Analysis of a heating system using hydrogen catalytic reactions for surface-supplied divers

The necessity for active diver heating during long duration, cold water operations is well established. Since the early 1960's, free flooding hot water suits have been used with bulky, surface supplied heat sources to provide acceptable exposures in cold waters. When using these systems, hot water is pumped from the surface through an umbilical into a loose fitting suit worn by the diver. While these systems do provide an effective means of protecting the surface-supplied diver against cold exposures, they are extremely inefficient and require an additional umbilical from the surface for the water supply. Recently, a new diver heating system, using hydrogen catalytic reactions, has been developed for heating divers' suits and breathing gases during deep diving applications. The high heat production demonstrated during these previous projects has shown that this approach could be used as a combined whole-body heater and breath heater to potentially minimize package size and power requirements and yet meet all the diver heating requirements for long duration missions. This paper discusses the application of this new technology to replace the combined breath and body heating requirements of current surface-supplied diver heating systems, and assesses the feasibility of using this approach over varying diver depths and activity levels.