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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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS2019

NASA Acoustic Stirling IRAD Thermal Recovery Energy Efficient System (TREES) Energy Conversion and Management in Aircraft

NASA Acoustic Stirling IRAD (Internal Research and Development) Thermal Recovery Energy Efficient System (TREES) Energy Conversion and Management in Aircraft. Presentation on energy conversion on aircraft. Thermal energy recovery changes aircraft thermal management from being a necessary burden on aircraft performance to a desirable asset. It improves the engine performance by recycling waste heat and ultimately rejecting all collected aircraft heat out through the engine nozzle.

Dyson, Rodger↗
DOE OSTI2024

SINGLE BUNCH TRACKING ON THE TEN-PASS ER@CEBAF ENERGY RECOVERY BEAMLINE

The proposed ten-pass energy recovery linac (ERL) demonstration (five accelerating, five decelerating) at the CEBAF accelerator, ER@CEBAF, involves a multi-GeV en- ergy range of a continuous electron beam. New CEBAF transverse optics were designed for this ERL demonstration. This redesign incorporates additional components in Arc A, including a path length chicane and new quadrupoles to ensure proper dispersion localization. The new five energy recovery passes with a shared arc transport scheme chal- lenge the overall beamline optics design, including large beta functions in the CEBAF spreaders and recombiners. Here we discuss results of bunch tracking performed using the elegant tracking code for the full ER@CEBAF beamline

Neththikumara, I.↗
NASA NTRS1975

Energy recovery from solid waste. Volume 1: Summary report

A systems analysis of energy recovery from solid waste which demonstrates the feasibility of several processes for converting solid waste to an energy form is presented. The social, legal, environmental, and political factors are considered and recommendations made in regard to legislation and policy. A technical and economic evaluation of available and developing energy-recovery processes is given with emphasis on thermal decomposition and biodegradation. A pyrolysis process is suggested. The use of prepared solid waste as a fuel supplemental to coal is considered to be the most economic process for recovery of energy from solid waste. Markets are discussed with suggestions for improving market conditions and for developing market stability. A decision procedure is given to aid a community in deciding on its options in dealing with solid waste.

Source record↗
DOE OSTI2023

A review of experimental methods to determine bioaerosol transfer in energy recovery ventilators

Increasing ventilation is an effective method to reduce indoor airborne disease transmission. An Energy recovery ventilator (ERV) is a passive energy recovery device used to reduce the energy consumption of heating, ventilation and air-conditioning (HVAC) systems for conditioning the ventilation air. It preconditions the ventilation air by transferring energy from building exhaust air. Therefore, the ventilation and exhaust air streams interact directly/indirectly in the ERV for energy transfer. It is surmised that the ERV may transfer bioaerosols (with pathogens) from the exhaust air to ventilation air, resulting in the spread of infectious diseases. Consequently, many pandemic HVAC guidelines recommend that the use of ERVs be limited. This is a highly unsustainable direction given the increased energy requirements associated with the high ventilation provision advocated for pandemic operation. It must be noted that no validated experimental evidence exists in literature for bioaerosol transfer in ERVs. Hence, it is necessary to conduct extensive bioaerosol transfer research before adopting the unsustainable practice of limiting the utilization of ERVs. The main objective of this review study is to summarize the experimental methods and instrumentation for bioaerosol transfer research in ERVs. This comprehensive article provides a detailed overview of the generation, sampling, and analysis of bioaerosols for conducting the experiments. Further, it explains the possible mechanisms for bioaerosol transfer in various types of ERVs based on which the ERVs that need immediate attention are identified. The main contribution of this research paper is that it provides a novel experimental method which encompasses the biosafety aspects, instrumentation, performance parameters and uncertainties in conducting virus contained bioaerosol transfer study in ERVs. The findings from this review will be helpful in designing bioaerosol transfer experiments and developing future ERV test standards for such experiments.

