Triveni NEWS · 2018-06-18 · Triveni NEWS Issue 5 May - June 2018 Admission/Injection CROSS -...
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Triveni NEWS Issue 5 May - June 2018 Admission/Injection CROSS - SECTIONAL VIEW OF ADMISSION / INJECTION TURBINE Front section of turbine operates relatively with full flow Low pressure section experiences large flow range variation. Hence, this blade section are to be designed for relatively flatter efficiency curve for the entire flow range In the mixing zone,temperature gradients are present between upstream and injection flow that depends on load conditions and solar cycle Mid section and LP section experience cyclic fatigue loads induced by thermal cycles and flow variations The mixing chamber flow dynamics is analyzed by CFD and suitable flow guide. Geometry and axial gaps are determined for minimizing the pressure losses and thermal shocks LOW PRESSURE INJECTION FLOW DESIGN : Steam Turbine Turbine mid section and LP section is subjected to cyclic fatigue loads induced by thermal cycles and flow variations Though CFD helps in minimizing the cycle amplitudes, the turbine casing, rotor and blades are analyzed for low cycle fatigue life under injection on and off conditions Separate creep fatigue interaction is carried out in creep zones If need be, high cycle fatigue design of blades are carried out with higher stimulus Rotor is designed with higher stability to off-set the excitations due to fluctuating injection steam loads. Turbine stage blades before and after injection are to be specially designed Metallurgy casing, rotor and blades are selected to take care of fluctuating load conditions STRUCTURAL DESIGN : TRIVENI OFFERINGS TO VARIABLE OR CYCLIC INJECTION TURBINE Cement Industry is very innovative in terms of adopting to new technologies and upgrading the existing one. Waste Heat became an integral part of the whole cement industry in order to improve the Industrial energy efficiency. Waste Heat Recovery is a way to gain energy from the exhaust gases in a cement plant. Due to inefficient heat transfer downstream of the clinker burning process, there are huge amounts of energy which is released with the waste gases into the atmosphere. The amount of the wasted energy depends on several process parameters: Temperature of the waste heat gases, amount of gases and thermal capacity of the waste gas, kiln system design and production capacity and the moisture content of the raw materials.The generation of power from kiln is about conversion of the waste heat from the clinkering process into useful electrical energy. Cogeneration of power is achieved by utilizing this waste heat streams from the preheater and the cooler, passing the waste gases through boilers, which in turn generate steam which is used to run the turbine to generates electricity. In Cement WHR process PH Steam Generators (Pre Heat Boilers) and AQC Steam Generators (AQC Boilers) generate steam at 12 ata -17 ata pressure and 390- 450°C temperature and at low pressure 2.5 ata - 4.0 ata at 180-190°C temperature. Medium pressure steam is given to turbine inlet and low pressure is injected mid stream in turbine. Hence Injection Condensing Turbine is used for WHR process in Cement Industry. Cement plants are huge energy consumers. The heat is generated to a considerable extent from fossil fuels and partly from alternative fuels such as waste. Therefore, the energy consumption of a cement plant creates direct and indirect CO2 emissions. This is a very important factor that has to be considered for installing a waste heat recovery system as requirements for industries to reduce greenhouse emissions increases year after year. In other words, waste heat shall be recovered to the maximum extent.
Transcript of Triveni NEWS · 2018-06-18 · Triveni NEWS Issue 5 May - June 2018 Admission/Injection CROSS -...
Triveni NEWS Issue 5 May - June 2018
Admission/Injection
CROSS - SECTIONAL VIEW OF ADMISSION / INJECTION TURBINE
Front section of turbine operates relatively with full flowLow pressure section experiences large flow range variation. Hence, this blade section are to be designed for relatively flatter efficiency curve for the entire flow rangeIn the mixing zone,temperature gradients are present between upstream and injection flow that depends on load conditions and solar cycleMid section and LP section experience cyclic fatigue loads induced by thermal cycles and flow variationsThe mixing chamber flow dynamics is analyzed by CFD and suitable flow guide. Geometry and axial gaps are determined for minimizing the pressure losses and thermal shocks
LOW PRESSURE INJECTION FLOW DESIGN :
Steam Turbine
Turbine mid section and LP section is subjected to cyclic fatigue loads induced by thermal cycles and flow variationsThough CFD helps in minimizing the cycle amplitudes, the turbine casing, rotor and blades are analyzed for low cycle fatigue life under injection on and off conditionsSeparate creep fatigue interaction is carried out in creep zonesIf need be, high cycle fatigue design of blades are carried out with higher stimulusRotor is designed with higher stability to off-set the excitations due to fluctuating injection steam loads. Turbine stage blades before and after injection are to be specially designedMetallurgy casing, rotor and blades are selected to take care of fluctuating load conditions
STRUCTURAL DESIGN :
TRIVENI OFFERINGS TO VARIABLE OR CYCLIC INJECTION TURBINE
Cement Industry is very innovative in terms of adopting to new technologies and upgrading the existing one. Waste Heat became an integral part of the whole cement industry in order to improve the Industrial energy efficiency.
Waste Heat Recovery is a way to gain energy from the exhaust gases in a cement plant. Due to inefficient heat transfer downstream of the clinker burning process, there are huge amounts of energy which is released with the waste gases into the atmosphere. The amount of the wasted energy depends on several process parameters: Temperature of the waste heat gases, amount of gases and thermal capacity of the waste gas, kiln system design and production capacity and the moisture content of the raw materials.The generation of power from kiln is about conversion of the waste heat from the clinkering process into useful electrical energy. Cogeneration of power is achieved by utilizing this waste heat streams from the preheater and the cooler, passing the waste gases through boilers, which in turn generate steam which is used to run the turbine to generates electricity.
In Cement WHR process PH Steam Generators (Pre Heat Boilers) and AQC Steam Generators (AQC Boilers) generate steam at 12 ata -17 ata pressure and 390- 450°C temperature and at low pressure 2.5 ata - 4.0 ata at 180-190°C temperature. Medium pressure steam is given to turbine inlet and low pressure is injected mid stream in turbine. Hence Injection Condensing Turbine is used for WHR process in Cement Industry. Cement plants are huge energy consumers. The heat is generated to a considerable extent from fossil fuels and partly from alternative fuels such as waste. Therefore, the energy consumption of a cement plant creates direct and indirect CO2 emissions. This is a very important factor that has to be considered for installing a waste heat recovery system as requirements for industries to reduce greenhouse emissions increases year after year. In other words, waste heat shall be recovered to the maximum extent.
THERMO-STRUCTURAL TRANSIENT ANALYSIS :
CONTROL PHILOSOPHY :
Injection steam line is provided with basket strainer, quick closing valve, pressure control valve and QCNRV
Injection line and turbine mid stage section is instrumented with pressure and temperature transmitters
Turbine is operated in load control mode and / or flow control modeDuring injection cycle, line pressure control valve is governed by target pressure generated by external controller which in turn is linked to mid stage pressure
In the event of grid outage, turbine trip valve and injection line trip valve is closed
It is recommended to have a dump provision in main condenser for accommodating large flow fluctuation in solar injection line
Transient analysis to address thermal shocks due to injection, LCF life and clearance study
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