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Sample records for heater head durability

  1. Advanced Stirling Convertor Heater Head Durability and Reliability Quantification

    Science.gov (United States)

    Krause, David L.; Shah, Ashwin R.; Korovaichuk, Igor; Kalluri, Sreeramesh

    2008-01-01

    The National Aeronautics and Space Administration (NASA) has identified the high efficiency Advanced Stirling Radioisotope Generator (ASRG) as a candidate power source for long duration Science missions, such as lunar applications, Mars rovers, and deep space missions, that require reliable design lifetimes of up to 17 years. Resistance to creep deformation of the MarM-247 heater head (HH), a structurally critical component of the ASRG Advanced Stirling Convertor (ASC), under high temperatures (up to 850 C) is a key design driver for durability. Inherent uncertainties in the creep behavior of the thin-walled HH and the variations in the wall thickness, control temperature, and working gas pressure need to be accounted for in the life and reliability prediction. Due to the availability of very limited test data, assuring life and reliability of the HH is a challenging task. The NASA Glenn Research Center (GRC) has adopted an integrated approach combining available uniaxial MarM-247 material behavior testing, HH benchmark testing and advanced analysis in order to demonstrate the integrity, life and reliability of the HH under expected mission conditions. The proposed paper describes analytical aspects of the deterministic and probabilistic approaches and results. The deterministic approach involves development of the creep constitutive model for the MarM-247 (akin to the Oak Ridge National Laboratory master curve model used previously for Inconel 718 (Special Metals Corporation)) and nonlinear finite element analysis to predict the mean life. The probabilistic approach includes evaluation of the effect of design variable uncertainties in material creep behavior, geometry and operating conditions on life and reliability for the expected life. The sensitivity of the uncertainties in the design variables on the HH reliability is also quantified, and guidelines to improve reliability are discussed.

  2. Heater head for stirling engine

    Science.gov (United States)

    Corey, John A.

    1985-07-09

    A monolithic heater head assembly which augments cast fins with ceramic inserts which narrow the flow of combustion gas and obtains high thermal effectiveness with the assembly including an improved flange design which gives greater durability and reduced conduction loss.

  3. "Starfish" Heater Head For Stirling Engine

    Science.gov (United States)

    Vitale, N.

    1993-01-01

    Proposed "starfish" heater head for Stirling engine enables safe use of liquid sodium as heat-transfer fluid. Sodium makes direct contact with heater head but does not come in contact with any structural welds. Design concept minimizes number of, and simplifies nonstructural thermal welds and facilitates inspection of such welds.

  4. Structural Benchmark Testing for Stirling Convertor Heater Heads

    Science.gov (United States)

    Krause, David L.; Kalluri, Sreeramesh; Bowman, Randy R.

    2007-01-01

    The National Aeronautics and Space Administration (NASA) has identified high efficiency Stirling technology for potential use on long duration Space Science missions such as Mars rovers, deep space missions, and lunar applications. For the long life times required, a structurally significant design limit for the Stirling convertor heater head is creep deformation induced even under relatively low stress levels at high material temperatures. Conventional investigations of creep behavior adequately rely on experimental results from uniaxial creep specimens, and much creep data is available for the proposed Inconel-718 (IN-718) and MarM-247 nickel-based superalloy materials of construction. However, very little experimental creep information is available that directly applies to the atypical thin walls, the specific microstructures, and the low stress levels. In addition, the geometry and loading conditions apply multiaxial stress states on the heater head components, far from the conditions of uniaxial testing. For these reasons, experimental benchmark testing is underway to aid in accurately assessing the durability of Stirling heater heads. The investigation supplements uniaxial creep testing with pneumatic testing of heater head test articles at elevated temperatures and with stress levels ranging from one to seven times design stresses. This paper presents experimental methods, results, post-test microstructural analyses, and conclusions for both accelerated and non-accelerated tests. The Stirling projects use the results to calibrate deterministic and probabilistic analytical creep models of the heater heads to predict their life times.

  5. Materials for a Stirling engine heater head

    Science.gov (United States)

    Noble, J. E.; Lehmann, G. A.; Emigh, S. G.

    1990-01-01

    Work done on the 25-kW advanced Stirling conversion system (ASCS) terrestrial solar program in establishing criteria and selecting materials for the engine heater head and heater tubes is described. Various mechanisms contributing to incompatibility between materials are identified and discussed. Large thermal gradients, coupled with requirements for long life (60,000 h at temperature) and a large number of heatup and cooldown cycles (20,000) drive the design from a structural standpoint. The pressurized cylinder is checked for creep rupture, localized yielding, reverse plasticity, creep and fatigue damage, and creep ratcheting, in addition to the basic requirements for bust and proof pressure. In general, creep rupture and creep and fatigue interaction are the dominant factors in the design. A wide range of materials for the heater head and tubes was evaluated. Factors involved in the assessment were strength and effect on engine efficiency, reliability, and cost. A preliminary selection of Inconel 713LC for the heater head is based on acceptable structural properties but driven mainly by low cost. The criteria for failure, the structural analysis, and the material characteristics with basis for selection are discussed.

  6. Accelerated Life Structural Benchmark Testing for a Stirling Convertor Heater Head

    Science.gov (United States)

    Krause, David L.; Kantzos, Pete T.

    2006-01-01

    For proposed long-duration NASA Space Science missions, the Department of Energy, Lockheed Martin, Infinia Corporation, and NASA Glenn Research Center are developing a high-efficiency, 110 W Stirling Radioisotope Generator (SRG110). A structurally significant limit state for the SRG110 heater head component is creep deformation induced at high material temperature and low stress level. Conventional investigations of creep behavior adequately rely on experimental results from uniaxial creep specimens, and a wealth of creep data is available for the Inconel 718 material of construction. However, the specified atypical thin heater head material is fine-grained with a heat treatment that limits precipitate growth, and little creep property data for this microstructure is available in the literature. In addition, the geometry and loading conditions apply a multiaxial stress state on the component, far from the conditions of uniaxial testing. For these reasons, an extensive experimental investigation is ongoing to aid in accurately assessing the durability of the SRG110 heater head. This investigation supplements uniaxial creep testing with pneumatic testing of heater head-like pressure vessels at design temperature with stress levels ranging from approximately the design stress to several times that. This paper presents experimental results, post-test microstructural analyses, and conclusions for four higher-stress, accelerated life tests. Analysts are using these results to calibrate deterministic and probabilistic analytical creep models of the SRG110 heater head.

  7. Long-Term Creep of a Thin-Walled Inconel 718 Stirling Power-Convertor Heater Head Assessed

    Science.gov (United States)

    Bowman, Randy R.

    2002-01-01

    The Department of Energy and NASA have identified Stirling power convertors as candidate power supply systems for long-duration, deep-space science missions. A key element for qualifying the flight hardware is a long-term durability assessment for critical hot section components of the power convertor. One such critical component is the power convertor heater head. The heater head is a high-temperature pressure vessel that transfers heat to the working gas medium of the convertor, which is typically helium. An efficient heater head design is the result of balancing the divergent requirements of thin walls for increased heat transfer versus thick walls to lower the wall stresses and thus improve creep resistance and durability. In the current design, the heater head is fabricated from the Ni-base superalloy Inconel 718 (IN 718, Inco Alloys International, Inc., Huntington, WV). Although IN 718 is a mature alloy system (patented in 1962), there is little long-term (>50,000-hr) creep data available for thin-specimen geometries. Since thin-section properties tend to be inferior to thicker samples, it is necessary to generate creep data using specimens with the same geometry as the actual flight hardware. Therefore, one facet of the overall durability assessment program involves generating relatively short-term creep data using thin specimens at the design temperature of 649 C (1200 F).

  8. Effect of Random Thermal Spikes on Stirling Convertor Heater Head Reliability

    Science.gov (United States)

    Shah, Ashwin R.; Korovaichuk, Igor; Halford, Gary R.

    2004-01-01

    Onboard radioisotope power systems being developed to support future NASA exploration missions require reliable design lifetimes of up to 14 yr and beyond. The structurally critical heater head of the high-efficiency developmental Stirling power convertor has undergone extensive computational analysis of operating temperatures (up to 650 C), stresses, and creep resistance of the thin-walled Inconel 718 bill of material. Additionally, assessment of the effect of uncertainties in the creep behavior of the thin-walled heater head, the variation in the manufactured thickness, variation in control temperature, and variation in pressure on the durability and reliability were performed. However, it is possible for the heater head to experience rare incidences of random temperature spikes (excursions) of short duration. These incidences could occur randomly with random magnitude and duration during the desired mission life. These rare incidences could affect the creep strain rate and therefore the life. The paper accounts for these uncertainties and includes the effect of such rare incidences, random in nature, on the reliability. The sensitivities of variables affecting the reliability are quantified and guidelines developed to improve the reliability are outlined. Furthermore, the quantified reliability is being verified with test data from the accelerated benchmark tests being conducted at the NASA Glenn Research Center.

  9. Benchmark Tests for Stirling Convertor Heater Head Life Assessment Conducted

    Science.gov (United States)

    Krause, David L.; Halford, Gary R.; Bowman, Randy R.

    2004-01-01

    A new in-house test capability has been developed at the NASA Glenn Research Center, where a critical component of the Stirling Radioisotope Generator (SRG) is undergoing extensive testing to aid the development of analytical life prediction methodology and to experimentally aid in verification of the flight-design component's life. The new facility includes two test rigs that are performing creep testing of the SRG heater head pressure vessel test articles at design temperature and with wall stresses ranging from operating level to seven times that (see the following photograph).

  10. An Experimental and Analytical Investigation of Stirling Space Power Converter Heater Head

    Science.gov (United States)

    Abdul-Aziz, Ali; Bartolotta, Paul; Tong, Mike; Allen, Gorden

    1995-01-01

    NASA has identified the Stirling power converter as a prime candidate for the next generation power system for space applications requiring 60000 hr of operation. To meet this long-term goal, several critical components of the power converter have been analyzed using advanced structural assessment methods. Perhaps the most critical component, because of its geometric complexity and operating environment, is the power converter's heater head. This report describes the life assessment of the heater head which includes the characterization of a viscoplastic material model, the thermal and structural analyses of the heater head, and the interpolation of fatigue and creep test results of a nickel-base superalloy, Udimet 720 LI (Low Inclusions), at several elevated temperatures for life prediction purposes.

  11. Experimental Creep Life Assessment for the Advanced Stirling Convertor Heater Head

    Science.gov (United States)

    Krause, David L.; Kalluri, Sreeramesh; Shah, Ashwin R.; Korovaichuk, Igor

    2010-01-01

    The United States Department of Energy is planning to develop the Advanced Stirling Radioisotope Generator (ASRG) for the National Aeronautics and Space Administration (NASA) for potential use on future space missions. The ASRG provides substantial efficiency and specific power improvements over radioisotope power systems of heritage designs. The ASRG would use General Purpose Heat Source modules as energy sources and the free-piston Advanced Stirling Convertor (ASC) to convert heat into electrical energy. Lockheed Martin Corporation of Valley Forge, Pennsylvania, is integrating the ASRG systems, and Sunpower, Inc., of Athens, Ohio, is designing and building the ASC. NASA Glenn Research Center of Cleveland, Ohio, manages the Sunpower contract and provides technology development in several areas for the ASC. One area is reliability assessment for the ASC heater head, a critical pressure vessel within which heat is converted into mechanical oscillation of a displacer piston. For high system efficiency, the ASC heater head operates at very high temperature (850 C) and therefore is fabricated from an advanced heat-resistant nickel-based superalloy Microcast MarM-247. Since use of MarM-247 in a thin-walled pressure vessel is atypical, much effort is required to assure that the system will operate reliably for its design life of 17 years. One life-limiting structural response for this application is creep; creep deformation is the accumulation of time-dependent inelastic strain under sustained loading over time. If allowed to progress, the deformation eventually results in creep rupture. Since creep material properties are not available in the open literature, a detailed creep life assessment of the ASC heater head effort is underway. This paper presents an overview of that creep life assessment approach, including the reliability-based creep criteria developed from coupon testing, and the associated heater head deterministic and probabilistic analyses. The approach also

  12. Structural Benchmark Creep Testing for the Advanced Stirling Convertor Heater Head

    Science.gov (United States)

    Krause, David L.; Kalluri, Sreeramesh; Bowman, Randy R.; Shah, Ashwin R.

    2008-01-01

    The National Aeronautics and Space Administration (NASA) has identified the high efficiency Advanced Stirling Radioisotope Generator (ASRG) as a candidate power source for use on long duration Science missions such as lunar applications, Mars rovers, and deep space missions. For the inherent long life times required, a structurally significant design limit for the heater head component of the ASRG Advanced Stirling Convertor (ASC) is creep deformation induced at low stress levels and high temperatures. Demonstrating proof of adequate margins on creep deformation and rupture for the operating conditions and the MarM-247 material of construction is a challenge that the NASA Glenn Research Center is addressing. The combined analytical and experimental program ensures integrity and high reliability of the heater head for its 17-year design life. The life assessment approach starts with an extensive series of uniaxial creep tests on thin MarM-247 specimens that comprise the same chemistry, microstructure, and heat treatment processing as the heater head itself. This effort addresses a scarcity of openly available creep properties for the material as well as for the virtual absence of understanding of the effect on creep properties due to very thin walls, fine grains, low stress levels, and high-temperature fabrication steps. The approach continues with a considerable analytical effort, both deterministically to evaluate the median creep life using nonlinear finite element analysis, and probabilistically to calculate the heater head s reliability to a higher degree. Finally, the approach includes a substantial structural benchmark creep testing activity to calibrate and validate the analytical work. This last element provides high fidelity testing of prototypical heater head test articles; the testing includes the relevant material issues and the essential multiaxial stress state, and applies prototypical and accelerated temperature profiles for timely results in a

  13. Benchmark Calibration Tests Completed for Stirling Convertor Heater Head Life Assessment

    Science.gov (United States)

    Krause, David L.; Halford, Gary R.; Bowman, Randy R.

    2005-01-01

    A major phase of benchmark testing has been completed at the NASA Glenn Research Center (http://www.nasa.gov/glenn/), where a critical component of the Stirling Radioisotope Generator (SRG) is undergoing extensive experimentation to aid the development of an analytical life-prediction methodology. Two special-purpose test rigs subjected SRG heater-head pressure-vessel test articles to accelerated creep conditions, using the standard design temperatures to stay within the wall material s operating creep-response regime, but increasing wall stresses up to 7 times over the design point. This resulted in well-controlled "ballooning" of the heater-head hot end. The test plan was developed to provide critical input to analytical parameters in a reasonable period of time.

  14. Candidate Materials Evaluated for a High-Temperature Stirling Convertor Heater Head

    Science.gov (United States)

    Bowman, Randy R.; Ritzert, Frank J.

    2005-01-01

    The Department of Energy and NASA have identified Stirling Radioisotope Generators (SRGs) as a candidate power system for use on long-duration, deep-space science missions and Mars rovers. One of the developments planned for an upgraded version of the current SRG design is to achieve higher efficiency by increasing the overall operating temperature of the system. Currently, the SRG operates with a heater head temperature of 650 C and is fabricated from the nickel-base superalloy 718. The current operating temperature is at the limit of alloy 718 s capability, and any planned increase in temperature will be contingent on identifying a more capable material from which to fabricate the heater head. To this end, personnel at the NASA Glenn Research Center are evaluating advanced materials for a high-temperature heater head to allow a higher convertor temperature ratio and, thus, increase the system efficiency. A generic list of properties that were used to screen the candidate materials follows: (1) creep, (2) fabricability, (3) helium gas containment, (4) long-term stability and compatibility, (5) ability to form a hermetical closeout seal, and (6) ductility and toughness.

  15. Alkali metal compatibility testing of candidate heater head materials for a Stirling engine heat transport system

    Science.gov (United States)

    Noble, Jack E.; Hickman, Gary L.; Grobstein, Toni

    The authors describe work performed as part of the 25-kWe advanced Stirling conversion system project. Liquid alkali metal compatibility is being assessed in an ongoing test program to evaluate candidate heater head materials and fabrication processes at the temperatures and operating conditions required for Stirling engines. Specific materials under evaluation are alloy 713LC, alloy 713LC coated with nickel aluminide, and Udimet 720, each in combination with Waspaloy. The tests were run at a constant 700 C. A eutectic alloy of sodium and potassium (NaK) was the working fluid. Titanium sheet in the system was shown to be an effective oxygen getter. Metallographic and microchemical examination of material surfaces, joints, and their interfaces revealed little or no corrosion after 1000 h. Tests are in progress, with up to 10,000 h exposure.

  16. Advanced Stirling Duplex Materials Assessment for Potential Venus Mission Heater Head Application

    Science.gov (United States)

    Ritzert, Frank; Nathal, Michael V.; Salem, Jonathan; Jacobson, Nathan; Nesbitt, James

    2011-01-01

    This report will address materials selection for components in a proposed Venus lander system. The lander would use active refrigeration to allow Space Science instrumentation to survive the extreme environment that exists on the surface of Venus. The refrigeration system would be powered by a Stirling engine-based system and is termed the Advanced Stirling Duplex (ASD) concept. Stirling engine power conversion in its simplest definition converts heat from radioactive decay into electricity. Detailed design decisions will require iterations between component geometries, materials selection, system output, and tolerable risk. This study reviews potential component requirements against known materials performance. A lower risk, evolutionary advance in heater head materials could be offered by nickel-base superalloy single crystals, with expected capability of approximately 1100C. However, the high temperature requirements of the Venus mission may force the selection of ceramics or refractory metals, which are more developmental in nature and may not have a well-developed database or a mature supporting technology base such as fabrication and joining methods.

  17. Experimental and Computational Analysis of Unidirectional Flow Through Stirling Engine Heater Head

    Science.gov (United States)

    Wilson, Scott D.; Dyson, Rodger W.; Tew, Roy C.; Demko, Rikako

    2006-01-01

    A high efficiency Stirling Radioisotope Generator (SRG) is being developed for possible use in long-duration space science missions. NASA s advanced technology goals for next generation Stirling convertors include increasing the Carnot efficiency and percent of Carnot efficiency. To help achieve these goals, a multi-dimensional Computational Fluid Dynamics (CFD) code is being developed to numerically model unsteady fluid flow and heat transfer phenomena of the oscillating working gas inside Stirling convertors. In the absence of transient pressure drop data for the zero mean oscillating multi-dimensional flows present in the Technology Demonstration Convertors on test at NASA Glenn Research Center, unidirectional flow pressure drop test data is used to compare against 2D and 3D computational solutions. This study focuses on tracking pressure drop and mass flow rate data for unidirectional flow though a Stirling heater head using a commercial CFD code (CFD-ACE). The commercial CFD code uses a porous-media model which is dependent on permeability and the inertial coefficient present in the linear and nonlinear terms of the Darcy-Forchheimer equation. Permeability and inertial coefficient were calculated from unidirectional flow test data. CFD simulations of the unidirectional flow test were validated using the porous-media model input parameters which increased simulation accuracy by 14 percent on average.

  18. Environmental Loss Characterization of an Advanced Stirling Convertor (ASC-E2) Insulation Package Using a Mock Heater Head

    Science.gov (United States)

    Schifer, Nicholas A.; Briggs, Maxwell H.

    2012-01-01

    The U.S. Department of Energy (DOE) and Lockheed Martin Space Systems Company (LMSSC) have been developing the Advanced Stirling Radioisotope Generator (ASRG) for use as a power system for space science missions. This generator would use two highefficiency Advanced Stirling Convertors (ASCs), developed by Sunpower Inc. and NASA Glenn Research Center (GRC). As part of ground testing of these ASCs, different operating conditions are used to simulate expected mission conditions. These conditions require achieving a specified electrical power output for a given net heat input. While electrical power output can be precisely quantified, thermal power input to the Stirling cycle cannot be directly measured. In an effort to improve net heat input predictions, the Mock Heater Head was developed with the same relative thermal paths as a convertor using a conducting rod to represent the Stirling cycle and tested to provide a direct comparison to numerical and empirical models used to predict convertor net heat input. The Mock Heater Head also served as the pathfinder for a higher fidelity version of validation test hardware, known as the Thermal Standard. This paper describes how the Mock Heater Head was tested and utilized to validate a process for the Thermal Standard.

  19. Preference Bias of Head Orientation in Choosing between Two Non-durables

    Directory of Open Access Journals (Sweden)

    Hiroyuki eFunaya

    2015-06-01

    Full Text Available The goal of this study is to investigate how customers’ gaze, head and body orientations reflect their choices. Although the relationship between human choice and gaze behavior has been well studied, other behaviors such as head and body are unknown. We conducted a two-alternatives-forced-choice task to examine (1 whether preference bias, i.e. a positional bias in gaze, head and body toward the item that was later chosen, exists in choice, (2 when preference bias is observed and when prediction of the resulting choice becomes possible (3 whether human choice is affected when the body orientations are manipulated. We used real non-durable products (cheap snacks and clothing on a shopping shelf. The results showed that there was a significant preference bias in head orientation at the beginning one second when the subjects stood straight toward the shelf, and that the head orientation was more biased toward the selected item than the gaze and the center of pressure at the ending one second. Manipulating body orientation did not affect the result of choice. The preference bias detected by observing the head orientation would be useful in marketing science for predicting customers’ choice.

  20. Preference bias of head orientation in choosing between two non-durables.

    Science.gov (United States)

    Funaya, Hiroyuki; Shibata, Tomohiro

    2015-01-01

    The goal of this study is to investigate how customers' gaze, head and body orientations reflect their choices. Although the relationship between human choice and gaze behavior has been well-studied, other behaviors such as head and body are unknown. We conducted a two-alternatives-forced-choice task to examine (1) whether preference bias, i.e., a positional bias in gaze, head and body toward the item that was later chosen, exists in choice, (2) when preference bias is observed and when prediction of the resulting choice becomes possible (3) whether human choice is affected when the body orientations are manipulated. We used real non-durable products (cheap snacks and clothing) on a shopping shelf. The results showed that there was a significant preference bias in head orientation at the beginning 1 s when the subjects stood straight toward the shelf, and that the head orientation was more biased toward the selected item than the gaze and the center of pressure at the ending 1 s. Manipulating body orientation did not affect the result of choice. The preference bias detected by observing the head orientation would be useful in marketing science for predicting customers' choice.

  1. Structural Benchmark Creep Testing for Microcast MarM-247 Advanced Stirling Convertor E2 Heater Head Test Article SN18

    Science.gov (United States)

    Krause, David L.; Brewer, Ethan J.; Pawlik, Ralph

    2013-01-01

    This report provides test methodology details and qualitative results for the first structural benchmark creep test of an Advanced Stirling Convertor (ASC) heater head of ASC-E2 design heritage. The test article was recovered from a flight-like Microcast MarM-247 heater head specimen previously used in helium permeability testing. The test article was utilized for benchmark creep test rig preparation, wall thickness and diametral laser scan hardware metrological developments, and induction heater custom coil experiments. In addition, a benchmark creep test was performed, terminated after one week when through-thickness cracks propagated at thermocouple weld locations. Following this, it was used to develop a unique temperature measurement methodology using contact thermocouples, thereby enabling future benchmark testing to be performed without the use of conventional welded thermocouples, proven problematic for the alloy. This report includes an overview of heater head structural benchmark creep testing, the origin of this particular test article, test configuration developments accomplished using the test article, creep predictions for its benchmark creep test, qualitative structural benchmark creep test results, and a short summary.

  2. Durable ultrathin silicon nitride/carbon bilayer overcoats for magnetic heads: The role of enhanced interfacial bonding

    Energy Technology Data Exchange (ETDEWEB)

    Yeo, Reuben J.; Dwivedi, Neeraj; Bhatia, Charanjit S., E-mail: elebcs@nus.edu.sg [Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore 117583 (Singapore); Zhang, Lu [Institute of Microelectronics (IME), A*STAR (Agency for Science, Technology, and Research), 11 Science Park Road, Singapore Science Park II, Singapore, Singapore 117685 (Singapore); Zhang, Zheng; Tripathy, S. [Institute of Materials Research and Engineering (IMRE), A*STAR (Agency for Science, Technology, and Research), 3 Research Link, Singapore, Singapore 117602 (Singapore); Lim, Christina Y. H. [Department of Mechanical Engineering, National University of Singapore, Singapore, Singapore 117575 (Singapore)

    2015-01-28

    Pole tip recession (PTR) is one of the major issues faced in magnetic tape storage technology, which causes an increase in the magnetic spacing and hence signal loss during data readback. Despite efforts to reduce the magnetic spacing, PTR, and surface wear on the heads by using protective overcoats, most of them either employ complex fabrication processes and approaches do not provide adequate protection to the head or are too thick (∼10–20 nm), especially for future high density tape storage. In this work, we discuss an approach to reduce the PTR and surface wear at the head by developing an ultrathin ∼7 nm bilayer overcoat of silicon/silicon nitride (Si/SiN{sub x}) and carbon (C), which is totally fabricated by a cost-effective and industrial-friendly magnetron sputtering process. When compared with a monolithic C overcoat of similar thickness, the electrically insulating Si/SiN{sub x}/C bilayer overcoat was found to provide better wear protection for commercial tape heads, as demonstrated by Auger electron spectroscopic analyses after wear tests with commercial tape media. Although the microstructures of carbon in the monolithic and bilayer overcoats were similar, the improved wear durability of the bilayer overcoat was attributed to the creation of extensive interfacial bonding of Si and N with the C overcoat and the alumina-titanium carbide composite head substrate, as predicted by time-of-flight secondary ion mass spectrometry and confirmed by in-depth X-ray photoelectron spectroscopy analyses. This study highlights the pivotal role of enhanced interfaces and interfacial bonding in developing ultrathin yet wear-durable overcoats for tape heads.

  3. Improving the Friction Durability of Magnetic Head-Disk Interfaces by Thin Lubricant Films

    Directory of Open Access Journals (Sweden)

    Shojiro Miyake

    2016-01-01

    Full Text Available Nanowear and viscoelasticity were evaluated to study the nanotribological properties of lubricant films of Z-tetraol, D-4OH, and A20H, including their retention and replenishment properties. For A20H and thick Z-tetraol-coated disks, the disk surface partially protrudes, and the phase lag (tan⁡δ increases with friction. This result is consistent with replenishment of the lubricant upon tip sliding. For the D-4OH-coated disk, the tan⁡δ value decreases with tip sliding, similar to the case for the unlubricated disk. The durability of the lubricant-coated magnetic disks was then evaluated by load increase and decrease friction tests. The friction force of the unlubricated disk rapidly increases after approximately 30 reciprocating cycles, regardless of the load. The lubrication state can be estimated by mapping the dependence of friction coefficient on the reciprocating cycle number and load. The friction coefficient can be classified into one of four areas. The lowest friction area constitutes fluid lubrication. The second area constitutes the transition to mixed lubrication. The third area constitutes boundary lubrication. The highest friction of the fourth area results from surface fracture. The boundary lubricating area of the A20H lubricant was wide, because of its good retention and replenishment properties.

  4. Transparent electric convection heater

    OpenAIRE

    Khalid, A.; Luck, J.L.

    2001-01-01

    An optically transparent electrically heated convection heater for use as a space heater in homes, offices, shops. Typically, said convection heater consists of a transparent layer 1 upon which is deposited a layer of a transparent electrically conductive material 2 such as indium-tin-oxide, electrodes 3 and 3a are formed on opposite edges of the transparent electrically conductive layer 2 and electrical wires 4 and 4a are connected to the electrodes. The transparent electrically conductive l...

  5. Grouped exposed metal heaters

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J [Bellaire, TX; Coit, William George [Bellaire, TX; Griffin, Peter Terry [Brixham, GB; Hamilton, Paul Taylor [Houston, TX; Hsu, Chia-Fu [Granada Hills, CA; Mason, Stanley Leroy [Allen, TX; Samuel, Allan James [Kular Lumpar, ML; Watkins, Ronnie Wade [Cypress, TX

    2012-07-31

    A system for treating a hydrocarbon containing formation is described. The system includes two or more groups of elongated heaters. The group includes two or more heaters placed in two or more openings in the formation. The heaters in the group are electrically coupled below the surface of the formation. The openings include at least partially uncased wellbores in a hydrocarbon layer of the formation. The groups are electrically configured such that current flow through the formation between at least two groups is inhibited. The heaters are configured to provide heat to the formation.

  6. Grouped exposed metal heaters

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J. (Bellaire, TX); Coit, William George (Bellaire, TX); Griffin, Peter Terry (Brixham, GB); Hamilton, Paul Taylor (Houston, TX); Hsu, Chia-Fu (Granada Hills, CA); Mason, Stanley Leroy (Allen, TX); Samuel, Allan James (Kular Lumpar, MY); Watkins, Ronnie Wade (Cypress, TX)

    2010-11-09

    A system for treating a hydrocarbon containing formation is described. The system includes two or more groups of elongated heaters. The group includes two or more heaters placed in two or more openings in the formation. The heaters in the group are electrically coupled below the surface of the formation. The openings include at least partially uncased wellbores in a hydrocarbon layer of the formation. The groups are electrically configured such that current flow through the formation between at least two groups is inhibited. The heaters are configured to provide heat to the formation.

  7. Thermal storage heaters

    Energy Technology Data Exchange (ETDEWEB)

    Stokes, K.H.; Broadbent, J.T.

    1991-02-27

    A storage heater, providing heat by radiation, comprises an internal circuit for the passage of heated air. The heater comprises: a heat storage core, comprising heat storage rods heated by resistance wiring, and an air space around the rods, the air space forming an inner pathway of circuit; heat insulation around the core; and outer pathways adjacent outer walls of the heater. A damper is arranged at the top of the inner and outer pathways to control the communication between. The damper may be movably supported on a support part by robust bi-metallic strips wound with heater wires to control the bending of the strips. The storage heater may be supplied in kit form for the purchaser to assemble and to this end the heat storage rods may comprise particulate material poured into tubes, or liftable core units. Further heat insulation may be selectively positioned in the outer pathways to provide an even heat distribution. (author).

  8. Explosives tester with heater

    Science.gov (United States)

    Del Eckels, Joel [Livermore, CA; Nunes, Peter J [Danville, CA; Simpson, Randall L [Livermore, CA; Whipple, Richard E [Livermore, CA; Carter, J Chance [Livermore, CA; Reynolds, John G [San Ramon, CA

    2010-08-10

    An inspection tester system for testing for explosives. The tester includes a body and a swab unit adapted to be removeably connected to the body. At least one reagent holder and dispenser is operatively connected to the body. The reagent holder and dispenser contains an explosives detecting reagent and is positioned to deliver the explosives detecting reagent to the swab unit. A heater is operatively connected to the body and the swab unit is adapted to be operatively connected to the heater.

  9. Coaxial Electric Heaters

    Science.gov (United States)

    Strekalov, Dmitry; Matsko, Andrey; Savchenkov, Anatoliy; Maleki, Lute

    2008-01-01

    Coaxial electric heaters have been conceived for use in highly sensitive instruments in which there are requirements for compact heaters but stray magnetic fields associated with heater electric currents would adversely affect operation. Such instruments include atomic clocks and magnetometers that utilize heated atomic-sample cells, wherein stray magnetic fields at picotesla levels could introduce systematic errors into instrument readings. A coaxial electric heater is essentially an axisymmetric coaxial cable, the outer conductor of which is deliberately made highly electrically resistive so that it can serve as a heating element. As in the cases of other axisymmetric coaxial cables, the equal magnitude electric currents flowing in opposite directions along the inner and outer conductors give rise to zero net magnetic field outside the outer conductor. Hence, a coaxial electric heater can be placed near an atomic-sample cell or other sensitive device. A coaxial electric heater can be fabricated from an insulated copper wire, the copper core of which serves as the inner conductor. For example, in one approach, the insulated wire is dipped in a colloidal graphite emulsion, then the emulsion-coated wire is dried to form a thin, uniform, highly electrically resistive film that serves as the outer conductor. Then the film is coated with a protective layer of high-temperature epoxy except at the end to be electrically connected to the power supply. Next, the insulation is stripped from the wire at that end. Finally, electrical leads from the heater power supply are attached to the exposed portions of the wire and the resistive film. The resistance of the graphite film can be tailored via its thickness. Alternatively, the film can be made from an electrically conductive paint, other than a colloidal graphite emulsion, chosen to impart the desired resistance. Yet another alternative is to tailor the resistance of a graphite film by exploiting the fact that its resistance

  10. Concrete durability

    Directory of Open Access Journals (Sweden)

    Gaspar Tébar, Demetrio

    1991-03-01

    Full Text Available The evidence that the concrete is not a material for ever was noticed from the beginning of its industrial use. In the present work, the author describes the studies carried out during the last century and the early ages of the present one, mainly devoted to the study of the durability in sea water. At the present days, and in spite of the numerous papers published from then, the study of the concrete durability continues focusing the research priorities and economical resources of researchers and industries related with this material. Moreover, the new laboratory techniques are allowing to understand old problems and even to open again the discussion on reaction mechanisms which were believed to be completely understood. The article finalizes with a brief description of the numerous studies carried out at the Institute Eduardo Torroja on concrete durability, mainly those related with the resistance against gypsum attack (so abundant in our country land and against sea water attack.

    La realidad de que el hormigón no es un material eterno y es susceptible de sufrir ataques por agentes químicos, fue constatada desde el comienzo mismo de su uso industrial. En el presente trabajo el autor enumera los estudios realizados el siglo pasado y a comienzos del presente sobre la durabilidad del hormigón en agua de mar. En la actualidad y a pesar de los numerosos trabajos desarrollados desde entonces, el estudio de la durabilidad del hormigón sigue centrando la atención prioritaria y los recursos económicos de los investigadores e industrias relacionadas con este material. Además las nuevas técnicas de estudio están permitiendo comprender antiguos problemas e incluso reabrir la discusión sobre mecanismos de reacción que se creían completamente explicados. Finaliza el artículo con una descripción somera de los múltiples trabajos realizados en el Instituto Eduardo Torreja sobre la materia, en especial los estudios realizados sobre

  11. Compact instantaneous water heater

    Energy Technology Data Exchange (ETDEWEB)

    Azevedo, Jorge G.W.; Machado, Antonio R.; Ferraz, Andre D.; Rocha, Ivan C.C. da; Konishi, Ricardo [Companhia de Gas de Santa Catarina (SCGAS), Florianopolis, SC (Brazil); Lehmkuhl, Willian A.; Francisco Jr, Roberto W.; Hatanaka, Ricardo L.; Pereira, Fernando M.; Oliveira, Amir A.M. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil)

    2012-07-01

    This paper presents an experimental study of combustion in an inert porous medium in a liquid heating device application. This project aims to increase efficiency in the application of natural gas in residential and commercial sectors with the use of advanced combustion and heat transfer. The goal is to facilitate the development of a high performance compact water heater allowing hot water supply for up to two simultaneous showers. The experiment consists in a cylindrical porous burner with an integrated annular water heat exchanger. The reactants were injected radially into the burner and the flame stabilizes within the porous matrix. The water circulates in a coiled pipe positioned at the center of the burner. This configuration allows for heat transfer by conduction and radiation from the solid matrix to the heat exchanger. This article presented preliminary experimental results of a new water heater based on an annular porous burner. The range of equivalence ratios tested varied from 0.65 to 0.8. The power range was varied from 3 to 5 kW. Increasing the equivalence ratio or decreasing the total power input of the burner resulted in increased thermal efficiencies of the water heater. Thermal efficiencies varying from 60 to 92% were obtained. The condition for the goal of a comfortable bath was 20 deg C for 8-12 L/min. This preliminary prototype has achieved water temperature of 11deg C for 5 L/min. Further optimizations will be necessary in order to achieve intense heating with high thermal efficiency. (author)

  12. Subsurface heaters with low sulfidation rates

    Energy Technology Data Exchange (ETDEWEB)

    John, Randy Carl; Vinegar, Harold J

    2013-12-10

    A system for heating a hydrocarbon containing formation includes a heater having an elongated ferromagnetic metal heater section. The heater is located in an opening in a formation. The heater section is configured to heat the hydrocarbon containing formation. The exposed ferromagnetic metal has a sulfidation rate that goes down with increasing temperature of the heater, when the heater is in a selected temperature range.

  13. 46 CFR 119.320 - Water heaters.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Water heaters. 119.320 Section 119.320 Shipping COAST... Machinery § 119.320 Water heaters. (a) A water heater must meet the requirements of Parts 53 and 63 in... electric water heater is also acceptable if it: (1) Has a capacity of not more than 454 liters (120...

  14. 46 CFR 182.320 - Water heaters.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Water heaters. 182.320 Section 182.320 Shipping COAST...) MACHINERY INSTALLATION Auxiliary Machinery § 182.320 Water heaters. (a) A water heater must meet the...), except that an electric water heater is also acceptable if it: (1) Has a capacity of not more than...

  15. Thermal behavior of a porous electric heater

    Energy Technology Data Exchange (ETDEWEB)

    Naji, M.; Al-Nimr, M.A. [Jordan University of Science and Technology, Irbid (Jordan). Dept. of Mechanical Engineering

    2002-03-01

    The performance of a proposed porous electric heater is investigated. The porous heater exchanges heat with the working fluid through its large volumetric surface area. As a result, it produces lower surface temperature as compared with the conventional heater for the same imposed heating power. Two mathematical models are presented to describe the thermal behavior of both heaters. Axial diffusion is included in the governing equation of the solid conventional heater. The predictions of both models are compared at different operating conditions where it is found that porous heaters have much better thermal performance than the conventional heaters. (author)

  16. ENERGY STAR Certified Water Heaters

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Water Heaters that are effective April 16, 2015....

  17. Solar Hot Water Heater

    Science.gov (United States)

    1978-01-01

    The solar panels pictured below, mounted on a Moscow, Idaho home, are part of a domestic hot water heating system capable of providing up to 100 percent of home or small business hot water needs. Produced by Lennox Industries Inc., Marshalltown, Iowa, the panels are commercial versions of a collector co-developed by NASA. In an effort to conserve energy, NASA has installed solar collectors at a number of its own facilities and is conducting research to develop the most efficient systems. Lewis Research Center teamed with Honeywell Inc., Minneapolis, Minnesota to develop the flat plate collector shown. Key to the collector's efficiency is black chrome coating on the plate developed for use on spacecraft solar cells, the coating prevents sun heat from "reradiating," or escaping outward. The design proved the most effective heat absorber among 23 different types of collectors evaluated in a Lewis test program. The Lennox solar domestic hot water heating system has three main components: the array of collectors, a "solar module" (blue unit pictured) and a conventional water heater. A fluid-ethylene glycol and water-is circulated through the collectors to absorb solar heat. The fluid is then piped to a double-walled jacket around a water tank within the solar module.

  18. Heat Pump Water Heater Durabliltiy Testing - Phase II

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, VAND.

    2004-05-29

    Ten heat pump water heaters (HPWH) were placed in an environmentally controlled test facility and run through a durability test program of approximately 7300 duty cycles (actual cycles accumulated ranged from 6640 to 8324 for the ten units). Five of the units were upgraded integral types (HPWH mounted on storage tank, no pump) from the same manufacturer as those tested in our first durability program in 2001 (Baxter and Linkous, 2002). The other five were ''add-on'' type units (HPWH with circulation pump plumbed to a separate storage tank) from another manufacturer. This durability test was designed to represent approximately 7-10 years of normal operation to meet the hot water needs of a residence. The integral units operated without incident apart from two control board failures. Both of these were caused by inadvertent exposure to very hot and humid (>135 F dry bulb and >120 F dew point) conditions that occurred due to a test loop failure. It is not likely that any residential water heater would be installed where such conditions were expected so these failures are not considered a long-term reliability concern. Two of the integral HPWHs featured a condensate management system (CMS) option that effectively eliminated any need for an evaporator condensate drain, but imposed significant efficiency penalties when operating in high humidity ambient conditions. The add-on units experienced no operational failures (breakdowns with loss of hot water production) during the course of the testing. However, their control systems exhibited some performance degradation under the high temperature, high humidity test conditions--HPWHs would shut off with tank water temperatures 15-20 F lower than when operating under moderate ambient conditions. One unit developed a refrigerant leak during the test program and lost about 50% of its charge resulting in reduced efficiency. Efficiency measurements on all the integral units and four of the add-on units showed

  19. Host-induced gene silencing of an essential chitin synthase gene confers durable resistance to Fusarium head blight and seedling blight in wheat.

    Science.gov (United States)

    Cheng, Wei; Song, Xiu-Shi; Li, He-Ping; Cao, Le-Hui; Sun, Ke; Qiu, Xiao-Li; Xu, Yu-Bin; Yang, Peng; Huang, Tao; Zhang, Jing-Bo; Qu, Bo; Liao, Yu-Cai

    2015-12-01

    Fusarium head blight (FHB) and Fusarium seedling blight (FSB) of wheat, caused by Fusarium pathogens, are devastating diseases worldwide. We report the expression of RNA interference (RNAi) sequences derived from an essential Fusarium graminearum (Fg) virulence gene, chitin synthase (Chs) 3b, as a method to enhance resistance of wheat plants to fungal pathogens. Deletion of Chs3b was lethal to Fg; disruption of the other Chs gene family members generated knockout mutants with diverse impacts on Fg. Comparative expression analyses revealed that among the Chs gene family members, Chs3b had the highest expression levels during Fg colonization of wheat. Three hairpin RNAi constructs corresponding to the different regions of Chs3b were found to silence Chs3b in transgenic Fg strains. Co-expression of these three RNAi constructs in two independent elite wheat cultivar transgenic lines conferred high levels of stable, consistent resistance (combined type I and II resistance) to both FHB and FSB throughout the T3 to T5 generations. Confocal microscopy revealed profoundly restricted mycelia in Fg-infected transgenic wheat plants. Presence of the three specific short interfering RNAs in transgenic wheat plants was confirmed by Northern blotting, and these RNAs efficiently down-regulated Chs3b in the colonizing Fusarium pathogens on wheat seedlings and spikes. Our results demonstrate that host-induced gene silencing of an essential fungal chitin synthase gene is an effective strategy for enhancing resistance in crop plants under field test conditions.

  20. Quench Heater Studies for the LHC Magnets

    CERN Document Server

    Rodríguez-Mateos, F

    2001-01-01

    About 2000 LHC (CERN's Large Hadron Collider) superconducting magnets will be protected with quench heaters against development of excessive voltage and overheating after a resistive transition. The quench heater strips are powered by capacitor bank discharge power supplies. The strips are made of stainless steel partially plated with copper to reduce their resistance and to allow for the connection of quench heaters in series. The strips are embedded in between two polyimide foils. The initial power density and the current decay time determine the quench heater effectiveness. Since only one type of heater power supply will be available, the copper plating cycle is adapted for the various magnet types to keep the resistance of the heater circuit constant. Different quench heater designs have been tested on various prototype magnets to optimise the copper-plating cycle and the electric insulation of the heater strip. This paper summarises the experimental results and computations that allowed to finalise the h...

  1. Shared savings gets realtor new water heaters

    Energy Technology Data Exchange (ETDEWEB)

    Mullin, R.

    1983-08-08

    The Grenadier Realty Co. of New York is financing four energy-efficient water heaters for apartment buildings with a shared savings arrangement. The arrangement allows Grenadier to avoid front-end costs, which were paid by Independent Water Heaters Inc. in exchange for a decreasing share of the savings. Grenadier will own the heaters when the five-year contract expires. By allowing a shutdown of boilers during the summer months, the heaters will further increase energy savings. (DCK)

  2. The performance of porous electric heaters

    Energy Technology Data Exchange (ETDEWEB)

    Al-Nimr, M.A.; Naji, M.

    2003-03-01

    The performance of a proposed porous electric heater is investigated. The porous heater exchanges heat with the working fluid through its large volumetric surface area. As a result, it produces lower surface temperature as compared with the conventional heater for the same imposed heating power. Two mathematical models are presented to describe the thermal behavior of both heaters and the predictions of both models are compared at different operating conditions. (author)

  3. 14 CFR 27.833 - Heaters.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Heaters. 27.833 Section 27.833 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... Heaters. Each combustion heater must be approved. Fire Protection ...

  4. 14 CFR 29.833 - Heaters.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Heaters. 29.833 Section 29.833 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... Heaters. Each combustion heater must be approved. Fire Protection ...

  5. Solar water heater design package

    Science.gov (United States)

    1981-01-01

    Package describes commercial domestic-hot-water heater with roof or rack mounted solar collectors. System is adjustable to pre-existing gas or electric hot-water house units. Design package includes drawings, description of automatic control logic, evaluation measurements, possible design variations, list of materials and installation tools, and trouble-shooting guide and manual.

  6. Durable solar mirror films

    Energy Technology Data Exchange (ETDEWEB)

    O' Neill, Mark B.; Henderson, Andrew J.; Hebrink, Timothy J.; Katare, Rajesh K.; Jing, Naiyong; North, Diane; Peterson, Eric M.

    2017-02-14

    The present disclosure generally relates to durable solar mirror films, methods of making durable solar mirror films, and constructions including durable solar mirror films. In one embodiment, the present disclosure relates to a solar mirror film comprising: a multilayer optical film layer including having a coefficient of hygroscopic expansion of less than about 30 ppm per percent relative humidity; and a reflective layer having a coefficient of hygroscopic expansion.

  7. Welding shield for coupling heaters

    Science.gov (United States)

    Menotti, James Louis

    2010-03-09

    Systems for coupling end portions of two elongated heater portions and methods of using such systems to treat a subsurface formation are described herein. A system may include a holding system configured to hold end portions of the two elongated heater portions so that the end portions are abutted together or located near each other; a shield for enclosing the end portions, and one or more inert gas inlets configured to provide at least one inert gas to flush the system with inert gas during welding of the end portions. The shield may be configured to inhibit oxidation during welding that joins the end portions together. The shield may include a hinged door that, when closed, is configured to at least partially isolate the interior of the shield from the atmosphere. The hinged door, when open, is configured to allow access to the interior of the shield.

  8. Space Station solar water heater

    Science.gov (United States)

    Horan, D. C.; Somers, Richard E.; Haynes, R. D.

    1990-01-01

    The feasibility of directly converting solar energy for crew water heating on the Space Station Freedom (SSF) and other human-tended missions such as a geosynchronous space station, lunar base, or Mars spacecraft was investigated. Computer codes were developed to model the systems, and a proof-of-concept thermal vacuum test was conducted to evaluate system performance in an environment simulating the SSF. The results indicate that a solar water heater is feasible. It could provide up to 100 percent of the design heating load without a significant configuration change to the SSF or other missions. The solar heater system requires only 15 percent of the electricity that an all-electric system on the SSF would require. This allows a reduction in the solar array or a surplus of electricity for onboard experiments.

  9. Starch gelatinization in coiled heaters.

    Science.gov (United States)

    Kelder, J D H; Ptasinski, K J; Kerkhof, P J A M

    2004-01-01

    A gelatinizing model food derived from a 5% w/w cross-linked waxy maize starch suspension was simulated in coiled heaters to assess the impact of centrifugal forces on flow and heat transfer. For four coil diameters (D = 0.25, 1, 2.5, and infinity m) and three flow rates (w = 0.5, 1, and 2 m/s), heat transfer, viscous development, and the severity of channeling were evaluated. Increasing curvature proved to suppress channeling as a result of more uniform heating and gelatinization. The maximum attainable viscosity was also higher, implying a lower starch consumption for a target viscosity. Higher flow rates necessitated longer heaters, and the maximum viscosity decreased. Moderate product velocities are therefore recommended.

  10. Experimental characteristics of vortex heaters

    Science.gov (United States)

    Piralishvili, Sh. A.; Novikov, N. N.

    The performance of a Ranque-Hilsch vortex tube is investigated experimentally for the case where the tube operates as a heater, with the mass of the heated gas remaining constant. The results obtained indicate that energy separation zones with sufficiently high (50 percent) relative heating effects can be achieved for a gas flow ratio of unity. A nomogram is presented for calculating the relative and absolute heating effects as a function of the tube geometry.

  11. Graphite/Epoxy Deicing Heater

    Science.gov (United States)

    Hung, Ching-Cheh; Dillehay, Michael E.; Stahl, Mark

    1988-01-01

    Heat applied close to surface protected. One ply of highly electrically- and thermally-conductive brominated-graphite fiber composite laminated between two plies of electrically-insulating composite material, with michel foil making contact with end portions of graphite fibers. Part of foil exposed beyond composite to serve as electrical contact. Graphite/Epoxy composite heater developed to prevent and reverse formation of ice on advanced composite surfaces of aircraft.

  12. Near-surface heater experiments

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, L.D.; Cuderman, J.F.; Krumhansl, J.L.; Lappin, A.

    1978-12-31

    Full-scale near-surface heater experiments are presently being conducted by Sandia Laboratories in the Conasauga Formation at Oak Ridge, Tennessee, and in the Eleana Formation on the Nevada Test Site, Nevada. The purposes of these experiments are: (1) to determine if argillaceous media can withstand thermal loads characteristic of high level waste; (2) to provide data for improvement of themomechanical modeling of argillaceous rocks; (3) to identify instrumentation development needed for further in situ testing; and (4) to identify unexpected general types of behavior, if any. The basic instrumentation of these tests consists of a heater in a central hole, surrounded by arrays of holes containing various instrumentation. Temperatures, thermal profiles, vertical displacements, volatile pressurization, and changes in in situ stresses are measured in each experiment as a function of time, and compared with pretest modeling results. Results to date, though in general agreement with modeling results assuming conductive heat transfer within the rock, indicate that the presence of even small amounts of water can drastically affect heat transfer within the heater hole itself, and that small amounts of upward convection of water may be occurring in the higher temperature areas of the Conasauga experiments.

  13. Transparent heaters made by ultrasonic spray pyrolysis of nanograined SnO2 layers on soda-lime glass substrates

    Science.gov (United States)

    Gharesi, Mohsen; Ansari, Mohammad; Akbari-Saatlu, Mehdi

    2017-07-01

    Transparent heaters have become important owing to the increasing demand in automotive and display device manufacturing industries. Indium tin oxide (ITO) is the most commonly used material for the production of transparent heaters, but the fabrication cost is high as the indium resources are diminishing fast. This has been the driving force behind the intense research for discovering more durable and cost-effective alternatives. Tin oxide, with its high temperature stability and coexisting high levels of conductivity and transparency, can replace expensive ITO in the fabrication of transparent heaters. Here, we propose nanograined tin oxide films deposited using ultrasonic spray pyrolysis as the raw material for the fabrication of transparent heaters. Silver contacts are paste printed on the deposited SnO2 layers, which provide the necessary connections to the external circuitry. Deposition of films having sheet resistance in the 120 Ω □-1 range takes only ~5 min and the utilized methods are fully scalable to the mass production level. Durability tests, carried out for weeks of continuous operation at different elevated temperatures, demonstrated the long load life of the produced heaters.

  14. Solar air heaters and their applications

    Science.gov (United States)

    Selcuk, M. K.

    1977-01-01

    The solar air heater appears to be the most logical choice, as far as the ultimate application of heating air to maintain a comfortable environment is concerned. One disadvantage of solar air heaters is the need for handling larger volumes of air than liquids due to the low density of air as a working substance. Another disadvantage is the low thermal capacity of air. In cases where thermal storage is needed, water is superior to air. Design variations of solar air heaters are discussed along with the calculation of the efficiency of a flat plate solar air heater, the performance of various collector types, and the applications of solar air heaters. Attention is given to collectors with nonporous absorber plates, collectors with porous absorbers, the performance of flat plate collectors with finned absorbers, a wire mesh absorber, and an overlapped glass plate air heater.

  15. Parallel heater system for subsurface formations

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Christopher Kelvin (Houston, TX); Karanikas, John Michael (Houston, TX); Nguyen, Scott Vinh (Houston, TX)

    2011-10-25

    A heating system for a subsurface formation is disclosed. The system includes a plurality of substantially horizontally oriented or inclined heater sections located in a hydrocarbon containing layer in the formation. At least a portion of two of the heater sections are substantially parallel to each other. The ends of at least two of the heater sections in the layer are electrically coupled to a substantially horizontal, or inclined, electrical conductor oriented substantially perpendicular to the ends of the at least two heater sections.

