论文部分内容阅读
对于超临界压力锅炉来说,如何使高温高压水冷壁、过热器和再热器等金属材料能长期安全工作是锅炉本体设计和运行的关键技术问题。为此,除从研制新型耐高温高压的金属材料方面着手外,还应进行超临界压力流体的传热特性和高温壁面的强化冷却等研究工作。本文对这后两个问题进行了一些分析。一、超临界压力流体的物性和传热特点与亚临界压力相比,超临界压力流体与压力在临界值以下的流体是明显不同的。亚临界压力锅炉(尤其是直流锅炉)往往要考虑水冷壁传热恶化问题。上海锅炉厂生产的300MW机组的锅炉水冷壁采用了内螺纹管来防止出现膜态沸腾。超临界压力流体的物性随温度的变
For supercritical pressure boilers, how to make long-term safe working of metal materials such as high temperature and pressure water wall, superheater and reheater is the key technical issue of boiler body design and operation. To this end, in addition to the development of new high temperature and pressure of metal materials from the start, but also for the supercritical pressure fluid heat transfer characteristics and high temperature wall cooling and other research work. This article analyzes some of the latter two issues. First, the supercritical pressure fluid properties and heat transfer characteristics Compared with subcritical pressure, supercritical pressure fluid and pressure below the critical value of the fluid is significantly different. Sub-critical pressure boiler (especially the DC boiler) often have to consider the water wall deterioration of heat transfer problems. The boiler water wall of the 300MW unit produced by Shanghai Boiler Factory uses a female threaded tube to prevent membrane boiling. The properties of supercritical pressure fluid change with temperature