Steam Turbine Solutions - Steam Turbine Engineering & Service
EFFICIENCY IMPROVEMENT IN HEAT-SUPPLY STEAM TURBINE
Transcript of EFFICIENCY IMPROVEMENT IN HEAT-SUPPLY STEAM TURBINE
1
Perica Jukic a, Zvonimir Guzovic b
a Croatian Electric Power Utility Company (HEP), Zagreb, Croatia b University of Zagreb, Faculty of Mechanical Engineering and Naval Architecture, Zagreb, Croatia
EFFICIENCY IMPROVEMENT IN HEAT-SUPPLY STEAM TURBINE
ABSTRTACT: Efficient use of energy is important for sustainable development, primarily from an
ecological aspect, but also economic and social. Combine heat and power (CHP) plants with installed heat-
supply steam turbines are facilities for achieving high efficiency of the utilization of heat energy generated
by combustion of fossil fuels. In this paper, the common characteristics of the heat-supply steam turbines
are systematized, the basic indicators of their efficiency are defined, and the paths of increase in the specific
conditions of simultaneous production of heat and electricity. The basic features of heat-supply extraction
and heat-supply in general also presented. In addition, the work has indicated the possibility of further
improvement of the operating regimes the heat-supply turbines by introducing a stage-wise heating of
District heating (DH) system water. In concrete example of the heat-supply steam turbine T-100/120-130-
3 located in CHP Power plant TE-TO Zagreb, introducing a stage-wise heating of DH system water and
shown how to utilize the waste heat of the steam in low pressure part of turbine, due to increase its
efficiency. For the purpose of this analysis, has been developed an original computer program with output
operating regimes, which can also be used for other heat-supply steam turbines in the range of 25 to 250
MW.
Keywords: Sustainable development, CHP plant, DH system, Stage-wise heating, Heat-supply steam
turbine, Efficiency, Diagram of operating regimes Nomenclature:
wc kJ/(kgK) specific heat of DH water
wq t/h flow rate of DH water
ww 12 , 0C DH water temperature at the outputs from DH exchanger ZVV1 and ZVV2
pov 0C DH network return temperature
pol 0C DH network supply temperature
1zvvh , 2zvvh , kJ/kg enthalpy of condensate of the lower and upper Heat exchanger
01th , 02th , kJ/kg extraction steam enthalpy upper and lower
t
turD t/h Live steam heat-supply flow rate
k
turD t/h Live steam condensing flow rate
turD t/h Live steam flow rate
01tD t/h flow rate upper extractions of steam to ZVV2
02tD t/h flow rate lower extractions of steam to ZVV1
t
eP MW heat-supply electric power
14. savjetovanje HRO CIGRÉ
Šibenik, 10. − 13. studenoga 2019.
HRVATSKI OGRANAK MEĐUNARODNOG VIJEĆA ZA VELIKE ELEKTROENERGETSKE SUSTAVE – CIGRÉ
X-XX
2
k
eP MW condensing electric power
eP MW generator electric power
tp bar extractions heat-supply pressure
turQ MW steam turbine heat load
toQ MW extractions heat-supply heat load
t
turQ MW heat-supply steam turbine heat load
k
turQ MW condensing steam turbine heat load
eQ MW heat consumption for electricity generation
TE
toQ MW heat load of CHP plant
eQ kJ/kWh specific heat rate for electricity generation
E kWhe/kWht specific generation of electricity by heat-supply flow rate
konQ MW waste heat of steam in condenser
mgzQ MW mechanical, electric generator and radiation losses
1. Introduction
Integration into the DH system of renewable energy sources (RES), the use of waste heat, cogeneration
heat, is one of the key points of Directive 2012/27/ EU on energy efficiency [1]. Increasing energy
efficiency contributes to the approach "total energy use", which is available in the system, and includes the
use of the overall thermal energy at different temperature levels. Highly efficient cogeneration and DH
systems [2] have a significant potential for saving primary energy that is still insufficiently used in the
European Union. They also represent a very important factor in planning future energy systems to increase
flexibility and enable a higher level of exploitation of intermittent renewable energy sources such as wind
and photovoltaic systems [3]. Renewable Energy (OIE) plays an increasingly important role in reducing
the fossil fuel consumption in the DH system and mitigating the environmental impact. CHP systems with
RES and energy storage system (ESS) are being investigated. Modelling and optimization methods are
being developed for planning and managing such CHP-DH systems [4].
