaging geometry may undergo unavoidable slight and continual changes due to self-heating effect or ambient temperature variations. Changes in imaging geometry lead to both shift and expansion in the recorded 2D or 3D images, and finally manifest as systematic displacement and strain errors in DIC/DVC measurements. Since measurement accuracy is always the most important requirement in various experimental mechanics applications, these thermal-induced errors (referred to as thermal errors) should be given serious consideration in order to achieve high accuracy, reproducible DIC/DVC measurements. In this work, theoretical analyses are first given to understand the origin of thermal errors. Then real experiments are conducted to quantify thermal errors. Three solutions are suggested to mitigate or correct thermal errors. Among these solutions, a reference sample compensation approach is highly recommended because of its easy implementation, high accuracy and in-situ error correction capability. Most of the work has appeared in our previously published papers, thus its originality is not claimed. Instead, this paper aims to give a comprehensive overview and more insights of our work on thermal error analysis and compensation for DIC/DVC measurements.

  3. Uncertainty Evaluation of the SFR Subchannel Thermal-Hydraulic Modeling Using a Hot Channel Factors Analysis

    International Nuclear Information System (INIS)

    Choi, Sun Rock; Cho, Chung Ho; Kim, Sang Ji

    2011-01-01

    In an SFR core analysis, a hot channel factors (HCF) method is most commonly used to evaluate uncertainty. It was employed to the early design such as the CRBRP and IFR. In other ways, the improved thermal design procedure (ITDP) is able to calculate the overall uncertainty based on the Root Sum Square technique and sensitivity analyses of each design parameters. The Monte Carlo method (MCM) is also employed to estimate the uncertainties. In this method, all the input uncertainties are randomly sampled according to their probability density functions and the resulting distribution for the output quantity is analyzed. Since an uncertainty analysis is basically calculated from the temperature distribution in a subassembly, the core thermal-hydraulic modeling greatly affects the resulting uncertainty. At KAERI, the SLTHEN and MATRA-LMR codes have been utilized to analyze the SFR core thermal-hydraulics. The SLTHEN (steady-state LMR core thermal hydraulics analysis code based on the ENERGY model) code is a modified version of the SUPERENERGY2 code, which conducts a multi-assembly, steady state calculation based on a simplified ENERGY model. The detailed subchannel analysis code MATRA-LMR (Multichannel Analyzer for Steady-State and Transients in Rod Arrays for Liquid Metal Reactors), an LMR version of MATRA, was also developed specifically for the SFR core thermal-hydraulic analysis. This paper describes comparative studies for core thermal-hydraulic models. The subchannel analysis and a hot channel factors based uncertainty evaluation system is established to estimate the core thermofluidic uncertainties using the MATRA-LMR code and the results are compared to those of the SLTHEN code

  4. Thermal performance of Danish solar combi systems in practice and in theory

    DEFF Research Database (Denmark)

    Andersen, Elsa; Shah, Louise Jivan; Furbo, Simon

    2004-01-01

    An overview of measured thermal performances of Danish solar combi systems in practice is given. The thermal performance varies greatly from system to system. Measured and calculated thermal performances of different solar combi systems are compared and the main reasons for the different thermal ...... as theoretically expected....

  5. Thermal Analysis Evaluation of Spent Fuel Storage Rack for Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sangjin; Oh, Jinho; Kwak, Jinsung; Lee, Jongmin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    Spent fuel storage rack is to store spent fuel assemblies. The spent fuel storage rack is submerged in the designated pool for cooling. Due to the condition change of the pool water, the effect of thermal load on spent fuel storage rack must be analyzed and evaluated. In this paper, thermal stress analysis is performed and evaluated on a spent fuel storage rack. For thermal stress evaluation of the spent fuel storage rack, load combinations and allowable criteria in ASME Sec. III NB-3220 are applied. In cases of A-1 and B-1, the same temperature applied on the whole model, thermal stress doesn't occur because there is no constraint about the thermal expansion. The support frame is located on the pool bottom in free standing type and the racks are located in the support frame with enough space. Thermal expansion was considered and reflected in the design of spent fuel storage rack in advance. Thermal stress analysis is performed and evaluated on a spent fuel storage rack with consideration of pool water temperature variation. The thermal analysis including a linear heat transfer and the thermal stress analysis is performed for the racks and support frame and resulted stresses are within allowable criteria.

