搭建蓄热水池分层取热缩尺实验平台,通过实验方法研究分层取热对水体温度场的影响,利用出口温度、混合数（$N_{\text {mix }}$）、理查森数（Ri）等评价参数对实验结果进行定量化分析。研究结果表明：取水口越靠近蓄热水池顶部,水体各层温度和取热温度降低趋势越明显,$N_{\text {mix }}$增大得越快,水体的热分层程度减小得越快。取热过程中蓄热水体Ri主要取决于进出口流量,取水口位置对其影响较小;当取水口位于水池体积中位线以上时,取热效率随取热时间不断增加,且布水器越靠近顶部,取热效率增加得越快;在取水口位置固定的情况下,随着流量的增大,水池各层温度、取热温度、$N_{\text {mix }}$、取热效率变化得越快,且取水口越靠近顶部,水体热分层程度受流量影响越大;取热时,取水流量的变化相比于取水口高度的变化对蓄热水体的热分层状态的影响更大。
Abstract
In this paper, a scale model experimental platform was built to research the effect of the stratified discharge on the thermal stratification by combining the evaluation methods of outlet temperature, Nmix number, and Ri number. The results show that the closer the outlet is to the top of the thermal storage tank, the more obvious the decreasing trend of the water temperature and outlet temperature is, the thinner the thermocline is, and the Nmix number increases faster, indicating that the degree of thermal stratification of the water body decreases. The Ri number is mostly determined by volume flow rates, and the position of the outlets has little bearing on it. The discharge efficiency increases with time when the outlet is located above the middle line of the pool volume. With fixed outlet positions, as flow rate increases, the water temperature, Nmix number, and discharge efficiency vary faster, and the closer the outlet is to the top, the more the volume flow rates affect the thermal stratification of the water body. The change in volume flow rates affects thermal stratification more than the change in outlet height.
关键词
太阳能 /
储热 /
热分层 /
取热 /
蓄热水池 /
缩尺实验
Key words
solar energy /
heat storage /
thermal stratification /
discharge /
PTES /
scale model experiment
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参考文献
[1] MAUTHNER F, HERKEL S.IEA SHC task 52: classification and benchmarking of solar thermal systems in urban environments[R]. AEE INTEC, Gleisdorf, Austria, 2016.
[2] FAN J H, HUANG J P, LIE ANDERSEN O, et al.Thermal performance analysis of a solar heating plant[C]//Proceedings of SWC2017/SHC2017. Abu Dhabi, United Arab Emirates, 2017.
[3] 王敏, 张昕宇, 李博佳, 等. 西藏太阳能区域供暖技术应用探讨[J]. 建筑科学, 2022, 38(10): 1-6, 14.
WANG M, ZHANG X Y, LI B J, et al.Discussion on the application of solar district heating technologies in Tibet[J]. Building science, 2022, 38(10): 1-6, 14.
[4] SHAH L J, FURBO S.Entrance effects in solar storage tanks[J]. Solar energy, 2003, 75(4): 337-348.
[5] XIANG Y T, XIE Z C, FURBO S, et al.A comprehensive review on pit thermal energy storage: technical elements, numerical approaches and recent applications[J]. Journal of energy storage, 2022, 55: 105716.
[6] OCHS F, NUßBICKER-LUX J, MARX R, et al. Solar assisted district heating system with seasonal thermal energy storage in Eggenstein-Leopoldshafen[C]//EuroSun. Lisboa, Portugal, 2008: 2101-2108.
[7] SØRENSEN P A, SCHMIDT T. Design and construction of large scale heat storages for district heating in Denmark[C]//14th International Conference on Energy Storage.Adana, Turkey, 2018: 25-28.
[8] CHANG C, LENG G H, LI C, et al.Investigation on transient cooling process in a water heat storage tank with inclined sidewalls[J]. Energy procedia, 2017, 142: 142-147.
[9] XU J, WANG R Z, LI Y.A review of available technologies for seasonal thermal energy storage[J]. Solar energy, 2014, 103: 610-638.
[10] YANG T R, LIU W, KRAMER G J, et al.Seasonal thermal energy storage: a techno-economic literature review[J]. Renewable and sustainable energy reviews, 2021, 139: 110732.