  16. SINGLE HEATER TEST FINAL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    J.B. Cho

    1999-05-01

    The Single Heater Test is the first of the in-situ thermal tests conducted by the U.S. Department of Energy as part of its program of characterizing Yucca Mountain in Nevada as the potential site for a proposed deep geologic repository for the disposal of spent nuclear fuel and high-level nuclear waste. The Site Characterization Plan (DOE 1988) contained an extensive plan of in-situ thermal tests aimed at understanding specific aspects of the response of the local rock-mass around the potential repository to the heat from the radioactive decay of the emplaced waste. With the refocusing of the Site Characterization Plan by the ''Civilian Radioactive Waste Management Program Plan'' (DOE 1994), a consolidated thermal testing program emerged by 1995 as documented in the reports ''In-Situ Thermal Testing Program Strategy'' (DOE 1995) and ''Updated In-Situ Thermal Testing Program Strategy'' (CRWMS M&O 1997a). The concept of the Single Heater Test took shape in the summer of 1995 and detailed planning and design of the test started with the beginning fiscal year 1996. The overall objective of the Single Heater Test was to gain an understanding of the coupled thermal, mechanical, hydrological, and chemical processes that are anticipated to occur in the local rock-mass in the potential repository as a result of heat from radioactive decay of the emplaced waste. This included making a priori predictions of the test results using existing models and subsequently refining or modifying the models, on the basis of comparative and interpretive analyses of the measurements and predictions. A second, no less important, objective was to try out, in a full-scale field setting, the various instruments and equipment to be employed in the future on a much larger, more complex, thermal test of longer duration, such as the Drift Scale Test. This ''shake down'' or trial aspect of the Single Heater Test applied

  17. SELECTED ORGANIC POLLUTANT EMISSIONS FROM UNVENTED KEROSENE HEATERS

    Science.gov (United States)

    An exploratory study was performed to assess the semivolatile and nonvolatile organic pollutant emission rates from unvented kerosene space heaters. A well-tuned radiant heater and maltuned convective heater were tested for semivolatile and nonvolatile organic pollutant emiss...

  18. Strategy Guideline. Proper Water Heater Selection

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, M. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Springer, D. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); German, A. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Staller, J. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Zhang, Y. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2015-04-09

    This Strategy Guideline on proper water heater selection was developed by the Building America team Alliance for Residential Building Innovation to provide step-by-step procedures for evaluating preferred cost-effective options for energy efficient water heater alternatives based on local utility rates, climate, and anticipated loads.

  19. Strategy Guideline: Proper Water Heater Selection

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, M. [Alliance for Residential Building Innovation, Davis, CA (United States); Springer, D. [Alliance for Residential Building Innovation, Davis, CA (United States); German, A. [Alliance for Residential Building Innovation, Davis, CA (United States); Staller, J. [Alliance for Residential Building Innovation, Davis, CA (United States); Zhang, Y. [Alliance for Residential Building Innovation, Davis, CA (United States)

    2015-04-01

    This Strategy Guideline on proper water heater selection was developed by the Building America team Alliance for Residential Building Innovation to provide step-by-step procedures for evaluating preferred cost-effective options for energy efficient water heater alternatives based on local utility rates, climate, and anticipated loads.

  20. 49 CFR 393.77 - Heaters.

    Science.gov (United States)

    2010-10-01

    ... all hot water and steam heater systems shall be specifically designed and constructed for that purpose... when used for heating the cargo of tank motor vehicles. (3) Heaters permitting fuel leakage. Any type... air, heated or to be heated, from the engine compartment or from direct contact with any portion...

  1. Solar Water-Heater Design Package

    Science.gov (United States)

    1982-01-01

    Information on a solar domestic-hot water heater is contained in 146 page design package. System consists of solar collector, storage tanks, automatic control circuitry and auxiliary heater. Data-acquisition equipment at sites monitors day-by-day performance. Includes performance specifications, schematics, solar-collector drawings and drawings of control parts.

  2. Subsurface connection methods for subsurface heaters

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J. (Bellaire, TX); Bass, Ronald Marshall (Houston, TX); Kim, Dong Sub (Sugar Land, TX); Mason, Stanley Leroy (Allen, TX); Stegemeier, George Leo (Houston, TX); Keltner, Thomas Joseph (Spring, TX); Carl, Jr., Frederick Gordon (Houston, TX)

    2010-12-28

    A system for heating a subsurface formation is described. The system includes a first elongated heater in a first opening in the formation. The first elongated heater includes an exposed metal section in a portion of the first opening. The portion is below a layer of the formation to be heated. The exposed metal section is exposed to the formation. A second elongated heater is in a second opening in the formation. The second opening connects to the first opening at or near the portion of the first opening below the layer to be heated. At least a portion of an exposed metal section of the second elongated heater is electrically coupled to at least a portion of the exposed metal section of the first elongated heater in the portion of the first opening below the layer to be heated.

  3. Designing concrete for durability

    Directory of Open Access Journals (Sweden)

    Boyd, A. J.

    2001-12-01

    Full Text Available Some of the factors affecting the durability of modern concrete structures are discussed, with an emphasis on the problems caused by modern portland cements. This is followed by a description of some concrete durability issues of current interest, such as plastic shrinkage, seawater attack, and sulfate attack. The strategies for testing for durability are also discussed. It is concluded that, to produce durable concretes, a holistic approach to concrete construction must be adopted.

    Se discuten algunos de los factores que influyen en la durabilidad de las estructuras de hormigón modernas, haciendo énfasis en los problemas causados por el cemento Portland. A esto sigue una descripción de algunas cuestiones de interés general de la durabilidad del hormigón tales como la retracción plástica, el ataque por agua de mar y el ataque por sulfatos. Se discuten también las estrategias de los ensayos de durabilidad. Se concluye que para producir hormigones durables se debe adoptar un enfoque holístico de la construcción con hormigón.

  4. Results of MPBX studies at the single heater test

    Energy Technology Data Exchange (ETDEWEB)

    Blair, S. C.,LLNL

    1997-10-01

    We have developed an extensometer for measurement of distance and displacements in a geologic repository for high-level nuclear waste. This is an optical extensometer that measures distance using a modulated laser beam. In this design, reflecting targets are placed at desired measurement locations, and distance between each target and an optical head are measured repeatedly using the modulated laser beam. Moreover, all electronic and moving parts are located outside of the hostile or difficult environment as the optical head is connected to the laser, switching and signal analysis hardware using optical fibers. A reference beam is utilized to provide direct correction of system behavior. `Be system also - utilizes movable reflective anchors that can be repositioned if desired. We have installed the system in the Single Heater Test being conducted in Alcove 5 of the Exploratory Studies Facility at Yucca Mountain, and report preliminary results.

  5. Effects of heated seat and foot heater on thermal comfort and heater energy consumption in vehicle.

    Science.gov (United States)

    Oi, Hajime; Yanagi, Kotaro; Tabata, Koji; Tochihara, Yutaka

    2011-08-01

    Subjective experiments involving 12 different conditions were conducted to investigate the effects of heated seats and foot heaters in vehicles on thermal sensation and thermal comfort. The experimental conditions involved various combinations of the operative temperature in the test room (10 or 20°C), a heated seat (on/off) and a foot heater (room operative temperature +10 or +20°C). The heated seat and foot heater improved the occupant's thermal sensation and comfort in cool environments. The room operative temperature at which the occupants felt a 'neutral' overall thermal sensation was decreased by about 3°C by using the heated seat or foot heater and by about 6°C when both devices were used. Moreover, the effects of these devices on vehicle heater energy consumption were investigated using simulations. As a result, it was revealed that heated seats and foot heaters can reduce the total heater energy consumption of vehicles. Statement of Relevance: Subjective experiments were conducted to investigate the effects of heated seats and foot heaters in vehicles on thermal comfort. The heated seat and foot heater improved the occupant's thermal sensation and comfort in cool environments. These devices can reduce the total heater energy consumption in vehicles.

  6. Biogas Digester with Simple Solar Heater

    OpenAIRE

    Kh S Karimov; Muhammad Abid

    2012-01-01

    ABSTRACT: In this research work, the design, fabrication and investigation of a biogas digester with simple solar heater are presented. For the solar heater, a built-in reverse absorber type heater was used. The maximum temperature (50°C) inside the methane tank was taken as a main parameter for the design of the digester. Then, the energy balance equation for the case of a static mass of fluid being heated was used to model the process. The parameters of thermal insulation of the methane tan...

  7. Particulate matter sensor with a heater

    Science.gov (United States)

    Hall, Matthew

    2011-08-16

    An apparatus to detect particulate matter. The apparatus includes a sensor electrode, a shroud, and a heater. The electrode measures a chemical composition within an exhaust stream. The shroud surrounds at least a portion of the sensor electrode, exclusive of a distal end of the sensor electrode exposed to the exhaust stream. The shroud defines an air gap between the sensor electrode and the shroud and an opening toward the distal end of the sensor electrode. The heater is mounted relative to the sensor electrode. The heater burns off particulate matter in the air gap between the sensor electrode and the shroud.

  8. Durable past, sustainable future

    NARCIS (Netherlands)

    Van Hees, R.P.J.; Naldini, S.; Roos, J.

    2014-01-01

    The section Heritage & Architecture of the Faculty of Architecture at Delft University of Technology deals with the built environment in terms of conservation, refurbishment and re-use. Reflecting the department philosophy, this book focuses on the durability and sustainability of existing buildings

  9. 46 CFR 52.25-15 - Fired thermal fluid heaters.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Fired thermal fluid heaters. 52.25-15 Section 52.25-15... Boiler Types § 52.25-15 Fired thermal fluid heaters. (a) Fired thermal fluid heaters shall be designed...) Each fired thermal fluid heater must be fitted with a control which prevents the heat transfer...

  10. 40 CFR 65.149 - Boilers and process heaters.

    Science.gov (United States)

    2010-07-01

    ... thermal units per hour) or greater. (ii) A boiler or process heater into which the vent stream is... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Boilers and process heaters. 65.149... System or a Process § 65.149 Boilers and process heaters. (a) Boiler and process heater equipment...

  11. 46 CFR 63.25-5 - Fired thermal fluid heaters.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Fired thermal fluid heaters. 63.25-5 Section 63.25-5... heaters. (a) Construction. Fired thermal fluid heaters must meet the requirements of part 52 of this chapter, as applicable. (b) Controls. Fired thermal fluid heaters must have a low fluid level...

  12. Varying properties along lengths of temperature limited heaters

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J. (Bellaire, TX); Xie, Xueying (Houston, TX); Miller, David Scott (Katy, TX); Ginestra, Jean Charles (Richmond, TX)

    2011-07-26

    A system for heating a subsurface formation is described. The system includes an elongated heater in an opening in the formation. The elongated heater includes two or more portions along the length of the heater that have different power outputs. At least one portion of the elongated heater includes at least one temperature limited portion with at least one selected temperature at which the portion provides a reduced heat output. The heater is configured to provide heat to the formation with the different power outputs. The heater is configured so that the heater heats one or more portions of the formation at one or more selected heating rates.

  13. Experimental studies of operating characteristics of a downhole electric heater

    Energy Technology Data Exchange (ETDEWEB)

    Simkin, E.M.; Sergeev, A.I.; Sheinman, A.B.

    1967-06-01

    A new type of electric downhole heater for deparaffinization and heating of formations in oil wells is described. The heater is a hollow hermetic cylinder, which contains an electrode insulated from the body of the heater. The cylinder contains a predetemined volume of water of fixed electrical resistance. Resistance of this water is adjusted by addition of salt. A cable supplying the electrode with electric current also ground the heater by body. The current passes through the water, heats it, and produces steam. The steam heats up the hermetically sealed body of the heater, and heat flows to the well fluid around the heater. A schematic diagram of the heater is shown. Thermal output of the heater depends on current supplied, dimension of heater and components, resistance and volume of water in heater, and other parameters. All these factors are correlated with heat output by a series of graphs and equations.

  14. Slat Heater Boxes for Thermal Vacuum Testing

    Science.gov (United States)

    Ungar, Eugene

    2003-01-01

    Slat heater boxes have been invented for controlling the sink temperatures of objects under test in a thermal vacuum chamber, the walls of which are cooled to the temperature of liquid nitrogen. A slat heater box (see Figure 1) includes a framework of struts that support electrically heated slats that are coated with a high-emissivity optically gray paint. The slats can be grouped together into heater zones for the purpose of maintaining an even temperature within each side. The sink temperature of an object under test is defined as the steady-state temperature of the object in the vacuum/ radiative environment during the absence of any internal heat source or sink. The slat heater box makes it possible to closely control the radiation environment to obtain a desired sink temperature. The slat heater box is placed inside the cold thermal vacuum chamber, and the object under test is placed inside (but not in contact with) the slat heater box. The slat heaters occupy about a third of the field of view from any point on the surface of the object under test, the remainder of the field of view being occupied by the cold chamber wall. Thus, the radiation environment is established by the combined effects of the slat heater box and the cold chamber wall. Given (1) the temperature of the chamber wall, (2) the fractions of the field of view occupied by the chamber wall and the slat heater box, and (3) the emissivities of the slats, chamber wall, and the surface of object under test, the slat temperature required to maintain a desired sink temperature can be calculated by solving the equations of gray-body radiation for the steady-state adiabatic case (equal absorption and emission by the object under test). Slat heater boxes offer an important advantage over the infrared lamps that have been previously used to obtain desired sink temperatures: In comparison with an infrared lamp, a slat heater box provides a greater degree of sink temperature uniformity for a test

  15. Diesel particulate filter with zoned resistive heater

    Science.gov (United States)

    Gonze, Eugene V [Pinckney, MI

    2011-03-08

    A diesel particulate filter assembly comprises a diesel particulate filter (DPF) and a heater assembly. The DPF filters a particulate from exhaust produced by an engine. The heater assembly has a first metallic layer that is applied to the DPF, a resistive layer that is applied to the first metallic layer, and a second metallic layer that is applied to the resistive layer. The second metallic layer is etched to form a plurality of zones.

  16. Note: Improved wire-wound heater.

    Science.gov (United States)

    Steinmann, Ricardo G; Vitoux, Hugo

    2015-01-01

    The authors have measured, at cryogenic temperature, the upper limit of the heat transfer in different configurations of a wire-wound heater. We found that the heat transferred has an upper limit of about 15 W/cm(2) and is dependent on the diameter of the wire. In this paper, we present three ways of increasing the heat transferred by this type of heater and its application in different continuous flow cryostats.

  17. Note: Improved wire-wound heater

    Science.gov (United States)

    Steinmann, Ricardo G.; Vitoux, Hugo

    2015-01-01

    The authors have measured, at cryogenic temperature, the upper limit of the heat transfer in different configurations of a wire-wound heater. We found that the heat transferred has an upper limit of about 15 W/cm2 and is dependent on the diameter of the wire. In this paper, we present three ways of increasing the heat transferred by this type of heater and its application in different continuous flow cryostats.

  18. Intelligent annunciator for solar water heater

    Science.gov (United States)

    Chen, Xiao

    2009-07-01

    The solar water heater has advantages of low cost, no pollution, safety, energy conservation and is very suitable for users in rural area. But many now used solar water heater has no alarm device resulting water and resource wasting because of forgetting to turn off the valve after water sailing upstream. To overcome this defect, an intelligent annunciator for solar water heater installed at the end of the return pipe is presented and designed in order to remind the user. Firstly, the advantages and disadvantages of automatic and manual sailing upstream are compared concluding that manual sailing upstream is more trustiness. Then an annunciator for solar water heater is studied and ameliorated. Its principle, parameters index and functions are introduced. The annunciator uses CD4069 chip as the core circuit with very little assistant circuit. It can provide sound and light alarm at the same time. This annunciator for solar water heater water is very simple in production, low cost, the use of safe and convenient. The annunciator is applicable to all solar power products, including various types of early installation of solar power water heaters and water tanks without changing their structures. It can meet family and industrial environmental applications.

  19. Decoration and durability

    DEFF Research Database (Denmark)

    Riisberg, Vibeke; Munch, Anders V.

    2015-01-01

    Throughout the scales of design there has been an exploding interest in the ornament that seems to be fuelled by different kinds of digital technology and media from CAD to digital printing in both 2D and 3D. In architecture and industrial design, it is discussed as a “return of ornament” because...... from fashion and tableware to archi- tecture and link ornamentation to the aesthetics of durability....

  20. Performance Study of Swimming Pool Heaters

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, R.J.

    2009-01-01

    The objective of this report is to perform a controlled laboratory study on the efficiency and emissions of swimming pool heaters based on a limited field investigation into the range of expected variations in operational parameters. Swimming pool heater sales trends have indicated a significant decline in the number of conventional natural gas-fired swimming pool heaters (NGPH). On Long Island the decline has been quite sharp, on the order of 50%, in new installations since 2001. The major portion of the decline has been offset by a significant increase in the sales of electric powered heat pump pool heaters (HPPH) that have been gaining market favor. National Grid contracted with Brookhaven National Laboratory (BNL) to measure performance factors in order to compare the relative energy, environmental and economic consequences of using one technology versus the other. A field study was deemed inappropriate because of the wide range of differences in actual load variations (pool size), geographic orientations, ground plantings and shading variations, number of hours of use, seasonal use variations, occupancy patterns, hour of the day use patterns, temperature selection, etc. A decision was made to perform a controlled laboratory study based on a limited field investigation into the range of expected operational variations in parameters. Critical to this are the frequency of use, temperature selection, and sizing of the heater to the associated pool heating loads. This would be accomplished by installing a limited amount of relatively simple compact field data acquisition units on selected pool installations. This data included gas usage when available and alternately heater power or gas consumption rates were inferred from the manufacturer's specifications when direct metering was not available in the field. Figure 1 illustrates a typical pool heater installation layout.

  1. Performance characterization of a hydrogen catalytic heater.

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Terry Alan; Kanouff, Michael P.

    2010-04-01

    This report describes the performance of a high efficiency, compact heater that uses the catalytic oxidation of hydrogen to provide heat to the GM Hydrogen Storage Demonstration System. The heater was designed to transfer up to 30 kW of heat from the catalytic reaction to a circulating heat transfer fluid. The fluid then transfers the heat to one or more of the four hydrogen storage modules that make up the Demonstration System to drive off the chemically bound hydrogen. The heater consists of three main parts: (1) the reactor, (2) the gas heat recuperator, and (3) oil and gas flow distribution manifolds. The reactor and recuperator are integrated, compact, finned-plate heat exchangers to maximize heat transfer efficiency and minimize mass and volume. Detailed, three-dimensional, multi-physics computational models were used to design and optimize the system. At full power the heater was able to catalytically combust a 10% hydrogen/air mixture flowing at over 80 cubic feet per minute and transfer 30 kW of heat to a 30 gallon per minute flow of oil over a temperature range from 100 C to 220 C. The total efficiency of the catalytic heater, defined as the heat transferred to the oil divided by the inlet hydrogen chemical energy, was characterized and methods for improvement were investigated.

  2. Dielectric Heaters for Testing Spacecraft Nuclear Reactors

    Science.gov (United States)

    Sims, William Herbert; Bitteker, Leo; Godfroy, Thomas

    2006-01-01

    A document proposes the development of radio-frequency-(RF)-driven dielectric heaters for non-nuclear thermal testing of the cores of nuclear-fission reactors for spacecraft. Like the electrical-resistance heaters used heretofore for such testing, the dielectric heaters would be inserted in the reactors in place of nuclear fuel rods. A typical heater according to the proposal would consist of a rod of lossy dielectric material sized and shaped like a fuel rod and containing an electrically conductive rod along its center line. Exploiting the dielectric loss mechanism that is usually considered a nuisance in other applications, an RF signal, typically at a frequency .50 MHz and an amplitude between 2 and 5 kV, would be applied to the central conductor to heat the dielectric material. The main advantage of the proposal is that the wiring needed for the RF dielectric heating would be simpler and easier to fabricate than is the wiring needed for resistance heating. In some applications, it might be possible to eliminate all heater wiring and, instead, beam the RF heating power into the dielectric rods from external antennas.

  3. Low Cost, Durable Seal

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, George; Parsons, Jason; Friedman, Jake

    2010-12-17

    Seal durability is critical to achieving the 2010 DOE operational life goals for both stationary and transportation PEM fuel cell stacks. The seal material must be chemically and mechanically stable in an environment consisting of aggressive operating temperatures, humidified gases, and acidic membranes. The seal must also be producible at low cost. Currentlyused seal materials do not meet all these requirements. This project developed and demonstrated a high consistency hydrocarbon rubber seal material that was able to meet the DOE technical and cost targets. Significant emphasis was placed on characterization of the material and full scale molding demonstrations.

  4. Decoration and Durability

    DEFF Research Database (Denmark)

    Riisberg, Vibeke; Munch, Anders V.

    2015-01-01

    Throughout the scales of design there has been an exploding interest in the ornament that seems to be fuelled by different kinds of digital technology and media from CAD to digital printing in both 2D and 3D. In architecture and industrial design it is discussed as a Return of ornament, because...... appropriate or not. This leads us to suggest an array of parameters that points out different situations and meanings of ornamentation: Product categories, Durability of materials, Styles, Aesthetic experience, Emotional attachment and Historical references. We discuss these parameters in cases from fashion...

  5. Hollow cathode heater development for the Space Station plasma contactor

    Science.gov (United States)

    Soulas, George C.

    1993-01-01

    A hollow cathode-based plasma contactor has been selected for use on the Space Station. During the operation of the plasma contactor, the hollow cathode heater will endure approximately 12000 thermal cycles. Since a hollow cathode heater failure would result in a plasma contactor failure, a hollow cathode heater development program was established to produce a reliable heater design. The development program includes the heater design, process documents for both heater fabrication and assembly, and heater testing. The heater design was a modification of a sheathed ion thruster cathode heater. Three heaters have been tested to date using direct current power supplies. Performance testing was conducted to determine input current and power requirements for achieving activation and ignition temperatures, single unit operational repeatability, and unit-to-unit operational repeatability. Comparisons of performance testing data at the ignition input current level for the three heaters show the unit-to-unit repeatability of input power and tube temperature near the cathode tip to be within 3.5 W and 44 degrees C, respectively. Cyclic testing was then conducted to evaluate reliability under thermal cycling. The first heater, although damaged during assembly, completed 5985 ignition cycles before failing. Two additional heaters were subsequently fabricated and have completed 3178 cycles to date in an on-going test.

  6. Primary helium heater for propellant pressurization systems

    Science.gov (United States)

    Reichmuth, D. M.; Nguyen, T. V.; Pieper, J. L.

    1991-01-01

    The primary helium heater is a unique design that provides direct heating of pressurant gas for large pressure fed propulsion systems. It has been conceptually designed to supply a heated (800-1000 R) pressurization gas to both a liquid oxygen and an RP-1 propellant tank. This pressurization gas is generated within the heater by mixing super critical helium (40-300 R and 3000-1600 psi) with an appropriate amount of combustion products from a 4:1 throttling stoichiometric LO2/LH2 combustor. This simple, low cost and reliable mixer utilizes the large quantity of helium to provide stoichiometric combustor cooling, extend the throttling limits and enhance the combustion stability margin. Preliminary combustion, thermal, and CFD analyses confirm that this low-pressure-drop direct helium heater can provide the constant-temperature pressurant suitable for tank pressurization of both fuel and oxidizer tanks of large pressure fed vehicles.

  7. Economic analysis of residential solar water heaters

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-09-23

    A typical residential solar water heater, and typical cost and performance information are described briefly. The monthly costs and savings of the typical system are discussed. Economic evaluations of solar water heaters are presented in increasingly complex levels of detail. Utilizing a typical system, the effective interest rate that the purchaser of a system would receive on money invested is shown for all regions of the country. The importance of numerous variables that can make a significant difference on the economics of the system is described. Methods for calculating the Payback Period for any non-typical solar water heater are described. This calculated Payback Period is then shown to be related to the effective interest rate that the puchaser of the system would receive for a typical set of economic conditions. A method is presented to calculate the effective interest rate that the solar system would provide. (MHR)

  8. Durability of critical infrastructures

    Directory of Open Access Journals (Sweden)

    Raluca Pascu

    2011-08-01

    Full Text Available The paper deals with those infrastructures by which world society, under the pressure ofdemographic explosion, self-survives. The main threatening comes not from terrorist attacks, but fromthe great natural catastrophes and global climate change. It’s not for the first time in history when suchmeasures of self-protection are built up. First objective of this paper is to present the background fordurability analysis. Then, with the aid of these mathematical tools the absolute durability of three linearmodels, typical for critical infrastructures, are successively calculated. In order to enhance the durabilityof critical infrastructures the solution based on redundancies is chosen. Five types of connection theredundancies for each of the three models are considered. Three topological schemes for connecting theredundancies are adopted: locally, by twining and globally. Absolute values of durability in all fifteenmodels with redundancies are further calculated. Then, the relative performances of enhanced durabilityin the same fifteen models, compared with the three original models, considered as references, areanalysed. The relative costs of the same fifteen models and in similar topologic conditions are furtheranalysed. By dividing the performance with cost the relative profitableness of each model is obtained.Finally, the three initial models, each reshaped with redundancies in three selective modes, arecompared from the perspective of their relative profitableness. The outcomes of this paper are original.They are of practical interests in planning the maintenance programs and checking the plausibility ofproposed interventions according to the clause 7.4 of ISO 13822:2001

  9. Measure Guideline. Transitioning to a Tankless Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    Brozyna, K. [IBACOS, Inc., Pittsburgh, PA (United States); Rapport, A. [IBACOS, Inc., Pittsburgh, PA (United States)

    2012-09-01

    This measure guideline provides information to help residential builders and retrofitters with the design, specification, selection, implementation, installation, and maintenance issues of transitioning from tank-type water heaters to tankless water heaters.

  10. Durability 5; Taikyusei 5

    Energy Technology Data Exchange (ETDEWEB)

    Hisada, Makoto [Niigata University, Niigata (Japan)

    1998-09-10

    The research report of 5 titles on material property of concrete bridge by durability of the concrete which abundantly used coal ash, frozen water quantity of the concrete which receives the action of sea water and pore structure, isothermal adsorption curve of the surface layer concrete, moisture conductivity, field study of ASR damage concrete structure in the Noto district and confession for a long time in this session was made. By replacing the coal ash to outside x 10 % 75 %, Kishida et al. showed being effective under the marine environment for the increase in compression strength and chloride ions osmotic fragility in the age in the long term. By distribution of the melting temperature of the mortar inside and change of class pore structure of the hardening body inside, O et al. did the description on the mechanism in the sea water action of scaling phenomena with the freezing of the concrete. Yuasa et al. by the difference of water cement ratio and drying commencing time, moisture content, release of humid heat quantity and moisture conductivity in the concrete inside changed, and it was shown that this change originated for the difference of the pore quantity of the hardening body inside. Tori et al. introduced research report on field study of ASR damage concrete structure in the Noto district which passed through common use start post-10{approx}25 and it indicated the possibility in which in addition, the expansion by ASR will continue in future too. MATSUSHITA et al. introduced the survey result of the concrete for bridge pier removed in the disassembly in passing through about 60 after common use, and it did the report that used concrete was sufficiently durable in investigation point of time. The concrete removed in the disassembly is very contrastive, though it is durable it, by passing through the concrete in which the already important damage becomes tangible and long years, while it will be used in future. The importance of the philosophy in the

  11. Durable consumption, saving and retirement

    DEFF Research Database (Denmark)

    Andersen, Torben M.; Hermansen, Mikkel Nørlem

    2014-01-01

    welfare in stationary equilibrium, we find that a redution in wealth locking-in in durables is not necessarily welfare improving due to the effects on bequest. From a social welfare perspective, individuals tend to choose too much financial savings, too little durable acquisition and too early retirement....

  12. 40 CFR 63.988 - Incinerators, boilers, and process heaters.

    Science.gov (United States)

    2010-07-01

    ... bed. (3) Where a boiler or process heater of less than 44 megawatts (150 million British thermal units... heaters. 63.988 Section 63.988 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Routing to a Fuel Gas System or a Process § 63.988 Incinerators, boilers, and process heaters....

  13. Heater size effect on subcooled pool boiling of FC-72

    Energy Technology Data Exchange (ETDEWEB)

    Raj, Rishi; Kim, Jungho [University of Maryland, College Park, MD (United States). Dept. of Mechanical Engineering

    2009-07-01

    Extensive research has been conducted on pool boiling using heaters larger than the capillary length. For large heaters and/or high gravity conditions, boiling is dominated by buoyancy, and the heat transfer is heater size independent. Much less is known about boiling on small heaters and at low gravity levels. The ratio of heater size L{sub h} to capillary length L{sub c} is an important parameter in the determination of heater size dependence on heat transfer. As the ratio L{sub h}/L{sub c} decreases due to a decrease in either heater size or gravity, surface tension forces become dominant. It is proposed that transition from buoyancy to surface tension dominated boiling occurs when the heater size and bubble departure diameter are of the same order. Previous work in variable gravity with flat surfaces has shown that the heat transfer was heater size independent only when the ratio L{sub h}/L{sub c} was considerably larger than 1. An array of 96 platinum resistance heater elements in a 10 x 10 configuration with individual elements 0.7 x 0.7 mm{sup 2} in size was used to vary heater size and measure the heat transfer. The threshold value of L{sub h}/L{sub c} above which pool boiling is heater size independent was found to be about 2.8. (author)

  14. 46 CFR 111.70-5 - Heater circuits.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Heater circuits. 111.70-5 Section 111.70-5 Shipping... REQUIREMENTS Motor Circuits, Controllers, and Protection § 111.70-5 Heater circuits. (a) If an enclosure for a... from a separate circuit, the heater circuit must be disconnected from its source of potential by...

  15. Analysis Approach to Improve Star Rating Of Water Heater

    Directory of Open Access Journals (Sweden)

    Sujata Dabhade

    2014-07-01

    Full Text Available Electric Water Heaters are widely used all over the world that can be categorized in two types i.e. Instant Water Heaters & Storage type Water Heaters. The energy consumption for 6 liter water heaters is much higher in the storage type of water heater. As energy is an important factor for economic development of country, therefore there is need to save the energy which implies the focus to use Storage type Water Heaters. In 6 Liter water heater, Existing model converting from 4 star rating to 5 star rating by thermal analysis & insulation. After the theoretical calculation of thickness of glass wool is the practical testing of product with BEE norms & got results for 5 Star Calculation. Finally we are doing the thermal analysis for theoretical & practical verification of the product

  16. Hot embossing and thermal bonding of poly(methyl methacrylate) microfluidic chips using positive temperature coefficient ceramic heater.

    Science.gov (United States)

    Wang, Xia; Zhang, Luyan; Chen, Gang

    2011-11-01

    As a self-regulating heating device, positive temperature coefficient ceramic heater was employed for hot embossing and thermal bonding of poly(methyl methacrylate) microfluidic chip because it supplied constant-temperature heating without electrical control circuits. To emboss a channel plate, a piece of poly(methyl methacrylate) plate was sandwiched between a template and a microscopic glass slide on a positive temperature coefficient ceramic heater. All the assembled components were pressed between two elastic press heads of a spring-driven press while a voltage was applied to the heater for 10 min. Subsequently, the embossed poly(methyl methacrylate) plate bearing negative relief of channel networks was bonded with a piece of poly(methyl methacrylate) cover sheet to obtain a complete microchip using a positive temperature coefficient ceramic heater and a spring-driven press. High quality microfluidic chips fabricated by using the novel embossing/bonding device were successfully applied in the electrophoretic separation of three cations. Positive temperature coefficient ceramic heater indicates great promise for the low-cost production of poly(methyl methacrylate) microchips and should find wide applications in the fabrication of other thermoplastic polymer microfluidic devices.

  17. Durability Evaluation of Superconducting Magnets

    Science.gov (United States)

    Inoue, Akihiko; Ogata, Masafumi; Nakauchi, Masahiko; Asahara, Tetsuo; Herai, Toshiki; Nishikawa, Yoichi

    2006-06-01

    It is one of the most essential things to verify the durability of devices and components of JR-Maglev system to realize the system into the future inauguration. Since the load requirements were insufficient in terms of the durability under vibrations under mere running tests carried out on Yamanashi Maglev Test Line hereinafter referred to YMTL, we have developed supplemental method with bench tests. Superconducting magnets hereinafter referred to SCM as used in the experimental running for the last seven years on the YMTL were brought to Kunitachi Technical Research Institute; we conducted tests to evaluate the durability of SCM up to a period of the service life in commercial use. The test results have indicated that no irregularity in each part of SCM proving that SCM are sufficiently durable for the practical application.

  18. Solar Air Heaters with Thermal Heat Storages

    Directory of Open Access Journals (Sweden)

    Abhishek Saxena

    2013-01-01

    Full Text Available Solar energy can be converted into different forms of energy, either to thermal energy or to electrical energy. Solar energy is converted directly into electrical power by photovoltaic modules, while solar collector converts solar energy into thermal energy. Solar collector works by absorbing the direct solar radiation and converting it into thermal energy, which can be stored in the form of sensible heat or latent heat or a combination of sensible and latent heats. A theoretical study has been carried out to rate the various thermal energy storage commonly used in solar air heaters. During the investigations rock bed storages have been found to be low type thermal heat storage, while phase change materials have been found to be high heat thermal storages. Besides this, a few other heat storing materials have been studied and discussed for lower to higher ratings in terms of thermal performance purposely for solar heaters.

  19. Improving the Gas Instantaneous Water Heaters Performances

    Directory of Open Access Journals (Sweden)

    Nasir Kloub

    2005-01-01

    Full Text Available This study presents a study of a theoretical and practical investigation of the gas Instantaneous (Tankless water Heaters performance. The results allow us to obtain realistic values of the control system in the various capacities gaseous flowing water heaters. The objective of this work is to study the operation of the plans in the field of controlling and checking low capacity gaseous flowing water in order to choose the proper plan of the logical values and measures for these equipments that may be used in industrial conditions. Also results of the work proved to be accurate. A design of the control system was made. The results of the practical experiment of the control system were similar to the arithmetic results.

  20. Single-heater test final report

    Energy Technology Data Exchange (ETDEWEB)

    Blair, S. C.; Buscheck, T. A.; DeLoach, L. D.; Lin, W.; Ramirez, A. I.

    1998-09-01

    The Single-Heater Test (SHT) was one phase of the field-scale thermal testing program of the Yucca Mountain Site Characterization Project. The primary purpose of the SHT was to study the thermomechanical (TM) behavior of the densely welded, non-lithophysal Topopah Spring tuff at the Exploratory Studies Facility. The SHT was also used as a shake-down for testing thermal-hydrologic-chemical-mechanical processes in situ, testing that will be conducted in the Drift-Scale Test. In the SHT, a line-heat source 5-m long was emplaced in a pillar and used to heat the pillar for approximately nine months. The thermal field was relatively cylindrical about the line-heat source. The heater was turned off after nine months of heating, and the rock mass was monitored during the cool-down for another nine months, until May 28, 1997, when the test was terminated.

  1. Solar water heater for NASA's Space Station

    Science.gov (United States)

    Somers, Richard E.; Haynes, R. Daniel

    1988-01-01

    The feasibility of using a solar water heater for NASA's Space Station is investigated using computer codes developed to model the Space Station configuration, orbit, and heating systems. Numerous orbit variations, system options, and geometries for the collector were analyzed. Results show that a solar water heater, which would provide 100 percent of the design heating load and would not impose a significant impact on the Space Station overall design is feasible. A heat pipe or pumped fluid radial plate collector of about 10-sq m, placed on top of the habitat module was found to be well suited for satisfying water demand of the Space Station. Due to the relatively small area required by a radial plate, a concentrator is unnecessary. The system would use only 7 to 10 percent as much electricity as an electric water-heating system.

  2. AWSWAH - the heat pipe solar water heater

    Energy Technology Data Exchange (ETDEWEB)

    Akyurt, M.

    1986-01-01

    An all weather heat pipe solar water heater (AWSWAH) comprising a collector of 4 m/sup 2/ (43 ft/sup 2/) and a low profile water tank of 160 liters (42 gal.) was developed. A single heat pipe consisting of 30 risers and two manifolds in the evaporator and a spiral condenser was incorporated into the AWSWAH. Condensate metering was done by synthetic fiber wicks. The AWSWAH was tested alongside two conventional solar water heaters of identical dimensions, an open loop system and a closed loop system. It was found that the AWSWAH was an average of 50% more effective than the open system in the temperature range 30-90 /sup 0/C (86-194 /sup 0/F). The closed loop system was the least efficient of the three systems.

  3. Firebox modeling of SRT cracking heaters

    Energy Technology Data Exchange (ETDEWEB)

    Sundaram, K.M.; Albano, J.V. [ABB Lummus Crest Inc., Bloomfield, NJ (United States)

    1994-12-31

    Thermal cracking of hydrocarbons remains the most economically attractive route for the production of ethylene. The heat for the endothermic cracking reaction is supplied in high capacity fired heaters which are designed specifically to have high selectivity to olefins. In the cracking process, coke is deposited within the tubes of the radiant coil. The rate of coke deposition in a cracking furnace is a function not only of process conditions but of other factors as well. High tube metal temperatures in certain areas of the coil or hot spots can cause locally high coking rate leading to partial blockage of the tubes and consequently, short runs. The small diameter tubes used in modern high selectivity heaters are more sensitive than older large tube designs. The occurrence of these hot zones is a strong function of fireside conditions. For satisfactory performance, the heat flux profile in a cracking heater must be maintained as uniform as possible. In addition, it is important to minimize the variation of process temperatures entering the various cracking coils. These fireside variables are not only a function of the type of burners, excess air, type of fuel(s) and distribution of air and fuel but depend significantly on the air and flue gas flow patterns associated with the firebox, i.e., the firebox aerodynamics. Poor aerodynamics can adversely affect firing patterns and hence heat flux profiles in commercial furnaces. A variety of modeling techniques have been used to evaluate the firebox aerodynamics of Lummus, Short Residence Time, cracking heaters. These include flow visualization, physical cold flow modeling, and computational techniques. These approaches are discussed in this paper.

  4. Water heaters subject to new regulations.

    Science.gov (United States)

    Clarke, Alan

    2014-06-01

    On 26 September 2015 the Ecodesign and Energy Labelling Directives for water heaters (Lot 2) come into force, meaning that water-heating products sold in the UK and other countries in the European Economic Area will need to meet minimum energy performance criteria in order to be legally placed on the market, and will require an energy label. Here Alan Clarke, technical support manager at Heatrae Sadia, explains more.

  5. Field Monitoring Protocol: Heat Pump Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Sparn, B.; Earle, L.; Christensen, D.; Maguire, J.; Wilson, E.; Hancock, E.

    2013-02-01

    This document provides a standard field monitoring protocol for evaluating the installed performance of Heat Pump Water Heaters in residential buildings. The report is organized to be consistent with the chronology of field test planning and execution. Research questions are identified first, followed by a discussion of analysis methods, and then the details of measuring the required information are laid out. A field validation of the protocol at a house near the NREL campus is included for reference.

  6. Field Monitoring Protocol. Heat Pump Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Sparn, B. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Earle, L. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Christensen, D. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Maguire, J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Wilson, E. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hancock, C. E. [Mountain Energy Partnership, Longmont, CO (United States)

    2013-02-01

    This document provides a standard field monitoring protocol for evaluating the installed performance of Heat Pump Water Heaters in residential buildings. The report is organized to be consistent with the chronology of field test planning and execution. Research questions are identified first, followed by a discussion of analysis methods, and then the details of measuring the required information are laid out. A field validation of the protocol at a house near the NREL campus is included for reference.

  7. Heater Validation for the NEXT-C Hollow Cathodes

    Science.gov (United States)

    Verhey, Timothy R.; Soulas, George C.; Mackey, Jonathan Ar.

    2017-01-01

    Swaged cathode heaters whose design was successfully demonstrated under a prior flight project are to be provided by the NASA Glenn Research Center for the NEXT-C ion thruster being fabricated by Aerojet Rocketdyne. Extensive requalification activities were performed to validate process controls that had to be re-established or revised because systemic changes prevented reuse of the past approaches. A development batch of heaters was successfully fabricated based on the new process controls. Acceptance and cyclic life testing of multiple discharge and neutralizer sized heaters extracted from the development batch was initiated in August, 2016, with the last heater completing testing in April, 2017. Cyclic life testing results substantially exceeded the NEXT-C thruster requirement as well as all past experience for GRC fabricated units. The heaters demonstrated ultimate cyclic life capability of 19050 to 33500 cycles. A qualification batch of heaters is now being fabricated using the finalized process controls. A set of six heaters will be acceptance and cyclic tested to verify conformance to the behavior observed with the development heaters. The heaters for flight use will be then be provided to the contractor. This paper summarizes the fabrication process control activities and the acceptance and life testing of the development heater units.

  8. Sticky Price Models and Durable Goods

    OpenAIRE

    Robert Barsky; Christopher L. House; Miles Kimball

    2005-01-01

    This paper shows that there are striking implications that stem from including durable goods in otherwise conventional sticky price models. The behavior of these models depends heavily on whether durable goods are present and whether these goods have sticky prices. If long-lived durables have sticky prices, then even small durables sectors can cause the model to behave as though most prices were sticky. Conversely, if durable goods prices are flexible then the model exhibits unwelcome behavio...

  9. Insulated conductor temperature limited heater for subsurface heating coupled in a three-phase WYE configuration

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J. (Bellaire, TX); Sandberg, Chester Ledlie (Palo Alto, CA)

    2010-11-09

    A heating system for a subsurface formation is described. The heating system includes a first heater, a second heater, and a third heater placed in an opening in the subsurface formation. Each heater includes: an electrical conductor; an insulation layer at least partially surrounding the electrical conductor; and an electrically conductive sheath at least partially surrounding the insulation layer. The electrical conductor is electrically coupled to the sheath at a lower end portion of the heater. The lower end portion is the portion of the heater distal from a surface of the opening. The first heater, the second heater, and the third heater are electrically coupled at the lower end portions of the heaters. The first heater, the second heater, and the third heater are configured to be electrically coupled in a three-phase wye configuration.

  10. Impact of kerosene space heaters on indoor air quality.

    Science.gov (United States)

    Hanoune, B; Carteret, M

    2015-09-01

    In recent years, the use of kerosene space heaters as additional or principal heat source has been increasing, because these heaters allow a continuous control on the energy cost. These devices are unvented, and all combustion products are released into the room where the heaters are operated. The indoor air quality of seven private homes using wick-type or electronic injection-type kerosene space heaters was investigated. Concentrations of CO, CO2, NOx, formaldehyde and particulate matter (0.02-10 μm) were measured, using time-resolved instruments when available. All heaters tested are significant sources of submicron particles, NOx and CO2. The average NO2 and CO2 concentrations are determined by the duration of use of the kerosene heaters. These results stress the need to regulate the use of unvented combustion appliances to decrease the exposure of people to air contaminants. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Measure Guideline: Transitioning to a Tankless Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    Brozyna, K.; Rapport, A.

    2012-09-01

    This Measure Guideline provides information to help residential builders and retrofitters with the design, specification, selection, implementation, installation, and maintenance issues of transitioning from tank-type water heaters to tankless water heaters. The report compares the differences between tankless and tank-type water heaters, highlighting the energy savings that can be realized by adopting tankless water heaters over tank-type water heaters. Selection criteria and risks discussed include unit sizing and location, water distribution system, plumbing line length and diameter, water quality, electrical backup, and code issues. Cost and performance data are provided for various types of tankless and tank-type water heaters, both natural gas fired and electric. Also considered are interactions between the tankless water heater and other functional elements of a house, such as cold water supply and low-flow devices. Operating costs and energy use of water distribution systems for single- and two-story houses are provided, along with discussion of the various types of distribution systems that can be used with tankless water heaters. Finally, details to prepare for proper installation of a tankless water heater are described.

  12. Field Performance of Heat Pump Water Heaters in the Northeast

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, Carl [Consortium for Advanced Residential Buildings, Norwalk, CT (United States); Puttagunta, Srikanth [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)

    2016-02-01

    Heat pump water heaters (HPWHs) are finally entering the mainstream residential water heater market. Potential catalysts are increased consumer demand for higher energy efficiency electric water heating and a new Federal water heating standard that effectively mandates use of HPWHs for electric storage water heaters with nominal capacities greater than 55 gallons. When compared to electric resistance water heating, the energy and cost savings potential of HPWHs is tremendous. Converting all electric resistance water heaters to HPWHs could save American consumers 7.8 billion dollars annually ($182 per household) in water heating operating costs and cut annual residential source energy consumption for water heating by 0.70 quads.

  13. Large-scale floor heater creating a comfortable space; Kaitekina kukan wo sozosuru daikibo yukadanbo

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-01

    Floor heater radiates at a low temperature from under, warming people from the feet upward and filling the chamber with warm air mildly and uniformly. Keeping one`s head cool and one`s feet warm is the key to one`s health, goes a Japanese adage. Not only residences but also school houses, welfare facilities, hospitals, retail shops, and offices have come to accept high-capability floor heating equipment. For Musashino Municipal Sakai Nursery School where infants play barefoot, a floor heater is the best choice. A floor heat creates an environment safe and healthy, ensuring sound sleep. It does not cause dust to rise because it does not produce air currents in the room, and does not pollute air or make noise because the heat source is installed outdoors. Tsunekiyo-no-Sato, which is a facility for senior citizens in general, serves chiefly as a special nursing home for the aged, and therefore is requested to be comfortable, safe, and clean. For the old people whose body temperature adjusting system has degraded in function, floor heaters are the best for warming because it does not involve abrupt temperature changes. The Hokkaido Branch of Asahi Breweries, Ltd., employs a floor warming system for its wine house to ensure proper storage, and the ambient temperature in winter is kept at 3degC or higher

  14. Crypto heater:a design fiction

    OpenAIRE

    Lindley, Joseph

    2015-01-01

    This proposal is to exhibit the work named Crypto Heater which is part of a design fiction [c.f 1,5,8:30] series intended to explore a near future world in which cryptographic currencies such as Bitcoin [6] have become commonplace. This work opens up space for discussion about the activities of the distributed peer-to-peer network of so-called "miners" that ensure the security of the Bitcoin network and regulate the supply of new currency in the Bitcoin economy. The physical part of the work ...

  15. The Industrial Design of Water Heater

    Institute of Scientific and Technical Information of China (English)

    张萌萌

    2014-01-01

    The design was inspired by the understanding to the fine life understanding of life, relaxed requirement and under-standing of fashion. Each link of easy life present in the water heater design. The principle of"artappliances, life"brand phi-losophy, refined and understated elegance is the core essence, is also the brand logo. In the"draw the fine life inspiration, the core brand design language create eternal artistic quality", every product tothe interpretation of home life art trend, to embody the elegant life style annotation and experience, committed to the urban elites to create exquisitelife style.

  16. Evaluation of candidate Stirling engine heater tube alloys after 3500 hours exposure to high pressure doped hydrogen or helium

    Science.gov (United States)

    Misencik, J. A.; Titran, R. H.

    1984-01-01

    The heater head tubes of current prototype automotive Stirling engines are fabricated from alloy N-155, an alloy which contains 20 percent cobalt. Because the United States imports over 90 percent of the cobalt used in this country and resource supplies could not meet the demand imposed by automotive applications of cobalt in the heater head (tubes plus cylinders and regenerator housings), it is imperative that substitute alloys free of cobalt be identified. The research described herein focused on the heater head tubes. Sixteen alloys (15 potential substitutes plus the 20 percent Co N-155 alloy) were evaluated in the form of thin wall tubing in the NASA Lewis Research Center Stirling simulator materials diesel fuel fired test rigs. Tubes filled with either hydrogen doped with 1 percent CO2 or with helium at a gas pressure of 15 MPa and a temperature of 820 C were cyclic endurance tested for times up to 3500 hr. Results showed that two iron-nickel base superalloys, CG-27 and Pyromet 901 survived the 3500 hr endurance test. The remaining alloys failed by creep-rupture at times less than 3000 hr, however, several other alloys had superior lives to N-155. Results further showed that doping the hydrogen working fluid with 1 vol % CO2 is an effective means of reducing hydrogen permeability through all the alloy tubes investigated.

  17. Status of Hollow Cathode Heater Development for the Space Station Plasma Contactor

    Science.gov (United States)

    Soulas, George C.

    1994-01-01

    A hollow cathode-based plasma contactor has been selected for use on the Space Station. During the operation of the plasma contactor, the hollow cathode heater will endure approximately 12000 thermal cycles. Since a hollow cathode heater failure would result in a plasma contactor failure, a hollow cathode heater development program was established to produce a reliable heater. The development program includes the heater design, process documents for both heater fabrication and assembly, and heater testing. The heater design was a modification of a sheathed ion thruster cathode heater. Heater tests included testing of the heater unit alone and plasma contactor and ion thruster testing. To date, eight heaters have been or are being processed through heater unit testing, two through plasma contactor testing and three through ion thruster testing, all using direct current power supplies. Comparisons of data from heater unit performance tests before cyclic testing, plasma contactor tests, and ion thruster tests at the ignition input current level show the average deviation of input power and tube temperature near the cathode tip to be +/-0.9 W and +/- 21 C, respectively. Heater unit testing included cyclic testing to evaluate reliability under thermal cycling. The first heater, although damaged during assembly, completed 5985 ignition cycles before failing. Four additional heaters successfully completed 6300, 6300, 700, and 700 cycles. Heater unit testing is currently ongoing for three heaters which have to date accumulated greater than 7250, greater than 5500, and greater than 5500 cycles, respectively.

  18. Evaluation of radiofrequency dielectric heaters workers exposure.

    Science.gov (United States)

    Benes, M; Del Frate, S; Villalta, R

    2008-01-01

    Radiofrequency dielectric heaters (RFDH) are widely used in the woodworking industry for gluing laminates by applying pressure and RF heating. The workers operating such equipment remain in the vicinity of the machinery all day and can therefore be exposed to considerable levels of electric and magnetic field at RFs. This work describes the method used to measure the strength of fields generated by this particular machinery. This procedure is based on current methods cited in the literature and introduces the necessary modifications to meet this specific case. In particular, as there is often a scarcity of technical data available relating to such heaters, it is suggested that a spectrum analyser be used for measurements in the frequencies domain. On the basis of the data obtained the norms of reference are established, the instrumentation to be used in successive stages determined as well as the identification of possible sources of interference from spurious signals. Furthermore, a mapping of the field strengths is presented and the means of determining the decay curve as a function of distance. This last type of measurement is done to estimate the effectiveness of grounding the machinery. The report ends with an estimate of the exposure of workers to electromagnetic fields and also some recommendations for reducing risk.

  19. Biogas Digester with Simple Solar Heater

    Directory of Open Access Journals (Sweden)

    Kh S Karimov

    2012-10-01

    Full Text Available ABSTRACT: In this research work, the design, fabrication and investigation of a biogas digester with simple solar heater are presented. For the solar heater, a built-in reverse absorber type heater was used. The maximum temperature (50°C inside the methane tank was taken as a main parameter for the design of the digester. Then, the energy balance equation for the case of a static mass of fluid being heated was used to model the process. The parameters of thermal insulation of the methane tank were also included in the calculations. The biogas digester consisted of a methane tank with built-in solar reverse absorber heater to harness the radiant solar energy for heating the slurry comprising of different organic wastes (dung, sewage, food wastes etc.. The methane tank was initially filled to 70% of its volume with organic wastes from the GIK institute’s sewage. The remaining volume was filled with sewage and cow dung from other sources. During a three month period (October-December, 2009 and another two month period (February-March, 2010, the digester was investigated. The effects of solar radiation on the absorber, the slurry’s temperature, and the ambient temperature were all measured during these investigations. It was found that using sewage only and sewage with cow dung in the slurry resulted in retention times of four and two weeks, respectively. The corresponding biogas produced was 0.4 m3 and 8.0 m3, respectively. Finally, this paper also elaborates on the upgradation of biogas through the removal of carbon dioxide, hydrogen sulphide and water vapour, and also the process of conversion of biogas energy into electric powerABSTRAK: Kajian ini membentangkan rekabentuk, fabrikasi dan penyelidikan tentang pencerna biogas dengan pemanas solar ringkas. Sebagai pemanas solar, ia dilengkapkan dengan penyerap pemanas beralik. Suhu maksimum(50oC di dalam tangki metana telah diambil sebagai parameter utama rekabentuk pencerna. Dengan menggunakan

  20. Parametric excitation of whistler waves by HF heater

    Science.gov (United States)

    Kuo, S. P.; Lee, M. C.

    1989-01-01

    Possible generation of whistler waves by Tromso HF heater is investigated. It is shown that the HF heater wave can parametrically decay into a whistler wave and a Langmuir wave. Since whistler waves may have a broad range of frequency, the simultaneously excited Langmuir waves can have a much broader frequency bandwidth than those excited by the parametric decay instability.

  1. 46 CFR 111.85-1 - Electric oil immersion heaters.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Electric oil immersion heaters. 111.85-1 Section 111.85-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Electric Oil Immersion Heaters § 111.85-1 Electric oil immersion...

  2. Durability of air lime mortar

    DEFF Research Database (Denmark)

    Nielsen, Anders

    2016-01-01

    This contribution deals with the physical and chemical reasons why pure air lime mortars used in masonry of burned bricks exposed to outdoor climate have shown to be durable from the Middle Ages to our days. This sounds strange in modern times where pure air lime mortars are regarded as weak...

