designing energy saving tools: pumps

EUROPEAN COMMISSION

European UnionSustainable Energy Week

11-15 April 2011

Designing energy saving tools: pumps

Energy efficient industrial pump manufacturer

Thomas Wuersch, CEO, CP Pumpen AG

12 April 2011

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Industry consumes about 42% of all electricity generated

Total energy consumption of pumps is estimated at 300 TWhAccording to Europump’s Ecopump Initiative, the potential for energy savings in pumping systems varies among major pump types:

• Water pumps: total energy consumption: 137 TWh– potential energy savings: 58 TWh (42%)

•• Industrial pumps: total energy consumption: 110 TWh– potential energy savings: 41 TWh (37%)

• Stand-alone circulators: total energy consumption: 29 TWh– potential energy savings: 13 TWh (45%)

• Boiler circulators: total energy consumption: 24 TW– potential energy savings: 11 TWh (45%)

Sources: “ECOPUMP” Initiative – European Pump Industry Energy Commitment; International Energy Agency (IEA)

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More efficient pumping systems allow energy savings

Pumping systems offer vast energy savings potentialAbout two-thirds of the electricity used in industry is consumed by motor systems. Electric motors drive machines, conveyors, compressors, fans andpumps in virtually all industrial sectors.

According to US and EU energy savings studies, the greatest potential for energy savings in pumping systems lies in:

• better system control: 20%

• better system design: 10%

• better sized pumps: 4%

• more efficient pumps: 3%

• better maintenance and installation: 3%

Sources: “ECOPUMP” Initiative – European Pump Industry Energy Commitment; ABB

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Energy savings potential varies on three different levels

Total energy savings potential in pumps is estimated at 123 TWh

According to Europump’s Ecopump Initiative, the potential for energy savings in pumping systems varies on three different levels:

• Product approach: savings up to 5 TWh

– improvements to the pumps themselves

• Extended product approach: savings up to 59 TWh

– improvements to the pump units (consisting of pump, motor, variable speed drive (VSD), control and monitoring)

• System approach: savings up to 59 TWh

– improvements to the pump units and the pipework in which the units operate

Source: “ECOPUMP” Initiative – European Pump Industry Energy Commitment

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Product approach: potential savings up to 5 TWh


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Extended product approach: potential savings up to 59 TWh


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System approach: potential savings up to 59 TWh

Source: CP Pumpen AG

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Pump manufacturers’ target: one third of energy savings

Better system control, better system design and better sized pumps can yield potential energy savings of 34%

CP’s pumps (industrial magnetic drive centrifugal pumps) are custom-built for their specific applications in areas such as the chemical, pharmaceutical, pulp and paper, and nutrition industries.

In our market, energy savings of at least one third are possible through better system control (20%), better system design (10%) and better sized pumps (4%).

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1. System control: 20% potential energy savings

CP’s first pump tool:

CP’s PumpSelector software (xls)

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System control: using VSDshas large energy leverage

Variable speed pumping increases energy savings

The use of variable speed drives (VSDs) in pumping systems may be

motivated not only by the need to match pump output to supply or demand,

but also by the prospect of economic benefits, primarily related to energy

and maintenance savings, and reliability improvements.

Other benefits may be a reduction of hydraulic transients as VSD pumps

can be soft started and stopped, a reduction in leakage from a system when

operating at reduced pressure, and benefits associated with better control of

the pumping operation.

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System control: flow control valves increase energy consumption

Minimised throttling with valves maximises energy savings

In pumping systems with more than one duty point, flow control valves are

widely used to control the system. With flow control valves, the pump runs

continuously and a valve in the pump discharge line is opened or closed to

adjust the flow to the required duty points.

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System control: case study with flow control valve or VSD


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System control: case study with flow control valve or VSD

Case study 25 m3/h:

Case 1: Pump size 65-40-160, throttled with a flow control valve

Reservoir 1, head 30 m throttled down to 11 m, 2500 hours per year

Reservoir 2, head 30 m, 500 hours per year

Case 2: Pump size 65-40-160, VSD



Example: liquid with viscosity of 1 mm2/s and a density of 1100 kg/m3, suction pipe with 5 elbows, 1 ball valve and 2 T-pieces, suction losses of 1.3 m, discharge pipe with 10 elbows, 2 ball valves and 3 T-pieces


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System control: a VSD saves 7516 kWh per year

Case 1: pump operating at 2930 rpm, pump efficiency 64%, eddy current losses 1 kWCase 2: pump operating at 2500/1700 rpm, pump efficiencies 68/71%, eddy current losses 0.85/0.35 kW


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CP’s pump tool to improve system control using VSDs

CP’s PumpSelector Software (xls) – CP’s pump tool

CP has developed a calculation tool to help users select pumps and make system calculations.

