Heat Exchanger and Technique for Cooling a Target Space and/or Device Via Stepped Sequencing of Multiple Working Fluids of Dissimilar Saturation Temperatures to Provide Condensation-by-Vaporization Cycles

A system for heat exchange includes a first condenser that places a first working fluid vapor in proximity to a second working fluid liquid. The two working fluids have respective saturation temperatures that enable the second working fluid to absorb sufficient amounts of heat from the first working fluid vapor to vaporize, while the first working fluid vapor condenses back into a liquid. The second working fluid vapor exits the first condenser via a first conduit and enters a first heat exchanger which places the second working fluid vapor in proximity to a third working fluid. The relative saturation temperatures of the second and third working fluids enables the transfer of sufficient amounts of heat from the second working fluid vapor to cause the second working fluid vapor to condense back into liquid while at least a portion of the third working fluid liquid vaporizes into third working fluid vapor.