  3. Infrared transparent graphene heater for silicon photonic integrated circuits.

    Science.gov (United States)

    Schall, Daniel; Mohsin, Muhammad; Sagade, Abhay A; Otto, Martin; Chmielak, Bartos; Suckow, Stephan; Giesecke, Anna Lena; Neumaier, Daniel; Kurz, Heinrich

    2016-04-18

    Thermo-optical tuning of the refractive index is one of the pivotal operations performed in integrated silicon photonic circuits for thermal stabilization, compensation of fabrication tolerances, and implementation of photonic operations. Currently, heaters based on metal wires provide the temperature control in the silicon waveguide. The strong interaction of metal and light, however, necessitates a certain gap between the heater and the photonic structure to avoid significant transmission loss. Here we present a graphene heater that overcomes this constraint and enables an energy efficient tuning of the refractive index. We achieve a tuning power as low as 22 mW per free spectral range and fast response time of 3 µs, outperforming metal based waveguide heaters. Simulations support the experimental results and suggest that for graphene heaters the spacing to the silicon can be further reduced yielding the best possible energy efficiency and operation speed.

  4. Toxic organic pollutants from kerosene space heaters in Iran.

    Science.gov (United States)

    Keyanpour-Rad, Mansoor

    2004-03-01

    The aim of this study was to investigate qualitatively the emission of toxic organic pollutants from an unventilated conventional kerosene space heater commonly used in Iran. A brand new common convective kerosene space heater, the "Aladdin," was used for this study. The well-tuned convective heater was operated in a 2.6-m(3) test chamber and then the emission was tested for organic pollutants. The emission was collected on Teflon-impregnated glass-fiber filters and XAD-2 resin and then analyzed by gas chromatography-mass spectroscopy. It was found that in addition to the ordinary pollutant gases, the heater emits aliphatic hydrocarbons, alcohols, polyaromatic hydrocarbons and the related nitrated compounds, phthalates, naphthalenes, and some other toxic organic compounds. However, it was found that the heater did not emit fluoranthene, cyclohexane, benzoic acid, and higher-molecular-weight alkylbenzenes, which could have resulted from the combustion of some other types of kerosene.

  5. Note: Improved heater design for high-temperature hollow cathodes

    Science.gov (United States)

    McDonald, M. S.; Gallimore, A. D.; Goebel, D. M.

    2017-02-01

    We present an improved heater design for thermionic cathodes using a rhenium filament encased in a boron nitride ceramic sleeve. This heater is relatively simple to fabricate, yet has been successfully used to reliably and repeatably light a lanthanum hexaboride (LaB6) hollow cathode based on a previously published design without noticeable filament degradation over hundreds of hours of operation. The high decomposition temperature of boron nitride (2800 C for inert environments) and melting point for rhenium (3180 C) make this heater especially attractive for use with LaB6, which may require operating temperatures upwards of 1700 C. While boron nitride decomposes in air above 1000 C, the heater was used only at vacuum with an inert gas discharge, and no degradation was observed. Limitations of current state of the art cathode heaters are also discussed and compared with the rhenium-boron nitride combination.

  6. 40 CFR 610.33 - Durability tests.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Durability tests. 610.33 Section 610... RETROFIT DEVICES Test Procedures and Evaluation Criteria Test Requirement Criteria § 610.33 Durability tests. The Administrator may determine that a device under evaluation will require durability testing...

  7. Building Design, Durability, Maintenance: Methodology for the Durability Forecasting

    Directory of Open Access Journals (Sweden)

    Riccardo Pollo

    2014-05-01

    Full Text Available The paper describes a research based on the use of the software BIM (Building Information Modeling which is associated with an experimental procedure of the evaluation of durability and the life cycle based on FMEA (Failure Mode and Effects Analysis, one of the methods for durability assessment indicated by the ISO 15686-1 standard. The study shows the methodology and develops a case study on the refurbishment of an old building and discusses its outcome. The experiment on one side illustrates the utility of the analytical approach of FMEA and on the other side the difficulty to use different data and information to be considered in the durability evaluation carried out by the designer  based on the expert assessment. The role of the experts is to design a model and to assess the criticality of each event and to define the relationship between the causes and effects on building elements function. The designer has to define the environmental conditions of the site, the specifications of the material used, the skills of workmanship. The study has shown a quite realistic outcome and significant indications for the designer. Such a result suggests the development of the research.

  8. Integrity Assessment of GOH Heater Tube

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Bong Sang; Hong, J. H.; Oh, Y. J.; Yoon, J. H.; Oh, J. M. [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1997-08-01

    An assessment of structural integrity of ASTM A312-TP347 GOH heater tube was performed. The surface notches which had been produced during tube manufacturing process were analyzed microscopically. Chemical analysis, hardness tests, tensile tests, and J-Integral fracture resistance tests were carried out to compare the mechanical properties with those of the material specification and also with the other material of the same type. The test results showed the mechanical properties of the GOH tube material are within the specification range. An elastic-plastic fracture mechanics analysis based on the DPFAD method reveals the tube an appropriate safety margin for the normal operation. 13 refs., 5 tabs., 24 figs. (author)

  9. High Efficiency Water Heating Technology Development Final Report. Part I, Lab/Field Performance Evaluation and Accelerated Life Testing of a Hybrid Electric Heat Pump Water Heater (HPWH)

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, Van D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Murphy, Richard W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rice, C. Keith [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Linkous, Randall Lee [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-04-01

    DOE has supported efforts for many years with the objective of getting a water heater that uses heat pump technology (aka a heat pump water heater or HPWH) successfully on the residential equipment market. The most recent previous effort (1999-2002) produced a product that performed very well in ORNL-led accelerated durability and field tests. The commercial partner for this effort, Enviromaster International (EMI), introduced the product to the market under the trade name Watter$aver in 2002 but ceased production in 2005 due to low sales. A combination of high sales price and lack of any significant infrastructure for service after the sale were the principal reasons for the failure of this effort. What was needed for market success was a commercial partner with the manufacturing and market distribution capability necessary to allow economies of scale to lead to a viable unit price together with a strong customer service infrastructure. General Electric certainly meets these requirements, and knowing of ORNL s expertise in this area, approached ORNL with the proposal to partner in a CRADA to produce a high efficiency electric water heater. A CRADA with GE was initiated early in Fiscal Year, 2008. GE initially named its product the Hybrid Electric Water Heater (HEWH).

  10. Durability of building materials and components

    CERN Document Server

    Delgado, JMPQ

    2013-01-01

    Durability of Building Materials and Components provides a collection of recent research works to contribute to the systematization and dissemination of knowledge related to the long-term performance and durability of construction and, simultaneously, to show the most recent advances in this domain. It includes a set of new developments in the field of durability, service life prediction methodologies, the durability approach for historical and old buildings, asset and maintenance management and on the durability of materials, systems and components. The book is divided in several chapters that intend to be a resume of the current state of knowledge for benefit of professional colleagues.

  11. Fluid bed solids heater. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Preuit, L. C.

    1980-01-01

    A solids heater which operates at up to 2000 F was designed, fabricated, installed and operated through checkout at the Morgantown Energy Technology Center at Morgantown, West Virginia. The system, designated the 2000 F Fluid Bed Solids Heater (FBSH) uses a fluidized bed to heat limestone to 600 F and aluminium oxide or silicon carbide to 2000 F and discharges heated solids upon demand. The FBSH with added valve handling and pressurization equipment is known as the Valve Hot Solids Test Unit and is intended for use by the US Department of Energy for testing of valves for severe service applications in coal conversion and utilization processes. The FBSH as designed and supplied by Combustion Power Company includes process equipment, controls, the enclosing building and other associated equipment. In the 600 F range of operation it can circulate limestone through two valve test trains simultaneously on a continuous basis. Only one valve test train is used for 2000 F solids and operation in that range is also continuous. Limestone, crushed to minus 5/16 size, is heated, discharged, and recycled at a maximum average rate of 250 lb/min while aluminum oxide or silicon carbide, No. 8 grit, is circulated at rates up to 167 lb/min. The FBSH control system is designed for automatic operation, and capability is included for external computerized data acquisition and/or supervisory control. An operating and maintenance manual and as-built drawings have been submitted. This report describes the FBSH equipment, its design basis, and its operation. It has been prepared and submitted in fulfillment of Contract Number DIAC05-77ET10499.

  12. Analysis of Leak and Plugging Condition for Feedwater Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hansul; Kang, Yeon Kwan; Heo, Gyunyoung [Kyung Hee University, Yongin (Korea, Republic of); Song, Seok Yoon; Oh, Seung Hwan [Korea Hydro and Nuclear Power, Daejeon (Korea, Republic of)

    2015-10-15

    Tube damage in feedwater heater occurs from damaged pressure boundary, inflow of foreign substances, erosion and corrosion. Once a heat tube is damaged, the water jet from the damaged spot is spread out to surrounding tubes. Since a feedwater heater is operated under 2-phase flow condition and has physically complicated structure, it cannot be approached on shell side. Therefore, test and inspection to check tube degradation is relatively difficult. Even though tube leak does not affect surrounding tubes, it obviously affects efficiency of turbine cycle and reduces economic feasibility in the long run. For this reason, systematic management is required on thermal performance for feedwater heaters. In this paper, PEPSE (Performance Evaluation of Power System Efficiency), one of the generic-purpose power plant simulation program, was used to construct a heat balance model for turbine cycle. The model was used to analyze the effect of change in key variables related to thermal performance of feedwater heater on turbine cycle, thereby preparing a thermal performance management strategy for feedwater heaters. Study was conducted on 6 units that represent each reactor type among domestic nuclear power plants (NPPs) in operation, but this paper described the results of high pressure feedwater heaters in a Korean standard NPP, which shows high possibility of tube damage due to large shell-tube pressure difference. In this paper, the heat balance models for turbine cycle were constructed as a part of effort to develop the thermal performance management system for feedwater heaters in NPPs.

  13. Thermal emission of neutron stars with internal heaters

    CERN Document Server

    Kaminker, A D; Potekhin, A Y; Yakovlev, D G

    2014-01-01

    Using 1D and 2D cooling codes we study thermal emission from neutron stars with steady state internal heaters of various intensities and geometries (blobs or spherical layers) located at different depths in the crust. The generated heat tends to propagate radially, from the heater down to the stellar core and up to the surface; it is also emitted by neutrinos. In local regions near the heater the results are well described with the 1D code. The heater's region projects onto the stellar surface forming a hot spot. There are two heat propagation regimes. In the first, conduction outflow regime (realized at heat rates $H_0 \\lesssim 10^{20}$ erg cm$^{-3}$ s$^{-1}$ or temperatures $T_\\mathrm{h} \\lesssim 10^9$ K in the heater) the thermal surface emission of the star depends on the heater's power and neutrino emission in the stellar core. In the second, neutrino outflow regime ($H_0 \\gtrsim 10^{20}$ erg cm$^{-3}$ s$^{-1}$ or $T_\\mathrm{h} \\gtrsim 10^9$ K) the surface thermal emission becomes independent of heater's...

  14. Durability of radon remedial actions

    Energy Technology Data Exchange (ETDEWEB)

    Naismith, S. [National Radiological Protection Board, Chilton (United Kingdom)

    1997-10-01

    In the UK, approximately 3600 householders are believed to have taken action to reduce high radon concentrations in their homes. In 1993 a number of those householders who had taken successful remedial actions were invited to participate in a study of durability of radon remedial actions. This involved the radon concentration being remeasured annually. Results for 26 such homes where a complete set of data are available and a further 32 with incomplete data are discussed here. All remedial actions were shown to remain durable during a period of 5 years. The largest variation in effectiveness was found in houses with natural ventilation of the underfloor void. The failure rate for all remedial measures was found to be 4.0% per annum, but in most cases the problems were noticed by the householder and corrected. The frequency of failures which were not noticed until a remeasurement was carried out was 0.4% per annum. (Author).

  15. Methodology for Composite Durability Assessment

    Science.gov (United States)

    2002-11-01

    structures from basic properties • Reduce the numbers of durability tests • Link the resin properties to composite properties • Effect of moisture and...in the fiber Critical invariants compare Electronic Carpet Plot Lamina modulus Ex, Ey=Ez, Gs Fiber and resin properties Vf, Efiber, Ematrix Laminate...CTE / Fiber CTE Fiber volume fraction Vf Ply Strength Predicted from Resin Properties Test Data 0 10 20 30 40 50 60 70 80 -2 0 2 4 Time to failure

  16. Substrate heater for the growth of epitaxial silicon films

    Science.gov (United States)

    Deming, Matthew; Varhue, Walter; Adams, Edward; Lavoie, Mark

    1999-03-01

    The single wafer processing of epitaxial Si films requires that special attention be paid to the design of the substrate heater assembly. This document describes the evolution and testing of an in situ heater used to deposit epitaxial Si films at temperatures as high as 700 °C. One problem encountered was the production of excessive levels of ultraviolet radiation which contributed to the desorption of water vapor from the vacuum chamber walls during the in situ cleaning process. A second problem involved the formation of a molybdenum containing film that poisoned epitaxial growth. A final proven in situ heater design is presented which avoids these problems.

  17. Design and Implementation of the MSL Cruise Propulsion Tank Heaters

    Science.gov (United States)

    Krylo, Robert; Mikhaylov, Rebecca; Cucullu, Gordon; Watkins, Brenda

    2008-01-01

    This slide presentation reviews the design and the implementation of the heaters for the Mars Science Laboratory (MSL). The pressurized tanks store hydrazine that freezes at 2 C, this means that heaters are required to keep the hydrazine and the helium at 36 C for the trip to Mars. Using the TMG software the heat loss was analyzed, and a thermal model simulates a half full tank which yielded a 13W heating requirement for each hemisphere. Views of the design, and the heater are included.

  18. 75 FR 52892 - Energy Conservation Program for Consumer Products: Test Procedures for Residential Water Heaters...

    Science.gov (United States)

    2010-08-30

    ... discretion, this direct measurement procedure is optional for vented heaters without thermal stack dampers... efficiency is calculated for vented heaters with manual controls and thermal dampers. For all other vented... Procedures for Residential Water Heaters, Direct Heating Equipment, and Pool Heaters AGENCY: Office of...

  19. 78 FR 2340 - Energy Conservation Program: Test Procedures for Residential Water Heaters and Commercial Water...

    Science.gov (United States)

    2013-01-11

    ... also questionable whether thermal efficiency is an appropriate metric for smaller storage water heaters... that the test procedure for residential water heaters utilized the thermal efficiency and standby loss..., particularly for heat pump water heaters and gas instantaneous water heaters. 3. Revised Thermal Efficiency...

  20. 75 FR 20111 - Energy Conservation Program: Energy Conservation Standards for Residential Water Heaters, Direct...

    Science.gov (United States)

    2010-04-16

    ... 46,000 65 Table II.3--Current Federal Energy Conservation Standards for Pool Heaters Thermal efficiency as of Product class January 1, 1990 Gas-Fired Pool Heater Thermal Efficiency = 78% ] 2. History of... Heaters, Direct Heating Equipment, and Pool Heaters; Final Rule #0;#0;Federal Register / Vol. 75, No....

  1. 76 FR 56347 - Energy Conservation Program for Consumer Products: Test Procedures for Residential Water Heaters...

    Science.gov (United States)

    2011-09-13

    ... of the pool heater as: E OUT = BOH Where: BOH = as defined in 5.2 of this appendix E t = thermal... defined in 5.3 of this appendix 5.4.3 Calculate the pool heater integrated thermal efficiency (TE I ) (in... Residential Water Heaters, Direct Heating Equipment, and Pool Heaters (Standby Mode and Off Mode)...

  2. Modeling heat transfer from quench protection heaters to superconducting cables in Nb3Sn magnets

    CERN Document Server

    Salmi, T; Caspi, S; Felice, H; Prestemon, S; Chlachidze, G; Kate, H H J ten

    2013-01-01

    We use a recently developed quench protection heater modeling tool for an analysis of heater delays in superconducting high-field Nb3Sn accelerator magnets. The results suggest that the calculated delays are consistent with experimental data, and show how the heater delay depends on the main heater design parameters.

  3. 40 CFR 279.23 - On-site burning in space heaters.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 26 2010-07-01 2010-07-01 false On-site burning in space heaters. 279... burning in space heaters. Generators may burn used oil in used oil-fired space heaters provided that: (a) The heater burns only used oil that the owner or operator generates or used oil received from...

  4. Performance and durability testing of parabolic trough receivers

    Science.gov (United States)

    Lei, Dongqiang; Fu, Xuqiang; Zhao, Dongming; Yuan, Guofeng; Wang, Zhifeng; Guo, Minghuan

    2017-06-01

    The paper describes the key performance and durability testing facilities of the parabolic trough receiver developed by Institute of Electrical Engineering, Chinese Academy of Sciences. The indoor heat loss test can be applied at 4-7 different temperature levels within 200-550 on receivers. The optical efficiency test bench consists of 12 metal halide lamps as the solar simulator and a 5 m length half-elliptical cylinder reflector with flat end reflectors. 3 ultra-precision temperature sensors are used in receiver each end to get the temperature difference. The residual gas analysis test bench is applied to analyze and predict the vacuum lifetime of the receiver. It can test the variations of composition and partial pressure of residual gases with temperature and time in the receiver annulus space by a high sensitivity quadrupole mass spectrometer gas analyzer. A coating accelerated ageing test bench, which is also used to test the thermal cycle, has been developed. This test bench uses the absorber tube of the recevier as the resistance heater to heat up the whole receiver. The coating lifetime can be predicted by the Arrhenius parameters. For the cycling test, the compressed air is used to directly cool the inner surface of the absorber tube. The thermal cycling test is performed with temperature cycles from 150 °C to 450 °C for 160 cycles. The maximum thermal cycling frequency is 8 cycles per day. The mechanical fatigue test bench is used to test the bellows and the glass-to-metal seals durability at the same time. Both bellows are expanded and compressed to 6.5 mm in turn with 10,000 cycles. A new rotating test bench was also developed to test the thermal efficiency of the receiver.

  5. Analytical Model for Ring Heater Thermal Compensation in Advanced LIGO

    CERN Document Server

    Ramette, Joshua; Brooks, Aidan; Blair, Carl; Wang, Haoyu; Heintze, Matthew

    2015-01-01

    Advanced laser interferometer gravitational-wave detectors use high laser power to achieve design sensitivity. A small part of this power is absorbed in the interferometer cavity mirrors where it creates thermal lenses, causing aberrations in the main laser beam that must be minimized by the actuation of "ring heaters," additional heater elements that are aimed to reduce the temperature gradients in the mirrors. In this article we derive the first analytical model of the temperature field generated by an ideal ring heater. We express the resulting optical aberration contribution to the main laser beam in this axisymmetric case. Used in conjunction with wavefront measurements, our model provides a more complete understanding of the thermal state of the cavity mirrors and will allow a more efficient use of the ring heaters in Advanced LIGO.

  6. ENERGY STAR Certified Water Heaters (V3.1)

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Water Heaters that are effective April 16, 2015....

  7. A High Performance Cathode Heater for Hall Thrusters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The current state-of-the-art co-axial swaged tantalum (Ta) heaters use magnesium oxide (MgO) insulators, which limits their operation to temperatures well below...

  8. New Home Buyer Solar Water Heater Trade-Off Study

    Energy Technology Data Exchange (ETDEWEB)

    Symmetrics Marketing Corporation

    1999-08-18

    This report details the results of a research conducted in 1998 and 1999 and outlines a marketing deployment plan designed for businesses interested in marketing solar water heaters in the new home industry.

  9. Temperature limited heater utilizing non-ferromagnetic conductor

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar,; Harold J. (Bellaire, TX), Harris; Kelvin, Christopher [Houston, TX

    2012-07-17

    A heater is described. The heater includes a ferromagnetic conductor and an electrical conductor electrically coupled to the ferromagnetic conductor. The ferromagnetic conductor is positioned relative to the electrical conductor such that an electromagnetic field produced by time-varying current flow in the ferromagnetic conductor confines a majority of the flow of the electrical current to the electrical conductor at temperatures below or near a selected temperature.

  10. Thermal performance of a new solar air heater

    Energy Technology Data Exchange (ETDEWEB)

    Tiris, C.; Ozbalta, N. [Ege Univ., Izmir (Turkey). Solar Energy Institute; Tiris, M.; Dincer, I. [TUBITAK-Marmara Research Center, Kocaeli (Turkey)

    1995-05-01

    A solar air heater, part of a food drying system using solar energy as a renewable energy source for heat, was developed and tested for several agricultural products (i.e., sultana grapes, green beans, sweet peppers, chili peppers). Drying processes were conducted in the chamber with forced natural air heated partly by solar energy. Solar air heater performances were discussed along with estimates of energy efficiency of the system. The obtained results indicate that the present system is efficiency and effective.

  11. Development of an Ultra-Low-Cost Solar Water Heater: Cooperative Research and Development Final Report, CRADA Number CRD-12-487

    Energy Technology Data Exchange (ETDEWEB)

    Merrigan, Tim [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-02-17

    NREL and RhoTech will collaborate to bring long-lived, ultra-low-cost, high-performance solar water heaters (SWH) to market readiness. An existing RhoTech design uses seam-welded polymer thin films to make an unglazed thermosiphon, and this design will be modified to improve durability through ultraviolet and overheat protection, and to improve performance by adding a glazing to the collector. Two generations of the new glazed systems will be tested in the field, resulting in a robust market-ready SWH design that can be installed for under $1,000 without rebates.

  12. Mathematical modeling of the area of tubular gas heater in the condensing mode of work

    OpenAIRE

    IRODOV V. F.; Bereziuk, G. G.

    2015-01-01

    Statement of the problem. Infrared tubular gas heaters are designed for burning gas, moving of the heated products of combustion with air inside the tubular heater and heating of the room where the heater is installed with the help of radiant and convective heat exchange with space of the room. Tubular gas heaters are simultaneously sources of heat supply and heating devices. Using of these heaters provides fuel economy and uniform distribution of comfortable heat. Maximum fuel economy can be...

  13. Gravity and Heater Size Effects on Pool Boiling Heat Transfer

    Science.gov (United States)

    Kim, Jungho; Raj, Rishi

    2014-01-01

    The current work is based on observations of boiling heat transfer over a continuous range of gravity levels between 0g to 1.8g and varying heater sizes with a fluorinert as the test liquid (FC-72/n-perfluorohexane). Variable gravity pool boiling heat transfer measurements over a wide range of gravity levels were made during parabolic flight campaigns as well as onboard the International Space Station. For large heaters and-or higher gravity conditions, buoyancy dominated boiling and heat transfer results were heater size independent. The power law coefficient for gravity in the heat transfer equation was found to be a function of wall temperature under these conditions. Under low gravity conditions and-or for smaller heaters, surface tension forces dominated and heat transfer results were heater size dependent. A pool boiling regime map differentiating buoyancy and surface tension dominated regimes was developed along with a unified framework that allowed for scaling of pool boiling over a wide range of gravity levels and heater sizes. The scaling laws developed in this study are expected to allow performance quantification of phase change based technologies under variable gravity environments eventually leading to their implementation in space based applications.

  14. Thermo-Electron Ballistic Coolers or Heaters

    Science.gov (United States)

    Choi, Sang H.

    2003-01-01

    Electronic heat-transfer devices of a proposed type would exploit some of the quantum-wire-like, pseudo-superconducting properties of single-wall carbon nanotubes or, optionally, room-temperature-superconducting polymers (RTSPs). The devices are denoted thermo-electron ballistic (TEB) coolers or heaters because one of the properties that they exploit is the totally or nearly ballistic (dissipation or scattering free) transport of electrons. This property is observed in RTSPs and carbon nanotubes that are free of material and geometric defects, except under conditions in which oscillatory electron motions become coupled with vibrations of the nanotubes. Another relevant property is the high number density of electrons passing through carbon nanotubes -- sufficient to sustain electron current densities as large as 100 MA/square cm. The combination of ballistic motion and large current density should make it possible for TEB devices to operate at low applied potentials while pumping heat at rates several orders of magnitude greater than those of thermoelectric devices. It may also enable them to operate with efficiency close to the Carnot limit. In addition, the proposed TEB devices are expected to operate over a wider temperature range

  15. Electromobility - challenges for structural durability

    Energy Technology Data Exchange (ETDEWEB)

    Hiebl, A.; Krueger, L. [BMW Group, Muenchen (Germany); Martin, D.

    2011-10-15

    In this lecture the challenges of testing the structural durability of electric vehicles are highlighted. The requirements and in particular differences in those for electric vehicles and cars with internal-combustion engines are compared and illustrated. Current experiences with the MINI E and actual BMW hybrid cars are shown. Furthermore, testing concepts for specific electromobility components and their structural integration into the vehicle are explained. Finally an insight into possible future hybrid cars is presented. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Durability Improvements Through Degradation Mechanism Studies

    Energy Technology Data Exchange (ETDEWEB)

    Borup, Rodney L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mukundan, Rangachary [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Spernjak, Dusan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Baker, Andrew M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lujan, Roger W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Langlois, David Alan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ahluwalia, Rajesh [Argonne National Lab. (ANL), Argonne, IL (United States); Papadia, D. D. [Argonne National Lab. (ANL), Argonne, IL (United States); Weber, Adam Z. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kusoglu, Ahmet [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Shi, Shouwnen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); More, K. L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Grot, Steve [Ion Power, New Castle, DE (United States)

    2015-08-03

    The durability of polymer electrolyte membrane (PEM) fuel cells is a major barrier to the commercialization of these systems for stationary and transportation power applications. By investigating cell component degradation modes and defining the fundamental degradation mechanisms of components and component interactions, new materials can be designed to improve durability. To achieve a deeper understanding of PEM fuel cell durability and component degradation mechanisms, we utilize a multi-institutional and multi-disciplinary team with significant experience investigating these phenomena.

  17. Hygrothermal Behavior, Building Pathology and Durability

    CERN Document Server

    Delgado, JMPQ

    2013-01-01

    The main purpose of this book, Hygrothermal, Building Pathology and Durability, is to provide a collection of recent research works to contribute to the systematization and dissemination of knowledge related to construction pathology, hygrothermal behaviour of buildings, durability and diagnostic techniques and, simultaneously, to show the most recent advances in this domain. It includes a set of new developments in the field of building physics and hygrothermal behaviour, durability approach for historical and old buildings and building pathology vs. durability. The book is divided in several chapters that are a resume of the current state of knowledge for benefit of professional colleagues, scientists, students, practitioners, lecturers and other interested parties to network.

  18. Water inflow into boreholes during the Stripa heater experiments

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, P.H.; Rachiele, R.; Remer, J.S.; Carlsson, H.

    1981-04-01

    During the operation of three in-situ heater experiments at Stripa, Sweden, groundwater flowed into many of the instrumentation and heater boreholes. These flows were recovered and measured routinely. The records of water inflow indicate two origins: inflow attributed to local hydrological pressure gradients, and water migration from cracks closing under the rapidly increasing, thermal-induced stress changes. The latter component appeared as a main pulse that occurred when the heaters were turned on, and lasted about 30 to 40 days, steadily declining over the next several months, and decreasing sharply when heater power was decreased or stopped. The magnitude of the total inflow per hole ranged over more than five decades, from 0.1 to over 10,000 liters over the 500 to 600 day time periods. When plotted against the logarithm of total volume, the frequency distribution displays a normal curve dependence with a mean of approximately 10 liters. Of this amount, 1 to 2 liters of flow into 38-mm-diam boreholes accompanied an increase in applied heat load. These amounts are compatible with rock porosities of a fraction of one percent. Inflow into the 3.6 and 5.0 kW heater holes peaked within 3 to 6 days after heater turn on, then declined to zero inflow, with no further inflow measured for the remainder of the experiments. In the heater holes of the time-scaled experiment, which operated at 1.125 kW or less, the initial pulse of inflow took much longer to decay, and 7 of 8 heater holes continued to flow throughout the experiment. The packing off and isolation of a borehole some 40 m distant in the ventilation drift dramatically increased the inflow into the heater holes in one of the three heater experiments. This demonstrated the existence of permeable flow paths among a number of boreholes. The records of water inflow demonstrate the need for a thorough understanding of the nature of fluid flow and storage in fractured crystalline rock.

  19. Combustion-Driven Oscillation in Process Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Seebold, J.G. [Chevron Corporation (Retired), 198 James Avenue, Atherton, CA 94027 (United States)

    2005-10-15

    At this moment in thousands of process heaters all over the world there are, to borrow a phrase from the late Carl Sagan, 'billions and billions' of Btu/hr beneficially being released entirely free of pulsation. On those few occasions, perhaps a dozen and a half in my career, when I would get the inevitable 'Why me?' call, I have generally responsed with something like, 'Consider yourself lucky, you have a rare scientific curiosity on your hands'. Reflecting on the solutions ultimately found, I'm reminded that many years ago my friend Abbott Putnam shared with me an early AGA (American Gas Association) field-service bulletin that included a prescription for eliminating combustion-driven oscillations in home heating units; viz., 'Drill a hole; if that doesn't work, drill another hole' or words to that effect. Many times have I wished that I still had a copy of that bulletin and in this paper we will have occasion, once again, to reflect upon the value of that advice. In this paper we will discuss an instance that arose in a pioneering installation of a breakthrough development of 'extremely', to distinguish it from 'ultra', low-NOx lean premix burner technology. We will illustrate how, when and under what circumstances combustion-driven oscillation can arise; we will touch on the many alternatives for its elimination that were considered and investigated; and we will discuss three practical alternatives for eliminating combustion-driven oscillations.

  20. Multifamily Heat Pump Water Heater Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, M. [Davis Energy Group, Davis, CA (United States). Alliance for Residential Building Innovation; Weitzel, E. [Davis Energy Group, Davis, CA (United States). Alliance for Residential Building Innovation

    2017-03-03

    Although heat pump water heaters (HPWHs) have gained significant attention in recent years as a high efficiency electric water heating solution for single family homes, central HPWHs for commercial or multi-family applications are not as well documented in terms of measured performance and cost effectiveness. To evaluate this technology, the Alliance for Residential Building Innovation team monitored the performance of a 10.5 ton central HPWH installed on a student apartment building at the West Village Zero Net Energy Community in Davis, California. Monitoring data collected over a 16 month period were then used to validate a TRNSYS simulation model. The TRNSYS model was then used to project performance in different climates using local electric rates. Results of the study indicate that after some initial commissioning issues, the HPWH operated reliably with an annual average efficiency of 2.12 (Coefficient of Performance). The observed efficiency was lower than the unit's rated efficiency, primarily due to the fact that the system rarely operated under steady-state conditions. Changes in the system configuration, storage tank sizing, and control settings would likely improve the observed field efficiency. Modeling results suggest significant energy savings relative to electric storage water heating systems (typical annual efficiencies around 0.90) providing for typical simple paybacks of six to ten years without any incentives. The economics versus gas water heating are currently much more challenging given the current low natural gas prices in much of the country. Increased market size for this technology would benefit cost effectiveness and spur greater technology innovation.

  1. Multifamily Heat Pump Water Heater Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, M. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Weitzel, E. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2013-11-22

    Although heat pump water heaters (HPWHs) have gained significant attention in recent years as a high efficiency electric water heating solution for single family homes, central HPWHs for commercial or multi-family applications are not as well documented in terms of measured performance and cost effectiveness. To evaluate this technology, the Alliance for Residential Building Innovation team monitored the performance of a 10.5 ton central HPWH installed on a student apartment building at the West Village Zero Net Energy Community in Davis, California. Monitoring data collected over a 16 month period were then used to validate a TRNSYS simulation model. The TRNSYS model was then used to project performance in different climates using local electric rates. Results of the study indicate that after some initial commissioning issues, the HPWH operated reliably with an annual average efficiency of 2.12 (Coefficient of Performance). The observed efficiency was lower than the unit's rated efficiency, primarily due to the fact that the system rarely operated under steady-state conditions. Changes in the system configuration, storage tank sizing, and control settings would likely improve the observed field efficiency. Modeling results suggest significant energy savings relative to electric storage water heating systems (typical annual efficiencies around 0.90) providing for typical simple paybacks of six to ten years without any incentives. The economics versus gas water heating are currently much more challenging given the current low natural gas prices in much of the country. Increased market size for this technology would benefit cost effectiveness and spur greater technology innovation.

  2. Multifamily Heat Pump Water Heater Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, M. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Weitzel, E. [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2017-03-01

    Although heat pump water heaters (HPWHs) have gained significant attention in recent years as a high efficiency electric water heating solution for single family homes, central HPWHs for commercial or multi-family applications are not as well documented in terms of measured performance and cost effectiveness. To evaluate this technology, the Alliance for Residential Building Innovation team monitored the performance of a 10.5 ton central HPWH installed on a student apartment building at the West Village Zero Net Energy Community in Davis, California. Monitoring data collected over a 16 month period were then used to validate a TRNSYS simulation model. The TRNSYS model was then used to project performance in different climates using local electric rates. Results of the study indicate that after some initial commissioning issues, the HPWH operated reliably with an annual average efficiency of 2.12 (Coefficient of Performance). The observed efficiency was lower than the unit's rated efficiency, primarily due to the fact that the system rarely operated under steady-state conditions. Changes in the system configuration, storage tank sizing, and control settings would likely improve the observed field efficiency. Modeling results suggest significant energy savings relative to electric storage water heating systems (typical annual efficiencies around 0.90) providing for typical simple paybacks of six to ten years without any incentives. The economics versus gas water heating are currently much more challenging given the current low natural gas prices in much of the country. Increased market size for this technology would benefit cost effectiveness and spur greater technology innovation.

  3. Comparative Study and Design of Solar Water Heater

    Directory of Open Access Journals (Sweden)

    K.Sainath,Y.krishna, Mohd Salahuddin, Mohammed Siddique Ahmed, Md Ismail, Syed Rahman,Mohammed Noman, Mohd Khaleel Ullah, Faraz Ur Rehman Azhar, Mohd Moizuddin,Mohd Riyaz Uddin.

    2014-10-01

    Full Text Available A solar water heater design is made from the plastic bottles of thumps up & plastic pipe(p.v.c run up by the centre of each solar heater in a row of bottles, these bottles act as glazing & hold reflectors made from the black paint. Solar water heaters are made of two basic parts: a solar collector that gathers radiant energy and a storage tank for the hot water inside. These systems are used to heat water for swimming pools, as well as for domestic cooking and cleaning needs. A system in which the sun’s heat is gathered by a solar collector and used to increase the temperature of a heat-transfer fluid , which flows through the pipes in the collector; the heat contained in this fluid then is conveyed and transferred to the water to be heated. Solar water heaters use the solar energy from the sun to generate heat (not electricity which can then be used to heat water for showering, space heating, industrial processes or even solar cooling. However, the research shows that the electric water spends about the 25% of its home energy costs on heating water. If we make a water heater without the collector then we can save a lot of money solar water heater do not polluted if one investing on SWH avoids carbon dioxide nitrogen oxide and sulphur dioxide and the other air pollution wastes and the utility generates power on your bum fuel to heat your household water when SWH replaces the an electric water heater. This electric displaced over 20 years replaced more than 50 tones avoided c02 emissions alone co2 traps heat in the upper most atmosphere thus, contributing to the ‘Green House Effect

  4. Engineering solutions for polymer composites solar water heaters production

    Science.gov (United States)

    Frid, S. E.; Arsatov, A. V.; Oshchepkov, M. Yu.

    2016-06-01

    Analysis of engineering solutions aimed at a considerable decrease of solar water heaters cost via the use of polymer composites in heaters construction and solar collector and heat storage integration into a single device representing an integrated unit results are considered. Possibilities of creating solar water heaters of only three components and changing welding, soldering, mechanical treatment, and assembly of a complicate construction for large components molding of polymer composites and their gluing are demonstrated. Materials of unit components and engineering solutions for their manufacturing are analyzed with consideration for construction requirements of solar water heaters. Optimal materials are fiber glass and carbon-filled plastics based on hot-cure thermosets, and an optimal molding technology is hot molding. It is necessary to manufacture the absorbing panel as corrugated and to use a special paint as its selective coating. Parameters of the unit have been optimized by calculation. Developed two-dimensional numerical model of the unit demonstrates good agreement with the experiment. Optimal ratio of daily load to receiving surface area of a solar water heater operating on a clear summer day in the midland of Russia is 130‒150 L/m2. Storage tank volume and load schedule have a slight effect on solar water heater output. A thermal insulation layer of 35‒40 mm is sufficient to provide an efficient thermal insulation of the back and side walls. An experimental model layout representing a solar water heater prototype of a prime cost of 70‒90/(m2 receiving surface) has been developed for a manufacturing volume of no less than 5000 pieces per year.

  5. DURABILITY OF HARDENED FLY ASH PASTE

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The mechanical properties and durability ( mainly frost-resistance and carbonation resistance ) of fly ash-CaO-CaSO4 .2H2O hardened paste are studied. The relationship among durability of harden ed fly ash paste, the quantity and distribution of hydrates and the initial p aste texture of hardened fly ash paste is presented.

  6. Hygrothermal behavior, building pathology and durability

    Energy Technology Data Exchange (ETDEWEB)

    Peixoto de Freitas V.; Delgado, J.M.P.Q. (eds.) [Porto Univ. (Portugal). Building Physics Lab.

    2013-03-01

    Includes a set of new developments in the field of building physics and hygrothermal behavior. Presents a new durability approach for historical and old buildings. Reviews the current state of knowledge. The main purpose of this book, Hygrothermal, Building Pathology and Durability, is to provide a collection of recent research works to contribute to the systematization and dissemination of knowledge related to construction pathology, hygrothermal behaviour of buildings, durability and diagnostic techniques and, simultaneously, to show the most recent advances in this domain. It includes a set of new developments in the field of building physics and hygrothermal behaviour, durability approach for historical and old buildings and building pathology vs. durability. The book is divided in several chapters that are a resume of the current state of knowledge for benefit of professional colleagues, scientists, students, practitioners, lecturers and other interested parties to network.

  7. Durability of radon remedial actions

    Energy Technology Data Exchange (ETDEWEB)

    Naismith, S. [National Radiological Protection Board, Chilton (United Kingdom)

    1997-07-01

    It is estimated that at least 3600 householders in the UK have taken remedial action to reduce radon concentrations found to be above the government Action Level. A study has been carried out on the durability of these remedial actions. It involved annual reassessment of the radon levels in a number of homes. The results for 26 of these homes where data over five years are available show that in general the remedial actions remained effective. The remedy with the largest variation in efficacy was natural ventilation of the underfloor void. The failure rate was found to be 4.0% per annum for all measures, but in the majority of cases the failure was discovered by the householder and rectified. The rate of failures not noticed by the householders was 0.4% per annum. (UK).

  8. Rubberized Concrete Durability Against Abrasion

    Directory of Open Access Journals (Sweden)

    Md Noor Nurazuwa

    2016-01-01

    Full Text Available Durability performance of rubberized concrete against abrasion is presented in this paper. Surface depth loss was measured when abrasion load was constantly applied on concrete surface at each 500 interval rotation. Specimen with water-to cement ratio of 0.50 and 0.35 was prepared and tested at 28 days of curing age. In addition, 10% silica fume, SF was added to provide denser concrete and to understand its effectiveness against wear when added with crumb rubber. Results showed that crumb rubber shows good potential in providing abrasion resistance to concrete mix. However, in the case of rubberized concrete with silica fume, abrasion resistance was found to be slightly decreased with compressive strength more than 50N/mm2 due to the lack of low elastic modulus of CR particles to accommodate with denser cement matrix.

  9. Ceramics: Durability and radiation effects

    Energy Technology Data Exchange (ETDEWEB)

    Ewing, R.C.; Lutze, W. [Univ. of New Mexico, Albuquerque, NM (United States); Weber, W.J. [Pacific Northwest National Lab., Richland, WA (United States)

    1996-05-01

    At present, there are three seriously considered options for the disposition of excess weapons plutonium: (1) incorporation, partial burn-up and direct disposal of MOX-fuel; (2) vitrification with defense waste and disposal as glass {open_quotes}logs{close_quotes}; (3) deep borehole disposal. The first two options provide a safeguard due to the high activity of fission products in the irradiated fuel and the defense waste. The latter option has only been examined in a preliminary manner, and the exact form of the plutonium has not been identified. In this paper, we review the potential for the immobilization of plutonium in highly durable crystalline ceramics apatite, pyrochlore, zirconolite, monazite and zircon. Based on available data, we propose zircon as the preferred crystalline ceramic for the permanent disposition of excess weapons plutonium.

  10. Heat Pump Water Heaters and American Homes: A Good Fit?

    Energy Technology Data Exchange (ETDEWEB)

    Franco, Victor; Lekov, Alex; Meyers, Steve; Letschert, Virginie

    2010-05-14

    Heat pump water heaters (HPWHs) are over twice as energy-efficient as conventional electric resistance water heaters, with the potential to save substantial amounts of electricity. Drawing on analysis conducted for the U.S. Department of Energy's recently-concluded rulemaking on amended standards for water heaters, this paper evaluates key issues that will determine how well, and to what extent, this technology will fit in American homes. The key issues include: 1) equipment cost of HPWHs; 2) cooling of the indoor environment by HPWHs; 3) size and air flow requirements of HPWHs; 4) performance of HPWH under different climate conditions and varying hot water use patterns; and 5) operating cost savings under different electricity prices and hot water use. The paper presents the results of a life-cycle cost analysis of the adoption of HPWHs in a representative sample of American homes, as well as national impact analysis for different market share scenarios. Assuming equipment costs that would result from high production volume, the results show that HPWHs can be cost effective in all regions for most single family homes, especially when the water heater is not installed in a conditioned space. HPWHs are not cost effective for most manufactured home and multi-family installations, due to lower average hot water use and the water heater in the majority of cases being installed in conditioned space, where cooling of the indoor environment and size and air flow requirements of HPWHs increase installation costs.

  11. Optimal Heater Control with Technology of Fault Tolerance for Compensating Thermoforming Preheating System

    Directory of Open Access Journals (Sweden)

    Zhen-Zhe Li

    2015-01-01

    Full Text Available The adjustment of heater power is very important because the distribution of thickness strongly depends on the distribution of sheet temperature. In this paper, the steady state optimum distribution of heater power is searched by numerical optimization in order to get uniform sheet temperature. In the following step, optimal heater power distribution with a damaged heater was found out using the technology of fault tolerance, which will be used to reduce the repairing time when some heaters are damaged. The merit of this work is that the design variable was the power of each heater which can be directly used in the preheating process of thermoforming.

  12. Generation of ionospheric ducts by the HAARP HF heater

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, J A; Pradipta, R; Burton, L M; Labno, A; Lee, M C [Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Watkins, B J; Fallen, C [University of Alaska Fairbanks, Fairbanks, AK 99775 (United States); Kuo, S P [New York University, Brooklyn, NY 11201 (United States); Burke, W J [Air Force Research Laboratory, Hanscom AFB, MA 01731 (United States); Mabius, D; See, B Z, E-mail: mclee@mit.edu [Boston University, Boston, MA 02215 (United States)

    2010-12-15

    We report an investigation of ionospheric ducts having the shape of large plasma sheets, generated by vertically transmitted HAARP HF heater waves in several experiments conducted in Gakona, Alaska. Theory predicts that O-mode heater wave-created ionospheric ducts form parallel-plate waveguides within the meridional plane, and those generated by the X-mode heater waves are orthogonal to the meridional plane. Our theoretical prediction is supported by measurements of ionosonde data (namely ionograms), range-time-intensity (RTI) plots of UHF and HF backscatter radars, as well as magnetometer data analyses. When these plasma sheets experienced ExB drifts, they were intercepted by the HAARP UHF radar and seen as slanted stripes in the RTI plots. This striking feature was also observed in our earlier experiments using the Arecibo UHF radar.

  13. Development of a cost effective microscope heater stage

    Science.gov (United States)

    Dugre, Joshua; Prayaga, Chandra; Wade, Aaron

    Utilizing 3D printing technology, a heater stage has been developed and implemented for microscopic systems. Due to the flexibility of 3D printing,the heater stage can be easily modified to fit any sample size with only slight modifications to the heating element being required. The sample in contact with the heating element can also easily be secured in a thermal insulator, such as aluminum foil. The thermal gradient of the heater stage has been recorded to be less than 1°C and has been compared to more expensive designs, and the cost effectiveness of the system has been determined. The system has been tested with a sample of the liquid crystal 8CB in order to determine the exact temperatures of the phase transitions of the crystal to verify that the system is applicable to a wide range of experimental physics. UWF Quality Enhancement Plan Award.

  14. Our Environment in Hot Water: Comparing Water Heaters, A Life Cycle Approach Comparing Tank and Tankless Water Heaters in California

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Alison; McMahon, James; Masanet, Eric; Lutz, Jim

    2008-08-13

    Residential water heating is a large source of energy use in California homes. This project took a life cycle approach to comparing tank and tankless water heaters in Northern and Southern California. Information about the life cycle phases was calculated using the European Union's Methodology study for EcoDesign of Energy-using Products (MEEUP) and the National Renewable Energy Laboratory's Life Cycle Inventory (NREL LCI) database. In a unit-to-unit comparison, it was found that tankless water heaters would lessen impacts of water heating by reducing annual energy use by 2800 MJ/year (16% compared to tank), and reducing global warming emissions by 175 kg CO2 eqv./year (18% reduction). Overall, the production and combustion of natural gas in the use phase had the largest impact. Total waste, VOCs, PAHs, particulate matter, and heavy-metals-to-air categories were also affected relatively strongly by manufacturing processes. It was estimated that tankless water heater users would have to use 10 more gallons of hot water a day (an increased usage of approximately 20%) to have the same impact as tank water heaters. The project results suggest that if a higher percentage of Californians used tankless water heaters, environmental impacts caused by water heating would be smaller.

  15. Flat plate solar air heater with latent heat storage

    Science.gov (United States)

    Touati, B.; Kerroumi, N.; Virgone, J.

    2017-02-01

    Our work contains two parts, first is an experimental study of the solar air heater with a simple flow and forced convection, we can use thatlaste oneit in many engineering's sectors as solardrying, space heating in particular. The second part is a numerical study with ansys fluent 15 of the storage of part of this solar thermal energy produced,using latent heat by using phase change materials (PCM). In the experimental parts, we realize and tested our solar air heater in URER.MS ADRAR, locate in southwest Algeria. Where we measured the solarradiation, ambient temperature, air flow, thetemperature of the absorber, glasses and the outlet temperature of the solar air heater from the Sunrise to the sunset. In the second part, we added a PCM at outlet part of the solar air heater. This PCM store a part of the energy produced in the day to be used in peak period at evening by using the latent heat where the PCMs present a grateful storagesystem.A numerical study of the fusion or also named the charging of the PCM using ANSYS Fluent 15, this code use the method of enthalpies to solve the fusion and solidification formulations. Furthermore, to improve the conjugate heat transfer between the heat transfer fluid (Air heated in solar plate air heater) and the PCM, we simulate the effect of adding fins to our geometry. Also, four user define are write in C code to describe the thermophysicalpropriety of the PCM, and the inlet temperature of our geometry which is the temperature at the outflow of the solar heater.

  16. Process for thermal imaging scanning of a swaged heater for an anode subassembly of a hollow cathode assembly

    Science.gov (United States)

    Patterson, Michael J. (Inventor); Verhey, Timothy R. R. (Inventor); Soulas, George C. (Inventor)

    2004-01-01

    A process for thermal imaging scanning of a swaged heater of an anode subassembly of a hollow cathode assembly, comprising scanning a swaged heater with a thermal imaging radiometer to measure a temperature distribution of the heater; raising the current in a power supply to increase the temperature of the swaged heater; and measuring the swaged heater temperature using the radiometer, whereupon the temperature distribution along the length of the heater shall be less than plus or minus 5 degrees C.

  17. Durability Environmental Regionalization for Concrete Structures

    Directory of Open Access Journals (Sweden)

    Daming Luo

    2013-01-01

    Full Text Available Environment is the external factor that affects the durability of concrete structures. Buildings in different regions with different climates will respond to durability deterioration in different ways. For macroenvironmental regionalization, the dominant factor analysis method of the climatic zonation was applied into the environmental regionalization in this paper. Based on the environmental characteristics in China and the effect of environmental factor on the durability of concrete structure, the proper regionalization indexes are chosen, and the environmental regionalization is made. For microenvironmental regionalization, fuzzy set and rough set theories were used in date mining on discrete measured data, and the weight determination of various factors affecting durability was transformed into evaluation of the significance of attributes among rough sets. The method of durability environmental regionalization is established by analyzing the degree of influence that various factors have on the durability of concrete structures. The result of durability environmental regionalization for concrete structures in Shenzhen city shows that the proposed approach is reasonable.

  18. Highly Dispersed Alloy Catalyst for Durability

    Energy Technology Data Exchange (ETDEWEB)

    Murthi, Vivek S.; Izzo, Elise; Bi, Wu; Guerrero, Sandra; Protsailo, Lesia

    2013-01-08

    Achieving DOE's stated 5000-hr durability goal for light-duty vehicles by 2015 will require MEAs with characteristics that are beyond the current state of the art. Significant effort was placed on developing advanced durable cathode catalysts to arrive at the best possible electrode for high performance and durability, as well as developing manufacturing processes that yield significant cost benefit. Accordingly, the overall goal of this project was to develop and construct advanced MEAs that will improve performance and durability while reducing the cost of PEMFC stacks. The project, led by UTC Power, focused on developing new catalysts/supports and integrating them with existing materials (membranes and gas diffusion layers (GDLs)) using state-of-the-art fabrication methods capable of meeting the durability requirements essential for automotive applications. Specifically, the project work aimed to lower platinum group metals (PGM) loading while increasing performance and durability. Appropriate catalysts and MEA configuration were down-selected that protects the membrane, and the layers were tailored to optimize the movements of reactants and product water through the cell to maximize performance while maintaining durability.

  19. Performance of Thermosyphon Solar Water Heaters in Series

    Directory of Open Access Journals (Sweden)

    Tsong-Sheng Lee

    2012-08-01

    Full Text Available More than a single thermosyphon solar water heater may be employed in applications when considerable hot water consumption is required. In this experimental investigation, eight typical Taiwanese solar water heaters were connected in series. Degree of temperature stratification and thermosyphon flow rate in a horizontal tank were evaluated. The system was tested under no-load, intermittent and continuous load conditions. Results showed that there was stratification in tanks under the no-load condition. Temperature stratification also redeveloped after the draw-off. Analysis of thermal performance of the system was conducted for each condition.

  20. Lightweight Radioisotope Heater Unit (LWRHU) production for the Cassini mission

    Energy Technology Data Exchange (ETDEWEB)

    Rinehart, G.H.

    1996-06-01

    The Lightweight Radioisotope Heater Unit (LWRHU) is a {sup 238}PuO{sub 2} fueled heat source designed to provide a thermal watt of power for space missions. The LWRHU will be used to maintain the temperature of various components on the spacecraft at the required level. The heat source consists of a {sup 238}PuO{sub 2} fuel pellet, a Pt-30Rh capsule, a pyrolytic graphite insulator, and a woven graphite aeroshell assembly. Los Alamos has fabricated 180 heater units, which will be used on the Cassini mission. This report summarizes the specifications, fabrication processes, and production data for the heat sources fabricated at Los Alamos.

  1. Development of heat pipes for solar water heaters

    Energy Technology Data Exchange (ETDEWEB)

    Akyurt, M.

    1984-01-01

    Numerous heat pipes were designed, manufactured, and filled on a specially developed filling rig. Each heat pipe was incorporated into a prototype solar water heater developed for this purpose, and was tested under actual insolation conditions. An extensive testing program lasting for more than a year revealed that the heat pipes perform satisfactorily as heat transfer elements in solar water heaters. A special heat pipe featuring a compact and effective condenser configuration was also tested. It was observed to likewise exhibit isothermal behavior and hence promised potential for large scale solar applications.

  2. Heater-Integrated Cantilevers for Nano-Samples Thermogravimetric Analysis

    Directory of Open Access Journals (Sweden)

    Valeria Toffoli

    2013-12-01

    Full Text Available The design and characteristics of a micro-system for thermogravimetric analysis (TGA in which heater, temperature sensor and mass sensor are integrated into a single device are presented. The system consists of a suspended cantilever that incorporates a microfabricated resistor, used as both heater and thermometer. A three-dimensional finite element analysis was used to define the structure parameters. TGA sensors were fabricated by standard microlithographic techniques and tested using milli-Q water and polyurethane microcapsule. The results demonstrated that our approach provides a faster and more sensitive TGA with respect to commercial systems.

  3. Compositional threshold for nuclear waste glass durability

    Energy Technology Data Exchange (ETDEWEB)

    Farooqi, Rahmatullah; Hrma, Pavel [Pohang Univ. of Science and Technology, Pohang (Korea, Republic of)

    2013-07-01

    The issue of major concern with the waste form, such as glass, is its chemical durability, I. e., the resistance to corrosion by aqueous media. A number of standard durability tests have been established for waste glasses, among which the product consistency test was selected as a criterion of HLW glass acceptability for the repository subsequently, a large PCT database has been collected containing over 1000 glasses. Such a database allows the development of models that relate PCT releases to glass is a strong function of composition, these models are used to formulate acceptable glasses in which the waste loading is maximized. Within the composition space of glasses, a distinct threshold appears to exist that separates 'good' glasses, I. e. these which are sufficiently durable, from 'bad' glasses of a low durability. According to Populate al., transition region between durable and less durable glasses lies around 2a m{sup -2} as determined by the 7-day PCT normalized B release. The objective of our research is to clarify the origin of this threshold by exploring the relationship between glass composition, glass structure and chemical durability around the threshold region. Our study is focused on the corrosion behavior of SiO{sub 2} - B{sub 2}O{sub 3} - Na{sub 2}O - Al{sub 2}O{sub 3} - Colleagues composition region. In particular, we try to identify the durability threshold separating durable from nondurable glasses in the composition space. So far we have explored the elemental releases of Na and B measured with the 7-day PCT.

