太阳能集热棚上极端离地风沙运动和沙粒沉积机理研究

在当前化石能源短缺、雾霾天气严重的背景下，利用广阔荒地发展太阳能热气流发电技术，开发清洁能源，具有促进能源转型的战略性意义。太阳能热气流集热棚在极端风沙流作用下可能存在因局部荷载过大而出现棚面破裂甚至框架倒塌等问题。本项目针对急需解决的问题，拟采用模型建立、数值计算和实验结果对比方法，开展太阳能集热棚上极端离地风沙运动和沙粒沉积机理研究。研究内容：（1）考虑棚高度、棚面光滑度、沙粒级配及形状、烟囱绕流、风速等因素，计入风沙电场和棚面高温影响，耦合气相流动子模型和颗粒离散元子模型，建立适合于光滑、高温集热棚的极端离地风沙流模型，并采用有效的计算方法进行求解；（2）研究热-电联合作用下风-沙动态耦合特性和一般规律，研究在无烟囱的集热棚上风沙运动和沙粒沉积机理，并设计模型风洞实验进行对比；（3）研究风沙烟囱绕流机理，并和已有相关实验对比。本项目为太阳能集热棚的抗极端风沙流设计和分析提供理论依据。

Due to shortage of fossil energy and heavy haze weather, it is very significant to use solar chimney thermal power generating technology to develop clean energy sources on vast desert regions and to promote energy transformation. The glass roof of the solar collector may crack, and even its framework supported by steel supports may collapse, under the effect of large sand loads due to strong wind sand flow. This project will study the mechanism of strong wind sand movement away from ground and sand deposition on solar collector by modeling, numerical computation, and comparison with experiments. This project includes: (1) Firstly, to build the model of strong wind sand flow away from the ground suitable for the smooth and high-temperature collector roof by coupling the air flow submodel and particle DEM submodel, with the inclusion of the factors such as the height and smoothness of the collector roof, the gradation and shape of the sands, the flow around the chimney, the wind speed, the wind sand electric field, and the high roof temperature, and use an effective computational procedure to solve the equations of the model. (2) Secondly, to study the general behavior of fluid-sand coupling interaction under the combined effect of heat of collector roof and electrification of wind-blown sands, study the mechanism of wind sand movement and sand deposition on the collector roof away from solar chimney, and compare the simulation results with the wind tunnel test data of the setups designed. (3) Thirdly, to study the mechanism of wind sand movement on the collector roof around the chimney, and compare the simulation results with the relevant existing experiment results regarding cylinders. This project will provide theoretical foundation for the collector’s design and analyses for resisting strong wind sand force.