中文摘要：

为提高正压法音速喷嘴标准装置压力和流量稳定性能，提出了正压法气源系统设计的方法，设计包括气源及压缩气体净化系统，以及气源稳压系统。针对空压机出口气体特点，净化系统采用水冷型后置冷却器、高效除油器、精密过滤器、冷干机及吸干机组合的方式，并合理选择净化系统各部分参数，使得压缩空气达到-65℃左右的压力露点。系统采用自力式调压阀与稳压罐实现稳压功能，并用各个参量评估系统压力、流量稳定性能指标。最后通过实验验证设计效果，结果表明在同一流量点．滞止压力稳定性可以保持在0．2％以内．流茸控制在0．03％以内．可以满足气体流量的检定需求。

英文摘要：

In order to improve the presure and flow rate stability of the sonic nozzle gas flow standard device based on positive pressure method, an air source system consisting of purification system and stable pressure system is presented. The after cooler, degreaser, accurate filter, refrigeration drier and absorbing type desiccators are included in the purification system. Through reasonably choosing the parameters of the purification system, the dew point of the compressed air could reach -65℃. Gasholders and self-operated pressure regulating valves are used in the stable pressure system. The stabilities of pressure and flow-rate are analyzed and evaluated with the parameters of the air source system. Experiment was carried out to verify the design. Experiment results show that the uncertainty of the pressure is within 0.2% and the stability of the flow-rate is within 0.03% , which satisfies the design goal.