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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

High Temperature, High Pressure Stability of Aqueous Foams for Potential Application in Enhanced Geothermal System (EGS)

Enhanced Geothermal Systems (EGS) are typically constructed by injecting high-pressure water into deep hot dry rocks (HDR) under carefully controlled conditions to create new or re-open existing fractures, which usually uses an immense quantity of water. In lieu, a more sustainable technique is to utilize aqueous foams as fracturing fluid to reduce water consumption and waste-water treatments of conventional hydraulic fracturing. Although foam-based fracturing has shown promising results in oil and gas industries, its feasibility is not demonstrated in EGS conditions that usually involve high temperature and high pressures. One potential barrier of utilizing foams in EGS applications is that foams are thermodynamically unstable and will become more unstable with increasing temperature due to liquid drainage, bubble coarsening, and coalescence. This work focuses on evaluation of the stability of selected aqueous foams under high-temperature and high-pressure conditions. Specifically, foams generated with surfactant alfa olefin sulfonate (AOS) were studied at temperature up to 200oC, while the pressure ranged between 100 psi and 1000 psi. The effect of additional stabilizing agents was also examined, including guar gum, bentonite clay, borate salt crosslinker, silicon dioxide nanoparticles (SiO2), and graphene oxide (GO) dispersion. Results showed that the stabilizing agents can enhance the foam thermal stability. Foams made with AOS and the borate salt crosslinker exhibited the longest half-life of 20 min at 200°C when the pressure was at 1000 psi. Data fitting showed that foam stability decreased exponentially as temperature increased. On the other hand, pressure increased the foam half-life which followed a power model. This study indicates that it may be possible to obtain highly stable foams at high-temperature and high-pressure conditions with appropriate stabilizing agents.

Thakore, Viren↗
DOE OSTI2017

The role of frequency on fretting corrosion of Alloy 690TT against 304 stainless steel in high temperature high pressure water

Highlights: • Delamination, material transfer and oxidation dominated fretting corrosion behavior in HTHP water. • Delamination was pure mechanical wear to produce fresh surface exposed to HTHP water for oxidation. • Increased frequency enhanced the maximum thickness of oxide film in worn surface. • Increased frequency accelerated the formation of tribologically transformed structure (TTS). • Increased frequency accelerated the escape of wear debris, which originated from the TTS and crushed oxide particles. - Abstract: In high temperature high pressure (HTHP) water, the role of frequency in fretting corrosion behavior and mechanism of Alloy 690TT against Type 304 stainless steel were investigated. Results indicated that wear mechanisms of delamination, material transfer and oxidation collectively dominated the fretting corrosion behavior. The delamination was related to pure mechanical wear to produce fresh surface exposed to HTHP water for oxidation, resulting in the increase of wear depth and volume. The increasing frequency played little role in oxide type of worn surfaces, which consisted of (Ni,Fe)(Fe,Cr){sub 2}O{sub 4} and Cr{sub 2}O{sub 3}. However, it enhanced the maximum thickness of oxide film in the worn surface. The increasing frequency resulted in the acceleration of the formation of nanostructured tribologically transformed structure (TTS) layer because it could aggravate the plastic deformation and increase the contact temperature for dynamic recrystallization. The increasing frequency accelerated the escape of the ultra-fine grained wear debris, which originated from not only the damage of TTS layer but also the crushed oxide particles generated in the contact gap.

36 MATERIALS SCIENCE↗
DOE OSTI2016

In Situ High Temperature High Pressure MAS NMR Study on the Crystallization of AlPO 4 -5

A damped oscillating crystallization process of AlPO4-5 at the presence of small amount of water is demonstrated by in situ high temperature high pressure multinuclear MAS NMR. Crystalline AlPO4-5 is formed from an intermediate semicrystalline phase via continuous rearrangement of the local structure of amorphous precursor gel. Activated water catalyzes the rearrangement via repeatedly hydrolysis and condensation reaction. Strong interactions between organic template and inorganic species facilitate the ordered rearrangement. During the crystallization process, excess water, phosphate, and aluminums are expelled from the precursor. The oscillating crystallization reflects mass transportation between the solid and liquid phase during the crystallization process. This crystallization process is also applicable to AlPO4-5 crystallized in the presence of a relatively large amount of water.