2. Characterictics of CHP plants and Heat-supply steam turbines
One of the best ways to improving the efficiency of a CHP plants (Fig. 1) is to temperature reduction of the
DH system water with simultaneously utilization the waste heat in the steam turbine condenser [5]. District
heating system should be revitalized to achive the higher level of generations (today is a developed system
of fourth generation) [6] based on a low-temperature regime. The CHP plant can be very efficient if uses
the waste heat of steam in the steam condenser, and if on the CHP plant [7] and on the DH system installed
heat pumps of the corresponding design and capacity [8], and even if the whole system is working combined
with heat storage tanks [4]. Power plant characteristics should ensure the safety of turbine and generator,
especially low pressure turbine blades [9]. Safety operation of the condenser at high cooling water
temperatures can be provided by lowering and switching to low temperature heating system [10]. The
experience acquired in exploitation confirms the possibility of increasing the thermal efficiency with
turbines power higher than 25 MW when using steam heat that goes into the condenser. CHP plants and
associated heat-supply turbines of higher than 50 MW have two heat-supply steam extractions, upper and
lower, intended for stage-wise heating of the DH water system [11] which significantly reduces the loss of
exergy. For turbines with a power greater than 50 MW, possible to use low pressure steam ventilation for
preheating return DH water [8]. This increases the economy and efficiency of the CHP plant [2]. The
construction of the condenser with an additional tube bundle which having an independent water chamber
and a common steam surface area of the base, allows the change the normal mode of operating to the mode
3
of operation using steam ventilation heat, and inversely during the operation of the turbine without its
stopping and limiting power [12].
Fig. 1. Scheme of CHP plant and DH system Fig 2. Heat distribution of heat-supply steam turbine
by utilizing vent. steam heat into condenser
Full recovery of waste heat [13] is an effective approach to increasing heating capacity and reducing
emissions of pollutants in the cogeneration plant. Turbines with two heat-supply extractions have an
extended range of regulated pressure in upper heat-supply extraction ranging from 0.6 to 2.5 bar, which
allows the supply temperature of the DH system from 70 to 125 0C [14]. Specific heat consumption is
defined by the equation e
toture
P
QQQ
, where is turQ -turbine heat consumption, toQ - heat load of heat-
supply extractions. Value of eQ is determined with sufficient accuracy in the turbine test, where is eP the
electric power generated by steam flows through the turbine. For heat-supply steam turbines specific heat
consumption depends on the relationship between the heating and electrical loads and the turbine's
perfection. Referring to Fig. 2, taking into account the general energy equation, can be written:
konmgztoetur QQQPQ (1)
3. Energy characterictics of heat-supply steam turbines
The energy characteristics of the heat-supply steam turbines express the same functional dependence as the
operating mode diagrams, but not in graphic but in analytical form. The operation regimes of the heat-
supply turbines are divided into two groups: condensing and heat-supply. The condensation regimes of the
heat-supply turbines, which include zero-heat load regimes, have independent energy characteristics. At
the heat-supply regime, electrical power and heat distribution are conditional in two flows:
Heat-supply electrical power and heat-supply turbine heat load t
eP , t
turQ
Condensing electrical power and condensing turbine heat load k
eP , k
turQ
Depending on the relationship between thermal and the electric load, the heat-supply regime can be either
a flow or only one heat-supply flow. The condensation power of the heat-supply regime is determined as
the difference between the total and heat-supply power turbo aggregate:
4
k
eP eP t
eP (2)
The condensation heat flow at the heat-supply regimes is determined as the difference between the total
and the heat-supply heat flow:
t
turtur
k
tur QQQ (3)
ZVV2
VVK
3
4
hto1
S
pol 2w 1w pov
ZVV1
3 3
to2h
pt1
to1 D
to2
p
D
t2
2
1 1
The most important facts related to heat-supply extractions and heat-supply are heat load, stage-wise
heating of the DH water (Fig. 3), reduction of the steam pressure extraction and use of waste steam heat
that goes into the condenser [8]. Heat-supply turbines are designed for stage-wise heating and work on a
heat diagram with nominal heat load to provide additional electricity generation during the heating period.
