355 Matching Results

Search Results

Advanced search parameters have been applied.

Waste Heat Recovery Fluids for Heavy-Duty Transportation Bottoming Cycle Systems : A Summary Report

Description: Working fluids used in Rankine bottoming cycle systems for heat recovery from long-haul trucks, marine vessels, and railroad locomotives are examined. Rankine bottoming cycle systems improve fuel economy by converting the exhaust heat from the prime mover into useful power. The report assesses fluid property requirements on the basis of previous experience with bottoming cycle systems. Also, the exhaust gas characteristics for the transportation modes of interest are summarized and compared. Candidate working fluids are discussed with respect to their potential for use in Rankine bottoming cycle systems. Analytical techniques are presented for calculating the thermodynamic properties of single-component working fluids. The resulting equations have been incorporated into a computer code for predicting the performance of Rankine bottoming cycle systems. In evaluating candidate working fluids, the code requires the user to input only a minimal amount of fluid property data.
Date: September 1983
Creator: Krazinski, J. L.; Uherka, K. L.; Holtz, Robert E. & Ash, J. E.
Partner: UNT Libraries Government Documents Department

Development and testing of a rotary solar engine. Final report

Description: A rotary solar engine has been constructed and tested. By sealing Freon (having the environmentally safe composition rather than the conventionally used harmful composition) in its bellows instead of air, sufficiently consistent operation can be achieved to serve the purely mechanical rotary light-load or no-load markets. Although its power efficiency is not sufficient to make it competitive as a prime power generator, even for power outputs as low as a few ounce inches per minute, it simplicity and reliability make it an attractive self-powered source of mechanical control power for critical slow speed actuators. Its simplicity and low cost make it particularly attractive for the small (less than 10 in/sup 3/) display markets. Other markets may now be identified, now that its strength/limitations are known.
Date: unknown
Creator: Kanaly, D.B.
Partner: UNT Libraries Government Documents Department

Sodium Heat Engine Development Program

Description: The Sodium Heat Engine (SHE) is an efficient thermoelectric conversion device which directly generates electricity from a thermally regenerative electrochemical cell that relies on the unique conduction properties of {beta}{double prime}-alumina solid electrolyte (BASE). Laboratory models of a variety of SHE devices have demonstrated the feasibility and efficiency of the system, engineering development of large prototype devices has been slowed by a series of materials and fabrication problems. Failure of the electrolyte tubes has been a recurring problem and a number of possible causes have been postulated. To address these issues, a two-phase engineering development program was undertaken. This report summarizes the final results of the first phase of the program, which included extensive materials characterization activities, a study of applicable nondestructive evaluation methods, an investigation of possible stress states that would contribute to fracture, and certain operational issues associated with the electromagnetic pumps used in the SHE prototype.
Date: January 1992
Creator: Singh, J. P.
Partner: UNT Libraries Government Documents Department

Electrocaloric devices based on thini-film heat switches

Description: We describe a new approach to refrigeration and electrical generation that exploits the attractive properties of thin films of electrocaloric materials. Layers of electrocaloric material coupled with thin-film heat switches can work as either refrigerators or electrical generators, depending on the phasing of the applied voltages and heat switching. With heat switches based on thin layers of liquid crystals, the efficiency of these thin-film heat engines can be at least as high as that of current thermoelectric devices. Advanced heat switches would enable thin-film heat engines to outperform conventional vaporcompression devices.
Date: January 1, 2009
Creator: Epstein, Richard I & Malloy, Kevin J
Partner: UNT Libraries Government Documents Department

Dish/Stirling for Department of Defense applications final report

Description: This report describes a Strategic Environmental Research and Development Program (SERDP) project to field a dish/Stirling system at a southwestern US military facility. This project entitled ``Dish/Stirling for DoD Applications`` was started in August 1993 and was completed in September 1996. The project`s objective was to assist military facilities to field and evaluate emerging environmentally sound and potentially economical dish/Stirling technology. Dish/Stirling technology has the potential to produce electricity at competitive costs while at the same time providing a secure and environmentally benign source of power. In accordance with the SERDP charter, this project leveraged a US Department of Energy (DOE) cost-shared project between Sandia National Laboratories and Cummins Power Generation, Inc. (CPG). CPG is a wholly owned subsidiary of Cummins Engine Company, a leading manufacturer of diesel engines. To accomplish this objective, the project called for the installation of a dish/Stirling system at a military facility to establish first-hand experience in the operation of a dish/Stirling system. To scope the potential DoD market for dish/Stirling technology and to identify the site for the demonstration, a survey of southwestern US military facilities was also conducted. This report describes the project history, the Cummins dish/Stirling system, results from the military market survey, and the field test results.
Date: March 1, 1997
Creator: Diver, R.B. & Menicucci, D.F.
Partner: UNT Libraries Government Documents Department

