Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Energy Recovery”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 325 records · Page 18
All sourcesNASA NTRSDOE OSTI
NASA NTRS1939

Experiments on the Recovery of Waste Heat in Cooling Ducts, Special Report

Tests have been conducted in the N.A.C.A. full-scale wind tunnel to investigate the partial recovery of the heat energy which is apparently wasted in the cooling of aircraft engines. The results indicate that if the radiator is located in an expanded duct, a part of the energy lost in cooling is recovered; however, the energy recovery is not of practical importance up to airplane speeds of 400 miles per hour. Throttling of the duct flow occurs with heated radiators and must be considered in designing the duct outlets from data obtained with cold radiators in the ducts.

Silverstein, Abe↗
NASA NTRS2015

Cost Scaling of a Real-World Exhaust Waste Heat Recovery Thermoelectric Generator: A Deeper Dive

Cost is equally important to power density or efficiency for the adoption of waste heat recovery thermoelectric generators (TEG) in many transportation and industrial energy recovery applications. In many cases the system design that minimizes cost (e.g., the $/W value) can be very different than the design that maximizes the system's efficiency or power density, and it is important to understand the relationship between those designs to optimize TEG performance-cost compromises. Expanding on recent cost analysis work and using more detailed system modeling, an enhanced cost scaling analysis of a waste heat recovery thermoelectric generator with more detailed, coupled treatment of the heat exchangers has been performed. In this analysis, the effect of the heat lost to the environment and updated relationships between the hot-side and cold-side conductances that maximize power output are considered. This coupled thermal and thermoelectric treatment of the exhaust waste heat recovery thermoelectric generator yields modified cost scaling and design optimization equations, which are now strongly dependent on the heat leakage fraction, exhaust mass flow rate, and heat exchanger effectiveness. This work shows that heat exchanger costs most often dominate the overall TE system costs, that it is extremely difficult to escape this regime, and in order to achieve TE system costs of $1/W it is necessary to achieve heat exchanger costs of $1/(W/K). Minimum TE system costs per watt generally coincide with maximum power points, but Preferred TE Design Regimes are identified where there is little cost penalty for moving into regions of higher efficiency and slightly lower power outputs. These regimes are closely tied to previously-identified low cost design regimes. This work shows that the optimum fill factor Fopt minimizing system costs decreases as heat losses increase, and increases as exhaust mass flow rate and heat exchanger effectiveness increase. These findings have profound implications on the design and operation of various thermoelectric (TE) waste heat 3 recovery systems. This work highlights the importance of heat exchanger costs on the overall TEG system costs, quantifies the possible TEG performance-cost domain space based on heat exchanger effects, and provides a focus for future system research and development efforts.

cost analysis↗
DOE OSTI2012

Designs for a Linac-Ring LHeC

We consider three scenarios for the recirculating electron linear accelerator (RLA) of a linac-ring type electron-proton collider based on the LHC (LHeC): (i) a pulsed linac with a final beam energy of 60 GeV ['p-60'], (ii) a higher luminosity configuration with two cw linacs and energy-recovery (ERL) also at 60 GeV ['erl'], and (iii) a high energy option using a pulsed linac with 140-GeV final energy ['p-140']. We discuss parameters, synchrotron radiation, footprints, and performance for the three scenarios.

43 PARTICLE ACCELERATORS↗
DOE OSTI2012

Superconducting RF systems for eRHIC

The proposed electron-hadron collider eRHIC will consist of a six-pass 30-GeV electron Energy Recovery Linac (ERL) and one of RHIC storage rings operating with energy up to 250 GeV. The collider design extensively utilizes superconducting RF (SRF) technology in both electron and hadron parts. This paper describes various SRF systems, their requirements and parameters.

43 PARTICLE ACCELERATORS↗
DOE OSTI2014

Capacitive energy storage and recovery for synchrotron magnets

Feasibility studies on capacitive energy storage and recovery in the main-ring synchrotron of the Japan Proton Accelerator Research Complex were conducted by circuit simulation. The estimated load fluctuation was 96 MVA in total for dipole magnets, which is likely to induce a serious disturbance in the main grid. It was found that the energy stored in the magnets after the excitation period can be recovered to the storage capacitor by controlling the voltage across the energy-storage capacitor using a pulse-width-modulation converter and reused in the next operational cycle. It was also found that the power fluctuation in the main grid can be reduced to 12 MVA. An experimental evaluation of an aluminum metalized film capacitor revealed that capacitance loss was induced by a fluctuating voltage applied to the storage capacitor when applying the proposed method. The capacitance loss was induced by corona discharge around the edges of segmented electrodes of a self-healing capacitor. The use of aluminum-zinc alloy was evaluated as a countermeasure to mitigate the effect induced by the corona discharge. For a zinc content of 8%, which was optimized experimentally, a capacitor with a sufficient life time expectancy of 20 years and a working potential gradient of 250 V/μm was developed.

