Download User Manual

5.4.1 Closed heat supply systems (heat meter configurations 2, 5, 6 and 8). Heat
energy is determined as:
W = ∫ Q m ⋅ ( H1 − H 2 ) ⋅ dt
(5.1)
t
where Qm is heat-carrier mass flow rate in supply pipeline, kg/hour;
H1 and H2 are heat-carrier specific enthalpies in supply and return pipes of the
heat-exchange system, correspondingly, Joule/kg;
t is operating time, hour.
5.4.2
Open heat supply systems (configurations 4 and 7):
W = ∫ Q m1 ⋅ H1 ⋅ dt − ∫ Q m 2 ⋅ H 2 ⋅ dt − ∫ ( Q m1 − Q m 2 ) ⋅ H cold ⋅ dt
t
t
(5.2)
t
where Qm1 and Qm2 are heat-carrier mass flow rates in supply and return pipelines, correspondingly, kg/hour;
H1, H2 are heat-carrier specific enthalpies in supply and return pipelines, correspondingly, Joule/kg;
Hcold is cold water specific enthalpy.
In 4th configuration we don’t measure cold water temperature, but enter it programmatically (this temperature is entered by user).
Meters of configurations 4 and 7 measure heat-carrier flow rate in supply and return
pipelines and calculate flow rate difference ∆GM. Meters of configurations 4 and 7 don’t
measure water leaks, water leak is calculated as flow rate difference in supply and return
pipelines.
5.4.3
Source of heat supply (configuration 9).
W = ∫ Q m1 ⋅ ( H1 − H 2 ) ⋅ dt + ∫ Q F ⋅ ( H 2 − H cold ) ⋅ dt
t
(5.9)
t
where Qm1 and QF are heat-carrier mass flow rates, correspondingly, in supply and
feeding pipelines, kg/hour;
H1, H2, Hcold are heat-carrier specific enthalpies, correspondingly, in supply, return and cold water pipelines, Joule/kg.
5.5 Calculation (and archiving) of average temperature values which are included in
process of heat energy determining for a time interval t0-t1, is carried out as weighted average
value T∫ defined under the following formula:
t1
T∫ =
∫ T(t) ⋅ Q
m
(t) ⋅ dt
t0
t1
∫Q
m
(t) ⋅ dt
(5.10)
t0
where T(t) are momentary (current) measured temperature values;
Qm(t) are momentary (current) measured heat-carrier (water) mass flow rate
values.
19