Development of a Signal Acquisition and Processing System to Determine the Operating Characteristic Curve of Domestic Refrigerators Axial Fans

This study presents the development of a signal acquisition and processing system to determine the operating characteristic curve of axial fans used in domestic refrigerator evaporators. The system was implemented in a wind tunnel test bench constructed under ANSI/AMCA 210-16 at the Universidad Politécnica Salesiana (UPS), Cuenca, Ecuador. The methodology included the design of specific algorithms in LabVIEW and MATLAB programs, through which signals from sensors that measure static and differential pressure, as well as temperature, were acquired and processed. This allowed the UPS test bench to be functional so that it can be used by industries nationwide dedicated to the manufacture of refrigerators, thus reducing the costs associated with carrying out these tests abroad. In this sense, the system contributes to the design of more energy-efficient and environmentally friendly chillers by identifying optimal operating points for fan efficiency. The validation of the acquisition and processing system was carried out by comparing the characteristic curve of a fan given by the manufacturer with the curve delivered by the implemented system, resulting in average errors of 7.78% for pressure and 5.38% for air flow.