P. Muthukumar

Thermal Modeling of Mg2Ni-Based Solid-State Hydrogen Storage Reactor

In this paper, a numerical study of coupled heat and hydrogen transfer characteristics in an annular cylindrical hydrogen storage reactor filled with Mg2Ni is presented. An unsteady, two-dimensional (2-D) mathematical model of a metal hydride reaction bed of cylindrical configuration is developed for predicting the hydrogen storage capacity. The effect of volumetric radiation is accounted in the thermal model. Effects of hydride bed thickness, initial absorption temperature, hydride bed thermal conductivity, and hydrogen supply pressure on the hydrogen storage capacity are studied. A thinner hydride bed is found to enhance the hydriding rate, accomplishing a rapid reaction. At an operating condition of 20 bar supply pressure and 573 K initial absorption temperature, Mg2Ni stores about 36.7 g hydrogen per kg alloy. For a given bed thickness and an overall heat transfer coefficient, there exists an optimum value of hydride bed thermal conductivity. The present numerical results are compared with the experimental data reported in the literature, and good agreement was observed.

A Review on Clean Combustion Within Porous Media

Technological growth of any nation demands more fossil fuels which cause two major threats. First one is the shortage of fossil fuel, and the second is environmental pollution. Recently, the age-old conventional combustion process is being substituted by an innovative combustion technology, called porous medium combustion. This surge of interest in porous radiant burner is driven by some of the important benefits such as high thermal efficiency, low emission characteristics, high power modulation range, extended flammability limits and high power density. In the last two decades, there has been a significant development in the research aiming at changing the operating parameters and the design configurations of the porous radiant burners to attain lower emissions and higher thermal performances. Various burners based on porous medium combustion have been developed for industrial and domestic applications and showed beneficial over their conventional burner counterparts. Porous radiant burners based on porous medium combustion technology showed good emission characteristics and offer higher thermal efficiencies. Although, durability of few burners is still a matter of concern which results in non-commercialization of these products. This chapter summarizes the development of various porous radiant burners used in both industrial and cooking applications.