Thermally-insulated, jacketed pipe for hydrocarbon pipelines, includes phase-change, thermal-storage material in annulus, together with volume compensator

摘要

A volume (5) filled with highly-compressible material (HCM) is located inside an annulus (4) which contains a phase-change material (PCM). The HCM (5) compensates variations in volume, as a result of phase change in the PCM. The highly compressible volume is formed by a flexible tube filled with inert gas and wound along the annular space as a spiral. It comprises a series of sleeves distributed longitudinally. It is positioned against the outer tube. In alternative designs, the sleeves themselves are annular or half-shells placed against the external tube. 5-30% of the annular volume is taken up by the compensator. The phase-change material is an alkane.