Study Of Three-dimensional Radiation Field Monitoring System Based On WSN

With the development of nuclear technology within the area of nuclear power plant’s radiation monitoring and extensive application of wireless sensor technology, the intellectualized radiation monitoring system has become the main study project of different scientific research institutions and nuclear owners in recent years. How to monitor the radiation of different areas and process flow while nuclear power plant is working, reduce manual workload when accidents happen and other design purposes have promote the application of wireless sensor technology in nuclear power plant.In nuclear power plant, the radiation field is much larger, so the stability needs to be enhanced, and the monitoring needs to be safer. This thesis bases theoretically on the application status of wireless sensor technology in nuclear power plant and the study reports of domestic and foreign scientific research institutions, fully analyzes the characteristics of wireless sensor systems in nuclear power plant, and then presents a 3D monitoring nuclear power plant method based on wireless sensor network technology and builds a system model. This system emphasize two questions:I. Design and build wireless sensor network, improve network’s structure and node development strategy. Chose the WirelessHART technology to build the wireless network model after contrastive study, analyze theoretically the reliability, safety and stability of mesh network structure, and validate that the WirelessHART module has extremely low power consumption and the network of it can be operated easily. Design double-layer network module since radiation monitors in nuclear power stations are located in a fixed place, use ILP (integral linear programming) to analyze qualitatively the restrictions of power dissipation, link integrity and data transmission without packet loss, in order to find the arrangement strategy of the number of relay nodes. This network module can achieve the wireless measurement of radiation dose to a large scale, guarantee all the measurement result from effective measurement locations can be sent to data receiving terminals accurately and unfailingly.II. Use advanced ultrasound technique to achieve wireless communication inside and outside the security shell. Since steel safety shell can shield wireless signals, this thesis analyzes the wireless communication requirements about the short communication distance and low bitrate, designs the wireless communication system carried by ultrasonic. The developed ultrasonic transmitting and receiving module with 40kHz frequency,2400bps baud rate has been proved workable by experiments when simulating the safety shell in nuclear power station working condition. This technique breaks the bottleneck of using wireless technique for safety shell, avoids damaging the safety shell while increasing penetration pieces.Supported by two above techniques, combining the developed 3D spontaneous reconstruction software, this thesis finds preliminarily the solution of radiation field’s wireless monitoring technology:"data monitoring inside safety shell-wireless network data transmission-ultrasonic technology communication."...