燃煤发电机组余热梯级释放与海水淡化的过程集成及优化

The falling film evaporation of seawater multi effect distillation is proposed to couple with the cascading utilization of low-grade energy in coal-fired power generating unit. The fundmental technologies of water and electricity co-generation will be explored under key unit processes as well as system. By experimental and theoretical analysis, the falling film evaporation of supersaturated brine and phase change interface transport phenomena with great variation of heat resistances on special-shaped surface will be studied. The characteristics of brine evaporation under near-zero temperature difference, two-phase flow, distribution and seperation in narrow special-shaped space will be explored either. With the investigation of coupling approach between seawater preheating, evaporating processes and heat resources with different grades, the bottleneck problems of novel system integration of water and electricity co-generation are expected to be promoted. Based on the results, the technical integration and optimization of cascading utalization of low-grade energy of power generating unit with transport process of seawater desalination will be explored by dynamic simulations. The operating characteristics under full conditions and distributions of energy consumption of the coupled water and electricity co-generating system will be revealed. The novel technics and approach of high efficiency and low cost seawater desalination coupled with coal-fired power generation are expected by the present investigation, in which, several scientific observations may be revealed, including that of thermal system integration of complex co-generation, as well as the falling film evaporation and two-phase flow of supersaturated brine on special-shaped surface.

将海水多效蒸馏降膜蒸发与机组余热能的梯级释放过程进行耦合匹配，在单元和系统两个层面上，围绕燃煤电厂水电联产的关键技术基础展开探讨。通过实验和理论研究，对过（热）饱和盐溶液的膜状蒸发机理和异型表面上大热阻相界面热质传递过程及强化开展探索，揭示海水近零温差降膜蒸发特性、狭窄异型空间内汽液两相流动与汽液分布、分离规律；探讨海水预热蒸发过程与多品位热源的耦合匹配方法，为水电联产新工艺系统集成解决关键问题。以此为基础，在系统层面上，利用动态仿真技术，研究燃煤发电机组不同品位热能梯级释放、及其与新型的海水淡化热质输运过程的集成方案；揭示水电多联产耦合热力系统的全工况运行性能和能耗时空分布。通过对复杂多联产热力系统集成和异型表面过饱和盐溶液降膜蒸发及两相流动等科学问题的探索和发现，衍生出在宽广热力学参数范围内与燃煤发电机组耦合的高性能、低成本海水淡化新工艺和新方法，推动水电联产海水淡化技术进步。

将海水多效蒸馏降膜蒸发与机组余热能的梯级释放过程进行耦合匹配，在单元和系统两个层面上，围绕燃煤电厂水电联产的关键技术基础展开探讨。通过实验和理论研究，对过（热）饱和盐溶液的膜状蒸发机理和异型表面上大热阻相界面热质传递过程及强化开展探索，揭示海水近零温差降膜蒸发特性、狭窄异型空间内汽液两相流动与汽液分布、分离规律；探讨海水预热蒸发过程与多品位热源的耦合匹配方法，为水电联产新工艺系统集成解决关键问题。以此为基础，在系统层面上，利用动态仿真技术，研究燃煤发电机组不同品位热能梯级释放、及其与新型的海水淡化热质输运过程的集成方案；揭示水电多联产耦合热力系统的全工况运行性能和能耗时空分布。本项目通过对复杂多联产热力系统集成和异型表面过饱和盐溶液降膜蒸发及两相流动等科学问题的探索和发现，衍生出在宽广热力学参数范围内与燃煤发电机组耦合的高性能、低成本海水淡化新工艺和新方法，推动水电联产海水淡化技术进步。项目执行期间，发表学术期刊论文23篇，其中SCI收录的国际学术期刊论文16篇；申请发明专利3项；培养博士后1名，研究生7名；分别在台北和北京参与组织2次国际学术会议。按照任务书要求达到了预期研究目标。