PESHEAT2V01
2016-01-08
8
2. TECHNICAL DATA
2.1. Energy measurement
2.1.1. Accuracy class - 2
Maximum permissible heat energy measurement error of calculator and flow sensor:
),
/
02
,
0
/
5
,
2
(
min
q
q
E
p
%;
Maximum permissible heat energy measurement error of complete meter (error of temperature
sensors pair included):
E =
(3+4
min
/
Θ +0,02q
p
/ q)
where:
min
- lower limit of the ntemperature difference, K;
- temperature difference, between the measured flow and return
temperatures of heat-conveying liquid K;
p
q
- permanent flow-rate, m³/h ;
q
- measured flow-rate, m³/h .
2.1.2. Thermal energy calculation
Consumed heat energy is calculated according to formulas given in Annex A
It is possible to perform calculations in two ways, using programmed or practically measured
pressure values ( 1-st pressure channel corresponds to the flow pipe, 2-nd – return pipe);
Possible heat energy measurement algorithms (selected in configuration mode):
Standard: Unidirectional flow measurement, energy is calculated without any restrictions,
Special: Unidirectional flow measurement,
Energy and quantity of liquid are not calculated in those cases:
- flow rate exceeds programmed maximum allowed value
- flow rate is under programmed minimum allowed value
-or temperature difference is under programmed minimum allowed value
Error code is generated when parameter values exceed given limits. Also, in that case
the device intermit calculating working time, and calculates error duration.
Winter / summer: Flow in 2-nd channel is measured in both directions, energy is calculated
taking into account flow direction without any limitations (only for A and
A1 measurement circuits – see Table 1).
2.1.3. Maximum power value 64 MW
2.2. Temperature measurement
- Number of sensor inputs (measurement channels) 1, 2 or 3*
- Temperature sensors type
Pt500
- Absolute temperature
measurement error
not more than
0,3
o
C
- Sensor connection method **
2-wire, 4-wire
- Max. cable length between calculator and
each of the temperature sensors:
for the 4-wire connection method
3; 5; 10; 15; 20; 40; 60; 80; 100 m,
for the 2-wire connection method
3; 5 m,
- Temperature measuring range (
1...
3)
0…180
o
C
- Temperature displaying range (
3)
-40…180
o
C
- Temperature difference (Θ1-Θ2 and Θ1-Θ3 )
measuring range
2…150 K (or 3…150 K)***
