| A nuclear power plant is a complex and large-scale system.In order to ensure the safe operation of nuclear power plants,a nuclear power plant monitoring system is of great significance.The environment of nuclear power installations often has harsh conditions such as high temperature,high pressure,high radiation,and strong vibration.Although the electronic sensor meets the application requirements,its large size,multiple wiring,and susceptibility to electromagnetic interference make the electronic sensor have many problems in its application.Optical fiber sensors have the advantages of small size,resistance to electromagnetic interference,electrical insulation,and low loss.They provide new ideas for exploring new nuclear power device monitoring systems.In response responds to the monitoring needs of liquid pressure and solid force in nuclear power plants,this paper proposes a high-sensitivity,low-temperature-coefficient fiber optic Fabry-Perot sensor,and conducts related application tests based on the characteristics of the fiber-optic Fabry-Perot sensor.The specific work is as follows:(1)Research on the sensing characteristics,basic characteristics and irradiation characteristics of fiber optic Fabry-Perot sensors.For the two sensing characteristics of strain and pressure of the optical fiber Fabry-Perot sensor,three types of Fabry-Perot sensors were fabricated based on the sensing principle to conduct a comparative test of the sensing characteristics,An enhanced sensitivity Fabry-Perot sensor with a strain sensitivity of 15 pm/??and a pressure sensitivity of 123 pm/MPa was selected as the sensor for subsequent application research.the characteristics test was performed based on the enhanced sensitivity Fabry-Perot sensor,and it was concluded that the Fabry-Perot sensor can respond to high frequency signals of 10 KHz.10~6 fatigue tests have good characteristics,long-term stability,resistance to 250?high temperature and100%high humidity and other excellent characteristics.the anti-radiation characteristics of the sensor were tudied by 13days gamma irradiation with a total dose of 2 MGy.Detailed,the change in the sensitivity and wavelength of the sensor were studied before and after the irradiation.It shows the sensitivity of the Fabry-Perot sensor did not change significantly before and after the irradiation and the wavelength drift before and after the irradiation.(2)Based on the pressure and strain characteristics of the enhanced sensitivity Fabry-Perot sensor,four types of liquid pressure and solid force sensors were designed and tested.The test accuracy of the liquid pressure sensor is 0.8%,and after 13 days of gamma irradiation with a total dose of 2 MGy,the deviation of the pressure coefficient of the sensor before and after irradiation is 0.0007,and the sensor still has good sensing characteristics after irradiation.the accuracy of the one-dimensional solid force sensor is0.5%.the accuracy of the designed two-dimensional solid force sensor is 0.8%.and the test accuracy of the designed three-dimensional solid force sensor is higher than 1%.This essay has mastered a series of characteristics of fiber optic Fabry-Perot sensor from structural design,simulation and testing,and has carried out a series of related tests based on its characteristics.The feasibility of the fiber optic Fabry-Perot sensor in the measurement of solid pressure and liquid pressure is verified,which lays the foundation for the application of actual working conditions in the later stage. |
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