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At least 469 records · Page 26

MEDLI2: MISP Measured Aftbody Aerothermal Environments

The Mars Entry, Descent, and Landing Instrumentation 2 (MEDLI2) sensor suite on the Mars 2020 mission included two total heat flux sensors and one radiometer on the backshell to directly measure the aftbody aerothermal environments during entry into the Martian atmosphere. All three sensors successfully returned aftbody entry heating measurements. Comparisons between the total heat flux sensor measurements and DPLR/NEQAIR predictions show excellent agreement and provide confidence in the models. The radiometer measured significant radiative heating but compared to the model predictions the signal was attenuated by 50% at the end of the entry heat pulse. The loss of signal is attributed to blockage by thermal protection system (TPS) ablation product deposits on the radiometer window. Ground-based testing in the NASA Ames arc jet facilities was conducted to understand the impact of ablation product deposits on the measured radiometer signal. A discussion of the test results, how flight-like the test conditions were, and future work to further characterize the effect of TPS ablation product deposits on the radiometer performance are presented. In addition to measuring the entry heat pulse all three sensors were sensitive enough to measure solar radiation during cruise, the radiometer measured solar flux during the entry heat pulse, and the leeside total heat flux sensor picked up the descent reaction control system firings.

Ruth A Miller↗

Magellan orbits Venus

Various events surrounding Magellan's orbit of Venus are recounted. Significant events include the successful firing of a solid rocket motor while the spacecraft was behind Venus to transfer it from a solar-centered trajectory to an orbit around the planet. The spacecraft orbits Venus every 3.26 hours at a maximum altitude of 8500 km and minimum altitude of 291 km in an elliptical orbit. The successful August 16 test of the synthetic-aperture radar system is discussed, noting that it produced two strips, each about 20 km x 16,000 km, revealing details as small as 120 m. Two anomalies causing a delay in the start of mapping operations and subsequent breaks in the communication link with earth for 14.5 hours and 17.7 hours are discussed. Protective measures directed from the spacecraft's ROM during breach of contact are listed, and possible causes of the anomalies are suggested, such as solar activity or hardware or software elements, although the actual cause is not yet known.

Mclaughlin, W. I.↗

An Overview of the Microgravity Science Glovebox (MSG) Facility and the Research Performed in the MSG on the International Space Station (ISS)

The Microgravity Science Glovebox (MSG) is a double rack facility aboard the International Space Station (ISS) designed for investigation handling. The MSG has been operating on the ISS since July 2002 and is currently located in the Columbus Laboratory Module. The unique design of the facility allows it to accommodate science and technology investigations in a workbench type environment. The facility has an enclosed working volume that is held at a negative pressure with respect to the crew living area. This allows the facility to provide two levels of containment for small parts, particulates, fluids, and gases. This containment approach protects the crew from possible hazardous operations that take place inside the MSG work volume. Research investigations operating inside the MSG are provided a large 255 liter enclosed work space, 1000 watts of dc power via a versatile supply interface (120, 28, +/- 12, and 5 Vdc), 1000 watts of cooling capability, video and data recording and real time downlink, ground commanding capabilities, access to ISS Vacuum Exhaust and Vacuum Resource Systems, and gaseous nitrogen supply. These capabilities make the MSG one of the most utilized facilities on ISS. In fact, the MSG has been used for over 5000 hours of scientific payload operations. MSG investigations involve research in cryogenic fluid management, fluid physics, spacecraft fire safety, materials science, combustion, plant growth, and life support technologies. MSG is an ideal platform for science investigations and research required to advance the technology readiness levels (TRLs) applicable to the Constellation Program. This paper will provide an overview of the MSG facility, a synopsis of the research that has already been accomplished in the MSG, an overview of future investigations currently planned for operation in the MSG, and potential applications of MSG investigations that can provide useful data to the Constellation Program. In addition, this paper will address the role of the MSG facility in the ISS National Lab.

Spivey, Reggie↗

The Microgravity Science Glovebox (MSG), a Resource for Gravity-Dependent Phenomena Research on the International Space Station (ISS)

The Microgravity Science Glovebox (MSG) is a double rack facility aboard the International Space Station (ISS) designed for gravity-dependent phenomena investigation handling. The MSG has been operating in the ISS US Laboratory Module since July 2002. The MSG facility provides an enclosed working area for investigation manipulation and observation in the ISS. The MSG's unique design provides two levels of containment to protect the ISS crew from hazardous operations. Research investigations operating inside the MSG are provided a large 255 liter work volume, 1000 watts of dc power via a versatile supply interface (120,28, plus or minus 12, and 5 Vdc), 1000 watts of cooling capability, video and data recording and real time downlink, ground commanding capabilities, access to ISS Vacuum Exhaust' and Vacuum Resource 'Systems, and gaseous nitrogen supply. With these capabilities, the MSG is an ideal platform for research required to advance the technology readiness levels (TRL) needed for the Crew Exploration Vehicle and the Exploration Initiative. Areas of research that will benefit from investigations in the MSG include thermal management, fluid physics, spacecraft fire safety, materials science, combustion and reacting control systems, in situ fabrication and repair, and advanced life support technologies. This paper will provide a detailed explanation of the MSG facility, a synopsis of the research that has already been accomplished in the MSG, an overview of investigations planning to operate in the MSG, and possible augmentations that can be added to-the MSG facility to further enhance the resources provided to investigations.

Spivey, Reggie A.↗

Estimating Everglades Peat Reserves and Losses on a Landscape-Scale

The Florida Everglades formed from sawgrass and other aquatic plant remains that have accumulated over thousands of years and is a patterned peatland. The region was initially drained for agricultural and urban development in the late 1800s by the lowering of Lake Okeechobee water levels through canal drainage. Over the course of the past century, the Everglades has further been altered by the construction of canals and levees to provide control of Lake Okeechobee and Everglades water levels. The drainage has caused the loss of much of the peat of the Everglades by peat fires and microbial oxidation, much of it occurring between the 1880s and the 1950s. Plans for Everglades restoration are designed to provide additional water to flow through the remaining Everglades. Additional water into the Everglades would prevent further peat loss by reducing oxidation and encouraging the accretion of peat that has been lost. This potentially could result in the sequestration of significant quantities of atmospheric carbon. We used historic records to determine how much peat was there originally and how much has been lost. Over the past century and a half, approximately 50% of the original Everglades has been lost to agricultural and urban development. In addition, much of the peat in the remaining Everglades Protection Area has been lost. We used Geographic Information Systems technologies to determine the volume and mass of peat, the mass of carbon for each of the predrainage landscapes as well as the current Everglades regions. To do this, historical and current surveys within the Everglades were used to create elevation maps. With these maps, along with a bedrock contour map of south Florida, and soils data from the USEPA, we estimated Everglades peat characteristics. These calculations provide rough, quantitative estimates of the historical Everglades, its current condition, and the changes in the peat soil that have taken place since the 19th century. Given the uncertainties in the hindcasting of some of these data sets, this analysis provides rough estimates for the peat volumes and related constituents. Our calculations indicate that the current Everglades roughly contains less than 24% of theoriginal peat volume, 17% of its mass and 19% of its carbon. The work described was fully supported by the South Florida Water Management District, West Palm Beach, FL

Thomas Walter Dreschel↗

Sewage Treatment Plant #1 Area, SWMU 117 Per- and Polyfluoroalkyl Substances (PFAS) Site Assessment Progress Report