42 ENGINEERING↗
DOE OSTI2022

Operation of an Energy Recovery Linac with an Internal Target

Because an Energy Recovery Linac (ERL) decelerates and dumps the beam after at most a few passes, beam degradation in the interaction region that is orders of magnitude larger than in a storage ring is tolerable in such a device. As a consequence, some new types of Nuclear Physics experiments can be carried out. In 2016, an experiment (the DarkLight experiment) was installed in the Jefferson Lab FEL Driver ERL to test out this idea. The ERL had previously been used for FEL applications where high peak current and a large growth in energy spread was present. For the internal target, the machine setup required very small energy spread, and had to deal with large transverse emittance growth in the target. Additionally, the addition of a strong solenoid in the transport complicated the details of energy recovery. This presentation will describe how these new machine physics challenges were addressed.

Benson, S. V.↗
DOE OSTI2021

Integration of Air Classification and Hydrothermal Carbonization to Enhance Energy Recovery of Corn Stover

Air classification (AC) is a cost-effective technology that separates the energy-dense light ash fraction (LAF) from the inorganic-rich high ash fraction (HAF) of corn stover. HAF could be upgraded into energy-dense solid fuel by hydrothermal carbonization (HTC). However, HTC is a high-temperature, high-pressure process, which requires additional energy to operate. In this study, three different scenarios (i.e., AC only, HTC only, and integrated AC–HTC) were investigated for the energy recovery of corn stover. AC was performed on corn stover at an 8 Hz fan speed, which yielded 84.4 wt. % LAF, 12.8 wt. % HAF, and 2.8 wt. % below screen particles. About 27 wt. % ash was reduced from LAF by the AC process. Furthermore, HTC was performed on raw corn stover and the HAF of corn stover at 200, 230, and 260 °C for 30 min. To evaluate energy recovery, solid products were characterized in terms of mass yield, ash yield, ultimate analysis, proximate analyses, and higher heating value (HHV). The results showed that the energy density was increased with the increase in HTC temperature, meanwhile the mass yield and ash yield were decreased with the increase in HTC temperature. Proximate analysis showed that fixed carbon increased 18 wt. % for original char and 27 wt. % for HAF char at 260 °C, compared to their respective feedstocks. Finally, the hydrochar resulting from HAF was mixed with LAF and pelletized at 180 bar and 90 °C to densify the energy content. An energy balance of the integrated AC–HTC process was performed, and the results shows that integrated AC with HTC performed at 230 °C resulted in an additional 800 MJ/ton of energy recovery compared to the AC-only scenario.

09 BIOMASS FUELS↗
DOE OSTI2026

Optimizing Heat Recovery with Storage: Control Validation and Sensitivity Analysis of the Time-Independent Energy Recovery Plant Using Modelica

Heat recovery in large building central plants saves energy but traditionally requires simultaneous heating and cooling. The Time-Independent Energy Recovery (TIER) plant shifts this paradigm by integrating thermal energy storage (TES) to enable heat recovery regardless of concurrent demand, offering a highly efficient, space-saving solution to achieve California’s energy goals. However, its integration of heat recovery chillers, cooling-only chillers, cooling towers, and trim air-source heat pumps (ASHPs) creates growing control and sizing complexity. To overcome this, this study employs high-fidelity Modelica dynamic simulation to validate TIER control sequences and optimize equipment sizing. We translated the written Sequences of Operation into executable Control Description Language (CDL) to test logic against sub-hourly loads. This verification workflow successfully identified and resolved critical vulnerabilities, such as thermal storage freezing and equipment short-cycling, in a virtual environment prior to physical deployment. Then, the study analyzes TIER plant performance across three simulated building types in three locations, and a real building load profile, ensuring variety in heating and cooling loads, and simultaneity factors and explores sizing rules for the TES and ASHP capacity. The analysis shows that the TIER plant operates equipment efficiently leading to a plant SCOP of around 7.5 across all scenarios, higher than a traditional ASHP plant, and a viable pathway to de-risk complex system design and control through simulation to identify optimal designs that maximize energy efficiency, minimize operational costs, and ensure robust operation in varied environmental conditions, thereby facilitating the broader adoption of such a solution for large buildings.