Using the CP PumpSelector, a variety of parameters can be specified to define a pump’s operating conditions.

For example, this allows the power consumption, head, power losses, efficiency etc. to be calculated for the required duty points.

This tool for comparing various alternatives enables users to always choose the best pump to suit each specific application.

PumpSelector runs in Microsoft Excel and utilises VBA macros.

Conclusion:CP’s PumpSelector Software helps users to consider the energy efficiency of a pumping system using a VSD to control multiple duty points.Source: CP Pumpen AG

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CP’s pump tool to improve system control using VSDs


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2. System design: 10% potential energy savings

CP’s second pump tool:

CP’s PipeCalculator software (xls)

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System design: liquid velocity in pipes has large energy leverage

Optimising pipework sizing increases energy savings

Several factors affect pipework sizing: system utilisation, length, pipe friction loss, fluid density and viscosity, percentage and content of solids, surge and pressure pulsation problems, noise, vibration, erosion and many others.

According to Europump’s System Efficiency Guide, the recommended liquid* velocities for an energy efficient system are:

• Delivery pipe work: 1.5 to 2.0 m/s (4.9 ft/s to 6.6 ft/s)

• Suction pipe work: 0.75 to 1.25 m/s (2.5 ft/s to 4.1 ft/s)

*Liquids having a maximum viscosity of 100 mm2/s and a density of between 700 and 1200 kg/m3.

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System design: frictional resistance raises energy consumption

Minimising frictional resistance maximises energy savings

In transfer systems, it is recommended to try and minimise the frictional

resistance to a maximum of 25% of the total head.

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System design: case study with 3 different pipe DNs


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System design: case study with 3 different pipe DNs

Case study 25 m3/h:

Case 1: DN XXX = 40 mm

Velocity = 5.5m/s, friction losses = 47.8m, total head = 54.1m


Velocity = 3.5m/s, friction losses = 16.4m, total head = 22.7m


Velocity = 2.1m/s, friction losses = 4.7m, total head = 11m

Example: liquid with viscosity of 1 mm2/s and a density of 1100 kg/m3, suction pipe with 5 elbows, 1 ball valve and 2 T-pieces, suction losses of 1.3 m, discharge pipe with 10 elbows, 2 ball valves and 3 T-pieces

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System Design: pipe DN +25 mm saves 16255 kWh/year

Example: Operating time 3000 hours / year, pump efficiencies 64 / 63 / 62 %, eddy current losses 2 / 1 / 1 kW


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CP’s pump tool to improve system design through pipe sizes

PipeCalculator Energy Software (xls) – CP’s pump tool

CP has developed a calculation tool to help users design and check the

efficiency of pipework.

Using this program, various alternatives can be compared so as to

maximise energy savings and operating safety.

Choosing the best pipe diameter, method of control and other parameters

helps users to vastly reduce the amount of energy required.

PipeCalculator runs in Microsoft Excel and utilises VBA macros.

Conclusion:CP’s PipeCalculator tool helps users to consider the energy efficiency of a pumping system when designing the pipe network.


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CP’s pump tool to improve system design through pipe sizes


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3. Better sized pumps: 4% potential energy savings

CP’s third pump tool:

CP’s PumpCurves software (xls)

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Better sized pumps: impeller size has energy leverage

Better matching pump size to the system increases energy savings

It is generally accepted best practice to run pumps near the best efficiency

point (BEP), but often flow and head requirements cannot be met with a

pump at the BEP and a maximum impeller diameter.

Assuming the best fitting pump size has been chosen for the required flow

and head, customising the impeller diameter to match the exact head

requirement impacts energy consumption.

With custom pump impellers, pumps run (without throttling) at the required

duty points using exactly the amount of energy required.

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Better sized pumps: maximum size impellers raise energy consumption

Maximising impeller size minimises energy savings

In plants with more than one pump, standard (maximum) pump impeller

sizes help to reduce the stock of spare parts.

But with maximum size pump impellers, the pumps must be throttled to

meet the required duty points and use more energy than the required

amount.

