Desenvolvimento de um protótipo para a medição e o monitoramento da temperatura de uma pilha de CAC/PEM utilizando sensor matricial infravermelho

Abstract

With the increasing increase in the demand for electric energy, together with the actions that seek to minimize pollution of the environment, seeking support in renewable and clean energy sources. A generating source that shows up promising is the fuel cell, which, together with other components, can act as energy storage. One prototype with this configuration was set up in the CEESP/UFSM laboratory for research purposes and the employ of different technologies. This prototype has an alkaline type electrolyzer, metallic hydrides and PEM type fuel cells. The operation of the CaC make up basically of physical-chemical processes, where the temperature has a high influence in its operation, as well as in its useful life. Therefore it is essential to carry out temperature control and monitoring. However, this monitoring isn't trivial, since the temperature distribution on the stack profile is not homogeneous, and it haves graphite parts, which it is conductive, ie the sensor must be isolated so that it does not short-circuit the cells. One solution adopted in the prototype was the use of thermocouple sensors, due to their small dimensions, allowing it to be inserted in the channels of the cells. However, this sensor needs an individual signal conditioner, and if want to map the temperature of the whole area of the stack, a network of thermocouples is needed, which ends up raising costs and blocking the reaction airflow in the channels that have the sensors. The proposal of this work is the use of infrared sensors to monitor the temperature of the CaC stack of the prototype present in CEESP. In this way, a greater number of measuring points can be obtained and physical contact with the stack is avoided. The infrared matrix sensor used requires some treatments across software to calibrate it for this specific application. The sensor temperature data, after calibration, are displayed as a thermal image at two different locations: in the control and monitoring supervisor of the storage plant, and one display united to the CaC stack cabinet. With the use of this sensor, obtain up not only the thermal image of the stack, which allows the study of the temperature behavior throughout its length, but also the maximum and average temperatures, guaranteeing that the temperature of the stack does not reach critical levels that it can compromise its useful life or even render it unusable. In this work, are presented the electronic components used, the communication between them, the developed codes and the design and dimensioning of a modular printed circuit board and of the support that ensures the correct location of the infrared sensor united to the cabinet of the stack CaC. Finally, are demonstrate the results achieved with the use this sensor on the stack CaC.