Launch Pad Closeout Operations for the Mars Science Laboratory's Heat Rejection System
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Multi-Mission Radioisotope Thermoelectric Generato↗
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Results for “Heating systems”
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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Initial operation of high power ICRF system for long pulse in EAST
The ICRF heating system on EAST upgraded by active cooling aims for long pulse operation. In this paper, the main technical features of the ICRF system are described. One of a major challenges for long pulse operation is RF-edge interactions induced impurity production and heat loading. In EAST, ICRF antenna protections and Faraday screen bars damaged due to LH electron beam are found. Preliminary results for the analysis of the interaction between LHCD and ICRF antenna are discussed. Increase of metal impurities in the plasma during RF pulse and in a larger core radiation are also shown. These RF-edge interactions at EAST and some preliminary results for the optimizing RF performance will be presented.
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
Thermal management of instruments on space platforms using a high capacity two-phase heat transport system
A system utilizing a pumped, two-phase single component working fluid for heat exchange and transport services necessary to meet the temperature control requirements of typical orbiting instrument payloads on space platforms is described. The design characteristics of the system is presented, together with a presentation of a laboratory apparatus for demonstration of proof of concept. Results indicate that the pumped two-phase design concept can meet a wide range of thermal performance requirements with the only penalty being the requirement for a small liquid pump.
Ollendorf, S.↗
Advanced, Low-Cost Indoor Heat Exchanger for Geothermal Heat Pump Systems
Explore the source record for details and available documents.
15 GEOTHERMAL ENERGY↗
In Hot Water! The Challenges and Barriers of Decarbonizing Water Heating in Multifamily Buildings: Preprint
Domestic hot water heating is responsible for 32% of the total energy consumption in multifamily buildings and offers a significant decarbonization opportunity. An extensive market assessment was conducted to understand and document key technical and economic barriers to electrification of domestic water heating in multifamily buildings throughout the U.S. Through the program, 77 interviews were conducted to understand key market drivers and technical challenges associated with electrification of water heating systems in both retrofit and new construction scenarios. Interviewees encompassed a wide range of stakeholders in the ecosystem surrounding water heating systems, including suppliers, manufacturers, designers, owners, utilities, and developers. This paper documents key interview takeaways, including an extensive list of market barriers, technical challenges, and sought-after technology attributes that can inform pertinent design criteria for electric water heating research, development, and deployment efforts. Among economics and energy efficiency features, interviewees overwhelmingly alluded to space constraints, cold air exhaust, and lack of clear guidance regarding distributed versus centralized design selections as key challenges associated with mass adoption of electric water heating. Owners and developers seek systems with minimal footprint, which maximize rentable space and profits. Moreover, distributed heat pump solutions should balance ducting costs that mitigate cold exhaust entrainment into conditioned zones. Lastly, the market needs clear guidance regarding the selection of distributed versus central electric hot water systems.
challenges of water heating electrification↗
Field Validation of Air-Source Heat Pumps for Cold Climates
Heating energy is the largest end-use for U.S. residential buildings accounting for approximately one-third of residential building energy consumption (EIA 2021). Historically, air-source heat pumps have been limited to temperate climates because of subpar performance at extremely cold outdoor air temperatures. However, recent advances to cold-climate air-source heat pump technology, which typically rely on inverter-driven, variable-speed compressors and variable-speed fans, have significantly improved low-temperature heat pump performance enabling the technology to save energy for many homes in cold climates. The primary objective of this project was to measure in-field performance of centrally ducted, variable-capacity air-source heat pumps in cold climates to validate performance and develop field-based performance maps. The project focused on quantifying heat pump performance at cold temperatures. The sites identified for the study were primarily located in the Northwest United States since homes in the region tend to have all-electric space heating systems and high-efficiency heat pumps have been incentivized in the region for several years. NREL partnered with Ecotope, Inc., a small energy consulting firm located in Seattle, WA, for site recruitment, monitoring equipment installation, data quality management. All the sites included in the study had previously installed a high-efficiency, central heat pump system. One site was in a Denver, CO suburb, which was the only dual fuel heat pump in the study. We used airside and power measurements, collected at 5-second intervals, to quantify heat pump capacity, coefficient of performance (COP), and auxiliary heater energy consumption. We developed algorithms to automatically determine the heat pump operating mode including defrost and auxiliary heating operation. A whole-house thermal and duct audit was completed during the initial site visit to estimate winter heating loads and assess heat pump sizing. Whole-home heating design loads were calculated at ASHRAE 99% design temperatures and compared to manufacturer-reported maximum capacities to assess the heat pump sizing at each site.
