对喷式二次雾化海水循环冷却系统中的液滴碰撞与传热传质耦合研究

Inter-spray secondary atomization cooling system refines the cooling water by means of breakup theory of droplets collision. Eliminating the fill makes the tower fully empty which is of far-reaching significance in cooling circulating seawater with high temperature and high turbidity. Taken the atomization and cooling process in the droplet collision-secondary atomization seawater circulation cooling as the object of the research,the project will study the droplet behavior characteristics and heat and mass transfer mechanism. Specific investigation includes: Droplet collision behavior and atomization results with multiple nozzles will be calculated and analyzed theoretically; The new coupled model of droplet collision with the air-water two-phase heat and mass transfer will be set up, which prives a thought for numerical calculation of the discrete phase system; The influence of coupled multi-factor including the water impinging way, the nozzle layout programs, water quality and working conditions on the water atomization and cooling performance will be revealed by means of theoretically analyzing the numerical simulation and experimental results, and the new coupled model of heat and mass transfer with droplet collision theory will be validated and improved. The project will provide a theoretical basis for seawater secondary atomization cooling technology.

对喷式二次雾化海水循环冷却技术利用液滴碰撞破碎原理对冷却水进行细化并冷却，由于去除了填料，避免了由于水质和温度原因引起的填料性能下降和破坏，对处理高温、高浊度、易结垢海水具有重要意义。本项目以液滴碰撞式的海水雾化过程和冷却过程为研究对象，对液滴碰撞后的雾化机理及传热传质规律进行基础科学研究。具体内容包括：1)通过对液滴碰撞进行理论分析、计算及实验研究，揭示对喷式雾化方式引起的液滴碰撞行为及多组喷头的综合雾化机理；2)结合液滴碰撞理论，建立气水两相传热传质的耦合模型，为离散相系统的数值计算提供一种思路；3)通过对数值模拟和实验结果进行理论分析，揭示喷头布置方案、海水水质及工况参数对海水雾化效果和冷却性能的影响规律，验证并完善基于液滴碰撞理论的气水两相传热传质耦合模型，为海水二次雾化冷却技术提供理论基础。

海水在循环冷却过程中水质会发生变化，导致其物性参数也变化，所以不同水质的海水与淡水的二次雾化效果不同，这会直接影响冷却系统内的气水传热传质过程。因此，研究不同水质的海水的二次雾化机理及其对海水传热传质过程的影响规律，对于海水循环冷却技术的设计、应用与发展具有重要意义。.为解决这些问题，本项目采用理论分析、数值模拟及实验研究相结合的方法，首先研究了单个液滴的运动及传热传质规律，以及两个液滴的碰撞行为；建立海水二次雾化冷却系统内流体力学模型、传热传质模型及液滴碰撞模型的耦合数学模型，对海水水滴在碰撞后的二次雾化规律以及气水的热质传递过程进行研究；并以此为基础探讨各参数对海水冷却性能的影响。此外，本项目还建立了无填料冷却系统的神经网络模型并进行研究。