Study on prediction and control of air-distribution within bi-production facilities.

在大型温室和畜舍中，风速、温度、湿度等气流组织特性对有效生产非常重要。另一方面，引入CFD（计算流体力学）技术来预测和控制生物生产设施内的气流分布环境。本研究的目的是利用CFD技术建立新的生物生产设施环境设计方法。首先，通过在中国和日本的大型温室中安装垫式和风扇冷却系统的实验，完成了气流组织的基本数据收集。然后利用CFD技术对温室内的三维气流和温度分布进行了数值计算和模拟。利用CFD技术计算得到的垫层和风扇冷却系统下温室内的风速和温度分布与实验数据非常接近，证明了CFD技术计算的有效性。此外，CFD技术的模拟结果表明，温室内部空间存在主气流区和回风区，温室空间温度分布存在垂直和水平的不均匀性。另一方面，来自冷却垫的低温空气受回风流的影响侵入到高屋顶空间，从而降低了冷却效果。为了收集垫扇冷却系统温室内气流分布的基本数据，在中国北京、上海和日本爱知县的不同气候条件下进行了实验测量。从实验中可以看出，在炎热的季节，垫和风扇冷却系统在相当潮湿的气候条件下是有效的。然而，在太阳辐射下，从垫板到风扇的整个气流方向的温度升高是垫板和风扇冷却温室的共同问题。采用CFD技术，对种植番茄等高产作物的垫扇降温温室室内气流和温度分布进行了数值模拟。如果气流方向与作物原料方向一致，且作物层具有有效的体积孔隙度和表面渗透率，则可以识别作物层内的冷却效果。少

Air distribution characteristics, such as air-velocity, temperature, humidity and do on, are very important for effective production in large-scale greenhouses and livestock housings. On the other hand, the CFD (computational fluid dynamics) technique is introducing to predict and control the air-distribution environment within the bio-production facilities. The objective of this study is to establish the new environmental design method for bio-production facilities using with the CFD technique. At first, the basic data collections of air-distribution were done through the experiments in large greenhouses equipped with the pad and fan cooling system in China and Japan. And then numerical calculation and simulation on the three dimensional airflow and temperature distribution inside the greenhouses were performed by using the CFD technique.1. Using the CFD technique, calculated air-velocity and temperature distribution in the greenhouse with the pad and fan cooling system were very clos … More e to the experimental data, so it was proved that there was a clear validity of the calculation by CFD technique. In addition, simulation results by the CFD technique showed the main and return air-flow areas existed in the space inside the greenhouse, and the vertical and horizontal non-uniformity of the temperature distribution existed in the greenhouse space. On other hand, the low temperature air from the cooling pad intruded into high roof space by the influence of return air-flow, and therefore the effect of cooling was decreased.2. In order to collect the basic data of air-distribution in the greenhouses with the pad and fan cooling system, experimental measurements were performed under different climatic conditions in Beijing and Shanghai in China and Aichi Prefecture in Japan. From the experiments, the pad and fan cooling system was considered to be effective in rather humid climatic conditions during hot season. However, the common problem in the pad and fan cooling greenhouse was the temperature rise across the airflow direction from the pad to fan under solar radiation.3. The interior air-flow and temperature distribution were simulated by using the CFD techniques in the pad and fan cooling greenhouse in which high crop such as tomatoes are grown. The cooling effect inside the crop layer was recognized if the directions of air-flow was coincide with the crop raw and the crop layer had effective volume porosity and surface permeability. Less