Full
Outline
To reduce the operational cost of air-conditioning systems in subway stations, a cold storage air-conditioning system using phase change materials (PCMs) is proposed. The system can operate in four modes, namely, space cooling and cold charging by chillers, space cooling by chillers, space cooling by cold discharging, space cooling by chillers and cold discharging modes. The PCM used is a commercially available inorganic material, and its phase change temperature range is 7.5℃～8.5℃ and heat of fusion is 140 kJ/kg. The PCM is encapsulated in panel containers. A series of PCM slabs are parallelly arranged in the cold storage tank. The gap between the two adjacent PCM slabs serves as the flow channel for water, which exchanges heat with PCMs to store and release cold energy. The characteristics of chillers and cooling towers are modeled with the curve fitting method using the measured performance data. A dynamic computational model of the cold storage system which consists of a heat transfer numerical model of PCM slabs and the performance curves of chillers and cooling towers is built. The simulations are performed under the measured data in a subway station in Guangzhou. A control strategy is developed, then, the performance of the cold storage system is studied and compared to the conventional air-conditioning system. The variations of the melted fractions of PCMs, the inlet temperature, outlet temperature and water flow rate of cold storage tank, chillers and cooling towers, and the input power of system versus time on May 1st in 2023 are analyzed. In addition, a economic analysis of the proposed cold storage system is performed. The results show that, under the demand tariff, 8.27% annual operational cost is saved by the cold storage system over the conventional system, with a static payback period of 6.3 years. While 13.34% can be saved by the cold storage system against the conventional system under the discounted electricity tariff, with a static payback period of 3.7 years.
75
9
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |
关闭全屏
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62662699(Operation and Technical Support)
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