The Heat load of CHP plant and the parameters of the DH water are connected by the equation:
)( povpolww
TE
to cqQ (4)
Where are: TE
toQ - Heat load of CHP plant; pol and pov - temperature supply and return DH network
water. The ratio of the extractions heat-supply heat load and the total heat load of CHP plant at the minimum
ambient air temperature is called the heat-supply coefficient TE . Temperature diagram of DH system and
accepted heat-supply coefficient, determine the DH water temperature w2 behind the basic DH heaters,
which are supplied by steam from the heat extractions. At the minimum ambient air temperature w2 is
determined directly from the known relationship for TE :
w2 )( povpolpov TE (5)
For any ambient air temperature it is worth it:
w2ww
topov
cq
Q (6)
For part of DH period, when the peak boiler is turned off and all of the heat load for CHP plant and district
heating covers with turbine heat-supply extractions, follows that w2 pol . The additional power,
obtained by two-stage of heating (compared to a single-stage of heating) with steam flow, which goes into
lower heat-supply extraction, is:
mgtototoII hhDP .212 )( (7)
where: 2toD - extraction steam rate to a DH heater (the numbering of the heat-supply extractions are in the
direction of the steam flow through the turbine, while the heaters numbering are in the direction of the DH
Fig 3. The principle P&D stage-wise heating
t01-upper heat-supply extraction;
t02-lower heat-supply extraction;
----------- DH water ;
- - - - - - - condensate;
------------ steam extractions
1- DH heaters ZVV1,2;
2-pick hot water boiler;
3-regenerative heaters; 4-turbine
5
water flow). In the afterwards heating in the Regenerative Low Pressure Heater (ZNT) enthalpy the
condensate of DH heater ZVV1 increases from 1zvvh to 2zvvh , for which it is necessary to consume the heat:
)( 1221 zvvzvvto hhDQ (8)
in the form of additional, over the network of DH water required, extraction of steam from upper heat-
supply extractions. With the steam of additional extractions the power is obtained:
11 QEPI (9)
where: 1E - specific generation of electricity by heat-supply flow rate at single-stage of heating. In this
way, when switching from single to two-stage of heating with unchanged heating load, provides additional
electrical power:
PIP IIP
and additional specific generation of electricity by heat-supply flow rate:
toQ
PE
2
(10)
4. Heat-supply steam turbine T-100-110/130-3 operating regimes
4.1. Design of the regime diagram
Turbine T-100-130 operation diagram based on actual operating data, normative data and other
measurements at CHP Power Plants Zagreb (TE-TO Zagreb), also on the basis of project materials obtained
from UTMZ turbine manufacturers. Heat-supply regime with single-stage of heating is used when heat load
up to 120 MW and when pressure in upper stage of heating begins to increase significantly. Then it goes to
work with a one heater a lower stage due to stop the increase specific heat consumption and significantly
reduce the additional electricity generation on the basis of heat demand. The two-stage heating mode is
used when the need heat load at least 120 MW. Based on the algorithm, a program is written by which all
possible modes of operation are calculated and displayed in the form of an output text file. On the basis of
the results it can be concluded that the heat-supply regimes of operation on the heat diagram is most
economical, as the specific heat consumption is the smallest, or the largest power plant efficiency.
4.2. Single-stage of heating
The dependence of the heat-supply steam flow and heat-supply electrical power on the heat load and the
pressure in lower heat-supply steam extraction, are shown in Fig. 4.2.a, b.
