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Int. J. Engg. Res. & Sci. & Tech. 2014 Rahul Kumar Singh et al., 2014
EFFECT OF STEAM INLET TEMPERATUREON PERFORMANCE OF PARTIAL ADMISSION
STEAM TURBINE
Rahul Kumar Singh1*, Abhishek Arya2 and Sphurti Sweta Pandey3
Energy analysis helps designers to find ways to improve the performance of a system in amany way. Most of the conventional energy losses optimization method are iterative in natureand require the interpretation of the designer at each iteration. Typical steady state plant operationconditions were determined based on available trending data and the resulting condition of theoperation hours. The energy losses from individual components in the plant is calculated basedon these operating conditions to determine the true system losses. In this, first law ofthermodynamics analysis was performed to evaluate efficiencies and various energy losses. Inaddition, variation in the percentage of carbon in coal content increases the overall efficiency ofplant that shows the economic optimization of plant.
Keywords: Steam inlet temperature, Energy losses, Economic optimization
*Corresponding Author: Rahul Kumar Singh [email protected]
INTRODUCTIONPower plants are part of the infrastructure of the
modern society and it is essential that these
power plant facility by constructed so as to
achieve a higher level of reliability. Moreover it is
mandate of power plants involved in this industry
to contribute to society by realizing higher
performance. Energy analysis helps designers
to find ways to improve the performance of a
system in a many ways. Most of the conventional
energy losses optimization method are iterative
in nature and require the interpretation of the
designer at each iteration. Typical steady state
1 M.Tech Scholar, SCOPE Engineering College, Bhopal, India.2 Assistant Professor, SCOPE Engineering College, Bhopal, India.3 M.Tech Scholar, BITS, Bhopal, India.
Int. J. Engg. Res. & Sci. & Tech. 2014
ISSN 2319-5991 www.ijerst.comVol. 3, No. 4, November 2014
© 2014 IJERST. All Rights Reserved
Research Paper
plant operation conditions were determined based
on available trending data and the resulting
condition of the operation hours.
LITERATURE REVIEWGhosh et.al. (2005) states that the limited primary
energy sources and awareness of environmental
pollution has led to ever increasing end over to
develop new steam turbine power plants with the
highest possible efficiency. Considering their
output, even small step increase in efficiency can
result in major saving for the customers. As
overall cycle efficiency is strongly dependent on
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Int. J. Engg. Res. & Sci. & Tech. 2014 Rahul Kumar Singh et al., 2014
steam turbine performance, Continuous
improvement are sought to increase the turbineefficiency. These effectors are directly primarilytowards improvements are blading as the keycomponent of the turbine
Kenji Nakamura et.al (2010) response to globalenvironmental issues, higher efficiency andimproved operational reliability are increasinglybeing requested for steam turbines, essentialequipment for thermal power generation. Byincreasing the temperature and pressure of thesteam turbine operating conditions, more efficientpower generation is realized, and in order torealize a turbine applied with the highertemperature conditions of 700oC for the future,Fuji Electric is participating in the METI-sponsoreddevelopment of advanced ultra-supercriticalpower generation, and is evaluating and verifyingthe reliability of materials used for high-temperature valves.
Paul I. Nippes et al. (2002) worked with thecurrent practices of extending periods betweenturbine-generator planned outages is the need forimproved and careful condition monitoring. Bydetermining the condition of the turbine generatorunits and their suitability for continuingsatisfactory operation, outages can be scheduled,often preventing forced outages. A relativenewcomer to the field of monitoring is shaftcondition monitoring, which also usually projectsto train condition monitoring. This is accomplishedby placing reliable shaft-riding brushes for shaftgrounding and voltage monitoring. As can beimagined, a wide plethora of shaft groundingcurrent and voltage data is available so the issuebecomes one of sifting through to identify andproject hidden messages as to the shaft, and unitcondition. Illustrations and descriptions of shaftgrounding currents and shaft voltages, based onmeasurements made on installed units is themain purpose of this paper.
PARTIAL ADMISSIONPartial admission applied as control stage yields
high part load efficiency and high specific work
output due to a maintained high inlet pressure for
the turbine in the fully admitted sectors. The
thermodynamics of partial admission can be
explained by a comparison to simple throttling
valve, as illustrated in Figure 1, where it is noted
that the average entropy of the steam into the
subsequent stage is lower for the control stage
than for a simple throttling valve due to the
maintained large pressure ratio across the open
admission arcs.
EXPERIMENTAL SETUPThe equipment has a data acquisition system to
collect the information. A systematic block
diagram of the experimental system is shown in
Figure 1.
Figure 1: Experimental Set up
The location and function of the data
instruments of the setup is given below:
Digital flow meter and display gauges
mounted on the steam supply lines are used to
measure and display the f low rate and
temperature of the steam. Controller monitored
pressure display is used to display the set point
and acquired pressure. Analog pressure gauges
mounted at various locations on the apparatus
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Int. J. Engg. Res. & Sci. & Tech. 2014 Rahul Kumar Singh et al., 2014
are used to measure and display the pressure of
the steam or water. Thermocouples mounted on
the condenser unit are used to measure the
temperature of steam entering condenser, water
entering condenser and water leaving condenser.
