Development of a hydrogen catalytic heater for heating metal hydride hydrogen storage systems

This paper describes the design, fabrication and performance evaluation of a high efficiency, compact heater that uses the catalytic oxidation of hydrogen to provide heat to a hydrogen storage system. The heater was designed to transfer up to 30 kW of heat from the catalytic reaction to the hydrogen storage system via a recirculating heat transfer fluid.The catalytic heater consists of three main parts: 1) the reactor, 2) the gas heat recuperator, and 3) oil and gas flow distribution manifolds. The reactor and recuperator are integrated, compact, finned-plate heat exchangers to maximize heat transfer efficiency and minimize mass and volume. Detailed, three-dimensional, multi-physics computational models were used to design and optimize the system.At full power the heater was able to catalytically combust a 10% hydrogen/air mixture flowing at over 80 cubic feet per minute and transfer 30 kW of heat to a 30 gallon per minute flow of oil over a temperature range from 100 °C to 220 °C. The total efficiency of the catalytic heater, defined as the heat transferred to the oil divided by the inlet hydrogen chemical energy, was determined to exceed the design goal of 80% for oil temperatures from 60 °C to 165 °C.

► Design, fabrication and performance evaluation of a 30 kW catalytic heater. ► Catalytic heater used to heat metal hydride hydrogen storage system. ► Reactor and recuperator are integrated, compact, finned-plate heat exchangers. ► Three-dimensional, multi-physics models used to design and optimize the system. ► Total efficiency of the catalytic heater exceeded 80% for operation from 60 °C to 165 °C.