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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 127 records · Page 7

All sources NASA NTRS DOE OSTI

NASA NTRS1991

Development of a nonazeotropic heat pump for crew hygiene water heating

A heat pump system is currently under development to produce hot water for crew hygiene on future manned space missions. The heat pump uses waste heat sources and a nonazeotropic working fluid in a highly efficient cycle. The potential benefits include a reduction in peak power draw from 2 to 5 kW for electric cartridge heaters to just more than 100 W for the heat pump. As part of the heat pump development project, a unique high efficiency compressor was developed to maintain lubrication in a zero-gravity environment.

Walker, David H.↗

NASA NTRS2001

Spacecraft Thermal Control

Thermal control of the spacecraft is typically achieved by removing heat from the spacecraft parts that tend to overheat and adding heat to the parts that tend get too cold. The equipment on the spacecraft can get very hot if it is exposed to the sun or have internal heat generation. The pans also can get very cold if they are exposed to the cold of deep space. The spacecraft and instruments must be designed to achieve proper thermal balance. The combination of the spacecraft's external thermal environment, its internal heat generation (i.e., waste heat from the operation of electrical equipment), and radiative heat rejection will determine this thermal balance. It should also be noted that this is seldom a static situation, external environmental influences and internal heat generation are normally dynamic variables which change with time. Topics discussed include thermal control system components, spacecraft mission categories, spacecraft thermal requirements, space thermal environments, thermal control hardware, launch and flight operations, advanced technologies for future spacecraft,

Birur, Gajanana C.↗

NASA NTRS1991

Concentric Regenerative Sorption Compressor

Proposed sorption compressor for cryogenic system features four sorption units. Concentric sorption units alternately connected and disconnected via timed gas-gap thermal switches. During given half cycle, one of C/Kr sorption units operates on waste heat from one of PCO sorption units, which in turn operates partially on waste heat from other PCO sorption unit. Required power equals that of mechanical compressor. Vibrates less, and more reliable because it contains only few moving parts actuated relatively infrequently.

Jones, Jack A.↗

NASA NTRSDate not supplied

Use of a Dynamic Radioisotope Power Source for a Long Duration Lunar Science Rover

The Radioisotope Power Systems (RPS) Program tasked the Compass Team to evaluate use of Dynamic Radioisotope Power Sources (DRPS) for lunar science rovers. The object was to identify their advantages and challenges as well as to influence the technology developments with flight-type requirements. This was done by using the promising Volatiles Investigating Polar Exploration Rover (VIPER) solar-powered rover mission as a platform to ‘swap in’ a DRPS. The resulting design used a ‘pickup truck bed’ approach which allowed simplified installation and operation of the DRPS while also keeping the forward lunar surface ‘blocked’ from the DRPS waste heat, which could sublimate the icy surface. It was found that with the Stirling DRPS option the mass is within the planned VIPER lander capability and is comparable to VIPER mass and size (the DRPS replaces large battery pack/solar arrays). The Stirling DRPS option produced ~300 Watts electrical (We) using six general purpose heat source (GPHS) bricks and eight Stirling convertors. Replacing the solar/battery power with radioisotope power allows a continuous presence (instead of six hours) in a permanently shadowed region (PSR) and over 18 months of operations with minimal science impact (rearward surface heating). It was also found that use of a dynamic system, instead of a thermoelectric system, reduces the heat impact on the science environment two-to-three times while still providing sufficient waste heat for the rover systems in the PSR (~ -200°C). The DRPS, along with a relay link (like Gateway), can provide extended access to PSR. The system was also found to be capable of roving for eight hours per day with a range of well over 100 km in 18 months.

Radioisotope Power↗

NASA NTRS1983

Thermal control - Heat buses will operate like a public utility

Active thermal control for the NASA space station concept requires long life heat rejection, highly versatile thermal transport, and efficient system integration. By a significant margin, the heat radiator will be the largest and most exposed portion of the space station thermal system. Transport requirements encompass the collection and movement of thermal energy from the space station's heat sources to the radiator heat sink at required temperature levels. In a decentralized thermal system, each space station module would collect and reject all of the waste heat generated, thereby requiring no module interconnections. This scheme does not, however, allow waste heat from one module to be used by another. In a centralized system, heat must be transported across module boundaries. A high capacity monogroove heat pipe has been developed to simplify space radiators design and operation.

