Energy-related technologies may be treated as a combination of engineering-technical methods of energy and work conversion employed to facilitate human life. The increase of human population in the Late Middle Ages and the resulting industrial revolution implied the necessity to replace the physical power of people and animals by the power of thermomechanical machines or thermal engines. An improvement in thermal engines gathered momentum in the mid-19th century and consisted of efficiency increase and the minimization of engine overall dimensions. In the diesel engine, fuel is injected at high pressure directly into the combustion chamber at the end of the second stroke. The thermal technology was widely applied in gas turbine and aviation turbo-jets, turbo-propeller motors and jets. As a whole, the Brayton thermal technology is highly efficient especially when accompanied by co-generation or recuperation of the energy of burnt gases. Gas and vapor compression is essentially important for the total efficiency of thermodynamic devices.