Analogy Analysis of Height Exergy and Temperature Exergy in Energy Storage System
As a pivotal technology and infrastructure component for modern power systems, energy storage has experienced significant advancement in recent years. A fundamental prerequisite for designing future energy storage facilities lies in the systematic evaluation of energy conversion capabilities across...
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2025-07-01
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| author | Yan Cui Tong Jiang Mulin Liu |
| author_facet | Yan Cui Tong Jiang Mulin Liu |
| author_sort | Yan Cui |
| collection | DOAJ |
| description | As a pivotal technology and infrastructure component for modern power systems, energy storage has experienced significant advancement in recent years. A fundamental prerequisite for designing future energy storage facilities lies in the systematic evaluation of energy conversion capabilities across diverse storage technologies. This study conducted a comparative analysis between pumped hydroelectric storage (PHS) and compressed air energy storage (CAES), defining the concepts of height exergy and temperature exergy. Height exergy is the maximum work capacity of a liquid due to height differences, while temperature exergy is the maximum work capacity of a gas due to temperature differences. The temperature exergy represents innovation in thermodynamic analysis; it is derived from internal exergy and proven through the Maxwell relation and the decoupling method of internal exergy, offering a more efficient method for calculating energy storage capacity in CAES systems. Mathematical models of height exergy and temperature exergy were established based on their respective forms. A unified calculation formula was derived, and their respective characteristics were analyzed. In order to show the meaning of temperature exergy more clearly and intuitively, a height exergy model of temperature exergy was established through analogy analysis, and it was concluded that the shape of the reservoir was a cone when comparing water volume to heat quantity, intuitively showing that the cold source had a higher energy storage density than the heat source. Finally, a typical hybrid PHS–CAES system was proposed, and a mathematical model was established and verified in specific cases based on height exergy and temperature exergy. It was demonstrated that when the polytropic exponent <i>n</i> = 1.2, the theoretical loss accounted for the largest proportion, which was 2.06%. |
| format | Article |
| id | doaj-art-77c486eb3cfa47e58f088476a468f049 |
| institution | DOAJ |
| issn | 1996-1073 |
| language | English |
| publishDate | 2025-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj-art-77c486eb3cfa47e58f088476a468f0492025-08-20T02:45:38ZengMDPI AGEnergies1996-10732025-07-011814367510.3390/en18143675Analogy Analysis of Height Exergy and Temperature Exergy in Energy Storage SystemYan Cui0Tong Jiang1Mulin Liu2School of Electrical and Electronic Engineering, North China Electric Power University, Beijing 102206, ChinaSchool of Electrical and Electronic Engineering, North China Electric Power University, Beijing 102206, ChinaSchool of Electrical and Electronic Engineering, North China Electric Power University, Beijing 102206, ChinaAs a pivotal technology and infrastructure component for modern power systems, energy storage has experienced significant advancement in recent years. A fundamental prerequisite for designing future energy storage facilities lies in the systematic evaluation of energy conversion capabilities across diverse storage technologies. This study conducted a comparative analysis between pumped hydroelectric storage (PHS) and compressed air energy storage (CAES), defining the concepts of height exergy and temperature exergy. Height exergy is the maximum work capacity of a liquid due to height differences, while temperature exergy is the maximum work capacity of a gas due to temperature differences. The temperature exergy represents innovation in thermodynamic analysis; it is derived from internal exergy and proven through the Maxwell relation and the decoupling method of internal exergy, offering a more efficient method for calculating energy storage capacity in CAES systems. Mathematical models of height exergy and temperature exergy were established based on their respective forms. A unified calculation formula was derived, and their respective characteristics were analyzed. In order to show the meaning of temperature exergy more clearly and intuitively, a height exergy model of temperature exergy was established through analogy analysis, and it was concluded that the shape of the reservoir was a cone when comparing water volume to heat quantity, intuitively showing that the cold source had a higher energy storage density than the heat source. Finally, a typical hybrid PHS–CAES system was proposed, and a mathematical model was established and verified in specific cases based on height exergy and temperature exergy. It was demonstrated that when the polytropic exponent <i>n</i> = 1.2, the theoretical loss accounted for the largest proportion, which was 2.06%.https://www.mdpi.com/1996-1073/18/14/3675pumped hydroelectric storagecompressed airtemperature exergyheight exergy |
| spellingShingle | Yan Cui Tong Jiang Mulin Liu Analogy Analysis of Height Exergy and Temperature Exergy in Energy Storage System Energies pumped hydroelectric storage compressed air temperature exergy height exergy |
| title | Analogy Analysis of Height Exergy and Temperature Exergy in Energy Storage System |
| title_full | Analogy Analysis of Height Exergy and Temperature Exergy in Energy Storage System |
| title_fullStr | Analogy Analysis of Height Exergy and Temperature Exergy in Energy Storage System |
| title_full_unstemmed | Analogy Analysis of Height Exergy and Temperature Exergy in Energy Storage System |
| title_short | Analogy Analysis of Height Exergy and Temperature Exergy in Energy Storage System |
| title_sort | analogy analysis of height exergy and temperature exergy in energy storage system |
| topic | pumped hydroelectric storage compressed air temperature exergy height exergy |
| url | https://www.mdpi.com/1996-1073/18/14/3675 |
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