Thermoacoustic engines and refrigerators

Description: This report is a transcript of a practice lecture given in preparation for a review lecture on the operation of thermoacoustic engines and refrigerators. The author begins by a brief review of the thermodynamic principles underlying the operation of thermoacoustic engines and refrigerators. Remember from thermodynamics class that there are two kinds of heat engines, the heat engine or the prime mover which produces work from heat, and the refrigerator or heat pump that uses work to pump heat. The device operates between two thermal reservoirs at temperatures T{sub hot} and T{sub cold}. In the heat engine, heat flows into the device from the reservoir at T{sub hot}, produces work, and delivers waste heat into the reservoir at T{sub cold}. In the refrigerator, work flows into the device, lifting heat Q{sub cold} from reservoir at T{sub cold} and rejecting waste heat into the reservoir at T{sub hot}.
Date: December 31, 1996
Creator: Swift, G.
Partner: UNT Libraries Government Documents Department

Life prediction methodology for ceramic components of advanced heat engines. Phase 1: Volume 1, Final report

Description: Emphasis of this program is to develop and demonstrate ceramics life prediction methods, including fast fracture, stress rupture, creep, oxidation, and nondestructive evaluation. Significant advancements were made in these methods and their predictive capabilities successfully demonstrated.
Date: March 1, 1995
Creator: Cuccio, J.C.; Brehm, P. & Fang, H.T.
Partner: UNT Libraries Government Documents Department

Life prediction methodology for ceramic components of advanced heat engines. Phase 1: Volume 2, Appendices

Description: This volume presents the following appendices: ceramic test specimen drawings and schematics, mixed-mode and biaxial stress fracture of structural ceramics for advanced vehicular heat engines (U. Utah), mode I/mode II fracture toughness and tension/torsion fracture strength of NT154 Si nitride (Brown U.), summary of strength test results and fractography, fractography photographs, derivations of statistical models, Weibull strength plots for fast fracture test specimens, and size functions.
Date: March 1, 1995
Partner: UNT Libraries Government Documents Department

Solar-Electric Dish Stirling System Development

Description: Electrical power generated with the heat from the sun, called solar thermal power, is produced with three types of concentrating solar systems - trough or line-focus systems; power towers in which a centrally-located thermal receiver is illuminated with a large field of sun-tracking heliostats; and dish/engine systems. A special case of the third type of system, a dish/Stirling system, is the subject of this paper. A dish/Stirling system comprises a parabolic dish concentrator, a thermal receiver, and a Stirling engine/generator located at the focus of the dish. Several different dish/Stirling systems have been built and operated during the past 15 years. One system claims the world record for net conversion of solar energy to electric power of 29.4%; and two different company`s systems have accumulated thousands of hours of on-sun operation. Due to de-regulation and intense competition in global energy markets as well as the immaturity of the technology, dish/Stirling systems have not yet found their way into the marketplace. This situation is changing as solar technologies become more mature and manufacturers identify high-value niche markets for their products. In this paper, I review the history of dish/Stirling system development with an emphasis on technical and other issues that directly impact the Stirling engine. I also try to provide some insight to the opportunities and barriers confronting the application of dish/Stirling in power generation markets.
Date: December 31, 1997
Creator: Mancini, T.R.
Partner: UNT Libraries Government Documents Department

Concentrating Solar Power Program overview

Description: Over the last decade, the US solar thermal industry has established a track record in the power industry by building and operating utility-scale power plants with a combined rated capacity of 354 megawatts (MW). The technology used in these power plants is based on years of research and development (R and D), much of it sponsored by the US Department of Energy (DOE). DOE`s Concentrating Solar Power (CSP) Program is collaborating with its partners in the private sector to develop two new solar technologies -- power towers and dish/engines -- to meet the huge commercial potential for solar power.
Date: April 1, 1998
Partner: UNT Libraries Government Documents Department

Rolling Thunder -- Integration of the Solo 161 Stirling engine with the CPG-460 solar concentrator at Ft. Huachuca