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
Optimization of System Operating Parameters for Heat Sterilizable Liquid Propulsion Systems
Operating parameters of liquid propulsion systems capable of being heat sterilized in loaded condition without venting
LIQUID PROPELLANT↗
Molten Salt Reactor Passive Heat Removal System Modeling
The direct reactor auxiliary cooling system is a very robust, passive safety system that is designed to remove up to 2.36 MW of heat from the reactor during accident conditions. This report details a variety of DRACS degradation conditions and their effect on the safety of the reactor. This preliminary investigation shows that only two of the three DRACS loops are necessary to quickly suppress the decay heat produced by a newly shut down reactor. Even with a single DRACS loop operational, the maximum salt temperature observed was far below the safety specification of the plant (1173 K). When investigating the degraded performance of each DRACS loop, the short-term maximum salt temperature observed was strongly dependent on the DHX performance but was unaffected by the TCHX performance. However, even a heavily degraded DHX heat transfer performance was sufficient to halt the rising salt temperature due to decay heat. Further investigation should be done to characterize the effects of TCHX performance degradation at longer time scales. High levels of TCHX degradation were shown to lead to a reactor salt temperature minimum after a few hours of operation followed by a steady increase in temperature. With reduced ability to exhaust heat to the environment, it is possible the DRACS would be unable to maintain cooling during a long loss of active cooling event.
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
Geothermal Heat Pump System for New Student Housing Project at the University at Albany Main Campus
University at Albany successfully designed, constructed and is operating a new student housing building that utilizes ground source heat pump (GSHP) for heating and cooling the entire 191,500SF building. The installed system consists of a well field with 150 bores, 450 feet deep and (189) terminal heat pump units for a total capacity of 358 Tons cooling and 4,300 MBtu/h heating. The building opened in Fall 2012. The annual energy use and cost intensity of the building, after the changes made during the first 2 years’ of operation is 57kBtu/SF/Year and $1.30/SF/Year respectively. This is approximately 50% lower than the other residential quads on campus, despite the fact that the quads are not air-conditioned. The total project cost from design through 3-years of operations is approximately $6 Million, out of which $5.7 Million is for construction of the GSHP system including the well field. The University received a $2.78 Million grant from the Department of Energy. The estimated utility cost savings, compared to a baseline building with conventional HVAC system, is approximately $185,000. The estimated simple payback, after grant incentives, is 15 years. Additionally, the project has created 8.5FTE equivalent jobs.
15 GEOTHERMAL ENERGY↗
Integrated Thermal Protection Systems and Heat Resistant Structures
In the early stages of NASA's Exploration Initiative, Snecma Propulsion Solide was funded under the Exploration Systems Research & Technology program to develop a CMC heatshield, a deployable decelerator, and an ablative heat shield for reentry vehicles. Due to changes within NASA's Exploration Initiative, this task was cancelled in early FY06. This paper will give an overview of the work that was accomplished prior to cancellation. The Snecma team consisted of MT Aerospace, Germany, and Materials Research & Design (MR&D), NASA Langley, NASA Dryden, and NASA Ames in the United States. An Apollo-type capsule was chosen as the reference vehicle for the work. NASA Langley generated the trajectory and aerothermal loads. Snecma and MT Aerospace began the design of a ceramic aft heatshield (CAS) utilizing C/SiC panels as the capsule heatshield. MR&D led the design of a C/SiC deployable decelerator, NASA Ames led the characterization of several ablators, NASA Dryden led the development of a heath management system and the high temperature structures testing, and NASA Langley led the insulation characterization. Though the task was pre-maturely cancelled, a significant quantity of work was accomplished.
