热电厂供热输送干线最大温差循环次数的研究
Maximum temperature difference cycle index of heating transmission main lines in thermal power plants
摘要：
温度波动性的参数表征对有效预测管道疲劳循环次数至关重要。目前对管道疲劳次数的小温差循环解析以天数为单位近似取值。提出了基于整个供暖季连续运行温度界定小温差循环。采集了山西省8个典型热电厂5个供暖季管网的热工参数，通过连续运行温度得出小温差等效温差循环次数；以管网事故循环次数为调查统计样本获得大温差循环次数。综合大小温差循环次数得到允许应力不超过960 MPa，大于现行规程规定的750 MPa，由于供暖季连续运行温度取值剔除了某些以天数为单位的非循环小温差，扩大了临界应力范围，为管件疲劳分析提供数据。
Abstract：
The parameter characterization of temperature fluctuation is very important to predict the frequency of fatigue cycles. At present, the small temperature difference in the frequency of pipe fatigue is approximately evaluated in unit of day. Proposes a small temperature difference cycle based on the continuous operating temperature of the whole heating season. Collects the thermal parameters of eight typical thermal power plants pipe network for five heating seasons in Shanxi province, and obtains the equivalent temperature difference cycle index of small temperature difference with continuous operating temperature. Determines the large temperature difference cycle index through statistical samples of pipeline accident cycles. Based on both of them, gains the maximum allowable stress of 960 MPa, which is higher than 750 MPa in the existing specification. Because eliminating noncircular small temperature difference in the continuous operating temperature in heating seasons, expands the range of the critical stress, and provides scientific data for the fatigue analysis of pipe fittings.
Keywords:heating network, transmission main line, fatigue analysis, cycle index, stress range