Zanetti, Ettore↗
DOE OSTI2024

A methodology for selection of solid desiccants in energy recovery ventilators

Controlling indoor humidity levels is essential for maintaining acceptable indoor air quality in buildings. The use of energy recovery ventilators (ERVs) is an energy-efficient way to regulate indoor air humidity. Fixed-bed regenerators and rotary wheels are widely used ERVs because of their high sensible and latent effectiveness. These ERVs are made of desiccant-coated substrates, which enable them to transfer moisture between the supply and exhaust air streams. However, the moisture transfer ability of ERVs depends on the physiochemical and sorption properties of desiccants. Extensive, full-scale experiments are required to determine the best desiccant material for these systems. This paper presents a simplified method of selecting suitable desiccant materials for ERVs. The methodology involves important characterization methods, literature correlations for performance prediction, and cost-effective testing methods prior to full-scale testing, and full-scale test methods are discussed in detail. Furthermore, the performance of a few newly derived materials is evaluated and compared with that of conventional desiccants such as silica gel and molecular sieves. The highest latent effectiveness was obtained for composite of super absorbent polymer (SAP) with potassium formate (SAP-HCO2K-50 %), all-polymer porous solid desiccant (APPSD) and metal organic framework (MOF)–MIL–101 (Cr), followed by activated carbon fibre felt (ACFF) Silica sol-LiCl30, SAP, silica gel, MOF–303, and molecular sieve. Researchers and manufacturers would benefit from the proposed methodology and presented data in developing new desiccant materials for ERV applications.

Energy recovery↗
DOE OSTI2021

Integrated heat and energy recovery ventilator system

A heat recovery ventilator (HRV) and/or energy recovery ventilator (ERV) that integrates with a residential capacity air handling unit (AHU) is embodied in a small footprint HRV or ERV unit that connects directly to the return side of an AHU and to outdoor air inlet and exhaust ducts. The ventilator includes a control system incorporating a processor and sensors that control the operation of the system to provide desired ventilation flow rates under varying conditions.

Puttagunta, Srikanth↗
NASA NTRS1975

Energy recovery from solid waste. Volume 2: Technical report

A systems analysis of energy recovery from solid waste demonstrates the feasibility of several current processes for converting solid waste to an energy form. The social, legal, environmental, and political factors are considered in depth with recommendations made in regard to new legislation and policy. Biodegradation and thermal decomposition are the two areas of disposal that are considered with emphasis on thermal decomposition. A technical and economic evaluation of a number of available and developing energy-recovery processes is given. Based on present technical capabilities, use of prepared solid waste as a fuel supplemental to coal seems to be the most economic process by which to recover energy from solid waste. Markets are considered in detail with suggestions given for improving market conditions and for developing market stability. A decision procedure is given to aid a community in deciding on its options in dealing with solid waste, and a new pyrolysis process is suggested. An application of the methods of this study are applied to Houston, Texas.

Huang, C. J.↗
DOE OSTI2020

Metal oxide supported Ni-impregnated bifunctional catalysts for controlling char formation and maximizing energy recovery during catalytic hydrothermal liquefaction of food waste

Nickel (Ni)-impregnated metal oxide catalysts, Ni/CeZrO x , Ni/ZrO 2 , and Ni/CeO 2 , were investigated to maximize energy recovery and reduce char yield during catalytic hydrothermal liquefaction (CHTL) of food waste. Yields of char, biocrude, water soluble products, and gas were measured at 300 °C and 1 hour for both the parent oxides (CeZrO x , ZrO 2 , and CeO 2 ) and the Ni-impregnated versions. Using Ni-based catalysts reduced the carbon-weighted char yield from 16–24% to <10% and decreased the energy recovery of char from 39–47% to <21%, as compared with control tests. In particular, using Ni/ZrO 2 resulted in the greatest biocrude yield, greatest reduction of char yield, and greatest energy recovered as biocrude (39.2%). After factoring in all forms of usable energy produced from food waste, the total energy recovery obtained for the catalysts studied here was >60%. Ni/ZrO 2 and Ni/CeO 2 show the greatest potential for controlling char growth and maximizing energy recovered from food waste. The crystalline structures of all three oxides were hydrothermally stable. Catalyst reuse tests indicate that the biocrude and char yields remained the same for the first and second use (within uncertainty) and that the catalyst retains its initial crystallinity and 93% of its initial Ni content. Molecular composition of biocrudes analyzed by the state-of-the-art analytical platforms (including GC-MS, GC × GC, FT-ICR MS, and 1H NMR) revealed minor differences in the chemical constituents of biocrudes obtained using different catalysts and provided some insight regarding reaction mechanism.

