Experimental Study of High-Temperature Range Latent Heat Thermal Energy Storage
Notice bibliographique
Résumé
Among all thermal energy storage (TES) systems, latent heat thermal energy storage (LHTES) attracts high interest due to its high energy density and high exergetic efficiency. Due to the high enthalpy of fusion and low cost, inorganic salts are becoming popular as phase change materials and are used as the storage media in LHTES systems. The main drawbacks for the inorganic salts are their low thermal conductivity and high reactivity above 500°C. Therefore, designing a cost-effective containment at these conditions with longevity is a challenge. Macro-encapsulation of the PCM is one way to solve both the PCM containment issue as well as the low thermal conductivity problem. However, finding a practically viable encapsulation technique is a challenge especially for temperatures above 500°C.\nIn the present study, encapsulation techniques were investigated for two temperature ranges; 500°C – 600°C and 600°C above. Metallic encapsulation was adopted for the 500°C – 600°C temperature. Commercially available, low-cost carbon-steel tubes were used, and the encapsulation shape was cylindrical. A 200µm coating of Ni was applied to strengthen the corrosion resistance. For temperatures above 600°C, a novel approach involving the use of ceramic materials was investigated for encapsulating chloride based PCMs. Low-cost ceramics with excellent thermal and chemical stability under molten-salt conditions were identified as the encapsulants. The influence of sintering temperature on the reactivity of feldspar, ball clay, kaolin and the mixture thereof with molten sodium chloride was investigated. The results were used to develop an optimum ceramic capsule fabrication procedure, using a green ceramic body followed by sintering at 1190°C. An innovative sealing process of in-situ layered eutectic formation was introduced. Sealing was performed at a temperature above the eutectic melting point of the salt mixture but below the individual melting points of each salt. The fabricated capsule survived more than 500 thermal cycles without showing degradation in its thermo-physical properties. Alumina (99%) based capsule containing NaCl-KCl was tested successfully for 1000 thermal cycles with a PCM weight loss of less than 5%.\nA lab-scale setup was designed and constructed to test an industry scalable LHTES system suitable for supplementing heat to a steam-powered cycle. Metallic cylindrical capsules were used with a eutectic of sodium sulfate (Na2SO4) and potassium chloride (KCl), which melts at 515°C, as the PCM for energy storage. This system was modeled and validated with experimental measurements. The calculated ratio of exergy to energy efficiency was around 89% (for 380-535°C). Flow irregularities were found due to a bend in the flow channel. Therefore, flow conditioners were investigated. A modified system with the flow conditioners and radiation shields showed 98% exergy to energy efficiency ratio (for 495-535°C). The overall efficiency of the system, however, was found to be low due to the heat losses from the storage tank.\nFinally, a novel design of a TES system using spherical capsules is proposed with additional enhancement gained from the experimental work on the lab-scale LHTES system. The innovation of this design lies in the manufacturing process to forms multiple spherical capsules using sheet metals. The adoptability of this technique for higher or lower temperature LHTES applications depends on the properties of the selected sheet metal. Any formable sheet metal can be used depending on the compatibility with PCM and HTF.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,001 | 0,001 |
| Communication savante | 0,000 | 0,001 |
| Science ouverte | 0,002 | 0,001 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».