Environmental Molecular Sciences Laboratory↗
DOE OSTI2019

Experimental Evaluation of Heat Transfer in a High Temperature High Pressure Test Facility

Performance of film cooling holes is generally evaluated near ambient conditions, so scaling the film cooling performance from ambient to engine conditions is important. These performance metrics can be reported in terms of net heat flux reduction, heat transfer enhancement, and effectiveness. There are several challenges and penalties in conducting experiments on a real engine or even on a stationary flat plate test article at near engine conditions. In this study, an experimental methodology capable of delivering film cooling performance for the experiments conducted in the high-temperature high-pressure test facility at NETL will be explored. More specifically, this study focuses on various challenges that are present and how these concerns are addressed to evaluate the heat transfer coefficient on the test article. Steady state experiments were conducted on a flat plate test article whose surface temperature distribution was obtained using an IR camera calibrated with a combination of bench top experiments and in-situ calibrations based on embedded thermocouple measurements. A detailed radiation analysis is conducted to enable differentiation of heat transfer by convection from heat transfer by radiation. The estimated surface heat flux and heat transfer coefficient were found to be higher than the one obtained from flat plate correlation.

Ramesh, Sridharan↗
DOE OSTI2024

Comparative Analysis of Heat Exchangers for High Temperature High Pressure Helium Component Testing

Helium gas loops have been designed and built to gain a better understanding of the gas thermohydraulic phenomena that take place in a helium system. Some of these loops are used for validation and testing of components for high temperature gas-cooled reactors (HTGRs). However, most of them operate at lower pressure and temperature than an HTGR. While these loops can provide valuable information about gas-cooled reactor components, the operating envelope of the experiment is constrained by the maximum operating conditions of the helium loop. In response to the lack of an experimental facility that can provide the infrastructure needed to validate and test components at nominal pressures and temperatures of HTGRS, the HElium Component Testing Out-of-pile Research (HECTOR) facility was designed at Idaho National Laboratory with the assistance of University of Idaho and Walsh Engineering. With the capability to test at temperatures up to 800°C and pressures of 8MPa, HECTOR serves as a critical tool for the advancement of HTGR technology. The facility's primary role is to provide a controlled, high-fidelity environment for the assessment of component resilience and efficiency under nominal HTGR conditions. In the quest to enhance the efficiency and performance of HECTOR, a comparative analysis of three distinct types of heat exchangers—shell and tube, offset strip fin, and printed-circuit—was conducted, focusing primarily on two critical metrics: the required surface area and pressure drop characteristics. The shell and tube heat exchanger, renowned for its robust design and widespread industrial application, was evaluated against the offset strip fin and the cuttingedge printed-circuit heat exchangers, both of which are lauded for their compactness and thermal effectiveness. This comparative study aims to provide detailed insights into the thermal management capabilities of each heat exchanger type under the conditions inherent to HECTOR, thereby facilitating an informed selection for systems demanding high operational integrity and efficiency.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2015

Sealed rotors for in situ high temperature high pressure MAS NMR

Magic angle spinning (MAS) nuclear magnetic resonance (NMR) investigations on heterogeneous samples containing solids, semi-solids, liquid and gases or a mixture of them under non-conventional conditions of a combined high pressure and high temperature, or cold temperature suffer from the unavailability of a perfectly sealed rotor. Here, we report the design of reusable and perfectly-sealed all-zircornia MAS rotors. The rotors are easy to use and are suitable for operation temperatures from below 0 to 250 °C and pressures up to 100 bar. As an example of potential applications we performed in situ MAS NMR investigations of AlPO₄-5 molecular sieve crystallization, a kinetic study of the cyclohexanol dehydration reaction using 13C MAS NMR, and an investigation of the metabolomics of intact biological tissue at low temperature using 1H HR-MAS NMR spectroscopy. The in situ MAS NMR experiments performed using the reported rotors allowed reproduction of the results from traditional batch reactions, while offering more detailed quantitative information at the molecular level, as demonstrated for the molecular sieve synthesis and activation energy measurements for cyclohexanol dehydration. The perfectly sealed rotor also shows promising application for metabolomics studies using 1H HR-MAS NMR.

36 MATERIALS SCIENCE↗
DOE OSTI2026

High Temperature High Vacuum Mechanical Property Assessment of Zirconium Nuclear Fuel Cladding

