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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 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS2016

Using Paraffin PCM to Make Optical Communication Type of Payloads Thermally Self-Sufficient for Operation in Orion Crew Module

An innovative concept of using paraffin phase change material with a melting point of 28 C to make Optical Communication type of payload thermally self-sufficient for operation in the Orion Crew Module is presented. It stores the waste heat of the payload and permits it to operate for about one hour by maintaining its temperature within the maximum operating limit. It overcomes the problem of relying on the availability of cold plate heat sink in the Orion Crew Module.

loop heat pipe; heater controller↗
NASA NTRS2017

Using Paraffin PCM, Cryogel and TEC to Maintain Comet Surface Sample Cold from Earth Approach Through Retrieval

An innovative thermal design concept to maintain comet surface samples cold (for example, 263 degrees Kelvin, 243 degrees Kelvin or 223 degrees Kelvin) from Earth approach through retrieval is presented. It uses paraffin phase change material (PCM), Cryogel insulation and thermoelectric cooler (TEC), which are commercially available.

comet surface sample return; thermoelectric cooler↗
NASA NTRS2019

Using Paraffin PCM for Thermal Management of BOLAS Planetary CubeSats with Ion Thrusters

The Bi-sat Observations of the Lunar Atmosphere above Swirls (BOLAS) is a NASA planetary CubeSat mission concept in low lunar orbit. The BOLAS lower CubeSat is at a 90 km altitude above the lunar surface during spiraling down from the Evolved Expendable Launch Vehicle (EELV) Secondary Payload Adapter (ESPA) to the Moon. Without phase change material (PCM), the worst hot case temperature prediction for the Command and Data Handling (C&DH) exceeds the 61°C maximum operating limit, and those for the Iris solid state power amplifier (SSPA) and transponder exceed the 50°C maximum operating limit. Miniature n-Tricosane PCM packs on the Iris SSPA and transponder, and miniature n-Hexacosane PCM packs on the C&DH are used to store thermal energy in sunlight and release it in the eclipse. With paraffin PCM, all the temperatures are within the maximum operating limits.

Choi, Michael K.↗
DOE OSTI2021

Oxidation of an iso-paraffinic alcohol-to-jet fuel and n-heptane mixture: an experimental and modelling study

Oxidation of ATJ/n-heptane blends was studied over a wide range of test conditions, using single pulse shock tubes. Test conditions were designed to study the effect of pressure (4 and 50 bar), and fuel loading (~100-1400 ppm) on the oxidation of the blends across a wide range of temperatures (800-1300 K). These effects were observed by measuring concentrations of intermediate species formed using in-line Gas Chromatography (GC) and GCxGC TOF-MS. Results showed that increasing the initial fuel load does not have a significant impact on the results. However, increasing the pressure shifts the mixture reactivity to a lower temperature by about 150 K and causes the fuel to be oxidized instead of decomposing pyrolytically as at lower pressures. Additional experiments for pure ATJ and pure n-heptane were performed at conditions matching the ATJ/n-heptane 50 bar experiments to analyze the differences between the pure and mixed fuels. Speciation measurements were compared against predictions from a detailed kinetic model. The ability of the kinetic model to capture the effects of varying experimental test conditions on the evolution of intermediate species is discussed and kinetic analyses have been conducted to identify the important reaction pathways.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Electrochemical conversion of methane to ethylene, olefins, and paraffins using metal-supported solid oxide cells

Electrochemical oxidative coupling of methane (E-OCM) with Sr 2 Fe 1·5 Mo 0·5 O 6–δ (SFM) catalyst is demonstrated with metal-supported solid oxide cells (MS-SOC). SFM anode and Pr 6 O 11 cathode catalysts are loaded into a porous symmetric-architecture cell by infiltration and firing. The most effective chelating agent (citric acid/ethyl glycol) and optimal firing/reducing temperatures (850 °C/750 °C) for the SFM catalyst precursor solution are selected and confirmed by cell testing. Operating temperature, cell voltage, and oxygen concentration at the cathode greatly affect the methane conversion rate and product selectivity by controlling the oxygen ion flow. CH 4 conversion of 85.8% is obtained, with C 2 H 4 , C 2 H 6 , and H 2 concentrations of 10.5%, 12.3%, and 25.6% at 800 °C, respectively, in the product exhaust gas. Reasonable stability of the current density and methane conversion is demonstrated during 200 h operation. Furthermore, this research demonstrates technical progress in catalyst and device development for the E-OCM reaction to synthesize valuable chemicals.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2025

Pressure-stable supported ionic liquid membranes using isoporous supports for evaluating pure- and mixed-gas light paraffin fractionation

Advances in horizontal drilling and hydraulic fracturing have spurred the growth of domestic U.S. energy production. Membranes, typically silicone rubbers, have found utility in shale gas treatment as fuel gas conditioning units to selectively remove C 2 + hydrocarbons at pressures up to 30 bar, producing clean CH 4 for gas engines. However, more selective materials could be beneficial for broader shale gas treatment applications, such as dew point control units. Supported ionic liquid membranes (SILMs) offer a potential opportunity for improving C 3 H 8 /CH 4 selectivity, but they lack pressure-stability. Here, we report C 3 H 8 /CH 4 selective and pressure-stable SILMs using isoporous supports. SILMs with supports that had minimal defects remained stable up to 15 bar of transmembrane pressure. This stability allowed for pure- and mixed-gas testing of the resulting membranes at elevated pressures. Furthermore, these tests revealed that low viscosity ILs (<100 cp) may display mixed-gas permeances and permselectivity nearly identical to pure-gas results. On the other hand, higher viscosity ILs may display increasing permeances and permselectivity with increasing C 3 H 8 fugacity, similar to rubbery polymers. Ultimately, the SILMs demonstrated relatively high pressure-stability due to the isoporous supports and competitive mixed-gas C 3 H 8 /CH 4 permselectivity compared to silicone rubber.

Rosenthal, Justin J. [University of Texas at Austi↗