43 PARTICLE ACCELERATORS↗
DOE OSTI2011

Low-Energy Run of Fermilab Electron Cooler's Beam Generation System

In the context of the evaluation of possibly using the Fermilab Electron Cooler for the proposed low-energy RHIC run at BNL, operating the cooler at 1.6 MeV electron beam energy was tested in a short beam line configuration. The main conclusion of this feasibility study is that the cooler's beam generation system is suitable for BNL needs. The beam recirculation was stable for all tested parameters. In particular, a beam current of 0.38 A was achieved with the cathode magnetic field up to the maximum value presently available of 250 G. The energy ripple was measured to be 40 eV. A striking difference with running the 4.3 MeV beam (nominal for operation at FNAL) is that no unprovoked beam recirculation interruptions were observed. Electron cooling proposed to increase the luminosity of the RHIC collider for heavy ion beam energies below 10 GeV/nucleon [1] needs a good quality, 0.9-5 MeV electron beam. Preliminary design studies indicate that the scheme of the Recycler's electron cooler at FNAL is suitable for low-energy RHIC cooling and most parts of the cooler can be re-used after the end of the Tevatron Run II. To analyze issues related to the generation of the electron beam in the energy recovery mode and to gain experience with the beam transport at lower beam energy, a dedicated study was performed at FNAL with a beam run through a short beam line (so called U-bend). This report summarizes our findings and observations in the course of the measurements.

43 PARTICLE ACCELERATORS↗
DOE OSTI2015

ERL with non-scaling fixed field alternating gradient lattice for eRHIC

The proposed eRHIC electron-hadron collider uses a "non-scaling FFAG" (NS-FFAG) lattice to recirculate 16 turns of different energy through just two beam lines located in the RHIC tunnel. This paper presents lattices for these two FFAGs that are optimized for low magnet field and to minimize total synchrotron radiation across the energy range. The higher number of recirculations in the FFAG allows a shorter linac (1.322GeV) to be used, drastically reducing cost, while still achieving a 21.2 GeV maximum energy to collide with one of the existing RHIC hadron rings at up to 250GeV. eRHIC uses many cost-saving measures in addition to the FFAG: the linac operates in energy recovery mode, so the beams also decelerate via the same FFAG loops and energy is recovered from the interacted beam. All magnets will be constructed from NdFeB permanent magnet material, meaning chillers and large magnet power supplies are not needed. This paper also describes a small prototype ERL-FFAG accelerator that will test all of these technologies in combination to reduce technical risk for eRHIC.

43 PARTICLE ACCELERATORS↗
DOE OSTI2019

DESIGN AND DYNAMICS OF HYBRID WAVE AND CURRENT ENERGY CONVERTER

The ocean has been identified as one of the most promising energy sources and it can be comprehended as the “unlimited” energy source as well. Therefore, a reasonable exploitation and development on ocean energy recovery are applicable in this energy shortage era. This paper investigates the design and dynamic analysis of the Hybrid Wave and Current Energy Converter (HWCEC), which uses current and wave to recover energy from the ocean. In general, the HWCEC system contains the oscillating buoy and rotating turbine, while the ocean wave and current pass through the system. The energy harvested from the ocean flows through the Mechanical Motion Rectifier (MMR) gearbox [1], and the oscillating motion is converted to a unidirectional rotational motion, which will drive the generator and produce electricity. The dynamic of the HWCEC is developed by combing the dynamics of a heaving buoy, a horizontal axis hydro-turbine and the working status of an MMR-based Power Take-off system (PTO). A 1:10 scaled down prototype has been manufactured and assembled. Further tests will be conducted in the cooperating facilities. Simulation is conducted based on hydrodynamic coefficients obtained from WAMIT and the blade element momentum theory for the scaled-down prototype. Considering a regular wave with 0.08 meters of wave height with 1 second of wave period together with 0.3m/s constant current velocity, Results show that the HWCEC has an improvement in the energy extraction ratio compared to a traditional Wave Energy Converter (WEC) by 53%. The simulation indicates the fact that harvesting energy from both wave and current is simply more efficient than the traditional types of ocean energy harvester, which consists of only harvesting energy from a single source.

