EAGER: Ejector Cooling System with Evaporation/Condensation Compact Condenser

[1439296]目前，美国十分之九的蒸汽发电厂需要冷凝水冷却，约占全国淡水总取水量的40%，约占全国淡水总消耗量的3%。为了显著减少或消除冷却发电厂的用水，拟议的研究将展示新一代基于喷射器的冷却技术，该技术可以显著减少或消除冷却发电厂的用水。利用低品位的蒸汽热能，喷射器可以创造一个超音速流和低压区，可以用来产生冷却。结合创新的蒸发/冷凝紧凑型冷凝器，利用混合疏水和亲水冷凝表面和薄膜蒸发，将展示一种基于喷射器的冷却技术的创新概念。这种创新和潜在的变革系统可以显着减少或消除水的使用，并显着减少冷凝器的尺寸；在环境温度为30℃的情况下，能显著降低冷凝温度，从50℃降至35℃。此外，该系统可以很容易地集成到正在进行的冷却系统中。拟议的冷却系统集成了由低等级热能驱动的喷射器制冷技术、疏水和亲水混合冷凝表面、薄膜蒸发和高效低成本振荡热管。利用蒸汽的低品位热能为喷射器制冷系统提供动力。对喷嘴、混合室和扩散器中的超声速流动及其对夹带的影响的基本理解，是限制喷射器制冷广泛应用的一个缺失部分。对超声速流动进行热力学分析和流体动力学建模，从而更好地了解喷射器的性能。5千瓦的原型，优化喷嘴，混合室和扩散器将被展示。疏水和亲水混合冷凝表面对冷凝传热的影响将被进行，以提供对流体流动和冷凝机制的深入了解。薄膜蒸发的优化可以进一步将蒸发传热极限提高到一个新的水平。嵌入无芯振荡热管的低成本翅片将被证明可以提高空气侧的传热效率。由此产生的基于喷射器的紧凑型冷凝器，如果成功，将对电厂的冷却产生重大影响。

1439296MaCurrently nine out of ten power plants in the United States that generate electricity from steam power require condensate cooling which accounts for approximately 40% of the nation's total freshwater withdrawals and approximately 3% of the nation's total freshwater consumption. In order to significantly reduce or eliminate the use of water for cooling power plants, the proposed research will demonstrate a new generation of ejector-based cooling technology that can result in significant reductions or elimination of the use of water for cooling power plants. Using low-grade thermal energy of steam, an ejector can create a supersonic flow and low pressure zone that can be used to produce cooling. Combining an innovative evaporation/condensation compact condenser, that utilizes hybrid hydrophobic and hydrophilic condensing surfaces and thin film evaporation, an innovative concept of ejector-based cooling technology will be demonstrated. This innovative and potentially transformative system can significantly reduce or eliminate the use of water and significantly reduce the condenser size; furthermore, and it can significantly reduce condensation temperature from 50 °C to 35 °C at an ambient temperature of 30 °C. In addition, this system can be easily integrated into ongoing cooling systems.The proposed cooling system integrates state-of-the-art technologies of ejector refrigeration powered by a low-grade thermal energy, hybrid hydrophobic and hydrophilic condensing surfaces, thin film evaporation, and efficient low-cost oscillating heat pipes. The low-grade thermal energy of steam is utilized to power the ejector refrigeration system. Fundamental understanding of supersonic flow in nozzles, mixing chambers, and diffusers, and its effect on the entrainment in particular, is a missing piece that has restrained ejector refrigeration from wide-spread application. Thermodynamic analysis and fluid dynamic modeling of the supersonic flow will be conducted resulting in a better understanding of ejector performance. A prototype of 5 kW with optimized nozzle, mixing chamber, and diffuser will be demonstrated. The effect of a hybrid hydrophobic and hydrophilic condensing surface on the condensation heat transfer will be conducted in order to provide an insight into fluid flow and condensation mechanisms. Optimization of thin film evaporation can further push the evaporating heat transfer limit to the next level. Low-cost fins embedded with no-wick oscillating heat pipes will be demonstrated to increase the heat transfer efficiency of the air side. The resulting ejector-based compact condenser, if successful, will have significant impact on power plant cooling.