R&M of Thermal Power Stations “Emerging Scenario” · 2019-03-14 · Supercritical boiler...
Transcript of R&M of Thermal Power Stations “Emerging Scenario” · 2019-03-14 · Supercritical boiler...
R&M of Thermal Power Stations
“Emerging Scenario”C Subramaniam &
AGMJoydeep NagSr. Manager
(OS-R&M)NTPC Ltd. EOC, Noida-24
*Views expressed in the presentation are not necessarily those of the management
15 - 20 years (PLF 50 - 70%)
19%
Less than 15 years (PLF >
60%)55%
20 - 30 years (PLF 40 - 55%)
16%
30 - 40 years (PLF 30 -40%)
8%
40 years & above (PLF <
40%)2%
Age & Performance (PLF) of Utility Industries
Present Drivers of R&M in India
Low PLF: R&M is resorted to when PLF deteriorates to unviable level
De-rated Capacity: Utilities take up R&M to recover lost capacity
Life Extension: To extend life of critical components
Obsolescence: Sometimes utilities are forced to take up R&M due to obsolescence & non-availability of spares
Environment / Safety: To meet the new norms
Incentives needed for projects targeting:
•Efficiency / Capacity improvement – e.g. by uprating process parameters, redesign of boiler, improved design of turbine blades.•Fuel switch-over / substitution – e.g. retrofitting for Naptha firing, bio-mass co-firing•Earning of CER (CDM) – e.g. green house gas reduction
Incentivisation of R&M
Some Emerging Facts
1. India is the 4th largest Greenhouse Gas emitter in the world and will soon become 3rd largest
2. As per the experts, India is going to be worst hit due to global warming as it has vast tracts of glaciers, a number of glacier-fed rivers and a very long coastline.
3. Heat rate of 56 stations aggregating 38611 MW has revealed an average heat rate of 2861 Kcal / Kwhr as against a design of 2398 Kcal / Kwhr (% deterioration 19.3%). The % deterioration per year is 3.35% over previous year. (Source CEA Report for 2006-07)
Emerging Business Challenges
1. Competition from the new generation of plants (with low Cost Of Generation and project completion time as low as 25-30 months for 500 MW units)
2. Impending pollution / emission tax in line with Kyoto protocol
3. Volatility in fuel cost
4. Fuel security issues
The bottom line is that the older fleet have to remain fighting fit to sustain their economic viability
reduced fuel consumption
operation free of restrictions
POWER PLANT R&M OBJECTIVES
environmental control updating
availability improvement
RESULTS
increased power output
reduced power generation cost
efficiency upgrading
increased electrical output
emissions within new norms
life extension
improved reliability
plusCDM BENEFITS
Focus of R&M in Developed World
Increase in generation with improved performance
Increase in safety, reliability, availability and operational flexibility
Recapturing and/ or enhancing of unit capacity
Extension of economic useful life by 15-20 years at comparatively lower capital cost
Benefit by way of additional life
Possibility of reducing cost of generation
R&M with Efficiency Increase
Fuel consumptionper kWh
0 20 40 years
Rehabilitation Rehabilitationw/o efficiency improvement
Rehabilitationwith efficiency improvement
Increased power output resulting from efficiency increase isfree of fuel cost, free of operational cost and free of emissions.
Internationally Utilities are adopting total R&M Solutions
• ComponentsBoiler + ESP
Turbines &Generators
Electrical
Instrumentation & Control
Cooling WaterSystems
Ash HandlingCoal Handling
Design Audit
Updating
Modernization
Replacement
EfficiencyImprovementReliabilityIncreaseReduction ofStart up TimesSparesAvailabilityCompliance toenvironmentalstandardsCyclic loadoperationExtended life time
• Benefits
Performance Improvement after R&M
Parameter Unit Pre-R&M Post-R&MBoiler Load T/hr 815 815Life steam temperature oC 517 535Reheat temperature oC 526 540Flue gas temperature oC 215 166Boiler efficiency % 83 90NOx mg/Nm3 400 190CO mg/Nm3 75 175SO2 mg/Nm3 4,300 170Particulate matter mg/Nm3 150 3Turbine capacity MW 514.3 536.5Spec. TG heat rate kJ/kWh 8,735.0 8,510.0Efficiency LP Turbine % 76.9 85.8Net unit efficiency % 31.5 35.8
Boxberg Power Station500 MW units
Case Study of a German Power Plant
Improvement of efficiency and environmental conditions by retrofitting the units
This was mainly achieved due to using low NOx burners in boiler, redesigning of LP turbine and cooling tower modernisation
The emission levels of the units was reduced drastically due to use of low NOx burners, installing Flue Gas Desulfurification plant and optimisation of operation of ESP
Flue gas discharge through cooling towers, automatic concrete cutter for existing chimneys
Reactive vs. Proactive Approach
R&M decisions in India are overwhelmingly Reactive in nature. Utilities wait for the performance parameters to go down, then R&M is conceived.