09 BIOMASS FUELS↗
DOE OSTI2024

End-Use Savings Shapes Measure Documentation: Heat Pump Rooftop Units With Exhaust Air Energy Recovery

This technical report documents the Advanced Rooftop Unit Control End Use Savings Shapes (EUSS) measure, including providing a description of the technology, modeling methods, and the energy savings calculated from applying the measure to applicable across the US commercial building stock using ComStock to quantify its potential. This measure replaces gas furnace and electric resistance rooftop units with high-efficiency variable speed heat pump rooftop units (HP-RTU) that include exhaust air heat or energy recovery. The measure uses the same assumptions and technology as the variable speed HP-RTU measure from EUSS 2023 release 1 but adds energy recovery to precondition outdoor ventilation air to reduce HVAC loads. The HP-RTU compressor lockout temperature is modeled as 0 degrees Fahrenheit; below this temperature, the heat pump is set to shut off. The unit is sized based on the design cooling loads, with backup electric resistance heating addressing any remaining loads including heating hours below the compressor lockout temperature when there is no heat pump heating.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2023

Experimental exploration of compressed beam dynamics in an energy recovery linac with comparison to simulations

The compact energy recovery linac (cERL) has been developed for industrial applications since 2017. Applications such as free electron laser require a compressed beam with a small energy spread and transverse emittance. The typical operation energy of cERL is an intermediate energy region close to 17.5 MeV; therefore, the electron bunch is easily affected by the longitudinal space-charge effects and the coherent synchrotron radiation wakefield effects. Bunch compression is demonstrated by optimizing a combination of a longitudinally chirped electron bunch and the arcs with nonzero R 56 parameters. When the bunch compression procedure is applied for a bunch charge of 60 pC, an increase in energy spread is observed at the short bunch length. We systematically explored the chirp phase to determine the best condition. The measurement results of the energy spread, bunch length, and transverse emittance were compared with the tracking simulation results to understand the compressed beam dynamics.

47 OTHER INSTRUMENTATION↗
DOE OSTI2025

Energy recovery proton linear accelerator

High-power proton linear accelerators have important applications in both scientific research and industry. However, the operation of such accelerators with megawatt-level beam power is expensive and limits the broad availability of these facilities. In this Letter, we propose a novel energy recovery proton linear accelerator in which the final GeV-level proton beam is reinjected into the linear accelerator from the accelerator exit and is decelerated in the same accelerator down to about 2 MeV, close to the initial beam energy. This substantially reduces the power consumption of the proton linear accelerator and also avoids the need for a high-power beam dump. We demonstrate this concept through self-consistent simulations and show that the beam-beam effect between the forward-accelerating beam and the backward-decelerating beam would not be a limiting factor for the proposed concept. A potential application of this concept to an electron-ion collider based on energy recovery electron and ion accelerators is discussed.

Energy recovery linacs↗
DOE OSTI2020

MBMS1.0: An Open-Source Code for Modeling and Simulation of Membrane-Based Dehumidification and Energy Recovery

Membrane-based dehumidification is currently being considered as a promising solution for the building application due to its low cost and very limited energy consumption. Developing a simple and efficient open-source code simulation tool is important for boosting the optimization and evaluation of such device in HVAC community. This paper reports a first-order physics based model which accounts for the fundamental heat and mass transfer of humid-air vapor at feed side to flow stream at permeate side. The current model comprises two membrane mass transfer submodels (i.e. microstructure model and performance map model); and it adopts a segment-by-segment methodology for discretizing heat and mass transfer governing equations. The model is capable of simulating both dehumidifiers and energy recovery ventilators with parallel-flow cross-flow, and counter-flow configurations. The model was validated with the measurements at appropriate device. The practices in dehumidification and energy recovery exchangers are also discussed. The model and open-source codes are expected to become a solid fundament for developing a more comprehensive and accurate membrane-based dehumidification in the future.

