Flow_Boiling_Hamilton_Avg
Function Flow_Boiling_Hamilton_avg(Fluid$, P_sat, G, d, x_1, x_2, q``) calculates the average convective boiling heat transfer coefficient by repeated calls to the Flow_Boiling_Hamilton procedure over the specified quality range to determine the local heat transfer coefficient. This correlation is applicable for saturated boiling of pure fluids.
Inputs
Fluid$ - string variable representing a real fluid in the EES data base.
P_sat = saturation pressure [Pa, kPa, bar, MPa, psia,atm]
G - mass velocity, i.e., the ratio of the mass flow rate to the cross-sectional area of the tube [kg/s-m^2] or [lbm/hr-ft^2]
d - diameter of the tube [m] of [ft]
x_in - quality at inlet (must be between 0 and 1)
x_out - quality at exit (must be between 0 and 1)
q`` - surface heat flux [W/m^2] or [Btu/hr-ft^2]
Output
Flow_Boiling_avg - average heat transfer coefficient [W/m^2-K] or [Btu/hr-ft^2-F] over the specified range of quality.
Notes:
This procedure uses the Flow_Boiling_Hamilton correlation to supply values for the local heat transfer coefficient and wall temperature at discrete values of quality. It then integrates these values over the range in quality and returns the integrated average heat transfer coefficient.
Example:
$UnitSystem SI K Pa J
$TabStops 3.5 in
$varInfo h_bar units=W/m^2-K
$VarInfo P_sat units=Pa
$VarInfo q`` units=W/m^2 Lower=0 Guess=5000
$VarInfo U units=W/m^2-K Lower=0
F$='R22'
T_sat=250 [K] "boiling saturation temperature"
P_sat=p_sat(F$,T=T_sat)
G=200 [kg/m^2-s] "mass velocity"
d=0.0172 [m] "tube inner diameter"
x_in=0.36 "quality"
x_out=1.00
h_bar=flow_boiling_hamilton_avg(F$, P_sat, G, d, x_in, x_out, q``)
q``=U*(T_h-T_sat) "heat flux"
T_h=261 [K] "temperature of fluid on outside of pipe"
h_h=5400 [W/m^2-K] "heat transfer coefficient on outside surface of pipe"
U=(1/h_bar+1/h_h)^(-1) "overall heat transfer coefficient between fluids on either side of the pipe wall"
{Solution:
h_bar=1289 [W/m^2-K]
q``=11447 [W/m^2]
U=1041 [W/m^2-K]}