This function computes the number of transfer units for a given heat exchanger effectiveness, capacity flow ratio and heat exchanger flow regime. The different options for the flow regime are declared in BuildingSystems.Fluid.Types.HeatExchangerFlowRegime.
Note that for the flow regime CrossFlowUnmixed
, computing the
function requires the numerical solution of an equation in one variable.
This is handled internally and not exposed to the global solver.
function ntu_epsilonZ import f = BuildingSystems.Fluid.Types.HeatExchangerFlowRegime; input Real eps(min = 0, max = 0.999) "Heat exchanger effectiveness"; input Real Z(min = 0, max = 1) "Ratio of capacity flow rate (CMin/CMax)"; input Integer flowRegime "Heat exchanger flow regime"; output Real NTU "Number of transfer units"; end ntu_epsilonZ;
Media.Common.OneNonLinearEquation
to use
Modelica.Math.Nonlinear.solveOneNonlinearEquation
because Media.Common.OneNonLinearEquation
will be obsolete in MSL 4.0.0.flowRegime
from
BuildingSystems.Fluid.Types.HeatExchangerFlowRegime
to Integer
.
This was done to have the same argument list as
BuildingSystems.Fluid.HeatExchangers.BaseClasses.epsilon_ntuZ,
in which the type had to be changed.
Internal.solve
to avoid a warning during model check in Dymola 2015.
Modelica.Media.Common.OneNonLinearEquation
instead of
BuildingSystems.Utilities.Math.BaseClasses.OneNonLinearEquation
.