1. What is 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 a pump converts mechanical energy into fluid flow energy.

2. How Does the Calculator Work?

The calculator uses the pump efficiency equation:

Where:

• \( \eta \) — Pump efficiency (unitless, 0 to 1)
• \( \rho \) — Fluid density (kg/m³)
• \( g \) — Gravitational acceleration (9.81 m/s²)
• \( Q \) — Volumetric flow rate (m³/s)
• \( H \) — Total dynamic head (meters)
• \( P_s \) — Shaft power input (Watts)

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. Ensure density is in kg/m³, flow rate in m³/s, head in meters, and power in Watts. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a good pump efficiency value?
A: Centrifugal pumps typically range from 40-85% efficiency. Values below 40% may indicate pump problems or improper sizing.

Q2: Why does efficiency matter?
A: A 10% improvement in pump efficiency can save significant energy costs over the pump's lifetime, often paying for itself quickly.

Q3: What affects pump efficiency?
A: Factors include pump design, operating point relative to BEP (Best Efficiency Point), fluid viscosity, and system conditions.

Q4: How can I improve pump efficiency?
A: Proper sizing, regular maintenance, impeller trimming if oversized, and variable speed drives can improve efficiency.

Q5: Is 100% efficiency possible?
A: No, all pumps have mechanical and hydraulic losses. The theoretical maximum is below 100% due to friction and other factors.