HEAT TRANSFER FROM LIQUID NITROGEN FLOWS IN SMOOTH PIPES

Convective heat transfer for subcooled liquid nitrogen in a smooth horizontal pipe with internal sources is studied by analytical and numerical methods. For high Reynolds numbers the numerical results are in good agreement with standard heat transfer correlations. At smaller Reynolds numbers (<10,000), large circumferential and longitudinal temperature distributions can observed. The effect of localized heat sources on the heat transfer process is also investigated to simulate insulation failures in cryogenic pipelines. Results show that the presence of constant heat sources is detrimental to the heat transfer from both laminar and turbulent flows.