Abstract: An apparatus for heating a multicomponent working fluid includes a circulating fluidized bed configured to combust a collection of solid particles producing flue gases carrying particulate matter. Heat from the flue gases is transferred to a multicomponent working fluid contained within a plurality of first fluid tubes forming an enclosure for containing and directing a flow of the flue gases. The enclosure may also contain additional tubes forming a superheater. A separator receives the flue gases from the enclosure and separates the particulate matter therefrom expelling a first portion of the flue gases substantially without the separated particulate matter and a second portion of the flue gases containing the particulate matter. A heat exchanger receives the second portion of the flue gases provided as an output from the separator. An adjustable flow controller regulates the flow from the separator of the second portion of the flue gases to the heat exchanger and to the enclosure.

Abstract: A system for changing the temperature of a working fluid, including amonia, includes a working fluid source and a steel tube. The working fluid source is configured to direct a flow of the working fluid. The working fluid from the source is at a temperature. The steel tube has a treated inner surface layer defining a flow passage. The surface may comprise a mill finish surface, an oxidizing surface and/or a chromized surface. The tube is configured to receive the working fluid from the source and to direct the flow of the received working fluid along a path to change the temperature of the received working fluid.