  4. Thermal injuries caused by ignition of volatile substances by gas water heaters.

    Science.gov (United States)

    Rutan, R L; Desai, M H; Herndon, D N

    1993-01-01

    Based on the cumulative data of this tertiary care facility over the past 25 years, one out of every 70 pediatric patients admitted to our institution sustained their injuries during an explosive event instigated by the ignition of volatile substances from gas water heaters. The majority of injuries related to gas water heaters can be prevented by decreasing the temperature setpoint of the heater, by protecting the heater element itself, and by elevating the water heater to 18 inches above the floor. The first two issues have been adequately addressed; however, gas-fueled water heaters continue to be installed at floor level. Current national guidelines are too rigid and do not adequately address water-heater installation in private residences. Although general prevention campaigns target appropriate storage of volatile substances, they rarely address the explosive potential of gas water heaters in combination with combustible fumes.

  5. High-Temperature Compatible Nickel Silicide Thermometer And Heater For Catalytic Chemical Microreactors

    DEFF Research Database (Denmark)

    Jensen, Søren; Quaade, U.J.; Hansen, Ole

    2005-01-01

    Integration of heaters and thermometers is important for agile and accurate control and measurement of the thermal reaction conditions in microfabricated chemical reactors (microreactors). This paper describes development and operation of nickel silicide heaters and temperature sensors...... for temperatures exceeding 700 °C. The heaters and thermometers are integrated with chemical microreactors for heterogeneous catalytic conversion of gasses, and thermally activated catalytic conversion of CO to CO2 in the reactors is demonstrated. The heaters and thermometers are shown to be compatible...

  6. Comparative performance of coriander dryer coupled to solar air heater and solar air-heater-cum-rockbed storage

    Energy Technology Data Exchange (ETDEWEB)

    Chauhan, P.M.; Choudhury, C.; Garg, H.P. [Indian Inst. of Technology, Centre for Energy Studies, New Delhi (India)

    1996-03-01

    In the present communication, efforts have been made to study the drying characteristics of coriander in a stationary 0.5 tonne/batch capacity deep-bed dryer coupled to a solar air heater and a rockbed storage unit to receive hot air during sunshine and off-sunshine hours, respectively. The drying bed was assumed to consist of a number of thin layers of grains stacked upon each other. The theoretical investigation was made by writing the energy and mass balance equations for different components of the dryer-cum-air-heater-cum-storage and by adopting a finite difference approach for simulation. (author)

  7. 77 FR 74559 - Energy Conservation Program for Consumer Products: Test Procedures for Residential Water Heaters...

    Science.gov (United States)

    2012-12-17

    ... descriptors (i.e., thermal efficiency and pool heater heating seasonal efficiency), as well as seasonal energy... thermal efficiency metric for pool heaters, but did not propose an integrated annual fuel utilization... states that for pool heaters, the descriptor shall be thermal efficiency. (42 U.S.C....

  8. 30 CFR 75.341 - Direct-fired intake air heaters.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Direct-fired intake air heaters. 75.341 Section... air heaters. (a) If any system used to heat intake air malfunctions, the heaters affected shall switch off automatically. (b) Thermal overload devices shall protect the blower motor from overheating....

  9. 46 CFR 61.30-5 - Preparation of thermal fluid heater for inspection and test.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Preparation of thermal fluid heater for inspection and... ENGINEERING PERIODIC TESTS AND INSPECTIONS Tests and Inspections of Fired Thermal Fluid Heaters § 61.30-5 Preparation of thermal fluid heater for inspection and test. For visual inspection, access plates and...

  10. 76 FR 63211 - Energy Efficiency Program: Test Procedures for Residential Water Heaters, Direct Heating...

    Science.gov (United States)

    2011-10-12

    ... descriptors (i.e., thermal efficiency and pool heater heating seasonal efficiency), as well as seasonal energy... ``efficiency descriptor,'' EPCA specifies that for pool heaters, the efficiency descriptor shall be ``thermal efficiency.'' (42 U.S.C. 6291(22)(E)) Further, EPCA defines the ``thermal efficiency of pool heaters'' as...

  11. Recovery Act: Water Heater ZigBee Open Standard Wireless Controller

    Energy Technology Data Exchange (ETDEWEB)

    Butler, William P. [Emerson Electric Co., St. Louis, MO (United States); Buescher, Tom [Emerson Electric Co., St. Louis, MO (United States)

    2014-04-30

    The objective of Emerson's Water Heater ZigBee Open Standard Wireless Controller is to support the DOE's AARA priority for Clean, Secure Energy by designing a water heater control that levels out residential and small business peak electricity demand through thermal energy storage in the water heater tank.

  12. TOTAL PARTICLE, SULFATE, AND ACIDIC AEROSOL EMISSIONS FROM KEROSENE SPACE HEATERS

    Science.gov (United States)

    Chamber studies were conducted on four unvented kerosene space heaters to assess emissions of total particle, sulfate, and acidic aerosol. The heaters tested represented four burner designs currently in use by the public. Kerosene space heaters are a potential source of fine part...

  13. Mountain Plains Learning Experience Guide: Appliance Repair. Course: Heater-Type Appliances.

    Science.gov (United States)

    Ziller, T.

    One of two individualized courses included in an appliance repair curriculum (see CE 027 767), this course covers minor and major heater-type appliances. The course is comprised of six units: (1) Irons, (2) Roasters, (3) Space Heaters, (4) Water Heaters, (5) Electric Ranges, and (6) Gas Ranges. Each unit begins with a Unit Learning Experience…

  14. 40 CFR 63.7506 - Do any boilers or process heaters have limited requirements?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 13 2010-07-01 2010-07-01 false Do any boilers or process heaters have limited requirements? 63.7506 Section 63.7506 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... or process heaters have limited requirements? (a) New or reconstructed boilers and process heaters...

  15. Durable Dust Repellent Coating for Metals Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Durable Dust Repellent Coating (DDRC) consists of nano-phase silica, titania, or other oxide coatings to repel dust in a vacuum environment over a wide range of...

  16. Laboratory Performance Evaluation of Residential Integrated Heat Pump Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Sparn, B.; Hudon, K.; Christensen, D.

    2014-06-01

    This paper explores the laboratory performance of five integrated Heat Pump Water Heaters (HPWHs) across a wide range of operating conditions representative of US climate regions. HPWHs are expected to provide significant energy savings in certain climate zones when compared to typical electric resistance water heaters. Results show that this technology is a viable option in most climates, but differences in control schemes and design features impact the performance of the units tested. Tests were conducted to map heat pump performance across the operating range and to determine the logic used to control the heat pump and the backup electric heaters. Other tests performed include two unique draw profile tests, reduced air flow performance tests and the standard DOE rating tests. The results from all these tests are presented here for all five units tested. The results of these tests will be used to improve the EnergyPlus heat pump water heater for use in BEopt(tm) whole-house building simulations.

  17. Laboratory Performance Evaluation of Residential Integrated Heat Pump Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Sparn, B.; Hudon, K.; Christensen, D.

    2014-06-01

    This paper explores the laboratory performance of five integrated Heat Pump Water Heaters (HPWHs) across a wide range of operating conditions representative of U.S. climate regions. HPWHs are expected to provide significant energy savings in certain climate zones when compared to typical electric resistance water heaters. Results show that this technology is a viable option in most climates, but differences in control schemes and design features impact the performance of the units tested. Tests were conducted to map heat pump performance across the operating range and to determine the logic used to control the heat pump and the backup electric heaters. Other tests performed include two unique draw profile tests, reduced air flow performance tests and the standard DOE rating tests. The results from all these tests are presented here for all five units tested. The results of these tests will be used to improve the EnergyPlus heat pump water heater for use in BEopt™ whole-house building simulations.

  18. Solar water heaters in China: A new day dawning

    NARCIS (Netherlands)

    Han, Jingyi; Mol, A.P.J.; Lu, Y.

    2010-01-01

    Solar thermal utilization, especially the application of solar water heater technology, has developed rapidly in China in recent decades. Manufacturing and marketing developments have been especially strong in provinces such as Zhejiang, Shandong and Jiangsu. This paper takes Zhejiang, a relatively

  19. Fast thermal nanoimprint lithography by a stamp with integrated heater

    DEFF Research Database (Denmark)

    Tormen, Massimo; Malureanu, Radu; Pedersen, Rasmus Haugstrup

    2008-01-01

    We propose fast nanoimprinting lithography (NIL) process based on the use of stamps with integrated heater. The latter consists of heavily ion implantation n-type doped silicon layer buried below the microstructured surface of the stamp. The stamp is heated by Joule effect, by 50 μs 25 Hz...

  20. Demand Response Performance of GE Hybrid Heat Pump Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    Widder, Sarah H.; Parker, Graham B.; Petersen, Joseph M.; Baechler, Michael C.

    2013-07-01

    This report describes a project to evaluate and document the DR performance of HPWH as compared to ERWH for two primary types of DR events: peak curtailments and balancing reserves. The experiments were conducted with GE second-generation “Brillion”-enabled GeoSpring hybrid water heaters in the PNNL Lab Homes, with one GE GeoSpring water heater operating in “Standard” electric resistance mode to represent the baseline and one GE GeoSpring water heater operating in “Heat Pump” mode to provide the comparison to heat pump-only demand response. It is expected that “Hybrid” DR performance, which would engage both the heat pump and electric elements, could be interpolated from these two experimental extremes. Signals were sent simultaneously to the two water heaters in the side-by-side PNNL Lab Homes under highly controlled, simulated occupancy conditions. This report presents the results of the evaluation, which documents the demand-response capability of the GE GeoSpring HPWH for peak load reduction and regulation services. The sections describe the experimental protocol and test apparatus used to collect data, present the baselining procedure, discuss the results of the simulated DR events for the HPWH and ERWH, and synthesize key conclusions based on the collected data.

  1. Assessment of a Hybrid Retrofit Gas Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, Marc [Davis Energy Group, Davis, CA (United States); Weitzel, Elizabeth [Davis Energy Group, Davis, CA (United States); Backman, Christine [Davis Energy Group, Davis, CA (United States)

    2017-02-28

    This project completed a modeling evaluation of a hybrid gas water heater that combines a reduced capacity tankless unit with a downsized storage tank. This product would meet a significant market need by providing a higher efficiency gas water heater solution for retrofit applications while maintaining compatibility with the 1/2 inch gas lines and standard B vents found in most homes. The TRNSYS simulation tool was used to model a base case 0.60 EF atmospheric gas storage water, a 0.82 EF non-condensing gas tankless water heater, an existing (high capacity) hybrid unit on the market, and an alternative hybrid unit with lower storage volume and reduced gas input requirements. Simulations were completed under a 'peak day' sizing scenario with 183 gpd hot water loads in a Minnesota winter climate case. Full-year simulations were then completed in three climates (ranging from Phoenix to Minneapolis) for three hot water load scenarios (36, 57, and 96 gpd). Model projections indicate that the alternative hybrid offers an average 4.5% efficiency improvement relative to the 0.60 EF gas storage unit across all scenarios modeled. The alternative hybrid water heater evaluated does show promise, but the current low cost of natural gas across much of the country and the relatively small incremental efficiency improvement poses challenges in initially building a market demand for the product.

  2. 14 CFR 25.859 - Combustion heater fire protection.

    Science.gov (United States)

    2010-01-01

    ... passages. (b) Ventilating air ducts. Each ventilating air duct passing through any fire zone must be..., the ventilating air duct downstream of each heater must be fireproof for a distance great enough to... fluids or vapors into the ventilating airstream. (c) Combustion air ducts. Each combustion air duct...

  3. 14 CFR 23.859 - Combustion heater fire protection.

    Science.gov (United States)

    2010-01-01

    ... passage that surrounds the combustion chamber. (b) Ventilating air ducts. Each ventilating air duct... fireproof valves or by equally effective means, the ventilating air duct downstream of each heater must be...) Combustion air ducts. Each combustion air duct must be fireproof for a distance great enough to...

  4. CHARACTERIZATION OF POPULATION AND USAGE OF UNVENTED KEROSENE SPACE HEATERS

    Science.gov (United States)

    The report gives results of a study of the market penetration of unvented kerosene space heaters (UKSHs) in the residential sector, The study was aimed at gathering baseline information to help assess the magnitude and potential severity of a problem involving emissions from unve...

  5. Assessment of a Hybrid Retrofit Gas Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, Marc [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Weitzel, Elizabeth [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Backman, Christine [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2017-02-01

    This project completed a modeling evaluation of a hybrid gas water heater that combines a reduced capacity tankless unit with a downsized storage tank. This product would meet a significant market need by providing a higher efficiency gas water heater solution for retrofit applications while maintaining compatibility with the 1/2 inch gas lines and standard B vents found in most homes. The TRNSYS simulation tool was used to model a base case 0.60 EF atmospheric gas storage water, a 0.82 EF non-condensing gas tankless water heater, an existing (high capacity) hybrid unit on the market, and an alternative hybrid unit with lower storage volume and reduced gas input requirements. Simulations were completed under a 'peak day' sizing scenario with 183 gpd hot water loads in a Minnesota winter climate case. Full-year simulations were then completed in three climates (ranging from Phoenix to Minneapolis) for three hot water load scenarios (36, 57, and 96 gpd). Model projections indicate that the alternative hybrid offers an average 4.5% efficiency improvement relative to the 0.60 EF gas storage unit across all scenarios modeled. The alternative hybrid water heater evaluated does show promise, but the current low cost of natural gas across much of the country and the relatively small incremental efficiency improvement poses challenges in initially building a market demand for the product.

  6. Thermomechanics of the granular bed T-joint water heater

    Science.gov (United States)

    Teplitskii, Yu. S.; Belonovich, D. G.

    2012-11-01

    On the basis of the heat transfer model taking into account the radiative transport the temperature distribution and the resistance of the water heater with a granular packing having two independent air inlets have been investigated. The generalized dependence for calculating the resistance of the granular bed has been obtained.

  7. an automatic safety control for immersion water heater

    African Journals Online (AJOL)

    NIJOTECH

    heater in the Nigerian market in its current form is depicted ... the comparator used is an open collector type. It is instructive to take a close look at the operation of the Schmitt trigger. The equivalent .... additional advantage of keeping the water.

  8. Electrothermal pumping with interdigitated electrodes and resistive heaters.

    Science.gov (United States)

    Williams, Stuart J; Green, Nicolas G

    2015-08-01

    Interdigitated electrodes are used in electrokinetic lab-on-a-chip devices for dielectrophoretic trapping and characterization of suspended particles, as well as the production of field-induced fluid flow via AC electroosomosis and electrothermal mechanisms. However, the optimum design for dielectrophoresis, that if symmetrical electrodes, cannot induce bulk electrohydrodynamic pumping. In addition, the mechanism of intrinsic electrothermal pumping is affected by the properties of the fluid, with thermal fields being generated by Joule Heating. This work demonstrates the incorporation of an underlying thin film heater, electrically isolated from the interdigitated electrodes by an insulator layer, to enhance bulk electrothermal pumping. The use of integrated heaters allows the thermal field generation to be controlled independently of the electric field. Numerical simulations are performed to demonstrate the importance of geometrical arrangement of the heater with respect to the interdigitated electrodes, as well as electrode size, spacing, and arrangement. The optimization of such a system is a careful balance between electrokinetics, heat transfer, and fluid dynamics. The heater location and electrode spacing influence the rate of electrothermal pumping significantly more than electrode width and insulator layer thickness. This demonstration will aid in the development of microfluidic electrokinetic systems that want to utilize the advantages associated with electrothermal pumping while simultaneously applying other lab-on-a-chip electrokinetics like dielectrophoresis.

  9. Mechanistic Enhancement of SOFC Cathode Durability

    Energy Technology Data Exchange (ETDEWEB)

    Wachsman, Eric [Univ. of Maryland, College Park, MD (United States)

    2016-02-01

    Durability of solid oxide fuel cells (SOFC) under “real world” conditions is an issue for commercial deployment. In particular cathode exposure to moisture, CO2, Cr vapor (from interconnects and BOP), and particulates results in long-term performance degradation issues. Here, we have conducted a multi-faceted fundamental investigation of the effect of these contaminants on cathode performance degradation mechanisms in order to establish cathode composition/structures and operational conditions to enhance cathode durability.

  10. International Conference on Durability of Critical Infrastructure

    CERN Document Server

    Cherepetskaya, Elena; Pospichal, Vaclav

    2017-01-01

    This book presents the proceedings of the International Conference on Durability of Critical Infrastructure. Monitoring and Testing held in Satov, Czech Republic from 6 to 9 December 2016. It discusses the developments in the theoretical and practical aspects in the fields of Safety, Sustainability and Durability of the Critical Infrastructure. The contributions are dealing with monitoring and testing of structural and composite materials with a new methods for their using for protection and prevention of the selected objects.

  11. Evaluation of the Demand Response Performance of Electric Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Mayhorn, Ebony T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Widder, Sarah H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Parker, Steven A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Pratt, Richard M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chassin, Forrest S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-03-17

    The purpose of this project is to verify or refute many of the concerns raised by utilities regarding the ability of large tank HPWHs to perform DR by measuring the performance of HPWHs compared to ERWHs in providing DR services. perform DR by measuring the performance of HPWHs compared to ERWHs in providing DR services. This project was divided into three phases. Phase 1 consisted of week-long laboratory experiments designed to demonstrate technical feasibility of individual large-tank HPWHs in providing DR services compared to large-tank ERWHs. In Phase 2, the individual behaviors of the water heaters were then extrapolated to a population by first calibrating readily available water heater models developed in GridLAB-D simulation software to experimental results obtained in Phase 1. These models were used to simulate a population of water heaters and generate annual load profiles to assess the impacts on system-level power and residential load curves. Such population modeling allows for the inherent and permanent load reduction accomplished by the more efficient HPWHs to be considered, in addition to the temporal DR services the water heater can provide by switching ON or OFF as needed by utilities. The economic and emissions impacts of using large-tank water heaters in DR programs are then analyzed from the utility and consumer perspective, based on National Impacts Analysis in Phase 3. Phase 1 is discussed in this report. Details on Phases 2 and 3 can be found in the companion report (Cooke et al. 2014).

  12. Durability Assessment of Gamma Tial

    Science.gov (United States)

    Draper, Susan L.; Lerch, Bradley A.; Pereira, J. Michael; Miyoshi, Kazuhisa; Arya, Vinod K.; Zhuang, Wyman

    2004-01-01

    Gamma TiAl was evaluated as a candidate alloy for low-pressure turbine blades in aeroengines. The durability of g-TiAl was studied by examining the effects of impact or fretting on its fatigue strength. Cast-to-size Ti-48Al-2Cr-2Nb was studied in impact testing with different size projectiles at various impact energies as the reference alloy and subsequently fatigue tested. Impacting degraded the residual fatigue life. However, under the ballistic impact conditions studied, it was concluded that the impacts expected in an aeroengine would not result in catastrophic damage, nor would the damage be severe enough to result in a fatigue failure under the anticipated design loads. In addition, other gamma alloys were investigated including another cast-to-size alloy, several cast and machined specimens, and a forged alloy. Within this Ti-48-2-2 family of alloys aluminum content was also varied. The cracking patterns as a result of impacting were documented and correlated with impact variables. The cracking type and severity was reasonably predicted using finite element models. Mean stress affects were also studied on impact-damaged fatigue samples. The fatigue strength was accurately predicted based on the flaw size using a threshold-based, fracture mechanics approach. To study the effects of wear due to potential applications in a blade-disk dovetail arrangement, the machined Ti-47-2-2 alloy was fretted against In-718 using pin-on-disk experiments. Wear mechanisms were documented and compared to those of Ti-6Al-4V. A few fatigue samples were also fretted and subsequently fatigue tested. It was found that under the conditions studied, the fretting was not severe enough to affect the fatigue strength of g-TiAl.

  13. Three-phase heaters with common overburden sections for heating subsurface formations

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J [Bellaire, TX

    2012-02-14

    A heating system for a subsurface formation is described. The heating system includes three substantially u-shaped heaters with first end portions of the heaters being electrically coupled to a single, three-phase wye transformer and second end portions of the heaters being electrically coupled to each other and/or to ground. The three heaters may enter the formation through a first common wellbore and exit the formation through a second common wellbore so that the magnetic fields of the three heaters at least partially cancel out in the common wellbores.

  14. 10 CFR 431.102 - Definitions concerning commercial water heaters, hot water supply boilers, and unfired hot water...

    Science.gov (United States)

    2010-01-01

    ... attached. Thermal efficiency for an instantaneous water heater, a storage water heater or a hot water... the amount of energy consumed by the water heater as measured during the thermal efficiency test... 10 Energy 3 2010-01-01 2010-01-01 false Definitions concerning commercial water heaters, hot...

  15. An Active Heater Control Concept to Meet IXO Type Mirror Module Thermal-Structural Distortion Requirement

    Science.gov (United States)

    Choi, Michael

    2013-01-01

    Flight mirror assemblies (FMAs) of large telescopes, such as the International X-ray Observatory (IXO), have very stringent thermal-structural distortion requirements. The spatial temperature gradient requirement within a FMA could be as small as 0.05 C. Con ventionally, heaters and thermistors are attached to the stray light baffle (SLB), and centralized heater controllers (i.e., heater controller boards located in a large electronics box) are used. Due to the large number of heater harnesses, accommodating and routing them is extremely difficult. The total harness length/mass is very large. This innovation uses a thermally conductive pre-collimator to accommodate heaters and a distributed heater controller approach. It minimizes the harness length and mass, and reduces the problem of routing and accommodating them. Heaters and thermistors are attached to a short (4.67 cm) aluminum portion of the pre-collimator, which is thermally coupled to the SLB. Heaters, which have a very small heater power density, and thermistors are attached to the exterior of all the mirror module walls. The major portion (23.4 cm) of the pre-collimator for the middle and outer modules is made of thin, non-conductive material. It minimizes the view factors from the FMA and heated portion of the precollimator to space. It also minimizes heat conduction from one end of the FMA to the other. Small and multi-channel heater controllers, which have adjustable set points and internal redundancy, are used. They are mounted to the mechanical support structure members adjacent to each module. The IXO FMA, which is 3.3 m in diameter, is an example of a large telescope. If the heater controller boards are centralized, routing and accommodating heater harnesses is extremely difficult. This innovation has the following advantages. It minimizes the length/mass of the heater harness between the heater controllers and heater circuits. It reduces the problem of routing and accommodating the harness on the

  16. Head Injuries

    Science.gov (United States)

    ... object that's stuck in the wound. previous continue Concussions Concussions — the temporary loss of normal brain function due ... also a type of internal head injury. Repeated concussions can permanently damage the brain. In many cases, ...

  17. Head Tilt

    Science.gov (United States)

    ... Healthy Living Healthy Living Healthy Living Nutrition Fitness Sports Oral Health Emotional Wellness Growing Healthy Sleep Safety & ... When this happens, the neck muscles go into spasm, causing the head to tilt to one side. ...

  18. Head Injuries

    Science.gov (United States)

    ... ATV) Safety Balance Disorders Knowing Your Child's Medical History First Aid: Falls First Aid: Head Injuries Preventing Children's Sports Injuries Getting Help: Know the Numbers Concussions Stay Safe: Baseball Concussions Concussions: Getting Better Sports and Concussions Dealing ...

  19. Head MRI

    Science.gov (United States)

    ... heart valves Heart defibrillator or pacemaker Inner ear (cochlear) implants Kidney disease or dialysis (you may not ... to: Abnormal blood vessels in the brain ( arteriovenous malformations of the head ) Tumor of the nerve that ...

  20. Cold head maintenance with minimal service interruption

    Science.gov (United States)

    Radovinsky, A. L.; Michael, P. C.; Zhukovsky, A.; Forton, E.; Paradis, Y.; Nuttens, V.; Minervini, J. V.

    2015-12-01

    Turn-key superconducting magnet systems are increasingly conduction-cooled by cryogenerators. Gifford-McMahon systems are reliable and cost effective, but require annual maintenance. A usual method of servicing is replacing the cold head of the cryocooler. It requires a complicated design with a vacuum chamber separate from the main vacuum of the cryostat, as well as detachable thermal contacts, which add to the thermal resistance of the cooling heat path and reduce the reliability of the system. We present a rapid warm-up scheme to bring the cold head body, which remains rigidly affixed to the cold mass, to room temperature, while the cold mass remains at cryogenic temperature. Electric heaters thermally attached to the cold head stations are used to warm them up, which permits conventional cold head maintenance with no danger of contaminating the inside of the cold head body. This scheme increases the efficiency of the cooling system, facilitates annual maintenance of the cold head and returning the magnet to operation in a short time.

  1. Electrical heater for very-low pressure helium gas

    CERN Document Server

    Benda, V; Vuillierme, B

    1996-01-01

    Testing superconducting magnets for the Large Hadron Collider (LHC) in superfluid helium requires large-capacity refrigeration at 1.8K. At CERN, this is provided by a combination of a cold compressor and a set of warm vacuum pumps capable of handling up to 18g/s at 1 kPa suction pressure. The cold helium vapour, after the cold compressor, is warmed up from about 5K to ambient temperature in a 32 kW electrical heater. The device is designed to operate reliably at flow rates varying from 1 to 18g/s, inlet pressure of 1 kPa to 3 kPa, with pressure drop 100 Pa. Design and construction of the heater, completely realised at CERN, are presented, as well as measured performance. Some technological problems are discussed.

  2. Thermal hydraulic analysis of the annular flow helium heater design

    Science.gov (United States)

    Chen, N. C.; Sanders, J. P.

    1982-05-01

    Core support performance test (CSPT) by use of an existing facility, components flow test loop (CFTL), as part of the high temperature gas cooled reactor (HTGR) application program were conducted. A major objective of the CSPT is to study accelerated corrosion of the core graphite support structure in helium at reactor conditions. Concentration of impurities will be adjusted so that a 6 month test represents the 30 year reactor life. Thermal hydraulic and structural integrity of the graphite specimen, will be studied at high pressure of 7.24 MPa (1050 psi) and high temperature of 1000 deg C in a test vessel. To achieve the required high temperature at the test section, a heater bundle has to be specially designed and properly manufactured. Performance characteristics of the heater which were determined from an analysis based on this design are presented.

  3. DESIGN OF A 500W RESONANT INDUCTION HEATER

    Directory of Open Access Journals (Sweden)

    Bekir Sami SAZAK

    1999-01-01

    Full Text Available In this paper a complete design procedure for a 500W induction heating system is given. An induction heating system basically consists of a coil and a DC/AC inverter. The use of a single switch resonant inverter, which is operated with Discontinuous Conduction Mode (DCM, allows the switching device to turn off under zero current conditions, therefore switching losses are much reduced. This inverter system transforms the DC into AC for the induction heater coil. The proposed coil design method is applicable to a load of any shape so long as the coil surrounds the workpiece. The basis of this method of coil design is the reduction of the induction heater coil and workpiece to their equivalent resistance and inductance.

  4. Development of Exhaust Gas Driven Absorption Chiller-Heater

    Science.gov (United States)

    Inoue, Naoyuki; Endou, Tetsuya; Saito, Kiyoshi; Kawai, Sunao

    Waste heat from co-generation systems are usually recovered by hot water or steam, those are used to drive absorption refrigerators at cooling time, and those are used for heating via heat exchangers at heating time. However waste heat from micro gas turbines are discharged in the form of exhaust gas, it is simple that exhaust gas is directly supplied to absorption chiller-heaters. In the first report we studied cooling cycle, and this second paper, we evaluated various absorption heating cycles for exhaust gas driven absorption chiller-heaters, and adopted one of these cycles for the prototype machine. Also, we experimented with the prototype for wide range condition and got the heating characteristics. Based on the experimental data, we developed a simulation model of the static characteristics, and then studied how to increase the output by limited exhaust gas.

  5. An experimental evaluation of multi-pass solar air heaters

    Energy Technology Data Exchange (ETDEWEB)

    Satcunanathan, S.; Persad, P.

    1980-12-01

    Three collectors of identical dimensions but operating in the single-pass, two-pass and three-pass modes were tested simultaneously under ambient conditions. It was found that the two-pass air heater was consistently better than the single-pass air heater over the day for the range of mass flow rates considered. It was also found that at a mass flow rate of 0.0095 kg s/sup -1/ m/sup -2/, the thermal performances of the two-pass and three-pass collectors were identical, but at higher flow rates the two-pass collector was superior to the three-pass collector, the superiority decreasing with increasing mass flow rate.

  6. Fabrication of light weight radioisotope heater unit hardware components

    Science.gov (United States)

    McNeil, Dennis C.

    1996-03-01

    The Light Weight Radioisotope Heater Unit (LWRHU) is planned to be used on the National Aeronautics and Space Administration (NASA) Cassini Mission, to provide localized thermal energy as strategic locations on the spacecraft. These one watt heater units will support the operation of many on-board instruments that require a specific temperature range to function properly. The system incorporates a fuel pellet encapsulated in a vented metallic clad fabricated from platinum-30% rhodium (Pt-30%Rh) tubing, sheet and foil materials. To complete the package, the clad assemblies are placed inside a combination of graphite components. This report describes the techniques employed by Mound related to the fabrication and sub assembly processes of the LWRHU clad hardware components. Included are details concerning configuration control systems, material procurement and certification, hardware fabrication specifics, and special processes that are utilized.

  7. Field Performance of Heat Pump Water Heaters in the Northeast

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, Carl [Consortium for Advanced Residential Buildings, Norfolk, CT (United States); Puttagunta, Srikanth [Consortium for Advanced Residential Buildings, Norfolk, CT (United States)

    2016-02-05

    Heat pump water heaters (HPWHs) are finally entering the mainstream residential water heater market. Potential catalysts are increased consumer demand for higher energy efficiency electric water heating and a new Federal water heating standard that effectively mandates use of HPWHs for electric storage water heaters with nominal capacities greater than 55 gallons. When compared to electric resistance water heating, the energy and cost savings potential of HPWHs is tremendous. Converting all electric resistance water heaters to HPWHs could save American consumers 7.8 billion dollars annually ($182 per household) in water heating operating costs and cut annual residential source energy consumption for water heating by 0.70 quads. Steven Winter Associates, Inc. embarked on one of the first in situ studies of these newly released HPWH products through a partnership with two sponsoring electric utility companies, National Grid and NSTAR, and one sponsoring energy efficiency service program administrator, Cape Light Compact. Recent laboratory studies have measured performance of HPWHs under various operating conditions, but publically available field studies have not been as available. This evaluation attempts to provide publicly available field data on new HPWHs by monitoring the performance of three recently released products (General Electric GeoSpring(TM), A.O. Smith Voltex(R), and Stiebel Eltron Accelera(R) 300). Fourteen HPWHs were installed in Massachusetts and Rhode Island and monitored for over a year. Of the 14 units, ten were General Electric models (50 gallon units), two were Stiebel Eltron models (80 gallon units), and two were A.O. Smith models (one 60-gallon and one 80-gallon unit).

  8. Field Performance of Heat Pump Water Heaters in the Northeast

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, C.; Puttagunta, S.

    2013-08-01

    Heat pump water heaters (HPWHs) are finally entering the mainstream residential water heater market. Potential catalysts are increased consumer demand for higher energy efficiency electric water heating and a new Federal water heating standard that effectively mandates use of HPWHs for electric storage water heaters with nominal capacities greater than 55 gallons. When compared to electric resistance water heating, the energy and cost savings potential of HPWHs is tremendous. Converting all electric resistance water heaters to HPWHs could save American consumers 7.8 billion dollars annually ($182 per household) in water heating operating costs and cut annual residential source energy consumption for water heating by 0.70 quads. Steven Winter Associates, Inc. embarked on one of the first in situ studies of these newly released HPWH products through a partnership with two sponsoring electric utility companies, National Grid and NSTAR, and one sponsoring energy efficiency service program administrator, Cape Light Compact. Recent laboratory studies have measured performance of HPWHs under various operating conditions, but publicly available field studies have not been as available. This evaluation attempts to provide publicly available field data on new HPWHs by monitoring the performance of three recently released products (General Electric GeoSpring(tm), A.O. Smith Voltex(r), and Stiebel Eltron Accelera(r)300). Fourteen HPWHs were installed in Massachusetts and Rhode Island and monitored for over a year. Of the 14 units, ten were General Electric models (50 gallon units), two were Stiebel Eltron models (80 gallon units), and two were A.O. Smith models (one 60-gallon and one 80-gallon unit).

  9. Dental adhesion: mechanism, techniques and durability.

    Science.gov (United States)

    Manuja, N; Nagpal, R; Pandit, I K

    2012-01-01

    Contemporary dental adhesives show favorable immediate results in terms of bonding effectiveness. However, the durability of resin-dentin bonds is their major problem. It appears that simplification of adhesive techniques is rather detrimental to the long-term stability of resin-tooth interface. The hydrostatic pulpal pressure, the dentinal fluid flow and the increased dentinal wetness in vital dentin can affect the intimate interaction of certain dentin adhesives with dentinal tissue. Bond degradation occurs via water sorption, hydrolysis of ester linkages of methacrylate resins, and activation of endogenous dentin matrix metalloproteinases. The three-step etch-and-rinse adhesives still remain the gold standard in terms of durability. This review discusses the fundamental process of adhesion to enamel and dentin with different adhesive techniques, factors affecting the long-term bonding performance of modern adhesives and addresses the current perspectives for improving bond durability.

  10. Description of Concrete Durability Damage Process

    Institute of Scientific and Technical Information of China (English)

    CHEN Yueshun; WEI Jun; ZHAO Xiaolong

    2006-01-01

    Based on the damage mechanics, the concrete damage grade of relative stable environment in measurable spatial is constructed in this paper, and the concrete damage evolving model and corresponding failure rule is constructed based on the damage grade fore-defined. Therefore, the concrete health status and the residual life-span can be assessed according to the measured damage grade. It is propitious to drive the development of concrete durability assessment and life-span forecast. Its feasibility of concrcte damage process description and health assessment is validated with the example in this paper, in which the damage state is described with the ultrasound velocity attenuation, and the freeze-thaw process is regarded as the concrete durability degradation influencing factor to reflect the concrete durability degradation process.

  11. Conasauga near-surface heater experiment. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Krumhansl, J.L.

    1979-11-01

    The Conasauga Experiment was undertaken to begin assessment of the thermomechanical and chemical response of a specific shale to the heat resulting from emplacement of high-level nuclear wastes. Canister-size heaters were implanted in Conasauga shale in Tennessee. Instrumentation arrays wee placed at various depths in drill holes around each heater. The heaters operated for 8 months and, after the first 4 days, were maintained at 385/sup 0/C. Emphasis was on characterizing the thermal and mechanical response of the formation. Conduction was the major mode of heat transport; convection was perceptible only at temperatures above the boiling point of water. Despite dehydration of the shale at higher temperatures, in situ thermal conductivity was essentially constant and not a function of temperature. The mechanical response of the formation was a slight overall expansion, apparently resulting in a general decrease in permeability. Metallurgical observations were made, the stability of a borosilicate glass wasteform simulant was assessed, and changes in formation mineralogy and groundwater composition were documented. In each of these areas, transient nonequilibrium processes occur that affect material stability and may be important in determining the integrity of a repository. In general, data from the test reflect favorably on the use of shale as a disposal medium for nuclear waste.

  12. Performance Analysis and Modeling of Thermally Sprayed Resistive Heaters

    Science.gov (United States)

    Lamarre, Jean-Michel; Marcoux, Pierre; Perrault, Michel; Abbott, Richard C.; Legoux, Jean-Gabriel

    2013-08-01

    Many processes and systems require hot surfaces. These are usually heated using electrical elements located in their vicinity. However, this solution is subject to intrinsic limitations associated with heating element geometry and physical location. Thermally spraying electrical elements directly on surfaces can overcome these limitations by tailoring the geometry of the heating element to the application. Moreover, the element heat transfer is maximized by minimizing the distance between the heater and the surface to be heated. This article is aimed at modeling and characterizing resistive heaters sprayed on metallic substrates. Heaters were fabricated by using a plasma-sprayed alumina dielectric insulator and a wire flame-sprayed iron-based alloy resistive element. Samples were energized and kept at a constant temperature of 425 °C for up to 4 months. SEM cross-sectional observations revealed the formation of cracks at very specific locations in the alumina layer after thermal use. Finite-element modeling shows that these cracks originate from high local thermal stresses and can be predicted according to the considered geometry. The simulation model was refined using experimental parameters obtained by several techniques such as emissivity and time-dependent temperature profile (infra-red camera), resistivity (four-probe technique), thermal diffusivity (laser flash method), and mechanical properties (micro and nanoindentation). The influence of the alumina thickness and the substrate material on crack formation was evaluated.

  13. Tip Heater for Minimum Quench Energy Measurements on Superconducting Strands

    CERN Document Server

    Bauer, P; Oberli, L R

    1999-01-01

    Superconducting strands can be characterized by their Minimum Quench Energy (MQE), i.e. the minimum heat pulse needed to trigger a quench in operation conditions (field, temperature, current), in the limit of a (temporally and spatially) d-shaped disturbance. The sub-mm/µs range of perturbation space has only recently been achieved using the electrical graphite-paste heater technique [1]. The present work has put this technique into practice for the strands of the LHC main magnets, which are designed to operate at 1.9K in peak fields of up to 9T [1]. No way has been found yet to calibrate MQE measurements. To make relative statements on the MQE of different samples possible, the reproducibility of the measurements was emphasized. First heater prototypes did not come up to this stipulation. Finally the tip-heater configuration was found to meet the requirements. It generates a heat pulse in a thin resistive graphite paste deposit on top of a small tip that is pressed against the sample with a clamp. The clamp...

  14. Control and Coordination of Frequency Responsive Residential Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Tess L.; Kalsi, Karanjit; Elizondo, Marcelo A.; Marinovici, Laurentiu D.; Pratt, Richard M.

    2016-07-31

    Demand-side frequency control can complement traditional generator controls to maintain the stability of large electric systems in the face of rising uncertainty and variability associated with renewable energy resources. This paper presents a hierarchical frequency-based load control strategy that uses a supervisor to flexibly adjust control gains that a population of end-use loads respond to in a decentralized manner to help meet the NERC BAL-003-1 frequency response standard at both the area level and interconnection level. The load model is calibrated and used to model populations of frequency-responsive water heaters in a PowerWorld simulation of the U.S. Western Interconnection (WECC). The proposed design is implemented and demonstrated on physical water heaters in a laboratory setting. A significant fraction of the required frequency response in the WECC could be supplied by electric water heaters alone at penetration levels of less than 15%, while contributing to NERC requirements at the interconnection and area levels.

  15. Probabilistic Durability Analysis in Advanced Engineering Design

    Directory of Open Access Journals (Sweden)

    A. Kudzys

    2000-01-01

    Full Text Available Expedience of probabilistic durability concepts and approaches in advanced engineering design of building materials, structural members and systems is considered. Target margin values of structural safety and serviceability indices are analyzed and their draft values are presented. Analytical methods of the cumulative coefficient of correlation and the limit transient action effect for calculation of reliability indices are given. Analysis can be used for probabilistic durability assessment of carrying and enclosure metal, reinforced concrete, wood, plastic, masonry both homogeneous and sandwich or composite structures and some kinds of equipments. Analysis models can be applied in other engineering fields.

  16. Four Bed Molecular Sieve - Exploration (4BMS-X) Virtual Heater Design and Optimization

    Science.gov (United States)

    Schunk, R. Gregory; Peters, Warren T.; Thomas, John T., Jr.

    2017-01-01

    A 4BMS-X (Four Bed Molecular Sieve - Exploration) design and heater optimization study for CO2 sorbent beds in proposed exploration system architectures is presented. The primary objectives of the study are to reduce heater power and thermal gradients within the CO2 sorbent beds while minimizing channeling effects. Some of the notable changes from the ISS (International Space Station) CDRA (Carbon Dioxide Removal Assembly) to the proposed exploration system architecture include cylindrical beds, alternate sorbents and an improved heater core. Results from both 2D and 3D sorbent bed thermal models with integrated heaters are presented. The 2D sorbent bed models are used to optimize heater power and fin geometry while the 3D models address end effects in the beds for more realistic thermal gradient and heater power predictions.

  17. The prospective buyer of consumer durables

    NARCIS (Netherlands)

    Jonge, Leendert de; Oppedijk van Veen, Walle Melis

    1982-01-01

    In this book, an empirical investigation is reported wich aims at the specification of models of individual households’ purchase behaviour for particular consumer durable goods, such as private passenger cars and television sets. In particular, the focus is on models wich can be used for predicting

  18. Facile preparation of super durable superhydrophobic materials.

    Science.gov (United States)

    Wu, Lei; Zhang, Junping; Li, Bucheng; Fan, Ling; Li, Lingxiao; Wang, Aiqin

    2014-10-15

    The low stability, complicated and expensive fabrication procedures seriously hinder practical applications of superhydrophobic materials. Here we report an extremely simple method for preparing super durable superhydrophobic materials, e.g., textiles and sponges, by dip coating in fluoropolymers (FPs). The morphology, surface chemical composition, mechanical, chemical and environmental stabilities of the superhydrophobic textiles were investigated. The results show how simple the preparation of super durable superhydrophobic textiles can be! The superhydrophobic textiles outperform their natural counterparts and most of the state-of-the-art synthetic superhydrophobic materials in stability. The intensive mechanical abrasion, long time immersion in various liquids and repeated washing have no obvious influence on the superhydrophobicity. Water drops are spherical in shape on the samples and could easily roll off after these harsh stability tests. In addition, this simple dip coating approach is applicable to various synthetic and natural textiles and can be easily scaled up. Furthermore, the results prove that a two-tier roughness is helpful but not essential with regard to the creation of super durable superhydrophobic textiles. The combination of microscale roughness of textiles and materials with very low surface tension is enough to form super durable superhydrophobic textiles. According to the same procedure, superhydrophobic polyurethane sponges can be prepared, which show high oil absorbency, oil/water separation efficiency and stability. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Advantage from Funding Durable Centers Leasing

    Directory of Open Access Journals (Sweden)

    Alina Zając

    2009-09-01

    Full Text Available In present market conditions huge number of businessmen has problems from gain over from banks capital on purchase of durable centers not only, but also on develop - ment and operating activity Individual can use with different forms funding investment, it which is between different leasing.

  20. Accelerated Testing of Solar Collector Durability

    DEFF Research Database (Denmark)

    Svendsen, Sv Aa Højgaard

    1996-01-01

    A climatic simulator has been build to test the reliability and durability of solar collectors. In the climatic simulator the collector is expåosed to extreme climatic conditions and temperature variations in an accelerated way and during this process the function of the collector is tested...... and the microclimate in the collector box is measured....

  1. Durability study of PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Wu, J.F.; Yuan, X.Z.; Martin, J.J.; Wang, H.J. [National Research Council of Canada, Vancouver, BC (Canada). Inst. for Fuel Cell Innovation; Bi, X.T. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Chemical and Biological Engineering; Pei, P.C.; Huang, H.Y. [Tsinghua Univ., Beijing (China). Dept. of Automotive Engineering

    2007-07-01

    Technical challenges limit the commercialization of polymer electrolyte membrane fuel cells (PEM) for use in stationary applications and transport. These include: on-board storage and infrastructure for hydrogen fuel as well as the fuel cell system itself; high costs; and, durability under a wide range of operational conditions. Durability is defined as the maximum service life of a fuel cell system with no more than 10 per cent loss in efficiency at the end of life. This paper presented a literature review and analysis in order to provide a unified definition of PEM fuel cell service life when operated at either steady state or dynamic load conditions. The paper presented an analysis of different operating conditions and the dependence of PEM fuel cell durability on the operating condition. The paper also reviewed durability studies of the different components of a PEM fuel cell, and also examined various degradation mechanisms. These included: load or thermal cycles; fuel or oxidant starvation; high or low humidification levels; and, reformate or simulated reformed gases as fuels. A relationship between the accelerated service life of a PEM fuel cell and the real service life was then developed. To obtain real service life under normal testing conditions, statistical models based on accelerated service life data were illustrated. It was concluded that the service life of a fuel cell and its components is a function of more than one or two variables. 46 refs., 4 tabs., 3 figs.

  2. Selection procedures for durable resistance in wheat.

    NARCIS (Netherlands)

    Beek, M.A.

    1988-01-01

    A wheat breeding programme for durable resistance to all locally important pathogens: leaf rust, stem rust, powdery mildew, Septoria nodorum, Septoria tritici, Cochliobolus sativus, Fusarium graminearum, Common Root Rot, Barley Yellow Dwarf Virus and Soil Borne Mosaic Virus was conducted in Brazil.

  3. Durability of cracked fibre reinforced concrete structures

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place; Nielsen, Laila

    1997-01-01

    (capillary water uptake) is used, involving an in-situ method and a laboratory method. Three different concrete qualities as well as steel fibres (ZP) and polypropylene fibres (PP) are used. Results of the durability tests on cracked FRC-beams are compared to results for uncracked FRC-beams and beams without...

  4. 14 CFR 35.19 - Durability.

    Science.gov (United States)

    2010-01-01

    ... and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: PROPELLERS Design and Construction § 35.19 Durability. Each part of the propeller must be designed and constructed to minimize the development of any unsafe condition of the propeller...

  5. DURABLE GLASS FOR THOUSANDS OF YEARS

    Energy Technology Data Exchange (ETDEWEB)

    Jantzen, C.

    2009-12-04

    The durability of natural glasses on geological time scales and ancient glasses for thousands of years is well documented. The necessity to predict the durability of high level nuclear waste (HLW) glasses on extended time scales has led to various thermodynamic and kinetic approaches. Advances in the measurement of medium range order (MRO) in glasses has led to the understanding that the molecular structure of a glass, and thus the glass composition, controls the glass durability by establishing the distribution of ion exchange sites, hydrolysis sites, and the access of water to those sites. During the early stages of glass dissolution, a 'gel' layer resembling a membrane forms through which ions exchange between the glass and the leachant. The hydrated gel layer exhibits acid/base properties which are manifested as the pH dependence of the thickness and nature of the gel layer. The gel layer ages into clay or zeolite minerals by Ostwald ripening. Zeolite mineral assemblages (higher pH and Al{sup 3+} rich glasses) may cause the dissolution rate to increase which is undesirable for long-term performance of glass in the environment. Thermodynamic and structural approaches to the prediction of glass durability are compared versus Ostwald ripening.

  6. Probabilistic modeling durability of wooden window frames

    NARCIS (Netherlands)

    Straalen, IJ.J. van; Abspoel-Bukman, L.M.; Courage, W.M.G.; Mennink, J.

    2014-01-01

    Nowadays, maintenance of wooden window frames strongly depends on the practical experience of the parties involved. To get a better understanding of the required maintenance period and maintenance actions, a model has been developed to predict durability. This model makes it possible to optimize mai

  7. DURABILITY OF FLEXIBLE PAVEMENTS: A CASE STUDY OF ...

    African Journals Online (AJOL)

    user

    estimate of durability and the poor design and construction factors and between the estimate of durability and maintenance ... accessibility of communities to high quality road networks [1]. .... assessment of road infrastructure in the SE and also.

  8. Assessing the Energy Savings of Tankless Water Heater Retrofits in Public Housing

    Energy Technology Data Exchange (ETDEWEB)

    Ries, R.; Walters, R.; Dwiantoro, D.

    2013-01-01

    This report describes the methodology, analysis, and findings from a case study of a 110 unit retrofit of gas tankless water heaters in a hot/humid climate in Alachua County, Florida. The housing units had their gas-fired tank type water heaters replaced with gas-fired tankless water heaters as part of a federal program that targeted reduced energy use in public housing.

  9. Assessing the Energy Savings of Tankless Water Heater Retrofits in Public Housing

    Energy Technology Data Exchange (ETDEWEB)

    Ries, R. [Univ. of Florida, Gainesville, FL (United States). Building Energy Efficient Housing for America (BEEHA)Team; Walters, R. [Univ. of Florida, Gainesville, FL (United States). Building Energy Efficient Housing for America (BEEHA)Team; Dwiantoro, D. [Univ. of Florida, Gainesville, FL (United States). Building Energy Efficient Housing for America (BEEHA)Team

    2013-01-01

    This report describes the methodology, analysis, and findings from a case study of a 110 unit retrofit of gas tankless water heaters in a hot/humid climate in Alachua County, Florida.The gas-fired tank type water heaters in the housing units were replaced with gas-fired tankless water heaters as part of a federal program that targeted reduced energy use in public housing.

  10. Comparison of Simulation and Experimental Results of Class - D Inverter Fed Induction Heater

    Directory of Open Access Journals (Sweden)

    S. Rama Reddy

    2010-10-01

    Full Text Available This research deals w ith simulation and experimentation of closed loop controlled class-D inverter fed induction heater system. This converter has reduced switching losses, stress and increased power density. The inverter system is designed and the simulation is done using Matlab. The results of simulation and experimentation are presented. The induction heater system uses embedded controller to generate driving pulses. The objective is to develop an induction heater system with minimum hardware.

  11. Thermal performance optimization of a flat plate solar air heater using genetic algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Varun; Siddhartha [Department of Mechanical Engineering, National Institute of Technology, Hamirpur 177 005 (H.P.) (India)

    2010-05-15

    Thermal performance of solar air heater is low and different techniques are adopted to increase the performance of solar air heaters, such as: fins, artificial roughness etc. In this paper an attempt has been done to optimize the thermal performance of flat plate solar air heater by considering the different system and operating parameters to obtain maximum thermal performance. Thermal performance is obtained for different Reynolds number, emissivity of the plate, tilt angle and number of glass plates by using genetic algorithm. (author)

  12. Do Flexible Durable Goods Prices Undermine Sticky Price Models?

    OpenAIRE

    Robert Barsky; Christopher L. House; Miles Kimball

    2003-01-01

    Multi-sector sticky price models have surprising implications when durable goods have flexible prices. While in actual data the production of virtually all durables exhibits strong negative responses to monetary contractions, in dynamic general equilibrium models a monetary contraction causes the output of flexibly priced durables to expand. Indeed, in the polar case in which only nondurables have sticky prices, the negative comovement of durable and nondurable production exactly offsets and ...

  13. Optical durability testing of candidate solar mirrors

    Energy Technology Data Exchange (ETDEWEB)

    Jorgensen, G.; Kennedy, C.; King, D.; Terwilliger, K.

    2000-03-24

    Durability testing of a variety of candidate solar reflector materials at outdoor test sites and in laboratory accelerated weathering chambers is the main activity within the Advanced Materials task of the Concentrated Solar Power (CSP) Program. Outdoor exposure testing (OET) at up to eight outdoor, worldwide exposure sites has been underway for several years. This includes collaboration under the auspices of the International Energy Agency (IEA) Solar Power and Chemical Energy Systems (SolarPACES) agreement. Outdoor sites are fully instrumented in terms of monitoring meteorological conditions and solar irradiance. Candidate materials are optically characterized prior to being subjected to exposure in real and simulated weathering environments. Optical durability is quantified by periodically re-measuring hemispherical and specular reflectance as a function of exposure time. By closely monitoring the site- and time-dependent environmental stress conditions experienced by the material samples, site-dependent loss of performance may be quantified. In addition, accelerated exposure testing (AET) of these materials in parallel under laboratory-controlled conditions may permit correlating the outdoor results with AET, and subsequently predicting service lifetimes. Test results to date for a large number of candidate solar reflector materials are presented in this report. Acronyms are defined. Based upon OET and AET results to date, conclusions can be drawn about the optical durability of the candidate reflector materials. The optical durability of thin glass, thick glass, and two metallized polymers can be characterized as excellent. The all-polymeric construction, several of the aluminized reflectors, and a metallized polymer can be characterized as having intermediate durability and require further improvement, testing and evaluation, or both.

  14. Head Start.

    Science.gov (United States)

    Greenman, Geri

    2000-01-01

    Discusses an art project in which students created drawings of mop heads. Explains that the approach of drawing was more important than the subject. States that the students used the chiaroscuro technique, used by Rembrandt and Caravaggio, in which light appears out of the darkness. (CMK)

  15. Zoned electrical heater arranged in spaced relationship from particulate filter

    Science.gov (United States)

    Gonze, Eugene V [Pinckney, MI

    2011-11-15

    A system comprises a particulate matter (PM) filter that comprises an upstream end for receiving exhaust gas and a downstream end. A zoned heater is arranged spaced from the upstream end and comprises N zones, where N is an integer greater than one, wherein each of the N zones comprises M sub-zones, where M is an integer greater than one. A control module selectively activates at least a selected one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones and deactivates non-selected ones of the N zones.

