PESHEAT2V01
2016-01-08
43
Annex A
Application type
Energy calculation formula
For combined heating - hot-water preparing systems
U1A3
- Two independent heat meters:
1st - For closed heating system with flow sensor in
flow pipe.
2nd -For accounting of hot water energy*
∑E = E1 + E2 *
E1=V1
1
(h
T1
-h
T2
)
E2= V2
3
(h
T3
-h
T4
) *
M1 =V1
1
M2 =V2
3
U2A3-
Two independent heat meters:
1st - For closed heating system with flow sensor in
return pipe.
2nd -For accounting of hot water energy
∑E = E1 + E2 *
E1=V1
2
(hT1-hT2)
E2= V2
3
(hT3-hT4) *
M1 =V1
2
M2 =V2
3
Remarks:
* -
In this case when the meter is used for measurement of thermal energy in open heating system, it is a subject of
Lithuanian national technical rules (“Rules on accounting of thermal energy and amount of heat-conveying liquid”, Official
Gazette:1999, No 112-3270, in Lithuanian).
Therein:
∑E , E1, E2
- The measured total energy and separate components of energy
V1...V3
– The measured values of volume of a liquid
M1...M3
– The calculated values of mass of liquid (For 1... 3 measuring channels)
Θ1...Θ2
– The measured values of temperature
h
T1
...h
T3
– The enthalpies, according to water temperatures
1,
2,
3 and corresponding to values
of pressure (depending on the preset values)
h
T4
– The enthalpy, calculated according to water temperature
4 (or preset temperature value T4)
and corresponding to value of pressure (depending on the preset value)
1
...
3
– Water densities, according
to water temperatures
1,
3 and corresponding to values of
pressure (depending on the preset value)
V2 T3
T1
T2
U1A3
p2
V3
V4
V1 p1
progr.
T4
V1
V2 T3
T1
T2
U2A3
p2
V3
V4
p1
progr.
T4
