Effect of packing density on thermal properties of granular activated carbon packed bed by using of inverse heat conduction method

Abstract

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.

The ability of granular activated carbon (GAC) to adsorb large mass of refrigerant gases makes it ideal for use in thermal compressor. In order to make thermal compressor economically viable, the size must be reduced and for that reason thermal responses should be increase as much as possible during heating and cooling process. This paper investigates the effect of GAC bed density on the thermal transient responses when a sudden change in temperature is imposed on wall of a test sample reactor. The test sample consists of 1” OD stainless steel with 0.71 [mm]thickness and 200[mm]length that is loaded with compacted granular activated. The granular carbon used is 208C (coconut shell base) with 13×30 mesh size and provided by ‘Chemviron Carbon Company’. To find the heat transfer coefficient of the contact wall/packed carbon (h) and packed bed thermal conductivity (k) a numerical inverse heat conduction method is used in conjunction with an iterative process based on minimizing the Mean Square Error (MSE) from measured temperatures. Experimental work is carried out by measuring the wall and centre temperatures of submerged sample in a temperature controlled water bath at around 85[oC]. Five samples with the packed bed density ranging from 500 [kg/m3] to 800 [kg/m3] were tested and the results show a quasi-linear increase of both thermal conductivity (k) and heat transfer coefficient of the contact wall/packed carbon (h) with the packed bed density: 0.15 [W/m.K]< k < 0.45[W/m.K]and 150 [W/m2.K]< h < 1400 [W/m2.K].