Search NASA⌕ Search

SEARCH · Search NASA

Results for “liquid sorption”

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 19 records

System for detecting and estimating concentrations of gas or liquid analytes

A sensor system for detecting and estimating concentrations of various gas or liquid analytes. In an embodiment, the resistances of a set of sensors are measured to provide a set of responses over time where the resistances are indicative of gas or liquid sorption, depending upon the sensors. A concentration vector for the analytes is estimated by satisfying a criterion of goodness using the set of responses. Other embodiments are described and claimed.

Homer, Margie L.↗

Aerogel Insulation Applications for Liquid Hydrogen Launch Vehicle Tanks

Aerogel based insulation systems for ambient pressure environments were developed for liquid hydrogen (LH2) tank applications. Solutions to thermal insulation problems were demonstrated for the Space Shuttle External Tank (ET) through extensive testing at the Cryogenics Test Laboratory. Demonstration testing was performed using a 1/10th scale ET LH2 intertank unit and liquid helium as the coolant to provide the 20 K cold boundary temperature. Cryopumping tests in the range of 20K were performed using both constant mass and constant pressure methods. Long-duration tests (up to 10 hours) showed that the nitrogen mass taken up inside the intertank is reduced by a factor of nearly three for the aerogel insulated case as compared to the un-insulated (bare metal flight configuration) case. Test results including thermal stabilization, heat transfer effectiveness, and cryopumping confirm that the aerogel system eliminates free liquid nitrogen within the intertank. Physisorption (or adsorption) of liquid nitrogen within the fine pore structure of aerogel materials was also investigated. Results of a mass uptake method show that the sorption ratio (liquid nitrogen to aerogel beads) is about 62 percent by volume. A novel liquid nitrogen production method of testing the liquid nitrogen physical adsorption capacity of aerogel beads was also performed to more closely approximate the actual launch vehicle cooldown and thermal stabilization effects within the aerogel material. The extraordinary insulating effectiveness of the aerogel material shows that cryopumping is not an open-cell mass transport issue but is strictly driven by thermal communication between warm and cold surfaces. The new aerogel insulation technology is useful to solve heat transfer problem areas and to augment existing thermal protection systems on launch vehicles. Examples are given and potential benefits for producing launch systems that are more reliable, robust, reusable, and efficient are outlined.

Fesmire, J. E.↗

Sorption Properties of Aerogel in Liquid Nitrogen

Aerogel products are now available as insulation materials of the future. The Cryogenics Test Laboratory at the NASA Kennedy Space Center is developing aerogel-based thermal insulation systems for space launch applications. Aerogel beads (Cabot Nanogel ) and aerogel blankets (Aspen Aerogels Spaceloft ) have outstanding ambient pressure thermal performance that makes them useful for applications where sealing is not possible. Aerogel beads are open-celled silicone dioxide and have tiny pores that run throughout the body of the bead. It has also recently been discovered that aerogel beads can be used as a filtering device for aqueous compounds at room temperature. With their hydrophobic covering, the beads absorb any non-polar substance and they can be chemically altered to absorb hot gases. The combination of the absorption and cryogenic insulating properties of aerogel beads have never been studied together. For future cryogenic insulation applications, it is crucial to know how the beads react while immersed in cryogenic liquids, most notably liquid nitrogen. Aerogel beads in loose-fill situation and aerogel blankets with composite fiber structure have been tested for absorption properties. Depending on the type of aerogel used and the preparation, preliminary results show the material can absorb up to seven times its own weight of liquid nitrogen, corresponding to a volumetric ratio of 0.70 (unit volume nitrogen per unit volume aerogel). These tests allow for an estimate on how much insulation is needed in certain situations. The theory behind the different processes of sorption is necessary for a better understanding of the preparation of the beads before they are used in an insulation system.

Johnson, Wesley L.↗

Carbon Sorption Cryogenic Regenerator

Liquid-helium refrigerator includes regenerator filled with carbon sorbent made from Saran polyvinylidene chloride. Material results in lower operating temperatures and longer times between maintenance than comparable refrigerators containing other regenerators. Sorbent material machined to various configurations to fit inside cylindrical regenerator can. Configuration chosen with regard to heat capacity, pressure drop, and rate of sorption.