Generally, the heat-supply steam flow at single-stage of heating can be represented by the following
equation:
jed
D
jed
to
jed
D
jed
to
jed
D
t
tur cQbQaDjed
2)( (4.2)
Parameters jed
D
jed
D
jed
D cba ,, are changed depending on the lower extraction pressure and can be
displayed in graphic form and interpolated with the fourth and third degree polynomials. Final analytic
expressions have the form:
6
Fig. 4.2.a,b. Turbine T-100-130 heat-supply performance curves for single-stage heating DH water:
Functional dependence of the heat-supply steam flow (a) and the heat-supply electrical power (b)
on the heat load and the lower extraction pressure
005222.0001496.0001757.000419.0001516.0 2
2
2
3
2
4
2 ttptt
jed
D ppppa (4.3)
896051.0619656.1721814.1522868.0 2
2
2
3
2 ttpt
jed
D pppb (4.4)
119.1938273.2648524.5096528.15 2
2
2
3
2 ttt
jed
D pppc (4.5)
Generally, the heat-supply electrical power at single-stage of heating can be represented by the following
equation:
jed
P
jed
to
jed
P
jed
to
jed
P
t
e cQbQaPjed
2)( (4.6)
Parameters jed
P
jed
P
jed
P cba ,, are changed depending on the extraction pressure and can be displayed in
graphic form and interpolated with the fourth and fifth degree polynomials:
002922.0012352.0026297.0023971.0009869.0001515.0 2
2
2
3
2
4
2
5
2 ttttt
jed
P pppppa (4.7)
359488.0433281.0082952.178443.0177584.0 2
2
2
3
2
4
2 tttt
jed
P ppppb (4.8)
9265.2781365.11171874.19104701.17039322.759778.12 2
2
2
3
2
4
2
5
2 ttttt
jed
P pppppc (4.9)
4.3. Two-stage of heating
The dependence of the heat-supply steam flow and heat-supply electrical power on the heat load and the
pressure in upper heat-supply steam extraction, are shown in Fig. 4.3.a,b.
The heat-supply steam flow at two-stage of heating can be represented by the following equation:
dvo
D
dvo
to
dvo
D
dvo
to
dvo
D
t
tur cQbQaDdvo
2)( (4.10)
Parameters dvo
D
dvo
D
dvo
D cba ,, are changed depending on the upper extraction pressure and can be displayed
in graphic form and interpolated with fifth degree polynomials:
Jednostupanjsko zagrijavanje
DNT zatvorena
Dttur = 0.004464Qto
2 + 1.340714Qto + 16.60
Dttur = 0.004643Qto
2 + 1.317143Qto + 27.00
Dttur = 0.005357Qto
2 + 1.222857Qto + 37.80
Dttur = 0.005357Qto
2 + 1.282857Qto + 41.60
Dttur = 0.004464Qto
2 + 1.430714Qto + 40.80
60.0
70.0
80.0
90.0
100.0
110.0
120.0
130.0
140.0
150.0
160.0
170.0
180.0
190.0
200.0
210.0
220.0
230.0
240.0
250.0
260.0
270.0
280.0
290.0
40.0 50.0 60.0 70.0 80.0 90.0 100.0 110.0 120.0
Toplinska snaga Qto [MW]
To
plif
ika
cijs
ki p
roto
k D
t tur
[t/h
]
Dttur(0,5)
Dttur(1,0)
Dttur(1,4)
Dttur(1,8)
Dttur(2,0)
Poly.
Poly.
(Dttur(0,5)
)Poly.
(Dttur(1,0)
)Poly.
(Dttur(1,4)
)Poly.
(Dttur(1,8)
)Poly.
(Dttur(2,0)
)
Jednostupanjsko zagrijavanje
DNT zatvorena
Pte = 0.000982Qto
2 + 0.385357Qto - 2.90
Pte = 0.001179Qto
2 + 0.328429Qto - 0.80
Pte = 0.001161Qto
2 + 0.314786Qto - 0.38
Pte = 0.001071Qto
2 + 0.340571Qto - 2.34
Pte = 0.001071Qto
2 + 0.328571Qto - 1.80
Pte = 0.001143Qto
2 + 0.343143Qto - 0.74
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
40.0 50.0 60.0 70.0 80.0 90.0 100.0 110.0 120.0
Toplinska snaga Qto [MW]
To
plif
ika
cijs
ka
ele
ktr
ičn
a s
na
ga
Pt e
[M
W]
Pte(0,5)
Pte(1,0)
Pte(1,4)
Pte(1,8)
Pte(2,0)
Pte(0,8)
Poly.
