PumpValvePowerLoss Class Reference

Calculate the electrical power loss for a pump throttled valve compared to wide-open. More...

#include <pump_valve_power_loss.h>

Classes
struct	Output

Public Member Functions
	PumpValvePowerLoss ()=default
	Default constructor.
PumpValvePowerLoss::Output	calculate (const double operating_hours, const double pump_efficiency, const double motor_efficiency, const double specific_gravity, const double flow_rate, const double upstream_pressure, const double upstream_gauge_elevation, const double downstream_pressure, const double downstream_gauge_elevation) const
	Calculate the electrical power loss for a pump throttled valve compared to wide-open.

Detailed Description

Definition at line 21 of file pump_valve_power_loss.h.

Member Function Documentation

calculate()

PumpValvePowerLoss::Output PumpValvePowerLoss::calculate	(	const double	operating_hours,
		const double	pump_efficiency,
		const double	motor_efficiency,
		const double	specific_gravity,
		const double	flow_rate,
		const double	upstream_pressure,
		const double	upstream_gauge_elevation,
		const double	downstream_pressure,
		const double	downstream_gauge_elevation
	)		const

Calculates pressure drop, head loss, frictional power loss, electrical power loss and annual energy loss.

Parameters

[in]	operating_hours	Number of hours the valve participates in the pumping system in a year. 8760 if it runs year-round @unit{\hours}.
[in]	pump_efficiency	The hydraulic efficiency of the pump, or how effectively it pumps fluid. 0.85 (85%) is typical. Fractional value should range from 0.01 – 1 @unit{\percentage}.
[in]	motor_efficiency	The electrical efficiency of the motor driving the pump. If the motor hasn’t been through rewind, this is the efficiency listed on the nameplate. 0.95 (95%) can be used as a default if unknown. Value should range from 1 – 100% @unit{\percentage}.
[in]	specific_gravity	Density of the working fluid relative to water, with water itself as 1. A fluid which is twice as dense as water has a specific gravity of 2. Value cannot be equal to or less than 0 @unit{\unitless}.
[in]	flow_rate	Volume of fluid flow through the valve. Best taken from immediately upstream of the valve assuming there are no branches downstream of measurement location. Value cannot be equal to or less than 0. @unit{\gallons\minute}.
[in]	upstream_pressure	Gauge pressure after the valve @unit{\PSI}.
[in]	upstream_gauge_elevation	Height difference of the pressure gauge from the valve. Can be negative, zero, or positive as the position is relative to the valve @unit{\feet}.
[in]	downstream_pressure	Gauge pressure before the valve @unit{\PSI}.
[in]	downstream_gauge_elevation	Height difference of the pressure gauge from the valve. Can be negative, zero, or positive as the position is relative to the valve @unit{\feet}.

Factors

• - @symbol{\text{kHeightToPressureConversion}; feet of fluid height to PSI, constant value 2.307249} @unit{\unitless}
• - @symbol{\text{kFluidPowerConversion}; flow rate to power lost, constant value 1714.231} @unit{\unitless}
• - @symbol{\text{kElectricalPowerConversion}; horsepower to kW, constant value 0.7457} @unit{\unitless}

@formula Pressure Drop = (upstream_pressure - downstream_pressure) + specific_gravity * (upstream_gauge_elevation - downstream_gauge_elevation) / KHeightToPressureConversion @unit{\PSI} Head Loss = pressureDrop * KHeightToPressureConversion @unit{\feet} Power Loss Frictional = pressureDrop * flow_rate / kFluidPowerConversion @unit{\hp} Power Loss Electrical = (kElectricalPowerConversion * powerLossFrictional / pump_efficiency) / motor_efficiency @unit{\kW} Annual Energy Loss = operating_hours * powerLossElectrical @unit{\kWHour}

Returns

PumpValvePowerLoss::Output.

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The documentation for this class was generated from the following file:

• include/motorDriven/pump/pump_valve_power_loss.h