“自由路径法则”在电厂热力系统分析中的应用

THE APPLICATION OF 揊REE PATH RULE?IN POWER PLANT THERMODYNAMIC SYSTEM ANALYSIS

基于矩阵热平衡方程式,提出了电厂热力系统内汽水流动的“虚拟”描述,即汽水可以沿热力系统内实际存在或不存在的路径流动。以凝汽器的热井为中心,汽水流动路径构成一个封闭的循环,并且汽水流动的方向和路径是任意的。对同一股流量,在热力系统内的流动可以存在多条不同的路径,选择任意一条路径结合热耗变换系数的概念及其计算原则,都能够计算该流量对整个热力系统热耗量的影响,并且与传统的计算方法相比使计算工作得到简化,而计算结果却是相同的。文中分别对轴封漏气、供热抽汽、小汽轮机用汽、再热减温水、高压门杆漏汽等的热经济性分析分项进行了叙述,并以300 MW机组额定工况的数据进行了验算。

The virtual expression of the flow of the steam and water system is provided based on the heat balance matrix equations in this paper. Steam and water can flow along the existent or inexistent path in the thermodynamic system. The path of the steam and water becomes a closed cycle centered the hot well of the condenser . Moreover, the direction of the path is random. To the same flux there are many different paths in the thermodynamic system. For any path chosed , the influence of the flux on the heat consumption of the whole thermodynamic system can be calculated based on the concept and the calculation rules of the heat rate transformation coefficient. Compared with the traditional calculation methods, the process is simplified while the result is same. Thermal economy analysis and the classification are given for the gland-packing leakage, extraction steam for heating, the steam for the auxiliary turbine, desuperheating water of reheater and the high pressure valve leakage. Based on a 300 MW unit, its economic load parameters are calculated.