Error analysis of specific frictional head loss in hotwater heating pipelines

Analyses the unreasonability of hydraulic calculation based on the mean temperature 60 ℃ in a heating system with 95 ℃/70 ℃ hot water. Obtains the theoretical errors of specific frictional head loss including 42.56% for laminar flow, -12.77% for critical area, 8.51% for turbulence smooth area, smaller than 8.51% for turbulence transition area and neglectable error for turbulence rough area. Gives a calculation formula of the absolute error of specific frictional head losses.