板式换热器冷却水污垢影响因素权重及结垢机理  

Impact factor weights and mechanism of cooling water fouling in a plate heat exchanger

作　　者：李煜[1,2,3] 徐志明[4] 陈健美[3] 龚金科[2] 袁文华[1] 刘冠麟[3] 李玉强[3] LI Yu XU Zhiming CHEN Jianmei GONG Jinke YUAN Wenhua LIU Guanlin LI Yuqiang(Department of Mechanical and Energy Engineering, Shaoyang University, Shaoyang 422000, China College of Mechanical ＆ Vehicle Engineering,Hunan University, Changsha 410082,China Department of Mechanical Engineering, Hunan International Economics University, Changsha 410205, China School of Energy and Power Engineering, Northeast Electric Power University, Jilin 132012, China)

机构地区：[1]邵阳学院机械与能源工程系,湖南邵阳422004 [2]湖南大学机械与运载工程学院,湖南长沙410082 [3]湖南涉外经济学院机械工程学院,湖南长沙410205 [4]东北电力大学能源与动力工程学院,吉林吉林132012

出　　处：《邵阳学院学报（自然科学版）》2016年第4期61-67,共7页Journal of Shaoyang University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51276056;51176045;91541121);湖南省教育厅科研项目(13C492)

摘　　要：通过更换BR0.015F型波纹板式换热器的不同几何参数的板片,改变冷、热水的入口温度与冷却水流量等途径,实验监测了其污垢热阻并测定了水质与运行状况特征参数,以灰色关联分析法计算了几何结构、水质、运行状况等因素对结垢的影响权重。结果表明在这些特征参数中,对结垢影响最大的为流速,最小的为溶解氧。并从流动与传热传质角度简要分析了该波纹板式换热器的几何结构要素(波纹节高比、波纹倾角)影响结垢的机理:波纹节高比的增加导致冷却水中结垢成分沉积且节点处剪切应力减小弱化了污垢剥蚀,最终结垢;波纹倾角的增大,板间流动渐变为"曲折流",故局部沉积增加,垢阻增加,而交叉成的流体漩涡会增强节点处剪切应力、增大其后流速,故节点处的污垢剥蚀加强,垢阻减小。The thermal resistance of fouling in a BR0. 015F-type corrugated plate heat exchanger was monitored experimentally as well as feature parameters of water quality and operating conditions of the exchanger were measured via changing plates whose geometry were different, inlet temperature of cooling ＆ hot water or/ and mass flow rate. Then weights of impact factors including geometry, water quality and operating conditions on fouling were calculated based on gray relation analysis method. Result shows that the most important impact factor on fouling is flow velocity while the least is dissolved oxygen among them. After that, impact mechanisms of geometric features such as the ratio of normal corrugated pitch to height as corrugated inclination angle on fouling in the exchanger were analyzed simply from the viewpoint of heat ＆ mass transfer. The mechanisms can be demonstrated that the increase of ratio of normal corrugated pitch to height will result in the deposition of fouling components while the removal of fouling weakened due to the decrease of shear stress on pitch points and finally producing fouling; besides, the flow type will gradually vary for ＂tortuous flow＂ when the corrugated angle increases, thus local deposition and thermal resistance of fouling will increase, while fluid vortex from the fluid crossing will increase the shear stress on pitch points as well as flow velocity after the points, thus the removal of fouling on the points will be enhanced as well as the thermal resistance of fouling will decrease.

关 键 词：板式换热器 污垢 灰色关联分析 权重 机理 

分 类 号：TK124[动力工程及工程热物理—工程热物理]