SBIR Phase I: Acoustic Expander for Air-Cycle Flash Freezers and Ultra-Low Temperature Refrigerators

The broader impact /commercial potential of this Small Business Innovation Research (SBIR) Phase I project is a new low temperature freezer system that does not use potentially harmful refrigerants. These freezers are used in flash freezing of food products, preservation of biological samples, and in the healthcare industry. The advantage of this technology over the current refrigeration solutions is that air can be used as the refrigerant instead of a synthetic refrigerant which may prevent ice build-up and improves technoeconomic performance. If this technology demonstration is successful, there will possibly be a joint partnership with an establish US manufacturer to commercialize the technology for the public. The unique patented acoustic based cooling system is the key enabler of this low temperature freezer concept. Initial market adoption is projected to be realized in the food processing space. This Small Business Innovation Research (SBIR) Phase I project is focused on a novel air cycle -80C refrigeration system that uses an acoustic expander to provide the cooling effect. Air cycle systems offer advantages over traditional vapor-compression machines that use synthetic or flammable refrigerants. These advantages are single compressor architectures, non-hermetically sealed components, and low ice build-up in the freezer all while maintaining similar or higher Coefficients Of Performance to that of a vapor-compression machine at much lower capital cost and with fewer operational/regulatory restrictions. Previous air-cycle systems were limited by the expensive turbine-based compressors and expanders. This project improves on previous attempts with an off the shelf compressor and a mechanically simple acoustic expander. The acoustic expander is a fundamentally different expansion machine is a drop-in replacement for a turbine expander in a Brayton-style refrigeration architecture. This dramatically reduces capital cost and can leverage existing off-the-shelf heat exchangers and compressors to reach scale. This SBIR will aim to demonstrate a reliable, 1 kW acoustic expander-based cooling system at -80C. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.