增压富氧气氛下锅炉高温对流受热面的优化及其换热特性研究  

Study on Structure Optimization and Heat-transfer Characteristics of High-temperature Convective Heating Surface in Pressurized Oxy-fuel Boilers

作　　者：高正阳[1] 赵航[1] 范军辉[1] 殷立宝 廖永进 

机构地区：[1]华北电力大学能源动力与机械工程学院,河北保定071003 [2]广东电网有限责任公司电力科学研究院,广州510080

出　　处：《动力工程学报》2016年第10期773-780,共8页Journal of Chinese Society of Power Engineering

摘　　要：以某300MW燃煤机组为例,运用Aspen Plus软件确定煤粉在增压富氧(CO2与O2体积比为70∶30,压力为1MPa)气氛下生成烟气的物性,采用Fluent软件,结合DO辐射模型,对高温再热器和高温过热器在不同烟气流速下的传热情况进行数值模拟,运用迭代法对其进行换热优化研究,分析优化后换热器参数的变化.结果表明:随着烟气流速的增大,优化后的高温再热器和高温过热器的对流传热系数逐渐增大,辐射传热系数逐渐减小,增压富氧气氛下高温再热器和高温过热器所需换热面积逐渐减小,且变化幅度变小;优化后换热器的烟道高度、烟道宽度、横向节距和管圈高度等尺寸参数均大幅减小,耗材量减少,但烟气压降大幅增大,厂用电耗增加.Taking a 300 MW coal-fired boiler as an object of study, the properties of flue gas formed in pressurized oxy-fuel combustion were studied at 1 MPa with CO2 to 02 volumetric ratio of 70 ： 30, while the heat-transfer characteristics of high-temperature reheater and superheater were numerically simulated using Fluent software combined with radiation model DO at different flue gas velocities, to which heat- transfer optimization was carried out by iterative method, and subsequently an analysis was conducted on parameter variation of above heat exchangers. Results show that with the rise of flue gas flow rate, the convective heat-transfer coefficients of structurally-optimized high-temperature superheater and reheater gradually increase, but their radiative heat-transfer coefficients generally reduce, and the heat-transfer area required for high-temperature superheater and reheater reduces accordingly under pressurized oxy-fuel con- ditions, with lowering variation amplitude. The dimensional parameters of optimized heat-exchangers de- crease, such as the flue height, flue width, horizontal pitch and tube size, etc. , meaning less material consumption, whereas the pressure drop of flue gas rises significantly, resulting in increased auxiliary power consumption.

关 键 词：增压富氧燃烧 高温对流受热面 优化 迭代法 数值模拟 

分 类 号：TK223.3[动力工程及工程热物理—动力机械及工程]