The Use of Ammonium Carbamate as a High Specific Thermal Energy Density Material for the Thermal Management of Low Grade Heat

2011 ◽  
Author(s):  
Douglas Dudis ◽  
Joel Schmidt ◽  
Douglas Miller ◽  
Joseph Susoreny
Keyword(s):  
Energy Density ◽  
Thermal Management ◽  
Thermal Energy ◽  
Low Grade ◽  
Ammonium Carbamate ◽  
Low Grade Heat

Efficient Co-Harvesting of Solar Energy and Low-Grade Heat by Molecular Photoswitches for High Energy Density, Long-Term Stable Solar Thermal Battery

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI
Keyword(s):  
Energy Density ◽  
Solar Energy ◽  
High Performance ◽  
High Energy ◽  
Solar Thermal ◽  
High Energy Density ◽  
Low Grade ◽  
Thermal Battery ◽  
Low Grade Heat

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.

Efficient Co-Harvesting of Solar Energy and Low-Grade Heat by Molecular Photoswitches for High Energy Density, Long-Term Stable Solar Thermal Battery

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI
Keyword(s):  
Energy Density ◽  
Solar Energy ◽  
High Performance ◽  
High Energy ◽  
Solar Thermal ◽  
High Energy Density ◽  
Low Grade ◽  
Thermal Battery ◽  
Low Grade Heat

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.

Simultaneous water and electricity harvesting from low-grade heat by coupling membrane distiller and electrokinetic power generator

2021 ◽  
Author(s):  
Lu Huang ◽  
An He ◽  
Mengyu Miao ◽  
Junxian Pei ◽  
Tong Liu ◽  
...  
Keyword(s):  
Fresh Water ◽  
Hybrid System ◽  
Thermal Energy ◽  
Low Grade ◽  
Clean Water ◽  
Power Generator ◽  
Energy Stress ◽  
Low Grade Heat

Producing clean water and electricity from low-grade thermal energy has attracted escalating interest to alleviate fresh water and energy stress. Here, we present a novel hybrid system by coupling membrane...

Low-Grade Heat Utilization Through Ultrasound-Enhanced Desorption of Activated Alumina/Water for Thermal Energy Storage

2020 ◽  
Author(s):  
Hooman Daghooghi Mobarakeh ◽  
Keshawa Bandara ◽  
Liping Wang ◽  
Robert Wang ◽  
Patrick E. Phelan ◽  
...  
Keyword(s):  
Water Vapor ◽  
Energy Storage ◽  
Thermal Energy ◽  
Input Power ◽  
Total Power ◽  
Low Grade ◽  
Ultrasonic Power ◽  
Activated Alumina ◽  
Heat Utilization ◽  
Low Grade Heat

Abstract Sorption thermal energy storage (TES) seems to be an auspicious solution to overcome the issues of intermittent energy sources and utilization of low-grade heat. Ultrasound-assisted adsorption/desorption of water vapor on activated alumina is proposed as a means of low-grade heat utilization through TES. The effects of ultrasonic power on the storing stage (desorption of water vapor) were analyzed to optimize the desorption and overall efficiencies. To determine and justify the effectiveness of incorporating ultrasound from an energy-savings point of view, an approach of constant total (heat plus ultrasound) input power of 25 W was adopted. To measure the extent of the effectiveness of using ultrasound, ultrasonic-power-to-total power ratios of 0.2 and 0.4 were investigated and the results compared with those of no-ultrasound (heat only) at the same total power. The regeneration temperature and desorption rate were measured simultaneously to investigate the effects of ultrasonication on regeneration temperature and utilization of low-grade heat. The experimental results showed that using ultrasound facilitates the regeneration of activated alumina at both power ratios without increasing the total input power. With regard to regeneration temperature, incorporating ultrasound decreases the regeneration temperature hence justifying the utilization of low-grade heat for thermal energy purposes. In terms of overall energy recovery of the adsorption thermal storage process, a new metric is proposed to justify incorporating ultrasound and any other auxiliary energy along with low-grade heat.

Enhanced power factor of n-type Bi2Te2.8Se0.2 alloys through an efficient one-step sintering strategy for low-grade heat harvesting

2020 ◽  
Vol 8 (46) ◽  
pp. 24524-24535
Author(s):  
Haoxiang Wei ◽  
Jiaqi Tang ◽  
Hongchao Wang ◽  
Dongyan Xu
Keyword(s):  
Energy Harvesting ◽  
Thermal Energy ◽  
Power Factor ◽  
Low Grade ◽  
Thermal Energy Harvesting ◽  
One Step ◽  
Low Grade Heat

This work reports the enhanced power factor of n-type Bi2Te2.8Se0.2 alloys through an efficient one-step sintering strategy for thermal energy harvesting.

