气瓶安全泄放量计算方法探讨

Calculation Methods of Safety Discharge Capacity for Cylinders

基于目前国内外标准中对气瓶安全泄放量的计算存在诸多差异的现状,对国内原气瓶用爆破片标准GB 16918—1997、美国压缩气体协会标准CGAS-1.1—2005、美国石油学会标准API521—2007中气瓶泄放量的计算方法进行了分析。将CGAS-1.1安全泄放量公式中空气的当量体积排放量推导转化为实际介质的安全泄放质量流量,该成果有助于正确理解和应用CGAS-1.1标准。分析比较认为:CGAS公式计算结果较API相比,爆破片计算面积差别不大,但泄放阀结果明显偏大。API 521中对受火引起超压的气瓶泄放面积计算,具有扎实的理论基础,但对因其他原因导致的超压,适用性有待考证。GB 16918中气瓶安全泄放量公式采用的是CGAS-1.1中适用于单一压力泄放阀的泄放量公式,因此当泄放装置采用爆破片时,不能采用GB 16918进行计算,建议补充完善GB 16918中安全泄放相关内容。

Based on the actuality that there is much difference for the calculation of safety discharge capacity in the various home and abroad standards, standards of cylinders were investigated and analyzed. The comparison was focused on the differentiate of calculation methods among GB 16918--1997, CGAS - 1.1-2005 and API 521-2007. The air equivalent volume discharge capacity in the formula CGAS - 1.1 is changed into the safety discharge quality flux of actual medium, which is benefit to understand and apply the standard CGAS - 1.1. The results indicate that compared CGAS with API, there is little differ- ence in the bursting disk calculating area, but the former is bigger for the relied valve value. API 521 has a well - knit theory to calculate the discharge area of cylinder surrounded by fire, but its applicability to calculate the parameters with overpressure derived from other reasons must be estimated further. Safety discharge capacity formula in GB 16918 is root in the formula CGAS - 1.1 that is fit for the single pres- sure relied valve. Therefore, GB 16918 can＇t be adopted when the bursting disk is used as discharge device. It is suggested that the content of GB 16918 should be reinforced and perfect.