摘要
传统日光温室被动的热环境调控模式难以满足温室作物冠层区空气温度和速度调控需求,且能源利用效率低下。为了改进日光温室热环境精准调控方法和提高温室能源利用效率,该研究结合日光温室围护结构特点,提出了一种日光温室拱架的送/回风方法,并基于温室作物多孔介质模型,建立了拱架送/回风系统温室的数值传热模型。采用空气温度与速度不均匀系数、气流速度适宜区面积比、能量利用系数以及累计有效积温等评价参数,研究了下送上回、中间回风和上送下回等3种温室拱架送/回风方式对日光温室冬季作物冠层区热环境的影响。结果表明,与中间回风和上送下回通风方式相比,下送上回通风方式对不同作物冠层高度处的空气温度和速度调控的结果最优,且不同作物冠层高度处气流速度适宜区面积比和累计有效积温都最大。当采用下送上回通风方式时,与送风干管风速为9、11和12 m/s相比,送风干管风速为10 m/s的能量利用系数最大,在作物冠层高度0.4、0.6、0.8和1.0 m处的能量利用系数分别为0.976、0.982、0.985和0.987,并且不同作物冠层高度处的空气温度不均匀系数和速度不均匀系数也都最小。因此,下送上回通风方式的推荐送风干管风速为10 m/s。该研究可为日光温室热环境的精准调控提供参考。
Solar greenhouses are one of the most important agricultural facilities for off-season vegetable production in northern China,particularly in the long-term,stable and safe supply of vegetables.The environmental control equipment of solar greenhouses is relatively simple with the low level of automation at present.Manual induction control can also result in low environmental control capabilities in the greenhouse.Thus,the traditional passive thermo-environment control mode cannot be used to regulate the air temperature and velocity in greenhouse crop canopy areas,due to the low energy efficiency.In this study,a new mode of air supply-air return was proposed to consider the enclosure structure using the arch frame of a solar greenhouse.A heat transfer model was developed with the crop porous media model for the solar greenhouse under the air supply-air return.Four evaluation parameters were selected,including 1)the non-uniformity coefficient of the air temperature and velocity;2)the area ratio of the suitable zone for air velocity;3)the energy utilization coefficient;4)the cumulative effective accumulated temperature.A systematic evaluation was implemented to clarify the effects of three air supply-air return modes on the thermal environment of the indoor crop canopy area for solar greenhouse in winter.The results showed that the downside air supply-upper air return mode outperformed the other two modes(the intermediate air return and the upper air supply-downside air return modes),in terms of air temperature and velocity at various crop canopy heights.The greatest area ratio of the suitable zone was achieved in the air velocity,corresponding to the crop canopy heights.Once the insulation quilt was turned off,the highest cumulative effective accumulated temperature of the downside air supply-upper air return was 132.86℃·h,which was higher than that of the intermediate return air and upper air supply-downside air return by 1.57%and 8.89%,respectively.When operating at the downside air supply-upper air return mode
作者
胡万玲
陈冲
管勇
马乔乔
叶文涛
HU Wanling;CHEN Chong;GUAN Yong;MA Qiaoqiao;YE Wentao(School of Environmental and Municipal Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;Key Laboratory of Yellow River Water Environment in Gansu Province,Lanzhou 730070,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2024年第4期262-272,共11页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金资助项目(51868035
51866006)。
关键词
日光温室
拱架
数值分析
送/回风方式
热环境
能量利用系数
作物冠层区
solar greenhouse
arch frame
numerical analysis
air supply-air return mode
thermal environment
energy utilization coefficient
crop canopy area
