Kamstrup MULTICAL 402, Техническое описание, Страница: 38 / 113

MULTICAL® 402
38
Kamstrup A/S · Technical Description · 5512-742_M1_GB_01.2016
7 Calculator functions
7.1 Measuring sequences
MULTICAL

402 uses time-based integration, which means that calculations of accumulated volume and energy
are carried out at fixed time intervals independent of the current water flow. In normal mode the integration
interval of MULTICAL

”Normal mode”
402 is 24 s., whereas the interval is 4 s. in ”fast mode”.
I normal mode MULTICAL

”Fast mode”
402 passes through an integration sequence of 24 sec. Through this sequence the
water flow is measured at intervals of 3 s. Forward and return temperatures are measured in the middle of the
sequence and at the end of the sequence energy and volume are calculated. All display readings are updated at
intervals of 24 s. However, the current flow reading is updated at intervals of 12 s.
In fast mode MULTICAL

Also see Meter cycle in paragraph 13.2.
402 passes through an integration sequence of 4 s. Through this sequence the water
flow is measured at intervals of 1 s. Forward and return temperatures are measured in the middle of the sequence
and at the end of the sequence energy and volume are calculated. Alle display readings are updated at intervals
of 4 s.
7.2 Energy calculation
MULTICAL

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.
402 calculates energy on the basis of the formula stated in prEN 1434-1:2009, which uses the
international temperature scale issued in 1990 (ITS-90) and the pressure definition of 16 bar.
E
[
Wh
]
=
V x
∆
Θ
x k x 1000
E
[
kWh
]
= E
[
Wh
]
/ 1,000
E
[
MWh
]
= E
[
Wh
]
/ 1,000,000
E
[
GJ
]
= E
[
Wh
]
/ 277,780
E
[
Gcal
]
= E
[
Wh
]
/ 1,163,100
V
is the added (or simulated) water volume in m
3
∆Θ
is the measured temperature difference. Heat energy (E1)
∆Θ
= forward temperature – return temperature
Cooling energy (E1)
∆Θ
= return temperature – forward 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 on the basis of the formula stated in prEN 1434-1:2009
(identical with the energy formula of OIML R75-1:2002).