Pichon, Thierry↗
Recent advance progress of HL-3 experiments
Since the first plasma realized in 2020, a series of key systems on HL-3 (known as HL-2M before) tokamak have been equipped/upgraded, including in-vessel components (the first wall, lower divertor, and toroidal cryogenic/water-cooling/baking/glow discharge systems, etc.), auxiliary heating system of 11 MW, and 28 diagnostic systems (to measure the plasma density, electron temperature, radiation, magnetic field, etc.). Magnet field systems were commissioned firstly for divertor plasma discharges. During the 2nd experimental campaign of HL-3 tokamak, several great progresses have been achieved. Firstly, the successful operation with plasma current larger than 1 MA was achieved under a divertor configuration. Secondly, the advanced divertor concept with two distinct snowflake configurations was realized. It is found that the distribution of ion saturation current and heat flux on bottom plate becomes wide due to magnetic surface expansion, demonstrating the advantage of such configuration in the heat flux mitigation. In addition, using the combination of NBI, ECRH and LHCD, the standard sawtoothing high confinement mode of megampere plasma was firstly accessed on the HL-3. The successful commissioning of HL-3 is beneficial for the initial operation of ITER.
1 MA plasma↗
Method for controlling exhaust gas heat recovery systems in vehicles
A method of operating a vehicle including an engine, a transmission, an exhaust gas heat recovery (EGHR) heat exchanger, and an oil-to-water heat exchanger providing selective heat-exchange communication between the engine and transmission. The method includes controlling a two-way valve, which is configured to be set to one of an engine position and a transmission position. The engine position allows heat-exchange communication between the EGHR heat exchanger and the engine, but does not allow heat-exchange communication between the EGHR heat exchanger and the oil-to-water heat exchanger. The transmission position allows heat-exchange communication between the EGHR heat exchanger, the oil-to-water heat exchanger, and the engine. The method also includes monitoring an ambient air temperature and comparing the monitored ambient air temperature to a predetermined cold ambient temperature. If the monitored ambient air temperature is greater than the predetermined cold ambient temperature, the two-way valve is set to the transmission position.
33 ADVANCED PROPULSION SYSTEMS↗
Space shuttle/food system study. Volume 1: Technical volume, oven study
The baseline space shuttle galley was designed to utilize lightweight rehydratable foods, to be prepared for consumption by rehydration with chilled or hot water. The impact is examined of an extension of food types to include thermostabilized food, at ambient temperature, and frozen foods on the baseline design of the shuttle galley. Weight, volume, and power penalities associated with heating thermostabilized and frozen foods by means of a hot air convection heating system and a conduction heating system are determined along with the impact on crew/galley interface and meal preparation.
Source record↗
Hydrodynamic behavior of wrapped coil water heater tank
In this work, a numerical investigation using computational fluid dynamics (CFD) has been carried out to analyze the thermal behavior of a water tank integrated to a heat pump water heating system (HPWH). The heat pump condenser is a long coil wrapped around the water tank and insulated from outside from which heat is transferred from the heat pump cycle into the water stored inside the tank. The simulated water tank has a capacity of about 170 L with the charging inlet located at the bottom segment of the tank and the discharging outlet located at the top segment of the tank like commercially available water heaters. The tank was simulated during charging/discharging process with isothermal boundary condition at the tank wall to represent the majority of the process for refrigerant condensation inside the heat pump condenser (excluding superheated and sub-cooled section). Three flow rates were selected to represent low, medium and high flow pattern. Both mean and turbulent flow properties were calculated and analyzed. Heat transfer mechanisms inside the tank are quantified by calculating Richardson and Péclet numbers to show the relative contribution of driving forces. The calculations show that advection is dominant over diffusion. Mixing factor is calculated and presented. It is found that the rate of increase of mixing is nonlinear with the increase in flow rate. Mixing increased by a factor of four when the flow rate increased by a factor of two.