  16. Exergetic performance evaluation and parametric studies of solar air heater

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, M.K.; Kaushik, S.C. [Centre for Energy Studies, Indian Institute of Technology, Delhi 110016 (India)

    2008-11-15

    The present study aims to establish the optimal performance parameters for the maximum exergy delivery during the collection of solar energy in a flat-plate solar air heater. The procedure to determine optimum aspect ratio (length to width ratio of the absorber plate) and optimum duct depth (the distance between the absorber and the bottom plates) for maximum exergy delivery has been developed. It is known that heat energy gain and blower work increase monotonically with mass flow rate, while the temperature of air decreases; therefore, it is desirable to incorporate the quality of heat energy collected and the blower work. First it is proved analytically that the optimum exergy output, neglecting blower work, and the corresponding mass flow rate depend on the inlet temperature of air. The energy and exergy output rates of the solar air heater were evaluated for various values of collector aspect ratio (AR) of the collector, mass flow rate per unit area of the collector plate (G) and solar air heater duct depth (H). Results have been presented to discuss the effects of G, AR and H on the energy and exergy output rates of the solar air heater. The energy output rate increases with G and AR, and decreases with H and the inlet temperature of air. The exergy-based evaluation criterion shows that performance is not a monotonically increasing function of G and AR, and a decreasing function of H and inlet temperature of air. Based on the exergy output rate, it is found that there must be an optimum inlet temperature of air and a corresponding optimum G for any value of AR and H. For values of G lesser than optimal corresponding to inlet temperature of air equals to ambient, higher exergy output rate is achieved for the low value of duct depth and high AR in the range of parameters investigated. If G is high, for an application requiring less temperature increase, then either low AR or high H would give higher exergy output rate. (author)

  17. High Efficiency R-744 Commercial Heat Pump Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Elbel, Dr. Stefan W.; Petersen, Michael

    2013-04-25

    The project investigated the development and improvement process of a R744 (CO2) commercial heat pump water heater (HPWH) package of approximately 35 kW. The improvement process covered all main components of the system. More specific the heat exchangers (Internal heat exchanger, Evaporator, Gas cooler) as well as the expansion device and the compressor were investigated. In addition, a comparison to a commercially available baseline R134a unit of the same capacity and footprint was made in order to compare performance as well as package size reduction potential.

  18. Thin film heater for removable volatile protecting coatings.

    Science.gov (United States)

    Karim, Abid

    2013-01-01

    Freshly coated aluminum mirrors have excellent reflectivity at far ultraviolet wavelengths. However, reflectivity rapidly degrades when the mirror surfaces are exposed to atmosphere. In order to avoid this problem, freshly coated aluminum surface can be protected by over-coating of a removable volatile protecting coating. This protecting coating can be re-evaporated by controlled heating or by some other methods when required. This type of removable coating has immediate application in UV space astronomy. The purpose of this paper is to demonstrate the feasibility of re-evaporation of removable volatile Zn protecting coating using a NiCr thin film heater without affecting the reflection properties of Al mirror surfaces.

  19. CVD diamond resistor as heater and temperature sensor

    Energy Technology Data Exchange (ETDEWEB)

    Yang, G.S.; Aslam, M. [Michigan State Univ., East Lansing, MI (United States)

    1995-12-31

    Heat generation and temperature control, essential for most heater applications, require different components in a conventional system. We achieve the heat generation and temperature measurement simultaneously by using a single diamond resistor. Chemical vapor deposited (CVD) p-type diamond resistors with different dimensions were fabricated on polycrystalline diamond or oxidized Si substrates using diamond film technology compatible with integrated circuit (IC) processing. The temperature response of the resistors was characterized in the temperature range of 25 - 500{degrees}C. Power densities in access of 600 watt/in{sup 2} were achieved.

  20. Integral finned heater and cooler for stirling engines

    Science.gov (United States)

    Corey, John A.

    1984-01-01

    A piston and cylinder for a Stirling engine and the like having top and bottom meshing or nesting finned conical surfaces to provide large surface areas in close proximity to the working gas for good thermal (addition and subtraction of heat) exchange to the working gas and elimination of the usual heater and cooler dead volume. The piston fins at the hot end of the cylinder are perforated to permit the gas to pass into the piston interior and through a regenerator contained therein.

  1. Structural Properties and Mechanical Durability of Extruded Fish Feed

    DEFF Research Database (Denmark)

    Haubjerg, Anders Fjeldbo; Veje, Christian; Jørgensen, Bo Nørregaard;

    2015-01-01

    This article investigates the possible correlation between mechanical properties of fish feed pellets and their mechanical durability. Mechanical properties were obtained by texture profile analysis (TPA) and stress relaxation test (SRT) of different types of fish feed. The results were correlated...... against a conventional test of mechanical durability (DORIS, Durability On a Realistic, test). From SRT it was found that for achieving a high durability, pellets should be able to relax an applied force nonelastically. From TPA, it was found that a durable pellet should also be able to return its...

  2. Monetary Policy with Sectoral Linkages and Durable Goods

    DEFF Research Database (Denmark)

    Petrella, Ivan; Rossi, Raffaele; Santoro, Emiliano

    We study the normative implications of a New Keynesian model featuring intersectoral trade of intermediate goods between two sectors that produce durables and non-durables. The interplay between durability and sectoral production linkages fundamentally alters the intersectoral stabilization trade....... Aggregating durable and non-durable inflation depending on the relative degrees of sectoral price stickiness may induce a severe bias. Input materials attenuate the response of sectoral inflations to movements in the real marginal costs, so that the effective slopes of the sectoral supply schedules...

  3. Simple Retrofit High-Efficiency Natural Gas Water Heater Field Test

    Energy Technology Data Exchange (ETDEWEB)

    Schoenbauer, Ben [NorthernSTAR, St. Paul, MN (United States)

    2017-03-01

    High-performance water heaters are typically more time consuming and costly to install in retrofit applications, making high performance water heaters difficult to justify economically. However, recent advancements in high performance water heaters have targeted the retrofit market, simplifying installations and reducing costs. Four high efficiency natural gas water heaters designed specifically for retrofit applications were installed in single-family homes along with detailed monitoring systems to characterize their savings potential, their installed efficiencies, and their ability to meet household demands. The water heaters tested for this project were designed to improve the cost-effectiveness and increase market penetration of high efficiency water heaters in the residential retrofit market. The retrofit high efficiency water heaters achieved their goal of reducing costs, maintaining savings potential and installed efficiency of other high efficiency water heaters, and meeting the necessary capacity in order to improve cost-effectiveness. However, the improvements were not sufficient to achieve simple paybacks of less than ten years for the incremental cost compared to a minimum efficiency heater. Significant changes would be necessary to reduce the simple payback to six years or less. Annual energy savings in the range of $200 would also reduce paybacks to less than six years. These energy savings would require either significantly higher fuel costs (greater than $1.50 per therm) or very high usage (around 120 gallons per day). For current incremental costs, the water heater efficiency would need to be similar to that of a heat pump water heater to deliver a six year payback.

  4. Simple Retrofit High-Efficiency Natural Gas Water Heater Field Test

    Energy Technology Data Exchange (ETDEWEB)

    Schoenbauer, Ben [NorthernSTAR, St. Paul, MN (United States)

    2017-03-28

    High performance water heaters are typically more time consuming and costly to install in retrofit applications, making high performance water heaters difficult to justify economically. However, recent advancements in high performance water heaters have targeted the retrofit market, simplifying installations and reducing costs. Four high efficiency natural gas water heaters designed specifically for retrofit applications were installed in single-family homes along with detailed monitoring systems to characterize their savings potential, their installed efficiencies, and their ability to meet household demands. The water heaters tested for this project were designed to improve the cost-effectiveness and increase market penetration of high efficiency water heaters in the residential retrofit market. The retrofit high efficiency water heaters achieved their goal of reducing costs, maintaining savings potential and installed efficiency of other high efficiency water heaters, and meeting the necessary capacity in order to improve cost-effectiveness. However, the improvements were not sufficient to achieve simple paybacks of less than ten years for the incremental cost compared to a minimum efficiency heater. Significant changes would be necessary to reduce the simple payback to six years or less. Annual energy savings in the range of $200 would also reduce paybacks to less than six years. These energy savings would require either significantly higher fuel costs (greater than $1.50 per therm) or very high usage (around 120 gallons per day). For current incremental costs, the water heater efficiency would need to be similar to that of a heat pump water heater to deliver a six year payback.

  5. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... Professions Site Index A-Z Computed Tomography (CT) - Head Computed tomography (CT) of the head uses special ... the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a CT ...

  6. Intermediate Ethanol Blends Catalyst Durability Program

    Energy Technology Data Exchange (ETDEWEB)

    West, Brian H; Sluder, Scott; Knoll, Keith; Orban, John; Feng, Jingyu

    2012-02-01

    In the summer of 2007, the U.S. Department of Energy (DOE) initiated a test program to evaluate the potential impacts of intermediate ethanol blends (also known as mid-level blends) on legacy vehicles and other engines. The purpose of the test program was to develop information important to assessing the viability of using intermediate blends as a contributor to meeting national goals for the use of renewable fuels. Through a wide range of experimental activities, DOE is evaluating the effects of E15 and E20 - gasoline blended with 15% and 20% ethanol - on tailpipe and evaporative emissions, catalyst and engine durability, vehicle driveability, engine operability, and vehicle and engine materials. This report provides the results of the catalyst durability study, a substantial part of the overall test program. Results from additional projects will be reported separately. The principal purpose of the catalyst durability study was to investigate the effects of adding up to 20% ethanol to gasoline on the durability of catalysts and other aspects of the emissions control systems of vehicles. Section 1 provides further information about the purpose and context of the study. Section 2 describes the experimental approach for the test program, including vehicle selection, aging and emissions test cycle, fuel selection, and data handling and analysis. Section 3 summarizes the effects of the ethanol blends on emissions and fuel economy of the test vehicles. Section 4 summarizes notable unscheduled maintenance and testing issues experienced during the program. The appendixes provide additional detail about the statistical models used in the analysis, detailed statistical analyses, and detailed vehicle specifications.

  7. High-performance, bare silver nanowire network transparent heaters.

    Science.gov (United States)

    Ergun, Orcun; Coskun, Sahin; Yusufoglu, Yusuf; Unalan, Husnu Emrah

    2016-11-04

    Silver nanowire (Ag NW) networks are one of the most promising candidates for the replacement of indium tin oxide (ITO) thin films in many different applications. Recently, Ag-NW-based transparent heaters (THs) showed excellent heating performance. In order to overcome the instability issues of Ag NW networks, researchers have offered different hybrid structures. However, these approaches not only require extra processing, but also decrease the optical performance of Ag NW networks. So, it is important to investigate and determine the thermal performance limits of bare-Ag-NW-network-based THs. Herein, we report on the effect of NW density, contact geometry, applied bias, flexing and incremental bias application on the TH performance of Ag NW networks. Ag-NW-network-based THs with a sheet resistance and percentage transmittance of 4.3 Ω sq(-1) and 83.3%, respectively, and a NW density of 1.6 NW μm(-2) reached a maximum temperature of 275 °C under incremental bias application (5 V maximum). With this performance, our results provide a different perspective on bare-Ag-NW-network-based transparent heaters.

  8. Asymmetric Pentagonal Metal Meshes for Flexible Transparent Electrodes and Heaters.

    Science.gov (United States)

    Lordan, Daniel; Burke, Micheal; Manning, Mary; Martin, Alfonso; Amann, Andreas; O'Connell, Dan; Murphy, Richard; Lyons, Colin; Quinn, Aidan J

    2017-02-08

    Metal meshes have emerged as an important class of flexible transparent electrodes. We report on the characteristics of a new class of asymmetric meshes, tiled using a recently discovered family of pentagons. Micron-scale meshes were fabricated on flexible polyethylene terephthalate substrates via optical lithography, metal evaporation (Ti 10 nm, Pt 50 nm), and lift-off. Three different designs were assessed, each with the same tessellation pattern and line width (5 μm), but with different sizes of the fundamental pentagonal unit. Good mechanical stability was observed for both tensile strain and compressive strain. After 1000 bending cycles, devices subjected to tensile strain showed fractional resistance increases in the range of 8-17%, while devices subjected to compressive strain showed fractional resistance increases in the range of 0-7%. The performance of the pentagonal metal mesh devices as visible transparent heaters via Joule heating was also assessed. Rapid response times (∼15 s) at low bias voltage (≤5 V) and good thermal resistance characteristics (213-258 °C cm(2)/W) were found using measured thermal imaging data. Deicing of an ice-bearing glass coupon on top of the transparent heater was also successfully demonstrated.

  9. Evaluation of Tube Wall Thickness of Feed Water Heater

    Science.gov (United States)

    Uchikura, Takahisa; Morisaki, Koichi; Hamada, Seiichi

    With regard to the high pressure (HP) feed water heater of thermal power plant at Tokyo Electric Power Company (TEPCO) sites, inspection of feed water (FW) tubes wall thickness are conducted whenever required such that frequent tube leak occurs. As a standard inspection methodology, FW heater is disassembled during planned outage, tube wall thickness is measured by the ultrasonic pulse techique (UT), then plugs are installed at the both ends of FW tube if its measured wall thickness is found below calculated threshold. However, the root causes of wall thinning of FW tube are various such as erosion and corrosion, based on wall thinning condition, the above threshold is not applied but utilizing the other technically well-grounded evaluation method is sometimes more rational. Therefore, TEPCO classified wall-thinning condition based on inspection data and established technically well-grounded and rational evaluation methodologies of FW tube wall thickness to suite each wall thinning condition. Moreover, with recent improvement of inspection technique, technology enabled faster, larger amount, and more accurate data acquisition, TEPCO has developed the systematized evaluation methodology that can transact data acquisition and evaluation simultaneously. This article introduces the logic of evaluation methods and examined algorithms to make them systematized.

  10. Eleana near-surface heater experiment final report

    Energy Technology Data Exchange (ETDEWEB)

    Lappin, A R; Thomas, R K; McVey, D F

    1981-04-01

    This report summarizes the results of a near-surface heater experiment operated at a depth of 23 m in argillite within the Eleana Formation on the Nevada Test Site (NTS). The test geometrically simulated emplacement of a single canister of High-Level Waste (HLW) and was operated at a power level of 2.5 kW for 21 days, followed by 3.8 kW to 250 days, when the power was turned off. Below 85 to 100{sup 0}C, there was good agreement between modeled and measured thermal results in the rock and in the emplacement hole, except for transient transport of water in the heater hole. Above 100{sup 0}C, modeled and measured thermal results increasingly diverged, indicating that the in-situ rock-mass thermal conductivity decreased as a result of dehydration more than expected on the basis of matrix properties. Correlation of thermomechanical modeling and field results suggests that this decrease was caused by strong coupling of thermal and mechanical behavior of the argillite at elevated temperatures. No hole-wall decrepitation was observed in the experiment; this fact and the codrrelation of modeled and measured results at lower temperatures indicate that there is no a priori reason to eliminate argillaceous rocks from further consideration as a host rock for nuclear wastes.

  11. A micro solar heater for portable energy generation

    Science.gov (United States)

    Zimmerman, Raúl; Morrison, Graham; The, Owen; Rosengarten, Gary

    2007-12-01

    This study presents a new concept that combines microtechnology with solar thermal energy to provide a free portable energy source. A water-methanol mixture flows through an array of parallel microchannels which are fabricated into a silicon matrix using conventional micro-fabrication techniques. A vacuum layer is interposed between the channels and the external surface to thermally insulate the channels from the ambient temperature. A selective coating is deposited on one of the vacuum walls to absorb the short wavelength incoming radiation and reduce the long wavelength radiation, hence reducing the heat losses. A geometry and material optimization is still being developed in order to obtain the highest possible efficiency for the micro-heater, while keeping a low pressure drop in the micro-channels. The methanol outlet temperature is predicted to be higher than 250°C. This temperature is required for hydrogen production in a methanol reforming micro-reactor. Therefore, it is envisaged that the micro-solar heater will supply the thermal energy needed for hydrogen generation, that can later be used as fuel for microfuel cells. Both technologies can be integrated in a portable device.

  12. 40 CFR 63.7491 - Are any boilers or process heaters not subject to this subpart?

    Science.gov (United States)

    2010-07-01

    ...., hazardous waste boilers). (e) A commercial and industrial solid waste incineration unit covered by 40 CFR... CATEGORIES (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Industrial, Commercial... process heaters not subject to this subpart? The types of boilers and process heaters listed in paragraphs...

  13. 46 CFR 52.01-35 - Auxiliary, donkey, fired thermal fluid heater, and heating boilers.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Auxiliary, donkey, fired thermal fluid heater, and... requirements for miscellaneous boiler types, such as donkey, fired thermal fluid heater, heating boiler, etc... (CONTINUED) MARINE ENGINEERING POWER BOILERS General Requirements § 52.01-35 Auxiliary, donkey, fired...

  14. CFD Study of Fluid Flow in an All-glass Evacuated Tube Solar Water Heater

    DEFF Research Database (Denmark)

    Ai, Ning; Fan, Jianhua; Li, Yumin

    2008-01-01

    Abstract: The all-glass evacuated tube solar water heater is one of the most widely used solar thermal technologies. The aim of the paper is to investigate fluid flow in the solar water heater by means of computational fluid dynamics (CFD). The investigation was carried out with a focus...

  15. 76 FR 28662 - Industrial, Commercial, and Institutional Boilers and Process Heaters and Commercial and...

    Science.gov (United States)

    2011-05-18

    ... AGENCY 40 CFR Parts 60 and 63 RIN 2060-AQ25; 2060-AO12 Industrial, Commercial, and Institutional Boilers and Process Heaters and Commercial and Industrial Solid Waste Incineration Units AGENCY: Environmental... Major Sources: Industrial, Commercial, and Institutional Boilers and Process Heaters'' and ``Standards...

  16. Demonstration of a heat pump water heater. Volume 3. Design report

    Energy Technology Data Exchange (ETDEWEB)

    Sloane, B.D.; Krise, R.C.; Kent, D.D.

    1979-12-01

    Work performed during the pilot run manufacturing and laboratory testing stages of a heat pump water heater for residential installations is described. A general description of the heat pump water heater is provided, as are detailed discussions of individual components. Also included is a description of the pilot run manufacturing facility and experience, laboratory operations, and laboratory test data.

  17. Analysis of Large- Capacity Water Heaters in Electric Thermal Storage Programs

    Energy Technology Data Exchange (ETDEWEB)

    Cooke, Alan L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Anderson, David M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Winiarski, David W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Carmichael, Robert T. [Cadeo Group, Washington D. C. (United States); Mayhorn, Ebony T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fisher, Andrew R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-03-17

    This report documents a national impact analysis of large tank heat pump water heaters (HPWH) in electric thermal storage (ETS) programs and conveys the findings related to concerns raised by utilities regarding the ability of large-tank heat pump water heaters to provide electric thermal storage services.

  18. Tankless water heaters fill the bill at fast-food restaurants

    Energy Technology Data Exchange (ETDEWEB)

    1988-02-01

    This article explains why Kentucky Fried Chicken has installed a PH-24 water heater. The tankless water heater meets the restaurant's criteria for space spacing, flow rates, certification and availability, and money saving efficiency. This article describes the system and its advantages.

  19. 75 FR 21981 - Energy Conservation Program: Energy Conservation Standards for Residential Water Heaters, Direct...

    Science.gov (United States)

    2010-04-27

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY 10 CFR Part 430 RIN 1904-AA90 Energy Conservation Program: Energy Conservation Standards for Residential Water Heaters, Direct Heating Equipment, and Pool Heaters Correction In rule document 2010-7611 beginning...

  20. High voltage bus and auxiliary heater control system for an electric or hybrid vehicle

    Science.gov (United States)

    Murty, Balarama Vempaty

    2000-01-01

    A control system for an electric or hybrid electric vehicle includes a vehicle system controller and a control circuit having an electric immersion heater. The heater is electrically connected to the vehicle's high voltage bus and is thermally coupled to a coolant loop containing a heater core for the vehicle's climate control system. The system controller responds to cabin heat requests from the climate control system by generating a pulse width modulated signal that is used by the control circuit to operate the heater at a duty cycle appropriate for the amount of cabin heating requested. The control system also uses the heater to dissipate excess energy produced by an auxiliary power unit and to provide electric braking when regenerative braking is not desirable and manual braking is not necessary. The control system further utilizes the heater to provide a safe discharge of a bank of energy storage capacitors following disconnection of the battery or one of the high voltage connectors used to transmit high voltage operating power to the various vehicle systems. The control circuit includes a high voltage clamping circuit that monitors the voltage on the bus and operates the heater to clamp down the bus voltage when it exceeds a pre-selected maximum voltage. The control system can also be used to phase in operation of the heater when the bus voltage exceeds a lower threshold voltage and can be used to phase out the auxiliary power unit charging and regenerative braking when the battery becomes fully charged.

  1. Analysis of Uncertainties in Protection Heater Delay Time Measurements and Simulations in Nb$_{3}$Sn High-Field Accelerator Magnets

    CERN Document Server

    Salmi, Tiina; Marchevsky, Maxim; Bajas, Hugo; Felice, Helene; Stenvall, Antti

    2015-01-01

    The quench protection of superconducting high-field accelerator magnets is presently based on protection heaters, which are activated upon quench detection to accelerate the quench propagation within the winding. Estimations of the heater delay to initiate a normal zone in the coil are essential for the protection design. During the development of Nb3Sn magnets for the LHC luminosity upgrade, protection heater delays have been measured in several experiments, and a new computational tool CoHDA (Code for Heater Delay Analysis) has been developed for heater design. Several computational quench analyses suggest that the efficiency of the present heater technology is on the borderline of protecting the magnets. Quantifying the inevitable uncertainties related to the measured and simulated delays is therefore of pivotal importance. In this paper, we analyze the uncertainties in the heater delay measurements and simulations using data from five impregnated high-field Nb3Sn magnets with different heater geometries. ...

  2. High thermal performance of SnO2:F thin transparent heaters with scattered metal nanodots.

    Science.gov (United States)

    Hudaya, Chairul; Jeon, Bup Ju; Lee, Joong Kee

    2015-01-14

    Facile production and novel transparent heaters consisting of fluorine-doped tin oxide (SnO2:F or FTO) thin films covered with three different scattered metal nanodots (Cr-nd, NiCr-nd and Ni-nd) prepared by plasma-enhanced sputtering system and electron cyclotron resonance-metal organic chemical vapor deposition are investigated. The heaters exhibit excellent optical transmittances of over 85% and superior saturated temperatures of more than 80 °C when a relatively low 12 V DC is supplied. The scattered metal nanodots FTO heaters successfully improve the specific power of bare FTO heater by 21, 15, and 12% for NiCr-nd FTO, Cr-nd FTO, and Ni-nd FTO, respectively. These results reveal that the FTO transparent heaters with scattered metal nanodots are the suitable heating materials that can be applied for various functional devices.

  3. Evaluation and certification of heater assemblies developed for thermal vacuum acceptance testing

    Science.gov (United States)

    Allen, J. E.

    1986-01-01

    Preparation of Rockwell International's Thermal Vacuum Chamber for acceptance testing of a mass produced satellite required the development of unique quartz lamp and hot wire heater assemblies. Testing performed on the basic elements of these heaters is described, as is the final testing done to certify that the heater assemblies meet the thermal requirements for acceptance testing. The methods and procedures of thermal mapping used during the development and final certification of these heater assemblies are presented. The absence of a definitive standard for determining flux distribution and heating boundaries for heaters of this type required the development of a test plan incorporating several thermal mapping techniques. These techniques include the development of heat flux using a multiple calorimeter array for both vacuum and ambient test conditions, and a photographic method for detecting heating boundaries. The test plan and thermal mapping techniques are discussed.

  4. Mutagenicity of organic emissions from unvented kerosene heaters in a chamber study.

    Science.gov (United States)

    Mumford, J L; Lewtas, J; Williams, K; Tucker, W G; Traynor, G W

    1992-06-01

    A study was conducted to assess the mutagenicity of semivolatile organics and particle-bound organics emitted from unvented kerosene space heaters. The units tested included a well-tuned radiant heater and a maltuned convective heater. The tests were conducted in a 27-m3 chamber with a prescribed on/off heater usage pattern. The organic emissions were collected on Teflon-coated glass filters backed by XAD-2 resin. The dichloromethane-extractable organics from both the filters and the XAD were analyzed for nitropolycyclic hydrocarbons using gas chromatography/mass spectrometry, and were bioassayed for mutagenicity in microsuspension assays using Salmonella typhimurium strains TA98 with and without S9 and TA98NR (a nitroreductase-deficient strain) without S9. The results showed that both the semivolatile and particle-bound organics emitted from the kerosene heaters were mutagenic, and the presence of nitropolycyclic hydrocarbons in these organic emissions substantiated these findings.

  5. Protection Heater Design Validation for the LARP Magnets Using Thermal Imaging

    CERN Document Server

    Marchevsky, M; Cheng, D W; Felice, H; Sabbi, G; Salmi, T; Stenvall, A; Chlachidze, G; Ambrosio, G; Ferracin, P; Izquierdo Bermudez, S; Perez, J C; Todesco, E

    2016-01-01

    Protection heaters are essential elements of a quench protection scheme for high-field accelerator magnets. Various heater designs fabricated by LARP and CERN have been already tested in the LARP high-field quadrupole HQ and presently being built into the coils of the high-field quadrupole MQXF. In order to compare the heat flow characteristics and thermal diffusion timescales of different heater designs, we powered heaters of two different geometries in ambient conditions and imaged the resulting thermal distributions using a high-sensitivity thermal video camera. We observed a peculiar spatial periodicity in the temperature distribution maps potentially linked to the structure of the underlying cable. Two-dimensional numerical simulation of heat diffusion and spatial heat distribution have been conducted, and the results of simulation and experiment have been compared. Imaging revealed hot spots due to a current concentration around high curvature points of heater strip of varying cross sections and visuali...

  6. Head Position and Internally Headed Relative Clauses.

    Science.gov (United States)

    Basilico, David

    1996-01-01

    Examines "Head Movement" in internally headed relative clauses (IHRCs). The article shows that in some cases, head movement to an external position need not take place and demonstrates that this movement of the head to a sentence-internal position results from the quantificational nature of IHRCs and Diesing's mapping hypothesis (1990, 1992). (56…

  7. Proceedings of a workshop on the utilization of coal fuels in process heaters

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-01

    Almost 5% of the nation's energy consumption takes place in tubular process heaters. Currently, these units are gas- and, to a lesser extent, oil-fired. Process heaters provide energy for refining petroleum and the manufacture of numerous chemicals and petrochemicals. Since the current state-of-the-art, using waste heat recovery and forced draft burners, can achieve thermal efficiencies of about 90%, it is unlikely that current process heat and fuel requirements will be dramatically reduced by process modifications and/or conservation measures. Hence, if this sizeable, inexorable drain on our fluid petroleum reserves is to be halted, it seems reasonable to consider the utilization of coal and/or coal-based fuels to fire process heaters. In order to assess the feasibility and potential for a coal-based process heater industry, Brookhaven National Laboratory (BNL) organized a workshop to define and explore the various problems that must be solved in order to burn coal in process heaters. A primary aim of the workshop was to consider the design methodology for process heaters when firing coal and compare it to those for gas and oil firing. The overall conclusions were: that retrofitting present process heaters to coal fuel was impractical; that it would be difficult to fit larger heaters designed to burn coal into present refineries; that there would be difficulties with process heaters burning coal; and that a better approach would be one large utility coal heater with a circulating heat transfer medium. Seven papers have been entered individually into EDB and ERA. (LTN)

  8. 10 CFR 431.106 - Uniform test method for the measurement of energy efficiency of commercial water heaters and hot...

    Science.gov (United States)

    2010-01-01

    ... Instantaneous Water Heaters and Hot Water Supply Boilers* Thermal Efficiency ANSI Z21.10.3-1998, § 2.9** A. For... Instantaneous Water Heaters and Hot Water Supply Boilers* Thermal Efficiency ANSI Z21.10.3-1998, § 2.9** (2) Oil...) Assume that the thermal efficiency (Et) of electric water heaters with immersed heating elements is...

  9. Prediction of heater power distribution in radiative cylindrical furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Ravichandran, M.; Dilber, I.; Torok, D.

    1999-07-01

    In the design of long radiative cylindrical furnaces, it is important to control the temperature variation along the furnace walls and consequently the temperature distribution in the processed material by selectively adjusting the power input to heater rods located circumferentially around the furnace walls. The heaters are grouped in zones located at different axial locations. By adjusting the power to each zone a specified temperature distribution along the furnace can be attained. The radiative interchange between different axial zones of the furnace affects the temperature distribution; this interchange is also impacted by the shadowing caused by the presence of the load, i.e. the processed material. A desired temperature distribution can only be achieved by selectively changing the power input to the heaters. For an a priori assessment of the commercial viability of using process friendly temperature distributions, it is necessary to determine: (a) the maximum power demand from each zone; (b) if active cooling is inevitable and (c) the bounds on temperature distribution that can be achieved without active cooling. It is therefore extremely useful to be able to predict the input power distribution for achieving desired furnace temperature profiles. For a given power input, the temperature distribution inside the furnace could be obtained by using a general purpose Computational Fluid Dynamics (CFD) software, such as FIDAP. A new methodology is developed within the framework of FIDAP software to eliminate the manual trial and error method. The method is based on obtaining the sensitivity of the temperature at the desired locations of the furnace as a function of the power input to the heating elements. Using these sensitivity coefficients, an iterative scheme is designed to adjust the boundary conditions (power to the heating elements in this case) based on the discrepancy of the solution temperatures from the desired temperature distribution. For each of these

  10. Analysis of thermal stresses in horizontal delivery water heaters

    Science.gov (United States)

    Bilan, A. V.; Plotnikov, P. N.

    2016-11-01

    Analysis of thermal stresses in tubes and a compensator, taking into account water heating in each heater bunch and temperature at which its mounting is implemented, and of stresses on pressure is presented. The 3D-model of the horizontal delivery water heater of PSG-4900-0.3-1.14 type is used. The tube plate is represented as the 3D-body with 6863 holes with offset center of the perforated area, the steam space shell is represented as a cylindrical casing, the bottoms of water chambers are considered as elliptical casings, the four-lens compensator is represented in the form of toroidal casings, and the tubes are considered as beams operating in tensile-compression and bending in two planes. Calculations were carried out for different temperatures of superheated steam and a steam space shell, respectively, as well as designs with compensator and without it. Various temperature values of the tubes on the passes were calculated and set. The studies were carried out taking into account nonaxis-symmetrical spacing the tube plate and compensator deformation. The calculation results of tensile-compression stresses in the tubes are presented. Furthermore, the central tubes experience compressive stresses, whose maximal values take place on the border between the tubes of the fourth and of the first passes. For its decrease, it is recommended to increase the distance between the tubes of these passes. The tension stresses in the peripheral tubes are the maximal stresses. To reduce the stresses and, therefore, increase service life of the delivery water heater at using wet or superheated (not more than by 30-50°C) steam in it (the larger value refers to the brass tubes and the water pressure of 1.6-2.5 MPa), it is necessary to recommend the noncompensatory design at using the steam superheated by more than 30-50°C (at Ural Turbine Works, it is the turbines of T-250/300-23.5 and T-113/145-12.4 types with intermediate superheating) and to recommend the installation of the

  11. Controlled cellular fusion using optically trapped plasmonic nano-heaters

    Science.gov (United States)

    Bahadori, Azra; Lund, Andreas R.; Semsey, Szabolcs; Oddershede, Lene B.; Bendix, Poul M.

    2016-09-01

    Optically trapped plasmonic nano-heaters are used to mediate efficient and controlled fusion of biological membranes. The fusion method is demonstrated by optically trapping plasmonic nanoparticles located in between vesicle membranes leading to rapid lipid and content mixing. As an interesting application we show how direct control over fusion can be used for studying diffusion of peripheral membrane proteins and their interactions with membranes and for studying protein reactions. Membrane proteins encapsulated in an inert vesicle can be transferred to a vesicle composed of negative lipids by optically induced fusion. Mixing of the two membranes results in a fused vesicle with a high affinity for the protein and we observe immediate membrane tubulation due to the activity of the protein. Fusion of distinct membrane compartments also has applications in small scale chemistry for realizing pico-liter reactions and offers many exciting applications within biology which are discussed here.

  12. Thermoacoustic Stirling Heat Pump Working as a Heater

    Science.gov (United States)

    Bassem, Mohamed Mehdi; Ueda, Yuki; Akisawa, Atsushi

    2011-10-01

    A prototype thermoacoustic heat pump working as a heater was demonstrated. The heat pump was composed of an acoustic driver, a branched tube, and a looped tube containing a regenerator; the looped tube was connected to the acoustic driver via the branched tube, and the regenerator consisted of many narrow flow channels. The measurement results of the acoustic impedance inside the looped tube indicated that the energy conversion of the acoustic power flow into the acoustic heat flow in the regenerator occurred through the inherently efficient Stirling cycle. Moreover, the heat pump generated a hot temperature of 370 °C, corresponding to a temperature lift along the regenerator of 340 °C.

  13. THE HEAT AND FLUID FLOW ANALYSIS FOR WATER HEATER

    Directory of Open Access Journals (Sweden)

    Chien-Nan Lin

    2011-01-01

    Full Text Available In this paper, the heat transfer and fluid flow are studied for the water heater of RV cars, in which the hot water is heated by the combustion energy of liquefied petroleum gases. Three types of combustion tubes are performed in this investigation, which are circular tube, elliptic tube and elliptic tube with screwed wire inserted. The heat transfer performances of numerical simulation results are compared with those of the experimental works; they are in good trend agreement. The elliptic combustion tube performs better than the circular one, which indicates the average 7% energy saving for the elliptic combustion tube and 12% energy saving for the elliptic combustion tube with screwed wire under static heating.

  14. Thin Film Heater for Removable Volatile Protecting Coatings

    Directory of Open Access Journals (Sweden)

    Abid Karim

    2013-01-01

    Full Text Available Freshly coated aluminum mirrors have excellent reflectivity at far ultraviolet wavelengths. However, reflectivity rapidly degrades when the mirror surfaces are exposed to atmosphere. In order to avoid this problem, freshly coated aluminum surface can be protected by over-coating of a removable volatile protecting coating. This protecting coating can be re-evaporated by controlled heating or by some other methods when required. This type of removable coating has immediate application in UV space astronomy. The purpose of this paper is to demonstrate the feasibility of re-evaporation of removable volatile Zn protecting coating using a NiCr thin film heater without affecting the reflection properties of Al mirror surfaces.

  15. Modelling of Closed Loop Class E Inverter Based Induction Heater

    Directory of Open Access Journals (Sweden)

    S. Arumugam

    2011-01-01

    Full Text Available This study presents simulation of class E inverter based induction heater system using simulink. DC is converted into high frequency AC using class E inverter. This high frequency AC is used for induction heating. Closed loop systems are modeled and they are simulated using Mat lab Simulink.The results of closed loop systems are presented. The proposed amplifier with two series-parallel resonant load networks will allow sinusoidal output voltage to be achieved by associating with the positive and negative quasi-sinusoidal waveforms. The complementarily activated configuration will provide continuous high-ripple-frequency inputcurrent waveforms; this approach significantly reduces electromagnetic interference and requires very little filtering. With the symmetry of the push-pull Class-E Circuit, there is the additional benefit that the even harmonics are suppressed at the load, and thus there are fewer harmonic distortions.

  16. Constant delivery temperature solar water heater - an integrated approach

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S. [C.A.S. Indian Institute of Technology, New Delhi (India); Kumar, N. [D.C.E. Muzaffarpur Institute of Technology, Bihar (India)

    1997-05-01

    An integrated model of a constant delivery temperature solar water heat-cum-active regenerative distillation system has been developed. The water used for the regenerative effect in the distiller of the proposed system is subsequently fed to the basin-cum-storage tank of the still through the heat exchanger (connected to the collector). The model varies the water mass flow rate in order to maintain a constant outlet temperature. With minor modifications in the solar water heater, the extra energy stored in the water mass due to non-utilization of capacity and/or non-linear utilization of capacity can be efficiently utilized for distillation purposes. In this process, the latent heat of vaporization is used for preheating the inlet water supply to the heat exchanger. The effect of insulation on maintaining the hot water temperature and distillate output is also presented. (Author)

  17. FEM Optimal Design of Wind Energy-based Heater

    Directory of Open Access Journals (Sweden)

    Tiberiu Tudorache

    2009-07-01

    Full Text Available This paper deals with the finite element based optimal design of a wind energybased heater. The proposed device ensures the conversion of the wind kinetic energy intoheat by means of Joule effect of eddy currents induced in the wall of a tubular stator due tothe rotating magnetic field produced by rotor permanent magnets. The transientelectromagnetic field problem associated to the operation of the device is solved using a2D finite element approach based on vector potential formulation. A simplified method forthe 2D heat transfer analysis of the device is also proposed. The influence of stator wallmaterial and thickness, number of poles, the airgap thickness and the geometricalparameters of the permanent magnets is analyzed in the aim of optimizing the studiedheater.

  18. Durable fear memories require PSD-95

    Science.gov (United States)

    Fitzgerald, Paul J.; Pinard, Courtney R.; Camp, Marguerite C.; Feyder, Michael; Sah, Anupam; Bergstrom, Hadley; Graybeal, Carolyn; Liu, Yan; Schlüter, Oliver; Grant, Seth G.N.; Singewald, Nicolas; Xu, Weifeng; Holmes, Andrew

    2014-01-01

    Traumatic fear memories are highly durable but also dynamic, undergoing repeated reactivation and rehearsal over time. While overly persistent fear memories underlie anxiety disorders such as posttraumatic stress disorder, the key neural and molecular mechanisms underlying fear memory durability remain unclear. Post-synaptic density 95 (PSD-95) is a synaptic protein regulating glutamate receptor anchoring, synaptic stability and certain types of memory. Employing a loss-of-function mutant mouse lacking the guanylate kinase domain of PSD-95 (PSD-95GK), we analyzed the contribution of PSD-95 to fear memory formation and retrieval, and sought to identify the neural basis of PSD-95-mediated memory maintenance using ex vivo immediate-early gene mapping, in vivo neuronal recordings and viral-mediated knockdown approaches. We show that PSD-95 is dispensable for the formation and expression of recent fear memories, but essential for the formation of precise and flexible fear memories and for the maintenance of memories at remote time points. The failure of PSD-95GK mice to retrieve remote cued fear memories was associated with hypoactivation of the infralimbic cortex (IL) (not anterior cingulate (ACC) or prelimbic cortex), reduced IL single-unit firing and bursting, and attenuated IL gamma and theta oscillations. Adeno-associated PSD-95 virus-mediated knockdown in the IL, not ACC, was sufficient to impair recent fear extinction and remote fear memory, and remodel IL dendritic spines. Collectively, these data identify PSD-95 in the IL as a critical mechanism supporting the durability of fear memories over time. These preclinical findings have implications for developing novel approaches to treating trauma-based anxiety disorders that target the weakening of overly persistent fear memories. PMID:25510511

  19. (Durability of building materials and components)

    Energy Technology Data Exchange (ETDEWEB)

    Naus, D.J.

    1990-11-27

    The traveler participated in the fourth meeting of RILEM 100-TSL, Techniques for Service Life Prediction,'' and The Fifth International Conference on Durability of Building Materials and Components.'' In addition, the traveler met with staff members at Taywood Engineering Ltd., Electricite de France, and AEA Technology. The meeting pertained to performance of concrete materials in nuclear power plant structures, time variation of concrete material properties, methods for evaluating concrete structures, and modeling to predict the effects of degradation factors on concrete materials. As many of the concrete structures in general civil engineering applications as well as nuclear power plant applications in Europe are aging, there is increasing emphasis on assessing the durability of these structures. Information was provided of direct application to the Structural Aging Program which would not have been available without these visits. Of equal, or possibly more importance, was the individual contacts established at the organizations visited. Each organization was extremely interested in both the approach and scope of the Structural Aging Program and requested that they be informed of progress. The initial steps were taken to cooperate with several of these researchers and this should help the Structural Aging Program keep abreast of related European activities. In summary, information obtained during this trip will benefit the ongoing Structural Aging Program by informing Oak Ridge National Laboratory (ORNL) of the extensive European research programs addressing the durability of concrete structures, and also by forming and strengthening acquaintances with counterparts in other countries, thus enhancing the basis for possible international cooperation.

  20. Durable fear memories require PSD-95.

    Science.gov (United States)

    Fitzgerald, P J; Pinard, C R; Camp, M C; Feyder, M; Sah, A; Bergstrom, H C; Graybeal, C; Liu, Y; Schlüter, O M; Grant, S G; Singewald, N; Xu, W; Holmes, A

    2015-07-01

    Traumatic fear memories are highly durable but also dynamic, undergoing repeated reactivation and rehearsal over time. Although overly persistent fear memories underlie anxiety disorders, such as posttraumatic stress disorder, the key neural and molecular mechanisms underlying fear memory durability remain unclear. Postsynaptic density 95 (PSD-95) is a synaptic protein regulating glutamate receptor anchoring, synaptic stability and certain types of memory. Using a loss-of-function mutant mouse lacking the guanylate kinase domain of PSD-95 (PSD-95(GK)), we analyzed the contribution of PSD-95 to fear memory formation and retrieval, and sought to identify the neural basis of PSD-95-mediated memory maintenance using ex vivo immediate-early gene mapping, in vivo neuronal recordings and viral-mediated knockdown (KD) approaches. We show that PSD-95 is dispensable for the formation and expression of recent fear memories, but essential for the formation of precise and flexible fear memories and for the maintenance of memories at remote time points. The failure of PSD-95(GK) mice to retrieve remote cued fear memory was associated with hypoactivation of the infralimbic (IL) cortex (but not the anterior cingulate cortex (ACC) or prelimbic cortex), reduced IL single-unit firing and bursting, and attenuated IL gamma and theta oscillations. Adeno-associated virus-mediated PSD-95 KD in the IL, but not the ACC, was sufficient to impair recent fear extinction and remote fear memory, and remodel IL dendritic spines. Collectively, these data identify PSD-95 in the IL as a critical mechanism supporting the durability of fear memories over time. These preclinical findings have implications for developing novel approaches to treating trauma-based anxiety disorders that target the weakening of overly persistent fear memories.

  1. Durability of Polymeric Glazing and Absorber Materials

    Energy Technology Data Exchange (ETDEWEB)

    Jorgensen, G.; Terwilliger, K.; Bingham, C.; Lindquist, C.; Milbourne, M.

    2005-11-01

    The Solar Heating and Lighting Program has set the goal of reducing the cost of solar water heating systems by at least 50%. An attractive approach to such large cost reduction is to replace glass and metal parts with less-expensive, lighter-weight, more-integrated polymeric components. The key challenge with polymers is to maintain performance and assure requisite durability for extended lifetimes. We have begun evaluation of several new UV-screened polycarbonate sheet glazing constructions. This has involved interactions with several major polymer industry companies to obtain improved candidate samples. Proposed absorber materials were tested for UV resistance, and appear adequate for unglazed ICS absorbers.

  2. The Durability of Epoxy Resin Coating

    Institute of Scientific and Technical Information of China (English)

    ZHAO Fujun; BA Hengjing; GAO Xiaojian

    2008-01-01

    The durability of epoxy resin coating was studied under environments with relative humidity(RH) of 98%-100%, at 55 ℃ for 900 h, at 65℃ for 700 h and at 75 ℃ for 400 h, respectively. Peel strength test, dynamical mechanical thermal analysis (DMTA), infrared spectroscopy (IR) and energy dispersive X-ray spectroscopy (EDX) were employed for measurements. Peel strength indicated the development of adhesive property of the coating, DMTA indicated the development of physical property, IR revealed the development of chemical structure, and EDX showed surface element change of the coating. All these results show a good time-temperature equivalence characteristic between humidity aging time and temperature.

  3. Pour une agriculture mondiale, productive et durable

    OpenAIRE

    Gautier, Henri

    2015-01-01

    Ancien directeur du département Agriculture et développement durable de la Banque mondiale, Michel Petit nous livre un essai directement inspiré de son expérience au service des agricultures du monde. La critique du productivisme, en particulier de son impact sur les ressources naturelles, peut-elle faire l’impasse sur le rôle déterminant de la productivité agricole dans les processus de développement économique ? Dans la lignée des travaux de Théodore Schultz, prix Nobel d’économie en 1979 p...

  4. Durability of cracked fibre reinforced concrete structures

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan De Place

    1998-01-01

    Durability studies are carried out at BKM as part of the research project "Design Methods for Fibre Reinforced Concrete" (FRC) involving BKM, The Concrete Research Center at DTI, Building Technology at Aalborg University, Rambøll, 4K-Beton and Rasmussen & Schiøtz. Concrete beams with or without...... structure are made on specimens drilled or sawed from beams after unloading (mechanical load). The pore structure of the concretes will be studied by microscopy, sorption and suction curves. The test programme involves three different concrete qualities (water-cement ratios). Both steel fibres (ZP...

  5. Durable, Low-Surface-Energy Treatments

    Science.gov (United States)

    Willis, Paul B.; Mcelroy, Paul M.; Hickey, Gregory S.

    1992-01-01

    Chemical treatment for creation of durable, low-surface-energy coatings for glass, ceramics and other protonated surfaces easily applied, and creates very thin semipermanent film with extremely low surface tension. Exhibits excellent stability; surfaces retreated if coating becomes damaged or eroded. Uses include water-repellent surfaces, oil-repellent surfaces, antimigration barriers, corrosion barriers, mold-release agents, and self-cleaning surfaces. Film resists wetting by water, alcohols, hydrocarbon solvents, and silicone oil. Has moderate resistance to abrasion, such as rubbing with cloths, and compression molding to polymers and composite materials.

  6. DURABILITY OF ASPHALT CONCRETE MIXTURES USING DOLOMITE AGGREGATES

    Directory of Open Access Journals (Sweden)

    Imad Al-Shalout

    2015-12-01

    Full Text Available This study deals with the durability of asphalt concrete, including the effects of different gradations, compaction temperatures and immersion time on the durability potential of mixtures. The specific objectives of this study are: to investigate the effect of compaction temperature on the mechanical properties of asphalt concrete mixtures; investigate the effect of bitumen content and different aggregate gradations on the durability potential of bituminous mixtures.

  7. Plasma spark discharge reactor and durable electrode

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Young I.; Cho, Daniel J.; Fridman, Alexander; Kim, Hyoungsup

    2017-01-10

    A plasma spark discharge reactor for treating water. The plasma spark discharge reactor comprises a HV electrode with a head and ground electrode that surrounds at least a portion of the HV electrode. A passage for gas may pass through the reactor to a location proximate to the head to provide controlled formation of gas bubbles in order to facilitate the plasma spark discharge in a liquid environment.

  8. Three-Dimensional Printable High-Temperature and High-Rate Heaters.

    Science.gov (United States)

    Yao, Yonggang; Fu, Kun Kelvin; Yan, Chaoyi; Dai, Jiaqi; Chen, Yanan; Wang, Yibo; Zhang, Bilun; Hitz, Emily; Hu, Liangbing

    2016-05-24

    High temperature heaters are ubiquitously used in materials synthesis and device processing. In this work, we developed three-dimensional (3D) printed reduced graphene oxide (RGO)-based heaters to function as high-performance thermal supply with high temperature and ultrafast heating rate. Compared with other heating sources, such as furnace, laser, and infrared radiation, the 3D printed heaters demonstrated in this work have the following distinct advantages: (1) the RGO based heater can operate at high temperature up to 3000 K because of using the high temperature-sustainable carbon material; (2) the heater temperature can be ramped up and down with extremely fast rates, up to ∼20 000 K/second; (3) heaters with different shapes can be directly printed with small sizes and onto different substrates to enable heating anywhere. The 3D printable RGO heaters can be applied to a wide range of nanomanufacturing when precise temperature control in time, placement, and the ramping rate are important.

  9. Thermal response of transparent silver nanowire/PEDOT:PSS film heaters.

    Science.gov (United States)

    Ji, Shulin; He, Weiwei; Wang, Ke; Ran, Yunxia; Ye, Changhui

    2014-12-10

    Thermal response behavior of transparent silver nanowire/PEDOT:PSS film heaters are intensively studied for manipulating heating temperature, response time, and power consumption. Influences of substrate heat capacity, heat transfer coefficient between air and heater, sheet resistance and dimension of Ag nanowire film, on the thermal response are investigated from thermodynamic analysis. Suggestion is given for practical applications that if other parameters are fixed, Ag nanowire coverage can be utilized as an effective parameter to adjust the thermal response. The heat transfer coefficient plays opposite roles on thermal response speed and achievable steady temperature. A value of ≈32 W m(-2) K(-1) is obtained from transient process analysis after correcting it by considering heater resistance variation during heating tests. Guidance of designing heaters with a given response time is provided by forming Ag nanowire film with a suitable sheet resistance on substrate of appropriate material and a certain thickness. Thermal response tests of designed Ag heaters are performed to show higher heating temperature, shorter response time, and lower power consumption (179 °C cm(2) W(-1)) than ITO/FTO heaters, as well as homogeneous temperature distribution and stability for repeated use. Potential applications of the Ag heaters in window defogging, sensing and thermochromism are manifested.

  10. Three-dimensional temperature field in a line-heater embedded by a spiral electric resistor

    Energy Technology Data Exchange (ETDEWEB)

    Hsiao, S.Y.; Wei, P.S.; Wang, Z.P. [Department of Mechanical and Electro-Mechanical Engineering, National Sun Yat-Sen University, 70, Lien-hai Road, Kaohsiung 804, Taiwan (China)

    2006-06-15

    In this study, three-dimensional temperature fields induced by AC and DC through a spiral electric resistor in a line-heater are numerically investigated. Electric heaters have been widely found, for example, in houses as dryers, stoves, and water heaters, and in industrial and research institutions as elements of equipments. The line-heater in the present model is realistically considered to have multiple regions composed of a spiral electric resistor, electrically insulated region, covering outer layer, and two terminal pins with distinct thermal and electrical properties. Solving unsteady three-dimensional heat conduction equations in distinct regions, the surface temperatures predicted as a function of time in this model are confirmed by the measured data. The calculated results quantitatively show that high surface temperatures of the heater can be reached by increasing dimensionless joule heat parameter, radius of the spiral electric resistor or pins, thermal diffusivity of the insulation region, and decreasing Biot number and radius of insulation region. The effects of the pins on surface temperature are also studied. Aside from showing that DC produces higher temperature than AC, the results indicate that the effects of current frequency on temperature fields are insignificant. The findings can be generalized to a curved heater, because any local location can be considered as a small line-segment. The present work provides general and quantitative data valuable for designing an efficient heater/furnace. [Author].

  11. Improving durability of hot forging tools by applying hybrid layers

    Directory of Open Access Journals (Sweden)

    Z. Gronostajski

    2015-10-01

    Full Text Available This paper deals with problems relating to the durability of the dies used for the hot forging of spur gears. The results of industrial tests carried out on dies with a hybrid layer (a nitrided layer (PN + physical vapor deposition (PVD coating applied to improve their durability are presented. Two types of hybrid layers, differing in their PVD coating, were evaluated with regard to their durability improvement effectiveness. The tests have shown that by applying hybrid layers of the nitrided layer/PVD coating type one can effectively increase the durability of hot forging tools.

  12. Durability of composites in a marine environment

    CERN Document Server

    Rajapakse, Yapa

    2014-01-01

    Composites are widely used in marine applications. There is considerable experience of glass reinforced resins in boats and ships but these are usually not highly loaded. However, for new areas such as offshore and ocean energy there is a need for highly loaded structures to survive harsh conditions for 20 years or more. High performance composites are therefore being proposed. This book provides an overview of the state of the art in predicting the long term durability of composite marine structures. The following points are covered: •       Modelling water diffusion •       Damage induced by water •       Accelerated testing •       Including durability in design •       In-service experience. This is essential reading for all those involved with composites in the marine industry, from initial design and calculation through to manufacture and service exploitation. It also provides information unavailable elsewhere on the mechanisms involved in degradation and how to t...

  13. Durable Nanocomposites for Superhydrophobicity and Superoleophobicity

    Science.gov (United States)

    Steele, Adam

    Anti-wetting surfaces and materials have the potential for dramatic performance improvements such as drag reduction on marine vehicles and fluid power systems as well as anti-fouling on aircraft and wind turbines. Although a wide variety of synthetic superhydrophobic surfaces have been developed and investigated, several critical obstacles remain before industrial application can be realized, including: (1) large surface area application, (2) multi-liquid anti-wetting, (3) environmentally friendly compositions, (4) mechanical durability and adhesion, and (5) long-term performance. In this dissertation, nanocomposite coatings have been investigated to generate high performance anti-wetting surfaces that address these obstacles which may enable application on wind turbine blades. Solution processable materials were used which self-assemble to create anti-wetting nanocomposite surfaces upon spray coating and curing. As a result, the first superoleophobic nanocomposite, the first environmentally friendly superhydrophobic compositions, and the first highly durable superhydrophobic nanocomposite coatings were created. Furthermore, the mechanisms leading to this improved performance were studied.

