日光温室相变蓄热墙体最佳组合厚度的模拟研究
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摘要
为合理确定日光温室复合相变墙体蓄热层与保温层的最佳厚度,该文从日光温室墙体动态传热特性角度出发,通过EnergyPlus热保温性能的增大随蓄热层与保温层厚度的增加是有限的,对于天津地区,推荐使用的日光温室三重结构墙体的最佳组合厚度为40 mm(expanded polystyrene board,EPS),其中40 mm PCM的复合相变墙体与同热阻的土墙、砖墙相比最高温度分别降低1.65、2.59℃,最低温度分别提高2.04、2.90℃,可明显减小温室全天温度波幅,有效改善温室热环境的整体水平;土地占用面积比同热阻的土墙、砖墙分别减少81%、60%,可提高土地利用率。
In order to reasonably determine the optimum thickness of heat storage layer and insulation layer of the composite wall in solar greenhouse,this paper studies the effect of different thickness of heat storage layer and insulation layer of the greenhouse by means of numerical simulation of EnergyPlus based on the dynamic heat transfer characteristics in Tianjin region.The results show that the heat preservation and storage capability of the wall is limited with the increase of the thickness of the heat storage layer and the insulation layer;the optimum combination thickness of composite phase change wall is 40 mm PCM+300 mm +50 mm EPS,and the 40 mm PCM,50 mm EPS are the "turning points" of wall thermal storage and heat preservation under typical meteorological conditions in Tianjin region. Compared with cob wall and brick wall with the same thermal resistance,the maximum temperature of the optimized composite phase change wall is reduced by 1.65 and 2.59 ℃,the minimum temperature is increased by 2.04 and 2.90 ℃,and the land occupation area of the optimized composite phase change wall is reduced by 81% and 60% respectively. As a result,the optimized composite phase change wall can significantly reduce the temperature fluctuation of greenhouse throughout the day and effectively improve the overall level of greenhouse thermal environment,and improve the utilization rate of land.
In order to reasonably determine the optimum thickness of heat storage layer and insulation layer of the composite wall in solar greenhouse,this paper studies the effect of different thickness of heat storage layer and insulation layer of the greenhouse by means of numerical simulation of EnergyPlus based on the dynamic heat transfer characteristics in Tianjin region.The results show that the heat preservation and storage capability of the wall is limited with the increase of the thickness of the heat storage layer and the insulation layer;the optimum combination thickness of composite phase change wall is 40 mm PCM+300 mm +50 mm EPS,and the 40 mm PCM,50 mm EPS are the "turning points" of wall thermal storage and heat preservation under typical meteorological conditions in Tianjin region. Compared with cob wall and brick wall with the same thermal resistance,the maximum temperature of the optimized composite phase change wall is reduced by 1.65 and 2.59 ℃,the minimum temperature is increased by 2.04 and 2.90 ℃,and the land occupation area of the optimized composite phase change wall is reduced by 81% and 60% respectively. As a result,the optimized composite phase change wall can significantly reduce the temperature fluctuation of greenhouse throughout the day and effectively improve the overall level of greenhouse thermal environment,and improve the utilization rate of land.
引文
[1]李建设,白青,张亚红.日光温室墙体与地面吸放热量测定分析[J].农业工程学报,2010,26(4):231-236.[1]Li Jianshe,Bai Qing,Zhang Yahong.Analysis on measurement of heat absorption and release of wall and ground in solar greenhouse[J].Transactions of the CSAE,2010,26(4):231-236.
[2]杨建军,邹志荣,张智,等.西北地区日光温室土墙厚度及其保温性的优化[J].农业工程学报,2009,25(8):180-185.[2]Yang Jianjun,Zhou Zhirong,Zhang Zhi,et al.Optimization of earth wall thickness and thermal insulation property of solar greenhouse in Northwest China[J].Transactions of the CSAE,2009,25(8):180-185.
[3]Berroug F,Lakhal E K,El-Omari M,et al.Thermal performance of a greenhouse with a phase change material north wall[J].Energy and Buildings,2011,43(11):3027-3035.
