Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “STEAM”

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 739 records · Page 41
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Analysis of AC-DC Converters for Grid-tied High Temperature Steam Electrolysis Systems

Grid-tied HTSE systems have the prospects to produce clean hydrogen enabling power and broad energy systems decarbonization. Most commercially available power electronic converter systems (PECS) are designed for batteries, solar PVs, wind, and other well-established renewable energy resources. Standards (such as IEEE 1547, UL 1741, CA Rule-21, HI Rule14) exist for PECS used for renewable energy systems such as battery storage and solar PVs. However, those that consider the dynamic behavior of HTSEs and that can be used for large-scale H2 systems are yet to be developed. This paper investigates the performance of these PECS for the HTSE application that are set up at the Idaho National Laboratory for hydrogen production testing, research and development. In particular, the performance analysis of two grid-tied PECS (A and B) is conducted for a 100 kW solid oxide HTSE system. System A consists of 6 units of 30kW MOSFET-switched bidirectional AC-DC rectifier while system B has a single unit of 150kW thyristor-switched AC-DC rectifier. Both systems are connected to the HTSE stacks via a DC-DC converter. Different operational conditions of the HTSE system are tested to analyze the dynamic response of the HTSE’s PECS. The experimental results show the need to develop advanced control strategies for PECS that incorporates the dynamics of HTSE systems for improved performance.

High temperature steam electrolysis↗
DOE OSTI2013

High Temperature Steam Corrosion of Cladding for Nuclear Applications: Experimental

Stability of cladding materials under off-normal conditions is an important issue for the safe operation of light water nuclear reactors. Metals, ceramics, and metal/ceramic composites are being investigated as substitutes for traditional zirconium-based cladding. To support down-selection of these advanced materials and designs, a test apparatus was constructed to study the onset and evolution of cladding oxidation, and deformation behavior of cladding materials, under loss-of-coolant accident scenarios. Preliminary oxidation tests were conducted in dry oxygen and in saturated steam/air environments at 1000OC. Tube samples of Zr-702, Zr-702 reinforced with 1 ply of a ß-SiC CMC overbraid, and sintered a-SiC were tested. Samples were induction heated by coupling to a molybdenum susceptor inside the tubes. The deformation behavior of He-pressurized tubes of Zr-702 and SiC CMC-reinforced Zr-702, heated to rupture, was also examined.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2017

Steam-air blown bubbling fluidized bed biomass gasification (BFBBG): Multi-scale models and experimental validation

During fluidized bed biomass gasification, complex gas-solid mixing patterns and numerous chemical and physical phenomena make identification of optimal operating conditions challenging. In this work, a parametric experimental campaign was carried out alongside the development of a coupled reactor network model which successfully integrates the individually validated sub-models to predict steady-state reactor performance metrics and outputs. The experiments utilized an integrated gasification system consisting of an externally-heated, bench-scale, 4-in., 5 kWth, fluidized bed steam/air blown gasifier fed with woody biomass equipped with a molecular beam mass spectrometer to directly measure tar species. The operating temperature (750-850°C) and air/fuel equivalence ratio (ER = 0-0.157) were independently varied to isolate their effects. Elevating temperature is shown to improve the char gasification rate and reduce tar concentrations. In conclusion, air strongly impacts the composition of tar, accelerating the conversion of lighter polycyclic-aromatic hydrocarbons into soot precursors, while also improving the overall carbon conversion.

09 BIOMASS FUELS↗
DOE OSTI2015

Rapid Screening of Immobilized Amine CO 2 Sorbents for Steam Stability by Their Direct Contact with Liquid H 2 O

Abstract Rapid testing of hydrophilic and hydrophobic basic immobilized amine sorbents (BIAS) for CO 2 capture stability under practical conditions was achieved by direct contact of the sorbents with flowing liquid water. Losses in both CO 2 capture capacity and amine content of sorbents after exposure to 0.5 mL min −1 of H 2 O at 25 °C for 40 min followed similar trends as losses observed after exposure to N 2 /steam (105 °C, 7 % H 2 O) for 10 h. We also found that hydrophobic TMPED helped stabilize sorbents to H 2 O, which was confirmed by DRIFTS and combined TGA‐DSC.

Wilfong, Walter Christopher↗
DOE OSTI2018

TiO 2-x /CoO x photocatalyst sparkles in photothermocatalytic reduction of CO 2 with H 2 O steam

Solar photocatalytic production of fuels from CO 2 and H 2 O remains a challenging goal. In this paper, we report a strategy to co-modify TiO 2 with oxygen vacancies and CoO x nanoclusters for enhanced photothermocatalytic reduction of CO 2 . The TiO 2-x /CoO x material exhibits prominently enhanced activity for the yield of CH 4 and CO under ultraviolet irradiation at elevated temperature of 393 K, which is 111.3 and 13.2 times greater yield of CH 4 and CO, respectively than the conventional photocatalytic process at 298 K, and 175.1 and 2.9 times greater yield of CH 4 and CO, respectively than the pristine TiO 2 under the same photothermocatalytic conditions. Control experiments over singly modified TiO 2 and doubly modified TiO 2 by different preparation history, together with HRTEM, EPR and transient photovoltage measurements reveal the synergistic effect of oxygen vacancies and surface-grafted CoO x on the photothermocatalytic reduction of CO 2 to CH 4 , i.e. oxygen vacancies at TiO 2 surface facilitate the adsorption and reduction of CO 2 and the dispersion of CoO x nanoclusters, whereas surface-grafted CoO x clusters facilitate the hole trapping and the oxidation of H 2 O. Thereby the coexistence of oxygen vacancies and CoO x nanoclusters at TiO 2 surface promote the separation of photogenerated electrons and holes, and remarkably enhance the eight-electron reduction of CO 2 to CH 4 under photothermocatalytic conditions. This study shows the great potential of photo-thermal synergy on CO 2 reduction and provides a promising means to design photothermocatalysts for solar photocatalytic reduction of CO 2 to fuel.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