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Better sized pumps: case study with 2 different impeller sizes


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Better sized pumps: case study with 2 different impeller sizes

Case study 25 m3/h:

Case 1: Pump size 65-40-160, maximum (180 mm) impeller diameter

Duty point 34.5 m3/h against 39 m head due to maximum impeller diameter

Case 2: Pump size 65-40-160, custom (152 mm) impeller diameter

Duty point 25 m3/h against 30 m head due to trimmed impeller diameter

Example: liquid with viscosity of 1 mm2/s and a density of 1000 kg/m3, operating time 3000 hours per year


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Better sized pumps: impeller -28mm saves 6000 kWh per year

Example: max. impeller size 180 mm, liquid with viscosity of 1 mm2/s and a density 1000 kg/m3, operating time 3000 hours per year


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CP’s pump tool to improve pump sizing through impeller sizing

CP’s PumpCurves Software (xls) – CP’s pump tool

CP has developed a calculation tool for each of its pump sizes to help users select the impeller and calculate the impeller size.

Using CP PumpCurves, a variety of parameters can be specified to define a pump’s operating conditions and enable the user to choose the right impeller diameter.

For example, this allows the power consumption, head, flow rate etc. to be calculated for the required duty point.

PumpCurves run in Microsoft Excel and utilise VBA macros.

Conclusion:CP’s PumpCurves Software helps users to consider the energy efficiency of a pumping system in selecting the correct impeller sizes.Source: CP Pumpen AG

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CP’s pump tool to improve pump sizing through impeller sizing


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1 kW saved = €700 cost savings each year*

Conclusion:

Increasing energy efficiency in industrial processes has monetary benefits for all stakeholders

For an industrial pump manufacturer keen on addressing the market for energy efficiency improvements, it is crucial to target pumping system designers and plant managers with tools offering them better system control, better system design and better sized pumps, giving potential energy savings estimated at 34%.

*Electricity cost at a kWh price of €0.08, 365 days x 24h operation


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Thank you very much for yourattention

Questions?

CP on energy efficiency in industrial pumping systems

CP on energy efficiency services & consulting

E-mail: [email protected]

Phone: +41 62 746 85 85

www.cp-pumps.com

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Appendix

Overview

• ABB’s PumpSave tool (VSD selection)

• Siemens’ SinaSave tool (VSD selection)

• Pipe Flow / Europump Energy tool (System design)

• CP’s references

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ABB’s pump tool to improve system control using VSDs

PumpSave Energy Saving Calculator (xls) – ABB’s pump tool

ABB’s calculation tool estimates the energy savings when applying electric speed control to pumps.

Using the PumpSave tool, energy usage with VSD control in pumps can be compared against traditional flow control methods such as throttling, on/off and hydraulic coupling control in pumps.

The tool also provides financial figures for assessing the profitability of purchasing a drive while also deriving other benefits such as soft starting and stopping, an improved power factor and integration in process automation.

PumpSave runs in Microsoft Excel and utilises VBA macros.

Source: ABB

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Siemens’ pump tool to improve system control using VSDs

SinaSave energy efficiency software* – Siemens’ pump tool

Based on the system characteristics, SinaSave energy efficiency software calculates the possible cost savings potential in specific drive applications. It also estimates the payback period when investing in a VSD.

For drive operation, SinaSave takes into account all the necessary plant-specific parameters as well as the values required for the process.

Based on the plant-specific data, this energy efficiency software identifies the optimum drive system, calculates the price of a suitable VSD and then determines the energy requirements of a VSD system compared with all other alternative concepts that could be considered.

*SinaSave energy efficiency software includes cost savings and payback period calculations for Siemens’ energy-saving motors.

Source: Siemens

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Pipe Flow’s pump tool to improve system design through pipe sizes

Pipe Flow’s / Europump’s Energy software – pump toolThe Pipe Flow Energy software included with this guide can be used to estimate the energy used in a pumping system when selecting different pipe sizes. It is not designed to undertake all the calculations necessary to arrive at the required pump selection criteria.

It works on a single pipe work size for the whole system but suction and delivery pipe work should be designed to have different velocities. Therefore if the delivery pipe work size is used for the whole system and a suitable liquid velocity is selected, a maximum energy figure will be calculated which will reduce if larger suction pipes are actually used. The diameter of suction pipe work should then be entered for a separate check on velocity but, in this instance, the energy figures will not be relevant.

The Pipe Flow Energy software helps users to consider the energyefficiency of a system when designing the pipe network.

Source: System Efficiency – A Guide for Energy Efficient Rotodynamic Pumping Systems, Europump

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CP has numerous references – plant designers & managers

Plant designers: Plant managers:

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Help us saving energy in industrial processes

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designing energy saving tools: pumps

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