CFD Simulation Optimization of Soft Seed Pomegranate Cold Protection Facility
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摘要:
为探索解决露地软籽石榴种植越冬问题的新途径,设计、搭建了一种简易式非固定防寒设施,针对该防寒设施冬季日间集热特性,利用ANSYS Fluent建立了稳态模拟模型,对其进行了验证试验,并使用该模型对防寒设施参数(空气间层和通风孔直径)进行优化试验。验证试验表明,华氏度相对误差
E RE<1‰,防寒设施内监测点温度模拟值的决定系数R 2和均方根误差E RMSE分别为0.9625与1.19 K,表明模型可信度较高。优化试验表明,防寒设施空气间层厚度最佳3 cm、通风孔直径最佳14 cm。Abstract:In order to explore a new way to solve overwintering problem of open-field soft seed pomegranate planting, a simple non-fixed cold-proof facility was designed and built.Aiming at daytime heat collection characteristics of facility in winter, ANSYS Fluent was used to establish a steady-state simulation model, and verification test was carried out.Then, the model was used to optimize facility parameters(air interlayer and diameter of ventilation hole).Verification experiments showed that, relative error of Fahrenheit degree
E RE was less than 1‰, and tcoefficient of determinationR 2 and root mean square errorE RMSE of temperature simulation values at monitoring points in the facility were 0.9625 and 1.19 K, indicating high reliability of the model.Optimization experiments showed that for cold proof facilities proposed, the best thickness of air interlayer was 3 cm, and the best diameter of ventilation hole was 14 cm.-
Keywords:
- soft seeded pomegranate /
- cold protection facility /
- CFD simulation
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表 1 防寒设施材料物理参数
Table 1. Physical parameters of facility materials
材料名称 密度/(kg·m−3) 热导率/(W·m−1·K−1) 比热/(J·kg−1·K−1) 吸收系数 折射率 空气 1.29 0.0242 1006.43 1 苯板 100 0.047 1380.00 土壤 1620 1.300 1480.00 铁 7874 46.520 460.00 草苫 120 0.060 1460.00 PVC膜 920 0.330 2550.00 1188.9 1.4 表 2 日间边界条件设置
Table 2. Daytime boundary condition setting
壁面 材料 边界类型 设定值 采光集热板仰侧 苯板 耦合 内部辐射率1 4个通风孔 苯板 耦合 内部辐射率0.85 塑料罩 PVC薄膜 混合 参与太阳辐射 地面 土壤 温度壁面 内部辐射率0.90 南侧草苫 草苫 混合 内部辐射率0.90 采光集热板背侧 苯板 耦合 内部辐射率0.85 其他壁面 苯板 热通量 内部辐射率0.85 表 3 模拟值与实测值相对误差
Table 3. Relative errors between simulated and measured values
测试点 模拟温度Tsim/K 测试温度Texp/K ERE/‰ T1,sun 290.26 292.05 0.613 T2,sun 278.63 277.95 0.245 T3,sun 281.87 280.95 0.327 T1,cloud 281.45 280.25 0.428 T2,cloud 274.54 273.35 0.435 T3,cloud 276.29 275.25 0.378 -
[1] 薛华柏,曹尚银,郭俊英,等.突尼斯软籽石榴气候区划北限及次适宜区的防寒栽培[J].中国果树,2010(2): 63 - 64 . [2] 李敏.突尼斯软籽石榴冻旱的发生与预防[D].泰安:山东农业大学,2013.LI Min.The happening and prevention of the cold and drought in Tunisia soft seeds pomegranate[D].Tai'an:Shandong Agricultural University,2013. [3] 李明婉,唐琳,李宗圈,等.河南省丘陵石榴主产区2009年冻害调查[J].河南农业科学,2010(11): 106 - 108 . doi: 10.3969/j.issn.1004-3268.2010.11.028 [4] 王宇翔,高小峰,雷梦瑶,等.南阳地区发展软籽石榴的冻害风险分析[J].南阳师范学院学报,2022,21(3): 45 - 50 .WANG Yuxiang,GAO Xiaofeng,LEI Mengyao,et al.Risk analysis of freezing injury in developing soft seed pomegranate in Nanyang area[J].Journal of Nanyang Normal University,2022,21(3): 45 - 50 . [5] 冯一峰,王艳,杨植,等.不同防寒措施对防寒设施软籽石榴越冬性的影响[J].北方园艺,2021(10): 53 - 58 .FENG Yifeng,WANG Yan,YANG Zhi,et al.Effects of different cold prevention measures on cold hardiness of soft seed pomegranate[J].Northern Horticulture,2021(10): 53 - 58 . [6] 李银芳,潘伯荣,孙永强,等.