  6. Analysis of an integrated packed bed thermal energy storage system for heat recovery in compressed air energy storage technology

    International Nuclear Information System (INIS)

    Ortega-Fernández, Iñigo; Zavattoni, Simone A.; Rodríguez-Aseguinolaza, Javier; D'Aguanno, Bruno; Barbato, Maurizio C.

    2017-01-01

    Highlights: •A packed bed TES system is proposed for heat recovery in CAES technology. •A CFD-based approach has been developed to evaluate the behaviour of the TES unit. •TES system enhancement and improvement alternatives are also demonstrated. •TES performance evaluated according to the first and second law of thermodynamics. -- Abstract: Compressed air energy storage (CAES) represents a very attracting option to grid electric energy storage. Although this technology is mature and well established, its overall electricity-to-electricity cycle efficiency is lower with respect to other alternatives such as pumped hydroelectric energy storage. A meager heat management strategy in the CAES technology is among the main reasons of this gap of efficiency. In current CAES plants, during the compression stage, a large amount of thermal energy is produced and wasted. On the other hand, during the electricity generation stage, an extensive heat supply is required, currently provided by burning natural gas. In this work, the coupling of both CAES stages through a thermal energy storage (TES) unit is introduced as an effective solution to achieve a noticeable increase of the overall CAES cycle efficiency. In this frame, the thermal energy produced in the compression stage is stored in a TES unit for its subsequent deployment during the expansion stage, realizing an Adiabatic-CAES plant. The present study addresses the conceptual design of a TES system based on a packed bed of gravel to be integrated in an Adiabatic-CAES plant. With this objective, a complete thermo-fluid dynamics model has been developed, including the implications derived from the TES operating under variable-pressure conditions. The formulation and treatment of the high pressure conditions were found being particularly relevant issues. Finally, the model provided a detailed performance and efficiency analysis of the TES system under charge/discharge cyclic conditions including a realistic operative

  7. Establishment of Safety Analysis System and Technology for CANDU Reactors

    International Nuclear Information System (INIS)

    Min, Byung Joo; Kim, W. Y.; Kim, H. T.; Rhee, B. W.; Yoon, C.; Kang, H. S.; Yoo, K. J.

    2005-03-01

    To improve the CANDU design/operation safety analysis codes and the CANDU safety analysis methodology, the following works have been done. From the development of the lattice codes (WIMS/CANDU), the lattice model simulates the real core lattice geometry and the effect of the pressure tube creep to the core lattice parameter has been evaluated. From the development of the 3-dimensional thermal-hydraulic analysis model of the moderator behavior (CFX4-CAMO), validation of the model against STERN Lab experiment has been executed. The butterfly-shaped grid structure and the 3-dimensional flow resistance model for porous media were developed and applied to the moderator analysis for Wolsong units 2/3/4. The single fuel channel analysis codes for blowdown and post-blowdown were unified by CATHENA. The 3-dimensional fuel channel analysis model (CFX-CACH) has been developed for validation of CATHENA fuel channel analysis model. The interlinking analysis system (CANVAS) of the thermal-hydraulic safety analysis codes for the primary heat transport system and containment system has been executed. The database system of core physics and thermal-hydraulics experimental data for safety analysis has been established on the URL: http://CANTHIS.kaeri.re.kr. For documentation and Standardization of the general safety analysis procedure, the general safety analysis procedure is developed and applied to a large break LOCA. The present research results can be utilized for establishment of the independent safety analysis technology and acquisition of the optimal safety analysis technology