This Per- and Polyfluoroalkyl Substances (PFAS) Site Assessment (SA) Progress Report (SAPR) discusses the investigation activities and findings for the Sewage Treatment Plant #1 (STP1) Area located at Kennedy Space Center (KSC), Florida (Figure 1-1). This site has been designated Solid Waste Management Unit (SWMU) 117 under KSC’s Resource Conservation and Recovery Act (RCRA) Corrective Action Program, as the sewage treatment plant and associated areas were identified as a potential source of PFAS to the environment. This PFAS SAPR was prepared by Tetra Tech, Inc., for the National Aeronautics and Space Administration (NASA) under Indefinite Delivery Indefinite Quantity Contract 80KSC019D0011-80KSC019F0070. This is the first progress report to document on-going SA activities; supplemental progress reports will be provided as additional data is collected. PFAS SA activities were conducted between April 2020 and March 2022 to collect additional data to supplement the existing datasets to better understand the extent of PFAS impacts to the environment in the STP1 Area. The SA for the STP1 Area covers an approximately 130-acre investigation area with multiple structures and buildings. The focus of the SA is the STP1 Complex and associated structures, including the former Polishing Pond, former Sludge Disposal8 Area, and former Spray Field. The STP1 Complex is located in the KSC Industrial Area, at the southwest corner of 4th Street SE and C Avenue SE. The STP1 Complex is located approximately ¼-mile south and downgradient of the Fire Station #1 site (SWMU 116), which is also currently undergoing a PFAS SA because of potential releases of PFAS-containing aqueous film-forming foam (AFFF). During the SA, a total of seven soil, 131 groundwater direct push technology (DPT), 24 groundwater monitoring well, and 11 surface water samples were collected between April 2020 and March 2022. Monitoring well samples were analyzed for 18 PFAS compounds, with all other samples analyzed for 28 PFAS compounds. The SA sample results were used along with historical results to evaluate the extent of PFAS impacts to the environment in the STP1 Area. Data generated to date and prior results were screened against the United States Environmental Protection Agency (USEPA) May 2022 Tap Water Regional Screening Levels (RSL) for groundwater and residential RSLs for soil (hazard quotient of 0.1). Surface water results were screened against the State of Florida Human Health Surface Water Screening Levels (SWSLs). Results from the SA showed exceedances of the applicable screening criteria for groundwater and surface water. Considering the current and historical dataset, PFOS is the prevalent PFAS compound. Based on these results, additional groundwater DPT and surface water sampling should be considered for PFAS analysis, focused on evaluating surface water bodies in the southeast portion of the Industrial Area, which discharge into the Banana River. Additionally, installation of monitoring wells should be considered to evaluate the interaction between the groundwater and surface water at the site. Collection of additional samples for TOC analysis should also be considered from representative groundwater (saturated soils) and surface water locations to further evaluate potential correlations between PFAS and TOC to provide a more comprehensive dataset to assist in fate and transport analyses.

Sewage Treatment Plant↗

Safe Haven Configurations for Deep Space Transit Habitats

Throughout the human space flight program there have been instances where smoke, fire, and pressure loss have occurred onboard space vehicles, putting crews at risk for loss of mission and loss of life. In every instance the mission has been in Low-Earth-Orbit (LEO) with access to multiple volumes that could be used to quickly seal off the damaged module or escape vehicles for a quick return to Earth. For long duration space missions beyond LEO, including Mars transit missions of about 1000 days, the mass penalty for multiple volumes has been a concern as has operating in an environment where a quick return will not be possible. In 2016 a study was done to investigate a variety of dual pressure vessel configurations for habitats that could protect the crew from these hazards. It was found that for a modest increase in total mass it should be possible to provide significant protection for the crew. Several configurations were developed that either had a small safe haven to provide 30-days to recover, or a full duration safe haven using two equal size pressure vessel volumes. The 30-day safe haven was found to be the simplest, yielding the least total mass impact but still with some risk if recovery is not possible during that timeframe. The full duration safe haven was the most massive option but provided the most robust solution. This paper provides information on the various layouts considered in the study and provides a discussion of the findings for implementing a safe haven in future habitat designs.

Smitherman, David↗

Understanding What's Critical in Protecting Our Society: Can Satellite Observations Help?

