A State-of-the-Art Review of Compact Vapor Compression Refrigeration Systems and Their Applications

Abstract

We present a critical review of the literature on the fundamentals, design, and application aspects of compact and miniature mechanical vapor compression refrigeration systems. Examples of such systems are those envisaged for electronics and personal cooling. In comparison to other refrigeration technologies (e.g., solid-state), vapor compression enables the attainment of low evaporating temperatures while maintaining a large cooling capacity per unit power input to the system. Over the past decade, there have been a significant number of studies devoted to the miniaturization of system components, with the most critical being the compressor. When compared with competing cooling technologies, such as flow boiling in microchannels, jet impingement, and spray cooling, refrigeration is the only one capable of lowering the junction temperature to values below the ambient temperature. The combination of vapor compression refrigeration with the aforementioned technologies is also possible, necessary, and beneficial, since it increases greatly the potential for reducing the system size. For each main application, this paper sheds some light on the thermodynamic and thermal aspects of the cooling cycle and on recent developments regarding its components (compressor, heat exchangers, and expansion device). Whenever appropriate, issues and challenges associated with the different cycle designs are addressed. An overview of the ongoing efforts in competing technologies is also presented.

Acknowledgments

The authors are indebted to CNPq through grant 573581/2008-8 (National Institute of Science and Technology in Cooling and Thermophysics).

Notes

A definition of the mesoscale has been given by Warren et al. [2] as that straddling the size range between conventional machines (e.g., a household refrigerator) and the relatively new genre of microscopic electromechanical systems (MEMS). Mesoscopic systems are, therefore, those in which the characteristic length scale is in the range of tenths of a millimeter to tenths of a meter.

The word passive is used here to describe a cooling technology that does not rely on refrigeration. Thus, in principle, an active cooling technology is capable of lowering the chip temperature below the ambient temperature.