【作者】 朱培纳；

【导师】 古新；

【作者基本信息】 郑州大学 ， 热能工程， 2013， 硕士

【摘要】 换热器在石油、化工等生产过程中应用广泛。提高换热器流体流动均匀性,改变和优化换热器结构,是节能降耗的重要途径。本文采用实体模型,对带有变截面导流筒装置的常规换热器进口截面上流体流动均匀性进行了研究,并根据导流筒装置不同几何参数下换热器进口截面上流体流动均化状态,确定了优化流动状态下变截面导流筒装置的结构参数。结果表明,选取合理的结构参数对换热器进口流体流动有较好的均化效果,同时还可以有效降低换热器壳程压力损失。将变截面导流筒装置安装到常规帘式折流片换热器中,采用FLUENT软件,研究常规帘式换热器在安装导流筒装置前后其壳程流体流动特性的变化,对比了安装变截面导流筒装置前后常规帘式换热器的壳程压降及进口截面上流体均匀性状态。通过对比分析,证明了安装有变截面导流筒装置的帘式折流片换热器具有较好的流动性能,并能够显著降低壳程压降。针对常规帘式折流片换热器,通过交错调整折流栅间距、折流片的倾角和宽度,建立计算模型,得到不同结构参数下帘式折流片换热器壳程的流体流动性能和传热特性。通过对比,得到了帘式折流片换热器内部流体优化传热状态下,换热器的结构参数。为进一步改进常规帘式折流片换热器的壳程结构提供了参考依据。针对文中所用的数值模拟方法和所得到的模拟结果,开发了帘式折流片换热器的实验装置,对其进行流体流动特性实验。结果表明,在相同的几何参数和工况条件下,数值模拟结果和实验结果吻合良好。更多还原

【Abstract】 Heat exchanger is widely used in the production process of oil industry and chemical industry, etc. Improving heat exchanger fluid flow homogeneity, changing and optimizing the structure of heat exchanger are important way of saving energy and reducing consumption.In this paper, on the basis of numerical simulation, the entity model has been used to study the homogeneity of inlet fluid in the conventional heat exchanger with variable cross-section guide cylinder device, And the better fluid flow state based on the inlet cross-section of heat exchanger of the guide cylinder device under the different geometric parameters are determined to the structure parameters of the variable cross-section guide cylinder. Results show that, for inlet fluid flow on the heat exchanger, selecting reasonable structure parameters has good homogenization effect. At the same time, It could effectively reduce the pressure drop of heat exchanger shell.The variable cross-section guide cylinder has been loaded into the shutter baffles heat exchanger, the flow characteristic in the shell side of heat exchanger with guide cylinder device before and after has been studied by FLUENT. Comparison of the pressure drop on the shell side and homogeneity of the fluid on the inlet section of the shutter baffles heat exchanger before and after the installation of variable cross-section guide cylinder device. Through comparative analysis, it proved that the variable cross-section draft tube device has good flow properties for the shutter baffles heat exchanger, and it can significantly reduce the pressure drop of shell side.By adjusting the rod-baffle pitch, the angle and the width of baffling, and establishing the calculation model, the fluid flow properties and heat transfer characteristics on the shell of shutter baffles heat exchanger is found under the different structural parameters. And contrast to the conventional shutter baffles heat exchanger, the structure parameters of heat exchanger are obtained when the internal heat transfer state is optimized, which provide a reference for the further improvement structure of shell of the conventional shutter baffles heat exchanger. In order to prove the numerical simulation results and methods are correct which are used in the paper, and research on its flow characteristics of the fluid flow field, the experimental device base on the shutter baffles heat exchanger are manufactured. The results show that, under the same set of parameters and operating conditions, the numerical simulation results and experimental results of the heat exchanger are in good agreement.更多还原