Designing a mesoscale vapor-compression refrigerator for cooling high-power microelectronics

A mesoscale vapor-compression refrigerator is defined here as one that is ∼5 cm or smaller in size. Such a refrigerator could then be integrated in high-power microelectronics packaging, and thus offer a new cooling solution. To begin the process of designing such a small-scale vapor-compression refrigerator, a comparison of three different refrigerants was carried out, revealing that ammonia (NH₃) leads to the most efficient refrigerator. From there, a review and discussion of five types of compressors shows that a scroll compressor appears to be the most promising candidate for miniaturizing down to the ∼5 cm size. This information was used to design three realistic vapor-compression refrigerators-for heat loads of 100, 200, and 300 W-using commercially-available scroll compressors and easily-fabricated heat exchangers. These design calculations demonstrate that, for a 100-W vapor-compression refrigerator, an air-cooled condenser can be made as small as almost 5 cm on a side, but that the compressor is still about 15 cm in its maximum dimensions. Thus, it is suggested that future research work concentrate on miniaturizing the compressor, to allow the entire system to fit within the ∼5 cm size limit.