NOVELTY - The exchanger (1) has a fluid flow plate positioned between stacked plates. One of the stacked plates and the fluid flow plate define slots that form a portion of a fluid flow path (2) such that fluid flowing along the fluid flow path flows into a flow channel along first direction and into one of the slots along second direction, where third direction is parallel to a stacked plate plane, fourth direction is non-parallel to the plane, the fluid flows into an adjacent flow channel along fifth direction, and the fifth direction is parallel to the plane.    USE - Stacked plate style evaporative heat exchanger for use as air-conditioning and refrigeration chillers in a refrigeration or climate control system, evaporators in a Rankine cycle waste heat recovery system and water and fuel vaporizers for fuel processing and fuel cell applications for transferring heat from a fluid flow i.e. flow of exhaust gas from an internal combustion engine, to another fluid flow e.g. Rankine cycle working fluid flow such as refrigerant flow e.g. water flow, ammonia flow, ethanol flow, methanol flow and R245fa flow, to vaporize the latter fluid flow.    ADVANTAGE - The exchanger improves pressure resistance and heat transfer performance of the exchanger by having uniform narrow channel width for the flow channel of the fluid flow plate and bypass prevention by providing notches in the fluid flow plate to receive portions of protrusions to provide a tortuous flow path. The exchanger provides smaller width slots to reduce negative impact on heat transfer performance caused by removal of corrugations in a slot area and to provide greater structural support to resist deformation of shells when the fluid flow is at higher pressure than another fluid flow in evaporative systems.    DETAILED DESCRIPTION - The fluid flow plate is a corrugated thin metal sheet.    DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of a stacked plate style evaporative heat exchanger.    Stacked plate style evaporative heat exchanger (1)    Fluid flow paths (2, 3)