In the Department of Thermal and Refrigeration Engineering, training is conducted in five doctoral programs:
- Energy conversion technologies and systems;
- Refrigeration machines and equipment for cooling and air conditioning;
- Theoretical thermal engineering;
- Industrial thermal engineering;
- Heating, gas supply, ventilation, and air conditioning.
The doctoral programs cover the entire energy conversion cycle – production, transmission, distribution, and consumption of energy, as well as its impact on the environment. Scientific research problems related to:
- modern high-efficiency and environmentally friendly energy conversion technologies and systems for ensuring the parameters of the microclimate in buildings and technological processes in industrial systems, as well as for converting and utilizing energy from renewable sources for the production of heat and cold;
- research of the energy and ecological characteristics of buildings and industrial systems, increasing their energy, economic and ecological efficiency;
- research of combined systems for medium-temperature and low-temperature cooling and freezing, including cryogenic technologies, as well as the entire cycle of artificial cold use in various fields of the chemical and food industry and buildings;
- research of the thermophysical and thermodynamic properties of substances and materials, and methods for thermodynamic analysis.
The training provides knowledge and skills for solving complex scientific problems, for managing design, technological and scientific units, as well as for teaching students in higher education institutions. Doctoral studies are conducted in three forms – full-time, part-time and independent study, for both Bulgarian and foreign citizens.
The Department of Thermal and Refrigeration Engineering has a rich, modern material base. The developed academic staff in an interdisciplinary research atmosphere and the capacity of the available laboratories provide doctoral students with the opportunity to acquire knowledge in a wide range, as well as to conduct joint scientific experiments with specialists from various fields and participate in national and international research programs and projects. European and global models for the exchange of experience and knowledge are successfully applied.