不同覆盖物对果树越冬的保温作用[J].北方园艺,2012(18): 19 - 22 .LI Yinfang,PAN Borong,SUN Yongqiang,et al.The heat preservation effects of different coverings for fruit trees' overwintering[J].Northern Horticulture,2012(18): 19 - 22 . [7] 李银芳,潘伯荣,孙永强,等.果树越冬不同覆盖方法的成本计算[J].北方园艺,2012(14): 197 - 200 .LI Yinfang,PAN Borong,SUN Yongqiang,et al.The cost calculation of different coverings for fruit trees' overwintering[J].Northern Horticulture,2012(14): 197 - 200 . [8] 李银芳.利用简易防寒设施防止果树冻害的栽培模式[J].北方园艺,2010(1): 92 - 94 .LI Yinfang.Cultivation mode of fruit tree for preventing freezing injury using minimum greenhouse[J].Northern Horticulture,2010(1): 92 - 94 . [9] 李银芳.寒冷地区双层覆盖式果树越冬技术[J].北方园艺,2008(12): 17 - 20 .LI Yinfang.The double coverage hibernalisation technology of fruit tree in the cold regions[J].Northern Horticulture,2008(12): 17 - 20 . [10] 宋娟,胡晓静,唐诚,等.防寒处理提升南疆突尼斯软籽石榴微域温度效应的研究[J/OL].果树学报:1-17. https://doi.org/10.13925/j.cnki.gsxb.20220643.SONG Juan,HU Xiaojing,TANG Cheng,et al.Temperature increasing effect of cold-prevention treatments in micro-environment of Tunisian soft seed pomegranate trees in South Xinjiang[J/OL].Journal of Fruit Science:1-17. https://doi.org/10.13925/j.cnki.gsxb.20220643. [11] 佟国红,王铁良,白义奎,等.日光温室土壤温度分布边际效应的数值模拟[J].北方园艺,2010(15): 65 - 68 .TONG Guohong,WANG Tieliang,BAI Yikui,et al.Numerical modeling of marginal effect on soil temperature distribution in a chinese solar greenhouse[J].North Horticulture,2010(15): 65 - 68 . [12] PASUT W,DE CARLI M.Evaluation of various CFD modelling strategies in predicting airflow and temperature in a naturally ventilated double skin façade[J].Applied Thermal Engineering,2012,37: 267 - 274 . doi: 10.1016/j.applthermaleng.2011.11.028 [13] 李宗翔,顾润红,张晓明,等.基于RNG k-ε湍流模型的3D采空区瓦斯上浮贮移[J].煤炭学报,2014,39(5): 880 - 885 .LI Zongxiang,GU Runhong,ZHANG Xiaoming,et al.Simulation of gas migration in 3D goaf based on RNG k-ɛ turbulence model[J].Journal of China Coal Society,2014,39(5): 880 - 885 . [14] BAJC T,TODOROVIC` M N,SVORCAN J.CFD analyses for passive house with Trombe wall and impact to energy demand[J].Energy & Buildings,2014,98: 39 - 44 . [15] 杨昭,徐晓丽.特朗勃壁温度场分析[J].工程热物理学报,2006(4): 568 - 570 . doi: 10.3321/j.issn:0253-231X.2006.04.009YANG Zhao,XU Xiaoli.Analysis on the temperature field of trombe wall[J].Journal of Engineering Thermophysics,2006(4): 568 - 570 . doi: 10.3321/j.issn:0253-231X.2006.04.009 [16] 程陈,冯利平,薛庆禹,等.日光温室黄瓜生长发育模拟模型[J].应用生态学报,2019,30(10): 3491 - 3500 .CHENG Chen,FENG Liping,XUE Qingyu,et al.Simulation model for cucumber growth and development in sunlight greenhouse[J].Chinese Journal of Applied Ecology,2019,30(10): 3491 - 3500 . [17] 黑赏罡,姜曙光,杨骏,等.特朗伯墙体冬季集热性能的CFD模拟分析[J].四川建筑科学研究,2018,44(3): 116 - 121 . doi: 10.3969/j.issn.1008-1933.2018.03.023HEI Shanggang,JIANG Shuguang,YANG Jun,et al.Simulation of the thermal performance of a Trombe wall in winter using computational fluid dynamics[J].Sichuan Building Science Research,2018,44(3): 116 - 121 . doi: 10.3969/j.issn.1008-1933.2018.03.023