Whereas, the need of the hour is Proactive Approach, that is, R&M is to be planned beforehand to sustain and improve performance
The Need of the Hour
Cost effective technology upgrades
In-kind replacement
Financial Risk based R&M optimization
From Time based R&M
Pro-active R&MReactive R&M
Improve upon design efficiency
Attain design efficiency
Uprating of capacityRestoration of lost capacity
Using the technological leverage, the focus of R&M should change from:
Parameter Pre-R&M Post-R&M
Design load of unit (MW) 110 120
PLF (%) 52.76 85.28
Boiler Efficiency (%) 84.0 86.5
Turbine Heat Rate (Kcal/KWHr) 2175 1993
Sp Coal Consumption (Kg/KWHr) 1.00 0.65
Exit Gas Temperature (ºC) 200 145
Ash Emission (mg/Nm3 ) 250 75
Auxiliary Power Consumption (%) 2 % Reduction
R&M –Technology Upgrades Kothagudam TPS (4 X 110 MW)
Source BHEL / PPIL
Performance Targetsunit as per operation post
PG Test (as informed) retrofit(Aug’81)
Rated output [MW] 110,0 110,0 120,0
Main steam flow [t/h] 367,4 > 375 365,79
TG heat rate [kcal/kWh] 2173.3 2477,3 < 2008
Addressed Areas for R&M• HP-, IP-, LP-Turbine • Generator• Boiler Re-heater• Control & Instrumentation (Option)• HP / LP Bypass (Option)
R&M –Technology Upgrades AECO Sabarmati (1 X 110 MW)
Source NASL
Advanced Technological Solutions
Advanced Supercritical Retrofit: Vertical Tube Supercritical boiler technology is ideal for retrofitting to existing sub-critical boilers. Such a retrofit, combined with modification of the steam turbine, steam pipe-work and some of the balance-of-plant can raise the plant cycle efficiency up to 43-46% with commensurate carbon dioxide reductions. Biomass Co-firing .
Source Doosan Babcock
Challenges in R&M
••Limited Agencies for R&M implementation Limited Agencies for R&M implementation in the country.in the country.••Prohibitive cost of New Technologies Prohibitive cost of New Technologies impediment for introduction on wider scale.impediment for introduction on wider scale.••Formulation of risk sharing formula so that Formulation of risk sharing formula so that R&M is a WinR&M is a Win--Win proposition both for the Win proposition both for the utility and the vendorutility and the vendor••Unfavorable cost Unfavorable cost -- benefit analysis.benefit analysis.••R&M activity to be linked with planned shut R&M activity to be linked with planned shut down.down.
Summary
There is huge potential in India for R&M activities There is huge potential in India for R&M activities because of large number of old plants which are because of large number of old plants which are inefficient and running below design capacityinefficient and running below design capacity
Implementation of the R&M Schemes has benefited Implementation of the R&M Schemes has benefited the stations by way ofthe stations by way of
••Overcoming Technological obsolescence.Overcoming Technological obsolescence.••Low cost capacity additionLow cost capacity addition••Extending the life of equipment / components.Extending the life of equipment / components.••Complying with Statutory and Environmental NormsComplying with Statutory and Environmental Norms••Sustaining availability and improved performance Sustaining availability and improved performance
R&M should focus on ‘costR&M should focus on ‘cost--effective technology effective technology upgrades’ instead of inupgrades’ instead of in--kind replacements.kind replacements.
Summary (contd)
R&M to be planned in advance before major R&M to be planned in advance before major deterioration or breakdown of unitdeterioration or breakdown of unit
Target Objectives of R&M to be clearly identified Target Objectives of R&M to be clearly identified upfrontupfront
R&M should be taken up on a ‘Project Mode’ with R&M should be taken up on a ‘Project Mode’ with clearly identified dates akin to ‘New Builds’.clearly identified dates akin to ‘New Builds’.
Tariff after R&M and potential CDM benefits to be Tariff after R&M and potential CDM benefits to be factored in while evaluating Optionsfactored in while evaluating Options
Urgent need to enhance manufacturing capacity to Urgent need to enhance manufacturing capacity to handle load of R&M / Creation of new manufacturing handle load of R&M / Creation of new manufacturing basebase