基于紧密性分析的法兰优化设计

Optimum design of flanges based on the tightness of connections.

在满足强度要求的前提下 ,为了减轻法兰质量 ,降低设备成本 ,在考虑了系统紧密性的基础上 ,探讨了法兰优化设计方法。优化设计中 ,以法兰质量为目标函数 ,以连接系统的最大允许泄漏率和法兰强度为约束条件 ,推导出了相应的数学表达式。设计示例中 ,采用网格法对法兰进行优化设计 ,结果表明 ,所求得的法兰的理论质量比据SH340 6— 96查得的法兰的近似质量减轻了 2 8%。基于紧密性分析的法兰优化设计 ,既可满足法兰的强度要求 ,又能使连接系统的泄漏率小于规定的指标 ,使得设计的法兰安全。

Bolted flanged connections are widely used in pressure vessels and piping.The equipment investment will be cut down greatly if the weight of flanges is reduced.The design procedures of bolted flanged connections prescribed in the codes in effect are mainly based on the strength criterion,in which the tightness of connections is not taken into account.In consideration of the maximal allowable leakage rate of connections,the optimum design method of flanges is investigated with the weight of flanges as the aim function and the strength as constraint conditions.As an example,a flange is designed with the grid method.The wight of the designed flange is reduced by 28 percent compared with that stipulated in Chinese industrial standard SH3406 96.