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91	Modeling The Temperature of a Calorimeter at Clab : Considering a Thermodynamic Model of The Temperature Evolution of The Calorimeter System 251 Ekman, Johannes January 2021 (has links) It is important to know the heat generated due to nuclear decay in the final repository for spent nuclear fuel. In Sweden, the heating powers generated in spent nuclear fuels are currently measured in the calorimeter System 251 at the Clab facility, Oskarshamn. In order to better measure, and increase understanding, of the temperature measurements in the calorimeter, a simple thermodynamic model of its temperature evolution was developed. The model was described as a system of ordinary differential equations, which were solved, and the solution was applied to calibration measurements of the calorimeter. How precise the model is, how its parameters affect the model, et cetera, are addressed. How the temperature evolution of the system changes as the values of parameters in the model are changed is addressed. The mass correction of the calorimeter could be estimated from this model, which validated the established mass correction of the calorimeter. How the measurement results from the calorimeter would be affected if the volume of the calorimeter was changed was also considered. Additionally, gamma radiation escape from the calorimeter without being detected as heat in the calorimeter. The gamma escape energy fraction was estimated by SERPENT simulations of the calorimeter, as a function of the initial photon energy. The gamma escape was also estimated for different values of the radius of System 251. calorimetry calorimeter System 251 temperature evolution spent nuclear fuel SNF MATLAB SERPENT2 Clab nuclear decay heat calibration measurements thermodynamic model gamma escape fraction mass correction calibration measurements electric heater three component system eigenvalues eigenvalue estimation temperature increase method sensitivity of mass correction calorimeter heat capacity mass correction uncertainty calorimeter calibration curve monoenergetic gamma spectrum Subatomic Physics Subatomär fysik Other Physics Topics Annan fysik
92	Výzkum vlastností materiálů pro použití ve vysokoteplotním solárním tepelně-akumulačním zásobníku / Material properties research for use in high-temperature solar thermal storage tank Šot, František January 2018 (has links) The use of thermal storage energy, using phase change materials appears to be an effective way to store thermal energy storage with the benefits of the high amount of energy while maintaining isothermal nature of the process. PCM methods are used in latent thermal storage systems for heat pumps, as well as in solar engineering or for temperature control in spacecraft. The past decade has extended these principles for cooling and heating in the building. There are a number of PCM systems, which operate over a wide temperature range, are used in various applications. This document includes a brief overview of the development and analysis of available thermal storage working mainly on the principle of PCM.

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Modeling The Temperature of a Calorimeter at Clab : Considering a Thermodynamic Model of The Temperature Evolution of The Calorimeter System 251

Výzkum vlastností materiálů pro použití ve vysokoteplotním solárním tepelně-akumulačním zásobníku / Material properties research for use in high-temperature solar thermal storage tank