The Use of Ammonium Carbamate as a High Energy Density Thermal Energy Storage Material

2011 ◽  
Vol 1325 ◽  
Author(s):  
Joel E. Schmidt ◽  
Douglas S. Dudis ◽  
Douglas J. Miller
Keyword(s):  
Energy Storage ◽  
Energy Density ◽  
Elevated Temperatures ◽  
High Energy ◽  
Heat Fluxes ◽  
High Energy Density ◽  
Low Grade ◽  
Temperature Range ◽  
Ammonium Carbamate ◽  
Thermally Conductive

ABSTRACTPhase change materials (PCMs) often have higher specific energy storage capacities at elevated temperatures. Thermal management (TM) systems capable of handling high heat fluxes in the temperature range from 20–100°C are necessary but lacking. State of the art PCMs in this temperature range are usually paraffin waxes with energy densities on the order of a few hundred kJ/kg or ice slurries with energy densities of the same magnitude. However, for applications where system weight and size are limited, it is necessary to improve this energy density by at least an order of magnitude. The compound ammonium carbamate, [NH4][H2NCOO], is a solid formed from the reaction of ammonia and carbon dioxide which endothermically decomposes back to CO2 and NH3 in the temperature range 20-100°C with an enthalpy of decomposition of ∼2,000 kJ/kg. Various methods to use this material for TM of low-grade, high-flux heat have been evaluated including: bare powder, thermally conductive carbon foams, thermally conductive metal foams, hydrocarbon based slurries, and a slurry in ethylene glycol or propylene glycol. A slurry in glycol is a promising system medium for enhancing heat and mass transfer for TM. Progress on material and system characterization is reported.

scholarly journals Heat Based Power Augmentation for Modular Pumped Hydro Storage in Smart Buildings Operation

2021 ◽  
Author(s):  
Yang Chen ◽  
Ahmad Abu-Heiba ◽  
Saiid Kassaee ◽  
Chenang Liu ◽  
Guodong Liu ◽  
...  
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Ground Level ◽  
Small Scale ◽  
Low Grade ◽  
Discharge Process ◽  
Gas Temperature ◽  
Oak Ridge ◽  
Storage Technology ◽  
Low Grade Heat

Abstract In the U.S., building sector is responsible for around 40% of total energy consumption and contributes about 40% of carbon emissions since 2012. Within the past several years, various optimization models and control strategies have been studied to improve buildings energy efficiency and reduce operational expenses under the constraints of satisfying occupants’ comfort requirements. However, the majority of these studies consider building electricity demand and thermal load being satisfied by unidirectional electricity flow from the power grid or on-site renewable energy generation to electrical and thermal home appliances. Opportunities for leveraging low grade heat for electricity have largely been overlooked due to impracticality at small scale. In 2016, a modular pumped hydro storage technology was invented in Oak Ridge National Laboratory, named Ground Level Integrated Diverse Energy Storage (GLIDES). In GLIDES, employing high efficiency hydraulic machinery instead of gas compressor/turbine, liquid is pumped to compress gas inside high-pressure vessel creating head on ground-level. This unique design eliminates the geographical limitation associated with existing state of the art energy storage technologies. It is easy to be scaled for building level, community level and grid level applications. Using this novel hydro-pneumatic storage technology, opportunities for leveraging low-grade heat in building can be economical. In this research, the potential of utilizing low-grade thermal energy to augment electricity generation of GLIDES is investigated. Since GLIDES relies on gas expansion in the discharge process and the gas temperature drops during this non-isothermal process, available thermal energy, e.g. from thermal storage, Combined Cooling, Heat and Power system (CCHP), can be utilized by GLIDES to counter the cooling effect of the expansion process and elevate the gas temperature and pressure and boost the roundtrip efficiency. Several groups of comparison experiments have been conducted and the experimental results show that a maximum 12.9% cost saving could be achieved with unlimited heat source for GLIDES, and a moderate 3.8% cost improvement can be expected when operated coordinately with CCHP and thermal energy storage in a smart building.

Low-Grade Heat Utilization Through Ultrasound-Enhanced Desorption of Activated Alumina/Water for Thermal Energy Storage

2021 ◽  
Author(s):  
Hooman Daghooghi ◽  
Keshawa Bandara ◽  
Liping Wang ◽  
Robert Wang ◽  
Mark Miner ◽  
...  
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Low Grade ◽  
Activated Alumina ◽  
Heat Utilization ◽  
Low Grade Heat
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