The concrete heat storage system of the solar dish type Stirling machine is designed, the molten salt and concrete heat transfer process are theoretically analyzed, the concrete heat storage and release process is simulated, and the multi-objective genetic algorithm is used for optimization. The following conclusions are obtained. In the heat release process, 290 ℃ is selected as the critical value of the effective temperature of the fluid outlet. When the effective heat release time is about 2.1 h, the outlet temperature of the fluid is about 563 K, and the heat release efficiency is about 71%. High temperature concrete and molten salt have a thermocline area along the direction of the process. With the extension of time, the thermocline also gradually moves downstream along the direction of the process. When the thermocline moves to the outlet, the outlet temperature of molten salt begins decreasing and the shorter the length of the thermocline is, the higher the efficiency of the heat storage system is. With the increase of thermal conductivity, the heat release efficiency and effective heat release time increase. The solution set was reordered by TOPSIS, and the optimal conditions were heat storage of 2885 MJ, heat transfer coefficient of 672 W/（m·K） and heat storage rate of 87%.
Key words
disk solar concentrator system /
Striling /
concrete /
heat storage /
heat storage /
thermocline region
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References
[1] BAHAROON D A, RAHMAN H A, OMAR W Z W, et al. Historical development of concentrating solar power technologies to generate clean electricity efficiently-A review[J]. Renewable and sustainable energy reviews, 2015, 41(1): 996-1027.
[2] PALACIOS A, BARRENECHE C, NAVARRO M E, et al.Thermal energy storage technologies for concentrated solar power-A review from a materials perspective[J]. Renewable energy, 2020, 156(8): 1244-1265.
[3] SETTINO J, SANT T, MICALLEF C.Overview of solar technologies for electricity heating and cooling production[J]. Renewable and sustainable energy reviews, 2018, 90(7): 892-909.
[4] SCHOENEBERGER C, MCMILLAN C, KURUP P, et al.Solar for industrial process heat: A review of technologies, analysis approaches, and potential applications in the United States[J]. Energy, 2020, 206(9): 1-18.
[5] ANDRAKA C E, KRUIZENGA B A, HERNANDEZ-SANCHEZ E N, et al. Metallic phase change material thermal storage for dish stirling[J]. Energy procedia, 2015, 69(5): 726-736.
[6] PRASAD L, MUTHUKUMAR P.Design and optimization of lab-scale sensible heat storage prototype for solar thermal power plant application[J]. Solar energy, 2013, 97(11): 217-229.
[7] TAMME R, LAING D, STEINMANN W D.Advanced thermal energy storage technology for parabolic trough[J]. Journal of solar energy engineering, 2004, 126: 794-800.
[8] LAING D, BAHL C, BAUER T, et al.Thermal energy storage for direct steam generation[J]. Solar energy, 2011, 85: 627-633.
[9] RAO C R C, NIYAS H, MUTHUKUMAR P. Performance tests on lab-scale sensible heat storage prototypes[J]. Applied thermal engineering, 2018, 129(1): 953-967.
[10] XU B, HAN J X, KUMAR A, et al.Thermal storage using sand saturated by thermal-conductive fluid and comparison with the use of concrete[J]. Journal of energy storage, 2017, 13(10): 85-95.
[11] 赵研. 太阳能地下混凝土存释热试验研究与数值模拟[D]. 长春: 吉林大学, 2011: 15-25.
ZHAO Y.Numerieal Simulation and experimental researeh on solar energy storage and extraetion of underground conerete pile[D]. Changchun: Jilin University, 2011: 15-25.
[12] ALONSO M C, VERA-AGULLO J, GUERREIRO L.Calcium aluminate based cement for concrete to be used as thermal energy storage in solar thermal electricity plants[J]. Cement and concrete research, 2016, 82(4): 74-86.
[13] WANG G, LIU Z J, JIANG T L.Impact evaluation of cold heat transfer fluid temperature on heat storage and mechanical behaviours of an energy storage system usingphase-change material[J]. International journal of thermophysics, 2021, 42(5): 1-18.
[14] 吴明, 李明佳, 何雅玲, 等. 太阳能热发电用高温混凝土储热系统性能分析[J]. 西安交通大学学报, 2013, 47(5): 1-5.
WU M, LI M J, HE Y L, et al.Thermal performance of high temperature concrete thermal storage system for solar thermal power generation[J]. Journal of Xi’an Jiaotong University, 2013, 47(5): 1-5.
[15] MCGLEN R J, JACHUCK R, LIN S.Integrated thermal management techniques for high power electronic devices[J]. Applied thermal engineering, 2003, 24(8): 1143.
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