There are many vital issues which are impacting our daily lives and will continue to haunt us as long as we live on this planet of ours. These issues range from food supply availability, drought, coastal zone erosion, volcanoes, hurricanes, terrorism, global warming, earthquakes, water resources, air quality, public health, and agriculture production. Such societal needs are directly linked to our geometric population growth, and abundance of automobiles, industrial emissions, industrial waste and extensive fishing of our oceans and elimination of our ecology. The questions which require serious thoughts, research, coordination, and resources to understand, plan and strike a sensible balance in our daily lives and the above issues are tough to deal with. However, with the advent of remote sensing technologies, tremendous progress has been made in applying space-based and airborne data and products in solving real societal problems. Several of these problems, such as coastal zone erosion, air quality, severe weather, water availability and quality, public health, fires, land slides and others are intricately related; and in the long run can have serious consequences if not properly addressed by scientists, regulatory bodies and policy makers. Although it is a much involved and tangled web to unravel, nevertheless we have an excellent start in understanding some of the phenomena and hopefully can mitigate some of the severe effects by advancing our scientific knowledge. This paper briefly discusses the applications of remote sensing data from Terra, Aqua, and other NASA satellites how to deal with such complex problems; it provides an excellent start.

Habib, Shahid↗

Safe Haven Configurations for Deep Space Transit Habitats

Throughout the human space flight program there have been instances where systems failures resulting in smoke, fire, and pressure loss have occurred onboard space vehicles, putting crews at risk for loss of mission and loss of life. In most instances the missions have been in Low-Earth-Orbit (LEO) or Earth-Moon vicinity, with access to multiple volumes that could be used to quickly seal off the damaged module or access escape vehicles for return to Earth. For long duration missions beyond LEO, including Mars transit missions of about 1100 days, the mass penalty for multiple volumes and operating in an environment where a quick return will not be possible have been concerns. In 2016, a study was done to investigate a variety of dual pressure vessel configurations for habitats that could protect the crew from these hazards. It was found that with a modest increase in total mass it should be possible to provide significant protection for the crew. Several configurations were considered that either had a small safe haven to provide 30-days to recover, or a full duration safe haven using two equal size pressure vessel volumes. The 30-day safe haven was found to be the simplest, yielding the least total mass impact but still with some risk if recovery is not possible during that timeframe. The full duration safe haven was the most massive option but provided the most robust solution. This paper provides information on the various layouts developed during the study and provides a discussion of the findings for implementing a safe haven in future habitat designs.

Smitherman, David↗

Overview of the Microgravity Science Glovebox (MSG) Facility and the Research Performed in the MSG

The Microgravity Science Glovebox (MSG) is a rack facility aboard the International Space Station (ISS) designed for investigation handling. The MSG was built by the European Space Agency (ESA) which also provides sustaining engineering support for the facility. The MSG has been operating on the ISS since July 2002 and is currently located in the US Laboratory Module. The unique design of the facility allows it to accommodate science and technology investigations in a "workbench" type environment. The facility has an enclosed working volume that is held at a negative pressure with respect to the crew living area. This allows the facility to provide two levels of containment for small parts, particulates, fluids, and gases. This containment approach protects the crew from possible hazardous operations that take place inside the MSG work volume. Research investigations operating inside the MSG are provided a large 255 liter enclosed work space, 1000 watts of direct current power via a versatile supply interface (120, 28, plus or minus 12, and 5 volts direct current), 1000 watts of cooling capability, video and data recording and real time downlink, ground commanding capabilities, access to ISS Vacuum Exhaust and Vacuum Resource Systems, and gaseous nitrogen supply. These capabilities make the MSG one of the most utilized facilities on ISS. The MSG has been used for over 27,000 hours of scientific payload operations. MSG investigations involve research in cryogenic fluid management, fluid physics, spacecraft fire safety, materials science, combustion, plant growth, biological studies and life support technology. The MSG facility is operated by the Payloads Operations Integration Center at Marshall Space Flight Center. Payloads may also operate remotely from different telescience centers located in the United States and Europe. The Investigative Payload Integration Manager (IPIM) is the focal to assist organizations that have payloads operating in the MSG facility. NASA provides an MSG engineering unit for payload developers to verify that their hardware is operating properly before actual operation on the ISS. This poster will provide an overview of the MSG facility, a synopsis of the research that has already been accomplished in the MSG, and an overview of video and biological upgrades. The author would like to acknowledge Teledyne Brown Engineering and the entire MSG Team for their inputs into this poster.