(Pte(0,5))Poly.
(Pte(1,0))Poly.
(Pte(1,4))Poly.
(Pte(1,8))Poly.
(Pte(2,0))Poly.
(Pte(0,8))
a
)
)
b
)
)
7
Fig. 4.3.a,b. Turbine T-100-130 heat-supply curves for two-stage heating DH water: Functional dependence of the
heat-supply steam flow (a) and the heat-supply electrical power (b) on the heat load and the upper extraction
pressure
008073.0015333.0051103.005743.0025966.0004119.0 1
2
1
3
1
4
1
5
1 ttttt
dvo
D pppppa (4.11)
917671.0186251.4060567.15222733.17872131.7259133.1 1
2
1
3
1
4
1
5
1 ttttt
dvo
D pppppb (4.12)
73158.1277944.27377346.107244892.12371809.57254839.92 1
2
1
3
1
4
1
5
1 ttttt
dvo
D pppppc (4.13)
The heat-supply electrical power at single-stage of heating can be represented by the following equation:
dvo
P
dvo
to
dvo
P
dvo
to
dvo
P
t
e cQbQaPdvo
2)( (4.14)
Parameters dvo
P
dvo
P
dvo
P cba ,, are changed depending on the upper extraction pressure and in the graphical
form are interpolated with the polynomials of the second degree in the range of 0.6 to 1.4 bar and fifth
degree polynomials in the pressure range of 1.4 to 2.5 bar:
001499.0001145.0000428.0 1
2
1 tt
dvo
P ppa (4.15a)
444287.0208139.1287444.1673167.0172862.001746.0 1
2
1
3
1
4
1
5
1 ttttt
dvo
P pppppa (4.15b)
386902.0212762.0100437.0 1
2
1 tt
dvo
P ppb (4.16a)
85117.15614618.42201589.44857253.233848.5903471.6 1
2
1
3
1
4
1
5
1 ttttt
dvo
P pppppb (4.16b)
5197.79851.84641.4 1
2
1 tt
dvo
P ppc (4.17a)
43274.105600162.2845754742.3015788113.1568605631.40061153.402 1
2
1
3
1
4
1
5
1 ttttt
dvo
P pppppc (4.17b)
4.4. Three stage of heating – utilize the steam waste heat in low pressure part of turbine
The dependence of the heat-supply steam flow and heat-supply electrical power on the heat load and the
pressure in upper heat-supply steam extraction, are shown in Fig. 4.4.a,b.
Generally, the heat-supply steam flow of a three-stage heating can be represented by a first degree
polynomial or straight line equation:
tro
D
tro
to
tro
D
t
tur bQaDtro
(4.18)
Parameters tro
D
tro
D ba , are changed depending on the upper extraction pressure and can be displayed in
graphic form and interpolated with fifth degree polynomials:
Dvostupanjsko zagrijavanje
DNT zatvorena
Dttur = 0.00617Qto
2 + 1.10361Qto + 60.36201
Dttur = 0.00587Qto
2 + 1.25335Qto + 36.67407
Dttur = 0.00678Qto
2 + 1.04923Qto + 36.85924
Dttur = 0.00826Qto
2 + 0.65309Qto + 53.90920
Dttur = 0.00791Qto
2 + 0.80541Qto + 34.33148
Dttur = 0.00387Qto
2 + 1.81701Qto + 10.86598
220
240
260
280
300
320
340
360
380
400
420
440
460
480
500
120 130 140 150 160 170 180 190
Toplinska snaga Qto [MW]
Topl
ifika
cijs
ki p
roto
k D
t tur [
t/h] Dttur(0,6)
Dttur(1,0)
Dttur(1,4)
Dttur(1,8)
Dttur(2,2)
Dttur(2,5)
Poly.