Gao, Zhiming↗
NASA NTRS2016

Heat Exchanger Performance Impacts on Optimum Cost Conditions in Thermoelectric Energy Recovery Designs

Cost is just as important as power density or efficiency for the adoption of waste heat recovery thermoelectric generators (TEG). Prior work [1] has shown that the system design that minimizes cost (e.g., the $/W value) can be close to the designs that maximize the system’s efficiency or power density, however, it is important to understand the relationship between those designs to optimize TEG performance-cost compromises. Expanding on recent work [1, 2, 3] the impact of heat exchanger conditions on the optimum TEG fill factors and cost scaling of a waste heat recovery thermoelectric generator with a detailed treatment of the hot side exhaust heat exchanger has been investigated further. The effect of the heat lost to the environment and updated relationships between the hot-side and cold-side conductances [4] that maximize power output are considered. The optimum fill factor to minimize TEG energy recovery system costs is strongly dependent on the heat leakage fraction, σ, the mass flow rate of the exhaust, the hot-side heat exchanger effectiveness, heat exchanger UAh, and heat flux. These relationships are explored and characterized for typical exhaust gas-flow conditions to show the inherent design complexities. The heat exchanger costs often dominate the TEG cost equation and it is critical to fully understand the tradeoff between heat exchanger performance, optimum TEG fill factors, and cost to establish potentially optimum design points within the cost-performance design space. This work will explore the design tradeoffs and relationships within the cost-efficiency-power density design space for a typical thermoelectric energy recovery system application. The interplay between optimum TEG fill factors and heat exchanger design can impact system footprint, volume, and mass in weight-sensitive applications. Less-effective, low-cost heat exchangers may outperform higher cost alternatives from a market adoption perspective. This shift of emphasis acknowledging the interdependence of optimum TEG fill factors and heat exchanger performance has significant implications on thermoelectric waste heat recovery systems designs and their operation. In addition, preferred TEG design regimes exist that accommodate reasonable compromises in TE performance and cost. This effort highlights how the optimum fill factor–heat exchanger performance relations couple to these optimum TEG performance-cost domains based on TEG-system-level analyses and provides a focus for future system research and development efforts.

Energy recovery↗
NASA NTRS1983

Energy Recovery System

Cogeneration system is one in which the energy ordinarily wasted in an industrial process is recovered and reused to create a second form of energy. Such an energy recovery system is in use at Crane Company's plant in Ferguson, KY, which manufactures ceramic bathroom fixtures. Crane's system captures hot stack gases from the company's four ceramic kilns and uses them to produce electrical power for plant operations.

Source record↗
DOE OSTI2023

Utah FORGE 4-2492: Design and Implementation of Innovative Stimulation Treatments to Maximize Energy Recovery - Workshop Presentation

This is a presentation on the Design and Implementation of Innovative Stimulation Treatments to Maximize Energy Recovery Efficiency at the Utah FORGE Site project by The University of Texas at Austin, presented by Professor Mukul M. Sharma. The project's objectives were to place fractures uniformly in a horizontal well (improve cluster efficiency) to ensure uniform distribution of flow into all hydraulic fractures, maximize the area of the created fracture network, ensure connectivity of the fractures from the injector to the producer, and optimize fracture size. This presentation was featured in the Utah FORGE R&D Annual Workshop on September 7, 2023. The workshop provided a valuable opportunity to explore the progress made in each of the 17 Research and Development projects funded under Solicitation 2020-1 which aim to enhance our understanding of the crucial factors influencing the development of Enhanced Geothermal Systems (EGS) reservoirs and resources.

15 GEOTHERMAL ENERGY↗