Description: Project Rolling Thunder is a dish/Stirling demonstration project at Ft. Huachuca, a US Army fort in southeastern Arizona (Huachuca means rolling thunder in Apache). It has been supported by the Strategic Environmental Research and Development Program (SERDP), a cooperative program between the Department of Defense (DoD) and the Department of Energy (DOE). As part of a 1992 SERDP project, Cummins Power Generation, Inc. (CPG) installed a CPG 7 kW(c) dish/Stirling system at the Joint Interoperability Test Command (JITC) in Ft. Huachuca, Arizona. The primary objective of the SERDP Dish/Stirling for DoD Applications project was to demonstrate a CPG 7-kW(c) dish/Stirling system at a military facility. Unfortunately, Cummins Engine Company decided to divest its solar operations. As a direct result of Ft. Huachuca`s interest in the Cummins dish/Stirling technology, Sandia explored the possibility of installing a SOLO 161 Stirling power conversion unit (PCU) on the Ft. Huachuca CPG-460. In January 1997, a decision was made to retrofit a SOLO 161 Stirling engine on the CPG-460 at Ft. Huachuca. Project Rolling Thunder. The SOLO 161 Demonstration at Ft. Huachuca has been a challenge. Although, the SOLO 161 PCU has operated nearly flawlessly and the CPG-460 has been, for the most part, a solid and reliable component, integration of the SOLO PCU with the CPG-460 has required significant attention. In this paper, the integration issues and technical approaches of project Rolling Thunder are presented. Lessons of the project are also discussed.
Date: September 1, 1998
Creator: Diver, R.B.; Moss, T.A.; Goldberg, V.; Thomas, G. & Beaudet, A.
Partner: UNT Libraries Government Documents Department

Development of a 75-kW heat-pipe receiver for solar heat-engines

Description: A program is now underway to develop commercial power conversion systems that use parabolic dish mirrors in conjunction with Stirling engines to convert solar energy to electric power. In early prototypes, the solar concentrator focused light directly on the heater tubes of the Stirling engine. Liquid-metal heat-pipes are now being developed to transfer energy from the focus of the solar concentrator to the heater tubes of the engine. The dome-shaped heat-pipe receivers are approximately one-half meters in diameter and up to 77-kW of concentrated solar energy is delivered to the absorber surface. Over the past several years, Sandia National Laboratories, through the sponsorship of the Department of Energy, has conducted a major program to explore receiver designs and identify suitable wick materials. A high-flux bench-scale system has been developed to test candidate wick designs, and full-scale systems have been tested on an 11-meter test-bed solar concentrator. Procedures have also been developed in this program to measure the properties of wick materials, and an extensive data-base on wick materials for high temperature heat pipes has been developed. This paper provides an overview of the receiver development program and results from some of the many heat-pipe tests.
Date: May 1, 1995
Creator: Adkins, D.R.; Andraka, C.E. & Moss, T.A.
Partner: UNT Libraries Government Documents Department

Stirling-Engine Thermodynamic Analysis: a Users Guide to SEAM1

Description: This report provides background and procedural information for the use of a general-purpose Stirling-engine analysis code developed at Argonne National Laboratory and available through the National Energy Software Center. Different engine configurations are easily specified, or the user may make use of provided data for existing engines, both kinematic and free piston. The code models heat transfer and fluid mechanics throughout the engine and accounts for system energy flows and losses. Good agreement is shown between code predictions and experimental measurements. The present analysis method was chosen for fast execution and useful information on energy flows in the system. A description is provided of the code structure that is intended to accept different analysis modules that can provide improved system modeling or optimization capability.
Date: September 1982
Creator: Heames, T. J.; Uherka, D. J.; Zabel, J. C. & Daley, J. G.
Partner: UNT Libraries Government Documents Department

Design, fabrication, and testing of a sodium evaporator for the STM4-120 kinematic Stirling engine

Description: This report describes the development and testing of a compact heat-pipe heat exchanger kW(e) designed to transfer thermal energy from hot combustion gases to the heater tubes of a 25-kW(e) Stirling engine. In this system, sodium evaporates from a surface that is heated by a stream of hot gases. The liquid metal then condenses on the heater tubes of a Stirling engine, where energy is transferred to the engine`s helium working fluid. Tests on a prototype unit illustrated that a compact (8 cm {times} 13 cm {times} 16 cm) sodium evaporator can routinely transfer 15 kW(t) of energy at an operating vapor temperature of 760 C. Four of these prototype units were eventually used to power a 25-kW(e) Stirling engine system. Design details and test results from the prototype unit are presented in this report.
Date: May 1, 1995
Creator: Rawlinson, K.S. & Adkins, D.R.
Partner: UNT Libraries Government Documents Department

Investigation of the rate-controlling mechanism(s) for high temperature creep and the relationship between creep and melting by using high pressure as a variable. Final report

