Small Grants for Exploratory Research: A Stirling Micro-Refrigerator for Cold Electronics

这个用于探索研究的小额赠款(SGER)项目的重点是开发一种用于冷电子产品的新型斯特林微型制冷机。这台硅玻璃机器将通过硅传感器行业开发的微机械加工技术批量制造。尽管它的体积很小(大约1立方厘米)，但微型制冷机将以比以前认为的斯特林循环机可能的更高的频率运行，从而泵出实际的热量。与其他流体动力系统中的设备一样，斯特林循环机中的换热和损失不取决于频率或速度等单个运行量，而取决于无量纲量组，如雷诺数和瓦伦西数。这些无量纲组允许通过利用小维度补偿高频来控制损耗。我们对初步设计的分析描述了一种机器，它比科学文献中描述的最先进的微型斯特林制冷机小30倍，热提升能力高100倍。在本研究中，将解决两个理论和实践可行性问题。我们将通过分析高频和小尺寸下的复杂传热和摩擦系数来确定基本的限制和机会，并将检查拟议的微型制冷机在多大程度上可以通过商业硅传感器行业采用的现有工艺来制造。我们还将设计一种热力和流体动力学“类似”的斯特林制冷机，在更大的尺寸和传统材料中，用于以后用传统仪器进行分析的实验验证。

The focus of this Small Grant for Exploratory Research (SGER) project is on the development of a novel Stirling micro- refrigerator for cold electronics. This silicon and glass machine is to be batch fabricated by micromachining techniques developed in the silicon sensor industry. Despite its small size (approximately one cubic centimeter), the micro- refrigerator will pump practical amounts of heat by operating at much higher frequencies than previously thought possible for Stirling cycle machines. Heat transfer and losses in Stirling cycle machines, like those in other fluid dynamic systems, depend not on individual operating quantities such as frequency or speed, but rather on dimensionless groups of quantities, such as Reynold's number and Valensi number. These dimensionless groups permit losses to be controlled by compensating for high frequencies by means of small dimensions. Our analysis of a preliminary design describes a machine that is 30 times smaller with 100 times more heat lifting capacity than the most advanced miniature Stirling cryocooler yet described in the scientific literature. In this research, two theoretical and practical feasibility issues will be addressed. We will identify fundamental limitations and opportunities by analyzing the complex heat transfer and friction factor coefficients at high frequencies and small dimensions, and we will examine the extent to which the proposed micro-refrigerator can be manufactured by existing processes employed in the commercial silicon sensor industry. We will also design a thermally and fluid- dynamically "similar" Stirling refrigerator in larger dimensions and in conventional materials for later experimental verification of analyses with conventional instrumentation.