Jordan, Lee↗

Arizona Water Resources: Utilizing Aerial Imagery and NASA Earth Observations to Assess Pinyon-Juniper Tree Mortality in Flagstaff, AZ

Pinyon-juniper woodlands (PJW) are a vital habitat and food source for several wildlife species and a source of both utility and cultural importance for Indigenous groups. In 2021, amidst a decades-long drought, an extensive juniper mortality event occurred at Wupatki National Monument (WNM) in Arizona. In response, the National Park Service (NPS) is evaluating which land management practices will be beneficial. In partnership with the NPS, the NASA DEVELOP team used remote sensing data to map PJW mortality and analyze the relation of tree mortality to stand density, climate, and topography in north-central Arizona from 2015 to 2021. To identify the extent of PJW, the team performed an unsupervised classification using National Agricultural Imagery Program (NAIP) data with validation sources including NPS-created land cover maps, Landscape Fire and Resource Management Planning Tools (LANDFIRE), NPS and United States Forest Service (USFS) vegetation maps, and Landsat 8 Operational Land Imager (OLI) and Thermal Infrared Sensor (TIRS) data. Terra Moderate Resolution Imaging Spectroradiometer (MODIS), Global Precipitation Measurement (GPM) Integrated Multi-satellite Retrievals for GPM (IMERG), Soil Moisture Active Passive (SMAP), Shuttle Radar Topography Mission (SRTM), and Landsat 8-derived Normalized Difference Vegetation Index (NDVI) and Normalized Difference Moisture Index (NDMI) were used to analyze factors contributing to pinyon-juniper mortality. Although no relationships were found in the broader study region, PJW mortality was weakly correlated to elevation, soil moisture, and land surface temperature within WNM. Results from this study can inform NPS vegetation management that best protects natural and cultural resources.

Margaret Jaenicke↗

Consequences of impacts of small asteroids and comets with Earth

The fragmentation of a small asteroid in the atmosphere greatly increases its cross sections for aerodynamic braking and energy dissipation. At a typical impact velocity of 22 km/s, the atmosphere absorbs more than half the kinetic energy of stony meteoroids with diameters, D(sub m), less than 220 m and iron meteoroids with D(sub m) less than 80 m. The corresponding diameter for comets with impact velocity 50 km/s is D(sub m) less than 1600 m. Most of the atmospheric energy dissipation occurs in a fraction of a scale height, so large meteors appear to 'explode' or 'flare' at the end of their visible paths. This dissipation of energy in the atmosphere protects the earth from direct impact damage (e.g., craters), but it produces a blast wave that can do considerable damage. The area of destruction around the impact point in which the over-pressure in the blast wave exceeds 4 lb/sq in = 2.8 x 10(exp 5) dynes/cu cm, which is enough to knock over trees and destroy buildings, increases rapidly from zero for chondritic meteoroids less than 56 m in diameter (15 megatons) to about 200 sq km for those 80 m in diameter (48 megatons); the probable diameter of the tunguska impactor of 1908 is about 80 m. Crater formation and earthquakes are not significant in land impacts by stony asteroids less than about 200 m in diameter because of the air protection. A tsunami is probably the most devastating type of damage for asteroids 200 m to 1 km in diameter. An impact by an asteroid this size anywhere in the Atlantic would devastate coastal areas on both sides of the ocean. An asteroid a few kilometers across would produce a tsunami that would reach the foothills of the Appalachian Mountains in the upper half of the East Coast of the United States. Most of Florida is protected from a tsunami by the gradual slope of the ocean off its coast, which causes most of the tsunami energy to be reflected back into the Atlantic. The atmosphere plume produced by asteroids with diameters exceeding about 120 m cannot be contained by the atmosphere, so this bubble of high-temperature gas forms a new layer on top of the atmosphere. The dust entrapped in this hot gas is likely to have optical depths exceeding tau = 10 for asteroids with diameters exceeding about 0.5 to 1 km. The optical flux from asteroids 60 m or more in diameter is enough to ignite pine forests. However, the blast wave from an impacting asteroid goes beyond the radius in which the fire starts. The blast wave tends to blow out the fire, so it is likely that the impact will char the forest, as at Tunguska, but the impact will not produce a sustained fire. Because comets dissipate their energy much higher in the atmosphere than asteroids, they illuminate a much larger region and their blast wave is weaker. So they are much more effective in producing large fires. This suggests that the KT impactor was a comet rather than an asteroid.

