Thermal performance of diffusion-bonded compact heat exchangers

Abstract This work presents an experimental and theoretical evaluation of the thermal performance of a square straight diffusion-bonded stainless steel compact heat exchanger. A one-dimensional steady-state thermal model was proposed to predict the thermal characteristics of the heat exchanger. To validate the model and to study the thermal behavior of the heat exchanger, an experimental test apparatus was developed. The heat exchanger was tested in several combinations of Reynolds ranging from 2600 to 7500, representing transition to turbulent regimes. The temperatures were varied from 70 °C to 80 °C for the water and from 25 °C to 42 °C for the air, at the inlet of the heat exchanger, respectively. A good agreement between the experimental data and the analytical model was obtained.