Experimental Procedure
1. At the moment of taking the readings, the
steam turbine will be operational in the no load
condition. So, the first step is to set the 1/2 of
the maximum load applied on the turbine by
the generator.
2. Allow the system to reach steady state, and
take readings. They are:
a) Turbine inlet temperature.
b) Turbine exit temperature.
c) Turbine inlet pressure.
d) Turbine exit pressure.
e) Mass of steam flow.
f) Time operation.
3. The above procedure is repeated for the 3/4
of the maximum load applied.
4. Finally apply the full load to the turbine and
allow the system to reach up to the steady
state. Now take the readings at full load.
Assumptions
As per literature survey, the following
assumptions are considered for the efficient
operation of power plant.
· Each component of the cycle is analyzed as
a control volume at steady state.
· The turbine operated adiabatically.
· Saturated vapor enters the turbine.
· Condensate exits the condenser as saturated
liquid.
· In calculating the turbine efficiencies, the
enthalpies at the relevant state points were
taken
Full Load Steam Turbine Performance
The load on the turbine is a variable that can affect
the output power and the efficiency. The load is
a number between 0 and 100, and it represents
a braking or drag resistance to the shaft rotation.
The greater the load, the greater the resistance
applied. The load affects the power output
because it influences the RPM and the mass flow
rate of the steam. For any steam turbine, if there
is increase in the load, the RPM will be going to
plummet unless the mass flow rate is increased.
Effect of Steam Inlet Temperature
Enthalpy of steam is a function of temperature
and pressure. At lower temperature, enthalpy will
be low, work done by the turbine will be low,
turbine efficiency will be low, hence steam
consumption for the required output will be higher.
In other words, at higher steam inlet temperature,
heat extraction by the turbine will be higher and
hence for the required output, steam consumption
will reduce. Figure 3 represents the effects of
steam inlet temperature on steam consumption,
keeping all other factors constant for the
condensing type turbine.
RESULTSFigure 2: Effect of Steam Temperature on
Steam Consumption
9 8 . 2 9 8 . 4 9 8 . 6 9 8 . 8 9 9 . 0 9 9 . 2 9 9 . 4 9 9 . 6 9 9 . 8 1 0 0 . 02 9 0
3 0 0
3 1 0
3 2 0
3 3 0
3 4 0
3 5 0
3 6 0
3 7 0
3 8 0
Ste
am te
mpe
ratu
re (
de
g C
)
S t e a m C o n s u m p t i o n %
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Int. J. Engg. Res. & Sci. & Tech. 2014 Rahul Kumar Singh et al., 2014
Figure 3: Effect of Steam Temperatureon Turbine Efficiency
290 300 310 3 20 330 340 350 360 370 38033 .0
33 .2
33 .4
33 .6
33 .8
34 .0
Tu
trb
ine
Eff
icie
ncy
%
S te am T e m p e ratu re (de g c )
EFFECT OF STEAM INLETTEMPERATURE AT 75% LOAD
Figure 4: Effect of Steam Temperatureon steam consumption
7 3 7 4 7 5 7 6 7 7 7 8 7 9 8 0 8 12 9 0
3 0 0
3 1 0
3 2 0
3 3 0
3 4 0
3 5 0
3 6 0
3 7 0
3 8 0
Ste
am
Te
mp
era
ture
(de
g c
)
S te a m C o n s u m p t io n %
2 2 .0 22 .2 2 2 .4 2 2 .6 22 .8 2 3 .0 2 3 .22 9 0
3 0 0
3 1 0
3 2 0
3 3 0
3 4 0
3 5 0
3 6 0
3 7 0
3 8 0
Ste
am T
emp
era
ture
(de
g c
)
T u rb in e E ffic ie n cy %
Figure 5: Effect of Steam Temperatureon Turbine Efficiency
EFFECT OF STEAM INLETTEMPERATURE AT 50% LOAD
5 2 5 3 5 4 5 5 5 6 5 7 5 82 9 0
3 0 0
3 1 0
3 2 0
3 3 0
3 4 0
3 5 0
3 6 0
3 7 0
3 8 0
Ste
am T
em
pera
ture
(deg
c)
S te a m C o n s u m p t io n %
Figure 6: Effect of Steam Temperatureon steam consumption
1 8 .0 1 8 .2 1 8 .4 1 8 .6 1 8 .8 1 9 .0 1 9 .2 1 9 .42 9 0
3 0 0
3 1 0
3 2 0
3 3 0
3 4 0
3 5 0
3 6 0
3 7 0
3 8 0
Ste
am T
em
pera
ture
(deg
c)
T u rb in e E f fic ie n c y %
Figure 7: Effect of Steam Temperatureon Turbine Efficiency
CONCLUSIONSteam Turbines are one of the main energy
consuming equipments, even though not much
attention is paid to them. Trimming of operating
parameters are essential for efficient operation
of these turbines. Illustration given in the work
shows impact of operating conditions on steam
turbines. Savings presented are for a typical
operating conditions.
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