基于普朗特类比的多种强化管内污垢数据分析

Analysis on In-Several-Enhanced-Tubes Fouling Data Based on the Prandtle Analogy

针对光管和四种不同结构的强化管(缩放管Ⅰ、缩放管Ⅱ、弧线管及波纹管)在相同条件(工质流速、入口温度、水浴温度及微粒浓度)下的颗粒污垢实验数据,基于普朗特类比法,以φ(φ=(K_m/K_(mp))/(f/f_p),K_m为质量传递系数,f为摩擦因子,下标p表示光管)和ψ(ψ=(j/j_p)/(f/f_p)^(1/3),j为传热因子)作为传热性能评价指标,η_φ(η_φ=(R_f/R_f_p)/φ,R_f为渐近污垢热阻)和η_ψ(η_ψ=(R_f/R_f_p)/ψ)作为换热面综合评价指标,结合强化管内流场模拟情况,进行分析。结果表明:不同类型的强化管,渐近污垢热阻比R_f/R_f_p与φ及ψ值的大小并非存在增函数关系;在给定的实验条件下,弧线管的综合性能优于其它三种强化管。所述方法为污垢研究工作提供有益参考。

Based on the Prandtle analogy,φ（φ=（K_m/K_（mp））/（f/f_p）,K_m is mass transfer coefficient, f is friction factor and the subscript p denotes the plain tube） andψ（ψ=（j/j_p）/（f/f_p）^（1/3）,j represents heat transfer factor） being used as evaluation indexes of heat transfer,η_φ（η_φ=（R_f~＊ /R_（fp）~＊）/φ, R_f~＊ means asymptotic fouling resistance） andη_ψ,（η_ψ,=（R_f~＊/R_（fp）~＊）/ψ） being regarded as comprehensive evaluation indexes of heat transfer surface,combining the conditions of in-several-enhanced-tubes flow-field simulation,it was analyzed for some particulate fouling data from smooth tube and four kinds of enhanced tubes（narrowed and expanded tubeⅠ,narrowed and expanded tubeⅡ,arc line tube and waved tube） under the same conditions（The velocity,the inlet temperature,the temperature of water bath and the concentration of particulate are respectively identical.）.Results show that the relationships of increasing functions are not found between the asymptotic fouling resistance ratio R_f~＊/R_（fp）~＊ and the value ofφandψfor different types of enhanced tubes,and the comprehensive properties of arc line tube are better than that of the other three enhanced tubes for given experimental conditions.The method mentioned above can offer beneficial references for the research work of fouling.