This project will develop an innovative refrigeration cycle to allow small scale refrigeration with low emissions and high energy efficiency

The Department of Agriculture's National Institute of Food and Agriculture awarded Energy Concepts Company, LLC $175,000 under the Small Business Innovation Research (SBIR) Program/Small Business Technology Transfer (STTR) Program to develop an innovative refrigeration cycle for small-scale refrigeration. Energy Concepts will modify an existing propane-fired diffusion absorption chiller to enable operation using heat from renewable energy sources like solar thermal, geothermal, waste heat, biogas, or biomass. The innovations involve optimizing the generator and bubble pump to allow wider temperature ranges and higher capacities. This diffusion absorption cycle with generator rectifier, or DACGR, technology will enable walk-in coolers and sub-freezing temperatures using no ozone-depleting refrigerants. The University of Alaska will collaborate to promote the technology's benefits for energy efficiency and resilience in rural Alaskan communities. The award period is from July 1, 2022 through February 28, 2023.

The innovations expand on the propane fired diffusion absorption chillers (DAC) already used in millions of RVS, allowing these cycles to be powered by heat from renewable energy sources such as solar thermal, geothermal, waste heat, biogas, or biomass. This chiller has no moving parts and uses refrigerants with no global warming and zero ozone depleting potential. The innovations involve modifying the generator to take in more heat and improve efficiency; and optimizing the bubble pump, to allow operation over a wider temperature range and higher capacity. The innovations are primarily in the generator / rectifier portion of the cycle, hence the name "diffusion absorption cycle with generator recitifier", or dacgr. This will enable walk-in size or larger coolers, and allow sub-freezing temperatures. Air conditioning, heat pumping, medical storage, and drying, are also possible with dacgr, providing low energy storage and cooling options for millions of rural and urban users. The proposed dacgr systems would specifically benefit agricultural communities, especially those with less reliable grid electricity and/or high utility rates. The proposed dacgr innovations will be modeled, designed, fabricated, and tested in phase i. Potential applications for community cold storage in alaska, utilizing power plant waste heat or renewable energy, will be developed.energy concepts is a world leader in absorption cycles, and will apply know-how developed in industrial applications to the smaller scale diffusion absorption refrigerator. University of alaska, including the alaska center for energy and power, has keen interest in promoting energy efficiency, renewable energy, sustainability, and resilience in rural alaskan communities. IT has direct knowledge of existing energy systems that can be integrated to provide energy neutral chilling. Energy concepts industrial partners- gaia energy research institute, cambridge capital, and sunrise CSP- can provide commercialization assistance with subsequent future awards, turning this innovation into a commercial product.