Ellis, W. E.↗

DOE OSTI2026

Advancing hydrogen production: A comprehensive review of wastewater reforming techniques, feedstocks, and opportunities

Wastewater is produced across nearly all human activities and requires treatment to safeguard human health and the natural environment. Treatment of wastewater often requires a large amount of thermal energy, resulting in wasted heat after the treatment process. Because hydrocarbon reforming needs both water and heat, the integration of wastewater treatment with hydrocarbon reforming, a process that produces synthesis gas rich in hydrogen, offers an excellent opportunity to utilize this waste heat and the impurities in wastewater to produce valuable hydrogen gas, to minimize waste from industrial processes, and to integrate water treatment with the hydrogen economy. Yet, no comprehensive literature review has been conducted to examine the integration of reforming and wastewater. To address this lack, we summarize the variety of catalytic reforming techniques available in the open literature and review the current literature on wastewater reforming with these techniques. Subsequently, we conduct a review of common types of wastewater contaminants and their possible effects on reforming catalyst performance and life. Lastly, three underexamined wastewater sources are identified, namely, oilfield wastewater, geothermal water, and mining and mineral processing wastewater, and their potential for future study as a reforming feedstock is examined.

08 HYDROGEN↗

NASA NTRS2020

Advanced Modular Power System Fully Populated Electronics Enclosure Thermal Testing

A thermal test of an enclosure housing the AMPS electronics cards was performed. The enclosure was fully populated with 17 nonfunctioning AMPS electronics cards. Heaters were applied to the cards to simulate their operation. A cold plate was installed on the top of the case. The case was then insulated to simulate its installation within an electronics rack with the face and rear of the enclosure left open. The cold plate was connected to a chiller which provided cooling water at a fixed input temperature to the cold plate. Flow rates from the chiller of 0.0 L/min, 1.4 L/min and 1.8 L/min were tested. The test was operated at each flow rate over a range of heater power levels until the steady state temperature of the electronics cards was reached. Heater power levels from 2.5 W/card to 45 W/card were tested. The data collected was used to determine the steady state operating temperature of the cards, the temperature distribution between the cards, the time to reach steady-state temperature, the change in steady state temperature with change in heater power, the temperature distribution between the cards at the steady state condition and the heat lost to the surrounds by the enclosure. One of the main goals of the testing was to determine how much waste heat the cards could generate and still maintain a touch temperature at or below 40°C. Based on this requirement, for the 3 cooling rates tested, the maximum card waste heat that could be generated by each individual card was 3.9 W, 16.3 W and 17.6 W respectively. An analysis was also set up to provide an analytical model to estimate the card temperature under different cold plate flow rates and card heater power levels. The results off the analysis was compared to that of the experiment of the range of flow rates and power levels tested.

Anthony Colozza↗

NASA NTRS1989

The Space Station active thermal control technical challenge

The overall conceptual design premise of the two major subsystems that make up the Space Station active thermal control system is discussed. Specifically, the thermal loop required to gather and collect the waste heat from the various systems, modules, and payloads of the Space Station and the large radiators necessary to dissipate the waste heat to space are described. The basic design concepts to be incorporated in the Space Station are described, and the ground and flight tests conducted to date to prove the feasibility of the design approaches are summarized. Future Space Shuttle flight tests planned to further verify the designs are outlined.

