关键词: 管道泄漏, 超临界二氧化碳, 压力响应, 最低温度, 杂质

Abstract:

Serious accidents will be caused by the leakage of supercritical CO₂ pipelines. Leakage experiments on small leakage diameters for pure supercritical CO₂ and CO₂ pipeline containing impurities were performed with a small scale (14.85m long, 15mm id) laboratory apparatus. The pressure and temperature responses and the characteristics of phase transitions during the leakage were studied with various leakage diameters and initial inner pressures. The results show that the temperature inside the pipeline reached a minima during the leakage of supercritical CO₂ pipeline and the CO₂ fluid transferred directly from the supercritical state to the gaseous state. Besides, the leakage time and the minimum temperature of the medium in the pipe decreased with the increasing of leakage sizes. The addition of N₂ shortened the whole leakage time and also increased the minimum temperature. The higher N₂ added, the higher the minimum temperature was. Furthermore, based on the self-preservation of leakage time for supercritical CO₂ pipeline, empirical formulas for the pressure responses inside the pipeline were obtainedunder different leakage nozzle diameters and initial inner pressures.under different leakage nozzle diameters and initial inner pressures.

Key words: pipeline leakage, supercritical carbon dioxide, pressure response, minimum temperature, impurity