1. Energy Savings in Water and Wastewater Segment
Danfoss Industries Pvt. Ltd.

2. Presentation Overview:
Introduction to Danfoss
Danfoss Core Business
Energy savings & other benefits with VFD control
VFD applications in water and wastewater segment

3. Danfoss in brief
78 years of experience within energy-efficient technologies
Solutions ready to combat climate challenge
Global competence center for energy efficiency – rooted in Southern Denmark
The Bitten and Mads Clausen Foundation holds the majority of shares in Danfoss

4. Danfoss’ core businesses focus on Climate & Energy

5. VFD evolution
Danfoss = First company to mass produce a.c. variable frequency drives (VFD)
1968
1973
1978
1983
1988
1993
1998

6. Water & energy --- precious resources
Climate change is increasing pressure on global fresh water resources
At the same time demand for energy is rising
Both are contributing to increased concern for the environment
VFD can provide significant energy savings, reduce water loss, and provide other benefits in water, wastewater & irrigation systems

7. Pump life cycle costs 5% 95%
~ 20% of the world’s energy is consumed by pumps #
Initial capital and whole of life maintenance costs = ~ 5% of the total life cycle cost
Energy costs = ~ 95%
~ 95% of pumps installed are over sized (Selected for worst case condition + safety margin)
Methods of flow control to meet average (lower) flow or varying demand include e.g.:
- Impeller trimming
Throttling valve
Bypass valve (3-way)
Variable Frequency Drive (VFD)
# British Pump Manufacturers Association 5%
95%

8. VFD (Variable Frequency Drive)
Electronic unit that varies the fixed mains voltage & frequency to control the speed of standard a.c. electric motors
Infinite speed control from 0-50Hz +over-speed operation with some limitations

9. Typical energy savings with VFD on centrifugal pumps
Flow is proportional to speed
Power varies to the cube of the speed
change
20% reduction in speed
= 50% reduction in energy
50% reduction in speed
= 80% reduction in energy

10. Throttling Valve compared to VFD

11. Throttling valve compared to VFD
Control with valves
Control with VSD
VFD gives ~35% energy savings compared to throttling valve (On typical variable flow applications)

12. Energy consumption of single & multiple pump systems
Single VFD controlled pump
100%
Standard cascade control with 1 x VFD pump & multiple fixed speed pumps
53%
48%
43%
Master – follower with 1 x VFD per pump
Note: kWh figures are approximate relative %, based on sample test
Master follower = best energy efficiency

13. Other benefit – reduced water loss
Smooth starting & stopping with VFD
reduces mechanical stress
Less damage to piping & valves
Lower possible system operating
pressure also reduces water loss
(Non – revenue water, which in
developing countries is ~ 30% of water
supply)

14. Application examples Ground water abstraction Reverse Osmosis
Water distribution
Wastewater treatment
Irrigation

15. Groundwater – abstraction
VFD allow control of draw down
on deep well submersible pumps
Constant level, flow or pressure
Benefits (e.g.:)
Energy savings
Reduced mechanical stress & leakage
Chemical dosing to match flow

16. Application examples Ground water abstraction Reverse Osmosis
Water distribution
Wastewater treatment
Irrigation

17. Reverse Osmosis Membranes are used to filter salt &
other impurities from water
Variables are Flow, Temperature
and Salinity
Brackish water requires less
pressure than sea water
Benefits (E.g.:)
VFD can maintain constant output flow
as filters block
Elimination of pressure surges
extends the membrane life.
Longer time between backwash cycles.
Less energy consumption -
lower speed with clean filters.

18. Application examples Ground water abstraction Reverse Osmosis
Water distribution
Wastewater treatment
Irrigation

19. Constant pressure with water tower/ elevated storage tank
Water Towers maintain constant pressure in the water distribution system
and provide a certain capacity
Pumps are used to fill the water tower, normally based on level control

20. Alternative system - pressure control with VFD
Water
reservoir
The VFD adjusts the pump speed based on a feedback signal from the pressure transmitter to maintain a constant pressure with changes in flow
Note: Booster pumps may also be utilised to overcome pressure loss in networks with e.g. significant elevation in the field.

