Miniaturized refrigeration system with absorption: Application to microelectronics cooling

The study develops an analytical model of an optimized small scale refrigeration system using a thermo-chemical compressor, with application to the cooling of the electronic components populating a Printed Circuit Board (PCB) in a High-Power Microelectronics System. This work continues the authors' previous study of a refrigeration system with mechanical compression and ejector compression [1-3]. However, the present study introduces the thermo-chemical compressor, comprised of an absorber-desorber unit, also known as refrigeration with absorption. This is a viable alternative to the mechanical compression systems, providing an improved feasibility and reliability at smaller scales. The proposed system includes miniaturized refrigeration components, designed to fit smaller scale power electronics, and uses a binary water-ammonia solution, compact heat exchangers with meso-channels and hydrogen as compensation gas in order to eliminate the circulation pump. The efficiency of the system is evaluated and further compared to mechanical compression designs at similar cooling powers. The study also discusses the thermodynamic cycle specifics and provides an extensive analytical evaluation and calculation of each miniaturized component design. The COP of the system is similar to 0.4 - 0.5. The study is concluded by identifying the pros and cons of implementing such an absorption system to real-life microelectronics applications. The advantages of the optimized refrigeration design are highlighted, establishing a performance vs. size comparison to vapor-compression refrigerators, to serve as the basis for the enhanced cooling of future miniaturized refrigeration applications.