stratification↗
Characterization of Energy Savings and Thermal Comfort Improvements Derived from Using Interior Storm Windows
This field study of a single historic home in Seattle, WA documents the performance of Indow ® Windows’s interior storm window inserts. Energy use and the temperature profile of the house were monitored before and after the installation of the window inserts and changes in the two recorded metrics were examined. Using the defined analysis approach, it was determined that the interior storm windows produced a 22% reduction of the HVAC energy bill and had an undetermined effect on the thermal comfort in the house. Although there was no measurable changes in the thermal comfort of the house, the occupant noted the house to be “warmer in the winter and cooler in the summer” and that the “temperatures are more even (throughout the house).” The interior storm windows were found to be not cost effective, largely due to the retrofits completed on its heating system. However, if the economic analysis was conducted based on the old heating system, a 72% efficient oil fired furnace, the Indow Windows proved to be economical and had a simple payback period of 9.0 years.
high performance housing↗
Ice Prevention on Aircraft by Means of Engine Exhaust Heat and a Technical Study of Heat Transmission from a Clark Y Airfoil
This investigation was conducted to study the practicability of employing heat as a means of preventing the formation of ice on airplane wings. The report relates essentially to technical problems regarding the extraction of heat from the exhaust gases and its proper distribution over the exposed surfaces. In this connection a separate study has been made to determine the variation of the coefficient of heat transmission along the chord of a Clark Y airfoil. Experiments on ice prevention both in the laboratory and in flight show conclusively that it is necessary to heat only the front portion of the wing surface to effect complete prevention. Experiments in flight show that a vapor-heating system which extracts heat from the exhaust and distributes it to the wings is an entirely practical and efficient method for preventing ice formation.
Theodorsen, Theodore↗
Solar Collectors
Solar Energy's solar panels are collectors for a solar energy system which provides heating for a drive-in bank in Akron, OH. Collectors were designed and manufactured by Solar Energy Products, a firm established by three former NASA employees. Company President, Frank Rom, an example of a personnel-type technology transfer, was a Research Director at Lewis Research Center, which conducts extensive solar heating and cooling research, including development and testing of high-efficiency flat-plate collectors. Rom acquired solar energy expertise which helped the company develop two types of collectors, one for use in domestic/commercial heating systems and the other for drying grain.
Source record↗
Challenges of Cold Conditioning and Static Testing the Second Ares Demonstration Motor (DM-2)
On August 31, 2010, a five-segment demonstration motor (DM) for the Ares program was successfully tested. A series of demonstration motors (DMs) will be tested in different conditioned environments to confirm they meet their design specifications. The second demonstration motor (DM-2) was the first cold motor. The motor needed to be subjected to sub-freezing temperatures for two months so that its internal propellant mean bulk temperature (PMBT) was approximately 40 F. Several challenges had to be overcome to make this a successful test. One challenge was to condition four field joints to get the O-rings approximately 32 F. This would be done by applying conditioning shrouds to externally cool each field joint after the test bay was pulled off. The purpose of this conditioning was to validate the new O-ring design and allow joint heaters to be eliminated. Another challenge was maintaining temperature requirements for components in the nozzle vectoring system. A separate heating system was used to warm these components during cold conditioning. There were 53 test objectives that required 764 channels of data to be recorded; 460 were specific to DM-2. This instrumentation had to be installed prior to conditioning, which meant the baseline process and timeline had to be modified to meet this time critical schedule.
Quinn, Shyla↗