This function uses the 1963 Chen correlation for subcooled boiling flow to calculate the wall temperature of a pipe, based on inlet pressure, an initial guess of the pressure at the pipe wall, and three constants: A, B, C
A = h_pb*S, h_pb is the pool boiling coefficient, and S is the Chen suppression factor
B = h_c, h_c is the forced convection coefficient
C = h_c*(Tsat - Tbulk) - q'', Tsat is the saturation temperature of the water in the pipe at the inlet pressure, Tbulk is the temperature of the bulk fluid, q'' is the heat flux of the pipe to the fluid.
This function makes use of the Steam Tables uploaded by Magnus Holsten.