EPRI: Collaborative Research: autoFlutter: Efficient, Waterless Power Plant Cooling

EPRI：合作研究：autoFlutter：高效、无水发电厂冷却

• 批准号: 1357819
• 负责人: Rajat Mittal
• 金额: $ 15.17万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-05-15 至 2018-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1357819&HistoricalAwards=false
• 关键词: EPRI; Collaborative; Research; autoFlutter; Efficient

CBET-1357819MittalThe rate of consumption and withdrawal of water for use in power plant cooling systems has become untenable in light of limited water supply and cost, as well as regulatory restrictions, and environmental concerns. However, the effectiveness of dry air cooling of current, conventional condenser systems has been hindered by the high thermal resistance and poor air thermal capacity of the cooling air. It is clear that in order to enable an appreciable decrease in water consumption for power generation, the heat transfer between the condensing steam and the air-side medium must be significantly enhanced. Earlier attempts to improve the air-side heat transfer focused on the addition of surface features (dimples, etc.) on the cooling fins with limited success and significant increase in fan power. The proposed program overcomes the limits of air-side heat transport by exploiting interactions between the cooling air flow and miniature, autonomously-fluttering reeds (AFRs) to induce the formation and advection of small-scale vortical motions near the condenser fin surfaces. A unique aspect of this approach is that reed flutter is generated by harnessing mechanical energy from the embedding cooling air flow at exceedingly low penalty in pressure losses. These low-cost thin reeds can be tailored for different regions of the condenser and fabricated either integral to the external condenser surfaces or as drop in retrofit assemblies for existing condensers. The reed assemblies are easy to install and maintain without plant level infrastructure modifications. Preliminary heat transfer enhancement and pressure drop analyses coupled with condenser designs and power plant simulations have shown that air-cooled condensers using AFR technology can increase plant efficiency while significantly reducing water consumption compared to wet cooling. The research program will focus on enabling advances in thermoelectric power plant condenser technology to overcome current limits of cooling by dry air and thereby significantly reduce water usage for evaporative cooling. The present approach overcomes the limits of air-side heat transport by exploiting interactions between the cooling air flow and miniature, autonomously-fluttering reeds (AFRs) to induce the formation and advection of small-scale vortical motions near the condenser fins. A unique aspect of this approach is that reed flutter is generated by harnessing mechanical energy from the embedding cooling air flow at exceedingly low penalty in pressure losses. The program encompasses integrated experimental/modeling/numerical investigations that will focus on the fundamental knowledge needed to implement, design, and optimize the use of the AFRs, and demonstrate their efficacy in improving the heat transfer characteristics of finned air-side passages of condensers in power plant configurations and operating conditions. The research at Georgia Tech will focus on experimental investigations of the heat transfer characteristics enhanced by the AFRs along with the modeling, design, and testing of novel condenser configurations enabled by the AFR technology. Johns Hopkins University will focus on CFD investigations of small-scale heat transfer and performance evaluation and optimization of AFR-enhanced condenser configurations. Small-scale heat transfer enhancement by AFRs was recently demonstrated in air-cooled heated ducts at Georgia Tech with significant heat transfer enhancement. These low-cost thin reeds can be tailored for different regions of the condenser and fabricated either integral to the external condenser surfaces or as drop in retrofit assemblies for existing condensers. The reed assemblies are easy to install and maintain without plant level infrastructure modifications.

CBET-1357819毫无疑问，鉴于水供应和成本有限，监管限制和环境问题，用于发电厂冷却系统的消费率和撤出水的使用率变得站不住下来。 然而，高温阻力和冷却空气的空气热容量较差，导致传统冷凝器系统的干燥空气冷却的有效性受到阻碍。 显然，为了使发电的水消耗明显减少，必须显着增强冷凝蒸汽和空气侧介质之间的热传递。 较早的尝试改善空气侧传热的尝试集中在添加表面特征（酒窝等）上的冷却鳍上，其成功率有限，风扇功率显着增加。 提出的程序通过利用冷却空气流与微型，自动融化的芦苇（AFRS）之间的相互作用来克服空中热传输的极限，以诱导冷凝器鳍表面附近的小规模涡流运动的形成和对流。 这种方法的一个独特方面是，通过从压力损失中嵌入冷却气流的嵌入冷却气流以极低的惩罚中来产生芦苇颤动。 这些低成本的薄芦苇可以针对冷凝器的不同区域量身定制，并为外部冷凝器表面不可或缺的组成部分，也可以作为现有冷凝器的翻新组件掉落。芦苇组件易于安装和维护，而没有植物级别的基础架构修改。 初步的传热增强和压降分析以及冷凝器设计和发电厂仿真的结合表明，使用AFR技术的气冷冷凝器可以提高植物效率，同时与湿冷却相比大大降低了水的消耗。 该研究计划将着重于实现热电厂冷凝器技术的进步，以克服干燥空气的当前冷却限制，从而大大减少用水量以蒸发冷却。 目前的方法通过利用冷却空气流与微型，自动铺设的芦苇（AFRS）之间的相互作用来克服空气侧热传输的极限，从而诱导了冷凝器鳍附近的小规模涡流运动的形成和对流。 这种方法的一个独特方面是，通过从压力损失中嵌入冷却气流的嵌入冷却气流以极低的惩罚中来产生芦苇颤动。 该计划涵盖了集成的实验/建模/数值研究，该研究将着重于实施，设计和优化AFRS所需的基本知识，并证明了它们在提高电源工厂配置和操作条件中冷凝器鳍空气侧通道的传热特征方面的功效。 佐治亚理工学院的研究将重点介绍对AFRS增强的传热特性的实验研究，以及AFR技术实现的新型冷凝器配置的建模，设计和测试。 约翰·霍普金斯大学（Johns Hopkins University）将重点介绍有关小规模传热和绩效评估的CFD调查，并优化了AFR-增强冷凝器配置。 最近在佐治亚理工学院的气冷加热管中证明了AFR的小规模传热增强，并具有显着的传热增强。 这些低成本的薄芦苇可以针对冷凝器的不同区域量身定制，并为外部冷凝器表面不可或缺的组成部分，也可以作为现有冷凝器的翻新组件掉落。芦苇组件易于安装和维护，而没有植物级别的基础架构修改。