Brochure

5656
3. Pumps operating in systems
3.5. Annual energy consumption
Like energy labelling of refrigerators and freezers, a corresponding labelling
for pumps exists. This energy label applies for small circulation pumps and
makes it easy for consumers to choose a pump which minimises the power
consumption. The power consumption of a single pump is small but because
the worldwide number of installed pumps is very large, the accumulated en-
ergy consumption is big. The lowest energy consumption is achieved with
speed regulation of pumps.
The energy label is based on a number of tests showing the annual runtime
and flow of a typical circulation pump. The tests result in a load profile defined
by a nominal operating point (Q
100%
) and a corresponding distribution of the
operating time.
The nominal operating point is the point on the pump curve where the product
of Q and H is the highest. The same flow point also refers to P
100%
, see figure
3.14. Figure 3.15 shows the time distribution for each flow point.
The representative power consumption is found by reading the power
consumption at the dierent operating points and multiplying this with
the time expressed in percent.
(3.1)
(3.2)
(3.3)
(3.4)
(3.5)
(3.6)
(2,19)
⋅ =
n
n
QQ
A
B
AB
n
n
HH
A
B
AB
2








⋅
=
n
n
PP
A
B
AB
3








⋅ =
n
n
NPSHNPSH
A
B
AB
2








⋅
=
PPPPP
L,avg 25%50%75%100%
0.440.350.150.06 ⋅+⋅+ ⋅+ ⋅=
[ ]
−=
Ref
L,avg
P
P
EEI
H
max
Flow % Time %
H
Q
Q
25%
Q
50%
Q
75%
Q
100%
Q
100%
Q
75%
Q
50%
Q
25%
H
Q
100
75
50
25
6
15
35
44
Figure 3.15: Load profile.
Figure 3.14: Load curve.
H
max
P
100%
P
1
H
Q
Q Q
100%
max { Q
.
H } ~ P
hyd,max
P
hyd,max
Q
25%
Q
50%
Q
75%
Q
100%
P
100%
P
75%
P
50%
P
25%
H
Q