Experimental evaluation of a new mini square channel air-cooled heat exchanger for an absorption chiller Articles uri icon

publication date

  • October 2022


  • 195

International Standard Serial Number (ISSN)

  • 0017-9310

Electronic International Standard Serial Number (EISSN)

  • 1879-2189


  • A mini square channel air-cooled heat exchanger, operating as subcooler in the typical temperature range of absorption cooling systems, is experimentally evaluated. Working fluid flows along 82 square minichannels of 2 mm side and 11 cm length, manufactured on stainless-steel. Hot fluid flows downward through the channels and two cases are evaluated: natural and forced air convection. In the last case, ambient air flows in the upward direction. Two additional operating parameters are modified: the inlet fluid temperature, between 34.8 and 75.4 °C and the fluid mass flow rate, in the range from 5.7 to 29.1 kg/h. Inlet and outlet temperature and pressure for the fluid and ambient temperature are measured, while the air velocity is kept constant at 0.75 m/s. Results obtained for the approach temperature, pressure drops, heat transferred and heat transfer coefficients for the air-cooled subcooler are provided. Correlations are derived to predict the heat transfer coefficient and pressure drop of the subcooler. Integration of the air-cooled subcooler in a single-effect absorption cooling system is evaluated, showing a notable increase in the cooling power mainly in the case of using forced air flow.


  • Industrial Engineering


  • air-cooled subcooler; square minichannels; approach temperature; pressure drop; heat transfer coefficient; absorption cooling system