A heat exchanger assembly includes a first stage heat exchange section defining one or more intakes for receiving a fluid. The first stage heat exchange section includes one or more preheater elements defining one or more preheat flowpaths extending radially inward from the one or more intakes with respect to a centrally disposed axis of the heat exchanger assembly. The one or more preheater elements include one or more guide vanes configured to guide a flow of the fluid in a spiral path from the one or more intakes toward the centrally disposed axis. A centrally disposed second stage heat exchange section is fluidly connected to the one or more preheat flowpaths to receive the fluid from the one or more preheat flowpaths.

A heat exchanger assembly includes an absorber element defining an axial flowpath for a fluid extending along an axis. The absorber element includes an outer support wall and one or more support members extending radially inward from the outer support wall with respect to the axis. The heat exchanger assembly also includes one or more heat exchange elements floatably coupled to the one or more support members where the one or more heat exchange elements extend along the axial flowpath.