Energy saving opportunities in pumping systems

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Pumps account for an incredible 10% of the world’s total electricity consumption. However, a large proportion of that is wasted. Energy saving opportunities are always there in pumping systems of industries and saving techniques are also abundantly found in websites, including text book techniques we know. 

In this blog, I would like to provide a concept map for all the saving opportunities out there. You may go on and plan a pump energy saving consulting business (specially those developing country students) that after doing a study that applies some of the selected tips on one particular industry. This is because the field is wide; you can do from simple text book saving tips to complex CFD analysis of the flow field and optimizations. Just give it a thought! But doing your final project on it will give you a very good initial test of this hypothesis.

Energy saving in pumping systems can be thought of as two wide approaches;

1) Improve the efficiency of the existing system

2) Design a new system

Lets see a typical pumping system and list out many opportunities

PUMP

1) Is it Over sized?

2)Best efficiency point?

3) Impeller trimming?

4) Change impeller?

5) Multiple pumping arrangement?

6) Multiple speed pumping?

FLOW RATE CONTROLS

1) Throttle and bypass versus adjustable speed drive

2) Multiple speed motor

PIPING

1) Pipe diameter

2) Piping layout

3) valves and fitting and loss

MOTORS

1) Oversized?

2) High efficiency motors

NEW system design

System

• Minimize pumping demand:

• Reduce pumping needs through good plant design

• Reduce leaks

• Lower pumping system flow rate

• Lower the operating pressure

• Choose efficient pumping components

• Use the latest energy prices in calculation of operating costs

Controls and operating

• Consider variable-speed drives for flow management philosophy rather than throttling valves

• Put pressure or flow sensors in the location that will help ensure process requirements are met without excess pumping energy

• Record system trend data

• Provide metering of components (such as flows, kWh)

Pump stations

• Consider multiple size pumps for varying flows

• Pay attention to pipework design with multiple pumps

Piping system

• Maximize pipe diameter configuration

 • Optimize pipe layout to minimize pressure loss

• Minimize pressure losses through valves and fittings

• Minimize bypass flow rates

Throttling controls

• Avoid bypass lines

• Avoid throttle valves

• Optimize use of throttling and adjustable/variable speed drives

Pumps and motors

• Ensure high motor efficiency

• Ensure high pump efficiency

• Ensure pump operates close to its BEP

• Don’t oversize pump

• Ensure the right impeller size

• Ensure the right pump type (axial, centrifugal and so on)

• Ensure compatibility with variable-speed drives

           • Check sealing method (gland packing, mechanical seal and so on)