300MW循环流化床锅炉屏式受热面传热系数计算及其变化规律

根据300MW循环流化床（CFB）锅炉现场测试数据并结合以往CFB锅炉传热系数的研究成果，建立了屏式受热面烟气侧的传热模型，包括辐射传热模型和对流传热半经验公式．利用该模型对某300MWCFB锅炉在94％锅炉最大连续蒸发量（BMCR）工况下炉膛内屏式受热面的传热系数进行了计算，分析了屏式受热面管间节距、炉膛温度、工质温度、壁面黑度及烟气速度等因素对传热系数的影响．结果表明：烟气速度、炉膛温度和壁面黑度对传热系数的影响较大，所建立的传热模型能够合理地反映主要因素对CFB锅炉屏式受热面传热的影响．

Calculation and Variation of Heat-transfer Coefficient of Platen Heating Surfaces in a 300 MW CFB Boiler

According to the test data obtained on site of a 300 MW CFB boiler and previous research a chievements concerning heat-transfer coefficients of CFB boilers, a heat-transfer model of platen heating surface at flue gas side was established, including a radiation heat-transfer model and a semi-empirical for- mula of convection heat transfer. Based on heat transfer coefficient calculation of platen heating surface on a 300 MW CFB boiler at 94~ boiler maximum continue rate（BMCR） load, the impact of following factors on the heat transfer coefficient was analyzed, such as the tube pitch of platen heating surface, the furnace temperature, the steam temperature, the emissivity of tube wall and the flue gas velocity, etc. Analysis results show that the flue gas velocity, the furnace temperature and the emissivity of tube wall are the leading factors influencing the heat-transfer coefficient. The heat-transfer model can reasonably reflect how the main factors affect the heat transfer of platen heating surface of CFB boilers.