Ellis, W. E.↗

DOE OSTI2026

Application of Ibuprofen Sodium Dihydrate for Thermochemical Energy Storage

Thermochemical energy storage (TCES) offers a transformative approach to address grid instability by harnessing reversible chemical reactions for efficient heat storage and release. Here, we introduce pharmaceutical organic salt hydrates as a class of materials with exceptional performance for low-grade waste heat recovery. We demonstrate ibuprofen sodium dihydrate (ISD) as an example organic hydrate exhibiting a dehydration temperature range of 60-110 °C and a remarkable dehydration enthalpy of up to 59.5 kJ/mol of water, ideally suited for capturing industrial and residential waste heat. Using rigorous multimodal characterization, including thermogravimetric analysis, differential scanning calorimetry, in-situ FTIR, in-situ PXRD, and NMR, we demonstrate ISD's superior thermal, chemical, and structural stability over 150 hydration-dehydration cycles, achieving an unprecedented cycling efficiency of ~99.9%. Compared to conventional inorganic salt hydrates like strontium chloride hexahydrate and calcium oxalate monohydrate, ISD showcases enhanced durability without deliquescence or pulverization, even under high-humidity conditions. In-situ analyses confirm the transition from ISD to ibuprofen sodium anhydrous (ISA) proceeds with structural reorganization, thereby combining the dehydration mechanism with phase transitions, resulting in higher energy storage capacity. Microstructural analyses reveal that repeated water intercalation and structural transitions aid in creating significant porosity that enhances water transport kinetics, further improving the hydration/dehydration performance. By combining the phase change and chemical dehydration mechanisms, ISD paves the way for designing a new class of organic salt hydrates, offering tunable properties to meet diverse thermal energy storage demands and supporting sustainable grid resilience.

Thangaraj, Kavin C.↗

DOE OSTI2024

An Advanced Cooling Device for Concentrated Photovoltaic Systems

Concentrated photovoltaics (CPV) have the potential to significantly enhance the energy conversion utilization of solar panels and reduce solar generation costs, making them a crucial area of advancement in solar power generation technology. However, the concentration of sunlight can lead to overheating of solar panels, resulting in a notable reduction in both the efficiency of solar power generation and the lifespan of the panels. This challenge remains the predominant technical hurdle that hinders the application of concentrated photovoltaic power generation technology. In this study, we propose a new cooling method for concentrated photovoltaic power generation systems via an integrated approach of incorporating Phase-Change Thermal Storage (PCTS) and Thermoelectric Generator (TEG) technology. This new method not only enhances the overall system's electricity generation efficiency but also effectively resolves the technical challenge of concentrated photovoltaic panel overheating issues, ensuring the continuity of concentrated photovoltaic power generation and extending the lifespan of solar panels and their components. In order to make full use of the wasted heat generated by photovoltaic power generation and effectively improve the power generation efficiency of the system, this work developed a phase change heat storage device based on a phase change material. This device uses the temperature difference between day and night to recover wasted heat from photovoltaic power generation. Through integration with the thermoelectric power generation system, thermal energy can be converted into electrical energy. In addition, the Peltier effect of thermoelectric materials is used to construct a photovoltaic panel overheating protection system, which significantly improves the reliability and service life of the system.

14 SOLAR ENERGY↗

NASA NTRS1987

Comparison of open and closed multimegawatt space power systems

One of the major questions that is being addressed at present by SDI Multimegawatt Space Power Project is whether or not space weapon power systems must be closed, i.e., whether effluents from the systems are tolerable. If they are not tolerable, the major penalty that must be paid to close space systems is increased mass. Open systems remove waste heat by producing effluents, e.g., hot hydrogen gas. Closed systems require radiators, thermal storage masses, effluent storage, or refrigeration to remove waste heat. The mass penalty incurred by addition of these devices is so severe that the option of closing space power systems should be avoided if at all possible. The mass penalty is even more severe if the weapon system itself must also be closed.

Gallup, D. R.↗

NASA NTRS2013

Spacecraft Crew Cabin Condensation Control

A report discusses a new technique to prevent condensation on the cabin walls of manned spacecraft exposed to the cold environment of space, as such condensation could lead to free water in the cabin. This could facilitate the growth of mold and bacteria, and could lead to oxidation and weakening of the cabin wall. This condensation control technique employs a passive method that uses spacecraft waste heat as the primary wallheating mechanism. A network of heat pipes is bonded to the crew cabin pressure vessel, as well as the pipes to each other, in order to provide for efficient heat transfer to the cabin walls and from one heat pipe to another. When properly sized, the heat-pipe network can maintain the crew cabin walls at a nearly uniform temperature. It can also accept and distribute spacecraft waste heat to maintain the pressure vessel above dew point.