Chen, Shuo↗
DOE OSTI2022

Improving bamboo’s fuel and storage properties with a net energy export through torrefaction paired with catalytic oxidation

Using torrefied char, or biocoal, as solid fuel provides an opportunity to introduce a sustainable feedstock into the energy market. The goals of this study were to investigate how torrefaction improves the energy content and the grindability of a Malaysian bamboo along with understanding the potential for integrated energy recovery from torrefaction gases. The feedstock was torrefied at 250–290 °C for 1 h and the combustion characteristics and grindability of the solid products along with the composition of torrefied gas species were measured. The results showed a beneficial increase in elemental carbon increased from 47 to 63 wt% at 290 °C torrefaction, reflecting an increase in higher heating value from 17.8 to 25.6 MJ/kg. The combustion behavior of all the products appeared to show three distinct combustion zones; however, torrefaction severity leading to higher combustion temperature and time as the fixed carbon augmented with the increase of torrefaction temperature. This increase in severity also lead to more friable and grindable material, and the 290 °C condition required a factor of 2.7 less hold-up time in the mill compared to the raw bamboo, and a factor of 8.5 less energy (938 and 111 kWh/tonne respectively). Through analysis of the gas and volatile formation, a case study showed that catalytic oxidation can convert nearly 100% of the embodied chemical energy into usable thermal energy. These experimental findings were scaled to a 100,000 tonne/y capacity torrefaction plant and in the moderate case of 270 °C operating temperature, the plant has 1.25 GJ/tonne excess energy beyond what the process needs.

09 BIOMASS FUELS↗
DOE OSTI2014

Beyond ITER: Neutral beams for a demonstration fusion reactor (DEMO) (invited)

In the development of magnetically confined fusion as an economically sustainable power source, International Tokamak Experimental Reactor (ITER) is currently under construction. Beyond ITER is the demonstration fusion reactor (DEMO) programme in which the physics and engineering aspects of a future fusion power plant will be demonstrated. DEMO will produce net electrical power. The DEMO programme will be outlined and the role of neutral beams for heating and current drive will be described. In particular, the importance of the efficiency of neutral beam systems in terms of injected neutral beam power compared to wallplug power will be discussed. Options for improving this efficiency including advanced neutralisers and energy recovery are discussed.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2012

Novel technique of suppressing TBBU in high-energy ERLs

Energy recovery linacs (ERLs) are an emerging generation of accelerators that promise to revolutionize the fields of high-energy physics and photon sciences. These accelerators combine the advantages of linear accelerators with that of storage rings, and augur the delivery of electron beams of unprecedented power and quality. However, one potential weakness of these devices is transverse beam break-up instability that could severely limit the available beam current. In this paper, I propose a novel method of suppressing these dangerous effects using the chromaticity of the transverse motion. In this short paper I am able only to touch the surface of the method and a complete description of the method with all relevant derivations can be found in [1].

43 PARTICLE ACCELERATORS↗
DOE OSTI2018

Start-up of a sequential dry anaerobic digestion of paunch under psychrophilic and mesophilic temperatures

Highlights: • Dry anaerobic digestion of paunch at 22 °C and 40 °C. • Digestion at 40 °C gave methane yields of 126.9–212.1 mL g{sup −1} VS at SRT of 40 d. • It took 3 cycles (3 × 100 d SRT) to reach a methane of 148.3 mL g{sup −1} VS at 22 °C. • An adapted inoculum is recommended for the start-up of 22 °C digestion. - Abstract: The present laboratory study evaluated the sequential leach bed dry anaerobic digestion (DAD) of paunch under psychrophilic (22 °C) and mesophilic (40 °C) temperatures. Three leach bed reactors were operated under the mesophilic temperature in sequence at a solid retention time (SRT) of 40 d with a new batch started 27 d into the run of the previous one. A total of six batches were operated for 135 d. The results showed that the mesophilic DAD of paunch was efficient, reaching methane yields of 126.9–212.1 mL g{sup −1} volatile solid (VS) and a VS reduction of 32.9–55.5%. The average daily methane production rate increased from 334.3 mL d{sup −1} to 571.4 mL d{sup −1} and 825.7 mL d{sup −1} when one, two and three leach bed reactors were in operation, respectively. The psychrophilic DAD of paunch was operated under a SRT of 100 d and a total of three batches were performed in sequence for 300 d with each batch starting after completion of the previous one. Improvements in the methane yield from 93.9 to 107.3 and 148.3 mL g{sup −1} VS and VS reductions of 24.8, 30.2 and 38.6% were obtained in the consecutive runs, indicating the adaptation of anaerobic microbes from mesophilic to psychrophilic temperatures. In addition, it took three runs for anaerobic microbes to reduce the volatile fatty acid accumulation observed in the first and second trials. This study demonstrates the potential of renewable energy recovery from paunch under psychrophilic and mesophilic temperatures.