(Dttur(2,2
))Poly.
(Dttur(1,8
))Poly.
(Dttur(1,4
))Poly.
(Dttur(1,0
))Poly.
(Dttur(0,6
))Poly.
(Dttur(2,5
))
Dvostupanjsko zagrijavanje
DNT zatvorena
Pte = 0.000966Qto
2 + 0.478402Qto - 11.303727
Pte = 0.000782Qto
2 + 0.499227Qto - 12.040761
Pte = 0.000735Qto
2 + 0.487912Qto - 11.349286
Pte = 0.000226Qto
2 + 0.602088Qto - 18.585329
Pte = 0.000730Qto
2 + 0.410979Qto - 3.866574
Pte = 0.000431Qto
2 + 0.498144Qto - 12.399366
50
60
70
80
90
100
110
120
120 130 140 150 160 170 180 190
Toplinska snaga Qto [MW]
Topl
ifika
cijs
ka e
lekt
ričn
a sn
aga
Pt e M
W
Pte(0,6)
Pte(1,0)
Pte(1,4)
Pte(1,8)
Pte(2,2)
Pte(2,5)
Poly.
(Pte(0,6)
)Poly.
(Pte(1,0)
)Poly.
(Pte(1,4)
)Poly.
(Pte(1,8)
)Poly.
(Pte(2,2)
)Poly.
(Pte(2,5)
)
a
)
)
b
)
)
8
Fig. 4.4.a,b.: Turbine T-100-130 heat-supply performance curves for three-stage heating DH water:
Functional dependence of the heat-supply steam flow (a) and the heat-supply electrical power (b)
on the heat load and the upper extraction pressure
62826.209535.380659.457742.329262.11781.0 1
2
1
3
1
4
1
5
1 ttttt
tro
D pppppa (4.19)
25737.3098336.61541964.89818853.67213565.24464469.33 1
2
1
3
1
4
1
5
1 ttttt
tro
D pppppb (4.20)
The heat-supply electric power of a three-stage heating can be shown similarly to single-stage and two-
stage of heating, with the following equation:
tro
P
tro
to
tro
P
tro
to
tro
P
t
e cQbQaPtro
2)( (4.21)
Parameters tro
P
tro
P
tro
P cba ,, are changed depending on the upper extraction pressure and in the graphical
form are interpolated with the polynomials of the second degree in the range of 0.6 to 1.4 bar and third
degree polynomials in the pressure range of 1.4 to 2.5 bar:
004115.0005452.0002008.0 1
2
1 tt
tro
P ppa (4.22a)
042543.0062717.0029495.0004538.0 1
2
1
3
1 ttt
tro
P pppa (4.22b)
332762.2115294.2789906.0 1
2
1 tt
tro
P ppb (4.23a)
75521.1215688.2055476.947381.1 1
2
1
3
1 ttt
tro
P pppb (4.23b)
9911.1619443.1572774.62 1
2
1 tt
tro
P ppc (4.24a)
9814.13166956.20202470.9530893.147 1
2
1
3
1 ttt
tro
P pppc (4.24b)
5. The results; single-stage, two-stage and three-stage DH system heating
5.1. Results single stage of heating
pt2 Qjed Dtjed Ptjed Dkjed Djed Pjed Q1tur qjedn
[bar] [MWt] [t/h] [MWe] [t/h] [t/h] [MWe] [MWt] [kJ/kWh]
.500 .4000E+02 .7733E+02 .1412E+02 .1000E+02 .8733E+02 .1705E+02 .6149E+02 .4539E+04
.500 .4000E+02 .7733E+02 .1412E+02 .2000E+02 .9733E+02 .1997E+02 .6853E+02 .5144E+04
.500 .4000E+02 .7733E+02 .1412E+02 .3000E+02 .1073E+03 .2289E+02 .7558E+02 .5595E+04
