【作者】 吴学慧；

【导师】 孙德兴；

【作者基本信息】 哈尔滨工业大学 ， 供热供燃气、通风及空调工程， 2008， 博士

【摘要】 能源与环境问题的压力日趋严重,“节能减排”已成为世界各国发展的大政方针。城市原生污水以水温适中、数量巨大、分布广泛等特点,成为极佳的可再生绿色低位能源。但由于城市污水的水质很差、对换热设备污染严重等问题限制了城市污水低位冷热源的推广与应用。把握污染对流动换热的影响是污水冷热源应用的重要问题之一。该方向上研究成果的成熟程度目前还不足以指导工程应用。本文围绕污水对换热设备的污染问题,对城市原生污水的流动、换热特性、设备污垢对系统流动换热的影响、钛纳米聚合物涂料在换热管内的应用等进行了分析,旨在为污水冷热源的应用与推广提供依据。污水的流动与换热特性是污水冷热源系统分析与应用的基础。论文通过实验对污水的流变特性进行了测定,分析得出了污水流变本构方程。论文还对污水在圆管中的速度分布与温度分布进行了分析,推导了圆管中污水紊流流动的阻力系数计算式与换热准则关联式。并给出与清水相比,流动阻力增大与对流换热系数减小的幅度。如何把握与克服污水换热设备的污垢对系统流动换热的影响是应用的重点难题。论文通过对换热设备内污垢成分的分析,发现污染换热设备的主要为有机污垢。论文分析了其增长模型,并发现流速对污垢的沉积过程影响很大。论文通过实验数据总结出了多种常用换热管内污垢热阻的增长模型;结果表明其为随时间变化的渐近型函数。在污垢对流动阻力的影响方面,论文进行了换热器的整体实验,得到了简便实用的污垢压降模型。纳米涂料的应用是对污水换热器防、抗垢技术的新探索。论文依据污水及管内污垢的特性选择适当的纳米涂料,并对纳米涂料管内的污水流动、换热、污垢增长特性等进行了实验研究。通过经济技术参数的对比分析,获知采用适合的纳米涂料是抗垢的有效手段。本文对城市原生冷热源系统内污水对换热设备污染特性的研究与分析,为污水冷热源的工程设计、设备开发,系统管理与进一步的研究提供了参考。更多还原

【Abstract】 With the serious issues about energy and environment increasingly,“saving energy and reducing emission”has become the one of important policy of many countries of world. And the city untreared sewage is an excellent renewable low potential energy because it is moderate temperature, large quantity and widespread distribution. But the application and popularization of city sewage cooling and heating source are limited because of the puzzle of bad quality of water, complex component and fouling of city sewage. How to calculate and analyse the characteristic of flow, heat transfer and fouling has been bottleneck of application and popularization of city sewage cooling and heating source. And it is not enough to application for present researches. Aiming at the requirements of engineering, the characteristics of flow, heat transfer, biofouling of sewage, the application of nanometer taitanium polimer covering material by theoretical derivation and field engineering experiments. These will supply base ground for the application and popularization of city sewage cooling and heating source.The characteristics of flow and heat transfer of sewage are the bases of application of city sewage cooling and heating source. In this paper the rheology of sewage is tested and measured and the constitutive equations of rheology is reached by experiments. And the velocity field and temperature field of sewage in circle pipe are analysed. In addition to, the equation of coefficient of drag of flow and heat transfer rule equation of sewage in circle pipe under turbulence are developed by calculated. The differences of coefficient of drag of flow and convection heat transfer between sewage and clean water are analyzed.How to analysis and overcome the impact of heat exchanger fouling is a key problem of application of sewage. The component of fouling is analysed in this paper. It is found that the foulings impact heat exchangers are organic foulings mainly. And the models of development of fouling formation are study. The impacts of velocity of sewage to biofouling deposit are explored base on the characteristic of stress and deposit model in every stage. The thermal resistance models of fouling of six common heat transfer pipes used is reached. They are asymptotic function of time. And the press loss model of fouling of heat exchanger is developed through calculation and experiments.The application of nanometer taitanium polimer covering material is new technology of anti-fouling of sewage heat exchanger. The proper nanometer covering material is chosen base on the characteristics of fouling. And the characteristics of flow, heat transfer and fouling of sewage in nanometer coat pipes are study. By contrast with other pipe material that can be known the proper nanometer coat is an availability anti-fouling method.In a word, the researches and analysis of characteristics of city sewage and fouling support supply to engineering application, management of system and further study of sewage cooling and heating source.更多还原