The book has been written by a group of scientists workingfor many years at Higher Educational Institutions of the SovietUnion and is a textbook for students both of Higher and ofSecondary Schools.The book contains the theoretical fundamentals of thermalengineering (engineering thermodynamics and heat transfer), containscharacteristics of fuels, describes combustion processes, boilerunits and heat engines, such as steam engines, internal-combustionengines, steam and gas turbines and steam power plants.Besides being a textbook for students, the book will also be ofinterest to specialists in the field of thermal engineering.