  8. A comparative study on three types of solar utilization technologies for buildings: Photovoltaic, solar thermal and hybrid photovoltaic/thermal systems

    International Nuclear Information System (INIS)

    Huide, Fu; Xuxin, Zhao; Lei, Ma; Tao, Zhang; Qixing, Wu; Hongyuan, Sun

    2017-01-01

    Highlights: • Models of Solar thermal, Photovoltaic and Photovoltaic/thermal systems are developed. • Experiments are performed to validate the simulation results. • Annual performances of the three solar systems used in china are predicted. • Energy comparison between the three solar systems is analyzed. - Abstract: Buildings need energy including heat and electricity, and both of them can be provided by the solar systems. Solar thermal and photovoltaic systems absorb the solar energy and can supply the heat and electricity for buildings, respectively. However, for the urban residential buildings, the limited available area makes installation of the solar thermal collectors and photovoltaic modules together impossible. A hybrid photovoltaic/thermal system can simultaneously generate heat and electricity, which is deemed to be quite suitable for the urban residential buildings application. And yet, for a rural house of China, the available area for installation of the solar collectors is large but daily domestic hot water demand of a rural family is generally not exceeded 300 L. If only the hybrid photovoltaic/thermal collectors are installed on the whole available area, this will lead to an overproduction of the thermal energy, especially in summer. Moreover, buildings requiring for the heat and electricity are different in different regions and different seasons. In this paper, simulation models of the solar thermal, photovoltaic and hybrid photovoltaic/thermal systems are presented, and experiments are also performed to validate the simulation results. Using the validated models, performances of the three solar systems for residential applications were predicted. And energy comparison between the three solar systems used in Hongkong, Lhasa, Shanghai and Beijing of China, respectively, were also studied. Results show that, for the urban residential building with limited available installation space, a hybrid photovoltaic/thermal system may have the

  9. Thermal Analysis of the Advanced Technology Large Aperture Space Telescope (ATLAST) 8 Meter Primary Mirror

    Science.gov (United States)

    Hornsby, Linda; Stahl, H. Philip; Hopkins, Randall C.

    2010-01-01

    The Advanced Technology Large Aperture Space Telescope (ATLAST) preliminary design concept consists of an 8 meter diameter monolithic primary mirror enclosed in an insulated, optical tube with stray light baffles and a sunshade. ATLAST will be placed in orbit about the Sun-Earth L2 and will experience constant exposure to the sun. The insulation on the optical tube and sunshade serve to cold bias the telescope which helps to minimize thermal gradients. The primary mirror will be maintained at 280K with an active thermal control system. The geometric model of the primary mirror, optical tube, sun baffles, and sunshade was developed using Thermal Desktop(R) SINDA/FLUINT(R) was used for the thermal analysis and the radiation environment was analyzed using RADCAD(R). A XX node model was executed in order to characterize the static performance and thermal stability of the mirror during maneuvers. This is important because long exposure observations, such as extra-solar terrestrial planet finding and characterization, require a very stable observatory wave front. Steady state thermal analyses served to predict mirror temperatures for several different sun angles. Transient analyses were performed in order to predict thermal time constant of the primary mirror for a 20 degree slew or 30 degree roll maneuver. This paper describes the thermal model and provides details of the geometry, thermo-optical properties, and the environment which influences the thermal performance. All assumptions that were used in the analysis are also documented. Parametric analyses are summarized for design parameters including primary mirror coatings and sunshade configuration. Estimates of mirror heater power requirements are reported. The thermal model demonstrates results for the primary mirror heated from the back side and edges using a heater system with multiple independently controlled zones.

