Image recognition method for frost sensing applications

Frost formation in the heat exchangers of refrigeration systems is a well-documented phenomenon. This frost accumulation creates a thermally insulating barrier that can restrict, or even block, the airflow between fins, resulting in decreased efficiency and degradation of the food products. Several methods of frost detection and defrosting have been developed, although there is not an efficient mainstream method to measure and control frost formation. In previous works, the results of a small low-cost resistive sensor for frost detection were shown to be promising. This paper extends that research using computer vision to compare the results of this sensor with the frost formed on the heat exchanger, allowing for a better study of the sensor. This method allowed to trace and plot a frost formation curve of the sensor detected values.This work has been supported by the project Centro-01-0145-FEDER000017 -EMaDeS -Energy, Materials and Sustainable Development, co-funded by the Portugal 2020 Program (PT 2020), within the Regional Operational Program of the Center (CENTRO 2020) and the EU through the European Regional Development Fund (ERDF). The authors thank the opportunity and financial support to carry on this project to Fundac¸ao para a Ci ˜ encia e ˆ Tecnologia (FCT) and R&D Unit “Centre for Mechanical and Aerospace Science and Technologies” (C-MAST), under project UIDB/00151/2020. This study is within the activities of project “PrunusPos - Optimization of processes for the storage, cold ´ conservation, active and/or intelligent packaging and food quality traceability in post-harvested fruit products”, project n. ◦ PDR2020-101-031695, Partnership n◦ 87, initiative n.◦ 175, promoted by PDR 2020 and co-funded by EAFRD within Portugal 2020.