半透明膜结构料场内部热环境形成机理及高效通风策略研究

Translucent membrane construction stockyard is believed to be one of the most promising methods to prevent the pollution caused by the open piled material heap. However, the thermal environment inside this kind of buildings is a big challenge constraining its practical application, especially in either extremely hot or cold climate. The present research will be focused on elucidating the formation mechanism of thermal environment inside the translucent membrane structure stockyard and exploring an efficient ventilation strategy suitable for the industrial membrane construction. On the basis of experiment, theoretical analysis, on-site testing and numerical simulation, the present research will be aimed at addressing the following four issues. First, we will determine both of the spatial scale characteristics and the building features by analyzing the data from literature and field survey. Second, we will reveal the heat transfer mechanism and load characteristics of membrane structure with ultra-thin lightweight envelope by carrying on the experiment of heat storage and exothermic characteristics of membrane structure and theoretically analyzing the load variation law. Third, by means of the on-site measurement and numerical simulation, the distributions of temperature field and velocity field inside industrial membrane building in the influence of coupled indoor and outdoor conditions will be obtained. Finally, we clarify the action law of the individual adjustable factor and the interaction of multiple factors by implementing the ventilation effect evaluation function. And we will propose an optimization model, solved by a modern multi-objective optimization method, to achieve the best combination of ventilation design parameters. The research results are expected to contribute to providing theoretical foundation and technical support for the ventilation design of membrane type architectural engineering, specifically, of membrane structural building for mineral storage.

半透明膜结构料场是解决露天开放性料堆引起的污染问题的重要途径之一，但在实际应用过程中该类建筑内部热环境令人堪忧，尤其是在极端炎热和寒冷气候条件下。本项目围绕半透明膜结构料场内部热环境形成机理这一核心问题，旨在探索适合膜建筑特性的高效通风策略。首先，通过调研掌握该类建筑的空间尺度特点、使用特征；然后，开展膜结构蓄放热特性实验和负荷变化规律理论分析，研究膜类超薄轻质围护结构的传热机理与负荷特性；其次，采用现场实测与数值模拟相结合的手段，揭示室内外参数耦合作用下工业膜建筑内温度场和速度场分布规律；最后，应用通风作用效果评价函数分析各单一可调性因素及多因素综合作用规律，并建立通风气流组织优化模型，使用现代多目标优化方法进行求解，得出最佳的通风设计参数组合。研究成果不仅在理论上有重要意义，而且为膜类建筑工程通风设计提供理论基础和技术支撑，对膜结构建筑在矿料仓储方面的推广应用具有很强的实用价值。

料场封闭工程的建设是实现源头削减污染、减少物料贮存损失的最佳方式。相对于传统钢网架结构，膜结构建筑由于自重轻、造价低、可利用自然光、易安装维护等优点，可用于原燃料仓储等中部无支撑的大跨度体系，但其透光性与保温隔热不易做到平衡，尤其在极端炎热或寒冷气候条件下，其内部热环境令人堪忧。鉴于此，本项目构建了轻薄半透明膜结构传热理论计算模型，提出了轻薄半透明膜类围护结构得热量的计算分析方法，查明了其蓄放热特性及负荷变化规律；并搭建了膜结构室内热环境测试缩尺实验平台，获取了轻薄半透明膜材围护结构建筑各朝向内外壁面温度、室内温度、室外气象参数、太阳辐射强度等关键实验数据，验证修正了计算模型，揭示了轻薄半透明膜材围护结构建筑内部空气温度分布和壁面温度受室内外参数耦合影响下的波动规律，发现膜建筑内部白天存在“温室效应”，夜间存在“冷室效应”。同时，构建了轻薄半透明膜结构建筑室内通风气流组织数值计算模型，实测数据很好地验证了该模型的准确性，并通过模拟和实验揭示了无物料堆放、堆放无自发热物料和堆放有自发热物料三种情况下封闭式工业半透明膜结构建筑室内温度场、速度场分布规律，阐明了进、排风口位置和通风口面积等通风策略改变对室内实际通风效果的影响；最后，基于膜建筑室内垂直温度梯度分布特征，提出了适宜于半透明膜结构料场的“热压强化置换通风”的高效节能通风策略，并对通风设计参数进行再优化。相关研究成果可有效解决现有的建筑热工设计方法不适用于半透明膜结构料场的难题，为膜结构建筑在矿料仓储方面的推广应用提供理论基础和技术支撑。