3.1.1.4 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 sav-
ings of more than 50% at the given flow distribution over a year. The payback period depends on the price per kWh and the price of
drive. In this example, it is less than a year when compared with valves and constant speed.
Energy savings
P
shaft
= P
shaft output
500
[h]
t
1000
1500
2000
200
100
300
[m
3
/h]
400
Q
e
7
5
h
a
2
1
0
.1
1
Illustration 6: Flow Distribution over 1 Year
e7
5h
a2
09
.1
1
60
50
40
30
20
10
H
s
0
100
200
300
400
(m w g)
B
C
A
750r pm
1050r pm
1350r pm
1650r pm
0
10
20
30
(kW )
40
50
60
200
100
300
(
m
3
/h
)
(
m
3
/h
)
400
750r pm
1050r pm
1350r pm
1650r pm
P
shaf t
C
1
B
1
A
1
Illustration 7: Energy
Table 5: Result
m
3
/h
Distribution
Valve regulation
Drive control
%
Hours
Power
Consumption
Power
Consumption
A
1
- B
1
kWh
A
1
- C
1
kWh
AJ363928382091en-000101 / 130R0983 | 17
Danfoss A/S © 2021.04
Product Overview
VLT® Flow Drive FC 111
Design Guide
