Danfoss VLT Micro Drive FC 51 Design Manual page 16

Safety and Conformity
2 2
Discharge
damper
Less energy savings
Costlier installation
Illustration 2.4 The 3 Common Energy Saving Systems
100
Discharge Damper Solution
80
60
40
20
0
0
Illustration 2.5 Energy Savings
Discharge dampers reduce power consumption. Inlet guide
vanes offer a 40% reduction, but are expensive to install.
The Danfoss frequency converter solution reduces energy
consumption with more than 50% and is easy to install. It
also reduces noise, mechanical stress and wear-and-tear,
and extends the life span of the entire application.
14
VLT
Maximum energy savings
IGV
IGV Solution
VLT Solution
60 0 60 0
Volume %
Danfoss A/S © 01/2016 All rights reserved.
®
Micro Drive FC 51
2.8.5 Example with Varying Flow over 1
Year
This example is calculated based on pump characteristics
obtained from a pump datasheet.
The result obtained shows energy savings more than 50%
at the given flow distribution over a year. The payback
period depends on the price per kWh and the price of
frequency converter. In this example, it is less than a year
when compared with valves and constant speed.
Energy savings
P =P
shaft shaft output
[h] t
2000
1500
1000
500
Illustration 2.6 Flow Distribution over 1 Year
60
100 200 300 400
Q
[m 3 /h]
MG02K402