Research on thermoacoustic refrigeration system driven by waste heat of industrial buildings

Industrial production process continuously produces a large amount of stable waste heat, which has great potential for recovery and utilization. As a new energy conversion and utilization technology, thermoacoustic technology has a good application prospect in low-grade heat sources utilization, with advantages of simple structure, long service life and low cost, and can be applied in waste heat recovery field. The current thermoacoustic studies pay more attention to the improvement of thermoacoustic conversion efficiency. Power output should be considered while paying attention to efficiency in the field of engineering application. The thermoacoustic refrigeration system proposed in this paper uses waste heat generated in industrial buildings to regulate indoor temperature. Based on the theory of traveling-standing wave acoustic field, a design concept of thermoacoustic system was proposed, that is, two thermoacoustic cores are placed on both sides of the high impedance zero phase position to limit the high impedance zero phase phenomenon at the independent thermoacoustic core position. On the basis of this study, the topology of thermoacoustic refrigeration system operating in traveling-standing wave phase was proposed. A two-stage thermoacoustic engine/refrigerator coupled loop structure was adopted to realize the traveling-standing wave acoustic field through the non-uniform alternate distribution of thermoacoustic units. Based on the topology, numerical simulation and system optimization were carried out, and an experimental prototype was set up for experimental studies. The experimental results show good consistency with the simulation results. Under the condition of no load, the lowest cooling temperature reached by thermoacoustic refrigerator is −12℃, and the maximum cooling capacity is 0.95 kW. This study shows that the thermoacoustic refrigeration system driven by waste heat can significantly reduce the energy consumption of industrial buildings in terms of indoor temperature regulation, and improve the energy utilization ratio of industrial buildings.