换热器管板两侧成对法兰的两种计算法的对比研究

A COMPARATIVE STUDY OF TWO CALCULATION METHODS FOR PAIR FLANGES ON BOTH SIDES OF TUBESHEET OF HEAT EXCHANGER

对于管板两侧成对法兰的计算,各国规范要求以两侧之间较大的螺栓载荷进行计算,部分设计者忽略两侧法兰的螺栓载荷应相同的原则,而采用两侧之间较大的设计压力进行法兰计算。针对换热器常用的压力容器法兰,详细分析了管板两侧成对法兰分别采用最大设计压力法和最大螺栓载荷法计算时螺栓设计载荷和法兰设计力矩的情况,发现最大设计压力法存在可能会使法兰设计过于保守或导致法兰设计不安全的情况。

For the design of pair flanges on both sides of tubesheet,relevant codes of various countries require that the calculation shall be based on the larger value as individually calculated under each side condition.Some engineers ignore the principle that the bolt load on the flanges on both sides should be the same,and use the higher design pressure in the flange calculation.In this paper,the maximum bolt load method and the maximum design pressure method for calculating design bolt load and design flange moment are studied in detail for the pressure vessel flange commonly used in heat exchanger,and it is found that the maximum design pressure method may cause conservative or unsafe design of flange.