  10. Parameter Uncertainty for Repository Thermal Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hardin, Ernest [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hadgu, Teklu [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Greenberg, Harris [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dupont, Mark [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-10-01

    This report is one follow-on to a study of reference geologic disposal design concepts (Hardin et al. 2011a). Based on an analysis of maximum temperatures, that study concluded that certain disposal concepts would require extended decay storage prior to emplacement, or the use of small waste packages, or both. The study used nominal values for thermal properties of host geologic media and engineered materials, demonstrating the need for uncertainty analysis to support the conclusions. This report is a first step that identifies the input parameters of the maximum temperature calculation, surveys published data on measured values, uses an analytical approach to determine which parameters are most important, and performs an example sensitivity analysis. Using results from this first step, temperature calculations planned for FY12 can focus on only the important parameters, and can use the uncertainty ranges reported here. The survey of published information on thermal properties of geologic media and engineered materials, is intended to be sufficient for use in generic calculations to evaluate the feasibility of reference disposal concepts. A full compendium of literature data is beyond the scope of this report. The term “uncertainty” is used here to represent both measurement uncertainty and spatial variability, or variability across host geologic units. For the most important parameters (e.g., buffer thermal conductivity) the extent of literature data surveyed samples these different forms of uncertainty and variability. Finally, this report is intended to be one chapter or section of a larger FY12 deliverable summarizing all the work on design concepts and thermal load management for geologic disposal (M3FT-12SN0804032, due 15Aug2012).

  11. Thermal analysis of cold vacuum drying of spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Piepho, M.G.

    1998-07-20

    The thermal analysis examined transient thermal and chemical behavior of the Multi canister Overpack (MCO) container for a broad range of cases that represent the Cold Vacuum Drying (CVD) processes. The cases were defined to consider both normal and off-normal operations at the CVD Facility for an MCO with Mark IV N, Reactor spent fuel in four fuel baskets and one scrap basket. This analysis provides the basis for the MCO thermal behavior at the CVD Facility for its Phase 2 Safety Analysis Report (revision 4).

  12. Metal hydride-based thermal energy storage systems

    Science.gov (United States)

    Vajo, John J.; Fang, Zhigang

    2017-10-03

    The invention provides a thermal energy storage system comprising a metal-containing first material with a thermal energy storage density of about 1300 kJ/kg to about 2200 kJ/kg based on hydrogenation; a metal-containing second material with a thermal energy storage density of about 200 kJ/kg to about 1000 kJ/kg based on hydrogenation; and a hydrogen conduit for reversibly transporting hydrogen between the first material and the second material. At a temperature of 20.degree. C. and in 1 hour, at least 90% of the metal is converted to the hydride. At a temperature of 0.degree. C. and in 1 hour, at least 90% of the metal hydride is converted to the metal and hydrogen. The disclosed metal hydride materials have a combination of thermodynamic energy storage densities and kinetic power capabilities that previously have not been demonstrated. This performance enables practical use of thermal energy storage systems for electric vehicle heating and cooling.

  13. Compatibility analysis of DUPIC fuel(4) - thermal hydraulic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jee Won; Chae, Kyung Myung; Choi, Hang Bok

    2000-07-01

    Thermal-hydraulic compatibility of the DUPIC fuel bundle in the CANDU reactor has been studied. The critical channel power, the critical power ratio, the channel exit quality and the channel flow are calculated for the DUPIC and the standard fuels by using the NUCIRC code. The physical models and associated parametric values for the NUCIRC analysis of the fuels are also presented. Based upon the slave channel analysis, the critical channel power and the critical power ratios have been found to be very similar for the two fuel types. The same dryout model is used in this study for the standard and the DUPIC fuel bundles. To assess the dryout characteristics of the DUPIC fuel bundle, the ASSERT-PV code has been used for the subchannel analysis. Based upon the results of the subchannel analysis, it is found that the dryout location and the power for the two fuel types are indeed very similar. This study shows that thermal performance of the DUPIC fuel is not significantly different from that of the standard fuel.

