Experimental study of a graphite disks absorber couple to a heat transformer

An experimental study was performed on a graphite disk absorber coupled to an absorption heat transformer. The working solution used was H2O/LiBr. Due to corrosion caused to materials such as carbon steel and stainless steel with the solution H2O/LiBr, it was necessary to consider the use of another material such as tar impregnated graphite. This material has interesting properties of corrosion resistance, withstands high temperatures and presents a high thermal conductivity than the graphite without impregnation. However, there does not exist a well established methodology for designing heat exchangers with new geometries for its implementation in heat transformers. For this reason, the heat exchanger was designed with a stainless steel shell and graphite disks arranged internally in a column to carry out the absorption process. In the experimental tests carried out for a thermal load in the range from 625 to 1460 W, heat transfer coefficients in the absorber were obtained in the range from 723 to 1535 W/m(2) K. As the number of Reynolds increases from 110 to 144, the heat transfer coefficient increases up to a maximum value of 954 W/m(2) K, at Reynolds number at about 144, but when Reynolds number was increased above 147, the heat transfer coefficient decreased. (c) 2012 Elsevier Inc. All rights reserved.