【作者】 王强；

【导师】 周乃君； 陈乔平；

【作者基本信息】 中南大学 ， 热能工程， 2002， 硕士

【摘要】 随着计算机技术的发展，计算方法在获取热工设备的时空性和微观信息方面发挥了越来越重要的作用。本论文以计算流体力学理论为基础，采用工程上广泛应用的k-ε双方程模型，对炉膛内气相流动特性进行分析，并在数值计算的基础上对炉膛内燃烧状况进行了诊断和分析。同时运用近年来在热能工程领域的工程设计、系统规划、生产运行、系统控制等方面广泛应用的最优化方法，以降低能耗、提高能量利用率或提高经济效益为主要目的，建立数学模型，针对中国铝业公司河南公司热力厂多台锅炉联产时的最佳运行方式进行了寻优求解。这对锅炉运行工况的诊断及出力的最优分配有一定的指导意义。 本论文的工作具体包括如下几方面内容： (1)针对BG-130／3.9-450型四角切圆燃烧煤粉锅炉炉膛内冷态动力场进行了数值计算，并对炉膛内的空气动力场进行了研究； (2)分析了数值计算过程中为达到较好的收敛性应该注意的问题和防止伪扩散的措施； (3)对锅炉进行了热平衡和(火用)平衡分析； (4)建立了蒸汽定价模型和锅炉出力分配最优化数学模型，运用最优化的方法确定了锅炉的最佳经济运行方式及出力的最优化分配。 本论文的上作表明，在研究冷态空气动力场时，采用k-ε模型和迎风差分格式既能满足工程的需要，又具有较好的计算经济性；在网格划分过程中采用正交、非均匀交错网格能有效减小伪扩散对数值计算结果的影响。本文研究还表明，(火用)效率是影响蒸汽生产成本高低的主要因素，对中国铝业公司河南公司热力厂来说，在实际操作时应优先运行130t／h的锅炉，并利用3~#炉(75t／h)进行负荷调峰，能有效降低蒸汽生产成本和提高经济效益。工程实践证明，本文所建立的数学模型是正确的和有效的，同时也说明数值模拟和最优化方法是处理实际工程流动和多台动力设备联产优化出力等问题的有效的、重要的工具。更多还原

【Abstract】 Based on fluid mechanics, heat transfer theory and computer simulation technique, the author simulated the strong cool swirl flow field in tangentially fired boiler. Furthermore, an optimization method was applied in analyzing the thermal power engineering system. The character of selected turbulence models and difference scheme were debated in details. With the development of society, optimization was widely applied in engineering design, systematic programming, management, and cybernation of industry enterprise. Nowadays, it chiefly aimed at reducing energy consumption, adding profits or improving efficiency of energy using. To achieve this goal, a mathematical model was constructed to search the best management of operation of whole thermal system in the China Great-wall Aluminum Corp’s thermal power plant. The work is important to boilers’ economical operation and diagnose, and essential to improving efficiency of energy using and enterprise’s economic gains.The dissertation mainly contains four parts:1. Simulating the air swirl flow field of BG-130/3.9-450 pulverized coal boiler, and expounding the flow characteristic and distribution of air velocity.2. Introducing the problems that result to false diffusion, the thesis supplies some good suggestion to prevent it and ensure result got a good astringency.3. Using energy analysis and exergy analysis method to test combustion status of boiler.4. Constructing steam price model and boilers load allocation model, and performing optimization method to calculate the economical load allocation and boilers’ operation under limited conditions.Therefore, based on computational fluid mechanics, the author has applied the K- e turbulence model to simulate the air flow field in a BG-130/3.9-450 pulverized coal boiler, to analyze the properties of flow field and to diagnose the combustion status in the boiler depending on numerical data, and then, using optimization method to analyze the boilers’ operation. The results show that K- ?turbulence model and up-wind difference scheme meet engineering requirements, and owning the property of saving computational time. The measures of using orthographic, heteropic grid system is able to improve grids quality and reduce the influence of false diffusion. Those measures were proved to be successful and efficient. Moreover, the research results show exergy efficiency of boilers is the chiefly factor influenced steam’s price. In this thermal plant, it should be operate preferentially boilers of 130t/h, and perform the boilers of 75t/h load to regulate the load summit. On the whole, it is obvious that numerical simulation and optimization is an efficient method to solve problems in thermal plant.更多还原