  14. CHP Fuel Cell Durability Demonstration - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Petrecky, James; Ashley, Christopher J

    2014-07-21

    Plug Power has managed a demonstration project that has tested multiple units of its high-temperature, PEM fuel cell system in micro-combined heat and power (μ-CHP) applications in California. The specific objective of the demonstration project was to substantiate the durability of GenSys Blue, and, thereby, verify its technology and commercial readiness for the marketplace. In the demonstration project, Plug Power, in partnership with the National Fuel Cell Research Center (NFCRC) at the University of California, Irvine (UCI), and Sempra, will execute two major tasks: • Task 1: Internal durability/reliability fleet testing. Six GenSys Blue units will be built and will undergo an internal test regimen to estimate failure rates. This task was modified to include 3 GenSys Blue units installed in a lab at UCI. • Task 2: External customer testing. Combined heat and power units will be installed and tested in real-world residential and/or light commercial end user locations in California.

  15. Is HEADS in our heads?

    DEFF Research Database (Denmark)

    Boisen, Kirsten A; Hertz, Pernille Grarup; Blix, Charlotte

    2016-01-01

    BACKGROUND: Outpatient clinic visits are a window of opportunity to address health risk behaviors and promote a healthier lifestyle among young people. The HEADS (Home, Education, Eating, Activities, Drugs [i.e. substance use including tobacco, alcohol, and illegal drugs], Sexuality [including...... care professionals participated. We found only small reported differences between staff and young patients regarding whether home, education, and activity were addressed. However, staff reported twice the rate of addressing smoking, alcohol, illegal drugs, sexuality, and contraception compared to young...... patients. Young patients reported that smoking, alcohol, illegal drugs, sexuality, and contraception were addressed significantly more at adult clinics in comparison to pediatric clinics. After controlling for age, gender and duration of illness, according to young patients, adjusted odds ratios...

  16. Effects of heater location and heater size on the natural convection heat transfer in a square cavity using finite element method

    Energy Technology Data Exchange (ETDEWEB)

    Ngo, Ich Long; Byon, Chan [Yeungnam University, Gyeongsan (Korea, Republic of)

    2015-07-15

    Finite element method was used to investigate the effects of heater location and heater size on the natural convection heat transfer in a 2D square cavity heated partially or fully from below and cooled from above. Rayleigh number (5 X 10{sup 2} ≤ Ra ≤ 5X10{sup 5}), heater size (0.1 ≤ D/L ≤ 1.0), and heater location (0.1 ≤ x{sub h}/L ≤ 0.5) were considered. Numerical results indicated that the average Nusselt number (Nu{sub m}) increases as the heater size decreases. In addition, when x{sub h}/L is less than 0.4, Nu{sub m} increases as x{sub h}/L increases, and Num decreases again for a larger value of x{sub h}/L. However, this trend changes when Ra is less than 10{sup 4}, suggesting that Nu{sub m} attains its maximum value at the region close to the bottom surface center. This study aims to gain insight into the behaviors of natural convection in order to potentially improve internal natural convection heat transfer.

  17. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... of the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a ... of page What are some common uses of the procedure? CT scanning of the head is typically ...

  18. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... of the Head? What is CT Scanning of the Head? Computed tomography, more commonly known as a ... of page What are some common uses of the procedure? CT scanning of the head is typically ...

  19. Head Impact Laboratory (HIL)

    Data.gov (United States)

    Federal Laboratory Consortium — The HIL uses testing devices to evaluate vehicle interior energy attenuating (EA) technologies for mitigating head injuries resulting from head impacts during mine/...

  20. Soil Stabilization: A Durability Test for Stabilized Soils

    Science.gov (United States)

    tensile strength at the surface of test specimens (slabs) subjected to laboratory cycles of weathering. This test, called the Durability Tensile Test , is...have been shown elsewhere to cause a loss in effective cohesion, also result in a loss in tensile strength. Therefore the Durability Tensile Test appears

  1. Further steps towards a quantitative approach to durability design

    NARCIS (Netherlands)

    Lounis, Z.; Lacasse, M.A.; Siemes, A.J.M.; Moser, K.

    1998-01-01

    Abstract This paper presents further steps in the development of reliability-based approaches for the durability design and service life prediction of building components which integrate the requirements of safety, serviceability and durability. In general, the load and resistance should be modelled

  2. Swift BAT Thermal Recovery After Loop Heat Pipe #0 Secondary Heater Controller Failure in October 2015

    Science.gov (United States)

    Choi, Michael K.

    2016-01-01

    The Swift BAT LHP #0 primary heater controller failed on March 31, 2010. It has been disabled. On October 31, 2015, the secondary heater controller of this LHP failed. On November 1, 2015, the LHP #0 CC temperature increased to as 18.6 C, despite that the secondary heater controller set point was 8.8 C. It caused the average DM XA1 temperature to increase to 25.9 C, which was 5 C warmer than nominal. As a result, the detectors became noisy. To solve this problem, the LHP #1 secondary heater controller set point was decreased in 0.5 C decrements to 2.2 C. The set-point decrease restored the average DM XA1 temperature to a nominal value of 19.7 C on November 21.

  3. Numerical Simulation of Induction Through-Heater in Dynamic Operation Mode

    Directory of Open Access Journals (Sweden)

    SCURTU Gheorghe Lucian

    2013-05-01

    Full Text Available The numeric model used in this paper is based on the finite element method and is aiming an inductive heating in volume of a cylindrical structure in a dynamic operation mode. Nowadays the inductionthrough-heaters are usually designed to provide the required characteristics in “quasi” steady-state operation mode mainly. However, in industrial practice the heaters can operate under various disturbances more than half of time, so the transient process playsignificant role in effectiveness and quality of the heating. Investigation of dynamic characteristics of the heaters in dynamic modes can be only done by numerical modeling based on special algorithms providing a time loop additionally to coupling betweenelectromagnetic and thermal analysis. Such numerical models have been developed and used for investigation of dynamic modes for heating billets. The results of numerical simulation can be used for design ofinduction through-heaters and improvement of their characteristics in dynamic operation modes.

  4. Analytical model for ring heater thermal compensation in the Advanced Laser Interferometer Gravitational-wave Observatory.

    Science.gov (United States)

    Ramette, Joshua; Kasprzack, Marie; Brooks, Aidan; Blair, Carl; Wang, Haoyu; Heintze, Matthew

    2016-04-01

    Advanced laser interferometer gravitational-wave detectors use high laser power to achieve design sensitivity. A small part of this power is absorbed in the interferometer cavity mirrors where it creates thermal lenses, causing aberrations in the main laser beam that must be minimized by the actuation of "ring heaters," which are additional heater elements that are aimed to reduce the temperature gradients in the mirrors. In this article we derive the first, to the best of our knowledge, analytical model of the temperature field generated by an ideal ring heater. We express the resulting optical aberration contribution to the main laser beam in this axisymmetric case. Used in conjunction with wavefront measurements, our model provides a more complete understanding of the thermal state of the cavity mirrors and will allow a more efficient use of the ring heaters in the Advanced Laser Interferometer Gravitational-wave Observatory.

  5. Self-regulating heater application to Shuttle/Centaur hydrazine fuel line thermal control

    Science.gov (United States)

    Unkrich, David B.

    1987-01-01

    The Shuttle/Centaur high energy upper stage vehicle thermal environments were more severe than previous Centaur vehicle thermal environments, creating need for a new hydrazine fuel line thermal control technique. Constant power heaters did not satisfy power dissipation requirements, because the power required to maintain fuel line thermal control during cold conditions exceeded the maximum power allowable during hot conditions. Therefore, a Raychem Thermolimit self-regulating heater was selected for this application, and was attached to the hydrazine fuel line with Kapton and aluminum foil tapes. Fuel line/heater thermal modeling and subsequent thermal vacuum chamber testing simulated heater thermal performance during all worst-case Shuttle/Centaur thermal environmental conditions. Fuel line temperatures were maintained between the 4C to 71C limits during all analytical and test cases. Finally, the thermal model predictions were correlated with the test data, thereby ensuring that the model would provide satisfactory predictions for future missions and/or vehicles.

  6. REFINED METHOD OF COMPUTING MODES OF OPERATING OF CAPACITY-TYPE SOLAR HEATERS OF

    Directory of Open Access Journals (Sweden)

    Ermuratschii Vl.V.

    2008-04-01

    Full Text Available The refined method procedure of thermal modes of solar heaters of water of the capacity type, based on use of an electro-thermal equivalent circuit and a method of central potentials is presented.

  7. Towards the Development of a Novel CNTs-based Flexible Mild Heater for Art Conservation

    Directory of Open Access Journals (Sweden)

    Tomas Markevicius

    2014-03-01

    tests performed on a series of prototypes of the designed heaters showed that the device was able to convey uniform heating on different working materials, thus proving to be effective for thermal consolidation.

  8. Temperature Profiles During Quenches in LHC Superconducting Dipole Magnets Protected by Quench Heaters

    CERN Document Server

    Maroussov, V; Siemko, A

    2000-01-01

    The efficiency of the magnet protection by quench heaters was studied using a novel method which derives the temperature profile in a superconducting magnet during a quench from measured voltage signals. In several Large Hadron Collider single aperture dipole models, temperature profiles and temperature gradients in the magnet coil have been evaluated in the case of protection by different sets of quench heaters and different powering and protection parameters. The influence of the insulation thickness between the quench heaters and the coil has also been considered. The results show clear correlation between the positions of quench heaters, magnet protection parameters and temperature profiles. This study allowed a better understanding of the quench process mechanisms and the efficiency assessment of the different protection schemes.

  9. Natural Convection of Nanofluids in a Square Enclosure with a Protruding Heater

    Directory of Open Access Journals (Sweden)

    J. Guiet

    2012-01-01

    Full Text Available This paper reports a numerical study on natural convection from a protruding heater located at the bottom of a square cavity filled with a copper-water nanofluid. The vertical walls of the cavity are cooled isothermally; the horizontal ones are adiabatic, and the heater is attached to the bottom wall. The heat source is assumed either to be isothermal or to have a constant heat flux. The effective viscosity and thermal conductivity of the nanofluid are modeled according to Brinkman and Patel, respectively. Numerical solutions of the full-governing equations, based on the lattice Boltzmann method, are obtained for a wide range of the governing parameters: the Rayleigh number, Ra; the Prandtl number, Pr; the geometrical parameters specifying the heater; the volume fraction of nanoparticles, Φ. For a particular geometry, it has been found that, for a given Ra, heat transfer is enhanced with increasing Φ, independently of the thermal boundary condition applied on the heater.

  10. Ultrathin Polyimide-Stainless Steel Heater for Vacuum System Bake-out

    CERN Document Server

    Rathjen, Christian; Henrist, Bernard; Kölemeijer, Wilhelmus; Libera, Bruno; Lutkiewicz, Przemyslaw

    2005-01-01

    Space constraints in several normal conducting magnets of the LHC required the development of a dedicated permanent heater for vacuum chamber bake-out. The new heater consists of stainless steel bands inside layers of polyimide. The overall heater thickness is about 0.3 mm. The low magnetic permeability is suitable for applications in magnetic fields. The material combination allows for temperatures high enough to activate a NEG coating. Fabrication is performed in consecutive steps of tape wrapping. Automation makes high volume production at low costs possible. About 800 m of warm vacuum system of the long straight sections of the LHC will be equipped with the new heater. This paper covers experience gained at CERN from studies up to industrialization.

  11. A Simple Substrate Heater Device With Temperature Controller for Thin Film Preparation

    Directory of Open Access Journals (Sweden)

    G. Rendón

    2012-08-01

    Full Text Available A simple substrate heater and its temperature controller were designed and built in order to prepare thin films in a highvacuum deposition system. The substrate heater was elaborated with a glass-ceramic body and a molybdenum foilheater. The applied power and the temperature are regulated by a power controller board using a microcontrollerprogrammed with a proportional-integrative-derivative algorithm. The heater/controller system was tested in a highvacuum deposition system and the results of its characterization at 100, 200, 300 and 400 °C are presented. Avariation in temperature better than ± 0.5 °C was obtained for all the tested temperatures. An application of thesubstrate heater is demonstrated by evaporating gold thin films on heated glass substrates.

  12. Technical support document: Energy efficiency standards for consumer products: Room air conditioners, water heaters, direct heating equipment, mobile home furnaces, kitchen ranges and ovens, pool heaters, fluorescent lamp ballasts and television sets. Volume 3, Water heaters, pool heaters, direct heating equipment, and mobile home furnaces

    Energy Technology Data Exchange (ETDEWEB)

    1993-11-01

    This is Volume 3 in a series of documents on energy efficiency of consumer products. This volume discusses energy efficiency of water heaters. Water heaters are defined by NAECA as products that utilize oil, gas, or electricity to heat potable water for use outside the heater upon demand. These are major appliances, which use a large portion (18% on average) of total energy consumed per household (1). They differ from most other appliances in that they are usually installed in obscure locations as part of the plumbing and are ignored until they fail. Residential water heaters are capable of heating water up to 180{degrees}F, although the setpoints are usually set lower.

  13. Energetic Performances Study of an Integrated Collector Storage Solar Water Heater

    Directory of Open Access Journals (Sweden)

    O. Helal

    2010-01-01

    Full Text Available Problem statement: Although that the interest attributed to the solar energy remains relatively limited, we attend today to the conception of several installations using the sun as energy source among which we quote the solar water heater. Approach: A study of energetic performances was taken on an integrated collector/storage solar water heater made in the National School of Engineers of Gabes. This water heater is equipped with a concentration system containing a reflector composed of three parabolic branches favorating a better absorption of solar radiance. Results: The comparison between this system and two other systems of solar water heater, composed of a storage ball with asymmetrical CPC and symmetrical CPC, showed important energetic performances despite the simplicity and the little cost of the collector. Conclusion: Several improvements are necessary to increase the direct flow whilst decrease the thermal losses and therefore make the system simpler to be installed on the building roof.

  14. Energy-efficient tunable silicon photonic micro-resonator with graphene transparent nano-heaters

    CERN Document Server

    Yu, Longhai; Dai, Daoxin; He, Sailing

    2015-01-01

    Thermally-tuning silicon micro-cavities are versatile and beneficial elements in low-cost large-scale photonic integrated circuits (PICs). Traditional metal heaters used for thermal tuning in silicon micro-cavities usually need a thick SiO2 upper-cladding layer, which will introduce some disadvantages including low response speed, low heating efficiency, low achievable temperature and complicated fabrication processes. In this paper, we propose and experimentally demonstrate thermally-tuning silicon micro-disk resonators by introducing graphene transparent nano-heaters, which contacts the silicon core directly without any isolator layer. This makes the graphene transparent nano-heater potentially to have excellent performances in terms of the heating efficiency, the temporal response and the achievable temperature. It is also shown that the graphene nano-heater is convenient to be used in ultrasmall photonic integrated devices due to the single-atom thickness and excellent flexibility of graphene. Both experi...

  15. Analysis of exergy and parametric study of a v-corrugated solar air heater

    Energy Technology Data Exchange (ETDEWEB)

    Hedayatizadeh, Mahdi [University of Tabriz, Department of Agricultural Machinery Engineering, Faculty of Agriculture, Tabriz (Iran, Islamic Republic of); University of Birjand, Faculty of Agriculture, P.O. Box 97175/331, Birjand (Iran, Islamic Republic of); Ajabshirchi, Yahya [University of Tabriz, Department of Agricultural Machinery Engineering, Faculty of Agriculture, Tabriz (Iran, Islamic Republic of); Sarhaddi, Faramarz; Farahat, Said [University of Sistan and Baluchestan, Department of Mechanical Engineering, Faculty of Engineering, P.O. Box 98164/161, Zahedan (Iran, Islamic Republic of); Safavinejad, Ali [University of Birjand, Department of Mechanical Engineering, Faculty of Engineering, Birjand (Iran, Islamic Republic of); Chaji, Hossein [University of Tabriz, Department of Agricultural Machinery Engineering, Faculty of Agriculture, Tabriz (Iran, Islamic Republic of); Center of Agriculture and Natural Resources of Khorasan Razavi Province, Ministry of Agriculture, Mashhad (Iran, Islamic Republic of)

    2012-07-15

    Solar air heater requires investigation for enhancement of solar energy conversion into heat. Different configurations with various artificial roughness geometries are proposed to date. In present study attention is paid on ways leading to more delivery of exergy by a v-corrugated solar air heater through parametric study. Effects of aspect ratio of the collector, inlet air temperature, mass flow rate per collector area etc. are studied. (orig.)

  16. Economics of residential gas furnaces and water heaters in US new construction market

    OpenAIRE

    Lekov, Alex B.; Franco, Victor H.; Wong-Parodi, Gabrielle; McMahon, James E.; CHAN, Peter

    2010-01-01

    New single-family home construction represents a significant and important market for the introduction of energy-efficient gas-fired space heating and water-heating equipment. In the new construction market, the choice of furnace and water-heater type is primarily driven by first cost considerations and the availability of power vent and condensing water heaters. Few analysis have been performed to assess the economic impacts of the different combinations of space and water-heating equipment....

  17. Economics of residential gas furnaces and water heaters in United States new construction market

    OpenAIRE

    Lekov, Alex B.

    2010-01-01

    New single-family home construction represents a significant and important market for the introduction of energy-efficient gas-fired space heating and water-heating equipment. In the new construction market, the choice of furnace and water-heater type is primarily driven by first cost considerations and the availability of power vent and condensing water heaters. Few analysis have been performed to assess the economic impacts of the different combinations of space and water-heating equipment....

  18. PREDICTION OF OPTIMUM ANGLE OF SOLAR WATER HEATER FOR COIMBATORE LOCATION

    OpenAIRE

    M. Sekar; DR M. SAKTHIVEL; O. MANIYARASU; N.ALAGU MURUGAN

    2013-01-01

    The objective of this work was to investigate ways to enhance the performance of solar water heater system to encourage many households using it. The integrated collector storage is the type of solar water heater that has retained its existence for well over a century. The flat absorber plate integrated collector storage type is a relatively recent addition. Being effective, low cost and simple to manufacture, their importance has been further enhanced by the recent upsurge in efforts to effe...

  19. Heading and head injuries in soccer.

    Science.gov (United States)

    Kirkendall, D T; Jordan, S E; Garrett, W E

    2001-01-01

    In the world of sports, soccer is unique because of the purposeful use of the unprotected head for controlling and advancing the ball. This skill obviously places the player at risk of head injury and the game does carry some risk. Head injury can be a result of contact of the head with another head (or other body parts), ground, goal post, other unknown objects or even the ball. Such impacts can lead to contusions, fractures, eye injuries, concussions or even, in rare cases, death. Coaches, players, parents and physicians are rightly concerned about the risk of head injury in soccer. Current research shows that selected soccer players have some degree of cognitive dysfunction. It is important to determine the reasons behind such deficits. Purposeful heading has been blamed, but a closer look at the studies that focus on heading has revealed methodological concerns that question the validity of blaming purposeful heading of the ball. The player's history and age (did they play when the ball was leather and could absorb significant amounts of water), alcohol intake, drug intake, learning disabilities, concussion definition and control group use/composition are all factors that cloud the ability to blame purposeful heading. What does seem clear is that a player's history of concussive episodes is a more likely explanation for cognitive deficits. While it is likely that the subconcussive impact of purposeful heading is a doubtful factor in the noted deficits, it is unknown whether multiple subconcussive impacts might have some lingering effects. In addition, it is unknown whether the noted deficits have any affect on daily life. Proper instruction in the technique is critical because if the ball contacts an unprepared head (as in accidental head-ball contacts), the potential for serious injury is possible. To further our understanding of the relationship of heading, head injury and cognitive deficits, we need to: learn more about the actual impact of a ball on the

  20. Durability of Silicate Glasses: An Historical Approach

    Energy Technology Data Exchange (ETDEWEB)

    Farges, Francois; /Museum Natl. Hist. Natur. /Stanford U., Geo. Environ. Sci.; Etcheverry, Marie-Pierre; /Marne la Vallee U.; Haddi, Amine; /Marne la Valle U.; Trocellier,; /Saclay; Curti, Enzo; /PSI, Villigen; Brown, Gordon E., Jr.; /SLAC, SSRL

    2007-01-02

    We present a short review of current theories of glass weathering, including glass dissolution, and hydrolysis of nuclear waste glasses, and leaching of historical glasses from an XAFS perspective. The results of various laboratory leaching experiments at different timescales (30 days to 12 years) are compared with results for historical glasses that were weathered by atmospheric gases and soil waters over 500 to 3000 years. Good agreement is found between laboratory experiments and slowly leached historical glasses, with a strong enrichment of metals at the water/gel interface. Depending on the nature of the transition elements originally dissolved in the melt, increasing elemental distributions are expected to increase with time for a given glass durability context.

  1. Durability of Silicate Glasses: An Historical Approach

    Energy Technology Data Exchange (ETDEWEB)

    Farges, Francois; /Museum Natl. Hist. Natur. /Stanford U., Geo. Environ. Sci.; Etcheverry, Marie-Pierre; /Marne la Vallee U.; Haddi, Amine; /Marne la Valle U.; Trocellier,; /Saclay; Curti, Enzo; /PSI, Villigen; Brown, Gordon E., Jr.; /SLAC, SSRL

    2007-01-02

    We present a short review of current theories of glass weathering, including glass dissolution, and hydrolysis of nuclear waste glasses, and leaching of historical glasses from an XAFS perspective. The results of various laboratory leaching experiments at different timescales (30 days to 12 years) are compared with results for historical glasses that were weathered by atmospheric gases and soil waters over 500 to 3000 years. Good agreement is found between laboratory experiments and slowly leached historical glasses, with a strong enrichment of metals at the water/gel interface. Depending on the nature of the transition elements originally dissolved in the melt, increasing elemental distributions are expected to increase with time for a given glass durability context.

  2. Fly ash for durable concrete construction

    Energy Technology Data Exchange (ETDEWEB)

    Dhir, R.K. [University of Dundee, Dundee (United Kingdom). Dept. of Civil Engineering

    1994-12-31

    This is essentially a review paper, bringing together the various studies undertaken at the University of Dundee as well as many others selected from published work. A full range of durability properties have been considered dealing with the effects of fly ash (FA) in concrete. It is shown that the use of FA generally effects improvement in the resistance of concrete to various forms of attack. FA is shown to greatly improve concrete resistance to chloride ingress and to reduce expansion caused by ASR. In the case of sulphate attack the use of FA is recommended. With regard to carbonation, FA can slightly reduce the resistance. It is also shown that FA concrete will benefit more from curing than OPC concrete in developing its resistance to deterioration with age. 78 refs., 8 figs., 5 tabs.

  3. Durable and Robust Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Hjalmarsson, Per; Knibbe, Ruth; Hauch, Anne

    The solid oxide fuel cell (SOFC) is an attractive technology for the generation of electricity with high efficiency and low emissions. Risø DTU (now DTU Energy Conversion) works closely together with Topsoe Fuel Cell A/S in their effort to bring competitive SOFC systems to the market. This 2-year...... for use within the CHP (Combined Heat and Power) market segment with stationary power plants in the range 1 – 250 kWe in mind. Lowered operation temperature is considered a good way to improve the stack durability since corrosion of the interconnect plates in a stack is lifetime limiting at T > 750 °C...... understanding of degradation and failure mechanisms. Improved understanding of performance and lifetime limiting factors will make it possible to develop strategies for counteracting degradation and improving the power density of SOFC based systems, both necessary to advance towards the goals set out...

  4. Advancing a comprehensive understanding of concrete durability

    Science.gov (United States)

    Moss, Gates Minckler

    The durability of concrete is vital to the health of our infrastructure and economy. Unfortunately, traditional, linear approaches to experimentation and specification have not provided a complete understanding and control of this complex material. This work seeks to further a comprehensive understanding of concrete durability through approaches including multi-variable mathematical modeling of premature deterioration, analysis of the microstructural changes of cement paste and mortar during freezing, and the development of quantitative computer models in parallel with actual experiments. The first section includes a summary of the collection and analysis of data describing concrete pavements in a number of Midwestern states. This involves the development of a thorough survey, completion of that survey by local organizations, and the creation of a database from pooled data. Statistical analysis of that data reveals a number of statistically significant trends in a pavement's tendency to deteriorate. Statistically important variables include total alkali and sulfate content of the cementitious material, the presence of type C fly ash, ambient paving temperature, age, and permeability of the base course material. In the second section, deformation mapping of cement paste during freezing illustrates the power and accuracy of this new technique. It also illustrates the effects of water/cement ratio, age, presence of aggregate, and repeated cycling on deformation during freezing. Finally, the increased resolution of this new technique allows for the identification of a number of new microstructural features of the freezing process. Computer modeling closely mirrors the deformation analysis described above. Effects of water/cement ratio, age, and the presence of aggregate are all predicted by the models. Also, the trends and magnitude of bulk deformation predicted are very similar to measured results. Any differences can be attributed to the elastic nature of the models

  5. Some durability aspects of hybrid alkaline cements

    Directory of Open Access Journals (Sweden)

    Donatello S.

    2014-04-01

    Full Text Available Blended cements that contain a high content of fly ash and a low content of Portland cement typically suffer from low early strength development and long setting times. Recently, one method of overcoming these problems has been to use an alkali activator to enhance the reactivity of fly ash particles at early ages. Such cements can be grouped under the generic term “hybrid alkaline cements”, where both cement clinker and fly ash, encouraged by the presence of alkalis, are expected to contribute to cementitious gel formation. The work presented here examines some of the durability aspects of high fly ash content hybrid alkaline cement. Specifically, the aspects investigated were: exposure at high temperatures (up to 1000°C, resistance to immersion in aggressive solutions and susceptibility to the alkali aggregate reaction. All tests were repeated with a commercially available sulfate resistant Portland cement for comparison. When exposed to high temperatures, the hybrid alkaline cement showed strikingly different behaviour compared to the control Portland cement, showing fewer micro-cracks and maintaining residual compressive strengths at least equal to original strengths. Beyond 700°C, the hybrid alkaline cement began to sinter, which resulted in shrinkage of around 5% and a 100% increase in residual compressive strengths. No such sintering event was noted in the control Portland cement, which showed a drastic loss in residual compressive strengths upon heating. In immersion tests, the hybrid alkaline cement possessed excellent resistance to sulfate and seawater attack, similar to the control sulfate resistant cement. Both cements were however severely degraded by immersion in 0.1M HCl for 90 days. Both binders complied with the accelerated alkali-aggregate test but when this test was extended, the hybrid alkaline binder showed much greater dimensional stability. Possible reasons for the differences in durability behaviour in both cements

  6. Design, Construction, and Qualification of a Microscale Heater Array for Use in Boiling Heat Transfer

    Science.gov (United States)

    Rule, T. D.; Kim, J.; Kalkur, T. S.

    1998-01-01

    Boiling heat transfer is an efficient means of heat transfer because a large amount of heat can be removed from a surface using a relatively small temperature difference between the surface and the bulk liquid. However, the mechanisms that govern boiling heat transfer are not well understood. Measurements of wall temperature and heat flux near the wall would add to the database of knowledge which is necessary to understand the mechanisms of nucleate boiling. A heater array has been developed which contains 96 heater elements within a 2.5 mm square area. The temperature of each heater element is held constant by an electronic control system similar to a hot-wire anemometer. The voltage that is being applied to each heater element can be measured and digitized using a high-speed A/D converter, and this digital information can be compiled into a series of heat-flux maps. Information for up to 10,000 heat flux maps can be obtained each second. The heater control system, the A/D system and the heater array construction are described in detail. Results are presented which show that this is an effective method of measuring the local heat flux during nucleate and transition boiling. Heat flux maps are obtained for pool boiling in FC-72 on a horizontal surface. Local heat flux variations are shown to be three to six times larger than variations in the spatially averaged heat flux.

  7. PREDICTION OF OPTIMUM ANGLE OF SOLAR WATER HEATER FOR COIMBATORE LOCATION

    Directory of Open Access Journals (Sweden)

    M. SEKAR

    2013-04-01

    Full Text Available The objective of this work was to investigate ways to enhance the performance of solar water heater system to encourage many households using it. The integrated collector storage is the type of solar water heater that has retained its existence for well over a century. The flat absorber plate integrated collector storage type is a relatively recent addition. Being effective, low cost and simple to manufacture, their importance has been further enhanced by the recent upsurge in efforts to effectively tap renewable energy resources. Having different inclinations based on latitude, the design of flat plate heaters can benefit from extensive amount of research on the topic of natural convection in inclined cavities. The thermal performance of the heater is recorded experimentally at angles 0°–30° from horizontal, in 10° intervals. It was found that for any given constant value of heat flux, the performance of the heater is a strong function of the angle of inclination. The optimum configuration of the heater for Coimbatore location is also evaluated.

  8. Energy Savings and Breakeven Cost for Residential Heat Pump Water Heaters in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Maguire, J.; Burch, J.; Merrigan, T.; Ong, S.

    2013-07-01

    Heat pump water heaters (HPWHs) have recently reemerged in the U.S. residential water heating market and have the potential to provide homeowners with significant energy savings. However, there are questions as to the actual performance and energy savings potential of these units, in particular in regards to the heat pump's performance in unconditioned space and the impact of the heat pump on space heating and cooling loads when it is located in conditioned space. To help answer these questions, simulations were performed of a HPWH in both conditioned and unconditioned space at over 900 locations across the continental United States and Hawaii. Simulations included a Building America benchmark home so that any interaction between the HPWH and the home's HVAC equipment could be captured. Comparisons were performed to typical gas and electric water heaters to determine the energy savings potential and cost effectiveness of a HPWH relative to these technologies. HPWHs were found to have a significant source energy savings potential when replacing typical electric water heaters, but only saved source energy relative to gas water heater in the most favorable installation locations in the southern US. When replacing an electric water heater, the HPWH is likely to break even in California, the southern US, and parts of the northeast in most situations. However, the HPWH will only break even when replacing a gas water heater in a few southern states.

  9. Energy Savings and Breakeven Costs for Residential Heat Pump Water Heaters in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Maguire, Jeff [National Renewable Energy Lab. (NREL), Golden, CO (United States); Burch, Jay [National Renewable Energy Lab. (NREL), Golden, CO (United States); Merrigan, Tim [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ong, Sean [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2013-07-01

    Heat pump water heaters (HPWHs) have recently re-emerged in the U.S. residential water heating market and have the potential to provide homeowners with significant energy savings. However, there are questions as to the actual performance and energy savings potential of these units, in particular in regards to the heat pump's performance in unconditioned space and the impact of the heat pump on space heating and cooling loads when it is located in conditioned space. To help answer these questions, NREL performed simulations of a HPWH in both conditioned and unconditioned space at over 900 locations across the continental United States and Hawaii. Simulations included a Building America benchmark home so that any interaction between the HPWH and the home's HVAC equipment could be captured. Comparisons were performed to typical gas and electric water heaters to determine the energy savings potential and cost effectiveness of a HPWH relative to these technologies. HPWHs were found to have a significant source energy savings potential when replacing typical electric water heaters, but only saved source energy relative to gas water heater in the most favorable installation locations in the southern United States. When replacing an electric water heater, the HPWH is likely to break even in California, the southern United States, and parts of the northeast in most situations. However, the HPWH will only break even when replacing a gas water heater in a few southern states.

  10. Solair heater program: solair applications study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1977-12-01

    General Electric has designed and tested a low-cost solar system using a vacuum tube solar air heater under ERDA Contract E(11-1)-2705. This contract extension has been provided to evaluate various applications of this solar collector. The evaluation identified attractive applications, evaluated corresponding control procedures, estimated system performance, compared economically insolation and insulation, and evaluated the repackaging of off-the-shelf equipment for improved cost effectiveness. The results of this study prompted General Electric's marketing group to do a detailed commercialization study of a residential domestic water heating system using the Solair concept which has been selected as the most attractive application. Other attractive applications are space/domestic water heating and a heat pump assisted solar system/domestic water heating where the heat pump and the solar system function in parallel. A prime advantage of heated air solar systems over liquid systems is cost and longer life which results in higher BTU's/dollar. Other air system advantages are no liquid leakage problems, no toxicity of freezing problems, and less complicated equipment. A hybrid solar system has been identified that can improve the market penetration of solar energy. This system would use the existing mass of the house for energy storage thereby reducing solar cost and complexity. Adequate performance can be obtained with house temperature swings comparable to those used in nighttime setback of the thermostat. Details of this system are provided.

  11. Heater induced thermal effects on the LTP dynamics

    CERN Document Server

    Gibert, Ferran; Lobo, Alberto; Díaz-Aguiló, Marc; Mateos, Ignacio; Karnesis, Nikolaos; Sanjuán, Josep; Gesa, Lluís; lloro, Ivan; Martín, Víctor

    2013-01-01

    The STOC (Science and Technology Operations Centre) simulator of the LPF (LISA PathFinder) mission is intended to provide a validation tool for the mission operations tele-commanding chain, as well as for a deeper understanding of the underlying physical processes happening in the LTP (LISA Technology Package). Amongst the different physical effects that will appear onboard, temperature fluctuations in the Electrode Housing (EH) could generate disturbances on the interferometer (IFO) readouts, therefore they must be known and controlled. In this article we report on the latest progress in the analysis at IEEC of the LTP response to thermal signals injected by means of heaters. More specifically, we determine the transfer functions relating heat input signals to forces on the Test Masses (TMs) in the LTP frequency band, from 1 mHz to 30 mHz. A complete thermal model of the entire LPF spacecraft plus payload, elaborated and maintained at European Space Technology Center (ESTEC), was used to obtain temperature d...

  12. Solar-Powered Cooler and Heater for an Automobile Interior

    Science.gov (United States)

    Howard, Richard T.

    2006-01-01

    The apparatus would include a solar photovoltaic panel mounted on the roof and a panellike assembly mounted in a window opening. The window-mounted assembly would include a stack of thermoelectric devices sandwiched between two heat sinks. A fan would circulate interior air over one heat sink. Another fan would circulate exterior air over the other heat sink. The fans and the thermoelectric devices would be powered by the solar photovoltaic panel. By means of a double-pole, double-throw switch, the panel voltage fed to the thermoelectric stack would be set to the desired polarity: For cooling operation, the chosen polarity would be one in which the thermoelectric devices transport heat from the inside heat sink to the outside one; for heating operation, the opposite polarity would be chosen. Because thermoelectric devices are more efficient in heating than in cooling, this apparatus would be more effective as a heater than as a cooler. However, if the apparatus were to include means to circulate air between the outside and the inside without opening the windows, then its effectiveness as a cooler in a hot, sunny location would be increased.

  13. Solar Biogas Digester with Built-In Reverse Absorber Heater

    Directory of Open Access Journals (Sweden)

    Khasan S. Karimov

    2013-01-01

    Full Text Available In this work the design, fabrication and investigation of a solar biogas digester with built-in RAH (Reverse Absorber Heater is presented. The maximum temperature (50 o C inside of the methane tank was taken as a main parameter at the design of the digester. Using energy balance equation for the case of a static mass of fluid being heated; the parameters of thermal insulation of the methane tank were counted. The biogas digester is consisting of methane tank with built-in solar RAH to utilize solar energy for the heating of the slurry prepared from the different organic wastes (dung, sewage, food wastes etc. The methane tank was filled up to 70% of volume by organic wastes of the GIK Institute sewage, firstly, and secondly, by sewage and cow dung as well. During three months (October-December, 2009 and two months (February-March, 2010 the digester was investigated. The solar irradiance incident to the absorber, slurry's temperature and ambient temperature were measured. It was found that using sewage only and sewage with cow dung the retention times was 4 weeks and two weeks respectively and biogas quantity produced was 0.4 and 8.0 m 3 respectively. In addition, biogas upgradation scheme for removal of carbon dioxide, hydrogen sulphide and water vapor from biogas and conversion of biogas energy conversion into electric power is also discussed.

  14. Light-weight radioisotope heater unit (LWRHU) impact tests

    Science.gov (United States)

    Reimus, M. A. H.; Rinehart, G. H.; Herrera, A.; Lopez, B.; Lynch, C.; Moniz, P.

    1998-01-01

    The light-weight radioisotope heater unit (LWRHU) is a 238PuO2-fueled heat source designed to provide one thermal watt in each of various locations on a spacecraft. Los Alamos National Laboratory designed, fabricated, and safety tested the LWRHU. The heat source consists of a hot-pressed 238PuO2 fuel pellet, a Pt-30Rh vented capsule, a pyrolytic graphite insulator, and a fineweave-pierced fabric graphite aeroshell assembly. To compare the performance of the LWRHUs fabricated for the Cassini mission with the performance of those fabricated for the Galileo mission, and to determine a failure threshold, two types of impact tests were conducted. A post-reentry impact test was performed on one of 180 flight-quality units produced for the Cassini mission and a series of sequential impact tests using simulant-fueled LWRHU capsules were conducted respectively. The results showed that deformation and fuel containment of the impacted Cassini LWRHU was similar to that of a previously tested Galileo LWRHU. Both units sustained minimal deformation of the aeroshell and fueled capsule; the fuel was entirely contained by the platinum capsule. Sequential impacting, in both end-on and side-on orientations, resulted in increased damage with each subsequent impact. Sequential impacting of the LWRHU appears to result in slightly greater damage than a single impact at the final impact velocity of 50 m/s.

  15. Post Test Evaluation of HSCT Nozzle Acoustic Liner Subcomponents Subjected to a Hot Acoustic Durability Test

    Science.gov (United States)

    Verrilli, Michael J.; Lee, Kuan

    2008-01-01

    The acoustic liner system designed for use in the High Speed Civil Transport (HSCT) was tested in a thermal-acoustic environment. Five ceramic matrix composite (CMC) acoustic tile configurations, five bulk acoustic absorbers, and one thermal protection system design were tested. The CMC acoustic tiles were subjected to two 2 3/4 hr ambient temperature acoustic exposures to measure their dynamic response. One exposure was conducted on the tiles alone and the second exposure included the tiles and the T-foam bulk absorber. The measured tile RMS strains were small. With or without the T-foam absorber, the dynamic strains were below strain levels that would cause damage during fatigue loading. After the ambient exposure, a 75-hr durability test of the entire acoustic liner system was conducted using a thermal-acoustic cycle that approximated the anticipated service cycle. Acoustic loads up to 139 dB/Hz and temperatures up to 1670 F (910 C) were employed during this 60 cycle test. During the durability test, the CMC tiles were exposed to temperatures up to 1780 F and a transient through thickness gradient up to 490 F. The TPS peak temperatures on the hot side of the panels ranged from 750 to 1000 F during the 60 cycles. The through thickness delta T ranged from 450 to 650 F, varying with TPS location and cycle number. No damage, such as cracks or chipping, was observed in the CMC tiles after completion of the testing. However, on tile warped during the durability test and was replaced after 43 or 60 cycles. No externally observed damage was found in this tile. No failure of the CMC fasteners occurred, but damage was observed. Cracks and missing material occurred, only in the fastener head region. No indication of damage was observed in the T-foam acoustic absorbers. The SiC foam acoustic absorber experienced damage after about 43 cycles. Cracking in the TPS occurred around the attachment holes and under a vent. In spite of the development of damage, the TPS maintained

  16. Designing Self-Healing Superhydrophobic Surfaces with Exceptional Mechanical Durability.

    Science.gov (United States)

    Golovin, Kevin; Boban, Mathew; Mabry, Joseph M; Tuteja, Anish

    2017-03-29

    The past decade saw a drastic increase in the understanding and applications of superhydrophobic surfaces (SHSs). Water beads up and effortlessly rolls off a SHS due to its combination of low surface energy and texture. Whether being used for drag reduction, stain repellency, self-cleaning, fog harvesting, or heat transfer applications (to name a few), the durability of a SHS is critically important. Although a handful of purportedly durable SHSs have been reported, there are still no criteria available for systematically designing a durable SHS. In the first part of this work, we discuss two new design parameters that can be used to develop mechanically durable SHSs via the spray coating of different binders and fillers. These parameters aid in the rational selection of material components and allow one to predict the capillary resistance to wetting of any SHS from a simple topographical analysis. We show that not all combinations of sprayable components generate SHSs, and mechanically durable components do not necessarily generate mechanically durable SHSs. Moreover, even the most durable SHSs can eventually become damaged. In the second part, utilizing our new parameters, we design and fabricate physically and chemically self-healing SHSs. The most promising surface is fabricated from a fluorinated polyurethane elastomer (FPU) and the extremely hydrophobic small molecule 1H,1H,2H,2H-heptadecafluorodecyl polyhedral oligomeric silsesquioxane (F-POSS). A sprayed FPU/F-POSS surface can recover its superhydrophobicity even after being abraded, scratched, burned, plasma-cleaned, flattened, sonicated, and chemically attacked.

  17. ACCELERATED METHODS FOR ESTIMATING THE DURABILITY OF PLAIN BEARINGS

    Directory of Open Access Journals (Sweden)

    Myron Czerniec

    2014-09-01

    Full Text Available The paper presents methods for determining the durability of slide bearings. The developed methods enhance the calculation process by even 100000 times, compared to the accurate solution obtained with the generalized cumulative model of wear. The paper determines the accuracy of results for estimating the durability of bearings depending on the size of blocks of constant conditions of contact interaction between the shaft with small out-of-roundedness and the bush with a circular contour. The paper gives an approximate dependence for determining accurate durability using either a more accurate or an additional method.

  18. Solar dryer with thermal storage and biomass-backup heater

    Energy Technology Data Exchange (ETDEWEB)

    Madhlopa, A. [Department of Physics and Biochemical Sciences, Malawi Polytechnic, P/Bag 303, Blantyre 3 (Malawi); Ngwalo, G. [Department of Mechanical Engineering, Malawi Polytechnic, P/Bag 303, Blantyre 3 (Malawi)

    2007-04-15

    An indirect type natural convection solar dryer with integrated collector-storage solar and biomass-backup heaters has been designed, constructed and evaluated. The major components of the dryer are biomass burner (with a rectangular duct and flue gas chimney), collector-storage thermal mass and drying chamber (with a conventional solar chimney). The thermal mass was placed in the top part of the biomass burner enclosure. The dryer was fabricated using simple materials, tools and skills, and it was tested in three modes of operation (solar, biomass and solar-biomass) by drying twelve batches of fresh pineapple (Ananas comosus), with each batch weighing about 20 kg. Meteorological conditions were monitored during the dehydration process. Moisture and vitamin C contents were determined in both fresh and dried samples. Results show that the thermal mass was capable of storing part of the absorbed solar energy and heat from the burner. It was possible to dry a batch of pineapples using solar energy only on clear days. Drying proceeded successfully even under unfavorable weather conditions in the solar-biomass mode of operation. In this operational mode, the dryer reduced the moisture content of pineapple slices from about 669 to 11% (db) and yielded a nutritious dried product. The average values of the final-day moisture-pickup efficiency were 15%, 11% and 13% in the solar, biomass and solar-biomass modes of operation respectively. It appears that the solar dryer is suitable for preservation of pineapples and other fresh foods. Further improvements to the system design are suggested. (author)

  19. Emission factors of gaseous pollutants from recent kerosene space heaters and fuels available in France in 2010.

    Science.gov (United States)

    Carteret, M; Pauwels, J-F; Hanoune, B

    2012-08-01

    Laboratory measurements of the gaseous emission factors (EF) from two recent kerosene space heaters (wick and injector) with five different fuels have been conducted in an 8-m(3) environmental chamber. The two heaters tested were found to emit mainly CO(2), CO, NO, NO(2), and some volatile organic compounds (VOCs). NO(2) is continuously emitted during use, with an EF of 100-450 μg per g of consumed fuel. CO is normally emitted mainly during the first minutes of use (up to 3 mg/g). Formaldehyde and benzene EFs were quantified at 15 and 16 μg/g, respectively, for the wick heater. Some other VOCs, such as 1,3-butadiene, were detected with lower EFs. We demonstrated the unsuitability of a 'biofuel' containing fatty acid methyl esters for use with the wick heater, and that the accumulation of soot on the same heater, whatever the fuel, leads to a dramatic increase in the CO EF, up to 16 mg/g, which could be responsible for chronic and acute CO intoxications. Our results show that in spite of new technologies and emission standards for unvented kerosene space heaters, as well as for the fuels, the use of these heaters in indoor environments still leads to NO(x) levels in excess of current health recommendations. Whereas injection heaters generate more nitrogen oxides than wick heaters, prolonged use of the latter leads to a soot buildup, concomitant with high CO emissions, which could be responsible for acute and chronic intoxications. The use of a biofuel in a wick heater is also of concern. Maintenance of the heaters and adequate ventilation of the room during use of kerosene space heaters are therefore of prime importance to reduce personal exposure. © 2011 John Wiley & Sons A/S.

  20. Building America Case Study: Simple Retrofit High-Efficiency Natural Gas Water Heater Field Test, Minneapolis, Minnesota

    Energy Technology Data Exchange (ETDEWEB)

    T. Schirber, B. Schoenbauer

    2017-06-01

    High-performance water heaters are typically more time consuming and costly to install in retrofit applications, making high-performance water heaters difficult to justify economically. However, recent advancements in high-performance water heaters have targeted the retrofit market, simplifying installations and reducing costs. Four high-efficiency natural gas water heaters designed specifically for retrofit applications were installed in single-family homes along with detailed monitoring systems to characterize their savings potential, their installed efficiencies, and their ability to meet household demands.

  1. Effect of Uniformly and Nonuniformly Coated Al2O3 Nanoparticles over Glass Tube Heater on Pool Boiling

    Directory of Open Access Journals (Sweden)

    Nitin Doifode

    2016-01-01

    Full Text Available Effect of uniformly and nonuniformly coated Al2O3 nanoparticles over plain glass tube heater on pool boiling heat transfer was studied experimentally. A borosilicate glass tube coated with Al2O3 nanoparticle was used as test heater. The boiling behaviour was studied by using high speed camera. Result obtained for pool boiling shows enhancement in heat transfer for nanoparticle coated surface heater and compared with plain glass tube heater. Also heat transfer coefficient for nonuniformly coated nanoparticles was studied and compared with uniformly coated and plain glass tube. Coating effect of nanoparticles over glass tube increases its surface roughness and thereby creates more nucleation sites.

  2. High durability antireflection coatings for silicon and multispectral ZnS

    Science.gov (United States)

    Joseph, Shay; Marcovitch, Orna; Yadin, Ygal; Klaiman, Dror; Koren, Nitzan; Zipin, Hedva

    2007-04-01

    In the current complex battle field, military platforms are required to operate on land, at sea and in the air in all weather conditions both day and night. In order to achieve such capabilities, advanced electro-optical systems are being constantly developed and improved. These systems such as missile seeker heads, reconnaissance and target acquisition pods and tracking, monitoring and alert systems have external optical components (window or dome) which must remain operational even at extreme environmental conditions. Depending on the intended use of the system, there are a few choices of window and dome materials. Amongst the more common materials one can point out sapphire, ZnS, germanium and silicon. Other materials such as spinel, ALON and yittria may also be considered. Most infrared materials have high indices of refraction and therefore they reflect a large part of radiation. To minimize the reflection and increase the transmission, antireflection (AR) coatings are the most common choice. Since these systems operate at different environments and weather conditions, the coatings must be made durable to withstand these extreme conditions. In cases where the window or dome is made of relatively soft materials such as multispectral ZnS, the coating may also serve as protection for the window or dome. In this work, several antireflection coatings have been designed and manufactured for silicon and multispectral ZnS. The coating materials were chosen to be either oxides or fluorides which are known to have high durability. Ellipsometry measurements were used to characterize the optical constants of the thin films. The effects of the deposition conditions on the optical constants of the deposited thin films and durability of the coatings will be discussed. The coatings were tested according to MIL-STD-810E and were also subjected to rain erosion tests at the University of Dayton Research Institute (UDRI) whirling arm apparatus in which one of the coatings showed

  3. Durability of Alkali Activated Blast Furnace Slag

    Science.gov (United States)

    Ellis, K.; Alharbi, N.; Matheu, P. S.; Varela, B.; Hailstone, R.

    2015-11-01

    The alkali activation of blast furnace slag has the potential to reduce the environmental impact of cementitious materials and to be applied in geographic zones where weather is a factor that negatively affects performance of materials based on Ordinary Portland Cement. The scientific literature provides many examples of alkali activated slag with high compressive strengths; however research into the durability and resistance to aggressive environments is still necessary for applications in harsh weather conditions. In this study two design mixes of blast furnace slag with mine tailings were activated with a potassium based solution. The design mixes were characterized by scanning electron microscopy, BET analysis and compressive strength testing. Freeze-thaw testing up to 100 freeze-thaw cycles was performed in 10% road salt solution. Our findings included compressive strength of up to 100 MPa after 28 days of curing and 120 MPa after freeze-thaw testing. The relationship between pore size, compressive strength, and compressive strength after freeze-thaw was explored.

  4. High gain durable anti-reflective coating

    Energy Technology Data Exchange (ETDEWEB)

    Maghsoodi, Sina; Brophy, Brenor L.; Colson, Thomas E.; Gonsalves, Peter R.; Abrams, Ze' ev R.

    2016-07-26

    Disclosed herein are polysilsesquioxane-based anti-reflective coating (ARC) compositions, methods of preparation, and methods of deposition on a substrate. In one embodiment, the polysilsesquioxane of this disclosure is prepared in a two-step process of acid catalyzed hydrolysis of organoalkoxysilane followed by addition of tetralkoxysilane that generates silicone polymers with >40 mol % silanol based on Si-NMR. These high silanol siloxane polymers are stable and have a long shelf-life in polar organic solvents at room temperature. Also disclosed are low refractive index ARC made from these compositions with and without additives such as porogens, templates, thermal radical initiator, photo radical initiators, crosslinkers, Si--OH condensation catalyst and nano-fillers. Also disclosed are methods and apparatus for applying coatings to flat substrates including substrate pre-treatment processes, coating processes and coating curing processes including skin-curing using hot-air knives. Also disclosed are coating compositions and formulations for highly tunable, durable, highly abrasion-resistant functionalized anti-reflective coatings.

  5. Optical enhancing durable anti-reflective coating

    Energy Technology Data Exchange (ETDEWEB)

    Maghsoodi, Sina; Varadarajan, Aravamuthan; Movassat, Meisam

    2016-07-05

    Disclosed herein are polysilsesquioxane based anti-reflective coating (ARC) compositions, methods of preparation, and methods of deposition on a substrate. In embodiments, the polysilsesquioxane of this disclosure is prepared in a two-step process of acid catalyzed hydrolysis of organoalkoxysilane followed by addition of tetralkoxysilane that generates silicone polymers with >40 mol % silanol based on Si-NMR. These high silanol siloxane polymers are stable and have a long shelf-life in the polar organic solvents at room temperature. Also disclosed are low refractive index ARC made from these compositions with and without additives such as porogens, templates, Si--OH condensation catalyst and/or nanofillers. Also disclosed are methods and apparatus for applying coatings to flat substrates including substrate pre-treatment processes, coating processes including flow coating and roll coating, and coating curing processes including skin-curing using hot-air knives. Also disclosed are coating compositions and formulations for highly tunable, durable, highly abrasion-resistant functionalized anti-reflective coatings.

  6. High gain durable anti-reflective coating

    Energy Technology Data Exchange (ETDEWEB)

    Maghsoodi, Sina; Brophy, Brenor L.; Colson, Thomas E.; Gonsalves, Peter R.; Abrams, Ze' ev R.

    2017-06-27

    Disclosed herein are polysilsesquioxane-based anti-reflective coating (ARC) compositions, methods of preparation, and methods of deposition on a substrate. In one embodiment, the polysilsesquioxane of this disclosure is prepared in a two-step process of acid catalyzed hydrolysis of organoalkoxysilane followed by addition of tetralkoxysilane that generates silicone polymers with >40 mol % silanol based on Si-NMR. These high silanol siloxane polymers are stable and have a long shelf-life in polar organic solvents at room temperature. Also disclosed are low refractive index ARC made from these compositions with and without additives such as porogens, templates, thermal radical initiator, photo radical initiators, crosslinkers, Si--OH condensation catalyst and nano-fillers. Also disclosed are methods and apparatus for applying coatings to flat substrates including substrate pre-treatment processes, coating processes and coating curing processes including skin-curing using hot-air knives. Also disclosed are coating compositions and formulations for highly tunable, durable, highly abrasion-resistant functionalized anti-reflective coatings.

  7. Durability of tannin-boron-treated timber

    Directory of Open Access Journals (Sweden)

    Gianluca Tondi

    2012-11-01

    Full Text Available Tannin-boron wood preservatives were investigated for their resistance against outdoor agents. This work focused on the analysis of the causes that affect the durability of the tannin-hexamine-treated samples. In particular, dimensional stability, resistance to leaching, and resistance to biological agents were investigated. The combined effect of deterioration agents was evaluated by subjecting the treated samples to simulated and natural weathering tests. The study of the appearance and of the color components (L*, a*, and b* according to CIELAB space of the exposed samples was monitored to assess the efficacy of the tannin-boron formulations for outdoor applications. Significant resistance against the action of water (EN 84, ENV 1250-2 and insects (EN 47 has been demonstrated in specific tests. Conversely, the continuous stress due to artificial and natural weathering deteriorates the color and the visible features of the treated specimens. The combined effect of moisture modifications, solar exposition, and leaching cycles damages the structure of the tannin-based polymeric network and subsequently it negatively affects its preservation properties.

