压水式曝气的升温、增氧效应及水体分层特性研究

Down-welling aeration, which can improve water quality, has been applied in European counties along Baltic Sea. However, the mechanism is still deficiency. Experiments and numerical simulation will be used in this research. The affections of aeration parameters (such as aeration flow, depth, pipe geometry, etc.) on water thermal field, flow field and dissolved oxygen (DO) will be analyzed comprehensively. Comparison method will be used to study on water column characters and changing processes, when single, double and multi-parameters of aeration changes. The relationship between aeration parameters and water thermal, water turbulence and DO distribution will be build, while the rules between sediments disturbance and sediment-water turbulence will be optimized. Temperature and DO increasing systems will be explored. What’s more, flow field visualization technology will be used to study internal wave creation, development and transformations, rules of water stratification will be explored. A down-welling aeration theory, which can gently warming, highly increasing DO, no disturbing sediment and keeping stratification, will be built. This research will be important significance and broad application prospects to artificial aeration and related projects.

压水式曝气作为一种改善分层水体水质的方法，在环波罗的海的欧洲国家已有所应用，但其机理的研究还不十分完善。本项目拟采用模型实验和数值计算相结合的方法，综合分析压水式曝气各参数（曝气流量、曝气深度、曝气管几何参数、曝气时间等）对水体温度场、流场和溶解氧分布的影响。采用比对法依次分析单一参数变化、双参数变化和多参数耦合作用下，水动力参数和溶解氧的变化过程和特性。建立各曝气参数与恒温层水体温度升量、溶解氧增量、水体紊流度变化及其有效作用范围之间的关系，完善沉积泥上覆水紊流度与沉积泥沉降之间的关系规律，探索压水式曝气的升温和增氧效应。应用流场可视化技术，对温跃层中内波的产生、发展和变化过程进行系统的研究，探究理想状况下水体分层的一般规律。最终，提炼出一种升温量小、增氧效率高、不搅动底泥且维持水体分层的压水式曝气理论方法，为曝气及其它相关工程的实施提供理论依据。

压水式曝气作为一种改善分层水体水质的方法，在环波罗的海的欧洲国家已有所应用，但其机理的研究还不完善。本项目自主开发了一套压水式曝气的实验平台，通过该平台完成模型实验研究，同时，基于ANSYS-CFX中的流体计算模块，对压水式曝气的过程进行了数值模拟，分析了压水式曝气各个参数（曝气流量、曝气深度、曝气时间等）对水体温度场、流场和溶解氧分布的影响。采用比对法依次分析单一参数（如曝气深度、曝气流量和曝气时间等）变化、多参数变化和多参数耦合作用下，实验水槽中水体流动速度、流场和溶解氧的变化过程和特性。在项目实施过程中，主要采用3D-PIV技术，研究了水体垂直方向流动对沉积泥上覆水流动的影响情况。此外，还对压水式曝气对表层沉积泥中微生物的种类和总量的影响进行了较系统的分析。