Ribbed tubeless heat exchanger for fluid heating systems including a rib component and methods of manufacture thereof

A method for transferring heat between a first fluid and a second fluid includes providing a tubeless heat exchanger having a tubeless heat exchanger core, the tubeless heat exchanger core having an inner casing and an outer casing disposed around the inner casing, the inner and outer casings defining therebetween a flow passage for a thermal transfer fluid to flow, the tubeless heat exchanger core having a core inlet arranged to receive the first fluid and a core outlet arranged to provide the first fluid, the core inlet and core outlet being fluidically connected to the flow passage, and at least one of the core inlet and core outlet being disposed on the inner casing, wherein each of the outer casing and the inner casing has an inner surface and an outer surface, wherein the respective inner surfaces face each other and define therebetween the flow passage for the first fluid to flow from the core inlet to the core outlet and wherein at least a portion of the respective outer surfaces are arranged to be contacted by the second fluid, and providing the first fluid into the core inlet to transfer heat between the first fluid and the second fluid through at least a portion of both the inner and outer casings. In some embodiments, the first fluid may be a thermal transfer fluid, the second fluid may be a production fluid, and the production fluid may be held in a vessel, such as a pressure vessel.