Description: Silicon nitride (Si3N4) offers the advantages of high strength, high thermal shock resistance and a low coefficient of thermal expansion, which are attractive for high thermal efficiency heat engine parts such as in the automotive industry. A consolidation process is required in which the equiaxed {alpha} phase of the starting powders are retained along with a submicrongrain size; after forming, the strong {beta} phase is then formed by heat treatment. Conventional sintering and the mechanisms of consolidation therein are discussed. The plasma-activated (or assisted) sintering (PAS) process, a form of electrical resistance sintering, uses a cycled current to create an electric discharge that would break down the oxide layers at points of contact between the particles, while the plasma would attack the oxide layers on the noncontacting areas of the particles. PAS consolidation experiments were conducted with pure and doped Si3N4. The ability to consolidate Si3N4 with additives to 99% TD while retaining >88% {alpha} phase was demonstrated with the PAS equipment. The additive should be a mixture of oxides rather than a single oxide, and the amount should be minimum. Once the parts have been densified and deformed, it may be possible to lock in the shape by completing the {alpha} to {beta} transformation in a furnace.
Date: December 31, 1994
Creator: Mukherjee, A.K. & Green, H.
Partner: UNT Libraries Government Documents Department

Survey of manufacturers of high-performance heat engines adaptable to solar applications

Description: This report summarizes the results of an industry survey made during the summer of 1983. The survey was initiated in order to develop an information base on advanced engines that could be used in the solar thermal dish-electric program. Questionnaires inviting responses were sent to 39 companies known to manufacture or integrate externally heated engines. Follow-up telephone communication ensured uniformity of response.
Date: June 15, 1984
Creator: Stine, W. B.
Partner: UNT Libraries Government Documents Department

Kinematic Stirling engine as an energy conversion subsystem for paraboloidal dish solar thermal power plants

Description: The potential of a suitably designed and economically manufactured Stirling engine as the energy conversion subsystem of a paraboloidal dish-Stirling solar thermal power module has been estimated. Results obtained by elementary cycle analyses have been shown to match quite well the performance characteristics of an advanced kinematic Stirling engine, the United Stirling P-40, as established by current prototypes of the engine and by a more sophisticated analytic model of its advanced derivative. In addition to performance, brief consideration has been given to other Stirling engine criteria such as durability, reliability, and serviceability. Production costs have not been considered here.
Date: April 15, 1984
Creator: Bowyer, J.M.
Partner: UNT Libraries Government Documents Department

Modeling of a second-generation solar-driven Rankine air conditioner. Final report

Description: Ten configurations of a second-generation (2G), solar-powered, Rankine-driven air conditioner were simulated and the data presented for use in companion studies. The results of the analysis show that the boiling-in-collector (BIC) configuration generates more power per collector area than the other configurations. The models used to simulate the configuration are presented in this report. The generated data are also presented. Experimental work was done under this study to both improve a novel refrigerant and oil lubrication system for the centrifugal compressor and investigate the aerodynamic unloading characteristics of the centrifugal compressor. The information generated was used to define possible turbo-gearbox configurations for use in the second generation computer simulation.
Date: July 1, 1984
Creator: Denius, M.W. & Batton, W.D.
Partner: UNT Libraries Government Documents Department

Rankine cycle machines for solar cooling

Description: A vigorous effort to develop and demonstrate practical uses of solar energy to heat and cool buildings, to process agricultural products, and to provide thermal and electrical energy for industry has been initiated. One significant part of this effort is the research, development, and demonstration of Rankine cycle machines using fluids heated by solar energy. Recent developments in three such devices are discussed briefly.
Date: August 1, 1978
Creator: Weathers, H.M.
Partner: UNT Libraries Government Documents Department

Solar heat pipe testing of the Stirling thermal motors 4-120 Stirling engine

Description: Stirling-cycle engines have been identified as a promising technology for the conversion of concentrated solar energy into usable electrical power. A 25kW electric system takes advantage of existing Stirling-cycle engines and existing parabolic concentrator designs. In previous work, the concentrated sunlight impinged directly on the heater head tubes of the Stirling Thermal Motors (STM) 4-120 engine. A Sandia-designed felt-metal-wick heat pipe receiver was fitted to the STM 4-120 engine for on-sun testing on Sandia`s Test Bed Solar Concentrator. The heat pipe uses sodium metal as an intermediate two-phase heat transfer fluid. The receiver replaces the directly-illuminated heater head previously tested. The heat pipe receiver provides heat isothermally to the engine, and the heater head tube length is reduced, both resulting in improved engine performance. The receiver also has less thermal losses than the tube receiver. The heat pipe receiver design is based on Sandia`s second-generation felt-wick heat pipe receiver. This paper presents the interface design, and compares the heat pipe/engine test results to those of the directly-illuminated receiver/engine package.
Date: July 1, 1996
Creator: Andraka, C.E.; Rawlinson, K.S.; Moss, T.A.; Adkins, D.R.; Moreno, J.B.; Gallup, D.R. et al.
Partner: UNT Libraries Government Documents Department