Carrillo, Laurie Y.↗

DOE OSTI2024

An Advanced Cooling Device for Concentrated Photovoltaic Systems

Gou, Yimeng↗

NASA NTRS2013

Performance of the Mechanically Pumped Fluid Loop Rover Heat Rejection System Used for Thermal Control of the Mars Science Laboratory Curiosity Rover on the Surface of Mars

The challenging range of landing sites for which the Mars Science Laboratory Rover was designed, required a rover thermal management system that is capable of keeping temperatures controlled across a wide variety of environmental conditions. On the Martian surface where temperatures can be as cold as -123 C and as warm as 38 C, the Rover relies upon a Mechanically Pumped Fluid Loop (MPFL) Rover Heat Rejection System (RHRS) and external radiators to maintain the temperature of sensitive electronics and science instruments within a -40 C to +50 C range. The RHRS harnesses some of the waste heat generated from the Rover power source, known as the Multi Mission Radioisotope Thermoelectric Generator (MMRTG), for use as survival heat for the rover during cold conditions. The MMRTG produces 110 Watts of electrical power while generating waste heat equivalent to approximately 2000 Watts. Heat exchanger plates (hot plates) positioned close to the MMRTG pick up this survival heat from it by radiative heat transfer and supply it to the rover. This design is the first instance of use of a RHRS for thermal control of a rover or lander on the surface of a planet. After an extremely successful landing on Mars (August 5), the rover and the RHRS have performed flawlessly for close to an earth year (half the nominal mission life). This paper will share the performance of the RHRS on the Martian surface as well as compare it to its predictions.

Mars↗

NASA NTRS2013

CFD Analysis for Assessing the Effect of Wind on the Thermal Control of the Mars Science Laboratory Curiosity Rover

The challenging range of landing sites for which the Mars Science Laboratory Rover was designed, requires a rover thermal management system that is capable of keeping temperatures controlled across a wide variety of environmental conditions. On the Martian surface where temperatures can be as cold as -123 C and as warm as 38 C, the rover relies upon a Mechanically Pumped Fluid Loop (MPFL) Rover Heat Rejection System (RHRS) and external radiators to maintain the temperature of sensitive electronics and science instruments within a -40 C to 50 C range. The RHRS harnesses some of the waste heat generated from the rover power source, known as the Multi Mission Radioisotope Thermoelectric Generator (MMRTG), for use as survival heat for the rover during cold conditions. The MMRTG produces 110 W of electrical power while generating waste heat equivalent to approximately 2000 W. Heat exchanger plates (hot plates) positioned close to the MMRTG pick up this survival heat from it by radiative heat transfer. Winds on Mars can be as fast as 15 m/s for extended periods. They can lead to significant heat loss from the MMRTG and the hot plates due to convective heat pick up from these surfaces. Estimation of this convective heat loss cannot be accurately and adequately achieved by simple textbook based calculations because of the very complicated flow fields around these surfaces, which are a function of wind direction and speed. Accurate calculations necessitated the employment of sophisticated Computational Fluid Dynamics (CFD) computer codes. This paper describes the methodology and results of these CFD calculations. Additionally, these results are compared to simple textbook based calculations that served as benchmarks and sanity checks for them. And finally, the overall RHRS system performance predictions will be shared to show how these results affected the overall rover thermal performance.

wind↗

DOE OSTI2024

Geospatial characterization of low-temperature heating and cooling demand in residential, commercial, manufacturing, agricultural, and data center sectors for potential geothermal applications in the United States