This report presents the mechanical characterization of a specific Zry-4 cladding batch serving as the foundation for a diverse range of fuel performance research at Oak Ridge National Laboratory (ORNL). This effort supports research needs for the U.S. Department of Energy (DOE), particularly regarding evaluating accident tolerant fuel (ATF) cladding coating concepts, expanding understanding of cladding response to loss-of-coolant accidents (LOCA) transients, refining post-critical heat flux (CHF) limits (t@T), and upcoming irradiation campaigns. The central objective was to define the baseline performance of the substrate Zircaloy-4 (Zry-4) material leveraged across ORNL Advanced Fuel Campaign (AFC) efforts through controlled high-temperature vacuum tensile testing. This work begins to address gaps in existing models where implementation based on nominal heat-treatment labels, such as stress relief annealed (SRA), often fail to capture the interplay of recovery, recrystallization, and grain growth. To quantify this, data was benchmarked against the Pacific Northwest National Laboratory (PNNL) stress strain model to determine where this material falls in comparison to assumed values for materials in the same heat treatment regime. Analysis of the tensile data revealed that this specific SRA batch exhibits a transitional microstructural state best described by an effective cold-work (CW) parameter of 0.09, diverging from the previous estimation of 0.5 for SRA materials. Additionally, comparative testing of Cr coated specimens demonstrated no distinct difference in axial strength relative to the bare substrate. This suggests that the strengthening benefits of Cr coatings observed in burst scenarios are driven by residual stress mechanisms acting solely in the hoop direction.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2022

High temperature high strength austenitic steel fabricated by laser powder-bed fusion

Extremely fast cooling rates during laser powder-bed fusion (LPBF) can result in materials with unique microstructures. For LPBF 316L stainless steel, the formation of sub-grain cellular structures with high dislocation density has been linked to superior tensile properties at room temperature. This cellular structure offers also a new route for the development of high temperature LPBF steels with the nucleation of nano-size strengthening carbides in the cell walls. HK30Nb steel (Fe-25Cr-20Ni-Nb-C) was, therefore, fabricated by LPBF to evaluate its potential for high temperature applications. Optimization of the fabrication parameters yielded material with density greater than 99.7%, with nano Nb-rich precipitates in the cell walls. Annealing at 800 °C for 5h resulted in the nucleation and growth of additional precipitates mainly in the cell walls and at grain boundaries. Furthermore, the high dislocation density led to yield strength at 20–900 °C two to three times higher than yield strength for cast HK30Nb and the nano carbides in the cell walls significantly improved the cellular structure stability at 800 °C.

36 MATERIALS SCIENCE↗
DOE OSTI2017

High performance aluminum–cerium alloys for high-temperature applications

Light-weight high-temperature alloys are important to the transportation industry where weight, cost, and operating temperature are major factors in the design of energy efficient vehicles. Aluminum alloys fill this gap economically but lack high-temperature mechanical performance. Alloying aluminum with cerium creates a highly castable alloy, compatible with traditional aluminum alloy additions, that exhibits dramatically improved high-temperature performance. These compositions display a room temperature ultimate tensile strength of 400 MPa and yield strength of 320 MPa, with 80% mechanical property retention at 240 °C. A mechanism is identified that addresses the mechanical property stability of the Al-alloys to at least 300 °C and their microstructural stability to above 500 °C which may enable applications without the need for heat treatment. Lastly, neutron diffraction under load provides insight into the unusual mechanisms driving the mechanical strength.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2017

High temperature high velocity direct power extraction using an open-cycle oxy-combustion system

The implementation of oxy-fuel technology in fossil-fuel power plants may contribute to increased system efficiencies and a reduction of pollutant emissions. One technology that has potential to utilize the temperature of undiluted oxy-combustion flames is open-cycle magnetohydrodynamic (MHD) power generators. These systems can be configured as a topping cycle and provide high enthalpy, electrically conductive flows for direct conversion of electricity. This report presents the design and modeling strategies of a MHD combustor operating at temperatures exceeding 3000 K. Throughout the study, computational fluid dynamics (CFD) models were extensively used as a design and optimization tool. A lab-scale 60 kWth model was designed, manufactured and tested as part of this project. A fully-coupled numerical method was developed in ANSYS FLUENT to characterize the heat transfer in the system. This study revealed that nozzle heat transfer may be predicted through a 40% reduction of the semi-empirical Bartz correlation. Experimental results showed good agreement with the numerical evaluation, with the combustor exhibiting a favorable performance when tested during extended time periods. A transient numerical method was employed to analyze fuel injector geometries for the 60-kW combustor. The ANSYS FLUENT study revealed that counter-swirl inlets achieve a uniform pressure and velocity ratio when the ports of the injector length to diameter ratio (L/D) is 4. An angle of 115 degrees was found to increase distribution efficiency. The findings show that this oxy-combustion concept is capable of providing a high-enthalpy environment for seeding, in order to render the flow to be conductive. Based on previous findings, temperatures in the range of 2800-3000 K may enable magnetohydrodynamic power extraction. The heat loss fraction in this oxy-combustion system, based on CFD and analytical calculations, at optimal operating conditions, was estimated to be less than 10 percent. Furthermore, the heat transfer design removed approximately 7 MW/m2. The results observed in the lab-scale system were employed to develop a 1-MW scaled prototype. Scaling methods were based on critical design criteria found in similar systems, aimed at replicating combustion flow fields and reducing possible instabilities. A numerical simulation of the combustor wall was developed for a combined thermal steady model and static structural model. This combined model was developed predict combined stress parameters within the wall during testing conditions. Both models were developed within ANSYS FEA software package. The relative accuracy presented as well major performance parameters are discussed to assess the design's validity and ensure safety. The scaled prototype was manufactured through selective laser melting (SLM)-based additive manufacturing to reduce lead times and increase geometrical complexity. Additional CFD models were developed to optimize coolant manifold system parameters and perform a parametric study on channel geometry. An investigation on coolant manifold geometry demonstrated improvements in channel flow distribution when enlarging manifold lengths and increasing the number of tubes feeding into the flow. A three-dimensional model based on a single channel was developed to capture the effect of variable properties and thermal stratification. All cases in the simulation exhibited higher wall temperatures and lower convective coefficients than those determined through 1-D analytical equations. This implies that pressure and velocity safety factors must be implemented during system operation. Overall, the findings made in this investigation are thought to be of value to researchers and industrial practitioners when designing oxy-fuel direct power extraction systems operating at temperatures exceeding 3000 K. In addition to this, the implementation of the developed technology at pilot and commercial scales could result in a significant improvement in the efficiencies of heritage and next-generation power cycles.