  14. ITHNA.SYS: An Integrated Thermal Hydraulic and Neutronic Analyzer SYStem for NUR research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Mazidi, S., E-mail: samirmazidi@gmail.com [Division Physique et Applications Nucléaires, Centre de Recherche Nucléaire de Draria (CRND), BP 43 Sebala, Draria, Alger (Algeria); Meftah, B., E-mail: b_meftah@yahoo.com [Division Physique et Applications Nucléaires, Centre de Recherche Nucléaire de Draria (CRND), BP 43 Sebala, Draria, Alger (Algeria); Belgaid, M., E-mail: belgaidm@yahoo.com [Faculté de Physique, Université Houari Boumediene, USTHB, BP 31, Bab Ezzouar, Alger (Algeria); Letaim, F., E-mail: fletaim@yahoo.fr [Faculté des Sciences et Technologies, Université d’El-oued, PO Box 789, El-oued (Algeria); Halilou, A., E-mail: hal_rane@yahoo.fr [Division Réacteur NUR, Centre de Recherche Nucléaire de Draria, BP 43 Sebala, Draria, Alger (Algeria)

    2015-08-15

    Highlights: • We develop a neutronic and thermal hydraulic MTR reactor analyzer. • The analyzer allows a rapid determination of the reactor core parameters. • Some NUR reactor parameters have been analyzed. - Abstract: This paper introduces the Integrated Thermal Hydraulic and Neutronic Analyzer SYStem (ITHNA.SYS) that has been developed for the Algerian research reactor NUR. It is used both as an operating aid tool and as a core physics engineering analysis tool. The system embeds three modules of the MTR-PC software package developed by INVAP SE: the cell calculation code WIMSD, the core calculation code CITVAP and the program TERMIC for thermal hydraulic analysis of a material testing reactor (MTR) core in forced convection. ITHNA.SYS operates both in on-line and off-line modes. In the on-line mode, the system is linked, via the computer parallel port, to the data acquisition console of the reactor control room and allows a real time monitoring of major physical and safety parameters of the NUR core. PC-based ITHNA.SYS provides a viable and convenient way of using an accumulated and often complex reactor physics stock of knowledge and frees the user from the intricacy of adequate reactor core modeling. This guaranties an accurate, though rapid, determination of a variety of neutronic and thermal hydraulic parameters of importance for the operation and safety analysis of the NUR research reactor. Instead of the several hours usually required, the processing time for the determination of such parameters is now reduced to few seconds. Validation of the system was performed with respect to experimental measurements and to calculations using reference codes. ITHNA.SYS can be easily adapted to accommodate other kinds of MTR reactors.

  15. PCB-level Electro thermal Coupling Simulation Analysis

    Science.gov (United States)

    Zhou, Runjing; Shao, Xuchen

    2017-10-01

    Power transmission network needs to transmit more current with the increase of the power density. The problem of temperature rise and the reliability is becoming more and more serious. In order to accurately design the power supply system, we must consider the influence of the power supply system including Joule heat, air convection and other factors. Therefore, this paper analyzes the relationship between the electric circuit and the thermal circuit on the basis of the theory of electric circuit and thermal circuit.

  16. Computational Analysis on Performance of Thermal Energy Storage (TES) Diffuser

    International Nuclear Information System (INIS)

    Adib, M A H M; Ismail, A R; Kardigama, K; Salaam, H A; Ahmad, Z; Johari, N H; Anuar, Z; Azmi, N S N; Adnan, F

    2012-01-01

    Application of thermal energy storage (TES) system reduces cost and energy consumption. The performance of the overall operation is affected by diffuser design. In this study, computational analysis is used to determine the thermocline thickness. Three dimensional simulations with different tank height-to-diameter ratio (HD), diffuser opening and the effect of difference number of diffuser holes are investigated. Medium HD tanks simulations with double ring octagonal diffuser show good thermocline behavior and clear distinction between warm and cold water. The result show, the best performance of thermocline thickness during 50% time charging occur in medium tank with height-to-diameter ratio of 4.0 and double ring octagonal diffuser with 48 holes (9mm opening ∼ 60%) acceptable compared to diffuser with 6mm ∼ 40% and 12mm ∼ 80% opening. The conclusion is computational analysis method are very useful in the study on performance of thermal energy storage (TES).

