液相有机热载体流动换热特性数值模拟与试验研究

In the 80s of last century, we developed the first liquid type organic thermal fluid heater based on the transferred technology. With its characteristics of “high temperature and low pressure, easy to adjust, uniform heat transfer, stable temperature, no heat of condensation loss, without water treatment equipment and safety”, it was widely used in all walks of life. But so far, its main body and system design mainly depend on the experience of hot-water and hreat boiler without the systematic knowledge to guide the design of organic thermal fluid(known as “thermal oil”), which lead to some problems in the process of popularizing, such as coking and tube explosion. Therefore, it is of great practical significance in the popularization and application of organic thermal fluid to carry out some systematic theory and experimental study. In this projectm according to the model experiment and field text, the methods of model experimental text combined with theoretical analysis and numerical simulate are adopted to verify and amend the theoretical analysis and numerical simulate computing in order to make sure the flowing resistant and heat transferring characteristic in the organic thermal fluid heater, and then to provide calculation method for thermal fluid heater, hydrodynamic calculation and system design. The feature and innovation lie in that to study the influence rules of temperature on the thermophysical property and flow drag characteristic of organic thermal fluid accoding to the thermophysical properties in the theoretical and experimental measurement.

上世纪80年代，我国在引进消化的基础上开发了第一台液相式有机热载体炉，由于其具有低压高温、调节方便、传热均匀、温度稳定、无冷凝热损失、无需水处理设备和安全性能好等一系列优点，在各行各业得到了广泛应用。但到目前为止，热载体炉本体的设计主要依靠热水和蒸汽锅炉的设计经验，缺乏指导有机热载体炉设计的系统理论知识，致使近年来有机热载体炉在推广过程中出现了有机热载体（俗称导热油）结焦和爆管等问题。因此，对其进行系统的理论和实验研究，对推动有机热载体炉的推广应用有着重要的实际意义。本项目拟采用理论分析、数值计算和实验相结合的研究方法，以理论分析计算为基础，通过试验进行修正，以确定有机热载体工作温度对有机热载体热物性及热载体炉炉管管内流体阻力特性的影响规律，为有机热载体炉本体及系统设计提供理论参考。项目的特色及创新在于根据理论和实验测试的热物性值，着重研究温度对有机热载体热物性和流动阻力特性的影响规律。

液相有机热载体加热系统具有高温低压、调节方便、温度稳定、无冷凝热损失、无需水处理设备和安全性能好等优点而获得广泛应用。但其热物性和阻力特性的研究成果尚不能满足热载体加热技术发展的需要，也制约了液相有机热载体炉的开发和推广应用。为此，本项目开展了以下工作：从理论上分析了特定条件下螺旋盘管直径、管径、螺距、流速、粘度和温度等参数对液相有机热载体在螺旋盘管管内流动速度分布和流动阻力的影响规律；分析了毛细管法、落球法、旋转法和振动法等粘度测量方法用于测量工作温度200℃以上液相有机热载体粘度的可行性，提出了相应的测试方法和测试台建设方案；对液相有机热载体粘度理论计算方法进行研究，探讨了现有油类液体粘度经验计算公式用于液相有机热载体粘度计算的适应性，认为双对数式比较适合。研究分析所取得一些初步结果，是在特定条件下分析计算得到的，具有局限性，不宜直接用于实际工程，尚需开展大量的分析计算和实验测试修正工作。