海水淡化旋转式压能回收过程流动自适应性机理研究

Pressure energy recovery technology ，which is one of three key technology in membrane desalination,is the important determinant of Seawater desalination cost. At present, study on the pressure exchange mechanism and its influencing factors is comparely deficient, and become the restriction bottleneck in pressure recovery technology nationalization.Then, the pressure energy recovery efficiency and stability of the system are the important reference index for pressure energy recovery technology.In order to improve the pressure energy recovery efficiency and stability of the system, must explore the effective research plan and reveal adaptive flow mechanism in pressure energy recovery according to the influence factors.By studying the interaction mechanism of liquid mixing, the project reveals the process of liquid mixing and the evolution mechanism, and puts forward the stability conditions of the mixing zone used as "liquid piston". Furthermore, the project explores the change relationship and movement rules of the mixing zone with flow velocity and time.The project also develops fluid-solid coupling model under the action of hydraulic rotor, and explores the balance characteristics between angular momentum and liquid membrane resistance.What's more, developing the liquid unsteady research model when rotor cutting in and cutting out liquid trough, establishing the numerical simulation method in transient process, and putting forward the prediction methods of system transient characteristics are all contained in this project.Finally, the project do much research on establishing the detection anti-jamming ability of method fluid system, exploreing the relationship between unexpected disturbance with mixing, fluid-solid coupling and transient characteristic.All the research achievements will provide the necessary theoretical basis on the domestic and foreign relevant field of research and engineering application.

压能回收技术是膜法海水淡化三大关键技术之一，它是海水淡化成本的重要决定因素。目前，国内对于压能交换机理及其性能影响因素的研究还比较匮乏，成为制约压能回收技术国有化的瓶颈。压能回收效率和系统稳定性是压能回收技术的重要参考指标。为提高压能回收效率和系统稳定性，重点研究液体掺混区的交互机理，揭示转子内液体掺混区的形成过程和演化机理，提出掺混区可作为"液体活塞"的稳定性条件，探索转子内掺混区形态及其运动规律与时间和流速的变化关系；发展转子在液力作用下的流固耦合研究模型，探索转子旋转角动量与转子液膜阻力的平衡特征；发展转子旋转切入集液槽和切出集液槽时非稳态研究模型，建立瞬态过程流动的数值模拟方法，提出系统的瞬态特性预测方法；建立检测流体系统抗干扰能力的方法，探索掺混、流固耦合及切入切出瞬态受扰动时的变化特征。本项目研究成果可为国内外相关领域研究及工程应用提供必要的理论基础。

压能回收技术是膜法海水淡化三大关键技术之一，它是海水淡化成本的重要决定因素。目前，国内对于压能交换机理及其性能影响因素的研究还比较匮乏，成为制约压能回收技术国有化的瓶颈。压能回收效率和系统稳定性是压能回收技术的重要参考指标。为提高压能回收效率和系统稳定性，针对海水淡化压能回收过程中转子旋转的动力及阻力特性，转子自适应旋转平衡特征，端盖流道的水力特性及优化，转子与端盖间的特性，转子旋转启动的瞬态特性，高压端出口压力变化特征以及转子高速旋转稳定性等方面展开研究，重点研究液体掺混区的交互机理，揭示转子内液体掺混区的形成过程和演化机理，提出掺混区可作为“液体活塞”的稳定性条件，探索转子内掺混区形态及其运动规律与时间和流速的变化关系；发展转子在液力作用下的流固耦合研究模型，探索转子旋转角动量与转子液膜阻力的平衡特征；通过转子动力矩变化波形的统计、比对、分析，建立转子转速与端盖三维流道曲面倾角的匹配变化特征，提出转子旋转角动量与转子液膜阻力的自平衡条件；发展转子旋转切入集液槽和切出集液槽时非稳态研究模型，建立瞬态过程流动的数值模拟方法，提出系统的瞬态特性预测方法；建立检测流体系统抗干扰能力的方法，探索掺混、流固耦合及切入切出瞬态受扰动时的变化特征，通过出口压力脉动波形的统计、比对、分析，建立转子转速与掺混区尺度速度的匹配变 化特征，提出转子旋转角动量与转子液膜阻力的自平衡条件；发展了基于出口压力波型监测的压能交换系统稳定性预判方法。通过项目实施，在转子直通道内的掺混区运动计算、转子与端盖微隙密封流动的计算分析、端盖流体驱动转子旋转的数值计算、转子转速与出口端压力脉动的瞬时同步测量、掺混率模拟测量和压能回收效率预测等方面取得了重要进展，可为国内外相关领域研究及工程应用提供必要的理论基础。