  17. Thermal analysis of a multi-layer microchannel heat sink for cooling concentrator photovoltaic (CPV) cells

    Science.gov (United States)

    Siyabi, Idris Al; Shanks, Katie; Mallick, Tapas; Sundaram, Senthilarasu

    2017-09-01

    Concentrator Photovoltaic (CPV) technology is increasingly being considered as an alternative option for solar electricity generation. However, increasing the light concentration ratio could decrease the system output power due to the increase in the temperature of the cells. The performance of a multi-layer microchannel heat sink configuration was evaluated using numerical analysis. In this analysis, three dimensional incompressible laminar steady flow model was solved numerically. An electrical and thermal solar cell model was coupled for solar cell temperature and efficiency calculations. Thermal resistance, solar cell temperature and pumping power were used for the system efficiency evaluation. An increase in the number of microchannel layers exhibited the best overall performance in terms of the thermal resistance, solar cell temperature uniformity and pressure drop. The channel height and width has no effect on the solar cell maximum temperature. However, increasing channel height leads to a reduction in the pressure drop and hence less fluid pumping power.

  18. Development of regulatory technology for thermal-hydraulic safety analysis

    International Nuclear Information System (INIS)

    Bang, Young Seok; Lee, S. H.; Ryu, Y. H.

    2001-02-01

    The present study aims to develop the regulation capability in thermal-hydraulic safety analysis which was required for the reasonable safety regulation in the current NPP, the next generation reactors, and the future-type reactors. The fourth fiscal year of the first phase of the research was focused on the following research topics: Investigation on the current status of the thermal-hydraulic safety analysis technology outside and inside of the country; Review on the improved features of the thermal-hydraulic safety analysis regulatory audit code, RELAP5/MOD3; Assessments of code with LOFT L9-3 ATWS experiment and LSTF SB-SG-10 multiple SGTR experiment; Application of the RELAP5/CANDU code to analyses of SLB and LBLOCA and evaluation of its effect on safety; Application of the code to IAEA PHWR ISP analysis; Assessments of RELAP5 and TRAC with UPTF downcomer injection test and Analysis of LBLOCA with RELAP5 for the performance evaluation of KNGR DVI; Setup of a coupled 3-D kinetics and thermal-hydraulics and application it to a reactivity accident analysis; and Extension of database and improvement of plant input decks. For supporting the resolution of safety issues, loss of RHR event during midloop operation was analyzed for Kori Unit 3, issues on high burnup fuel were reviewed and performance of FRAPCON-3 assessed. Also MSLB was analyzed to figure out the sensitivity of downcomer temperature supporting the PTS risk evaluation of Kori Unit 1. Thermal stratification in pipe was analyzed using the method proposed. And a method predicting the thermal-hydraulic performance of IRWST of KNGR was explored. The PWR ECCS performance criteria was issued as a MOST Article 200-19.and a regulatory guide on evaluation methodology was improved to cover concerns raised from the related licensing review process

  19. thermal power stations' reliability evaluation in a hydrothermal system

    African Journals Online (AJOL)

    Dr Obe

    A quantitative tool for the evaluation of thermal power stations reliability in a hydrothermal system is presented. ... (solar power); wind (wind power) and the rest, thermal power and ... probability of a system performing its function adequately for ...

  20. Energy and exergy analysis of photovoltaic-thermal collector with and without glass cover

    International Nuclear Information System (INIS)

    Chow, T.T.; Pei, G.; Fong, K.F.; Lin, Z.; Chan, A.L.S.; Ji, J.

