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HeatPipe_Wickless_Limits_CL

 

 

Call HeatPipe_Wickless_Limits_CL(T_e, L_e, L_a, L_c, theta, R_in, Fluid$, th_ds, A, WFF, roughness, Flag: Q_dot_sonic, Q_dot_entr)

The function HeatPipe_Wickless_Limits_CL calculates the limits of performance of a wickless heat pipe using the techniques described by Prenger (1979) and Woloshun and Merrigan (1988)

 

Inputs:

 T_e - temperature of vapor leaving the evaporator [K, C, F, or R]

 L_e - length of evaporator [m or ft]

 L_a - length of adiabatic section [m or ft]

 L_c - length of condenser [m or ft]

 theta - angle of heat pipe [rad or deg], note that positive corresponds to evaporator down

 R_in - inner radius of heat pipe [m or ft]

 Fluid$ - fluid ('lithium', 'sodium', 'potassium', 'mercury', or 'water')

 th_ds - the thickness of the distribution screen [m or ft]

 A - velocity profile correction factor used by HTPIPE [-]

  A is defined as u^2/V^2 where u = local velocity and V = average velocity at the evaporator exit

  A = 1.234 for laminar flow and A = 2.22 for turbulent flow

 WFF - wall friction factor [-], note, set to <0 to internally calculate

 roughness - 1/2 peak-to-peak spacing of wall roughness [m or ft]

 Flag - flag to set flow condition, set to 0 to ignore

  1 = laminar vapor and laminar liquid

  2 = turbulent vapor and laminar liquid

  3 = laminar vapor and turbulent liquid

  4 = turbulent vapor and turbulent liquid

 

Outputs:

 Q_dot_sonic - sonic limit [W or Btu/hr]

 Q_dot_entr - entrainment limit [W or Btu/hr]

 

The units for the inputs to the function are based on the unit setting in EES. 

 

Example:

$Load Component Library

$UnitSystem SI Mass J K Pa Radian

$VarInfo Q_dot_sonic Units = 'W'

$VarInfo Q_dot_entr Units = 'W'

 

 

T_e = 775 [K]

L_e = 1.35 [m]

L_a = 0.35 [m]

L_c = 1.5 [m]

theta = 0 [rad]

R_in = 0.0185 [m]

Fluid$ = 'Sodium'

th_ds = 0.03048 [cm]*Convert(cm,m)

A = 1.4 [-]

WFF = -1 [-]

roughness = 0.0025 [cm]*Convert(cm,m)

Flag = 0 [-]

Call Heatpipe_Wickless_Limits_CL(T_e, L_e, L_a, L_c, theta, R_in, Fluid$, th_ds, A, WFF, roughness, Flag: Q_dot_sonic, Q_dot_entr)

 

{Solution:

Q_dot_sonic = 3488 [W]

Q_dot_entr = 25451 [W]}

 

Index