functionntu_epsilonZ
Computes number of transfer units for given heat exchanger effectiveness and heat exchanger flow regime
Information
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 IBPSA.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.
Inputs
| Type | Name | Default | Description |
|---|---|---|---|
| Real | eps | Heat exchanger effectiveness | |
| Real | Z | Ratio of capacity flow rate (CMin/CMax) | |
| Integer | flowRegime | Heat exchanger flow regime |
Outputs
| Type | Name | Default | Description |
|---|---|---|---|
| Real | NTU | Number of transfer units |
Contents
| Name | Description |
|---|---|
| Internal function to solve eps=f(NTU, Z) for NTU for cross flow unmixed |
Revisions
-
February 28, 2020, by Michael Wetter:
Replaced call toMedia.Common.OneNonLinearEquationto use Modelica.Math.Nonlinear.solveOneNonlinearEquation becauseMedia.Common.OneNonLinearEquationwill be obsolete in MSL 4.0.0.
This is for issue 1299. -
September 28, 2016, by Massimo Cimmino:
Added case for constant temperature phase change on one side of the heat exchanger. -
July 7, 2014, by Michael Wetter:
Changed the type of the inputflowRegimefromIBPSA.Fluid.Types.HeatExchangerFlowRegimetoInteger. This was done to have the same argument list as IBPSA.Fluid.HeatExchangers.BaseClasses.epsilon_ntuZ, in which the type had to be changed. -
April 29, 2013, by Michael Wetter:
Added dummy argument to function call ofInternal.solveto avoid a warning during model check in Dymola 2015. -
August 10, 2011, by Michael Wetter:
Changed implementation to useModelica.Media.Common.OneNonLinearEquationinstead ofIBPSA.Utilities.Math.BaseClasses.OneNonLinearEquation. -
February 11, 2010, by Michael Wetter:
First implementation.