03 NATURAL GAS↗
DOE OSTI2019

High-temperature, high pressure acoustic resonance cell

A compact, rugged and portable measurement cell design for the determination of sound speed in fluids at temperatures up to 250° C. and pressures up to 3,000 psi is described. Swept Frequency Acoustic Interferometry measurement for liquid sound speed determinations in liquids up to 250° C. is of both fundamental interest, as in the case of basic equations of state, and applied interest, such as for characterizing geothermal or petroleum down hole environments. Representative sound speeds for water, as a function of temperature and pressure, are in agreement with an internationally accepted standard for the sound speed of water.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2020

High Temperature, High AN2 Last Stage Blade for 65% Efficiency Phase I (Final Report)

GE Power (GEP), in partnership with GE Global Research (GEGR)(GEP and GEGR are divisions of General Electric Company) developed hot and large Last Stage Blade (LSB) technologies necessary for state-of-the art gas turbines to successfully realize ~3100°F turbine inlet temperatures (TIT), an essential element to reaching the DOE goal of 65% combined cycle efficiency (CCeff). The objective of this project was to develop conceptual LSB designs and advance the technological understanding of synchronous vibrations (SV), nonsynchronous vibrations (NSV), and damping that limit the current state-of-the-art LSB designs and applications. In the Phase I project GE Power leveraged existing design and analysis knowledge and techniques for LSB design and performed extensive analytical evaluations to identify and characterize conceptual design concepts.

20 FOSSIL-FUELED POWER PLANTS↗
DOE OSTI2020

High Temperature, High AN2 Last Stage Blade for 65% Efficiency (Phase I Final Report)

GE Power (GEP), in partnership with GE Global Research (GEGR)(GEP and GEGR are divisions of General Electric Company) have hot and large Last Stage Blade (LSB) technologies necessary for state-of-the art gas turbines to successfully realize ~3100°F turbine inlet temperatures (TIT), an essential element to reaching the DOE goal of 65% combined cycle efficiency (CCeff). The objective of this project was to develop conceptual LSB designs and advance the technological understanding of synchronous vibrations (SV), nonsynchronous vibrations (NSV), and damping that limit the current state-of-the-art LSB designs and applications. In the Phase I project GE Power leveraged existing design and analysis knowledge and techniques for LSB design and performed extensive analytical evaluations to identify and characterize conceptual design concepts. The most promising designs are the basis for development and testing in a potential Phase II project.

20 FOSSIL-FUELED POWER PLANTS↗
DOE OSTI2016

An Integrated Study on a Novel High Temperature High Entropy Alloy

This report summarizes our recent works of theoretical modeling, simulation, and experimental validation of the simulation results on the new refractory high entropy alloy (HEA) design and oxide doped refractory HEA research. The simulation of the stability and thermal dynamics simulation on potential thermal stable candidates were performed and related HEA with oxide doped samples were synthesized and characterized. The HEA ab initio density functional theory and molecular dynamics physical property simulation methods and experimental texture validation techniques development, achievements already reached, course work development, students and postdoc training, and future improvement research directions are briefly introduced.

36 MATERIALS SCIENCE↗