Trostupanjsko zagrijavanje, DNT zatvorena
Dttur = 3.3750Qto - 192.75
Dttur = 3.3850Qto - 210.55
Dttur = 3.3450Qto - 218.35
Dttur = 3.2900Qto - 222.20
Dttur = 3.1600Qto - 208.30
Dttur = 3.1200Qto - 206.60
160.0
180.0
200.0
220.0
240.0
260.0
280.0
300.0
320.0
340.0
360.0
380.0
400.0
420.0
440.0
460.0
480.0
500.0
520.0
150.0 160.0 170.0 180.0 190.0 200.0 210.0
Toplinska snaga Qto [MW]
To
plifi
ka
cijs
ki p
roto
k D
t tur [t
/h]
Dttur(0,6)
Dttur(1,0)
Dttur(1,4)
Dttur(1,8)
Dttur(2,2)
Dttur(2,5)
Linear
(Dttur(0,6
))Linear
(Dttur(1,0
))Linear
(Dttur(1,4
))Linear
(Dttur(1,8
))Linear
(Dttur(2,2
))Linear
(Dttur(2,5
))
Trostupanjsko zagrijvanje, DNT zatvorena
Pte = -0.001562Qto
2 + 1.345000Qto - 89.568750
Pte = -0.000688Qto
2 + 1.018000Qto - 66.596250
Pte = -0.000375Qto
2 + 0.893000Qto - 62.2525
Pte = -0.001250Qto
2 + 1.165000Qto - 89.5750
Pte = -0.001000Qto
2 + 1.038000Qto - 81.0400
Pte = -0.000813Qto
2 + 0.9480Qto - 75.233750
30.0
40.0
50.0
60.0
70.0
80.0
90.0
100.0
110.0
120.0
130.0
150.0 160.0 170.0 180.0 190.0 200.0 210.0
Toplinska snaga Qto [MW]
To
plifi
ka
cijs
ka
el. s
na
ga
Pt e
[M
W]
Pte(0,6)
Pte(1,0)
Pte(1,4)
Pte(1,8)
Pte(2,2)
Pte(2,5)
Poly.
(Pte(0,6
))Poly.
(Pte(1,0
))Poly.
(Pte(1,4
))Poly.
(Pte(1,8
))Poly.
(Pte(2,2
))Poly.
(Pte(2,5
))
a
)
)
b
)
)
9
.500 .1200E+03 .2417E+03 .5695E+02 .2300E+03 .4717E+03 .1155E+03 .3322E+03 .6610E+04
.500 .1200E+03 .2417E+03 .5695E+02 .2400E+03 .4817E+03 .1178E+03 .3392E+03 .6699E+04
.500 .1200E+03 .2417E+03 .5695E+02 .2500E+03 .4917E+03 .1201E+03 .3463E+03 .6784E+04
.
2.000 .4000E+02 .1050E+03 .1303E+02 .1000E+02 .1150E+03 .2563E+02 .8095E+02 .5752E+04
2.000 .4000E+02 .1050E+03 .1303E+02 .2000E+02 .1250E+03 .2812E+02 .8799E+02 .6144E+04
2.000 .4000E+02 .1050E+03 .1303E+02 .3000E+02 .1350E+03 .3062E+02 .9503E+02 .6471E+04
.
2.000 .1200E+03 .2766E+03 .5289E+02 .2000E+03 .4766E+03 .1055E+03 .3356E+03 .7359E+04
2.000 .1200E+03 .2766E+03 .5289E+02 .2100E+03 .4866E+03 .1080E+03 .3427E+03 .7423E+04
2.000 .1200E+03 .2766E+03 .5289E+02 .2200E+03 .4966E+03 .1105E+03 .3497E+03 .7485E+04
5.2. Results two-stage of heating
pt1 Qdvo Dtdvo Ptdvo Dkdvo Ddvo Pdvo Q2tur qdvos
[bar] [MWt] [t/h] [MWe] [t/h] [t/h] [MWe] [MWt] [kJ/kWh]
.600 .1200E+03 .2449E+03 .6002E+02 .1000E+02 .2549E+03 .6294E+02 .1795E+03 .3615E+04
.600 .1200E+03 .2449E+03 .6002E+02 .2000E+02 .2649E+03 .6586E+02 .1865E+03 .3636E+04
.600 .1200E+03 .2449E+03 .6002E+02 .3000E+02 .2749E+03 .6879E+02 .1936E+03 .3850E+04
.
