The disclosure relates to a water-tube boiler with concentric heat-exchange coils with an ash-removal system, which includes a coil-shaped heat-exchange tube forming a coil with layers having a section concentric with the turns of the coils joined laterally, wherein when the boiler is operational, the heat-exchange tube turns with a rotary movement on the axis of the coil and is heated via a forced-ventilation hot-air intake that flows through the layers having a concentric section in order to generate a movement of the ash and the slag, moving them through the layers having a concentric section following a path, allowing them to be extracted via output collectors.

The disclosure relates to a water-tube boiler with concentric heat-exchange coils with an ash-removal system, which includes a coil-shaped heat-exchange tube forming a coil with layers having a section concentric with the turns of the coils joined laterally, wherein when the boiler is operational, the heat-exchange tube turns with a rotary movement on the axis of the coil and is heated via a forced-ventilation hot-air intake that flows through the layers having a concentric section in order to generate a movement of the ash and the slag, moving them through the layers having a concentric section following a path, allowing them to be extracted via output collectors.

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.