Ejector refrigeration systems for waste heat recovery applications: effects of condensation on performance.

As worldwide electricity demand increases and stresses electricity grids to the point of collapse, energy-saving devices have assumed increasing importance. Waste heat recovery systems are currently being considered for applications in air conditioning and refrigeration, like the ejector-based chiller considered here. The key ejector component is a steady-state device with no moving parts, obviating the need for lubricating oils, maintenance, or expensive repairs. An ejector-based chiller is constructed and experiments are conducted to demonstrate cooling over a range of conditions with a miniaturized ejector. It has been hypothesized that the occurrence of condensation at some operational conditions can be used to passively enhance momentum transfer and reduce losses within the ejector. This study experimentally determines the effect of flow condensation on ejector performance and, with analytical treatments of the expected degree of condensation within the ejector itself, uses this information to provide guidance on achieving maximum ejector efficiency and system COP.

随着全球电力需求持续增长，电网压力日益加剧甚至濒临崩溃，节能设备的重要性愈发凸显。余热回收系统目前正被考虑应用于空调和制冷领域，例如本文所研究的喷射式冷水机组。核心部件喷射器是一种无运动部件的稳态装置，无需润滑油、维护或昂贵维修。本文构建了一台喷射式冷水机组，并通过实验验证了微型喷射器在多种工况下的制冷效果。研究假设，在某些工况下发生的冷凝现象可用于被动增强喷射器内的动量传递并减少损失。本研究通过实验确定了流动冷凝对喷射器性能的影响，并结合对喷射器内部预期冷凝程度的分析处理，为实现喷射器效率最大化和系统COP提供指导。