Cond_Tube

Cond_Tube

Procedure Cond_Tube(Fluid$, theta, m_dot, x, T_sat, D : h_TP) calculates the local heat transfer coefficient for condensation of saturated vapor of quality, x, in plain conventional channels and mini/micro channels for all orientations. This procedure implements the correlations presented in Shah (2016).

Inputs:
Fluid$ - string variable representing a fluid/vapor in the EES data base
theta - angle of tube between -90° (flow down) and 90° (flow up). Horizontal is 0°.
m_dot - mass flow rate [kg/s] or [lbm/min]
x - mass vapor fraction (quality) of vapor
T_sat - the saturation temperature of the incoming vapor in [C], [K], [F], or [R].
D - inner diameter of the tube in [m] or [ft]

Outputs:
h_TP - the local two-phase heat transfer coefficient in [W/m^2-K] or [Btu/hr-ft^2-R]

Notes:
This procedure is responsible for determining the property data of the specified fluid.

According to Shah, the correlations in this procedure have been tested for 33 fluids, for channel diameters between 0.10 and 49 mm, for reduced pressures between 0.0008 and 0.946, for mass fluxes between 1.1 and 1400 kg/m^2-s, and for horizontal, vertical up and down, and included channels. The mean absolute deviation is 17%.

Procedure Cond_HorizontalTube calculates the heat transfer coefficient for condensation of saturated vapor of quality, x, inside a circular tube, which overlaps with the capabilies of this procedure. This procedure is recommended in place of Cond_HorizontalTube as it is newer, more comprehensive, and extensively validated.

Procedure Cond_Tube_Avg provides the average heat transfer coefficient integrated over a specified range of quality.

Example:
$UnitSystem SI C Pa J
$VarInfo h_TP units=W/m^2-K
Fluid$='R134a'
x=0.2
m_dot=0.005 [kg/s]
T_sat=50 [C]
D=0.01 [m]
theta=0[°]
Call cond_tube(Fluid$, theta, m_dot, x, T_sat, D: h_TP)

{Solution:
h_TP=832.2 [W/m^2-K]}

Condensation Index

See also: Procedure Cond_HorizontalTube
Procedure Cond_Tube_Avg