【作者】 王晓霞；

【导师】 姬长发；

【作者基本信息】 西安科技大学 ， 安全技术及工程， 2008， 硕士

【摘要】 近年来由于生产和科学技术发展的需要,强化传热技术已得到较大的发展,并且广泛的应用于石油、化工、动力和制冷等工程领域的换热设备中。研究各种换热过程的强化问题来提高换热设备的性能或设计新颖的高效换热器,不仅是现代工业发展过程中必须解决的重要课题,同时也是开发新能源和开展节能工作的一项紧迫任务。本文以实验手段对自行设计的新型酒窝板换热器的换热及流动特性进行了研究。从酒窝板的制作到实验台的热力系统、水力系统、测量系统、控制系统的设计等方面都做了细致、深入的分析和研究,建立了易于测试、精度较高的板式换热器性能测定实验台,通过实践,并对本实验装置的进一步改进提出了建设性的建议。实验中,以普通平板和酒窝板为研究对象,首先对介质为水的两种板式换热器内的不同流速情况下的对流换热问题进行理论分析,然后在建立的实验台上,对本文提出的酒窝板式换热器以及现有的实际生产中常用的平板式换热器换热及流动性能进行了实验测试,且对两者进行了数据的误差分析及数据对比,分别得到了不同入口温度下的酒窝板与平板出口温度、壁面换热系数、换热量的对比曲线,从而分析了酒窝板的换热性能,结果表明:(1)在相同的入口温度条件下,换热量是与雷诺数有密切关系的,酒窝板的换热量在总体上是大于平板的,不过同时压降也增大;(2)入口温度相同的条件下,雷诺数较低的时候,酒窝板的强化换热效果并不明显;随着雷诺数的增大,酒窝板的壁面换热系数、换热量也是呈增大趋势的,同时它的进出口温差越来越小,这是因为流速过大,会使水箱内换热速度太快,换热可利用的时间过短,不足以达到所需的传热温度;(3)通过进一步将实验结果与数值模拟结果的对比,验证了数值模拟的方法对于这种新型的板式换热器的有效性及可行性,从而得到此种酒窝板式换热器相较平板式的优点所在。更多还原

【Abstract】 With the requirement of manufacture and science technology in recent years, the technique of enhancing heat transfer has been developed greatly, and has been widely used in many areas such as oil, chemistry, dynamic and refrigeration, and so on. It can improve heat transfer performance by improving heat exchanger’s structure. It is not only a subject to be figured out in modern industry but also an urgent task in new energy exploration and energy conversation to design new high-efficiency heat exchangers by researching all kinds of heat transfer enhancement.The paper is based on experimental means of a new type of self-dimple designed plate heat exchanger, and it studies the heat flow characteristics. There is a detailed, in-depth analysis and research for the dimple plate, from the production of the experimental station thermal system, hydraulic system, measurement system, and control system design, and is also establish an easy test, high precision performance of plate heat exchanger Experimental Desk. Through practice, it provides a further improvement to the constructive recommendations with the experimental device.In this paper, experiment and study is for common plate and dimple plate. At the first, there is a theoretical analysis for the two water medium for plate heat exchanger within the different circumstances velocity convection heat transfer problems, and then on the established experimental stage, the paper do a mobile laboratory tests for the heat transfer performance between the dimple plate heat exchanger and the flat-plate heat exchanger which exists commonly and widely used in the actual production, and then give a data comparison and error data analysis between the two, and then obtained the outlet temperature of dimple plate and the plate under different inlet temperature, the wall surface heat transfer coefficient, the heat transfer quantity correlation curve separately, thus it has analyzed the heat transfer performance of dimple plate, the results showed that:(1)In the same inlet temperature, the heat transfer is closely related with the Reynolds number, and generally the dimple plate heat transfer number is more than flat, but meanwhile with the pressure increasing.(2)In the same inlet temperature, with a lower velocity, the exchanger effects of the dimple plate heat is not so obvious. Along with the increasing of Reynolds number, the wall plate heat transfer coefficient of dimple also has an increasing trend, at the same time the temperature difference between its import and export is smaller and smaller. It is because with the too big velocity, the heat exchangers in the water tanks will too fast, so the time which the heat exchanger can use is too short, then it is not enough to attain the required heat transfer temperature;(3)Through further comparison between numerical simulation results and experimental results, then prove the effectiveness and feasibility of the numerical simulation validation for this new type of plate heat exchanger, and so came to the conclude that such a dimple to be compared to flat plate heat exchanger is better.更多还原