"三电极平衡式”微量溶解氧传感（器）技术的研究

In order to solve the scientific issues and technical difficulties about tri-electrode balances-like online detection technology of trace amounts of dissolved oxygen, this paper will study the working mode mechanism model and the fast response mechanism model of balances-like sensor. The solenoid-type tri-electrode structure will be designed innovatively and the mechanism models of three-dimension potential flow in the equilibrium steady flow field will be established. Concluding the mathematical relation between the polarization response current and electrode reaction area in reversible equilibrium steady state can improve the response time of sensor and measurement accuracy. The implementation of new-style sensors is guided by the results of mechanism research.. The new-style tri-electrode electrochemical sensor is composed of Working Electrode(WE), Auxiliary Electrode(AE) and Reference Electrode(RE), which can overcome some disadvantages of the existing sensors such as the limit reaction area of the WE, the long reaction time, the little reaction cavity and the unstable output signal. The nano-porous gold electrode with high specific surface area will be made to increase the reaction area ration of the AE and the WE, and the polarization potential system of deep negative feedback will be designed to achieve the advantages of sensors such as the strong disturbance rejection ability, the stable performance, the short response time, and the high detection accuracy. This project has significant science meaning and application value in terms of water supply of power plant boiler and replenishment of nuclear power plant.

针对“三电极平衡式”微量溶解氧(PPB级)在线检测技术亟待解决的科学问题和技术难点，研究平衡式传感器工作模式的机理模型、平衡式传感器快速响应的机理模型；创新设计螺线管型三电极结构体系，从而建立平衡稳流场三维势流的机理模型，建立可逆平衡稳态下极化反应电流与电极反应面积的数学关系，提高传感器的响应时间及测量精度，以机理研究的结果去指导新型传感器的实现。. 传感器采用新型的三电极结构，三个电极分别由工作电极(WE)，辅助电极(AE)和参比电极(RE)构成，该结构可克服扩散式传感器反应面积小，反应速度慢，反应空间小，输出信号不稳定等缺点，通过制备高比表面积纳米多孔金电极，增大辅助电极与工作电极反应面积比；而深度负反馈极化电势系统的设计，实现了传感器抗干扰能力强，性能稳定、响应速度快、检测精度高的特点。项目的研究在电厂锅炉供水和核电站补水方面具有重要的科学意义和应用价值。

针对电极平衡式微量溶解氧(PPB级)在线检测技术亟待解决的科学问题和技术难点，本项目研究平衡式传感器工作模式和快速响应（反应速度）模式的机理研究，推导了微量溶解氧传感器的阳极和阴极所需施加的固定极化电压；推导出阳极的氧化反应速率和阴极的还原反应速率；计算了还原反应速率和氧化反应速率的比值，优化了阳极与电解液接触的有效表面积，建立了极化电势E与传感器工作时间和透氧膜两侧溶解氧浓度达到平衡时间的函数关系，同时，传感器透氧膜的研究和实验给出了使用FEP薄膜的传感器综合性能最优，通过制备高比表面积纳米多孔金电极，增大辅助电极与工作电极反应面积比；而深度负反馈极化电势系统的设计，实现了传感器抗干扰能力强，性能稳定、响应速度快、检测精度。在此基础上，提出了一种双螺旋结构辅助电极，实验得出双螺旋结构辅助电极溶解氧传感器的稳定性良好，响应速度快，线性度好，相对误差小，且综合性能优于单螺旋结构辅助电极溶解氧传感器。在此基础上,对影响传感器检测性能的温度、大气压、盐度等参数进行了机理分析,并进行了补偿方法的研究，补偿后的传感器具有较高的稳定性及抗干扰能力;大大提高了Clark电极型微量溶解氧传感器的检测精度。