| Temperature measurement is widely used in industrial process control and energy metering,higher and higher demands to fluid temperature measuring are proposed in industrial development.The precise measurement of the nuclear power plant condenser export large pool water temperature reflects the equipment efficiency of high and low,but the current flow of large area existing in the cervix temperature low temperature measurement precision,high cost,complex operation such as faults,thus developed a measuring plant water temperature of large area long pole heat resistance temperature measuring device is urgent.Based on the theoretical analysis of thermal resistance temperature measurement,the structure design of the thermal resistance device calibration and optimization experiment research,this paper proposes a measurement of large area of the fluid temperature scheme,developed the long pole heat resistance temperature measuring device.(1)In this paper,based on the theory of thermal resistance temperature measurement,combined with the long pole resistance development requirement of the temperature measuring device,for the long pole heat resistance temperature measurement device structure design,determine the design parameters of the following:select 0.1 mm in diameter,the purity of 99.99% high purity enameled copper wire as the resistance wire,0.18 mm in diameter precision of manganese copper wire as compensation resistance wire,the insulation of the diameter of 1.0 mm copper bar as a skeleton,insulation diameter of 0.5 mm quartz sand particles as insulation fillingmaterial,6.0 mm in diameter,wall thickness of 0.5 mm 316 stainless steel pipe as protection.(2)With length × width × height 490 mm × 570 mm × 986 mm rectangular medium temperature cycle bath and high precision thermometer calibration of temperature sensing element,the results show that thermal element within the range of0 to 100℃ can achieve B platinum resistance tolerance requirements.With long ×diameter 3000 mm × 120 mm calibration device to calibrate the long pole resistance,the results show that the long pole resistance within the range of 0 to 50℃ can achieve A platinum resistance tolerance requirements.(3)In order to improve the accuracy and stability of the temperature measuring device,further to the purity of enameled copper wire,compensation resistance wire skeleton material,insulation skeleton material,welding method,different ratio of resistance to optimize the effect factors of temperature measuring experiment.Results show that the suitable ratio of resistance value range,with purity of more than 99.99%of the enameled copper wire as resistance wire,precision manganese copper wire as compensation resistance wire,enamelled copper bar as insulation skeleton,brine welding as an electric resistance welding way,90.890 Ω copper wire and 9.110 Ωmanganese copper wire as the optimal proportion,developed a better precision,better stability of temperature measuring device.The temperature measuring device compared with similar foreign products,can achieve the relevant requirements of similar products abroad,and is expected to replace the expensive abroad long pole platinum resistance temperature measurement device. |
