A Wireless Mesh Network-based Temperature Monitoring System For Blast Furnaces

In order to ensure the safety of blast furnace production,extend the service life of furnace and improve the production technology,nearly thousands of thermocouples are used to measure the temperature at each point in the hearth to monitor the health of the hearth of blast furnace.For a long time,blast furnace hearth temperature field monitoring system are construct based on cable distributed control system.Normally in these wired temperature monitoring systems for blast furnaces,analog signals of thermocouples will be transmitted to main control room by compensating wires in long distance,which brings severe problems such as high cost,low reliability and maintenance difficulty.In view of the characteristics of blast furnace,this study proposed a wireless monitoring system for blast furnace hearth temperature field based on wireless mesh network.To improve the reliability of the wireless mesh network,an OLSR-based dual-path adaptive routing protocol is proposed.By routing the two paths,the adaptive routing protocol improves the reliability of the transmission network and avoids the single point failure problem of the wireless network.In addition,in order to optimize the consumption of network resources by routing protocols,an adaptive route maintenance mechanism is also proposed,which effectively reduces the number of TC control packets in the network and improves the network utilization efficiency.To verify and test the actual performance of this system,a prototype system was implemented to test on site in a blast furnace.This dissertation reports the design and implementation of a thermocouple temperature wireless acquisition node and completes the circuit design of thermocouple multi-channel check circuit,analog-digital conversion circuit,I/O control circuit,the network function module.Based on Open Wrt,we developed device firmware to achieve improved routing protocol and the device software.Based on the temporal and spatial relevance of the data,the tested data were preprocessed,and the outliers of the data were corrected.Finally,based on the differential equation of the three-dimensional heat conduction in the blast furnace hearth,the finite difference method is used to solve the temperature field of blast furnace hearth.After a long period of testing and stable operation,the feasibility of the wireless monitoring system for the temperature field of the new hearth based on the mesh wireless network proposed in this paper is fully verified,which has the advantages of low system cost,simple system structure,easy maintainability and high reliability,with high promotional value and application prospects.