SBIR Phase I: High Efficiency Multi-fluid Jet Refrigeration

这个小型企业创新研究第一阶段项目将展示一种高效的超音速喷射器蒸汽压缩技术，该技术可以在较高的冷凝器温度(100-120F)下将中低等级热能(200-400F)转化为有用的制冷(20F-50F)。所提出的多流体喷射冷却器通过使用潜伏期相对较低的推进剂来连续携带和压缩相对较高潜伏期的不相容低温制冷剂，从而最大化了换热效率。最初的原型比传统的单流体喷射器的效率高400%。IResearch阶段将在较高的冷凝器温度下运行时延长这些收益。具体的研究重点是：1)高效喷射喷嘴，用于超音速膨胀高摩尔质量、低比热比推进剂，而不会出现使用常规喷嘴设计时观察到的膨胀/压缩损失；2)在超音速推进剂中混合亚音速制冷剂，动能损失最小；以及3)最大压力恢复扩散器，利用弱的斜压缩波而不是强的正常冲击波将混合的超音速流动转变为亚音速速度。双流体喷射器压缩技术的潜在应用包括自然燃气动力空调、集中式太阳能冷水机组、成本较低的联合供热和制冷机组，以及热力驱动的水淡化。该项目的更广泛的影响/商业潜力是减少与世界相关的经济和气候负担？S对空间制冷的需求日益增长。空调是美国高峰时段电力的主要使用方式，也是商业建筑最大的能源消耗。在全球范围内，价值650亿美元的空调设备市场正以每年5%的速度增长；由于它以电力驱动的机械蒸汽压缩循环为主，电网的压力--以及环境和经济的延伸--也在增加。安静、清洁、可靠和经济高效的热驱动解决方案将极大地降低这些风险。不幸的是，目前的技术效率低，外形尺寸大，需要昂贵的水冷冷凝器。最初的研发工作已经证明，在温和的环境条件下运行时，使用低成本组件制造的优化流体对的喷射器蒸汽压缩机的运行效率可以与电动压缩机竞争。然而，大众市场的采用需要在极端室外温度下高效运行。第一阶段的研究将最大限度地提高冷却功率和排放压力(从而在高冷凝器温度下可操作)，将不相容流体对在超音速膨胀和压缩过程中产生的不可逆损失降至最低。项目发现将使高超声速航空电子设备和低大气喷气推进系统的邻近领域受益

This Small Business Innovation Research Phase I project will demonstrate a highly efficientsupersonic ejector vapor compression technology that converts low-to-medium grade thermal energy(200-400F) into useful refrigeration (20F-50F) at high condenser temperatures (100-120F). The proposedmulti-fluid jet cooler maximizes heat transfer efficiency by using a propellant with relatively low latent tocontinuously entrain and compress an immiscible low temperature refrigerant of relatively high latentheat. Initial prototypes have 400% higher efficiencies than conventional single-fluid ejectors. Phase Iresearch will extend these gains while operating at elevated condenser temperatures. Specific researchfoci are: 1) Highly efficient jet nozzles to supersonically expand a high molar mass, low specific heatratio propellant without the expansion/compression losses observed when using conventional nozzledesigns; 2) Mixing of subsonic refrigerant into the supersonic propellant with minimal kinetic energy lossby avoiding sonic choking of the refrigerant; and 3) Maximum pressure recovery diffusers utilizing weak,oblique compression waves instead of strong, normal shock waves to transition the mixed supersonic flowto subsonic velocity. Potential applications for the two-fluid ejector compression technology includenatural gas powered air conditioning, concentrated solar thermal chiller plants, lower cost combinedheating power and cooling plants, and thermally-driven water desalination.The broader impact/commercial potential of this project is reduced economic and climate burdenassociated with the world?s growing demand for space cooling. Air conditioning is the leading usage forpeak-time electricity in the U.S. and largest energy expense for commercial buildings. Globally, the$65billion air conditioning equipment market is growing at 5% p.a.; and because it is dominated by theelectrically-driven mechanical vapor compression cycle the strain on electrical grids - and by extensionthe environment and economy - is rising likewise. A quiet, clean, reliable and cost effective heat-drivensolution would greatly reduce these risks. Unfortunately, status quo technologies suffer low efficiencies,large form factors, and require expensive water-cooled condensers. Initial R&D efforts have proven anejector vapor compressor using optimized fluid pairs built with low cost components can operate atefficiencies competitive with electric compressors when operating in moderate ambient conditions. Massmarketadoption, however, requires efficient operation at extreme outside temperatures. Phase I researchwill maximize cooling power and discharge pressure (thus operability at high condenser temperatures) byminimizing irreversible losses incurred during supersonic expansion and compression of the immisciblefluid pairs. Project findings will benefit adjacent fields of hypersonic avionics and low atmosphere jetpropulsion