Hills, J. G.↗

Two New Pieces of Emergency Response Equipment for use in Confined Space Environments

NASA is developing two new pieces of emergency response equipment that recognize and address the constraints of a confined space environment. One piece of equipment is a respirator designed for use in a post fire environment. Traditional first responders generally use supplied air respirators - they provide cool, dry, safe breathing air to the first responder, and because they are supplied at above ambient pressure, the system is tolerant to a loose-fitting mask. Supplied air respirators have a limited supply of air, but because the traditional first responder intends to address the emergency from outside and then retreat, this limited air supply does not pose a serious problem. NASA uses a supplied oxygen respirator for first response to an emergency affecting air quality on the International Space Station. The air supply is rated for 15 minutes - ISS program managers sponsored a hardware development activity to provide the astronauts up to 8 hours of breathing protection after the supplied air system is exhausted. Size and weight limitations prevent the use of a supplied air system for 8 hours for six crew members. A trade study resulted in the selection of a filtering respirator system over a re-breather system; due to design simplicity, operational simplicity, and likely threats to air quality on ISS. The respirator cartridge that filters smoke particles, adsorbs organics and acid gases, and catalytically converts carbon monoxide to carbon dioxide has been qualified for use on ISS, and was delivered on STS-135, the final mission of the Space Shuttle Program.

Graf, John↗

Fission gas trapped in Chornobyl fuel microparticles reveals details of reactor operations

The isotopic ratios of fission gas would provide important source information of a nuclear fuel sample found in the environment. However, it is believed that during a reactor accident like Chornobyl all fission gas is lost and that the radioactive particles found in the Chornobyl Exclusion Zone today are depleted in gases by the initial explosion and subsequent fire. We disprove this hypothesis by detection and analysis of trapped krypton and xenon in these particles. Our analysis of krypton and xenon isotopes by noble gas mass spectroscopy in combination with resonance ionization mass spectrometry establishes that important information about reactor operations like age, neutron flux and plutonium fission fraction can still be reconstructed from individual micrometer-sized particles even after decades of weathering in the environment.

Chornobyl↗

Technical Evaluation Motor no. 5 (TEM-5)

Technical Evaluation Motor No. 5 (TEM-5) was static test fired at the Thiokol Corporation Static Test Bay T-97. TEM-5 was a full scale, full duration static test fire of a high performance motor (HPM) configuration solid rocket motor (SRM). The primary purpose of TEM static tests is to recover SRM case and nozzle hardware for use in the redesigned solid rocket motor (RSRM) flight program. Inspection and instrumentation data indicate that the TEM-5 static test firing was successful. The ambient temperature during the test was 41 F and the propellant mean bulk temperature (PMBT) was 72 F. Ballistics performance values were within the specified requirements. The overall performance of the TEM-5 components and test equipment was nominal. Dissembly inspection revealed that joint putty was in contact with the inner groove of the inner primary seal of the ignitor adapter-to-forward dome (inner) joint gasket; this condition had not occurred on any previous static test motor or flight RSRM. While no qualification issues were addressed on TEM-5, two significant component changes were evaluated. Those changes were a new vented assembly process for the case-to-nozzle joint and the installation of two redesigned field joint protection systems. Performance of the vented case-to-nozzle joint assembly was successful, and the assembly/performance differences between the two field joint protection system (FJPS) configurations were compared.

