Heat Storage Based on PCM for Concentrated Solar Power Applications
Translated title
Varmelager Baseret på Faseskifte Materialer til Koncentreret Solenergi Applikationer
Authors
Reinholdt, Nis Peter ; Kragbæk, Jan
Term
4. term
Education
Publication year
2011
Submitted on
2011-06-09
Pages
136
Abstract
Koncentreret solkraft kan lagre varme i faseændringsmaterialer (PCM), som smelter og størkner. Dette speciale undersøgte, hvordan varme overføres i et KNO3–NaNO3-baseret PCM-varmelager ved hjælp af computersimuleringer (computational fluid dynamics, CFD) og numeriske modeller. Studiet gik fra simple til mere detaljerede repræsentationer: quasi‑1D, 2D og 3D. To design blev sammenlignet, et med grafitribber og et med stålribber. Hver model blev simuleret i 3, 10, 30 og 60 minutter. De vigtigste resultater var: under afladning (når lageret afgiver varme) betyder valget af ribbemateriale mindre, fordi PCM størkner på de opvarmede overflader og danner et isolerende lag, som reducerer varmeoverførsel; og naturlig konvektion—bevægelsen af den flydende PCM drevet af temperaturforskelle—har stor betydning for den samlede varmeoverførsel.
Concentrated solar power can store heat in phase change materials (PCM) that melt and solidify. This thesis investigated how heat is transferred in a KNO3–NaNO3 PCM storage using computer simulations (computational fluid dynamics, CFD) and numerical models. The study progressed from simpler to more detailed representations: quasi‑1D, 2D, and 3D. Two designs were compared, one with graphite fins and one with steel fins. Each model was simulated for 3, 10, 30, and 60 minutes. The key findings were: during discharge (when the storage releases heat), the choice of fin material mattered less because the PCM solidifies on the heating surfaces and forms an insulating layer that reduces heat transfer; and natural convection—the movement of the liquid PCM driven by temperature differences—plays a major role in overall heat transfer.
[This abstract was generated with the help of AI]
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