Thermal demand for heating and cooling has been predominantly supplied by fossil fuel combustion in the United States, although low-carbon alternatives are extensively available including geothermal, solar thermal, and waste heat. Here, this study analyzed end-use energy consumption, fuel expenditure, and data center commissioned power data to geospatially characterize the U.S. low-temperature heating and cooling demand at the county level in residential, commercial, manufacturing, agricultural, and data center sectors and understand potential opportunities for geothermal applications. In the analysis, the regional-scale energy consumption data was incorporated with system efficiencies to address actual demand and was then disaggregated with weighting factors to the county level. The results indicated that total low-temperature heating and cooling demand is 16.7 EJ, combining heating demand of 10.8 EJ and cooling demand of 5.9 EJ. Overall, 59.9 % (10 EJ) of the low-temperature heating and cooling demand occurred in the residential sector. The heating and cooling demand visualized in maps represented that the geospatial distribution of heating and cooling demand in the residential and commercial sectors is governed by the number of housing units and climate zone designations, while heating and cooling demand in the manufacturing, agricultural, and data center sectors is dependent on the number and location of facilities. The results also demonstrated that geothermal heat pumps are broadly used in the residential and commercial sectors for heating and cooling in the U.S. Midwest, South, and Northeast regions but are limited in the West, implying great decarbonization potential in the future.

15 GEOTHERMAL ENERGY↗

NASA NTRS1994

Non-isolated 30 kW class arcjet PCU

A 30 kW class arcjet Power Conditioning Unit, PCU, was built and tested during this Phase 2 SBIR contract. The PCU is an improved version of two previously developed PCU's. All of these units are 3-phase, 20 kHz buck regulators with current mode feed back to modulate the duty cycle to control the arcjet current at any selected operating point. The steady state control can assure arcjet stability despite the negative dynamic resistance of the arc discharge. The system also has a circuit to produce a high voltage start pulse to breakdown the gas and initiate the arc. The start pulse is formed by temporarily switching a short current path across the output terminals with a special solid state switching array. The switches then open rapidly, and the energy stored in the output inductors of the buck regulator produces a pulse of approximately 2500 V for approximately 500 nsec. The system was tested and modified until the transition to steady operation occurred after start up with a very small surge current overshoot. The system also can withstand a direct short circuit across the output without damage. The automatic feed back control simply reduces the duty cycle to hold the current at the set point. When the short is removed the full power output is immediately restored. This latest version arcjet PCU is conduction cooled to remove waste heat by conduction to the base plate. This unit is closer to flight a type of design than the previous functional bread boards. Waste heat is small because the PCU has a very high efficiency, 296 percent. The PCU was extensively tested with resistor loads to simulate operation with an arcjet. The unit was tested with ammonia arcjets at the Jet Propulsion Laboratory. Approximately 400 hours of testing were completed, with several starts. Many hours were also demonstrated with resistive loads. Some testing with hydrogen arcjets was also carried out at NASA LeRC. This system concept is now the design base for the ATTD program.

Wong, See-Pok↗

NASA NTRSDate not supplied

Assessment of the Impact of an Advanced Power System on a Turboelectric Single-Aisle Concept Aircraft

Electrified aircraft propulsion concepts show potential in using propulsion airframe inte-gration in order to increase efficiency in flight and therefore decrease fuel burn and emissions.Electrification offers component efficiency values greater than 90 percent, but the loss is in the form of low grade waste heat. A major challenge of electrified aircraft propulsion is managing that heat while minimizing any penalties associated with a thermal management system. This paper explores the effect of two innovations in the management of waste heat at the aircraft system level for a turboelectric single aisle concept. The first innovation is achieving a 3 times reduction in heat by developing high-efficiency components rather than managing the high levels of heat. The second takes advantage of the outer mold line of the aircraft to reject heat directly to the environment passively instead of adding active cooling loops that negatively impact the weight, power, and drag of the aircraft. In order to fully grasp the impact of the advanced power system, we develop methods of modeling the power and thermal management systems to be integrated in the full aircraft conceptual model. We then model the aircraft with a state of the art DC transmission system and active cooling loops as a baseline for our study. Our second model includes the advanced power system with active cooling, which results in a fuel burn reduction of 2.5 percent. Finally, in our third model we assess the benefit of an outer mold line cooling scheme with the advanced power system. The outer mold line cooling scheme with an advanced power system yields an additional 0.8 percent reduction in fuel burn,for an overall fuel burn reduction potential of 3.3 percent in addition to aerodynamic benefits of electrified aircraft propulsion.

Electric Aircraft↗