Centrifugal Pump Efficiency Calculator

Pump Efficiency Equation:

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

Fluid Density (ρ):

kg/m³

Flow Rate (Q):

m³/s

Head (H):

Shaft Power (P_s):

Pump Efficiency (η):

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1. What is Centrifugal Pump Efficiency?

Pump efficiency (η) is the ratio of hydraulic power delivered to the fluid to the mechanical power input at the pump shaft. It measures how effectively the pump converts mechanical energy into fluid flow energy.

2. How Does the Calculator Work?

The calculator uses the pump efficiency equation:

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

Where:

\( \eta \) — Pump efficiency (unitless, 0 to 1)
\( \rho \) — Fluid density (kg/m³)
\( g \) — Acceleration due to gravity (9.81 m/s²)
\( Q \) — Volumetric flow rate (m³/s)
\( H \) — Head (m)
\( P_s \) — Shaft power (W)

Explanation: The numerator represents the hydraulic power delivered to the fluid, while the denominator is the mechanical power input to the pump.

3. Importance of Pump Efficiency

Details: Pump efficiency is crucial for energy conservation, operating cost reduction, and proper pump selection. Higher efficiency means less energy is wasted as heat and vibration.

4. Using the Calculator

Tips: Enter all values in the specified units. Density should be for the actual fluid being pumped. Flow rate and head should be measured at the same operating conditions.

5. Frequently Asked Questions (FAQ)

Q1: What is a good pump efficiency value?
A: Centrifugal pumps typically range from 40-85% efficiency. Larger pumps tend to be more efficient. Values below 40% may indicate pump problems.

Q2: Why can efficiency be greater than 1?
A: Efficiency should never exceed 1 (100%). If your calculation shows >1, check your input values - likely an error in measurement or units.

Q3: How does viscosity affect pump efficiency?
A: Higher viscosity generally reduces efficiency due to increased friction losses. This calculator is most accurate for water-like fluids.

Q4: What's the difference between overall and hydraulic efficiency?
A: This calculator gives hydraulic efficiency. Overall efficiency also accounts for mechanical losses in bearings, seals, etc.

Q5: How can I improve my pump's efficiency?
A: Proper maintenance, correct sizing for the application, minimizing system losses, and operating near the pump's best efficiency point (BEP).