【摘要】 对平板式极限电流型氧传感器冷启动时的热应力耦合场进行了模拟。通过施加阶跃电压取代恒定电压的方法,解决了响应时间和稳定工作温度的矛盾。电热耦合模拟分析结果显示,设计的传感器响应时间为5 s,稳定工作温度为800℃。热力耦合模拟分析显示,在氧传感器实际安装使用时,热应力主要取决于装配应力,由于LSCM/3YSZ扩散障材料的热膨胀系数与YSZ电解质材料相近,用它制备氧传感器,其最大热应力小于各层材料的断裂强度,解决了LSM与YSZ热不匹配的问题。更多还原

【Abstract】 In this paper,thermal stress coupled field for cold start of the planar amperometric oxygen sensors was simulated and analyzed. Loading step voltage instead of constant voltage is a good method to resolve this contradiction of response time and stable working temperature. The result of electro- thermal coupling analysis shows that the response time of this sensor is 5 s and the stable working temperature is 800 ℃. The result of thermo- mechanical coupling analysis shows that the thermal stress mainly depends on the assembly stress in actual installation. As the thermal expansion coefficient of LSCM /3YSZ diffusion barrier material is close to the YSZ electrolyte material’s,the LSCM /3YSZ material is used to make oxygen sensor. This sensor’s maximum thermal stress is less than the rupture strength of all layers,which can overcome the thermal mismatch of LSM and YSZ.更多还原