The National Conference on Thermodynamics with International Participation (NACOT2019) held in Galaţi is the 22nd meeting of a series of conferences initiated in 1990 by the Romanian Society of Thermotechnics (SRT). NACOT2019 was organized by the Department of Thermal Systems and Environmental Engineering, Faculty of Engineering from "Dunărea de Jos" University of Galati in collaboration with the Romanian Association of Frigotehnists and Cryogenics (AFCR). More than 80 academicians, researchers, industry professionals, experts in thermodynamics from 14 countries participated and presented papers at the event. The conference topics included: applied thermodynamics, heat and mass transfer, fluid mechanics and CFD, refrigeration and heat pumps, power plants and CHP, internal combustion engines, renewable energy, energy use and storage, environmental impact of energy conversion. The conference offered participants the opportunity to present new research, discuss the results, exchange ideas and establish links between different research directions in the field. The format of the conference was based on plenary presentations, oral presentations, poster presentations, and presentations of equipment and technologies. The NACOT2019 organizing committee thanks the reviewers, plenary speakers and sponsors. NACOT2019 organizing committee