Operation of Tokyo Electric Power's Hirono No. 5 Thermal Power Plant commenced in July, 2004. It is a 600 MW coal-firing supercritical pressure plant that operatesunder the highest global standards for steam conditions (24.5 MPa x 600/600 degree-C).
The plant's main line-up, featuring a steam turbine and a boiler, is supplied by MHI. MHI has utilized all of its dynamic competence in establishing this plant, by setting it up with key equipment such as: a flue gas treatment system laid out in a harmonious design plan that makes use of a dry selective catalytic NOx removal system, a low-low temperature dry electrostatic precipitator and a double contact flow scrubber type FGD absorber; and also a comprehensive waste water treatment system and self-supported group stacks.
The steam turbine (TC2F-48) utilized in this plant is a two cylinder type that is made up of a combined cylinder which is comprised of a high-pressure and an intermediate-pressure turbine, and a single low-pressure turbine cylinder. This unit has the largest capacity in the world in its two cylinder layout.
The achievement of a single low-pressure turbine cylinder was made possible by implementing the world's longest 48-inch last stage steel blades for 3,000 rpm turbines, making it possible to realize a compact and high-efficiency turbine.
As for the boiler, a vertical water wall furnace type of sliding pressure operation once-through boiler was utilized due to its vast array of merits and proven track record. The plant is extremely environment friendly due to the implementation of a low NOx combustion system that is composed of a Mitsubishi circular firing system featuring an A-PM (Advanced-Pollution Minimum) burner, an infurnace NOx removal method (A-MACT), a fine particle MRS (Mitsubishi Rotary Separator) mill and a flue gas NOx removing device.
While, the utilization of an axial flow fan which is MHI's largest capacity machine available makes it possible to unify flue gas and air system into a single line. Furthermore, the usage of a very simple system arrangement and design realized an extremely streamlined and efficient plant, applying a single line feed water heating system arrangement, and sea water circulation with a single pump, and also the plant start-up method does not rely on a boiler circulation pump.