Simulations and modeling of planar amperometric oxygen sensors

The electrochemical zirconia solid electrolyte oxygen sensor is extensively utilized in automobiles to monitor the exhaust gas composition and control the air-to-fuel ratio, thus reducing harmful emission components and improving fuel economy. With small size, fast light off, low power, easy to integrate and operating stability in the rough environment, planar zirconia oxygen sensors is the dominating products in the automotive oxygen sensor market at present. In this paper, a simulation model was developed to predict the temperature distribution and the associated thermal stresses of an amperometric oxygen sensor during the warm-up stage. Transient heat transfer analysis and thermal stress analysis were performed. In the simulation, the electrical resistance, material properties were considered temperature dependent. The simulation results show that the designed sensor have fast response, even temperature distribution and acceptable thermal stress. It is believed that the modeling techniques and computational approaches incorporated in this study are useful and can be applied for the development of similar products.