Abstract
Power cables in air- or water-filled pipes are the thermal
bottleneck in many installations. Some parts of the industry
reduce the complexity of their numerical models by
combining conduction, convection, and surface-surface
radiation into an effective thermal conductivity by formulas
and constants from IEC 60287. In this work, case studies
show that such simplification can become too inaccurate
for air-filled pipes. The simplification can be used as an
estimate for some engineering purposes in water-filled
pipes. A brief review of the heat transfer equations shows
that IEC 60287 thermal resistance does not accurately
represent the actual thermal resistance T4'.
KEYWORDS
Power cables; ampacity calculations; cables in pipes; finite
element analysis; IEC 60287.
bottleneck in many installations. Some parts of the industry
reduce the complexity of their numerical models by
combining conduction, convection, and surface-surface
radiation into an effective thermal conductivity by formulas
and constants from IEC 60287. In this work, case studies
show that such simplification can become too inaccurate
for air-filled pipes. The simplification can be used as an
estimate for some engineering purposes in water-filled
pipes. A brief review of the heat transfer equations shows
that IEC 60287 thermal resistance does not accurately
represent the actual thermal resistance T4'.
KEYWORDS
Power cables; ampacity calculations; cables in pipes; finite
element analysis; IEC 60287.