PmpFlowCalcHQ (FB)

FUNCTION_BLOCK PmpFlowCalcHQ EXTENDS AbbLConC3

The function block PmpFlowHQ calculates the flow rate of pumps using the pump head flow (HQ) curve characteristics. This function is applicable only for pumps run by variable frequency drives.

InOut:

Scope

Name

Type

Initial

Comment

Input

HQCurveHead

ARRAY [1..5] OF REAL
2: The input HQCurveHead defines an array of head values for the HQ curve of pumps run by variable frequency drives. The values are in meters. HQ parameters are available in the pump characteristics of manufacturer’s specification.

  • Value in HQCurveHead[1] < HQCurveHead[2]…..< HQCurveHead[5]

HQCurveFlow

ARRAY [1..5] OF REAL
3: The input HQCurveFlow defines an array of flow rate values for HQ curve of pumps run by variable frequency drives. The values are in cubic meters per hour. HQ parameters are available in the pump characteristics of manufacturer’s specification.

  • Value in HQCurveFlow[1] < HQCurveFlow[2]…..< HQCurveFlow[5]

NominalSpeed

INT

1400

4: To enter the rated speed of the pump, in rpm. Range- Value>0

ActualSpeed

INT

10

5: Actual speed of the VFD in rpm. Read from the drive parameters. Range-Value>0

FluidDensity

REAL

1000.0

6: Fluid density in Kg/m3, Default value is fluid density of water. Range-Value>0.0

InletPressure

REAL

0.0

7: Inlet pressure from the measurement of suction pressure. Range-Value>=0.0

OutletPressure

REAL

0.0

8: Outlet pressure from the measurement of discharge pressure. Range-Value>=0.0

HeadDiffInletOutlet

REAL

0.0

9: The input HeadDiffInletOutlet defines the differential pressure of inlet and outlet head values in meters. The input is used only when direct measurement of differential pressure is available. If direct measurement of differential pressure is not available, then this input must be left as unassigned.Value>=0.0

LowSpeedCalc

INT

50

10: The input LowSpeedCalc defines the low speed limit in rpm. This function block calculates the actual flow only when input ActualSpeed is more than this value. Range>=0.0

Output

ErrorID

ERROR_ID

3: Error code in case of error in the function block execution.

ActualFlow

REAL

0.0

4: Calculated actual flow in m3 per hour. Range- Value>=0.0

Methods:

A_StartAction

B_CyclicAction

C_CleaningAction

D_AbortAction

E_ResetAction

Structure: