Study on Heat Flux Measurement and Wall Temperature Distribution of Superheated Specimen in 700℃Coal-Fired Power Generation Component Test Facility
With the increase of main steam parameters of boilers,monitoring the wall temperature distribution of heating surface in the furnace is becoming increasingly important for safe operation,and beneficial for material selection to reduce costs.In the 700℃component test facility at Nanjing Power Plant there are 12 different materials distributed throughout its superheater,and understanding wall temperature distribution and its variation with load is the basis for accurately analyzing material validation results.The flame intensity heat flux meter is used to measure the spatial distribution of heat flux density inside the furnace,and combined with actual measurements of steam parameters at inlet and outlet of superheater,the wall temperature distribution is calculated.The results show that heat flux density in different directions ranges from 15 kW/m2 to 180 kW/m2,and indicate obvious regularity.The heat flux density from ahead direction is the maximum,followed by the heat flux density from below,while the density at the panel bottom is the highest and that at top position is the lowest,and the horizontal tube's average thermal flow density at the panel bottom is about 1.3 times of that of vertical tube.Along steam flow direction,there is a rapid increase in superheater wall temperatures which peaks near panel bottom,then slowing down and finally decreasing slightly near the outlet.The tube wall-to-steam temperature difference shows a phenomenon of first increasing and then decreasing,and a significant peak at the panel bottom,and is the maximum value of 88℃at the panel bottom,while drops to around 25℃at the panel top.Higher boiler loads result in higher thermal flow densities as well as faster increases in wall temperatures.The maximum deviation between measurements and the calculations results is less than 2%which indicates good consistency.According to the calculation results,for the superheated specimen,about 51.2%of tubes require nickel-based alloys,which can significantly reduce cost compared to using nickel-based alloy material entirely.
700℃component test facilitysuperheated specimenhigh-temperature materialwall temperature distributionheat flux
万方数据
维普
