Fully-wetted, refractory-free tubeless fluid heating system with negligible thermal expansion stress

A method for heating a production fluid in a fluid heating system, comprising:

• receiving the production fluid by a pressure vessel, the pressure vessel comprising a vessel inlet arranged to receive the production fluid to be heated and a vessel outlet arranged to provide heated production fluid, the pressure vessel containing the production fluid to be heated;
• receiving a thermal transfer fluid by a tubeless heat exchanger core, the tubeless heat exchanger core disposed at least partially within the vessel, the tubeless heat exchanger core comprising an inner casing and an outer casing disposed around the inner casing, the inner and outer casings defining therebetween a flow passage for the thermal transfer fluid to flow, the tubeless heat exchanger core further comprising a core inlet arranged to receive the thermal transfer fluid and a core outlet arranged to provide the thermal transfer 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;
• and
• 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 which guides a flow volume of the thermal transfer fluid continuously from the core inlet to the core outlet, the flow volume traversing at least once around a perimeter of the heat exchanger core, and wherein at least a portion of the respective outer surfaces are arranged to be contacted by the production fluid;
• and
• transferring heat from the thermal transfer fluid to the production fluid through at least a portion of both the inner and outer casings.

A method for transferring heat between a first fluid and a second fluid in a fluid heating system, comprising:

• receiving the second fluid by a pressure vessel, the pressure vessel comprising a vessel inlet arranged to receive the second fluid to be heated and a vessel outlet arranged to provide heated second fluid, the pressure vessel containing the second fluid to be heated;
• receiving the first fluid by a tubeless heat exchanger core, the tubeless heat exchanger core disposed at least partially within the vessel, the tubeless heat exchanger core comprising an inner casing and an outer casing disposed around the inner casing, the inner and outer casings defining therebetween a flow passage for the first fluid to flow, the tubeless heat exchanger core further comprising 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 which provides continuously guided flow of a flow volume of the first fluid from the core inlet to the core outlet, the flow volume traversing at least once around a perimeter of the heat exchanger core, and wherein at least a portion of the respective outer surfaces are arranged to be contacted by the production fluid;
• and
• transferring heat from the first fluid to the second fluid through at least a portion of both the inner and outer casings.