The black box model of a double-tube counter-flow heat exchanger

• DOI: 10.1007/s00231-014-1482-2
• Publication Date: 2014-12-24T07:58:25Z
• Authors: Rafał Laskowski
• Keywords: NTU method

Variable working conditions of a double-tube counter-flow heat exchanger were analysed. During operation the exchanger, parameters (temperatures and mass flow rates) both fluids at its inlet change, which leads to change in performance. Heat transfer effectiveness is commonly used assess performance, defined as ratio actual maximum rate. In present paper, was considered be ‘black box’, aim investigate how rates fluids) affect outlet ones fluids), thus attempt introduce new relation for function only parameters. Following analysis, with five constant coefficients obtained. These depend on geometry properties fluids; they are not general-purpose, but specific exchanger. The form proposed satisfactory it involves coefficients; therefore, approach chosen, consisting analysing parameter minimum arithmetic mean temperature difference. Using this way, obtained two parameters: capacity fluids, NTU, no coefficients. relations verified against data produced by simulator