    2009-01-01

    In photovoltaic-thermal (PV/T) technology, the use of glass cover on the flat-plate hybrid solar collector is favorable to the photothermic process but not to the photovoltaic process. Because of the difference in the usefulness of electricity and thermal energy, there is often no straight forward answer on whether a glazed or unglazed collector system is more suitable for a specific application. This glazing issue was tackled in this paper from the viewpoint of thermodynamics. Based on experimental data and validated numerical models, a study of the appropriateness of glass cover on a thermosyphon-based water-heating PV/T system was carried out. The influences of six selected operating parameters were evaluated. From the first law point of view, a glazed PV/T system is found always suitable if we are to maximize the quantity of either the thermal or the overall energy output. From the exergy analysis point of view however, the increase of PV cell efficiency, packing factor, water mass to collector area ratio, and wind velocity are found favorable to go for an unglazed system, whereas the increase of on-site solar radiation and ambient temperature are favorable for a glazed system

  1. Thermo-economic analysis of Shiraz solar thermal power plant

    Energy Technology Data Exchange (ETDEWEB)

    Yaghoubi, M. [Academy of Science, Tehran (Iran, Islamic Republic of); Mokhtari, A.; Hesami, R. [Shiraz Univ., Shiraz (Iran, Islamic Republic of). School of Engineering

    2007-07-01

    The Shiraz solar thermal power plant in Iran has 48 parabolic trough collectors (PTCs) which are used to heat the working oil. There is potential to significantly increase the performance and reduce the cost of PTC solar thermal electric technologies. Conventional energy analysis based on the first law of thermodynamics does qualitatively assess the various losses occurring in the components. Therefore, exergy analysis, based on the second law of thermodynamics, can be applied to better assess various losses quantitatively as well as qualitatively. This paper presented a newly developed exergy-economic model for the Shiraz solar thermal power plant. The objective was to find the minimum exergetic production cost (EPC), based on the second law of thermodynamics. The application of exergy-economic analysis includes the evaluation of utility supply costs for production plants, and the energy costs for process operations. The purpose of the analysis was to minimize the total operating costs of the solar thermal power plant by assuming a fixed rate of electricity production and process steam. 21 refs., 3 tabs., 8 figs.

  2. Evaluation of a thermal SCWR core with sub-channel analysis

    International Nuclear Information System (INIS)

    Liu Xiaojing; Cheng Xu

    2008-01-01

    A previous study shows that the two-row fuel assembly has much more favorable neutron-physical and thermal-hydraulic behaviour than the existing one-row fuel assemblies. With this new developed two-row fuel assembly, a thermal SCWR core design is proposed Assessment of this design is carried out in this paper. The performance of this new core design is investigated with 3-D coupled thermal-hydraulic/neutronic calculations. During the coupling procedure, the thermal-hydraulic behaviour is analyzed using a single-channel code and the neutron-physical performance is computed with a 3-D reactor physical code. This paper presents the main results achieved so far related to the distribution of some neutronic and thermal-hydraulic parameters. Since the power distribution in some fuel assemblies is extremely uneven, sub-channel analysis is applied to the hottest and most non-uniform assembly in the core. The sub-channel analysis is performed with the power and thermal hydraulic parameters from the coupling results. It provides the hot channel factor and the maximal cladding surface temperature more precisely. The power and mass flux distribution in these assemblies are illustrated in detail for the demonstration purpose. The difference of the results evaluated with two different methods, i.e. sub-channel analysis and single-channel analysis, shows the importance of applying sub-channel analysis. A sensitivity analysis of some important parameters is also carried out. (author)

  3. Thermophysical and Thermomechanical Properties of Thermal Barrier Coating Systems

    Science.gov (United States)

    Zhu, Dongming; Miller, Robert A.

