Function ResolveLoopFlowVsPressure

src/EnergyPlus/PlantPressureSystem.cc:811–964

}

Real64 ResolveLoopFlowVsPressure(EnergyPlusData &state,
                                 int const LoopNum,            // - Index of which plant/condenser loop is being simulated
                                 Real64 const SystemMassFlow,  // - Initial "guess" at system mass flow rate [kg/s]
                                 int const PumpCurveNum,       // - Pump curve to use when calling the curve manager for psi = f(phi)
                                 Real64 const PumpSpeed,       // - Pump rotational speed, [rps] (revs per second)
                                 Real64 const PumpImpellerDia, // - Nominal pump impeller diameter [m]
                                 Real64 const MinPhi,          // - Minimum allowable value of phi, requested by the pump manager from curve mgr
                                 Real64 const MaxPhi           // - Maximum allowable value of phi, requested by the pump manager from curve mgr
)
{

    // FUNCTION INFORMATION:
    //       AUTHOR         Kaustubh Phalak
    //       DATE WRITTEN   Feb 2010
    //       MODIFIED       na
    //       RE-ENGINEERED  na

    // PURPOSE OF THIS FUNCTION:
    // To provide a means to simulate a constant speed pump curve and system curve to
    //  find a more realistic operating point for the plant.

    // METHODOLOGY EMPLOYED:
    // Pressure drop of complete loop is found for a particular flow rate.
    //  i.e. pressuredrop = K * massflow ^ 2
    // System curve is then solved with pump curve already entered
    //  and flow rate provided by the pump will be calculated.
    // This routine does not trap for errors if a pressure simulation is not to be performed.
    // Calling routine should only call this if needed.

    // Using/Aliasing
    using Curve::CurveValue;

    // Return value
    Real64 ResolvedLoopMassFlowRate;

    // FUNCTION PARAMETER DEFINITIONS:
    static constexpr std::string_view RoutineName("ResolvedLoopMassFlowRate: ");
    int constexpr MaxIters(100);
    Real64 constexpr PressureConvergeCriteria(0.1); // Pa
    Real64 constexpr ZeroTolerance(0.0001);

    // FUNCTION LOCAL VARIABLE DECLARATIONS:
    Real64 PumpPressureRise;
    Real64 NodeTemperature;
    Real64 NodeDensity;
    Real64 SystemPressureDrop;
    Real64 PhiPump;
    Real64 PhiSystem;
    Real64 PsiPump;
    int Iteration;
    Real64 LocalSystemMassFlow;
    Real64 LoopEffectiveK;
    bool Converged;
    Array1D<Real64> MassFlowIterativeHistory(3);
    Real64 MdotDeltaLatest;
    Real64 MdotDeltaPrevious;
    Real64 DampingFactor;