.600 .1800E+03 .4356E+03 .1061E+03 .6000E+02 .4956E+03 .1211E+03 .3490E+03 .5025E+04
.600 .1900E+03 .4729E+03 .1145E+03 .1000E+02 .4829E+03 .1170E+03 .3401E+03 .4619E+04
.600 .1900E+03 .4729E+03 .1145E+03 .2000E+02 .4929E+03 .1195E+03 .3471E+03 .4734E+04
.
2.500 .1200E+03 .2842E+03 .5355E+02 .1000E+02 .2942E+03 .5844E+02 .2072E+03 .5371E+04
2.500 .1200E+03 .2842E+03 .5355E+02 .2000E+02 .3042E+03 .6093E+02 .2142E+03 .5567E+04
2.500 .1200E+03 .2842E+03 .5355E+02 .3000E+02 .3142E+03 .6343E+02 .2213E+03 .5748E+04
.
2.500 .1800E+03 .4624E+03 .9120E+02 .1000E+02 .4724E+03 .9370E+02 .3326E+03 .5865E+04
2.500 .1800E+03 .4624E+03 .9120E+02 .2000E+02 .4824E+03 .9619E+02 .3397E+03 .5976E+04
2.500 .1800E+03 .4624E+03 .9120E+02 .3000E+02 .4924E+03 .9868E+02 .3467E+03 .6082E+04
5.3. Results three-stage of heating
pt1 Qtro Dttro Pttro Q3tur qtros
[bar] [MWt] [t/h] [MWe] [MWt] [kJ/kWh]
.600 .1800E+03 .4148E+03 .1022E+03 .2921E+03 .3946E+04
.600 .1900E+03 .4485E+03 .1099E+03 .3158E+03 .4121E+04
.600 .2000E+03 .4822E+03 .1173E+03 .3396E+03 .4285E+04
.600 .2100E+03 .5160E+03 .1243E+03 .3633E+03 .4440E+04
.
2.500 .1800E+03 .3549E+03 .6910E+02 .2499E+03 .3642E+04
2.500 .1900E+03 .3861E+03 .7558E+02 .2719E+03 .3901E+04
2.500 .2000E+03 .4173E+03 .8189E+02 .2939E+03 .4127E+04
2.500 .2100E+03 .4486E+03 .8804E+02 .3159E+03 .4329E+04
6. Conclusion
Considering this techno-economic area, most of the different operational targets, district heating systems
(DHs) and Combine Heat and Power plants (CHPs) in the future must find a way to cover costs and to work
efficiently. For a T-100/120-130-3 type turbine based on actual data, normative data, other measurements
data, and on the basis of theoretical knowledge, a uniform diagram the mode of operation in the graphic
form was prepared, from which all possible operating modes can be read. A complete diagram is translated
and described by analytical dependencies in the form of energy characteristics. Based on the algorithm, a
program is written by which all possible modes of operation are calculated and displayed in the form of an
10
output text file. From the output data it can be concluded that the heat-supply operating regimes of the heat
diagram are most economical, as the specific heat consumption is the smallest, or the largest power plant
efficiency. Also, the algorithm derived from the operating regime diagram of heat-supply steam turbine T-
100/120-130-3 can be used to construct diagram of the operating regime for other heat-supply steam
turbines in range of 25 to 250 MW. The average specific heat consumption at mode of operation when
utilize steam waste heat in the condenser is 3850 kJ/kWh or 94% efficiency. For the steam turbine T-100-
130, which operates at TETO Zagreb beginning of November to the end of February, possible to save about
3x106 m3 of natural gas, and reduce 6x103 tons of CO2, compared to the operating regime without the use
the steam waste heat in the turbine condenser.
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