Current trends in the development of energy exchange apparatus and units

This paper reviews research and technologies related to wave energy exchangers that use acoustic and shock-wave processes to transfer energy. It presents a classification of devices by wave type, purpose, and methods of energy exchange organization. Operating principles and designs of thermoacoustic and shock-wave units are described. Particular attention is paid to thermoacoustic systems, including engines, coolers, and their combinations into thermoacoustic pairs. We consider operating principles of pulsation, rotary-wave, and resonant gas coolers, as well as their application in cooling, compression of gases, ejection, and flow separation. The paper presents engineering approaches to improving efficiency: the use of multistage systems and optimization of designs. Examples of rotary-wave technologies in the cryogenic industry for methane liquefaction and the creation of environmentally friendly refrigeration cycles are given. The prospects for using wave rotor technologies in power engineering and industry are discussed. The article contains recommendations for research and design solutions to reduce losses and improve the efficiency of energy exchangers.