[4]张勇,高文波,邹志荣.主动蓄热后墙日光温室传热CFD模拟及性能试验[J].农业工程学报,2015,31(5):203-211.[4]Zhang Yong,Gao Wenbo,Zou Zhirong.Performance experiment and CFD simulation of heat exchange in solar greenhouse with active thermal storage back-wall[J].Transactions of the CSAE,2015,31(5):203-211.
[5]李明,周长吉,魏晓明.日光温室墙体蓄热层厚度确定方法[J].农业工程学报,2015,31(2):177-183.[5]Li Ming,Zhou Changji,Wei Xiaoming.Thickness determination of heat storage layer of wall in solar greenhouse[J].Transactions of the CSAE,2015,31(2):177-183.
[6]Gosselin L.Thermal shielding of multilayer walls with phase change materials under different transient boundary conditions[J].International Journal of Thermal Sciences,2009,48(9):1707-1717.
[7]管勇,陈超,马彩雯,等.日光温室墙体保温层最佳厚度的确定[J].新疆农业科学,2015,52(3):542-550.[7]Guan Yong,Chen Chao,Ma Caiwen,et al.Determination of optimum insulation thicknessfor solar greenhouse wall[J].Xinjiang Agricultural Sciences,2015,52(3):542-550.
[8]Crawley D,Lawrie L,Pedersen C,et al.Energy Plus:Energy simulation program[J].ASHRAE Journal Online,2000,42(4):49-56.
[9]Tabares-Velasco P C,Christensen C,Bianchi M.Verification and validation of Energy Plus phase change material model for opaque wall assemblies[J].Building and Environment,2012,54:186-196.
[10]Zhu Dandan,Hong Tianzhen,Yan Da,et al.A detailed loads comparison of three building energy modeling programs:EnergyPlus,DeST and DOE-2.1E[J].Building Simulation,2013,6(3):323-335.
[2]杨建军,邹志荣,张智,等.西北地区日光温室土墙厚度及其保温性的优化[J].农业工程学报,2009,25(8):180-185.[2]Yang Jianjun,Zhou Zhirong,Zhang Zhi,et al.Optimization of earth wall thickness and thermal insulation property of solar greenhouse in Northwest China[J].Transactions of the CSAE,2009,25(8):180-185.
[3]Berroug F,Lakhal E K,El-Omari M,et al.Thermal performance of a greenhouse with a phase change material north wall[J].Energy and Buildings,2011,43(11):3027-3035.
[4]张勇,高文波,邹志荣.主动蓄热后墙日光温室传热CFD模拟及性能试验[J].农业工程学报,2015,31(5):203-211.[4]Zhang Yong,Gao Wenbo,Zou Zhirong.Performance experiment and CFD simulation of heat exchange in solar greenhouse with active thermal storage back-wall[J].Transactions of the CSAE,2015,31(5):203-211.
[5]李明,周长吉,魏晓明.日光温室墙体蓄热层厚度确定方法[J].农业工程学报,2015,31(2):177-183.[5]Li Ming,Zhou Changji,Wei Xiaoming.Thickness determination of heat storage layer of wall in solar greenhouse[J].Transactions of the CSAE,2015,31(2):177-183.
[6]Gosselin L.Thermal shielding of multilayer walls with phase change materials under different transient boundary conditions[J].International Journal of Thermal Sciences,2009,48(9):1707-1717.
[7]管勇,陈超,马彩雯,等.日光温室墙体保温层最佳厚度的确定[J].新疆农业科学,2015,52(3):542-550.[7]Guan Yong,Chen Chao,Ma Caiwen,et al.Determination of optimum insulation thicknessfor solar greenhouse wall[J].Xinjiang Agricultural Sciences,2015,52(3):542-550.
[8]Crawley D,Lawrie L,Pedersen C,et al.Energy Plus:Energy simulation program[J].ASHRAE Journal Online,2000,42(4):49-56.
[9]Tabares-Velasco P C,Christensen C,Bianchi M.Verification and validation of Energy Plus phase change material model for opaque wall assemblies[J].Building and Environment,2012,54:186-196.
[10]Zhu Dandan,Hong Tianzhen,Yan Da,et al.A detailed loads comparison of three building energy modeling programs:EnergyPlus,DeST and DOE-2.1E[J].Building Simulation,2013,6(3):323-335.