21. Water – Distribution
VFD controlled pumps replace water tower to maintain constant pressure, irrespective of demand
Flow
PRESSURE
Benefits:
Constant pressure with changing flow
Elimination of water hammer
Reduced water leakage
Less energy consumption
Less maintenance / lower whole of life cycle cost

22. Application examples Ground water abstraction Reverse Osmosis
Water distribution
Wastewater treatment
Irrigation

23. Typical modern Wastewater treatment plant

24. Typical Wastewater treatment plant (WWTP) process

25. Typical energy distribution at WWTP
Typical cost distribution at WWTP
Typical energy distribution at WWTP
Activated sludge processes (fans/blowers) account for more than one half of energy consumption at typical wwt facilities. Pumps also consume a large share of energy, generally requiring about 15 % of total plant use. Heating and solids dewatering are processes sometimes employed to treat solid waste matter that has been removed from wastewater streams. Other processes such as chlorine mixing and effluent filtering each use less than 4% of consumed energy

26. Fans Applications (E.g.) Odour control Ventilation Cooling towers
Benefits
Exact air flow to match demand
Energy savings (20% reduction in
speed gives ~ 50% saving in energy)
Constant pressure or temperature etc.
Less wear (EG: Extends belt life)
Reduced audible noise
Parallel fan operation possible

27. Application examples Ground water abstraction Reverse Osmosis
Water distribution
Wastewater treatment
Irrigation

28. Irrigation Applications Lift station pumps (Level control)
Deep well submersible pumps
Transfer pumps
Benefits
Constant level with changing flow
Less water hammer / mechanical stress
Lower risk of pipe breakage
Potential energy savings

29. Summary of benefits of VFD control
Energy savings (E.g. ~35% when compared to throttling valve)
Low in rush current / low torque surges = less mechanical stress (E.g.: prevent water hammer, gearbox damage, belt breakage)
Less water leakage due to lower possible operating pressure (I.e.: extend life of aging infrastructure)
Increased flexibility /improved system performance (E.g.: control to match actual demand & not design demand)
Advanced control & diagnostic interface possibilities (E.g.: SCADA)
Less maintenance / lower whole of life cycle costs
Environmentally friendly solution!

30. VLT® AQUA Drive
Dedicated VFD for all applications in Water, wastewater & irrigation
0.35kW – 1.4MW power range
Suit both constant & variable torque loads
Automatic Energy optimiser
Built-in pump control & protection
functions
Optimum ingress protection
High efficiency ( 98%)
Lowest cost of ownership

31. Global focus
Water
Wastewater
Irrigation
Power generation
Steam, hot water & gas supply
Waste processing & recovery
Our vision is to be recognized as the most dedicated supplier of Drives solutions in the Water & Wastewater & Irrigation sector world wide
Sales & service in ~100 countries, including India
~ 40 year track record
Dedicated product & organisation

32. Over 25 year track record globally & in Asia Pacific
1000’s of Drives & Soft Starters in service
Water supply & treatment
RO / Desalination & recycling
Wastewater treatment
Pumping Stations
Irrigation
Power generation
District heating
Waste processing & recycling

33. Global References
Bisalpur Water  Supply Project: Project aims to reduce dependence of
Jaipur city on ground water resources. Under this project 400 MLD of raw water is
pumped from Bisalpur Dam to Clear Water treatment plant at Surajpura.
Yamuna Interceptor project: Delhi Jal board.
Yen So Park is one of Vietnam’s most important development projects,
Yen So Park entrails the development of a sewage treatment plant capable
of treating 200,000m3 or half of Hanoi’s waste water per day.
Energy saving using back channel cooling and installation space saving.
Pressurized system for Booster pumping stations in Bulgaria.
Danfoss can accept no responsibility for possible errors in printed material.
Please consult equipment design guides / manuals for specific details / verify data.
All images contained in this presentation are the property of Danfoss A/S or other parties where relevant & must not be copied. VLT® is a registered trademark of Danfoss Drives)

34. Please consider the environment & use VFD for your next application
Thank you!
Danfoss can accept no responsibility for possible errors in printed material.
Please consult equipment design guides / manuals for specific details / verify data.
All images contained in this presentation are the property of Danfoss A/S or other parties where relevant & must not be copied. VLT® is a registered trademark of Danfoss Drives)