间接式太阳能热水系统储热水箱盘管换热器设计分析

Design and Analysis of Coil Heat Exchanger for Solar Hot Water Storage Tank

结合工程实例阐述了间接式太阳能热水系统运行原理,从换热设计、结构设计、阻力计算三方面分析了储热水箱中盘管换热器的设计方法。换热设计方面详细介绍了储热水箱盘管换热器中换热液与盘管内壁的管内受迫对流换热、盘管内壁至外壁的导热以及盘管外壁与冷水的自然对流换热等三个热过程的换热分析及参数选取,得出总传热系数为517.15 W/(m^(2)·K),4个区域盘管换热器总换热面积123.27 m^(2);结构与阻力设计方面对比了经济比摩阻、同类文献阻力损失限值及水泵富裕扬程限值3种方案下的盘管结构,得出水泵富裕扬程限值方案最为贴合本工程的盘管结构设计,4个区域共需φ25×1.2不锈钢盘管50组,每组以450 mm外径缠绕19圈。为相关工程设计应用提供了参考。

The operation principle of indirect solar water heating system is explained in combination with engineering examples.In terms of heat exchange design,the forced convection heat exchange between the heat exchange liquid and the inner wall of the coil in the heat exchanger of the hot water storage tank coil,the heat conduction from the inner wall to the outer wall of the coil,and the natural convection heat transfer between the outer wall of the coil and the cold water are introduced in detail.According to the heat transfer analysis and parameter selection of the three thermal processes,the total heat transfer coefficient is 517.15 W/(m^(2)·K),and the total heat transfer area of the four regional coil heat exchangers is 123.27 m^(2).In terms of structure and resistance design,the coil structures under the three schemes of economic specific friction resistance,the resistance loss limit of similar literature and the pump’s rich head limit are compared,and it is concluded that the pump’s rich head limit scheme is the most suitable for the coil structure of this project.In the design,a total of fifty groups ofφ25×1.2 stainless steel coils are required in the four areas,and each group is nineteen laps with an outer diameter of 450 mm.This research provides a reference for related engineering design applications.