高速高压超临界二氧化碳干气密封性能试验研究

Experimental Study on Sealing Performance of Supercritical Carbon Dioxide Dry Gas Seal at High Rotating Speed and High Pressure Condition

超临界二氧化碳(supercritical carbon dioxide,S-CO_(2))布雷顿循环发电技术具有多方面优势,未来应用潜力巨大。S-CO_(2)叶轮机械一般选用泄漏量极低的干气密封,但是S-CO_(2)的特殊物性对干气密封的密封性能的影响显著,针对S-CO_(2)干气密封的性能研究多以理论仿真为主,少有试验研究支撑。针对不同运行工况下的S-CO_(2)干气密封的稳态性能,该文搭建高速高压干气密封试验台,试验研究不同转速、进气压力、进气温度对SCO_(2)干气密封的泄漏量和摩擦耗功的影响规律,并将泄漏量的理论计算结果与试验值进行对比。结果表明:S-CO_(2)干气密封的泄漏量及摩擦耗功随转速、压力的升高及温度的降低而增大,转速与压力的影响较大,温度的影响较小。泄漏量计算值与试验值存在一定偏差,最大偏差在20%左右。结果可为理论计算模型及计算方法的修正提供参考,以进一步分析S-CO_(2)干气密封的密封性能。

Supercritical carbon dioxide(S-CO_(2))Brayton cycle power generation technology has multiple advantages and huge potential for future applications.S-CO_(2)turbomachinery generally uses dry gas seals with extremely low leakage,but the special physical properties of S-CO2 have a significant influence on the steady-state performance of dry gas seals.Currently,the research on the performance of S-CO_(2)dry gas seals is mainly based on theoretical simulation,with little experimental research support.To study the steady-state performance of S-CO_(2)dry gas seal under different operating conditions,a high-speed and high-pressure dry gas seal test-rig is established.The effects of rotating speeds,inlet pressure and inlet temperature on the gas leakage and friction loss of the seal are studied.And the theoretically predicted results are compared to the experimental results.The results show that the leakage and friction loss of S-CO_(2)dry gas seal increase at the higher rotating speed and the higher pressure,and decrease at the lower temperature.The influence of rotational speed and pressure is greater,while the influence of temperature is smaller.There is a certain deviation between the calculated leakage value and the experimental value,with a maximum deviation of around 20%.The experimental results provide a reference for the correction of theoretical models and design methods for S-CO_(2)dry gas seals,so as to further analyze the sealing performance of S-CO_(2)dry gas seals.