[11] BOTT C, DRESSEL I, BAYER P.State-of-technology review of water-based closed seasonal thermal energy storage systems[J]. Renewable and sustainable energy reviews, 2019, 113: 109241.
[12] CHANG C, WU Z Y, NAVARRO H, et al.Comparative study of the transient natural convection in an underground water pit thermal storage[J]. Applied energy, 2017, 208: 1162-1173.
[13] CARLSSON P F.Heat storage for large low flow solar heating systems[C]//International Solar Energy Society world congress. Budapest, Hungary, 1993: 9-13.
[14] ASSARI M R, BASIRAT TABRIZI H, SAVADKOHY M.Numerical and experimental study of inlet-outlet locations effect in horizontal storage tank of solar water heater[J]. Sustainable energy technologies and assessments, 2018, 25: 181-190.
[15] 黄华杰, 王子龙, 张华, 等. 均流结构蓄热水箱热特性的模拟与实验研究[J]. 太阳能学报, 2020, 41(6): 348-356.
HUANG H J, WANG Z L, ZHANG H, et al.CFD simulation and exeperiment research on thermal stratification of hot water storage tank with eaualizer[J]. Acta energiae solaris sinica, 2020, 41(6): 348-356.
[16] DENG Y J, SUN D L, NIU M Y, et al.Performance assessment of a novel diffuser for stratified thermal energy storage tanks: The nonequal-diameter radial diffuser[J]. Journal of energy storage, 2021, 35: 102276.
[17] 刘凯丽, 王登甲, 刘艳峰, 等. 分层-掺混切换式蓄热水箱热特性实验及评价研究[J]. 太阳能学报, 2022, 43(8): 181-187.
LIU K L, WANG D J, LIU Y F, et al.Experimental and evaluation research on thermal performance of stratified-mixing switching heat storage water tank[J]. Acta energiae solaris sinica, 2022, 43(8): 181-187.
[18] 周光坰, 严宗毅, 许世雄, 等. 流体力学下册[M]. 2版. 北京: 高等教育出版社, 2011: 55-60.
ZHOU G J, YAN Z Y, XU S X, et al.Fluid mechanics[M]. 2nd ed. Peking: Higher Education Press, 2011: 55-60.
[19] 龙天渝, 蔡增基. 流体力学[M]. 3版. 北京: 中国建筑工业出版社, 2018: 268-281.
LONG T Y, CAI Z J.Fluid mechanics[M]. 3rd ed. Beijing: China Architecture & Building Press, 2018: 268-281.
[20] 方修睦. 建筑环境测试技术[M]. 3版.北京: 中国建筑工业出版社, 2016.
FANG X M.Measurement of building environment[M]. 3rd ed. Beijing: China Architecture & Building Press, 2016.
[21] 王崇愿, 张华, 王子龙. 储热水箱分层性能指标的研究进展[J]. 制冷技术, 2016, 36(4): 47-51.
WANG C Y, ZHANG H, WANG Z L.Research status on stratification performance indices of hot water storage tanks[J]. Chinese journal of refrigeration technology, 2016, 36(4): 47-51.
[22] 孙东亮, 王丽, 徐进良, 等. 跨季节蓄热水箱温度分层模型的研究及应用[J]. 太阳能学报, 2014, 35(2): 291-298.
SUN D L, WANG L, XU J L, et al.Research and application of water tank temperature statification model for seasonal heat storage[J]. Acta energiae solaris sinica, 2014, 35(2): 291-298.
[23] MUSSER A, BAHNFLETH W.Evolution of temperature distributions in a full-scale stratified chilled-water storage tank with radial diffusers[J]. Ashrae transactions, 2001, 104: 55-67.
[24] ANDERSEN E, FURBO S, FAN J H.Multilayer fabric stratification pipes for solar tanks[J]. Solar energy, 2007, 81(10): 1219-1226.
[25] ORÓ E, CASTELL A, CHIU J, et al.Stratification analysis in packed bed thermal energy storage systems[J]. Applied energy, 2013, 109: 476-487.
[26] CHAN A M C, SMEREKA P S, GIUSTI D. A numerical study of transient mixed convection flows in a thermal storage tank[J]. Journal of solar energy engineering, 1983, 105(3): 246-253.
基金
“十四五”国家重点研发计划（2022YFC3802705）; 国家自然科学基金青年项目（52108094）
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