Desenvolvimento de um sistema de monitoramento de óleo em tempo real para sistemas de lubrificação

Abstract

In oil-lubricated hydraulic systems with skids for heat exchange between oil and water, monitoring humidity, ferrous particles, and temperature is essential to ensure the system's proper functioning under normal operating conditions, safeguarding the safety of the final equipment being lubricated or cooled. Given the importance of this monitoring, this work proposes the study and development of a real-time monitoring system to evaluate the operational conditions of lubricating oil in industrial hydraulic systems, focusing on applications in hydroelectric power plants. To achieve this objective, three sensors were designed and validated: a capacitive sensor for detecting and monitoring the water content in the oil, an inductive sensor for detecting and monitoring ferrous particles, and a three-wire RTD PT100 resistive sensor for temperature measurement. The sensor for detecting water in the oil consists of a parallel-plate capacitive sensor with four electrodes. By inserting water samples into the piping with the sensor submerged in the oil, the capacitance variation was observed as saturation increased. The ferrous particle detection sensor consists of two coils, one for excitation and the other for detection. With the presence of ferrous particles in the center of the detection coil, a variation in the measured potential difference can be observed. For temperature measurement, a commercial PT100 RTD sensor was used, with a range between -70°C and 420°C. The sensors were integrated into the analog converter, and Modbus communication allowed for the integration of measurements with the supervisory system, developed using the ScadaBR software. The results obtained through experimental tests and implementation of the remote monitoring system demonstrate the technical feasibility of developing the proposed sensors for industrial applications, as well as the importance and relevance of constantly measuring these quantities to maintain the perfect and safe operation of oil-lubricated equipment.