金属氢化物的导热系数和比热测试

There are extensive efforts underway worldwide to develop inexpensive and
practical hydrogen storage materials for the implementation of a hydrogen-based
energy economy. Metal hydrides are leading candidates for hydrogen storage
applications because they are solid at room temperature and release hydrogen on
demand when heated. HSM systems Inc. has developed a practical hydrogen
storage system in which the metal hydride is housed in a sealed stainless-steel
vessel. Hydrogen is generated by simply heating the enclosed metal hydride. It is
important to understand the thermal response of the metal hydride as it is heated to
determine when and at what rate the hydrogen will be released. Heat transfer can
be modeled with the appropriate knowledge of the vessels geometry, composition
and intrinsic thermal characteristics (i.e. thermal conductivity and specific heat).
Although the thermal properties of stainless steel are well known, those of metal
hydrides are poorly characterized. This paper presents a simple and efficient
measurement technique for determining the thermal conductivity and the specific
heat of metal hydrides. Since practical hydrogen storage applications will likely
involve the use of compacted powders, the thermal conductivity of both powdered
and pressed pellets of select metal hydrides have been determined; namely:
• NaAlH4 powder/compressed pellet
• NaAlH4 + 2% TiCl3 powder/compressed pellet
• LiAlH4 powder/compressed pellet
• LiNH2+2LiH powder/compressed pellet
• 7:1 MgH2:LiBH4 + 1 % TiCl3 powder/compressed pellet
The thermal conductivity of each sample has been measured via the modified
transient plane source technique. Specific heat measurements have been made
using differential scanning calorimetry (DSC). TCi导热系数仪