A supercritical steam generator includes a downdraft furnace enclosure, a hopper tunnel, and a convection pass enclosure, with the hopper tunnel joining the downdraft furnace enclosure and convection pass enclosure together. Flue gas passes down through the downdraft furnace enclosure through the hopper tunnel and up through the convection pass enclosure. This structure permits the outlet steam terminals, which provide access to the resultant supercritical steam and/or reheat steam, to be located at a base of the steam generator rather than at the top of the steam generator as with conventional boilers. This reduces the length of the steam leads from the steam generator to a steam turbine that produces electricity using the supercritical steam.

A supercritical steam generator includes a downdraft furnace enclosure, a hopper tunnel, and a convection pass enclosure, with the hopper tunnel joining the downdraft furnace enclosure and convection pass enclosure together. Flue gas passes down through the downdraft furnace enclosure through the hopper tunnel and up through the convection pass enclosure. This structure permits the outlet steam terminals, which provide access to the resultant supercritical steam and/or reheat steam, to be located at a base of the steam generator rather than at the top of the steam generator as with conventional boilers. This reduces the length of the steam leads from the steam generator to a steam turbine that produces electricity using the supercritical steam.

A superheated steam recycling apparatus includes a superheated steam generating part; a steam supply flow path for supplying saturated steam to the superheated steam generating part; a superheated steam utilization part that is supplied with superheated steam generated by the superheated steam generating part; a steam return flow path for returning used steam having passed through the superheated steam utilization part to the superheated steam generating part; and a flowmeter that measures a flow rate of the used steam returned to the superheated steam generating part, and on the basis of the difference between a desired flow rate of the superheated steam to be generated by the superheated steam generating part and the flow rate of the used steam obtained by the flowmeter, controls a flow rate of the saturated steam to be supplied to the superheated steam generating part through the steam supply flow path.