09 BIOMASS FUELS↗
DOE OSTI2011

High luminosity electron-hadron collider eRHIC

We present the design of a future high-energy high-luminosity electron-hadron collider at RHIC called eRHIC. We plan on adding 20 (potentially 30) GeV energy recovery linacs to accelerate and to collide polarized and unpolarized electrons with hadrons in RHIC. The center-of-mass energy of eRHIC will range from 30 to 200 GeV. The luminosity exceeding 10{sup 34} cm{sup -2} s{sup -1} can be achieved in eRHIC using the low-beta interaction region with a 10 mrad crab crossing. We report on the progress of important eRHIC R&D such as the high-current polarized electron source, the coherent electron cooling, ERL test facility and the compact magnets for recirculation passes. A natural staging scenario of step-by-step increases of the electron beam energy by building-up of eRHIC's SRF linacs is presented.

43 PARTICLE ACCELERATORS↗
DOE OSTI2011

Lattice Design for ERL Options at SLAC

SLAC is investigating long-range options for building a high performance light source machine while reusing the existing linac and PEP-II tunnels. One previously studied option is the PEP-X low emittance storage ring. The alternative option is based on a superconducting Energy Recovery Linac (ERL) and the PEP-X design. The ERL advantages are the low beam emittance, short bunch length and small energy spread leading to better qualities of the X-ray beams. Two ERL configurations differed by the location of the linac have been studied. Details of the lattice design and the results of beam transport simulations with the coherent synchrotron radiation effects are presented.

43 PARTICLE ACCELERATORS↗
DOE OSTI2015

Thermal and mechanical stabilization process of the organic fraction of the municipal solid waste

Graphical abstract: Display Omitted - Highlights: • A domestic scale prototype for the pre-treatment of OFMSW has been tested. • Two grinding techniques are compared and thermopress is used for the drying stage. • Increasing temperature up to 170 °C reduces energy consumption of the drying stage. • In the range 5–10 bar a reduction of 97% of the initial volume is obtained. • In most cases energy recovery from the dried waste matches energy consumption. - Abstract: In the present study a thermo-mechanical treatment for the disposal of the Organic Fraction of Municipal Solid Waste (OFMSW) at apartment or condominium scale is proposed. The process presents several advantages allowing to perform a significant volume and moisture reduction of the produced waste at domestic scale thus producing a material with an increased storability and improved characteristics (e.g. calorific value) that make it available for further alternative uses. The assessment of the applicability of the proposed waste pretreatment in a new scheme of waste management system requires several research steps involving different competences and application scales. In this context, a preliminary study is needed targeting to the evaluation and minimization of the energy consumption associated to the process. To this aim, in the present paper, two configurations of a domestic appliance prototype have been presented and the effect of some operating variables has been investigated in order to select the proper configuration and the best set of operating conditions capable to minimize the duration and the energy consumption of the process. The performances of the prototype have been also tested on three model mixtures representing a possible daily domestic waste and compared with an existing commercially available appliance. The results obtained show that a daily application of the process is feasible given the short treatment time required and the energy consumption comparable to the one of the common domestic appliances. Finally, the evaluation of the energy recovered in the final product per unit weight of raw material shows that in most cases it is comparable to the energy required from the treatment.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2012

Long-Term Results: New Construction Occupied Test House, Urbana, Illinois

For this study, a house was designed and built to the Passive House (Passivhaus) Standard for low energy consumption. The house incorporates an airtight, super-insulated thermal enclosure, southern facing windows with overhangs, a single point mini-split heat pump and electric resistance heaters, and a balanced energy recovery ventilator (ERV). The house was instrumented with sub-metering on all major electrical circuits, temperature and humidity measurements in each room, domestic hot water consumption, and recovery efficiency of the ERV. The energy performance was documented and compared to modeled predictions, and the thermal comfort performance of the heat pump was assessed.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