Jones, Jack A.↗

Improved Regenerative Sorbent-Compressor Refrigerator

Conceptual regenerative sorbent-compressor refrigerator attains regeneration efficiency and, therefore, overall power efficiency and performance greater than conventional refrigerators. Includes two fluid loops. In one, CH2FCF3 (R134a) ciculates by physical adsorption and desorption in four activated-charcoal sorption compressors. In other, liquid or gas coolant circulated by pump. Wave of regenerative heating and cooling propagates cyclically like peristatic wave among sorption compressors and associated heat exchangers. Powered by electricity, oil, gas, solar heat, or waste heat. Used as air conditioners, refrigerators, and heat pumps in industrial, home, and automotive applications.

Jones, Jack A.↗

An integrated development facility for the calibration of low-energy charged particle flight instrumentation

A system was developed for the calibration and development of thermal ion instrumentation. The system provides an extended beam with usable current rates, approx. 1 pA/sq cm, at beam energies as low as 1 eV, with much higher values available with increasing energy. A tandem electrostatic and variable geometry magnetic mirror configuration within the ion source optimizes the use of the ionizing electrons. The system is integrated under microcomputer control to allow automatic control and monitoring of the beam energy and composition and the mass and angle-dependent response of the instrument under test. The system is pumped by a combination of carbon vane and cryogenic sorption roughing pumps and ion and liquid helium operating pumps.

Biddle, A. P.↗

Magnetic-Flux-Compression Cooling Using Superconductors

Proposed magnetic-flux-compression refrigeration system produces final-stage temperatures below 4.2 K. More efficient than mechanical and sorption refrigerators at temperatures in this range. Weighs less than comparable liquid-helium-cooled superconducting magnetic refrigeration systems operating below 4.2 K. Magnetic-flux-compression cooling stage combines advantages of newly discovered superconductors with those of cooling by magnetization and demagnetization of paramagnetic salts.

Strayer, Donald M.↗

Cryogenic system design for a hydrogen sorption cooler

For several future space applications, long life vibration free collers are needed to cover the temperature range from 60K to about 4K. We describe the development of a novel cryogenic system capable of reaching 18K in coupled resevoirs that provide distributed cooling with small temperature fluctuations.

sorption cryocoolers Joule-Thomson expansion liqui↗

Providing Oxygen for the Crew of a Lunar Outpost

Oxygen (O2) is obviously essential for human space missions, but it is important to examine all the different ways it will be used and the potential sources that it may come from. This effort will lead to storage and delivery requirements and help to determine the optimum architecture from an overall systems engineering point of view. Accounting for all the oxygen in a Lunar Outpost mission includes meeting the metabolic needs of the crew while in the surface Habitat, leakage through the Habitat or Pressurized Rover walls, recharge of the space suit backpack and emergency situations. Current plans indicate that both primary and secondary O2 bottles for the space suit will be filled to a pressure of 20.7 MPa (3000 psia). Other uses of O2 require much lower pressure. Sources of O2 at a Lunar Outpost include compressed or liquefied O2 brought along specifically for life support, scavenged O2 from the Lander propulsion system, recovered O2 from waste water or exhaled carbon dioxide and O2 mined from the moon itself. Previously, eight technology options were investigated to provide the high pressure space suit O2. High pressure O2 storage was treated as the baseline technology and compared to the other seven. The other seven were cryogenic storage followed by high pressure vaporization, scavenging liquid oxygen (LOX) from Lander followed by vaporization, LOX delivery followed by sorption compression, low pressure water electrolysis followed by mechanical compression, high pressure water electrolysis, sharing a high pressure electrolyzer with a regenerative fuel cell power system, and making use of In- Situ Resource Utilization (ISRU). This system-level analysis was conducted by comparing equivalent system mass of the eight technologies in open and closed loop life support architectures. The most promising high pressure O2 generation technologies were recommended for development. Updates and an expansion of the earlier study have been made and the results are reported in this paper. Examples of recent analyses include feasibility of recovering space suit purge O2 in a Pressurized Rover and using sub-critical LOX for primary supply while using high-pressure gaseous O2 as the secondary supply for the space-suit. Preliminary analysis on scavenging LOX from the Lander and delivering it to the Habitat has also been incorporated into this integrated lunar fluids analysis

Ewert, Michael K.↗

Cryogenic probe station for use in automated microwave and noise figure measurements

A cryogenic measurement system capable of performing on-wafer RF testing of semiconductor devices and circuits has been developed. This 'CryoProbe Station' can wafer-probe devices and circuits at cryogenic temperatures, thus eliminating the need for wire bonds. The system operates under vacuum created by a sorption pump. It uses an open cycle cooling system that can be cooled with either liquid nitrogen or liquid helium. Presently, it can reach temperatures, as low as 80 K and 37 K for each of the coolants, respectively. The temperature can be raised using a heater and it is stabilized to within 0.2 K by use of a temperature controller. The CryoProbe Station features a 1 by 2 inch stage that can hold large circuits and calibration standards simultaneously. The system is used with a Hewlett Packard 8510C Automatic Network Analyzer (ANA) to obtain S-parameter data over the frequency range 0.045-26.5 GHz. S-parameter data on HEMT (high electron mobility transistors) devices has been obtained with this station. With the use of DEEMBED software from NIST, detailed transmission line studies have been performed. Although the CryoProbe Station is designed for frequencies up to 26.5 GHz, useful transmission line data has been obtained for frequencies as high as 40 GHz. The CryoProbe station has also been used with the ATN noise figure measurement system to perform automatic, temperature dependent noise figure measurements.

