Final answer:
Superheated steam is preferred in steam turbines to enhance efficiency, reduce moisture-related damage, and maximize the cycle's thermal efficiency by leveraging a greater temperature difference, which aligns with the principles of Carnot efficiency.
Step-by-step explanation:
Superheated steam is used in most steam turbines because it contains more energy than saturated steam at the same pressure. Superheating the steam reduces the moisture content during the expansion in the turbine, which in turn minimizes the corrosion and erosion of turbine blades, improving efficiency and longevity of the machinery. Additionally, operating with superheated steam allows for a greater thermal efficiency of the cycle, which is partly attributable to the higher average temperature at which heat is added to the system. The use of superheated steam aligns with the goal of achieving the maximum theoretical efficiency for a heat engine, as described by the Carnot efficiency, which depends on the temperature difference between the heat source and the condenser. By condensing the steam to water at a lower temperature and operating with a hot, high-temperature steam source, the steam cycle efficiency is optimized.