Centrifugal Pump Power Calculator

Pump Power Equation:

\[ P = \frac{\rho \times g \times Q \times H}{\eta} \]

Density (ρ):

kg/m³

Flow Rate (Q):

m³/s

Head (H):

meters

Efficiency (η):

(0 to 1)

Pump Power (P):

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1. What is Centrifugal Pump Power?

The power required by a centrifugal pump is the energy needed to move fluid against the system head at a given flow rate, accounting for the pump's efficiency. It's a crucial parameter for pump selection and motor sizing.

2. How Does the Calculator Work?

The calculator uses the pump power equation:

\[ P = \frac{\rho \times g \times Q \times H}{\eta} \]

Where:

\( P \) — Pump power (W)
\( \rho \) — Fluid density (kg/m³)
\( g \) — Gravitational acceleration (9.81 m/s²)
\( Q \) — Volumetric flow rate (m³/s)
\( H \) — Total dynamic head (m)
\( \eta \) — Pump efficiency (0 to 1)

Explanation: The equation calculates the theoretical power required to move the fluid, then divides by efficiency to account for energy losses in the pump.

3. Importance of Pump Power Calculation

Details: Accurate power calculation ensures proper motor selection, prevents under/over-sizing, and helps estimate energy costs. It's essential for system design and energy efficiency.

4. Using the Calculator

Tips:

For water at 20°C, density is approximately 1000 kg/m³
Typical pump efficiencies range from 0.7 to 0.9
Convert flow rates from L/s to m³/s by dividing by 1000
Total head includes static head and friction losses

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between hydraulic power and brake power?
A: Hydraulic power is the theoretical power needed to move the fluid, while brake power (calculated here) includes pump inefficiencies.

Q2: How do I account for motor efficiency?
A: For total electrical power required, divide the result by motor efficiency (typically 0.85-0.95 for electric motors).

Q3: What if my flow is in L/s or GPM?
A: Convert to m³/s (1 L/s = 0.001 m³/s, 1 GPM ≈ 0.00006309 m³/s) before calculation.

Q4: How does viscosity affect pump power?
A: Higher viscosity fluids require more power and may reduce pump efficiency. Specialized calculations are needed for highly viscous fluids.

Q5: What is typical efficiency for centrifugal pumps?
A: Efficiency varies with size and design, but typically ranges from 60-85% for most industrial centrifugal pumps.