Taub, Susan R.↗

High-Pressure Oxygen Generation for Outpost EVA Study

The amount of oxygen consumption for crew extravehicular activity (EVA) in future lunar exploration missions will be significant. Eight technologies to provide high pressure EVA O2 were investigated. They are: high pressure O2 storage, liquid oxygen (LOX) storage followed by vaporization, scavenging LOX from Lander followed by vaporization, LOX delivery followed by sorption compression, water electrolysis followed by compression, stand-alone high pressure water electrolyzer, Environmental Control and Life Support System (ECLSS) and Power Elements sharing a high pressure water electrolyzer, and ECLSS and In-Situ Resource Utilization (ISRU) Elements sharing a high pressure electrolyzer. A trade analysis was conducted comparing launch mass and equivalent system mass (ESM) of the eight technologies in open and closed ECLSS architectures. Technologies considered appropriate for the two architectures were selected and suggested for development.

Jeng, Frank F.↗

Liquid Metering Centrifuge Sticks (LMCS): A Centrifugal Approach to Metering Known Sample Volumes for Colorimetric Solid Phase Extraction (C-SPE)

Phase separation is one of the most significant obstacles encountered during the development of analytical methods for water quality monitoring in spacecraft environments. Removing air bubbles from water samples prior to analysis is a routine task on earth; however, in the absence of gravity, this routine task becomes extremely difficult. This paper details the development and initial ground testing of liquid metering centrifuge sticks (LMCS), devices designed to collect and meter a known volume of bubble-free water in microgravity. The LMCS uses centrifugal force to eliminate entrapped air and reproducibly meter liquid sample volumes for analysis with Colorimetric Solid Phase Extraction (C-SPE). C-SPE is a sorption-spectrophotometric platform that is being developed as a potential spacecraft water quality monitoring system. C-SPE utilizes solid phase extraction membranes impregnated with analyte-specific colorimetric reagents to concentrate and complex target analytes in spacecraft water samples. The mass of analyte extracted from the water sample is determined using diffuse reflectance (DR) data collected from the membrane surface and an analyte-specific calibration curve. The analyte concentration can then be calculated from the mass of extracted analyte and the volume of the sample analyzed. Previous flight experiments conducted in microgravity conditions aboard the NASA KC-135 aircraft demonstrated that the inability to collect and meter a known volume of water using a syringe was a limiting factor in the accuracy of C-SPE measurements. Herein, results obtained from ground based C-SPE experiments using ionic silver as a test analyte and either the LMCS or syringes for sample metering are compared to evaluate the performance of the LMCS. These results indicate very good agreement between the two sample metering methods and clearly illustrate the potential of utilizing centrifugal forces to achieve phase separation and metering of water samples in microgravity.

Gazda, Daniel B.↗

Novel Aprotic Heterocyclic Anion-based Ionic Liquids for Carbon Dioxide Capture

Ionic liquids (ILs), or organic salts with melting points at or below room temperature are an incredibly versatile class of materials with many possible applications for NASA’s exploration needs. In particular, appropriately designed ILs can have a high affinity for absorbing carbon dioxide, making them excellent candidates for use as liquid sorbents in cabin air revitalization systems. Unfortunately, many of these ILs have high viscosity, which is only exacerbated by carbon dioxide uptake. High viscosity limits the rate of carbon dioxide uptake. A new class of IL sorbent containing aprotic heterocyclic anions (AHA) has been shown to offer excellent carbon dioxide uptake without a corresponding increase in viscosity. However, there is a paucity of sorption data for these AHA ILs at low partial pressures of carbon dioxide. This paper reports on the characterization of sorption behavior for AHA ILs previously reported in the literature at low concentrations of carbon dioxide and the synthesis and characterization of new, water miscible AHA ILs. Characterization of the new ILs includes measurement of density, viscosity, thermal stability, carbon dioxide capacity, carbon dioxide absorption kinetics, and water-IL vapor liquid equilibrium. Overall, these news ILs are promising alternatives to many of the commonly used IL sorbents.

Eric Townsend Fox↗

(abstract) Development of Sorbent Bed Assembly for a Periodic 10K Solid Hydrogen Cryocooler

A closed-cycle 10K sorption cryocooler is being fabricated for microgravity testing during a future space shuttle mission. A critical component of this cryogenic refrigerator is the metal hydride sorbent bed assembly (SBA). The SBA uses hydrides which absorb hydrogen gas at low pressure, (i.e., about 0.25 MPa from liquid hydrogen at 25K and below 0.2 kPa from solid hydrogen near 10K) and subsequently delivers hydrogen at nearly 10 MPa to a storage reservoir to repeat the Joule-Thomson (J-T) expansion process. The SBA includes three independent hydride beds where two contain LaNi(sub 4.8)Sn(sub 0.2) alloy and the third ZrNi. Detailed descriptions will be given for the three beds, which have specialized design features to enhance performance at each step of operation. In particular, two beds must rapidly absorb hydrogen in order for the J-T cold stage to reach 10K within two minutes from a 65K holding temperature. Performance characterization results will be compared to model analyses of the SBA.

applications microgravity↗

Novel approaches to the construction of miniaturized analytical instrumentation

This paper focuses on the design, construction, preliminary testing, and potential applications of three forms of miniaturized analytical instrumentation. The first is an optical fiber instrument for monitoring pH and other cations in aqueous solutions. The instrument couples chemically selective indicators that were immobilized at porous polymeric films with a hardware package that provides the excitation light source, required optical components, and detection and data processing hardware. The second is a new form of a piezoelectric mass sensor. The sensor was fabricated by the deposition of a thin (5.5 micron) film of piezoelectric aluminum nitride (AIN). The completed deposition process yields a thin film resonator (TFR) that is shaped as a 400 micron square and supports a standing bulk acoustic wave in a longitudinal mode at frequencies of approx. 1 GHz. Various deposition and vapor sorption studies indicate that the mass sensitivity of the TFR's rival those of the most sensitive mass sensors currently available, though offering such performance in a markedly smaller device. The third couples a novel form of liquid chromatography with microlithographic miniaturization techniques. The status of the miniaturization effort, the goal of which is to achieve chip-scale separations, is briefly discussed.

Porter, Marc D.↗

Novel approaches to the construction of miniaturized analytical instrumentation

This paper focuses on the design, construction, preliminary testing, and potential applications of three forms of miniaturized analytical instrumentation. The first is an optical fiber instrument for monitoring pH and other cations in aqueous solutions. The instrument couples chemically selective indicators that were immobilized at porous polymeric films with a hardware package that provides the excitation light source, required optical components, and detection and data processing hardware. The second is a new form of a piezoelectric mass sensor. The sensor was fabricated by the deposition of a thin (5.5 micron) film of piezoelectric aluminum nitride (AIN). The completed deposition process yields a thin film resonator (TFR) that is shaped as a 400 micron square and supports a standing bulk acoustic wave in a longitudinal mode at frequencies of approx. 1 GHz. Various deposition and vapor sorption studies indicate that the mass sensitivity of the TFR's rival those of the most sensitive mass sensors currently available, though offering such performance in a markedly smaller device. The third couples a novel form of liquid chromatography with microlithographic miniaturization techniques. The status of the miniaturization effort, the goal of which is to achieve chip-scale separations, is briefly discussed.

Porter, Marc D.↗

Hydride absorption refrigerator system for ten Kelvin and below

A very long-life, lightweight and efficient hydride absorption refrigerator system was built to operate at ten Kelvin and below. The system consists of four basic stages of refrigeration. The first stage is accomplished by an active refrigeration system. The second stage is operated by a hydride absorption system, wherein a heated hydride powder drives off high pressure hydrogen through a Joule-Thomson/heat exchanger expansion loop such that the hydrogen is partially liquefied. In the third stage, the vapor pressure over the collected liquid hydrogen is lowered by absorbing the hydrogen vapor onto a different low pressure, worn hydride. With a 1.7 torr partial pressure of hydrogen gas in the hydride, liquid hydrogen is solidified and sublimes at 10 K. Long-life adiabatic demagnetization refrigerators, helium desorption, or helium diaphragm compressors are used to cool to 4 K or below. It is shown that the hydride concepts provide an extremely efficient means of refrigeration to 10 K, and that an entire sorption refrigeration process can be accomplished solely by using low grade heat energy at about 150 C.

Jones, J. A.↗