BuildSysPro.IBPSA.Fluid.HeatExchangers.BaseClasses.ntu_epsilonZ

# .BuildSysPro.IBPSA.Fluid.HeatExchangers.BaseClasses.ntu_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.

#### Interface

>     function ntu_epsilonZ
>       import f = BuildSysPro.IBPSA.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;

## Revisions

- February 28, 2020, by Michael Wetter:
  Replaced call to `Media.Common.OneNonLinearEquation` to use Modelica.Math.Nonlinear.solveOneNonlinearEquation because `Media.Common.OneNonLinearEquation` will 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 input `flowRegime` from `IBPSA.Fluid.Types.HeatExchangerFlowRegime` to `Integer`. 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 of `Internal.solve` to avoid a warning during model check in Dymola 2015.
- August 10, 2011, by Michael Wetter:
  Changed implementation to use `Modelica.Media.Common.OneNonLinearEquation` instead of `IBPSA.Utilities.Math.BaseClasses.OneNonLinearEquation`.
- February 11, 2010, by Michael Wetter:
  First implementation.

Generated at 2026-05-12T20:19:03Z by OpenModelicaOpenModelica 1.26.7 using GenerateDoc.mos