    2000-01-01

    Thermal barrier coatings have been developed for advanced gas turbine and diesel engine applications to improve engine reliability and fuel efficiency. However, the issue of coating durability under high temperature cyclic conditions is still of major concern. The coating failure is closely related to thermal stresses and oxidation in the coating systems. Coating shrinkage cracking resulting from ceramic sintering and creep at high temperatures can further accelerate the coating failure process. The purpose of this paper is to address critical issues such as ceramic sintering and creep, thermal fatigue and their relevance to coating life prediction. Novel test approaches have been established to obtain critical thermophysical and thermomechanical properties of the coating systems under near-realistic temperature and stress gradients encountered in advanced engine systems. Emphasis is placed on the dynamic changes of the coating thermal conductivity and elastic modulus, fatigue and creep interactions, and resulting failure mechanisms during the simulated engine tests. Detailed experimental and modeling results describing processes occurring in the thermal barrier coating systems provide a framework for developing strategies to manage ceramic coating architecture, microstructure and properties.

  4. Study of thermal sensitivity and thermal explosion violence of energetic materials in the LLNL ODTX system

    International Nuclear Information System (INIS)

    Hsu, P C; Hust, G; Zhang, M X; Lorenz, T K; Reynolds, J G; Fried, L; Springer, H K; Maienschein, J L

    2014-01-01

    Incidents caused by fire and combat operations can heat energetic materials that may lead to thermal explosion and result in structural damage and casualty. Some explosives may thermally explode at fairly low temperatures (< 100 °C) and the violence from thermal explosion may cause significant damage. Thus it is important to understand the response of energetic materials to thermal insults. The One Dimensional Time to Explosion (ODTX) system at the Lawrence Livermore National Laboratory has been used for decades to measure times to explosion, threshold thermal explosion temperature, and determine kinetic parameters of energetic materials. Samples of different configurations (pressed part, powder, paste, and liquid) can be tested in the system. The ODTX testing can also provide useful data for assessing the thermal explosion violence of energetic materials. Recent ODTX experimental data are reported in the paper.

  5. Model and analysis of solar thermal generators to reduce the intermittency of photovoltaic systems with the use of spectrum splitting

    Science.gov (United States)

    Ayala, Silvana; Wu, Yuechen; Vorndran, Shelby; Santiago, Raphael P.; Kostuk, Raymond K.

    2015-09-01

    In this paper we introduce an approach to damping intermittency in photovoltaic (PV) system output due to fluctuations in solar illumination generated by use of a hybrid PV-thermal electric (TE) generation system. We describe the necessary constrains of the PV-TE system based on its thermodynamic characteristics. The basis for the approach is that the thermal time constant for the TE device is much longer than that of a PV cell. When used in combination with an optimized thermal storage device short periods of intermittency (several minutes) in PV output due to passing clouds can be compensated. A comparison of different spectrum splitting systems to efficiently utilize the incident solar spectrum between the PV and TE converters are also examined. The time-dependent behavior of a hybrid PV-TE converter with a thermal storage element is computed with SMARTS modeled irradiance data and compared to real weather and irradiation conditions for Tucson, Arizona.

  6. The art of software thermal management for embedded systems

    CERN Document Server

    Benson, Mark

    2014-01-01

    This book introduces Software Thermal Management (STM) as a means of reducing power consumption in a computing system, in order to manage heat, improve component reliability, and increase system safety.  Readers will benefit from this pragmatic guide to the field of STM for embedded systems and its catalog of software power management techniques.  Since thermal management is a key bottleneck in embedded systems design, this book focuses on power as the root cause of heat. Since software has an enormous impact on power consumption in an embedded system, this book guides readers to manage heat effectively by understanding, categorizing, and developing new ways to reduce dynamic power. Whereas most books on thermal management describe mechanisms to remove heat, this book focuses on ways to avoid generating heat in the first place.   • Explains fundamentals of software thermal management, application techniques and advanced optimization strategies; • Describes a novel method for managing dynamic power, e...

  7. Statistical analysis of thermal conductivity of nanofluid containing ...

    Indian Academy of Sciences (India)

    Thermal conductivity measurements of nanofluids were analysed via two-factor completely randomized design and comparison of data means is carried out with Duncan's multiple-range test. Statistical analysis of experimental data show that temperature and weight fraction have a reasonable impact on the thermal ...