Abstract
Modern steam turbines of Mitsubishi Heavy Industries, Ltd. (MHI) are based on advanced technologies, including advanced steam path design through fully 3-D viscous computational fluid dynamics (CFD) analysis, high efficiency seals, steam cooled casings, enhanced LP sections that include the world longest LP last blades such as 3600rpm 40-inch/3000rpm 48-inch steel blade, hetero material welded rotor, and state-of-the -art material technologies for high temperature up to 630℃. These advanced technologies result in more compact, cost-effective, opposed-flow HP/IP combined cylinder design that ensures high reliability, higher efficiency and ease of maintenance. This paper illustrates the features and operation experience of large steam turbines with MHI's new advanced technologies through two specific examples : a typical 240MW combined-cycle steam turbine recently developed for the American market, and a 700MW 3-cylinder steam turbine with 3600rpm 40-inch steel blades. HP/IP 1-cylinder design with 600℃ class high temperature steam conditions for 1000MW class turbine is also discussed.
