Accession Number : ADA570405


Title :   Thermal Battery Operating Gas Atmosphere Control and Heat Transfer Optimization


Descriptive Note : Final rept.


Corporate Author : ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE


Personal Author(s) : Krieger, Frank C ; Ding, Michael S


Full Text : http://www.dtic.mil/get-tr-doc/pdf?AD=ADA570405


Report Date : Sep 2012


Pagination or Media Count : 68


Abstract : The effects of gases and gas mixtures on global thermal conductivity values of porous thermal insulation packages of fully assembled Low Cost Competent Munition (LCCM) thermal batteries using transient and quasi-steady-state heat transfer techniques are reported. These results show that the volumetric energy densities of most presently fielded munitions thermal batteries can be increased by factors ranging from 1.5 to 3 if hydrogen gas can be removed. Zirconium (Zr) based gas getters are highly effective in atmospheres of pure hydrogen and are potentially useful in mixtures of hydrogen and air. Barium chromate (BaCrO4) placed in contact with heat paper made from Zr/BaCrO4 heat powder forms an effective oxidizing ash for hydrogen gas when the heat paper is ignited. Because the oxidizing ash is not present until the battery is initiated there is no need to protect a chemically active surface during the required 20-year storage lifetime. Water formed from the hydrogen/oxidizing ash reaction did not react to form additional hydrogen during LCCM thermal battery operation.


Descriptors :   *HEAT TRANSFER , *THERMAL BATTERIES , *THERMAL CONDUCTIVITY , ENERGY DENSITY , HYDROGEN , OPTIMIZATION , STEADY STATE , SURFACE ACTIVE SUBSTANCES , THERMAL INSULATION


Subject Categories : Electrochemical Energy Storage
      Thermodynamics


Distribution Statement : APPROVED FOR PUBLIC RELEASE