Thermal Storage and Transport Properties of Rocks, I: Heat Capacity and Latent Heat

2012 ◽  
Keyword(s):  
Heat Capacity ◽  
Transport Properties ◽  
Latent Heat ◽  
Thermal Storage

Change in inter-atomic communication character in the formation of solid and liquid solutions. Relationship of vibrational and configuration entropy and their physical interpretation

2021 ◽  
pp. 28-40
Author(s):  
A. M. Savchenko ◽  
Yu. V. Konovalov ◽  
A. V. Laushkin
Keyword(s):  
Heat Capacity ◽  
Heat Release ◽  
Latent Heat ◽  
Physical Interpretation ◽  
Latent Heat Release ◽  
Statistical Entropy ◽  
Average Heat ◽  
Configuration Entropy ◽  
Liquid Solutions ◽  
Relationship Of

The purpose of this work is to show that during mixing, two hidden (latent) processes proceed simultaneously and compensate each other: the first initiates an increase in the average heat capacity, equal in magnitude to the entropy of mixing, which requires energy absorption to ensure a constant temperature, the second initiates simultaneous latent heat release by strengthening interatomic bonds. The passage of these two processes during mixing shows the identity of the vibrational and configurational (statistical) entropy.

scholarly journals Molten Salt Spectroscopy for Quantification of Radiative Absorption in Novel Metal Chloride-Enhanced Thermal Storage Media

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Philip D. Myers ◽  
D. Yogi Goswami ◽  
Elias Stefanakos
Keyword(s):  
Heat Transfer ◽  
Transition Metal ◽  
Melting Temperature ◽  
Latent Heat ◽  
Thermal Storage ◽  
Metal Chloride ◽  
Eutectic System ◽  
Metal Chlorides ◽  
Storage Media ◽  
Radiative Absorption

This study describes the development and characterization of novel high-temperature thermal storage media, based on inclusion of transition metal chlorides in the potassium–sodium chloride eutectic system, (K–Na)Cl (melting temperature of 657 °C, latent heat of 278 J/g). At the melting temperature of (K–Na)Cl, infrared (IR) radiation can play a major role in the overall heat transfer process—90% of spectral blackbody radiation falls in the range of 2–13 μm. The authors propose inclusion of small amounts (less than 0.2 wt.%) of IR-active transition metal chlorides to increase radiative absorption and thereby enhance heat transfer rates. A new IR-reflectance apparatus was developed to allow for determination of the spectral absorption coefficient of the newly formulated phase-change materials (PCMs) in the molten state. The apparatus consisted of an alumina crucible coated at the bottom with a reflective (platinum) or absorptive (graphite) surface, a heated ceramic crucible-holder, and a combination of zinc sulfide (ZnS) and zinc selenide (ZnSe) windows for containment of the salt and allowance of inert purge gas flow. Using this apparatus, IR spectra were obtained for various transition metal chloride additives in (K–Na)Cl and improved IR activity, and radiative transfer properties were quantified. Further, thermophysical properties relevant to thermal energy storage (i.e., melting temperature and latent heat) are measured for the pure and additive-enhanced thermal storage media.

Thermodynamic analysis of a packed bed latent heat thermal storage system simulated by an effective packed bed model

Energy ◽  
2017 ◽  
Vol 140 ◽  
pp. 861-878 ◽  
Author(s):  
R. Pakrouh ◽  
M.J. Hosseini ◽  
A.A. Ranjbar ◽  
R. Bahrampoury
Keyword(s):  
Latent Heat ◽  
Thermodynamic Analysis ◽  
Storage System ◽  
Thermal Storage ◽  
Packed Bed

scholarly journals A Domestic Solar/Heat Pump Heating System Incorporating Latent and Stratified Thermal Storage

2008 ◽  
Author(s):  
Christoph Trinkl ◽  
Wilfried Zo¨rner ◽  
Vic Hanby
Keyword(s):  
Latent Heat ◽  
Heat Pump ◽  
Solar Collector ◽  
Energy Demand ◽  
Heat Storage ◽  
Thermal Storage ◽  
Heating System ◽  
System Control ◽  
Latent Heat Storage ◽  
Solar Heat

Both solar and heat pump heating systems are innovative technologies for sustaining ecological heat generation. They are gaining more and more importance due to the accelerating pace of climate change and the rising cost of limited fossil resources. Against this background, a heating system combining solar thermal collectors, heat pump, stratified thermal storage and water/ice latent heat storage has been investigated. The major advantages of the proposed solar/heat pump heating system are considered to be its flexible application (suitable for new and existing buildings because of acceptable space demand) as well as the improvement of solar fraction (extended solar collector utilisation time, enhanced collector efficiency), i.e. the reduction of electric energy demand for the heat pump. In order to investigate and optimise the heating system, a dynamic system simulation model was developed. On this basis, a fundamental control strategy was derived for the overall coordination of the heating system with particular regard to the performance of the two storage tanks. In a simulation study, a fundamental investigation of the heating system configuration was carried out and optimisation derived for the system control as well as the selection of components and their dimensioning. The influence of different parameters on the system performance was identified, where the collector area and the latent heat storage volume were found to be the predominant parameters for system dimensioning. For a modern one-family house, a solar collector area of 30m2 and a latent heat store volume of 12.5m3 are proposed. In this configuration, the heating system reaches a seasonal performance factor of 4.6, meaning that 78% of the building’s and users’ heat demand are delivered by solar energy. The results show that the solar/heat pump heating system can give an acceptable performance using up-to-date components in a state-of-the-art building.

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