MULTICAL® 302
36
Kamstrup A/S · Technical Description · 5512-1334_F1_GB_12.2016
7.2
Energy calculation
MULTICAL
302 calculates energy on the basis of the formula stated in EN 1434-1:2007, which uses the international
temperature scale issued in 1990 (ITS-90) and the pressure definition of 16 bar.
In a simplified form the energy calculation can be expressed as: Energy = V x
∆Θ
x k. The calculator always calculates
energy in
[
Wh
]
, and then converts the value to the selected measuring unit.
E
[
Wh
]
=
V x
∆
Θ
x k x 1,000
E
[
kWh
]
=
E
[
Wh
]
/ 1,000
E
[
MWh
]
=
E
[
Wh
]
/ 1,000,000
E
[
GJ
]
=
E
[
Wh
]
/ 277,780
V
is the added (or simulated) water volume
in m
3
∆Θ
is the measured temperature difference
Heat energy (E1):
∆Θ
= inlet temperature – outlet temperature
Cooling energy (E3):
∆Θ
= outlet temperature – inlet temperature
Both in the display and during data reading each energy type is uniquely defined, e.g.
Heat energy: E1 = V1(T1-T2)k
Cooling energy: E3 = V1 (T2-T1)k
k
is the heat coefficient of water, which is calculated according to the formula of EN 1434-1:2007
(identical with the energy formula of OIML R75-1:2002)
Note:
In case of temperature sensor error
ΔΘ
is set at 0.00 K, which causes the meter's energy calculation to stop. A
sensor error also stops volume accumulation. Energy calculation and volume accumulation continue as soon as the
error has been remedied. Please note that the error will remain visible in the info-event-counter if static info codes
have been selected (until the error has been deleted via METERTOOL HCW), although the error has been corrected and
the meter counts again.
Kamstrup can supply an energy calculator for check measurement:
