固体电蓄热装置的传热特性研究

发布时间：2018-04-27 09:16

本文选题：固体电蓄热 + 不同工况　；参考：《哈尔滨工业大学》2014年硕士论文

【摘要】：随着我国风力发电规模的逐步扩大，并网和消纳问题已成为制约其持续稳定发展的最重要因素，导致平均利用小时数大幅降低，严重影响风力发电运行的经济性。针对以上难题，近年来国内外一些科研机构提出一种固体电蓄热技术，该技术能够利用风电场的“弃风”电能或常规低谷电能，通过相应的蓄热装置转化成较高温度的显热能储存，可应用于冬季热用户采暖或进行其他热能利用，从而在一定程度上解决了由于风电场限电导致的大规模能源损失问题。在实行峰谷电价的地区，该技术可通过高温蓄热节约系统运行费用，同时克服了传统水蓄热存在的一系列缺陷。本文深入研究了固体电蓄热技术理论及其装置的热工特性。首先，确立了固体电蓄热装置的蓄热材料及其结构形式。以蓄热单元作为研究对象，在合理简化的基础上对其进行数学建模，结合贝塞尔方程的有关性质并采用分离变量法，得到均匀初始温度下蓄热单元传热过程的温度场解析解。分别对三种不同工况的热过程进行模拟分析，并做出相关结构参数与运行参数的影响研究。基于以上温度场解析解，对蓄热单元在非均匀初始温度下的不同工况组合情况进行分类，并将初始温度条件进行积分平均近似处理，进而分别求得温度场理论解表达式。选取一典型周期模拟了不同初始和边界条件组合连续作用下的运行过程，得到不同时刻与相对位置的蓄热单元温度场及其相关热量参数的变化特性。最后，针对固体电蓄热装置整体建立了蓄热单元棒簇与取热流体之间热过程的数学模型，通过分析各项数量级对微分方程进行了简化处理，求解出取热流体以及单排蓄热棒簇外表面的温度场分布表达式。以一个具体案例，在某一释热阶段内进行蓄热棒簇与取热流体的温度场及其热量参数的分析，揭示了固体电蓄热装置的传热特性，并为其设计与运行模拟提供了理论依据和计算方法。本文研究成果为固体电蓄热装置的深化设计及各运行参数的合理匹配建立了理论研究基础，同时为系统的应用与推广提供相应的技术参考。
[Abstract]:With the gradual expansion of the scale of wind power generation in China, the problem of grid connection and absorption has become the most important factor that restricts its sustainable and stable development, resulting in a significant reduction in the average number of hours utilized, which seriously affects the economy of the operation of wind power generation. In view of the above problems, in recent years, some research institutions at home and abroad have put forward a kind of solid electric energy storage technology, which can utilize wind farm "abandoned wind energy" or conventional low energy. The heat storage device can be used for heating or other thermal energy utilization in winter, thus solving the problem of large-scale energy loss caused by wind farm power limitation to a certain extent. In the areas where peak and valley electricity prices are implemented, the technology can save the operating cost of the system by means of high temperature heat storage and overcome a series of defects existing in the traditional water heat storage. In this paper, the theory of solid-state electric heat storage and the thermal characteristics of the device are studied. Firstly, the thermal storage material and its structure of solid electric thermal storage device are established. Taking the heat storage unit as the object of study, the mathematical model is established on the basis of reasonable simplification. Combining with the properties of the Bessel equation and the method of separating variables, the analytical solution of the heat transfer process of the heat storage unit at uniform initial temperature is obtained. The thermal processes under three different operating conditions were simulated and analyzed respectively, and the effects of related structural parameters and operation parameters were studied. Based on the analytical solution of the temperature field above, the different working conditions of the heat storage unit under the non-uniform initial temperature are classified, and the initial temperature conditions are treated with the integral average approximation, and the theoretical expressions of the temperature field are obtained respectively. A typical period is selected to simulate the operation process under the combined continuous action of different initial and boundary conditions, and the variation characteristics of the temperature field and the related heat parameters of the regenerative unit at different time and relative position are obtained. Finally, the mathematical model of the thermal process between the heat storage unit cluster and the heat recovery fluid is established for the solid electric heat storage device, and the differential equations are simplified by analyzing the various orders of magnitude. The expressions of the temperature field distribution on the outer surface of the heat extraction fluid and the single row regenerative rod cluster are obtained. In a specific case, the heat transfer characteristics of the solid electric heat storage device are revealed by analyzing the temperature field and the heat parameters of the regenerative rod cluster and the heat recovery fluid in a certain heat release stage. It also provides theoretical basis and calculation method for its design and operation simulation. The research results of this paper have established the theoretical research foundation for the deepening design of the solid electric heat storage device and the reasonable matching of the operation parameters, and also provided the corresponding technical reference for the application and popularization of the system.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM614

【参考文献】