Cook, M.↗

Informing Dionaea muscipula (Venus Flytrap) Conservation Through Habitat Modeling and Forecasted Land Cover Change

The carnivorous Dionaea muscipula (Venus flytrap, Droseraceae) is threatened by habitat loss, fire suppression, and poaching. For rare plant species like D. muscipula with specialized habitat requirements and fragmented distribution, habitat suitability modeling is an important method for guiding conservation efforts. To support the D. muscipula conservation, this study: 1) modeled suitable habitat across the extent of the species’ known range and 2) forecasted land cover change due to development in the study area to the year 2050. Habitat modeling was conducted by overlaying high-confidence presence data observed since 1980 (n=292) with environmental predictor variables (n=23). Suitable habitats were then compared with land cover change to identify areas at risk of habitat loss due to human development. According to those models, nearly half (107.1km2) of modeled highly suitable D. muscipula habitat outside of protected lands are likely to face development pressure. On the other hand, 39.4% (139.9km2) of highly suitable habitats overlap with protected lands and may serve as lasting D. muscipula habitat. Results from this study can inform D. muscipula conservation, including targeted seed banking of populations at risk of extirpation, prioritization of habitats for protection and management, and reintroduction to suitable habitats within protected areas.

Kathryn Caruso↗

South Africa National Cooling Plan

South Africa is committed to preserving the environment and addressing climate change related issues based on science and equity. In 2019, South Africa ratified the Kigali Amendment to the Montreal Protocol to reduce the consumption and production of hydrofluorocarbons (HFCs) to simultaneously protect the ozone layer and contribute to mitigating climate change. In 2015, South Africa also signed the United Nations Framework Convention on Climate Change (UNFCCC) Paris Agreement to fight against climate change and committed to achieve a “peak, plateau and decline” greenhouse gas (GHG) trajectory at a level between 398 and 614 MtCO2e/year by 20301. In 2021 revised target ranges of 398-510 Mt CO 2 -eq for 2025, and 398-440 Mt CO 2 -eq for 2030 were issued, as well as aspiring to reach a net zero carbon economy by 2050. Addressing the environmental impacts of cooling products converges the objectives of these two treaties. Cooling products are the main source of HFC use and they consume a significant amount of electricity produced from emission intensive coal fired power plants. South Africa’s efforts to mitigate global warming can therefore be amplified if the energy efficiency (EE) of cooling products is improved at the same time a refrigerant transition from HFC is considered. Synergistic actions with respect to sustainable cooling access across sectors will have a higher impact than actions taken in isolation.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Low NO subx heavy fuel combustor concept program. Phase 1A: Coal gas addendum

The performance and emissions from a rich-lean combustor fired on simulated coal gas fuels were investigated using a 12.7-cm diameter axially-staged burner originally designed for operation with high heating value liquid fuels. A simple, tubular fuel injector was substituted for the liquid fuel nozzle; no other combustor modifications were made. Four test fuels were studied including three chemically bound nitrogen-free gas mixtures with higher heating values of 88, 227, and 308 kj/mol (103, 258 and 349 Btu/scf), and a 227 kj/mol (258 Btu/scf) heating value doped with ammonia to produce a fuel nitrogen content of 0.5% (wt). Stable, ultra-low nitrogen oxide, smoke-free combustion was attained for the nitrogen-free fuels. Results with the doped fuel indicated that less than 5% conversion of NH3 to nitrogen oxide levels below Environmental Protection Agency limits could be achieved. In some instances, excessive CO levels were encountered. It is shown that use of a burner design employing a less fuel-rich primary zone than that found optimum for liquid fuels would yield more acceptable CO emissions.

Rosfjord, T.↗