  8. Development of an Accurate Feed-Forward Temperature Control Tankless Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    David Yuill

    2008-06-30

    The following document is the final report for DE-FC26-05NT42327: Development of an Accurate Feed-Forward Temperature Control Tankless Water Heater. This work was carried out under a cooperative agreement from the Department of Energy's National Energy Technology Laboratory, with additional funding from Keltech, Inc. The objective of the project was to improve the temperature control performance of an electric tankless water heater (TWH). The reason for doing this is to minimize or eliminate one of the barriers to wider adoption of the TWH. TWH use less energy than typical (storage) water heaters because of the elimination of standby losses, so wider adoption will lead to reduced energy consumption. The project was carried out by Building Solutions, Inc. (BSI), a small business based in Omaha, Nebraska. BSI partnered with Keltech, Inc., a manufacturer of electric tankless water heaters based in Delton, Michigan. Additional work was carried out by the University of Nebraska and Mike Coward. A background study revealed several advantages and disadvantages to TWH. Besides using less energy than storage heaters, TWH provide an endless supply of hot water, have a longer life, use less floor space, can be used at point-of-use, and are suitable as boosters to enable alternative water heating technologies, such as solar or heat-pump water heaters. Their disadvantages are their higher cost, large instantaneous power requirement, and poor temperature control. A test method was developed to quantify performance under a representative range of disturbances to flow rate and inlet temperature. A device capable of conducting this test was designed and built. Some heaters currently on the market were tested, and were found to perform quite poorly. A new controller was designed using model predictive control (MPC). This control method required an accurate dynamic model to be created and required significant tuning to the controller before good control was achieved. The MPC

  9. The hydrogen: a clean and durable energy; L'hydrogene: une energie propre et durable

    Energy Technology Data Exchange (ETDEWEB)

    Alleau, Th. [Association Francaise de l' Hydrogene (France); Nejat Veziroglu, T. [Clean Energy Research Institute, University of Miami (United States); Lequeux, G. [Commission europeenne, DG de la Recherche, Bruxelles (Belgium)

    2000-07-01

    All the scientific experts agree, the hydrogen will be the energy vector of the future. During this conference day on the hydrogen, the authors recalled the actual economic context of the energy policy with the importance of the environmental policy and the decrease of the fossil fuels. The research programs and the attitudes of the France and the other countries facing the hydrogen are also discussed, showing the great interest for this clean and durable energy. They underline the importance of an appropriate government policy, necessary to develop the technology of the hydrogen production, storage and use. (A.L.B.)

  10. Durability of styrene-butadiene latex modified concrete

    Energy Technology Data Exchange (ETDEWEB)

    Shaker, F.A.; El-Dieb, A.S.; Reda, M.M. [Ain Shams Univ., Cairo (Egypt). Dept. of Structural Engineering

    1997-05-01

    The durability of reinforced concrete structures represents a major concern to many investigators. The use of latex modified concrete (LMC) in construction has urged researchers to review and investigate its different properties. This study is part of a comprehensive investigation carried on the use of polymers in concrete. The main objective of this study to investigate and evaluate the main durability aspects of Styrene-Butadiene latex modified concrete (LMC) compared to those of conventional concrete. Also, the main microstructural characteristics of LMC were studied using a Scanning Electron Microscope (SEM). The SEM investigation of the LMC showed major differences in its microstructure compared to that of the conventional concrete. The LMC proved to be superior in its durability compared to the durability of conventional concrete especially its water tightness (measured by water penetration, absorption, and sorptivity tests), abrasion, corrosion, and sulphate resistance.

  11. Durability of Bricks Coated with Red mud Based Geopolymer Paste

    Science.gov (United States)

    Singh, Smita; Basavanagowda, S. N.; Aswath, M. U.; Ranganath, R. V.

    2016-09-01

    The present study is undertaken to assess the durability of concrete blocks coated with red mud - fly ash based geopolymer paste. Concrete blocks of size 200 x 200 x 100mm were coated with geopolymer paste synthesized by varying the percentages of red mud and fly ash. Uncoated concrete blocks were also tested for the durability for comparison. In thermal resistance test, the blocks were subjected to 600°C for an hour whereas in acid resistance test, they were kept in 5% sulphuric acid solution for 4 weeks. The specimens were thereafter studied for surface degradation, strength loss and weight loss. Pastes with red mud percentage greater than 50% developed lot of shrinkage cracks. The blocks coated with 30% and 50% red mud paste showed better durability than the other blocks. The use of blocks coated with red mud - fly ash geopolymer paste improves the aesthetics, eliminates the use of plaster and improves the durability of the structure.

  12. Durability of optically variable devices on bank notes

    Science.gov (United States)

    Bartz, William J.

    2002-04-01

    Currency producers are facing dual marketplace demands to increase bank note circulation life and to employ increasingly effective security features against counterfeiting. Diffractive optically variable devices such as foil patches, stripes and windowed thread have become popular security features used for bank notes throughout the world, but historically have suffered in their ability to match the durability of the bank note substrate itself. A study to find a durable, diffractive OVD led to the development of a windowed-thread feature designed to pass stringent durability criteria for laundry, chemical soak and other performance tests. Diffractive-film production methods, demetallization techniques, thread construction and applied coatings were key factors in achieving this durability.

  13. Nanocomposites for Improved Physical Durability of Porous PVDF Membranes

    Directory of Open Access Journals (Sweden)

    Chi Yan Lai

    2014-02-01

    Full Text Available Current commercial polymer membranes have shown high performance and durability in water treatment, converting poor quality waters to higher quality suitable for drinking, agriculture and recycling. However, to extend the treatment into more challenging water sources containing abrasive particles, micro and ultrafiltration membranes with enhanced physical durability are highly desirable. This review summarises the current limits of the existing polymeric membranes to treat harsh water sources, followed by the development of nanocomposite poly(vinylidene fluoride (PVDF membranes for improved physical durability. Various types of nanofillers including nanoparticles, carbon nanotubes (CNT and nanoclays were evaluated for their effect on flux, fouling resistance, mechanical strength and abrasion resistance on PVDF membranes. The mechanisms of abrasive wear and how the more durable materials provide resistance was also explored.

  14. Temperature optimization of an electric heater by emissivity variation of heating elements

    Directory of Open Access Journals (Sweden)

    Cédric Hemmer

    2014-11-01

    Full Text Available This note addresses an industrial application concerning the way to optimize the surface temperature of commercial electrical heater. The aim of this paper is to reduce the temperature on accessible surfaces and electrical heater in order to respect the European standards and quality criteria imposed by the manufacturer. This target must be achieved by changing only the emissivity distribution of the electric heater components. A numerical study of the natural convection flow coupled with radiation is carried out in a heated room with an electric heater. The physical model includes the transport equations of mass, momentum, energy and radiative transfer which are solved numerically. Thermo-physical properties of the fluid are assumed to be dependent of the temperature. The numerical simulations are carried out for a two-dimensional, steady and turbulent flow using the finite volume approach. Results showed the influence of emissivity distribution of the electric heater components. The reducing of the heating foil emissivity allowed to decrease the radiative contribution on the foil and its temperature.

  15. Accelerator Magnet Quench Heater Technology and Quality Control Tests for the LHC High Luminosity Upgrade

    CERN Document Server

    Meuter, Florian

    The High Luminosity upgrade of the Large Hadron Collider (HL-LHC) foresees the installation of new superconducting Nb3Sn magnets. For the protection of these magnets, quench heaters are placed on the magnet coils. The quench heater circuits are chemically etched from a stainless steel foil that is glued onto a flexible Polyimide film, using flexible printed circuit production technology. Approximately 500 quench heaters with a total length of about 3000 m are needed for the HL-LHC magnets. In order to keep the heater circuit electrical resistance in acceptable limits, an approximately 10 µm-thick Cu coating is applied onto the steel foil. The quality of this Cu coating has been found critical in the quench heater production. The work described in this thesis focuses on the characterisation of Cu coatings produced by electrolytic deposition, sputtering and electron beam evaporation. The quality of the Cu coatings from different manufacturers has been assessed for instance by ambient temperature electrical res...

  16. A modernized high-pressure heater protection system for nuclear and thermal power stations

    Science.gov (United States)

    Svyatkin, F. A.; Trifonov, N. N.; Ukhanova, M. G.; Tren'kin, V. B.; Koltunov, V. A.; Borovkov, A. I.; Klyavin, O. I.

    2013-09-01

    Experience gained from operation of high-pressure heaters and their protection systems serving to exclude ingress of water into the turbine is analyzed. A formula for determining the time for which the high-pressure heater shell steam space is filled when a rupture of tubes in it occurs is analyzed, and conclusions regarding the high-pressure heater design most advisable from this point of view are drawn. A typical structure of protection from increase of water level in the shell of high-pressure heaters used in domestically produced turbines for thermal and nuclear power stations is described, and examples illustrating this structure are given. Shortcomings of components used in the existing protection systems that may lead to an accident at the power station are considered. A modernized protection system intended to exclude the above-mentioned shortcomings was developed at the NPO Central Boiler-Turbine Institute and ZioMAR Engineering Company, and the design solutions used in this system are described. A mathematical model of the protection system's main elements (the admission and check valves) has been developed with participation of specialists from the St. Petersburg Polytechnic University, and a numerical investigation of these elements is carried out. The design version of surge tanks developed by specialists of the Central Boiler-Turbine Institute for excluding false operation of the high-pressure heater protection system is proposed.

  17. Development of the robot for pressurizer electric heater inspection and repairing

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Seung Ho; Kim, Seung Ho; Su, Yong Chil

    1998-01-01

    In this study a robot system has been developed for inspection and maintenance of the pressurizer and the rod heater. The developed robot system consists of four parts: two links, a support frame, a movable gripper, and a controller box. The robot is attached on the support frame, which is attached at the man-way flange of the pressurizer such that the robot is positioned inside pressurizer. To access arbitrary heater, at first two links horizontally rotate, and then the gripper suspended by two steel wires moves up and down by turing wire drum because the rod heaters are located about 8 meters under the robot and are arranged in two circular rows. The robot must be designed under several constraint such as its weight and collision with pressurizer wall or spray nozzle because the robot is positioned and moves inside the pressurizer. To verify that the designed robot is free from collision during installation procedure and it can access any desired rod heater, it is simulated by 3-dimensional graphic software (RobCAD). For evaluating stress of the support frame finite element analysis is performed by using the ANSYS code. For gripping the rod heater the passive self-locking mechanism is adopted, which is made up three balls and springs. Because the mechanism is very simple, it is very hardly defected than that adopted motor. (author). 11 refs., 8 tabs., 13 figs

  18. The effects of operating conditions on emissions from masonry heaters and sauna stoves

    Energy Technology Data Exchange (ETDEWEB)

    Tissari, Jarkko; Hytoenen, Kati; Sippula, Olli [Fine Particle and Aerosol Technology Laboratory, University of Kuopio, PO Box 1627, 70211 Kuopio (Finland); Jokiniemi, Jorma [Fine Particle and Aerosol Technology Laboratory, University of Kuopio, PO Box 1627, 70211 Kuopio (Finland)]|[VTT, Technical Research Centre of Finland, Fine Particles, PO Box 1000, 02044 VTT, Espoo (Finland)

    2009-03-15

    Emissions from masonry heaters and sauna stoves were studied. In the sauna stove the production of organic gaseous carbon (OGC) at 10 gC kg{sup -1} (per kilogram of fuel), carbon monoxide (CO) at 55 g kg{sup -1}, fine particle mass (PM{sub 1}) at 5 g kg{sup -1} and number emissions (N) at 1.8 x 10{sup 15} kg{sup -1} was higher than in other measured appliances. In a modern technology masonry heater with a unique grate, the emissions were very low: 0.4 gC kg{sup -1} OGC, 14 g kg{sup -1} CO and 0.7 g kg{sup -1} PM{sub 1}. Conventional masonry heaters, using small logs, clearly produced higher emissions when compared to using large logs. Doubling the fuel load caused emission factors to increase by up to 4- times (OGC), except for the number emission, which decreased from 4.0 x 10{sup 14} to 2.0 x 10{sup 14} kg{sup -1}. From the conventional masonry heater 90% of the PM was emitted during the firing phase. Its combustion process is different to that in stoves or conventional open fireplaces. The insufficient supply of air, due to too fast pyrolysis, and increased ash release, due to the high combustion temperature, are the main parameters which cause high particle and gas emissions in masonry heaters and sauna stoves. (author)

  19. Experimental investigation of three different solar air heaters: Energy and exergy analyses

    Energy Technology Data Exchange (ETDEWEB)

    Alta, Deniz; Ertekin, C.; Yaldiz, Osman [Department of Farm Machinery, Faculty of Agricultural Engineering, Akdeniz University, 07059 Antalya (Turkey); Bilgili, Emin [Cukurova Agricultural Research Institute, Adana (Turkey)

    2010-10-15

    The present study aims to compare three different types of designed flat-plate solar air heaters, two having fins (Type II and Type III) and the other without fins (Type I), one of the heater with a fin had single glass cover (Type III) and the others had double glass covers (Type I and Type II). The energy and exergy output rates of the solar air heaters were evaluated for various air flow rates (25, 50 and 100 m{sup 3}/m{sup 2} h), tilt angle (0 , 15 and 30 ) and temperature conditions versus time. Based on the energy and exergy output rates, heater with double glass covers and fins (Type II) is more effective and the difference between the input and output air temperature is higher than of the others. Besides, it is found that the circulation time of air inside the heater played a role more important than of the number of transparent sheet. Lower air flow rates should be preferred in the applications of which temperature differences is more important. (author)

  20. Durability of hydrophobic coatings for superhydrophobic aluminum oxide

    Science.gov (United States)

    Jenner, Elliot; Barbier, Charlotte; D'Urso, Brian

    2013-10-01

    Robust and easily produced superhydrophobic surfaces are of great interest for mechanical applications, including drag reduction and MEMS. We produce novel superhydrophobic surfaces with several different coatings and tested the durability of each of these coatings with respect to long term immersion in water in order to determine the most long-lasting surface preparation. A pair of combinations of spin on polymers, surface features, and adhesion promoters was found that provide long term durability.

  1. Durable Development Of Tourism In Pitesti And Arges County

    OpenAIRE

    Bianca DABU; Mihaela DIACONU

    2010-01-01

    Durable development is one of the main concerns of the contemporary period. The complex relationship between tourism, development and natural environment is an example of the changes that have taken place in this filed of tourism considered an important polluter of the natural environment. Tourism is the key element of durable development having an important impact on the economy, being considered a source of economic growth. Romania has to find its way through the differences given by the ne...

  2. Durability of compressed soil-cement bricks

    Directory of Open Access Journals (Sweden)

    Acosta Valle, A.

    2001-06-01

    Full Text Available This papers shows the evaluation process of the durability of compressed soil-cement bricks. A great number of tests were made to determine the behavior of bricks when they are compression loaded and under the influence of moisture. Two different types of soils were used to produce the bricks, a lime-clay soil and a sand one. The sand soil is very resistant. The other one has a limited use. An experimental design was used to test the bricks. It is a rotational and quadratic method with a hexagonal figure which contains replicas at the central point. This method ensures the reliability of test results. Otherwise, it would reduce the amount of specimens necessary for the tests. The optimun moisture content is obtained by using a press machine. It is more rational than the standard Proctor compactation test, because it applies the same type and amount of energy used to produce the bricks. The obtained results show the behavior differences between the two compressed soil-cement bricks subjected to the compression test, water absorption and wetting and drying tests. The durability tests results are very important in the possible use of the bricks produced.

    En el trabajo se evalúa la durabilidad de elementos aglomerados de suelo estabilizado. Se realiza un amplio número de ensayos encaminados a determinar el comportamiento frente a la acción de las cargas y la humedad de dos suelos con características diferentes: uno limo-arcilloso y el otro arenoso. Este último presenta resultados muy favorables en ambas direcciones. El otro, con un posible uso más limitado. Se emplea un método de diseño experimental del tipo rotacional cuadrático en hexágono, con réplicas en el punto central, el que garantiza la confiabilidad de los resultados de los ensayos, a la vez que disminuye la cantidad de especímenes a ensayar. Se determina la humedad óptima a utilizar en las diferentes dosificaciones empleando la máquina compactadora, que resulta m

  3. Building America Case Study: Simple Retrofit High-Efficiency Natural Gas Water Heater Field Test, Minneapolis, Minnesota

    Energy Technology Data Exchange (ETDEWEB)

    2017-06-12

    High performance water heaters are typically more time consuming and costly to install in retrofit applications, making high performance water heaters difficult to justify economically. However, recent advancements in high performance water heaters have targeted the retrofit market, simplifying installations and reducing costs. Four high efficiency natural gas water heaters designed specifically for retrofit applications were installed in single-family homes along with detailed monitoring systems to characterize their savings potential, their installed efficiencies, and their ability to meet household demands. The water heaters tested for this project were designed to improve the cost-effectiveness and increase market penetration of high efficiency water heaters in the residential retrofit market. The retrofit high efficiency water heaters achieved their goal of reducing costs, maintaining savings potential and installed efficiency of other high efficiency water heaters, and meeting the necessary capacity in order to improve cost-effectiveness. However, the improvements were not sufficient to achieve simple paybacks of less than ten years for the incremental cost compared to a minimum efficiency heater. Significant changes would be necessary to reduce the simple payback to six years or less. Annual energy savings in the range of $200 would also reduce paybacks to less than six years. These energy savings would require either significantly higher fuel costs (greater than $1.50 per therm) or very high usage (around 120 gallons per day). For current incremental costs, the water heater efficiency would need to be similar to that of a heat pump water heater to deliver a six year payback.

  4. Computed Tomography (CT) -- Head

    Medline Plus

    Full Text Available ... limitations of CT Scanning of the Head? What is CT Scanning of the Head? Computed tomography, more ... the body being studied. top of page How is the procedure performed? The technologist begins by positioning ...

  5. Assessment of Performance Characteristic of Solar Air Heater with Assorted Geometries - A Review

    Directory of Open Access Journals (Sweden)

    Alok Kumar Rohit

    2016-01-01

    Full Text Available Artificial roughness is an efficient way for increasing the heat transfer rate in solar air heater with the corresponding improvement in its thermal performance. A viscous sub-layer is responsible for the low heat transfer coefficient between absorber plate and flowing air. Repeated ribs in form of artificial roughness are an effective way to increase the heat transfer rate and improving the performance of solar air heater. Artificial roughness of the absorber plate is much economical and effective way to improve the thermal performance of solar air heater. Several investigators have done various investigations to improve heat transfer coefficient with little penalty of friction factor. They have also developed different correlation for heat transfer coefficient and friction factor. The correlations developed for heat transfer and friction factor by various investigators have been reviewed and presented.

  6. STUDY ON THE OPTIMIZATION OF IGBT THERMAL MANAGEMENT FOR PTC HEATER

    Directory of Open Access Journals (Sweden)

    J. W. JEONG

    2015-12-01

    Full Text Available It is essential to optimize HVAC (Heating, Ventilation and Air-Conditioning system for a thermal plant or an electric vehicle since it has a significant effect on the thermal efficiency. PTC (positive temperature coefficient heaters are often used for a heating system and the power module of the PTC heaters, IGBT (insulated gate bipolar mode transistor, requires thermal management. In this study, in order to maximize the cooling performance for IGBT, a novel method that uses forced convection inside the HVAC duct with heat sinks was developed. In addition, heat sinks were optimized in terms of IGBT junction temperature and heat sink weight by 3-dimensional CFD (Computational Fluid Dynamics simulation. The results show that the junction temperature of IGBT for 5.6kW PTC heater can be maintained at about 335K.

  7. A novel domestic electric water heater model for a multi-objective demand side management program

    Energy Technology Data Exchange (ETDEWEB)

    Paull, Liam; Li, Howard; Chang, Liuchen [University of New Brunswick, Department of Electrical Engineering, Fredericton, NB (Canada)

    2010-12-15

    This paper presents a novel domestic hot water heater model to be used in a multi-objective demand side management program. The model incorporates both the thermal losses and the water usage to determine the temperature of the water in the tank. Water heater loads are extracted from household load data and then used to determine the household water usage patterns. The benefits of the model are: (1) the on/off state of the water heater and temperature of the water in the tank can be accurately predicted, and (2) it enables the development of water usage profiles so that users can be classified based on usage behaviour. As a result, the amount of ancillary services and peak shaving that can be achieved are accurately predictable and can be maximized without adversely affecting users. (author)

  8. Development of Industrially Produced Composite Quench Heaters for the LHC Superconducting Lattice Magnets

    CERN Document Server

    Szeless, Balázs; Calvone, F

    1996-01-01

    The quench heaters are vital elements for the protection of the LHC superconducting lattice magnets in the case of resistive transitions of the conductor. The basic concept of magnet protection and technical solutions are briefly presented. The quench heater consists of partially copper clad stainless steel strips sandwiched in between electric insulating carrier foils with electrical and mechanical properties such as to withstand high voltages, low temperatures, pressures and ionizing radiation. Testing of some commercial available electric insulation foils, polyimide (PI), polyetheretherketon (PEEK) and polyarylate (PA) and combinations of adhesive systems which are suitable for industrial processing are described. Possible industrial methods for series production for some 80 km of these composite quench heaters are indicated.

  9. Building America Case Study: Assessment of a Hybrid Retrofit Gas Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    M. Hoeschele, E. Weitzel, C. Backman

    2017-06-01

    This project completed a modeling evaluation of a hybrid gas water heater that combines a reduced capacity tankless unit with a downsized storage tank. This product would meet a significant market need by providing a higher efficiency gas water heater solution for retrofit applications while maintaining compatibility with the half-inch gas lines and standard B vents found in most homes. The TRNSYS simulation tool was used to model a base case 0.60 EF atmospheric gas storage water, a 0.82 EF non-condensing gas tankless water heater, an existing (high capacity) hybrid unit on the market, and an alternative hybrid unit with lower storage volume and reduced gas input requirements.

  10. Preliminary Modeling, Testing, and Analysis of a Gas Tankless Water Heater: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Burch, J.; Hoeschele, M.; Springer, D.; Rudd, A.

    2008-05-01

    Today's gas tankless water heaters offer significant energy savings over conventional gas storage tank water heaters, but savings depends on the draw pattern. A one-node model incorporating heat exchanger mass is used to address this and other issues. Key model parameters are determined from least-squares regression on short-term data, including burner efficiency, thermal capacitance, and thermal loss coefficient. The calibrated model agrees with data to ~5% on Qgas, with temperature RMS deviation of ~4..deg..C. Efficiency with a standard realistic draw is 71%, compared to 81% predicted from standard energy-factors. Adding a small tank controlled by the tankless heater solves issues of oscillations with solar pre-heat, low-flow and hot-water-delay issues. Future work includes model refinements and developing optimal data protocols for model parameter extraction.

  11. Study on Ag mesh/conductive oxide hybrid transparent electrode for film heaters

    Science.gov (United States)

    Kwon, Namyong; Kim, Kyohyeok; Heo, Jinhee; Yi, Insook; Chung, Ilsub

    2014-07-01

    Ag mesh-indium tin oxide (ITO) hybrid transparent conductive films were fabricated and evaluated for use in film heaters. PS monolayer templates were prepared using highly mono-dispersed PS spheres (11.2 μm) obtained by a filtering process with micro-sieves. At first, three Ag meshes with different sheet resistances (20, 100, and 300 Ω sq-1) and transmittances (70, 73, and 76%) were evaluated for film heaters in terms of voltage and long-term stability. Subsequently, in an effort to obtain better transmittance, Ag mesh-ITO hybrid heaters were fabricated utilizing finite ITO depositions. At the optimised ITO thickness (15 nm), the sheet resistance and the transmittance were 300 Ω sq-1 and 88%, respectively, which indicates that this material is a good potential candidate for an efficient defroster in vehicles.

  12. Performance estimation of artificially roughened solar air heater duct provided with continuous ribs

    Directory of Open Access Journals (Sweden)

    Mridul Sharma, Varun

    2010-09-01

    Full Text Available The use of an artificial roughness on a surface is an effective technique to enhance the rate of heat transfer to fluid flow in the duct of a solar air heater. This paper presents a comparison of exergetic performance of solar air heaters having different types of geometry of roughness elements (continuous ribs on the absorber plate. The exergy efficiency has been computed by using the correlations for heat transfer and friction factor developed by various investigators within the investigated range of operating and system parameters. The exergy efficiency based criterion shows the better results at lower value of Re. There is not a single roughness geometry which gives best exergetic performance for whole range of Reynolds number. Solar air heater having rib-grooved and arc shaped wire as artificial roughness is found to have better exergy efficiency in the lower range of Reynolds number. However, smooth duct is found suitable in the higher range of Reynolds number.

  13. The benefit of solid oxide fuel cells with integrated air pre-heater

    Energy Technology Data Exchange (ETDEWEB)

    Costamagna, P. [Univ. degli Studi di Genova, Fac. di Ingegneria, ISTIC, Inst. di Ingegneria Chimica e di Processo `G.B. Bonino`, Genova (Italy)

    1997-11-01

    A new design has recently been proposed in the field of solid oxide fuel cells, consisting of a traditional electrochemical cell integrated with a pre-heater. In this paper a simulation model for the rectangular planar solid oxide fuel cell with integrated air pre-heater is presented. A two-dimensional stack simulation is presented as well, one axis coincides with the fuel flow direction, the other with the stack height. Local quantities such as current density, gas and solid temperatures are reported and cell characteristics predicted. In a parameter study, effects of oxygen utilisation and heat-transfer conditions in the pre-heater on the local temperature distribution of the solid structure are considered. As a result, the benefit of the new cell design becomes evident when low air flow rates are applied. A further advantage associated with the reduced flow rate is the low air temperature at the inlet. (orig.)

  14. Active compensation of wavefront aberrations by controllable heating of lens with electric film heater matrix.

    Science.gov (United States)

    Chen, Hua; Hou, Lv; Zhou, Xinglin

    2016-08-20

    We present a new apparatus for active compensation of wavefront aberrations by controllable heating of a lens using a film heater matrix. The annular electric film heater matrix, comprising 24 individual heaters, is attached to the periphery of a lens. Utilizing the linear superposition, and wavefront change proportional to the heating energy properties induced by heating, a controllable wavefront can be defined by solving a linear function. The two properties of wavefront change of a lens have been confirmed through a specially designed experiment. The feasibility of the compensation method is validated by compensating the wavefront of a plate lens. The results show that the wavefront of the lens changes from 12.52 to 2.95 nm rms after compensation. With a more precise electric controlling board, better results could be achieved.

  15. Effective efficiency prediction for discrete type of ribs used in solar air heaters

    Directory of Open Access Journals (Sweden)

    Muneesh Sethi, Mridul Sharma, Varun

    2010-03-01

    Full Text Available The use of an artificial roughness on a surface is an effective technique to enhance the heat transfer from the collector plate to the air in a solar air heater duct. However, artificial roughness leads to even more fluid pressure thereby increasing the pumping power. Number of geometries of roughness elements has been investigated on the heat transfer and friction characteristics of solar air heater ducts. This paper presents a comparison of effective efficiency of solar air heaters having different types of geometry of roughness elements (discrete ribs on the absorber plate. The effective efficiency has been computed by using the correlations for heat transfer and friction factor developed by various investigators within the investigated range of operating and system parameters.

  16. Design of high-pressure direct contact heater for promising power supply units: Experimental substantiation

    Science.gov (United States)

    Somova, E. V.; Shvarts, A. L.; Turkin, A. V.

    2016-11-01

    The results of experimental studies of superheated steam condensation on feed water jets in a highpressure, direct-contact heat exchanger are presented. Direct contact feed water heater (DCFWH) can be used in a dual-flow diagram of a steam-power unit with ultrasupercritical steam parameters (35 MPa, 700/720°C). The direct contact feed water heater is included in the flow diagram of the II circuit in a promising power unit; it provides feed water heating to 340°C in all maintenance and emergency operation modes of the unit. The reliability of the high-pressure direct contact heater operation in this flow diagram is of major importance in relation to the danger of lead solidification in the tube space of the steam generator. Technical requirements to the design of the high-pressure direct contact heater for increasing the heat exchange efficiency are formulated based on the results of earlier studies with steam-water mixture as the heating medium. The results of studies of superheated steam condensation on jets presented in this study testify that feed water is additionally heated to the required temperature at the output of the installation. The influence of initial feed water parameters (outflow velocity and temperature) on the jet heating length is elucidated. The numerical approximation of the experimental data for determination of the jet heating length in the nominal and partial power unit loads is obtained. The results of the calculations are used to simplify the design of the water-supplying element for the direct contact feed water heater. The proposed design of direct contact feed water heater is characterized by simplicity and low metal intensity, which provides the installation reliability at the considered pressure level due to the minimum number of structural elements.

  17. MATHEMATICAL AND INFORMATION SUPPORT FOR CALCULATION AND DESIGN OF TUBE GAS HEATERS LOCATED IN STRUCTURES

    Directory of Open Access Journals (Sweden)

    CHORNOMORETS H. Y.

    2016-02-01

    Full Text Available Raising of problem. For the design and construction of tube gas heaters in building structures to need solve the problems of analysis and synthesis of such heating system. The mathematical model of this system is consists of: mathematical model of the tube gas heater, mathematical model of heat distribution in the building structure and corresponding boundary conditions. To solve the tasks of analysis and synthesis must be appropriate mathematical and information support. Purpose. The purpose of this paper is to describe the developed mathematical and information support that solve the problems of analysis and synthesis of heating systems with gas tube heaters, located in building constructions.Conclusion. Mathematical support includes the development of algorithms and software for the numerical solution of problems analysis and synthesis heating system. Information support includes all the necessary parameters characterizing the thermal properties of materials which used in the heating system, and the parameters characterizing the heat exchange between the coolant and components of the heating system. It was developed algorithms for solving problems of analysis and synthesis heating system with tube gas heater located in structures to use evolutionary search algorithm and software. It was made experimental study and was obtained results allow to calculate the heat transfer from the gas-air mixture to the boundary surface of the building structure. This results and computation will provide full information support for solving problems of analysis and synthesis of the heating system. Was developed mathematical and software support, which allows to solve the problems of analysis and synthesis heating systems with gas tube heaters, located in building structures. Tube gas heaters located in the building structures allows with small capital expenditures to provide space heating. Is necessary to solve the problems of analysis (calculation and

  18. Water loss from the skin of term and preterm infants nursed under a radiant heater.

    Science.gov (United States)

    Kjartansson, S; Arsan, S; Hammarlund, K; Sjörs, G; Sedin, G

    1995-02-01

    The rate of evaporation from the skin (g/m2/h) was measured in 12 full-term and 16 preterm infants (gestational age 25-34 wk) both during incubator care and when nursed under a radiant heater. The method for evaporation rate measurement is noninvasive and based on determination of the water vapor pressure gradient close to the skin surface. Measurements were first made with the infant nursed in an incubator with a controlled environment with respect to humidity, temperature, and air velocity. The measurements in the term infants were performed at an ambient relative humidity (RH) of 50%, and in the preterm infants first at 50% and subsequently at 30-40%. Evaporation rate was then measured with the infant nursed under a radiant heater. In term infants, mean evaporation rate was 3.3 g/m2/h during incubator care (RH 50%) and 4.4 g/m2/h during care under the radiant heater. In preterm infants, the corresponding values were 15.5 g/m2/h in the incubator at RH 50%, 16.7 g/m2/h at RH 30-40%, and 17.9 g/m2/h under the radiant heater. It is concluded that the evaporative water loss from the skin depends on the ambient water vapor pressure, irrespective of whether the infant is nursed in an incubator or under a radiant heater. The higher rate of evaporation during care under a radiant heater is due to the lower ambient water vapor pressure and not to any direct effect of the nonionizing radiation on the skin.

  19. Rate of heat transfer in polypropylene tubes in solar water heaters

    Energy Technology Data Exchange (ETDEWEB)

    Razavi, J.; Mahmoodi, M. [Sharif University of Technology, Tehran (Iran). Chemical Engineering Dept.; Riazi, M.R. [Kuwait Univ., Safat (Kuwait). Chemical Engineering Dept.

    2003-06-01

    A heat transfer rate was determined for polypropylene tubes in solar water heaters for the Reynolds number range 800-5600. Experiments were conducted in ambient temperatures of 34 to 37 {sup o}C. Data were correlated in the form of Nusselt numbers as: Nu=0.0015 Re{sup 0.75}Pr{sup 1/3} with correlation coefficient of 0.95. Such data can be used to predict heat transfer rates in a polypropylene solar heater in Tehran where the experiments were performed. An application of the results is shown in an example. (author)

  20. Experimental comparison of alternative convection suppression arrangements for concentrating integral collector storage solar water heaters

    Energy Technology Data Exchange (ETDEWEB)

    Smyth, M.; McGarrigle, P.; Eames, P.C. [Ulster Univ., School of the Built Environment, Newtownabbey, Northern Ireland (United Kingdom); Norton, B. [Dublin Inst. of Technology, Dublin (Ireland)

    2005-02-01

    An experimental investigation of an inverted absorber integrated collector storage solar water heater mounted in the tertiary cavity of a compound parabolic concentrator with a secondary cylindrical reflector has been performed under simulated solar conditions. The solar water heaters performance was determined with the aperture parallel to the simulator for a range of transparent baffles positioned at different locations within the collector cavity. Results indicate that glass baffles located at the upper portion of the exit aperture of the CPC can reduce thermal losses through convection suppression without significantly increasing optical losses. (Author)

  1. Boiling Heat Transfer Measurements on Highly Conductive Surfaces Using Microscale Heater and Temperature Arrays

    Science.gov (United States)

    Kim, J.; Bae, S. W.; Whitten, M. W.; Mullen, J. D.; Quine, R. W.; Kalkur, T. S.

    1999-01-01

    Two systems have been developed to study boiling heat transfer on the microscale. The first system utilizes a 32 x 32 array of diodes to measure the local temperature fluctuations during boiling on a silicon wafer heated from below. The second system utilizes an array of 96 microscale heaters each maintained at constant surface temperature using electronic feedback loops. The power required to keep each heater at constant temperature is measured, enabling the local heat transfer coefficient to be determined. Both of these systems as well as some preliminary results are discussed.

  2. Enhanced Heat Transfer Tubes for Absorber of Absorption Chiller/Heater

    Science.gov (United States)

    Furukawa, Masahiro; Sasaki, Naoe; Kaneko, Toshiyuki; Nosetani, Tadashi

    For the purpose of development of high performance absorption chiller/heater utilizing lithium bromide aqueous solution as working fluid, it is the most effective to improve the performance of absorber with the largest heat transfer area of the four heat exchangers. This paper introduces two kinds of double fluted tubes for the absorber of absorption chiller/heater. Arm tube and floral tube have about 40% higter heat transfer performance than the plain tube conventionally used in absorber. The former is manufactured by double drawbench process, while the latter by single drawbench process. Therefore, floral tube is expected to realize both high heat transfer perfoemance and low cost.

  3. Single-structure heater and temperature sensor using a p-type polycrystalline diamond resistor

    Energy Technology Data Exchange (ETDEWEB)

    Yang, G.S.; Aslam, D.M. [Michigan State Univ., East Lansing, MI (United States). Dept. of Electrical Engineering

    1996-05-01

    Heat generation and temperature sensing are required for heating applications and for liquid level sensors, mass flow meters, and vacuum and pressure gauges which are based on variations of heat dissipation. Heat generation and temperature sensing are reported in a single p-type diamond resistor fabricated on an oxidized Si substrate using diamond film technology compatible with integrated circuit (IC) processing. Power densities in excess of 600 W/in.{sup 2} are observed for the heaters. The temperature response of the sensor is characterized in the temperature range of 300--725 K. Such a diamond heater/sensor device is reported for the first time.

  4. Particle impaction efficiency and size distribution in a MSWI super heater tube bundle

    CERN Document Server

    Haugen, Nils Erland L; Bugge, Mette; Warnecke, Ragnar; Weghaus, Martin

    2010-01-01

    Particle impaction in the super heater geometry found in the municipal solid waste incinerator (MSWI) of GKS in Schweinfurt, Germany, has been investigated. By using direct numerical simulations for the fluid flow, inertial particles coupled to the fluid through the classical Stokes' drag law have been tracked. Focus has been on the effect of flow velocity, and it is shown that decreasing the flow velocity will drastically decrease the impaction efficiency for some particle radii. Finally particle size distribution measurements are presented and used to find quantitative mass fluxes both on the front and the back side of the tubes in the super heater tube bundle.

  5. Light Weight Radioisotope Heater Unit (LWRHU) production for the Galileo mission

    Science.gov (United States)

    Rinehart, Gary H.

    The Light Weight Radioisotope Heater Unit (LWRHU) is a (Pu-238)O2-fueled heat source designed to provide a thermal watt of power for space missions. The LWRHU will be used to maintain the temperature of various components on the spacecraft at the required level. The heat source consists of a (Pu-238)O2-fuel pellet, a Pt-30 pct Rh capsule, a pyrolytic graphite insulator, and a woven graphite aeroshell assembly. Los Alamos National Laboratory has fabricated 134 heater units which will be used on the Galileo mission.

  6. Feed-water heaters alternative design comparison; Comparacion de disenos alternativos de calentadores

    Energy Technology Data Exchange (ETDEWEB)

    Torres Toledano, Gerardo [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1988-12-31

    A procedure is presented for the alternative design comparison of feed water heaters, based in the failure records of damaged tubes during operation. The procedure is used for cases in which non-continuous or random inspections are made to the feed-water heaters. [Espanol] Se presenta un procedimiento para comparar disenos alternativos de calentadores, basandose en los registros de fallas de los tubos rotos acumuladas durante su operacion. El procedimiento se emplea para casos en los que se realizan inspecciones a los calentadores no continuas, ya sea periodicas o al azar.

  7. Experimental studies on PCM filled Flat Plate Solar Water Heater without and with Fresnel lens glazing

    Directory of Open Access Journals (Sweden)

    R. Sivakumar

    2016-07-01

    Full Text Available Flat Plate Solar Water Heater (FPSWH is commonly used to harvest solar energy. Solar concentration techniques help to achieve higher temperatures of energy. The aim of this article is to compare the performance of a Fresnel lens glazed Flat Plate Solar Water Heater with Phase Change Material (PCM with that provided with an ordinary glazing. The effect of solar concentration using Fresnel lens on energy storage in PCM and heat gained by water are studied and compared with that having an ordinary glazing. Experiments showed 47% improvements in the heat gained by water.

  8. 41 CFR 102-74.190 - Are portable heaters, fans and other such devices allowed in Government-controlled facilities?

    Science.gov (United States)

    2010-07-01

    ... § 102-74.190 Are portable heaters, fans and other such devices allowed in Government-controlled facilities? Federal agencies are prohibited from operating portable heaters, fans, and other such devices in... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Are portable...

  9. Using Loop Heat Pipes to Minimize Survival Heater Power for NASA's Evolutionary Xenon Thruster Power Processing Units

    Science.gov (United States)

    Choi, Michael K.

    2017-01-01

    A thermal design concept of using propylene loop heat pipes to minimize survival heater power for NASA's Evolutionary Xenon Thruster power processing units is presented. It reduces the survival heater power from 183 W to 35 W per power processing unit. The reduction is 81%.

  10. 10 CFR Appendix P to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Pool Heaters

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Uniform Test Method for Measuring the Energy Consumption... Subpart B of Part 430—Uniform Test Method for Measuring the Energy Consumption of Pool Heaters 1. Test... 2.9 of ANSI Z21.56-1994. The measurement of energy consumption for oil-fired pool heaters in Btu is...

  11. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses ... of the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive medical ...

  12. Biological Durability of Oil Heat Treated Alder Wood

    Directory of Open Access Journals (Sweden)

    Robert Lacić

    2014-06-01

    Full Text Available The article presents preliminary results of the biological durability of oil heat treated (OHT alder wood (Alnus glutinosa against pure cultures of rot fungi (Postia placenta and Trametes versicolor in lab conditions. The modification was performed by heating of specimens immersed in soya oil. There were four heating regimes of different duration (6 and 10 hours at final temperature of 180 and 200 ºC. The increase in mass (MI caused by modification and mass loss of wood caused by fungal decay (ML were determined. In addition, the natural durability of alder wood was determined and compared to the natural durability of beech wood as the reference wood species. After modification of alder wood at 200 °C, MI was lower than after treatment at 180 °C. MI was also lower after 10 hours of treatment than after 6 hours of treatment. The results showed significantly increased biological durability of modified alder wood against both tested fungi. The effect of OHT on increasing the biological durability of alder wood was higher against the fungus P. placenta. It seems that the fungus T. versicolor favours the remained oil after modification causing higher mass loss. The results showed that alder wood, thermally modified in soya oil by testing regimens, is not suitable for applications in use classes 3-5.

  13. Material Studies Related to the Use of NaK Heat Exchangers Coupled to Stirling Heater Heads

    Science.gov (United States)

    Locci, Ivan E.; Bowman, Cheryl L.; Geng, Steven M.; Robbie, Malcolm G.

    2011-01-01

    NASA has been supporting design studies and technology development that could provide power to an outpost on the Moon, Mars, or an asteroid. Technology development efforts have included fabrication and evaluation of components used in a Stirling engine power conversion system. Destructive material evaluation was performed on a NaK shell heat exchanger that was developed by the NASA Glenn Research Center (GRC) and integrated with a commercial 1 kWe Stirling convertor from Sunpower Incorporated. The NaK Stirling test demonstrated Stirling convertor electrical power generation using a pumped liquid metal heat source under thermal conditions that represent the heat exchanger liquid metal loop in a Fission Power Systems (FPS) reactor. The convertors were operated for a total test time of 66 hr at a maximum temperature of 823 K. After the test was completed and NaK removed, the heat exchanger assembly was sectioned to evaluate any material interactions with the flowing liquid metal. Several dissimilar-metal braze joint options, crucial for the heat exchanger transfer path, were also investigated. A comprehensive investigation was completed and lessons learned for future heat exchanger development efforts are discussed.

  14. A figure of merit for selective absorbers in flat plate solar water heaters

    CSIR Research Space (South Africa)

    Roberts, DE

    2013-12-01

    Full Text Available We derive from first principles an analytical expression for a figure of merit (FM) for a selective solar absorber in a single glazed flat plate water heater. We first show that the efficiency of a collector with an absorber with absorptance α...

  15. Tip-based chemical vapor deposition with a scanning nano-heater

    NARCIS (Netherlands)

    Gaitas, A.

    2013-01-01

    In this preliminary effort, a moving nano-heater directs a chemical vapor deposition reaction (nano-CVD) demonstrating a tip-based nanofabrication (TBN) method. Localized nano-CVD of copper (Cu) and copper oxide (CuO) on a silicon (Si) and silicon oxide (SiO2) substrate from gasses, namely sublimate

  16. 16 CFR Appendix J1 to Part 305 - Pool Heaters-Gas

    Science.gov (United States)

    2010-01-01

    ... Part 305—Pool Heaters—Gas Range Information Manufacturer's rated heating capacity Range of Thermal... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Pool Heaters-Gas J1 Appendix J1 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS RULE...

  17. An efficient water flow control approach for water heaters in direct load control

    NARCIS (Netherlands)

    Belov, Alexander; Meratnia, Nirvana; Zwaag, van der Berend Jan; Havinga, Paul

    2014-01-01

    Tank water heaters (WHs) are present in a prevailing number of European households. Serving as energy buffers WHs have come under the spotlight of various direct load control (DLC) programs over the last few decades. Although DLC has proven to be an efficient measure towards daily peak demand shavin

  18. 16 CFR Appendix J2 to Part 305 - Pool Heaters-Oil

    Science.gov (United States)

    2010-01-01

    ... Part 305—Pool Heaters—Oil Range Information Manufacturer's rated heating capacities Range of Thermal... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Pool Heaters-Oil J2 Appendix J2 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS RULE...

  19. Development of Multi-Stage Steam Injector for Feedwater Heaters in Simplified Nuclear Power Plant

    Science.gov (United States)

    Narabayashi, Tadashi; Ohmori, Shuichi; Mori, Michitsugu; Asanuma, Yutaka; Iwaki, Chikako

    A steam injector (SI) is a simple, compact and passive pump and also acts as a high-performance direct-contact compact heater to heat up feedwater by using extracted steam from the turbine. To develop high performance compact feedwater heater, it is necessary to quantify the characteristics between physical properties of the flow field. Its performance depends on the phenomena of steam condensation onto the water jet surface and heat transfer in the water jet due to turbulence on to the phase-interface. The analysis was conducted by using CFD code embedded separate two-phase flow models that were confirmed by the experimental data. As the four-stage SI is compact heater, the system is expected to bring about great simplification and materials-saving effects, and high reliability of its operation. Therefore, it is confirmed that the simplification of the power plant by replacing all low-pressure feedwater heaters with the four-stage SI system, having steam extraction pressures equal to those for the existing ABWR system.

  20. Study of Exhaust Emissions Reduction of a Diesel Fuel Operated Heater During Transient Mode of Operation

    Directory of Open Access Journals (Sweden)

    Miklánek Ľubomír

    2014-10-01

    Full Text Available Diesel fuel operated heaters (FOHs are generally used as an independent heat source for any system in which a diesel fuel and battery power is available. Based on the fact that future engines will become even more efficient and thus less waste heat will be available to heat the passenger compartment, independent heat sources will be even more necessary.

  1. 16 CFR Appendix D2 to Part 305 - Water Heaters-Electric

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Water Heaters-Electric D2 Appendix D2 to... PRODUCTS REQUIRED UNDER THE ENERGY POLICY AND CONSERVATION ACT (âAPPLIANCE LABELING RULEâ) Pt. 305, App. D2 Appendix D2 to Part 305—Water Heaters—Electric Range Information CAPACITY FIRST HOUR RATING Range of...

  2. 78 FR 7394 - Notification of Proposed Production Activity; GE Appliances; Subzone 29C (Electric Water Heaters...

    Science.gov (United States)

    2013-02-01

    ... Foreign-Trade Zones Board Notification of Proposed Production Activity; GE Appliances; Subzone 29C (Electric Water Heaters), Louisville, KY GE Appliances, operator of Subzone 29C, submitted a notification of proposed production activity for its facility in Louisville, Kentucky. The notification conforming to the...

  3. Regional Variation in Residential Heat Pump Water Heater Performance in the U.S.: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Maguire, J.; Burch, J.; Merrigan, T.; Ong, S.

    2014-01-01

    Residential heat pump water heaters (HPWHs) have recently reemerged on the U.S. market. These units have the potential to provide homeowners significant cost and energy savings. However, actual in use performance of a HPWH will vary significantly with climate, installation location, HVAC equipment, and hot water use. To determine what actual in use energy consumption of a HPWH may be in different regions of the U.S., annual simulations of both 50 and 80 gallon HPWHs as well as a standard electric water heater were performed for over 900 locations across the U.S. The simulations included a benchmark home to take into account interactions between the space conditioning equipment and the HPWH and a realistic hot water draw profile. It was found that the HPWH will always save some source energy when compared to a standard electric resistance water heater, although savings varies widely with location. In addition to looking at source energy savings, the breakeven cost (the net installed cost a HPWH would have to have to be a cost neutral replacement for a standard water heater) was also examined. The highest breakeven costs were seen in cases with high energy savings, such as the southeastern U.S., or high energy costs, such as New England and California. While the breakeven cost is higher for 80 gallon units than 50 gallon units, the higher net installed costs of an 80 gallon unit lead to the 50 gallon HPWHs being more likely to be cost effective.

  4. Regional Variation in Residential Heat Pump Water Heater Performance in the U.S.

    Energy Technology Data Exchange (ETDEWEB)

    Maguire, Jeff [National Renewable Energy Lab. (NREL), Golden, CO (United States); Burch, Jay [National Renewable Energy Lab. (NREL), Golden, CO (United States); Merrigan, Tim [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ong, Sean [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2014-01-01

    Residential heat pump water heaters (HPWHs) have recently re-emerged on the U.S. market, and they have the potential to provide homeowners significant cost and energy savings. However, actual in use performance of a HPWH will vary significantly with climate, installation location, HVAC equipment, and hot water use. To determine the actual energy consumption of a HPWH in different U.S. regions, annual simulations of both 50 and 80 gallon HPWHs as well as a standard electric water heater were performed for over 900 locations across the United States. The simulations included a benchmark home to take into account interactions between the space conditioning equipment and the HPWH and a realistic hot water draw profile. It was found that the HPWH will always save some source energy when compared to a standard electric resistance water heater, although savings varies widely with location. In addition to looking at source energy savings, the breakeven cost (the net installed cost a HPWH would have to have to be a cost neutral replacement for a standard water heater) was also examined. The highest breakeven costs were seen in cases with high energy savings, such as the southeastern U.S., or high energy costs, such as New England and California. While the breakeven cost is higher for 80 gallon units than 50 gallon units, the higher net installed costs of an 80 gallon unit lead to the 50 gallon HPWHs being more likely to be cost effective.

  5. Building America Case Study: Assessment of a Hybrid Retrofit Gas Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    2017-06-19

    This project completed a modeling evaluation of a hybrid gas water heater that combines a reduced capacity tankless unit with a downsized storage tank. This product would meet a significant market need by providing a higher efficiency gas water heater solution for retrofit applications while maintaining compatibility with the half-inch gas lines and standard B vents found in most homes. The TRNSYS simulation tool was used to model a base case 0.60 EF atmospheric gas storage water, a 0.82 EF non-condensing gas tankless water heater, an existing (high capacity) hybrid unit on the market, and an alternative hybrid unit with lower storage volume and reduced gas input requirements. Simulations were completed under a 'peak day' sizing scenario with 183 gpd hot water loads in a Minnesota winter climate case. Full-year simulations were then completed in three climates (ranging from Phoenix to Minneapolis) for three hot water load scenarios (36, 57, and 96 gpd). Model projections indicate that the alternative hybrid offers an average 4.5% efficiency improvement relative to the 0.60 EF gas storage unit across all scenarios modeled. The alternative hybrid water heater evaluated does show promise, but the current low cost of natural gas across much of the country and the relatively small incremental efficiency improvement poses challenges in initially building a market demand for the product.

  6. Measure Guideline. Heat Pump Water Heaters in New and Existing Homes

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, Carl [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Puttagunta, Srikanth [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Owens, Douglas [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    2012-02-01

    This Building America Measure Guideline is intended for builders, contractors, homeowners, and policy-makers. This document is intended to explore the issues surrounding heat pump water heaters (HPWHs) to ensure that homeowners and contractors have the tools needed to appropriately and efficiently install HPWHs

  7. Local Adaptive Control of Solar Photovoltaics and Electric Water Heaters for Real-time Grid Support

    DEFF Research Database (Denmark)

    Bhattarai, Bishnu Prasad; Mendaza, Iker Diaz de Cerio; Bak-Jensen, Birgitte

    2016-01-01

    , such as electric vehicles, electric water heaters (EWHs) etc. An adaptive control using only local measurements for the EWHs and PVs is proposed in this study to alleviate OV as well as UV issues. The adaptive control is designed such that it monitors the voltage at the point of connection and adjusts active...

  8. Microbunching Instability Effect Studies and Laser Heater Optimization for the SPARX FEL Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Vaccarezza, C.; Chiadroni, E.; Ferrario, M.; Giannessi, L.; Quattromini, M.; Ronsivalle, C.; Venturini, C.; Migliorati, M.; Dattoli, G.

    2010-05-23

    The effects of microbunching instability for the SPARX accelerator have been analyzed by means of numerical simulations. The laser heater counteracting action has been addressed in order to optimize the parameters of the compression system, either hybrid RF plus magnetic chicane or only magnetic, and possibly enhance the FEL performance.

  9. Application for the On-line Isotope Mass Separator ISOLDE Facility: the Target Heater

    CERN Document Server

    Sánchez-Conejo, Jorge

    2003-01-01

    The purpose of the Heater Application is to heat and cool the target and line used on the On-Line Isotope Mass Separator ISOLDE facility up to a desired temperature selected by the user. The application has been developed in Java, making use of the Java Development Kit 1.4 and the PS Java environment.

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

    Energy Technology Data Exchange (ETDEWEB)

    None

    1983-02-01

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

  11. One-year assessment of a solar space/water heater--Clinton, Mississippi

    Science.gov (United States)

    1981-01-01

    Unit called "System 4" integrated into space-heating and hot-water systems of dormitory satisfied 32 percent of building heat load. System 4 includes flat-plate air collectors, circulation blowers, rock storage bed with heat exchanger, two hot water tanks, and auxiliary heaters. Report describes performance of system and subsystems, operating-energy requirements and savings, and performance parameters.

