This book presents the principles of thermo-mechanical energy conversion and the development of thermodynamic processes. It offers a structured exposition of thermodynamic theory, clarifying fundamental concepts, the scope and limitations of thermodynamic laws, and the relationships between processes and state parameters.

The thermodynamic properties of key working fluids, including ideal and real gases, humid air, and water vapor, are examined in detail. The book also introduces the operating principles, cycle performance, and models of major energy-conversion systems, including internal combustion engines, steam turbines, refrigeration systems, compressors, and nozzles, along with applications in chemical engineering. Advanced topics such as exergy analysis and finite-time thermodynamics are included, and key concepts are reinforced through summaries, conceptual questions, and exercises. Emphasizing fundamental knowledge while incorporating innovative developments, the book is written in a clear, accessible, and reader-friendly style. Each chapter includes a summary as well as carefully selected conceptual questions and exercises to strengthen understanding and application.

Designed primarily as a textbook for university programs in energy and power engineering, mechanical engineering, aerospace engineering, and civil engineering, it also serves as a valuable reference for researchers and professionals in HVAC, refrigeration, and solar thermal systems.