Development of improved processing and evaluation methods for high reliability structural ceramics for advanced heat engine applications Phase II. Final report

Description: The research program had as goals the development and demonstration of significant improvements in processing methods, process controls, and nondestructive evaluation (NDE) which can be commercially implemented to produce high reliability silicon nitride components for advanced heat engine applications at temperatures to 1370{degrees}C. In Phase I of the program a process was developed that resulted in a silicon nitride - 4 w% yttria HIP`ed material (NCX 5102) that displayed unprecedented strength and reliability. An average tensile strength of 1 GPa and a strength distribution following a 3-parameter Weibull distribution were demonstrated by testing several hundred buttonhead tensile specimens. The Phase II program focused on the development of methodology for colloidal consolidation producing green microstructure which minimizes downstream process problems such as drying, shrinkage, cracking, and part distortion during densification. Furthermore, the program focused on the extension of the process to gas pressure sinterable (GPS) compositions. Excellent results were obtained for the HIP composition processed for minimal density gradients, both with respect to room-temperature strength and high-temperature creep resistance. Complex component fabricability of this material was demonstrated by producing engine-vane prototypes. Strength data for the GPS material (NCX-5400) suggest that it ranks very high relative to other silicon nitride materials in terms of tensile/flexure strength ratio, a measure of volume quality. This high quality was derived from the closed-loop colloidal process employed in the program.
Date: February 1, 1996
Creator: Pujari, V. J.; Tracey, D. M. & Foley, M. R.
Partner: UNT Libraries Government Documents Department

Life prediction methodology for ceramic components of advanced vehicular heat engines: Volume 2, Appendices 1 and 2. Final report

Description: The two appendices are included: I. Fast fracture testing of MOR Type- B (3x4x50 mm) specimens in air at Allison from 25 to 1400 C. II. Fast fracture tensile testing of button-head specimens in air at Southern Research Institute from 25 to 1400 C. The material is silicon nitride.
Date: February 1, 1996
Creator: Khandelwal, P.K.; Provenzano, N.J. & Schneider, W.E.
Partner: UNT Libraries Government Documents Department

DEVELOPMENT OF A THERMOACOUSTIC NATURAL GAS LIQUEFIER-UPDATE

Description: Thermoacoustic heat engines and refrigerators are being developed for liquefaction of natural gas. This is the only technology capable of producing refrigeration power at cryogenic temperatures with no moving parts. A prototype, with a projected natural gas liquefaction capacity of 500 gallons/day, has been built and tested. The power source is a natural gas burner. Systems are developed with liquefaction capacities up to 10,000 to 20,000 gallons per day. The technology, the development project, accomplishments and applications are discussed.
Date: May 1, 2001
Creator: WOLLAN, J. & SWIFT, G.
Partner: UNT Libraries Government Documents Department

High-speed, low-damage grinding of advanced ceramics Phase 1. Final report

Description: In manufacture of structural ceramic components, grinding costs can comprise up to 80% of the entire manufacturing cost. Most of these costs arise from the conventional multi-step grinding process with numerous grinding wheels and additional capital equipment, perishable dressing tools, and labor. In an attempt to reduce structural ceramic grinding costs, a feasibility investigation was undertaken to develop a single step, roughing-finishing process suitable for producing high-quality silicon nitride ceramic parts at high material removal rates at lower cost than traditional, multi-stage grinding. This feasibility study employed combined use of laboratory grinding tests, mathematical grinding models, and characterization of resultant material surface condition. More specifically, this Phase 1 final report provides a technical overview of High-Speed, Low-Damage (HSLD) ceramic grinding and the conditions necessary to achieve the small grain depths of cut necessary for low damage grinding while operating at relatively high material removal rates. Particular issues addressed include determining effects of wheel speed and material removal rate on resulting mode of material removal (ductile or brittle fracture), limiting grinding forces, calculation of approximate grinding zone temperatures developed during HSLD grinding, and developing the experimental systems necessary for determining HSLD grinding energy partition relationships. In addition, practical considerations for production utilization of the HSLD process are also discussed.
Date: March 1, 1995
Creator: Kovach, J.A. & Malkin, S.
Partner: UNT Libraries Government Documents Department