  12. Infrared Heater Used in Qualification Testing of International Space Station Radiators

    Science.gov (United States)

    Ziemke, Robert A.

    2004-01-01

    Two heat rejection radiator systems for the International Space Station (ISS) have undergone thermal vacuum qualification testing at the NASA Glenn Research Center (GRC), Plum Brook Station, Sandusky, Ohio. The testing was performed in the Space Power Facility (SPF), the largest thermal vacuum chamber in the world. The heat rejection system radiator was tested first; it removes heat from the ISS crew living quarters. The second system tested was the photovoltaic radiator (PVR), which rejects heat from the ISS photovoltaic arrays and the electrical power-conditioning equipment. The testing included thermal cycling, hot- and cold-soaked deployments, thermal gradient deployments, verification of the onboard heater controls, and for the PVR, thermal performance tests with ammonia flow. Both radiator systems are orbital replacement units for ease of replacement on the ISS. One key to the success of these tests was the performance of the infrared heater system. It was used in conjunction with a gaseous-nitrogen-cooled cryoshroud in the SPF vacuum chamber to achieve the required thermal vacuum conditions for the qualification tests. The heater, which was designed specifically for these tests, was highly successful and easily met the test requirements. This report discusses the heating requirements, the heater design features, the design approach, and the mathematical basis of the design.

  13. COMPARISON OF MEASUREMENT TECHNIQUES FOR QUANTIFYING SELECTED ORGANIC EMISSIONS FROM KEROSENE SPACE HEATERS

    Science.gov (United States)

    The report goes results of (1) a comparison the hood and chamber techniques for quantifying pollutant emission rates from unvented combustion appliances, and (2) an assessment of the semivolatile and nonvolatile organic-compound emissions from unvented kerosene space heaters. In ...

  14. Increasing reliability of system water heaters for steam-turbine installations at the design stage

    Science.gov (United States)

    Brezgin, V. I.; Brodov, Yu. M.; Brezgin, D. V.

    2015-12-01

    A system for designing water heaters of steam-turbine installations based on uniting standards, reference information, and some numerical procedures with design procedures via wide use of parameterization is considered. The developed design system is based on extensive application of modern information technologies.

  15. Development of the robot for pressurizer electric heater inspection and repairing

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Seung Ho; Kim, Seung Ho; Su, Yong Chil

    1999-01-01

    In this study a robot system has been developed for inspection and maintenance of the pressurizer and the rod heaters. The developed robot system consists of four parts: two links, a support frame, a movable gripper, and a controller box. The robot is attached on the support frame, which is attached at the man-way flange of the pressurizer such that the robot is positioned inside pressurizer. To access arbitrary heater, at first two links horizontally rotate, and then the gripper suspended by two steel wires moves up and down by turing wire drum because the rod heaters are located about 8 meters under the robot and are arranged in two circular rows. The robot must be designed under several constraints such as its weight and collision with pressurized wall or spray nozzle because the robot is positioned and moves inside the pressurizer. To verify that the designed robot is free from collision during installation procedure and it can access any desired rod heater, it is simulated by 3-dimensional graphic software (RobCAD). For evaluating stress of the support frame finite element analysis is performed by using the ANSYS code.

  16. 16 CFR Appendix D3 to Part 305 - Water Heaters-Oil

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Water Heaters-Oil D3 Appendix D3 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS RULE CONCERNING... Part 305—Water Heaters—Oil Range Information CAPACITY FIRST HOUR RATING Range of Estimated...

  17. Acceptability of the integral solar water heater by householders in the low income urban community

    CSIR Research Space (South Africa)

    Basson, FA

    1984-01-01

    Full Text Available A research and demonstration project on the use and performance of low cost integral solar water heaters in urban low-income dwellings was carried out in 1982/83. The project involved technical and socio-economic components. This report summarises...

  18. 16 CFR Appendix D5 to Part 305 - Water Heaters-Heat Pump

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Water Heaters-Heat Pump D5 Appendix D5 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC ACTS OF CONGRESS RULE... Appendix D5 to Part 305—Water Heaters—Heat Pump Range Information CAPACITY FIRST HOUR RATING Range of...

  19. Guidebook for the Development of a Nationally Appropriate Mitigation Action for Solar Water Heaters

    DEFF Research Database (Denmark)

    Haselip, James Arthur; Lütken, Søren E.; Sharma, Sudhir

    This guidebook provides an introduction to designing government-led interventions to scale up investment in solar water heater (SWH) markets, showing how these interventions can be packaged as Nationally Appropriate Mitigation Actions (NAMAS). Reflecting the changing balance in global greenhouse...

  20. Development of High Efficiency Carbon Dioxide Commercial Heat Pump Water Heater

    Energy Technology Data Exchange (ETDEWEB)

    Michael PETERSEN; Chad D. BOWERS; Stefan ELBEL; Pega HRNJAK

    2012-07-01

    Although heat pump water heaters are today widely accepted in both Japan and Europe, where energy costs are high and government incentives for their use exist, acceptance of such products in the US has been limited. While this trend is slowly changing with the introduction of heat pump water heaters into the residential market, but acceptance remains low in the commercial sector. The objective of the presented work is the development of a high efficiency R744 heat pump water heater for commercial applications with effective utilization of the cooling capability for air conditioning and/or refrigeration. The ultimate goal is to achieve total system COP of up to 8. This unit will be targeted at commercial use where some cooling load is typically needed year round, such as restaurants, hotels, nursing homes, and hospitals. This paper presents the performance results from the development of four R744 commercial heat pump water heater packages of approximately 35 kW and comparison to a commercially available baseline R134a unit of the same capacity and footprint. In addition, the influences of an internal heat exchanger and an enhanced evaporator on the system performance are described and recommendations are made for further improvements of the R744 system.

  1. An International Survey of Electric Storage Tank Water Heater Efficiency and Standards

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Alissa; Lutz, James; McNeil, Michael A.; Covary, Theo

    2013-11-13

    Water heating is a main consumer of energy in households, especially in temperate and cold climates. In South Africa, where hot water is typically provided by electric resistance storage tank water heaters (geysers), water heating energy consumption exceeds cooking, refrigeration, and lighting to be the most consumptive single electric appliance in the home. A recent analysis for the Department of Trade and Industry (DTI) performed by the authors estimated that standing losses from electric geysers contributed over 1,000 kWh to the annual electricity bill for South African households that used them. In order to reduce this burden, the South African government is currently pursuing a programme of Energy Efficiency Standards and Labelling (EES&L) for electric appliances, including geysers. In addition, Eskom has a history of promoting heat pump water heaters (HPWH) through incentive programs, which can further reduce energy consumption. This paper provides a survey of international electric storage water heater test procedures and efficiency metrics which can serve as a reference for comparison with proposed geyser standards and ratings in South Africa. Additionally it provides a sample of efficiency technologies employed to improve the efficiency of electric storage water heaters, and outlines programs to promote adoption of improved efficiency. Finally, it surveys current programs used to promote HPWH and considers the potential for this technology to address peak demand more effectively than reduction of standby losses alone

  2. A new regulation for terrace heaters; ERP: parasols chauffants et cuisson mobile

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2003-09-01

    After a year of discussions, the terrace heaters are from now on entirely authorized. They have indeed just coming to be included in a clear and explicit way in the 'safety rule against the fire and panic risks in the establishments receiving the public. Some precise details are given too for the use of LPG in movable kitchens (exhibition). (O.M.)

  3. Properties and durability of metakaolin blended cements

    Directory of Open Access Journals (Sweden)

    Ezzat, El-Sayed

    2010-09-01

    Full Text Available This paper evaluates the optimal calcination temperature and replacement ratio to ensure high metakaolin (MK pozzolanicity in blended cement. The MK used was prepared by firing two types of local at temperatures ranging from 700 to 850 ºC. Dry blends of ordinary Portland cement (OPC and varying proportions of MK were mixed with the amount of water required to ensure optimal consistency of the resulting pastes. The specimens were cured at 100% RH for 24 h and then immersed in water for 3, 7, 28, 90 or 180 days. At each test time, the degree of hydration and compressive strength of the hardened cement pastes were measured The findings showed that the most suitable calcination temperature to obtain metakaolin is 700 ºC, while the optimal replacement ratio ranges from 25 to 30%. DTA was used to determine the phases comprising the hydration products forming at the ages studied. Pure OPC and OPC-MK specimens were immersed in 3% NaCl and 5% MgSO4 solutions for 30, 90 and 180 days to measure their durability. The OPC-MK pastes immersed in the 3% NaCl solution were observed to be highly resistant to chloride attack.

    El presente trabajo evalúa el comportamiento puzolánico de metacaolín (MK, producto de la calcinación a distintas temperaturas de dos tipos de caolín local de composiciones químicas diferentes, al incorporarse al cemento en diferentes proporciones. Se preparó un cemento adicionado mediante la mezcla en seco de cemento Portland ordinario (OPC y metacaolín (MK, a los que se añadió la cantidad óptima de agua para obtener una pasta de la consistencia deseada. Las probetas se curaron a una HR del 100% durante 24 horas, sumergiéndose posteriormente en agua durante 3, 7, 28, 90 o 180 días. A cada tiempo de ensayo se controló el grado de hidratación de las pastas endurecidas y se comprobó la resistencia a la compresión de las probetas cúbicas a las edades de curado establecidas. Los resultados obtenidos indican que la

  4. Durability/life of fiber composites in hygrothermomechanical environments

    Science.gov (United States)

    Chamis, C. C.; Sinclair, J. H.

    1982-01-01

    Statistical analysis and multiple regression were used to determine and quantify the significant hygrothermomechanical variables which influence the tensile durability/life (cycle loading, fatigue) of boron-fiber/epoxy-matrix (B/E) and high-modulus-fiber/epoxy-matrix (HMS/E) composites. The use of the multiple regression analysis reduced the variables from fifteen, assumed initially, to six or less with a probability of greater than 0.999. The reduced variables were used to derive predictive models for compression and intralaminar shear durability/life of B/E and HMS/E composites assuming isoparametric fatigue behavior. The predictive models were subsequently generalized to predict the durability/life of graphite/fiber-r generalized model is of simple form, predicts conservative values compared with measured data and should be adequate for use in preliminary designs. Previously announced in STAR as N82-14287

  5. The phenomenon of durability variable dies for aluminum extrusion profiles

    Directory of Open Access Journals (Sweden)

    J. Borowski

    2016-04-01

    Full Text Available Extrusion dies are usually regenerated several times (min 4 times. The phenomenon of extended life after each regenerative nitriding process has not been explained. In this work, the regeneration process of dies used in the extrusion of aluminium profiles has been presented. In the article, it was sought to explain the cause of increased die durability after the third or fourth nitriding. Also in this work is presented an analysis of the influence of the parameters of gas nitriding with the ZeroFlow method on hardness of dies. Results were verified under industrial conditions at extrusion company, comparing the durability of the dies nitrided with the ZeroFlow method with so-far-used dies nitrided in the commercial way. An increase of the dies durability was achieved after a single ZeroFlow nitriding.

  6. Durable Catalysts for High Temperature Proton Exchange Membrane Fuel Cells

    DEFF Research Database (Denmark)

    Durability of proton exchange membrane fuel cells (PEMFCs) is recognized as one of the most important issues to be addressed before the commercialization. The failure mechanisms are not well understood, however, degradation of carbon supported noble metal catalysts is identified as a major failure...... corrosion, in turn, triggers the agglomeration of platinum particles resulting in reduction of the active surface area and catalytic activity. This is a major mechanism of the catalyst degradation and a key challenge to the PEMFC long-term durability. High temperature PEMFC, on the other hand, has attached...... the selectivity for platinum loading. Fuel cell durability tests in term of performance degradation were performed with acid doped polybenzimidazole membrane fuel cells at temperatures of up to 160°C. The tests were focused on catalyst degradation by means of a potential cycling protocol. The electrochemical...

  7. Effects of slag fineness on durability of mortars

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In recent years, the usages of by-products and wastes in industry have become more important. The importance of the sustainable development is also of increasing. The utilizations of wastes, as mineral admixture or fine aggregate, reduce the consumption of the natural resources and improve the durability of concrete. In this study, the effect of the fineness on the high temperature and sulphate resistances of concrete mortar specimens, produced with ground granulated blast-furnace slag (GBFS)replacing cement, is investigated. The compressive and flexural strength test results for all series related to durability effects,exposing temperature and solutions, exposure times for these durability effects, slag content and fineness are discussed. Consequently, the optimum slag contents are determined for producing the sulphate and high temperature resistant mortars.

  8. Stirling engine - Approach for long-term durability assessment

    Science.gov (United States)

    Tong, Michael T.; Bartolotta, Paul A.; Halford, Gary R.; Freed, Alan D.

    1992-01-01

    The approach employed by NASA Lewis for the long-term durability assessment of the Stirling engine hot-section components is summarized. The approach consists of: preliminary structural assessment; development of a viscoplastic constitutive model to accurately determine material behavior under high-temperature thermomechanical loads; an experimental program to characterize material constants for the viscoplastic constitutive model; finite-element thermal analysis and structural analysis using a viscoplastic constitutive model to obtain stress/strain/temperature at the critical location of the hot-section components for life assessment; and development of a life prediction model applicable for long-term durability assessment at high temperatures. The approach should aid in the provision of long-term structural durability and reliability of Stirling engines.

  9. Highly durable graphene nanoplatelets supported Pt nanocatalysts for oxygen reduction

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Yuyan; Zhang, Sheng; Wang, Chongmin; Nie, Zimin; Liu, Jun; Lin, Yuehe [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Wang, Yong [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); The Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA 99164 (United States)

    2010-08-01

    We report graphene nanoplatelets (GNPs), which exhibit the advantages of both single-layer graphene and highly graphitic carbon, as a durable alternative support material for Pt nanoparticles for oxygen reduction in fuel cells. Pt nanoparticles are deposited on poly(diallyldimethylammonium chloride) (PDDA)-coated GNP, and characterized with transmission electron microscopy, X-ray diffraction, Raman spectra, and electrochemical tests. Pt/GNP exhibits greatly enhanced electrochemical durability (2-3 times that of Pt/CNT and commercial Etek Pt/C). These are attributed to the intrinsic high graphitization degree of GNP and the enhanced Pt-carbon interaction in Pt/GNP. If considering that GNP can be easily mass produced from graphite, GNP is a promising, low-cost, and durable electrocatalyst support for oxygen reduction in fuel cells. (author)

  10. Mechanical durability and combustion characteristics of pellets from biomass blends

    Energy Technology Data Exchange (ETDEWEB)

    Gil, M.V.; Oulego, P.; Casal, M.D.; Pevida, C.; Pis, J.J.; Rubiera, F. [CSIC, Oviedo (Spain)

    2010-11-15

    Biofuel pellets were prepared from biomass (pine, chestnut and eucalyptus sawdust, cellulose residue, coffee husks and grape waste) and from blends of biomass with two coals (bituminous and semianthracite). Their mechanical properties and combustion behaviour were studied by means of an abrasion index and thermogravimetric analysis (TGA), respectively, in order to select the best raw materials available in the area of study for pellet production. Chestnut and pine sawdust pellets exhibited the highest durability, whereas grape waste and coffee husks pellets were the least durable. Blends of pine sawdust with 10-30% chestnut sawdust were the best for pellet production. Blends of cellulose residue and coals (<20%) with chestnut and pine sawdusts did not decrease pellet durability. The biomass/biomass blends presented combustion profiles similar to those of the individual raw materials. The addition of coal to the biomass in low amounts did not affect the thermal characteristics of the blends.

  11. Studying creation of bulk elementary excitation by heaters in superfluid helium-Ⅱ at low temperatures

    Institute of Scientific and Technical Information of China (English)

    ZAKHARENKO A.A.

    2007-01-01

    In this paper, the obtained experimental results concerning creation of bulk elementary excitations (BEEs) in isotopically pure liquid 4He at low temperatures ~60 mK are discussed. Positive rotons' (R+-rotons) creation by a pulsed heater was studied. Signals were recorded for the following quantum processes: quantum evaporation of 4He-atoms from the free liquid-helium surface by the BEEs of the liquid helium-Ⅱ, and BEEs reflection from the free surface back into the bulk liquid. Typical signals are shown, and ratios of signal amplitudes are evaluated. For long heater pulses from 5 to 10 μs, appearance of the second atomic cloud consisting of evaporated 4He-atoms was observed in addition to the first atomic cloud. It is thought that the first atomic cloud of the evaporated helium atoms consists of very fast 4He-atoms with energies ~35 K evaporated by positive rotons with the special energies ~17 K (~2ER~2×8.6 K with ER representing the roton minimum energy) corresponding to the third non-dispersive Zakharenko wave. The second cloud of slower 4He-atoms was created by surface elementary excitations (SEEs or ripplons) possessing the special energies ~7.15 K representing the binding energy. It was assumed that such SEEs can be created by phonons incoming to the liquid surface with special energies ~6.2 K corresponding to the first non-dispersive Zakharenko wave,which can interact at the liquid surface with the same phonons already reflected from the surface for long heater pulses. Also, some pulsed-heater characteristics were studied in order to better understand the features of such heaters in low temperature experiments.

  12. Research and development of a high efficiency gas-fired water heater. Volume 2. Task reports

    Energy Technology Data Exchange (ETDEWEB)

    Vasilakis, A.D.; Pearson, J.F.; Gerstmann, J.

    1980-01-01

    Design and development of a cost-effective high efficiency gas-fired water heater to attain a service efficiency of 70% (including the effect of exfiltration) and a service efficiency of 78% (excluding exfiltration) for a 75 GPD draw at a 90/sup 0/F temperature rise, with a stored water to conditioned air temperature difference of 80/sup 0/F, are described in detail. Based on concept evaluation, a non-powered natural draft water heater was chosen as the most cost-effective design to develop. The projected installed cost is $374 compared to $200 for a conventional unit. When the project water heater is compared to a conventional unit, it has a payback of 3.7 years and life cycle savings of $350 to the consumer. A prototype water heater was designed, constructed, and tested. When operated with sealed combustion, the unit has a service efficiency of 66.4% (including the effect of exfiltration) below a burner input of 32,000 Btu/h. In the open combustion configuration, the unit operated at a measured efficiency of 66.4% Btu/h (excluding exfiltration). This compares with a service efficiency of 51.3% for a conventional water heater and 61% for a conventional high efficiency unit capable of meeting ASHRAE 90-75. Operational tests showed the unit performed well with no evidence of stacking or hot spots. It met or exceeded all capacity or usage tests specified in the program test plan and met all emission goals. Future work will concentrate on designing, building, and testing pre-production units. It is anticipated that both sealed combustion and open draft models will be pursued.

  13. Durability, adaptability and energy conservation (DAEC) assessment tool

    Energy Technology Data Exchange (ETDEWEB)

    Langford, D.A.; Macleod, I.; Dimitrijevic, B. [University of Strathclyde, Glasgow (United Kingdom). Dept. of Civil Engineering; Maver, T.W. [University of Strathclyde, Glasgow (United Kingdom). Dept. of Architecture and Building

    2002-07-01

    This paper presents an evaluation tool for assessing the durability, adaptability and energy conservation of existing buildings and new building designs - DAEC Tool. The tool is one of the outcomes of the research project 'Sustainability of Buildings: Durability, Adaptability and Energy Conservation'. The paper examines the issues which were the basis for developing the metrics, and the application of the DAEC Tool in the evaluation of selected higher education buildings and a new building design for a community hospital. The paper explains how the DAEC Tool can be used in building design and building management. (author)

  14. Développement et tourisme : une relation durable

    OpenAIRE

    Bédard, François; Kadri, Boualem

    2011-01-01

    Depuis les années 1990, le processus international d’aide au développement favorise le tourisme comme outil stratégique d’appui à un développement durable. Désormais, le développement est reconnu comme devant être durable dans ses dimensions environnementale, économique et sociale. De grandes organisations internationales contribuent depuis plusieurs décennies à construire la relation entre développement et tourisme. Pour illustrer la contribution des membres du CIFORT, nous présenterons sous...

  15. Long time durability tests of fabric inlet stratification pipes

    DEFF Research Database (Denmark)

    Andersen, Elsa; Furbo, Simon

    2008-01-01

    The long time durability of seven different two layer fabric inlet stratification pipes for enhancing thermal stratification in hot water stores is investigated experimentally. Accelerated durability tests are carried out with the inlet stratification pipes both in a domestic hot water tank...... and that this destroys the capability of building up thermal stratification for the fabric inlet stratification pipe. The results also show that although dirt, algae etc. are deposited in the fabric pipes in the space heating tank, the capability of the fabric inlet stratifiers to build up thermal stratification...

  16. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent

    Energy Technology Data Exchange (ETDEWEB)

    Jha, M.C.; Berggren, M.H.

    1988-11-14

    AMAX Research Development Center (AMAX R D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such As size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.

  17. High performance, durable polymers including poly(phenylene)

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, Cy; Pratt, Harry; Anderson, Travis Mark

    2017-02-28

    The present invention relates to functionalized polymers including a poly(phenylene) structure. In some embodiments, the polymers and copolymers of the invention include a highly localized concentration of acidic moieties, which facilitate proton transport and conduction through networks formed from these polymers. In addition, the polymers can include functional moieties, such as electron-withdrawing moieties, to protect the polymeric backbone, thereby extending its durability. Such enhanced proton transport and durability can be beneficial for any high performance platform that employs proton exchange polymeric membranes, such as in fuel cells or flow batteries.

  18. Utilization of Durability Criterion to Develop Automotive Components

    DEFF Research Database (Denmark)

    Ricardo, Luiz Carlos Hernandes

    2010-01-01

    . This paper will present a review of the techniques used in the automotive industry regarding durability before mentioned systems. The paper will present the procedures to obtain the spectrum loading to use in finite element analysis and the validation in laboratory and proving grounds.......Today the automotive companies must reduce the time to development of new products with improvement in performance, durability and low cost reductions where possible. To achieve this goal the carmakers need to improve the design criterion of car systems like body, chassis and suspension components...

  19. Head and Neck

    DEFF Research Database (Denmark)

    Højgaard, Liselotte; Berthelsen, Anne Kiil; Loft, Annika

    2014-01-01

    Positron emission tomography (PET)/computed tomography with FDG of the head and neck region is mainly used for the diagnosis of head and neck cancer, for staging, treatment evaluation, relapse, and planning of surgery and radio therapy. This article is a practical guide of imaging techniques......, including a detailed protocol for FDG PET in head and neck imaging, physiologic findings, and pitfalls in selected case stories....

  20. EFFECT OF DISCRETE HEATER AT THE VERTICAL WALL OF THE CAVITY OVER THE HEAT TRANSFER AND ENTROPY GENERATION USING LBM

    Directory of Open Access Journals (Sweden)

    Mousa Farhadi

    2011-01-01

    Full Text Available In this paper Lattice Boltzmann Method (LBM was employed for investigation the effect of the heater location on flow pattern, heat transfer and entropy generation in a cavity. A 2D thermal lattice Boltzmann model with 9 velocities, D2Q9, is used to solve the thermal flow problem. The simulations were performed for Rayleigh numbers from 103 to 106 at Pr = 0.71. The study was carried out for heater length of 0.4 side wall length which is located at the right side wall. Results are presented in the form of streamlines, temperature contours, Nusselt number and entropy generation curves. Results show that the location of heater has a great effect on the flow pattern and temperature fields in the enclosure and subsequently on entropy generation. The dimensionless entropy generation decreases at high Rayleigh number for all heater positions. The ratio of averaged Nusselt number and dimensionless entropy generation for heater located on vertical and horizontal walls was calculated. Results show that higher heat transfer was observed from the cold walls when the heater located on vertical wall. On the other hand, heat transfer increases from the heater surface when it located on the horizontal wall.

  1. A high turndown, ultra low emission low swirl burner for natural gas, on-demand water heaters

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, Vi H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cheng, Robert K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Therkelsen, Peter L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-06-13

    Previous research has shown that on-demand water heaters are, on average, approximately 37% more efficient than storage water heaters. However, approximately 98% of water heaters in the U.S. use storage water heaters while the remaining 2% are on-demand. A major market barrier to deployment of on-demand water heaters is their high retail cost, which is due in part to their reliance on multi-stage burner banks that require complex electronic controls. This project aims to research and develop a cost-effective, efficient, ultra-low emission burner for next generation natural gas on-demand water heaters in residential and commercial buildings. To meet these requirements, researchers at the Lawrence Berkeley National Laboratory (LBNL) are adapting and testing the low-swirl burner (LSB) technology for commercially available on-demand water heaters. In this report, a low-swirl burner is researched, developed, and evaluated to meet targeted on-demand water heater performance metrics. Performance metrics for a new LSB design are identified by characterizing performance of current on-demand water heaters using published literature and technical specifications, and through experimental evaluations that measure fuel consumption and emissions output over a range of operating conditions. Next, target metrics and design criteria for the LSB are used to create six 3D printed prototypes for preliminary investigations. Prototype designs that proved the most promising were fabricated out of metal and tested further to evaluate the LSB’s full performance potential. After conducting a full performance evaluation on two designs, we found that one LSB design is capable of meeting or exceeding almost all the target performance metrics for on-demand water heaters. Specifically, this LSB demonstrated flame stability when operating from 4.07 kBTU/hr up to 204 kBTU/hr (50:1 turndown), compliance with SCAQMD Rule 1146.2 (14 ng/J or 20 ppm NOX @ 3% O2), and lower CO emissions than state

  2. Deciphering durable resistance one R gene at a time.

    Science.gov (United States)

    White, Frank F; Frommer, Wolf

    2015-12-01

    Characterizations of durable resistance genes in crop plants are coming to the fore. A new study characterizing the wheat gene Lr67 shows that how a plant manages sugar transport affects the ability of a broad group of fungal pathogens to colonize their host.

  3. Solid oxide cell oxygen electrode with enhanced durability

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention provides various methods of producing a solid oxide cell with an enhanced durability. Dopants are provided at the interface of the electrode comprising LSM and electrolyte and prevent especially the diffusion of Mn from the electrode layer into the electrolyte, stabilizing...

  4. Recent advances in the mechanical durability of superhydrophobic materials.

    Science.gov (United States)

    Milionis, Athanasios; Loth, Eric; Bayer, Ilker S

    2016-03-01

    Large majority of superhydrophobic surfaces have very limited mechanical wear robustness and long-term durability. This problem has restricted their utilization in commercial or industrial applications and resulted in extensive research efforts on improving resistance against various types of wear damage. In this review, advances and developments since 2011 in this field will be covered. As such, we summarize progress on fabrication, design and understanding of mechanically durable superhydrophobic surfaces. This includes an overview of recently published diagnostic techniques for probing and demonstrating tribo-mechanical durability against wear and abrasion as well as other effects such as solid/liquid spray or jet impact and underwater resistance. The review is organized in terms of various types of mechanical wear ranging from substrate adhesion, tangential surface abrasion, and dynamic impact to ultrasonic processing underwater. In each of these categories, we highlight the most successful approaches to produce robust surfaces that can maintain their non-wetting state after the wear or abrasive action. Finally, various recommendations for improvement of mechanical wear durability and its quantitative evaluation are discussed along with potential future directions towards more systematic testing methods which will also be acceptable for industry.

  5. Durable Tactile Glove for Human or Robot Hand

    Science.gov (United States)

    Butzer, Melissa; Diftler, Myron A.; Huber, Eric

    2010-01-01

    A glove containing force sensors has been built as a prototype of tactile sensor arrays to be worn on human hands and anthropomorphic robot hands. The force sensors of this glove are mounted inside, in protective pockets; as a result of this and other design features, the present glove is more durable than earlier models.

  6. Measuring Happiness: From Fluctuating Happiness to Authentic–Durable Happiness

    Science.gov (United States)

    Dambrun, Michaël; Ricard, Matthieu; Després, Gérard; Drelon, Emilie; Gibelin, Eva; Gibelin, Marion; Loubeyre, Mélanie; Py, Delphine; Delpy, Aurore; Garibbo, Céline; Bray, Elise; Lac, Gérard; Michaux, Odile

    2012-01-01

    On the basis of the theoretical distinction between self-centeredness and selflessness (Dambrun and Ricard, 2011), the main goal of this research was to develop two new scales assessing distinct dimensions of happiness. By trying to maximize pleasures and to avoid displeasures, we propose that a self-centered functioning induces a fluctuating happiness in which phases of pleasure and displeasure alternate repeatedly (i.e., Fluctuating Happiness). In contrast, a selfless psychological functioning postulates the existence of a state of durable plenitude that is less dependent upon circumstances but rather is related to a person’s inner resources and abilities to deal with whatever comes his way in life (i.e., Authentic–Durable Happiness). Using various samples (n = 735), we developed a 10-item Scale measuring Subjective Fluctuating Happiness (SFHS) and a 13-item scale assessing Subjective Authentic–Durable Happiness (SA–DHS). Results indicated high internal consistencies, satisfactory test–retest validities, and adequate convergent and discriminant validities with various constructs including a biological marker of stress (salivary cortisol). Consistent with our theoretical framework, while self-enhancement values were related only to fluctuating happiness, self-transcendence values were related only to authentic–durable happiness. Support for the distinction between contentment and inner-peace, two related markers of authentic happiness, also was found. PMID:22347202

  7. Durable chemical sensors based on field-effect transistors

    NARCIS (Netherlands)

    Reinhoudt, D.N.

    1995-01-01

    The design of durable chemical sensors based on field-effect transistors (FETs) is described. After modification of an ion-sensitive FET (ISFET) with a polysiloxane membrane matrix, it is possible to attach all electroactive components covalently. Preliminary results of measurements with a sodium-se

  8. Low viscosity automatic transmission fluids with enhanced friction durability

    Institute of Scientific and Technical Information of China (English)

    Kenji Yatsunami; Samuel H. Tersigni; TANG Hong- zhi; Lee D. Saathoff; Christopher S. Cleveland; Mark Jones

    2009-01-01

    This study focused on the development of a new low viscosity automatic transmission fluid (ATF) with enhanced friction durability to meet the needs of new step type automatic transmissions. Recent high fuel prices encourage increased efficiency in the driveline, including the transmission. Reduction in fluid viscosity and wider use of slip control in torque con-verter clutches are two ways to practically improve fuel efficiency. Increased torque and more shifting is seen with a variety of new transmission hardware platforms, such as wet starting clutches, dual clutches and seven - or eight - speed ATs.This suggests the need for enhanced levels of friction durability from the ATF. The new challenge from this hardware for the ATF formulator lies in the need to simultaneously meet the wear, friction durability and torque capacity requirements at low viscosity in a cost- effective manner. This report introduced a new low viscosity fluid that represents a different commercial ATF formulation style. The new chemistry employs a low viscosity for increased fuel economy, while easily doubling the friction durability of current conven-tional ATFs and offering higher torque and better EP.

  9. The Search for Durable Exterior Clear Coatings for Wood

    Directory of Open Access Journals (Sweden)

    Philip D. Evans

    2015-11-01

    Full Text Available The goal of a durable exterior clear coating has eluded generations of coatings technologists, despite long-standing desire amongst the public for such a coating. The journey towards this goal initially focused on modifications to coating formulation, but took a completely different direction when it was found that a UV-transparent silicone clear coating on wood modified with chromic acid met consumer expectations of coating durability. This finding sparked world-wide interest in wood pre-treatments as a way of enhancing the durability of clear coatings. This interest initially focused on transition metal compounds, but has now shifted in the direction of organic and inorganic photostabilizers or even more drastic pre-treatments. Pre-treatments that dimensionally stabilize wood, protect it from microbial degradation and photostabilize lignin, when combined with flexible, photostable, coatings provide the next way-stop on the journey towards achieving the goal of durable exterior clear coatings for wood. This paper reviews this journey, drawing upon our research and that of other groups who have focused on this elusive goal.

  10. What does moisture-related durability of wood bonds mean?

    Science.gov (United States)

    Charles R. Frihart; Daniel J. Yelle; Alex C. Wiedenhoeft

    2008-01-01

    The accelerated test methods that distinguish between acceptable and unacceptable wood adhesives generally involve subjecting the bonded assembly to abnormally rapid and extreme moisture exposure or cycling. In the United States and Canada, these tests for moisture durability have been established, but selection of the appropriate test methods for the different service...

  11. Has durable goods spending become less sensitive to interest rates?

    National Research Council Canada - National Science Library

    Van Zandweghe, Willem; Braxton, John Carter

    2013-01-01

    ... on this category of spending has weakened in the current recovery. Durable goods purchases, which include residential investment as well as spending on vehicles, recre- ational goods, and household goods, are a particularly interest-sensitive component of consumer spending. In the first four years of previous recoveries, a decline in interest rate...

  12. Cycles and Multiple Equilibria in the Market for Durable Lemons

    NARCIS (Netherlands)

    M.C.W. Janssen (Maarten); V.A. Karamychev (Vladimir)

    2000-01-01

    textabstractWe investigate the nature of market failure in a dynamic version of Akerlof (1970) where identical cohorts of a durable good enter the market over time. In the dynamic model, equilibria with qualitatively different properties emerge. Typically, in equilibria of the dynamic model, sellers

  13. Durable phosphate-selective electrodes based on uranyl salophenes

    NARCIS (Netherlands)

    Wroblewski, Wojciech; Wojciechowski, Kamil; Dybko, Artur; Brzozka, Zbigniew; Egberink, Richard J.M.; Snellink-Ruel, Bianca H.M.; Reinhoudt, David N.

    2001-01-01

    Lipophilic uranyl salophenes derivatives were used as ionophores in durable phosphate-selective electrodes. The influence of the ionophore structure and membrane composition (polarity of plasticizer, the amount of incorporated ionic sites) on the electrode selectivity and long-term stability were st

  14. Making IBSE durable through pre-service teacher education

    NARCIS (Netherlands)

    Berg, van den Ed; Damsma, Welmoet; Herik, van den Maaike; Mulken, van Frans; Ruis, Paul; Blagotinsek, Ana; Cronin, Sue; Holub, Sigrid; Holub, Peter; Sokolowska, Dagmara; Sporea, Dan; Sporea, Adelina

    2013-01-01

    How can we make Inquiry-Based Science and Mathematics Education (IBSME) durable? …. by incorporating it in the pre-service programs for elementary teachers! With pre-service students the training can be much more intensive than with inservice teachers. To have an impact in the classroom the minimum

  15. Durability Quality Research of Concrete Containing Solar PV Cells

    Directory of Open Access Journals (Sweden)

    Chao Sao-Jeng

    2015-01-01

    Full Text Available In this article we demonstrated the study results of durability quality of concrete containing waste solar PV cells. The study used alkali activator to improve the activity of alkali-activated materials in solar PV cells so as to replace Portland cement as binder in concrete. By using sodium hydroxide as an alkali-activator, a high-pH environment is generated to excite the binding characteristics of alkali-activated materials in solar PV cells, and thus develops better durability of the mixes. The conclusions were made on effect of this cement replacement. As a result, we identified the durability for those of 16 concrete specimens predefined and made to consider various possible control factors. The conclusions also depicted that all experiments but the drying shrinkage may be helpful with the suitable use of control factors as far as concerning the recycled solar PV cells for mixing in concrete. In other words, the durability quality of concrete may be partially unacceptable of containing solar PV cells.

  16. Head Injuries in Children

    Science.gov (United States)

    Pennington, Nicole

    2010-01-01

    School nurses play a crucial role in injury prevention and initial treatment when injuries occur at school. The role of school nurses includes being knowledgeable about the management of head injuries, including assessment and initial treatment. The school nurse must be familiar with the outcomes of a head injury and know when further evaluation…

  17. Modernization of the feedwater heaters control level of the Almaraz I Nuclear Power Plant by OVATION system; Modernizacion del control de nivel de los calentadores de agua de alimentacion de C.N. Almaraz I mediante el sistema OVATION

    Energy Technology Data Exchange (ETDEWEB)

    Madronal Rodriguez, E.; Cabrero Munoz, J. E.

    2010-07-01

    As a result of the process of technological renovation of the heaters system and the power increase project, Almaraz Nuclear Power Plant has made several design changes in the feedwater heaters system. Within these changes, the old heaters control loops are replaced because the new power will increase the heaters drainage caudal. This modernization is carried out using the OVATION control system.

  18. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent

    Energy Technology Data Exchange (ETDEWEB)

    Berggren, M.H.; Jha, M.C.

    1989-10-01

    AMAX Research Development Center (AMAX R D) investigated methods for enhancing the reactivity and durability of zinc ferrite desulfurization sorbents. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For this program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such as size, strength, and specific surface area during 10 cycles of sulfidation and oxidation. Two base case sorbents, a spherical pellet and a cylindrical extrude used in related METC-sponsored projects, were used to provide a basis for the aimed enhancement in durability and reactivity. Sorbent performance was judged on the basis of physical properties, single particle kinetic studies based on thermogravimetric (TGA) techniques, and multicycle bench-scale testing of sorbents. A sorbent grading system was utilized to quantify the characteristics of the new sorbents prepared during the program. Significant enhancements in both reactivity and durability were achieved for the spherical pellet shape over the base case formulation. Overall improvements to reactivity and durability were also made to the cylindrical extrude shape. The primary variables which were investigated during the program included iron oxide type, zinc oxide:iron oxide ratio, inorganic binder concentration, organic binder concentration, and induration conditions. The effects of some variables were small or inconclusive. Based on TGA studies and bench-scale tests, induration conditions were found to be very significant.

  19. Design of concrete structures for durability. Example: Chloride penetration in the lining of a bored tunnel

    NARCIS (Netherlands)

    Siemes, A.J.M.

    1998-01-01

    The present design method for durability of concrete is based on a set of rules that give no objective in-sight in the service life to expect from the concrete structure. An objective comparison between different durability measures is therefor not possible. Especially if the lack of durability can

  20. Study on the Durabilities of Trouser's Appearance and the Fabric Designing

    Institute of Scientific and Technical Information of China (English)

    王府梅; 杨莉; 王善元

    2001-01-01

    The durability of trouser's appearance involves the durability of crease and seam line after pressing, bagging resistance, wrinkle resistance, pilling resistance on the surface during wear. These properties are very important for the tailored trousers. It is investigated how the durability of trousers appearance is related to properties of the blend ratio of wool and PET, the yarn structure and fabric mechanical properties.

  1. 30 CFR 817.73 - Disposal of excess spoil: Durable rock fills.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Disposal of excess spoil: Durable rock fills...-UNDERGROUND MINING ACTIVITIES § 817.73 Disposal of excess spoil: Durable rock fills. The regulatory authority may approve the alternative method of disposal of excess durable rock spoil by gravity placement...

  2. 30 CFR 816.73 - Disposal of excess spoil: Durable rock fills.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Disposal of excess spoil: Durable rock fills...-SURFACE MINING ACTIVITIES § 816.73 Disposal of excess spoil: Durable rock fills. The regulatory authority may approve the alternative method of disposal of excess durable rock spoil by gravity placement...

  3. Investigation on natural durability and sorption properties of Italian Chestnut (Castanea sativa Mill.) from coppice stands

    NARCIS (Netherlands)

    Militz, H.; Busetto, D.; Hapla, F.

    2003-01-01

    Castanea sativa Mill. from coppice stands in Italy were evaluated. Fungi trials with different white rot, brown rot and soft rot fungi showed, that the heartwood of chestnut can be classified following EN 350 in durability class 2 as ¿durable¿. However, the durability within the tested material (bet

  4. Influence of Superheated Steam Temperature Regulation Quality on Service Life of Boiler Steam Super-Heater Metal

    Directory of Open Access Journals (Sweden)

    G. T. Kulakov

    2009-01-01

    Full Text Available The paper investigates influence of change in quality of superheated steam temperature regulations on service life of super-heater metal. А dependence between metal service life and dispersion value for different steel grades has been determined in the paper. Numerical values pertaining to increase of super-heater metal service life in case of transferring from manual regulation to standard system of automatic regulation (SAR have been determined and in case of transferring from standard SAR to improved SAR. The analysis of tabular data and plotted dependencies makes it possible to conclude that any change in conditions of convection super-heater metal work due to better quality of the regulation leads to essential increase of time period which is left till the completion of the service life of a super-heater heating surface.

  5. Application of computational fluid dynamics (CFD) to a gas heater used for the drying of agricultural products

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Douglas Romeu da; Coradi, Paulo Carteri; Visser, Evan Michael; Martins, Marcio Aredes [Universidade Federal de Vicosa (UFV), MG (Brazil). Dept. de Engenharia Agricola

    2008-07-01

    The objective of this study was to evaluate a gas heater used for the drying of agricultural products. The effects of fuel, primary air and secondary air flows on the distribution on temperature and velocity in a heater were evaluated with the objective of rationalizing combustion fuel. LPG was used as the energy source to provide heated air for drying. The Navier-Stokes equations were used to resolve the problem of air and fuel flow, respecting the energy conservation, equations in the heater. From the results generated, it was confirmed that greater temperature were obtained with the convection coefficient was minimal (h = 0.01). Velocity presented a parabolic, fully developed profile. The greatest velocity was encountered in the central region of the flow, obtained when the Reynolds number was at its greatest. CFD software proved to be applicable in order to resolve heat and mass transfer problems in heaters. (author)

  6. Performance and energy costs associated with scaling infrared heater arrays for warming field plots from 1 to 100 m

    Science.gov (United States)

    To study the likely effects of global warming on open-field vegetation, hexagonal arrays of infrared heaters are currently being used for low-stature (scales, herein we show that excellent uniformity of the warming can be achieved using...

  7. An in-situ heater for the XAS beamline (12-ID) in Australia

    Science.gov (United States)

    Johannessen, B.; Hussain, Z. S.; East, D. R.; Gibson, M. A.

    2013-04-01

    To accommodate for a growing number of requests by our user community an in-situ heater has been commissioned for the X-ray absorption spectroscopy (XAS) beamline 12-ID at the Australian Synchrotron. Here, we present an in-situ method for calibrating the temperature of the heating stage based on an anharmonic, correlated Einstein model. Specifically, we show that a temperature-dependant study of a bulk metallic foil (7.5 μm Cu) can be used to accurately calibrate the temperature of the heater. We also present the temperature-dependant coordination number, bond length, Debye-Waller factor, and third order cumulant to the bond length distribution function of the material from 18K to 1074K. At the higher temperatures we find that the atomic structure is comparable to that of an amorphous or liquid material indicating a gradual transition from crystalline to disordered atomic structure.

  8. Solar Probe Plus MAG Sensor Thermal Design for Low Heater Power and Extreme Thermal Environment

    Science.gov (United States)

    Choi, Michael K.

    2015-01-01

    The heater power available for the Solar Probe Plus FIELDS MAG sensor is less than half of the heritage value for other missions. Nominally the MAG sensors are in the spacecraft's umbra. In the worst hot case, approximately 200 spacecraft communication downlinks, up to 10 hours each, are required at 0.7 AU. These downlinks require the spacecraft to slew 45 deg. about the Y-axis, exposing the MAG sensors and boom to sunlight. This paper presents the thermal design to meet the MAG sensor thermal requirements in the extreme thermal environment and with low heater power. A thermal balance test on the MAG sensor engineering model has verified the thermal design and correlated the thermal model for flight temperature predictions.

  9. Performance study of solar air heater duct having absorber plate with V down perforated baffles

    Directory of Open Access Journals (Sweden)

    Sunil Chamoli

    2014-04-01

    Full Text Available This paper presents results of a study of the performance of solar air heaters with V down perforated baffles as roughness on the air flow side of the absorber plate. Investigations have been carried out using a mathematical model to study the effects of ambient conditions, operating and design parameters on effective efficiency of such air heaters. The thermal and effective efficiencies differ only marginally at lower flow rates. With an increase in the flow rate, the difference between the thermal and effective efficiencies increases because of the increase in the pumping power. The results of the study are presented in the form of plots to show the effect of ambient, design and operating conditions on thermal and effective efficiency.

  10. Large eddy simulation of combustion instability in a tripropellant air heater

    Science.gov (United States)

    Yuan, Lei; Shen, Chibing

    2016-12-01

    This research is motivated by the issue associated with high frequency combustion instability. Large eddy simulation was performed to investigate spontaneous combustion instability in an air/LO2/C2H5OH tripropellant air heater. The simulation predicts self-excited transverse oscillations. Overall behavior of combustion instability including pressure time histories, mode shapes, Rayleigh index and unsteady response of the injector were studied in detail. Special emphasis was given to the flame behavior, droplet trajectories, pressure evolutions, and formation of large-scale vortical structures during combustion instability in present air heater. Furthermore, in contrast to previous investigations, a new process is identified in the simulation that may feed energy into the acoustic mode and drive combustion instability.

  11. Application of a Linear Input/Output Model to Tankless Water Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Butcher T.; Schoenbauer, B.

    2011-12-31

    In this study, the applicability of a linear input/output model to gas-fired, tankless water heaters has been evaluated. This simple model assumes that the relationship between input and output, averaged over both active draw and idle periods, is linear. This approach is being applied to boilers in other studies and offers the potential to make a small number of simple measurements to obtain the model parameters. These parameters can then be used to predict performance under complex load patterns. Both condensing and non-condensing water heaters have been tested under a very wide range of load conditions. It is shown that this approach can be used to reproduce performance metrics, such as the energy factor, and can be used to evaluate the impacts of alternative draw patterns and conditions.

  12. Heat Pump Water Heater Technology Assessment Based on Laboratory Research and Energy Simulation Models: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Hudon, K.; Sparn, B.; Christensen, D.; Maguire, J.

    2012-02-01

    This paper explores the laboratory performance of five integrated Heat Pump Water Heaters (HPWHs) across a wide range of operating conditions representative of US climate regions. Laboratory results demonstrate the efficiency of this technology under most of the conditions tested and show that differences in control schemes and design features impact the performance of the individual units. These results were used to understand current model limitations, and then to bracket the energy savings potential for HPWH technology in various US climate regions. Simulation results show that HPWHs are expected to provide significant energy savings in many climate zones when compared to other types of water heaters (up to 64%, including impact on HVAC systems).

  13. MHD air heater technology development. Annual technical progress report, January 1, 1980-December 31, 1980

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-03-01

    Progress on the technology development of the directly-fired high temperature air heater (HTAH) for MHD power plants is described in detail. The objective of task 1 is to continue development of ceramic materials technology for the directly-fired HTAH. The objectives of task 2 are to demonstrate the technical feasibility of operating a directly-fired HTAH (including both the heater matrix and valves), to continue obtaining information on life and corrosion resistance of HTAH materials, and to obtain design information for full-scale studies and future design work. The objectives of task 3 are to begin the identification of HTAH control requirements and control system needs, and to continue full-scale study efforts incorporating updated materials and design information in order to identify development needs for the HTAH development program. (WHK)

  14. A highly crystalline single Au wire network as a high temperature transparent heater.

    Science.gov (United States)

    Rao, K D M; Kulkarni, Giridhar U

    2014-06-07

    A transparent conductor which can generate high temperatures finds important applications in optoelectronics. In this article, a wire network made of Au on quartz is shown to serve as an effective high temperature transparent heater. The heater has been fabricated by depositing Au onto a cracked sacrificial template. The highly interconnected Au wire network thus formed exhibited a transmittance of ∼87% in a wide spectral range with a sheet resistance of 5.4 Ω □(-1). By passing current through the network, it could be joule heated to ∼600 °C within a few seconds. The extraordinary thermal performance and stability owe much to the seamless junctions present in the wire network. Furthermore, the wire network gets self-annealed through joule heating as seen from its increased crystallinity. Interestingly, both transmittance and sheet resistance improved following annealing to 92% and 3.2 Ω □(-1), respectively.

  15. Energy and exergy analysis in double-pass solar air heater

    Indian Academy of Sciences (India)

    P VELMURUGAN; R KALAIVANAN

    2016-03-01

    In this study, an attempt is made to improve the energy and exergy performance of solar air heater by employing double pass with different absorber surface geometries (roughened, finned, and v-corrugated wire mesh) in the second pass, and also by mounting longitudinal fins in the back side of the absorber plate (first pass). The effect of varied mass flow rate and solar intensity on temperature rise of air, energy efficiency, exergy gain and pressure drop at steady state condition was determined for different types of solar air heaters utilizing an indoor solar simulator. The temperature rise of air, thermal efficiency and exergy gain depends on mass flow rate, surface geometries of absorber and solar intensity, whereas the pressure drop depends on mass flow rate andsurface geometries of absorber.

  16. Characterization of large cadmium zinc telluride crystals grown by traveling heater method

    DEFF Research Database (Denmark)

    Chen, H.; Awadalla, S.A.; Iniewski, K.

    2008-01-01

    The focus of this paper is to evaluate thick, 20 X 20 X 10 and 10 X 10 X 10 mm(3), cadmium zinc telluride (CZT), Cd0.9Zn0.1Te, crystals grown using the traveling heater method (THIM). The phenomenal spectral performance and small size and low concentration of Te inclusions/precipitates of these c......The focus of this paper is to evaluate thick, 20 X 20 X 10 and 10 X 10 X 10 mm(3), cadmium zinc telluride (CZT), Cd0.9Zn0.1Te, crystals grown using the traveling heater method (THIM). The phenomenal spectral performance and small size and low concentration of Te inclusions...

  17. A novel role of three dimensional graphene foam to prevent heater failure during boiling.

    Science.gov (United States)

    Ahn, Ho Seon; Kim, Ji Min; Park, Chibeom; Jang, Ji-Wook; Lee, Jae Sung; Kim, Hyungdae; Kaviany, Massoud; Kim, Moo Hwan

    2013-01-01

    We report a novel boiling heat transfer (NBHT) in reduced graphene oxide (RGO) suspended in water (RGO colloid) near critical heat flux (CHF), which is traditionally the dangerous limitation of nucleate boiling heat transfer because of heater failure. When the heat flux reaches the maximum value (CHF) in RGO colloid pool boiling, the wall temperature increases gradually and slowly with an almost constant heat flux, contrary to the rapid wall temperature increase found during water pool boiling. The gained time by NBHT would provide the safer margin of the heat transfer and the amazing impact on the thermal system as the first report of graphene application. In addition, the CHF and boiling heat transfer performance also increase. This novel boiling phenomenon can effectively prevent heater failure because of the role played by the self-assembled three-dimensional foam-like graphene network (SFG).

  18. Modeling of a split type air conditioner with integrated water heater

    Energy Technology Data Exchange (ETDEWEB)

    Techarungpaisan, P.; Theerakulpisut, S.; Priprem, S. [Mechanical Engineering Department, Faculty of Engineering, Khon Kaen University, 123 Mittrapab Rd., Muang, Khon Kaen 40002 (Thailand)

    2007-04-15

    This paper presents a steady state simulation model to predict the performance of a small split type air conditioner with integrated water heater. The mathematical model consists of submodels of system components such as evaporator, condenser, compressor, capillary tube, receiver and water heater. These submodels were built based on fundamental principles of heat transfer, thermodynamics, fluid mechanics, empirical relationships and manufacturer's data as necessary. The model was coded into a simulation program and used to predict system parameters of interest such as hot water temperature, condenser exit air temperature, evaporator exit air temperature, mass flow rate of refrigerant, heat rejection in the condenser and cooling capacity of the system. The simulation results were compared with experimental data obtained from an experimental rig built for validating the mathematical model. It was found that the experimental and simulation results are in good agreement. (author)

  19. Electric tubing heater improves well production in CO[sub 2] flood

    Energy Technology Data Exchange (ETDEWEB)

    Baud, W. (Shell Western E and P, Houston, TX (United States)); Eastlund, B. (Production Technologies International Inc., Houston, TX (United States))

    1994-04-18

    Installation of a downhole heater in a well eliminated production interruption caused by downhole paraffin and hydrate buildup, exacerbated by cooling effects of CO[sub 2]. The well is one of 20 operated by Shell Western E and P Inc. in the CO[sub 2]-flooded portion of the South Crossett Devonian Unit (SCDU) in the Permian basin of West Texas. Prior to heater installation, the well's production routinely choked off in 2 days unless the downhole impairment was mechanically removed. Mechanical cutting established that the paraffin and hydrate buildup was in the upper 2,000 ft of the 5,300-ft well. The fluid exit temperature, depending on the choke setting, fluctuated between 14 and 30 F. The paper describes the unsuccessful results from conventional treatments, and the new method.

  20. Static Characteristics of Absorption Chiller-Heater Supplying Cold and Hot Water Simultaneously

    Science.gov (United States)

    Inoue, Naoyuki; Irie, Tomoyoshi

    Absorption chiller-heaters which can supply both chilled water and hot water at the same time, are used for cooling and heating air conditioning systems. In this paper, we classified absorption cold and hot water generating cycles and control methods, studied these absorption cycles by cycle simulation. In economizer cycle, condensed refrigerant which heats hot water is transported to cooling cycle and used effectively for cooling chilled water, Concerning with transported condensed refrigerant, there are two methods, all condensed refrigerant or required refrigerant for cooling are transported to cooling cycle, and required refrigerant method is better for energy saving. Adding improvement of solution control to this economizer cycle, simultaneous cold and hot water supplying chiller-heaters have good characteristics of energy saving in the all region.