李瑜, 樊义辉, 卞平艳, .同轴反应流反应速率的唯象表征与影响规律研究[J].河南理工大学学报（自然科学版）,2025,44(1):109-116.

LI Y, FAN Y H, BIAN P Y, et al. Phenomenological characterization and effect of reaction rate of coaxial reaction flow[J]. Journal of Henan Polytechnic University(Natural Science) , 2025, 44(1): 109-116.

同轴反应流反应速率的唯象表征与影响规律研究

李瑜1, 樊义辉1, 卞平艳1, 张海光2,曲海军1, 王建平1

1.河南理工大学 机械与动力工程学院，河南 焦作  454000;2.上海大学 工程训练国家级实验教学示范中心，上海  200444

摘要: 目的 为了提高同轴反应流工艺的控制精度，探索反应速率的宏观唯象表征方法和影响规律， 方法 通过紫脲酸铵对Ca2+进行示踪，在线观测海藻酸钙水凝胶中空纤维的交联成形过程，利用洗脱法对交联层边界的灰度阈值进行标定，从宏观唯象的角度定义同轴反应流的平均反应速率，通过在线监测提取的交联层厚数据，计算得到反应速率值，并通过试验研究海藻酸钠和氯化钙溶液的流量（定流率比）、质量分数、共流距离对交联层厚和平均反应速率的影响规律。 结果 结果表明：对比在线图像识别和洗脱法实测所得中空纤维尺寸，两者误差仅1.09%，满足工程应用需求；增加反应物质量分数能提高平均反应速率，增加交联层厚，且氯化钙质量分数具有更好的调控性能；定流率比条件下，随着两溶液流速增加，中空纤维交联层厚减小而平均反应速率增大；随着反应流共流距离增加，交联层厚增加而平均反应速率逐渐减小。上述唯象平均反应速率受流体速度场和化学反应物质量分数的影响规律与经典反应速率是一致的，说明该唯象定义是有效的。 结论 研究采用的同轴反应流在线监测方法、反应速率的唯象表征方法、材料工艺参数影响规律等有助于实现中空纤维结构尺寸、交联层厚和保留溶胶层厚的精确控制，有助于同轴反应流工艺的推广与应用。

关键词:同轴挤出;反应流;反应速率;唯象表征;精确控制

doi: 10.16186/j.cnki.1673-9787.2022120002

基金项目:国家自然科学基金资助项目（52275498，52275419）；河南省自然科学基金资助项目（222300420447）；河南省高校基本科研业务费专项项目（NSFRF210341）；河南理工大学博士基金资助项目（B2017-29，B2013-025）；河南理工大学青年骨干教师培养计划项目（2022XQG-07）

收稿日期:2022/12/01

修回日期:2023/10/31

出版日期:2025/01/02

Phenomenological characterization and effect of reaction rate of coaxial reaction flow

LI Yu1, FAN Yihui1, BIAN Pingyan1, ZHANG Haiguang2,QU Haijun1, WANG Jianping1

1. School of Mechanical and Power Engineering， Henan Polytechnic University， Jiaozuo  454000， Henan， China; 2. National Demonstration Center for Experimental Engineering Training Education， Shanghai University， Shanghai  200444， China

Abstract: Objectives For precise control of the coaxial reaction flow process， the macroscopic phenomenological characterization method and control law of reaction rate， Methods the cross-linking process of calcium alginate hydrogel hollow fiber was observed online by tracing Ca2+ with murexide indicator. The gray threshold of the crosslinking boundary was calibrated by the elution method. The average reaction rate of the coaxial reaction flow was defined from a macroscopic phenomenological perspective. The reaction rate value was calculated through the cross-linked layer thickness data extracted by online monitoring. The effects of the flow rate（constant flow rate ratio），concentration and co-flow distance of sodium alginate and calcium chloride solution on the thickness of cross-linked layer and average reaction rate were studied experimentally. Results The results showed that： Compared with the hollow fiber size detected by online image recognition and elution method，the error between the two was only 1.09%， which could satisfy the engineering application requirements. With the increase of reactant concentration， the average reaction rate and cross-linked layer thickness were increased， and the calcium chloride concentration had a better regulation performance. Under constant flow rate ratio conditions， the cross-linked layer thickness decreased while the average reaction rate increased as the flow rate of the two solutions increased. As the co-flow distance of the reaction flow increased， the cross-linked layer thickness increased， and the average reaction rate gradully decreased. The above trends of the phenomenological average reaction rate affected by the fluid velocity field and the concentration of chemical reactants， which was consistent with the classical reaction rate indicating the validity of the phenomenological definition. Conclusions The online monitoring method of coaxial reaction flow， the phenomenological characterization method of reaction rate， and the influence law of material process parameters provided in this study， could help to realize the accurate control of hollow fiber’s structure size， cross-linked layer thickness and retained sol layer thickness， which could be helpful to promote and apply the coaxial reaction flow process.

Key words: coaxial extrusion; reaction flow; reaction rate; phenomenological representation; precise control